KR20220138606A - Direct retinal projection-type augmented reality device - Google Patents

Abstract

Provided is a pupil-direct-line-type augmented reality device capable of increasing an observable pupil allowance region by using a holographic optical element. A pupil-direct-line-type augmented reality device according to an embodiment of the present invention comprises: an image combiner located at the front of the eye of a user to reflect or diffract light beams emitted from a projection system, thereby concentrating the reflected or diffracted light beams at a pupil location of the user; and a holographic optical element (HOE) located between the projection system and the image combiner to expand a field of vision, which is a pupil allowance region. Therefore, a compact optical structure, which is a conventional advantage, can be maintained while increasing the size of a field of vision, which is a pupil allowance region, such that the size of the pupil allowance region, which is inconvenient to a general user, can be increased. Therefore, an image can be observed without being cut out even though the user freely moves a pupil during use of the same technology-based device, such that inconvenience of the user is solved.

Description

Direct retinal projection-type augmented reality device

The present invention relates to a pupil-directed augmented reality device for providing augmented reality content images worn by a person, and more particularly, a pupil-directed augmented reality capable of increasing the observable pupil permissible area using a holographic optical element. It's about the device.

The pupil-directed augmented reality device has the advantage of providing an image of a wide angle of view with a compact design, but has a very narrow viewing area as a limitation.

It is designed in such a way that the pupil-directed augmented reality device condenses light bundles corresponding to individual pixels at one point (with a diameter of about 1 mm), and the user can observe the entire augmented reality image only when the pupil is correctly positioned at the converging point. because there is

However, when considering 1) pupil rotation and left and right movement, and 2) different distances between the left and right eyes for each user, such a limited viewing area has no choice but to limit the general use of augmented reality devices, so the advantages of the existing direct pupil type device It is necessary to develop an imaging device capable of providing a field of view of several mm or more while maintaining it.

The present invention has been devised to solve the above problems, and an object of the present invention is to use the scattering function of a holographic optical element in the form of a thin film to increase the size of the viewing area, which is the pupil-permissive region, while providing advantages of the prior art. An object of the present invention is to provide a pupil-directed augmented reality device capable of maintaining a compact optical structure.

According to an embodiment of the present invention for achieving the above object, the pupil direct-type augmented reality device is an image that is located in front of the user's eyes, reflects or diffracts the light beams emitted from the projection system to focus on the user's pupil position Image combiner; and a holographic optical element (Hologrpahic optical element, HOE) positioned between the projection system and the image combiner so that the viewing area, which is the pupil-allowing region, is expanded.

In addition, the holographic optical element is manufactured by recording interference patterns of a reference beam and a signal beam incident from different directions on a holographic recording medium, wherein the recorded interference pattern is periodically repeated in the holographic recording medium. It can be composed of a volume grating of

In addition, the holographic optical element is a reproducing beam through a diffraction phenomenon when an incoming ray beam satisfies the Bragg condition of the volume grating so that the beam width of the ray is expanded when the ray beams emitted from the projection system are reproduced. is output, and when the incident light beam deviates from the Bragg condition of the recorded volume grating, it is transmitted as it is without separate diffraction, so that it can serve as a transparent scattering layer (diffuser).

In addition, the holographic optical element causes the light beams incident at a specific angle to be scattered and diffused by a predetermined angular range in the direction of the image combiner, and when the pupil is located, the image by the light beams after passing through the image combiner and the holographic optical element The width of the eye-box, which is the visible area, may be increased as the scattering and diffusion preset angle range increases.

In addition, the holographic optical element performs the function of a kind of unidirectional diffuser, as a ray beam that departs from a live-action environment or a diffracted light returns through an image combiner deviates from the Bragg condition of the volumetric grating. It can be transmitted without diffraction and distortion to be incident on the user's pupil.

On the other hand, the pupil direct-type augmented reality device according to another embodiment of the present invention is located in front of the user's eyes, and reflects or diffracts the light beams emitted from the projection system and diffuses the first holographic optical element (Hologrpahic optical element). , HOE); and a second holographic optical element (Hologrpahic optical element, HOE) that is spaced apart from the first holographic optical element to have a predetermined gap, condenses the diffused light beams and delivers them to the user.

