Light field 3D display screen based on time sequence switching liquid crystal lens array

Abstract

The invention provides a light field 3D display screen based on a time sequence switching liquid crystal lens array. The light field 3D display screen comprises a 2D display screen, a polarization conversion layer, a lower-layer liquid crystal lens array and an upper-layer liquid crystal lens array. The 2D display screen is used for alternately displaying horizontal-direction light field images and vertical-direction light field images corresponding to different voltage states, the polarization directions of the horizontal-direction light field images and the vertical-direction light field images are controlled through sequential power-on or power-off of the polarization conversion layer, and the polarization directions of light rays of the horizontal-direction light field images and the vertical-direction light field images are orthogonal. The lower-layer liquid crystal lens array is used for reproducing a 3D image in the horizontal direction, and the upper-layer liquid crystal lens array is used for reproducing a 3D image in the vertical direction. The time interval of alternately displaying the horizontal light field images and the vertical light field images corresponding to the different voltage states by the 2D display screen is smaller than or equal to the persistence time of human vision and is the same as the voltage switching time interval of the polarization conversion layer, and the two images are switched synchronously. By means of a time division multiplexing method, through the polarization conversion layer, the lower-layer liquid crystal lens array and the upper-layer liquid crystal lens array, fusion display of a horizontal 3D image and a vertical 3D image is achieved, and the total information amount of the light field 3D display screen is increased.

Description

I. Technical Field

[0001] The present invention relates to the technical field of 3D display, and more specifically, to a light field 3D display screen based on a time-sequential switching liquid crystal lens array. II. Background Art

[0002] Light field 3D display is considered to be one of the 3D display technologies with development prospects because of its advantages such as high definition, quasi-continuous viewing viewpoints, and full-color display. The performance parameters of the current mainstream light field 3D display screens include the 3D image viewing angle, depth, and resolution, and there is a mutually restrictive relationship among them. It is difficult to increase the total amount of information of the light field 3D display screen, so it is impossible to improve each performance parameter simultaneously. Liquid crystal lenses have certain advantages in improving the 3D display performance parameters due to their adaptability, zooming without mechanical movement, and light structure. In order to increase the total amount of information of the light field 3D display screen, domestic and foreign research scholars have carried out a series of research works using liquid crystal lenses. For example, a multi-depth plane light field 3D display technology based on variable-focus liquid crystal lenses and a 2D / 3D switching display technology based on liquid crystal lenses have been proposed to increase the total amount of information of the 3D display screen, but these technologies have problems such as high system complexity and difficulty in implementation. III. Summary of the Invention

[0003] To overcome the deficiencies of the prior art, the present invention proposes a light field 3D display screen based on a time-sequential switching liquid crystal lens array, which includes a 2D display screen, a polarization conversion layer, a lower liquid crystal lens array, and an upper liquid crystal lens array.

[0004] The 2D display screen is used to alternately display horizontal direction light field images and vertical direction light field images corresponding to different voltage states.

[0005] Preferably, the light emitted by the 2D display screen is linearly polarized light.

[0006] The polarization conversion layer is used to control the polarization direction of the linearly polarized light emitted by the 2D display screen by time-sequential power-on or power-off. The polarization conversion layer includes a lower substrate, a lower transparent planar electrode, a lower alignment layer, a liquid crystal layer, an upper alignment layer, an upper transparent planar electrode, and an upper substrate. The lower transparent planar electrode and the upper transparent planar electrode are made of transparent conductive materials such as indium tin oxide or indium zinc oxide. The lower transparent planar electrode and the upper transparent planar electrode have the same thickness. The upper transparent planar electrode is grounded, and a voltage is applied to the lower transparent planar electrode.

