Image display apparatus

Abstract

The invention discloses an image display device. The image display device comprises a first lens group, a diffraction assembly, a second lens group and a light coupling assembly. The first lens group receives a display image and converts the display image into a plurality of image beams parallel to each other. The diffraction assembly receives the image light beams, diffracts the image light beams and generates a plurality of image sub-light beams. The second lens group receives the image sub-beams corresponding to the image beams. The second lens group provides a focal length and focuses the image sub-beams according to the focal length to generate a plurality of zoom image sub-beams corresponding to the image beams. The light coupling assembly receives the zoom image sub-beams, reflects the zoom image sub-beams to a target plane, and enables the zoom image sub-beams to form a plurality of image imaging points on the target plane.

Description

Technical Field

[0001] The invention relates to an image display device, in particular to an image display device capable of adjusting viewpoint spacing. Background Art

[0002] In the field of augmented reality (AR), fixed image depth optical designs are often used, such as waveguide and birdbath architectures. If the external image viewed by the user and the virtual image provided by the augmented reality display are at different depths, it is difficult for the user to see both the external image and the virtual image at the same time. Therefore, the eyes need to switch focus on multiple focal planes for a long time, which can easily cause fatigue. Summary of the invention

[0003] The present invention is directed to an image display device which has the function of adjusting the viewpoint distance.

[0004] According to an embodiment of the present invention, an image display device includes a first lens group, a diffraction component, a second lens group and a light coupling component. The first lens group receives a display image and converts the display image into a plurality of image beams parallel to each other. The diffraction component receives the image beam, diffracts each image beam and generates a plurality of image sub-beams. The second lens group receives an image sub-beam corresponding to each image beam. The second lens group provides a focal length and focuses the image sub-beam according to the focal length to generate a plurality of zoomed image sub-beams corresponding to each image beam. The light coupling component receives the zoomed image sub-beam, reflects the zoomed image sub-beam to a target plane, and causes the zoomed image sub-beam to form a plurality of image imaging points on the target plane.

[0005] Based on the above, the image display device of the present invention converts each image beam into multiple image sub-beams through the diffraction component, and then through the focusing action of the second lens group and the light coupling component, the multiple zoom image sub-beams form multiple image imaging points on the target plane, and generate multiple viewpoints. In the embodiment of the present invention, the second lens group can adjust the distance between the viewpoints by adjusting the provided focal length, and can expand the viewpoints to improve the display quality of the image. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 A schematic diagram of an image display device according to an embodiment of the present invention;

[0007] Figure 2 is a schematic diagram of an imaging light path of an image display device according to an embodiment of the present invention;

[0008] Figure 3A , Figure 3B Schematic diagrams of different implementations of image display devices according to embodiments of the present invention;

[0009] Figure 4A , Figure 4B Schematic diagram of different implementations of an image display device according to another embodiment of the present invention;

[0010] Figure 5 A schematic diagram of a plurality of image imaging points formed on a target plane by an image display device according to an embodiment of the present invention;

[0011] Figure 6 FIG. 4 is a schematic diagram of an image display device according to another embodiment of the present invention. DETAILED DESCRIPTION

[0012] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals are used in the drawings and the description to refer to the same or like parts.

[0013] Please refer to Figure 1 , Figure 1 A schematic diagram of an image display device according to an embodiment of the present invention is shown. The image display device may be provided in an augmented reality display. The image display device includes lens groups 110, 130, a diffraction component 120, and a light coupling component 140. The lens group 110, the diffraction component 120, the lens group 130, and the light coupling component 140 are provided in sequence. The center points of the lens group 110, the diffraction component 120, and the lens group 130 may be provided on the optical axis AXIS of the display image DIM received by the lens group 110.

[0014] In this embodiment, the lens group 110 is used to convert the received display image DIM into a plurality of image beams IMB. The display image DIM may be emitted by a light source and may be composed of a plurality of scattered light beams. The lens group 110 includes a collimating lens and is used to focus the received display image DIM to convert the display image DIM to generate a plurality of mutually parallel image beams IMB.

[0015] The diffraction component 120 is disposed adjacent to the light-emitting surface of the lens group 110. The diffraction component 120 is used to receive the image beam IMB and diffract each image beam IMB to generate a plurality of image sub-beams SB1 and SB2. The diffraction component 120 also projects the image sub-beams SB1 and SB2 to the lens group 130. The lens group 130 is a focusing lens group. The lens group 130 provides a focal length and is used to focus the image sub-beams SB1 and SB2 according to the provided focal length, and thereby generate a plurality of zoom image sub-beams FSB1 and FSB2 respectively.

