JPH05215958A - Main object detecting device for camera - Google Patents

Abstract

PURPOSE:To accurately detect a main object by detecting a point for outputting an object at the shortest distance, out of respective points in the vicinity of the center of a picture and on a golden split line. CONSTITUTION:An object distance distribution detecting device 12 outputs out-of-focus information and object distance information corresponding to eighty- one areas obtained by dividing each of the length and breadth of the picture into nine equal parts. A main object detecting device 17 detects the point for outputting the object at the shortest distance, and decides whether the point is on the central part or the line for golden splitting the picture, in a photographic picture or not. When it is decided that the point is on the central part or the golden line, it is judged that the main object is on the point, and when it is decided that the point is not on the central part or the golden line, the detecting device 17 further, detects the point for outputting the object at the shortest distance, out of respective points in the vicinity of the center and on the golden split line in the picture and judges that the main object is on the point.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera, and more particularly to a camera which automatically detects a main subject in a photographing screen and performs focus adjustment and exposure control according to the position of the main subject.

[0002]

2. Description of the Related Art In recent years, cameras have become highly functional and multifunctional with the development of electronic circuit technology. This is also because information relating to the operation of the camera can be electrically detected and signal processed accurately.

For example, in the field of camera exposure,
By increasing the sensitivity of the AE sensor, it is possible to perform photometry by dividing the subject, and it is also possible to execute a more complex algorithm using the CPU, so that more appropriate exposure can be given to the subject. I came. These have been achieved by the development of sensor technology, IC technology, and CPU.

Also in the field of AF, with the development of sensor technology and CPU for AF, high sensitivity, high speed and wide field of view are advanced, and the distance to the object and the amount of focus deviation are accurate. It can be detected by.

[0005]

By the way, with the widening of the field of view, there has been considered an area sensor as a sensor for photometry and distance measurement. By using an area sensor as the sensor, it becomes possible to perform photometry and distance measurement at a plurality of points within the shooting screen. Then, the position of the main subject is detected from the sensor outputs of the plurality of points, and each camera element is controlled so that the main subject is brought into a focused state / appropriate exposure state.

However, if the position of the main subject is determined based on the sensor output from all the above points, and the exposure value is determined and the focus is adjusted, the following problems occur. That is,
Normally, it is determined that the main subject exists at the point where the distance measurement result outputs the closest distance value, but normally, there is no main subject, for example, the closest distance value to the corner of the screen. If there is one that does, the focus adjustment and the exposure value will be determined based on the output at that point. As a result, the main subject may be out of focus, or the photograph may have an improper exposure.

The main subject detecting device for a camera of the present invention has been made in view of such a problem, and its purpose is to focus on the main subject in the photographing screen and to give proper exposure. Another object of the present invention is to provide a main subject detection device for a camera that can accurately detect a main subject.

[0008]

In order to achieve the above object, a main subject detecting device for a camera according to the present invention includes a distance measuring means for outputting the distances of the subject at a plurality of points in a photographing screen, and this distance measuring means. A first detection unit that detects a point at which the object at the shortest distance is output from the output of the distance unit and a point at which the object at the closest distance is output are a line that golden-divides the central portion of the photographing screen or the screen. If it is determined that the point for outputting the shortest distance is not in the central portion or on the golden line by the determining means for determining whether or not it is on the upper side and the golden division The second detection means for detecting the point that outputs the shortest distance among the points on the line and the point detected by the first detection means by the determination means are on the central portion or on the golden line. If judged, the If it is determined that there is a main subject in the image, and it is determined that the point detected by the first detecting means is not on the central portion or on the golden section line, the point detected by the second detecting means is detected. Judge that there is a main subject.

[0009]

That is, in the present invention, the first detecting means detects the point at which the object at the shortest distance is output, and the point at which the object at the closest distance is output is the central portion or the screen in the photographing screen. It is determined whether or not the line is on the golden section. When it is determined that the point is not on the central portion or on the golden line, the second detecting means further detects the point which outputs the closest distance among the points on the golden division line near the center in the screen. When it is determined that the point detected by the first detecting means is on the central portion or on the golden line, it is determined that the main subject exists at that point, and the main detecting object detects the point. If it is determined that the point is not on the central portion or on the golden section line, it is determined that the main subject exists at the point detected by the second detecting means.

[0010]

EXAMPLE An example of a camera using the present invention is shown below.

As shown in FIG. 1, the present invention comprises a photographing condition detecting means 1, a control exposure amount calculating means 2 and an exposure control section 3 for controlling exposure based on the output of the control exposure calculating means 2. .. FIG. 2 shows the configuration of each part of FIG. 1 in more detail.

In the photographing condition detection means 1, the photographing condition detection calculation means 10 detects the object as a photographing condition detecting means of the camera for detecting the situation and the purpose of photographing. Luminance distribution detection device 1
1. Object distance distribution detecting device 12, object magnification distribution detecting device 13, object size / shape distribution detecting device 1
4, object movement distribution detection device 15, film sensitivity,
Latitude detection device 16 and main subject detection device 1
7, a photographer correction data storage unit 18, and a winding mode detection unit 21 are attached.

The main subject detecting device 17 includes a subject brightness distribution detecting device 11, a subject distance distribution detecting device 12, a subject magnification distribution detecting device 13, a subject size / shape distribution detecting device 14, and a subject Moving distribution detector 1
5 is connected.

A subject image signal detecting device 19 is connected to the subject luminance distribution detecting device 11, the subject distance distribution detecting device 12, the subject size / shape distribution detecting device 14, and the subject moving distribution detecting device 15. ing. Further, a subject distance distribution detection device 12 and a photographic lens focal length detection device 20 are connected to the subject magnification distribution detection device 13.

The photographing condition detecting / calculating means 10 includes a subject brightness distribution detecting device 11, a subject distance distribution detecting device 12,
Subject magnification distribution detection device 13, subject size / shape distribution detection device 14, subject movement distribution detection device 15, film sensitivity / latitude detection device 16, main subject detection device 17, photographer correction data storage unit 18 , A signal from the winding mode detection unit 21 is received, the recommended AV value, A
V priority, TV recommended value, TV priority, guide number control strobe recommended value, guide number control strobe priority, TTL strobe priority, plus exposure deviation allowance value, minus exposure deviation allowance value, main subject brightness, main subject image Calculates and outputs the speed.

