Directional backlight display device with mirror curvature auxiliary diffuser

Abstract

A directional backlight display device with a mirror curvature assisted diffuser includes a light source module, a reflective narrow-angle diffuser, a concave mirror, and a backlit display panel. The light source module is configured to project light. The reflective narrow-angle diffuser has a concave or flat surface as a reflecting surface, and the reflecting surface has an array of micro-curved mirrors. The light is reflected and diffused by the reflective narrow-angle diffuser and the concave mirror to become a uniform directional light beam. The backlit display panel is configured to display an image. After the uniform directional light beam passes through the backlit display panel, it becomes a directional image light beam and is projected to a projection area. Such a configuration can use a reflective narrow-angle diffuser with a low concave curvature to achieve high directional image projection.

Description

Technical Field

[0001] This invention relates to a directional backlight display device with a reflector curvature-assisted diffuser sheet. By using a low-curvature or planar reflective narrow-angle diffuser sheet, and combining it with a high-curvature concave reflector sheet to assist the missing concave curvature, highly directional image projection can be achieved. This reduces the manufacturing difficulty of the diffuser sheet, improves the yield, and reduces costs. Background Technology

[0002] like Figure 1 As shown, US20180252915A1 is the applicant's application. The function of the reflective narrow-angle diffuser 2 is to reflect and diffuse the image projected by the projector 41 into the viewer's eyes at a narrow angle, thereby improving light utilization and increasing the brightness of the viewed image.

[0003] In this system, each pixel of the image is reflected and diffused through a reflective narrow-angle diffuser, ensuring uniform diffusion to the viewer's eye area. The aforementioned projector 41 can be an LCD projector, a DLP projector, or a laser projector.

[0004] like Figure 2 As shown, the reflective narrow-angle diffuser 2 can be planar or curved, and the reflective narrow-angle diffuser 2 has an array of multiple micro-curved mirrors 200 arranged in a square or hexagonal honeycomb pattern (i.e., Figure 7A The reflective narrow-angle diffuser 20 shown has a size of 2.5um to 0.25mm for each micro-curved mirror 200.

[0005] Each micro-curved mirror 200 may have the same or different curvature and angle.

[0006] The quantity of these 200 micro-curved mirrors can be customized according to the resolution and optical path design requirements.

[0007] like Figure 3A As shown, the surface of a plane mirror is flat and smooth. The incident angle of the incident light is equal to the reflection angle of the reflected light, so the diffusion angle of the beam remains unchanged, there is no diffusion effect, and the viewing angle is limited.

[0008] In order for viewers from all angles to see the projection screen as a flat surface, a wide scattering surface is needed to diffuse the light projected onto the flat surface in all directions, such as... Figure 3B As shown, it also significantly reduces image brightness.

[0009] like Figure 3C As shown, the micro-curved mirror of the reflective narrow-angle diffuser can diffuse incident light in a predetermined direction with a predetermined and narrow diffusion angle θ2, thus significantly improving the brightness of the viewed image within the predetermined direction and diffusion angle θ2 range. The reflective surface of the micro-curved mirror can be concave or convex.

[0010] like Figure 4A The light source shown is a directional light source after the light source 11 is focused, which easily leads to uneven brightness, such as higher brightness in the center and lower brightness around the edges. To improve this problem, another invention of the applicant projects the light source 11 onto a reflective narrow-angle diffuser, such as... Figure 4B As shown, the light reflected by the micro-curved mirror array can diffuse in a predetermined direction with a narrow diffusion angle, producing a directional light source with uniform brightness.

[0011] like Figure 5A , Figure 5B The reflective narrow-angle diffuser shown is a hyperbolic concave surface, which means it is a concave surface that is curved in both the X-axis and Y-axis sections.

[0012] Based on the magnitude of the concave curvature, it can be divided into planes with no curvature at all, such as... Figure 6D It has a slightly concave surface with low curvature, such as Figure 6B and Figure 6C and concave surfaces with high curvature, such as Figure 6A .

[0013] The aforementioned reflective narrow-angle diffuser can be manufactured using rigid materials (such as metals, ceramics, or rigid polymers) through molding, but the cost is high.

[0014] like Figure 7A As shown, another method for manufacturing a diffuser sheet is to first create a planar structure with an array of micro-curved mirrors 200 using an elastic material (such as rubber or elastic polymer material), then coat it with a reflective film to form a planar reflective narrow-angle diffuser sheet 20, and finally create a hyperbolic concave substrate S1 using a rigid material. The elastic planar reflective narrow-angle diffuser sheet 20 is then attached to the hyperbolic concave substrate S1 to form a reflective narrow-angle diffuser sheet 21 with a hyperbolic concave surface.

