JP3424386B2 - Vehicle rear 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 rear monitoring device, and is particularly applied to a case where one camera is shared to perform rearward confirmation when moving backward and distance detection to a following vehicle when moving forward. It is useful.

[0002]

2. Description of the Related Art Conventionally, in some vehicles, a vehicle rear view image captured by a camera is displayed on a monitor in order to minimize a blind spot behind the vehicle that cannot be visually checked directly when the vehicle is moving backward. A rear monitoring device is provided.

FIG. 4 is a block diagram showing the configuration of such a vehicle rear monitoring system, FIG. 5 is an explanatory diagram showing both corners of the CCD camera shown in FIG. 4, and FIG. 6 is a rear view of the vehicle displayed on the monitor shown in FIG. It is explanatory drawing which shows a video.

In FIG. 4, reference numeral 2 is a CCD camera, and 3 is a camera ECU (Electronic Control).
d Unit), 18 is a monitor, and 7 is an inhibitor switch.

As shown in FIG. 5, the CCD camera 2 is a wide-angle (120 °) CCD camera installed in the center of the rear spoiler 13 of the vehicle 11 toward the rear of the vehicle. Image. Camera ECU3
Receives an image pickup signal c from the CCD camera 2 based on a control signal h from the monitor 18, processes the signal, and outputs a video signal d to the monitor 18. The monitor 18 is installed at a position visible from the driver's seat in the vehicle, and when the backward signal R is input from the inhibitor switch 7, the camera EC is displayed.
The control signal g is output to U3, and the video signal d is input from the camera ECU 3, and the video of the rear view of the vehicle is displayed on the display screen 5a by the video signal d. The inhibitor switch 7 is a switch interlocking with a selector lever (for example, to select parking P, reverse R, neutral N, forward D, 2, L) of an automatic transmission (not shown), and the reverse R is selected by the selector lever. When this is done, the backward signal R is output to the monitor 5a.

Therefore, according to the vehicle rear monitoring device having the above structure, when the driver selects the reverse R by the selector lever, the image of the vehicle rear view captured by the CCD camera 2 at this time is displayed on the display screen 5a of the monitor 5. For example, it is displayed as shown in FIG. On the display screen 5a, in addition to the image of the rear view of the vehicle, a mark representing a bumper or a distance is fixedly displayed. For example, when the image of the obstacle 14 is displayed as shown in the figure, the driver can see the 0. It can be seen that there is an obstacle 14 at a position of 5 m.

Further, as another rear monitoring means, at present,
There is a vehicle distance detection device that detects a distance to a following vehicle based on a monocular camera image. Based on FIG. 7 and FIG.
This vehicle distance detection device will be described. FIG. 7 is an explanatory diagram showing the principle of vehicle distance detection by the vehicle distance detection device, and FIG. 8 is an explanatory diagram showing an image of the rear view of the vehicle taken by the CCD camera shown in FIG.

In FIG. 7, 20 is a narrow-angle (45 °) C
It is a CD camera. This CCD camera 20 is a CCD 20
It is equipped with a and a lens 20b, and is installed in the rear part of the vehicle so as to be inclined downward so that the optical axis 16 forms an angle θ with respect to the road surface 17. Then, the focal length of the lens 20b is f, the height to the center of the CCD camera 20a is L, and the road surface 1
The image position P _{2 of the} vehicle at the point P ₁ on 7 and the image center (C
Assuming that the deviation from the center of CD2) is dv and the distance to the vehicle at the point P ₁ is D, this vehicle distance D is given by
It can be calculated by a formula.

[0009]

[Equation 1]

That is, in the image of the rear view of the vehicle shown in FIG. 8, the deviation width dv changes depending on where in the vertical direction (direction of arrow A) the image of the vehicle 15 is located. 1], the distance to the vehicle 15 can be obtained.

[0011]

By the way, when the vehicle rear monitoring device and the vehicle distance detecting device are to be provided in one vehicle, the angle of view of the CCD camera used in each device is different. Therefore, it is necessary to install two wide-angle and narrow-angle CCD cameras.

That is, a wide-angle C suitable for a vehicle rear monitoring device.
If the CD camera 2 is used in the vehicle distance detection device, the image of the following vehicle becomes too small at about 20 m behind,
Even if the distance to the following vehicle changes to some extent, the image position of the following vehicle hardly changes, so the detection error becomes too large, and effective vehicle distance detection becomes impossible. On the contrary, if the narrow-angle CCD camera 20 suitable for the vehicle distance detection device is used for the vehicle rear monitoring device, it becomes impossible to obtain an image of the vehicle rear visual field in the vicinity. Therefore, it is not suitable for rearward confirmation when moving backward.

