JPH089253A - Camera head part of head separate type ccd camera and camera head control method - Google Patents

Abstract

PURPOSE:To attain connection between the signal processing part of a head separate type CCD camera and many camera head parts via a single coaxial cable. CONSTITUTION:A camera head part 10 of a head separate type CCD camera contains a clock reproduction means 15, a CCD 11 and a drive control means 13. The means 13 outputs a control pulse to the CCD 11 and also outputs a read signal in response to the timing when a video data signal is outputted from the CCD 11. A control signal separating means 25 includes a selected signal detecting circuit 27 which outputs an actuation signal when a head selection signal is equal to a prescribed pulse. A switching circuit 21 is provided between the output terminal of the CCD 11 and a camera head external connection terminal 19. Then a switching control circuit 23 outputs a signal to ensure conduction of the circuit 21 when the actuation signal and the read signal are inputted from the circuit 27 and the means 13 respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head-separated CCD camera, and more particularly to a head-separated CCD camera in which a plurality of camera heads are connected to one signal processing section. Is.

[0002]

2. Description of the Related Art Today, in surveillance cameras and the like, images taken by a plurality of monitor cameras are monitored by a single monitor television. When connecting the images taken by the plurality of monitor cameras to one monitor television, a switching control device 61 such as a switcher is used as shown in FIG. Are connected by camera cables, and the switching control device 61 selects the camera cable of the specific camera 60 to output the video signal from the specific camera 60 to the monitor television 65.

Further, in order to reduce the size of the monitor camera 60 to reduce the space required for installing the monitor camera 60 and to easily install the monitor camera in a narrow space, the head separation type C
CD cameras are also becoming popular. As shown in FIG. 6, this head-separated CCD camera includes a CCD 11 in a camera head section 10, an image sensor drive pulse generator 12 for driving the CCD 11, and a synchronous oscillator 16 using a phase-locked loop circuit. The signal processing unit 40 is provided with a power circuit.
41, a reference oscillator 44 that outputs a reference frequency signal, a synchronization signal generator 45, and a video signal processing means 48 are provided, and the signal processing unit 40 and the camera head unit 10 are connected to the power supply line 36, the clock signal line 37, and the synchronization. The signal line 38 and the CCD output signal line 39 are used for connection, and the synchronous oscillator 16 of the camera head unit 10 reproduces the clock signal in accordance with the clock signal from the signal processing unit 40. Synchronized oscillator
Based on the clock signal from 16, the image pickup device drive pulse generator 12 outputs various control pulses according to the format of the CCD 11, such as a transfer gate pulse and a transfer clock pulse, in accordance with the synchronization signal from the signal processing unit 40, and the CCD 11 The CCD 11 is controlled by this control pulse to output a video data signal as a CCD output signal at a predetermined timing excluding the horizontal blanking period and the vertical blanking period. In the signal processing means 48, this C
The CD output signal is subjected to detection processing such as correlated double sampling, and further, a horizontal synchronization signal and a vertical synchronization signal are added by clamp processing or the like to form a video signal I.

In the head-separated CCD camera, the camera head section 10 and the signal processing section 40 are shared by sharing the clock signal line 37 and the synchronization signal line 38 with a single cable.
The number of connecting cables with and is also reduced. Therefore, when a surveillance camera using a plurality of camera heads of this head separation type CCD camera is used, for example, as shown in FIG.
As shown in, the signal processing unit 40 and each camera head unit 10 are connected by one synchronization signal line 38 or the like to send a clock signal or a synchronization signal to each camera head unit 10,
The CCD output signal line 39 from the camera head can be connected to the signal processing means 48 of the signal processing unit 40 via the switching control device 61 such as a switcher, and the camera head for synchronizing signals and clock signals via the synchronizing signal line 38. A CCD output signal sent from each camera head unit 10 by sending a signal necessary for controlling the operation of the unit 10 to each camera head unit 10 to operate each camera head unit 10 while synchronizing each camera head unit 10. One of the signals is selected by the switching control device 61, and the signal processing unit 40 is selected.
Therefore, the video signal I is used for monitoring by the monitor television 65.

[0005]

As described above, when a large number of cameras or camera heads are arranged through a switching control device such as a switcher, at least the same number of camera cables as the number of cameras or camera heads are required. However, there is a drawback that the volume occupied by the camera cable in the entire system becomes large and not only the wiring of each device and wiring becomes complicated but also the cost required for the camera cable becomes large.

