JP2001286444A - Fundus camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the operation performance including precise positioning of a fundus camera. SOLUTION: An eyeground illumination light passage 01 and an eyeground observation imaging light passage 02 are split by an apertured mirror 13 at a nearly conjugate position with the pupil relative to an object lens 14. The image of the anterior ocular segment illuminated by a light source 1 for illuminating the anterior ocular segment is taken by a monochromatic video camera 4 by way of a light passage changing mirror 19 and a dichroic mirror 22, and is displayed on a monitor 5. A light source 2 for illuminating the eyeground projects infrared light or visible light from the action of a filter unit 6 on the eyeground, while the light source 1 for illuminating the anterior ocular segment projects infrared light, different from the visible light from the light source 2 on the anterior ocular segment. Concave lenses 16 and 27 with the same focal distance are disposed symmetrically relative to a focus light reflecting mirror 15 on the eyeground observation imaging light passage 02 and on a focus light projecting light passage 05. A fixing eye index 26 is projected on an examined eye E while the image of the anterior ocular segment or the eyeground is displayed on the monitor 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fundus camera used in an ophthalmic hospital or the like.

[0002]

2. Description of the Related Art A conventional fundus camera of this type is an optical unit for projecting a light beam to an eye to be examined and guiding the reflected light beam to image receiving means, and a positioning means for manually or automatically aligning the optical unit with the eye to be inspected. And a monitor for displaying an anterior eye image or a fundus image received by the image receiving means.

The optical unit includes an anterior segment illumination light source for illuminating the anterior segment, an anterior segment observation optical path for guiding reflected light from the anterior segment to imaging means, a fundus illumination source for illuminating the fundus, and a light beam from the fundus illumination source. A fundus illuminating optical path that guides the eye to the subject's eye, a fundus observation photographing optical path that guides a reflected light beam from the fundus to the imaging element means, a display means for displaying an anterior ocular segment image and a fundus image captured by the imaging means,
It has a fixation target for stabilizing the line of sight of the eye to be examined.

[0004] When observing or photographing the eye to be examined, the optical unit is positioned and focused on the eye to be examined while observing the anterior eye image displayed on the display means. Operate to photograph the fundus.

On the other hand, the optical unit is provided with an objective lens for the eye to be examined, and a fundus illumination optical path and a fundus observation photographing optical path are divided by a perforated mirror arranged substantially conjugate with respect to the objective lens, and a lens is inserted into the fundus observation photographing optical path. In some cases, the anterior eye image is observed from an oblique direction. Also, when projecting the light flux from the fundus illumination light source to the fundus as visible light, observe the fundus with an optical system finder, and when projecting the fundus as infrared light, image the fundus with imaging means and display it with display means. Sometimes we observe.

Further, the fundus camera disclosed in Japanese Patent Application Laid-Open No. 53-129059 has mirrors disposed on both sides of a fundus observation photographing optical path near a perforated mirror and focuses on the fundus observation photographing optical path. The lens is placed. Then, focus light from the focus light projection system is projected onto the fundus via a mirror, and the focus light projection system and the focus lens are driven integrally to perform focusing.

[0007]

However, with the conventional fundus camera, it is difficult to accurately position and focus the anterior eye image on the screen. Further, since it is not easy to switch between the anterior eye image and the fundus image, it is not possible to photograph the fundus image while observing the anterior eye image. When positioning is performed using infrared light, it is not easy to photograph the periphery of the fundus. Furthermore, a fixation target cannot be projected when observing the anterior eye, and the fundus cannot be observed with infrared light and visible light. In a fundus camera that performs focusing by integrally driving the focus light projection system and the focus lens, since the focus adjustment amount is small compared to the movement amount of the focus lens, various diopter ranges in which focus can be performed are narrow. There is a problem.

An object of the present invention is to solve the above-mentioned problems,
An object of the present invention is to provide a fundus camera capable of performing accurate positioning and improving operability.

[0009]

According to a first aspect of the present invention, there is provided a fundus camera for dividing a fundus illumination optical path and a fundus observation photographing optical path at a position substantially conjugate with a pupil with respect to an objective lens. A fundus camera characterized by observing an anterior eye part via a light splitting member provided in the fundus illumination light path.

