Large depth-of-field display device based on virtual pupil

Abstract

The invention provides a large depth-of-field display device based on a virtual pupil in order to solve the problems that traditional 3D display has depth-of-field limitation and viewers are prone to asthenopia. The large-depth-of-field display device based on the virtual pupil comprises a light source array, a lens, a reflecting surface, a transparent liquid crystal display panel and a slit grating. The light source array, the lens, the transparent liquid crystal display panel and the slit grating are sequentially arranged from back to front. The light source array and the lens are used for providing light energy for display and achieving a virtual pupil, and the diameter of the virtual pupil is smaller than that of the pupil of the human eye. And the transparent liquid crystal display panel and the slit grating form a stereoscopic display structure for realizing stereoscopic display. The diameter of the virtual pupil is smaller than that of the human eye pupil, so that the imaging light beam can be limited, the light forms a smaller light spot after passing through the human eye, and the depth of field of the image is improved.

Description

Technical Field

[0001] The present invention belongs to the field of display technology, and more particularly, relates to a large depth-of-field display device based on a virtual pupil. Background Art

[0002] In order to solve the problem that traditional 3D display has limited depth of field and viewers are prone to visual fatigue, the present invention proposes a large depth of field display device based on virtual pupil. Summary of the Invention

[0003] The large depth-of-field display device based on a virtual pupil comprises a light source array, a lens, a reflective surface, a transparent liquid crystal display panel and a slit grating.

[0004] The light source array, lens, transparent liquid crystal display panel and slit grating are placed in sequence from back to front; the reflective surface is placed perpendicular to the light source array; the distance from the light source array to the reflective surface is g, and the interval between light sources in the light source array is 2g, so that the mirror image of the light source array and the light source array form a uniform pitch.

[0005] The light source array and the lens are used to provide light energy for display and realize the virtual pupil; the image formed by any light source in the light source array through the lens is the virtual pupil.

[0006] The transparent liquid crystal display panel and the slit grating form a three-dimensional display structure for realizing three-dimensional display. The slit grating projects the pixels of different parallax images on the transparent liquid crystal display panel to the corresponding viewing areas. The human eye will see the corresponding parallax images at the virtual pupils in different viewing areas, thus realizing 3D display.

[0007] The distance from the light source array to the lens is L1, the focal length of the lens is F, and the image distance of the light source array image formed by the light source array through the lens is L2. L1>L2, L1>2F, and 1 / L1+1 / L2=1 / F.

[0008] The width of each light source in the light source array is w1, the width of the image formed by the light source (i.e., the virtual pupil) is w2, the width of the human eye pupil is Q, w2=w1×L2 / L1, and w2 <Q。

[0009] It is worth noting that, because the smaller the pupil size, the greater the depth of field, L1>2F is required to enable the light source to be magnified. Moreover, if magnified imaging is used, it is difficult to ensure brightness with a smaller light source.

[0010] The working principle of the present invention is as follows:

[0011] (1) 3D display working principle

[0012] Light emitted by each light source can pass through the lens to provide light energy for display to the transparent liquid crystal display panel. Because the lens is a transparent structure, the light source array can illuminate all pixels on the transparent liquid crystal display panel. The transparent liquid crystal display panel and the slit grating form a grating 3D display structure. The slit grating projects pixels of different parallax images on the transparent liquid crystal display panel into corresponding viewing areas. The human eye can see the corresponding parallax images in different viewing areas, thus realizing 3D display.

[0013] (2) Principle of virtual pupil implementation

[0014] Because neither the transparent LCD panel nor the slit grating changes the direction of light propagation, light only exists at the positions where the light sources in the light source array form an image, while light does not exist at other positions along the image distance. Because these image points allow light to exist and continue to propagate forward, they constitute a virtual pupil.

