Head-up display using backlight annular mirror to adjust eye box

Abstract

A head-up display using a backlight annular mirror to adjust an eye box is suitable for being used in cooperation with an imaging half-reflecting mirror and comprises a backlight source, the backlight annular mirror, a display panel and an imaging concave mirror. The backlight annular mirror is rotatable, has an X-axis curvature and a Y-axis curvature different from the X-axis curvature, and can reflect a backlight beam of the backlight source. Backlight beams reflected by the backlight annular mirror pass through the display panel, the imaging concave mirror and the imaging half-reflecting mirror and then form a backlight source real image located on the eyes of a viewer, and the backlight source real image is the eye box. The rotation of the backlight annular mirror enables the eye box to be lengthened or shortened, so that the eyes of the viewer are still kept in the eye box when moving back and forth.

Description

Technical Field

[0001] The invention relates to a head-up display, in particular to a head-up display utilizing backlight to adjust an eye box. Background Art

[0002] like Figure 1A and Figure 1B As shown, in the prior art, a backlight concave mirror Mr_BL is used to reflect the backlight light Lt_BL emitted by the backlight source BL to form a backlight beam Bm_BL, and a backlight source virtual image BL_im is formed behind the backlight concave mirror Mr_BL. The backlight beam Bm_BL penetrates the display panel DP to form an image beam Bm_G, and the image beam Bm_G is then reflected by the imaging concave mirror Mr_F. The display panel DP forms an image virtual image DP_im behind the imaging concave mirror Mr_F, and the backlight source virtual image BL_im forms a backlight source real image BL_re in front of the imaging concave mirror Mr_F.

[0003] After the virtual image DP_im behind the imaging concave mirror Mr_F is reflected by the imaging semi-reflective mirror Mr_SR, a virtual image DP_im is formed in front of the vehicle. After the real image BL_re of the backlight source in front of the imaging concave mirror Mr_F is reflected by the imaging semi-reflective mirror Mr_SR, a real image BL_re of the backlight source is formed in the viewer's eye E, that is, the eye box EB.

[0004] The imaging half mirror Mr_SR can be Figure 1A windshield, or Figure 1B Combiner.

[0005] like Figure 1C As shown, when the viewer's eye E moves forward and backward, the original eye box EB will not be able to overlap with the moved eye E, which will make the image seen by the viewer dark and blurred, defective, or even invisible. Summary of the invention

[0006] In order to solve the above problems, the present invention proposes a head-up display with a rotating backlight annular mirror to adjust the eye box, so that the viewer can see bright, clear and complete images when the eyes move back and forth.

[0007] A head-up display using a backlight annular mirror to adjust an eye box provided by the present invention according to an embodiment is suitable for use with an imaging semi-reflective mirror and comprises: a backlight source for projecting a backlight beam; a backlight annular mirror that is rotatable and has an X-axis curvature and a Y-axis curvature, the X-axis curvature being different from the Y-axis curvature, the backlight annular mirror being used to reflect the backlight beam of the backlight source; a display panel configured to display an image and allow the backlight beam reflected by the backlight annular mirror to pass through to form an image beam; and an imaging concave mirror configured to reflect the image beam to the imaging semi-reflective mirror to form a display located on a side of the imaging semi-reflective mirror away from a viewer. The panel virtual image and a backlight real image are formed on the imaging semi-reflecting mirror close to the viewer side and at the viewer's eyes, and the backlight real image is an eye box; wherein, an off-axis optical path is between the backlight source and the backlight annular mirror, the backlight source is reflected and focused on an X-axis backlight focusing plane by the X-axis curvature, the backlight source is reflected and focused on a Y-axis backlight focusing plane by the Y-axis curvature, the range of the eye box is from the X-axis backlight focusing plane to the Y-axis backlight focusing plane, and the rotation of the backlight annular mirror lengthens or shortens the range of the eye box on the imaging optical path of the backlight real image, so that the viewer's eyes remain in the eye box when moving on the imaging optical path of the backlight real image.

[0008] Optionally, the backlight annular mirror rotates with its central axis as the rotation center.

[0009] Optionally, when there is an angle in the Y-axis direction between the optical axis of the backlight beam and the central axis of the backlight annular mirror, the backlight annular mirror rotates at an angle with its central axis as the rotation center, and the X-axis curvature of the surface of the backlight annular mirror illuminated by the backlight beam is smaller than the Y-axis curvature, the range of the eye box is lengthened as the rotation angle increases from 0 degrees to 90 degrees, and the range of the eye box is shortened as the rotation angle decreases from 90 degrees to 0 degrees.

[0010] Optionally, when there is an angle in the Y-axis direction between the optical axis of the backlight beam and the central axis of the backlight annular mirror, the backlight annular mirror rotates at an angle with its central axis as the rotation center, and the X-axis curvature of the surface of the backlight annular mirror illuminated by the backlight beam is greater than the Y-axis curvature, the range of the eye box shortens as the rotation angle increases from 0 degrees to 90 degrees, and the range of the eye box lengthens as the rotation angle decreases from 90 degrees to 0 degrees.

[0011] Optionally, when there is an angle in the X-axis direction between the optical axis of the backlight beam and the central axis of the backlight annular mirror, the backlight annular mirror rotates at an angle with its central axis as the rotation center, and the X-axis curvature of the surface of the backlight annular mirror illuminated by the backlight beam is smaller than the Y-axis curvature, the range of the eye box shortens as the rotation angle increases from 0 degrees to 90 degrees, and the range of the eye box lengthens as the rotation angle decreases from 90 degrees to 0 degrees.