According to a second aspect of the present invention, the anterior ocular segment observation optical path and the fundus oculi observation optical path are combined to observe the anterior ocular segment image and the fundus oculi image by a single imaging means. It is a fundus camera.

According to a third aspect of the present invention, the wavelength of the anterior ocular segment observation light is different from the wavelength of the fundus oculi observation light.
2. A fundus camera according to 1.

According to a fourth aspect of the present invention, there is provided a focus light projection system for projecting focus light to a fundus via mirrors arranged on both sides of a fundus photographing optical path near a perforated mirror. In a fundus camera that performs focusing by driving the disposed focus lens and the focus light projection system integrally, two concave lenses having the same focal length are provided on the fundus imaging optical path and the optical path of the focus light projection system with respect to the mirror. It is a fundus camera characterized by being arranged symmetrically.

According to a fifth aspect of the present invention, there is provided an illumination unit for illuminating the fundus with infrared light, an imaging unit for imaging the fundus with an optical system including a focus lens, and a light dividing member provided in the optical system. An anterior segment imaging unit for imaging the anterior segment with the imaging unit; a display unit for displaying the photographed fundus image and the anterior segment image; and fixation on the subject's eye via the focus lens and the light splitting member. A fundus camera having a fixation system for projecting a target, wherein the fixation target is projected onto an eye to be examined when the anterior segment is displayed on the display means.

According to a sixth aspect of the present invention, there is provided a method of selectively illuminating a fundus with infrared light or fundus illumination visible light.
Illuminating means, a second illuminating means for illuminating the anterior ocular segment with anterior ocular segment illumination infrared light different from the fundus illuminating infrared ray, An imaging unit for selectively imaging the eye unit, and a display unit for displaying an image from the imaging unit, wherein the anterior segment illumination infrared light is transmitted to the imaging unit via the anterior segment optical system. Guiding the fundus illumination infrared light or the fundus illumination visible light to the imaging means via the fundus optics to selectively image the fundus with the fundus illumination infrared light or the fundus illumination visible light. A fundus camera characterized in that:

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail based on the illustrated embodiment. FIG. 1 is an optical configuration diagram of a first embodiment of a fundus camera. The fundus camera projects a light beam from an anterior segment illumination light source 1 or a fundus illumination light source 2 that is selectively turned on to an eye E to be examined. An optical unit (not shown) for guiding the reflected light beam to the color digital camera 3 or the monochrome video camera 4 having sensitivity to visible light and infrared light, and a positioning unit (not shown) for manually or automatically aligning the optical unit with the eye E to be inspected. And a monitor 5 for displaying an anterior eye image and a fundus image captured by the monochrome video camera 4.

The anterior ocular segment illumination light source 1 is a light emitting diode that emits infrared light having a main wavelength of 780 nm indicated by a characteristic curve a in FIG. Then, the examiner observes the image of the anterior eye part displayed on the monitor 5 and adjusts the position and the focus of the optical unit with respect to the eye E to be examined, and operates a photographing switch (not shown) to photograph the fundus image with the color digital camera 3. It is supposed to.

A fundus illumination light path O1 through which a light beam from the fundus illumination light source 2 travels has a wavelength 800 shown by a characteristic curve b in FIG.
a filter unit 6 for selectively inserting a filter 6a transmitting infrared light of nm or more or a filter 6b transmitting visible light indicated by a characteristic curve c into the optical path O1, a lens 7, a strobe light source 8 for fundus photography, a ring slit 9, lens 1
0, visible light indicated by a characteristic curve d in FIG.
transmits infrared light of nm or more and has a wavelength of 700 to 800.
A dichroic mirror 11, a lens 12, and a perforated mirror 13 that reflect infrared light of nm are arranged in this order.
Then, in the fundus observation photographing optical path O2 in front of the subject's eye E,
An objective lens 14 that forms an image of the pupil of the eye E in the vicinity of the perforated mirror 13 is provided. The anterior segment illumination light source 1 is arranged around the objective lens 14, and the lens 7 forms an image of the fundus illumination light source 2 on the ring slit 9.

