Head-up display device

Abstract

Provided is a head-up display (HUD) device that can suppress stray light by using a simple configuration. This HUD device 100 comprises a display unit 11 that radiates display light L for displaying an image, a case 30, and a light-shielding member 40. The case 30 has an accommodation part 32 that accommodates the display unit 11, a pass-through port 33, and a bottom part 310 in which the display light L from the pass-through port 33 passes the front side. The light-shielding member 40 has a frame part 41 positioned between the display unit 11 and the pass-through part 33 and a plate part 42 fixed to the rear side of the bottom part 310. The accommodation part 32 has a cover section 320 that covers the display unit 11 from the front side, and the pass-through port 33 is formed between the cover part 320 and the bottom part 310. In addition, the frame part 41 forms a shape along the edge of the pass-through port 33. The plate part 42 has a hook section to which a cord is hooked. The cord includes a display cord electrically connected to the display unit 11.

Description

[Technical field]

[0001] The present invention relates to a head-up display device. [Background technology]

[0002] 2. Description of the Related Art Head-Up Display (HUD) devices are known that emit display light representing an image toward a light-transmitting member (such as a windshield of a vehicle) and display a virtual image of the image.

[0003] For example, Patent Document 1 describes an HUD device that includes a display element that emits display light and a shading member that blocks a portion of the display light emitted from the display element in order to suppress light (hereinafter referred to as "stray light") that is unnecessary for displaying a virtual image. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5556019 Summary of the Invention [Problem to be solved by the invention]

[0005] Simply providing a dedicated light blocking member to suppress stray light as in Patent Document 1 may increase the number of parts and complicate the configuration.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a head-up display device capable of suppressing stray light with a simple configuration. [Means for solving the problem]

[0007] In order to achieve the above object, a head-up display device according to the present invention comprises: A display unit that emits display light representing an image; a reflecting portion that reflects the display light emitted from the display portion toward an external light-transmitting member; a case including a housing portion that houses the display portion, a passage opening through which the display light emitted from the display portion passes, and a bottom portion through which the display light from the passage opening to the reflector passes on a front side; a frame portion located between the display portion and the passage opening, and a light-shielding member having a plate portion fixed to a back side of the bottom portion, the housing portion has a cover portion that covers the display portion from a front side, The passage opening is formed between the cover portion and the bottom portion, The frame portion has a shape that conforms to an edge of the passage opening, The plate portion has a hook portion to which a cord can be hung, The cord includes a display cord electrically connected to the display unit. Effect of the Invention

[0008] According to the present invention, stray light can be suppressed with a simple configuration. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing a virtual image display mode of a head-up display (HUD) device according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a perspective view of the HUD device according to the embodiment. [Diagram 3] 3 is a schematic cross-sectional view of the HUD device according to the above embodiment taken along line AA in FIG. 2. [Figure 4] FIG. [Diagram 5] FIG. 2 is a rear view of the case of the HUD device according to the embodiment. [Figure 6] FIG. 2 is a perspective view of a light blocking member and an optical element according to the embodiment. [Figure 7] FIG. 2 is a schematic diagram for mainly explaining the relationship between a display unit and an optical element according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] An embodiment of the present invention will be described with reference to the drawings.

[0011] As shown in FIG. 1, a head-up display (HUD) device 100 according to this embodiment is disposed, for example, in a dashboard 2 of a vehicle 1. The HUD device 100 emits a display light L toward a windshield 3 (windshield). The display light L reflected by the windshield 3 allows a user 4 (mainly a driver of the vehicle 1) to visually recognize an image represented by the display light L as a virtual image V. The virtual image V is displayed in front of the vehicle 1 through the windshield 3. This allows the user 4 to visually recognize the virtual image V superimposed on the scenery ahead. The virtual image V displays various information related to the vehicle 1 (hereinafter referred to as vehicle information). Note that the vehicle information may include not only information about the vehicle 1 itself but also information about the outside of the vehicle 1.

[0012] The HUD device 100 includes a display unit 10, a reflector 20, a case 30, a light blocking member 40, an optical element 50, and a circuit board 60, as shown in FIG. In the following, each configuration may be described using the left-right, up-down, and front-rear directions of the vehicle 1. The X-axis along the left-right direction, the Y-axis along the up-down direction, and the Z-axis along the front-rear direction are shown in each drawing. Also, the upper side of the case 30 may be referred to as the "front side," and the lower side of the case 30 may be referred to as the "back side."

[0013] The display unit 10 includes a display section 11, a holder 12 that holds the display section 11, and an illumination section 13 that illuminates the display section 11 from behind.