[0015] (3) Working principle of virtual pupil

[0016] Combining the principles of 3D display and virtual pupil implementation, multiple virtual pupils are distributed within each viewing area, and only the virtual pupil positions allow light to exist and continue to propagate forward. Because the virtual pupil diameter is smaller than the human eye's pupil diameter, it can increase the depth of field of the 3D image. Specifically, based on the principles of geometric optics, the virtual pupil can act as an aperture stop to further restrict the light beam participating in the imaging, resulting in a smaller spot after the light passes through the human eye, making the image clearer and improving the image depth of field.

[0017] In summary, because the present invention can realize multiple virtual pupils within the viewing area, and because the diameter of the virtual pupil is smaller than that of the human eye pupil, it helps to limit the imaging light beam, so that the light forms a smaller light spot after passing through the human eye, thereby improving the image depth of field. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the present invention.

[0019] Figure 2 This is a schematic diagram of the principle of realizing the virtual pupil of the present invention.

[0020] Figure 3 This is a schematic diagram of the principle of implementing 3D display in the present invention.

[0021] Figure 4 Schematic diagram of the principle of virtual pupil-assisted clear imaging in the present invention.

[0022] Icons: 100-light source; 200-reflecting surface; 300-lens; 400-transparent liquid crystal display panel; 500-slit grating; 101-image formed by the light source; 410-pixels in the first viewing area; 420-pixels in the second viewing area; 610-first viewing area; 620-second viewing area; 700-3D pixels; 800-eyeball; 810-pupil; 820-lens.

[0023] It should be understood that the above drawings are merely schematic and not drawn to scale. DETAILED DESCRIPTION

[0024] Figure 1 This embodiment provides a large depth-of-field display device based on a virtual pupil.

[0025] The large depth of field display device based on virtual pupil includes a light source array, a lens 300, a reflective surface 200, a transparent liquid crystal display panel 400 and a slit grating 500. The light source array includes a plurality of light sources 100 arranged in two dimensions.

[0026] The light source array, lens 300, transparent liquid crystal display panel 400, and slit grating 500 are placed in sequence from back to front; the reflective surface 200 is placed perpendicular to the light source array; the distance g from the light source array to the reflective surface 200 is 10 mm, and the interval 2g between the light sources 100 in the light source array is 20 mm, so that the mirror image of the light source array and the light source array form a uniform pitch.

[0027] Please refer to Figure 2 The light source array and the lens 300 are used to provide light energy for display and realize a virtual pupil; the image 101 formed by any light source 100 in the light source array through the lens is the virtual pupil.

[0028] Please refer to Figure 3 The transparent liquid crystal display panel 400 and the slit grating 500 constitute a three-dimensional display structure for realizing three-dimensional display. The slit grating 500 projects pixels of different parallax images on the transparent liquid crystal display panel 400 to corresponding viewing areas. The human eye will see corresponding parallax images in different viewing areas, thereby realizing 3D display.

[0029] The distance L1 from the light source array to the lens 300 is 600 mm, the focal length F of the lens 300 is 100 mm, and the image distance L2 of the light source array image formed by the light source array through the lens 300 is 120 mm, which satisfies L1>L2, L1>2F, and 1 / L1+1 / L2=1 / F.

[0030] The width w1 of each light source in the light source array is 2 mm, the width w2 of the image 101 (i.e., virtual pupil) formed by the light source is 0.4 mm, the pupil width Q of the human eye is 6 mm, w2=w1×L2 / L1, and w2 <Q。

[0031] It is worth noting that, since the smaller the pupil size, the greater the depth of field, L1>2F is required to enable the light source 100 to perform reduced imaging. Moreover, if magnified imaging is used, it is difficult to ensure the brightness of the smaller light source 100.

