Head-up display

Abstract

The head-up display device of this application uses a polarization assembly and a polarization control assembly in conjunction with a backlight to achieve local dimming functionality. The polarization assembly and polarization control assembly have high transmittance, thus improving the overall transmittance of the head-up display device, while using a low-power backlight. The head-up display device further employs a biaxial compensation film or two uniaxial compensation films to improve its contrast.

Description

Technical Field

[0001] This application relates to a head-up display device, and more particularly to a head-up display device with improved transmittance and contrast. Background Technology

[0002] A head-up display (HUD) allows information from the vehicle's infotainment system to be displayed at the driver's line of sight while driving. This eliminates the need for the driver to look down, preventing brief periods of distraction and potential hazards. For example, information such as vehicle speed allows the driver to know their speed without looking down at the dashboard, thus improving safety.

[0003] Figure 1 This diagram illustrates the application of a traditional head-up display (HUD) in a car. Figure 1 The head-up display 10 includes a picture generation unit (PGU) 12, a freeform surface mirror (FFM) 14, and a freeform surface mirror 16. The picture generation unit 12 is used to display and project an image P1. The freeform surface mirrors 14 and 16 are positioned in the optical path of the image P1 to reflect the image P1 onto the windshield 18 of the vehicle. Finally, the image P1 is reflected through the windshield 18 to the driver's eyes 20, allowing the driver to see a virtual image 22, the content of which is consistent with the image P1.

[0004] A conventional image generation unit 12 includes a display panel and a backlight panel. The backlight panel provides light to the display panel. The display panel displays an image P1 and generates transmitted light including the image P1 based on the light source. The backlight panel may have a local dimming function to control the intensity distribution of the transmitted light.

[0005] Figure 2a Display backlight panel 122 with local dimming function. Figure 2b show Figure 2a The virtual image 22 when the entire area of ​​the backlight panel 122 is lit. Figure 3a Display backlight panel 122 with local dimming function. Figure 3b show Figure 3a The virtual image 22 when a portion of the backlight panel 122 is illuminated. For example... Figures 2a to 3b As shown, the backlight panel 122 has multiple regions 1222, and the brightness of each region 1222 can be individually controlled. When all regions 1222 of the backlight panel 122 are lit, the virtual image 22 can display the complete image P1, as shown. Figure 2a and Figure 2b As shown. When only a portion of the backlight panel 122 is illuminated, the virtual image 22 only displays a portion of the image P1, as shown. Figure 3a and Figure 3b As shown. Figures 2a to 3b As shown, when only a portion of the display panel displays the image P1, the backlight panel 122 can only illuminate the area 1222 corresponding to the image P1 to reduce power consumption.

[0006] Figure 4 This is a cross-sectional schematic diagram of a traditional head-up display device with local dimming functionality. Figure 4 The head-up display device 30 includes a backlight panel 32, a display panel 34, and a mirror assembly 36. The backlight panel 32 and the display panel 34 constitute... Figure 1 The image generation unit 12. The lens group 36 includes Figure 1 At least one of freeform mirrors 14 and 16. The display panel 34 includes a first polarizer 342, a thin-film transistor liquid crystal display 344, and a second polarizer 346. The first polarizer 342 and the second polarizer 346 are respectively disposed on a first side and a second side of the thin-film transistor liquid crystal display 344, wherein the first side and the second side are opposite to each other. The backlight panel 32 has a plurality of regions 322, each region 322 being independently controllable in brightness. However, in Figure 4 In the head-up display device 30, to avoid mutual interference between the light from different areas 322, the emission angle θ of each area 322 is relatively small, thus making it easier to generate stray light, such as... Figure 5 The light rays are shown in 40 and 42.

