KR20230167579A - Hologram-based direct retinal projection-type augmented reality device for expanding FoV by replicating FoV - Google Patents

Abstract

A hologram-based pupil direct projection augmented reality device that expands the viewing area by duplicating the viewing area is provided. An augmented reality device according to an embodiment of the present invention includes a projection system that generates and projects an image, a replication unit that copies the image projected from the projection system and emits images with different optical paths, and images emitted from the replication unit. and an image combiner that combines external light incident from the real world. As a result, the compact device increases the size of the pupil tolerance area, which was inconvenient for general users, and allows images to be observed without being cut off even when the pupil moves freely, relieving the user's discomfort and designing the viewing area to accommodate various binocular distances. By securing a margin of , it is possible to reduce production costs by escaping the limitations of customized design during mass production.

Description

Hologram-based direct retinal projection-type augmented reality device for expanding FoV by replicating FoV}

The present invention relates to augmented reality technology, and more specifically, to a pupil-direct augmented reality device that provides augmented reality content images while worn by a person.

Direct pupil augmented reality devices have the advantage of providing images with a wide angle of view with a compact design, but have a very narrow viewing area as a limitation. This is a direct-pupil augmented reality device that is designed in a structure in which bundles of light corresponding to individual pixels are concentrated on a single point (about 1 mm in diameter), and the user must correctly position the pupil at the point of concentration to view the entire augmented reality image. Because there is.

However, when considering ① the rotation and left and right movement of the pupil, and ② the gap between the left and right eyes, which differs for each user, this limited viewing range inevitably limits the general use of the augmented reality device, so while maintaining the advantages of the existing direct-pupil device, There is a need to develop an imaging device that can provide a viewing range of several millimeters or more.

The present invention was created to solve the above problems, and the purpose of the present invention is to increase the size of the viewing area, which is the pupil tolerance area, in a thin film-type holographic lens-based pupil direct-projection augmented reality device, while also providing compactness, which has the advantage of the prior art. The aim is to provide a method for maintaining an optical structure.

An augmented reality device according to an embodiment of the present invention for achieving the above object includes a projection system that generates and projects an image; a duplication unit that copies the image projected from the projection system and emits images with different optical paths; It includes an image combiner that combines images emitted from the replica unit with external light incident from the real world.

Different images can form different viewing areas.

The replica unit may emit a part of the images projected from the projection system through the first optical path, and may emit another part of the images projected from the projection system through the second optical path.

The second optical path may be an optical path that uses a first point spaced apart from the exit pupil of the projection system as a virtual exit pupil.

The replica part is an optical medium; A first part located on one side of the optical medium, emitting part of the image projected from the projection system to the first optical path and reflecting the other part, and emitting the image reflected from the second partial reflection surface to the second optical path. reflective surface; and a second partial reflective surface located on the other surface opposite to one surface of the optical medium, and reflecting the image reflected from the first partial reflective surface to the first partial reflective surface.

The separation distance between the first viewing area formed by the image emitted through the first optical path and the second viewing area formed by the image emitted through the second optical path may be proportional to the thickness of the optical medium.

The first partial reflective surface may have different transmittance and reflectance depending on the light output area.

The replica unit may emit another part of the image projected from the projection system to the third optical path.

The third optical path may be an optical path that uses a second point spaced apart from the exit pupil of the projection system as a virtual exit pupil.

A method of providing an augmented reality image according to another embodiment of the present invention includes the steps of a projection system generating and projecting an image; A copying unit duplicating the image projected from the projection system and emitting images with different optical paths; and combining, by an image combiner, images emitted from the replica unit and external light incident from the real world.

An augmented reality optical device according to another embodiment of the present invention includes a replication unit that copies an image and emits images with different optical paths; and an image combiner that combines images emitted from the replica unit with external light incident from the real world.

A method of providing an augmented reality image according to another embodiment of the present invention includes the steps of: a duplication unit duplicating an image and emitting images with different optical paths; and combining, by an image combiner, images emitted from the replica unit and external light incident from the real world.

As described above, according to embodiments of the present invention, by adding a small optical element that can optically replicate the exit pupil position of the projector without a separate complex and thick composite optical element, a compact device can be provided to general users. By increasing the size of the pupil tolerance area, which was causing discomfort, the image can be observed without being cut off even when the pupil moves freely, thereby relieving the user's discomfort.

In addition, according to embodiments of the present invention, by securing a margin when designing the viewing area to accommodate various binocular distances, it is possible to reduce the production cost by avoiding the limitations of user-customized design during mass production.

Figure 1 is a diagram showing the structure and concept of a holographic lens-based pupil direct projection augmented reality device;
2 to 4 are diagrams provided to explain the structure and concept of a pupil-directed augmented reality device according to an embodiment of the present invention;
Figure 5 is a diagram showing the detailed configuration of the viewing area replication element and the optical path folding that occurs inside;
Figures 6 and 7 are simulation results for the exit pupil position of the duplicate viewing area in the holographic lens.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

Figure 1 is a diagram showing the structure and concept of a holographic lens-based direct-pupil augmented reality device. As shown, the pupil direct projection augmented reality device is composed of an optical structure that diffracts the image ray bundle generated and projected by the projection system 110 at the holographic lens 130 located in front of the user's eyes and focuses it at the position of the user's pupil.

