JP2010220043A - Vehicle photographing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle photographing device which can be an optional combination between a CCD camera and an infrared light projector while eliminating the need for provision of an additional special component. <P>SOLUTION: The vehicle photographing device is a combination between a CCD camera and an infrared light projector. The infrared light projector receives a vertical synchronization signal from video signals of the CCD camera, stops the projection of infrared light therefrom for a predetermined constant period of time after signal reception, and allows the projection of infrared light for the same time period as a set exposure time period with a lapse of a constant time period after the predetermined period of signal reception. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle photographing apparatus disposed at a toll gate on a toll road, and more particularly to a vehicle photographing apparatus in which a CCD camera and an infrared projector are arbitrarily combined.

  In this type of CCD camera, in order to obtain a still image of a subject moving at high speed, the subject is imaged using strobe illumination, and the captured image is temporarily captured in a storage medium such as a memory, and thereafter image processing is performed. The method of doing is taken. In this case, one frame of imaging charge is transferred to a memory in the video processing circuit in synchronization with the charge transfer timing.

  The current television camera employs an interlace scanning method, and the same applies to the CCD camera described above. In this interlace scanning type CCD camera, a strobe light is used to illuminate the subject for a very short time, and both the first and second field image charges of the CCD element are taken out to form an image as one frame image. Processing is in progress.

  If strobe light emission is performed during transmission of imaging charges from the CCD element, the amount of imaging charges changes and a normal image cannot be obtained. In view of this, there has been proposed a technique for detecting strobe light emission when the charge transfer of the CCD element is performed in the CCD camera (Patent Document 1).

  In FIG. 3, a video signal (including a synchronization signal) from the CCD camera 101 is supplied to a video signal processing unit (not shown) and also supplied to the strobe control circuit 102. In the strobe control circuit 102, the sync separator 121 separates the sync signal from the video signal, and the vertical sync signal V and the horizontal sync signal H are derived, respectively.

  The vertical synchronizing signal V is a reset input for the counter 122, and the horizontal synchronizing signal H is a count-up input for the counter 122. The count output of the counter 122 is supplied to the comparator 123, and it is determined whether or not the count output exists within a certain range determined by the upper limit value MAX and the lower limit value MIN. If it is determined by this determination that the count output is within the certain range, the strobe light emission inhibition pulse 125 is generated from the comparator 123 during that period.

  The strobe emission prohibiting pulse 125 is input to the strobe driving circuit 124, and the strobe 103 is forcibly prohibited from emitting light during the period in which the strobe emission prohibiting pulse 125 exists.

  For example, it is assumed that the imaging charge of the CCD element is transferred within the generation period of the eighth vertical synchronization signal from the fourth vertical synchronization signal counting from the start timing of the vertical synchronization signal V. In this case, the upper limit value MAX of the comparator 123 is set to “8” and the lower limit value MIN is set to “4” in advance.

  Then, when the count output of the counter 122 becomes “4” from the start timing of the vertical synchronization signal V, the strobe light emission inhibition pulse 125 is enabled, and when it becomes “8”, it is disabled. The flash emission is forcibly prohibited. Accordingly, it is possible to prevent strobe light emission when transferring the imaging charge of the CCD element.

  As a vehicle photographing apparatus using this type of CCD camera, for example, the one shown in Patent Document 2 has been proposed. As shown in FIG. 4, the vertical synchronization signal V and the horizontal synchronization signal H among the video signals from the CCD camera 100 are received, and the number of times the horizontal synchronization signal H is received after the vertical synchronization signal V is received is counted. Based on this, the light emission timing of the strobe as the infrared projector 120 is determined. In this example, in the main body of the CCD camera 100, a counter 114 that counts horizontal synchronizing pulses is provided in order to generate CCD driving pulses. This count output is input to the comparator 115, and when the count output exists between the upper limit value MAX and the lower limit value MIN, a strobe emission prohibiting pulse d is generated and derived from the terminal 117 to the outside. Light emission of the infrared projector 120 connected to the terminal 117 is operated.

  According to this configuration, it is possible to generate a strobe light emission inhibition pulse by simply adding a comparator using the output of a counter that already exists in the camera, and the entire system can be simplified.