Incidentally, Japanese Laid-Open Patent Publication No. 2-92753 discloses a vehicle rear view display device characterized by including a daytime camera and a nighttime camera, and the like. Even when an attempt is made to share a camera with the vehicle distance detection device of (1), the same problem as described above still occurs.

Therefore, in view of the above-mentioned prior art, the present invention provides a vehicle rear monitoring device capable of obtaining a video signal having an angle of view suitable for each device (monitor etc.) for rear monitoring by sharing one camera. The purpose is to provide.

[0015]

According to a first aspect of the present invention which achieves the above object, there is provided one camera arranged rearward of a vehicle, and the camera captures a field of view behind the vehicle. An image pickup means for outputting a video signal at this time, a view angle switching signal output means for outputting a view angle switching signal, a view angle switching means for switching a view angle of the camera based on the view angle switching signal, and the view Tsunokiri determines the output destination of the video signal based on the signal, the video signal of the angle of view suitable for each device for the rear monitoring, possess a determination means for outputting to each of these devices, the rear monitoring The device for displaying
Nita and the distance to the following vehicle are detected based on the video signal
In the vehicle distance detecting device,
The video signal of is output to the monitor, and the narrow-angle video signal is
It is characterized by outputting to the vehicle distance detecting device .

[0016]

[0017] The second configuration, in the first configuration, the angle switching signal output means, which has the inhibitor switch in conjunction with the selector lever of the automatic transmission, based on an output signal from the inhibitor switch By outputting the angle-of-view switching signal by the selector lever, when the backward movement is selected by the selector lever, the angle-of-view switching means switches the angle of view of the camera from the narrow angle to the wide-angle, and the determination means suits the wide-angle video signal at this time. On the other hand, when the forward movement is selected by the sector lever, the field angle switching means switches the field angle of the camera from the wide angle to the narrow angle, and the determination means determines the narrow angle video signal at this time. It is characterized by outputting to.

According to a third structure, in the first or second structure, the angle-of-view switching means changes the angle of view of the camera by a lens, and based on the angle-of-view switching signal, the lens is connected to the camera. It is characterized in that it has an attachment / detachment mechanism for attaching to the front or detaching the lens from the front of the camera.

[0019]

According to the first aspect of the present invention, the angle of view of the camera is switched by the angle of view switching means on the basis of the angle of view switching signal of the angle of view switching signal output means to image the rear view of the vehicle. A video signal having an angle of view suitable for each device for rearward monitoring is output to each device by the determination means. That is, wide
The video signal in the corner is output to the monitor, and the video signal in the narrow angle is output to the vehicle.
It is output to both distance detection devices. Therefore, when the monitor moves backward
Video suitable for confirming the rear view of the vehicle (rear view of the vehicle including close-up view)
Image) is displayed, and the
Good vehicle distance detection is performed.

[0020]

According to the second aspect of the present invention, the angle of view of the camera is switched to a wide angle and the wide-angle video signal is transmitted to the device (monitor, etc.) in association with selection by the selector lever at the time of backward movement. On the other hand, when the vehicle is moving forward, the angle of view of the camera is switched to a narrow angle and a narrow-angle video signal is output to the device (inter-vehicle distance detecting device or the like).

According to the third aspect of the present invention, the angle of view of the camera can be easily switched by attaching / detaching the lens by the attaching / detaching mechanism.

[0023]

Embodiments of the present invention will now be described in detail with reference to the drawings. The same parts as those in the prior art are designated by the same reference numerals, and duplicate description will be omitted.

FIG. 1 is a block diagram showing the structure of a vehicle rear monitoring apparatus according to an embodiment of the present invention, FIG. 2A is a top view of the view angle switching mechanism shown in FIG. 1, and FIG. FIG. 3 is a front view of the corner switching mechanism, and FIG. 3 is a flowchart showing the operation of the vehicle rear monitoring device shown in FIG.

In FIG. 1, reference numeral 8 is a view angle switching mechanism 1 and CC.
A camera unit including a D camera 20 and a camera E
CU, 4 is a vehicle direction determination circuit, 5 is a monitor installed at a position visible from the driver's seat in the vehicle, 6 is a vehicle distance detection device, and 7 is an inhibitor switch.