[0012] Optionally, when there is an angle in the X-axis direction between the optical axis of the backlight beam and the central axis of the backlight annular mirror, the backlight annular mirror rotates at an angle with its central axis as the rotation center, and the X-axis curvature of the surface of the backlight annular mirror illuminated by the backlight beam is greater than the Y-axis curvature, the range of the eye box is lengthened as the rotation angle increases from 0 degrees to 90 degrees, and the range of the eye box is shortened as the rotation angle decreases from 90 degrees to 0 degrees.

[0013] Optionally, when the backlight annular mirror is rotated to extend the range of the eye box, the brightness of the backlight source is increased.

[0014] Optionally, when the backlight annular mirror is rotated to shorten the range of the eye box, the brightness of the backlight source is reduced.

[0015] Optionally, the imaging semi-reflective mirror is a windshield or a stacked mirror, which is used to reflect part of the image light beam from the imaging concave mirror to the eyes of the viewer, while allowing part of the light from the scene in front of it to penetrate into the eyes of the viewer. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Other aspects and advantages of the present invention will be discovered after studying the detailed description in conjunction with the following drawings:

[0017] Figure 1A A schematic diagram of a head-up display using windshield projection in the prior art;

[0018] Figure 1B It is a schematic diagram of a head-up display using a stacked mirror projection in the prior art;

[0019] Figure 1C for Figure 1A A schematic diagram of the forward and backward movement of the viewer's eye position of the head-up display in the prior art;

[0020] Figure 2A and 2B A schematic diagram of a backlit annular mirror used in a head-up display;

[0021] Figure 3A , 3B and 3C are schematic diagrams of the equivalent focal lengths of the X-axis and the Y-axis when the backlight annular mirror is at different incident angles;

[0022] Figure 4 is a schematic diagram of a real image imaging state when a point light source is on the central axis of a backlit annular mirror and the object distance is greater than the focal length;

[0023] Figure 5 is a schematic diagram of a virtual image forming state when a point light source is on the central axis of a backlit annular mirror and the object distance is less than the focal length;

[0024] Figure 6 is a schematic diagram of a real image imaging state when a rectangular light source is on the central axis of a backlit annular mirror and the object distance is greater than the focal length;

[0025] Figure 7 Schematic diagram of the real image imaging state when the rectangular light source deviates from the central axis of the backlight annular mirror on the Y axis and the object distance is greater than the equivalent focal length;

[0026] Figure 8 For the general Figure 7 Schematic diagram of a real image imaging state when the backlit annular mirror is rotated 90 degrees;

[0027] Fig. 9 is a schematic diagram of a virtual image forming state when a rectangular light source is on the central axis of a backlight annular mirror and the object distance is less than the focal length;

[0028] Fig.10 It is a schematic diagram of the virtual image imaging state when the rectangular light source deviates from the central axis of the backlight annular mirror on the Y axis and the object distance is less than the equivalent focal length;

[0029] Fig.11 For the general Fig.10 Schematic diagram of a virtual image imaging state when the backlit annular mirror is rotated 90 degrees;

[0030] Fig.12 A list of different backlight annular mirror curvature configurations, different off-axis directions, different rotation angle changes, and corresponding backlight real image lengthening or shortening;

[0031] Fig.13A and 13B is a schematic diagram of the eye box when the backlit annular mirror has not yet rotated;

[0032] Fig. 13C Schematic diagram of rotating the backlit toroidal mirror to lengthen the eye box as the viewer moves forward and backward;

[0033] Fig.14A A schematic diagram of a smaller eye box formed when the backlight source is arranged in the off-axis direction of the Y-axis of the backlight annular mirror;

[0034] Fig. 14B For the general Fig.14ASchematic diagram of the elongated eye box formed when the backlit annular mirror is rotated 90 degrees;

[0035] Fig.15A A schematic diagram of a slightly larger eye box formed when the backlight source is arranged in the off-axis direction of the Y-axis of the backlight annular mirror;

[0036] Fig. 15B For the general Fig.15A Schematic diagram of the elongated eye box formed when the backlit annular mirror is rotated 45 degrees;

[0037] Fig. 15C For the general Fig.15A Schematic diagram of the eye box that is stretched longer when the backlit annular mirror is rotated 90 degrees;

[0038] Fig.16A A schematic diagram of a smaller eye box formed when the backlight source is arranged in the off-axis direction of the X-axis of the backlight annular mirror;

[0039] Fig. 16B For the general Fig.16A Schematic diagram of the elongated eye box formed when the backlit annular mirror is rotated 90 degrees;

[0040] Fig.17A A schematic diagram of a slightly larger eye box formed when the backlight source is arranged in the off-axis direction of the X-axis of the backlight annular mirror;

[0041] Fig. 17B For the general Fig.17A A schematic diagram of an elongated eye box formed when the backlit annular mirror is rotated 45 degrees; and

[0042] Fig. 17C For the general Fig.17A Schematic diagram of the elongated eye box formed when the backlit annular mirror is rotated 90 degrees.