The present invention eliminates such drawbacks and provides a camera head part of a head-separated CCD camera and a camera head control method capable of connecting a large number of camera head parts to one camera cable. Is.

[0007]

According to the present invention, a control pulse is output to a CCD to a camera head section having a clock regenerating means by a synchronous oscillator, a CCD, and drive control means for outputting a control pulse for driving the CCD. With CCD
Is a control signal separating means for separating a head synchronizing signal and a head selecting signal input to the camera head section by using a drive controlling means for outputting a read signal in accordance with a timing of outputting a video data signal from the head synchronizing signal. Is provided to the clock reproduction means and the drive control means, and a control signal separation means including a selection signal detection circuit that outputs an operation signal when the head selection signal has a predetermined number of pulses or pulse intervals is provided, and the CCD output A switch circuit is provided between the terminal and the external connection terminal of the camera head, and when the operation signal from the selection signal detection circuit is input and the read signal from the drive control means is input, both signals are input. During this period, a switch control circuit that outputs a conduction signal that makes the switch circuit conductive is provided.

In addition, a plurality of camera heads and one signal processing unit are connected by one coaxial cable, and a DC voltage is applied to the coaxial cable by the signal processing unit, and a horizontal blanking period is set. A clock signal is applied to the coaxial cable within a horizontal blanking period in accordance with the timing, and the number of pulses used as a clock signal for each frame period is set as a specific number to be a frame start reference signal, and a vertical retrace line is based on the frame start reference signal. A predetermined number of pulses are applied as a head selection signal to the coaxial cable in accordance with the clock signal within the period, and one frame section or several frame sections from a specific camera head section to the coaxial cable based on the head selection signal. The control method for outputting the video data signal of is used.

[0009]

[Operation] In the present invention, since an analog switch is provided between the external connection terminal of the camera head section and the CCD, CC
The output of the CCD output signal output by D from the camera head unit can be controlled by this switch circuit. Further, since the head synchronizing signal is extracted from the signal input to the external connection terminal and the control signal separating means for sending to the synchronizing oscillator and the drive controlling means is provided, the synchronous oscillator which is the clock reproducing means based on the head synchronizing signal is used. The clock signal can be regenerated, and the control pulse necessary for driving the CCD at the predetermined timing can be formed by the drive control means based on the head synchronization signal, and the selection signal of the control signal separation means can be detected. Since the circuit detects that the external connection terminal contains a specific head selection signal and outputs the operation signal to the switch control circuit, the switch control circuit can be operated only in a specific case by the operation signal.

Further, the drive control means outputs the control pulse to the CCD and also outputs the read signal to the switch control circuit at the timing when the video data signal is output from the CCD. When the operation signal is input, the conduction signal is sent to the switch circuit at the output timing of the video data signal, and the switch circuit outputs the CCD output signal to the external connection terminal only when the conduction signal is input. Will output a signal.

The method of connecting the camera head section and the signal processing section with a single coaxial cable and applying a DC voltage to the coaxial cable at the signal processing section is necessary for operating the camera head section using a signal line. Since power can be supplied and the clock signal is applied to the coaxial cable within the horizontal blanking period, the clock signal can be sent to the camera head section without interference with the video data signal.

Further, since a specific number of pulses to be used as a clock signal are output for each frame period and used as a frame start reference signal, CCs should be synchronized to synchronize all camera heads.
Since the signal processing unit can control the output of the video data signal from D, and the video data signal is output only to the specific camera head unit by the head selection signal, the video from the selected one camera head unit The data signal can be input to the signal processing unit via the coaxial cable.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a camera head portion 10 in a head separation type CCD camera according to the present invention is as shown in FIG.
The external connection terminal 19 has one external connection terminal 19, and the external connection terminal 19 includes a power source separation means 17, and a control signal separation means 25 including a control signal separation circuit 26, a synchronization signal separation circuit 28, and a selection signal detection circuit 27. A switch circuit 21 provided with a switch element 22 such as a switch or analog switch is connected, and a sync signal separation circuit 28 in the control signal separation means 25 is provided to the clock regeneration means 15 and the drive control means 15 and a selection signal detection in the control signal separation means 25 is performed. The circuit 27 is connected to the switch control circuit 23, the clock signal output terminal of the clock regeneration means 15 is connected to the drive control means 15, and each control pulse output terminal of the drive control means 15 is C.
The read signal output terminal of the drive control means 15 is connected to the CD11 and the switch control circuit 23, and the CCD11
The output terminal of is connected to an appropriate switch element 22 such as the analog switch via a buffer, and a switch control circuit
Continuity signal output terminal used as the output terminal of 23 is a switching element 22
It is connected to the control terminal of.

