JP7635782B2 - Head-up display device - Google Patents

Description

The present disclosure relates to a head-up display device.

A head-up display (HUD) device is known that emits display light representing an image onto the windshield of a vehicle and displays a virtual image of the image.

For example, Patent Document 1 describes a HUD device that includes a housing having a passage opening for passing display light toward the windshield and a light-shielding section adjacent to the passage opening. The HUD device described in Patent Document 1 prevents the image of the light-shielding section from being reflected in the virtual image by attaching a low-reflection sheet that suppresses the reflection of sunlight to the light-shielding section.

JP 2017-3897 A

Simply installing a low-reflection sheet in the light-shielding area may not be enough to sufficiently suppress unwanted image reflections, so there is still room for improvement.

This disclosure has been made in consideration of the above-mentioned situation, and aims to provide a head-up display device that can effectively suppress the reflection of unwanted images.

In order to achieve the above object, a head-up display device according to the present disclosure includes:
A display unit that emits display light representing an image;
a reflecting portion that reflects the display light toward a windshield of a vehicle;
a housing that includes a passage opening through which the display light reflected by the reflecting portion passes toward the windshield and a light blocking portion adjacent to the passage opening, and that accommodates the display portion and the reflecting portion;
A cover portion that covers the light-shielding portion and has a light-shielding property,
The cover portion has a plate portion disposed at a distance from the light blocking portion,
The plate portion has a plurality of holes formed therein.

According to the present disclosure, unwanted image reflections can be effectively suppressed.

FIG. 1 is a schematic configuration diagram of a head-up display (HUD) device according to an embodiment of the present disclosure. FIG. 2 is a schematic perspective view of the HUD device according to the embodiment. FIG. 3 is a diagram showing a cross section of the covering portion and a cross section of the light-shielding portion taken along line AA in FIG. 2 according to the embodiment of the present invention, for explaining the function of the covering portion; 4A to 4C are diagrams for explaining the function of the cover part according to the embodiment; 4A to 4C are diagrams for explaining the function of the cover part according to the embodiment; 13A to 13C are diagrams for explaining the function of a cover portion according to a modified example.

One embodiment of the present disclosure is described with reference to the drawings.

The head-up display (HUD) device 100 according to this embodiment is provided in the dashboard (also called the instrument panel) of a vehicle, and emits display light 2 representing an image onto a windshield 1, as shown in Fig. 1, and displays a virtual image of the image. The virtual image is displayed in front of the vehicle through the windshield 1.

In the following, each configuration may be explained using the left-right, up-down, and front-to-rear directions of the vehicle. In the appropriate drawings, the X-axis along the left-right direction, the Y-axis along the up-down direction, and the Z-axis along the front-to-rear direction are shown.

As shown in FIG. 1, the HUD device 100 comprises a display unit 10, a first mirror 21, a second mirror 22, a housing 30, a control board 40, and a cover unit 50.

The display unit 10 displays an image and emits display light 2 representing the image toward the first mirror 21. The display unit 10 has, for example, an LCD (Liquid Crystal Display) and a backlight that illuminates the LCD from behind. The LCD is, for example, a TFT (Thin Film Transistor) type. The backlight is, for example, composed of an LED (Light Emitting Diode), a light-guiding member, etc.

The first mirror 21 is, for example, a concave mirror, and reflects the display light 2 from the display unit 10 toward the second mirror 22. The second mirror 22 is, for example, a concave mirror, and reflects the display light 2 from the first mirror 21 toward the windshield 1 located outside the HUD device 100. The second mirror 22 is driven to rotate around a rotation axis 22a by a drive mechanism (not shown).

The first mirror 21 has a curvature such that the focal point 21a of the first mirror 21 is located between the first mirror 21 and the second mirror 22. As a result, the rays of the display light 2 reflected by the first mirror 21 cross above and below before reaching the second mirror 22. Hereinafter, an optical system using the first mirror 21 and the second mirror 22 in such a relationship is referred to as a cross optical system.

The housing 30 houses the display unit 10, the first mirror 21, the second mirror 22, etc., and comprises a lower case 31, a middle case 32, and an upper case 33.