[0007] The lower liquid crystal lens array is used to reproduce 3D images in the horizontal direction, and includes a lower substrate, a lower transparent rectangular electrode, a lower alignment layer, a liquid crystal layer, an upper alignment layer, an upper transparent planar electrode, and an upper substrate. The lower transparent rectangular electrode and the upper transparent planar electrode are made of transparent conductive materials such as indium tin oxide or indium zinc oxide. The lower transparent rectangular electrode and the upper transparent planar electrode have the same thickness. The upper transparent planar electrode is grounded, and a voltage is applied to the lower transparent rectangular electrode. The included angle between the long side of the lower transparent rectangular electrode and the short side of the lower substrate is θ. The rubbing directions of the lower alignment layer and the upper alignment layer are perpendicular to the long side direction of the lower transparent rectangular electrode.

[0008] Preferably, the gap l of the lower transparent rectangular electrode is greater than or equal to 150 μm, and the width w is less than or equal to 10 μm.

[0009] The upper liquid crystal lens array is used to reproduce 3D images in the vertical direction, and includes a lower substrate, a lower transparent rectangular electrode, a lower alignment layer, a liquid crystal layer, an upper alignment layer, an upper transparent planar electrode, and an upper substrate. The lower transparent rectangular electrode and the upper transparent planar electrode are made of transparent conductive materials such as indium tin oxide or indium zinc oxide. The lower transparent rectangular electrode and the upper transparent planar electrode have the same thickness. The upper transparent planar electrode is grounded, and a voltage is applied to the lower transparent rectangular electrode. The included angle between the long side of the lower transparent rectangular electrode and the long side of the lower substrate is θ. The rubbing directions of the lower alignment layer and the upper alignment layer are perpendicular to the long side direction of the lower transparent rectangular electrode.

[0010] Preferably, the gap l of the lower transparent rectangular electrode is greater than or equal to 150 μm, and the width w is less than or equal to 10 μm.

[0011] Further, the upper substrate of the lower liquid crystal lens array and the lower substrate of the upper liquid crystal lens array are the same substrate.

[0012] Further, the upper substrate of the polarization conversion layer and the lower substrate of the lower liquid crystal lens array are the same substrate.

[0013] Further, the voltages of the lower transparent rectangular electrode of the lower liquid crystal lens array and the lower transparent rectangular electrode of the upper liquid crystal lens array are always in an applied state.

[0014] Further, the lower substrates of the lower liquid crystal lens array and the upper liquid crystal lens array have the same size and overlap in the horizontal direction.

[0015] Further, the time interval for the 2D display screen to alternately display the horizontal direction light field images and the vertical direction light field images corresponding to different voltage states is less than or equal to the human eye's visual persistence time.

[0016] Further, the time interval for the 2D display screen to alternately display the horizontal-direction light field image and the vertical-direction light field image is the same as the switching time interval of the voltage applied to the polarization conversion layer, and the two are switched synchronously.

[0017] The working principle of the light field 3D display screen based on the time-sequential switching liquid crystal lens array is as follows: In the T1 time period, the 2D display screen displays the horizontal-direction light field image, the polarization conversion layer is powered off, the incident linear polarization direction of the horizontal-direction light field image is A, and it becomes linearly polarized light with the polarization direction B after passing through the polarization conversion layer, and then is refracted by the lower-layer liquid crystal lens array to reproduce the 3D image in the horizontal direction; In the T2 time period, the 2D display screen displays the vertical-direction light field image, the polarization conversion layer is powered on, the incident linear polarization direction of the vertical-direction light field image is A, and the polarization direction remains unchanged after passing through the polarization conversion layer, and then is refracted by the upper-layer liquid crystal lens array to reproduce the 3D image in the vertical direction; In the T1 and T2 time periods, external voltages are applied to both the upper-layer liquid crystal lens array and the lower-layer liquid crystal lens array, and they are in the working state. The polarization directions A and B are orthogonal. IV. DESCRIPTION OF THE DRAWINGS

[0018] The foregoing aspects and advantages of the present invention will be further clarified and easily understood from the following detailed description in conjunction with the drawings and embodiments, where:

[0019] FIG Figure 1 is a schematic structural diagram of a light field 3D display screen based on a time-sequential switching liquid crystal lens array provided by an embodiment of the present invention.

