Vehicle-mounted projection display system

Abstract

The utility model belongs to the technical field of vehicle-mounted display. The utility model provides a vehicle-mounted projection display system. The light beams emitted by the backlight source uniformly lighten the image display screen, the image display screen displays the image through the thin film transistor liquid crystal panel, and the image light beams formed by the light beams emitted by the image display screen and the image pass through the light beam modulation device and then are reflected to the windshield glass through the at least one reflection element. And the formed virtual image plane is presented in front of the visual field of human eyes. And when external sunlight enters the projection display system, the light beam modulation device blocks most of solar radiation, so that the damage of heat accumulation to internal components of the projection display system is reduced.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the field of vehicle-mounted display technology, and in particular to a vehicle-mounted projection display system. Background Art

[0002] Buses and coaches, used for public and group transport, have long driving distances, high cabs and long vehicles resulting in large blind spots, and complex road conditions. This creates significant workload for drivers, and coupled with the constant need to check the instrument panel and rearview mirror, driving accidents are highly likely to occur. Because public transportation is a form of mass transportation, accidents often result in major incidents and even numerous casualties.

[0003] The in-vehicle HUD displays driving information on the windshield, allowing the driver to quickly access information without looking down. Currently, in a bus cockpit, the driver's normal field of vision is primarily focused on the instrument panel, requiring repeated head-down adjustments to confirm information. This interaction undoubtedly impacts bus driving safety. The HUD, however, projects auxiliary driving information onto the windshield through "reflective projection." It is the visual interaction device closest to the driver's head-on field of view, effectively preventing the driver from looking down, allowing them to maintain a normal line of sight and clearly perceive relevant auxiliary information. Furthermore, its location within the main driving interface effectively ensures the driver's focus, reducing the safety risks associated with frequent shifts of sight.

[0004] Therefore, it is necessary to improve one or more problems existing in the above-mentioned related technical solutions.

[0005] It should be noted that this section is intended to provide background or context for the technical solutions of the present disclosure stated in the claims. The description herein is not admitted to be prior art by virtue of being included in this section. Utility Model Content

[0006] An object of the embodiments of the present disclosure is to provide a vehicle-mounted projection display system, thereby overcoming one or more problems caused by limitations and defects of related technologies, at least to a certain extent.

[0007] According to an embodiment of the present disclosure, a vehicle-mounted projection display system is provided, the system comprising:

[0008] Image display assembly and windshield; wherein,

[0009] The image display assembly includes a projection lighting unit, a light beam modulating device and a reflective element, wherein the projection lighting unit is connected to the light beam modulating device;

[0010] The image light beam emitted by the projection lighting unit passes through the light beam modulating device and is reflected by at least one of the reflective elements onto the windshield.

[0011] Furthermore, the projection lighting unit includes:

[0012] Backlight source and image display screen; wherein,

[0013] The backlight source is connected to the image display screen. The light beam emitted by the backlight source evenly illuminates the image display screen. The image and the light beam emitted by the image display screen pass through the light beam modulating device and are reflected by at least one of the reflective elements onto the windshield.

[0014] Furthermore, the backlight source includes:

[0015] LED light board, light mixing components, field lens and diffusion film; among them,

[0016] The LED light board, the light mixing component, the field lens and the diffusion film are connected in sequence.

[0017] Furthermore, the LED light board is a white light LED array, the light mixing component is a light rod or a fly-eye lens, the field lens is a Fresnel lens, and the divergence angle (H, V) of the diffusion film is (±6, ±3).

[0018] Furthermore, the image display screen includes:

[0019] Lower polarizer, thin film liquid crystal tube, alignment film, filter film, upper polarizer and LCD display; Among them,

[0020] The lower polarizer, the thin film liquid crystal tube, the alignment film, the filter film, the upper polarizer and the LCD display screen are connected in sequence.

[0021] Furthermore, the transmittance of the image display screen is 8.5% to 50%, the operating temperature is -40°C to 85°C, the power supply voltage is 3V to 6.5V, and the input voltage is 0.1V to 0.3V.

[0022] Furthermore, the light beam modulation device includes:

[0023] A linear polarizer and a phase modulator, wherein the linear polarizer includes an infrared cold light reflecting film and a visible light reflecting polarizing film; wherein,

[0024] The backlight source, the visible light reflecting polarizing film, the image display screen, the phase modulator and the infrared cold light reflecting film are connected in sequence.

[0025] Furthermore, the reflectivity of the infrared cold light reflective film is 50%~90%, the transmittance is 43%~80%, and the operating temperature is -40℃~105℃; the reflectivity of one side of the visible light reflective polarizing film is 90%~100%, and the transmittance of the other side is 80%~100%.