Depending on the output of the CCD 11, the buffer may be omitted and only the switch element 22 may be used as the switch circuit 21. The power supply separating means 17 is composed of, for example, a low-pass filter or a regulator, extracts DC power from a signal applied to the external connection terminal 19, and makes each circuit or each element constituting each means of the camera head unit 10 as a constant voltage. It supplies the DC power supply voltage necessary for the.

The control signal separating means 25 is composed of the buffer 2
9, control signal separation circuit 26, synchronization signal separation circuit 28, and
The control signal separation circuit 26 extracts a pulse signal of a specific frequency or less, and the synchronization signal separation circuit 28 separates a head synchronization signal of a constant frequency to drive control means 13 and clock reproduction. When the number of pulse signals extracted by the control signal separation circuit 26 or the pulse interval is a specific value, the selection signal detection circuit 27 outputs an operation signal to the switch control circuit 23, and the operation signal is 1 The output is made to last only for 1/30 second, which is the time for a frame.

Further, the clock recovery means 15 uses a synchronous oscillator such as a phase locked loop circuit, and uses a synchronous signal separation circuit 28.
It is assumed that a pulse signal synchronized with the pulse frequency of the head synchronizing signal output by the device is formed and output, and the pulse signal output by the clock reproducing device 15 is input to the drive control device 15 as a clock signal. Further, the drive control means 15 outputs a control pulse to the CCD 11 by using an image pickup device drive pulse generator which outputs a control pulse necessary for operating the CCD 11 such as a transfer gate pulse or a read clock pulse according to the type of the CCD 11. When outputting this control pulse from the drive control means 15, of the control pulses such as the transfer gate pulse based on the frame start reference signal in the head synchronization signal input from the synchronization signal separation circuit 28. The video data signal is output at a fixed timing, and the video data signal of each image sensor in the CCD 11 is transferred to the CCD in accordance with this control pulse.
When outputting as an output signal, the image data signal of each image pickup device is output so that a horizontal blanking period or a vertical blanking period is provided. When outputting one frame of image data signal, one line of the image pickup device For example, H according to the timing of outputting the minute video data signal.
The level read signal is output to the switch control circuit 23.

The switch control circuit 23 to which this read signal is input operates when the operation signal from the selection signal detection circuit 27 is input, and the drive control means 15
A conduction signal is output when a read signal from the device is input, and the switch element 22 of the switch circuit 21 is rendered conductive by the conduction signal. Therefore, the switch circuit 21 outputs the operation signal from the selection signal detection circuit 27 in the control signal separation means 25, and the drive control means.
Only when the read signal is output from 15, the switch element 22 is made conductive.

The head synchronizing signal extracted by the synchronizing signal separating circuit 28 in the control signal separating means 25 and the head selecting signal extracted by the selecting signal detecting circuit 27 are pulsed as a clock signal matching the operating speed of the CCD 11,
As shown in FIG. 2, for example, 17 of the clock pulses are output as frame start reference signals A at intervals of the frame cycle, and one horizontal scanning period is set with reference to the frame start reference signals A. For example, 16 clock pulses are repeatedly formed every 63.5 microseconds as a clock reference signal B to form a head synchronization signal, which is within the vertical blanking period A based on the frame start reference signal A. An appropriate number of clock pulses are formed within the first horizontal scanning period of the field, and an appropriate number of clock signals whose output timing is widened so that the interval between these pulses is a predetermined interval is used as the head selection signal C. The selection signal detection circuit 27 determines that the number and interval of pulse signals forming the head selection signal C match the set number and interval. It is assumed that only outputs an operation signal for one second is for example of 30 minutes at 1 frame forming time.

The output time of the operation signal is not limited to the formation time of one frame but may be a time length corresponding to the time of several frames. Therefore, this camera head
10 is, when the selection signal detection circuit 27 outputs the operation signal,
That is, when a specific head selection signal is input to the camera head unit 10, the read signal G and the operation signal, which match the timing at which the CCD 11 outputs the video data signal F, cause the switch control circuit 23 to output a conduction signal. Even when the switch element 22 is turned on and the CCD output signal E is output to the external connection terminal 19, the timing at which the video data signal F is not output, that is, the horizontal blanking period or the vertical blanking period, and the selection signal detection circuit 27. Does not output an operation signal, the analog switch 22 becomes non-conductive, the video data signal F is not output as the CCD output signal E from the camera head section 10, and the camera head section seen from the external connection terminal 19 10 is a high impedance state.