Next, in the control exposure amount calculation means 2,
Recommended AV value, AV priority, TV from shooting condition detection means
Receives recommended value, TV priority, recommended guide number control strobe value, guide number control strobe priority, TTL strobe priority, plus exposure deviation tolerance value, minus exposure deviation tolerance value, main subject brightness, and main subject image speed. , Control AV value, control TV value, strobe guide number value, and TTL strobe control command code are calculated.

These values are displayed on the control exposure value display section 22. Further, the photographer correction unit 23 accepts changes in AV, TV, and guide number by the photographer's operation. Which value and how much has been changed are stored in the photographer correction data storage unit 18.

Next, the output of the control exposure calculation means 2 and the control A
V value, control TV value, strobe guide number value, TTL
Based on the strobe control command code, the exposure control unit 3 controls the exposure of driving the diaphragm, driving the shutter, and strobe light emission. The operation of the photographing condition detection means 1 will be described below. To detect the shooting condition, it is necessary to detect the film condition, the subject condition, the camera condition, and the will of the photographer. In other words, you have to detect what, where, when, who, why, how, and what you are trying to shoot. The "what" to be photographed is analyzed by the image signal. They are classified as people, landscapes, animals, and things. Also, the absolute color and brightness of the item itself are important. When shooting white in white or black in black, it is out of the general proper exposure. “Where” you are trying to take can be classified as, for example, outdoors, indoors, dark places, wide places, narrow places, etc. Regarding the problem of "when" to shoot, rather than absolute time, for example, during continuous shooting,
Information such as one shot is useful.

"Who" reflects the individuality of the photographer. That is, it depends on the past history of whether or not the photographer intentionally corrects the exposure value previously determined by the camera in a scene estimated to be the same scene. The problem of "why" is, for example, whether to shoot for a commemorative photo or to shoot with an emphasis on artistry.

"How" generally refers to a photograph with proper exposure and no blur. However, in the case of panning shot, blurring is intentionally caused. There is also a condition of whether it is macro photography or portrait photography.

The "what" problem is a film problem. It is the sensitivity and latitude of the film. Therefore, as the photographing condition detecting means of the camera, a subject brightness distribution detecting device 11, a subject distance distribution detecting device 12, a subject magnification distribution detecting device 13, a subject size / shape distribution detecting device 14, and a subject A movement distribution detection device 15, a film sensitivity / latitude detection device 16, a main subject detection device 17, and a photographer correction data storage unit 18 are used.

Among them, the subject brightness distribution detecting device 11, the subject distance distribution detecting device 12, the subject size / shape distribution detecting device 14, and the subject moving distribution detecting device 1
5 uses the detection signal of the image signal detection device 19 of the subject.

In this embodiment, as shown in FIG. 3, the image signal detection device 19 for the object is composed of two CCDs 19a and 19b offset in the optical axis direction. In addition, the screen imaged by these CCDs is a subject image in a range substantially equivalent to the image projected on the film. The subject light that has passed through the taking lens is projected on each of these CCDs.

The object brightness distribution detecting device 11 detects the brightness corresponding to each coordinate of the screen by the detection signal of the image signal detecting device 19 of the object. The detected brightness is divided into blocks which are easy to control the camera and output.
In the present embodiment, it is assumed that the luminance of the subject is output according to 81 areas obtained by dividing the screen vertically and horizontally into nine equal parts (see FIG. 4). In this case, the output of one of the two CCDs may be used, or both outputs of the two CCDs may be used.

As shown in FIG. 5, the object distance distribution detecting device 12 first detects the signal from the image signal detecting device 19 by 2
In the MTF calculators 12a and 12b corresponding to one image, the MTF values are converted into MTF values having a predetermined spatial frequency according to each area of the screen. The area to be divided here is 81 areas obtained by dividing the screen vertically and horizontally into nine equal parts.

From the ratio of MTFs of the areas of the same coordinates of the CCD 19a and the CCD 19b, it is known that the focus shift in that area can be obtained. A method for detecting the focus shift from the MTF ratio is disclosed in JP-A-2-275.
Although disclosed in Japanese Laid-Open Patent Publication No. 916, it has no direct relationship with the present invention, and therefore detailed description thereof is omitted. The focus shift amount corresponding to each area is calculated by the focus shift amount calculation unit 12c.
Done in.

Further, the distance of the subject in each area is calculated from the amount of focus shift in each area. For this purpose, a known subject distance calculation algorithm is used. That is, the object distance distribution detection device 12 has a coefficient peculiar to the photographing lens for converting the shift amount of the focus of each area into the movement amount in the optical axis direction of the focus adjustment optical system of the photographing lens up to the focal point. Focusing for converting the constant storage unit 12d, the information stored in the coefficient / constant storage unit 12d, and the focus shift amount of each area into the movement amount in the optical axis direction until the focus of the photographing lens. Moving amount calculation unit 12e
And a focus adjustment optical system extension amount detection means 12f for detecting an extension position from a reference position (for example, an infinity position) of the focus adjustment optical system of the taking lens, and an extension amount of the focus adjustment optical system of the taking lens as an object distance. A coefficient / constant storage unit 12g for conversion, a movement amount of the focus adjustment optical system until the subject in each area is in focus, a current extension amount of the focus adjustment optical system, and the coefficient / constant storage unit 12g. A subject distance calculation unit 12h that calculates the distance from the camera of the subject for each area based on the information stored in the area is set.

With these functions, the object distance distribution detecting device 12 outputs the focus deviation amount information and the object distance information according to 81 areas which are obtained by dividing the screen vertically and horizontally into nine equal parts.

As shown in FIG. 6, the object magnification distribution detecting device 13 detects the object distance information of each area of the 81 divided areas from the object distance distribution detecting device 12 and the focus of the photographing lens. Based on the current focal length information of the photographing lens from the distance detection device 20, the photographing magnification information of the subject in each area of the screen divided into 81 pieces is calculated and output. In FIG. 7, a subject size / shape distribution detection device 14
Outputs the data of the size and shape of continuous areas having the same brightness from the signal of the image signal detecting device 19. In this case, a plurality of data is output for an area having a large area and an area having a characteristic shape. Regarding the shape, ○ type, □ type, △ type, ▽ type,
◇ It is replaced with the data that shows the shape that represents the contour of the mold or human. In this case, a CCD with two sides
It may be based on the output of one of the two, or both outputs of the two CCDs may be used.