In addition, as the size of the gap between the first holographic optical element and the second holographic optical element increases, the viewing area, which is the pupil permissive region, may be greatly expanded.

In addition, when the second holographic optical element is implemented as a lens-type holographic optical element, the optical performance is operated on-axis rather than off-axis to prevent distortion and deterioration in the side part. It may consist of a lens that

As described above, according to the embodiments of the present invention, it is possible to maintain a compact optical structure, which is an advantage of the prior art, while increasing the size of the viewing area, which is the pupil-allowing region, thereby reducing the size of the pupil-allowing region, which is inconvenient to general users. When using a motion technology-based device, the image can be observed without clipping even when the pupil is moved freely, thereby relieving the user's discomfort.

In addition, according to embodiments of the present invention, by securing a margin at the time of designing the viewing area to respond to various binocular distances, it is possible to reduce the production cost by escaping the limitation of user-customized design during mass production.

1 is a view provided for the description of an image combiner provided in an existing direct retinal projection-type augmented reality device;
Figure 2 is a view provided for the description of the pupil direct-type augmented reality device according to an embodiment of the present invention;
3 is a view provided for the description of the holographic optical element according to the embodiment of FIG. 2, and
4 is a view provided for the description of the pupil direct-type augmented reality device according to another embodiment of the present invention.

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

1 is a view provided for explanation of an image combiner provided in an existing direct retinal projection-type augmented reality device.

The direct retinal projection-type augmented reality device reflects or diffracts the image ray beams emitted from the projection system by an image combiner located in front of the user's eyes as illustrated in FIG. 1 to position the user's pupil. It consists of an optical structure that focuses on the

In this case, the image combiner may correspond to a general spherical/aspherical mirror and semi-mirror, a holographic optical device, a diffractive optical device, a meta-surface type lens based on nano-patterning, and the like.

Such a direct retinal projection-type augmented reality device has the advantage of providing an image of a wide viewing angle without a complicated optical structure, but the beam width of the light beams emitted from the projection system is usually very small (less than 1 mm). ), because of the condensed characteristics, it has a disadvantage that it is impossible to observe an image at a place other than the corresponding converging point.

In particular, even in a situation where the augmented reality device is already fixed on the user's head, when the diameter of the converging point is about 1 mm, there are problems such as impossible to observe the image even for pupil rotation due to simple gaze movement or the observed image is cut off. Occurs.

In addition, since 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 for each individual accordingly, resulting in an increase in production cost in mass production and commercialization have.

2 is a view provided for the description of the pupil direct-type augmented reality device according to an embodiment of the present invention.

The pupil-directed augmented reality device according to this embodiment has been devised to solve the above-described problems with reference to FIG. By using this, it is possible to increase the size of the viewing area, which is the pupil permissible region, while maintaining a compact optical structure, which is an advantage of the prior art.

To this end, the present pupil-directed augmented reality device is an image combiner 110 that reflects or diffracts light beams emitted from the projection system to focus on the user's pupil position, and a hole located between the projection system and the image combiner 110 . It may include a graphic optical element 120 .

The image combiner 110 may be located in front of the user's eyes, and may reflect or diffract the light beams emitted from the projection system to focus them on the user's pupil position.

The holographic optical element 120 may be positioned between the projection system and the image combiner 110 so that a viewing area, which is a pupil-permissive region, is expanded.

Specifically, the holographic optical device 120 may be manufactured by recording interference patterns of a reference beam and a signal beam incident from different directions on a holographic recording medium (eg, photopolymer, photorefractive polymer, silver halide, etc.). In this case, the recorded interference pattern may be composed of a volume grating in the form of periodically repeating in the holographic recording medium.

In addition, the holographic optical element 120, when reproducing the light beams emitted from the projection system, so that the beam width of the light beam is expanded, when the incoming light beam satisfies the Bragg condition of the volumetric grating, the diffraction phenomenon By allowing the reproduction beam to be output through and allowing the incoming light beam to be transmitted as it is without generating separate diffraction when it deviates from the Bragg condition of the recorded volume grating, it can serve as a transparent scattering layer (diffuser).

