Backlight module, head-up display and automobile

Abstract

The utility model discloses a backlight module, a head-up display and an automobile, and relates to the technical field of head-up displays. The backlight module comprises a light source, a light bar and an image display unit which are sequentially arranged in the light path direction, a reflecting layer is arranged in the light bar so that part of light emitted by the light source can be reflected to the image display unit through the reflecting layer, and a shading part is further arranged on the light bar. The shading part is used for preventing the other part of light emitted by the light source from emitting to the image display unit. The backlight module, the head-up display and the automobile can solve the problem that in the prior art, due to the fact that light rays are concentrated on the image display unit, the temperature of the image display unit is too high, and the image display unit is prone to damage.

Description

Technical Field

[0001] The present application relates to the technical field of head-up displays, and in particular to a backlight module, a head-up display and a car. Background Art

[0002] Head Up Display (HUD), also known as HUD, is widely used in the aviation field. It originated from the pilot's helmet display and the head-up display in the flight cockpit. The pilot can see the important information he needs without lowering his head, keeping his sight level at all times, which solves the trouble of the pilot needing to lower his head to check the information and the discomfort of constantly adjusting the eye focus. Now it is increasingly entering the automotive field, used to display important driving information such as speed, navigation steering, fuel consumption, etc., so that the driver can focus on driving without having to lower his head to look at the dashboard, which well ensures safe driving and improves the driver's driving experience.

[0003] In the prior art, the backlight module of the head-up display is mostly used to effectively guide the light emitted by the light source to a specific direction through a light rod, so that the light can be concentrated or focused on the image display unit. Since the light rod is an optical element with a cone-shaped structure, it has the structural characteristics of a small-diameter end and a large-diameter end. Therefore, in actual use, the small-diameter end is generally set on the side where the light source is located, so that the small-diameter end is used as the light entrance surface of the light rod, and the large-diameter end is set on the side where the image display unit is located, so that the large-diameter end is used as the light exit surface of the light rod. However, in this way, since the light is concentrated on the image display unit, it is easy to cause the temperature of the image display unit to be too high, and in severe cases, the image display unit may be damaged. Utility Model Content

[0004] The purpose of the present application is to provide a backlight module, a head-up display and a car, which can solve the problem in the prior art that the image display unit is easily damaged due to excessive temperature caused by light concentration on the image display unit.

[0005] The embodiment of the present application is implemented as follows:

[0006] In a first aspect of the embodiments of the present application, a backlight module is provided, comprising a light source, a light rod and an image display unit arranged in sequence along a light path, wherein a reflective layer is arranged inside the light rod so that a part of the light emitted by the light source is reflected to the image display unit through the reflective layer, and a light shielding portion is also arranged on the light rod, and the light shielding portion is used to prevent another part of the light emitted by the light source from being emitted to the image display unit. The backlight module can solve the problem in the prior art that the image display unit is easily damaged due to excessive temperature caused by the light concentrated on the image display unit.

[0007] Optionally, the shading portion is a truncation structure, so that another part of the light emitted by the light source is emitted to the outside of the image display unit through the truncation structure.

[0008] Optionally, the cross-sectional shape of the light rod is a rectangle, and the truncation structure is arranged on a side where the long side of the rectangle is located.

[0009] Optionally, the shading portion is a transparent structure, so that another part of the light emitted by the light source is emitted to the outside of the image display unit through the transparent structure.

[0010] Optionally, the shading portion is a light-extinction structure, so that another part of the light emitted by the light source is absorbed by the light-extinction structure.

[0011] Optionally, the matte structure is made by flocking, spraying or sun-texturing.

[0012] Optionally, the cross-sectional shape of the shading portion is trapezoidal.

[0013] Optionally, the reflective layer is a reflective film.

[0014] The second aspect of the embodiment of the present application provides a head-up display, comprising the above-mentioned backlight module. The backlight module can solve the problem in the prior art that the image display unit is easily damaged due to excessive temperature caused by light concentrated on the image display unit.

[0015] The third aspect of the embodiment of the present application provides a car, comprising the above-mentioned head-up display. The backlight module can solve the problem in the prior art that the image display unit is easily damaged due to excessive temperature caused by light concentrated on the image display unit.