[0043] in,

[0044] BL: Backlight

[0045] BL_im, BL_im1, BL_im2, BL_im3, BL_im4, BL_im5: Backlight virtual image

[0046] BL_im6,BL_im7,BL_im8,BL_im9,BL_im10: Backlight virtual image

[0047] BL_im11, BL_im12, BL_im13, BL_im14, BL_im15: Backlight virtual image

[0048] BL_re,BL_re1,BL_re2,BL_re3,BL_re4,BL_re5,BL_re6: backlight real image

[0049] BL_re7,BL_re8,BL_re9,BL_re10,BL_re11,BL_re12: Backlight real image

[0050] BL_re13, BL_re14, BL_re15: Backlight real image

[0051] Bm_G: Image beam

[0052] Bm_BL: Backlight beam

[0053] CA: Central axis

[0054] DP: Display Panel

[0055] DP_im: Virtual image

[0056] E: Eyes

[0057] EB:Eye Box

[0058] Fx: Focus

[0059] Fy: Focus

[0060] FL_x: focal length

[0061] FL_x1,FL_x2,FL_x3,FL_x4,FL_x5: equivalent focal length

[0062] FL_y: focal length

[0063] FL_y1,FL_y2,FL_y3,FL_y4,FL_y5: equivalent focal length

[0064] FPX: X-axis backlight focusing plane

[0065] FPY: Y-axis backlight focusing plane

[0066] Lt_BL: Backlight

[0067] Mr_BL: Backlit concave mirror

[0068] Mr_F: Imaging concave mirror

[0069] Mr_SR: Imaging Half Mirror

[0070] P: Point light source

[0071] q1,q2,q3,q4,q5,q6,q7,q8,q9,q10,q11: location

[0072] TMr: Backlit Toroidal Mirror

[0073] X,Y: Axis

[0074] θy, θy1, θy2, θy3, θy4, θx5, θx6: angle DETAILED DESCRIPTION

[0075] Please refer to FIG. 2A to FIG. 17C As shown, a head-up display provided by the present invention according to an embodiment can use a backlight annular mirror to adjust the eye box EB, is suitable for use with an imaging semi-reflective mirror Mr_SR, and includes a backlight source BL, a backlight annular mirror TMr, a display panel DP and an imaging concave mirror Mr_F. The imaging semi-reflective mirror Mr_SR can be as follows Figure 1A Windshield or Figure 1B The following description will be made based on an embodiment in which the imaging half-reflective mirror Mr_SR is a windshield.

[0076] The backlight source BL can project a backlight beam to the backlight annular mirror TMr.

[0077] Since the head-up display is designed with an off-axis optical path rather than a coaxial optical path, in order to keep the image bright and clear without distortion, the backlight concave mirror and the imaging concave mirror used are both concave mirrors with two curvatures, that is, toroidal mirrors. The backlight source BL and the backlight toroidal mirror TMr are off-axis optical paths, and there is an angle between the optical axis of the backlight beam and the central axis of the backlight toroidal mirror. The angle is greater than 0 degrees and less than 90 degrees. The backlight toroidal mirror TMr is rotatable and has an X-axis curvature and a Y-axis curvature. The X-axis curvature refers to the curvature on the axial direction X, and the Y-axis curvature refers to the curvature on the axial direction Y, and the X-axis curvature is different from the Y-axis curvature. The backlight toroidal mirror TMr can reflect the backlight beam of the backlight source BL to the display panel DP. The backlight toroidal mirror TMr can, for example, be as follows Figure 2A The backlit annular mirror TMr shown in the figure has a focal length FL_x corresponding to its X-axis curvature greater than the focal length FL_y corresponding to its Y-axis curvature; or Figure 2B For the annular mirror TMr shown, the focal length FL_x corresponding to the X-axis curvature is smaller than the focal length FL_y corresponding to the Y-axis curvature.

[0078] The display panel DP can display an image and allow the backlight beam from the backlight annular mirror TMr to pass through to form an image beam.

[0079] The imaging concave mirror Mr_F can reflect the image beam to the imaging semi-reflective mirror Mr_SR to form a display panel virtual image located on the side of the imaging semi-reflective mirror Mr_SR away from the viewer and a backlight real image (BL_re1-BL_re15) located on the side of the imaging semi-reflective mirror Mr_SR close to the viewer and located at the viewer's eyes. This backlight real image is the eye box EB.

[0080] The rotation of the backlight annular mirror TMr causes the eye box EB to lengthen or shorten on the imaging light path of the backlight real image, so that the viewer's eyes remain in the eye box EB when moving on the imaging light path of the backlight real image.

[0081] The function and principle of the backlight annular mirror TMr are explained as follows.

[0082] like Figure 3A As shown, when the light Lt travels on the central axis CA of the backlight annular mirror TMr, the focal length FL_x of the focus Fx on the axial direction X is greater than the focal length FL_y of the focus Fy on the axial direction Y.

[0083] like Figure 3B As shown in the figure, when the light path of the light Lt rotates an angle θy greater than 0 degrees on the axis Y with the center of the backlight annular mirror TMr as the pivot point, the equivalent focal length FL_x1 corresponding to the curvature of the X axis is shortened to FL_x×cosθy, and the equivalent focal length FL_y1 corresponding to the curvature of the Y axis is elongated to FL_y / cosθy. If the appropriate focal lengths FL_x and FL_y and angle θy are designed, the equivalent focal length FL_x1 can be almost equal to the equivalent focal length FL_y1, that is, FL_x×cosθy≒FL_y / cosθy.

[0084] like Figure 3C As shown, Figure 3B The backlit annular mirror TMr is rotated 90 degrees with its central axis CA as the rotation center, so that the value of the X-axis curvature is exchanged with the value of the Y-axis curvature. At this time, the equivalent focal length FL_x2 corresponding to the X-axis curvature becomes shorter FL_y×cosθy, and the equivalent focal length FL_y2 corresponding to the Y-axis curvature becomes longer FL_x / cosθy, that is, FL_x / cosθy>FL_x>FL_y>FL_y×cosθy.

