TW202144938A - Holographic display device - Google Patents

Abstract

The present disclosure provides a holographic display device, including: a display module for emitting at least a first color light and a second color light, a luminous efficiency of the first color light is higher than that of the second color light; and a diffraction module on exit paths of the first color light and the second color light, the diffraction module is configured to diffract the first color light with a first diffraction efficiency, and diffract the second color light with a second diffraction efficiency, so as to generating a holographic image. The first diffraction efficiency is smaller than the second diffraction efficiency.

Description

Holographic display device

The invention relates to the field of holographic display, in particular to a holographic display device.

The holographic display method combines the holographic technology and the waveguide technology, and realizes the purpose of superimposing the virtual image and the external scene image together by means of projection.

The holographic product in the prior art includes a head-mounted holographic display, which is worn on the head by a user to see a three-dimensional holographic image. In the holographic display, the light source light of various colors is diffracted by the diffractive structure, thereby obtaining a diffracted image. Of course, the light source light usually includes light of various colors, and the emission efficiency of light of various colors is related to the diffractive structure. Different colors of light have different diffraction efficiencies, which often lead to color shift and image distortion in the final diffraction image.

One aspect of the present invention provides a holographic display device, comprising: a display module for emitting at least a first color light and a second color light, the luminous efficiency of the first color light is higher than the luminous efficiency of the second color light; and Diffraction module, the diffraction module is arranged on the outgoing path of the first color light and the second color light, used for diffracting the first color light with the first diffraction efficiency, and using A second diffraction efficiency diffracts the second color light, thereby generating a holographic image, wherein the first diffraction efficiency is smaller than the second diffraction efficiency.

In the above-mentioned holographic display device, according to the luminous efficiency of the first color light and the second color light, the characteristics and matching order of the first diffraction component and the second diffraction component in the diffraction module are correspondingly set, so as to reduce the first color light The difference in luminous intensity between the light of the second color and the light of the second color is beneficial to improve the color shift problem of the holographic image generated by the holographic display device and avoid the distortion of the holographic image.

This embodiment provides a holographic display device, specifically, the holographic display device is a head-mounted holographic display device. When the holographic display device is worn on the user's head, a three-dimensional holographic image can be displayed to the user.

Referring to FIG. 1 , the holographic display device 10 provided in this embodiment includes a display module 20 , a diffraction module 30 , and an optical waveguide 40 disposed between the display module 20 and the diffraction module 30 . The display module 20 is used for emitting the first color light, the second color light and the third color light. In other embodiments, the display module 20 is used for emitting the first color light and the second color light. The diffraction module 30 is configured to diffract the first color light, the second color light and the third color light and then emit the light. The optical waveguide 40, as a light propagation medium, is arranged on the emission paths of the first color light, the second color light and the third color light, and is used for guiding the first color light, the second color light and the second color light. The color light and the third color light propagate between the display module 20 and the diffraction module 30, and the first color light, the second color light and the third color light diffracted by the diffraction module 30 out. In this embodiment, the optical waveguide 40 can be made of transparent optical glass or optical plastic.

Referring to FIG. 2 , the display module 20 includes a substrate 23 and a plurality of light-emitting elements 21 disposed on the same surface of the substrate 23 , and each light-emitting element 21 is used for emitting the first color light. In this embodiment, each light-emitting component 21 is a Micro Light-Emitting Diode (Micro-LED); each light-emitting component 21 is used for emitting blue light, that is, the first color light is blue light.

Please refer to FIG. 2 , the display module 20 further includes a color conversion layer 22 . The color conversion layer 22 is disposed on the exit path of the first color light, and is used for converting part of the first color light into the second color. light, converts part of the first color light into the third color light, and is used to directly transmit the rest of the first color light. In this embodiment, the second color light is green light, and the third color light is red light. In this embodiment, the color conversion layer 22 is a quantum dot layer, and the color conversion layer 22 includes a complex first conversion unit 221 , a complex second conversion unit 222 and a complex transmission unit 223 . Contains different types of quantum dots, the transmission unit 223 does not contain quantum dots, each first conversion unit 221 is used for converting part of the first color light into the second color light, and each second conversion unit 222 is used for Part of the second color light is converted into the third color light, and each transmission unit 223 is used to directly transmit the remaining unconverted first color light.

