JP3203809B2 - Vehicle exterior monitoring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle exterior monitoring apparatus for photographing the rear of a vehicle with a video camera and displaying the image on a display to monitor the rear of the vehicle.

[0002]

2. Description of the Related Art Conventionally, a video camera has been installed at the rear of a vehicle so that a driver of the vehicle can easily visually recognize the rear of the vehicle from the driver's seat. There is known a rear monitor device for displaying on a display device such as a CRT provided in the company.

[0003] A video camera of this type of device is mounted rearward on the rear of an automobile, but if the angle of the camera changes due to vibration of the automobile or the like, the position or range of the rear image to be photographed greatly changes. Because the video camera
Usually, it is fixed to the rear part of the vehicle with its mounting angle set accurately.

[0004]

For this reason, for various types of vehicles having different sizes and shapes, it is necessary to accurately set the mounting angle and the mounting position of the video camera for each type of vehicle. When actually performing the mounting work, one person had to adjust the angle and position of the video camera in the rear part to an optimum state while looking at the image taken in the driver's seat.

In order to adjust the mounting angle of the video camera, it has been considered to mount the camera on the vehicle body via a mechanical angle adjusting mechanism. However, the mechanical angle adjusting mechanism requires a large number of mechanical parts. At the same time, there is a problem that the mechanism becomes large-sized, and the camera is likely to rattle or malfunction due to vibration or the like.

The present invention has been made in view of the above points, and does not require accurate adjustment or setting of the mounting angle of a video camera, and does not require a mechanical angle adjustment mechanism to reduce the range of a displayed image. It is an object of the present invention to provide a vehicle exterior monitoring device that can be arbitrarily changed by a user.

[0007]

In order to achieve the above-mentioned object, a vehicle exterior monitoring apparatus according to the present invention is mounted on a part of an automobile so as to photograph the exterior of the vehicle, as shown in FIG. The image capturing unit, an image memory that stores the digital video signal output from the image capturing unit and converted into a digital signal as pixel data constituting an image, and a display range of an image captured by the image capturing unit provided in the vehicle. An operation switch that outputs a command signal for changing, and a read address signal is created in accordance with a display range changing command signal output from the operation switch, and the read address signal is added to the image memory to operate from the image memory. Reading control means for reading image data in a display range instructed by the switch, and image data read from the image memory by the operation of the reading control means. Characterized by comprising a display device for displaying an image.

[0008]

In the vehicle exterior monitoring device thus configured, a video signal output from an imaging unit for photographing the outside of the vehicle is converted into a digital signal, and the digital video signal is converted into pixel data constituting an image. It is written into the image memory and stored once. Next, the read control unit sends a read address signal to the image memory to read image data from the image memory, and the display device displays a captured image based on the read image data. The image displayed on the display device is an image in a range narrower than the image captured by the imaging unit.

On the other hand, when it is desired to change the display range of the display image so as to be shifted up and down or left and right, an operation switch in the vehicle is operated to send a command signal for changing the display range to the reading control means.

[0010] The read control means receiving this command signal,
In response to the command signal, a read address signal is created shifted to a higher or lower position than normal, the read address signal is applied to the image memory, and image data in a display range shifted from the normal position from the image memory is created. read out.

[0011] The image data read from the image memory is converted into an analog signal and then sent to a display device, and the image is displayed on the display device based on the image data. The image is shifted vertically or horizontally as instructed by operating the operation switch.

As described above, the display range of the image displayed on the display device can be shifted within the image range photographed by the image pickup unit in accordance with the operation of the operation switch. The setting of the mounting angle and the mounting position does not require much accuracy, and the camera can be easily mounted.

Further, the driver can arbitrarily change the display range by operating the operation switch, and the angle adjustment mechanism and the like can be changed as compared with the case where the display range is changed by mechanically changing the angle of the camera. This eliminates the need for any of the mechanical parts described above, and can prevent rattling of the camera.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a vehicle exterior monitoring device.
FIG. 2 shows a schematic view of an automobile equipped with an external monitoring device. Reference numeral 1 denotes an imaging unit of a video camera attached to a rear part of the automobile, which is fixed facing rearward.