[0020] FIG Figure 2 is a schematic diagram for generating a 3D image in the horizontal direction of a light field 3D display screen based on a time-sequential switching liquid crystal lens array provided by an embodiment of the present invention.

[0021] FIG Figure 3 is a schematic diagram for generating a 3D image in the vertical direction of a light field 3D display screen based on a time-sequential switching liquid crystal lens array provided by an embodiment of the present invention.

[0022] FIG Figure 4 is a schematic structural diagram of the lower-layer liquid crystal lens array.

[0023] FIG Figure 5 is a schematic structural diagram of the upper-layer liquid crystal lens array.

[0024] The reference numerals in the above-mentioned drawings are as follows: 1 2D display screen, 2 polarization conversion layer, 3 lower liquid crystal lens array, 4 upper liquid crystal lens array, 101 horizontal light field image, 102 vertical light field image, 103 reproduced horizontal 3D image, 104 reproduced vertical 3D image, 201 lower substrate of the polarization conversion layer, 202 lower transparent planar electrode of the polarization conversion layer, 203 lower alignment layer of the polarization conversion layer, 204 liquid crystal layer of the polarization conversion layer, 205 upper alignment layer of the polarization conversion layer, 206 upper transparent planar electrode of the polarization conversion layer, 207 upper substrate of the polarization conversion layer, 301 lower substrate of the lower liquid crystal lens array, 302 lower transparent rectangular electrode of the lower liquid crystal lens array, 303 lower alignment layer of the lower liquid crystal lens array, 304 liquid crystal layer of the lower liquid crystal lens array, 305 upper alignment layer of the lower liquid crystal lens array, 306 upper transparent planar electrode of the lower liquid crystal lens array, 307 upper substrate of the lower liquid crystal lens array, 401 lower substrate of the upper liquid crystal lens array, 402 lower transparent rectangular electrode of the upper liquid crystal lens array, 403 lower alignment layer of the upper liquid crystal lens array, 404 liquid crystal layer of the upper liquid crystal lens array, 405 upper alignment layer of the upper liquid crystal lens array, 406 upper transparent planar electrode of the upper liquid crystal lens array, 407 upper substrate of the upper liquid crystal lens array.

[0025] It should be understood that the above-mentioned drawings are only schematic and are not drawn to scale. V. Specific Embodiments

[0026] The following details an embodiment of a light field 3D display screen based on a time-sequential switching liquid crystal lens array proposed by the present invention to further describe the present invention. The following embodiments are only for further illustration of the present invention and should not be construed as limiting the protection scope of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above-mentioned invention content, and still fall within the protection scope of the present invention.

[0027] The present invention proposes a light field 3D display screen based on a time-sequential switching liquid crystal lens array, as shown in the attached Figure 1 drawings, which includes a 2D display screen 1, a polarization conversion layer 2, a lower liquid crystal lens array 3, and an upper liquid crystal lens array 4.

[0028] The 2D display screen 1 is used to alternately display a horizontal light field image 101 and a vertical light field image 102 corresponding to different voltage states, as shown in the attached Figure 2 drawings and the attached Figure 3 drawings. In one embodiment, the 2D display screen 1 is a liquid crystal display screen with a resolution of 3840×2160 pixels. The light emitted by the 2D display screen 1 is linearly polarized light with a polarization direction of A.

