JP2020069804A - On-vehicle rear view display device - Google Patents

Abstract

To provide an on-vehicle rear view display device which can prevent the occurrence of a double image when it is in a display mode.SOLUTION: An on-vehicle rear view display device 1 comprises a display part 12 for displaying a camera image L3 of a rear view field of a vehicle imaged by an on-vehicle camera and a mirror part which is disposed at a display surface side of the display part. The mirror part comprises: a prism glass 111 having a first surface which is in parallel with the display surface of the display part and a second surface which is inclined relative to the first surface; a dimming member 112 which can switch between a reflecting state and a transmitting state and is disposed on the first surface; and a control part for controlling the reflecting and transmitting states of the dimming member.SELECTED DRAWING: Figure 4

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear-view in-vehicle display device mounted in a vehicle compartment.

  Conventionally, a display device (for example, a liquid crystal display) that displays a rear view of a vehicle captured by a camera is built-in, and a rear view in-vehicle display device (hereinafter, referred to as a “rear view on-vehicle display device” that allows the rear view to be visually recognized by a reflection image by a mirror or a camera image from the display device. A "electronic mirror device" is put to practical use (for example, Patent Documents 1 to 3). In the following, a mode in which the rear view is visually recognized by the reflection image from the mirror is referred to as a “mirror mode”, and a mode in which the rear view is visually recognized by a camera image from the display device is referred to as a “display mode”. In the display mode, the rear field of view can be visually recognized by the dimmed camera image, which is useful, for example, when the light of the headlight of the following vehicle is dazzling.

  FIG. 1A is a diagram showing an electronic mirror device 5 disclosed in Patent Document 1. The electronic mirror device 5 shown in FIG. 1A includes a one-way mirror that reflects a part of incident light and transmits a part of the incident light, and a monitor arranged on the back side of the half mirror. In the electronic mirror device 5, in the mirror mode, the monitor is in the off state, and the high reflection image from the half mirror is visually recognized. On the other hand, in the display mode, the monitor is on, and the camera image from the monitor that has passed through the half mirror is visible.

  FIG. 1B is a diagram showing an electronic mirror device 6 disclosed in Patent Document 2. The electronic mirror device 6 shown in FIG. 1B includes a cholesteric filter capable of switching between a reflective state and a transmissive state, and a display device arranged on the back side of the cholesteric filter. In the electronic mirror device 6, in the mirror mode, the display device is in the off state, the cholesteric filter is in the reflective state, and a high reflection image from the cholesteric filter is visually recognized. On the other hand, in the display mode, the display device is on and the cholesteric filter is in the transmissive state, and the camera image from the display device that has passed through the cholesteric filter is visually recognized.

  FIG. 1C is a diagram showing an electronic mirror device 7 disclosed in Patent Document 3. In the electronic mirror devices 5 and 6 described above, the camera image from the monitor or the display device is visually recognized in the display mode, but the reflected image from the half mirror is also incident on the eyes. Therefore, a double image of the camera image and the reflected image occurs. Conventionally, as shown in FIG. 1C, by tilting the optical unit including the mirror and the monitor as a whole (in FIG. 1C, tilting toward the floor surface), the occurrence of a double image in the display mode is prevented.

Japanese Patent Laid-Open No. 11-78693 Japanese Patent Publication No. 2009-506928 JP, 2002-120649, A

  However, the conventional electronic mirror device cannot sufficiently reduce the occurrence of double images in the display mode.

  An object of the present invention is to provide a vehicle-mounted display device for rear view, which can prevent the occurrence of double images in the display mode.

The in-vehicle display device for rear view according to the present invention,
A display unit that displays a camera image of the rear view of the vehicle captured by the vehicle-mounted camera;
A mirror unit arranged on the display surface side of the display unit,
The mirror section is
A prism glass having a first surface parallel to the display surface of the display unit and a second surface inclined with respect to the first surface, and a reflective state and a transmissive state that can be switched to the first surface. It is characterized by having a light control member to be arranged and a control unit for controlling a reflection / transmission state of the light control member.

  According to the present invention, it is possible to prevent the occurrence of double images in the display mode.

1A to 1C are views showing an example of a conventional electronic mirror device. It is a figure which shows the installation mode of the electronic mirror apparatus which concerns on embodiment. It is a figure which shows the structure of an electronic mirror device. 4A and 4B are diagrams showing a mirror mode and a display mode. It is a figure which shows the modification of an electronic mirror device.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 2 is a diagram showing an installation mode of the electronic mirror device 1 according to the embodiment. FIG. 3 is a diagram showing the configuration of the electronic mirror device 1. The electronic mirror device 1 is hung on the ceiling of the passenger compartment near the windshield of the vehicle V, for example, and is used for rearward confirmation. The electronic mirror device 1 is communicatively connected to the rear camera RC.