Among the first color light, the second color light and the third color light emitted from the color conversion layer 22, the first color light is directly emitted from the transmission unit 223 without the color conversion layer 22, and has not undergone color conversion. The second color light and the third color light are obtained by color conversion of the first color light emitted by each light-emitting element 21 , and then the first color light, the second color light and the third color light emitted from the color conversion layer 22, The luminous efficiency of the first color light is higher than the luminous efficiency of the second color light and the third color light. According to the properties of different types of quantum dots, the color conversion efficiency of the quantum dots in each first conversion unit 221 is higher than the color conversion efficiency of the quantum dots in each second conversion unit 222, so the luminous efficiency of the second color light is higher than the luminous efficiency of the third color light.

When each light-emitting element 21 is driven to emit light with a preset driving voltage, the measured luminous intensity of the first color light emitted from the color conversion layer 22 is A ₁ , the luminous intensity of the second color light is A ₂ , and the third color light is The luminous intensity is A ₃ , and the luminous efficiency is proportional to the luminous intensity, then A ₁ >A ₂ >A ₃ . Since the luminous efficiency of the first color light, the second color light and the third color light is different, that is, the luminous intensity is different, the holographic image generated by the holographic display device 10 is likely to have color shift phenomenon, which affects the image display effect.

In this embodiment, the above-mentioned color shift problem is improved by the diffraction module 30 .

Please refer to FIG. 1 again, the diffraction module 30 is disposed on the side of the optical waveguide 40 away from the display module 20 . The diffraction module 30 includes a first diffraction unit 31 and a second diffraction unit 32 which are separated from each other. The first diffraction unit 31 is used for the first diffraction of the first color light, the second color light and the third color light, and the second diffraction unit 32 is used for the first color light, the second color light and the third color light. The three-color light is diffracted for the second time to generate the holographic image. The optical waveguide 40 is used to guide the first color light, the second color light, and the third color light in the display module 20 and the first diffraction unit. 31 and the second diffraction unit 32.

Please continue to refer to FIG. 1 , the first diffraction unit 31 includes a first diffraction element 311 , a second diffraction element 312 and a third diffraction element 313 . In this embodiment, the first diffraction element 311 , the second diffraction element 312 and the third diffraction element 313 are diffraction gratings. The first diffraction element 311 , the second diffraction element 312 and the third diffraction element 313 are stacked in sequence. The first diffraction element 311 is used for diffracting the first color light, the second diffraction element 312 is used for diffracting the second color light, and the third diffraction element 313 is used for diffracting the third color light.

It should be understood that in this embodiment, the first diffractive element 311 is mainly used for diffracting the first color light, and the second color light and the third color light both pass through the first diffractive element 311 , so the first diffractive element 311 also has a certain diffraction effect on the second color light and the third color light, but the diffraction effect of the first diffraction element 311 on the first color light is much greater than that on the second color light and the third color light. shooting effect. Similarly, the second diffraction component 312 is mainly used to diffract the second color light, and the diffraction effect of the second diffraction component 312 on the second color light is much greater than that on the first color light and the third color light. The third diffraction component 313 is mainly used to diffract the third color light, and the diffraction effect of the third diffraction component 313 on the third color light is much greater than that on the first color light and the second color light. effect.

That is, the first color light, the second color light and the third color light are all absorbed by the first diffraction element 311 , the second diffraction element 312 and the third diffraction element 313 in the first diffraction unit 31 . Define the total diffraction efficiency of the first diffraction element 311, the second diffraction element 312 and the third diffraction element 313 for the first color light as the diffraction efficiency of the first diffraction unit 31 for the first color light; define The total diffraction efficiency of the first diffraction element 311, the second diffraction element 312 and the third diffraction element 313 for the second color light is the diffraction efficiency of the first diffraction element 31 for the second color light; The total diffraction efficiency of the first diffraction element 311 , the second diffraction element 312 and the third diffraction element 313 for the third color light is the diffraction efficiency of the first diffraction unit 31 for the third color light.