[0007] Figure 6 This is a cross-sectional schematic diagram of a traditional head-up display device for improving stray light issues. Figure 6 Head-up display device 50 and Figure 4 The head-up display device 30 also includes a display panel 34 and a lens assembly 36. In addition, the head-up display device 50 also includes a backlight 52, a third polarizer 54, and a thin-film transistor liquid crystal display 56. The backlight 52 is a single light source, thus reducing stray light problems, such as... Figure 7 As shown, the head-up display (HUD) 50 uses a third polarizer 54 and a thin-film transistor liquid crystal display (TFT-LCD) 56 to achieve local dimming. Specifically, the TFT-LCD 56 has multiple regions (not shown). The TFT-LCD 56 controls the twisting of liquid crystal molecules in each region to control the transmittance of each region, thereby achieving local dimming. However, the light emitted by the backlight 52 must pass through the third polarizer 54 and the TFT-LCD 56, resulting in a lower overall transmittance of the HUD 50. Therefore, the HUD 50 requires a higher-power backlight 52, leading to a decrease in the efficiency of the HUD 50. Summary of the Invention

[0008] One of the purposes of this application is to provide a head-up display device with improved transmittance.

[0009] One of the objectives of this application is to provide a head-up display device with improved contrast.

[0010] The head-up display device of this application includes: a backlight for providing a first light source, the first light source being unpolarized light; a display panel for displaying and projecting images; a polarizing component between the backlight and the display panel for generating a second light source based on the first light source, the second light source being linearly polarized light; and a polarization control component between the polarizing component and the display panel, having multiple regions for generating a third light source for the display panel based on the second light source, the polarization control component controlling the transmittance of the multiple regions.

[0011] In one embodiment, the head-up display device of this application further includes a mirror group disposed on the light path of the image to reflect the image to the outside of the head-up display device.

[0012] In one embodiment, the head-up display device of this application further includes a biaxial compensation film, which is located near the surface of the display panel in multiple regions and generates a fourth ray to the display panel based on the third ray. The biaxial compensation film is used to convert the elliptically polarized light in the third ray into linearly polarized light.

[0013] In one embodiment, the head-up display device of this application further includes a biaxial compensation film, which is located on the surface of the display panel near the polarization control component and generates a fourth ray to the display panel based on the third ray. The biaxial compensation film is used to convert the elliptically polarized light in the third ray into linearly polarized light.

[0014] In one embodiment, the head-up display device of this application further includes: a first uniaxial compensation film located near the surface of the display panel in multiple regions, and generating a fourth ray to the display panel based on a third ray, the first uniaxial compensation film being used to convert elliptically polarized light in the third ray into linearly polarized light; and a second uniaxial compensation film located near the surface of the polarization control component in the display panel, and generating a fifth ray to the display panel based on the fourth ray, the second uniaxial compensation film being used to convert elliptically polarized light in the fourth ray into linearly polarized light; wherein the optical axis direction of the first uniaxial compensation film is perpendicular to the direction of the second uniaxial compensation film.

[0015] In one embodiment, the display panel includes: a thin-film transistor liquid crystal display (TFT-LCD) for displaying images; a first polarizer disposed on a first side of the TFT-LCD; and a second polarizer disposed on a second side of the TFT-LCD opposite to the first side.

[0016] In one embodiment, the polarizing component includes a reflective polarizer.

[0017] In one embodiment, the polarizing component includes a reflective polarizing brightness enhancement film.

[0018] In one embodiment, the polarization control component includes a twisted liquid crystal display.

[0019] In one embodiment, the polarization control component includes a super-twist liquid crystal display. Attached Figure Description

[0020] Figure 1 This diagram illustrates the application of a traditional head-up display (HUD) in a car.

[0021] Figure 2a Displays a backlight panel with local dimming functionality.

[0022] Figure 2b show Figure 2a The virtual image when the entire backlight panel is lit.

[0023] Figure 3a Displays a backlight panel with local dimming functionality.

[0024] Figure 3b show Figure 3a The virtual image when a portion of the backlight panel is illuminated.