As shown in FIG. 8, an object image signal detecting device 19 is connected to the object movement distribution detecting device 15. Further, the image signal from the image signal detection device 19 of the previous subject is stored. The difference, that is, the change, between these two kinds of signals having a temporal difference is detected, what kind of vector the subject has in the XY axis directions of the screen at each coordinate of the screen is calculated, and this movement distribution information is output. To do. In this case, it may be based on the output of one of the two CCDs, or both outputs of the two CCDs may be used. This movement distribution detection information of the subject is output as a value corresponding to 81 areas obtained by dividing the screen vertically and horizontally into nine equal parts.

The film sensitivity / latitude detection device 16 detects the state of the film mounted on the camera. The state of the film is information on the sensitivity and latitude of the film. These can be obtained by reading the so-called DX code written on the film cartridge case.

Further, the main subject detecting device 17 obtains the subject brightness information corresponding to 81 areas obtained by dividing the vertical and horizontal directions of the screen into nine equal parts from the subject brightness distribution detecting device 11 and the subject distance distribution detecting device 12. From the above, the focus shift amount information and the subject distance information corresponding to each of the above areas are obtained, and from the subject magnification distribution detecting device 13, the photographing magnification information of the subject in each of the above areas is obtained and the subject movement distribution detecting device 1 is obtained.
5 from the object movement distribution detection information according to each of the above areas, and from the object size / shape distribution detection device 14, the size and shape of a continuous screen range having the same brightness. Receive data.

The main subject detecting device 17 determines what the main subject is from these data, and the size, brightness, distance, photographing, magnification, X-axis movement state of the main subject,
The Y-axis movement status is detected. In addition, a temporal change in the distance of the main subject (Z-axis movement state) is calculated. The results of these calculations are sent to the shooting condition detection means 10.

What the main subject is, that is, what the photographer is trying to photograph is based on the analysis of the magnification distribution information of the subject and the size / shape distribution information of the subject. You can also get information on "how" you are going to shoot. Generally, a subject at a short distance, that is, a subject having the highest shooting magnification is the main subject. In particular, when there is a subject at a short distance at the center of the screen, or horizontally or vertically with respect to the screen, the probability is high. This is because the photographer unconsciously thinks about the composition of the screen and acts according to the human nature. Arranging the subject in the center of the screen is naturally easy to take when shooting a subject straight. In addition, the stability of the composition regarding the golden section has been recognized in the world since ancient times, and the probability that the main subject is at that position is high. Also, if the size of the subject with respect to the screen is sufficiently large, and if the shape is meaningful such as people, landscapes, animals, it is possible that the subject is the main subject. high. In order to determine what the main subject is, the height of the above-mentioned shooting magnification, is it placed at the center of the screen, is it placed at the point that gives the golden section to the screen, or does its shape have a specific meaning? Is comprehensively judged. Golden division is a division method that divides the screen according to the following formula.

[0035]

[Equation 1] As shown in FIG. 9, the screen is vertically and horizontally divided into nine equal parts.
The coordinates indicating the positions of the 81 divided areas are (x, y) = (x ₁ , y ₁ ) on the lower left and (x, y) = (x on the upper right.
₇ , ₇ , ₉ ).

In this case, the line that divides the screen into the left and right is represented by two lines that pass through almost the center of the x4 column and the x6 column. Similarly, the golden division line in the vertical direction is y
There are two lines that pass through almost the center of the 4th row and the y6th row.

By dividing the screen vertically and horizontally into nine equal areas in this way, it is possible to arrange photometry and AF detection points for detecting a subject at the golden division points of the screen. This does not mean that the photometry and AF detection points are arranged in all the 81 areas. It shows the priority area of these areas.

That is, it is possible to detect a subject in the columns x ₁ and x _{9 and} the rows y ₁ and y ₉ on the outer side of the screen without disposing a detector. In the present embodiment, a case will be described where a subject is detected in all 81 areas. In the detection of the main subject, whether the subject is present at the center of the screen or at the golden section point is first determined based on the distance of the subject and the shooting magnification. Further, if the area close to the obtained area has the same photographing magnification or the subject distance, that area is also determined to be the main subject. With this, it is possible to obtain the size of the subject. The signal processing operation of the main subject detection device will be described below with reference to the flowchart of FIG. First, at address # 1, 3 with high shooting magnification in 81 areas in total.
Area coordinates β ₁ , β ₂ , and β ₃ are obtained for the point.

Next, at the address # 2, the obtained β ₁ ,
β ₂ and β ₃ are consecutive ₃ in the x or y direction of the screen
It is judged whether it is one area. In the case of continuous areas, it is determined whether the address # 3 to # 7 includes the center or is in a position where golden division is performed. If these conditions are met, the process proceeds to address # 20. If not, proceed to address # 8.

At address # 20, three points of area coordinates β ₁ , β ₂ , and β ₃ are set as candidates for the main subject. Next, in # 23, a main subject area, which will be described later, is calculated.

Next, at addresses # 27 to # 32, the brightness, distance, photographing magnification, and x-axis / y-axis / z-axis movement status of the main subject are calculated from the area indicating the main subject as average values. This completes the detection of the main subject.

If at address # 2, β ₁ , β ₂ , and β ₃ are not in a continuous area, the address # 7 is used again from # 7.
When proceeding to 8, β ₁ and β ₂ are in the x direction in # 8,
It is determined whether or not it is continuous in the y direction. When it is determined that the two areas are continuous, it is determined at addresses # 9 to # 13 whether β ₁ and β ₂ are at the center of the screen or at the golden section.

In this case, the position for determining the golden section is restricted from the center of the screen. That is, for example, to determine whether the golden section is on the x ₄ column, y ₃
It is determined only in a section of ~y _7. This is because it is unlikely that a small subject exists as a main subject around the screen, so that the processing time is shortened and erroneous detection is prevented. If it is determined, the process proceeds to # 21.

