JP2002185828A - Head separation type camera, camera head and control method for the head separation type camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head separation type camera, a camera head and a control method for the head separation type camera, that can store various adjustment values specific to a CCD in the head into the head, without the need for increasing the number of cable core wires, transmit information from the head to a CCU(camera control unit) and can freely replace the head and the CCU. SOLUTION: A head 10a superimposes adjustment values (the gain and VSUB (substrate voltage) or the like), specific to a CCD 11 on a CCD drive signal line for horizontal and vertical drive pulses, and sample hold pulses for a CDS(correlated double sampling) circuit as a DC voltage. Detection circuits 60, 62 at the side of the CCU 40A detect it and the detected voltage is used for a control voltage for each circuit. Thus, the head 10A stores the adjustment values specific to the CCD 11, the signal line other than the existing image pickup signal lines is used to transmit the adjustment values to the CCU 40A. As a result, pairing-free between the head 10A and the CCU 40A can be attained, and increasing the number of cable core wires can be dispensed with.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head-separated camera, a camera head, and a control method for a head-separated camera, which allow a camera head and a camera control unit to be freely replaced (pairing free).

[0002]

2. Description of the Related Art Conventionally, CCD (Charge Cuppled Device)
A head-separated camera is a typical example of a small camera using a solid-state imaging device such as a charge-coupled device.

A head-separated camera generally includes a camera head (hereinafter simply referred to as a head) that outputs an image signal obtained from an image sensor, and a display head based on the image signal from the camera head. A camera control unit (hereinafter, CC) having a signal processing circuit for obtaining a video signal
U), and the head and the CCU are connected by a dedicated camera cable.
By further guiding the video signal from the CCU to a CRT display device for display, the subject can be observed. In the head-separated camera, since most of the signal processing circuits are configured in the CCU, the configuration on the camera head side can be reduced in size.

FIG. 4 is a block diagram showing the configuration of a conventional head-separated camera. In FIG. 4, the head separated type camera includes a head 10, a CCU 40, a head 10 and a CCU.
40 and a camera cable 70 composed of a plurality of signal lines.

The head 10 includes a CCD 11 as an image pickup device for receiving an object image and converting it into an electric signal, and a CCU 40.
Buffer amplifiers 12 and 13 for inputting horizontal CCD driving pulses H1 and H2 supplied from the CCD and supplying the same to the CCD 11, inputting output signals in pixel units from the CCD 11, sample-hold and outputting as imaging signals (Correlated double sampling) circuit 16 and CC
Sample hold pulse SH supplied from U11
Buffer amplifiers 14 and 15 for inputting P and SHD, respectively, and supplying them to the CDS circuit 16;
And a buffer amplifier 17 for inputting the image pickup signal from the CCU 40 and supplying it to the CCU 40 side.

The CCU 40 includes a timing generator 41 composed of an IC circuit for generating various timing signals including horizontal CCD driving pulses, and a horizontal CCD driving pulse H1 from the timing generator 41.
, H2, respectively, and supplies them to the head 10 side, and sample and hold pulses SHP, SH from the timing generator 41.
Buffer amplifiers 44 and 45 for inputting and supplying D to the head 10 side, and a timing generator 41
A vertical CCD driver 46 for generating a charge sweeping-out pulse (shutter pulse) and a vertical CCD driving pulse φV based on a timing signal from the CPU, and a DC voltage supply terminal 50 as a means for setting (holding) the CCD substrate voltage VSUB. And its voltage adjusting volume 51 and the vertical C
The charge sweeping pulse from the CD driver 46 is supplied to the CC
A DC blocking capacitor 47 for supplying the D substrate voltage VSUB to an application point g; and a charge sweeping pulse passing through the capacitor 47 on the adjustable CCD substrate voltage VSUB at the point g. A diode 48, a resistor 49, a DC voltage supply terminal 53 as a means for setting (holding) a gain control voltage, and a voltage adjusting volume 54 thereof, and the gain can be controlled by the adjustable gain control voltage, and the head can be controlled. And a gain control amplifier circuit 52 for amplifying the image pickup signal from the digital camera 10.