[0025] Figure 4 This is a cross-sectional schematic diagram of a traditional head-up display device with local dimming functionality.

[0026] Figure 5 show Figure 4 The problem of stray light from head-up display devices.

[0027] Figure 6 This is a cross-sectional schematic diagram of a traditional head-up display device for improving stray light issues.

[0028] Figure 7 show Figure 6 The head-up display device can improve the stray light problem.

[0029] Figure 8 This invention discloses a first embodiment of the head-up display device.

[0030] Figure 9 This invention discloses a second embodiment of the head-up display device.

[0031] Figure 10 This application shows a third embodiment of the head-up display device.

[0032] Figure 11 This application shows a fourth embodiment of the head-up display device.

[0033] Explanation of reference numerals in the attached figures:

[0034] 10: Head-up display device

[0035] 12: Image Generation Unit

[0036] 122: Backlight

[0037] 1222: Region

[0038] 14: Freeform Mirror

[0039] 16: Freeform Mirror

[0040] 20: The Driver's Eyes

[0041] 22:Virtual image

[0042] 30: Head-up display device

[0043] 32: Backlight

[0044] 322: Area

[0045] 34: Display panel

[0046] 342: First polarizer

[0047] 344: Thin-film transistor liquid crystal display

[0048] 346: Second polarizer

[0049] 36: Lens assembly

[0050] 40: Light

[0051] 42: Light

[0052] 50: Head-up display device

[0053] 52: Backlight

[0054] 54: Third polarizer

[0055] 56: Thin-film transistor liquid crystal display

[0056] 60: Head-up display device

[0057] 62: Backlight

[0058] 64: Pivot Component

[0059] 66: Polarization control component

[0060] 68: Display panel

[0061] 682: First polarizer

[0062] 684: Thin-film transistor liquid crystal display

[0063] 686: Second polarizer

[0064] 70: Lens assembly

[0065] 72: Biaxial compensation membrane

[0066] 74: Biaxial compensation membrane

[0067] 80: Head-up display device

[0068] 90: Head-up display device

[0069] L1: First Ray

[0070] L2: Second Ray

[0071] L3: Third Ray

[0072] L3_E: Elliptically polarized light

[0073] L3_L: Linearly polarized light

[0074] L4: Fourth Ray

[0075] L5: Fifth Ray

[0076] P1: Image Detailed Implementation

[0077] Figure 8 This invention discloses a first embodiment of the head-up display device. Figure 8The head-up display device 60 includes a backlight 62, a polarizing assembly 64, a polarization control assembly 66, a display panel 68, and a lens assembly 70. The backlight 62 is a single light source, thus reducing stray light issues. The backlight 62 provides a first ray L1, where the first ray L1 is unpolarized light. The polarizing assembly 64, located between the backlight 62 and the display panel 68, generates a second ray L2 based on the first ray L1, where the second ray L2 is linearly polarized light. In one embodiment, the polarizing assembly 64 may be, but is not limited to, a reflective polarizer (RP) or a dual brightness enhancement film (DBEF). The polarization control assembly 66, located between the polarizing assembly 64 and the display panel 68, has multiple regions (not shown). The polarization control assembly 66 generates a third ray L3 for the display panel 68 based on the second ray L2. The polarization control assembly 66 controls the transmittance of the multiple regions, thereby achieving local dimming functionality. In one embodiment, the polarization control component 66 may be, but is not limited to, a twisted nematic (TN) liquid crystal display or a super twisted nematic (STN) liquid crystal display. The display panel 68 is used to display and project the image P1. The display panel 68 includes a first polarizer 682, a thin-film transistor liquid crystal display 684, and a second polarizer 686. The first polarizer 682 and the second polarizer 686 are respectively disposed on a first side and a second side of the thin-film transistor liquid crystal display 684, wherein the first side and the second side are opposite to each other. Figure 8 It consists of a backlight 62, a polarization assembly 64, a polarization control assembly 66, and a display panel 68. Figure 1 The image generation unit 12. The mirror assembly 70 is positioned along the optical path of image P1 to reflect image P1 to the outside of the head-up display device 60. The mirror assembly 70 includes... Figure 1 At least one of the freeform mirrors 14 and 16.

