Novel naked-eye 3D display device and viewpoint stepless modulation method therefor

Abstract

Disclosed in the present invention are a novel naked-eye 3D display device and a viewpoint stepless modulation method therefor. The device comprises a backlight source, a liquid crystal light valve, a cylindrical lens array and a liquid crystal panel which are sequentially arranged in a light propagation direction, wherein a light field emitted by the backlight source passes through the liquid crystal light valve, the liquid crystal light valve comprises a liquid crystal light valve grayscale and a light valve switch, the liquid crystal light valve grayscale and the light valve switch are controlled on the basis of the position of pupil of an observer, and a light source is simulated at different positions, such that the irradiation center of light emitted by the liquid crystal panel remains at the position of pupil of the observer; the light source passes through the cylindrical lens array to form a directional light source, and then passes through the liquid crystal panel to form a viewing image in a viewing area. According to the present invention, by controlling the liquid crystal light valve grayscale and the light valve switch, simulated light sources are formed at different positions, such that when the observer moves within the viewing area, two or more viewpoints can be observed all the time, and at each position, directional light beams can be accurately projected to the pupil of the observer, so as to avoid the problem of viewing flicker caused by the absence of light beam delivery when the pupil of the observer is positioned between two viewpoints.

Description

A novel naked-eye 3D display device and its viewpoint stepless modulation method Technical Field

[0001] The present invention relates to the field of stereoscopic display technology, and more particularly to a novel naked-eye 3D display device and a viewpoint stepless modulation method thereof. Background Art

[0002] With the continuous advancement of display technology, directional backlit glasses-free 3D display technology, by separating the light source from the image source, compensates for the resolution loss of traditional 3D displays. By targeting the viewer's spatial position and the characteristics of their eyes, it precisely controls the parallax images presented when alternating between the left and right eyes. This achieves independent projection of left and right eye images. This innovation ensures that the left eye receives only the left-eye image, while the right eye receives the right-eye image. By leveraging the human brain's ability to process residual visual information, viewers can clearly perceive the 3D effect. Furthermore, by leveraging the freedom of light source control between the left and right eyes, crosstalk is effectively reduced across viewing positions.

[0003] However, ultra-high-resolution, ultra-wide-field-of-view, ultra-compact autostereoscopic displays are technically challenging due to the conflict between high resolution, ultra-wide field-of-view, and wide viewing angle. For example, in traditional glasses-free 3D displays, the optimal viewing experience depends on a specific viewing distance. However, if the observer deviates from this distance, the image information beam cannot be accurately projected onto the human eye, resulting in a decrease in stereoscopic image quality, which can cause symptoms such as dizziness or loss of stereoscopic vision.

[0004] Furthermore, directional display devices currently on the market still use traditional LED arrays as backlight sources. This requires the support of smaller LEDs based on optical system design parameters. However, when such small LEDs are used as light sources, they would require large, dense arrays, resulting in complex manufacturing processes and high costs, making them unsuitable for mass production and market adoption.

[0005] At the same time, when the backlight source uses a liquid crystal panel with a compact structure, when repeated or periodic structures are superimposed and observed, moiré patterns such as grids, screens, or gratings are generated. In a thin, glasses-free 3D display system, a periodic cylindrical lens array is overlaid on a monochrome liquid crystal panel, projecting light from different subpixels to different eyes of the observer. Simultaneously, the parallax image displayed on the color liquid crystal panel is also loaded into a directional beam and projected to the human eye. Due to interference from the color filter in the color liquid crystal panel, the moiré pattern becomes obvious. The moiré phenomenon can be suppressed by rotating the lens array to a specific angle. In traditional cylindrical lens grating stereoscopic displays, the tilt angle of this lens is heavily dependent on the arrangement of the subpixels and can only be tilted to a few fixed angles, which is not conducive to eliminating moiré fringes and reducing crosstalk by rotating to the optimal angle.

[0006] Summary of the Invention

[0007] One of the purposes of the present invention is to provide a new naked-eye 3D display device to solve the technical problem in the prior art that insufficient light source leads to a discontinuous number of viewpoints, causing the human eye to perceive drastic changes in brightness and darkness and produce obvious flicker; one of the purposes of the present invention is to provide a new naked-eye 3D display device with a stepless viewpoint modulation method.

[0008] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0009] A novel naked-eye 3D display device includes a backlight source, a liquid crystal light valve, a cylindrical lens array, and a liquid crystal panel arranged in sequence along the light propagation direction, wherein:

[0010] The light field emitted by the backlight source passes through the liquid crystal light valve, which includes a liquid crystal light valve grayscale and a light valve development. The liquid crystal light valve grayscale and light valve switch are controlled according to the position of the observer's pupil, simulating light sources at different positions so that the illumination center of the light emitted by the liquid crystal panel remains at the position of the observer's pupil;

[0011] After passing through the cylindrical lens array, the light source forms a directional light source, and then passes through the liquid crystal panel to form a viewing image in the visible area.

