JP7643208B2 - Head-up display device - Google Patents

Description

This disclosure relates to a head-up display device.

For example, Patent Document 1 describes a conventional head-up display (HUD) device in which display light reflected by a reflector constituted by a concave mirror or the like is emitted to the outside from an opening formed in an upper case. This upper case has a wall portion (see reference numeral 11 in Figure 7 of the same document) that is formed to hang down and faces the side of the reflector.

International Publication No. 2021/059953

The wall portion described in Patent Document 1 has a free lower end, and so if it deforms due to heat or other factors, it may come into contact with the reflecting portion. If the wall portion comes into contact with the reflecting portion, the position of the reflecting portion may shift or the operation of the reflecting portion may be hindered, which is undesirable.

This disclosure was made in consideration of the above-mentioned circumstances, and aims to provide a head-up display device that can prevent the wall from hitting the reflector.

In order to achieve the above object, a head-up display device according to the present disclosure includes:
A housing having an upward opening;
a reflecting section that is accommodated in the housing and reflects display light representing an image toward the opening,
the housing includes a first case and a second case located above the first case and having the opening formed therein;
the second case has a wall portion that hangs down from an end of the opening and faces a side surface of the reflecting portion,
The display device further includes a suppression section that suppresses the wall section from contacting the reflecting section by applying a force to the wall section in a direction away from the side surface.

This disclosure makes it possible to prevent the wall from hitting the reflecting part.

1 is a schematic side view of a head-up display (HUD) device according to an embodiment of the present disclosure. FIG. 2 is a perspective view of a main part of a reflecting portion and a housing according to the embodiment. FIG. 4 is a perspective view of a main part of a reflecting portion, a wall portion, and a suppressing portion according to the embodiment of the present invention. FIG. 4 is a diagram showing the configuration of a suppression unit according to the embodiment; 13 is a diagram showing a configuration of a suppression unit according to a modified example.

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

The head-up display (HUD) device 1 shown in FIG. 1 is mounted, for example, on the dashboard of a vehicle and emits display light L toward the vehicle's windshield. The display light L reflected by the windshield allows the user to visually recognize a virtual image of the image represented by the display light L. The virtual image indicates various information related to the vehicle and is displayed in front of the vehicle through the windshield.

The HUD device 1 includes a display unit 10, a light path changing mirror 20, a reflector 30, and a housing 40.

The display unit 10 displays an image and emits display light L that represents the image. The display unit 10 includes, 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 light path changing mirror 20 changes the light path of the display light L emitted from the display unit 10. Specifically, the display light L reflected by the light path changing mirror 20 travels toward the reflecting unit 30. The light path changing mirror 20 is made of a flat mirror or a curved mirror, and is fixed to the second case 42 (described later) via a member not shown.

The reflecting unit 30 is configured to reflect the display light L from the optical path changing mirror 20 toward an opening formed in the housing 40. In detail, the reflecting unit 30 has a concave mirror 31 and a holder 32 shown in FIG. 2.

The concave mirror 31 reflects the display light L from the optical path changing mirror 20 toward the opening. Due to the function of the concave mirror 31, the virtual image is visually recognized by the user as an enlarged version of the image displayed on the display unit 10.

The holder 32 holds the concave mirror 31 from behind. The holder 32 is supported by the housing 40 via a bearing member (not shown) so as to be rotatable around the axis AX shown in FIG. 2. Therefore, the reflecting unit 30 is provided so as to be rotatable around the axis AX.

The HUD device 1 includes a mirror driver (not shown) that rotates the reflector 30. The mirror driver is composed of a motor, a drive circuit that drives the motor, and a gear mechanism that transmits the rotation of the motor to the holder 32.

The housing 40 houses the various components described above, and has a first case 41 and a second case 42 located above the first case 41. Note that each figure shows only a portion of the housing 40. Of course, the housing 40 may have further components other than the first case 41 and the second case 42. For example, the housing 40 may further have a cover that covers the second case 42 from below.

The first case 41 is formed, for example, from a metal and is located behind the reflecting section 30 as shown in FIG. 1.

The second case 42 is formed, for example, from a synthetic resin, and is connected to the first case 41 by known means such as screwing, engaging, or fitting. The second case 42 has an opening H facing upward (facing the windshield of the vehicle in this embodiment). A light-transmitting plate (not shown) that covers the opening H is attached to the second case 42. The display light L emitted from the display unit 10 and reflected by the light path changing mirror 20 and the concave mirror 31 in this order passes through the light-transmitting plate and is emitted toward the windshield. The HUD device 1 is equipped with a control unit (not shown) made of a computer. The control unit controls the operation of the display unit 10 and the aforementioned mirror drive unit.