[0078] The head-up display device 60 of this application uses a polarization component 64 (such as RP or DBEF) and a polarization control component 66 (such as TN or STN) with high transmittance. Therefore, the overall transmittance of the head-up display device 60 is high, so the head-up display device 60 can use a lower power backlight 62 to improve efficiency.

[0079] like Figure 8 As shown, when the incident angle of the second ray L2 from the polarization assembly 64 is greater than the default value, the third ray L3 output by the polarization control assembly 66 may exhibit elliptically polarized light L3_E. In other words, the third ray L3 may include elliptically polarized light L3_E in addition to linearly polarized light L3_L. Elliptically polarized light L3_E may cause a decrease in the contrast of the head-up display device 60. Figure 9 This invention discloses a second embodiment of the head-up display device. Figure 9 The head-up display device 80 includes a backlight 62, a polarizing assembly 64, a polarization control assembly 66, a display panel 68, a lens assembly 70, and a biaxial compensation film 72. The backlight 62 is a single light source, thus reducing stray light problems. The backlight 62 provides a first ray L1, where the first ray L1 is unpolarized light. The polarizing assembly 64, located between the backlight 62 and the display panel 68, generates a second ray L2 based on the first ray L1, where the second ray L2 is linearly polarized light. The polarization control assembly 66, located between the polarizing assembly 64 and the display panel 68, has multiple regions (not shown). The polarization control assembly 66 generates a third ray L3 based on the second ray L2. The polarization control assembly 66 controls the transmittance of the multiple regions, thereby achieving local dimming functionality. The biaxial compensation film 72 is located near the surface of the display panel 68 in the multiple regions of the polarization control assembly 66. The biaxial compensation film 72 generates a fourth ray L4 for the display panel 68 based on the third ray L3. The biaxial compensation film 72 is used to convert the elliptically polarized light L3_E in the third ray L3 (e.g., Figure 8 The image P1 is converted into linearly polarized light L4_L (as shown). The display panel 68 is used to display and project the image P1. The display panel 68 includes a first polarizer 682, a thin-film transistor liquid crystal display 684, and a second polarizer 686. The first polarizer 682 and the second polarizer 686 are respectively disposed on a first side and a second side of the thin-film transistor liquid crystal display 684, wherein the first side and the second side are opposite to each other. Figure 9 It consists of a backlight 62, a polarization assembly 64, a polarization control assembly 66, a display panel 68, and a biaxial compensation film 72. Figure 1 The image generation unit 12. The mirror assembly 70 is positioned along the optical path of image P1 to reflect image P1 to the outside of the head-up display device 60. The mirror assembly 70 includes... Figure 1 At least one of the freeform mirrors 14 and 16.

[0080] The head-up display device 80 of this application uses a polarizing component 64 (such as RP or DBEF) and a polarization control component 66 (such as TN or STN) with high transmittance. Therefore, the overall transmittance of the head-up display device 80 is high, so the head-up display device 80 can use a lower power backlight 62 to improve efficiency. The head-up display device 80 of this application uses a biaxial compensation film 72 to eliminate or reduce elliptically polarized light L3_E, thereby improving the contrast of the head-up display device 80.