[0012] In the above-mentioned technical means, by controlling the grayscale and light valve switch of the liquid crystal light valve, simulated light sources are formed at different positions, so that when the observer moves within the viewing area, two or more viewpoints can always be observed. At each position, the pointing light beam can be accurately projected onto the observer's pupil, avoiding the viewing flicker problem caused by the observer's pupil being located between two viewpoints and no light beam being projected.

[0013] Furthermore, the cylindrical lens array is tilted at an arbitrary tilt angle, and the tilt angle of the liquid crystal panel when it is turned on is the same as the tilt angle of the cylindrical lens array.

[0014] Furthermore, the pitch P of each cylindrical lens unit in the cylindrical lens array is: P≥2*l*S / L

[0015] Where l is the object-side distance of the cylindrical lens unit in the cylindrical lens array, L is the image-side distance of the cylindrical lens unit in the lens array, and S is the pupil distance of the human eye. The pupil distance S is expressed as:

[0016] Where w is the width of the simulated light source.

[0017] Furthermore, the backlight source is a partitioned backlight source divided into N areas in a longitudinal direction, wherein each area of ​​the partitioned backlight source is independently controlled.

[0018] Furthermore, it also includes a first polarizing film layer, a second polarizing film layer, a scattering sheet and a linear diffusion film, wherein:

[0019] The first polarizing film layer is disposed between the liquid crystal light valve and the cylindrical lens array;

[0020] The scattering sheet is arranged between the backlight source and the liquid crystal light valve, and the linear diffusion film is arranged between the cylindrical lens array and the liquid crystal panel;

[0021] The second polarizing film layer is arranged between the linear diffusion film and the liquid crystal panel;

[0022] The polarization directions of the first polarizing film layer and the second polarizing film layer are consistent.

[0023] Furthermore, it also includes a control module and an eye tracking module, wherein:

[0024] The control module is connected to the liquid crystal panel, liquid crystal light valve, backlight source and human eye tracking module;

[0025] The human eye tracking module tracks the position of the observer's pupil, and the control module controls the opening and closing states of the backlight source and the liquid crystal light valve according to the position of the observer's pupil and the refresh rate of the liquid crystal panel.

[0026] A second aspect of the present invention provides a viewpoint stepless modulation method, which is applied to the novel naked-eye 3D display device, and comprises the following steps:

[0027] Determine the viewpoint width and magnification at the optimal viewing position, and calculate the light-on width in the horizontal direction of the liquid crystal panel;

[0028] The tilt angle of the LCD panel to turn on the light is controlled to be consistent with the tilt angle of the cylindrical lens array;

[0029] Turning on the light according to the light-on width and tilt angle of the liquid crystal panel to form a parallelogram-shaped light-on area within a row of sub-pixels;

[0030] Divide the width of a sub-pixel into multiple segments according to the number of simulated viewpoints to be inserted between the viewpoint before and after the movement;

[0031] The light-on area is moved in the horizontal direction by a width of one segment each time, and each time the light-on area moves, the brightness modulation value of the sub-pixel is adjusted according to the area covered by the light-on area on the sub-pixel.

[0032] Furthermore, adjusting the brightness modulation value of the analog light source according to the area covered by the light-on region on the sub-pixel includes:

[0033] Where GB To simulate the pixel brightness of the light source, S0 is the area of ​​the sub-pixel, and S1 is the area of ​​the light-on area covered on the sub-pixel.

[0034] Furthermore, when the novel naked-eye 3D display device performs 3D display, the following steps are included:

[0035] When the liquid crystal panel displays the first frame of the left-eye parallax picture, the control module controls the human eye tracking module to track the position of the left pupil of the human eye;

[0036] The control module opens the liquid crystal light valve according to the position of the left pupil of the person, and controls the lighting area of ​​the partitioned backlight source according to the refresh rate of the liquid crystal panel;

[0037] When the first frame ends, the control module turns off the area illuminated by the partitioned backlight source and the liquid crystal light valve;

[0038] When the liquid crystal panel displays the second frame of the right eye parallax picture, the control module controls the human eye tracking module to track the position of the right eye pupil of the human eye;

[0039] The control module opens the liquid crystal light valve according to the position of the right pupil of the person, and controls the lighting area of ​​the partitioned backlight source according to the refresh rate of the liquid crystal panel;

[0040] When the second frame ends, the control module turns off the area illuminated by the partitioned backlight source and the liquid crystal light valve;

[0041] Repeat the above steps to achieve stereoscopic display.