Japanese Patent Laid-Open No. 1-222581 JP-A-6-284317

In the case of the vehicle imaging device of Patent Document 2, dedicated components such as the comparator 115 are required to analyze two types of synchronization signals, which causes a cost increase. Further, in order to match the drive of the CCD camera 100 and the light emission timing of the infrared projector 120, the conditions for the light emission timing when the number of reception times of the horizontal synchronization signal after the reception of the vertical synchronization signal is satisfied. Need to set based on. However, the number of horizontal synchronization signals received after receiving the vertical synchronization signal may vary depending on the type of CCD camera, and it is difficult to arbitrarily combine the CCD camera and the infrared projector.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle photographing apparatus that can be arbitrarily combined with a CCD camera and an infrared projector without providing a separate dedicated part.

  A vehicle photographing apparatus according to the present invention is a vehicle photographing apparatus that is a combination of a CCD camera and an infrared projector, and the infrared projector receives a vertical synchronization signal from video signals from the CCD camera and is predetermined. In addition, the irradiation of infrared rays is stopped for a certain period after reception, and infrared irradiation is performed for the same period of time as the set exposure time after a predetermined period after reception. In the present invention, the transfer timing by the CCD drive circuit varies depending on the CCD camera manufacturer, standard, etc., but it has been found that charge transfer is performed for a predetermined period after reception, and based on this. It is.

That is, the present invention is a vehicle photographing apparatus including a CCD camera and an infrared projector, wherein the infrared projector receives a vertical synchronization signal among video signals from the CCD camera, and after receiving the vertical synchronization signal, The infrared irradiation is stopped for a predetermined period, and the infrared irradiation is performed for a time corresponding to a set exposure time after the predetermined period.
According to this configuration, the vertical synchronization signal is extracted from the output signal of the CCD camera and the infrared projector is driven to secure the light emission prohibition period. Therefore, the counter or comparator that generates the timing for generating the CCD drive pulse Can be eliminated, and the entire system can be simplified and reduced in price.

According to the present invention, in the vehicle imaging apparatus, the infrared projector receives a vertical synchronization signal from a video signal from a CCD camera, and irradiates infrared rays for a predetermined period after receiving the vertical synchronization signal. And a timing signal generating means for irradiating infrared light for a time corresponding to a set exposure time after elapse of the predetermined period after reception, wherein the timing signal generating means is provided for the infrared projector. It is configured to generate a drive signal.
According to this configuration, the vertical synchronization signal is extracted from the output signal of the CCD camera and the infrared light projector is driven to secure the light emission prohibition period. Therefore, reliable timing control can be performed with a simple device configuration.

  As described above, in the vehicle photographing apparatus of the present invention, the infrared projector receives the vertical synchronization signal from the video signal from the CCD camera, and receives the infrared synchronization signal for a predetermined period after receiving the vertical synchronization signal. Irradiation is stopped, and after the elapse of the predetermined period after reception, infrared irradiation is performed for a time corresponding to the set exposure time, so that no special parts are required. It is possible to provide a vehicle photographing apparatus that can arbitrarily combine a CCD camera and an infrared projector.

1 is a block diagram of a vehicle photographing apparatus according to a first embodiment of the present invention. The figure which shows the timing of the signal in the vehicle imaging device of Embodiment 1 of this invention. Illustration of a conventional device Illustration of a conventional device

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram of a vehicle imaging apparatus according to an embodiment of the present invention.
The vehicle image pickup apparatus according to the embodiment of the present invention is used by combining an infrared light projecting unit 2 with a CCD camera 1, and the CCD camera 1 includes a CCD element including a switching transistor and a photodiode, A CCD driving circuit 11 for driving the same, a video processing circuit 12 for processing an output signal, and a sync separator 13 are provided. The vertical sync signal V obtained by the sync separator 13 is used as a projector for the infrared projector 23. It is configured to output to the drive unit 24.

Here, the CCD element is a photoelectric element that accumulates charges generated in response to light reception.
The CCD drive circuit 11 generates and transmits a transfer timing for transferring the charge on the CCD element 10 to the video processing circuit 12. The video processing circuit 12 processes the transferred charges into image data. The synchronization signal generation circuit generates at least a vertical synchronization signal.

With the above configuration, the imaging charge by the CCD element is transferred to the video processing circuit 12 in response to the charge transfer timing by the CCD drive circuit 11, and the vertical synchronization signal V and the horizontal synchronization signal H generated from the synchronization separator 13 are respectively obtained. In addition, it is led out as a video signal to the outside through a terminal.
Here, the transfer timing by the CCD drive circuit 11 varies depending on the manufacturer, standard, etc. of the CCD camera 1, but it has been found that charge transfer is performed for a predetermined period after reception. It was made with attention.