If it is determined in # 8 that β ₁ and β ₂ are not continuous, and if it is determined in # 9 to # 13 that β ₁ and β ₂ are not at the center or the golden section, the address In # 14 to # 18, it is determined whether β ₁ is at the center of the screen or at the point where the golden section is performed. In the judgment about the golden section in this case, the detection range is further narrowed down for the above reason. For example, in the case of the judgment on the x ₄ column, x _{4 to} y ₆
Regulated by.

When β ₁ is in the center or the golden section point in # 14 to # 18, the process proceeds to address # 22. At addresses # 21 and # 22, (β ₁ , β ₂ ) (β ₁ ) are set as main subject candidates, and the process proceeds to address # 23. If it is determined that β ₁ is not at the center or the golden section point at addresses # 14 to # 18, address # 19
Proceed to step x for high-magnification areas β ₁ , β ₂ , and β ₃ .
₄ ~x _6, y ₄ are re-set only within a range of the center of the screen of ~y _6, proceeds to the address # 2 again. In this case, one of # 20, # 21, and # 22 of addresses # 2 to # 18 is surely proceeded. The main subject area calculation routine indicated by address # 23 will be described below with reference to the flowchart of FIG.

First, for the main subject candidate selected based on the magnification in # 101, the lowest photographing magnification among them is determined as β ₀ . In step # 102, the number of areas selected as main subject candidates is substituted into a variable N that determines an upper limit for repeating a loop described later. That is, # 2 in FIG.
If it passes 0, it becomes “3”, and if it passes # 22, it becomes “1”.

At # 103, the variable M for the radix of the new main subject candidate used as the initial value to be substituted into the loop counter i for repeating the loop to be described later is set to 1. When a new candidate is selected, this radix is used to limit the range to be searched next so that the next new candidate is not wasted. The purpose of the calculation in this routine is to determine whether the subject adjacent to the area selected as the candidate for the main subject is the same as the subject looking into the candidate area and is determined to be the same. The adjacent area is also determined to be the main subject, and information about the size and shape of the main subject is obtained. In addition, the information of the entire main subject is reflected in the information such as the brightness and blur of the main subject. Of course, the size of the main subject mentioned above,
Although it is possible to obtain it by the output of the shape detection device, even without it, it becomes possible to obtain information about the size and shape of the main subject by this calculation. Therefore,
In this embodiment, the photographing magnification of each subject in the area adjacent to the main subject candidate is used.

Of course, attention may be paid to the distance to the subject, or brightness and other information may be used. The loop for evaluating the adjacent area is addresses # 104 to #.
Denoted by 112. Therefore, in # 104, the variable M is substituted as an initial value into the counter i of this loop. Then #
At 105, 0 is assigned to a variable j (main subject extension counter) representing the number of areas extended for the main subject. In other words, one area is not expanded until the operation of this loop.

At # 106, i in the main subject area
Substitute the x and y coordinates of the th one for (x, y).
In this embodiment, both x and y coordinates are represented by subscripts of 1-9. Therefore, since the coordinates of the area adjacent to the area represented by the coordinates (x, y) are also within the range of x _{1 to} y ₉ , for example, the area to the left of (x, y) is evaluated. To do so, it is only necessary to satisfy x> x ₁ . Therefore, the determination of (x> x ₁ ) is made at the address # 107. If true, it is determined at address # 116 whether the area of coordinates (x-1, y) is a subject candidate. Therefore, the subject candidate determination calculation routine shown in FIG. 12 is used. After this calculation, or in the case of false determination in # 107, the area on the right of the coordinate (x, y) at address # 107 is processed in the same manner as the above-described calculation. The same applies to the areas adjacent to each other in the y-axis direction, that is, the areas adjacent to the top and bottom.
8 and # 119.

In the subject candidate determination calculation routine, as shown in FIG. 12, it is first determined whether the area designated in # 120 has already been designated as a main subject candidate. If it is true, the process directly returns from # 124.

If not specified, the flow proceeds to # 121 and the photographing magnification of the area of the specified coordinates is β ₀ obtained in # 101.
Compared to. In this case, in this embodiment, a range that can be regarded as an equivalent photographing magnification is (β ₀ + 0.05 · β ₀ ), that is, β ₀
And the difference is ± 5%.

If it is out of this range, the process returns from # 124. If it is within the range, the process proceeds to # 122 and the main subject extension counter j is incremented. Next, in # 123, the area of the designated coordinates is set as the (N + j) th main subject candidate. After that, the process returns at # 124. # 1 in FIG. 11
After the determination calculation of 07 to # 110 is completed, the process proceeds to # 111.

Here, it is determined whether the calculation of the loop is completed. If the loop counter is still smaller than the variable N, it is not finished yet, so the counter variable i is incremented in # 112 and the process returns to # 106. When it is determined that the processing is finished in # 111, the extension counter j is checked in # 113. If the extension counter j is 0, it means that a new main subject candidate has not been added, and the process proceeds to address # 115. This main subject area calculation routine ends.

When the main subject extension counter j is not 0, that value indicates the number of added main subject candidates.
In # 114, the number N of main subject candidate areas is set to (N = N +
In j), the new main subject candidate cardinal number M is set to (M = M + j), and the process proceeds to address # 104 to determine whether the area adjacent to the area indicated by new M to N is a main subject candidate. After the main subject area calculation routine ends, the process proceeds to address # 27 in FIG. At this time, the main subject candidate is officially regarded as the main subject.

FIG. 13 shows an example of using the output from the object size / shape distribution detection device 14 as the second embodiment. Here, another example of the above-described example of the main subject area calculation performed at # 23 in FIG. 10 is shown. First, the area selected as the main subject candidate at address # 130 is included in the set of areas having the largest area of the subject in the output signal from the subject size / shape distribution detection device 14. It is judged whether or not. If it is determined to be included, in # 131, the entire set of areas indicated by the size information of the subject is set as the area of the main subject.

If not included, the data about the shape is cleared in # 132, and the area of the main subject is set as the candidate in # 133. After that, the routine ends at # 134.

The photographer correction data storage unit 18 determines how much the photographer corrects the control exposure value (AV, TV, guide number) calculated by the control exposure amount calculation unit 2 by the photographer correction unit 23. Remember the changes. By configuring this storage unit with a non-volatile storage means such as an EEPROM, it is possible to store and reproduce the correction amount set by the photographer even when the power is turned off.