[0026] Furthermore, the phase modulator is a quarter-wave plate.

[0027] The technical solutions provided by the embodiments of the present disclosure may have the following beneficial effects:

[0028] In an embodiment of the present disclosure, the above-mentioned vehicle-mounted projection display system, on the one hand, uses a light beam emitted by a backlight source to evenly illuminate an image display screen, which displays images using a thin-film transistor liquid crystal panel. An image beam, consisting of the light beam emitted by the image display screen and the image, passes through a light beam modulator and is reflected by at least one reflective element onto the windshield, resulting in a virtual image plane that appears in front of the human eye's field of view. Furthermore, when external sunlight enters the projection display system, the light beam modulator blocks most of the solar radiation, reducing damage to the internal components of the projection display system caused by heat accumulation. On the other hand, the image beam is projected onto the front windshield, which is almost perpendicular to the ground, for imaging. The light beam modulator controls the solar radiation entering the projection display system, reducing heat accumulation within the system, increasing the brightness of the projected image, and enhancing the display effect, so that a high-definition, high-brightness image is displayed in front of the driver's field of view, thereby improving driving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification, are used to explain the principles of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0030] Figure 1 A schematic diagram showing an in-vehicle projection display system in an exemplary embodiment of the present disclosure is shown;

[0031] Figure 2 A schematic structural diagram showing a flowchart image display component in an exemplary embodiment of the present disclosure is shown;

[0032] Figure 3 A flowchart of an image display screen in an exemplary embodiment of the present disclosure is shown.

[0033] In the figure, 1. Backlight source; 101. LED light board; 102. Light mixing component; 103. Field lens; 104. Diffuser film; 2. Image display screen; 201. Lower polarizer; 202. Thin-film liquid crystal tube; 203. Alignment film; 204. Filter film; 205. Upper polarizer; 206. LCD display screen; 3. Light beam modulation device; 301. Infrared cold light reflective film; 302. Phase modulator; 303. Visible light reflective polarizing film; 4. Reflective element; 5. Front windshield; 6. Human eye; 7. Virtual image plane. DETAILED DESCRIPTION

[0034] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be embodied in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0035] In addition, the accompanying drawings are merely schematic illustrations of embodiments of the present disclosure and are not necessarily drawn to scale. Like reference numerals in the figures represent like or similar parts, and thus repeated descriptions thereof will be omitted. Some of the blocks shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically separate entities.

[0036] This exemplary embodiment provides a vehicle-mounted projection display system. Figure 1 As shown in , the vehicle-mounted projection display system may include: an image display component and a windshield; wherein,

[0037] The image display assembly comprises a projection lighting unit, a light beam modulating device (3) and a reflective element (4), wherein the projection lighting unit and the light beam modulating device (3) are connected; an image light beam emitted by the projection lighting unit passes through the light beam modulating device (3) and is reflected onto the windshield by at least one of the reflective elements (4).

[0038] Specifically, the projection lighting unit passes the image light beam generated by it through the light beam modulation device (3) and is reflected by at least one reflective element (4) onto the windshield. The windshield then refracts the image light beam to the human eye (6), so that the human eye can see the formed virtual image plane (7).

[0039] With the above-described vehicle-mounted projection display system, on the one hand, the light beam emitted by the backlight source evenly illuminates the image display screen, which displays images on a thin-film transistor liquid crystal panel. The image beam, composed of the light beam emitted by the image display screen and the image, passes through a beam modulator and is reflected by at least one reflective element onto the windshield, resulting in a virtual image plane that appears in front of the human eye's field of view. Furthermore, when external sunlight enters the projection display system, the beam modulator blocks most of the solar radiation, reducing damage to the internal components of the projection display system caused by heat accumulation. Furthermore, the image beam is projected onto the front windshield, which is nearly perpendicular to the ground, for imaging. The beam modulator controls the solar radiation entering the projection display system, reducing heat accumulation within the system, increasing the brightness of the projected image, and enhancing the display quality. This allows a high-definition, high-brightness image to be displayed in front of the driver's field of view, thereby improving driving safety.

[0040] Below, we will refer to Figures 1 to 3 Each part of the above-mentioned vehicle-mounted projection display system in this exemplary embodiment will be described in more detail.

[0041] In one embodiment, Figure 2 As shown, the backlight source (1) comprises: an LED light board (101), a light mixing component (102), a field lens (103) and a diffusion film (104); wherein the LED light board (101), the light mixing component (102), the field lens (103) and the diffusion film (104) are connected in sequence.

