JP7589638B2 - Vehicle display device - Google Patents

Description

This disclosure relates to a display device for a vehicle.

For example, the head-up display described in Patent Document 1 is known as a head-up display for a vehicle. The head-up display has a display and a concave mirror. The light of the display information emitted from the display surface of the display is reflected by the reflective surface of the concave mirror and enters the inner surface of the vehicle's front windshield. The incident light (display information) is then reflected in the driver's line of sight and formed as a virtual image in front of the inner surface.

The curvature of the portion of the inner surface of the front windshield that is laterally spaced from the center (to the right in the case of right-hand drive vehicles) (within a specified angle range of 20 degrees to 30 degrees) is approximately 1.4 times the curvature of the center. In addition, the curvature of the portion of the reflective surface of the concave mirror that is a specified angle to the right from the reflection center is set to approximately 1.06 times (1.04 to 1.08 times) the curvature of the reflection center.

In this way, in Patent Document 1, the rate of change of the curvature of the reflective surface of the concave mirror is set to match the rate of change of the curvature of the windshield, making it possible to form a less distorted virtual image in front of the windshield.

JP 2002-31774 A

However, in the above-mentioned Patent Document 1, the curvature of the reflective surface of the concave mirror is varied (curvature distribution) in accordance with the rate of change of the curvature of the vehicle's front windshield, which increases the effort required to form the reflective surface of the concave mirror.

In view of the above problems, the objective of this disclosure is to provide a vehicle display device that is simple in configuration and capable of forming a virtual image with minimal distortion.

To achieve the above objective, this disclosure employs the following technical means:

In the present disclosure, a display (120) that emits display light for an image;
a reflecting portion (130) that is rectangular and disposed so that an upper side (131a) is in the left-right direction of the vehicle (1) and reflects the display light;
A display device for a vehicle, which projects display light reflected by a reflecting portion onto a windshield (20) of a vehicle located in front of a driver, and allows the driver to visually recognize the virtual image (30) in front of the windshield,
The reflecting portion is disposed so that the upper side is inclined downward toward the outside in the lateral direction of the vehicle when viewed from the driver's side ,
The angle of inclination is set so that the distance of the reflected display light to the windshield is equal on the left and right ends of the reflecting portion .

According to this disclosure, by tilting the reflector, the distance from the reflector to the windshield for the display light can be made equal on the left and right ends of the reflector, thereby suppressing distortion of the virtual image. With this disclosure, distortion can be suppressed by simply tilting the attitude of the reflector.

The symbols in parentheses for each of the above means indicate the corresponding relationship with the specific means described in the embodiments below.

1 is an explanatory diagram showing an overall configuration of a vehicle display device according to a first embodiment; FIG. 13 is an explanatory diagram showing the mounting posture of a reflecting portion according to the present disclosure in comparison with a comparative example. FIG. 2 is an explanatory diagram showing an optoface relative to a reflecting portion. FIG. 11 is an explanatory diagram showing a vehicle display device according to a second embodiment.

Below, several embodiments for implementing the present disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to matters described in the preceding embodiment may be given the same reference numerals, and duplicated descriptions may be omitted. In each embodiment, when only a part of the configuration is described, other previously described embodiments may be applied to the other parts of the configuration. In addition to combinations of parts that are specifically specified as being possible in each embodiment, it is also possible to partially combine embodiments even if not specified, as long as there is no particular problem with the combination.

First Embodiment
A vehicle display device 100 in the first embodiment will be described with reference to Fig. 1 to Fig. 3. As shown in Fig. 1, the vehicle display device 100 is mounted on a vehicle 1 (for example, an automobile), and causes display light, which represents display information, emitted from a liquid crystal display 120 to be incident on a projection position 20a on a windshield 20 of the vehicle 1. The vehicle display device 100 forms a display image 30 of the display information on a forward extension of a line connecting the driver (operator) and the projection position 20a, and allows the driver to view the display image 30 as a virtual image.

This vehicle display device 100 allows the driver to visually recognize the display image 30 superimposed on the view in front of the vehicle 1. The vehicle display device 100 is a so-called head-up display device (virtual image display device). Hereinafter, the vehicle display device 100 will be referred to as the display device 100. Note that, in the vehicle 1, the left-right direction is defined as the X direction, the front-rear direction is defined as the Y direction, and the up-down direction is defined as the Z direction.

The windshield 20 is provided on the front side of the vehicle 1, and is made of, for example, laminated glass formed of two pieces of glass and an intermediate film provided between them. When viewed from the side as shown in FIG. 1, the windshield 20 is inclined so that the ceiling side faces rearward from the lower end on the instrument panel 10 side. The inclined surface of the windshield 20 is curved (has a curvature) so as to be slightly convex toward the front side. Also, when viewed from the ceiling side, the left and right ends of the windshield 20 are curved (has a curvature) so that they wrap around toward the rear from the center. In this way, because the windshield 20 is curved, it has the same effect as a general concave mirror, allowing the display image 30 to be enlarged and displayed at a greater distance.