The lower case 31 is box-shaped and opens upward, and is made of metal or resin. The lower case 31 covers the middle case 32 from below, and houses the display unit 10 and the control board 40 inside. The lower case 31 is fixed to the middle case 32 by known fixing means such as screws.

The middle case 32 is box-shaped and opens upward, and is made of metal or resin. The middle case 32 houses the second mirror 22 and a drive mechanism (not shown) inside. An opening H1 is formed at the rear bottom of the middle case 32, through which the display light 2 from the display unit 10 to the first mirror 21 passes.

The upper case 33 covers the middle case 32 from above and is fixed to the middle case 32 by known fixing means such as screws. As shown in Fig. 2, the upper case 33 is formed in a frame shape. The upper case 33 supports, for example, the first mirror 21. The upper case 33 is formed, for example, from black resin and has light-blocking properties.

The upper case 33 has a passage H2 through which the display light 2 reflected by the second mirror 22 passes toward the windshield 1, and a light-shielding portion 330 adjacent to the passage H2.

2, the light shielding portion 330 includes a main wall portion 331, side walls 332 and 333, and a front wall portion 334. As shown in FIG. 1, the main wall portion 331 faces the windshield 1 and prevents external light 3, such as sunlight, from entering the housing 30. The main wall portion 331 is inclined, with the front end portion positioned lower than the rear end portion. As shown in FIG. 1, the front wall portion 334 generally faces the main wall portion 331 in the front-rear direction. The front wall portion 334 stands along the up-down direction. The side wall portion 332 and the side wall portion 333 face each other in the left-right direction and connect the main wall portion 331 and the front wall portion 334. The passage opening H2 is surrounded by the main wall portion 331, the side walls 332 and 333, and the front wall portion 334, and is generally rectangular as shown in FIG. 2. A part of the edge of the passage opening H2 runs along the lower end of the main wall portion 331. In this embodiment, the main wall portion 331 is provided with a cover portion 50, as will be described later.

A cover glass (not shown) is provided at the upper end of the upper case 33. The cover glass covers the aforementioned passage opening H2, the light shielding portion 330, and the cover portion 50 from above.

The control board 40 is a printed circuit board equipped with a microcomputer that controls the overall operation of the HUD device 100. The control board 40 controls the display position of the virtual image in the vertical direction by controlling a drive mechanism (not shown) and rotating the second mirror 22. The control board 40 also communicates with systems such as an ECU (Electronic Control Unit) that controls each part of the vehicle, and causes the display unit 10 to display an image showing information about the vehicle.

The covering portion 50 shown in FIG. 1 is configured to cover the light-shielding portion 330 from the windshield 1 side (i.e., to cover the surface of the light-shielding portion 330 facing the windshield 1) and suppress the image of the light-shielding portion 330 from being reflected in the virtual image. The covering portion 50 is attached to the main wall portion 331 of the light-shielding portion 330 with elastic double-sided tape T. The covering portion 50 is provided along the surface of the main wall portion 331 facing the windshield 1, and is inclined like the main wall portion 331, with the front end positioned lower than the rear end. The covering portion 50 is formed from a material having light-shielding properties.

In Figure 2, the cover portion 50 is shown partially for ease of viewing, but the cover portion 50 in this embodiment is provided over the area 4 of the main wall portion 331, which is indicated by the dashed line.

As shown in Fig. 3, the cover 50 includes a fixed portion 51 and a plate portion 52. The cover 50 is formed from a metal plate with a matte coating applied to the entire surface. For example, the cover 50 is made by forming a thin plate (e.g., with a thickness of 1 mm or less) made of SECC (electro-galvanized steel plate) and then applying a black matte coating.

The fixed portion 51 is the outer edge of the cover portion 50 and is the portion that is fixed to the main wall portion 331 of the light shielding portion 330. In other words, the fixed portion 51 is the portion to which the aforementioned double-sided tape T (see FIG. 1) is attached.

