KR-102962649-B1 - Holographic lens and apparatus including the same

Abstract

A holographic lens and a display device that applies the same as a combiner are disclosed. A holographic lens has a phase profile obtained through a positional optimization process to form an imaging optical system that forms a virtual image from light emitted from multiple regions.

Inventors

• 문석일
• 이창건
• 성기영
• 이홍석

Assignees

• 삼성전자주식회사

Dates

Publication Date

20260507

Application Date

20201202

Claims (20)

1. It has a phase profile obtained through a position-specific optimization process to form an imaging optical system that forms images on multiple virtual points corresponding to light emitted from multiple regions, and Let ρ be the phase of the light emerging from the above region, φ be the phase of the holographic lens, δ be the phase of the light coming from the virtual image, T be the projection matrix, and φ target be the phase providing the desired virtual image, The phase of the above holographic lens by region A holographic lens designed to have optimized values that satisfy [the condition].
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3. In claim 1, for light emitted from each of the plurality of regions, the holographic lens is formed to have p region-specific phases, and A holographic lens formed such that the number of regions of the phase profile of the holographic lens is smaller than the product of the number of regions of the holographic lens corresponding to light emitted from each of the plurality of regions and the number of the plurality of regions.
4. In claim 1, the holographic lens is a holographic lens having a phase profile that forms an image on a virtual image plane corresponding to each of the plurality of regions.
5. In claim 1, the phase distribution of the holographic lens is such that the error with the phase of an ideal holographic lens for an imaging optical system is minimized.
6. In claim 1, the holographic lens is a holographic lens formed by recording the entire phase profile of the holographic lens under the control of a spatial light modulator using a phase profile obtained through optimization calculation.
7. In claim 6, the phase profile of the holographic lens is formed using a holographic printing technique in which the phase profile obtained through the optimization calculation is divided into multiple sections and the phase corresponding to each section is recorded by the control of a spatial light modulator.
8. In claim 6, the phase profile of the holographic lens is a holographic lens formed in a single recording by mounting the phase profile obtained through the optimization calculation on a spatial light modulator and enlarging it to the size of the holographic lens to be recorded.
9. In claim 8, the reference light applied to the phase profile recording of the holographic lens is a parallel light or a holographic lens having a phase corresponding to the light emitted from the plurality of regions.
10. In claim 1, the phase profile of the holographic lens is formed using a free-form lens having a curvature corresponding to the phase profile obtained through the optimization process.
11. A video providing device that provides video; and A combiner configured to combine an image emitted from the above image providing device with an external foreground; comprising, The above combiner is, A holographic lens having a phase profile obtained through a position-specific optimization process to form an imaging optical system that forms a virtual image for light emitted from different pixels of the image providing device; The above holographic lens is, When ρ is the phase of light emitted from the pixel of the image providing device, φ is the phase of the holographic lens, δ is the phase of light emitted from the virtual image, T is the projection matrix, and φ target is the phase that provides the desired virtual image, The phase of the above holographic lens by region A display device configured to have an optimized value that satisfies
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13. In claim 11, for light emitted from each pixel of the image providing device, the holographic lens is formed to have p region-specific phases, and A display device formed such that the number of regions of the phase profile of the holographic lens is smaller than the product of the number of regions of the holographic lens corresponding to light emitted from each pixel of the image providing device and the number of pixels of the image providing device.
14. In claim 11, the holographic lens is a display device having a phase profile that forms an image on a virtual image plane corresponding to each pixel of the image providing device.
15. In claim 11, a display device wherein the phase distribution of the holographic lens is configured to minimize the error with the phase of the holographic lens for an ideal imaging optical system.
16. In claim 11, the holographic lens is a display device formed by recording the entire phase profile of the holographic lens under the control of a spatial light modulator using a phase profile obtained through optimization calculation.
17. In claim 16, the phase profile of the holographic lens is a display device formed using a holographic printing technique in which the phase profile obtained through the optimization calculation is divided into multiple sections and the phase corresponding to each section is recorded by the control of a spatial light modulator.
18. In claim 16, the phase profile of the holographic lens is a display device formed by mounting the phase profile obtained through the optimization calculation on a spatial light modulator and enlarging it to the size of the holographic lens to be recorded in a single recording.
19. In paragraph 18, the reference light applied to the phase profile recording of the holographic lens is parallel light or a display device having a phase corresponding to the light coming from the pixel of the image providing device.
20. In claim 11, the phase profile of the holographic lens is formed using a free-form lens having a curvature corresponding to the phase profile obtained through the optimization process.

