JPH06121202A - Head-separated CCD camera head - Google Patents

Abstract

(57) [Summary] [Object] In a head-separated CCD camera, the camera head unit 10 and the signal processing unit 60 are connected to the camera head unit 10 capable of using a single coaxial cable 51. [Structure] CCD 11 and image sensor drive pulse generator 1
4, a power source separating means 1 for extracting DC power from the signal line
7, an oscillator 21 for outputting a reference frequency signal, and C
A camera head having a signal mixing means 25 for adding a vertical transfer timing signal and a horizontal transfer timing signal to a CD output signal, and a modulating means 31 for modulating a reference frequency signal output from the oscillator 21 with a CCD output signal obtained by mixing the timing signals. And

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head separation type CCD having a small camera head for use in an endoscope or the like, in which a camera head section and a signal processing section are separated via a cable.
It's about the camera.

[0002]

2. Description of the Related Art Today, two-dimensional solid-state image pickup devices (hereinafter simply referred to as C
In a television camera using a CD (hereinafter referred to as a CD), the camera head is separated from the signal processing unit so that the camera head unit is small in size and arranged in a narrow space, or is used as an endoscope or the like. In such a head-separated CCD camera, as shown in FIG. 7, the camera head unit 10 is composed of only the CCD 11, and the power supply circuit unit 61, the oscillator 63, the synchronization signal generator 64, the imaging element drive pulse generator 67, and the like. The video signal forming circuit 69 using the signal processing integrated circuit is a signal processing unit 60 separate from the camera head unit 10, and the camera head unit 10 and the signal processing unit 60 are connected to the power line 53 and the CCD output signal line 54. In addition, the camera head unit 10 is configured by connecting various pulse signal lines 55, 56, 57 for driving the CCD 11 and the CCD 11 and the image pickup device driving pulse generator 13 as shown in FIG. The processing unit 60 includes a power supply circuit unit 61, an oscillator 63, a synchronizing signal generator 64, and a video signal forming circuit 69. The power supply line 53 from the power supply circuit unit 61 and the reference clock from the oscillator 63. Signal line 58, the synchronization signal line 59 from the sync generator 61, and, CCD
The CCD output signal line 54 from the camera head unit 1
0 and the signal processing unit 60 are connected.

[0003]

As described above, it is easy to make the camera head small in size in the camera head composed of only the CCD or the CCD and the image sensor driving pulse generator. A large number of signal lines are required to connect the camera head section and the signal processing section, and the reference clock signal line, CCD output signal, and various pulse signals for driving the CCD are high-frequency signals. It is necessary to use a coaxial cable, and such a composite cable connecting the camera head section and the signal processing section has a drawback that the structure is complicated and the cost is high.

In order to eliminate this drawback, the present invention is a head-separated type CCD camera which can be assembled into a small camera head as a camera head which can connect the camera head section and the signal processing section with a single coaxial cable. The head is provided.

[0005]

According to the present invention, in addition to a CCD and an image pickup device driving pulse generator, a power source separating means and an oscillator are provided.
And a camera head section provided with signal mixing means for superimposing a horizontal transfer timing signal and a vertical transfer timing signal from the pulse generator on the output signal of the CCD, and a modulating means for modulating the carrier signal by the output of the signal mixing means. The camera head section and the signal processing section are connected by a single coaxial cable.

Further, in addition to providing a CCD, an image sensor driving pulse generator and a power source separating means, a resonator resonating with a reference frequency signal which is a specific high frequency in a signal transmitted by a single coaxial cable is separated from a synchronizing signal. A synchronization separating means is provided, and the driving pulse generator is driven by the output signal of the resonator and the synchronization signal from the synchronization separating means, and the modulating means for modulating the carrier signal having a frequency different from the reference frequency signal by the CCD output signal is provided. It may be provided.

[0007]

[Operation] Since the present invention is a camera head section having a CCD, an image pickup element drive pulse generator, a power supply separating means for supplying electric power, and an oscillator, the CCD can be correctly operated only by the camera head section. Since the signal mixing means superimposes the horizontal transfer timing signal and the vertical transfer timing signal on the output signal of the CCD, and the carrier signal is modulated by the output of this signal mixing means, the CCD output and the horizontal signal are output horizontally with a single carrier frequency. The transfer timing and the vertical transfer timing can be transmitted to the signal processing unit.