The view angle switching mechanism 1 is for switching the view angle of the CCD camera 20, and is constructed as shown in FIG. That is, a pair of guide rails 1c and 1g are arranged in parallel in front of the CCD camera 20, and the wide conversion lens 1 is provided on the upper guide rail 1c.
The engaging portion 1f fixed to the upper end of a is a guide rail 1c.
A rack 1e fixed to the lower end of the wide conversion lens 1a is movably engaged with the lower guide rail 1g along the guide rail 1g. The rack 1e meshes with a pinion 1d fixed to the rotating shaft of the switching motor 1b. When the angle of view switching signal b is input from the vehicle direction determination circuit 4, the switching motor 1b rotates counterclockwise to move the rack 1e to the position shown in FIG.
While moving to the left in (b), the angle of view switching signal b
When is OFF, the rack 1e is rotated clockwise to move the rack 1e to the right in FIG. 2B.

Therefore, according to the angle-of-view switching mechanism 1 having the above-described configuration, when the angle-of-view switching signal b is input, the switching motor 1b rotates counterclockwise, so that the wide conversion lens 1a is guided together with the rack 1e. 1
c, 1g to the left in FIG. 2 (b), CC
The D camera 20 is mounted in front of the camera. As a result, CC
The angle of view of the D camera 20 changes from a narrow angle (45 °) to a wide angle (120
Switch to °). On the other hand, when the angle-of-view switching signal b is OFF, the switching motor 1b rotates clockwise, so that the wide conversion lens 1a moves along with the rack 1e along the guide rails 1c and 1g to the right in FIG. 2B. Moves in the direction and becomes unmounted. As a result, the field angle of the CCD camera 20 is switched from the wide angle to the original narrow angle.

The vehicle direction determination circuit 4 determines the output destination of the video signal d based on the output signal of the inhibitor switch 7. That is, when the reverse signal R is input from the inhibitor switch 7, it is determined that the vehicle will move backward based on the reverse signal R, and the above-described angle-of-view switching signal b is output to the angle-of-view switching mechanism 1 and the video signal at this time is also output. b is output to the monitor 5. On the other hand, when the reverse signal R is OFF, it is determined that the vehicle is moving forward, the angle of view switching signal b described above is turned OFF, and the video signal b at this time is output to the vehicle distance detection device 6.

The vehicle distance detection device 6 is the same as the vehicle distance detection device described in the section "Prior Art", but here, the video signal d output from the camera ECU 3 is supplied to the vehicle direction determination circuit 4. The distance to the following vehicle is detected based on the video signal d, and the distance detection signal e is output to the approaching vehicle warning device. The approaching vehicle warning device outputs a warning when the value of the distance detection signal e is equal to or less than the set value and it is determined that the danger is present.

The inhibitor switch 7 is the same as the inhibitor switch 7 shown in FIG. 4, but here outputs a reverse signal R to the vehicle direction determination circuit 4.

Therefore, according to the vehicle rear monitoring device having the above structure, the flowchart of FIG. 3 (S1 to S8 for each step)
When the backward movement R is selected by the selector lever, the backward movement signal R output from the inhibitor switch 7 at this time is input (S1, S).
2) The wide-angle conversion lens 1a is mounted by the view angle switching mechanism 1. Therefore, the angle of view of the CCD camera 20 is switched from the narrow angle to the wide angle (S3). And
The video signal d at this time is output to the monitor 5 by the vehicle direction determination circuit 4 (S4). As a result, on the display screen 5a of the monitor 5, the image of the rear view of the vehicle captured in a wide angle is displayed, and the close view is secured. Therefore, the driver can surely confirm the rearward direction when the vehicle moves backward by the monitor 5.

On the other hand, when a position other than reverse R is selected by the selector lever, the inhibitor switch 7
Since the backward signal R is turned off, the wide angle conversion lens 1a is not attached by the view angle switching mechanism 1. Therefore, the angle of view of the CCD camera 20 is switched from the wide angle to the original narrow angle (S5). Then, the narrow-angle video signal d at this time is output to the vehicle distance detection device 6 by the vehicle direction determination circuit 4 (S6).

Therefore, the vehicle distance detection device detects the distance to the following vehicle based on the narrow-angle video signal d at this time (S7), and outputs the distance detection signal e to the approaching vehicle warning device (S8). . Since the vehicle distance can be detected based on the narrow-angle video signal d as described above, the detection accuracy is high. Therefore, the approaching vehicle warning device accurately determines whether the following vehicle has approached a dangerous distance. Then, an alarm can be output.