As shown in FIG. 1, the display device 100 includes a backlight 110, a liquid crystal display 120, a reflector 130, a drive unit 140, a housing 150, a dustproof sheet 160, a position adjustment switch 170, and a control device 180.

The main components of the display device 100, namely the backlight 110, the liquid crystal display 120, the reflector 130, the drive unit 140, and the control device 180, are housed in a housing 150. The housing 150 is disposed inside an instrument panel 10 that extends downward from the lower end of the windshield 20 to the rear of the vehicle interior. A dustproof sheet 160 is provided in an opening 151 of the housing 150. The position adjustment switch 170 is provided in a position that is easy for the driver to operate, for example, on the surface of the instrument panel 10 that faces the driver.

In addition, an opening 10a is provided on the top surface of the instrument panel 10 to allow the display light from the reflector 130 to pass through. The following describes the details of each component of the display device 100.

The backlight 110 is a light-emitting element that emits light toward the liquid crystal display 120 when electricity is applied, and for example, a light-emitting diode (LED) is used. The backlight 110 emits light along an optical axis toward the liquid crystal display 120.

The liquid crystal display 120 is a display that emits display light that represents display information (images), and is driven and controlled by a drive circuit of the control device 180. The liquid crystal display 120 may be, for example, a TFT liquid crystal panel that uses thin film transistors (TFTs), a dual scan type display (Dual Scan Super Twisted Nematic = D-STN), or a TN (Twisted Nematic) segment liquid crystal.

The liquid crystal display 120 emits display information formed on its surface (display surface) as display light using light emitted from the backlight 110 toward the reflector 130 on the opposite side of the backlight 110. The surface of the liquid crystal display 120 that emits the display light is, for example, arranged along an imaginary X-Z plane, and is arranged so that the optical axis of the display light faces in the fore-and-aft direction of the vehicle 1 (so that the emission direction faces the front side of the vehicle 1).

The display information formed by the liquid crystal display 120 can be, for example, map information in a vehicle navigation system, information on the current position of the vehicle on the map, or guidance information to a destination. Alternatively, the display information may be vehicle information while the vehicle 1 is traveling, such as vehicle speed, engine RPM, engine coolant temperature, and battery voltage.

The LCD display 120 is capable of displaying the above-mentioned types of display information one by one, or in combination, on the surface of the LCD display 120. The driver can select which display information to display using a display changeover switch.

The reflector 130 is a device that reflects the display light from the liquid crystal display 120 and projects it onto the projection position 20a on the windshield 20 through the opening 151 in the housing 150 and the opening 10a in the instrument panel 10. The reflector 130 has a concave mirror 131, a shaft 132, etc.

The concave mirror 131 is a magnifying mirror with a curved surface that is concave on the side, and is, for example, a quadrangle (rectangle) that is long in the left-right direction (X direction) of the vehicle 1, and is positioned so that the top side 131a (long side) of the quadrangle is in the left-right direction of the vehicle 1. The concave mirror 131 magnifies the display information provided by the display light from the liquid crystal display 120 and reflects it onto the windshield 20.

The shaft 132 is a shaft that protrudes from the center of the left and right sides 131b (short sides) of the concave mirror 131 toward the upper side 131a (left and right direction of the vehicle 1). The shaft 132 is supported by a shaft support provided inside the housing 150. The concave mirror 131 is rotatable (pivotable) around the shaft 132.

Here, as shown in FIG. 2(b), the reflecting portion 130 (concave mirror 131) is arranged so that its upper edge 131a is inclined downward toward the lateral outside of the vehicle 1 when viewed from the driver's side, as compared to FIG. 2(a) of the comparative example. Accordingly, the shaft portion 132 is also inclined in a similar manner. In the case of a right-hand drive vehicle, the right end side of the reflecting portion 130 is inclined so as to face downward when viewed from the driver's seat. Also, in the case of a left-hand drive vehicle, the left end side of the reflecting portion 130 is inclined so as to face downward when viewed from the driver's seat.

The angle of inclination of the upper edge 131a of the reflector 130 is set so that the distance of the reflected display light to the windshield 20 is roughly the same on the left and right ends of the reflector 130.

The lower end of the concave mirror 131 is connected to an arm 141 of the drive unit 140, which will be described later. The concave mirror 131 rotates clockwise (forward) or counterclockwise (backward) around the shaft 132 as the arm 141 slides in the fore-and-aft direction of the vehicle 1 (Y direction in FIG. 1).

