JP2000217100A - On-vehicle camera system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-vehicle camera system where supervisory objects can clearly be displayed on a monitor even when the contrast of the objects is large. SOLUTION: A running vehicle 5 is mounted with a front supervisory camera 1, side supervisory cameras 2, 3 and a rear supervisory camera 4 that synthesize two pictures with optionally different exposure times into one picture together with their microphones. The front and side supervisory cameras 1-3 recognize objects (photographing objects) whose contrast is large such as an object at an entrance/exit of a tunnel, an object emitted by the evening (morning) sun, an object lighted by a head light at night and its vicinity and an object at a sunny and shady place so as to convert information at the outside of the vehicle into a video signal or a voice signal, the converted signal is digitized further, processed and the resulting signal is expressed for a driver in the vehicle as a picture or voice (sound).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-vehicle camera system, and more particularly to a camera for combining a camera such as a surveillance camera mounted on a vehicle with two images having arbitrarily different exposure times and outputting as one image. Thus, the monitoring target is clearly displayed on the monitor even under a situation where the contrast is large, so that the driver can recognize the monitoring target.

[0002]

2. Description of the Related Art Conventionally, surveillance cameras and the like mounted on vehicles are:
When imaging subjects with very different contrasts such as tunnel entrances, sunsets (morning sun), nighttime headlights and their surroundings, shade, and the like, simultaneous imaging of both “bright” and “dark” on the other hand when such reflected in properly either because the dynamic range is insufficient there is a problem that not appear on the right.

[0003]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention extends the dynamic range of a camera such as a monitoring camera mounted on a vehicle so that a monitoring target can be clearly displayed on a monitor even in a situation with a large contrast. It is an object of the present invention to provide an in-vehicle camera system capable of displaying images on a vehicle.

[0004]

A vehicle-mounted camera system according to the present invention combines a camera such as a monitoring camera mounted on a vehicle with two images having arbitrarily different exposure times and outputs a single image. Thus, the monitoring target is clearly displayed on the monitor even in a situation where the contrast is large.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, a surveillance camera (a camera for visual confirmation) such as a rear camera, a front side camera, or a rear side camera mounted on a vehicle is arbitrarily exposed to a different light. This is a vehicle-mounted camera system that combines two images at different times and outputs them as a single image, so that the subject to be visually monitored can be clearly displayed on a monitor even in a situation with high contrast. There is an effect that the visual monitoring target can be clearly displayed on the monitor even in a situation where the contrast is large.

According to a second aspect of the present invention, a white line detecting camera such as a front white line detecting camera or a rear white line detecting camera mounted on a vehicle combines two images with arbitrarily different exposure times into one image. The on-board camera system enables the detection target to be clearly displayed on the monitor even in situations where the contrast is high by using a camera that outputs the image as an image. It has the effect that it can be clearly displayed.

According to a third aspect of the present invention, an obstacle detection camera, such as a front obstacle detection camera or a rear side obstacle detection camera, mounted on a vehicle is used to detect two images having different exposure times. By combining and outputting a single image as a camera, it is a vehicle-mounted camera system that can clearly display obstacles on the monitor even in situations where the contrast is large. This has the effect that obstacles can be clearly displayed on the monitor.

According to a fourth aspect of the present invention, there is provided a camera for synthesizing two images having arbitrarily different exposure times and outputting the combined image as a single image. An in-vehicle camera system according to any one of claims 1 to 3, wherein the on-vehicle camera system according to any one of claims 1 to 3, wherein speed control can be performed. It has the effect that the shutter speed can be controlled outside.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram for explaining a vehicle-mounted camera system according to an embodiment of the present invention. The vehicle 5 has a front monitoring camera 1, a side monitoring camera 2,
The side monitoring camera 3 and the rear monitoring camera 4 are mounted together with the microphone. At this time, it is not necessary to prepare all of them, and it may be limited depending on the purpose, or may be mounted on the lower part of the vehicle or on the ceiling depending on the purpose, and a white line may be used instead of the surveillance camera described above. A detection camera or an obstacle detection camera may be appropriately mounted.

[0010] In addition, as a situation to be confirmed as an outside situation, for example, a road sign 10 indicating that a vehicle traveling in the lane 7 has a pedestrian crossing in front of the vehicle, or another vehicle traveling in the lane 8 is a simultaneous vehicle 9 However, when driving in the lane, you may enter or exit a tunnel, or on a sunny morning or evening, drive toward the sun (backlit). They may drive in the shade and sunshine, and may even be exposed to headlights at night.