The imaging section 1 of the video camera has a light receiving section with a CCD.
An image pickup device 2 is provided, an ultra-wide-angle lens unit (not shown) and a color filter (not shown) are provided in front of the device, and a CCD output signal serving as an image signal is output from the CCD image pickup device 2.

Reference numeral 3 denotes a sample-and-hold circuit connected to the CCD image sensor 2, which samples the CCD output signal output from the CCD image sensor 2 at a fixed period and holds the sampled signals for a fixed period of time. To output. The sample-and-hold circuit 3 has an automatic gain control circuit built therein, and when a captured image is excessively dark or bright,
The brightness of the image is corrected by adjusting the signal level.

Reference numeral 4 denotes an image signal processor to which the output side of the sample hold circuit 3 is connected. The image signal processor receives a CCD output signal, and outputs a Y signal (luminance signal) and a color difference signal (RY signal, BY signal) from the CCD output signal. And outputs the Y signal and the color difference signal to the A / D converter 6. Further, the image signal processor 4 outputs a signal indicating the light amount to the CCD driver 5 based on the Y signal.

The CCD driver 5 is composed of an analog shift register or the like, and generates a reset pulse signal, a horizontal transfer pulse signal, and a vertical transfer pulse signal having a predetermined cycle determined by the NTSC standard or the like, and sends them to the CCD image pickup device 2. The signal is output to drive the CCD image sensor 2. Further, the CCD driver 5 has an auto iris function of changing the timing of the transfer pulse according to the light amount signal and adjusting the output level of the CCD image sensor 2.

Reference numeral 7 denotes an image memory, such as a DRAM or an SRAM, for storing a digital image signal output from the A / D converter 6. The memory 7 has memory cells corresponding to all pixels of one captured image, and stores images in real time. Write and read data. The writing and reading of the image memory 7 are controlled by the display processor 8.

The display processor 8 is composed of a write address generator, a read address generator, a CPU, etc., sends a write address signal and a read address signal to the image memory 7 at a predetermined cycle, and stores the image data for one screen in the image memory 7. The image data is held, and the image data is read out at a predetermined timing.

An operation switch 10 is connected to the display processor 8 to move the range of the display image. The operation switch 10 is provided on an instrument panel or the like in the vehicle. The operation switch 10 is provided with an upper switch, a lower switch, a left switch, and a right switch. When the user operates these switches, a command signal for changing the display range is displayed on the display processor 8.
Send to

When a signal indicating the moving direction of the display range is sent from the operation switch 10, the display processor 8 applies the read address signal to the image memory 7 with a shift corresponding to the direction, and the read address signal is displayed on the display device. The display range up, down, or left and right.

Reference numeral 9 denotes a D / A converter for converting image data read from the image memory 7 into an analog signal. An NTSC encoder 11 is connected to the output side of the D / A converter 9.

The NTSC encoder 11 outputs a Y signal, a color difference signal (RY signal,
BY signal) and a composite video signal (Y signal, C signal) based on the NTSC standard from those signals.
Is generated and output to the display device 12.

The display device 12 comprises a CRT display device, a liquid crystal display device, or the like. As shown in FIG.
A composite video signal sent from the TSC encoder 11 is input, and an image is displayed based on the signal.

Reference numeral 13 denotes a clock signal generator, which generates a clock signal having a predetermined period and sends the clock signal to the CCD driver 5, image signal processor 4, display processor 8, and the like.

Next, the operation of the vehicle exterior monitoring device having the above configuration will be described.

When the vehicle exterior monitoring device is started, for example, when the shift lever of the automobile is set to "R", the CCD output signal generated from the CCD image sensor 2 of the imaging unit 1 of the video camera located at the rear is sampled. The signal is output to the hold circuit 3, the signal is sampled at a fixed period in the sample and hold circuit 3, and the sampled image signal is sent to the image signal processor 4.

The image signal processor 4 converts the image signal into Y
Signal and color difference signal (RY signal, BY signal),
The Y signal and the color difference signal are output to the A / D converter 6, which converts the Y signal and the color difference signal into digital signals and sends them to the image memory 7.

The display processor 8 sends a write address signal and a read address signal to the image memory 7 at a predetermined cycle, holds the image data for one screen in the image memory 7, and outputs the image data at a predetermined timing. Read.