[0015] Before bonding, because air exists between the planar reflective narrow-angle diffuser 20 and the hyperbolic concave substrate S1, even with multiple evacuation holes on the substrate, air can still easily remain during bonding. These residual air bubbles cannot be eliminated after bonding, affecting the flatness of the reflective surface and making it difficult to control the deformation of each micromirror, thus impacting the quality of the optical image and reducing yield. The greater the curvature of the concave surface of the substrate S1, the higher the manufacturing difficulty and the more severe the problems. Although the bonding process can be performed in a high-vacuum environment by pre-fixing the planar reflective narrow-angle diffuser 20 onto the convex fixture T1, such as... Figure 8A As shown, this method solves the problem of residual bubbles, but it is costly and requires expensive equipment. Summary of the Invention

[0016] This invention provides a low-curvature reflective narrow-angle diffuser, paired with a high-curvature concave mirror as an auxiliary element, replacing the hyperbolic concave reflective narrow-angle diffuser and generating a directional light source. This reduces the manufacturing difficulty of the diffuser, improves the yield rate, and reduces costs.

[0017] like Figure 4C As shown, the aforementioned directional light source can serve as the backlight source for a backlit display panel, projecting and diffusing the image of the backlit display panel onto a defined eye box area, so that the light passing through each pixel on the backlit display panel can diffuse to the entire eye box area.

[0018] The present invention also provides a directional backlight display device with a reflector curvature-assisted diffuser, comprising:

[0019] A light source module projects a beam of light;

[0020] A reflective narrow-angle diffuser has a hyperbolic and low-curvature micro-concave surface formed along two perpendicular axes as a reflective surface, which has an array of multiple micro-curved mirrors.

[0021] A concave mirror forms a hyperbolic concave surface along two perpendicular axes. The two axes of the concave surface correspond to the two axes of the micro-concave surface of the reflective narrow-angle diffuser. The concave mirror assists the curvature of the micro-concave surface of the reflective narrow-angle diffuser to make the light beam a uniformly directional beam through reflection and diffusion by the reflective narrow-angle diffuser and the concave mirror.

[0022] A backlit display panel displays an image. The diffused beam of light passes through the backlit display panel and becomes a directional image beam, which is projected onto a projection area (i.e., the eye box range of a viewer).

[0023] The concave reflector is placed between the light source module and the reflective narrow-angle diffuser. The hyperbolic concave surface of the concave reflector converges the light for the first time and then reflects it to the reflective narrow-angle diffuser. The hyperbolic micro-concave surface of the reflective narrow-angle diffuser converges the light for the second time and diffuses the light at each point at a narrow angle. This ensures that the uniformly directional light beam after reflection and diffusion can have high directivity and be projected into the projection area after passing through the backlight display panel.

[0024] Alternatively, the concave reflector can be placed between the reflective narrow-angle diffuser and the backlight display panel, so that the hyperbolic concave surface of the reflective narrow-angle diffuser first converges the light and diffuses the light at each point at a narrow angle, and then reflects it to the concave reflector, so that the hyperbolic concave surface of the concave reflector converges the light a second time, so that the homogeneous directional light beam after reflection and diffusion can have high directivity and be projected into the projection area after passing through the backlight display panel.

[0025] The curvature of the micro-concave surface of the reflective narrow-angle diffuser along both axes is smaller than the curvature of the concave surface of the concave mirror along both axes.

[0026] The curvature of the micro-concave surface of the reflective narrow-angle diffuser along one of its axes is less than the curvature of the concave surface of the concave mirror along the corresponding axis, and the curvature of the micro-concave surface of the reflective narrow-angle diffuser along another axis is greater than the curvature of the concave surface of the concave mirror along the corresponding axis.

[0027] The present invention also provides a directional backlight display device with a reflector curvature-assisted diffuser, comprising:

[0028] A light source module projects a beam of light;

[0029] A reflective narrow-angle diffuser has a concave surface formed along a single axis as a reflective surface, which has an array of multiple micro-curved mirrors.

[0030] A concave mirror has a single curved concave surface formed along a single axis, the axis of which is perpendicular to the axis of the concave surface of the reflective narrow-angle diffuser. The concave mirror assists the concave surface of the reflective narrow-angle diffuser in lacking axial curvature, so that the light is reflected and diffused by the reflective narrow-angle diffuser and the single curved concave mirror to become a uniformly directional beam.

[0031] A backlit display panel displays an image. The diffused beam of light passes through the backlit display panel and becomes a directional image beam, which is projected onto a projection area (i.e., the eye box range of a viewer).

[0032] The concave reflector is placed between the light source module and the reflective narrow-angle diffuser. The concave surface of the concave reflector converges the light for the first time and then reflects it to the reflective narrow-angle diffuser. The reflective narrow-angle diffuser then converges the light a second time on the concave surfaces of different axes and diffuses the light at each point at a narrow angle. This ensures that the uniformly directional light beam after reflection and diffusion can have high directivity and be projected into the projection area after passing through the backlight display panel.