[0042] Furthermore, the control module controls the backlight source according to the refresh rate of the liquid crystal panel, including the following steps:

[0043] The backlight source is divided into N areas in the vertical direction, and the liquid crystal panel is controlled by the control module to refresh the display line by line from top to bottom, and the total number of lines of the liquid crystal panel is M;

[0044] When the LCD panel is refreshed to row n*M / N, the control module turns on the nth partition of the backlight source after a delay of TD time, and turns off the nth partition of the backlight source after a delay of TW time, where n is a positive integer from 1 to N, until a frame of image is refreshed.

[0045] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0046] The present invention introduces a low-crosstalk naked-eye 3D display device with synchronized partitioned backlight and liquid crystal light valves. This system has a compact structure while achieving excellent directional display. A simulated light source method is used on the liquid crystal light valve of this device to add multiple simulated viewpoints between two actual viewpoints. The simulated light source lighting method determines the pixel brightness by the ratio of the lighted area to the area actually covering the liquid crystal light valve pixels, and the stepless viewpoint movement strategy successfully eliminates the observer's movement flicker and reduces temporal crosstalk. At the same time, it can achieve light bar tilt at any angle, no longer relying on the arrangement of pixels. The naked-eye 3D display device of the present invention also has the ability to project the images required by the observer's left and right eyes to the corresponding eyes, respectively, so that the audience can enjoy high-brightness, low-crosstalk, and 3D images with no loss of resolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] FIG1 is a schematic structural diagram of a novel naked-eye 3D display device provided by an embodiment of the present invention.

[0048] FIG2 is a schematic diagram of an observation method of a novel naked-eye 3D display device provided by an embodiment of the present invention;

[0049] FIG3 is a schematic flow chart of a novel viewpoint stepless modulation method for a naked-eye 3D display device provided by an embodiment of the present invention;

[0050] FIG4 is a schematic diagram of a simulated stepless viewpoint movement strategy provided by an embodiment of the present invention;

[0051] FIG5 is a schematic diagram of a simulated stepless moving viewpoint light spot according to an embodiment of the present invention;

[0052] FIG6 is a schematic diagram of a one-dimensional light intensity distribution of a simulated stepless moving viewpoint light spot according to an embodiment of the present invention;

[0053] FIG7 is a schematic diagram of a method for implementing a simulated tilted light source according to an embodiment of the present invention;

[0054] FIG8 is a comparison diagram of microscopic images and display effects of a non-simulated tilted light source and a simulated tilted light source provided by an embodiment of the present invention;

[0055] FIG9 is a schematic diagram of a continuous longitudinal observation area solution provided by an embodiment of the present invention;

[0056] FIG10 is a schematic flow chart of a method for performing 3D display in a novel naked-eye 3D display device provided by an embodiment of the present invention.

[0057] In the figure, 11 is an eye tracking module, 12 is a control module, 13 is a liquid crystal panel, 14 is a linear diffusion film, 15 is a cylindrical lens array, 16 is a liquid crystal light valve, 17 is a scattering sheet, and 18 is a backlight source. DETAILED DESCRIPTION

[0058] The accompanying drawings are for illustrative purposes only and are not to be construed as limiting this patent;

[0059] In order to better illustrate this embodiment, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product size;

[0060] It is understandable to those skilled in the art that some well-known structures and descriptions thereof may be omitted in the drawings.

[0061] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0062] Example

[0063] This embodiment provides a novel naked-eye 3D display device, as shown in FIG1 , in which a backlight source 18 , a liquid crystal light valve 16 , a cylindrical lens array 15 , and a liquid crystal panel 13 are sequentially arranged along the light propagation direction, wherein:

[0064] The light field emitted by the backlight source 18 passes through the liquid crystal light valve 16. The liquid crystal light valve 16 includes a grayscale and a light valve development. The grayscale and light valve switch of the liquid crystal light valve 16 are controlled according to the position of the observer's pupil, simulating light sources at different positions so that the illumination center of the light emitted by the liquid crystal panel 13 remains at the position of the observer's pupil.

[0065] After passing through the cylindrical lens array 15 , the light source forms a directional light source, and then passes through the liquid crystal panel 13 to form a viewing image in the visible area.