The camera cable 70 includes signal lines L1 and L2 for horizontal CCD drive pulses H1 and H2, signal lines L3 and L4 for CDS circuit sample and hold pulses SHP and SHD, a CCD substrate voltage VSUB, and a vertical CCD.
It has signal lines L5 and L6 for the drive pulse φV and a signal line L7 for the imaging signal from the CDS circuit 16.

In the above arrangement, the horizontal CCD driving pulses (H1, H2) and the vertical CCD driving pulses (φV) output from the driving means (timing generator 41 and vertical CCD driver 46) for generating the CCD driving pulses.
Is connected to the head 10 via cables (L1, L2, L6).
Is applied to the CCD 11 on the side.

The output signal read from the CCD 11 is
After being sampled and held by the CDS circuit 16 using the sample and hold pulses SHP and SHD from the timing generator 41 and sent as an image signal to the CCU 40 via the cable L7, and gain-controlled by the gain control amplifier circuit 52, Further, a signal processing circuit (not shown) at the subsequent stage performs processes such as color demodulation, gamma correction, encoding to NTSC, and addition of horizontal and vertical synchronizing signals to obtain a video signal for display. Prior to performing such video signal processing, adjustment of a substrate voltage (VSUB) specific to the CCD 11 and gain adjustment for absorbing sensitivity variations are performed.
Various adjustments due to the CD 11 need to be performed.

In the prior art as shown in FIG.
The adjustment values (gain control voltage, CCD substrate voltage) specific to the CCD 11 used in the camera are set on the CCU 40 which is a control device separate from the head 10.

That is, the head 10 caused by the CCD 11
Means for setting an adjustment value specific to the side (ie, the CCD 11 used)
The head 10 and the CCU 40 must always be paired and used because the adjustment value setting means (which is to be adjusted every time) is on the CCU 40 side. As a result, the head 10 and the CCU 40 cannot be freely replaced, and when replacement is required, readjustment on the CCU 40 side is required to match the head 10 to be used.

The above-mentioned head-separable video cameras are disclosed in Japanese Patent Application Laid-Open Nos. 10-93982 and 2000-92352 as conventional examples.

Japanese Patent Laid-Open Publication No. Hei 10-93982 discloses an EEP provided on an optical head as a means for simplifying the adjustment of a photographing camera in which the optical head is detachable.
It is described that parameters for spectral characteristic correction are stored in the ROM as adjustment value data, and the parameters are read out by a control circuit on the camera body side when the power is turned on or the optical head is mounted, and are used for calculating a correction signal. Have been.

However, if the adjustment value data is incorporated in the camera head as disclosed in Japanese Patent Application Laid-Open No. Hei 10-93982, there is a disadvantage that the number of cable cores connecting the head and the camera body increases.

On the other hand, Japanese Patent Application Laid-Open No. 2000-92352 discloses that a video signal includes effective line number information for identifying the number of effective vertical lines of a picked-up video signal, according to the format of a CCD unit of a video camera. Automatically switch the signal processing of the video signal.

However, Japanese Patent Application Laid-Open No. 2000-92352
The publication discloses that the video signal output from the CCD unit includes information on the number of effective lines, and does not transmit various adjustment values necessary for each CCD mounted in the CCD unit together with the video signal. In addition, the signal lines used are limited to video signal lines, and various adjustment values are not transmitted to subsequent circuits using signal lines other than the video signal lines. It was missing.

[0017]

As described above, in the prior art, the CCU sets and holds the adjustment values (gain control voltage, CCD substrate voltage, etc.) specific to the CCD in the head. The CCU had to be paired and used, and could not be freely exchanged. In the case of replacement, re-adjustment on the CCU side is required, so that considering the case where the CCU is mounted in a place where re-adjustment cannot be easily performed such as a surveillance camera system, the work becomes complicated and serviceability is lacking. On the other hand, there is a problem in that when the adjustment value data is incorporated in the head side and read out and used on the CCU side, the number of cable cores increases.

In view of the above problems, the present invention can transmit various adjustment values specific to the CCD in the head to the CCU without increasing the number of cable cores, and can exchange the head and the CCU freely. It is an object of the present invention to provide a separation type camera, a camera head, and a control method for a head separation type camera.