By rotating the concave mirror 131, the reflection angle is adjusted and the height position of the display information projected onto the windshield 20 is changed, which in turn changes the height position of the display image 30. When the concave mirror 131 is rotated clockwise, the position of the display image 30 is moved to the upper side of the windshield 20. When the concave mirror 131 is rotated counterclockwise, the position of the display image 30 is moved to the lower side of the windshield 20.

The driving unit 140 is a device that drives (rotates) the reflecting unit 130 to adjust the reflection angle with respect to the display light. The driving unit 140 has an arm 141 that is slid in the fore-and-aft direction of the vehicle 1 by a motor. The motor is, for example, a synchronous motor (step motor) that operates in synchronization with an input pulse voltage.

The arm 141 is a rod-shaped member that connects the motor side and the concave mirror 131. One end of the arm 141 is fixed to a sliding member that is slid in the fore-and-aft direction of the vehicle 1 by the motor, and the other end of the arm 141 is connected to, for example, the lower end of the concave mirror 131. The concave mirror 131 and the arm 141 form a link mechanism. In other words, the arm 141 slides due to the sliding member, causing the concave mirror 131 to rotate (pivot).

The more the arm 141 slides toward the concave mirror 131, the more the concave mirror 131 rotates clockwise, and the inclination of the concave mirror 131 becomes smaller (standing up vertically). Conversely, the more the arm 141 slides away from the concave mirror 131, the more the concave mirror 131 rotates counterclockwise, and the inclination of the concave mirror 131 becomes larger (laying down horizontally). Also, the smaller the sliding range of the arm 141, the smaller the amount of change in the inclination of the concave mirror 131, and conversely, the larger the sliding range of the arm 141, the greater the amount of change in the inclination of the concave mirror 131.

The housing 150 is a container member that houses the backlight 110, the liquid crystal display 120, the reflector 130, the drive unit 140, and the control device 180. As described above, an opening 151 is provided on the top surface of the housing 150 so as to correspond to the opening 10a of the instrument panel 10. The opening 151 allows the display light reflected by the reflector 130 to pass through toward the windshield 20.

The dustproof sheet 160 is a blocking member that blocks the opening 151 of the housing 150 and prevents the intrusion of dust, dirt, and the like through the opening 151. The sheet portion that serves as the base material of the dustproof sheet 160 is plate-shaped and has translucency that allows the display light from the concave mirror 131 and sunlight (visible light) to pass through. The sheet portion is formed, for example, from a transparent resin material (polycarbonate, acrylic, etc.). Note that the material of the sheet portion may be a glass material instead of the above-mentioned resin material.

The position adjustment switch 170 is an input unit that generates a request signal for adjusting the position of the display image 30 on the windshield 20 upward or downward according to the driver's preference when the driver operates the position adjustment switch 170. The position adjustment switch 170 has, for example, a rectangular switch surface facing the driver. Pressing the upper side of this switch surface generates a request signal to change the position of the display image 30 upward, and pressing the lower side of the switch surface generates a request signal to change the position of the display image 30 downward. The generated request signal is then output to the control device 180.

The control device 180 is a control means that controls the display information of the liquid crystal display 120 and also controls the operation of the motor in the drive unit 140 in response to a request signal from the position adjustment switch 170 or an on/off signal from the ignition switch.

The display device 100 is configured as described above, and the operation of the display device 100 by the control device 180 will be described below.

When the ignition switch of the vehicle 1 is turned off, the control device 180 operates the motor of the drive unit 140 to change the rotational position (reflection angle) of the reflector 130 from the driver setting position normally used to a reset position to suppress reflection caused by sunlight entering the housing 150.

When the ignition switch is turned on, the control device 180 operates the drive unit 140 to perform origin control, which moves the rotational position of the reflecting unit 130 from the reset position to the origin position, and then returns it to the driver setting position that was set by the driver during the previous operation. The origin position is the basic position for the rotation of the motor, and is used for control to the reset position and the driver setting position.

The control device 180 then determines the display information to be displayed based on the driver's instructions using the display changeover switch, and causes the LCD display 120 to form the display information via the drive circuit.

As shown in FIG. 1, the liquid crystal display 120 emits display information as display light to the reflector 130 (concave mirror 131) using light emitted from the backlight 110. The reflector 130 reflects the display light emitted from the liquid crystal display 120 through the opening 151, the dustproof sheet 160, and the opening 10a to the projection position 20a on the windshield 20. The display light (display information) reflected to the projection position 20a is displayed (formed) as a display image 30 (virtual image) on the forward extension of the line connecting the driver and the projection position 20a (forward of the driver's field of vision) of the vehicle 1, and is visible to the driver.

When the driver operates the position adjustment switch 170 to generate a request signal to change the position of the display image 30, the control device 180 activates the drive unit 140 and rotates the reflector 130 in the requested direction using the arm 141 to adjust it to the driver's set position.

