Autostereoscopic image display device for backlight real image formation

Abstract

To provide an autostereoscopic image display device which solves a problem of a distance required between a light source and a concave mirror and a problem of crosstalk and an afterimage generated when a switching speed of a display panel does not catch up with the distance.SOLUTION: Provided is an autostereoscopic image display device for backlight real image formation that is suitable for being used in combination with an imaging semi-reflective mirror, wherein by combining the backlight module with the off-axis dual mirror module, a directional backlight beam can be generated in a smaller space, and the equivalent distance between the backlight module and the imaging concave mirror is greater than the focal length of the imaging concave mirror, generating a real image of the eye-box array of the backlight module through the imaging concave mirror. According to the position of the eye movement, the backlight source is switched so that the image beam intersects with the corresponding small eye-box in the eye-box array, and multiple small eye-boxes are used to correspond to one eye, thereby improving the tracking buffer when the eyes move quickly and avoiding image interruptions.SELECTED DRAWING: Figure 6A

Description

[Technical Field]

[0001] The present invention relates to an autostereoscopic image display device, and more particularly to an autostereoscopic image display device for backlight real image formation. [Background technology]

[0002] As shown in Figures 1A and 1B, a conventional head-up display (HUD) uses a backlight source 01 to emit a backlight beam. The backlight beam passes through a display panel 03 to form an image beam, which is then reflected by an imaging concave mirror 5. The imaging concave mirror 5 is a concave reflecting mirror. An image on the display panel 03 forms a corresponding virtual image behind the imaging concave mirror 5, and the backlight source 01 forms a real image of the backlight source in the optical path in front of the imaging concave mirror 5.

[0003] The imaging semi-reflecting mirror is used to reflect a portion of the image beam from the imaging concave mirror to the observer's eye while simultaneously transmitting a portion of the light from the scene in front of the observer to the observer's eye. The imaging semi-reflecting mirror may be, for example, a windshield WS as shown in FIG. 1A or a combiner C as shown in FIG. 1B. After the image virtual image behind the imaging concave mirror 5 is reflected by the imaging semi-reflecting mirror (windshield or combiner), it forms an image virtual image G_im on the side of the imaging semi-reflecting mirror away from the observer. After the real image of the backlight source in front of the imaging concave mirror 5 is reflected by the imaging semi-reflecting mirror, it forms a focused real image of the backlight source on the side of the imaging semi-reflecting mirror closer to the observer. This is the eyebox EB.

[0004] When the observer's eyes are positioned at the eyebox, that is, at the actual focal point of the light emitted from the backlight source, the observer can see the brightest and clearest virtual image.

[0005] In order to allow the backlight source to form a real image of the backlight source in front of the imaging concave mirror, the distance between the backlight source and the imaging concave mirror must be longer than the focal length of the imaging concave mirror, which is even more difficult in a car dashboard where space is limited.

[0006] As shown in Figure 1C, a conventional directional backlight autostereoscopic head-up display device uses a directional backlight source array as a backlight source 01 in combination with a fast-response display panel 03. The directional backlight source array 01 projects a directional backlight beam B onto the display panel 03. The display panel 03 rapidly switches between displaying left-eye and right-eye parallax images. The directional backlight beam B passes through the display panel 03 to form a directional image beam D carrying image information. The directional image beam D is reflected by the imaging concave mirror 5 and the imaging semi-reflecting mirror 7, forming a real image of the backlight source on the side of the imaging semi-reflecting mirror 7 facing the observer, i.e., forming an eyebox array EBA. This creates a real image of the image virtual image G_im on the side of the imaging semi-reflecting mirror 7 facing away from the observer. The observer's left and right eyes can see the left-eye and right-eye virtual parallax images G_im within the area of ​​the eyebox array EBA, respectively. The image seen by the observer's right eye is the right-eye parallax virtual image, and the image seen by the left eye is the left-eye parallax virtual image. The brain integrates the left-eye parallax virtual image and the right-eye parallax virtual image and interprets them as a three-dimensional image.

[0007] Light emitted or reflected from the backlight light source array is reflected by the imaging concave mirror 5 to form a backlight light source real image in front of the imaging concave mirror 5, and the backlight light source real image is reflected by the imaging semi-reflecting mirror 7 to be projected onto the observer's eyebox array EBA. The left-eye parallax image of the display panel 03 is reflected by the imaging concave mirror 5 to form first left-eye parallax image virtual images located behind the imaging concave mirror 5. Next, the left-eye parallax images reflected by the imaging semi-reflecting mirror 7 become second left-eye parallax image virtual images G_im located away from the observer on the imaging semi-reflecting mirror 7. The gaze tracking module 6 detects relative position information between the observer's left and right eyes and the gaze tracking module. The control and calculation module 61 receives the detection information from the eye tracking module 6 and obtains the left eye position E_L and the right eye position E_R in the observer's space through identification, calculation, table lookup, or inference. Then, it obtains the corresponding left eye small eyebox EB_L and right eye small eyebox EB_R in the eyebox array EBA from the left and right eye positions, and obtains the left eye backlight light source Led_L and the right eye backlight light source Led_R from the left and right eye small eyeboxes. When the display panel 03 displays a left eye parallax image, the left eye backlight light source Led_L is turned on, and when the right eye parallax image is displayed, the right eye backlight light source Led_R is turned on. The switching time between the two images is shorter than the visual duration of the human eye, so the left eye and right eye can continue to view the left parallax image and the right parallax image, respectively.

[0008] Although the time interval between when the display panel 03 switches and when the left-eye parallax image and the right-eye parallax image are displayed is very short, it takes time for the liquid crystal to respond. If part of the liquid crystal does not switch in time, the other eye will see the area that has not switched (part of the previous image) or the area that is being switched, causing crosstalk and afterimages. Summary of the Invention [Problem to be solved by the invention]

[0009] In summary, to achieve bright and clear naked-eye 3D images, it is necessary to solve the problem of the distance required between the backlight source and the imaging concave mirror, and to solve the problems of crosstalk and image retention that occur when the display panel cannot keep up with the switching speed. [Means for solving the problem]

[0010] Based on the above object, the present invention provides an autostereoscopic image display device.

[0011] The autostereoscopic image display device is suitable for use in combination with an imaging semi-reflecting mirror, a backlight module including a backlight source array configured with a plurality of backlight sources and emitting a backlight beam; an off-axis dual mirror module including a first mirror and a second curved mirror whose optical axes are offset from each other, the first mirror and the second curved mirror sequentially reflecting a backlight beam to form a directional backlight beam; a display including a main display module and a light-shielding module stacked on top of each other, the main display module alternately displaying left-eye parallax images and right-eye parallax images, and forming an image beam after a directional backlight beam passes through; an imaging concave mirror that reflects the image beam; an eye tracking module that detects relative position information between the left and right eyes; a control and calculation module that acquires the detection information of the gaze tracking module and acquires the left eye position and the right eye position in the observer's space; Includes:

[0012] In the autostereoscopic display device of the present invention, an off-axis dual mirror module is used to make the backlight source array form a backlight source array virtual image. The equivalent distance between the backlight source array virtual image and the imaging concave mirror is greater than the focal length of the imaging concave mirror. The backlight beam corresponding to the backlight source array virtual image (or the backlight beam considered to be emitted from the position of the backlight array virtual image) is reflected by the imaging concave mirror and the imaging semi-reflecting mirror, and then projected and converged on the backlight focusing surface on the side closer to the viewer of the imaging semi-reflecting mirror 7, forming a backlight source array real image. Each backlight source forms an independent small eyebox, and all the small eyeboxes constitute a backlight source array real image, thereby defining an eyebox array, which includes multiple eyeboxes.

[0013] In addition, the equivalent distance between the main display module and the imaging concave mirror is smaller than the focal length of the imaging concave mirror, and based on the left-eye parallax image and the right-eye parallax image, a left-eye parallax image virtual image and a right-eye parallax image virtual image are formed, respectively, on the side of the imaging semi-reflecting mirror away from the eyebox array.

[0014] In addition, the polarizer closest to the light-entering side of the display is a reflective polarizer, and there is only one polarizer between the liquid crystal layer of the main display module and the liquid crystal layer of the light-blocking module.

[0015] In addition, the main display module defines a plurality of display blocks, and the shading module defines a plurality of switching blocks, each switching block corresponding to a display block, and when the main display module displays an image, at least one switching block is selected in a time-division manner to control the display block to project an image beam in a time-division manner, and the remaining switching blocks shield partial blocks of the main display module that are still in a switching state or have not yet been switched.

[0016] In addition, when the main display module displays an image for one eye, at least one switching block is selected in a time-division manner to control the display block to project the image beam in a time-division manner, and the remaining switching blocks shield the display block for the image for the other eye.

[0017] In addition, by combining each display block with a backlight light source at the same or a different position, it is possible to define more small eyeboxes, including the original eyebox array, outside the eyebox array space on both sides of the backlight focusing surface, and to define a wider extended eyebox array, so that a complete left-eye parallax image virtual image or right-eye parallax image virtual image can be viewed even at spatial positions away from the backlight focusing surface.

[0018] Furthermore, by switching between small eyeboxes at different positions in the eyebox array or the extended eyebox array, it is possible to accommodate the movement of the observer's eyes to different positions along the up / down, left / right, front / back directions.

[0019] The control and calculation module also obtains left-eye and right-eye small eyeboxes based on the left-eye position, right-eye position, and extended eyebox array, and then obtains corresponding left-eye and right-eye matrices according to the small eyebox-display block-backlight source matrix table. The left-eye and right-eye matrices respectively include corresponding display blocks, switching blocks, and backlight sources. The display blocks, switching blocks, and backlight sources are controlled to display left-eye and right-eye parallax images, respectively.