[0019]

A head-separated camera according to the present invention comprises a camera head, a camera control unit, and a camera cable comprising a plurality of signal lines connecting the camera head and the camera control unit. A head-separated camera having at least one of an image sensor for capturing light incident from a subject, adjustment value setting means for holding various adjustment values unique to the image sensor, and the camera cable. A signal line, superimposing means for superimposing the various adjustment values as adjustment value information, wherein the camera control unit supplies a driving signal to the camera head via the camera cable; The image signal transmitted from the camera head via the camera cable is signal-processed. Signal processing means, detection means for extracting adjustment value information superimposed on at least one signal line of the camera cable, and using the adjustment value information from the detection means as a control signal, the driving means to control the camera head And a means for controlling a driving signal supplied to the camera head or an imaging signal supplied from the camera head to the signal processing means.

The adjustment value is a gain control voltage value for controlling a gain of a gain control amplification circuit in the camera control unit, or an image pickup device (CCD or the like) substrate voltage value in the camera head.

The signal line on which the adjustment value information is superimposed is
A signal line other than the image signal line in the camera cable, for example, a horizontal image sensor (CCD or the like) driving pulse input from the camera control unit to the camera head, or a signal line of a sample and hold pal for a correlated double sampling circuit. .

In the head-separated camera of the present invention, the adjustment (gain, VS) specific to the image pickup device (CCD, etc.) is performed on the head side.
UB, etc.) values for horizontal drive pulses and samples for CDS circuits.
Superimposed as a DC voltage on a high-speed pulse such as a hold pulse. This is detected on the CCU side and used as a voltage for controlling each circuit. This allows the head side to have an adjustment (gain, VSUB, etc.) value specific to the imaging device (CCD, etc.), and thus allows free pairing between the head and the CCU. In addition, since transmission is performed while being superimposed on an already used CCD drive signal line or the like, the number of cable cores does not increase.

Further, the camera head according to the present invention is connected to an image pickup device for picking up light incident from a subject, adjustment value setting means for holding various adjustment values unique to the image pickup device, and an external camera control unit. And superimposing means for superimposing the various adjustment values as adjustment value information on at least one signal line among a plurality of signal lines for inputting and outputting signals.

Further, a method of controlling a head-separated camera according to the present invention includes a camera head, a camera control unit, and a camera cable including a plurality of signal lines connecting the camera head and the camera control unit. A method of controlling a head-separated camera, wherein in the camera head, various adjustment values specific to an image sensor that captures light incident from a subject are held by adjustment value setting means, and at least one of the camera cables is controlled. On one signal line, the various adjustment values are superimposed as adjustment value information by superimposing means, and the camera control unit supplies a driving signal to the camera head via the camera cable by a driving means, The imaging signal transmitted from the camera head via the camera cable is signaled. The adjustment value information superimposed on at least one signal line of the camera cable is taken out by a detection unit, and the adjustment value information is used as a control signal. Control is performed on a drive signal supplied to the head or an image pickup signal supplied from the camera head to the signal processing means.

[0025]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a head-separated camera according to an embodiment of the present invention.

In FIG. 1, the head-separated type camera has a head 1
0A, CCU40A, head 10A and CCU40A
And a camera cable 70 composed of a plurality of signal lines connecting the two.

The head 10A includes a CCD 11 which is an image pickup device for receiving an object image and converting the image into an electric signal.
(Correlation double sampling) circuit 16 for inputting an output signal in pixel units from, sampling and holding, and outputting as an imaging signal, and buffer amplifiers 12, 13, 1
4, 15, 17 and horizontal CCD driving pulses H1, H2
DC blocking capacitors 23 and 24 which constitute a part of a superimposing means for superimposing each adjustment value on the signal line, a DC voltage supply terminal 19 and a DC voltage adjusting volume 2
0, an adjustment value setting means for the CCD substrate voltage VSUB comprising a DC voltage supply terminal 21 and an adjustment value setting means for the gain control voltage comprising a DC voltage adjustment volume 22; A DC voltage supply terminal 25 for superimposing (reproducing) an appropriate DC voltage necessary for the CCD 11 on the signal H1 line between the DC voltage supply terminal 25 and the resistive voltage dividing circuits (26, 27); It has a DC voltage supply terminal 28 for superimposing (reproducing) an appropriate DC voltage necessary for the CCD 11 on the signal H2 line in between and a resistive voltage dividing circuit (29, 30).