[0029] The polarization conversion layer 2 is used to control the polarization direction of the linearly polarized light emitted by the 2D display screen 1 by powering on or off in sequence, as shown in the appendix Figure 1 as shown. The polarization conversion layer 2 includes a lower substrate 201, a lower transparent planar electrode 202, a lower alignment layer 203, a liquid crystal layer 204, an upper alignment layer 205, an upper transparent planar electrode 206, and an upper substrate 207. The lower transparent planar electrode 202 and the upper transparent planar electrode 206 are made of transparent conductive materials such as indium tin oxide (ITO) or indium zinc oxide (IZO). The lower transparent planar electrode 202 and the upper transparent planar electrode 206 have the same thickness. The upper transparent planar electrode 206 is grounded, and a voltage is applied to the lower transparent planar electrode 202. As shown in the appendix Figure 2 and the appendix Figure 3 as shown, in one embodiment, when the 2D display screen 1 displays a horizontal light field image 101, the polarization direction of the linearly polarized light emitted is A. No voltage is applied between the upper transparent planar electrode 206 and the lower transparent planar electrode 202. The linearly polarized light with a polarization direction of A of the horizontal light field image 101 becomes linearly polarized light with a polarization direction of B after passing through the polarization conversion layer 2. When the 2D display screen 1 displays a vertical light field image 102, the polarization direction of the linearly polarized light emitted is A. A voltage is applied between the upper transparent planar electrode 206 and the lower transparent planar electrode 202. The linearly polarized light with a polarization direction of A of the vertical light field image 102 has an unchanged polarization direction after passing through the polarization conversion layer 2.

[0030] The lower liquid crystal lens array 3 is used to reproduce a 3D image 103 in the horizontal direction, as shown in the appendix Figure 1 and the appendix Figure 2 as shown. It includes a lower substrate 301, a lower transparent rectangular electrode 302, a lower alignment layer 303, a liquid crystal layer 304, an upper alignment layer 305, an upper transparent planar electrode 306, and an upper substrate 307. The lower transparent rectangular electrode 302 and the upper transparent planar electrode 306 are made of transparent conductive materials such as indium tin oxide (ITO) or indium zinc oxide (IZO). The lower transparent rectangular electrode 302 and the upper transparent planar electrode 306 have the same thickness. The upper transparent planar electrode 306 is grounded, and a voltage is applied to the lower transparent rectangular electrode 302. The included angle between the long side of the lower transparent rectangular electrode 302 and the short side of the lower substrate 301 is θ. The rubbing directions of the lower alignment layer 303 and the upper alignment layer 305 are perpendicular to the long side direction of the lower transparent rectangular electrode 302. The appendix Figure 4 is a schematic structural diagram of the lower liquid crystal lens array. In one embodiment, the included angle θ between the long side of the lower transparent rectangular electrode 302 and the short side of the lower substrate 301 is 23°.

[0031] Preferably, the gap l between the lower transparent rectangular electrodes 302 is greater than or equal to 150 μm, and the width w is less than or equal to 10 μm. As shown in the appendixFigure 4 As shown, in one embodiment, the gap l of the lower transparent rectangular electrode 302 is 360 μm, and the width w is 10 μm. The lower liquid crystal lens array 3 only refracts light with a polarization direction B and has no refraction effect on light with a polarization direction A.

[0032] The upper liquid crystal lens array 4 is used to reproduce the 3D image 104 in the vertical direction. As shown in the appendix Figure 1 and the appendix Figure 3 As shown. It includes a lower substrate 401, a lower transparent rectangular electrode 402, a lower alignment layer 403, a liquid crystal layer 404, an upper alignment layer 405, an upper transparent planar electrode 406, and an upper substrate 407. The lower transparent rectangular electrode 402 and the upper transparent planar electrode 406 are made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). The lower transparent rectangular electrode 402 and the upper transparent planar electrode 406 have the same thickness. The upper transparent planar electrode 406 is grounded, and a voltage is applied to the lower transparent rectangular electrode 402. The included angle between the long side of the lower transparent rectangular electrode 402 and the long side of the lower substrate 401 is θ. The rubbing directions of the lower alignment layer 403 and the upper alignment layer 405 are perpendicular to the long side direction of the lower transparent rectangular electrode 402. As shown in the appendix Figure 5 FIG. is a schematic structural diagram of the upper liquid crystal lens array. In one embodiment, the included angle θ between the long side of the lower transparent rectangular electrode 402 and the side of the lower substrate 401 is 23°.