As shown in FIG. 2, the second case 42 has a wall portion 420 that hangs down from the end of the opening H. The wall portion 420 faces the side surface 30a of the reflecting portion 30. Here, the side surface 30a of the reflecting portion 30 may be the side surface of the concave mirror 31 or the holder 32, but in this embodiment, the side surface of the holder 32 that is closer to the wall portion 420 is given a reference symbol indicating the side surface 30a of the reflecting portion 30. The wall portion 420 is provided so that no unnecessary members are exposed in the space inside the housing 40 through which the display light L passes. If unnecessary members were exposed in that space, their image would be visible to the user.

The wall portion 420 is provided at a distance from the side surface 30a so as not to interfere with the rotational movement of the reflecting portion 30. However, if the wall portion 420 is deformed due to factors such as heat and bent toward the reflecting portion 30, there is a risk that it may come into contact with the reflecting portion 30. To prevent this, the HUD device 1 further includes a suppression unit 50 that suppresses the wall portion 420 from touching the reflecting portion 30 by pressing the wall portion 420 in a direction away from the side surface 30a (hereinafter, the separation direction D). The suppression unit 50 may press at least when the wall portion 420 is bent toward the side surface 30a. In other words, in a normal state, the suppression unit 50 may only be in contact with the wall portion 420, or may not be in contact with the wall portion 420. In the present disclosure, as an example, a mode in which the wall portion 420 is always pressed by the suppression unit 50 is shown.

In this embodiment, the suppression section 50 is formed integrally with the first case 41. As shown in FIG. 3, the first case 41 has a base section 410 located below the wall section 420. The upper surface of the base section 410 is located at a distance from the lower end of the wall section 420. The suppression section 50 is formed by protruding upward from the base section 410.

As shown in FIG. 3 or FIG. 4, the suppression section 50 is convex toward the top, and specifically, is formed in a trapezoidal shape tapering toward the top. The suppression section 50 has an inclined surface 51 whose lower end is farther away from the side surface 30a of the reflecting section 30 than its upper end, an upper surface 52, and an opposing surface 53 located behind the inclined surface 51 and opposing the side surface 30a.

A corresponding portion 60 that corresponds to the suppression portion 50 is formed at the lower end of the wall portion 420. The corresponding portion 60 is a concave portion into which the suppression portion 50 is inserted, and as shown in FIG. 4, has a pressed surface 61 that has a similar inclination to the inclined surface 51 and is pressed against the inclined surface 51, and a covering surface 62 that covers the upper surface 52.

When the suppression section 50 provided on the first case 41 is inserted into the corresponding section 60 of the wall section 420, the pressed surface 61 of the corresponding section 60 is pressed by the inclined surface 51 of the suppression section 50. This applies a force in the separation direction D to the wall section 420, preventing the wall section 420 from touching the reflecting section 30 (the holder 32 in this example). In particular, in this embodiment, the suppression section 50 formed integrally with the first case 41 is made of a metal that is more rigid than the second case 42, which is made of resin. This makes it possible to better prevent the wall section 420 from thermally deforming toward the reflecting section 30.

The upper surface 52 of the suppression unit 50 is covered by the cover surface 62 of the corresponding unit 60 provided on the wall portion 420. In other words, the upper surface 52 of the suppression unit 50 is covered by the wall portion 420. This prevents the upper surface 52 of the suppression unit 50 from being exposed to the space inside the housing 40 through which the display light L passes, and prevents the upper surface 52 from being viewed by the user as an unnecessary image.

As shown in FIG. 4, the main surface 421 of the wall portion 420 facing the side surface 30a of the reflecting portion 30 and the opposing surface 53 of the suppressing portion 50 are flush with each other. This prevents a step from occurring between the wall portion 420 and the suppressing portion 50, preventing the step from being visually recognized by the user as an unnecessary image.

The rib 422 shown in FIG. 1 is provided on the back surface of the main surface 421 of the wall portion 420. The rib 422 connects the bezel portion 42a surrounding the opening H in the second case 42 to the wall portion 420, and reinforces the wall portion 420. The rib 422 also prevents the wall portion 420 from deforming in a direction approaching the reflecting portion 30. This concludes the description of this embodiment.

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

In the above embodiment, an example was shown in which the corresponding portion 60 was formed by hollowing out a part of the wall portion 420 in a concave shape. However, as in the modified example shown in FIG. 5, the corresponding portion 60 may be formed by providing a convex portion 413 that protrudes toward the base portion 410 at the lower end of the wall portion 420. The function of the corresponding portion 60 shown in FIG. 5 is the same as in the above embodiment. In other words, it is not limited to a configuration in which a convex suppression portion 50 is inserted into a concave portion provided in the wall portion 420, and a configuration in which the convex suppression portion 50 presses the convex portion provided in the wall portion 420 in the separation direction D may be adopted.