The CCU 40A includes an IC for generating various timing signals including a horizontal CCD driving pulse.
A timing generator 41 composed of a circuit, a charge sweeping pulse (shutter pulse) and a vertical CC based on a timing signal from the timing generator 41;
A vertical CCD driver 46 for generating a D drive pulse φV, a gain control amplifier circuit 52 for amplifying an image pickup signal from the CDS circuit 16, and buffer amplifiers 42 and 4.
3, 44, 45, resistors 56, 57, and a DC blocking capacitor 5 which constitutes a part of superimposing means for superimposing each adjustment value on the signal lines of the horizontal CCD driving pulses H1, H2.
8, 59, and at least one of the camera cables 70.
The adjustment value information superimposed on one of the signal lines, for example, the signal lines L1 and L2, is applied to the horizontal CCD driving pulses H1 and H2.
2 and DC amplifying circuits 61 and 62, which are detection means for detecting and extracting DC voltages.
And vertical C with respect to the detected CCD substrate voltage VSUB.
A circuit of a diode 48, a resistor 49 and a DC blocking capacitor 47 for superimposing a charge sweeping pulse from the CD driver 46 and an image signal from the CDS circuit 16 are amplified and then subjected to color demodulation, gamma correction, NTSC and the like. Performs processing such as encoding and adding horizontal and vertical synchronization signals,
And a signal processing circuit (not shown) which is a signal processing means for generating a video signal for display.

The camera cable 70 is the same as that shown in FIG. 4, and the number of signal lines does not increase or decrease. The signal lines L1 and L2 of the horizontal CCD drive pulses H1 and H2 and the sample and hold pulses SHP and SHD for the CDS circuit are used. Each signal line L3, L4, CCD substrate voltage VSUB, vertical CCD
It is configured to include signal lines L5 and L6 for the drive pulse φV and a signal line L7 for an image pickup signal from the CDS circuit 16.

Next, the operation of the head-separated camera configured as described above will be described. One end of the signal line L1 of the camera cable 70 receives a horizontal CCD drive pulse H1 from the first horizontal CCD drive pulse output terminal of the timing generator 41 in the CCU 40A in series with the buffer amplifier 42, the resistor 56 and the DC blocking capacitor 58. The horizontal CCD drive pulse H1 is supplied from the other end of the signal line L1 in the head 10A through the DC blocking capacitor 23 and the buffer amplifier 12 in series, and at the connection point c between the DC blocking capacitor 23 and the buffer amplifier 12 at the connection point c. Are reproduced (superimposed) and input to the first horizontal CCD drive pulse input terminal of the CCD 11.

FIG. 2A shows a horizontal CCD drive pulse H1 in which a DC voltage component is reproduced (superimposed) at a connection point c. When the amplitude of the horizontal CCD drive pulse H1 is 5V, 5V is applied to the DC voltage supply terminal 25, and 2.5V divided into two by resistors 26 and 27 is applied to the horizontal CCD drive pulse H1 at the connection point c. Have been added.

Similarly, in the CCU 40A, a horizontal CCD driving pulse H2 is applied to one end of a signal line L2 from a second horizontal CCD driving pulse output terminal of the timing generator 41 in series with a buffer amplifier 43, a resistor 57, and a DC blocking capacitor 59. The horizontal CCD driving pulse H is supplied from the other end of the signal line L2 in the head 10A.
The DC voltage component applied to the CCD 11 is reproduced (superimposed) at a connection point d between the DC blocking capacitor 24 and the buffer amplifier 13 through the DC blocking capacitor 24 and the buffer amplifier 13 in series. It is input to the CCD drive pulse input terminal. Connection point d
Horizontal CCD in which DC voltage component is reproduced (superimposed)
The driving pulse H2 also has a signal waveform similar to that shown in FIG.

