JP6268738B2 - Image display device for vehicle - Google Patents

Description

  The present invention relates to an improvement of an image display device for a vehicle.

  2. Description of the Related Art Conventionally, in a vehicle image display device, a liquid crystal display device (display) is provided inside a vehicle-mounted inner mirror body (housing), and an image captured by a vehicle-mounted camera is displayed on the liquid crystal display device. A configuration is known in which a driver can visually recognize the rear of a vehicle through a half mirror provided on the front surface of the mirror body (see, for example, Patent Document 1).

JP 2011-57023 A

  By the way, in the vehicle-mounted inner mirror, when the direction of the half mirror is changed, the rear image of the vehicle that is directly reflected by the half mirror to the driver changes. However, since the vehicle-mounted camera is fixed to the vehicle body, the image displayed on the display screen of the liquid crystal display device does not change even if the direction of the half mirror is changed.

  For this reason, even if the driver changes the range of the image that appears directly on the half mirror, when the image taken by the in-vehicle camera is displayed on the display, the half mirror An image different from the image that appears directly on the screen is displayed, giving the driver a sense of incongruity.

  The vehicular image display device according to the present invention has been made in view of the above circumstances, and the object thereof is to display the vehicular image display that can change the image displayed on the display in accordance with the direction of the half mirror. An object is to provide an apparatus.

An image display device for a vehicle according to the present invention includes a housing having a half mirror that can visually recognize the rear of the vehicle, a vehicle-mounted camera fixed to the vehicle, and a subject image that is built in the housing and captured by the vehicle-mounted camera. the Ru and a visible display through the half mirror.
The onboard camera, a photographing optical system for photographing a subject, Ru comprising at least an imaging device in which the subject image is formed by the photographing optical system.
A processing circuit for processing the object image in between said imaging device display, a digital-analog converter circuit for outputting to the display the subject image is converted into a video signal processed by the processing circuit, but provided Ru.
The processing circuit includes a cut-out circuit that cuts out an image of a rectangular area narrower than the subject image, and an image that can be directly seen by the half mirror to the driver when the half mirror is oriented. An image cut-out position changing unit that changes a cut-out position of the rectangular area with respect to the subject image so that an image in a corresponding rectangular area is displayed on the display; the image cut-out circuit; and the digital / analog conversion circuit And an image decompression circuit that decompresses the clipped image cut out by the image cutout circuit and creates a decompressed image having a predetermined aspect ratio in the vertical and horizontal directions .
The digital / analog conversion circuit converts the decompressed image from the image decompression circuit into a video signal and outputs the video signal to the display.

  According to the present invention, since the cutout portion of the image of the subject image formed on the image sensor is changed according to the attitude of the housing, it corresponds to an image that appears directly to the driver by the half mirror. There is an effect that the image in the rectangular area can be displayed on the display.

FIG. 1 is a plan view of a vehicle equipped with a vehicle image display device according to the present invention as viewed from above. 2 is a cross-sectional view of a main part of the vehicle inner mirror shown in FIG. 3 is a front view of the vehicle inner mirror shown in FIG. FIG. 4 is an explanatory view showing an example of a rear vehicle and a distant vehicle that are directly reflected in the half mirror shown in FIG. FIG. 5 is a block circuit diagram of the vehicle image display apparatus according to the present invention. FIG. 6 is an explanatory diagram showing an example of a subject image formed on the image sensor shown in FIG. FIG. 7 is an explanatory diagram showing a rectangular area for the subject image shown in FIG. FIG. 8 is an explanatory diagram showing an example of decompression of a cutout image. FIG. 9 is an explanatory view showing an image from which distortion obtained by the expanded image shown in FIG. 8 is removed. FIG. 10 is an explanatory diagram of an image that appears to the driver by the half mirror when the attitude of the half mirror is changed. FIG. 11 is an explanatory diagram of an image displayed on the display when the posture of the half mirror is changed in the direction shown in FIG.

FIG. 1 is a plan view of a vehicle equipped with a vehicle image display device according to the present invention as viewed from above.
In FIG. 1, reference numeral 1 denotes a vehicle provided with the vehicle image display device according to the present invention, reference numeral 1 ′ denotes a subsequent vehicle, and reference numeral 1 ″ denotes a distant vehicle located farther than the subsequent vehicle 1 ′. Show.