[0066] In this embodiment, a backlight, liquid crystal light valves, a lenticular lens array, and a liquid crystal panel constitute a glasses-free 3D display device with a liquid crystal light valve backlight. As shown in Figure 1, the light field emitted by the backlight sequentially passes through the liquid crystal light valve to form a uniform linear light source, passes through the lenticular lens array to form a directional light source, and passes through the liquid crystal panel to form a viewing image in the visible area. The liquid crystal light valve is a combination of two or more single adjustable pixels, with a one-to-one correspondence between the illumination viewpoint and the pixel combination. An algorithm can control the grayscale and opening and closing of the liquid crystal light valve, simulating a light source at different positions, achieving stepless viewpoint movement and continuous depth viewing.

[0067] The simulated light source refers to determining the pixel brightness of the liquid crystal light valve by the ratio of the light-on area to the area actually covering the pixels of the liquid crystal light valve;

[0068] Continuous depth viewing is achieved by adjusting the width of the simulated light source and the spacing between adjacent light source cycles;

[0069] The stepless viewpoint movement method uses the aforementioned simulated light source method to add multiple simulated viewpoints between two actual viewpoints. Each lens array unit must maintain consistent brightness, and the brightness modulation value of each group should be equal. The magnitude of the brightness modulation value is related to factors such as the viewpoint width at the optimal viewing position, the tilt angle of the lens, and the magnification of the cylindrical lens array unit.

[0070] In a further embodiment, the cylindrical lens array 15 is tilted at any tilt angle, and the tilt angle of the liquid crystal panel 13 when it is turned on is the same as the tilt angle of the cylindrical lens array 15 .

[0071] In a further embodiment, as shown in FIG2 , in order to prevent the pitch between lens units from being observed by the observer, thereby affecting the viewing quality, it is necessary to minimize the distance between the lenses. At the same time, it is necessary to eliminate the occurrence of crosstalk visual areas formed by light passing through adjacent lenses at the optimal viewing position. Therefore, the pitch P of each cylindrical lens unit in the cylindrical lens array 15 is: P ≥ 2*l*S / L

[0072] Wherein, l is the object-side distance of the cylindrical lens unit in the cylindrical lens array 15, L is the image-side distance of the cylindrical lens unit in the lens array, and S is the pupil distance of the human eye. The pupil distance S is expressed as:

[0073] Where w is the width of the simulated light source.

[0074] Figure 2 shows that the periodic distance of the backlight from the same viewpoint is W. The monochrome panel unit is imaged by adjacent columns of the cylindrical lens array. The distance from the center of one column of cylindrical lens array units to the center of the next column of cylindrical lens array units is P, and the light is also projected to the same viewpoint. Based on geometric knowledge, it can be obtained:

[0075] P is the distance between adjacent lens units in the lens array.

[0076] In a further embodiment, the width w of the simulated light source is the horizontal width of the light on the liquid crystal panel, which is calculated by the viewpoint width and the magnification, and the calculation formula is as follows:

[0077] Where l is the object distance of the lens unit in the lens array, L is the image distance of the lens unit in the lens array, and D V The viewpoint width is about 60-65mm. is the magnification.

[0078] In traditional naked-eye 3D displays, the best viewing experience depends on a specific viewing distance. However, when the observer deviates from this position, the image information beam cannot be accurately projected onto the human eye, which will cause a decrease in the quality of the stereoscopic image, thereby causing symptoms such as dizziness or loss of stereoscopic vision. Since the transmission of optical imaging is separated from the illumination in the pointing backlight naked-eye 3D display, the expansion of the longitudinal viewing area can no longer be related to the image quality, but only to the illumination quality. Therefore, a wider and more uniform longitudinal viewing area can be achieved. As shown in Figure 9, when the pointing backlight system configuration remains unchanged, the focus of the illumination path, that is, the observation point position, can be controlled by adjusting the width of the light source and the spacing between adjacent light source cycles. The spacing between adjacent light source cycles can be controlled using Calculation, the depth range is Wherein, W1 is the minimum distance between two adjacent simulated light sources, and W3 is the maximum distance between two adjacent simulated light sources.

[0079] In a further embodiment, the backlight source 18 is a partitioned backlight source 18 divided into N regions in the longitudinal direction, wherein each region of the partitioned backlight source 18 is independently controlled.

[0080] In a further embodiment, the first polarizing film layer, the second polarizing film layer, the scattering sheet 17 and the linear diffusion film 14 are further included, wherein:

[0081] The first polarizing film layer is disposed between the liquid crystal light valve 16 and the cylindrical lens array 15;

[0082] The scattering sheet 17 is disposed between the backlight source 18 and the liquid crystal light valve 16 , and the linear diffusion film 14 is disposed between the cylindrical lens array 15 and the liquid crystal panel 13 ;

[0083] The second polarizing film layer is disposed between the linear diffusion film 14 and the liquid crystal panel 13;

[0084] The polarization directions of the first polarizing film layer and the second polarizing film layer are consistent.