The plate portion 52 is disposed at a distance from the main wall portion 331 of the light-shielding portion 330, and is located, for example, inside the fixed portion 51. In this embodiment, the bottom surfaces (surfaces facing the main wall portion 331) of the plate portion 52 and the fixed portion 51 are flush, and the thickness of the double-sided tape T ensures a distance between the plate portion 52 (specifically, the opposing portion 5a described below) and the main wall portion 331. This distance can prevent the plate portion 52 and the main wall portion 331 from rubbing against each other and wearing away due to vehicle vibration. In addition, the double-sided tape T that ensures this distance can absorb the tolerances of each part due to its elasticity and ensure cushioning.

As shown in FIG. 3, the plate portion 52 is formed in a louver shape and includes a plurality of strip-like extending blades 5 and a plurality of holes 52a. The blades 5 extend along the left-right direction (X direction) of the vehicle and are arranged side by side in the short side direction. The holes 52a are located between adjacent blades 5 and are long holes extending along the blades 5. For example, the blades 5 are arranged at equal intervals in the short side direction. Therefore, the holes 52a located between adjacent blades 5 are also arranged at equal intervals in the short side direction.

As shown in Fig. 4, the blade 5 has an opposing portion 5a that faces the main wall portion 331 of the light-shielding portion 330 with a gap therebetween, and an inclined portion 5b that is connected to the opposing portion 5a. The inclined portion 5b is connected to one end of the opposing portion 5a (specifically, the end close to the second mirror 22 shown in Fig. 1) and is inclined away from the main wall portion 331.

Here, of the external light 3 (see FIG. 1) that passes through the windshield 1 and enters the housing 30, the light reflected by the second mirror 22 may head toward the main wall 331 of the light-shielding part 330. In this case, if no measures are taken, the light reflected by the main wall 331 of the light-shielding part 330 will be further reflected by the windshield 1 toward the viewer of the virtual image, causing unwanted images to be reflected in the virtual image. To prevent this, the cover part 50 is formed to have the following functions.

In the following, for ease of explanation, as shown in Figures 4 to 6, of the adjacent blades 5, the one farther from the second mirror 22 (see Figure 1) is referred to as the first blade 5f, and the one closer to the second mirror 22 is referred to as the second blade 5n. Furthermore, of the external light 3 (see Figure 1) that passes through the windshield 1 and enters the housing 30, the light that is reflected by the second mirror 22 and heads toward the main wall portion 331 of the light-shielding portion 330 mainly follows the optical path indicated by the lights 3a, 3b, and 3c, which will be described in order below.

As shown in Figure 4, the inclined portion 5b of the first blade 5f passes through the hole 52a between the first blade 5f and the second blade 5n, is reflected by the light-shielding portion 330, and blocks the light 3a traveling toward the windshield 1 (see Figure 1).

As shown in Figure 5, the inclined portion 5b of the first blade 5f is reflected by the opposing portion 5a of the second blade 5n, blocking the light 3b traveling toward the windshield 1.

As shown in FIG. 6, the inclined portion 5b of the first blade 5f reflects the light 3c toward the windshield 1, passes through the hole 52a between the first blade 5f and the second blade 5n, and is reflected by the shading portion 330, thereby blocking the light 3c.

As described above, the cover 50 has an inclined portion 5b that blocks each of the lights 3a, 3b, and 3c. Most of the external light that reaches the cover 50 or the main wall 331 through optical paths other than the lights 3a, 3b, and 3c heads outside the eye box, which is set as the range in which the user can see the virtual image. In other words, the cover 50 can reduce the external light 3 that is reflected by the cover 50 or the light-shielding portion 330 (specifically the main wall 331) and further reflected by the windshield 1 and then heads into the eye box. Therefore, the reflection of unnecessary images can be effectively suppressed.

In addition, various conditions such as the inclination of the inclined portion 5b in the covering portion 50 and the arrangement interval of the blades 5 and the holes 52a can be obtained by simulation. In particular, since external light reflected at the upper end of the second mirror 22 and directed toward the main wall portion 331 of the light-shielding portion 330 is likely to cause unwanted images to be reflected, it is preferable to perform a simulation taking this point into consideration. In addition, it is preferable that the formation range of the fixed portion 51 in the covering portion 50 is narrow.