Description

Holographic lens and apparatus including the same This invention relates to a holographic lens and a device including the same. Virtual reality is a technology that allows people to have realistic experiences in a computer-generated virtual world. Augmented reality is a technology that enables virtual images to be blended with the physical environment or space of the real world. Displays providing virtual reality (VR) have now reached the commercialization stage and are being widely applied in the entertainment industry. In addition, they are evolving into forms applicable in the medical, educational, and industrial sectors. Augmented reality (AR) displays, an advanced form of VR, are video devices that combine the real world with virtual reality, enabling interaction between the two. This interaction between reality and virtual reality is based on the function of providing real-time information about the actual situation, and can further enhance the effect of reality by overlaying virtual objects or information onto the real-world environment. Such augmented reality displays include a combiner designed to combine virtual images with the actual external foreground and present them to the observer. Recently, active research has been conducted on glasses-type display devices that provide augmented reality, namely Augmented Reality Glasses (AR glasses), and studies are underway to utilize the angle selectivity, wavelength selectivity, and thin volume characteristics of holographic optical elements (HOE) in the combiners of such augmented reality devices. A combiner utilizing holographic optical elements focuses the image directly onto the viewer's eyes, enabling the viewer to see the image. The holographic optical element that focuses the image directly onto the viewer's eyes functions as a holographic lens; however, because the area where the image is focused is very small, the eye box—the area where the user can fully observe the virtual image—is severely limited, and depth representation is difficult. Consequently, the image can only be observed if the user places their eyes precisely on the point where the light converges; if the eyes rotate or the Augmented Reality Glasses (AR glasses) implementing the augmented reality display shake even slightly from the face, the image becomes invisible. Since the eye box is severely restricted in this way, a calibration process is required to adjust the viewing point to match the user's eye spacing after wearing the glasses. Consequently, it is extremely cumbersome for users with varying eye spacings to use a single pair of augmented reality glasses. Figure 1 schematically shows the configuration of a display device in which a holographic lens according to an embodiment is applied as a combiner. FIG. 2 schematically illustrates the principle of forming an imaging optical system that forms a virtual image for light emitted from different pixels of an image providing device by applying a holographic lens according to an embodiment as a combiner to the display device of FIG. 1. FIGS. 3 and 4 illustrate the optimization process of a positional phase profile of a holographic lens according to an embodiment. FIG. 3 shows a schematic diagram of a display device to be constructed and a sampled view of each component, and FIG. 4 shows the process of deriving an optimization equation to obtain the positional phase of the holographic lens forming an imaging optical system according to an embodiment. FIG. 5 shows a virtual image of a plurality of pixels of an image providing device formed using a holographic lens according to an embodiment. Figure 6a shows a method of recording a holographic lens by using parallel light as a reference beam and light that converges after passing through a lens as a signal beam. Figure 6b shows the light path when a holographic lens recorded in the manner of Figure 6a is utilized as an imaging optical system. Figure 6c shows the formation of a virtual image of multiple pixels of an image providing device using a holographic lens recorded in the manner of Figure 6a. Figure 7a shows a method of recording a holographic lens by using light from a point source as a reference beam and light that converges after passing through a lens as a signal beam. Figure 7b shows the light path when a holographic lens recorded in the manner of Figure 7a is utilized in the form of an imaging optical system. FIG. 7c shows the formation of a virtual image of multiple pixels of an image providing device using a holographic lens recorded in the manner of FIG. 7a. FIGS. 8 to 11 show various methods for recording the phase profile of a holographic lens according to an embodiment. FIG. 12 schematically shows an augmented reality display device in which a holographic lens according to an embodiment is applied as a combiner. FIGS. 13 and 14 schematically show an augmented reality display device according to an embodiment. FIG. 15 shows an example of implementing an augmented r