[0016] The beneficial effects of the embodiments of the present application include:

[0017] The backlight module includes a light source, a light rod and an image display unit which are sequentially arranged along the light path direction. A reflective layer is arranged inside the light rod, so that a part of the light emitted by the light source is reflected to the image display unit through the reflective layer, so that the image display unit can project the virtual image of the head-up display into the field of vision of the driver in front of the car, so as to ensure the normal operation of the head-up display; on this basis, a shading portion is also arranged on the light rod, and the shading portion is used to prevent another part of the light emitted by the light source from being emitted to the image display unit, so that another part of the light emitted by the light source that does not participate in the imaging is emitted to the outside of the image display unit under the action of the shading portion or is simply directly absorbed by the shading portion, thereby avoiding the other part of the light emitted by the light source that does not participate in the imaging from hitting the image display unit, and then causing the temperature of the image display unit to rise and cause screen burn-in and other phenomena, thereby improving the service life of the head-up display without affecting the imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic diagram of the structure of a backlight module provided in an embodiment of the present application;

[0020] Figure 2 A schematic diagram of the structure of a backlight module provided in the first embodiment of the present application;

[0021] Figure 3 A schematic diagram of the structure of a backlight module provided in the second embodiment of the present application;

[0022] Figure 4 This is a schematic structural diagram of a backlight module provided in the third embodiment of the present application.

[0023] Icon: 100 - backlight module; 10 - light source; 20 - light rod; 21 - reflective layer; 221 - truncation structure; 222 - transparent structure; 223 - matte structure; 30 - image display unit. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0026] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0027] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the products of the present application are usually placed when in use. They are only for the convenience of describing the present application 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 cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0028] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0029] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be a connection between two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0030] Please refer to Figures 1 to 4 The embodiment of the present application provides a backlight module 100, comprising a light source 10, a light rod 20 and an image display unit 30 arranged in sequence along the light path direction, a reflective layer 21 is arranged inside the light rod 20, so that a part of the light emitted by the light source 10 is reflected to the image display unit 30 through the reflective layer 21, and a light shielding part is also arranged on the light rod 20, which is used to prevent another part of the light emitted by the light source 10 from being emitted to the image display unit 30. The backlight module 100 can solve the problem in the prior art that the image display unit 30 is easily damaged due to excessive temperature caused by the light concentrated on the image display unit 30.

[0031] It should be noted that if Figure 1As shown, the backlight module 100 includes a light source 10, a light rod 20 and an image display unit 30, wherein the light source 10, the light rod 20 and the image display unit 30 are sequentially arranged along the light path direction, so that the light emitted by the light source 10 can be injected into the light rod 20 and emitted toward the image display unit 30 under the light guiding effect of the light rod 20, so that the corresponding image information is projected into the driver's field of vision in front of the car through the image display unit 30. Generally, the light source 10 uses an LED, and the LED has a large divergence angle. Therefore, in order to achieve the above function, a reflective layer 21 is arranged inside the light rod 20, so that the light emitted by the light source 10 can be reflected, focused and uniformed through the reflective layer 21, so that the light emitted by the light source 10 can be reflected to the image display unit 30 through the reflective layer 21. Optionally, the reflective layer 21 is a reflective film.

[0032] In the prior art, the image formed by the head-up display is a virtual image, and is usually rectangular. The virtual images of the head-up displays of different manufacturers have different aspect ratios, such as 9×2.3, 10×3, etc. The image formed by the image display unit 30 after passing through the reflector and the windshield is also a virtual image, and usually the aspect ratio of the image display unit 30 is close to the aspect ratio of the virtual image. This leads to the designers generally designing the aspect ratio of the large-diameter end of the light rod 20 close to the image display unit 30 to be close to the aspect ratio of the virtual image when designing the structure of the light rod 20. In this way, the LED reaches the image display unit 30 through the light rod 20. When the length of the light rod 20 is the same, the divergence angles of the long axis and the short axis reaching the image display unit 30 are different, so a part of the surplus light will hit the image display unit 30. However, due to the large angle, it does not participate in the imaging of the head-up display, but will make the temperature of the image display unit 30 too high.