The cover 50 described above is formed, for example, by cutting the portion corresponding to the end of the inclined portion 5b from a single metal plate by laser processing, and then bending the inclined portion 5b. As a result, the shape of the metal plate after molding becomes a louver shape in which the blades 5 and holes 52a are arranged alternately. The cover 50 is produced by applying a matte paint to the entire surface of the metal plate molded into a louver shape.

Note that this disclosure is not limited to the above-described embodiments and drawings. Appropriate modifications (including the deletion of components) may be made without departing from the spirit of this disclosure.

For example, the inclined portion 5b may be omitted from the blade 5, as in the cover portion 50M according to the modified example shown in Fig. 7. By adjusting the distance between the opposing portion 5a and the light shielding portion 330, the first blade 5f can block a portion of the light 3a that passes through the hole 52a between the first blade 5f and the second blade 5n, is reflected by the light shielding portion 330, and travels toward the windshield 1 (see Fig. 1). In this case, the hole 52a is not limited to an elongated hole extending in the left-right direction of the vehicle, but may be a round hole.

In the above, an example in which the cover portion 50 is provided only on the main wall portion 331 of the light-shielding portion 330 has been shown, but this is not limited to the above, and the location of the cover portion 50 in the light-shielding portion 330 can be changed as desired. For example, the cover portion 50 may be provided on the side wall portions 332, 333 or the front wall portion 334. In this case, the direction in which the blades 5 and the holes 52a extend is set to a direction that can effectively block reflection of external light, and is not limited to the left-right direction of the vehicle, and may be the front-rear direction of the vehicle, etc. Note that, from the viewpoint of effectively suppressing the reflection of unwanted images, it is preferable that the cover portion 50 is provided at least on the main wall portion 331.

The optical system in the HUD device 100 may be configured in any way as long as it can radiate the display light 2 from the display unit 10 to the windshield 1, and the number, shape, and arrangement of the mirrors that reflect the display light 2 may be changed as appropriate. However, as described in the above embodiment, the covering unit 50 is particularly suitable when a cross optical system is adopted. This is because in a cross optical system, the light irradiated to the main wall portion 331 of the light blocking portion 330 tends to be stronger.

Although the above describes a display unit 10 using an LCD, the configuration of the display unit 10 is not limited and is arbitrary. For example, the display unit 10 may use an OLED (Organic Light-Emitting Diode). The display unit 10 may also include a DMD (Digital Micromirror Device) and a transmissive screen that receives light reflected by the DMD and displays an image.

There is no limit to the type of vehicle on which the HUD device 100 is installed, and it can be applied to a variety of vehicles, including four-wheeled motor vehicles and motorcycles.

The HUD device 100 described above includes a display unit 10 that emits display light 2, a reflecting unit (corresponding to the second mirror 22) that reflects the display light 2 toward the windshield 1, a housing 30 that houses the display unit 10 and the reflecting unit, and covering units 50, 50M. The housing 30 has a passage opening H2 through which the display light 2 reflected by the reflecting unit passes toward the windshield 1, and a light-shielding unit 330 adjacent to the passage opening H2. The covering units 50, 50M cover the light-shielding unit 330 from the windshield 1 side and have light-shielding properties. The covering units 50, 50M have a plate unit 52 that is spaced apart from the light-shielding unit 330, and the plate unit 52 has a plurality of holes 52a formed therein.
With this configuration, a part of the external light that passes through the hole 52a and is reflected by the light shielding portion 330 can be blocked by the rear surface (the surface on the light shielding portion 330 side) of the plate portion 52. Therefore, it is possible to effectively suppress the reflection of unwanted images.

The plate portion 52 of the cover portion 50 in the embodiment has a band-like extending blade 5, with multiple blades 5 arranged side by side in the short direction, and the hole 52a is located between adjacent blades 5 and extends along the blades 5.
This configuration makes it possible to effectively block external light that passes through the hole 52a, is reflected by the light-shielding portion 330, and travels toward the windshield 1. When the cover portion 50 is provided on the main wall portion 331 of the light-shielding portion 330, the blades 5 and the holes 52a are set to extend in the left-right direction of the vehicle, as described above.