Specifically, if the request signal is an upward request, the motor is rotated in the forward direction, and the arm 141 moves toward the reflector 130. Then, in FIG. 1, the upper end of the reflector 130 is rotated in a direction approaching the driver, and the display image 30 is moved upward on the windshield 20. Conversely, if the request signal is a downward request, the motor is rotated in the reverse direction, and the arm 141 moves to the side opposite the reflector 130. Then, in FIG. 1, the upper end of the reflector 130 is rotated in a direction away from the driver, and the display image 30 is moved downward on the windshield 20.

In this embodiment, the upper edge 131a of the reflecting portion 130 (concave mirror 131) is inclined downward toward the outside in the lateral direction of the vehicle 1 when viewed from the driver's side.

As a result, even if the windshield 20 is curved so as to wrap around the rear, the distance from the reflector 130 to the windshield 20 (projection position 20a) of the display light can be made equal on the left and right ends of the reflector 130 (Figure 2(b)), thereby suppressing distortion of the display image 30 (virtual image). In this embodiment, distortion can be suppressed by simply tilting the attitude of the reflector 130.

In addition, by tilting the reflecting portion 130 compared to FIG. 3(a) in the comparative example, it becomes possible to create the concave mirror 131 along the optoface OP as shown in FIG. 3(b), so that the size of the concave mirror 131 can be made smaller than that of the comparative example.

Second Embodiment
A display device 100A according to the second embodiment is shown in Fig. 4. The display device 100A according to the second embodiment is different from the display device 100 according to the first embodiment in that the arrangement of the liquid crystal display 120 is changed and another reflecting section 130A is added.

The display surface of the liquid crystal display 120 is arranged, for example, along a virtual X-Y plane, that is, with the emission direction facing the upper side of the vehicle 1. The other reflector 130A is provided to reflect the display light from the liquid crystal display 120 and make it enter the reflector 130. The reflector surface of the other reflector 130A is formed, for example, as a plane mirror.

As a result, even if the direct distance between the liquid crystal display 120 and the reflector 130 is reduced, the distance of the display light from the liquid crystal display 120 to the reflector 130 can be made the same by reflecting the display light from the liquid crystal display 120 by another reflector 130A. Therefore, the direct distance between the liquid crystal display 120 and the reflector 130 can be reduced, and the dimension of the display device 100A in the fore-and-aft direction of the vehicle 1 can be reduced.

(Modification of the second embodiment)
In the second embodiment, the reflecting surface of the other reflecting portion 130A is a flat mirror, but the present invention is not limited to this and may be formed to be non-flat so as to be able to correct distortion of the display image 30 (virtual image). The non-flat surface may be, for example, a convex surface, a concave surface, an S-shaped surface, or the like.

As a result, in addition to the effect of suppressing distortion of the display image 30 by tilting the upper edge 131a of the concave mirror 131 as described in the first embodiment above, the effect of reducing distortion by the other reflecting portion 130A can be obtained, thereby further improving the display quality.

Other Embodiments
The disclosure in this specification and drawings, etc. is not limited to the exemplified embodiments. The disclosure includes the exemplified embodiments and modifications by those skilled in the art based thereon. For example, the disclosure is not limited to the combination of parts and/or elements shown in the embodiments. The disclosure can be implemented by various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure includes the omission of parts and/or elements of the embodiments. The disclosure includes the replacement or combination of parts and/or elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. Some of the disclosed technical scopes are indicated by the description of the claims, and should be interpreted as including all modifications within the meaning and scope equivalent to the description of the claims.

The liquid crystal display 120 (display) has been described as using a TFT liquid crystal panel, a dual scan type display, a TN segment liquid crystal, etc., but is not limited to this and may be a self-luminous display such as electroluminescence. Furthermore, it may be a laser projector that scans a laser.

1 Car 1
20 Windshield 30 Display image (virtual image)
100, 100A Vehicle display device 120 Liquid crystal display (display)
130 Reflection portion 130A Other reflection portion 131a Upper side

Claims (3)

A display (120) that emits display light for an image;
a reflecting portion (130) that is rectangular and disposed so that an upper side (131a) is in the left-right direction of the vehicle (1) and reflects the display light;
A vehicle display device that projects the display light reflected by the reflecting portion onto a windshield (20) of the vehicle located in front of a driver, and causes the driver to visually recognize the virtual image (30) in front of the windshield,
The reflecting portion is disposed so that the upper side is inclined downward toward a lateral outer side of the vehicle as viewed from the driver's side ,
The inclination angle is set so that the distance of the reflected display light reaching the windshield is equal on the left and right ends of the reflecting portion . The display device for a vehicle according to claim 1 , further comprising: another reflecting portion (130A) that reflects display light from the display device and makes the display light incident on the reflecting portion. The display device for a vehicle according to claim 2 , wherein the reflection surface of the other reflection portion is formed to be non-flat so that distortion of the virtual image can be corrected.

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