[0020] In addition, the corresponding small eyebox lights up depending on the position of the left or right eye movement. By switching between different small eyeboxes, the eye displacement amount can be adjusted, including two-dimensional displacement and three-dimensional displacement, and the eye position can be tracked to project an image.

[0021] The backlight module also includes a cone-shaped light cup array made up of cone-shaped light cups with different tilt angles, each of which increases in tilt angle with increasing distance from the center of the array.

[0022] The backlight module further includes a conical light cup array, a polarizing lens array, and a condensing lens array, which are arranged in this order from the light output side of the backlight light source array.

[0023] Furthermore, the second curved mirror is a concave mirror, the first mirror is a concave mirror, a convex mirror or a plane mirror, and the imaging position of the backlight module after being reflected by the first mirror is within the focal length of the second curved mirror.

[0024] Furthermore, the optical path from the backlight module to the first mirror and the optical path from the second curved mirror to the display module may or may not intersect.

[0025] In addition, the light incident side or the light emitting side of the main display module overlaps with the light blocking module.

[0026] In addition, the main display module and the light-shielding module are bonded together with an optical adhesive, and there is no polarizer between the optical adhesive and the liquid crystal layer of the main display module, or there is no polarizer between the optical adhesive and the liquid crystal layer of the light-shielding module.

[0027] In addition, by adjusting the length of time that the switching block is on and the length of time that the backlight light source is turned on, the brightness of the observed left-eye parallax image virtual image and right-eye parallax image virtual image can be controlled.

[0028] In addition, the liquid crystal switching speed of the main display module is slower than that of the light blocking module.

[0029] Additionally, the left-right direction (horizontal direction) or up-down direction (vertical direction) of the observer corresponds to one eye using 2n+1 adjacent small eyeboxes, where n>0 and n is a positive integer, a central small eyebox among the multiple small eyeboxes is aligned with the pupil, and the other 2n small eyeboxes are located on both the upper and lower or left and right sides of the central small eyebox.

[0030] Furthermore, the main display module alternately displays the left-eye parallax image and the right-eye parallax image, and the switching interval time during which each display block projects image light to the same eye is shorter than 41.67 ms.

[0031] An imaging semi-reflector is also a windshield or combiner that is used to reflect a portion of the image beam from the imaging concave mirror to the observer's eye while partially transmitting light from the scene in front of it to the observer's eye. [Effects of the Invention]

[0032] The present invention improves the problems faced by conventional naked-eye stereoscopic image display devices, eliminates image retention and crosstalk, improves image brightness, uniforms screen brightness, prevents image flicker, and expands the visible range, thereby realizing a naked-eye stereoscopic image display device that best meets the requirements of moving bodies such as vehicles, ships, and aircraft. [Brief explanation of the drawings]

[0033] [Figure 1A] FIG. 1 is an explanatory diagram of a conventional backlight type head-up display device in combination with an imaging semi-reflecting mirror. [Figure 1B] FIG. 1 is an explanatory diagram of a conventional backlight type head-up display device in combination with an imaging semi-reflecting mirror. [Figure 1C] FIG. 1 is an explanatory diagram of a conventional directional backlight type head-up display device for autostereoscopic images. [Figure 2A] FIG. 1 is an explanatory diagram of an off-axis dual mirror module. [Figure 2B] FIG. 1 is an explanatory diagram of an off-axis dual mirror module. [Figure 2C] FIG. 1 is an explanatory diagram of an off-axis dual mirror module. [Figure 2D] FIG. 1 is an explanatory diagram of an off-axis dual mirror module. [Figure 3A] FIG. 1 is an explanatory diagram of a backlit display device in which an off-axis dual mirror module is combined. [Figure 3B] 10 is an explanatory diagram of the diffusion angle of a backlight light source beam that passes through an off-axis dual mirror module and a beam that does not pass through an off-axis dual mirror module. [Figure 4A] FIG. 1 is an illustration of a directional backlight array module. [Figure 4B] FIG. 1 is an illustration of a directional backlight array module. [Figure 4C] FIG. 1 is an illustration of a directional backlight array module. [Figure 4D] FIG. 1 is an illustration of a directional backlight array module. [Figure 5A] FIG. 1 is an explanatory diagram of a lens-equipped backlight light source array module. [Figure 5B] FIG. 1 is an explanatory diagram of a lens-equipped backlight light source array module. [Figure 5C] FIG. 1 is an explanatory diagram of a lens-equipped backlight light source array module. [Figure 6A] FIG. 10 is an explanatory diagram of a display device in which a backlight light source array combined with an off-axis dual mirror module forms a real image. [Figure 6B] FIG. 10 is another explanatory diagram of a display device in which a backlight light source array combined with an off-axis dual mirror module forms a real image. [Figure 7] FIG. 1 is an explanatory diagram of a naked-eye three-dimensional image display device. [Figure 8A] FIG. 1 is a diagram illustrating the correspondence between the eyebox array and the positions of the left and right eyes. [Figure 8B] FIG. 1 is a diagram illustrating the correspondence between the eyebox array and the positions of the left and right eyes. [Figure 8C] FIG. 10 is an explanatory diagram showing a plurality of small eye boxes corresponding to the position of one eye. [Figure 8D]FIG. 10 is an explanatory diagram showing a plurality of small eye boxes corresponding to the position of one eye. [Figure 9] FIG. 10 is an explanatory diagram of the display of a switching image of the main display module in an ideal state. [Figure 10A] FIG. 10 is an explanatory diagram of a liquid crystal conversion time. [Figure 10B] 10A and 10B are explanatory diagrams of pixel conversion states of a liquid crystal display panel. [Figure 11A] FIG. 2 is an explanatory diagram of a main display module and a light-blocking module. [Figure 11B] FIG. 10 is an explanatory diagram showing the overlapping of the main display module and the light-blocking module. [Figure 11C] FIG. 1 is an explanatory diagram of the response times of IPS liquid crystal and TN liquid crystal. [Figure 11D] 10A and 10B are explanatory diagrams showing the detailed structure of the overlapping of the main display module and the light-blocking module. [Figure 11E] 10A and 10B are explanatory diagrams showing the detailed structure of the overlapping of the main display module and the light-blocking module. [Figure 11F] 10A and 10B are explanatory diagrams showing the detailed structure of the overlapping of the main display module and the light-blocking module. [Figure 11G] 10A and 10B are explanatory diagrams showing the detailed structure of the overlapping of the main display module and the light-blocking module. [Figure 11H] 10A and 10B are explanatory diagrams showing the detailed structure of the overlapping of the main display module and the light-blocking module. [Figure 11I] 10A and 10B are explanatory diagrams showing the detailed structure of the overlapping of the main display module and the light-blocking module. [Figure 12A] FIG. 2 is an illustration of the pixel conversion cycle of the main display module. [Figure 12B] FIG. 2 is an explanatory diagram showing a plurality of blocks defined by a main display module and a light blocking module. [Figure 13] 10 is an explanatory diagram of a plurality of block switching timings of the main display module, the light blocking module, and the backlight module. FIG. [Figure 14] 10 is an explanatory diagram of switching between blocks of a main display module, a light blocking module, and a backlight module. FIG. [Figure 15] FIG. 1 is an explanatory diagram of an image seen by the left and right eyes at different times. [Figure 16A] 10 is an explanatory diagram of a real image formed by a backlight module and a virtual image formed by a main display module. FIG. [Figure 16B] 10A and 10B are explanatory diagrams illustrating real image formation in the divided regions of the backlight module and virtual image formation in the divided regions of the main display module. [Figure 16C] 10A and 10B are explanatory diagrams illustrating real image formation in the divided regions of the backlight module and virtual image formation in the divided regions of the main display module. [Figure 17A] FIG. 10 is an explanatory diagram of a spatial light path for a combination of a first backlight source and each display block. [Figure 17B] FIG. 10 is an explanatory diagram of a spatial light path for a combination of a first backlight source and each display block. [Figure 17C] FIG. 10 is an explanatory diagram of a spatial light path for a combination of a first backlight source and each display block. [Figure 17D] 10 is an explanatory diagram showing a combination of a first backlight source and a divided area of ​​a main display module, and an intersection of the combination and the spatial light path. FIG. [Figure 17E] 10 is an explanatory diagram showing a combination of a first backlight source and a divided area of ​​a main display module, and an intersection of the combination and the spatial light path. FIG. [Figure 18A] FIG. 10 is an explanatory diagram of the spatial light path of the combination of the second backlight source and each display block. [Figure 18B] FIG. 10 is an explanatory diagram of the spatial light path of the combination of the second backlight source and each display block. [Figure 18C] FIG. 10 is an explanatory diagram of the spatial light path of the combination of the second backlight source and each display block. [Figure 18D] 10 is an explanatory diagram showing a combination of a second backlight source and a divided area of ​​the main display module, and an intersection of the two in the spatial light path. FIG. [Figure 18E] 10 is an explanatory diagram showing a combination of a second backlight source and a divided area of ​​the main display module, and an intersection of the two in the spatial light path. FIG. [Figure 19A]10 is an explanatory diagram of a spatial light path for a combination of a third backlight source and each display block. FIG. [Figure 19B] 10 is an explanatory diagram of a spatial light path for a combination of a third backlight source and each display block. FIG. [Figure 19C] 10 is an explanatory diagram of a spatial light path for a combination of a third backlight source and each display block. FIG. [Figure 19D] 10 is an explanatory diagram showing a combination of a third backlight source and a divided area of ​​the main display module, and an intersection of the combination and the spatial light path. FIG. [Figure 19E] 10 is an explanatory diagram showing a combination of a third backlight source and a divided area of ​​the main display module, and an intersection of the combination and the spatial light path. FIG. [Figure 20A] FIG. 10 is an explanatory diagram of a spatial light path for a combination of a first backlight source and a first display block. [Figure 20B] FIG. 10 is an explanatory diagram of a spatial light path for a combination of a second backlight source and a second display block. [Figure 20C] FIG. 10 is an explanatory diagram of a spatial light path for a combination of a third backlight source and a third display block. [Figure 20D] 10 is an explanatory diagram showing combinations of divided areas of the backlight module and divided areas of the main display module, and the intersections of these in spatial light paths. FIG. [Figure 20E] 10 is an explanatory diagram showing combinations of divided areas of the backlight module and divided areas of the main display module, and the intersections of these in spatial light paths. FIG. [Figure 21A] FIG. 10 is an explanatory diagram of a spatial light path for a combination of a third backlight source and a first display block. [Figure 21B] FIG. 10 is an explanatory diagram of a spatial light path for a combination of a second backlight source and a second display block. [Figure 21C] FIG. 10 is an explanatory diagram of a spatial light path for a combination of a first backlight source and a third display block. [Figure 21D] 10 is an explanatory diagram showing combinations of divided areas of the backlight module and divided areas of the main display module, and the intersections of these in spatial light paths. FIG. [Figure 21E]10 is an explanatory diagram showing combinations of divided areas of the backlight module and divided areas of the main display module, and the intersections of these in spatial light paths. FIG. [Figure 22A] FIG. 10 is an explanatory diagram illustrating a combination of an autostereoscopic image display device with an imaging semi-reflecting mirror. [Figure 22B] FIG. 10 is an explanatory diagram illustrating a combination of an autostereoscopic image display device with an imaging semi-reflecting mirror. [Figure 23A] FIG. 1 is an explanatory diagram of an extended eyebox array. [Figure 23B] FIG. 1 is an explanatory diagram of an extended eyebox array. [Figure 24A] 1 is an explanatory diagram showing an example of a backlight module, a main display module, and a light-blocking module. FIG. [Figure 24B] FIG. 1 is an illustration of an example of an extended eyebox array. [Figure 24C] FIG. 1 is an illustration of an example of an extended eyebox array. [Figure 25A] FIG. 10 is an explanatory diagram showing an example of a matrix table of small eyeboxes, display blocks, and backlight sources. [Figure 25B] FIG. 10 is an explanatory diagram showing an example of a matrix table of small eyeboxes, display blocks, and backlight sources. [Figure 26A] 1 is an explanatory diagram showing the timing of switching between the small eyeboxes of the left and right eyes, the display block of the main display module, the switching block of the shading module, and the backlight light source of the backlight module in a naked eye 3D image display device. [Figure 26B] 1 is an explanatory diagram showing the timing of switching between the small eyeboxes of the left and right eyes, the display block of the main display module, the switching block of the shading module, and the backlight light source of the backlight module in a naked eye 3D image display device. [Figure 26C] 1 is an explanatory diagram showing the timing of switching between the small eyeboxes of the left and right eyes, the display block of the main display module, the switching block of the shading module, and the backlight light source of the backlight module in a naked eye 3D image display device. [Figure 26D]1 is an explanatory diagram showing the timing of switching between the small eyeboxes of the left and right eyes, the display block of the main display module, the switching block of the shading module, and the backlight light source of the backlight module in a naked eye 3D image display device. DETAILED DESCRIPTION OF THE INVENTION