The holographic lens 130 functions as an image combiner that reflects the image of the projection system 110 to the user's pupil, while transmitting external light incident from the real world and combining it with the image of the projection system 110. do.

The pupil-directed augmented reality device shown in Figure 1 has the advantage of being able to provide images with a wide viewing angle without a complicated optical structure, but the beam width of the light bundle emitted from the projection system 110 is usually very small (within 1 mm). Due to the nature of condensing light, it is impossible to observe images from places other than the point of concentration.

In particular, in a situation where the augmented reality device is already fixed to the user's head, if the diameter of the light collection point is about 1 mm, problems such as not being able to observe the image or the observed image being cut off even when the pupil rotates due to simple gaze movement occur. do.

In addition, because it is difficult to respond to different binocular distances for each user, a separate custom process is required to measure the binocular distance of each user and optimize it accordingly, which may lead to an increase in production costs in mass production and commercialization. .

Accordingly, an embodiment of the present invention presents a pupil-direct augmented reality device that expands the viewing area through viewing area replication.

Specifically, in order to increase the permissible pupil area that can be observed while using the holographic lens 130, the image rays emitted from one projection system 110 are divided and the optical path is adjusted to replicate image rays as if they were coming from multiple projection systems. Thus, the exit pupil position of the augmented reality device is increased by the number of copies.

A holographic lens is manufactured by recording the interference pattern of two light waves (reference beam and signal beam) coming from different directions on a recording medium (e.g. photopolymer, photorefractive polymer, silver halide, etc.). The interference pattern recorded at this time forms a periodically repeating volume grating within the holographic recording medium, and if the incident beam meets the Bragg condition of the volume grating in the later reproduction stage, it will be diffracted. A reproduced beam is output through the phenomenon.

If the incident light deviates from the Bragg condition of the recorded volume grating within a certain condition, the direction of the diffracted light can be tuned without significant decrease in efficiency.

Accordingly, in an embodiment of the present invention, the viewing area is replicated by utilizing the Off-Bragg condition of the holographic lens, and a method is presented in which the position condition of the projection system that satisfies the Off-Bragg condition can be satisfied even with a single projection system. .

This can be implemented through the introduction of an additional optical element that can simulate a bundle of light emitted from one projection system as if it were emitted from an array of projection systems existing at a plurality of different positions.

Figure 2 is a diagram provided to explain the structure and concept of a pupil-directed augmented reality device according to an embodiment of the present invention. The pupil direct projection augmented reality device according to an embodiment of the present invention includes a projection system (not shown in FIG. 2), a viewing area replication element 120, and a hologram lens 130.

The pupil-directed augmented reality device according to an embodiment of the present invention is capable of replicating the viewing area by adding a viewing area replication element 120, a small optical element, to the front of the projection system 110 in the device shown in FIG. 1.

The viewing area duplication element 120 is an element for duplicating an image projected from a projection system and emitting images with different optical paths, and will be described in detail below.

As shown in Figure 2, starting from the 'exit pupil 210 of the projection system' (since it is an exit pupil from which the image of the original viewing area is actually emitted in the projection system, hereinafter referred to as 'original viewing area exit pupil 210') After the light ray 220 enters the viewing area duplication element 120, some of it goes out and some of it is partially reflected and undergoes optical path folding inside the viewing area duplicating element 120.

Specifically, some 230 of the light rays 220 departing from the original exit pupil 210 do not reflect from the viewing area replication element 120 and exit directly, enter the hologram lens 130, and then diffract to form the original viewing area.

And, as shown in FIG. 3, among the light rays 220 originating from the original exit pupil 210, the light ray 320 that does not directly exit the viewing area replication element 120 is reflected twice inside the viewing area replicating element 120. After that, the light exits 330, enters the hologram lens 130, and then diffracts to form a duplicate viewing area around the original viewing area.

Since the direction and position of the light ray 330 entering the hologram lens 130 are different from the light ray 230 forming the original viewing area, a duplicate viewing area is formed at a different location from the original viewing area.

In Figure 4, a virtual exit pupil for the duplicate viewing area is displayed. Since it is a virtual exit pupil that simulates the image to be displayed in the duplicate viewing area, it is indicated as 'replicated viewing area exit pupil 310.

Figure 5 shows in detail the detailed configuration of the viewing area replication element 120 and the optical path folding that occurs inside. As shown, the viewing area replication device 120 can be implemented by coating or bonding partial reflection surfaces 122 and 123 to both sides of the optical medium 121 in a facing form.

In the case of the right limit ray 420 emitted from the original exit pupil 410, after entering the optical medium 121, part of it is emitted from the partial reflection surface 123 to form the right limit ray 421 of the original image. . Meanwhile, the remaining ray reflected from the partially reflective surface 123 is reflected from the partially reflective surface 122 and then exits the partially reflective surface 123 to form the right limit ray 425 of the duplicate image.