[0014] The display unit 11 is composed of, for example, a TFT (Thin Film Transistor) type liquid crystal panel, and displays an image on a display surface 11a facing forward. As shown in Fig. 3, the display unit 11 is electrically connected to a display substrate 11b on which a drive circuit for driving the liquid crystal panel and the like are mounted. The display substrate 11b is provided so as to protrude forward from the lower end of the display unit 11.

[0015] The holder 12 is made of, for example, resin, and has a first holding part 12a for holding the display part 11 and a second holding part 12b for holding the display substrate 11b. The first holding part 12a is in the form of a frame that exposes the display surface 11a from an opening, and has a fixing part 12c for fixing the optical element 50 on its front surface. In this embodiment, the fixing parts 12c are a pair sandwiching the display surface 11a in the X direction, and an elastic member T is attached to each of them. The elastic member T will be described later. The second holding part 12b protrudes forward from the lower end of the first holding part 12a. As a result, the cross section of the holder 12 consisting of the first holding part 12a and the second holding part 12b is L-shaped as shown in FIG. 3. As shown in FIG. 3 and FIG. 5, the display substrate 11b is fixed to the back side of the second holding part 12b.

[0016] As shown in FIG. 3, the illumination unit 13 mainly includes a light source 13a, a light source substrate 13b, a lens 13c, and a housing 13d. The light source 13a is, for example, an LED (Light Emitting Diode) and emits light in the Z direction. The light source substrate 13b is a substrate on which the light source 13a is mounted, and in this embodiment, is installed so that the main surface is parallel to the XY plane and the normal to the main surface is parallel to the Z axis. The lens 13c is, for example, a condenser lens, and collects the light emitted from the light source 13a. The housing 13d holds the light source substrate 13b and the lens 13c, and forms an illumination chamber that guides the light from the light source 13a to the display unit 11. The housing 13d is, for example, formed of a combination of a plurality of members. The display unit 11 displays an image on the display surface 11a by being illuminated by the illumination unit 13. As a result, display light L representing the image is emitted from the display unit 11.

[0017] The reflecting unit 20 shown in Fig. 2 is, for example, a concave mirror, and reflects the display light L from the display unit 11 toward the windshield 3 shown in Fig. 1. Due to the display light L reflected by the concave mirror, the virtual image V viewed by the user 4 is enlarged compared to the image displayed on the display unit 11. The reflecting unit 20 may be composed of multiple mirrors. The number of mirrors constituting the reflecting unit 20 can be arbitrarily changed depending on the design.

[0018] 3, the case 30 has an optical path forming chamber 31 that forms an optical path for the display light L emitted from the display unit 11, a storage section 32 that stores the display unit 11, and a passage opening 33 that passes the display light L emitted from the display unit 11. The case 30 is formed, for example, from a metal, and the optical path forming chamber 31, the storage section 32, and the passage opening 33 are integrally formed.

[0019] The light path forming chamber 31 is box-shaped with an opening at the top, and includes a bottom 310 and a support 311 that supports the reflector 20. As shown in FIG. 2 and FIG. 3, the bottom 310 passes the display light L from the display 11 to the reflector 20 on the front side. As shown in FIG. 5, the bottom 310 also has a board placement section 310a on which the circuit board 60 is placed, and an adjacent section 310b adjacent to the board placement section 310a on the back side. A plate section 42 of the light blocking member 40, which will be described later, is provided in the adjacent section 310b. The support 311 is composed of a pair of walls that rise upward from both ends of the bottom 310 in the X direction. The support 311 supports the reflector 20 via a mirror holder (not shown) that holds the reflector 20. The reflector 20 may be configured to be rotatable around an axis that is generally along the X direction.

[0020] As shown in FIG. 3, the storage section 32 is formed in a box shape having a portion protruding upward from the bottom section 310. The storage section 32 opens downward and stores most of the display unit 10 including the display section 11 therein. The display unit 10 is inserted into the storage section 32 from below. The storage section 32 has a cover section 320 that covers the display unit 10 from the front side (upper side) and a wall section 321 that hangs down from the rear end of the cover section 320. As shown in FIG. 3, the wall section 321 faces the light source board 13b of the illumination section 13. In addition, the wall section 321 has a heat sink 321a as shown in FIG. 2 and FIG. 3. The heat sink 321a has a plurality of heat dissipation fins provided toward the outside of the wall section 321.

[0021] 2 and 3, the passage opening 33 is formed between the cover portion 320 and the bottom portion 310. As shown in FIG. 2, the passage opening 33 is formed in a rectangular shape.