In the case where a resonator is provided in the camera head section instead of the oscillator, the signal processing section resonates with a reference frequency signal output to a single cable and can be used as a clock of the image pickup element drive pulse generator. , The CCD by the sync signal output from the signal processing unit to the single cable by the sync separation means
The output timing of the CCD can be controlled by the signal processing unit in accordance with the operation timing of C.
The CD output can be superimposed on a single cable with a carrier frequency different from the reference frequency signal.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a camera head portion of a head-separated CCD camera according to the present invention includes a CCD 11 as a two-dimensional solid-state image pickup device, and an image pickup device drive for outputting various clock pulses for driving the CCD 11. Pulse generator 14
An oscillator 21 for outputting a reference frequency signal to the image sensor drive pulse generator 14, and a signal for superposing the vertical transfer timing signal and the horizontal transfer timing signal output by the image sensor drive pulse generator 14 on the output signal of the CCD 11. It has a mixing means 25, a modulating means 31 for modulating the reference frequency signal output from the oscillator 21 by the output of the signal mixing means 25, and a power supply separating means 17.

The power source separating means 17 comprises a low-pass filter 18 and a regulator 19, and the signal processing unit 6
The DC power output from 0 to the single coaxial cable 51 is supplied to each means and circuit of the camera head unit 10 as a constant voltage. Further, the image sensor drive pulse generator 14 is
A transfer gate pulse and a transfer clock pulse necessary for driving the CCD 11 according to the format of the CCD 11, and
In addition to outputting a read clock pulse to the CCD 11, C
CCD1 according to the clock pulse output to CD11
The horizontal transfer timing signal indicating the output timing of the first pixel of one line in 1 and the vertical transfer timing signal indicating the output timing of the first pixel of the CCD 11 together with the horizontal transfer timing signal are sent to the signal mixing means 25. It is what is output.

Then, the signal mixing means 25 simply superimposes the vertical transfer timing signal and the horizontal transfer timing signal output from the image pickup device drive pulse generator 14 on the output signal of the CCD 11 by using a bias resistor or the like, or Adder 2
A vertical transfer timing signal and a horizontal transfer timing signal are added to the CCD output signal by 6 to output a signal obtained by mixing the horizontal transfer timing signal or the vertical transfer timing signal and the CCD output signal which is the video data, as shown in FIG. At this time, the voltage of the vertical transfer timing signal is made higher than the maximum value of the CCD output signal, and further, the voltage of the horizontal transfer timing signal is made higher than the voltage of the vertical transfer timing signal so that both timing signals are transferred to the CCD. It is supposed to be superimposed on the output signal.

Further, the modulating means 31 amplifies the mixed signal output from the signal mixing means 25 by the reference frequency signal having a high frequency of, for example, 10 megahertz output from the oscillator 21, and thereby the amplitude modulator into the reference frequency signal. After being modulated by 33, noise is removed by a bandpass filter corresponding to the frequency of the reference frequency signal serving as a carrier signal, and then the signal is sent to the signal processing unit 60 via the buffer 37, the impedance matching resistor 38 and the coupling capacitor 39. The signal is output to the single coaxial cable 51, and the output signal of the modulating means 31 is a signal obtained by amplitude-modulating a reference frequency signal, which is a carrier signal, with a mixed signal.

Therefore, the single coaxial cable 51 is supplied with the power source power of the DC component, the CCD output signal which becomes the image data, and the high frequency carrier signal including the signal components of the vertical transfer timing signal and the horizontal transfer timing signal. All the data necessary for forming power and video signals can be transmitted between the camera head section 10 and the signal processing section 60 by one coaxial cable 51, and the signal mixing means 25, the modulation means 31, etc. Since it can be configured with a small number of transistors, resistors, capacitors, etc., it is easy to keep the size of the camera head 10 small.

The CC included in the carrier signal of a specific frequency
The signal processing unit 60, which reproduces the D output signal and the horizontal transfer timing signal and the vertical transfer timing signal to form a video signal, is a power supply for supplying electric power to each means and circuit of the signal processing unit 60 as shown in FIG. From the circuit portion 61 to the power mixing means 87
DC power is supplied to the single coaxial cable 51 via the bandpass filter 7 according to the frequency of the reference frequency signal of the oscillator 21 provided in the camera head section 10.
2 and a resonator 73 are provided to provide a clock separating means 23 for shaping the carrier signal from the camera head unit 10 to reproduce a clock pulse for driving the CCD 11, a coupling capacitor 76, a bandpass filter 77, and a detector. 7
From the carrier signal using the signal separation means 75
The mixed signal of the output signal and the vertical transfer timing signal and the horizontal transfer timing signal is demodulated, and in the sync separation means 81, only the horizontal transfer timing signal having the highest voltage is extracted by the first comparator 82, and the horizontal transfer timing signal and the vertical transfer timing signal are also extracted. After the timing signal is extracted by the second comparator 83, the vertical transfer timing signal is reproduced by the low pass filter 84.