As described above, according to the vehicle rear monitoring apparatus of this embodiment, the CCD camera 2 is driven by the view angle switching mechanism 1.
By switching the angle of view of 0 and determining the output destination of the video signal 4 by the vehicle direction determination circuit 4, one C
Only by providing the CD camera 20, it is possible to have a backward confirmation function when the vehicle moves backward, which is equivalent to that of the conventional vehicle rear monitoring device, and to have vehicle distance detection accuracy equivalent to that of the conventional vehicle distance detection device. Therefore, the cost can be reduced as compared with the case where two CCD cameras are installed.

In the above embodiment, the distance detection signal e is output to the approaching vehicle warning device. However, of course, the distance detection signal e may be output to that device if there is a use in another device. As another device in this case, an overtaking vehicle detection device can be cited, for example.

Further, in the above embodiment, the monitor 5 and the vehicle distance detecting device 6 are provided as the device for rearward monitoring, but, of course, if there is another device for rearward monitoring using the video signal, that device is used. A video signal d having an angle of view suitable for a device may be output to the device.

[0037]

According to the present invention as specifically described above with reference to the embodiments, the angle of view of the camera is switched by the angle of view switching means and the output destination of the video signal is determined by the determination circuit. Since a video signal having an angle of view suitable for each device for monitoring can be output to each of these devices, one camera can be shared without impairing the function of each device. That is , it is possible to output a wide-angle video signal to the monitor to secure a close-range visual field and to output a narrow-angle video signal to the vehicle distance detection device to secure vehicle distance detection accuracy. Therefore, you only need to have one camera,
The cost can be reduced.

Further, by the angle switching signal output means having an inhibitor switch, in conjunction with the selector lever, it is possible to reliably perform the angle switching of the forward-movement of the camera at the time of retraction.

[Brief description of drawings]

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

FIG. 2A is a top view of the view angle switching mechanism shown in FIG.
(B) is a front view of the view angle switching mechanism.

FIG. 3 is a flowchart showing an operation of the vehicle rear monitoring device shown in FIG.

FIG. 4 is a block diagram showing a configuration of a vehicle rear monitoring device according to a conventional technique.

5 is an explanatory diagram showing an angle of view of the CCD camera shown in FIG.

6 is an explanatory diagram showing an image of a rear view of the vehicle displayed on the monitor shown in FIG.

FIG. 7 is an explanatory diagram showing a principle of detecting a vehicle distance by the vehicle distance detecting device.

8 is an explanatory diagram showing an image of a rear view of the vehicle captured by the CCD camera shown in FIG. 7. FIG.

[Explanation of symbols]

1 Image switching mechanism 1a Wide conversion lens 1b Switching motor 1c, 1g Guide rail 1d pinion 1e rack 1f engaging part 3 camera ECU 4 Vehicle direction determination circuit 5 monitors 5a display screen 6 Vehicle distance detection device 7 Inhibitor switch b Angle of view switching signal c Imaging signal d video signal e Distance detection signal R backward signal

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Claims (3)

(57) [Claims] 1. An image pickup means for outputting a video signal at this time, and an angle-of-view switching signal, which has one camera arranged toward the rear of the vehicle and picks up an image of the field of view behind the vehicle with this camera. Angle switching signal output means for switching the angle of view of the camera based on the angle of view switching signal, and an output destination of the video signal based on the angle of view switching signal for rearward monitoring monitoring the video signal of the angle of view suitable for each device, possess a determination means for outputting to each of these devices, devices for the rear monitoring, for displaying an image for
And detect the distance to the following vehicle based on the video signal
It is a vehicle distance detection device, and the determination means uses a wide-angle image.
The image signal is output to the monitor, and the narrow-angle video signal is output to the vehicle.
A vehicle rear monitoring device that outputs to both distance detection devices. 2. A vehicle rear monitoring system according to claim 1, the angle switching signal output means, those having an inhibitor switch that works with the selector lever of the automatic transmission, based on an output signal from the inhibitor switch By outputting the angle-of-view switching signal by the selector lever, when the backward movement is selected by the selector lever, the angle-of-view switching means switches the angle of view of the camera from the narrow angle to the wide-angle, and the determination means suits the wide-angle video signal at this time. On the other hand, when the forward movement is selected by the sector lever, the field angle switching means switches the field angle of the camera from the wide angle to the narrow angle, and the determination means determines the narrow angle video signal at this time. The vehicle rear monitoring device is characterized by outputting to the. 3. A vehicle rear monitoring system according to claim 1 or 2, image Tsunokiri switching means comprises a lens for switching the camera angle of view, in front of the camera the lens based on the image Tsunokiri signal And a detaching mechanism for detaching the lens from the front of the camera.