In the transmission direction of the perforated mirror 13, the optical path O
2, a focusing light reflecting mirror 15, a concave lens 16, and a focusing lens 1 moving on an optical path O2.
7, an imaging lens 18, an optical path switching mirror 19, a relay lens 20, and the above-described color digital camera 3 are sequentially arranged. The anterior ocular segment imaging optical path O3 divided by the dichroic mirror 11 reflects the lens 21, most of infrared light having a wavelength of 800 nm or more and visible light indicated by the characteristic curve e in FIG. A dichroic mirror 22, a lens 23, and the above-described monochrome video camera 4 that transmit light having a wavelength of?

A lens 24, a dichroic mirror 22, a lens 25, and a fixation target 26 are sequentially arranged on the fundus observation fixation target optical path O4 in the incident direction of the light path switching mirror 19. A concave lens 27 and a mirror 2 are provided on the focus light projection optical path O5 incident on the focus light reflection mirror 15.
8. A split light projection system 29 is provided. The concave lens 27 has the same focal length as the concave lens 16, and is arranged symmetrically with the concave lens 16 with respect to the focus light reflecting mirror 15. The split light projection system 29 emits infrared light,
It is driven in the optical axis direction in conjunction with the focus lens 17.

When the anterior segment illumination light source 1 illuminates the anterior segment of the eye E, the light beam reflected by the anterior segment passes through the objective lens 14, is reflected by the perforated mirror 13, and passes through the lens 12. The light is reflected by the dichroic mirror 11, reaches the monochrome video camera 4 via the lens 21, the dichroic mirror 22, and the lens 23, and an anterior eye image is captured. At this time,
If the subject's eye E is at the correct position, the pupil is conjugate to the image plane of the monochrome video camera 4.

The light beam from the fundus illumination light source 2 passes through the filter 6a of the filter unit 6 to become infrared light, and is projected on the fundus of the eye E through the dichroic mirror 11, the perforated mirror 13, and the objective lens 14. You. The light reflected by the fundus passes through the hole of the perforated mirror 13, is reflected by the optical path switching mirror 19, is reflected by the dichroic mirror 22, and is captured by the monochrome video camera 4.

When split light due to infrared light is projected from the split light projection system 29 onto the fundus, the reflected light flux of the split light on the fundus passes through the hole of the perforated mirror 13, the optical path switching mirror 19, and the dichroic mirror 22. The image is captured by the monochrome video camera 4 and the split image S is displayed on the monitor 5.
Is displayed. The light beam from the fixation target 26 passes through the dichroic mirror 22 and passes through the optical path switching mirror 19.
And is projected on the eye E through the hole of the perforated mirror 13.

When positioning the optical unit with respect to the eye E to be examined, the anterior segment illumination light source 1 is turned on and the monitor 5 is turned on.
To display the anterior segment image F. At this time, since the alignment mark M is also displayed on the monitor 5, the optical unit is driven so that the pupil image is aligned with the alignment mark M, and the alignment of the optical unit and the focusing of the pupil image are performed. Then, after completing the positioning and focusing, a photographing switch (not shown) is pressed. As a result, the optical path switching mirror 19 is retracted out of the optical path, the photographing strobe light source 8 emits light, and the fundus image, which is reflected light by the illumination light, is photographed by the color digital camera 3 with visible light.

In the first embodiment, the anterior segment illumination light source 1
By switching between the fundus illumination light source 2 and the fundus illumination light source 2, the anterior ocular segment image F and the fundus oculi image can be selectively displayed on the monitor 5, and the fundus oculi image can be photographed by pressing the shutter while observing the anterior ocular segment image F. Regardless of which of the anterior segment illumination light source 1 and the fundus illumination source 2 is selected, the split image S is displayed on the monitor 5 at a position corresponding to the center of the fundus, so that the fundus is focused on while observing the anterior segment. it can. Further, while the anterior segment is displayed on the monitor 5, the fixation target 26 is presented to the subject's eye E in the same manner as when observing the fundus, so that the subject's eye E is stabilized and positioning is easily performed. be able to.