That is, the holographic optical element 120 outputs the reproduction beam through a diffraction phenomenon when the incident beam in the reproduction step satisfies the Bragg condition of the volume grating. When the grating deviates from the Bragg condition, separate diffraction does not occur and transmits as it is, which is called wavelength and angle selectivity.

Due to the selectivity, the holographic optical element 120 can replace the function of a specific optical element even in the form of a transparent and thin film. It serves to broaden the beam width of the ray.

FIG. 3 is a view provided for explanation of the holographic optical device 120 according to the embodiment of FIG. 2 .

)에서 입광하는 광선빔들(B1)이 영상 결합기(110) 방향으로 기설정된 각도 범위(θ _d)만큼 산란 및 확산(B2)되도록 하며, 이때, 눈동자가 위치하면 영상 결합기(110) 및 홀로그래픽 광학소자(120)를 거친 후의 광선빔들에 의해 영상이 보이는 영역인 아이 박스(Eye-box)의 폭은, 산란 및 확산되는 기설정된 각도 범위가 커질수록, 크게 형성될 수 있다. As illustrated in FIG. 3 , the holographic optical element 120 has a specific angle (

) so that the light beams B1 incident on the image combiner 110 are scattered and diffused (B2) by a preset angular range ( θ _d) in the direction, at this time, when the pupil is located, the image combiner 110 and the holographic The width of the eye-box, which is a region in which an image is viewed by the light beams after passing through the optical element 120 , may be formed larger as the scattering and diffusion preset angle range increases.

In addition, the holographic optical element 120, to perform a kind of unidirectional diffuser (Unidirectional diffuser), the light beam (B3) from the real-world environment, or the diffracted light returns through the image combiner of the volume grating As it departs from the Bragg condition, it can be transmitted (B4) without diffraction and distortion to be incident into the user's pupil.

)에서 입광하는 광선빔들(B1)을 영상 결합기(110) 방향으로 θ _d의 각도 범위로 산란 및 디퓨징(확산)시키게 되며(B2), 이때 디퓨징 각도가 커질수록 영상 결합기(110)를 거친 후의 최종 Eye-box 폭을 확대시킬 수 있다. That is, the holographic optical element 120 has a specific angle (

) is scattering and diffusing (diffusing) the light beams B1 incident on the image combiner 110 in the angular range of θ _d in the direction (B2), and at this time, as the diffusing angle increases, the image combiner 110 is You can enlarge the final eye-box width after roughing.

Through this, the size of the pupil permissible area, which was inconvenient to general users, is increased, so that the image can be observed without being clipped even when the pupil is moved freely when using the device based on the same technology. By securing a margin at the time of designing the city area, it is possible to reduce the production cost by escaping the limitation of user-customized design in mass production.

On the other hand, in the case of a ray beam (B3) from the other side, that is, from the real-world environment, or from which the diffused diffracted light returns through the image combiner 110, as it departs from the Bragg condition of the HOE, it is transmitted without diffraction and distortion (B4) Thus, it is possible to enter the user's pupil. Therefore, the holographic optical device 120 according to the present embodiment may be used as a transparent film-type optical device 120 that functions as a kind of unidirectional diffuser.

4 is a view provided for the description of the pupil direct-type augmented reality device according to another embodiment of the present invention.

Referring to FIG. 4 , the pupil-directed augmented reality device according to this embodiment is positioned in front of the user's eyes to be implemented with a very compact design implemented with the holographic optical element 120, and is emitted from the projection system. The first holographic optical element 210 and the first holographic optical element 210 that reflect or diffract the light beams are spaced apart to have a predetermined gap, and the diffused light beams are condensed and delivered to the user. It may include a second holographic optical element 220 .

That is, the two holographic optical elements 210 and 220 may be arranged in a layered form with a slight gap.

In this case, as the size of the gap between the first holographic optical device 210 and the second holographic optical device 220 increases, the viewing area, which is the pupil-allowing region, may be greatly expanded.

