JPH0522652A - Image input device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an image input device that can obtain almost the same video signal level both in the daytime and at night and is hardly affected by a temporary change in light amount. [Configuration] The imaging camera 1 with an electronic shutter
A video signal is sent to the flash synchronization control unit 3. In addition,
The flash synchronization controller 3 causes the strobe 2 to generate and send a flash timing pulse synchronized with the exposure time of the imaging camera 1. Then, the image obtained by the imaging camera 1 is recorded in the image memory 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image input device such as a vehicle number image pickup device for picking up an image of a high-speed moving subject outdoors.

[0002]

2. Description of the Related Art FIG. 3 shows the configuration of a conventional image input device. In FIG. 3, reference numeral 5 is an image pickup camera for photographing a vehicle or the like. Reference numeral 2 denotes a strobe used in the image pickup camera 5, which flashes by a signal from the outside. An image memory 4 records the image of the imaging camera 5. A video / flash synchronization control unit 7 flashes a strobe in synchronization with an image signal and sends an image from the imaging camera 5 to the image memory 4.

Next, the operation of the above conventional example will be described.
In FIG. 3, in the imaging camera 5, when the shooting operation is started,
An image signal divided into a video period and a video blanking period is generated. When the video / flash synchronization control unit 7 receives this image signal, it sends a flash timing pulse to the strobe 2 to set the video blanking period to "L" and the video period to "H". Next, the strobe 2 flashes in synchronization with the rising pulse of "H" of this flash timing pulse, and flashes at least for a longer video period. The image captured in this way is transmitted via the video / flash synchronization control unit 7.
It is recorded in the image memory 4.

As described above, in the above-described embodiment, as shown in FIG. 4, the strobe 2 is in the image period (see FIG.
(Period (c)), it is possible to illuminate the subject with a uniform light amount for the image even at night.
It can be recorded in the image memory 4.

[0005]

However, in the above-mentioned conventional image input device, when the image is taken at night as shown in FIG. 4, for example, a spotlight such as a headlight of a car is directly applied to the image pickup camera 5. And the amount of light more than that which illuminates the subject with the strobe is input to the image pickup camera 5, and the image signal level becomes equal to or more than that in the daytime ((b) in FIG. 4).
Period), and in particular, a part of the screen is illuminated ((a) in FIG. 4).
(Period) and a part thereof becomes an abnormally high video signal level.

The present invention solves the above-mentioned conventional problems, and reduces the effect of an image when a large amount of light is temporarily radiated on an image pickup camera such as a headlight, and excellent image input which is not affected during the day and night. The purpose is to provide a device.

[0007]

In order to achieve the above object, the present invention provides an image pickup camera having an electronic shutter function, and a flash timing for operating the electronic flash of the image pickup camera so that a strobe flashes during an exposure period. An exposure / flash synchronization control unit that produces pulses, a strobe,
It is composed of an image memory.

[0008]

Therefore, according to the present invention, since the strobe light can be made to flash during the exposure period of the image pickup camera by the electronic shutter, irradiation light suitable for image recording can be provided in an extremely short exposure time to distinguish between daytime and nighttime. It has an effect of being able to take a good image without the need.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic block diagram showing an embodiment of the image input apparatus of the present invention. In FIG. 1, reference numeral 1 denotes an image pickup camera having an electronic shutter function for taking an image, which captures an image for a very short time during an image blanking period during the electronic shutter operation. Reference numeral 2 denotes a strobe, which irradiates a subject captured by the imaging camera 1 toward the subject. An image memory 4 records the image of the imaging camera 5. An exposure / flash synchronization control unit 3 flashes the strobe in synchronization with the exposure period of the electronic shutter, and sends the image from the imaging camera 1 to the image memory 4.

Next, the operation of the above conventional example will be described.
In FIG. 1, the image pickup camera 1 using the electronic shutter has a period (exposure period) for capturing an image during a video blanking period, and the image captured during this period is reproduced as an image for the next video period. Is done. When the exposure / flash synchronization control unit 3 receives this image signal, a flash timing pulse is generated that sets the exposure period of the video blanking period to "H" and the other periods to "L", and sends it to the strobe 2. To do. Next, the strobe 2 flashes at least for a longer period than the exposure period in synchronization with the rising pulse of "H" of the flash timing pulse. The image thus captured is recorded in the image memory 4 via the exposure / flash synchronization controller.

As described above, according to the above-described embodiment, since the strobe light can be made to flash during the exposure period of the image pickup camera by the electronic shutter, irradiation light suitable for image recording can be provided in a very short exposure time, which is favorable. It has the effect of taking various images. That is, as shown in FIG. 2, the exposure timing located in the vertical blanking period (the period (d) in FIG. 2) and the strobe irradiation trigger operate in the same state. Therefore, for example, the electronic shutter speed (exposure time) is 1000 minutes. If it is operated for 1 second, 1/16 of the actual image will suffice. As a result, the irradiation capability of the strobe can be increased 256 times that of the conventional one, and the strobe at this time can give the same amount of light to the subject even during nighttime shooting. Then, as shown in FIG. 2, an image having no difference in video signal level can be obtained in both daytime and nighttime, and even if a temporary spotlight is irradiated ((a) period in FIG. 2,
(B) period, this effect can be avoided unless the spotlight is irradiated for an extremely short exposure time.
Therefore, the present embodiment has an effect that the image is not easily affected by a temporary change in the light amount.

[0013]

As is apparent from the above embodiment, the present invention makes it possible to flash the strobe during the exposure period of the image pickup camera using the electronic shutter, so that the irradiation light suitable for image recording can be obtained in a very short exposure time. Therefore, it is possible to take a good image having almost the same video signal level regardless of whether it is daytime or nighttime. Further, since the exposure time of the image pickup camera is extremely short, there is an effect that the image is not affected even when the light amount changes temporarily.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of an image input device according to an embodiment of the present invention.

FIG. 2 is a video signal waveform diagram in the image input device of the present invention.

FIG. 3 is a schematic block diagram of a conventional image input device.

FIG. 4 is a waveform diagram of a video signal in a conventional image input device.

[Explanation of symbols]

 1 Imaging camera with shutter function 2 Strobe 3 Exposure / flash synchronization controller 4 Image memory

Claims (1)

Claim: What is claimed is: 1. An imaging camera having an electronic shutter function, an image memory for storing an image taken by the imaging camera, a strobe, and an exposure timing when the electronic shutter of the imaging camera is used. An image input device including a synchronization control unit that synchronously activates the strobe.