JP2003209733A - Imaging system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging system capable of displaying a color bar or the like on a monitor even when no camera head is connected to a CCU so as to control the CCU and eliminating the need for phase management of frequency division clock between a patient and a secondary circuit. <P>SOLUTION: When the camera head 3 is connected to the CCU 6, a connection detection circuit 162 detects whether or not an ACK (first clock) is received, the circuit 162 controls a changeover circuit 161 when connected to output (ACK) of a first frequency divider circuit 132 as a CK (clock signal). When no camera head 3 is connected to the CCU 6, the connection detection circuit 162 detects that no ACK is received and controls the changeover circuit 161 to output an output (BCK) of a second frequency divider circuit 139 in a floating circuit 135 as the CK. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to an image pickup system, and more particularly to an image pickup system characterized by a control section of a CCD drive signal and an image pickup signal. 2. Description of the Related Art In recent years, an insertion section is inserted into an observation site such as a body cavity, and illumination light is transmitted by illumination light transmission means such as a light guide fiber bundle and the like, and the observation site is irradiated from the distal end of the insertion section. 2. Description of the Related Art Endoscope devices that obtain an image of an observation site and perform observation and treatment of the observation site are widely used. In one of the endoscope apparatuses, a solid-state image sensor, for example, a CCD is provided at the tip of an insertion portion, and an image of an observation site is formed on an image pickup surface by an objective optical system and converted into an electric signal. There is an electronic endoscope apparatus that can display an image of an observation region on a monitor or the like by processing the electric signal and can store the image as image data in an information recording device or the like. In the field of surgery, for example, a rigid insertion part of a rigid endoscope is inserted into an observation site such as a body cavity, and illumination light is transmitted by illumination light transmission means to irradiate the observation site from the distal end of the insertion unit. The image of the observation site is transmitted from the tip of the unit to the eyepiece by image transmission means such as a relay lens, and the image of the observation site is captured and monitored by the CCD of an external TV camera detachably attached to this eyepiece. For example, there is a surgical rigid endoscope apparatus which performs an operation by displaying an image of an observation site. [0005] For example, Japanese Patent Application No. 200
In the publication No. 0-309674, even if a camera head (or an electronic endoscope) using a plurality of types of CCDs is used, each CCD can be driven at a specified frequency, and one type of signal processing clock of a signal processing circuit is used. Has proposed an imaging system that can perform processing with a clock of (i). [0006] The above-mentioned Japanese Patent Application No. 2000-3.
No. 09674, a CXO (oscillator) is provided in a secondary circuit, its clock is sent to a patient circuit, a clock frequency dividing circuit is provided in a camera head, and the frequency-divided clock is returned to the patient circuit. Processing is performed as the main clock of the circuit. In the secondary circuit, the output of CXO is set to SS
G, and performs various processes such as frequency division of the clock in the SSC to generate various synchronization signals. As a problem of this configuration, since the CXO frequency dividing circuit is different between the patient circuit and the secondary circuit, unless a proper reset signal is prepared, the phase of the divided clock signal between the patient and the secondary becomes 180 degrees. It could have shifted. This allows
Since the timing of the drive signal of the CCD and the clock of the color separation processing in the secondary circuit are shifted, an appropriate color may not be reproduced depending on the power-on timing or the like. In order to solve this problem, the frequency-divided clock generated in the camera head is used not only for the patient circuit but also for the patient circuit.
It is also conceivable to return to the next circuit for processing, but in this case, if the camera head is not connected, the main clock of the entire CCU will not be supplied, so that processing of the CCU cannot be performed at all, or processing is restricted. There was a case. As a result, when a camera head is not connected, it is preferable to display a color bar or a blue screen on a monitor, but this may not be possible. The present invention has been made in view of the above circumstances, and can display a color bar or the like on a monitor even when a camera head is not connected to a CCU.