The DC CCD substrate voltage VSUB from the adjustment value setting means (19, 20) is superimposed on the horizontal CCD drive pulse H1 which is a high frequency pulse at the connection point a on the signal line L1 in the head 10A. . Horizontal CCD
CCD substrate voltage VSUB superimposed on drive pulse H1
Is output to the DC detection circuit 60 at a connection point e on the signal line L1 in the CCU 40A, only the DC CCD substrate voltage VSUB is taken out, and the CCU is subjected to DC amplification.
It is supplied to a connection point g on a signal line L5 in 40A.

FIG. 2 (b) shows the DC C at connection point a.
Horizontal CCD with CD substrate voltage (VSUB) information superimposed
The driving pulse H1 is shown. Horizontal CCD drive pulse H
1 is 5 V, and 5 V is applied to the DC voltage supply terminal 19.
Is applied to the horizontal CCD driving pulse H1 at the connection point a as an adjustment value at 3V obtained by dividing the voltage at the voltage dividing point of the variable resistor 20. FIG. 2C shows a 3V adjustment value derived from the detection circuit 60.

The DC gain control voltage from the adjustment value setting means (21, 22) is applied to the horizontal point C, which is a high-frequency pulse, at the connection point b on the signal line L2 in the head 10A.
It is superimposed on the CD drive pulse H2. The gain control voltage superimposed on the horizontal CCD drive pulse H2 is led out to the DC detection circuit 62 at the connection point f on the signal line L2 in the CCU 40A, and only the DC gain control voltage is taken out, and the gain control voltage in the CCU 40A is obtained. It is supplied to the gain control terminal of the amplifier circuit 52. The horizontal CCD drive pulse H2 on which the DC gain control voltage is superimposed at the connection point b also has a signal waveform similar to that shown in FIG.
Derives a DC value similar to that shown in FIG.

The DC detection circuit 60 comprises a low-pass filter including a resistor R1 and a capacitor C1, as shown in FIG. DC terminal C
A high-frequency horizontal CCD drive pulse H1 on which the CD substrate voltage VSUB is superimposed is input, and the high-frequency component of the horizontal CCD drive pulse H1 is removed by a low-pass filter including a resistor R1 and a capacitor C1.
B) Information is output from the output terminal 602.

Similarly, the DC detection circuit 62 comprises a low-pass filter including a resistor R1 and a capacitor C1, as shown in FIG. A high-frequency horizontal CCD drive pulse H2 on which a DC gain control voltage is superimposed is input to an input terminal 601, and a high-frequency horizontal CCD drive pulse H2 is applied by a low-pass filter including a resistor R1 and a capacitor C1.
And the gain control voltage for the direct current is output from the output terminal 602.

In this embodiment, the CCD is controlled by adjusting the gain control voltage adjusting volume 22 on the head 10A side.
Horizontal gain control voltage that can absorb sensitivity variation
The voltage for VSUB adjustment unique to the CCD 11 is superimposed on the D drive pulse H2, and the voltage for VSUB adjustment unique to the CCD 11 is similarly adjusted by adjusting the substrate voltage (VSUB) adjustment volume 20 on the head 10A side.
The control voltage is superimposed on the driving pulse H1 and each superimposed adjustment voltage is applied to CC
The signals are detected by the detection circuits 60 and 62 on the U40A side, and are used as control voltages via the DC amplification circuit 61 as necessary.

In this manner, the adjustment value setting means on the head 10A side holds the adjustment value unique to the CCD 11, and superimposes the adjustment value information on the existing CCD drive signal line as the adjustment value information.
By transmitting the adjustment value information to the U40A side and extracting and using the adjustment value information on the CCU 40A side, it is possible to realize the pairing free of the head 10A and the CCU 40A without increasing the number of cable cores. In particular, when the CCU is installed in a place where readjustment cannot be easily performed, such as a surveillance camera, readjustment on the CCU side is not required, and maintenance and serviceability can be significantly improved. It becomes possible.

In the embodiment described above, the horizontal CC
Although the adjustment value information is superimposed on the signal lines L1 and L2 of the D drive pulses H1 and H2, the present invention is not limited to this, and the CDS circuit sample and hold pulse SH is not limited to this.
The adjustment value information may be superimposed on the P and SHD signal lines L3 and L4.