[0033] The concave reflector can also be placed between the reflective narrow-angle diffuser and the backlight display panel. The concave surface of the reflective narrow-angle diffuser will first converge the light and then diffuse the light at each point at a narrow angle before reflecting it to the concave reflector. The concave reflector will then converge the light a second time on the concave surfaces of different axes. This will ensure that the uniformly directional light beam after reflection and diffusion can have high directivity and be projected into the projection area after passing through the backlight display panel.

[0034] The axial direction of the concave surface of the reflective narrow-angle diffuser can correspond to the vertical direction, horizontal direction, 45-degree oblique direction, or any other direction of the displayed image.

[0035] The present invention also provides a directional backlight display device with a reflector curvature-assisted diffuser, comprising:

[0036] A light source module projects a beam of light;

[0037] A reflective narrow-angle diffuser has a single-curved, low-curvature micro-concave surface formed along a single axis as a reflective surface, which has an array of multiple micro-curved mirrors.

[0038] A concave mirror forms a hyperbolic concave surface along two perpendicular axes. One of the axes of the concave surface is parallel to the axis of the micro-concave surface of the reflective narrow-angle diffuser. The concave mirror assists the concave surface of the reflective narrow-angle diffuser in providing the curvature of the axis that is insufficient or lacking, so that the light is reflected and diffused by the reflective narrow-angle diffuser and the concave mirror into a uniformly directional beam.

[0039] A backlit display panel displays an image. The diffused beam of light passes through the backlit display panel and becomes a directional image beam, which is projected onto a projection area (i.e., the eye box range of a viewer).

[0040] The concave reflector is placed between the light source module and the reflective narrow-angle diffuser. The hyperboloid of the concave reflector converges the light for the first time and then reflects it to the reflective narrow-angle diffuser. The single-curved micro-concave surface of the reflective narrow-angle diffuser converges the light for the second time and diffuses the light at each point at a narrow angle. This ensures that the uniformly directional light beam after reflection and diffusion can have high directivity and be projected into the projection area after passing through the backlight display panel.

[0041] The concave reflector can also be placed between the reflective narrow-angle diffuser and the backlight display panel. The single-curved micro-concave surface of the reflective narrow-angle diffuser will first converge the light and then diffuse the light at each point at a narrow angle before reflecting it to the concave reflector. The hyperbolic concave surface of the concave reflector will then converge the light a second time, so that the homogeneous directional light beam after reflection and diffusion can have high directivity and be projected into the projection area after passing through the backlight display panel.

[0042] The axial direction of the micro-concave surface of the reflective narrow-angle diffuser can correspond to the vertical direction, horizontal direction, 45-degree oblique direction, or any direction of the displayed image.

[0043] The present invention also provides a directional backlight display device with a reflector curvature-assisted diffuser, comprising:

[0044] A light source module projects a beam of light;

[0045] A reflective narrow-angle diffuser has a planar reflective surface with an array of multiple micro-curved mirrors on the reflective surface;

[0046] A concave mirror forms a hyperbolic concave surface along two perpendicular axes. The concave mirror assists the curvature missing in the two axes of the reflective narrow-angle diffuser, so that the light is diffused into a uniformly directional beam through the reflection of the reflective narrow-angle diffuser and the concave mirror.

[0047] A backlit display panel displays an image. The diffused beam of light passes through the backlit display panel and becomes a directional image beam, which is projected onto a projection area (i.e., the eye box range of a viewer).

[0048] The concave reflector is placed between the light source module and the reflective narrow-angle diffuser. The hyperboloid of the concave reflector converges the light and then reflects it to the reflective narrow-angle diffuser, which then diffuses the light at each point at a narrow angle. This ensures that the uniformly directional light beam after reflection and diffusion can have high directivity and be projected into the projection area after passing through the backlit display panel.

[0049] The concave reflector can also be placed between the reflective narrow-angle diffuser and the backlight display panel, so that the reflective narrow-angle diffuser first diffuses the light at each point at a narrow angle, and then reflects it to the concave reflector. The hyperboloid concave surface of the concave reflector converges the light, so that the uniformly directional light beam after reflection and diffusion can have high directivity and be projected into the projection area after passing through the backlight display panel.

[0050] The two axes of the concave mirror correspond to the vertical and horizontal directions of the displayed image, respectively.

[0051] The curvature of the concave surface of the concave mirror can be the same or different in both axes.

[0052] The aforementioned directional backlight display device with a reflector curvature-assisted diffuser further includes a windshield in front, onto which the image light is projected, and the windshield reflects a portion of the image light to the projection area.

[0053] The aforementioned directional backlight display device with a reflector curvature-assisted diffuser may include a concave mirror. The image light is first magnified by the concave mirror and then projected onto the windshield. The windshield reflects part of the image light to the projection area. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of a publicly disclosed invention implementation.