It is an object of the present invention to provide an imaging system which can control the frequency of the divided clock and does not need to manage the phase of the divided clock between the patient and the secondary circuit. An image pickup system according to the present invention includes an image pickup unit having an image pickup element for picking up an image of a subject and readout signal generation means for generating a readout signal for reading out an image pickup signal of the image pickup element. A signal processing unit having image signal processing means capable of processing the image signal from the image sensor by detachably connecting the image unit, and a clock generating means provided in the signal processing unit to generate a reference clock signal; A first circuit for dividing the reference clock signal generated by the clock generator provided in the imaging unit and outputting the divided signal to the readout signal generator;
Frequency dividing means, second frequency dividing means provided in the signal processing unit for frequency dividing the reference clock signal generated by the clock generating means, and the first frequency dividing means provided in the signal processing unit. Switching means capable of switching between a frequency-divided signal from the means and a frequency-divided signal from the second frequency-dividing means; and a timing signal capable of controlling the imaging signal processing means based on the frequency-divided signal from the switching means. And a timing signal generating means provided in the signal processing unit. Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 relate to an embodiment of the present invention. FIG. 1 is a block diagram showing a configuration of an endoscope apparatus, and FIG. 2 shows a configuration of a preprocessing circuit and a video processing circuit of FIG. It is a block diagram. (Structure) As shown in FIG. 1, an endoscope apparatus 1 according to the present embodiment is an external endoscope with a television camera in which a television camera 3 provided with an image pickup means is mounted on an optical endoscope 2. 4
A light source device 5 that supplies illumination light to the optical endoscope 2,
A camera control unit (hereinafter abbreviated as CCU) 6 which is detachably connected to the television camera 3 and performs video signal processing for generating a standard video signal, and a television monitor 7 which displays a video signal output from the CCU 6 It is composed of The optical endoscope 2 includes, for example, a hard insertion portion 1.
1 and a gripper 12 provided at the rear end of the insertion portion 11
And an eyepiece 13 provided at the rear end of the grip 12. A light guide 14 is inserted into the insertion portion 11, and the light guide 14 is connected to the light source device 5 via a light guide cable connected to a light guide base of the grip portion 12. Illumination light from a lamp (not shown) is transmitted and emitted from the distal end surface of the light guide 14 to illuminate a subject such as an affected part. At the tip, an objective lens 16 is provided. An optical image formed by the objective lens 16 is transmitted to the rear side by, for example, a relay lens system 17 and is observed by an eyepiece 18 provided in the eyepiece 13. can do. A camera head 21 detachably mounted (externally attached) to the eyepiece 13 of the television camera 3, and a camera cable (as a signal transmission system) having a base end extending from the camera head 21. 22 and a connector 23 provided at the end of the camera cable 22. The connector 23 is detachably connected to the CCU 6. An image forming lens 24 is disposed in the camera head 21 so as to face the eyepiece 18, and a charge-coupled device (hereinafter abbreviated as CCD) 25 as a solid-state image pickup device is disposed at the image forming position. I have. Note that a CCD that performs photoelectric conversion
A mosaic filter 25 a is arranged on the front surface of the CCD 25, and optically separates the subject image into colors and guides the subject image to the imaging surface of the CCD 25. On the back side of the CCD 25, for example, a circuit board for forming a buffer amplifier (not shown) is arranged.
25 and the circuit board, one end of the camera cable 22 (internal signal cable 27) is connected, and the other end is a connector 2
The electrical contact No. 3 is connected via a pre-processing circuit 28 provided in the connector 23. By connecting the connector 23 to the CCU 6, the connector 23 is electrically connected to the video processing circuit 29 in the CCU 6 of the pre-processing circuit 28. Then, the video processing circuit 29
The standard video signal generated by the
Is output to Next, a detailed configuration of the pre-processing circuit 28 and the video signal processing circuit 29 will be described with reference to FIG. In the pre-processing circuit 28, a preamplifier 130 for amplifying the CCD output signal, a drive signal to the CCD 25 and a CDS and A / D
A timing generator 131 (hereinafter abbreviated as TG) that supplies a sampling signal to the conversion unit, and a first frequency dividing circuit 132 that divides a clock supplied from the video signal processing circuit 29 are configured. The preprocessing circuit 28 includes a scope detection level output section 133 for outputting a scope detection level for specifying what CCD 25 the camera head 21 uses. The video signal processing circuit 29 in the CCU 6 comprises a floating circuit 135 and a secondary circuit 136. Photocouplers (PC) 141 and 15 are provided between the two.