[0085] The point light source P forms a real image in front of the backlit annular mirror TMr, such as Figure 4 As shown, the point light source P is on the central axis CA of the backlight annular mirror TMr, the focal length FL_x of the focus Fx corresponding to the X-axis curvature is greater than the focal length FL_y of the focus Fy corresponding to the Y-axis curvature, and the distance between the point light source P and the backlight annular mirror TMr is greater than the focal length FL_x and also greater than the focal length FL_y. Since the point light source P is closer to the focus Fx and farther from the focus Fy, the light emitted by the point light source P is reflected by the surface of the X-axis curvature on the backlight annular mirror TMr and focused on the position q1, and the light emitted by the point light source P is reflected by the surface of the Y-axis curvature on the backlight annular mirror TMr and focused on the position q2, and the distance between the position q1 and the backlight annular mirror TMr is greater than the distance between the position q2 and the backlight annular mirror TMr.

[0086] The light reflected by the surface of the X-axis curvature will pass through position q2 and remain unfocused before reaching position q1. The light reflected by the surface of the Y-axis curvature will begin to diverge forward after being focused at position q2, and then pass through position q1. The circle of least confusion is located at position q3 between position q1 and position q2. Therefore, the area with the highest light brightness on the central axis CA is the area from position q1 to position q2, and the light brightness of other areas before and after this area will decrease.

[0087] The point light source P forms a virtual image behind the backlight annular mirror TMr, such as Figure 5 As shown, the point light source P is on the central axis CA of the backlight annular mirror TMr, the focal length FL_x of the focus Fx is smaller than the focal length FL_y of the focus Fy, and the distance between the point light source P and the backlight annular mirror TMr is smaller than the focal length FL_x and also smaller than the focal length FL_y. Since the point light source P is closer to the focus Fx and farther from the focus Fy, the virtual image light generated by the light emitted by the point light source P when it is reflected by the surface of the X-axis curvature on the backlight annular mirror TMr and extends backward will be focused on position q4, and the virtual image light generated by the light emitted by the point light source P when it is reflected by the surface of the Y-axis curvature on the backlight annular mirror TMr and extends backward will be focused on position q5. The distance between position q4 and the backlight annular mirror TMr is greater than the distance between position q5 and the backlight annular mirror TMr.

[0088] The virtual image light generated by the light reflected by the surface of the X-axis curvature extends backward, first focuses to position q4 from far back, and then diverges forward to pass position q5. The virtual image light generated by the light reflected by the surface of the Y-axis curvature extends backward, and then passes through position q4 and remains unfocused before focusing to position q5 from far back. The minimum circle of confusion is located at position q6 between position q4 and position q5, so the area with the highest brightness of the virtual image light on the central axis CA is the area from position q4 to position q5, and the brightness of the virtual image light in other areas before and after this area will decrease.

[0089] The surface light source forms a real image in front of the backlit annular mirror TMr, such as Figure 6As shown, the rectangular backlight source BL is on the central axis CA of the backlight annular mirror TMr, the focal length FL_x of the focus Fx corresponding to the X-axis curvature is greater than the focal length FL_y of the focus Fy corresponding to the Y-axis curvature, and the distance between the backlight source BL and the backlight annular mirror TMr is greater than the focal length FL_x and also greater than the focal length FL_y. Since the backlight source BL is closer to the focus Fx and farther from the focus Fy, the light emitted by the backlight source BL will be reflected by the surface of the X-axis curvature on the backlight annular mirror TMr and will be focused on the position q7, that is, the X-axis backlight focusing plane FPX, and the brightness is higher in the axial direction X close to the central axis CA. The light emitted by the backlight source BL will be reflected by the surface of the Y-axis curvature on the backlight annular mirror TMr and will be focused on the position q8, that is, the Y-axis backlight focusing plane FPY, and the brightness is higher in the axial direction Y close to the central axis CA. The distance between the position q7 and the backlight annular mirror TMr is greater than the distance between the position q8 and the backlight annular mirror TMr.

[0090] Before reaching position q7, the light reflected by the surface with X-axis curvature will first pass through position q8 and remain unfocused. After the light reflected by the surface with Y-axis curvature is focused at position q8, it will diverge forward and pass through position q7. Therefore, the area with the highest light brightness near the central axis CA is the area from position q7 to position q8. The brightness is higher in the X-axis direction near the central axis CA at position q7, and higher in the Y-axis direction near the central axis CA at position q8. The light brightness will decrease in other areas before and after the area from position q7 to position q8.

[0091] Therefore, after the light emitted by the backlight source BL is reflected by the backlight annular mirror TMr, a backlight source real image BL_re1 with an enlarged area and an elongated range (depth) is formed in front of the backlight annular mirror TMr.

[0092] like Figure 7 As shown, when the rectangular backlight source BL rotates an angle θy1 on the axis Y with the center of the backlight annular mirror TMr as the pivot point (i.e., the angle between the optical axis of the backlight beam of the backlight source BL and the central axis CA of the backlight annular mirror TMr on the axis Y is angle θy1), the equivalent focal length FL_x2 corresponding to the curvature of the X-axis is shortened to FL_x×cosθy1, and the equivalent focal length FL_y2 corresponding to the curvature of the Y-axis is elongated to FL_y / cosθy1. If the focal lengths FL_x and FL_y and the angle θy1 are properly adjusted, there is a chance that FL_x×cosθy1 can be almost equal to FL_y / cosθy1. Under this condition, the light emitted by the backlight source BL will be focused at position q9 after being reflected by the backlight annular mirror TMr, and become a real image BL_re2 of the backlight source with an enlarged area, a small volume, and an overall bright color.