[0055] Figure 2 This is a schematic diagram of a reflective narrow-angle diffuser.

[0056] Figure 3A , Figure 3B , Figure 3C This is a schematic diagram showing the diffusion of projected light on different reflective surfaces.

[0057] Figure 4A , Figure 4B , Figure 4C This is a schematic diagram illustrating the implementation of generating directional backlight using a reflective narrow-angle diffuser.

[0058] Figure 5A , Figure 5B This is a schematic diagram of a hyperbolic concave reflective narrow-angle diffuser.

[0059] Figure 6A , Figure 6B , Figure 6C , Figure 6D Schematic diagram of reflective narrow-angle diffusers with different concave curvatures.

[0060] Figure 7A , Figure 7B , Figure 7C This is a schematic diagram of the bonding of a reflective narrow-angle diffuser.

[0061] Figure 8A , Figure 8B , Figure 8C This is a schematic diagram of the bonding process for a reflective narrow-angle diffuser.

[0062] Figure 9A , Figure 9B This is a schematic diagram illustrating the projection differences between a hyperbolic concave reflective narrow-angle diffuser and a hyperbolic micro-concave reflective narrow-angle diffuser.

[0063] Figure 10A , Figure 10B , Figure 10C A schematic diagram of projection using a concave mirror paired with a reflective narrow-angle diffuser.

[0064] Figure 11A , Figure 11B This is a schematic diagram of the first embodiment of the present invention.

[0065] Figure 12A , Figure 12B , Figure 12C This is a schematic diagram illustrating the projection differences between a hyperbolic concave reflective narrow-angle diffuser and a monobolic concave reflective narrow-angle diffuser.

[0066] Figure 13A A schematic diagram of a single-curved concave mirror paired with a single-curved concave reflective narrow-angle diffuser.

[0067] Figure 13B , Figure 13C , Figure 14A , Figure 14B This is a schematic diagram of the second embodiment of the present invention.

[0068] Figure 15A , Figure 15B , Figure 16A , Figure 16B This is a schematic diagram of the third embodiment of the present invention.

[0069] Figure 17 This is a schematic diagram of the projection of a planar reflective narrow-angle diffuser.

[0070] Figure 18A , Figure 18B A schematic diagram of projection using a hyperbolic concave mirror paired with a flat reflective narrow-angle diffuser.

[0071] Figure 19A , Figure 19B This is a schematic diagram of the fourth embodiment of the present invention.

[0072] Figure 20 This is a schematic diagram illustrating the use of the present invention inside a vehicle.

[0073] Figure 21 This is another schematic diagram illustrating the use of the present invention inside a vehicle.

[0074] List of reference numerals in the attached diagram:

[0075] [Prior Art]—2: Reflective narrow-angle diffuser; 20: Planar reflective narrow-angle diffuser; 21: Reflective narrow-angle diffuser; 200: Micro-curved mirror; 41: Projector; θ1, θ2: Diffusion angle; 11: Light source; S1: Hyperbolic concave substrate.

[0076] [Invention]—1: Light source module; 2, 20, 22, 23, 24: Reflective narrow-angle diffuser; 200: Micro-curved mirror; 3, 31, 33: Concave reflector; 4: Backlit display panel; 5: Windshield; 6: Concave mirror; L: Light beam; D: Uniform directional beam; I: Image; DI: Directional image beam; E: Eye box range; S2: Hyperbolic micro-concave substrate; S3: Single-curved concave substrate; T2, T3: Bonding rollers. Detailed Implementation

[0077] The term "micro-concave surface" or "concave surface" used below refers to a surface with a smaller focusing effect compared to the concave surface of a conventional reflective narrow-angle diffuser. In some embodiments, the curvature of the concave surface is greater than that of the micro-concave surface; in other embodiments, the curvature of the concave surface is the same as that of the micro-concave surface.

[0078] In the following text, the term "auxiliary" refers to the fact that after the light is reflected by the reflective narrow-angle diffuser and the concave mirror, the concave mirror can compensate for the insufficient light focusing effect when the light is reflected by the reflective surface of the (micro-curved mirror) of the reflective narrow-angle diffuser, so that after the light passes through the backlit display panel, all the light can be focused on the same projection area and is sufficient to cover the set projection area.

[0079] Compared to the manufacturing difficulty of hyperbolic concave reflective narrow-angle diffusers, this invention reduces manufacturing difficulty by giving the concave surface of the reflective narrow-angle diffuser a lower curvature. Figure 7B As shown, by attaching a planar reflective narrow-angle diffuser 20 to a hyperbolic micro-concave substrate S2, a hyperbolic micro-concave reflective narrow-angle diffuser can be formed, significantly improving the process yield. Figure 8B As shown, a spindle-shaped bonding roller T2 can be used to ensure a tight fit and avoid air bubble residue.