The infrared projector 2 includes an infrared LED as the infrared projector 23, an infrared LED driver as the projector driver 24, a vertical synchronization signal receiver 22, and a timer 26.
Here, the infrared LED is a light source and irradiates infrared rays by light emission.
The projector driving unit 24 generates and transmits the light emission timing.
The vertical synchronization signal receiving unit 22 separates and receives only the vertical synchronization signal from the video signal.
The timer 26 is built in the microcomputer for control.

  An example of each signal used here is shown in FIG. (A) is a vertical synchronizing signal V, (b) is a horizontal synchronizing signal H, (c) is a charge transfer timing Cd in the CCD drive circuit 11, and (d) is a light emission prohibiting pulse T for a projector. As is apparent from FIG. 2, the charge transfer timing is substantially at the center of the projector light emission prohibiting pulse, and it can be seen that light emission of the infrared light projector is prohibited during charge transfer.

  With the above configuration, the timer 26 measures a certain period determined according to the CCD camera after receiving the vertical synchronization signal, and during that time, the infrared LED driving unit does not emit the infrared LED, and then the preset exposure is performed thereafter. Irradiation of infrared rays for the same time as the time can be performed.

  The fixed period determined according to the camera after receiving the vertical synchronization signal is determined as follows. For example, in combination with the CCD camera 1 and the infrared projector 23, test shooting is performed with various exposure timings after receiving the vertical synchronization signal at a preset exposure time, and the most preferable timing is set to the certain period. . By setting this in the timer in advance, the timing of infrared light transmission is detected after the usual means only by adding the timer. Therefore, it is possible to provide a highly reliable vehicle image pickup device by adding the timer 26 without increasing the number of device parts.

  Here, after receiving the vertical synchronization signal, the infrared projector stops the infrared irradiation for a predetermined period, and after the predetermined period after the reception, the infrared light for a time corresponding to the set exposure time. Irradiation. This time is the same as the normal exposure time.

  The projector driving unit 24 outside the CCD camera 1 can receive the strobe light emission prohibiting pulse T (d) only and can control the strobe light emission to the prohibited state while the projector light emission prohibiting pulse T is enabled. Become.

  As described above, according to the present invention, since the vertical synchronization signal is extracted from the video signal of the CCD camera 1, the configuration of the projector control circuit outside the camera is extremely simplified, and the system can be simplified and the cost can be reduced. Can be planned.

  As described above, according to the present invention, the vertical synchronization signal is extracted from the output signal of the CCD camera and the infrared projector is driven to secure the light emission prohibition period. There is no need for a counter or a comparator for generating timing, and the entire system can be simplified and the cost can be reduced.

DESCRIPTION OF SYMBOLS 1 CCD camera 10 CCD element 11 CCD drive circuit 12 Image processing circuit 2 Infrared light projector 22 Vertical sync signal receiver 23 Infrared projector 24 Projector drive 25 Vertical sync signal 26 Timer T Projector light emission inhibition pulse V Vertical sync signal H Horizontal sync Signal Cd Charge transfer timing 101 CCD camera 111 CCD element 112 Video processing circuit 113 Synchronization signal generation circuit 114 Counter 115 Comparator 116 CCD drive circuit 117 Strobe light emission inhibition pulse output terminal 120 Projector

Claims (2)

A vehicle photographing device comprising a CCD camera and an infrared projector,
The infrared projector receives a vertical synchronization signal from a video signal from a CCD camera, and after receiving the vertical synchronization signal, stops infrared irradiation for a predetermined period of time,
A vehicle photographing apparatus configured to perform infrared irradiation for a time corresponding to a set exposure time after elapse of the predetermined period after reception. The vehicle photographing device according to claim 1,
The CCD camera receives a vertical synchronization signal from the video signal from the CCD camera, and after receiving the vertical synchronization signal, stops infrared irradiation for a predetermined period of time,
A timing signal generating means for performing infrared irradiation for a time corresponding to a set exposure time after elapse of the predetermined period after reception;
A vehicle photographing apparatus configured such that the timing signal generating means generates a drive signal for the infrared projector.

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