The external connection terminal 19 is connected to the camera head 10
Not only when installed directly on the exterior of the
There is also a case where a coaxial cable of an appropriate length is drawn out from the cable and a connector is provided at the tip of the drawn coaxial cable. The signal processing unit 40 of the head-separated CCD camera which controls the camera head unit 10 and forms a video signal from the CCD output signal E supplies electric power to each circuit of the signal processing unit 40 as shown in FIG. A DC voltage is applied to the coaxial cable 31 from a power supply circuit 41 via a power supply means 42 such as a low-pass filter, and further, a CCD output signal E of the coaxial cable 31 is sent to a video signal processing means 48 via an input buffer circuit 47. This video signal processing means 48
Uses a signal processing integrated circuit as in the conventional case, and performs detection processing such as correlated double sampling by various processing pulses from the synchronization signal generation means 45, performs blanking processing, etc., and adds a synchronization signal to the video signal. The synchronization signal from the synchronization signal generating means 45 is also input to the head selection synchronization control means 51, and the head selection synchronization control means 51
Forms a head synchronizing signal including the frame start reference signal A shown in FIG. 2 in accordance with the vertical synchronizing signal based on the clock signal from the synchronizing signal generating means 45, and also forms a head selecting signal C. The data is output to the coaxial cable 31 via the matching circuit 53.

When the head selection synchronizing control means 51 forms the head selection signal C, the external input means 55 is used.
The number of pulses and the pulse interval can be changed and set. Such a signal processing unit 40 and the camera head unit
When connecting with 10, as shown in FIG. 4, a large number of camera heads 10 are connected to one coaxial cable 31, one end of this coaxial cable 31 is connected to the signal processing unit 40, and the other end is connected. Termination processing is performed by the matching resistor 33, and when the head synchronization signal is output from the signal processing unit 40, all the camera head units 10 are brought into a synchronized state by the head synchronization signal from the signal processing unit 40. All the camera heads 10 turn off the switch elements 22 at the timing when this head synchronization signal is output from the signal processing unit 40, and the external connection terminals 19 of each camera head unit 10 are connected.
Is in a high impedance state, the sync signal can be transmitted to each camera head unit 10 without being attenuated.

The camera head section 10 provided with the selection signal detection circuit 27 having the data with which the specific head selection signal C set by the external input means 55 coincides with the selection signal detection circuit 27 of the camera head section 10. The switch element 22 is turned on in accordance with the timing at which the CCD 11 outputs the video data signal F by the operation signal output from the camera head unit 10, and the camera head unit 10 is at a timing excluding the horizontal blanking period and the vertical blanking period. The video data signal F is output to the coaxial cable 31.

By setting the pulse interval and the number of pulses set in the selection signal detection circuit 27 of each camera head unit 10 connected to this coaxial cable 31 to be different for each camera head unit 10, each camera head unit 10 If the content of the head selection signal C is changed, only one specific camera head unit 10 outputs the video data signal F, and the other camera head unit 10 outputs the video data signal F which is the CCD output signal E. Is not output to the coaxial cable 31, signals do not interfere with each other, and the external connection terminal 19 of the camera head unit 10 that does not output the CCD output signal E is in a high impedance state. Without being affected, the CCD output signal E output from the specific camera head unit 10 is transmitted to the signal processing unit 40 without being attenuated.

As described above, the coaxial cable 31 is used in this embodiment.
Since the video data for one frame or several frames is to be output to a specific camera head unit, a large number of camera head units 10 are connected to one coaxial cable 31 and set by the external input / output unit 55. Video data signals taken by 10 are output, and a single monitor TV can be used to select an arbitrary camera head unit.
It is possible to monitor 10 images, and since one cable wiring is sufficient, the camera head unit 10 can be easily arranged.

Even in the camera head section where the CCD output signal line is connected separately from the synchronization signal line, by providing the selection signal detection circuit 27, the switch control circuit 23, and the switch circuit 21 in the camera head section, A large number of camera heads can be connected to one CCD output signal line, and the camera head and the signal processor can be connected with a small number of signal lines without using a switcher to connect the camera head and the signal processor. Can be connected.