The luminous intensity of the light diffracted by the first diffraction unit 31 is the product of the luminous intensity before the light is incident on the first diffraction unit 31 and the diffraction efficiency of the first diffraction unit 31 . Define the diffraction efficiency of the first diffraction unit 31 to the first color light as η ₁ %, and the luminous intensity of the first color light after being diffracted by the first diffraction unit 31 is A ₁₁ ; define the first diffraction unit 31 to The diffraction efficiency of the second color light is η ₂ %, and the luminous intensity of the second color light after being diffracted by the first diffraction unit 31 is A ₂₂ ; define the diffraction efficiency of the first diffraction unit 31 for the third color light is η ₃ %, and the luminous intensity of the third color light after being diffracted by the first diffraction unit 31 is A ₃₃ . Then: A ₁₁ =A ₁ *η ₁ %, A ₂₂ =A ₂ *η ₂ %, A ₃₃ =A ₃ *η ₃ %.

In this embodiment, the stacking sequence among the first diffractive element 311 , the second diffractive element 312 and the third diffractive element 313 makes the first diffractive unit 31 affect the first color light, the second color light and the third color light. Diffraction efficiency of color light is affected. Therefore, by adjusting the stacking sequence of the first diffraction element 311 , the second diffraction element 312 and the third diffraction element 313 , the effect of the first diffraction unit 31 on the first color light, the second color light and the Diffraction efficiency of the third color light. In this embodiment, the stacking order among the first diffraction element 311 , the second diffraction element 312 and the third diffraction element 313 is determined according to the luminous efficiency of the first color light, the second color light and the third color light, That is, the stacking order among the first diffractive element 311 , the second diffractive element 312 and the third diffractive element 313 is determined according to the luminous intensities of the first color light, the second color light and the third color light. Specifically, when A ₁ >A ₂ >A ₃ , adjust the stacking sequence of the first diffractive element 311 , the second diffractive element 312 and the third diffractive element 313 such that η ₁ %<η ₂ %<η ₃ %.

Since A ₁ >A ₂ >A ₃ , η ₁ %<η ₂ %<η ₃ %, the first color light, the second color light, and the third color light are respectively diffracted by the first diffracting element 311 and the second diffracting light. After the element 312 and the third diffraction element 313 are diffracted, _{the difference between the luminous intensities A 11} , A ₂₂ and A ₃₃ is smaller than the difference between the luminous intensities A ₁ , A ₂ and A ₃ .

Therefore, in the holographic display device 10 provided in this embodiment, according to the luminous efficiency of the first color light, the second color light and the third color light, the first diffraction element 311 and the second diffraction element in the diffraction module 30 are arranged. 312 and the third diffractive element 313 are stacked in order to adjust the effects of the first diffractive element 311, the second diffractive element 312 and the third diffractive element 313 on the first color light, the second color light and the third color Diffraction efficiency of light, so as to adjust the luminous intensity of the first color light, the second color light and the third color light diffracted by the first diffraction element 311, the second diffraction element 312 and the third diffraction element 313 , so as to reduce the difference in luminous intensity among the first color light, the second color light and the third color light, which is beneficial to improve the color shift problem of the holographic image generated by the holographic display device 10 and avoid image distortion.