Then, the reproduced vertical transfer timing signal and horizontal reproduction timing signal are applied to the synchronizing signal generating means 6.
At 5 the timing is adjusted according to the clock signal reproduced by the clock separating means 23, and the adjusted horizontal transfer timing signal and vertical transfer timing signal are sent from the synchronizing signal generating means 65 to the video data reproducing means 85,
Further, the horizontal synchronizing signal based on the horizontal transfer timing signal and the vertical synchronizing signal based on the vertical transfer timing signal are sent to the video signal forming circuit 69, and the video data reproducing means 85
The horizontal transfer timing signal and the vertical transfer timing signal output from the synchronizing signal generating means 65 cancel the horizontal transfer timing signal and the vertical transfer timing signal from the mixed signal output from the signal separating means 75, and only the CCD output signal to be the video data is obtained. To play.

CCD from this video data reproducing means 85
Forming a video signal by the video signal forming circuit 69 by the horizontal sync signal and the vertical sync signal from the output signal and the sync signal generating means 65 is the same as in the prior art. In the above-described embodiment, the camera head unit 10 having the oscillator 21 is provided. However, the signal processing unit 60 is provided with an oscillator or a synchronizing signal generator for forming the reference frequency signal to the image pickup device driving pulse generator. Even with a head-separated camera that controls a plurality of camera heads 10 in synchronization, each camera head 10 and the signal processor 60 can be connected to each other by a single coaxial cable.

In the second embodiment, for example, as shown in FIG. 4, an oscillator 63 that outputs a reference frequency signal having a high frequency of 20 MHz, and a horizontal frequency based on the reference frequency signal output by the oscillator 63. The camera head unit 10 is connected to a signal processing unit 60 that outputs a synchronization signal to a single coaxial cable and that has a synchronization signal generation unit 66 that forms a synchronization signal and a vertical synchronization signal. When outputting the vertical synchronization signal and the horizontal synchronization signal to the camera head unit 10, the amplitude modulation is performed by the amplitude modulator 94 by the synchronization signal synthesized by the adder 93 with the reference frequency signal from the oscillator 63, and the bandpass filter 95 is used. The noise is removed, and the single coaxial cable 5 is connected via the buffer 96, the impedance matching resistor 97, and the coupling capacitor 98. It is intended to output a synchronization signal to.

The adder 93 is a synchronizing signal generating means 66.
The levels of the vertical synchronizing signal and the horizontal synchronizing signal output from are synthesized so as to provide a difference as shown in FIG.
The switcher 89 switches the camera head unit 10 that sends the DC power and the synchronizing signal from the power supply circuit unit 61. In this way, the separate type camera head unit 1 in the camera system in which the synchronization signal or the like is output from the signal processing unit 60
As shown in FIG. 6, 0 is the power source separating means 17, CCD 1
1, modulator 31, and image sensor drive pulse generator 1
5 in the same manner as in the first embodiment, and a sync signal separating means 7
5 and a resonator 24 as the clock separating means 23. The resonator 24 resonates with the reference frequency signal output from the oscillator 63 provided in the signal processing unit 60.

Then, the sync separation means 41 has a band pass filter 43 corresponding to the frequency of the reference frequency signal, and
The detector 45 reproduces the synchronization signal to reproduce the first comparator 47.
The horizontal sync signal having a high level is extracted by, the noise is removed by the second comparator 48 to extract the horizontal sync signal and the vertical sync signal, and then the low pass filter 49 is used.
By using the reference frequency signal shaped by the resonator 24 and the horizontal synchronizing signal and the vertical synchronizing signal from the sync separating means 41, the drive pulse generator 15 transfers the CCD 11 to the transfer gate. It outputs a pulse or a clock pulse.

The image pickup element drive pulse generator 15 divides the reference frequency signal so that it can output a carrier signal of, for example, 10 MHz whose frequency is different from that of the reference frequency signal. Send to modulator 31 C
With the CD output signal, the amplitude modulator 3 is used as in the first embodiment.
In 3, the carrier signal is modulated. Therefore, the camera head unit 10 operates based on the clock signal and the synchronization signal output from the signal processing unit 60, and the CCD is generated by the carrier signal having a frequency different from the reference frequency which is the clock signal.
Since the output signal is output, the CCD output signal can be transmitted to the signal processing unit 60 without being mixed with other signals by the single coaxial cable 51 or being changed by noise.