The blade 5 preferably has an opposing portion 5a that faces the light-shielding portion 330 with a gap therebetween, and an inclined portion 5b that is connected to the end of the opposing portion 5a that is closer to the reflecting portion and inclined away from the light-shielding portion 330. As described with reference to Figures 4 to 6, the inclined portion 5b is shaped to block at least one of the lights 3a, 3b, and 3c, and preferably blocks all of the lights 3a, 3b, and 3c.

The plate portion 52 is made of a metal plate with a matte coating, and the inclined portion 5b is formed by bending the blade 5.
This configuration makes it easy to manufacture the cover 50. In addition, since the plate portion 52 of the cover 50 can be made thin, it is possible to reduce, for example, reflected light from the tip surface of the inclined portion 5b. In addition, by using a metal, heat resistance can be ensured.

In addition, when the requirement for heat resistance is not high (for example, when a cross optical system is not adopted), the cover portion 50 can be molded from resin. When resin is used, the reflection of light on the surface of the cover portion 50 can be reduced by a known method other than matte painting. It is also possible to form the plate portion 52 of the cover portion 50 from metal and the fixed portion 51 from resin. The cover portion 50 may be fixed to the light-shielding portion 330 via an elastic member, spacer, etc. other than the double-sided tape T, and the distance between the plate portion 52 and the light-shielding portion 330 may be secured. The fixed portion 51 itself may function as a spacer, and the distance between the plate portion 52 and the light-shielding portion 330 may be secured.

In the above explanation, explanations of well-known technical matters have been omitted as appropriate to facilitate understanding of this disclosure.

REFERENCE SIGNS LIST 100 Head-up display (HUD) device 1 Windshield 2 Display light 3 External light 4 Area 10 Display section 21 First mirror 22 Second mirror (an example of a reflecting section)
30 Housing 33 Upper case H2 Passage port 330 Light shielding part 331 Main wall part 332, 333 Side wall part 334 Front wall part 40 Control board 50 Cover part 51 Fixed part 52 Plate part 52a Hole 5 Wing board 5a Opposing part 5b Slanted part 5f First wing board 5n Second wing board

Claims (7)

A display unit that emits display light representing an image;
a reflecting portion that reflects the display light toward a windshield of a vehicle;
a housing that includes a passage opening through which the display light reflected by the reflecting portion passes toward the windshield and a light blocking portion adjacent to the passage opening, and that accommodates the display portion and the reflecting portion;
A cover portion that covers the light-shielding portion and has a light-shielding property,
The cover portion has a plate portion disposed at a distance from the light blocking portion,
A plurality of holes are formed in the plate portion.
Head-up display device. The plate portion includes a blade extending in a band shape,
The blades are arranged in a plurality of rows in the short side direction,
The holes are located between adjacent blades and extend along the blades.
The head-up display device according to claim 1 . The blade is
an opposing portion opposed to the light-shielding portion with a gap therebetween;
an inclined portion connected to an end of the facing portion close to the reflecting portion and inclined away from the light blocking portion;
The head-up display device according to claim 2 . Among the adjacent blades, the one farther from the reflecting portion is designated as a first blade, and the one closer to the reflecting portion is designated as a second blade.
The inclined portion of the first blade passes through the hole between the first blade and the second blade, is reflected by the light-shielding portion, and blocks light traveling toward the windshield.
The head-up display device according to claim 3 . The inclined portion of the first blade is reflected by the opposing portion of the second blade to block light traveling toward the windshield.
The head-up display device according to claim 4. The inclined portion of the first blade reflects the light toward the windshield, passes through the hole between the first blade and the second blade, and is reflected by the light-shielding portion, thereby blocking the light.
The head-up display device according to claim 4 or 5. The plate portion is made of a metal plate with a matte coating,
The inclined portion is formed by bending the blade.
The head-up display device according to any one of claims 3 to 6.

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