[0042] Specifically, the backlight module is used to transform the light emitted by the light source into a surface light source through diffuse reflection. The light source is responsible for providing device illumination; the lighting system converges and guides the light emitted by the light source, shrinking the light to the angle required by the optical path design while increasing the light diffusion area; the diffusion film scatters the light to form a secondary light source, eliminating optical images, forming uniform illumination, and ultimately achieving good brightness uniformity and high-resolution images. Figure 2 In the projection lighting system, a backlight source (1) uses an LED light panel (101) as a light source to emit a light beam. The light beam passes through a light mixing component (102) to make the light beam uniformly emitted. The light output angle is optimized by a field lens (103). The light is then mixed again by a diffusion film (104) and the output angle is distributed. The light beam uniformly illuminates the image display screen (2).

[0043] Furthermore, the LED light board (101) is a white light LED array with a brightness of not less than 1,200,000 nits, the light mixing component (102) can be a light rod or a compound eye lens, the field lens (103) can be a Fresnel lens, and the divergence angle (H, V) of the diffusion film (104) should be not less than (±6, ±3). The backlight brightness uniformity is not less than 80%.

[0044] In one embodiment, Figure 3 As shown, the image display screen (2) comprises: a lower polarizer (201), a thin film liquid crystal tube (202), an alignment film (203), a filter film (204), an upper polarizer (205) and an LCD display screen (206); wherein the lower polarizer (201), the thin film liquid crystal tube (202), the alignment film (203), the filter film (204), the upper polarizer (205) and the LCD display screen (206) are connected in sequence.

[0045] Specifically, the image display screen (2) is a thin film transistor liquid crystal display liquid crystal panel, which uses a transmissive liquid crystal light valve with fast response and high contrast as a spatial light modulator. Since liquid crystal is a substance between liquid and solid and does not emit light itself, the arrangement of liquid crystal molecules can change under the action of an electric field. Therefore, by utilizing the photoelectric effect of liquid crystal and controlling the transmittance of the liquid crystal unit through an electrical signal, the purpose of accurately controlling the light passing through the liquid crystal unit can be achieved, thereby generating images with different gray levels and colors on the screen. Figure 3 The outgoing light beam of the backlight source (1) is converted into vertically polarized light through the lower polarizer (201). The vertically polarized light passes through the thin film liquid crystal tube (202). The polarized light is configured using the alignment film (203). Under the action of the liquid crystal molecules, the vertically polarized light is converted into horizontally polarized light and passes through the upper polarizer (205). The LCD display (206) will display white. The electric field generated by the electrodes on both sides of the liquid crystal tube is energized. Under the action of the electric field, the liquid crystal molecules will be twisted. The vertically polarized light passes through the liquid crystal tube without changing the vibration direction and cannot pass through the upper polarizer (205). The LCD display (206) will display black.

[0046] Furthermore, the image display screen (2) projects colors, and utilizes a color filter film (204). The light beam passes through the color filter film (204) to form red light, green light, and blue light. By changing the chromaticity of the three sub-pixels of red, green, and blue, the LCD display screen (206) displays a color image.

[0047] Furthermore, the projection light beam of the image display screen (2) is reflected to the windshield by at least one reflective element (4), and the reflective element (4) can be a plane mirror, a convex mirror, a concave mirror, etc. In this embodiment, a free-form surface reflective mirror is selected as the optical reflective element (4).

[0048] Furthermore, the LCD display (206) utilizes a backlight source (1). Under the action of an external electric field, the liquid crystal deflects and changes the polarization direction of light. The voltage is controlled to change the deflection direction of the liquid crystal in the alignment film (203), and the light beam is regulated to pass through the color filter film (204) to form a color image. The image display (2) can be selected in sizes of 3.1 inches, 4.1 inches, etc., with a transmittance of not less than 8.5%, an operating temperature of -40°C to 85°C, a power supply voltage of not more than 6.5V, and an input voltage of not more than 0.3V.

[0049] In one embodiment, the light beam modulation device (3) comprises: a linear polarizer and a phase modulator (302), wherein the linear polarizer comprises an infrared cold light reflection film (301) and a visible light reflection polarization film (303); wherein the backlight source (1), the visible light reflection polarization film (303), the image display screen (2), the phase modulator (302) and the infrared cold light reflection film (301) are connected in sequence.

[0050] Specifically, the light beam modulator (3) uses an infrared cold light reflective film (301) to filter infrared light and half of the visible light in the ambient light incident on the projection display system, thereby reducing at least 40% of solar radiation in the projection display system. The phase modulator (302) uses a quarter-wave plate to modulate the polarization direction of the polarized light passing through the cold light film, and the visible light reflective polarizing film (303) reflects the visible light passing through the display screen. The light beam modulator (3) has a high transmittance for the output light beam of the projection lighting system, thereby improving the display effect of the projection display system while preventing external ambient light from entering the projection lighting system, reducing heat accumulation, and extending the service life of the projection display system components.