[0032] The working principle of the present invention is as follows:

[0033] (1) 3D display working principle

[0034] Please refer to Figure 1 , the light emitted by each light source 100 can provide light energy for display to the transparent liquid crystal display panel 400 through the lens 300; because the lens 300 is a transparent structure, the light source array can illuminate all pixels on the transparent liquid crystal display panel 400; for further information, please refer to Figure 3 The transparent liquid crystal display panel 400 and the slit grating 500 constitute a grating 3D display structure. The slit grating 500 projects pixels of different parallax images on the transparent liquid crystal display panel 400 to corresponding viewing zones. The human eye can see corresponding parallax images in different viewing zones, thereby realizing 3D display. The first viewing zone pixel 410 is projected to the first viewing zone 610 by the slit grating; the second viewing zone pixel 420 is projected to the second viewing zone 620 by the slit grating; the image 101 formed by the light source exists in the first viewing zone 610 and the second viewing zone 620, and the light used for display exists only at the position of the image 101 formed by the light source.

[0035] (2) Principle of virtual pupil implementation

[0036] Please refer to Figure 2 Because neither the transparent LCD panel 400 nor the slit grating 500 changes the direction of light propagation, light only exists at the locations where the light sources in the light source array form images 101, while light does not exist at other locations along the image distance. Because these image points allow light to exist and continue to propagate forward, they constitute a virtual pupil.

[0037] (3) Working principle of virtual pupil

[0038] Combining the principles of 3D display and virtual pupil implementation, multiple virtual pupils are distributed within each viewing area, and only the virtual pupil positions allow light to exist and continue to propagate forward. Because the virtual pupil diameter is smaller than the human eye's pupil diameter, it can increase the depth of field of the 3D image. Specifically, based on the principles of geometric optics, the virtual pupil can act as an aperture stop to further restrict the light beam participating in the imaging, resulting in a smaller spot after the light passes through the human eye, making the image clearer and improving the image depth of field.

[0039] Please refer to Figure 4The eyeball 800 has a pupil 810 and a lens 820. Any 3D pixel 700, due to its depth, is not coplanar with the transparent liquid crystal display panel 400 and therefore cannot converge at the fundus. When it is imaged through the pupil, the light spot size at the fundus is S2. However, when the present invention forms a virtual pupil, i.e., the image 101 of the light source, the imaging light can only pass through this virtual pupil. Because the virtual light source size w2 is smaller than the size Q of the pupil 810, the light spot size S1 at the fundus is necessarily smaller than S2, resulting in clearer imaging.

[0040] In summary, because the present invention can realize multiple virtual pupils within the field of view, and because the diameter of the virtual pupil is smaller than that of the human eye pupil, according to the aperture stop principle, it helps to limit the imaging light beam, so that the light forms a smaller light spot after passing through the human eye, thereby improving the image depth of field.

Claims

1. A large depth of field display device based on a virtual pupil, characterized by: The large depth of field display device based on virtual pupil includes a light source array, a lens, a reflective surface, a transparent liquid crystal display panel and a slit grating; The light source array, lens, transparent liquid crystal display panel, and slit grating are placed in order from back to front; the reflective surface is placed perpendicular to the light source array; the distance from the light source array to the reflective surface is g, and the interval between light sources in the light source array is 2g, so that the mirror image of the light source array and the light source array form a uniform pitch; The light source array and lens are used to provide light energy for display and realize the virtual pupil; the image formed by any light source in the light source array through the lens is the virtual pupil; The transparent liquid crystal display panel and the slit grating form a stereoscopic display structure for achieving stereoscopic display. The slit grating projects pixels of different parallax images on the transparent liquid crystal display panel to corresponding viewing areas. The human eye will see the corresponding parallax images at the virtual pupils in different viewing areas, thus achieving 3D display. The distance from the light source array to the lens is L1, the focal length of the lens is F, the image distance of the light source array formed by the light source array through the lens is L2, L1>L2, L1>2F, and 1 / L1+1 / L2=1 / F; The width of each light source in the light source array is w1, the width of the image formed by the light source is w2, the width of the pupil of the human eye is Q, w2=w1×L2 / L1, and w2 <Q 。

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