[0041]

As described above, according to the present invention, various adjustment values unique to the image pickup element in the head can be held in the head without increasing the number of cable cores, and can be transmitted from the head to the CCU. And CCU pairing free. In particular, readjustment on the CCU side can be made unnecessary only by replacing the head, and workability during maintenance can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a head-separated camera according to an embodiment of the present invention.

FIG. 2 is a waveform chart showing signal waveforms of various parts of the camera in FIG.

FIG. 3 is a circuit diagram showing a configuration example of a DC detection circuit in FIG. 1;

FIG. 4 is a block diagram showing a conventional head-separated camera.

[Explanation of symbols]

10A: Head (camera head) 11: CCD (imaging element) 19, 21: DC voltage supply terminal 20, 22 ... Voltage adjustment volume (variable resistor) 19 and 20: CCD substrate voltage adjustment value setting means 21 and 22 ... Gain control voltage adjustment value setting means 23, 24, 47, 58, 59 DC blocking capacitors 23 and 58 ... CCD board voltage adjustment value superimposing means 24 and 59 ... Gain control voltage adjustment value superimposing means 40A ... CCU (Camera control unit) 41 ... Timing generator 46 ... Vertical CCD driver 41 and 46 ... Drive means 47,48 and 49 ... Means for controlling drive signals 52 ... Gain control amplifier circuit (Control for image pickup signals) Means for performing) 60, 62: DC detection circuit (detection means) 70: camera cable

Claims (7)

[Claims] 1. A head-separated camera comprising: a camera head; a camera control unit; and a camera cable including a plurality of signal lines connecting the camera head and the camera control unit. An image sensor that captures light incident from a subject; an adjustment value setting unit that holds various adjustment values unique to the image sensor; and at least one signal line of the camera cable, the various adjustment values are stored in the adjustment value information. The camera control unit is provided with a driving unit that supplies a driving signal to the camera head via the camera cable, and is transmitted from the camera head via the camera cable. Signal processing means for performing signal processing on the image pickup signal; and at least the camera cable One of a detection means for retrieving the adjustment value information superimposed on the signal line, by using the adjustment value information from 該検 decoupling means as the control signal,
A head-separated camera comprising: means for controlling a driving signal supplied from the driving means to the camera head or an imaging signal supplied from the camera head to the signal processing means. 2. An image pickup device for picking up light incident from a subject, adjustment value setting means for holding various adjustment values unique to the image pickup device, and a plurality of input / output signals connected to an external camera control unit. A camera head, comprising: superimposing means for superimposing the various adjustment values as adjustment value information on at least one signal line among the signal lines. 3. The camera head according to claim 2, wherein said adjustment value is a gain control voltage value for controlling a gain of a gain control amplifier circuit in said camera control unit. 4. The camera head according to claim 2, wherein the adjustment value is a voltage value of an imaging device substrate in the camera head. 5. The signal line on which adjustment value information is superimposed,
The camera head according to any one of claims 2 to 4, wherein the camera cable is a signal line other than an imaging signal line in the camera cable. 6. The signal line on which adjustment value information is superimposed,
6. The signal line of a horizontal imaging element driving pulse input to the camera head from the camera control unit and a signal line of a sample / hold pulse for a correlated double sampling circuit. Camera head. 7. A method for controlling a head-separated camera, comprising: a camera head; a camera control unit; and a camera cable including a plurality of signal lines connecting the camera head and the camera control unit. In the camera head, various adjustment values specific to the image sensor that captures light incident from a subject are held by adjustment value setting means, and the various adjustment values are superimposed on at least one signal line of the camera cable by the superposition means. The adjustment value is superimposed as adjustment value information, and in the camera control unit, a driving signal is supplied to the camera head via the camera cable by a driving unit, and is transmitted from the camera head via the camera cable. The image signal is processed by a signal processing unit to reduce the number of camera cables. Taking out the adjustment value information is also superimposed on one signal line by detecting means, by using the adjustment value information as a control signal,
A control method for a head-separated camera, comprising controlling a driving signal supplied from the driving unit to the camera head or an imaging signal supplied from the camera head to the signal processing unit.