[0033] Preferably, the gap l of the lower transparent rectangular electrode 402 is greater than or equal to 150 μm, and the width w is less than or equal to 10 μm. As shown in the appendix Figure 5 As shown, in one embodiment, the gap l of the lower transparent rectangular electrode 402 is 360 μm, and the width w is 10 μm. The upper liquid crystal lens array 4 only refracts light with a polarization direction A and has no refraction effect on light with a polarization direction B.

[0034] Furthermore, the upper substrate 307 of the lower liquid crystal lens array 3 and the lower substrate 401 of the upper liquid crystal lens array 4 are the same substrate.

[0035] Furthermore, the upper substrate 207 of the polarization conversion layer 2 and the lower substrate 301 of the lower liquid crystal lens array 3 are the same substrate.

[0036] Furthermore, the voltages of the lower transparent rectangular electrode 302 of the lower liquid crystal lens array 3 and the lower transparent rectangular electrode 402 of the upper liquid crystal lens array 4 are always in an applied state.

[0037] Further, the lower substrate 301 of the lower liquid crystal lens array has the same size as the lower substrate 401 of the upper liquid crystal lens array and coincides with it in the horizontal direction. In one embodiment, the sizes of the lower substrate 301 of the lower liquid crystal lens array 3 and the lower substrate 401 of the upper liquid crystal lens array 4 are both 18 cm × 18 cm.

[0038] Further, the time interval for the 2D display screen 1 to alternately display the horizontal light field image 101 and the vertical light field image 102 corresponding to different voltage states is less than or equal to the human eye's visual persistence time. The human eye's visual persistence time is a time set according to the visual inertia of the human eye. Visual inertia is an important characteristic of the human eye, that is, when an image is formed on the human eye's retina, the human eye will maintain the image formed on the retina for a limited time in vision, and this limited time is the human eye's visual persistence time, which is about 0.05 to 0.2 seconds. In one embodiment, the time interval is 16.67 ms.

[0039] Further, the time interval for the 2D display screen 1 to alternately display the horizontal light field image 101 and the vertical light field image 102 is the same as the switching time interval of the voltage applied to the polarization conversion layer 2, and the two are switched synchronously. In one embodiment, the switching time interval of the voltage of the polarization conversion layer 2 is 16.67 ms.

[0040] The specific implementation process of a light field 3D display screen based on a time-sequential switching liquid crystal lens array provided by the present invention is as follows:

[0041] In the T1 time period, the 2D display screen 1 displays the horizontal light field image 101, the polarization conversion layer 2 is powered off, the incident linear polarization direction of the horizontal light field image 101 is A, and it becomes linearly polarized light with a polarization direction of B after passing through the polarization conversion layer 2, and then is refracted by the lower liquid crystal lens array 3 to reproduce the 3D image 103 in the horizontal direction; in the T2 time period, the 2D display screen 1 displays the vertical light field image 102, the polarization conversion layer 2 is powered on, the incident linear polarization direction of the vertical light field image 102 is A, and the polarization direction remains unchanged after passing through the polarization conversion layer 2, and then is refracted by the upper liquid crystal lens array 4 to reproduce the 3D image 104 in the vertical direction; in the T1 and T2 time periods, external voltages are applied to both the lower liquid crystal lens array 3 and the upper liquid crystal lens array 4, and they are in a working state. The polarization directions A and B are orthogonal.

[0042] The present invention realizes the fusion display of two sets of stereoscopic images, namely horizontal stereoscopic images and vertical stereoscopic images, by using the time-division multiplexing method, and increases the information volume of the light field 3D display screen.

[0043] The above-disclosed are only the preferred embodiments of the present invention, and thus cannot be used to limit the scope of the patent protection of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention still fall within the scope covered by the present invention.