Needless to say, the band pass filter 77 as the signal separating means 75 in the signal processing unit 60 has a band corresponding to the carrier frequency.
Reference numeral 8 reproduces the CCD output signal, and the video signal forming circuit 69 is the same as the conventional one.

[0022]

The camera head portion according to the present invention is a CCD
In addition to the image sensor drive pulse generator and the oscillator and the modulation means, it operates by being supplied with DC power from the signal processing unit, and a high-frequency reference frequency signal output from the oscillator is used as a carrier wave to generate a CCD output signal or Since the data of the horizontal transfer timing signal and the vertical transfer timing signal is output to the signal processing unit, it is a camera head unit that can be connected to the signal processing unit with a single coaxial cable, and has the advantage of not requiring an expensive connection cable. I have.

Further, in the head-separated type camera head in which the signal processing unit outputs a synchronizing signal or the like, the image pickup device extracts the reference frequency signal and the synchronizing signal used for the carrier wave of the synchronizing signal by the synchronizing separating circuit and the clock separating circuit. The drive pulse generator and thus the CCD can be operated,
Since the output signal of D is output to the signal processing unit by using a carrier having a frequency different from that of the reference frequency signal, the CCD is operated based on the synchronization signal from the signal processing unit, and the carrier having different frequencies is used. The CCD output signal can be accurately sent to the signal processing unit with one coaxial cable.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit example of a camera head unit according to the present invention.

FIG. 2 is a diagram showing an output signal waveform of a signal mixing unit used in the camera head unit according to the present invention.

FIG. 3 is a block diagram showing a circuit example of a signal processing unit for performing signal reproduction of the camera head unit according to the present invention.

FIG. 4 is a block diagram showing a circuit example of a signal processing unit that outputs a synchronization signal.

FIG. 5 is a diagram showing a waveform example of a synchronization signal output from a signal processing unit.

FIG. 6 is a block diagram showing an example of a circuit of a camera head unit that operates by a synchronization signal from a signal processing unit.

FIG. 7 is a block diagram showing a circuit example of a conventional head-separated CCD camera.

FIG. 8 is a block diagram showing another circuit example of a conventional head separated CCD camera.

[Explanation of symbols]

10 camera head section 11 CCD 13, 14, 15 image sensor driving pulse generator 17 power source separating means 21 oscillator 23 clock separating means 25 signal mixing means 31 modulating means 41 sync separating means 51 single coaxial cable 53 power supply line 54 CCD output signal Line 55 Horizontal drive pulse signal line 56 Vertical drive pulse signal line 58 Clock signal line 59 Sync signal line 60 Signal processing unit 61 Power supply unit 63 Oscillator 65 Sync signal generator 67 Image sensor drive pulse generator 69 Video signal forming circuit 71 Clock separation Means 75 Signal Separating Means 81 Synchronous Separating Means 85 Video Data Reproducing Means

Claims (2)

[Claims] 1. A camera head for a CCD camera in which a signal processing unit and a camera head unit are connected by a single cable, and a two-dimensional solid-state image pickup device, a power source separating unit, and an oscillator for outputting a reference frequency signal, Image sensor drive pulse generator that outputs a transfer pulse or a read pulse based on a reference frequency signal output by the oscillator, a horizontal transfer timing signal and a vertical transfer timing signal output by the drive pulse generator, and the two-dimensional solid-state imaging A head-separated CCD camera head, comprising: signal mixing means for superimposing an output signal of an element, and modulation means for modulating a carrier signal by the mixed signal output by the signal mixing means. 2. A camera head for a CCD camera, in which a signal processing unit and a camera head unit are connected by a single cable, and which resonates with a power source separating means and a carrier signal of a synchronizing signal in addition to a two-dimensional solid-state image pickup device. A clock separating means for separating a reference frequency signal, a sync separating means for separating a horizontal synchronizing signal and a vertical synchronizing signal, and an image pickup element drive pulse generation for outputting a transfer pulse or a read pulse based on the reference frequency signal and the synchronizing signal. A head-separated CCD camera head, characterized in that the head-separated CCD camera head is provided with a modulator and a modulator that modulates a carrier signal having a frequency different from a reference frequency signal by an output signal of the two-dimensional solid-state image sensor.