  The vehicle 1 is provided with a vehicle-mounted camera 2 at the rear thereof. The in-vehicle camera 2 is connected to the in-vehicle inner mirror 3 through a signal line. Reference numeral 4 denotes a driver, and reference numeral 5 denotes an interior ceiling.

  The in-vehicle inner mirror 3 is supported on the interior ceiling 5 via a support member 6 as shown in FIG. The support member 6 is provided with a spherical pivot portion 7.

  The in-vehicle inner mirror 3 is configured such that a housing 8 serving as an in-vehicle inner mirror body can tilt up and down and left and right with the spherical pivot portion 7 as a fulcrum. Thereby, the attitude of the housing 8 is changed.

  A half mirror 9 is provided on the front surface of the housing 8 as shown in FIG. On the back surface of the half mirror 9, a liquid crystal display screen 10a is provided as shown in FIG.

  A backlight illumination unit 10b is provided on the back surface of the liquid crystal display screen 10a, and an electric circuit board unit 10c is provided on the back surface of the backlight illumination unit 10b.

The liquid crystal display screen 10a, the backlight illumination unit 10b, and the electric circuit board unit 10c constitute a known display 10.
On the display 10, a subject image photographed by the vehicle-mounted camera 2 can be viewed through the half mirror 9.

  Further, when the backlight illumination unit 10b of the display 10 is turned off, the rear of the vehicle is directly seen by the driver 4 due to the reflection of light from the half mirror 9.

  The support member 6 is provided with a sensor mounting plate 11 as shown in FIG. The sensor mounting plate 11 is provided with potentiometers 12 and 13 as posture detection sensors.

  2 and 3, the potentiometer 12 detects the horizontal (left-right) tilt of the housing 8, and the potentiometer 13 detects the vertical (vertical) tilt of the housing 8. Play a role.

  Here, for example, as shown in FIG. 4, the image of the following vehicle 1 ′ and the image of the distant vehicle 1 ″ are directly projected to the driver 4 on the half mirror 9 (housing 8). The description will be made assuming that the posture of the housing 8 is adjusted so that it can be seen.

  Here, as shown in FIG. 5, the in-vehicle camera 2 includes a photographing optical system 16 for photographing a subject, an imaging element 17 in which a subject image is formed by the photographing optical system 16, a processing circuit 18, A digital / analog conversion circuit 19 is provided.

  As shown in FIG. 6, a subject image composed of a following vehicle 1 ′ and a distant vehicle 1 ″ is formed on the image sensor 17. The aspect ratio (V: H) of the image sensor 17 is 3 In contrast, the aspect ratio (V: H) of the liquid crystal display screen 10a and the half mirror 9 is 1: 4.

  The processing circuit 18 is disposed between the image sensor 17 and the display 10 and functions to process a video signal output from the image sensor 17. The processing circuit 18 digitizes the video signal from the image sensor 17 and temporarily stores it as a digital image in a frame memory (buffer memory).

  As shown in FIG. 7, the processing circuit 18 includes an image cutout circuit 18 a that cuts out an image (cutout image) of a rectangular region REC narrower than the subject image G <b> 1 imaged on the image sensor 17, and removes image distortion. For this purpose, an image decompression circuit 18b and an image cutout position changing unit 18c are provided. The image cutout circuit 18a will be described later, and the image decompression circuit 18a will be described first.

The image decompression circuit 18b has a function of decompressing the cutout image G1 ′ shown in FIG. 7 and creating an decompressed image having a vertical / horizontal aspect ratio (V: H) of 3: 4.
For example, the image expansion circuit 18b creates three lines of the same image data from image data corresponding to one line in the horizontal direction. As a result, as shown in FIG. 8, an expanded image G1 ″ extending in the vertical direction is formed.

The image data composed of the expanded image G1 ″ is input to the digital / analog conversion 19. The digital / analog conversion circuit 19 converts the expanded image G1 ″ into an NTSC video signal and outputs it to the display 10.
As a result, the expanded image G1 ″ extended in the vertical direction is compressed as shown in FIG. 9 and an image without distortion is displayed on the display screen 10a of the display 10.