[0033] In order to solve the above problems, Figures 2 to 4 As shown, in the present application, a shading portion is further provided on the light rod 20, and the shading portion is used to prevent another part of the light emitted by the light source 10 that does not participate in imaging from being emitted to the image display unit 30, so that the other part of the light emitted by the light source 10 that does not participate in imaging is emitted to the outside of the image display unit 30 under the action of the shading portion or is simply directly absorbed by the shading portion, thereby preventing the other part of the light emitted by the light source 10 that does not participate in imaging from hitting the image display unit 30, and then causing the temperature of the image display unit 30 to increase and cause screen burn-in and the like, thereby improving the service life of the head-up display without affecting the imaging.

[0034] Generally speaking, the short-side brightness uniformity and eye-box uniformity of the virtual image formed by the head-up display will be more than enough. If the length of the light rod 20 in the short-side direction is the same as the length of the light rod 20 in the long-side direction, some large-angle light will pass through the large-aperture end of the light rod 20 close to the image display unit 30 and return to the center of the surface of the image display unit 30. This will cause some light that cannot be used by the head-up display during imaging to increase the temperature of the surface of the image display unit 30, posing a risk of screen burn-in.

[0035] In order to solve the above problems, for example, in some embodiments, Figure 2 As shown, the shading portion is a truncated structure 221, so that another part of the light emitted by the light source 10 is emitted to the outside of the image display unit 30 through the truncated structure 221. Optionally, the cross-sectional shape of the light rod 20 is a rectangle, and the truncated structure 221 is arranged on the side where the long side of the rectangle is located.

[0036] In other words, during the manufacturing process, a portion of the light rod 20 in the long side direction can be cut off to form a truncation structure 221, so that another portion of the light emitted by the light source 10 that does not participate in imaging is emitted through the truncation structure 221 to an area outside the image display unit 30, thereby reducing the maximum irradiance and total irradiance on the surface of the image display unit 30.

[0037] On this basis, the length of the light rod 20 in the short side direction can be adjusted through simulation, so that the brightness of the virtual image formed by the head-up display is not reduced, and the temperature of the surface of the image display unit 30 can be reduced, thereby further improving the service life of the head-up display without affecting the imaging.

[0038] Of course, in other embodiments, such as Figure 3 As shown, the shading portion may also be a transparent structure 222, so that another part of the light emitted by the light source 10 is emitted to the outside of the image display unit 30 through the transparent structure 222. For example, during the manufacturing process, when the reflective layer 21 is formed by coating the inside of the light rod 20, a part of the area is not coated, so that a shading portion with a transparent structure 222 can be formed, and another part of the light emitted by the light source 10 that does not participate in the imaging can be emitted to the area outside the image display unit 30 through the transparent structure 222, thereby reducing the maximum irradiance and total irradiance on the surface of the image display unit 30.

[0039] Alternatively, in other embodiments, Figure 4As shown, the shading portion may also be a matte structure 223, so that another part of the light emitted by the light source 10 is absorbed by the matte structure 223. For example, during the manufacturing process, when the interior of the light rod 20 is coated to form the reflective layer 21, a matte treatment may be performed on a part of the area, so that a shading portion having a matte structure 223 may be formed, and when another part of the light emitted by the light source 10 that does not participate in imaging passes through the matte structure 223, it may be directly absorbed by the matte structure 223, and the other part of the light emitted by the light source 10 that does not participate in imaging may be prevented from being emitted to the image display unit 30, thereby reducing the maximum irradiance and total irradiance on the surface of the image display unit 30.

[0040] Optionally, the matte structure 223 is manufactured by flocking, spraying or sun-texturing. Regarding the specific manufacturing process of the matte structure 223, those skilled in the art should be able to make a reasonable selection according to the actual situation, and no specific limitation is made here.

[0041] It should be noted that, first, the matt structure 223 can be electrostatically adsorbed on the light rod 20 using light-absorbing fluff, or the matt structure 223 can be pasted on the light rod 20 using light-absorbing flocking cloth through tooling positioning (can be pasted with 3M glue), that is, the matt structure 223 can be made using flocking technology, and the made matt structure 223 has the advantages of soft touch, non-toxic and odorless, moisture-proof and moisture-retaining, no shedding, friction-resistant and smooth and gap-free.