The photographing lens focal length detecting device 20 detects and outputs the focal length of the photographing lens. When the taking lens is a zoom lens, a known zoom encoder detects the operation amount of the photographer with respect to the variable magnification optical system of the taking lens, and the focal length of the taking lens according to the operation amount is stored in the ROM or the like. It reads from the existing information and outputs it.

The take-up mode detecting section 21
It is detected whether one frame at a time is being photographed or continuous photographing is being performed in the continuous photographing mode. Further, in the case of single frame shooting, it is determined whether the time elapsed from the previous shooting can be regarded as continuous shooting (approximately several seconds), and signals for these three states are output as continuous shooting degree information.

The control exposure value display section 22 displays information about the aperture value, shutter speed, and use of the strobe, which are controlled by the camera when the film is actually exposed by the camera, outside the camera and in the viewfinder of the camera. The display method is performed using, for example, a known liquid crystal module.

The photographer correction unit 23 is a control exposure value (AV, T calculated by the photographer in the control exposure amount calculation means 2) by a known method such as a rotary encoder or an up / down key.
V, guide number) can be changed.

The photographing condition detecting / calculating means 10 includes a subject brightness distribution detecting device 11, a subject distance distribution detecting device 12,
Subject magnification distribution detection device 13, subject size / shape distribution detection device 14, subject movement distribution detection device 15, film sensitivity / latitude detection device 16, main subject detection device 17, photographer correction data storage unit 18 , A signal from the winding mode detection unit 21 is received, the recommended AV value, A
V priority, TV recommended value, TV priority, guide number control strobe recommended value, guide number control strobe priority, TTL strobe priority, plus exposure deviation allowance value, minus exposure deviation allowance value, main subject brightness, main subject image Calculates and outputs the speed. As described above, in order to detect the shooting condition, it is necessary to detect what, where, when, who, why, how and what the user is trying to shoot.

The "what" to be photographed is output by the main subject detection device 17. Even if it is difficult to judge clearly whether it is a person or an animal, the main subject is anywhere on the screen, and the size, brightness, distance,
Information on shooting, magnification, X-axis movement status, Y-axis movement status, and Z-axis movement status can be obtained.

From these, it is possible to guess what the main subject is. A person (face), a person (upper body), a person (whole body), a person (plurality), an animal, a landscape, a moving body, and the like are determined. This is done by increasing or decreasing the classification according to the information processing ability. This information is used as a part of information for determining a recommended value for the guide number values of AV, TV, and strobe at the time of exposure depending on the main subject. For example, when photographing the upper half of a person, the aperture should be open.

At the same time, when color estimation is established, correction is added to the luminance information of the main subject in each of white, bright color, dark color, and black. This is because, without correction, white and black are reproduced in gray because normal proper exposure is based on the brightness of gray. Further, the main subject image velocity is calculated from the X and Y axis movement status information.

"How" often means "what". Even if it is difficult to determine clearly whether it is a person or an animal, the main subject is anywhere on the screen, and the size, brightness, distance, shooting, magnification, X-axis movement status of the main subject,
It is determined from the information on the Y-axis movement status and the Z-axis movement status.

When the main subject is to be macro-photographed with a small object (when the magnification is larger than 1/5), the depth of focus is shallow, so it is better to narrow down according to the magnification.

Further, in general, a photograph is taken aiming at a proper exposure or no collapse. However, in the case of panning shot, blurring is intentionally caused. If the background other than the main subject constantly moves in a certain direction, it is considered to be panning. In this case, a shutter speed where the background is blurred and the main subject is not blurred is recommended.

When the main subject and the background are dark and point light sources are scattered on the background and a strobe is required, night scene photography in which the amount of strobe light is adjusted to the subject at a shutter speed that allows an appropriate night scene is preferable. However, you should not expose the main subject for a long time. “Where” you are trying to shoot is classified as backlight, dark or bright, wide or narrow.

These are related to strobe control. If it is dark or there is backlight, it is judged which is better to compensate for the lack of light quantity by exposure for a long time or strobe.

In a narrow space, the strobe light wraps around, so TTL direct strobe control is appropriate. Guide number strobe control is appropriate in wide areas.

Regarding the problem of "when" to take a picture, it is desirable to treat the TV preferentially according to the magnitude of the continuous shooting degree of the continuous shooting degree information from the winding mode detecting unit 21. This judgment can be applied to the setting of the permissible circle of confusion diameter. This point can also be applied to ASF (automatic focus adjustment). The permissible blur size is approximately equal to the permissible circle of confusion. In the case of continuous shooting and other shooting that values high-speed shooting, it is possible to loosen the setting of the limit value and improve the quick-shooting performance.

In order to reflect the individuality of the photographer, "who" changes which value of AV, TV and guide number by the photographer's operation of the photographer correction data storage section 18 and how much. By using such information, the control exposure value obtained by other than this information is corrected. In this case, the correction is applied to the high recommended values of AV, TV, and strobe. This is because the photographer considers a past history of whether or not the exposure value previously determined by the camera is intentionally corrected in a scene estimated to have the same information.

The question "why" is, for example, whether to shoot for a commemorative photo or to shoot with an emphasis on artistry. If you value recordability like a commemorative photo, the focus should be taken deeply, and if you value artisticity, the photo should be shallow depth and less extra things are called subtractive art. There is a need.

In order to judge this, the distribution of the distance of the object is used in this embodiment. In other words, when the distance distribution on the screen is greatly deviated from the short distance and the long distance, and when these values are discrete, the author intentionally considers the composition etc., judging that it is a special shooting situation. Emphasize artistry as things. In addition, the printability is emphasized for the subject whose distance distribution changes continuously. Nothing else is considered.

The judgment as to whether the commemorative photograph or the artistry is valued can be applied to the setting of the permissible circle of confusion and the permissible blurring amount. This point can also be applied to AF (automatic focus adjustment). The allowable blur size is
It is almost equal to the size of the permissible circle of confusion. For commemorative photographs, the limit value can be set loosely, and for photographs that emphasize artistry, it can be made strict.