[0080] like Figure 9A As shown, the original hyperbolic concave reflective narrow-angle diffuser 21 could reflect and diffuse light L into a set projection area. However, after being replaced with the hyperbolic micro-concave reflective narrow-angle diffuser 22 provided by this invention, as... Figure 9B As shown, the reduction in curvature of the reflective narrow-angle diffuser 22 also reduces the curvature of the micro-concave mirror, resulting in insufficient light L to cover the set projection area after reflection and diffusion, and light from different positions on the diffuser cannot be projected onto the same area.

[0081] In order to converge the reflected and diffused light rays L, such as Figure 10A As shown, a concave reflector 31 can be added between the light source module 1 and the reflective narrow-angle diffuser 22, or as shown in the diagram. Figure 10B As shown, a concave reflector 31 is added after the reflective narrow-angle diffuser 22 to compensate for the insufficient axial concave curvature of the reflective narrow-angle diffuser 22, so that the projected light rays converge to the same area and are sufficient to cover the set projection area. Figure 10C As shown, the effect of adding the concave reflector 31 is similar to adding a convex lens 30 to the light path, changing the light path and diffusion area projected by each micro-mirror, so that light from different positions on the diffuser can be projected and diffused in the same projection area.

[0082] like Figure 11A and Figure 11B As shown, the first embodiment of the present invention is a directional backlight display device with a reflector curvature-assisted diffuser, comprising: a light source module 1 for projecting a light ray L, a reflective narrow-angle diffuser 22, a concave reflector 31, and a backlight display panel 4.

[0083] The reflective narrow-angle diffuser 22 has a hyperbolic and low-curvature concave surface (i.e., a hyperbolic micro-concave surface) formed along two mutually perpendicular axes as a reflective surface. The reflective surface has an array of multiple micro-curved mirrors 200 to reflect and diffuse the light L.

[0084] The concave mirror 31 forms a hyperbolic concave surface along two mutually perpendicular axes. The two axes of the concave surface correspond to the two axes of the concave surface of the reflective narrow-angle diffuser 22. The concave mirror 31 assists the insufficient curvature of the concave surface of the reflective narrow-angle diffuser 22, so that the light L is reflected and diffused by the reflective narrow-angle diffuser 22 and the concave mirror 31 to become a uniformly directional light beam D.

[0085] The backlit display panel 4 displays an image I. The diffused beam D passes through the backlit display panel 4 and becomes a directional image beam DI. The directional image beam DI is projected onto a projection area (i.e., the eye box range E of a viewer).

[0086] like Figure 11A As shown, the concave reflector 31 is placed between the light source module 1 and the reflective narrow-angle diffuser 22. The hyperbolic concave surface of the concave reflector 31 converges the light L for the first time and then reflects it to the reflective narrow-angle diffuser 22, allowing the hyperbolic micro-concave surface of the reflective narrow-angle diffuser 22 to converge the light a second time and diffuse the light at each point at a narrow angle. This ensures that the uniformly directional light beam D after reflection and diffusion can have high directivity and be projected into the eye box range E after passing through the backlight display panel 4.

[0087] like Figure 11B As shown, the concave reflector 31 can also be placed between the reflective narrow-angle diffuser 22 and the backlight display panel 4, so that the hyperbolic micro-concave surface of the reflective narrow-angle diffuser 22 first converges the light L and diffuses the light at each point at a narrow angle, and then reflects it to the concave reflector 31, so that the hyperbolic concave surface of the concave reflector 31 converges the light a second time, so that the homogeneous directional light beam D after reflection and diffusion can have high directivity and be projected into the eye box range E after passing through the backlight display panel 4.

[0088] The curvature of the micro-concave surface of the reflective narrow-angle diffuser 22 along both axes is smaller than the curvature of the concave surface of the concave reflector 31 along both axes.

[0089] The micro-concave surface of the reflective narrow-angle diffuser 22 is along one of its axial directions (e.g., Figure 11A The curvature of the concave surface (shown on the X-axis) is less than the curvature of the concave surface of the concave mirror 31 along the corresponding axis, and the micro-concave surface of the reflective narrow-angle diffuser 22 along another axis (e.g. Figure 11AThe curvature of the concave surface of the concave mirror 31 along the Y-axis is greater than the curvature of the concave surface along the corresponding axis.

[0090] like Figure 7C As shown, the reflective narrow-angle diffuser can also be formed by bending along a single axis to create a concave surface, thus reducing manufacturing difficulty. By attaching the planar reflective narrow-angle diffuser 200 to the concave substrate S3, a concave reflective narrow-angle diffuser can be formed, significantly improving manufacturing yield. Figure 8C As shown, a cylindrical bonding roller T3 can be used to ensure a tight fit and avoid air bubble residue.