[0034] In the following description of the optical path, the light emission direction from the light emitting surface is defined as the forward direction, in accordance with the common understanding of those skilled in the art. However, when the terms "forward" and "rearward" are used to describe an imaging position, it means that the imaging position is located in front of or behind the curved mirror reflecting surface when the corresponding image is a real image or a virtual image.

[0035] An off-axis dual mirror module 2 can be used to extend the equivalent distance of the backlight source, satisfy the condition that the object distance of the real image is greater than the focal length of the concave mirror, reduce space usage, and form a directional beam. As shown in FIGS. 2A-2D, the off-axis dual mirror module 2 includes a first mirror 21 and a second curved mirror 22, which are offset from each other in terms of their optical axes. The mirror centers MC of the first mirror (here, the curved mirror) 21 and the second curved mirror 22 are not aligned with each other's optical axes OA. By using a backlight module 1 with a smaller area, a larger, more distant virtual image of the backlight source is formed behind the second curved mirror 22 after reflection by the first mirror 21 and the second curved mirror 22. The position of the virtual image of the backlight source is outside the focal length of the imaging concave mirror 5, and the real image of the backlight source is formed through the imaging concave mirror 5.

[0036] Light emitted from the backlight source of the backlight module 1 is projected onto the first mirror 21, reflected by the first mirror 21 and projected onto the second curved mirror 22, and then reflected by the second curved mirror 22 and projected onto the display 3. A concave mirror can be used for the second curved mirror 22 to form a virtual image of the backlight source that is separate from the imaging concave mirror.

[0037] After light from the backlight module 1 is reflected by the first mirror 21, regardless of whether it is a real backlight image formed in front of the first mirror 21 or a virtual backlight image behind the first mirror 21, the light must be between the second curved mirror 22 and the focal length of the second curved mirror 22, so that the light is reflected by the second curved mirror 22 and forms a virtual backlight image 1_im behind the second curved mirror 22. Therefore, the first mirror 21 may be a concave mirror as shown in FIGS. 2A and 2C, a convex mirror as shown in FIGS. 2B and 2D, or a flat mirror, as long as it can form an image within the focal length of the second curved mirror 22. The light is then reflected by the second curved mirror 22 and forms a virtual backlight image 1_im behind the second curved mirror 22 as shown in FIG. 3A.

[0038] The first optical path from the backlight source to the first mirror 21 and the second optical path from the second curved mirror 22 to the display 3 may intersect with each other as shown in Figures 2A and 2B, or may not intersect with each other as shown in Figures 2C and 2D.

[0039] FIG. 3A shows a display device that combines an off-axis dual mirror module 2 with a relatively small backlight module 1, which has the advantages of reducing the overall space and allowing a clear and bright image to be viewed in the eye box EB where the real image of the backlight source is formed.

[0040] As shown in Figure 3B, the equivalent backlight source of the display 3 is the backlight source virtual image 1_im formed behind the second curved mirror 22, and the mirror diameter of the second curved mirror 22 is smaller than the cross section of the beam diffused from the backlight source virtual image 1_im to the second curved mirror 22, i.e., the boundary 221 of the second curved mirror 22 limits the beam diffusion angle of the backlight source virtual image 1_im, equivalent to forming a directional backlight beam B.

[0041] In the design of the backlight module, LEDs are used as backlight sources to form a backlight source array 11 as shown in FIG. 4A, which can be further combined with a conical light cup array 12. The conical light cup array 12 is composed of multiple conical light cups. The conical light cups can be hollow light cups with a reflective film coating on the surface or transparent solid light guides. By placing the conical light cup array on the light output side of the backlight source array 11, the diffusion angle of the light source can be reduced, forming a directional backlight.

[0042] 4B, a conical light cup array 12, a polarizing lens array 13T, and a condensing lens array 13L are sequentially arranged on the light output side of the backlight light source array 11. The polarizing lens array 13T is used to concentrate the projection angle of each light source, and the condensing lens array 13L further reduces the diffusion angle of the light sources to form a directional backlight.

[0043] Alternatively, a conical light cup array 12 can be added with a focusing lens 14, as shown in Figure 4C. Alternatively, a conical light cup array 12 can be included with different tilt angles, such as the tilted conical light cup array 12 of Figure 4D, where the tilt angle of each light cup increases with distance from the center of the array, decreasing the spread angle of the light sources and concentrating the projection angle of each light source.

[0044] As shown in Fig. 5A, the backlight light source array 11 may be configured using LEDs 13 with built-in lenses on a flat substrate. Alternatively, as shown in Fig. 5B, the backlight light source array 11 may be configured using LEDs 13 with built-in lenses on a curved substrate. Alternatively, as shown in Fig. 5C, the backlight light source array 11 may be configured using LEDs 13 with built-in lenses on a flat substrate, with a condenser lens 14 added in front of the backlight light source array 11.

[0045] 6A, the backlight light source array 10 of the backlight module is formed outside the focal length of the imaging concave mirror 5 through imaging (backlight light source array virtual image 10_im) of the off-axis dual mirror module 2. The backlight beam reflected from the off-axis dual mirror module 2 passes through imaging (backlight light source array real image 10_re) of the imaging concave mirror 5, and the backlight light source array real image 10_re is then projected onto the imaging semi-reflecting mirror 7 (windshield) and reflected by the imaging semi-reflecting mirror 7 (windshield) to the backlight focusing plane BFP, forming an eyebox array EBA. The backlight light source array 10 includes multiple backlight light sources, each of which forms an independent small eyebox EB after passing through the off-axis dual mirror module 2 and the imaging concave mirror 5 (see FIG. 7), and all the small eyeboxes EB are combined into the eyebox array EBA. As shown in FIG. 6B, in this eyebox array EBA, the observer's eyes can see a virtual image G_im that is distant from the observer through the imaging semi-reflecting mirror 7.