  The electronic mirror device 1 has a mirror mode in which rearward viewing is performed by a reflection image reflected on the mirror surface (the dimming mirror 112) of the mirror unit 11 and a display mode in which rearward viewing is performed by a camera image of the display unit 12.

  The rear camera RC is installed, for example, at the rear end of the vehicle body roof. The rear camera RC has an image sensor such as a CCD (charge-coupled device) type image sensor or a CMOS (complementary metal oxide semiconductor) type image sensor. An electric signal indicating an image of the rear view photoelectrically converted by the image pickup device is transmitted to the electronic mirror device 1 by wireless communication or wire communication. The electronic mirror device 1 displays a rear view camera image captured by the rear camera RC on the display unit 12.

  The electronic mirror device 1 includes an optical unit 10, a housing 20 that houses the optical unit 10, a support portion 30 that rotatably supports the electronic mirror device 1, and the like. The support 30 is attached to the upper end of the windshield or the front end of the ceiling. By rotating the housing 20 around a ball joint (not shown) of the support portion 30, the mirror portion 11 is adjusted to match the driver's eye position (eye point), specifically, in the mirror mode. The mounting angle is adjusted so that the driver can visually recognize the reflected image of the rear view.

  The optical unit 10 includes a mirror section 11 and a display section 12. The mirror unit 11 is arranged on the forefront (the opening of the housing 20), and the display unit 12 is arranged on the back side of the mirror unit 11 (inside the housing 20).

The mirror unit 11 includes a prism glass 111 and a dimming mirror 112.
The prism glass 111 has a first surface 111a that is parallel to the display surface of the display unit 12 and a second surface 111b that is inclined with respect to the first surface 111a. The inclination angle θ of the first surface 111a with respect to the second surface 111b is, for example, 4.5 °.

  The dimming mirror 112 is switchable between a reflective state and a transmissive state, and is arranged on the first surface 111a. The light control mirror 112 is, for example, a film-shaped light control member, and is bonded to the prism glass 111. The dimming mirror 112 is, for example, a liquid crystal shutter that can switch between a reflective state and a transmissive state by changing the alignment state of liquid crystal molecules. Further, for example, the dimming mirror 112 may perform switching by an electrochromic method or a gas chromic method. The reflection / transmission state of the dimming mirror 112 is controlled by the control unit 14. The control unit 14 controls the voltage applied to the dimming mirror 112, for example.

  The dimming mirror 112 is controlled in the reflective state in the mirror mode and in the transmissive state in the display mode. The dimming mirror 112 may be controlled in conjunction with on / off control of the display unit 12 (backlight 122).

  The display unit 12 is, for example, a liquid crystal display having a liquid crystal panel 121 and a backlight 122. Further, for example, the display unit 12 may be an organic EL display. The display unit 12 displays a camera image of the rear view of the vehicle captured by the rear camera RC. The liquid crystal panel 121 has an outer shape similar to that of the mirror section 11 or an outer shape adapted to the display area. The display unit 12 is, for example, on / off controlled in conjunction with the operation of a changeover switch (not shown).

  The dimming mirror 112 and the display unit 12 may be arranged such that an air layer is interposed therebetween, or they may be arranged so as to be in close contact with each other.

  4A and 4B are diagrams showing a mirror mode and a display mode of the electronic mirror device 1.

  As shown in FIG. 4A, in the mirror mode, the dimming mirror 112 is controlled to the reflective state, and the display unit 12 is controlled to the off state. In the mirror mode, the rear view is visually recognized by the high reflection image L1 reflected by the first surface 111a of the prism glass 111 (interface with the light control mirror 112). At this time, since the second surface 111b of the prism glass 111 is inclined, the low-reflection image L21 in the rear view reflected by the second surface 111b of the prism glass 111 advances downward and is not visually recognized. Therefore, a double image of the high reflection image L1 and the low reflection image L21 does not occur.

  As shown in FIG. 4B, in the display mode, the dimming mirror 112 is controlled to the transmissive state, and the display unit 12 is controlled to the on state. The light control mirror 112 and the prism glass 111 in the transmissive state have substantially the same refractive index. In the display mode, the rear view is visually recognized by the camera image L3 from the display unit 12. At this time, since the second surface 111b of the prism glass 111 is inclined, the low-reflection image L21 in the rear view reflected by the second surface 111b of the prism glass 111 advances downward and is not visually recognized. In addition, the reflection image reflected by the first surface 111a of the prism glass 111 (interface with the light control mirror 112) is in a transmissive state with low reflectance, so that the reflection image is lower than the low reflection image L21. The low reflection image L22 with low intensity is obtained. This is because the reflectance R2 at the interface between the first surface 111a and the dimming mirror 112 is extremely small compared to the reflectance R (for example, 4%) on the second surface 111b. If the prism glass 111 and the dimming mirror 112 are bonded by OCA (Optical Clear Adhesive), which has the same refractive index as the prism glass 111, theoretically the reflection at the interface can be 0%. OCA is, for example, a resin material. Therefore, a double image of the camera image L3 and the low reflection image L21 or the low reflection image L22 does not occur.