[0016] The zoom image sub-beams FSB1 and FSB2 are projected onto the light coupling component 140. The light coupling component 140 is used to reflect the zoom image sub-beams FSB1 and FSB2, so that the reflected zoom image sub-beams FSB1 and FSB2 are projected onto a target plane TGP, and the zoom image sub-beams FSB1 and FSB2 form a plurality of image imaging points IP1-IP3 on the target plane TGP.

[0017] In this embodiment, the target plane TGP is located at the position of the user's eyeball EYE. The image imaging points IP1 to IP3 can form multiple viewpoints corresponding to the user's eyeball EYE. Among them, in each viewpoint, the light beam at each angle records different image information. In addition, in actual operation, the number of zoom image sub-beams can be greater than 2, and the corresponding multiple image imaging points can be distributed in an array, such as N times N, where N can be 3 or other integers greater than 3.

[0018] Please note that the focal length provided by the lens group 130 is adjustable. By adjusting the focal length provided by the lens group 130, the distribution range of the image imaging points IP1 to IP3 on the target plane TGP can be adjusted. When the lens group 130 provides a first focal length, the image imaging points IP1 to IP3 have a first distribution range on the target plane TGP; when the lens group 130 provides a second focal length, the image imaging points IP1 to IP3 have a second distribution range on the target plane TGP, wherein when the first focal length is smaller than the second focal length, the first distribution range is smaller than the second distribution range.

[0019] In this embodiment, an angle between the normal vector of the light coupling component 140 and the advancing directions of the zoom image sub-beams FSB1 and FSB2 is not 0 degrees.

[0020] Please refer to the following Figure 2 , Figure 2 Schematic diagram showing the imaging light path of the image display device of an embodiment of the present invention. The image display device 200 can be applied in an augmented reality display. The user's eyes can observe the virtual object VO through the image display device 200, and can also directly observe the actual object RO. Figure 2 In the example, each object point of the virtual object VO and the real object RO only emits a beam of light in a single angle direction. The user's eyeball EYE does not need to converge the virtual image beam, so no matter how far the actual object the eye focuses on is, the corresponding imaging images VIMG and RIMG generated by the virtual object VO and the real object RO can present clear images.

[0021] Please refer to Figure 3A as well as Figure 3B , Figure 3A , Figure 3BSchematic diagrams showing different implementations of an image display device according to an embodiment of the present invention. The image display device 300 may be provided in an augmented reality display. The image display device 300 includes lens groups 310, 330, a diffraction component 320, and a light coupling component 340. An image light source 350, a lens group 310, a diffraction component 320, a lens group 330, and a light coupling component 340 are provided in sequence. The image light source 350 is used to project a display image DIM onto the lens group 310. The lens group 310 is used to focus the display image DIM as a scattered light beam, and to generate a plurality of image light beams IMB1 to IMBN as parallel light beams. The lens group 310 projects the image light beams IMB1 to IMBN to the diffraction component 320. The diffraction component 320 diffracts each image light beam IMB1 to IMBN to generate a plurality of image sub-beams SB1 to SBN, respectively.

[0022] The lens group 330 has a variable focus lens 331. The variable focus lens 331 can receive the image sub-beams SB1-SBN and focus the image sub-beams SB1-SBN to generate a plurality of zoom image sub-beams respectively. The variable focus lens 331 can be an electrically controlled variable focus lens. Figure 3A In the implementation manner, the variable focus lens 331 can adjust the provided focal length to the first focal length according to the control signal CT1. The variable focus lens 331 focuses the image sub-beams SB1~SBN according to the first focal length, and provides the generated zoomed image sub-beams to the coupling component 340. The coupling component 340 is used to reflect the zoomed image sub-beams to the target plane TGP, and generate multiple image imaging points IP1~IP3 on the target plane TGP. Among them, the zoomed image sub-beams corresponding to each image imaging point IP1~IP3 respectively record multiple different image information, and the distribution of the image imaging points IP1~IP3 can have a first range.

[0023] In addition, Figure 3B In the embodiment of the invention, the variable focus lens 331 can adjust the provided focal length to a second focal length according to the control signal CT2, wherein the second focal length can be greater than the first focal length. The variable focus lens 331 focuses the image sub-beams SB1-SBN according to the second focal length, and provides the generated zoomed image sub-beams to the coupling component 340. The coupling component 340 is used to reflect the zoomed image sub-beams to the target plane TGP, and generate a plurality of image imaging points IP1-IP3 on the target plane TGP, and the distribution of the image imaging points IP1-IP3 can have a second range. The second range can be greater than the first range.