[0046] As shown in Figure 7, the autostereoscopic image display device includes a backlight module 1, an off-axis dual mirror module 2, a display 3, an imaging concave mirror 5, and an eye tracking module 6. The backlight module 1, the display 3, and the eye tracking module 6 are all connected to a control and calculation module 61, which transmits detection information and control signals.

[0047] The backlight module 1 includes a backlight source array 11 that is configured with a plurality of backlight sources and emits a backlight beam B.

[0048] The off-axis dual mirror module 2 includes a first mirror 21 and a second curved mirror, and reflects the backlight beam B.

[0049] The display 3 (see FIG. 11A) includes a main display module 31 and a light blocking module 4 stacked on top of each other.

[0050] The main display module 31 alternately displays left-eye and right-eye parallax images and defines a plurality of display blocks. The shading module 4 defines a plurality of switching blocks, each corresponding to a display block, and alternately blocks light penetration.

[0051] The backlight beam B passes through the display 3 to form an image beam D.

[0052] The imaging concave mirror 5 reflects the image beam D.

[0053] The gaze tracking module 6 detects relative position information between the left and right eyes of the observer in the gaze tracking module.

[0054] The control and calculation module 61 receives the detection information from the eye tracking module 6 and obtains the left eye position E_L and the right eye position E_R in the observer's space through identification, calculation, table lookup, or estimation. The values ​​may be coordinates in a Cartesian coordinate system, a cylindrical coordinate system, a spherical coordinate system, or other coordinate systems. From the left eye position E_L and the right eye position E_R, the corresponding left eye small eyebox EB_L and right eye small eyebox EB_R are obtained in the eyebox array EBA, and the corresponding left eye backlight light source Led_L and right eye backlight light source Led_R are obtained from the left eye small eyebox EB_L and right eye small eyebox EB_R.

[0055] Light emitted from the backlight source array 11 of the backlight module 1 is reflected by the off-axis dual mirror module 2, the imaging concave mirror 5, and the imaging semi-reflecting mirror 7, and converges on a backlight focusing plane BFP on the side of the imaging semi-reflecting mirror 7 closer to the viewer, forming a backlight source real image, which is an eyebox array EBA including multiple small eyeboxes EB. The main display module 31 displays a parallax image for the left or right eye, and the emitted light is reflected by the imaging concave mirror 5 and the imaging semi-reflecting mirror 7 to form a parallax image virtual image G_im for the left or right eye on an image focal plane IFP on the side of the imaging semi-reflecting mirror 7 farther from the viewer.

[0056] When the main display module 31 displays a left-eye parallax image, it turns on the left-eye backlight light source Led_L, and the shading module 4 switches the switching block. When the main display module 31 displays a right-eye parallax image, it turns on the right-eye backlight light source Led_R, and the shading module 4 switches the switching block. The display blocks of the displayed left-eye parallax image or right-eye parallax image can be displayed in a time-division manner, allowing both the left and right eyes to continuously see a bright and clear left-eye or right-eye parallax image virtual image G_im without crosstalk afterimage, and creating a stereoscopic vision.

[0057] Because the backlight module 1, in combination with the off-axis dual mirror module 2, forms a directional backlight beam, the small eyeboxes EB included in the eyebox array EBA are not only distributed on the backlight focusing plane BFP, but their effective areas extend to the front and rear of the viewer's line of sight. That is, the effective area of ​​the eyebox array EBA extends along both the Z axis. The Z axis is perpendicular to the X axis (horizontal) and the Y axis (vertical). Depending on the current position of the eye, different small eyeboxes EB can be switched, and the effective area of ​​the small eyebox EB shrinks as it moves forward and backward along the Z axis, and becomes smaller the further it is from the backlight focusing plane BFP. In addition, by combining each display block with at least one backlight source located at a different position, it is possible to define another group of multiple small eyeboxes EB_V outside the space of the eyebox array EBA on both sides of the backlight focusing plane BFP, thereby forming a single extended eyebox array EBA_V with a wider range that includes the original eyebox array EBA.The entire extended eyebox array EBA_V includes another group of multiple small eyeboxes EB_V, like a combination of two trapezoidal three-dimensional structures joined to each other at the bottom, so that it covers the possible range of movement when the eyes move up and down, left and right, and back and forth, and a wide-field autostereoscopic image display device can be provided.

[0058] The shading module 4 switches between the switching blocks according to the settings. Each time, it selects one or more switching blocks to be used to shade the display blocks that have not yet been converted on the screen of the main display module 31. By simply not displaying the display blocks that have not yet been converted, no afterimages are displayed, and the left and right eyes can continue to see images without afterimages or crosstalk, thereby realizing a high-quality autostereoscopic image display device.

[0059] The on-time interval of the switching blocks, the number of on-time switching blocks, or the time interval between lighting of the backlight source can be used to adjust the brightness of the image viewed. The more display blocks that are displayed simultaneously, or the longer the display time of each display block, the brighter the image viewed.

[0060] The gaze tracking module 6 detects the relative positions of the observer's left and right eyes and the gaze tracking module using imaging, ultrasound, millimeter-wave radar, laser, or a combination of these detectors. The control and calculation module 61 receives the detection information from the gaze tracking module 6 and obtains the left eye position E_L and the right eye position E_R in the observer's space through identification, calculation, table lookup, or estimation. The values ​​may be coordinates in a Cartesian coordinate system, a cylindrical coordinate system, a spherical coordinate system, or other coordinate systems.

[0061] 8A , if we look only at the eyebox array EBA on the backlight focusing plane BFP without considering the distribution of the small eyeboxes in the Z-axis direction, the eyebox array EBA is composed of many small eyeboxes, and the control and calculation module 61 finds small eyeboxes EB_43 and EB_23 corresponding to the left and right eye positions, respectively, in the eyebox array EBA based on the left eye position E_L and the right eye position E_R. When the main display module 31 displays a left-eye parallax image, the backlight light source Led_43 corresponding to the small eyebox EB_43 is turned on, and when the main display module 31 displays a right-eye parallax image, the backlight light source Led_23 corresponding to the small eyebox EB_23 is turned on.

[0062] As shown in Figure 8B, when the observer moves their head, the corresponding backlight light sources Led_52 and Led_32 are switched on depending on the small eyeboxes EB_52 and EB_32 corresponding to the positions E_L' and E_R' after the eyes move, so that the left and right eyes continue to view the parallax images, forming a stereoscopic vision.

[0063] As shown in FIG. 8C , one eye can correspond to 2n+1 adjacent small eyeboxes EB in the eyebox array EBA, where n>0 and n is a positive integer. For example, one eye can correspond to three (n=1), five (n=2), or seven (n=3) small eyeboxes. Taking three adjacent small eyeboxes as an example, the corresponding central small eyebox EB_93 and its two adjacent small eyeboxes EB_83 and EB_103 are selected according to the position of the pupil of the left eye, and the corresponding central small eyebox EB_43 and its two adjacent small eyeboxes EB_33 and EB_53 are selected according to the position of the pupil of the right eye. When the main display module 31 displays a left-eye parallax image, the backlight sources Led_83, Led_93, and Led_103 corresponding to the small eyeboxes EB_83, EB_93, and EB_103 are simultaneously lit. When the main display module 31 displays a right-eye parallax image, the backlight sources Led_33, Led_43, and Led_53 corresponding to the small eyeboxes EB_33, EB_43, and EB_53 are simultaneously turned on.

[0064] As shown in Figure 8D, when the pupil of the observer's left eye moves left to the position of small eyebox EB_103 and the pupil of the right eye moves left to the position of small eyebox EB_53, three small eyeboxes EB_93, EB_103, and EB_113 are reselected according to the position of the left pupil, and three small eyeboxes EB_43, EB_53, and EB_63 are reselected according to the position of the right pupil. This allows each eye to continue viewing a parallax image, reducing the image interruption that occurs when switching between horizontally adjacent small eyeboxes is not completed in time when the gaze moves quickly horizontally, and avoiding image flicker.

[0065] It can be configured using 2n+1 adjacent small eyeboxes in the left-right (horizontal) or up-down (vertical) direction. The central small eyebox is aligned with the eye pupil to dynamically switch between small eyeboxes. The adjacent small eyeboxes on the left, right, or top and bottom are used as buffers when tracking eye movement.

[0066] When the human eye sees an object, the image of the object is formed on the retina, stimulating the optic nerve, which is converted into a nerve impulse in about 1-2 ms and input to the cerebrum via the optic nerve, giving the person an impression of the object. However, when the object is removed, the impression the optic nerve has of the object does not disappear immediately, but persists for 0.1-0.4 seconds. This property is called the "persistence of visual perception of the eye."

[0067] When the frame rate for still images is faster than 10-16 fps (frames per second), humans perceive the image as continuous and flicker-free. However, for dynamic images, the frame rate must be 24-60 fps so that the brain perceives the image as smooth. Therefore, the image interval per eye must be less than 1 / 24-1 / 60 second, meaning the image pause time Tg must be less than 41.67-16.78 ms. The slower the movement of the scene on the screen, the longer the acceptable image pause time Tg, approaching 41.67 ms. The faster the image movement, the shorter the acceptable image pause time Tg, approaching 16.78 ms until the image appears continuous and flicker-free.

[0068] As shown in Figure 9, when switching between left-eye images and right-eye images using the same liquid crystal display panel, the image interruption time Tg of the two previous and next left-eye images or the two previous and next right-eye images must be 1 / 24 to 1 / 60 seconds or less, i.e., ≦41.67 ms to 16.78 ms.