[0093] like Figure 8 As shown, when Figure 7When the backlight annular mirror TMr rotates 90 degrees with its central axis CA as the rotation center, the equivalent focal length FL_x3 corresponding to the X-axis curvature is shortened to FL_y×cosθy1, and the equivalent focal length FL_y3 corresponding to the Y-axis curvature is elongated to FL_x / cosθy1, FL_x / cosθy1>FL_x>FL_y>FL_y×cosθy1. Under this condition, the light emitted by the backlight source BL will be reflected by the backlight annular mirror TMr to become a backlight source real image BL_re3 with an enlarged area and a longer range, ranging from the X-axis backlight focusing plane FPX to the Y-axis backlight focusing plane FPY.

[0094] like Fig. 9 As shown, the rectangular backlight source BL is on the central axis CA of the backlight annular mirror TMr, the focal length FL_x of the focus Fx corresponding to the X-axis curvature is greater than the focal length FL_y of the focus Fy corresponding to the Y-axis curvature, and the distance between the backlight source BL and the backlight annular mirror TMr is less than the focal length FL_x and also less than the focal length FL_y. Since the backlight source BL is farther from the focal point Fx and closer to the focal point Fy, the virtual image light generated by the light emitted by the backlight source BL after being reflected by the surface of the X-axis curvature on the backlight annular mirror TMr and extending backward will be focused on position q9, and the brightness in the axial direction X close to the central axis CA is higher, and the virtual image light generated by the light emitted by the backlight source BL after being reflected by the surface of the Y-axis curvature on the backlight annular mirror TMr and extending backward will be focused on position q10, and the brightness in the axial direction Y close to the central axis CA is higher. The distance between position q9 and the backlight annular mirror TMr is less than the distance between position q10 and the backlight annular mirror TMr.

[0095] The virtual image light generated by the light reflected by the surface of the X-axis curvature extends backwards and passes through position q10 before being focused at position q9 from far back. The virtual image light generated by the light reflected by the surface of the Y-axis curvature extends backwards and is focused at position q10 from far back, and then diverges forward and passes through position q9. The area with the highest light brightness on the central axis CA is the area from position q9 to position q10. The brightness is higher in the axial direction X near the central axis CA at position q9, and higher in the axial direction Y near the central axis CA at position q10. The light brightness in other areas before and after the area from position q9 to position q10 will decrease.

[0096] Therefore, after the light emitted by the backlight source BL is reflected by the backlight annular mirror TMr, a backlight source virtual image BL_im1 with an enlarged area and an elongated range is formed behind the backlight annular mirror TMr, ranging from the X-axis backlight focusing plane FPX to the Y-axis backlight focusing plane FPY.

[0097] like Fig.10As shown, the rectangular backlight source BL rotates an angle θy2 on the axis Y with the center of the backlight annular mirror TMr as the pivot point, and the equivalent focal length FL_x4 corresponding to the curvature of the X axis is shortened to FL_x×cosθy2, and the equivalent focal length FL_y4 corresponding to the curvature of the Y axis is elongated to FL_y / cosθy2. If the focal lengths FL_x and FL_y and the angle θy2 are properly adjusted, there is a chance that FL_x×cosθy2 can be almost equal to FL_y / cosθy2. Under this condition, the light emitted by the backlight source BL will be reflected by the backlight annular mirror TMr and will be focused at position q11, becoming a virtual image BL_im2 of the backlight source with an enlarged area, a small volume, and an overall bright color.

[0098] like Fig.11 As shown, Fig.10 The backlight annular mirror TMr rotates 90 degrees with its central axis CA as the rotation center. At this time, the equivalent focal length FL_x5 corresponding to the X-axis curvature is shortened to FL_y×cosθy2, and the equivalent focal length FL_y5 corresponding to the Y-axis curvature is elongated to FL_x / cosθy2, FL_x / cosθy2>FL_x>FL_y>FL_y×cosθy2. Under this condition, the light emitted by the backlight source BL is reflected by the backlight annular mirror TMr to become a backlight source real image BL_im3 with an enlarged area and a longer range, ranging from the X-axis backlight focusing plane FPX to the Y-axis backlight focusing plane FPY.

[0099] like Fig.12 A list showing the change of the real image of the backlight source as lengthening or shortening when the off-axis direction is the X-axis or the off-axis direction is the Y-axis, if the rotation angle is from 0 degrees to 90 degrees or from 90 degrees to 0 degrees, under the condition that the X-axis curvature of the backlight annular mirror is greater than the Y-axis curvature, or the X-axis curvature is less than the Y-axis curvature.

[0100] From the above results, it can be seen that if the equivalent focal length of the backlit annular mirror TMr in the axial X and axial Y is almost equal, Fig.13A As shown, the light emitted by the backlight source BL is reflected by the backlight annular mirror TMr and focused to form a backlight source virtual image BL_im4 with enlarged area, small volume and overall brightness. The backlight source virtual image BL_im4 is then reflected by the imaging concave mirror Mr_F and the imaging semi-reflective mirror Mr_SR to form a backlight source real image BL_re4 with small volume and overall brightness, which is the eye box EB.

[0101] If the equivalent focal length of the backlit annular mirror TMr in the X-axis and the Y-axis is different, such as Fig. 13BAs shown, the light emitted by the backlight source BL is reflected by the backlight annular mirror TMr and focused into a bright backlight source virtual image BL_im5 with an enlarged area and a slightly larger volume. The backlight source virtual image BL_im5 is then reflected by the imaging concave mirror Mr_F and the imaging semi-reflective mirror Mr_SR to form a bright backlight source real image BL_re5 with a slightly longer range, which is the eye box EB.