When the fundus is observed with infrared light,
The lesion may not be clearly determined. In this case,
Filter 6 instead of filter 6a of filter unit 6
b is inserted into the fundus illumination optical path O1, and the fixation target 26 is turned off because it cannot be used. As a result, the light beam from the fundus illumination light source 2 is projected on the fundus as visible light, and the light beam reflected from the fundus is reflected by the optical path switching mirror 19 and the dichroic mirror 22.
The image is captured by the monochrome video camera 4 through the camera, and a fundus image by visible light is displayed on the monitor 5. At this time,
The light flux reflected from the fundus becomes a parallel light flux between the focus lens 17 and the imaging lens 18 when the focus is achieved. Since the concave lenses 16 and 27 act to reduce the amount of movement of the focus lens 17 and the split light projection system 29, the diopter of the eye E can be adjusted over a wide range by such small movements.

FIG. 4 is an optical configuration diagram of the second embodiment. Members having the same functions as those of the first embodiment are denoted by the same reference numerals. The dichroic mirror 11 on the fundus illumination optical path O1 is moved between the ring slit 9 and the lens 10. Further, the focus light reflecting mirror 15, the concave lens 16, the focus lens 17, the imaging lens 18, the concave lens 27, the mirror 28, and the split light projection system 29 of the first embodiment are removed, and instead, the split light projection system for focusing is used. 31 is the lens 10 and the lens 1 of the fundus illumination optical path O1
2 and the focus lens 32
And an imaging lens 33 are disposed between the perforated mirror 13 in the optical path O2 and the optical path switching mirror 19.

The split light projection system 31 has a bar mirror 31.
a is arranged conjugate with the fundus, so that the light beam from the light source 31b is reflected by the perforated mirror 13, and the split light projection system 31 and the focus lens 32 are linked.
Further, when photographing the fundus by observing the fundus with visible light, the rod mirror 31a of the split light projection system 31 is driven out of the optical path O1.

The reflected light from the anterior segment is reflected by the perforated mirror 13.
And the light is reflected by the dichroic mirror 11 and transmitted through the dichroic mirror 22, respectively.
And an anterior eye image F is displayed on the monitor 5. Further, in the split light projection system 31, the split light obtained by reflecting the light from the light source 31b by the bar mirror 31a is reflected by the perforated mirror 13 and projected on the fundus. Then, when observing the fundus with visible light and photographing, the rod mirror 31a of the split light projection system 31 retreats outside the optical path O1, and
The light beam from the fundus illumination light source 2 becomes visible light and is projected on the fundus, and the light beam reflected by the fundus passes through the hole of the perforated mirror 13, the focus lens 32 and the imaging lens 33, and the light path switching mirror 19 and the dichroic mirror 22. , And are imaged by the monochrome video camera 4.

In the second embodiment, since the rod mirror 31a of the split light projection system 31 is conjugate with the fundus and the light beam of the split light projection system 31 is thick, the anterior ocular segment image F
Does not show the shadow of the split image S. By selectively lighting the anterior segment illumination light source 1 or the fundus illumination source 2, the anterior segment image F and the fundus image can be displayed on the monitor 5.
In any case, it is needless to say that the split image S for focus can be displayed and the fixation target 26 can be presented to the subject.

[0030]

As described above, according to the first aspect of the present invention, the anterior segment is observed through the light splitting member provided on the fundus illumination optical path. By switching on and turning on the light source, the anterior eye image and the fundus image can be easily switched, the fundus can be photographed while observing the anterior eye image, and the operability can be improved.

Further, since the anterior segment can be observed by imaging the anterior segment with a thick light beam from the front, focusing can be performed on the screen of the anterior segment image, and accurate positioning can be performed. . Furthermore, since the positioning can be accurately performed using the pupil, the periphery of the fundus can be easily photographed even when performing the positioning using infrared light.

According to the second aspect of the present invention, since the anterior ocular segment image and the fundus oculi image can be picked up by a single image pick-up means, an increase in component costs can be suppressed.