Meanwhile, in the case of the left limit ray 430 emitted from the original exit pupil 410, after entering the optical medium 121, part of it is emitted from the partial reflection surface 123 to form the left limit ray 431 of the original image. do. Meanwhile, the remaining ray reflected from the partially reflective surface 123 is reflected from the partially reflective surface 122 and then exits the partially reflective surface 123 to form the left limit ray 435 of the duplicate image.

Meanwhile, so that light can be emitted uniformly from the partial reflective surface 123, partial reflective surfaces with different transmittances/reflectances depending on the area are connected to form an array, or a holographic reflective surface with different transmittances/reflectances depending on the area is created. It can be manufactured and implemented.

In addition, due to the difference in the position of the output light between the original images (421 to 431) and the duplicate images (425 to 435), the original viewing area and the duplicate viewing area formed by diffraction from the holographic lens 130 are separated from each other, and the separation distance is determined by the optical medium 121. is proportional to the thickness d. This means that the separation distance between the original viewing area and the duplicate viewing area can be adjusted by adjusting the thickness d of the optical medium 121.

FIG. 6 shows the results of simulating the positions of the duplicate viewing area exit pupil 610 and 630 required to form the duplicate viewing area 510 and 530 1 mm to the left and right of the original viewing area 520 in the hologram lens 130. The positions of the left replication viewing area exit pupil 610 for forming the left replication viewing area 510 and the positions of the right replication viewing area exit pupil 630 for forming the right replication viewing area 530 are shown, respectively.

In Figure 7, the relative positions of the left duplicate viewing area exit pupil 610 and the right duplicate viewing area exit pupil 630 based on the position of the original viewing area exit pupil 620 are shown in relative coordinates (unit: mm). .

So far, a hologram-based pupil-directed augmented reality device that expands the viewing area by duplicating the viewing area has been described in detail with a preferred embodiment.

In an embodiment of the present invention, by adding a small optical element that can optically replicate the exit pupil position of the projector without a separate complex and thick composite optical element, the pupil acceptance area, which was inconvenient to general users, is reduced with a compact device. By increasing the size, the image can be observed without being cut off even when the pupil moves freely.

In addition, by securing a margin when designing the viewing area to accommodate various binocular spacing, we were able to reduce production costs by escaping the limitations of customized design during mass production.

In addition, although preferred embodiments of the present invention have been shown and described above, the present invention is not limited to the specific embodiments described above, and the technical field to which the invention pertains without departing from the gist of the present invention as claimed in the claims. Of course, various modifications can be made by those of ordinary skill in the art, and these modifications should not be understood individually from the technical idea or perspective of the present invention.

110: projection system
120: View area replication element
121: optical medium
122,123: Partial reflective surface
130: Holographic lens

Claims (12)

A projection system that generates and projects images;
a duplication unit that copies the image projected from the projection system and emits images with different optical paths;
An augmented reality device comprising: an image combiner that combines images emitted from the replica unit with external light incident from the real world.
In claim 1,
The different videos are,
An augmented reality device characterized by forming different viewing areas.
In claim 1,
The replication department,
An augmented reality device characterized in that some of the images projected from the projection system are emitted through a first optical path, and other parts of the images projected from the projection system are emitted through a second optical path.
In claim 3,
The second optical path is,
An augmented reality device characterized in that it is an optical path with a first point spaced apart from the exit pupil of the projection system as a virtual exit pupil.
In claim 3,
The replication department,
optical medium;
A first part located on one side of the optical medium, emitting part of the image projected from the projection system to the first optical path and reflecting the other part, and emitting the image reflected from the second partial reflection surface to the second optical path. reflective surface; and
An augmented reality device comprising: a second partial reflective surface located on the other surface opposite to one surface of the optical medium, and reflecting the image reflected from the first partial reflective surface to the first partial reflective surface.
In claim 5,
The separation distance between the first viewing area formed by the image emitted through the first optical path and the second viewing area formed by the image emitted through the second optical path is,
An augmented reality device characterized in that it is proportional to the thickness of the optical medium.
In claim 5,
The first partial reflective surface is,
An augmented reality device characterized by different transmittance and reflectance depending on the light output area.
In claim 4,
The replication department,
An augmented reality device characterized by projecting another part of the image projected from the projection system to a third optical path.
In claim 8,
The third optical path is,
An augmented reality device characterized in that it is an optical path with a second point spaced apart from the exit pupil of the projection system as a virtual exit pupil.
A projection system generating and projecting an image;
A copying unit duplicating the image projected from the projection system and emitting images with different optical paths; and
An augmented reality image providing method comprising: an image combiner combining images emitted from the replica unit with external light incident from the real world.
a duplication unit that copies the image and emits images with different optical paths; and
An augmented reality optical device comprising: an image combiner that combines images emitted from the replica unit with external light incident from the real world.
A copying unit duplicating the image and emitting images with different optical paths; and
An augmented reality image providing method comprising: an image combiner combining images emitted from the replica unit with external light incident from the real world.