[0069] In an ideal situation, when the entire screen of the LCD panel is completely switched to the left-eye image, the backlight array also switches to the light source corresponding to the left eye, and when the entire screen of the LCD panel is completely switched to the right-eye image, the backlight array also switches to the light source corresponding to the right eye, and so on.

[0070] As shown in Figure 10A, in actual situations, switching of liquid crystal takes time, and the liquid crystal response time is the rise time Tr + fall time Tf, which respectively refer to the 10% to 90% and 90% to 10% brightness ranges of one pixel. The conversion is not performed simultaneously for all pixels on the screen, but is scanned and switched in order, so there will be a time difference between the conversions of pixels in different areas.

[0071] As shown in Figure 10B, current typical automotive LCD panels have difficulty switching all pixels on the entire screen to the image for the other eye and then back to the image for the original eye within the image interruption time Tg, allowing the backlight to penetrate the entire display panel for at least 2 ms to stimulate the optic nerve and convert it into nerve impulses to display a complete image. During this process, some pixels on the screen will be in the converted state (pix_t), and some will be in the previous image state (pix_p).

[0072] At this time, when the light source corresponding to the backlight array is turned on, the observer may see an image in which the transformed pixel pix_t and the previous state pixel pix_p are mixed, which is known as image retention or crosstalk, and this will have a significant impact on the quality of the observed image and may even cause dizziness or discomfort to the observer.

[0073] 11A and 11B, to solve the above problem, a light-shielding module 4 is superimposed on the light-incident side or light-exiting side of the main display module 31. In this embodiment, the light-shielding module 4 is also a display module. The two display modules are bonded together with an optical clear adhesive (OCA). The backlight beam B must pass through both the main display module 31 and the light-shielding module 4 simultaneously to generate the image beam D.

[0074] When the light incident side of the main display module 31 overlaps with the shading module 4, the multiple switching blocks of the shading module 4 are switched in a time-division manner to control the area through which the backlight beam B can pass through the main display module 31, so that the image of a specific display area is formed by an image beam D and projected.

[0075] When the light emission side of the main display module 31 overlaps with the light blocking module 4, the multiple switching blocks of the light blocking module 4 are switched in a time-division manner, and the image beam D is controlled to pass through only a specific display area and be projected forward.

[0076] For convenience of explanation, the following description will only cover a method of forming the display 3 by overlapping the light-blocking module 4 on the light-incident side of the main display module 31.

[0077] As shown in FIG. 11C, the main display module 31 uses, for example, an IPS (In Plane Switching) color liquid crystal display panel with a wide color gamut, and the light-shielding module 4 uses, for example, a liquid crystal material with a faster response time, such as a TN (Twisted Nematic) black-and-white liquid crystal display panel, whose response time (Tr+Tf) is shorter than that of the IPS liquid crystal.

[0078] As shown in the detailed overlapping structure in FIG. 11D, the main display module 31 includes a lower polarizer 32, a liquid crystal layer 33, and an upper polarizer 34, while the light-blocking module 4 includes a lower polarizer 42, a liquid crystal layer 43, and an upper polarizer 44, with an optical adhesive OCA between the main display module 31 and the light-blocking module 4. The lower polarizer 32 of the main display module 31 and the upper polarizer 34 of the light-blocking module 4 have the same polarization direction. Eliminating one of them maintains the original function of reducing light source loss and cost. Therefore, as shown in FIG. 11E, the upper polarizer 44 of the light-blocking module 4 can be eliminated. Alternatively, as shown in FIG. 11F, the lower polarizer 32 of the main display module 31 can be eliminated.

[0079] A display system that projects parallax images for the left and right eyes requires a high-brightness backlight module 1 because the backlight brightness is evenly divided over time by timing switching. However, approximately 50% of the backlight beam B projected by the backlight module 1 has a polarization direction different from that of the lower polarizer 42 and is absorbed by the lower polarizer 42. The remaining 50% of the light has the same polarization direction as the lower polarizer 42 and passes through the lower polarizer 42 before entering the liquid crystal layer 43. Under the irradiation of the backlight beam B, the lower polarizer 42 absorbs almost half of the energy of the backlight beam B, causing a rapid rise in temperature and easily damaging the light-blocking module 4 and the main display module 31.

[0080] Therefore, by replacing the lower polarizer 42 closest to the light incident side (display 3) with a reflective polarizer 45, light with a different polarization direction from that of the lower polarizer 42 can be reflected and prevented from being absorbed by the lower polarizer 42, significantly reducing the temperature of the light-blocking module 4 and the main display module 31. This allows the use of a brighter backlight module, increasing display brightness, and preventing damage to the light-blocking module 4 and the main display module 31 due to high temperatures. FIG. 11G shows an example in which the lower polarizer 42 of FIG. 11D is replaced with a reflective polarizer 45, FIG. 11H shows an example in which the lower polarizer 42 of FIG. 11E is replaced with a reflective polarizer 45, and FIG. 11I shows an example in which the lower polarizer 42 of FIG. 11F is replaced with a reflective polarizer 45.

[0081] When the display 3 is stacked such that the light-blocking module 4 is stacked on the light-exiting side of the main display module 31, the bottom polarizer 32 closest to the light-incident side is replaced with a reflective polarizer 45.

[0082] As shown in the liquid crystal conversion cycle curve of the main display module 31 in Figure 12A, when a complete cycle of liquid crystal conversion of the main display module 31 is T, the time interval between when image light is projected to the left eye and when the next image light is projected to the left eye is 2T. As shown in Figure 12B, the main display module 31 is a color liquid crystal display panel, and is defined as three display blocks, for example, a first display block IPS_1, a second display block IPS_2, and a third display block IPS_3, each of which includes multiple pixels, and when a pixel is switched ON, it transmits backlight and displays a set color and brightness, and when the pixel is switched OFF, it becomes opaque. The light-blocking module 4 is a black-and-white liquid crystal display panel, and for example, it also defines three switching blocks of the same size, which are the first switching block TN_1, the second switching block TN_2 and the third switching block TN_3, respectively, the first switching block TN_1 corresponds to the first display block IPS_1, the second switching block TN_2 corresponds to the second display block IPS_2, and the third switching block TN_3 corresponds to the third display block IPS_3, and each switching block can include multiple pixels or a single pixel, and when the pixel is switched ON, it transmits light, and when the pixel is switched OFF, it is opaque.

[0083] As shown in Figure 13, the image for the left eye is displayed first. After the liquid crystal of the first display block IPS_1 is turned on, the first switching block TN_1 and the backlight light source for the left eye are turned on. Next, the backlight light source for the left eye and the first switching block TN_1 are turned off, and then the liquid crystal of the first display block IPS_1 is turned off.

[0084] The timing of IPS_2 is slightly slower than that of IPS_1. The switching timings of the second display block IPS_2, the second switching block TN_2, and the left-eye backlight light source are the same as those of the first display block IPS_1, the first switching block TN_1, and the left-eye backlight light source, respectively.

[0085] The timing of IPS_3 is slightly slower than that of IPS_2. The switching timings of the third display block IPS_3, the third switching block TN_3, and the left-eye backlight light source are the same as those of the first display block IPS_1, the first switching block TN_1, and the left-eye backlight light source, respectively.

[0086] After the display of the left-eye image is completed and the first display block IPS_1 liquid crystal is switched OFF, the first display block IPS_1 liquid crystal is switched from OFF to ON to display the right-eye image, and then the first switching block TN_1 and the right-eye backlight light source are switched ON, then the right-eye backlight light source and the first switching block TN_1 are switched OFF, and then the liquid crystal of the first display block IPS_1 is switched OFF.

[0087] The liquid crystal of the second display block IPS_2 is turned OFF, and then turned ON to display the right-eye image. The switching timing of the second display block IPS_2, the second switching block TN_2, and the right-eye backlight light source is the same as that of the first display block IPS_1, the first switching block TN_1, and the right-eye backlight light source, respectively.

[0088] The liquid crystal of the third display block IPS_3 is turned off, and then turned on to display the image for the right eye. The switching timing of the third display block IPS_3, the third switching block TN_3, and the right-eye backlight light source is the same as that of the first display block IPS_1, the first switching block TN_1, and the right-eye backlight light source, respectively.

[0089] The switching order is IPS_1 → IPS_2 → IPS_3 → IPS_1, switching one block each time in this cycle, or switching multiple blocks at once, for example, switching two blocks at once, IPS_1&IPS_2 → IPS_2&IPS_3 → IPS_3&IPS_1 → IPS_1&IPS_2, and so on.

[0090] When the image of a display block is being switched or has not yet been switched (previous eye image), the corresponding backlight light source is turned off or the corresponding switching block is turned off until the image switching is completed, and then the corresponding switching block and the corresponding backlight light source are turned on to avoid projection afterimages.

[0091] Generally speaking, the ON duration of the TN switching block is shorter than the ON duration of the IPS display block, and the ON duration of the backlight source is shorter than the ON duration of each TN switching block. The time interval between the backlight beams projected onto the same eye twice before and after the IPS display block pixel must be shorter than the image interruption time Tg (16.78ms to 41.67ms). That is, the switching interval time of each display block projecting an image beam onto the same eye must be shorter than Tg to meet the visual duration time requirement, resulting in smooth dynamic images.

[0092] The backlight source illuminates the entire display area, and the IPS display blocks, which are switching or not switching (previous eye image), are shielded by the TN switching blocks in the OFF state, preventing the backlight from passing through and preventing the viewer from seeing afterimages or crosstalk.