The "what" problem is a film problem. It is the sensitivity and latitude of the film. The latitude is ± 1/2, ± 1, -1 to +2, -1 to +3 [E
V], and this degree of exposure deviation is just allowed. In the present invention, for safety, half of each of the plus side value and the minus side value is set as the plus exposure deviation allowance value and the minus exposure deviation allowance value. In summary, in FIG. 14, the shooting situation detection calculation means 10
For the "what" problem, the latitude information shows that latitude [EV] ± 1/2 ± 1 −1 to +2 −1 to +3 plus exposure deviation tolerance [EV] 0.25 0.5 1 1.5 minus exposure deviation tolerance [ EV] 0.25 0.5 0.5 Give a positive exposure deviation allowance and a negative exposure deviation allowance of 0.5 0.5. Next, a main subject estimation calculation is performed. Next, the image velocity of the main subject is calculated. Next, from the results obtained by estimating the color of the main subject, white-2.5 [EV] bright color -1.0 [EV] dark color +1.0 [EV] black +2.5 [ EV] brightness correction calculation is performed to obtain a more accurate main subject brightness. Next, the following judgment is made for the "what time" problem. One frame AV priority One frame (continuous shooting) TV priority Shutter speed without blurring as much as possible Continuous shooting TV priority Shutter speed as high as possible Here, in the case of TV priority, the correction calculation of "who" is skipped. In the case of the AV priority, the problem of “what” is further classified by the subject's estimation calculation. Case (person) (face) AV priority depth 5 cm Person (upper body) AV priority depth 10 cm Person (whole body) AV priority depth 20 cm People (multiple) AV priority depth deep Animal AV priority depth 1 m Landscape AV priority depth deep Mobile TV priority Shutter speed without blur Others AV / TV moderate setting is set. Next, "how" is calculated. Macro AV priority Squeezing according to magnification

Portrait AV priority Open the aperture to a depth of about 10 cm Follow shot TV priority Shutter speed where the main subject does not shake and the background shakes Night view TV priority Shutter speed where the main subject does not shake and the night view appears Other settings as before The set priority and the control value at that time are canceled by a later calculation. Next, think about "where." Dark and narrow TTL strobe recommended Dark and wide guide number control Strobe recommended Guide number depends on the distance of the main subject Bright backlit guide number control Strobe recommended The ratio of natural light and strobe light of the main subject is set to 1: 1. Next, "why" is investigated. Commemorative photo If the above settings are AV priority, deepen the depth (narrow down one step from the settings above) Artisticity If the settings above are AV priority, decrease the depth (open one step above the settings) Others above Next, correct the "who". The settings so far are for AV priority. The correction values for AV are those for TV priority. The correction values for TV are for the guide number. Strobe light amount ratio correction values are classified and calculated.

As a result, the photographing condition detection calculation means 10
AV recommended value, AV priority, TV recommended value, TV priority, guide number control strobe recommended value, guide number control strobe priority, TTL strobe priority, plus exposure deviation allowance value, minus exposure deviation allowance value, main subject brightness ,
Calculates and outputs the main subject image velocity.

In the above embodiment, the respective priorities are divided according to the cases, but the priorities and recommended values are determined and added for each item, and the final priorities are the sum of the respective priorities and the average values are recommended. The value may be obtained. It is also possible to introduce an inference system based on fuzzy theory, which has recently been put into practical use, into these operations. It is also possible to use the learning function of the neural network for creating rules, and the neural network for control itself. When using a neural network, the camera creator uses each detection signal as an input to let the camera learn in advance, and when the user uses it, it is possible to use a simple neural network that does not have a learning function, or There are two possible methods of activating the learning function at any time so that the user does not need to change or reset each exposure control value during use. When the required aperture value is calculated from the depth of focus, it is obtained from the known Newton's equation of the optical system and the relational expression of the focus shift and the aperture. The focus deviation d, the aperture value F, and the permissible circle of confusion diameter δ (generally about 30 to 50 μm) are d = δ · F (1 + m) where m is the photographing magnification. This equation can be approximately d = δ · F when m is small.

This will be described with reference to FIG. When the length from the principal point on the front side of the taking lens to the subject is A, the length from the principal point on the back side of the taking lens to the image forming point (corresponding to the film surface) is B, and the focal length of the taking lens is f , F · f = A
・ B holds.

If the shift of the image formation point of the image point of the point shifted by the distance D on the subject side is d, then f.f = (A.D). (B +
d), therefore d = −D · f · f / {A · (A + D)}, and if f and A are known, d is determined and the aperture value is determined by F = d / δ. For A, approximately (subject distance −
Even if 2 · f), the error is small when the distance is a certain distance.

Further, a known subject distance calculation formula R (x)
= Α / x + β + γ · x (distance of R subject from film, x is amount of extension, α, β, γ are coefficients), D = R (x + d) −R (x)

=-(Α · d / {x · (x + d)} + γ ·
d), where γ · d is a relatively small value and is ignored, and d is obtained as d = D · x · x / (α + x · D),
The aperture value may be set as F = d / δ. The control exposure amount calculation means 2 will be described below.

First, the control exposure amount calculation means 2 receives the AV recommended value (Avs), AV priority, TV recommended value (Tvs), TV priority, guide number control strobe recommended value (from the shooting situation detection means 1). ks), guide number control strobe priority, TTL strobe priority, plus exposure deviation allowance (Evp), minus exposure deviation allowance (Ev)
m), main subject brightness (Bv), main subject image velocity (O
In response to the signal v), the control AV value, control TV value, strobe guide number value, and TTL strobe control command code are calculated. A known apex arithmetic expression is used to calculate the control exposure amount.