[0091] like Figure 12A As shown, the hyperbolic concave reflective narrow-angle diffuser 21 could originally reflect and diffuse light into the designated projection area. However, as... Figure 12B and Figure 12C As shown, after changing to a single-curved concave reflective narrow-angle diffuser 23, the light rays reflected and diffused by the single-curved concave reflective narrow-angle diffuser 23 cannot be projected onto the same area at different positions on the diffuser. The reflected and diffused light rays will be distributed beyond the set projection area along the non-curved axis of the reflective narrow-angle diffuser 23. Figure 12B As shown, when the Y-axis is the non-curved axis of the reflective narrow-angle diffuser 23, the reflected and diffused light will be distributed beyond the set projection area along the Y-axis. Figure 12C As shown, when the X-axis is the non-curved axis of the reflective narrow-angle diffuser 23, the reflected and diffused light will be distributed beyond the set projection area along the X-axis.

[0092] To resolve the issues explained in the previous paragraph, such as Figure 13A As shown, a single-curved concave reflective narrow-angle diffuser 23 can be paired with a single-curved concave reflector 33 to compensate for the lack of axial concave curvature in the reflective narrow-angle diffuser 23. When the concave surface of the reflective narrow-angle diffuser 23 is curved along the X-axis, the concave surface of the paired single-curved concave reflector 33 is curved along the Y-axis. When the concave surface of the reflective narrow-angle diffuser 23 is curved along the Y-axis, the concave surface of the paired single-curved concave reflector 33 is curved along the X-axis. By utilizing the complementary characteristics of the concave surfaces of the reflective narrow-angle diffuser 23 and the concave surface of the concave reflector 33 with different axial curvatures, the projected light is converged to the same projection area, which is sufficient to cover the set projection area.

[0093] like Figure 13B , Figure 13C , Figure 14A , Figure 14BAs shown, this is the second embodiment of the present invention, a directional backlight display device with a reflector curvature-assisted diffuser, comprising: a light source module 1 that projects a light ray L, a reflective narrow-angle diffuser 23, a concave reflector 33, and a backlight display panel 4.

[0094] The reflective narrow-angle diffuser 23 forms a concave surface along a single axis as a reflective surface, which has an array of multiple micro-curved mirrors 200 to reflect and diffuse light L.

[0095] The concave mirror 33 forms a single-curved concave surface along a single axis, the axis of which is perpendicular to the axis of the concave surface of the reflective narrow-angle diffuser 23. The concave mirror 33 assists in the curvature of the axis missing by the concave surface of the reflective narrow-angle diffuser 23, so that the light L is diffused into a uniformly directional beam D by the reflection of the reflective narrow-angle diffuser 23 and the concave mirror 33.

[0096] The backlit display panel 4 displays an image I. The directional light beam D passes through the backlit display panel 4 and becomes a directional image beam DI. The directional image beam DI is projected onto the eye box range E of a viewer.

[0097] like Figure 13B and Figure 13C As shown, the concave reflector 33 is placed between the light source module 1 and the reflective narrow-angle diffuser 23. The concave surface of the concave reflector 33 converges the light L for the first time and then reflects it to the reflective narrow-angle diffuser 23. The reflective narrow-angle diffuser 23 then converges the light a second time on the concave surfaces of different axes and diffuses the light at each point at a narrow angle. This ensures that the uniformly directional light beam D after reflection and diffusion can have high directivity and be projected into the eye box range E after passing through the backlight display panel 4.

[0098] like Figure 14A and Figure 14B As shown, the concave reflector 33 can also be placed between the reflective narrow-angle diffuser 23 and the backlight display panel 4, so that the concave surface of the reflective narrow-angle diffuser 23 first converges the light L and diffuses the light at each point at a narrow angle, and then reflects it to the concave reflector 33. The concave reflector 33 then converges the light a second time on the concave surfaces of different axes, so that the homogeneous directional light beam D after reflection and diffusion can have high directivity and be projected into the eye box range E after passing through the backlight display panel 4.

[0099] The axial direction of the concave surface of the reflective narrow-angle diffuser 23 can correspond to the vertical direction, horizontal direction, 45-degree oblique direction, or any direction of the displayed image I.

[0100] Furthermore, the curvature of the concave surface of the reflective narrow-angle diffuser can be further reduced to create a single-curved, slightly concave reflective narrow-angle diffuser, simplifying the manufacturing process and reducing costs. To converge the reflected and diffused light, the single-curved, slightly concave reflective narrow-angle diffuser can be paired with a hyperbolic concave mirror to compensate for the lack of axial curvature in the reflective narrow-angle diffuser, ensuring that the projected light converges to the same area and is sufficient to cover the designated projection area.

[0101] like Figure 15A , Figure 15B , Figure 16A , Figure 16B As shown, this is the third embodiment of the present invention, a directional backlight display device with a reflector curvature-assisted diffuser, comprising: a light source module 1 that projects a light ray L, a reflective narrow-angle diffuser 24, a concave reflector 31, and a backlight display panel 4.