Claims

1. A light field 3D display based on a time-sequential switching liquid crystal lens array, characterized in that The display screen includes a 2D display screen, a polarization conversion layer, a lower liquid crystal lens array, and an upper liquid crystal lens array: The 2D display screen is used to alternately display horizontal-direction light field images and vertical-direction light field images corresponding to different voltage states; The polarization conversion layer is used to control the polarization direction of the linearly polarized light emitted by the 2D display screen by powering on or off in sequence; The lower liquid crystal lens array is used to reproduce a 3D image in the horizontal direction; The upper liquid crystal lens array is used to reproduce a 3D image in the vertical direction.

2. The light field 3D display screen based on a time-sequential switching liquid crystal lens array according to claim 1, wherein, The polarization conversion layer includes a lower substrate, a lower transparent planar electrode, a lower alignment layer, a liquid crystal layer, an upper alignment layer, an upper transparent planar electrode, and an upper substrate. The upper transparent planar electrode is grounded, and a voltage is applied to the lower transparent planar electrode.

3. The 3D light field display based on a time-sequential switching liquid crystal lens array according to claim 1, wherein The lower liquid crystal lens array includes a lower substrate, a lower transparent rectangular electrode, a lower alignment layer, a liquid crystal layer, an upper alignment layer, an upper transparent planar electrode, and an upper substrate. The upper transparent planar electrode is grounded, and a voltage is applied to the lower transparent rectangular electrode; the included angle between the long side of the lower transparent rectangular electrode and the short side of the lower substrate is θ, and the rubbing directions of the lower alignment layer and the upper alignment layer are perpendicular to the long side direction of the lower transparent rectangular electrode.

4. The 3D light field display based on a time-sequential switching liquid crystal lens array according to claim 1, wherein The upper liquid crystal lens array includes a lower substrate, a lower transparent rectangular electrode, a lower alignment layer, a liquid crystal layer, an upper alignment layer, an upper transparent planar electrode, and an upper substrate. The upper transparent planar electrode is grounded, and a voltage is applied to the lower transparent rectangular electrode; the included angle between the long side of the lower transparent rectangular electrode and the long side of the lower substrate is θ, and the rubbing directions of the lower alignment layer and the upper alignment layer are perpendicular to the long side direction of the lower transparent rectangular electrode.

5. The 3D light field display based on a time-sequential switching liquid crystal lens array according to claim 1, wherein The time interval for the 2D display screen to alternately display the horizontal-direction stereoscopic image and the vertical-direction stereoscopic image corresponding to the different voltage states is less than or equal to the human eye's visual persistence time.

6. The 3D light field display based on a time-sequential switching liquid crystal lens array according to claim 1, characterized in that, The time interval for the 2D display screen to alternately display the horizontal-direction light field image and the vertical-direction light field image is the same as the switching time interval of the voltage applied to the polarization conversion layer, and the two are switched synchronously.

7. The 3D light field display based on a time-sequential switching liquid crystal lens array according to claim 1, wherein In time period T1, the 2D display screen displays a horizontal-direction light field image, the polarization conversion layer is powered off, the incident linearly polarized light direction of the horizontal-direction light field image is A, and after passing through the polarization conversion layer, it becomes linearly polarized light with a polarization direction of B, and then is refracted by the lower liquid crystal lens array to reproduce a 3D image in the horizontal direction; in time period T2, the 2D display screen displays a vertical-direction light field image, the polarization conversion layer is powered on, the incident linearly polarized light direction of the vertical-direction light field image is A, and the polarization direction remains unchanged after passing through the polarization conversion layer, and then is refracted by the upper liquid crystal lens array to reproduce a 3D image in the vertical direction; in time periods T1 and T2, an external voltage is applied to both the upper liquid crystal lens array and the lower liquid crystal lens array, and they are in a working state; the polarization directions A and B are orthogonal.

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