[0085] In a specific embodiment, the linear diffusion film is used to eliminate moiré fringes and liquid crystal grids, and forms a viewable image in the visual area through the liquid crystal panel. The lenticular lens array and the linear diffusion film are made of polarization-maintaining optical materials.

[0086] In a further embodiment, the refresh rate of the liquid crystal light valve and the liquid crystal panel is greater than 120 Hz.

[0087] In a further embodiment, a control module 12 and an eye tracking module are further included, wherein:

[0088] The control module 12 is connected to the liquid crystal panel 13, the liquid crystal light valve 16, the backlight source 18 and the human eye tracking module 11;

[0089] The eye tracking module 11 tracks the position of the observer's pupil, and the control module 12 controls the opening and closing states of the backlight source 18 and the liquid crystal light valve 16 according to the position of the observer's pupil and the refresh rate of the liquid crystal panel 13 .

[0090] An embodiment of the present invention further provides a viewpoint stepless modulation method, as shown in FIG3 , which is applied to the novel naked-eye 3D display device according to any one of claims 1 to 6, and comprises the following steps:

[0091] Determine the viewpoint width and magnification at the optimal viewing position, and calculate the light-on width in the horizontal direction of the liquid crystal panel 13;

[0092] The tilt angle of the liquid crystal panel 13 when turning on the light is controlled to be consistent with the tilt angle of the cylindrical lens array 15;

[0093] Turning on the light according to the light-on width and tilt angle of the liquid crystal panel 13, forming a parallelogram-shaped light-on area within a row of sub-pixels;

[0094] Divide the width of a sub-pixel into multiple segments according to the number of simulated viewpoints to be inserted between the viewpoint before and after the movement;

[0095] The light-on area is moved in the horizontal direction by a width of one segment each time, and each time the light-on area moves, the brightness modulation value of the sub-pixel is adjusted according to the area covered by the light-on area on the sub-pixel.

[0096] In a further embodiment, the width of a sub-pixel is divided into multiple segments according to the number of simulated viewpoints to be inserted between the viewpoint before and after the movement, including:

[0097] The number of segments used to divide the width of one sub-pixel is the same as the number of simulated viewpoints inserted.

[0098] In traditional directional backlit naked-eye 3D displays, there is a one-to-one mapping relationship between viewpoints and light sources. Insufficient light sources may lead to a sparse number of viewpoints, causing the human eye to perceive drastic changes in brightness and darkness, and produce flicker. As shown in Figure 4, when the observer's position transitions from Figure 4(a) to Figure 4(f), the sub-pixel brightness modulation will synchronously transition from the rapid transition in Figure 4(a) to Figure 4(f), resulting in increased crosstalk and flicker. An effective solution is to construct simulated stepless mobile viewpoints, which requires covering a large number of sub-pixels (light sources) under each microlens unit. However, this requires a higher-resolution monochrome LCD panel, which is a huge technical challenge. To solve this problem, a strategy for achieving ultra-dense simulated stepless mobile viewpoints while maintaining the resolution of the monochrome panel unchanged is further proposed, aiming to provide a more comfortable stereoscopic visual experience.

[0099] As shown in Figure 4, when transitioning from Figure 4(a) to Figure 4(f), multiple simulated viewpoints are added between viewpoints (a) and (f) using the simulated tilted light strip method. This ensures that the illumination center of the light beam remains at the position of the observer's pupil as the eye moves. It is important to emphasize that each lens array unit must maintain consistent brightness, and the brightness modulation value of each group should be equal. The size of the brightness modulation value is related to factors such as the viewpoint width at the optimal viewing position, the tilt angle of the lens, and the magnification of the cylindrical lens array unit.

[0100] The specific implementation method is as follows: First, determine the viewpoint width S and the system magnification β at the optimal viewing position. This allows calculation of the corresponding horizontal width of the monochrome LCD panel (modulating the monochrome LCD panel's subpixels to a transmissive state). Because the lens must be tilted to avoid moiré fringes, the monochrome LCD panel also requires tilted lighting, with the tilt angle consistent with the tilt angle of the lens array unit. Determining the lighting width and tilt angle allows the formation of a parallelogram-shaped lighting area within a row of subpixels. Dividing the width of a subpixel into N equal segments and shifting this parallelogram-shaped lighting area segment by segment in the horizontal direction can simulate ultra-dense viewpoints. The brightness modulation value of each subpixel is determined by the ratio of the area covered by this parallelogram-shaped lighting area on the subpixel to the total subpixel area. Theoretically, the range between two subpixel moving viewpoints can simulate 255 dense viewpoints. As an example, the number of simulated viewpoints is set to four.