In the above embodiment, the configuration near one side of the reflecting portion 30 is mentioned, but it goes without saying that the configuration near the other side (not shown) may be similar. In other words, there may be a pair of combinations of the suppressing portion 50 and the wall portion 420 pressed by the suppressing portion 50.

The suppression unit 50 does not have to be formed integrally with the first case 41, and may be composed of a member that is fixed directly or indirectly to the first case 41 and is immovable relative to the first case 41. In the above, an example in which the suppression unit 50 presses the wall portion 420 in the separation direction D has been shown, but the configuration of the suppression unit 50 can be changed as desired as long as it can apply a force in the separation direction D to the wall portion 420. For example, a force in the separation direction D may be applied to the wall portion 420 by providing an adhesive or a pressure-sensitive adhesive between the member located on the back side of the wall portion 420 (the back side of the main surface 421) and the wall portion 420. In this case, the adhesive or the pressure-sensitive adhesive functions as the suppression unit 50. The member located on the back side of the wall portion 420 may be, for example, a bearing member not shown. The suppression unit 50 may also be composed of an elastic member, wire, or the like that pulls the wall portion 420 in the separation direction D. In this case, the tensile force may be adjusted so that the wall portion 420 does not deform in the separation direction D.

In the above, an example has been shown in which the first case 41 and the suppression unit 50 are made of metal and the second case 42 is made of resin, but the first case 41 and the suppression unit 50 may also be made of resin. Here, the second case 42 having the wall portion 420 is located higher than the first case 41, and is therefore susceptible to thermal deformation due to the effects of sunlight. Therefore, even if the first case 41 has the same rigidity as the second case 42, the suppression unit 50, which is integral with the first case 41 or immovable relative to the first case 41, can prevent the wall portion 420 from touching the reflector 30.

In the optical path of the display light L connecting the display unit 10 and the concave mirror 31, the number of mirrors used, how the optical path of the display light L is folded, etc. can be changed as appropriate according to the design.

In the above, an example has been shown in which the reflecting unit 30 is rotatably arranged relative to the housing 40, but the reflecting unit 30 may be arranged to be movable in parallel. For example, the reflecting unit 30 may be movable in parallel along the wall portion 420.

The display unit 10 is not limited to one that uses an LCD, and may be one that uses an OLED (Organic Light-Emitting Diode). The display unit 10 may also be one that uses a reflective display device such as a DMD (Digital Micro Mirror Device) or LCOS (Liquid Crystal On Silicon).

The target onto which the display light L is projected is not limited to the windshield of the vehicle, but may also be a combiner composed of a plate-shaped half mirror, a hologram element, etc.

The type of vehicle on which the HUD device 1 is mounted is not limited, and the HUD device 1 can be mounted on various vehicles such as four-wheeled motor vehicles and motorcycles. The HUD device 1 may also be mounted on vehicles other than cars, such as aircraft, ships, and snowmobiles.

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

Reference Signs List 1...Head-up display (HUD) device, L...Display light 10...Display unit, 20...Light path changing mirror 30...Reflecting unit, 30a...Side, 31...Concave mirror, 32...Holder, AX...Axis 40...Housing 41...First case, 410...Platform 42...Second case, H...Opening 420...Wall unit, 421...Main surface, 422...Rib 50...Suppressing unit, 51...Inclined surface, 52...Upper surface, 53...Opposing surface 60...Corresponding unit, 61...Pressed surface, 62...Covering surface D...Separation direction

Claims (4)

A housing having an upward opening;
a reflecting section that is accommodated in the housing and reflects display light representing an image toward the opening,
the housing includes a first case and a second case located above the first case and having the opening formed therein;
the second case has a wall portion that hangs down from an end of the opening and faces a side surface of the reflecting portion,
The wall portion is further provided with a suppression portion that suppresses the wall portion from contacting the reflection portion by applying a force in a direction away from the side surface to the wall portion.
Head-up display device. the suppression portion is integral with the first case or is immovable relative to the first case, is formed to protrude upward, and has an inclined surface that presses the wall portion in a direction away from the side surface,
The wall portion has a pressed surface that is pressed by the inclined surface.
The head-up display device according to claim 1 . The upper surface of the suppression portion is covered by the wall portion.
The head-up display device according to claim 1 or 2. A main surface of the wall portion facing the side surface and a surface of the suppression portion facing the side surface are flush with each other.
The head-up display device according to any one of claims 1 to 3.