[0102] When using a heads-up display, as the viewer's eyes move back and forth, Fig.13A and Fig. 13B The eye box EB will not overlap with the moved eye, making the image seen by the viewer dim and blurry. At this time, the backlight annular mirror TMr can be rotated 90 degrees with its central axis CA as the rotation center, as shown in FIG. Fig. 13C As shown, the eye box EB is stretched forward and backward so that the eye box EB can still cover the viewer's eyes after moving, so that the viewer can see bright and clear images.

[0103] The following is an exemplary description of how the head-up display adjusts the range of the eye box EB through the backlight annular mirror TMr.

[0104] <Example 1>

[0105] like Fig.14A As shown, the Y-axis curvature of the backlight annular mirror TMr is greater than the X-axis curvature, so that the focal length of the axial Y is smaller than the focal length of the axial X; the backlight source BL deviates downward from the central axis CA of the backlight annular mirror TMr by an angle θy3 in the axial Y. Under this condition, the backlight beam forms a backlight source virtual image BL_im6 behind the backlight annular mirror TMr, which is enlarged in area, small in volume, and bright overall.

[0106] After the light emitted by the backlight virtual image BL_im6 passes through the display panel DP, it is reflected by the imaging concave mirror Mr_F and the imaging semi-reflective mirror Mr_SR to form a small and bright backlight real image BL_re6, that is, the eye box EB. At this time, the viewer's eyes overlap with the eye box EB.

[0107] like Fig. 14B As shown, Fig.14A The backlight annular mirror TMr rotates 90 degrees with its central axis CA as the rotation center, and the backlight beam of the backlight source BL will form an elongated backlight source virtual image BL_im7 behind the backlight annular mirror TMr.

[0108] After the light emitted by the backlight virtual image BL_im7 passes through the display panel DP, it is reflected by the imaging concave mirror Mr_F and the imaging semi-reflective mirror Mr_SR to form an elongated backlight real image BL_re7, that is, an eye box EB elongated front to back. The range of this eye box EB is from the X-axis backlight focusing plane FPX to the Y-axis backlight focusing plane FPY, which can keep the viewer's eyes within the eye box EB when the viewer's eyes move back and forth.

[0109] Although the brightness of this elongated eye box EB is dispersed into an elongated range, the image seen by the viewer within the elongated eye box range can still remain bright and clear as long as the brightness of the backlight source is increased.

[0110] <Example 2>

[0111] like Fig.15A As shown, the Y-axis curvature of the backlight annular mirror TMr is greater than the X-axis curvature, so that its focal length in the axial Y is smaller than the focal length in the axial X; the backlight source BL deviates downward from the central axis CA of the backlight annular mirror TMr in the axial Y by an angle θy4. Under this condition, the backlight beam will form a bright backlight source virtual image BL_im8 with an enlarged area, slightly larger volume, behind the backlight annular mirror TMr.

[0112] After the light emitted by the backlight virtual image BL_im8 passes through the display panel DP, it is reflected by the imaging concave mirror Mr_F and the imaging semi-reflective mirror Mr_SR to form a slightly longer and overall bright backlight real image BL_re8, which is the eye box EB. The range of this eye box EB is from the X-axis backlight focusing plane FPX to the Y-axis backlight focusing plane FPY. At this time, the viewer's eyes are in the eye box EB.

[0113] like Fig. 15B As shown, Fig.15A The backlight annular mirror TMr rotates 45 degrees with its central axis CA as the rotation center, and the backlight beam of the backlight source BL will form an elongated backlight source virtual image BL_im9 behind the backlight annular mirror TMr.

[0114] After the light emitted by the backlight virtual image BL_im9 penetrates the display panel DP, it is reflected by the imaging concave mirror Mr_F and the imaging semi-reflective mirror Mr_SR to form an elongated backlight real image BL_re9, that is, an eye box EB elongated front to back. The range of this eye box EB is from the X-axis backlight focusing plane FPX to the Y-axis backlight focusing plane FPY, which can keep the viewer's eyes within the eye box EB when the viewer's eyes move a short distance forward and backward.

[0115] like Fig. 15C As shown, Fig.15AThe backlight annular mirror TMr rotates 90 degrees with its central axis CA as the rotation center, and the backlight beam of the backlight source BL will form a relatively long backlight source virtual image BL_im10 behind the backlight annular mirror TMr.

[0116] After the light emitted by the backlight virtual image BL_im10 penetrates the display panel DP, it is reflected by the imaging concave mirror Mr_F and the imaging semi-reflective mirror Mr_SR to form an elongated backlight real image BL_re10, that is, an eye box EB that is elongated front to back. The range of this eye box EB is from the X-axis backlight focusing plane FPX to the Y-axis backlight focusing plane FPY, which can keep the viewer's eyes within the eye box EB when the viewer's eyes move a long distance back and forth.

[0117] Although the brightness of the extended eye box EB is dispersed into a longer range, the image seen by the viewer in the extended eye box EB can still be bright and clear as long as the brightness of the backlight source BL is increased.

[0118] <Example 3>

[0119] like Fig.16A As shown, the X-axis curvature of the backlight annular mirror TMr is greater than the Y-axis curvature, so that the focal length of the axial X is smaller than the focal length of the axial Y; the backlight source BL deviates from the central axis CA of the backlight annular mirror TMr to the right by an angle θx5 in the axial X. Under this condition, the backlight beam forms a backlight source virtual image BL_im11 behind the backlight annular mirror TMr with an enlarged area, a shallow range, and an overall bright color.