[0101] This embodiment simulates a simulated ultra-dense viewpoint scene. According to the proposed simulated ultra-dense viewpoint strategy, four simulated viewpoints, namely, simulated viewpoint 1 in Figure 5(b), simulated viewpoint 2 in Figure 5(c), simulated viewpoint 3 in Figure 5(d), and simulated viewpoint 4 in Figure 5(e), are inserted between the actual viewpoint 1 in Figure 5(a) and the actual viewpoint 2 in Figure 5(g) by controlling the brightness ratio of the light source. This increases the viewpoint density between two adjacent actual viewpoints. When the observer moves within the viewing area, the pointing light beam at each position can be accurately projected onto the observer's pupil, avoiding the viewing flicker problem caused by the observer's pupil being located between two viewpoints and no light beam being projected.

[0102] Figure 6 compares the one-dimensional light intensity distribution of the simulated ultra-dense viewpoint spot cross-section, showing that four simulated viewpoints were evenly added between actual viewpoint 1 and actual viewpoint 2. Before adding the simulated viewpoints, the spacing between actual viewpoint 1 and actual viewpoint 2 was approximately 20 mm. After adding the simulated viewpoints, the spacing between two adjacent viewpoints was shortened to 4 mm, equivalent to the diameter of the human pupil. Therefore, when viewing naked-eye 3D with the addition of simulated viewpoints, the human eye can always observe two or more viewpoints, thus avoiding motion flicker. Furthermore, due to the use of a monochrome LCD backlight, the theoretical grayscale variation of an 8-bit LCD light valve is between 0 and 255. Therefore, 0-255 simulated viewpoints can be added between two adjacent actual viewpoints as needed to meet the viewing needs of different observers. Four simulated viewpoints are added here as an example.

[0103] The liquid crystal light valve includes a liquid crystal light valve grayscale and a light valve switch. According to the liquid crystal light valve grayscale and the light valve switch, a simulated light source is formed at different positions, and the sub-pixel brightness value of the simulated light source is adjusted by the area covered by the light-on area on the sub-pixel.

[0104] Adjusting the sub-pixel brightness value of the simulated light source according to the area covered by the light-on region on the sub-pixel includes:

[0105] Where G B To simulate the pixel brightness of the light source, S0 is the area of ​​the sub-pixel, and S1 is the area of ​​the light-on area covered on the sub-pixel.

[0106] In a further embodiment, the tilt angle of the lens array is any angle.

[0107] In a specific embodiment, when repeated or periodic structures are superimposed and observed, a moiré pattern is generated, such as a grid, screen, or grating. In a thin, glasses-free 3D display system, a periodic cylindrical lens array is overlaid on a monochrome liquid crystal panel, projecting light emitted from different subpixels to different eyes of the observer. Simultaneously, the parallax image displayed on the color liquid crystal panel is also loaded into a directional beam and projected to the human eye. Due to interference from the color filter in the color liquid crystal panel, the moiré pattern becomes apparent. Moiré can be suppressed by rotating the lens array to a specific angle. In traditional cylindrical lens grating stereoscopic displays, the lens tilt angle is heavily dependent on the subpixel layout and can only be tilted to a few fixed angles, which is not conducive to eliminating moiré and reducing crosstalk by rotating to the optimal angle. Therefore, to avoid the limitation of the lens array tilt angle, this embodiment proposes a method for simulating tilted light strips, as shown in Figure 7. When the desired illuminated tilted strip area does not cover the entire subpixel, the brightness value of the subpixel is adjusted based on the ratio of the area of ​​the desired illuminated tilted strip area covering the subpixel to the entire pixel. The grayscale value of each pixel can be calculated as follows:

[0108] As shown in Figure 7(a), G B1 , G B2 , G B3 These are the brightness values ​​of the sub-pixels on the left, middle, and right in Figure 7(a), respectively. Figure 7(c) is a partial magnification of Figure 7(b), and the grayscale value corresponding to each pixel is calculated.

[0109] Figure 8 is a comparison of the microscopic images and display effects of non-simulated tilted light sources and simulated tilted light sources. The liquid crystal light valve lighting combination usually cannot determine the appropriate arrangement, and discontinuous arrangement will occur. As shown in Figure 8(a), when tilted by 12.5°, the adjacent rows in the upper red frame are offset by one column of sub-pixels, while the adjacent rows in the lower red frame are offset by two columns of sub-pixels to achieve the specified tilt angle. This leads to the appearance of black bands in the display screen, as shown in Figure 8(b). The proposed method based on simulated tilted light strips can simulate tilted pixel lighting combinations at any angle. As shown in Figure 8(c), which simulates a 12.5-degree lighting combination arrangement, the discontinuity of pixel misalignment is eliminated, and the display screen is uniform without black bands, as shown in Figure 8(d).