[0026]

The present invention has a switch circuit between the CCD and the external connection terminal of the camera head section, and has a switch control circuit capable of making the switch circuit conductive by a head selection signal. Is a camera head section that conducts a switch circuit at the timing when the CCD outputs a video data signal based on a read signal from the drive control means. Therefore, this camera head section receives a specific head selection signal, and , Only when the CCD outputs the video data signal, the switch circuit is turned on to output the CCD output signal to the external connection terminal.
When the CCD does not output a video data signal and when the output of the CCD output signal from the camera head is not selected by the head selection signal, the external connection terminal is in a high impedance state. Since it does not change the line impedance even if it is connected to a single coaxial cable, it is possible to easily connect multiple camera heads to the same cable without attenuating the high frequency signals to be transmitted. It is a camera head part that can be.

A method of connecting the camera head section and the signal processing section with one coaxial cable, applying a DC voltage to the coaxial cable, and adding a head synchronizing signal and a head selecting signal to this coaxial cable is as follows. A large number of camera heads connected to one coaxial cable are controlled by a head synchronization signal from the signal processing unit, and CC from the camera head unit is controlled.
This is a control method capable of transmitting the D output signal to the signal processing unit without causing interference.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a camera head portion of a head separation type CCD camera according to the present invention.

FIG. 2 is a time chart diagram showing each signal of the head separated CCD camera according to the present invention.

FIG. 3 is a block diagram showing a circuit example of a signal processing unit of a head-separated CCD camera according to the present invention.

FIG. 4 is a diagram showing a connection example of a head-separated CCD camera according to the present invention.

FIG. 5 is a diagram showing an example of a conventional monitoring device using a large number of monitor cameras.

FIG. 6 is a block diagram showing an example of a conventional head separated CCD camera.

FIG. 7 is a diagram showing an example of a monitoring device using a conventional head-separated CCD camera.

[Explanation of symbols]

10 camera head section 11 CCD 12 imaging element drive pulse generator 13 drive control means 15 clock regeneration means 17 power source separation means 19 external connection terminal 21 switch circuit 22 switch element 23 switch control circuit 25 control signal separation means 26 control signal separation circuit 27 Selection signal detection circuit 28 Sync signal separation circuit 31 Coaxial cable 33 Matching resistor 36 Power supply line 37 Clock signal line 38 Sync signal line 39 CCD output signal line 40 Signal processing unit 41 Power supply circuit 42 Power supply means 44 Reference oscillator 45 Sync signal generation Means 47 Input buffer circuit 48 Video signal processing means 51 Head selection synchronization control means 53 Matching circuit 55 External input means 60 Monitor camera 61 Switching control device 65 Monitor TV

Claims (2)

[Claims] 1. A clock regenerating means using a synchronous oscillator,
A camera head part of a head-separated CCD camera having a CCD and a drive control means for outputting a control pulse for driving the CCD, the control pulse being output to the CCD and the video data signal being output from the CCD. It has a drive control means for outputting a read signal matched to the timing and serves as a control signal separating means for separating a head synchronizing signal inputted from an external connection terminal and a head selecting signal, and the head synchronizing signal is used as a clock reproducing means and a drive control. And a control signal separation means including a selection signal detection circuit for outputting an operation signal when the head selection signal is sent to the means at a predetermined number of pulses or a pulse interval, and the CCD output terminal and the camera head section A switch circuit is provided between the external connection terminal and the operation signal from the selection signal detection circuit, and When a read signal is input from the drive control means, a switch control circuit that outputs a conduction signal that makes the switch circuit conductive while both signals are input is provided with a switch control circuit. Camera head part. 2. A plurality of camera head units are connected to one coaxial cable connected to one signal processing unit, and a DC voltage is applied to the coaxial cable by the signal processing unit,
It is assumed that a plurality of pulse clock signals are applied to the coaxial cable within the horizontal blanking period matched to the timing of the horizontal blanking period, and the number of pulses in the clock signal when outputting for each frame period is a specific number of frames. A start reference signal is applied to the coaxial cable as a head selection signal with a predetermined number of pulses at predetermined intervals according to the clock signal within a vertical blanking period based on the frame start reference signal, and the plurality of pulses are output based on the head selection signal. 2. A method of controlling a camera head, characterized in that a video data signal for one frame to several frame sections is output from the specific one of the camera head parts to the coaxial cable.