[0093] As shown in FIG. 14, within the first 1 / 3T (= 1 / 6 × 2T) time, the first display block IPS_1 completes the left-eye image conversion, and the backlight light source corresponding to the left-eye small eyebox is turned on, but only the backlight beam passing through the first switching block TN_1 passes through the first display block IPS_1 to form the left-eye IPS_1 image beam.

[0094] During the second 1 / 3T time, the second display block IPS_2 completes the left-eye image conversion, and the backlight source corresponding to the left-eye small eyebox is turned on, but only the backlight beam passing through the second switching block TN_2 passes through the second display block IPS_2 to form the left-eye IPS_2 image beam.

[0095] During the third 1 / 3T time, the third display block IPS_3 completes the left-eye image conversion, and the backlight light source corresponding to the left-eye small eyebox is turned on, but only the backlight beam passing through the third switching block TN_3 passes through the third display block IPS_3 to form the left-eye IPS_3 image beam.

[0096] At the fourth 1 / 3T time, the first display block IPS_1 completes the right-eye image conversion, and the backlight light source corresponding to the right-eye small eyebox is turned on, but only the backlight beam passing through the first switching block TN_1 passes through the first display block IPS_1 to form the right-eye IPS_1 image beam, thereby circulating.

[0097] The projection effect of FIG. 14 is as shown in FIG. In the first 1 / 3T period, only the image of the first display block IPS_1 is projected to the left eye, and no image is projected to the right eye. During the second 1 / 3T period, only the image of the second display block IPS_2 is projected to the left eye, and no image is projected to the right eye. During the third 1 / 3T period, only the image of the third display block IPS_3 is projected to the left eye, and no image is projected to the right eye. During the fourth 1 / 3T period, no image is projected to the left eye, and only the image of the first display block IPS_1 is projected to the right eye. At the fifth 1 / 3T time, no image is projected to the left eye, and only the image of the second display block IPS_2 is projected to the right eye. At the sixth 1 / 3T period, no image is projected to the left eye, and only the image of the third display block IPS_3 is projected to the right eye. In the seventh 1 / 3T period, only the image of the first display block IPS_1 is projected to the left eye, and no image is projected to the right eye. The projection effect of the seventh 1 / 3T period and the first 1 / 3T period is the same, which creates a cycle.

[0098] The left eye sequentially views each display block IPS_1, IPS_2, and IPS_3 of the left-eye image, combining the images from each display block to form a complete left-eye image. Then, from 16.78 ms to 41.67 ms, the left eye sequentially views each display block of the left-eye image again, with the interval between the two left-eye images for each display block being shorter than the time it takes for the visual afterimage to disappear. Correspondingly, the right eye sequentially views each display block IPS_1, IPS_2, and IPS_3 of the right-eye image, with the interval between the two right-eye images for each display block being shorter than the time it takes for the visual afterimage to disappear. This allows both the left and right eyes to form continuous, smooth images.

[0099] 16A, 16B, and 16C illustrate the imaging of the backlight module 1 and the main display module 31. The white blocks of the backlight module 1 are blocks where LEDs are lit, and also correspond to the small eyeboxes where the eyebox array EBA is lit. The white blocks of the main display module 31 are display blocks that are switched ON, and also correspond to the parallax virtual image G_im that can be seen on the image focal plane IFP.

[0100] As shown in Figure 16A, the backlight light source array of the backlight module 1 emits a backlight beam B, which passes through the shading module 4 and the main display module 31 to form an image beam D, which is reflected by the imaging concave mirror 5, and the backlight light source array of the backlight module 1 forms a backlight light source real image (eye box array EBA) on the backlight focusing plane BFP in front of the imaging concave mirror 5, and the parallax image of the main display module 31 forms a parallax image virtual image G_im behind the imaging concave mirror 5.

[0101] As shown in FIG. 16B, when only the second backlight light source Led_2 of the backlight module 1 is lit, the shading module 4 switches only the first switching block TN_1 to ON, and only the second small eyebox EB_2 can clearly see the image virtual image IPS_1_im of the first display block IPS_1.

[0102] As shown in FIG. 16C, when only the third backlight light source Led_3 of the backlight module 1 is lit, the shading module 4 only turns on the second switching block TN_2 and the third switching block TN_3, and only the third small eyebox EB_3 can clearly see the image virtual images IPS_2_im and IPS_3_im of the second display block IPS_2 and the third display block IPS_3.

[0103] A set of Figures 17A to 21E shows a small eyebox at a specific position formed by a backlight source and a display block. The backlight source shown in the set of figures is a surface light source, and the real image formed is a surface real image on the focal plane.

[0104] When only the first backlight light source Led_1 is lit, the optical paths shown in Figures 17A to 17C are displayed in combination with the first display block IPS_1, the second display block IPS_2, and the third display block IPS_3, and the image beams in these optical paths are focused on the first small eyebox EB_1.

[0105] As shown in Figure 17D, the optical paths in Figures 17A to 17C overlap to form an intersection region, defined as a small eyebox EB_1V. The intersection region, like the small eyebox EB_1V shown in Figure 17E, which is the intersection of the three shaded regions, has a volume in three-dimensional space and gradually decreases in volume toward the front and rear. When the backlight light source and display block combinations shown in Figures 17A to 17C, i.e., IPS_1 and Led_1, IPS_2 and Led_1, and IPS_3 and Led_1, are combined and displayed in sequence, the images of IPS_1 to IPS_3 are visible in the small eyebox EB_1V region, i.e., the complete image is visible.

[0106] When only the second backlight light source Led_2 is lit, the optical paths shown in Figures 18A to 18C are displayed in combination with the first display block IPS_1, the second display block IPS_2, and the third display block IPS_3, and the image beams in these optical paths are focused on the second small eyebox EB_2.

[0107] As shown in Figure 18D, the optical paths in Figures 18A to 18C are overlapped to form an intersection region, which is defined as the small eyebox EB_2V, as shown by the intersection of the three shaded regions in Figure 18E. The state of the small eyebox EB_2V is similar to the state of the small eyebox EB_1V in Figures 17D and 17E. If the combinations of backlight sources and display blocks shown in Figures 18A to 18C, i.e., IPS_1 and Led_2; IPS_2 and Led_2; and IPS_3 and Led_2, are combined and displayed in sequence, the images of IPS_1 to IPS_3 will be visible in the small eyebox EB_2V region, i.e., the complete image will be visible.

[0108] When only the third backlight light source Led_3 is lit, the optical paths shown in Figures 19A to 19C are displayed in combination with the first display block IPS_1, the second display block IPS_2, and the third display block IPS_3, and the image beams in these optical paths are focused on the third small eyebox EB_3.

[0109] As shown in Figure 19D, the optical paths in Figures 19A to 19C are overlapped to form an intersection region, defined as small eyebox EB_3V. As shown by the intersection of the three shaded regions in Figure 19E, the state of small eyebox EB_3V is similar to the state of small eyebox EB_1V in Figures 17D and 17E. When the backlight source and display block combinations shown in Figures 19A to 19C, i.e., IPS_1 and Led_3, IPS_2 and Led_3, and IPS_3 and Led_3, are combined and displayed in sequence, the images of IPS_1 to IPS_3 are visible in the area of ​​small eyebox EB_3V, i.e., the complete image can be seen.

[0110] When a directional backlight beam is used, the image beams passing through the small eyeboxes EB_1, EB_2, and EB_3 become closer to parallel, and the small eyeboxes EB_1V, EB_2V, and EB_3V become correspondingly longer and have larger volume areas, which can accommodate different eye positions in the front-to-back direction and widen the visible area.

[0111] Each optical path shown in Figures 20A to 20C is combined with the first backlight light source Led_1, the second backlight light source Led_2, and the third backlight light source Led_3, respectively, and the image beams of these optical paths are focused on the first small eyebox EB_1, the second small eyebox EB_2, and the third small eyebox EB_3, respectively.

[0112] As shown in Figure 20D, the optical paths of Figures 20A to 20C overlap to form an intersection region, defined as small eyebox EB_123_123V. The intersection region has a volume in three-dimensional space and is located between the imaging concave mirror 5 and the small eyeboxes EB_1, EB_2, and EB_3. The intersection region is a small eyebox that gradually shrinks toward the rear, as shown by the small eyebox EB_123_123V indicated by the intersection of the three shaded regions in Figure 20E. Figures 20A to 20C show the combinations of backlight sources and display blocks, namely, IPS_1 and Led_1, IPS_2 and Led_2, and IPS_3 and Led_3, which are displayed in sequence. Images from IPS_1 to IPS_3 are visible in the small eyebox EB_123_123V region, i.e., the complete image can be seen. This allows for different positions of the eye forward, thereby widening the visible area.

[0113] Each of the optical paths shown in Figures 21A to 21C combines the third backlight light source Led_3, the second backlight light source Led_2, and the first backlight light source Led_1 with the first display block IPS_1, the second display block IPS_2, and the third display block IPS_3, respectively, and the image beams of these optical paths are focused on the third small eyebox EB_3, the second small eyebox EB_2, and the first small eyebox EB_1, respectively.

[0114] As shown in Figure 21D, the optical paths of Figures 21A to 21C overlap to form an intersection region, which is defined as small eyebox EB_123_321V, as shown in the shaded area of ​​Figure 21E. The intersection region has a volume in three-dimensional space and is located behind small eyeboxes EB_1, EB_2, and EB_3. It is a small eyebox that gradually shrinks both forward and backward, as shown by small eyebox EB_123_321V, which is shown as the intersection of the three shaded areas in Figure 21E. Figures 21A to 21C show the combination of a backlight source and a corresponding display block. Images from IPS_1 to IPS_3 are all visible only in the small eyebox EB_123_321V region, i.e., the complete image can be seen. This can accommodate different positions behind the eye, thereby widening the visible area.