[0110] Continuous depth viewing is achieved by adjusting the width of the simulated light source and the distance between two adjacent simulated light sources.

[0111] In a further embodiment, when the novel naked-eye 3D display device performs 3D display, as shown in FIG10 , the following steps are included:

[0112] When the liquid crystal panel 13 displays the first frame of the left eye parallax picture, the control module 12 controls the human eye tracking module 11 to track the position of the left eye pupil of the human eye;

[0113] The control module 12 opens the liquid crystal light valve 16 according to the position of the left pupil of the person, and controls the lighting area of ​​the partitioned backlight source 18 according to the refresh rate of the liquid crystal panel 13;

[0114] When the first frame ends, the control module 12 turns off the illuminated area of ​​the partitioned backlight source 18 and the liquid crystal light valve 16;

[0115] When the liquid crystal panel 13 displays the second frame of the right eye parallax picture, the control module 12 controls the human eye tracking module 11 to track the position of the right eye pupil of the human eye;

[0116] The control module 12 opens the liquid crystal light valve 16 according to the position of the right pupil of the person, and controls the lighting area of ​​the partitioned backlight source 18 according to the refresh rate of the liquid crystal panel 13;

[0117] When the second frame ends, the control module 12 turns off the area illuminated by the partitioned backlight source 18 and the liquid crystal light valve 16;

[0118] Repeat the above steps to achieve stereoscopic display.

[0119] In this embodiment, the partitioned backlight source 18 is used as a backlight module for backlighting. The light field it emits is homogenized in sequence through the scattering plate 17, forms a uniform line light source through the liquid crystal light valve 16, forms a directional light source through the cylindrical lens array 15, diffuses longitudinally through the linear diffusion film 14 to eliminate moiré fringes and liquid crystal grids, and forms a viewing image in the visible area through the liquid crystal panel 13.

[0120] In a further embodiment, the control module 12 controls the backlight source 18 according to the refresh rate of the liquid crystal panel 13, including the following steps:

[0121] The backlight source 18 is divided into N areas in the vertical direction. The liquid crystal panel 13 is controlled by the control module 12 to refresh the display line by line from top to bottom. The total number of lines of the liquid crystal panel 13 is M.

[0122] When the liquid crystal panel 13 is refreshed to the n*M / N row, the control module 12 turns on the nth partition of the backlight source 18 after a delay of TD time, and turns off the nth partition of the backlight source 18 after a delay of TW time, where n is a positive integer from 1 to N, until a frame of image is refreshed.

[0123] The embodiment of the present invention introduces a low-crosstalk naked-eye 3D display device with synchronous zoned backlight and liquid crystal light valve. This system has a compact structure and can achieve excellent directional display.

[0124] An embodiment of the present invention uses a simulated light source method on the liquid crystal light valve of this device to add multiple simulated viewpoints between two actual viewpoints. The simulated light source lighting method determines the pixel brightness by the ratio of the lighted area to the area actually covering the liquid crystal light valve pixels, and the stepless moving viewpoint strategy successfully eliminates the observer's movement flicker and reduces temporal crosstalk. At the same time, it can achieve light strip tilt at any angle, no longer relying on the arrangement of pixels.

[0125] The naked-eye 3D display device of the embodiment of the present invention can project the images required by the left and right eyes of the observer to the corresponding eyes respectively, so that the audience can enjoy 3D images with high brightness, low crosstalk and no loss of resolution.

[0126] The same or similar reference numerals correspond to the same or similar components;

[0127] The terms used in the drawings to describe positional relationships are for illustrative purposes only and should not be construed as limiting this patent;

[0128] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A new type of naked eye 3D display device, characterized in that: A backlight source, a liquid crystal light valve, a cylindrical lens array and a liquid crystal panel are sequentially arranged along the light propagation direction, wherein: The light field emitted by the backlight source passes through the liquid crystal light valve, which includes a liquid crystal light valve gray scale and a light valve development. The liquid crystal light valve gray scale and the light valve switch are controlled according to the position of the observer's pupil, and light sources are simulated at different positions, so that the illumination center of the light emitted by the liquid crystal panel is maintained at the position of the observer's pupil; After passing through the cylindrical lens array, the light source forms a directional light source, and then passes through the liquid crystal panel to form a viewing image in the visible area.

2. The novel naked eye 3D display device according to claim 1, characterized in that: The cylindrical lens array is tilted at an arbitrary tilt angle, and the tilt angle of the liquid crystal panel when it is turned on is the same as the tilt angle of the cylindrical lens array.