[0120] After the light emitted by the backlight virtual image BL_im11 passes through the display panel DP, it is reflected by the imaging concave mirror Mr_F and the imaging semi-reflective mirror Mr_SR to form a shallow and overall bright backlight real image BL_re11, that is, the eye box EB. At this time, the viewer's eyes overlap with the eye box EB.

[0121] like Fig. 16B As shown, Fig.16A The backlight annular mirror TMr rotates 90 degrees with its central axis CA as the rotation center, and the backlight beam of the backlight source BL will form an elongated backlight source virtual image BL_im12 behind the backlight annular mirror TMr.

[0122] After the light emitted by the backlight virtual image BL_im12 passes through the display panel DP, it is reflected by the imaging concave mirror Mr_F and the imaging semi-reflective mirror Mr_SR to form an elongated backlight real image BL_re12, that is, an eye box EB elongated front to back. The range of this eye box EB is from the X-axis backlight focusing plane FPX to the Y-axis backlight focusing plane FPY, which can keep the viewer's eyes within the eye box EB when the viewer's eyes move back and forth.

[0123] Although the brightness of the elongated eye box EB is dispersed into the elongated range, the image seen by the viewer in the elongated eye box EB can still be bright and clear as long as the brightness of the backlight source BL is increased.

[0124] <Example 4>

[0125] like Fig.17A As shown, the X-axis curvature of the backlight annular mirror TMr is greater than the Y-axis curvature, so that the focal length of the axial X is smaller than the focal length of the axial Y; the backlight source BL deviates from the central axis CA of the backlight annular mirror TMr to the right by an angle θx6 in the axial X. Under this condition, the backlight beam forms a bright backlight source virtual image BL_im13 behind the backlight annular mirror TMr with an enlarged area and a slightly longer range.

[0126] After the light emitted by the backlight virtual image BL_im13 passes through the display panel DP, it is reflected by the imaging concave mirror Mr_F and the imaging semi-reflective mirror Mr_SR to form a slightly longer and overall bright backlight real image BL_re13, which is the eye box EB. The range of this eye box EB is from the X-axis backlight focusing plane FPX to the Y-axis backlight focusing plane FPY. At this time, the viewer's eyes are in the eye box EB.

[0127] like Fig. 17B As shown, Fig.17A The backlight annular mirror TMr rotates 45 degrees with its central axis CA as the rotation center, and the backlight beam of the backlight source BL will form an elongated backlight source virtual image BL_im14 behind the backlight annular mirror TMr.

[0128] After the light emitted by the backlight virtual image BL_im14 passes through the display panel DP, it is reflected by the imaging concave mirror Mr_F and the imaging semi-reflective mirror Mr_SR to form an elongated backlight real image BL_re14, that is, an eye box EB elongated front to back. The range of this eye box EB is from the X-axis backlight focusing plane FPX to the Y-axis backlight focusing plane FPY, which can keep the viewer's eyes within the eye box EB when the viewer's eyes move a short distance forward and backward.

[0129] like Fig. 17C As shown, Fig.17AThe backlight annular mirror TMr rotates 90 degrees with its central axis CA as the rotation center, and the backlight beam of the backlight source BL will form a relatively long backlight source virtual image BL_im15 behind the backlight annular mirror TMr.

[0130] After the light emitted by the backlight virtual image BL_im15 penetrates the display panel DP, it is reflected by the imaging concave mirror Mr_F and the imaging semi-reflective mirror Mr_SR to form an elongated backlight real image BL_re15, that is, an eye box EB that is elongated front to back. The range of this eye box EB is from the X-axis backlight focusing plane FPX to the Y-axis backlight focusing plane FPY, which can keep the viewer's eyes within the eye box EB when the viewer's eyes move a long distance back and forth.

[0131] Although the brightness of the extended eye box EB is dispersed into a longer range, the image seen by the viewer in the extended eye box EB can still be bright and clear as long as the brightness of the backlight source BL is increased.

[0132] exist Fig. 17C In the case of the backlight annular mirror TMr, if the backlight annular mirror TMr is rotated 45 degrees in the opposite direction with its central axis CA as the rotation center, the eye box EB is shortened from a long range to a short range. Fig. 17B The range is slightly shorter.

[0133] exist Fig. 17C In the state of the backlight annular mirror TMr, if the backlight annular mirror TMr is rotated 90 degrees in the opposite direction with its central axis CA as the rotation center, the eye box EB is shortened from a long range to a short range. Fig.17A A state with a shorter range.

[0134] In the present invention, the angle of rotation of the backlight annular mirror TMr in situ can be 45 degrees and 90 degrees, or it can be a rotation angle of any angle value. Different rotation angle amplitudes can have different degrees of eye box lengthening or shortening effects. For example, in the range of 0 to 90 degrees, the larger the rotation angle amplitude, the greater the range change of the eye box EB, and the smaller the rotation angle amplitude, the smaller the range change of the eye box EB. The effect from 90 degrees to 180 degrees is the same as the effect from 90 degrees to 0 degrees; the effect from 180 degrees to 270 degrees is the same as the effect from 0 degrees to 90 degrees; the effect from 270 degrees to 360 degrees is the same as the effect from 90 degrees to 0 degrees.

[0135] In the present invention, the longer the eye box EB is stretched, the more dispersed the brightness is, and the higher the backlight source BL brightness needs to be increased; the shorter the eye box EB is, the less dispersed the brightness is, and the lower the backlight source BL brightness needs to be increased.