[0102] The reflective narrow-angle diffuser 24 forms a concave surface (i.e., a single-curved micro-concave surface) with low curvature along a single axis as a reflective surface. The reflective surface has an array of multiple micro-curved mirrors 200 to reflect and diffuse the light L.

[0103] The concave mirror 31 forms a hyperbolic concave surface along two perpendicular axes. One of the axes of the concave surface corresponds to the axis of the micro-concave surface of the reflective narrow-angle diffuser 24. The concave mirror 31 assists the micro-concave surface of the reflective narrow-angle diffuser 24 in providing the curvature of the axis that is insufficient or lacking, so that the light L is reflected and diffused by the reflective narrow-angle diffuser 24 and the concave mirror 31 into a uniformly directional light beam D.

[0104] The backlit display panel 4 displays an image I. The directional light beam D passes through the backlit display panel 4 and becomes a directional image beam DI. The directional image beam DI is projected onto the eye box range E of a viewer.

[0105] like Figure 15A and Figure 15B As shown, the concave reflector 31 is placed between the light source module 1 and the reflective narrow-angle diffuser 24. The hyperbolic concave surface of the concave reflector 31 converges the light L for the first time and then reflects it to the reflective narrow-angle diffuser 24. The single-curved micro-concave surface of the reflective narrow-angle diffuser 24 converges the light a second time and diffuses the light at each point at a narrow angle. This ensures that the uniformly directional light beam D after reflection and diffusion can have high directivity and be projected into the eye box range E after passing through the backlight display panel 4.

[0106] like Figure 16A and Figure 16BAs shown, the concave reflector 31 can also be placed between the reflective narrow-angle diffuser 24 and the backlight display panel 4, so that the single-curved micro-concave surface of the reflective narrow-angle diffuser 24 first converges the light L and diffuses the light at each point at a narrow angle, and then reflects it to the concave reflector 31, so that the hyperbolic concave surface of the concave reflector 31 converges it a second time, so that the homogeneous directional light beam D after reflection and diffusion can have high directivity and be projected into the eye box range E after passing through the backlight display panel 4.

[0107] The axial direction of the micro-concave surface of the reflective narrow-angle diffuser 24 can correspond to the vertical direction, horizontal direction, 45-degree oblique angle direction, or any direction of the displayed image I.

[0108] Furthermore, the present invention can directly use a planar reflective narrow-angle diffuser sheet, eliminating the need for a curved surface bonding process, resulting in the highest yield and lowest cost.

[0109] like Figure 17 As shown, after changing to a planar reflective narrow-angle diffuser 20, because the diffuser uses a plane as the reflective surface and lacks a concave surface (the curvature of the plane is zero), the light L is insufficient to cover the set projection area after reflection and diffusion, and the light from different positions on the diffuser cannot be projected onto the same area.

[0110] In order to converge the reflected and diffused light rays L, such as Figure 18A As shown, a hyperbolic concave reflector 31 can be added between the light source module 1 and the planar reflective narrow-angle diffuser 20, or as shown... Figure 18B As shown, a hyperbolic concave reflector 31 is added after the planar reflective narrow-angle diffuser 20 to compensate for the lack of axial concave curvature in the reflective narrow-angle diffuser 20, so that the projected light converges to the same area and is sufficient to cover the set projection area.

[0111] like Figure 19A and Figure 19B As shown, this is the fourth embodiment of the present invention, a directional backlight display device with a reflector curvature-assisted diffuser, comprising: a light source module 1 that projects a light ray L, a reflective narrow-angle diffuser 20, a concave reflector 31, and a backlight display panel 4.

[0112] The reflective narrow-angle diffuser 20 has a planar reflective surface with an array of multiple micro-curved mirrors 200 to reflect and diffuse light L.

[0113] The concave mirror 31 forms a hyperbolic concave surface along the two perpendicular axes. The concave mirror 31 assists the curvature missing in the two perpendicular axes of the reflective narrow-angle diffuser 20, so that the light L is reflected and diffused by the reflective narrow-angle diffuser 20 and the concave mirror 31 to become a uniformly directional light beam D.

[0114] The backlit display panel 4 displays an image I. The directional light beam D passes through the backlit display panel 4 and becomes a directional image beam DI. The directional image beam DI is projected onto the eye box range E of a viewer.

[0115] like Figure 19A As shown, the concave reflector 31 is placed between the light source module 1 and the reflective narrow-angle diffuser 20. The hyperbolic concave surface of the concave reflector 31 first converges the light L and then reflects it to the reflective narrow-angle diffuser 20, so that the reflective narrow-angle diffuser 20 diffuses the light at each point at a narrow angle, so that the uniformly directional light beam D after reflection and diffusion can have high directivity and be projected into the eye box range E after passing through the backlight display panel 4.