  The details of the removal of the distortion of the cutout image G1 ′ are described in, for example, Japanese Patent Application No. 2013-21893, and the removal of the distortion of the cutout image is not directly related to the present invention. Omitted.

  In the processing circuit 18, a rectangular area corresponding to the subject image G1 is displayed on the liquid crystal display screen 10a so that an image equivalent to the image directly seen by the half mirror 9 with respect to the driver 4 is displayed on the liquid crystal display screen 10a. An image cutout location changing unit 12c that changes the cutout location of REC is provided as shown in FIG.

  Here, when the display 10 is off, as shown in FIG. 4, the driver 4 sees the following vehicle 1 ′ in the center of the half mirror 9, and one of the far vehicles 1 ″ appears on the right end side of the half mirror 9. The part appears to be missing.

  Assume that the driver 4 changes the orientation of the housing 8 so that both the succeeding vehicle 1 'and the distant vehicle 1 "can be visually recognized without being lost, as shown in FIG.

  Then, the potentiometers 12 and 13 convert the inclination of the housing 8 into an electric signal and output it to the processing circuit 18. For example, a table memory (not shown) is provided in the image cutout location changing unit 18 c of the processing circuit 18.

  The table memory stores the cutout portions of the rectangular region REC in a matrix corresponding to the outputs of the potentiometers 12 and 13.

  When the orientation of the housing 8 is changed, the image cutout location changing unit 18c outputs an image cutout location change signal toward the image cutout circuit 18a.

Thus, when the direction of the housing 8 is tilted outward so that both the following vehicle 1 ′ and the distant vehicle 1 ″ can be visually recognized without being lost, the rectangular region REC indicated by a solid line in FIG. Is changed to a rectangular region REC ′ indicated by a two-dot chain line in FIG.

As a result, as shown in FIG. 11, an image equivalent to the image directly seen by the driver 4 by the half mirror 9 is displayed on the liquid crystal display screen 10 a.

That is, according to the direction of the half mirror 9, an image in the rectangular area REC corresponding to an image that is directly seen by the half mirror 9 with respect to the driver 4 is displayed on the display 10.

In this embodiment, the processing circuit 18 is provided in the in-vehicle camera 2, but the present invention is not limited to this. For example, processing circuitry 18 may be provided between the vehicle-mounted camera 2 and the display 10.

2 ... In-vehicle camera 8 ... Housing 9 ... Half mirror 10 ... Display 16 ... Shooting optical system 17 ... Imaging element 18 ... Processing circuit 18a ... Image cut-out circuit 18c ... Image cut-out location changing unit REC ... Rectangular area

Claims (3)

A housing having a half mirror capable of visually recognizing the rear of the vehicle, an in-vehicle camera fixed to the vehicle, and a display that is incorporated in the housing and is capable of visually recognizing a subject image captured by the in-vehicle camera through the half mirror. Prepared,
The in-vehicle camera includes at least a photographic optical system for photographing a subject, and an image sensor on which the subject image is formed by the photographic optical system,
A processing circuit that processes the subject image between the imaging element and the display; and a digital / analog conversion circuit that converts the subject image processed by the processing circuit into a video signal and outputs the video signal to the display. Provided,
The processing circuit includes
An image cut-out circuit that cuts out an image of a rectangular area narrower than the subject image;
According to the direction of the half mirror, the image with respect to the subject image is displayed on the display so that an image in a rectangular region corresponding to an image that appears directly to the driver by the half mirror is displayed on the display. An image cutout location changing section for changing the cutout location of the rectangular area;
An image decompression circuit is provided between the image cropping circuit and the digital / analog conversion circuit, and decompresses the clipped image cut out by the image cropping circuit to create a decompressed image with a predetermined aspect ratio in length and width.
The digital / analog conversion circuit converts the decompressed image from the image decompression circuit into a video signal and outputs the video signal to the display.   The vehicular image display device according to claim 1, wherein the processing circuit is provided in the in-vehicle camera. The image cutout portion changing unit is connected to the attitude detection sensor for detecting a posture of the housing, according to claim 1 or claim 2, characterized in that the attitude detection sensor is provided on the inner mirror for vehicles Vehicle image display device.