Please continue to refer to FIG. 1 , the second diffraction unit 32 includes a first diffraction element 321 , a second diffraction element 322 and a third diffraction element 323 . The stacking sequence of the first diffraction element 321 , the second diffraction element 322 and the third diffraction element 323 is the same as the stacking sequence of the first diffraction unit 31 . In other embodiments, the stacking sequence of the first diffraction element 321 , the second diffraction element 322 and the third diffraction element 323 may be different from the stacking sequence of the first diffraction unit 31 . The first diffraction element 321 is used to diffract the light of the first color emitted from the first diffraction unit 31 , the second diffraction element 322 is used to diffract the light of the second color emitted from the first diffraction unit 31 , the third The diffractive component 323 is used for diffracting the third color light emitted from the first diffractive unit 31 . By setting the stacking sequence of the first diffraction element 321 , the second diffraction element 322 and the third diffraction element 323 in the second diffraction unit 32 , the first diffraction element 321 emitted from the second diffraction unit 32 can be further reduced. The difference in luminous intensity among the light of the first color, the light of the second color and the light of the third color is beneficial to further improve the color shift problem of the holographic image generated by the holographic display device 10 . It will not be repeated here.

Those skilled in the art should realize that the above embodiments are only used to illustrate the present invention, but not to limit the present invention, as long as the above embodiments are appropriately made within the spirit and scope of the present invention Changes and changes all fall within the scope of the claimed invention.

10: Holographic display device 20: Display module 21: Lighting components 22: Color conversion layer 221: first conversion unit 222: Second conversion unit 223: Transmission unit 23: Substrate 30: Diffraction module 31: The first diffraction unit 311, 321: The first diffraction component 312, 322: The second diffraction component 313, 323: The third diffraction component 32: The second diffraction unit 40: Optical Waveguide

FIG. 1 is a schematic structural diagram of a holographic display device according to an embodiment of the present invention.

FIG. 2 is a schematic structural diagram of the display module in FIG. 1 .

10: Holographic display device

20: Display module

30: Diffraction module

31: The first diffraction unit

311, 321: The first diffraction component

312, 322: The second diffraction component

313, 323: The third diffraction component

32: The second diffraction unit

40: Optical Waveguide

Claims (10)

A holographic display device, which is improved in that it includes: a display module for emitting at least a first color light and a second color light, the luminous efficiency of the first color light is higher than the luminous efficiency of the second color light; and Diffraction module, the diffraction module is arranged on the outgoing path of the first color light and the second color light, used for diffracting the first color light with the first diffraction efficiency, and using A second diffraction efficiency diffracts the second color light, thereby generating a holographic image, wherein the first diffraction efficiency is smaller than the second diffraction efficiency. The holographic display device according to claim 1, wherein the display module is further configured to emit a third color light, and the diffraction module is further configured to diffract the third color light with a third diffraction efficiency ; The luminous efficiency of the second color light is higher than the luminous efficiency of the third color light, and the second diffraction efficiency is lower than the third diffraction efficiency. The holographic display device according to claim 2, wherein the diffraction module comprises a first diffraction component, a second diffraction component and a third diffraction component that are stacked in sequence; The first diffraction component is used for diffracting the first color light, the second diffraction component is used for diffracting the second color light, and the third diffraction component is used for diffracting the first color light. Three color lights. The holographic display device according to claim 3, wherein the holographic display device comprises a first diffraction unit and a second diffraction unit that are independent of each other, the first diffraction unit and the second diffraction unit each Including a said first diffraction element, a said second diffraction element and a said third diffraction element; The first color light, the second color light and the third color light are subjected to the first diffraction by the first diffraction unit, and then subjected to the second diffraction by the second diffraction unit to generate the holographic image. The holographic display device according to claim 4, wherein the holographic display device further comprises an optical waveguide, and the optical waveguide is arranged between the display module and the diffraction module for guiding the first A color light, the second color light, and the third color light propagate among the display module, the first diffraction unit, and the second diffraction unit. The holographic display device according to claim 2, wherein the first diffraction element, the second diffraction element and the third diffraction element are all diffraction gratings. The holographic display device according to claim 1, wherein the display module comprises: a plurality of light-emitting components for emitting the first color light; and The color conversion layer is disposed on the exit path of the first color light, and is used for converting part of the first color light into at least the second color light. The holographic display device according to claim 7, wherein the color conversion layer is further configured to convert part of the first color light into third color light. The holographic display device according to claim 8, wherein the first color light is blue light, the second color light is green light, and the third color light is red light. The holographic display device according to claim 7, wherein the color conversion layer is a quantum dot layer.

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