[0022] Here, the attitude of the display unit 11 will be described with reference to FIG. 7. The display unit 11 is provided with a display surface 11a tilted with respect to the XY plane in order to suppress the generation of stray light caused by external light (not shown). When external light enters the HUD device 100, the external light reflected by the reflecting unit 20 may be further reflected by the display surface 11a of the display unit 11. In order to suppress the external light reflected by the display surface 11a from reaching the reflecting unit 20, the display surface 11a is set to be tilted at an angle α with respect to the XY plane. The angle α can be arbitrarily set to an appropriate value according to the optical system in the HUD device 100, and can be set within a range of 10° to 30°, for example. In addition, the optical element 50 described later is provided with an opposing surface 50a facing the display surface 11a tilted by an angle β with respect to the display surface 11a. The reason for this will be described later.

[0023] The light blocking member 40 is made of, for example, resin to have light blocking properties, and has a frame portion 41 and a plate portion 42 as shown in FIGS.

[0024] As shown in Fig. 2, the frame portion 41 has a frame shape that follows the edge of the passage opening 33. The frame portion 41 is positioned between the display unit 11 and the passage opening 33 so as to fill the gap that occurs between the display unit 11 and the passage opening 33 by disposing the display unit 11 at an angle as described above. The frame portion 41 has a flat plate portion 41a whose upper surface is flush with the bottom 310 of the case 30. As shown in Fig. 3, the second holding portion 12b of the holder 12 is positioned on the back side (below) of the flat plate portion 41a.

[0025] 6, the frame 41 has a plurality of protrusions P protruding in the Z direction at its open end. The protrusions P are cylindrical and provided at locations corresponding to the vertices of a triangle in this embodiment, with a total of three protrusions P. The three protrusions P abut against one surface of the optical element 50 (the surface opposite the aforementioned opposing surface 50a). The optical element 50 is positioned relative to the frame 41 by the three protrusions P.

[0026] The plate portion 42 is a plate-like portion fixed to the back side of the bottom portion 310 of the case 30. Specifically, as shown in Fig. 3, the plate portion 42 is connected to the flat portion 41a of the frame portion 41 via a step portion 41b, and extends to the back side of the bottom portion 310. The plate portion 42 is fixed to an adjacent portion 310b of the bottom portion 310.

[0027] The plate 42 is also formed with a hook portion on which a cord distributed on the back side of the bottom 310 is hung. Specifically, as shown in FIG. 5, the plate 42 has a first hook portion H1 on which the display cord C1 is hung and a second hook portion H2 on which the light source cord C2 is hung. Here, the display cord C1 is made of an FFC (Flexible Flat Cable) that electrically connects the display unit 11 and the circuit board 60. The light source cord C2 is made of a lead wire that electrically connects the light source board 13b and the circuit board 60. In this embodiment, one first hook portion H1 and multiple second hook portions H2 are provided, but the number, arrangement, and shape of the first hook portion H1 and the second hook portion H2 are arbitrary depending on the arrangement of the cord.

[0028] The optical element 50 is a known optical member that transmits the display light L traveling from the display unit 11 to the reflector 20, and has a plate shape. As shown in FIG. 3, the optical element 50 is located on the side of the passage opening 33 of the display unit 11. The optical element 50 is provided, for example, for the purpose of preventing reflection, and is composed of a retardation plate such as a λ / 4 plate (also called a 1 / 4 wavelength plate). The optical element 50 may be an AR (Anti-Reflection) film or a transparent plate having an AR film, a hot mirror, or the like.

[0029] As shown in FIG. 3, the optical element 50 is sandwiched between the holder 12 and the frame portion 41 of the light blocking member 40 with the opposing surface 50a tilted relative to the display surface 11a of the display unit 11. Specifically, as shown in FIG. 4, the optical element 50 is fixed to the holder 12 via an elastic member T attached to the fixing portion 12c of the holder 12 (the optical element 50 is omitted in FIG. 4). The elastic member T is plate-shaped and is made of, for example, an elastic double-sided tape. The optical element 50 fixed to the holder 12 via the elastic member T has the surface opposite to the opposing surface 50a pressed in the Z direction by three protrusions P (see FIG. 6) provided on the frame portion 41. In this manner, the optical element 50 is sandwiched between the holder 12 and the frame portion 41.

[0030] Here, the inclination of the optical element 50 with respect to the display unit 11 will be described with reference to Fig. 7. The angle β of the opposing surface 50a with respect to the display surface 11a is set to an angle at which secondary reflected light Ls, which is light that is reflected by the opposing surface 50a and then further reflected by the display surface 11a, among the display light L emitted from the display unit 11, does not reach the reflecting unit 20. The angle β can be set to any appropriate value depending on the optical system in the HUD device 100, and can be set within the range of 5° to 15°, for example.