[0115] As can be seen from Figures 17A to 21E, each display block is combined with at least one backlight source at a different position to define multiple small eyeboxes EB_V, including the original eyebox array EBA, outside the eyebox array EBA space on both sides of the backlight focusing plane BFP. This forms a wider extended eyebox array EBA_V, i.e., a three-dimensional array including more small eyeboxes EB_V. The effective area of ​​the small eyeboxes EB_V extends in the front-to-back direction along the Z axis. By switching between different backlight sources and different display blocks, image beams can be projected onto small eyeboxes EB_V at different positions. Even if the eyes are positioned outside the backlight focusing plane, different small eyeboxes EB_V can be selected to accommodate vertical, horizontal, and front-to-back movement of the eyes. As long as the left-eye or right-eye parallax image virtual image is visible within the extended eyebox array EBA_V, a wide-viewing-area autostereoscopic image display device is provided. In the extended eyebox array EBA_V, 2n+1 adjacent small eyeboxes EB_V in the left-right or up-down direction correspond to the left or right eye and function as buffers when tracking eye movement.

[0116] As shown in Figures 22A and 22B, the backlight module 1, main display module 31 and shading module 4, combined with the reflection of the imaging semi-reflecting mirror 7 (windshield), project images onto the small eyeboxes EB_V of the extended eyebox array EBA_V according to different positions of the observer's eyes, allowing the observer to view a complete parallax image virtual image G_im without image retention, crosstalk or image interruption, thereby realizing a high-quality naked-eye stereoscopic image display device.

[0117] As shown in Figures 23A and 23B, the small eyeboxes EB_V included in the wide-field extended eyebox array EBA_V are not only distributed on the backlight focusing plane (the XY plane at Z=0), but also extend beyond the viewer's line of sight, extending for example 20 cm in front and behind (Z=20 to Z=-20). The distribution area shrinks slightly as it moves away from the backlight focusing plane. The extended eyebox array EBA_V resembles a combination of two trapezoidal 3D structures joined together at their bases, covering the range of visible eye movement required for an autostereoscopic image display device. The relationships between the small eyeboxes EB_V at different positions in the extended eyebox array EBA_V, the corresponding backlight sources of the backlight module 1, and the display blocks of the main display module 31 can be obtained through simulation or actual measurement, and a small eyebox-display block-backlight source matrix table can be created. The small eyebox-display block-backlight source matrix table can be stored, for example, in the control and calculation module 61 or in a storage device connected to the control and calculation module 61, and the table can be referenced during actual operation.

[0118] As shown in FIG. 24A, in this embodiment, the backlight module 1 has 7×3 backlight light sources (Led_11 to Led_73) forming an array. The light blocking module 4 has three switching blocks TN_1, TN_2, and TN_3 on the light incident side of the main display module 31. The main display module 31 also has three display blocks IPS_1, IPS_2, and IPS_3, each corresponding to the switching blocks TN_1, TN_2, and TN_3. For example, as shown in FIG. 24B, the distribution of small eyeboxes with Z=0 in the extended eyebox array EBA_V is shown. The observer's eyes are located on a plane with a Z coordinate of 0 cm. The left eye corresponds to the small eyebox EB_V(0,0,0), and the right eye corresponds to the small eyebox EB_V(4,0,0). For example, as shown in FIG. 24C, the distribution of small eyeboxes with Z=20 in the extended eyebox array EBA_V is shown. The observer's eyes are located on a plane with a Z coordinate of 20 cm. The left eye corresponds to the small eyebox EB_V(-2,-1,20), and the right eye corresponds to the small eyebox EB_V(2,-1,20).

[0119] A small eyebox-display block-backlight source matrix table can be obtained through simulation or actual measurement. For example, the small eyebox-display block-backlight source matrix table MT shown in FIG. 25A is a matrix table of backlight sources (LEDs) corresponding to small eyeboxes (EB_V) at different positions in the X-axis direction and different display blocks (IPS) when Y=2 and Z=0. The small eyeboxes (EB_V) at these positions are close to the backlight focusing surface (XY plane at Z=0) of the extended eyebox array EBA_V, and the backlight sources (LEDs) of the display blocks (IPS) corresponding to the same small eyebox (EB_V) are all backlight sources at the same position. For example, when the left eye is located in the small eyebox EB_V(4,2,0), the matrix for the left eye is as follows:

[0120]

number

[0121] 25B shows another portion of the small eyebox-display block-backlight source matrix table MT, which is a matrix table of backlight source (LED) corresponding to small eyeboxes (EB_V) at different positions in the X-axis direction and different display blocks (IPS) when Y=-2 and Z=10. The small eyeboxes (EB_V) at these positions are far away from the backlight collection plane (XY plane at Z=0) of the extended eyebox array EBA_V, and the backlight source (LED) corresponding to the display block (IPS) of the same small eyebox (EB_V) may correspond to a backlight source at the same position, such as EB_V(0,-2,10), or may correspond to a backlight source at a different position. For example, when the left eye is in the small eyebox EB_V(4,-2,10), the matrix for the left eye is as follows:

[0122]

number

[0123] The control and calculation module 61 obtains the detection information of the left and right eyes from the gaze tracking module 6 to obtain the position coordinates of the left and right eyes, and then obtains the corresponding left and right small eyeboxes from the position coordinates of the left and right eyes.Then, from these small eyebox-display block-backlight source matrix table MT, it finds the display block-backlight source matrix corresponding to the current left small eyebox and the display block-backlight source matrix corresponding to the current right small eyebox, and selects to switch the display block and backlight source, so that the entire virtual image of the left eye's parallax image is shown to the observer's left eye, and the entire virtual image of the right eye's parallax image is shown to the right eye, forming a naked-eye stereoscopic image.

[0124] Turning on all the switching blocks is equivalent to removing the shading module 4. In this case, only the small eyebox-backlight source matrix table is used, and each eye can correspond to one or more small eyeboxes. The control and calculation module 61 obtains the left and right eye position coordinates by obtaining the left and right eye detection information from the gaze tracking module 6, and then obtains the corresponding left and right eyeboxes from the left and right eye position coordinates. Then, from the small eyebox-backlight source matrix table MT, it finds the left-eye backlight source corresponding to the current left eye small eyebox and the right-eye backlight source corresponding to the current right eye small eyebox, and combines it with the display module to switch between the left-eye backlight source and the right-eye backlight source, so that the entire left-eye virtual parallax image is displayed to the viewer's left eye and the entire right-eye virtual parallax image is displayed to the right eye, forming a naked-eye stereoscopic image.

[0125] When only the backlight module 1 and the off-axis dual mirror module 2 are present in the projection optical path, the directional backlight can penetrate the light beam intersection area of ​​the display panel and further expand in the front-to-back direction, and the shading module 4 is not present (similar to Figures 17E, 18E, and 19E). Not only can the complete image be seen in the eyebox area on the focal plane, but the complete image can also be seen in the intersection area extending forward and backward in the Z-axis direction. That is, the effective area of ​​the small eyeboxes expands in the Z-axis direction. As the eye moves along the Z-axis, it may enter the small eyebox area. When the backlight module 1, the off-axis dual mirror module 2, and the shading module 4 are present in the projection optical path, another group of multiple small eyeboxes can be defined in a wider range outside the intersection of all beams (see Figures 20E and 21E), allowing the complete image to be seen over a wider range. That is, when the projection optical path is composed of only the backlight module 1 and the off-axis dual mirror module 2, the range of the eyebox array extending forward and backward in the Z-axis direction is narrower. When combined with the light blocking module 4, the formed extended eyebox array has a wider range extending forward and backward in the Z-axis direction.

[0126] From a timing perspective, examples of system control switching are shown in FIGS. 26A to 26D. As shown in Figure 26A, all the different display blocks corresponding to the left eye correspond to the same backlight source Led_42, and all the different display blocks corresponding to the right eye correspond to the same backlight source Led_62. The control timing is such that, since a parallax image is displayed to the left eye first, the image of the first display block IPS_1 is first switched ON, then the first switching block TN_1 is switched ON, and finally the backlight source Led_42 is switched ON. At this time, the small eyebox EB_V(0,0,0) corresponding to the left eye sees the image of the first display block IPS_1, and then the blocks are switched OFF in the reverse order.

[0127] After the image of the first display block IPS_1 starts to be switched ON, the image of the second display block IPS_2 is switched ON, the second switching block TN_2 is switched ON, and the backlight light source Led_42 is switched ON. At this time, the small eyebox EB_V(0,0,0) corresponding to the left eye sees the image of the second display block IPS_2 and then switches OFF in the reverse order.

[0128] After the second display block IPS_2 image starts to turn on, the third display block IPS_3 image turns on, the third switching block TN_3 image turns on, and the backlight light source Led_42 image turns on in turn. At this time, the small eyebox EB_V(0,0,0) corresponding to the left eye sees the image of the third display block IPS_3 and turns off in the reverse order.