[0024] Depend on Figure 3A as well as Figure 3BIt can be known from the implementation method that the image display device 300 of the embodiment of the present invention can adjust the distribution range of the image imaging points IP1~IP3 by adjusting the focal length provided by the lens group 330, and further adjust the distance between the individual viewpoints.

[0025] In this embodiment, the image light source 350 may be a scanning laser light source, and the lens group 310 may be a collimating light lens.

[0026] Please refer to Figure 4A as well as Figure 4B , Figure 4A , Figure 4B Schematic diagrams showing different implementations of an image display device according to another embodiment of the present invention. Image display device 400 includes lens groups 410, 430, a diffraction component 420, and a light coupling component 440. Image light source 450, lens group 410, diffraction component 420, lens group 430, and light coupling component 440 are arranged in sequence. Figure 3A , Figure 3B The image light source 450 is used to project the display image DIM to the lens group 410. The lens group 410 is used to focus the display image DIM as a scattered light beam and generate a plurality of image light beams IMB1-IMBN as parallel light. The lens group 410 projects the image light beams IMB1-IMBN to the diffraction element 420. The diffraction element 420 diffracts each image light beam IMB1-IMBN to generate a plurality of image sub-beams SB1-SBN respectively.

[0027] and Figure 3A , Figure 3B In different embodiments, the lens group 430 includes a first lens 431 and a second lens 432. The first lens 431 and the second lens 432 are arranged parallel to each other. The first lens 431 and the second lens 432 can both be focusing lenses. Figure 3A The first lens 431 and the second lens 432 have a center distance d1 . The first lens 431 can receive the image sub-beams SB1 -SBN , and the second lens 432 receives the outgoing beam of the first lens 431 and projects the generated zoomed image sub-beams to the light coupling component 440 .

[0028] Under the premise that both the first lens 431 and the second lens 432 are focusing lenses with fixed focal lengths, the spacing distance d1 between the first lens 431 and the second lens 432 can determine the focal length provided by the lens group 430 as a first focal length, and enable the distribution of the image imaging points IP1-IP3 generated on the target plane TGP to have a first range.

[0029] exist Figure 3BIn the embodiment, the center points of the first lens 431 and the second lens 432 have a spacing distance d2, wherein the spacing distance d2 is greater than the spacing distance d1. Similarly, under the premise that the first lens 431 and the second lens 432 are both focusing lenses with fixed focal lengths, the spacing distance d2 between the first lens 431 and the second lens 432 can determine that the focal length provided by the lens group 430 is the second focal length, and the distribution of the image imaging points IP1-IP3 generated on the target plane TGP can have a second range. The first focal length is smaller than the second focal length, and the first range can be smaller than the second range.

[0030] exist Figure 4A as well as Figure 4B In the embodiment of the present invention, the lens group 430 can effectively adjust the focal length of the lens group 430 by adjusting the spacing between the first lens 431 and the second lens 432. In this way, the distribution range of the image imaging points IP1 to IP3 can be adjusted, and the spacing between the viewpoints can be adjusted.

[0031] Please refer to Figure 5 , Figure 5 A schematic diagram showing a plurality of image imaging points formed on a target plane by an image display device according to an embodiment of the present invention. In this embodiment, a plurality of zoom image sub-beams FSB2_11 to FSB2_33 may form a 3 by 3 array and enter the user's eyeball 501. The zoom image sub-beams FSB2_11 to FSB2_33 are respectively focused to form an array formed by 3 by 3 image imaging points ISP11 to ISP33.

[0032] Please refer to Figure 6 , Figure 6 A schematic diagram of an image display device according to another embodiment of the present invention is shown. The image display device 600 can be arranged in an augmented reality display. The image display device 600 includes an image light source 650, a lens group 610, 630, a diffraction component 620, and a light coupling component 640. The image light source 650 is used to project a display image DIM to the lens group 610. The lens group 610 is used to focus the display image DIM as a scattered light beam and generate a plurality of image light beams as parallel light. The lens group 610 projects the above-mentioned image light beams to the diffraction component 620. The diffraction component 620 causes each image light beam to diffract to generate a plurality of image sub-beams SB1 to SBN, respectively.

[0033] Different from the above-mentioned embodiment, the lens group 630 includes a lens 631 and a concave mirror 632. The lens 631 is arranged between the diffraction component 620 and the light coupling component 640. The lens 631 receives the image sub-beams SB1~SBN and generates a plurality of first light beams by focusing the image sub-beams SB1~SBN. The lens 631 transmits the generated first light beams to the light coupling component 640. The light coupling component 640 can reflect the first light beam to generate a plurality of second light beams and project them onto the reflection surface of the concave mirror 632. The concave mirror 632 is used to focus and reflect the received second light beam to generate a third light beam. The concave mirror 632 projects the third light beam to the light coupling component 640. Further, the light coupling component 640 can transmit the third light beam to generate a plurality of zoom image sub-beams FSB1~FSB3. The zoom image sub-beams FSB1~FSB3 can be focused in the user's eyeball 601 respectively and generate image imaging points ISP1~ISP3 respectively.