[0116] like Figure 19B As shown, the concave reflector 31 can also be placed between the reflective narrow-angle diffuser 20 and the backlight display panel 4, so that the reflective narrow-angle diffuser 20 first diffuses the light at each point at a narrow angle, and then reflects it to the concave reflector 31, so that the hyperbolic concave surface of the concave reflector 31 converges, so that the uniformly directional light beam D after reflection and diffusion can have high directivity and be projected into the eye box range E after passing through the backlight display panel 4.

[0117] The two axes of the concave reflector 31 correspond to the vertical and horizontal directions of the displayed image I, respectively.

[0118] The concave surface of the concave mirror 31 may have the same or different curvatures in the two axes.

[0119] like Figure 20 As shown, the directional backlight display device of the first to fourth embodiments described above may include a windshield 5, allowing the viewer to simultaneously view the projected image and the scenery outside the windshield 5. A light source module 1 projects a light beam L, which is reflected and diffused by a concave reflector 3 and a reflective narrow-angle diffuser 2 to form a uniformly directional light beam D. The uniformly directional light beam D penetrates a backlight display panel 4 and becomes a directional image beam DI. The directional image beam DI is projected onto the windshield 5, and the windshield 5 reflects a portion of the directional image beam DI to the eye box area E.

[0120] like Figure 21As shown, the optical path of the directional backlight display device in the first to fourth embodiments may further include a concave mirror 6 to magnify the image and lengthen the virtual image distance. A light beam L is projected from a light source module 1. After being reflected and diffused by a concave mirror 3 and a reflective narrow-angle diffuser 2, the light beam L forms a uniformly directional beam D. The uniformly directional beam D penetrates a backlight display panel 4 and becomes a directional image beam DI. The directional image beam DI is projected onto the concave mirror 6, and the concave mirror 6 reflects the directional image beam DI onto the windshield 5. The windshield 5 reflects a portion of the directional image beam DI onto the eye box area E.

Claims

1. A directional backlight display device with a reflector curvature-assisted diffuser, characterized in that, Include: A light source module projects a beam of light; A reflective narrow-angle diffuser has a concave or flat surface as a reflective surface, and the reflective surface has an array of multiple micro-curved mirrors. A concave mirror has a concave surface as a reflecting surface, which assists the insufficient concave curvature of the reflective narrow-angle diffuser, so that the light is diffused by the reflection of the reflective narrow-angle diffuser and the concave mirror into a uniformly directional beam; and A backlit display panel displays an image. The diffused directional light beam passes through the backlit display panel and becomes a directional image beam, which is then projected onto a projection area. Wherein, the curvature of the concave surface of the concave mirror in at least one axis is greater than the curvature of the reflective narrow-angle diffuser in at least one axis.

2. The directional backlight display device with a reflector curvature-assisted diffuser as described in claim 1, characterized in that, The reflective surface of the reflective narrow-angle diffuser is concave along two mutually perpendicular axes, and the reflective surface of the concave mirror is concave along two mutually perpendicular axes, the two axes of the concave mirror corresponding to the two axes of the reflective narrow-angle diffuser.

3. The directional backlight display device with a reflector curvature-assisted diffuser according to claim 1, characterized in that, The reflective surface of the reflective narrow-angle diffuser is concave along a single axis, and the reflective surface of the concave mirror is concave along another single axis, the single axis of the concave mirror being perpendicular to the single axis of the reflective narrow-angle diffuser.

4. The directional backlight display device with a reflector curvature-assisted diffuser according to claim 1, characterized in that, The reflective surface of the reflective narrow-angle diffuser is concave along a single axis, and the reflective surface of the concave mirror is concave along two mutually perpendicular axes, one of which is parallel to the single axis of the reflective narrow-angle diffuser.

5. The directional backlight display device with a reflector curvature-assisted diffuser according to claim 1, characterized in that, The reflective surface of the reflective narrow-angle diffuser is a plane, and the reflective surface of the concave mirror is concave along two perpendicular axes.

6. The directional backlight display device with a reflector curvature-assisted diffuser sheet according to any one of claims 2 to 5, characterized in that, The concave mirror is placed in the optical path between the light source module and the reflective narrow-angle diffuser.

7. The directional backlight display device with a reflector curvature-assisted diffuser sheet according to any one of claims 2 to 5, characterized in that, The concave mirror is placed in the optical path between the reflective narrow-angle diffuser and the backlit display panel.

8. The directional backlight display device with a reflector curvature-assisted diffuser according to claim 1, characterized in that, It also includes a windshield onto which the directional image beam is projected, and the windshield reflects a portion of the directional image beam to the projection area.

9. The directional backlight display device with a reflector curvature-assisted diffuser according to claim 8, characterized in that, It also includes a concave mirror, through which the directional image beam is first reflected before being projected onto the windshield, and the windshield reflects a portion of the directional image beam onto the projection area.

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