[0031] As shown in FIG. 5, the circuit board 60 is disposed and fixed in the board disposing portion 310a of the bottom portion 310. The circuit board 60 is a printed circuit board on which various circuits are formed and a control portion consisting of a microcomputer is mounted. The circuit board 60 is electrically connected to the display portion 11 via the display board 11b and the display cord C1. The circuit board 60 is also electrically connected to the light source board 13b via the light source cord C2. The control portion mounted on the circuit board 60 controls the overall operation of the HUD device 100, and controls the display operation of the display portion 11 and the light emission operation of the light source 13a. The control portion communicates with a system such as an ECU (Electronic Control Unit) that controls each portion of the vehicle 1, and causes the display portion 11 to display an image showing vehicle information.

[0032] An upper cover provided with a cover glass (not shown) is attached to the upper part of the case 30. The display light L reflected by the reflector 20 passes through the cover glass and travels toward the windshield 3. In addition, a lower cover (not shown) is attached to the lower part of the case 30 to cover the circuit board 60 and the like from below.

[0033] (1) The HUD device 100 described above includes a display unit 11 that emits display light L that represents an image, a reflecting unit 20 that reflects the display light L emitted from the display unit 11 toward a windshield 3 (an example of an external light-transmitting member), a case 30, and a light-shielding member 40. The case 30 has a housing portion 32 that houses the display unit 11, a passage opening 33 that passes the display light L emitted from the display unit 11, and a bottom portion 310 through which the display light L passes from the passage opening 33 to the reflecting unit 20 on the front side. The light-shielding member 40 has a frame portion 41 located between the display unit 11 and the passage opening 33, and a plate portion 42 fixed to the back side of the bottom portion 310. The housing portion 32 has a cover portion 320 that covers the display unit 11 from the front side, and the passage opening 33 is formed between the cover portion 320 and the bottom portion 310. The frame portion 41 has a shape that follows the edge of the passage opening 33. The plate portion 42 has hook portions (a first hook portion H1, a second hook portion H2) on which cords (a display cord C1, a light source cord C2) are hung. The cords include the display cord C1 that is electrically connected to the display unit 11. According to the above configuration, it is possible to suppress the display light L from leaking out and the outside light from entering between the display unit 11 and the passage opening 33, thereby suppressing stray light. Also, since the light blocking member 40 is provided with a hook portion for hanging a cord and is given multiple functions, it is possible to reduce the number of parts and simplify the configuration.

[0034] (2) The HUD device 100 also includes a circuit board 60 that is provided on the back side of the bottom portion 310 and is electrically connected to the display unit 11 by a display cord C1. With this configuration, the display cord C1 leading to the circuit board 60 located on the back side of the case 30 can be organized by hanging it on the hook portion located on the back side of the case 30, making it easy to assemble components on the back side of the case 30.

[0035] (3) The HUD device 100 is also provided with a holder 12 that is located within the accommodation portion 32 and that holds the display portion 11, and an optical element 50 that is located between the display portion 11 and the passage opening 33 and through which the display light L passes. The optical element 50 is sandwiched between the holder 12 and the frame portion 41 with an opposing surface 50a that faces the display portion 11 in an orientation that is inclined with respect to the display surface 11a of the display portion 11. According to this configuration, the number of parts can be reduced because an additional function can be imparted to the light blocking member 40. Also, the tilted optical element 50 can prevent the secondary reflected light Ls from becoming stray light.

[0036] (4) In order to prevent the secondary reflected light Ls from becoming stray light, it is preferable that the angle of the opposing surface 50a with respect to the display surface 11a is an angle at which the secondary reflected light Ls, which is light that is reflected by the opposing surface 50a and then further reflected by the display surface 11a, does not reach the reflecting unit 20.

[0037] (5) In order to more effectively reduce stray light, it is preferable that the frame 41 has a shape that fills the gap between the optical element 50 and the passage opening 33 .

[0038] (6) The optical element 50 is fixed to the holder 12 via an elastic member T. This configuration can improve the cushioning properties of the optical element 50.

[0039] (7) Furthermore, frame portion 41 has a plurality of protrusions P that protrude toward optical element 50, and optical element 50 is sandwiched between holder 12 and frame portion 41 while being pressed by the plurality of protrusions P. This configuration allows the optical element 50 to be satisfactorily positioned relative to the frame portion 41 in a state of almost point contact.