Specifically, the first holographic optical element 210 and the second holographic optical element 220 adjust the size of the gap spaced apart from each other even when the first holographic optical element 210 of the same specification is used. Since the light incident area to the second holographic optical element 220 can be adjusted, it can be used to adjust the entire viewing area.

In other words, if the gap is designed to be large, a flexible design that can increase the viewing area of the entire system may be possible.

On the other hand, when the second holographic optical element 220 is implemented as the lens-type holographic optical element 120, the optical performance is not distorted and deteriorated in the side part, so that it is not off-axis. It may be composed of a lens that operates on-axis.

That is, in the second holographic optical element 220, the optical performance of the lens-type holographic optical element 120 is greatly distorted/degraded in the side part due to the optical system driven off-axis in the existing structure. limitations can be overcome.

In summary, in the structure of FIG. 4 , the second holographic optical element 220 can provide almost the same optical performance as a general lens when operating in the normal axis to overcome the limitations of distortion and deterioration in the side part. For this purpose, it may be configured as a lens operating in an on-axis rather than an off-axis.

In the above, preferred embodiments of the present invention have been illustrated and described, but the present invention is not limited to the specific embodiments described above, and it is common in the technical field to which the present invention pertains without departing from the gist of the present invention as claimed in the claims. Various modifications may be made by those having the knowledge of, of course, and these modifications should not be individually understood from the technical spirit or perspective of the present invention.

110: Image combiner
120: Holographic optical element (Hologrpahic optical element, HOE)
210: first holographic optical element (Hologrpahic optical element, HOE)
220: second holographic optical element (Hologrpahic optical element, HOE)

Claims (8)

an image combiner positioned in front of the user's eyes, reflecting or diffracting the light beams emitted from the projection system, and condensing them on the user's pupil position; and
A holographic optical element (Hologrpahic optical element, HOE) positioned between the projection system and the image combiner so that the viewing area, which is the pupil-permissive region, is expanded.
The method according to claim 1,
The holographic optical element,
It is produced by recording the interference patterns of a reference beam and a signal beam incident from different directions on a holographic recording medium,
The recorded interference pattern is
A pupil-directed augmented reality device, characterized in that it is composed of a volume grating of a periodically repeated form in a holographic recording medium.
3. The method according to claim 2,
The holographic optical element,
When the light beams emitted from the projection system are reproduced, the reproduction beam is output through diffraction phenomenon when the incoming light beam satisfies the Bragg condition of the volumetric grating so that the beam width of the light beam is enlarged, and the incoming light beam When the beam deviates from the Bragg condition of the recorded volume grating, it transmits as it is without generating a separate diffraction, thereby acting as a transparent scattering layer (diffuser).
4. The method of claim 3,
The holographic optical element,
so that light beams incident at a specific angle are scattered and diffused by a predetermined angular range in the direction of the image combiner,
When the pupil is positioned, the width of the eye-box, the area where the image is visible by the light beams after passing through the image combiner and the holographic optical element, is,
As the scattering and diffusion preset angle range increases, the pupil direct type augmented reality device is formed to be larger.
5. The method according to claim 4,
The holographic optical element,
In order to perform the function of a kind of unidirectional diffuser, as the light beam that starts from the real-world environment or the diffracted light returns through the image combiner deviates from the Bragg condition of the volumetric grating, it is transmitted without diffraction and distortion, so that the user's A pupil-directed augmented reality device, characterized in that it is incident into the pupil.
a first holographic optical element (Hologrpahic optical element, HOE) which is located in front of the user's eyes and diffuses the light beams emitted from the projection system by reflecting or diffracting them; and
Direct pupil enhancement including; a second holographic optical element (Hologrpahic optical element, HOE) that is spaced apart to have a predetermined gap in the first holographic optical element, condenses the diffused light beams and delivers them to the user; real device.
7. The method of claim 6,
The first holographic optical element and the second holographic optical element,
As the size of the mutually spaced gap increases, the viewing area, which is the pupil permissible region, is greatly expanded.
8. The method of claim 7,
The second holographic optical element,
When implemented as a lens-type holographic optical element, the pupil, characterized in that it is composed of a lens that operates in an on-axis rather than an off-axis to prevent distortion and deterioration of optical performance in the side part A direct augmented reality device.

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