3. The novel naked eye 3D display device according to claim 1, characterized in that: The spacing P of each cylindrical lens unit in the cylindrical lens array is: P≥2*l*S / L Where l is the object distance of the cylindrical lens unit in the cylindrical lens array, L is the image distance of the cylindrical lens unit in the lens array, and S is the pupil distance of the human eye. The pupil distance S is expressed as: Where w is the width of the simulated light source.

4. The novel naked eye 3D display device according to claim 1, characterized in that: The backlight source is a partitioned backlight source divided into N regions in a longitudinal direction, wherein each region of the partitioned backlight source is independently controlled.

5. The novel naked eye 3D display device according to claim 4, characterized in that: It also includes a first polarizing film layer, a second polarizing film layer, a scattering sheet and a linear diffusion film, wherein: The first polarizing film layer is disposed between the liquid crystal light valve and the cylindrical lens array; The scattering sheet is arranged between the backlight source and the liquid crystal light valve, and the linear diffusion film is arranged between the cylindrical lens array and the liquid crystal panel; The second polarizing film layer is disposed between the linear diffusion film and the liquid crystal panel; The polarization directions of the first polarizing film layer and the second polarizing film layer are consistent.

6. The novel naked-eye 3D display device according to any one of claims 1 to 5, characterized in that: It also includes a control module and an eye tracking module, wherein: The control module is connected with the liquid crystal panel, the liquid crystal light valve, the backlight source and the human eye tracking module; The human eye tracking module tracks the position of the observer's pupil, and the control module controls the opening and closing states of the backlight source and the liquid crystal light valve according to the position of the observer's pupil and the refresh rate of the liquid crystal panel.

7. A viewpoint stepless modulation method, characterized in that: The method is applied to the novel naked-eye 3D display device according to any one of claims 1 to 6, and the method comprises the following steps: Determine the viewpoint width and magnification at the best viewing position, and calculate the light-on width in the horizontal direction of the liquid crystal panel; The tilt angle of the liquid crystal panel when turning on the light is controlled to be consistent with the tilt angle of the cylindrical lens array; Turning on the light according to the light-on width and tilt angle of the liquid crystal panel to form a parallelogram-shaped light-on area within a row of sub-pixels; According to the number of simulated viewpoints to be inserted between the viewpoint before and after the movement, the width of a sub-pixel is evenly divided into multiple segments; The light-on area is moved in the horizontal direction by a width of one segment each time, and each time the light-on area moves, the brightness modulation value of the sub-pixel is adjusted according to the area covered by the light-on area on the sub-pixel.

8. The viewpoint stepless modulation method according to claim 7, characterized in that: Adjusting the brightness modulation value of the simulated light source according to the area covered by the light-on area on the sub-pixel includes: In the formula, G B To simulate the pixel brightness of the light source, S0 is the area of ​​the sub-pixel, and S1 is the area of ​​the light-on area covered on the sub-pixel.

9. The viewpoint stepless modulation method according to claim 7, characterized in that: When the novel naked-eye 3D display device performs 3D display, the following steps are included: When the liquid crystal panel displays the first frame of the left eye parallax picture, the control module controls the human eye tracking module to track the left eye pupil position of the human eye; The control module opens the liquid crystal light valve according to the position of the left eye pupil of the person, and controls the lighting area of ​​the partitioned backlight source according to the refresh rate of the liquid crystal panel; When the first frame ends, the control module turns off the area and liquid illuminated by the partition backlight source. Crystal light valve; When the liquid crystal panel displays the second frame of the right eye parallax picture, the control module controls the human eye tracking module to track the position of the right eye pupil of the human eye; The control module opens the liquid crystal light valve according to the position of the right eye pupil of the person, and controls the lighting area of ​​the partitioned backlight source according to the refresh rate of the liquid crystal panel; When the second frame ends, the control module turns off the area lit by the subarea backlight source and the liquid crystal light valve; The above steps are repeated to realize stereoscopic display.

10. The viewpoint stepless modulation method according to claim 9, characterized in that: The control module controls the backlight source according to the refresh rate of the liquid crystal panel, comprising the following steps: The backlight source is divided into N areas vertically, and the liquid crystal panel is controlled by the control module to refresh the display line by line from top to bottom, and the total number of lines of the liquid crystal panel is M; When the LCD panel is refreshed to n*M / N rows, the control module turns on the nth partition of the backlight source after a delay of TD time, and turns off the nth partition of the backlight source after a delay of TW time, where n is a positive integer from 1 to N, until a frame of image is refreshed.

Images