That is, the digitally converted image signal is
Data for one screen is used as pixel data that constitutes an image.
It is written into the image memory 7 once. Next, a read address signal is applied at a predetermined timing, and image data for one screen is read from the image memory 7. When reading the image data, the display processor 8 sets the range of the display image to the range of the captured image. The read address signal is applied to the image memory 7 so that the image data is read out so as to be set slightly smaller than the range.

The image data read from the image memory 7 is sent to the D / A converter 9 and converted into analog signals by the D / A converter 9 and color difference signals (RY signal, B signal).
-Y signal) is then sent to the NTSC encoder 11,
From these signals, a composite video signal (Y signal, C signal) based on the NTSC standard is created, and the display device 1
2 is output.

The display device 12 displays a photographed image based on the input composite video signal. Due to the operation of the display processor 8, the display image becomes a display range G1 slightly smaller than the range G0 captured by the imaging unit 1 of the video camera, as shown in FIG.

On the other hand, the display range of the display image is
When it is desired to shift to the left or right, the upper switch, the lower switch, the left switch,
Alternatively, by operating the right switch, a command signal for changing the display range is sent to the display processor 8.

The display processor 8 receiving this command signal
Executes a display range moving process as shown in the flowchart of FIG. 4, and if it is determined in step 100 that the upper switch is turned on, in step 110, the read address is moved so as to move the display range upward. The signal is generated by shifting the signal, and the shifted read address is applied to the image memory 7 to read data.

Similarly, if it is determined in step 120 that the lower switch has been turned on, in step 130, the read address signal is shifted so as to move the display range downward, and the read address signal is created in the image memory 7. Data is read by applying the shifted read address. Step 1
If it is determined at 40 that the left switch has been turned on,
In step 150, the read address signal is shifted so as to move the display range to the left, and the shifted read address is applied to the image memory 7 to read data. If it is determined in step 160 that the right switch has been turned on, in step 170, the read address signal is shifted so as to move the display range to the right, and the shifted read address signal is stored in the image memory 7. Data is read by applying an address.

The image data read out from the image memory 7 in this manner is sent to the D / A converter 9, where the D / A
The Y signal and color difference signal (RY signal, BY signal) converted to analog by the converter 9 are then sent to the NTSC encoder 11, and a composite video signal (Y signal , C signals) are generated and output to the display device 12.

The display device 12 displays a photographed image based on the input composite video signal, and the display image of the display image is, for example, the upper switch and the right switch of the operation switch 10 turned on. In this case, the display is shifted to the upper right as in the range G2 in FIG. 3, and when the lower switch and the left switch are turned on, the range G in FIG.
It is displayed shifted to the lower left like 3.

As described above, in accordance with the operation of the operation switch 10, the display range of the image displayed on the display device 12 can be shifted within the image range photographed by the imaging section 1 of the video camera. When the image pickup unit 1 is mounted, the setting of the mounting angle and the mounting position does not require much accuracy, and the camera can be easily mounted.

In the above-described embodiment, a video camera is provided at the rear part to monitor the rear side. However, a camera may be installed in a front bumper, headlights, or the like to monitor the front side or the like.

[Brief description of the drawings]

FIG. 1 is a block diagram of a vehicle exterior monitoring device according to an embodiment of the present invention.

FIG. 2 is a schematic view of an automobile equipped with an external monitoring device.

FIG. 3 is an explanatory diagram of a display screen of a display device.

FIG. 4 is a flowchart of a display range moving process.

FIG. 5 is an overall configuration diagram of the present invention.

[Explanation of symbols]

 1-imaging section of video camera, 4-image signal processor, 7-image memory, 8-display processor, 10-operation switch, 12-display device.

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H04N 7/18 B60R 21/00 621 B60R 21/00 626 G08G 1/16

Claims (1)

(57) [Claims] An image pickup unit attached to a part of an automobile so as to photograph the outside of a vehicle, and an image storing a digital video signal output from the image pickup unit and converted into a digital signal as pixel data constituting an image A memory, an operation switch provided in the vehicle, for outputting a command signal for changing a display range of an image captured by the imaging unit, and a display range changing command signal output from the operation switch. Read control means for generating a read address signal, adding the read address signal to the image memory, and reading out image data in a display range instructed by the operation switch from the image memory; and A display device for displaying an image based on image data read from an image memory, and an external monitoring device for a vehicle.