In the above-mentioned running conditions, the present invention is particularly applicable to the imaging of a subject having a very different contrast, such as the entrance and exit of a tunnel, sunset (morning sun), nighttime headlights and its surroundings, and sunshine. Is to pick up images and sounds outside the vehicle by the above-described on-vehicle cameras 1 to 4 so as to grasp the state and contribute to safe driving.
First, the example shown is explained, and then
The operation of the subject according to the present invention in a situation with a large contrast will be described.

FIG. 2 shows an outline of an on-vehicle camera system of the present invention for processing information detected by an on-vehicle camera and / or a microphone and displaying the same on a monitor or the like according to the embodiment of the present invention. In FIG. 2, the front surveillance camera 33, the side surveillance camera 32, the side surveillance camera 31, the rear surveillance camera 30, and the microphones 37, 36, 35, and 34 attached at the same time.
Are connected to video amplifiers 84 to 81 and audio amplifiers 88 to 85 for microphones, which are input to a mixing device 66 for display on a monitor 67 in a driver's seat and are simultaneously displayed to a driver. The display is displayed to the driver through the selection of the display device operation device 69 for selecting whether to perform the display or individually.

The signals are branched before being input to the mixing device 66 for display, and the video system is input to the video filters 53, 52, 51, and 50 to be processed for digitization, and at the same time, to perform audio processing. For example, audio filter 49,
Optimal processing is performed for digitization at 48, 47 and 46. The video signal of the processed signal is converted to an A / D converter
At 61, 59, 57, and 55, digitization processing appropriate for CPU processing is performed and input to the CPU 64. The audio is subjected to optimal digitization processing for CPU processing by A / D converters 60, 58, 56, and 54, and is input to CPU 64.

The signal input to the CPU 64 is a CPU operation unit.
A condition is set in accordance with 75, processing such as comparison of information in the memory 65 with each input is performed, and information from the CPU 64 is displayed on the monitor 67. Similarly, the audio digital signal is also converted to analog audio by the audio converter 63. The CPU 64 is provided with an I / F (interface) 72 for speed detection information 77 for detecting vehicle information from information of a vehicle control device 73 or the like possessed by the vehicle in order to compare various inputs with the running state of the vehicle. Information is input to the CPU 64 to create information and the like.

A recording device 71 for recording the information of the CPU 64 for a certain period of time or continuously storing the information as vehicle information may be provided. The signal obtained by converting the digital signal into an analog signal is input to a mixing device 66 and displayed on a monitor 67, for example, a pedestrian crossing or the like is displayed ahead. Alternatively, the voice is displayed to the driver by a voice display 79 such as "there is a pedestrian crossing ahead" from the speaker 68 by voice. In addition, there is also a method in which these signals are notified to the driver on the vehicle display device 70 on the vehicle dashboard 78 by a liquid crystal monitor 89 or blinking display.

Next, the same operation as described above is basically performed for a subject in a situation where the contrast is large. A camera that synthesizes and outputs a single image is used. If you use a camera that combines two images with arbitrarily different exposure times and outputs it as a single image, high brightness due to sun reflection or strobe reflection, etc. Information can be obtained without breaking the picture.

That is, a camera that combines two images with arbitrarily different exposure times and outputs a single image has an operation speed twice that of a normal CCD, two images in a time-division manner, and a minimum of two images. Can be taken out at different times. Moreover, the exposure time of the two images can be changed by controlling the driving of the CCD instead of changing the lens aperture. For example, an image with an exposure time of about 1/60 second (same as a normal camera, actually about 1 / 63.8 second) is taken out as an indoor image (this is called a long image signal in the sense of long exposure). Next, when the exposure time is reduced to 1/1000 second, an image equivalent to the case where the lens aperture is narrowed down is obtained and taken out as an outdoor image (short image signal in the sense that the exposure time is short). ).

Thus, two images with different exposure times are read out in the same field at twice the normal speed. 2
Since a single image is output for each horizontal line at double speed, if normal speed reading is performed after writing at double speed using storage means for two horizontal lines, conversion to normal speed and time axis Matching (simultaneous) becomes possible. In the image processing LSI, the two synchronized video signals are converted into a long image signal below a certain luminance level and a long image signal above a certain luminance level.
One image is created by synthesizing using a short image signal.

In order to make this a practical image, it is necessary to perform tone correction according to the luminance distribution of the screen after the combination, as described in Japanese Patent Application No. As described in No. 9-83422 “Gradation correction method of imaging device”, various gray-scale characteristics are detected by detecting a maximum gray-scale value of histogram data and calculating a gray-scale characteristic according to the maximum gray-scale value. Optimal gradation correction can be performed according to the subject, and a natural image can be reproduced even for a low-luminance subject while effectively utilizing the dynamic range of the subsequent signal processing.