According to the third aspect of the present invention, since the wavelength of the anterior ocular segment observation light and the wavelength of the fundus oculi observation light are made different, the anterior ocular segment observation light and the fundus oculi observation light can be accurately divided.

According to the fourth aspect of the present invention, the two concave lenses having the same focal length are arranged symmetrically with respect to the mirror in the fundus imaging optical path and the optical path of the focus light projection system, so that the diopter adjustment range can be expanded.

According to the fifth aspect of the present invention, when the anterior segment is displayed on the display means, the fixation target is projected onto the subject's eye in the same manner as when the fundus is displayed. During this operation, the fixation target can be projected, the eye to be examined can be stabilized, and the alignment can be easily performed.

According to a sixth aspect of the present invention, the anterior segment illumination infrared light is guided to the image pickup means via the anterior segment optical system, and the fundus illumination infrared light or the fundus illumination visible light is converted through the fundus optical system. By guiding to the imaging means, the fundus is selectively imaged with the fundus illumination infrared light or the fundus illumination visible light, so that the anterior eye part can be observed with infrared light and the fundus can be observed with one imaging means and display means. It can be observed by infrared light or visible light, and operability can be improved.

[Brief description of the drawings]

FIG. 1 is an optical configuration diagram of a first embodiment.

FIG. 2 is a graph showing the transmittance of a filter and the intensity of an anterior segment illumination light source.

FIG. 3 is a graph showing the transmittance of a dichroic mirror.

FIG. 4 is an optical configuration diagram of a second embodiment.

[Explanation of symbols]

 Reference Signs List 1 anterior eye illumination light source 2 fundus illumination light source 3 color digital camera 4 monochrome video camera 5 monitor 6 filter unit 11, 22 dichroic mirror 13 perforated mirror 14 objective lens 15 focus light reflection mirror 16, 27 concave lens 17, 32 focus lens 19 Optical path switching mirror 26 Fixation target 29, 31 Split light projection system

Claims (6)

[Claims] 1. A fundus camera for dividing a fundus illumination optical path and a fundus observation photographing optical path at a position substantially conjugate with a pupil with respect to an objective lens, wherein an anterior ocular segment is observed via a light dividing member provided on the fundus illumination optical path. A fundus camera characterized in that: 2. The fundus camera according to claim 1, wherein the anterior segment observation optical path and the fundus observation optical path are combined to observe the anterior segment image and the fundus image by a single imaging unit. 3. The fundus camera according to claim 1, wherein the wavelength of the anterior ocular segment observation light is different from the wavelength of the fundus oculi observation light. 4. A focus lens projection system for projecting focus light to the fundus via mirrors disposed on both sides of a fundus photographing optical path near a perforated mirror, wherein the focus lens and the focus are disposed on the fundus photographing optical path. In a fundus camera that performs focusing by driving an optical projection system integrally, two concave lenses having the same focal length are arranged symmetrically with respect to the mirror in the fundus imaging optical path and the optical path of the focus light projection system. Fundus camera. 5. An illuminating unit for illuminating the fundus with infrared light, an imaging unit for imaging the fundus with an optical system including a focus lens, and the imaging of the anterior eye via a light dividing member provided in the optical system. Anterior ocular segment imaging means for imaging means, display means for displaying the captured fundus image and anterior ocular segment image, and a fixation system for projecting a fixation target to the eye to be examined via the focus lens and the light splitting member A fundus camera, comprising: projecting the fixation target onto an eye to be examined when displaying the anterior segment on the display means. 6. A first illuminating means for selectively illuminating the fundus with fundus illumination infrared light or fundus illumination visible light, and an anterior ocular segment with anterior eye illumination infrared light different from the fundus illumination infrared light. A second illuminating means for illuminating the eye, an imaging means for selectively imaging the fundus oculi or anterior eye via the fundus optics or anterior eye optics, and a display means for displaying an image from the imaging means. Guiding the anterior ocular segment illumination infrared light to the imaging unit via the anterior ocular segment optical system, and applying the fundus illumination infrared light or the fundus illumination visible light to the imaging unit via the fundus optical system A fundus camera characterized by selectively imaging the fundus with the fundus illumination infrared light or the fundus illumination visible light.