[0129] When a viewer views a parallax image with their left eye, the corresponding switching block switches ON after a display block switches ON, and the corresponding display block starts switching OFF after the switching block switches OFF. The backlight source Led_42 illuminates the entire display 3, but the switching block blocks the display blocks that are being converted or not being displayed, so the viewer does not see an afterimage of the display block that is being converted. Furthermore, when a parallax image is displayed for the left eye, only the backlight source Led_42 corresponding to the left eye is lit, and when a parallax image is displayed for the right eye, only the backlight source Led_62 corresponding to the right eye is lit. This prevents the left and right eyes from seeing each other's parallax images, and prevents crosstalk. The backlight beam penetration time for each display block is controlled to be the same, and the brightness of the entire screen is adjusted to be uniform.

[0130] As shown in FIG. 26B, to increase the brightness of the image viewed by the human eye, the time the switching block in FIG. 26A is turned on and the time the backlight source is turned on can be synchronized to increase the time the backlight source penetrates the display block, thereby improving brightness. That is, the brightness of the image can be changed by changing the length of time the light is projected onto the display block. The longer the display time the backlight source penetrates the display block, the higher the image brightness, and the shorter the display time the backlight source penetrates the display block, the lower the image brightness. In this case, there is no temporal overlap between the switching blocks, and this can be applied when the display blocks correspond to the same backlight source or different backlight sources. The backlight beam penetration time for each display block is controlled to be the same, adjusting the brightness of the entire image to be uniform.

[0131] As shown in Figure 26C, when the display blocks of the same eye all correspond to the same backlight source, in order to further improve the brightness of the image, the time for which the switching block is turned ON can be extended, so that the switching block is turned ON after the display block is turned ON and turned OFF just before the display block is turned OFF, so that the backlight source is turned on when the first switching block TN_1 is turned ON and turned off only when the third switching block is turned OFF. The backlight beam penetration time of each display block is controlled to be the same, and the brightness of the entire image is adjusted to be uniform.

[0132] As shown in Figure 26D, when the display blocks of the same eye correspond to different backlight sources, each backlight source changes the image brightness by turning on the backlight source for the entire period when the corresponding switching block is on, or by turning on the backlight source for a partial period when the corresponding switching block is on. The longer it takes for the backlight source to penetrate the display block, the brighter the image will be, and the shorter it takes for the backlight source to penetrate the display block, the less bright the image will be. The backlight beam penetration time for each display block is controlled to be the same, so that the brightness of the entire screen is uniform.

[0133] In this way, the problems of image retention and crosstalk in autostereoscopic image display devices can be effectively solved, the observer is less likely to experience dizziness, and the observed image quality is improved.

[0134] By combining all the above technical features, the problems faced by conventional naked-eye stereoscopic image display devices are improved, afterimages and crosstalk are eliminated, image brightness is improved, screen brightness is made uniform, image flicker is avoided, and the visible range is expanded, thereby realizing a naked-eye stereoscopic image display device that best meets the requirements of moving bodies such as vehicles, ships, and aircraft. [Explanation of symbols]

[0135] [Prior art] 01 Backlight source 03 Display panel 5 Imaging concave mirror 6. Eye Tracking Module 61 Control and calculation module 7 Imaging semi-reflector G_im Image virtual image B. Directional backlight beam D directional image beam EB Eyebox EBA Eyebox Array WS Windshield C Combiner E_L Eye position E_R Eye position EB_L Left eye small eye box EB_R Right eye small eye box [The present invention] 1 Backlight Module 1_im Backlight source virtual image 10 Backlight light source array 11 Backlight light source array 10_im Backlight light source array virtual image 10_re Backlight light source array real image 12 conical light cup array 13 LED 13T polarized lens array 13L Condenser Lens Array 14 Condenser lens 2 Off-axis Dual Mirror Modules 21 1st mirror 22 Second curved mirror 221 Boundary 3. Display 31 Main display module 32 Lower polarizer 33 Liquid crystal layer 34 Upper polarizer 4. Shading module 42 Lower polarizer 43 Liquid crystal layer 44 Upper polarizer 45 Reflective Polarizer 5 Imaging concave mirror 6. Eye Tracking Module 61 Control and calculation module 7 Imaging semi-reflector B Backlight beam BFP backlight condensing surface D Image Beam EB Small Eye Box EB_1, EB_2, EB_3, EB_11~EB144, EB_V Small Eye Box EB_1V, EB_2V, EB_3V, EB_123_123V, EB_123_321V Small Eye Box EB_L Small Eye Box EB_R Small Eye Box EBA Eyebox Array EBA_V Extended Eyebox Array E_L Left eye position E_L' Left eye position E_R Right eye position E_R' Right eye position G_im Image virtual image IFP Image Focal Plane IPS_1 display block IPS_2 display block IPS_3 display block IPS_1_im Image virtual image IPS_2_im Image virtual image IPS_3_im Image virtual image Led_1, Led_2, Led_3, Led_11~Led144 Backlight light source LED_L backlight light source LED_R backlight source MC mirror center MT Small Eyebox - Display Block - Backlight Light Source Matrix Table OA optical axis OCA Optical Adhesive pix_p pixels pix_t pixels TN_1 Switching Block TN_2 switching block TN_3 Switching Block

Claims

1. A backlight real image forming autostereoscopic image display device suitable for use in combination with an imaging semi-reflecting mirror, comprising: a backlight module including a backlight source array configured with a plurality of backlight sources and emitting a backlight beam; an off-axis dual mirror module including a first mirror and a second curved mirror whose optical axes are offset from each other, the first mirror and the second curved mirror sequentially reflecting the backlight beam to form a directional backlight beam; a display module that alternately displays left-eye parallax images and right-eye parallax images and forms an image beam after the directional backlight beam passes through; an imaging concave mirror that reflects the image beam; Including, the off-axis dual mirror module is used to make the backlight light source array form a backlight light source array virtual image, the equivalent distance between the backlight light source array virtual image and the imaging concave mirror is greater than the focal length of the imaging concave mirror, the backlight beam corresponding to the backlight light source array virtual image is reflected by the imaging concave mirror and the imaging semi-reflecting mirror, and then projected and converged on a backlight focusing plane to form a backlight light source array real image, each of the backlight light sources forms an independent small eyebox, and all the small eyeboxes constitute the backlight light source array real image and define an eyebox array.

2. 2. The naked-eye three-dimensional image display device for backlight real image formation according to claim 1, wherein an equivalent distance between the display module and the imaging concave mirror is smaller than a focal length of the imaging concave mirror, and a left-eye parallax image virtual image and a right-eye parallax image virtual image are formed on the side of the imaging semi-reflecting mirror away from the eyebox array based on the left-eye parallax image and the right-eye parallax image, respectively.

3. 2. The naked-eye three-dimensional image display device for backlight real image formation according to claim 1, wherein the effective area of ​​each small eyebox extends on both sides of the backlight focusing surface, and the small eyeboxes gradually shrink along the front-to-back direction of the backlight focusing surface.

4. 2. The autostereoscopic display device for backlit real image formation according to claim 1, wherein the backlight module further comprises a cone-shaped light cup array composed of cone-shaped light cups having different inclination angles, the inclination angle of each of the cone-shaped light cups increasing with increasing distance from the center of the array.

5. 2. The autostereoscopic display device for backlight real image formation according to claim 1, wherein the backlight module further comprises a conical light cup array, a polarizing lens array, and a condensing lens array, which are arranged in this order from the light output side of the backlight light source array.

6. 2. The naked-eye three-dimensional image display device for backlight real image formation according to claim 1, wherein different small eyeboxes are switched to correspond to the displacement amount of the eye, and the displacement amount of the eye includes displacement in two dimensions or displacement in three dimensions.

7. 2. The autostereoscopic image display device for backlight real image formation according to claim 1, wherein a switching interval time for alternately displaying the left-eye parallax image and the right-eye parallax image of the display module is shorter than 41.67 ms.

8. 2. The autostereoscopic image display device for backlight real image formation according to claim 1, wherein the imaging semi-reflecting mirror is a windshield or a combiner.

9. 2. The naked-eye three-dimensional image display device for backlight real image formation according to claim 1, wherein the second curved mirror is a concave mirror, the first mirror is a concave mirror, a convex mirror or a plane mirror, and the imaging position of the backlight module after reflection by the first mirror is within the focal length of the second curved mirror.

10. 10. The autostereoscopic display device for backlit real image formation described in claim 9, wherein the backlight beam is defined as a first optical path between the backlight module and the first mirror, and the backlight beam is defined as a second optical path from the second curved mirror to the display module, and the first optical path intersects with the second optical path.

11. an eye tracking module that detects relative position information between the left and right eyes; a control and calculation module connected to the backlight module, the display module and the gaze tracking module, for obtaining detection information from the gaze tracking module, obtaining a left eye position and a right eye position, obtaining a left eye small eyebox and a right eye small eyebox according to the left eye position, the right eye position and the eyebox array, and then obtaining a corresponding left eye backlight light source and a right eye backlight light source according to a small eyebox-backlight light source matrix table; Further comprising: The left-eye backlight light source and the right-eye backlight light source are configured to project the image beam of the left-eye parallax image onto the left eye position, and project the image beam of the right-eye parallax image onto the right eye position, respectively. A naked-eye stereoscopic image display device for backlight real image formation as described in any one of claims 1 to 10.

12. 12. The autostereoscopic image display device for backlight real image formation according to claim 11, wherein the eyebox array defines 2n+1 small eyeboxes adjacent to each other corresponding to the left eye position or the right eye position, n>0 and n is a positive integer, a central small eyebox among the 2n+1 small eyeboxes is aligned with the pupil of one eye, and the other 2n small eyeboxes are distributed on both sides above and below or on both sides to the left and right of the central small eyebox.

Images