[0136] In addition, the head-up display of the present invention may further include a controller (not shown), an eye tracking system (not shown) and a driving module (not shown). The controller is electrically connected to the eye tracking system, the driving module, the backlight source and the display panel DP to control the operation of the driving module and the backlight source according to information provided by the eye tracking system.

[0137] The eye tracking system can detect the forward and backward displacement of the viewer's eyes. The controller adjusts the rotation angle of the backlight ring mirror TMr accordingly, and adjusts the brightness of the backlight source accordingly, so that the eye box is stretched or shortened to the position of the eyes, ensuring that the viewer can continue to see the same bright, clear and complete image.

[0138] The driving module drives the backlight annular mirror TMr to make the backlight annular mirror TMr rotate according to the angle set by the controller.

[0139] Although the present invention is disclosed as above with the aforementioned embodiments, these embodiments are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, all modifications, modifications and combinations of various embodiments are within the scope of patent protection of the present invention. Please refer to the attached patent application for the scope of protection defined by the present invention.

Claims

1. A head-up display using a backlit annular mirror to adjust the eye box, suitable for use with an imaging half-reflective mirror, characterized in that: Include: a backlight source for projecting a backlight beam; a backlight annular mirror, rotatable and having an X-axis curvature on the X-axis and a Y-axis curvature on the Y-axis, the X-axis curvature being different from the Y-axis curvature, the backlight annular mirror being used to reflect the backlight beam of the backlight source; a display panel configured to display an image and allow the backlight beam reflected by the backlight annular mirror to pass through to form an image beam; and an imaging concave mirror, configured to reflect the image beam to the imaging semi-reflective mirror to form a display panel virtual image located on a side of the imaging semi-reflective mirror away from a viewer and a backlight real image located on a side of the imaging semi-reflective mirror close to the viewer and located at the viewer's eyes, the backlight real image being an eye box; Among them, there is an off-axis optical path between the backlight source and the backlight annular mirror, the backlight source is reflected by the X-axis curvature and focused on an X-axis backlight focusing plane, the backlight source is reflected by the Y-axis curvature and focused on a Y-axis backlight focusing plane, the range of the eye box is from the X-axis backlight focusing plane to the Y-axis backlight focusing plane, and the rotation of the backlight annular mirror makes the range of the eye box lengthen or shorten on the imaging optical path of the real image of the backlight source, so that the viewer's eyes remain in the eye box when moving on the imaging optical path of the real image of the backlight source.

2. The head-up display with eye box adjustment using a backlit annular mirror according to claim 1, characterized in that: The backlight annular mirror rotates with its central axis as the rotation center.

3. The head-up display with eye box adjustment using backlit annular mirror according to claim 1, characterized in that: When there is an angle in the Y-axis direction between the optical axis of the backlight beam and the central axis of the backlight annular mirror, the backlight annular mirror rotates at an angle with its central axis as the rotation center, and the X-axis curvature of the surface of the backlight annular mirror illuminated by the backlight beam is smaller than the Y-axis curvature, the range of the eye box is lengthened as the rotation angle increases from 0 degrees to 90 degrees, and the range of the eye box is shortened as the rotation angle decreases from 90 degrees to 0 degrees.

4. The head-up display with eye box adjustment using backlit annular mirror according to claim 1, characterized in that: When there is an angle in the Y-axis direction between the optical axis of the backlight beam and the central axis of the backlight annular mirror, the backlight annular mirror rotates at an angle with its central axis as the rotation center, and the X-axis curvature on the surface of the backlight annular mirror illuminated by the backlight beam is greater than the Y-axis curvature, the range of the eye box shortens as the rotation angle increases from 0 degrees to 90 degrees, and the range of the eye box lengthens as the rotation angle decreases from 90 degrees to 0 degrees.

5. The head-up display with eye box adjustment using backlit annular mirror according to claim 1, characterized in that: When there is an angle in the X-axis direction between the optical axis of the backlight beam and the central axis of the backlight annular mirror, the backlight annular mirror rotates at an angle with its central axis as the rotation center, and the X-axis curvature of the surface of the backlight annular mirror illuminated by the backlight beam is smaller than the Y-axis curvature, the range of the eye box shortens as the rotation angle increases from 0 degrees to 90 degrees, and the range of the eye box lengthens as the rotation angle decreases from 90 degrees to 0 degrees.

6. The head-up display with eye box adjustment using backlit annular mirror according to claim 1, characterized in that: When there is an angle in the X-axis direction between the optical axis of the backlight beam and the central axis of the backlight annular mirror, the backlight annular mirror rotates at an angle with its central axis as the rotation center, and the X-axis curvature of the surface of the backlight annular mirror illuminated by the backlight beam is greater than the Y-axis curvature, the range of the eye box is lengthened as the rotation angle increases from 0 degrees to 90 degrees, and the range of the eye box is shortened as the rotation angle decreases from 90 degrees to 0 degrees.

7. The head-up display with eye box adjustment using backlit annular mirror according to claim 1, characterized in that: When the backlight annular mirror rotates to extend the range of the eye box, the brightness of the backlight source is increased.

8. The head-up display with eye box adjustment using backlit annular mirror according to claim 1, characterized in that: When the backlight annular mirror rotates to shorten the range of the eye box, the brightness of the backlight source is reduced.

9. The head-up display with eye box adjustment using backlit annular mirror according to claim 1, characterized in that: The imaging semi-reflecting mirror is a windshield or a stacking mirror, which is used to reflect the image light beam from the imaging concave mirror to the eyes of the viewer, and at the same time allow the light of the scene in front of it to penetrate partially to the eyes of the viewer.

Images