  As described above, the electronic mirror device 1 (vehicle-mounted display device for rear view) displays the camera image L3 of the rear view of the vehicle captured by the rear camera RC (vehicle camera), and the display of the display unit 12. The mirror part 11 arrange | positioned at the surface side. The mirror unit 11 switches between a prism glass 111 having a first surface 111a parallel to the display surface of the display unit 12 and a second surface 111b inclined with respect to the first surface 111a, and a reflective state and a transmissive state. It has a dimming mirror 112 (dimming member) which is possible and is arranged on the first surface 111a, and a control unit 14 which controls the reflection / transmission state of the dimming mirror 112.

  According to the electronic mirror device 1, it is possible to prevent the occurrence of a double image in the display mode without tilting the optical unit 10. Therefore, unlike the conventional case, it is not necessary to provide an angle adjusting mechanism for preventing a double image, so that the electronic mirror device 1 can be downsized and the cost can be reduced.

  As shown in FIG. 1C, the method of preventing the double image in the display mode by tilting the optical unit cannot be applied to a moon roof type vehicle when the optical unit is tilted toward the ceiling, for example. This is because a double image of the reflected image of light from the moon roof and the camera image is generated. On the other hand, the electronic mirror device 1 can be applied to a vehicle with a moon roof specification because a reflected image of light from the moon roof is not visible.

  Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments and can be modified without departing from the scope of the invention.

  For example, the electronic mirror device 1 may be provided with the angle adjusting mechanism 13 so that the optical unit 10 can be tilted (see FIG. 5). It is assumed that the backlight of the following vehicle is illuminated while the electronic mirror device 1 is in the mirror mode (the dimming mirror 112 is in the reflecting state) shown in FIG. 4A. At this time, if the optical unit 10 is tilted as shown in FIG. 5, the rear view can be visually recognized by the low reflection image L21. That is, the angle of the optical unit 10 is switched from the angle using the first surface 111a as a mirror to the angle using the second surface 111b as a mirror. Therefore, when the backlight of the following vehicle is dazzling, it is possible to prevent glare in the mirror mode without switching to the display mode. For example, it is suitable when the driver prefers the visual recognition in the mirror mode or wants to avoid an increase in power consumption in the display mode. The tilt angle of the optical unit 10 during the antiglare operation is 6.5 °, for example.

  Further, when the optical unit 10 is tilted as shown in FIG. 5, the display unit 12 may be in the off state and the dimming mirror 112 may be in the transmissive state. In a vehicle with a moon roof, the reflected image of the light from the moon roof reflected by the first surface 111a may enter the eyes, but if the dimming mirror 112 is in the transmissive state, the light from the moon roof is reflected. Is hardly reflected, it is possible to prevent a double image from forming with the low reflection image L21.

  The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

  INDUSTRIAL APPLICABILITY The electronic mirror device according to the present invention is suitable for an electronic mirror device that is mounted in a vehicle compartment and is used for rearward viewing.

1 Electronic mirror device (vehicle display device for rear view)
11 Mirror Part 111 Prism Glass 111a First Surface 111b Second Surface 112 Light Control Mirror (Light Control Member)
12 display unit 121 liquid crystal panel 122 backlight 13 angle adjusting mechanism 14 control unit

Claims (5)

A display unit that displays a camera image of the rear view of the vehicle captured by the vehicle-mounted camera;
A mirror unit arranged on the display surface side of the display unit,
The mirror section is
A prism glass having a first surface parallel to the display surface of the display unit and a second surface inclined with respect to the first surface, and a reflective state and a transmissive state that can be switched to the first surface. An on-vehicle display device for rear visual recognition, comprising: a dimming member that is arranged; and a control unit that controls a reflection / transmission state of the dimming member.   The control unit controls the dimming member to a transmissive state when the display unit visually recognizes the camera image, and controls the dimming member when the reflection image is visually recognized by the dimming member. The in-vehicle display device for rear view according to claim 1, wherein the in-vehicle display device is controlled to a reflective state.   The in-vehicle display device for rear view according to claim 1 or 2, wherein the light control member is a liquid crystal shutter.   The in-vehicle display device for rear visual recognition according to any one of claims 1 to 3, further comprising an angle adjusting unit that tilts an optical unit including the display unit and the mirror unit.   The angle of the said mirror part switches from the angle which uses the said 1st surface as a mirror to the angle which uses the said 2nd surface as a mirror at the time of anti-glare operation, The angle of Claim 4 characterized by the above-mentioned. In-vehicle display device for rear view.

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