[0051] Furthermore, the infrared cold light reflective film (301) reduces the visible light and infrared light entering the image display component of the vehicle projection display system, has a reflectivity higher than 50%, a transmittance higher than 43%, and an operating temperature of -40°C to 105°C; the visible light reflective polarizing film (303) increases the projection brightness while reducing the entry of visible light, with a reflectivity of one side being no less than 90% and a transmittance of the other side being no less than 80%.

[0052] In a specific embodiment, the vehicle-mounted projection display system is used in commercial vehicles such as buses, coaches, and public buses.

[0053] With the above-described vehicle-mounted projection display system, on the one hand, the light beam emitted by the backlight source evenly illuminates the image display screen, which displays images on a thin-film transistor liquid crystal panel. The image beam, composed of the light beam emitted by the image display screen and the image, passes through a beam modulator and is reflected by at least one reflective element onto the windshield, resulting in a virtual image plane that appears in front of the human eye's field of view. Furthermore, when external sunlight enters the projection display system, the beam modulator blocks most of the solar radiation, reducing damage to the internal components of the projection display system caused by heat accumulation. Furthermore, the image beam is projected onto the front windshield, which is nearly perpendicular to the ground, for imaging. The beam modulator controls the solar radiation entering the projection display system, reducing heat accumulation within the system, increasing the brightness of the projected image, and enhancing the display quality. This allows a high-definition, high-brightness image to be displayed in front of the driver's field of view, thereby improving driving safety.

[0054] It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like in the above description indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present disclosure.

[0055] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly indicate the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0056] In the embodiments of the present disclosure, unless otherwise expressly specified or limited, the terms "installed," "connected," "connected," "fixed," and the like should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present disclosure based on specific circumstances.

[0057] In the embodiments of the present disclosure, unless otherwise expressly specified and limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0058] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0059] Other embodiments of the present disclosure will readily occur to those skilled in the art after considering the specification and practicing the utility model disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the appended claims.

Claims

1. A vehicle-mounted projection display system, characterized in that: The system includes: Image display assembly and windshield; wherein, The image display assembly includes a projection lighting unit, a light beam modulating device and a reflective element, wherein the projection lighting unit is connected to the light beam modulating device; The image light beam emitted by the projection lighting unit passes through the light beam modulating device and is reflected by at least one of the reflective elements onto the windshield.

2. The vehicle-mounted projection display system according to claim 1, characterized in that: The projection lighting unit comprises: Backlight source and image display screen; wherein, The backlight source is connected to the image display screen. The light beam emitted by the backlight source evenly illuminates the image display screen. The image emitted by the image display screen and the light beam pass through the light beam modulating device and are reflected by at least one of the reflective elements onto the windshield.

3. The vehicle-mounted projection display system according to claim 2, characterized in that: The backlight source comprises: LED light board, light mixing components, field lens and diffusion film; among them, The LED light board, the light mixing component, the field lens and the diffusion film are connected in sequence.

4. The vehicle-mounted projection display system according to claim 3, characterized in that: The LED light board is a white light LED array, the light mixing component is a light rod or a fly-eye lens, the field lens is a Fresnel lens, and the divergence angle (H, V) of the diffusion film is (±6, ±3).

5. The vehicle-mounted projection display system according to claim 2, characterized in that: The image display screen includes: Lower polarizer, thin film liquid crystal tube, alignment film, filter film, upper polarizer and LCD display; Among them, The lower polarizer, the thin film liquid crystal tube, the alignment film, the filter film, the upper polarizer and the LCD display screen are connected in sequence.

6. The vehicle-mounted projection display system according to claim 5, characterized in that: The image display screen has a transmittance of 8.5% to 50%, an operating temperature of -40°C to 85°C, a power supply voltage of 3V to 6.5V, and an input voltage of 0.1V to 0.3V.

7. The vehicle-mounted projection display system according to claim 2, characterized in that: The light beam modulation device comprises: A linear polarizer and a phase modulator, wherein the linear polarizer includes an infrared cold light reflecting film and a visible light reflecting polarizing film; wherein, The backlight source, the visible light reflecting polarizing film, the image display screen, the phase modulator and the infrared cold light reflecting film are connected in sequence.

8. The vehicle-mounted projection display system according to claim 7, characterized in that: The reflectivity of the infrared cold light reflective film is 50%~90%, the transmittance is 43%~80%, and the operating temperature is -40℃~105℃; the reflectivity of one side of the visible light reflective polarizing film is 90%~100%, and the transmittance of the other side is 80%~100%.

9. The vehicle-mounted projection display system according to claim 7, characterized in that: The phase modulator is a quarter wave plate.

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