Also, because of the necessity of white balance adjustment, Japanese Patent Application No. 9-7916 filed earlier by the present applicant.
As described in No. 8 "Imaging device", when subjects with different color temperatures such as indoor and outdoor are combined, two types of video signals with different exposure amounts can be adjusted independently. Therefore, correct white balance is simultaneously performed both indoors and outdoors.

In addition to the above, in the present invention, as shown in FIG. 3, a shutter time a for extracting a long image signal and a shutter time b for extracting a short image signal are set to a subject (image pickup) having a very different contrast. Target)
To extract the long image signal and the short image signal alternately. The sum of the shutter time a and the shutter time b is 1/60 second (one horizontal line period)
So that By doing so, the dynamic range can be further expanded as compared with the above-mentioned two applications. For example, the contrast of the entrance and exit of a tunnel, the sunset (morning sun), the headlight and its surroundings at night, and the sunshine and the like can be improved. Even a very different subject (imaging target) can be accurately displayed on the monitor.

First of all, how to actually set the shutter time “a” and the shutter time “b” in a situation where the contrast is large can be set for each situation by obtaining numerical data by gaining much experience. Becomes In addition, each situation is possible by attaching a sensor that grasps each situation.

As described above, by combining two images with arbitrarily different exposure times mounted on a vehicle and processing an image captured by a camera that outputs a single image, much safety information and vehicle information can be obtained. It can inform the driver.

[0024]

As is apparent from the above description, according to the present invention, a camera such as a surveillance camera mounted on a vehicle synthesizes two images with arbitrarily different exposure times and forms one image. By using a camera for output, it is possible to clearly display the monitoring target on the monitor even in a situation where the contrast is large, so that it is possible to contribute to safe driving.

Further, even if the lens aperture of the camera is fixed, the object to be monitored can be displayed on the monitor from the dark part to the bright part, and the automatic light quantity adjustment of the camera can be omitted, so that a smaller camera can be mounted. It has the effect of being able to.

[Brief description of the drawings]

FIG. 1 is a block diagram for explaining a vehicle-mounted camera system according to an embodiment of the present invention;

FIG. 2 is a diagram showing a configuration for processing information detected by the on-vehicle camera system according to the embodiment of the present invention and displaying the information on a monitor or the like;

FIG. 3 is a diagram for explaining an outline of shutter control in the vehicle-mounted camera system according to the embodiment of the present invention.

[Explanation of symbols]

 1 Forward monitoring camera 2, 3 Side monitoring camera 4 Rear monitoring camera 5 Vehicle 6, 8 lanes (continuous) 7 Lanes (intermittent) 9 Simultaneous vehicles 10, 11 Road marking 30-33 Camera 34-37 Microphone 46-49 Voice filter 50-53 Video filter 54-61 A / D converter 62 Video converter 63 Audio converter 64 CPU 65 Memory 66 Mixing device 67 Monitor 68 Speaker 69 Display device operation section 71 Recording device 72 I / F (Interface) 73 Vehicle control Device 75 CPU operation unit 76 Common interface 77 Speed detection information 78 Vehicle dashboard 79 Audio display 80 Character display 81-84 Video amplifier 85-88 Audio amplifier 89 Dashboard monitor

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Osamu Sugawara 3-1, Tsunashimahigashi 4-chome, Kohoku-ku, Yokohama-shi, Kanagawa Prefecture F-term (reference) 5C022 AA04 AB17 AB68 AC01 AC52 AC69 5C054 CE11 CH00 DA01 ED11 EJ01 FE18 HA30 5C066 AA01 AA03 BA20 CA00 CA11 EA14 ED01 ED04 EE01 GA01 GA02 GA05 KA12 KE02 KE17 KM00 KM01

Claims (4)

[Claims] 1. A surveillance camera (a visual confirmation camera) such as a rear camera, a front side camera, and a rear side camera mounted on a vehicle.
Is a camera that combines two images with arbitrarily different exposure times and outputs it as a single image, so that the subject to be visually monitored can be clearly displayed on the monitor even in situations where the contrast is large. Camera system. 2. A white line detection camera such as a front white line detection camera and a rear white line detection camera mounted on a vehicle is a camera that combines two images with arbitrarily different exposure times and outputs a single image. The on-vehicle camera system enables the detection target to be clearly displayed on the monitor even in a situation where the contrast is large. 3. A front obstacle detection camera mounted on a vehicle,
An obstacle detection camera, such as a rear side obstacle detection camera, is a camera that combines two images with arbitrarily different exposure times and outputs it as a single image, so that an obstacle can be detected even under a large contrast situation. On-board camera system that can clearly display on a monitor. 4. A camera for synthesizing two images with arbitrarily different exposure times and outputting as one image,
4. The in-vehicle camera system according to claim 1, wherein shutter speed control can be performed in addition to white balance correction and gradation correction.