[0081] Figure 10 This application shows a third embodiment of the head-up display device. Figure 10The head-up display device 90 includes a backlight 62, a polarizing assembly 64, a polarization control assembly 66, a display panel 68, a lens assembly 70, and a biaxial compensation film 74. The backlight 62 is a single light source, thus reducing stray light problems. The backlight 62 provides a first ray L1, where the first ray L1 is unpolarized light. The polarizing assembly 64, located between the backlight 62 and the display panel 68, generates a second ray L2 based on the first ray L1, where the second ray L2 is linearly polarized light. The polarization control assembly 66, located between the polarizing assembly 64 and the display panel 68, has multiple regions (not shown). The polarization control assembly 66 generates a third ray L3 based on the second ray L2. The polarization control assembly 66 controls the transmittance of the multiple regions, thereby achieving local dimming functionality. The biaxial compensation film 74, located on the surface of the display panel 68 near the polarization control assembly 66, generates a fourth ray L4 for the display panel 68 based on the third ray L3. The biaxial compensation film 74 is used to convert the elliptically polarized light L3_E in the third ray L3 into linearly polarized light. The display panel 68 is used to display and project the image P1. The display panel 68 includes a first polarizer 682, a thin-film transistor liquid crystal display 684, and a second polarizer 686. The first polarizer 682 and the second polarizer 686 are respectively disposed on a first side and a second side of the thin-film transistor liquid crystal display 684, wherein the first side and the second side are opposite to each other. Figure 10 It consists of a backlight 62, a polarization assembly 64, a polarization control assembly 66, a display panel 68, and a biaxial compensation film 74. Figure 1 The image generation unit 12. The mirror assembly 70 is positioned along the optical path of image P1 to reflect image P1 to the outside of the head-up display device 60. The mirror assembly 70 includes... Figure 1 At least one of the freeform mirror 14 and freeform mirror 16.

[0082] The head-up display device 90 of this application uses a polarizing component 64 (such as RP or DBEF) and a polarization control component 66 (such as TN or STN) with high transmittance. Therefore, the overall transmittance of the head-up display device 90 is high, so the head-up display device 90 can use a lower power backlight 62 to improve efficiency. The head-up display device 90 of this application uses a biaxial compensation film 74 to eliminate or reduce elliptically polarized light L3_E, thereby improving the contrast of the head-up display device 90.

[0083] Figure 11 This application shows a fourth embodiment of the head-up display device. Figure 11The head-up display device 100 includes a backlight 62, a polarizing assembly 64, a polarization control assembly 66, a display panel 68, a lens group 70, a first uniaxial compensation film 76, and a second uniaxial compensation film 78. The backlight 62 is a single light source, thus reducing stray light problems. The backlight 62 provides a first ray L1, where the first ray L1 is unpolarized light. The polarizing assembly 64, located between the backlight 62 and the display panel 68, generates a second ray L2 based on the first ray L1, where the second ray L2 is linearly polarized light. The polarization control assembly 66, located between the polarizing assembly 64 and the display panel 68, has multiple regions (not shown). The polarization control assembly 66 generates a third ray L3 based on the second ray L2. The polarization control assembly 66 controls the transmittance of the multiple regions, thereby achieving local dimming functionality. The first uniaxial compensation film 76 is located near the surface of the display panel 68 in the multiple regions of the polarization control assembly 66. The first uniaxial compensation film 76 generates a fourth ray L4 based on the third ray L3. The first uniaxial compensation film 76 is used to convert the elliptically polarized light in the third ray L3 into linearly polarized light. The second uniaxial compensation film 78 is located on the surface of the display panel 68 near the polarization control component 66. The second uniaxial compensation film 78 generates a fifth ray L5 based on the fourth ray L4 and sends it to the display panel 68. The fourth ray L4 output by the first uniaxial compensation film 76 may still contain elliptically polarized light; therefore, the second uniaxial compensation film 78 is used to convert the elliptically polarized light in the fourth ray L4 into linearly polarized light. The display panel 68 is used to display and project the image P1. The display panel 68 includes a first polarizer 682, a thin-film transistor liquid crystal display 684, and a second polarizer 686. The first polarizer 682 and the second polarizer 686 are respectively disposed on a first side and a second side of the thin-film transistor liquid crystal display 684, wherein the first side and the second side are opposite each other. Figure 10 It consists of a backlight 62, a polarization assembly 64, a polarization control assembly 66, a display panel 68, and a biaxial compensation film 74. Figure 1 The image generation unit 12. The mirror assembly 70 is positioned along the optical path of image P1 to reflect image P1 to the outside of the head-up display device 60. The mirror assembly 70 includes... Figure 1 At least one of the freeform mirror 14 and freeform mirror 16.