The basic apex arithmetic expression has a unit of [E
V], the luminance of the main subject is Bv, the film sensitivity is Sv, the exposure correction amount is Cv, the aperture value is Av, and the shutter speed is Tv. Bv + Sv−Cv = Av + Tv (1) Also, set the flash guide number to G,
When the distance to the subject is D, and the apex expressions are Gv and Dv, respectively (power is represented by [^]) Gv = log ₂ (G ^ 2) (2) DV = log ₂ (D ^ 2) (3) (However, G ^ 2 = G ² , D ^ 2 = D ² Is. ), And the ratio of the amount of strobe light to the amount of exposure is ks
Then, (amount of natural light) = (1-ks) ・ (2 ^ Bv) ・ {2 ^ (Sv-Cv)} /
{(2 ^ Av)-(2 ^ Tv)} ... (4) (Strobe light intensity) = ks- (2 ^ Gv)-{2 ^ (Sv-Cv)} /
{(2 ^ Av) * (2 ^ Dv)} ... (5), and the relation of the proper exposure amount can be described as log ₂ {(natural light amount) + (strobe light amount)} = 0 (6), Furthermore, the apex arithmetic expression considering natural light and the amount of strobe light is Sv-Cv = Av-log ₂ [ks ・ {2 ^ (Gv-Dv) -2 ^ (Bv-Tv)}
+ 2 ^ (Bv-Tv)] ... (7) The recommended guide number control strobe value is processed as a signal equivalent to the ratio of the amount of strobe light to the amount of exposure. When ks = 0,
Equation (1) is derived from equation (6). Exposure calculation is divided into the following cases. (A) AV priority> TV priority, no flash priority (b) AV priority> TV priority, TTL strobe priority (c) AV priority> TV priority, guide number control strobe priority ( d) AV priority <TV priority, no strobe priority (e) AV priority <TV priority, TTL strobe priority (f) AV priority <TV priority, guide number control strobe priority (g) ) AV priority = TV priority, without strobe priority (h) AV priority = TV priority, with TTL strobe priority (i) AV priority = TV priority, with guide number control strobe priority First (a ) Will be described. In this case, the Tv value is obtained from the Apex operation expression (6) when ks = 0. By the way, as a condition for good photography, there is a condition that the exposure amount is correct, but it is also very important that there is no blur. Consider the relationship between the main subject image speed (Ov) and the shutter speed.

FIG. 16 is a graph showing the amount of image blur during exposure depending on the shutter speed (TV value) at the image velocity of a certain subject. As shown in FIG. 16, it may be said that the image blur does not occur if a certain shutter speed is made high. This shutter speed is set to Tvb. In FIG. 16, the image velocity of the image of the subject is illustrated as 1 [mm / S].

From the analysis of blur, it was found from the analysis of blur that the size of the blur that can be judged as having no blur is the permissible circle of confusion diameter δ level. Therefore, the limit shutter speed Tvb without blur can be calculated as Tvb = log ₂ (δ / Ov). In the example of FIG. 16, the permissible circle of confusion δ is 50
If [μm], then Tvb = log ₂ (0.05 [mm]
/ 1 [mm / S]), so about 4.32 from this
It becomes [EV]. When determining the control exposure value, the priority aperture value (Avs) and the shake-free shutter speed (Tvb) are taken into consideration.

FIG. 17 shows a program diagram of exposure in this case.
Shown in. Here, the aperture value of the open aperture of the aperture value that can be linked with the camera is (Avo), the maximum aperture value is (Avm),
The highest shutter speed is (Tvm) and the lowest shutter speed is (Tvo). Also, Lv = B
Let v + Sv-Cv.

Since the exposure deviation that can be tolerated with respect to the exposure is defined as the plus exposure deviation allowance value (Evp) and the minus exposure deviation allowance value (Evm), {Tvo- (T
In the case of the shutter speed of (vb-Evm)}, the corrective calculation is performed so as to prevent blurring as much as possible by correcting the shutter speed to a high speed side so that Evm is underexposed with respect to the proper exposure. In addition, {(Avs + Evp) ~
In the range of Avm}, the aperture value is Evp-corrected so that the exposure is over Evp so that the shooting can be performed with the target aperture value as much as possible. In the example of FIG. 17, the priority aperture value (Avs) is set to 8 [EV]. Aperture value (Avc) for control, shutter speed (T
vc), the strobe OFF signal is set.

In the case of (b), if the charging of the strobe is completed, the aperture value is set to AVs and the shutter speed is set to the synchronized speed Tvx which is the interlocking value. That is, aperture value (Avc) = Avs, shutter speed (Tvc) = Tvx, strobe TTLON for control.
The signal is set. When the strobe charge is not completed, the control is performed in the same manner as in (a).

In the case of (c), if the charging of the strobe is not completed, the same control as in (a) is performed. If it is completed, the guide number Gv is calculated using the aperture value AVs, the value ks indicating the ratio of strobe light, and the shutter speed Tvx. Aperture value (Avc) = Avs for control, shutter speed (Tvc) =
Tvx, strobe guide number control ON signal, and control guide number Gv are set.

In the case of (d), the arithmetic expression (6) of Apex
Therefore, A when ks = 0 and shutter speed Tvs
Find the v value. Figure 1 shows the program diagram of exposure in this case.
8 shows. As an example, Tvs = 5 [EV] is set. The exposure deviation that can be tolerated with respect to the exposure can be calculated as the plus exposure deviation allowance value (Evp) and the minus exposure deviation allowance value (Ev
Therefore, when Av = Avo, the corrective calculation is performed so as to prevent blurring as much as possible by correcting the shutter speed to a high speed side so that Evm is under the proper exposure. When Av = Avm,
The shutter speed is corrected so that the exposure is over Evp so that shooting with the desired aperture value is possible as much as possible. Aperture value for control (Av
c), shutter speed (Tvc), strobe off
The signal is set.

In the case of (e), if the charging of the strobe is not completed, the same control as in (d) is performed. Even if the charging is completed, if Tvs is higher than Tvx, the process is the same as that of (d). If charging is completed and Tvs is lower than Tvx, ks = 0, shutter speed Tv is calculated from Apex's equation (6).
In the case of s, the Av value is obtained and used as the aperture value for control, and the shutter speed Tvs and the strobe TTLON signal are set.

In the case of (f), if the charging of the strobe is not completed, the same control as in (d) is performed. Even if the charging is completed, if Tvs is higher than Tvx, the process is the same as that of (d). When the shutter can be linked, the same calculation as in (d) is performed, and the guide number is obtained from the subject distance and the AV value of the calculation result. And
The aperture value (Avc), shutter speed (Tvc), strobe guide number control ON signal, and control guide number Gv for control are set.

In the case of (g), there is no great feature in photographing, but in this case, the Av value and the Tv value are determined according to the brightness of the object using a program diagram as in the conventional case.
However, the calculated Tv value is regulated to the shutter speed that is the limit of camera shake so that a camera shake photograph is not generated, as in (a). This program diagram is shown in FIG.

In the cases of (h) and (i), the same processing as in (g) is performed, and the aperture value, shutter speed, and strobe control signal for control are set in the form according to (b) and (c). It Next, the exposure control of the exposure control unit 3 will be described with reference to FIG.