[0042] The flocking process uses the physical property that like charges repel each other and opposite charges attract each other to make the fluff carry a negative charge. The object to be flocked (i.e. the plant object) is placed under zero potential or grounding conditions. The fluff is attracted by the plant object with different potential and accelerates vertically to the surface of the plant object. Since the surface of the plant object is coated with adhesive, the fluff can stick vertically to the plant object.

[0043] Second, the matte structure 223 can be sprayed on the light rod 20 using light-absorbing ink, that is, the matte structure 223 can be made by spraying. The principle of the spraying process is to use compressed air to spray from the center of the air nozzle of the spray gun, forming a negative pressure area at the front end of the ink nozzle, so that the paint in the ink container is sprayed from the nozzle and quickly enters the high-speed compressed air flow, so that the liquid-gas phase is rapidly diffused, the ink is micronized, and the ink flies to and adheres to the surface of the product in the form of paint mist, and the ink mist particles quickly gather into a continuous oil film.

[0044] Third, the matt structure 223 can also be processed by light-absorbing sun-texturing on the mold of the light rod 20 to achieve the light-absorbing effect of the matt structure 223, that is, the matt structure 223 can be made by sun-texturing process, which has the advantages of low cost, rich effects and fast speed.

[0045] The sun-texture process is also called mold sun-texture, mold bite, mold etching and mold etching. The principle of the sun-texture process is to use chemical solutions (such as sulfuric acid, nitric acid, etc.) to react with mold steel and control the reaction process to obtain various effects. The process of the sun-texture process includes: mold preparation - film exposure - film attachment - exposure - corrosion - cleaning - post-processing.

[0046] Optionally, the cross-sectional shape of the light shielding portion is a trapezoid, that is, the length of the light rod 20 is reduced to different degrees in the long side direction and the short side direction, so as to form the light shielding portion.

[0047] The embodiment of the present application further provides a head-up display, comprising the above-mentioned backlight module 100. Since the structure and beneficial effects of the backlight module 100 have been described in detail in the above-mentioned embodiment, they will not be described again here.

[0048] The embodiment of the present application further provides a car, comprising the above-mentioned head-up display. Since the structure and beneficial effects of the head-up display have been described in detail in the above-mentioned embodiment, they will not be repeated here.

[0049] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0050] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this application will not further describe various possible combinations.

Claims

1. A backlight module, characterized in that: The invention comprises a light source, a light rod and an image display unit which are sequentially arranged along the light path direction. A reflective layer is arranged inside the light rod so that a part of the light emitted by the light source is reflected to the image display unit through the reflective layer. A shading part is also arranged on the light rod, and the shading part is used to prevent another part of the light emitted by the light source from being emitted to the image display unit.

2. The backlight module according to claim 1, characterized in that: The light shielding portion is a cut-off structure, so that another part of the light emitted by the light source is emitted to the outside of the image display unit through the cut-off structure.

3. The backlight module according to claim 2, characterized in that: The cross-sectional shape of the light rod is a rectangle, and the truncation structure is arranged on the side where the long side of the rectangle is located.

4. The backlight module according to claim 1, characterized in that: The light shielding portion is a transparent structure, so that another part of the light emitted by the light source is emitted to the outside of the image display unit through the transparent structure.

5. The backlight module according to claim 1, characterized in that: The shading portion is a light-extinction structure, so that another part of the light emitted by the light source is absorbed by the light-extinction structure.

6. The backlight module according to claim 5, characterized in that: The matte structure is made by flocking, spraying or sun-texturing.

7. The backlight module according to any one of claims 1 to 6, characterized in that: The cross-section of the light shielding portion is a trapezoid.

8. The backlight module according to claim 1, characterized in that: The reflective layer is a reflective film.

9. A head-up display, characterized in that: The backlight module comprises any one of claims 1 to 8.

10. An automobile, characterized in that: Includes the head-up display as claimed in claim 9.

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