[0034] It is worth noting that in this embodiment, by adjusting the distance between the lens 631 and the light coupling component 640 or adjusting the distance between the concave mirror 632 and the light coupling component 640, the focal length provided by the lens group 630 can be adjusted, and the distribution range of the image imaging points ISP1 to ISP3 can be adjusted. In addition, by adjusting the focal length of at least one of the lens 631 and the concave mirror 632, the focal length provided by the lens group 630 can also be adjusted.

[0035] In summary, the image display device of the present invention is designed with a large depth of field optical image, which can provide a clear image at any focal plane when the eyeball is focused. The image display device of the present invention also has the functions of expanding the viewpoint and adjusting the viewpoint spacing. The expansion of the number of viewpoints can make it easier for the user to receive the viewpoint beam, and the function of adjusting the viewpoint spacing can prevent the user from receiving multiple viewpoints at the same time and generating ghosting. Having the viewpoint expansion and spacing adjustment functions at the same time can give the user better image quality.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An image display device, comprising: A first lens group receives a display image and converts the display image into a plurality of image beams parallel to each other; A diffraction component receives the plurality of image beams, diffracts each of the image beams and generates a plurality of image sub-beams; a second lens group, receiving the plurality of image sub-beams corresponding to each of the image beams, the second lens group providing a focal length, and focusing the plurality of image sub-beams according to the focal length to generate a plurality of zoomed image sub-beams corresponding to each of the image beams; as well as The light coupling component receives the multiple zoom image sub-beams, reflects the multiple zoom image sub-beams to a target plane, and makes the multiple zoom image sub-beams form multiple image imaging points on the target plane. 2 . The image display device according to claim 1 , wherein the second lens group comprises a variable-focus focusing lens.

3. The image display device according to claim 1, wherein the second lens group adjusts the distribution range of the multiple image imaging points on the target plane by adjusting the provided focal length.

4. An image display device according to claim 2, wherein when the second lens group provides a first focal length, the multiple image imaging points have a first distribution range in the target plane, and when the second lens group provides a second focal length, the multiple image imaging points have a second distribution range in the target plane, wherein when the first focal length is smaller than the second focal length, the first distribution range is smaller than the second distribution range.

5. The image display device according to claim 1, wherein the second lens group comprises: First lens; as well as The second lens is arranged parallel to the first lens, and a center point of the second lens is spaced apart from a center point of the first lens.

6. An image display device according to claim 5, wherein when the spacing distance is a first distance, the second lens group provides a first focal length, and when the spacing distance is a second distance, the second lens group provides a second focal length, wherein the first distance is smaller than the second distance, and the first focal length is smaller than the second focal length. 7 . The image display device according to claim 5 , wherein the first lens and the second lens are both focusing lenses.

8. The image display device according to claim 1, wherein the second lens group comprises: a first lens, receiving the plurality of image sub-beams corresponding to each of the image light beams, focusing the plurality of image sub-beams to generate a plurality of first light beams, and projecting the plurality of first light beams to the light coupling component, wherein the light coupling component reflects the plurality of first light beams to generate a plurality of second light beams respectively; as well as a concave mirror, receiving the plurality of second light beams, reflecting and focusing the plurality of second light beams to generate a plurality of third light beams, The plurality of third light beams are projected onto the light coupling component, and the light coupling component transmits the plurality of third light beams to generate the plurality of zoom image sub-beams.

9. The image display device according to claim 1, wherein the plurality of image imaging points are distributed on the target plane in an array manner.

10. The image display device according to claim 1, wherein the normal vector of the light coupling component and the advancing direction of the zoom image sub-beam have an angle that is not 0 degrees.

11. The image display device according to claim 1, further comprising: The image light source is used to emit the display image. 12 . The image display device according to claim 11 , wherein the image light source is a scanning laser light source. 13 . The image display device according to claim 1 , wherein center points of the first lens group, the diffractive element, and the second lens group are arranged on optical axes of the plurality of image light beams. 14 . The image display device according to claim 1 , wherein the multiple zoom image sub-beams of each image imaging point respectively record multiple different image information.

15. The image display device according to claim 1, wherein the first lens group comprises a collimating lens.

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