[0084] The head-up display device 100 of this application uses a polarizing component 64 (such as RP or DBEF) and a polarization control component 66 (such as TN or STN) with high transmittance. Therefore, the overall transmittance of the head-up display device 100 is high, so the head-up display device 100 can use a lower power backlight 62 to improve efficiency. The head-up display device 100 of this application uses a first uniaxial compensation film 76 and a second uniaxial compensation film 78 to eliminate or reduce elliptically polarized light L3_E, thereby improving the contrast of the head-up display device 100.

[0085] The above description is merely an embodiment of this application and is not intended to limit this application in any way. Although this application has been disclosed above with reference to embodiments, it is not intended to limit this application. For those skilled in the art, without departing from the scope of the technical solution of this application, some modifications or alterations can be made to the above-disclosed technical content to create equivalent embodiments. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of this application without departing from the content of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A head-up display device, characterized in that, include: A backlight is used to provide a first light source, which is unpolarized light; Display panel, used to display and project images; A polarizing component is located between the backlight and the display panel to generate a second ray based on the first ray, wherein the second ray is linearly polarized light. A polarization control component, between the polarizing component and the display panel, has multiple regions for generating a third ray to the display panel based on the second ray, wherein the polarization control component controls the transmittance of the multiple regions. The head-up display device further includes a biaxial compensation film, which is located near the surface of the display panel in the multiple regions and generates a fourth ray to the display panel based on the third ray. The biaxial compensation film is used to convert elliptically polarized light in the third ray into linearly polarized light.

2. The head-up display device according to claim 1, characterized in that, The head-up display device also includes a lens group, which is disposed on the light path of the image and reflects the image to the outside of the head-up display device.

3. The head-up display device according to claim 1, characterized in that, The head-up display device further includes a biaxial compensation film on the surface of the display panel near the polarization control component, which generates a fourth ray to the display panel based on the third ray. The biaxial compensation film is used to convert the elliptically polarized light in the third ray into linearly polarized light.

4. The head-up display device according to claim 1, characterized in that, The head-up display device also includes: A first uniaxial compensation film is disposed near the surface of the display panel in the plurality of regions, and generates a fourth ray to the display panel according to the third ray, wherein the first uniaxial compensation film is used to convert elliptically polarized light in the third ray into linearly polarized light; and A second uniaxial compensation film is disposed on the surface of the display panel near the polarization control component, and generates a fifth ray to the display panel according to the fourth ray. The second uniaxial compensation film is used to convert the elliptically polarized light in the fourth ray into linearly polarized light. The optical axis of the first uniaxial compensation film is perpendicular to the direction of the second uniaxial compensation film.

5. The head-up display device according to claim 1, characterized in that, The display panel includes: A thin-film transistor liquid crystal display (TFT-LCD) for displaying the image; A first polarizer is disposed on a first side of the thin-film transistor liquid crystal display; and A second polarizer is disposed on the second side of the thin-film transistor liquid crystal display opposite to the first side.

6. The head-up display device according to claim 1, characterized in that, The polarizing assembly includes a reflective polarizer.

7. The head-up display device according to claim 1, characterized in that, The polarizing component includes a reflective polarizing brightness enhancement film.

8. The head-up display device according to claim 1, characterized in that, The polarization control component includes a twisted liquid crystal display.

9. The head-up display device according to claim 1, characterized in that, The polarization control component includes a super-twist liquid crystal display.

Images