The exposure control section 3 is an output of the control exposure calculation means 2 for controlling the aperture value (Avc), shutter speed (Tvc), strobe TTL ON signal, strobe guide number control ON signal, control guide number signal ( Based on Gv), the aperture drive device, shutter drive device, strobe circuit, and strobe control circuit are used to control exposure.

The operation of the strobe control circuit changes depending on the strobe control signal. If there is a strobe TTLON signal, the strobe performs known TTL direct photometry. Further, when there is a strobe guide number control ON signal, the strobe performs known guide number control based on the control guide number signal (Gv).

Further, the output of the judgment of the condition of the subject shown in the above example can be used not only for automatic exposure of the camera but also for automatic focus detection and the like. For example, the achievement level of focus adjustment (the amount of focus shift remaining after focus adjustment) can be loosened or stricter depending on whether the shooting is a commemorative photograph or one aimed at high artistry.

Further, in the above-mentioned embodiment, the example in which the image signal of the subject is used for detecting the blur of the subject is shown, but a sensor for detecting the vibration of the camera, for example, an angular velocity sensor or an acceleration sensor is used. Of course, it is also possible to detect camera shake and camera shake and calculate the slow shutter speed, which is the limit without shake, depending on the size of the camera shake.

Further, regarding the strobe control, in addition to the TTL control and the guide number control shown in the above example, the so-called rear curtain synchronization and front curtain synchronization may be automatically determined from the situation of the subject. ..

[0103]

As described in detail above, the present invention provides a main subject detecting device for a camera which can accurately detect a main subject in order to focus on the main subject in a photographic screen and provide appropriate exposure. It is possible to

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of the present invention.

FIG. 2 is a diagram showing in detail the configuration of each part of FIG.

FIG. 3 is a diagram showing an arrangement of CCDs constituting an image signal detecting device.

FIG. 4 is a diagram showing a screen divided vertically and horizontally into nine equal parts and divided into 81 areas.

FIG. 5 is a diagram showing a configuration of an object distance distribution detection device.

FIG. 6 is a diagram for explaining the operation of a magnification distribution detection device for a subject.

FIG. 7 is a diagram for explaining the operation of the object size / shape distribution detection device.

FIG. 8 is a diagram for explaining the operation of the movement distribution detection device for a subject.

FIG. 9 is a diagram showing a screen which is vertically and horizontally divided into nine equal parts by golden section.

FIG. 10 is a flowchart for explaining an operation of detecting a main subject.

FIG. 11 is a flowchart for explaining a main subject area calculation operation.

FIG. 12 is a flowchart for explaining a subject candidate determination calculation operation.

FIG. 13 is a flowchart for explaining a main subject area calculation operation.

FIG. 14 is a flowchart for explaining a shooting condition detection calculation operation.

FIG. 15 is a diagram illustrating a method of determining an aperture value.

FIG. 16 is a graph showing an image blur amount during exposure according to a shutter speed (TV value).

FIG. 17 is a diagram showing an example of an exposure program diagram.

FIG. 18 is a diagram showing another example of an exposure program diagram.

FIG. 19 is a diagram showing another example of an exposure program diagram.

FIG. 20 is a diagram for explaining an exposure control operation of the exposure control unit.

[Explanation of symbols]

1 ... Shooting situation detecting means, 2 ... Control exposure amount calculating means, 3 ...
Exposure control unit, 10 ... Shooting situation detection calculation means, 11 ... Luminance distribution detection device, 12 ... Distance distribution detection device, 13 ... Magnification distribution detection device, 14 ... Size / shape distribution detection device, 15 ...
Moving distribution detecting device, 16 ... Sensitivity / latitude detecting device, 17 ... Main subject detecting device, 18 ... Photographer correction data
Data storage unit, 19 ... Image signal detecting device, 20 ... Focal length detecting device.

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[Procedure amendment]

[Submission date] December 26, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

[0008]

In order to achieve the above-mentioned object, a main subject detecting device for a camera according to the present invention comprises distance measuring means for outputting the distances of his body at a plurality of points within a photographing screen, The first detecting means for detecting the point at which the object at the shortest distance is output from the output of the distance measuring means and the point at which the object at the closest distance is output are the golden section of the central portion of the photographing screen or the screen. And a judgment means for judging whether or not it is on the line, and in the case where it is judged by this judgment means that the point outputting the closest distance is not on the central part or on the golden section line, near the center in the screen. In addition, the second detection means for detecting the point that outputs the shortest distance among the points on the golden division line, and the point detected by the first detection means by the determination means is the central portion or the golden division line. If it is determined to be above If it is determined that there is a main subject at that point and the point detected by the first detecting means is not on the central portion or on the golden section line, it is detected by the second detecting means. It is determined that the main subject is at the point.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

[0009]

That is, according to the present invention, the point at which the subject at the closest distance is output is detected by the first detecting means, and the point at which the image of the subject at the closest distance is output is at the center of the photographing screen or It is determined whether or not the screen is on the golden division line. When it is determined that the point is not on the central portion or on the golden section line, the second detecting means further detects the point which outputs the closest distance among the points near the center in the screen and on the golden section line. .. Then, when it is determined that the point detected by the first detecting means is on the central portion or on the golden section line, it is determined that the main subject exists at that point, and the point is detected by the first detecting means. When it is determined that the determined point is not on the central portion or on the golden section line, it is determined that the main subject exists at the point detected by the second detecting means.

Claims (1)

[Claims] 1. A distance measuring means for outputting distances of a subject at a plurality of points on a photographing screen, and a first detecting means for detecting a point at which an object at the closest distance is outputted from the output of the distance measuring means. A determination unit that determines whether or not the point at which the subject at the closest distance is output is on the center portion of the photographing screen or on the line that divides the screen into the golden section, and the determination unit outputs the closest distance. Second detecting means for detecting a point that outputs the shortest distance among points on the golden division line near the center in the screen and when it is determined that the point is not on the central portion or on the golden line. When the determination means determines that the point detected by the first detection means is on the central portion or on the golden line,
If it is determined that there is a main subject at that point, and it is determined that the point detected by the first detecting means is not on the central portion or on the golden section line, it is detected by the second detecting means. A main subject detection device for a camera, characterized by determining that a main subject is present at a point.