[0040] The present invention is not limited to the above-described embodiment and drawings, and can be modified (including the deletion of components) as appropriate without departing from the spirit of the present invention.

[0041] The cord that is hooked on at least one of the first hook portion H1 and the second hook portion H2 is not limited to a lead wire or an FFC, but may include an FPC (Flexible Printed Circuit).

[0042] The elastic member T is not limited to an elastic double-sided tape and may be any material as long as it can be fixed to the holder 12. For example, the elastic member T may be a sponge material such as urethane foam, an elastomer including rubber, or the like that is fixed to the holder 12 by adhesion or the like.

[0043] In the above, an example has been shown in which the display section 11 of the display unit 10 is made of a liquid crystal panel, but the configuration of the display section 11 and the display unit 10 is not limited and is arbitrary. For example, the display section 11 may be made of an OLED (Organic Light-Emitting Diode). The display unit 10 may also be configured to include a DMD (Digital Micromirror Device) and the display section 11 made of a transmissive screen that receives light reflected by the DMD and displays an image. In this case, the transmissive screen can be considered as the display surface 11a.

[0044] The light-transmitting member that reflects the HUD device 100 toward the user 4 is not limited to the windshield 3 of the vehicle 1, but may be a combiner constituted by a plate-shaped half mirror, a hologram element, or the like.

[0045] The type of vehicle 1 on which the HUD device 100 is mounted is not limited, and the HUD device 100 can be applied to various vehicles such as four-wheeled motor vehicles, motorcycles, etc. The HUD device 100 may also be mounted on vehicles other than the vehicle 1, such as aircraft, ships, snowmobiles, etc.

[0046] In the above description, in order to facilitate understanding of the present invention, descriptions of well-known technical matters have been omitted as appropriate. [Explanation of symbols]

[0047] 100...Head-up display (HUD) device 10...Display unit 11...display section, 11a...display surface, 11b...display board 12... holder, 12a... first holding portion, 12b... second holding portion 12c...fixed portion, T...elastic member 13: Illumination unit, 13a: Light source, 13b: Light source board, 13c: Lens, 13d: Housing 20…Reflector 30…Case 31...Optical path forming chamber 310: bottom portion, 310a: substrate placement portion, 310b: adjacent portion, 311: support portion 32: container portion, 320: cover portion, 321: wall portion, 321a: heat sink 33... Passage gate 40...Light blocking member 41...frame part, 41a...flat plate part, 41b...stepped part, P...protrusion part 42...Plate part H1: First hook part, H2: Second hook part C1: Display code, C2: Light source code 50...optical element, 50a...opposing surface 60...Circuit board 1...vehicle, 2...dashboard, 3...windshield, 4...user L: display light, V: virtual image, Ls: secondary reflected light

Claims

1. A display unit that emits display light representing an image; a reflecting portion that reflects the display light emitted from the display portion toward an external light-transmitting member; a case including a housing portion that houses the display portion, a passage opening through which the display light emitted from the display portion passes, and a bottom portion through which the display light passes from the passage opening to the reflector; a frame portion located between the display portion and the passage opening, and a light-shielding member having a plate portion fixed to a back side of the bottom portion, the housing portion has a cover portion that covers the display portion from a front side, The passage opening is formed between the cover portion and the bottom portion, The frame portion has a shape that conforms to an edge of the passage opening, The plate portion has a hook portion to which a cord can be hung, The cord includes a display cord electrically connected to the display unit. Head-up display device.

2. A circuit board is provided on the back side of the bottom and is electrically connected to the display unit by the display cord. The head-up display device according to claim 1 .

3. a holder located within the housing and holding the display unit; an optical element located between the display unit and the passage opening and through which the display light passes; The optical element is sandwiched between the holder and the frame with a surface facing the display unit inclined with respect to a display surface on which the image of the display unit is displayed. The head-up display device according to claim 1 or 2.

4. The angle of the opposing surface with respect to the display surface is an angle at which secondary reflected light, which is light of the display light emitted from the display unit that is reflected by the opposing surface and then further reflected by the display surface, does not reach the reflecting unit. The head-up display device according to claim 3 .

5. The frame portion has a shape that fills a gap that occurs between the optical element and the passage port. The head-up display device according to claim 3 or 4.

6. The optical element is fixed to the holder via an elastic member. The head-up display device according to any one of claims 3 to 5.

7. the frame portion has a plurality of protrusions protruding toward the optical element, the optical element is sandwiched between the holder and the frame in a state where the optical element is pressed by the plurality of protrusions; The head-up display device according to any one of claims 3 to 6.

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