6, 157, 158, 159, 160 and the like. The floating circuit 135 is provided with a CDS circuit 137 for performing correlated double sampling of a video signal, and an A / D conversion circuit 138 for performing an A / D conversion of an output signal thereof. The floating circuit 135 has an original oscillation clock (GC) supplied from a secondary circuit described later.
K), a second frequency divider 139, and a preprocessing circuit 2
8, a switching circuit 161 for switching between the first clock (ACK) output from the first frequency dividing circuit 132 and the second clock (BCK) output from the second frequency dividing circuit 139.
And a connection detection circuit 162 for detecting the connection of the camera head from the input of the first clock (ACK). Further, in the floating circuit 135, the A / D conversion circuit 1 for A / D converting the analog signal for scope detection from the level output unit 133 for scope detection is provided.
40 are provided. The secondary circuit 136 has a A color separation circuit 142 for color-separating the video digital signal transmitted by C141 into a luminance signal Y and a color-difference signal C; an enhancement circuit 143 for performing edge enhancement processing on the color-separated luminance signal; Is provided with a color difference signal synchronizing circuit 144 that generates an RY signal and a BY symbol. The enhanced Y signal and RY, B-
The Y signal is input to the RGB matrix circuit 145 and the RGB signal
Separated into signals. The separated RGB signals are input to a detection circuit 146. The detection circuit 146 creates a detection signal for white balance control and a dimming signal for controlling the light source device 5. Also, this RGB signal is paint,
The image data is input to the W / B circuit 147, and the image is subjected to white balance processing and color tone correction processing. The RGB signals subjected to white balance processing are gamma-processed by gamma circuits 148a, 148b, and 148c, and then masked by a mask circuit 149 except for an image portion. After that, the color bar superimposing circuit 150 performs a process of switching color bar superimposition, and then the D / A conversion circuit 151 converts the signal into an analog signal. The RGB output is output to the television monitor 7 as it is, and the encoder 152 creates a Y / C signal and a composite signal and outputs them to the television monitor 7. The secondary circuit 136 is provided with a CPU 153, which receives a scope detection signal supplied from the A / D conversion circuit 140 of the floating circuit 135, and enhances, an RGB matrix, a detection circuit, a white balance, Switches processing such as mask and color bar superposition. The secondary circuit has an original oscillation clock (GC
K) that generates the clock signal (CK) from the floating circuit and generates various synchronization signals, and also outputs the horizontal synchronization signal (HD) and the vertical synchronization signal (VD) to the P.O. The signal is supplied to the floating circuit 135 via C157 and C158. (Operation) Next, the operation of this embodiment will be described with reference to FIG. The original oscillation clock (GCK) oscillated by the CXO 155 is supplied to the frequency dividing circuit 132 and the second frequency dividing circuit 139 in the pre-processing circuit 28 via the photocoupler (PC) 156. . At this time, when the camera head 3 is connected to the CCU 6, the GCK is frequency-divided by the first frequency dividing circuit 132 in the pre-processing circuit 28, and then the TG 131 is supplied with a clock (ACK). Supplied. The ACK is also returned to the floating circuit 135, and the switching circuit 16
1 and the connection detection circuit 162. The connection detection circuit 8162 detects whether or not ACK is input, and if it is, controls the switching circuit 161 to output ACK as CK. When the camera head 3 is not connected, ACK does not return from the first frequency dividing circuit 132.
The connection detecting circuit 162 detects that ACK is not input, controls the switching circuit 161 and outputs the output (BC) of the second frequency dividing circuit 139 in the floating circuit 135.
K) is output as CK. (Effect) According to the present embodiment, the disadvantage that the clock is not supplied to the CCU when the camera head of the conventional example is not connected is improved, and even when the camera head is not connected, the second effect is obtained. Since the clock is supplied from the frequency dividing circuit, an output such as a color bar can be supplied to the monitor. [Supplementary note] (Supplementary note 1) A camera head for endoscope observation including a solid-state imaging device and a timing generator for driving the solid-state imaging device, and the camera head is connected to the camera head. In an endoscope imaging system configured with a video signal processing device for processing a video signal from, the video signal processing device, a clock generator,
A first frequency dividing circuit for dividing a clock signal output from the clock generator, wherein the camera head includes a second frequency dividing circuit for dividing a clock signal output from the clock generator.
An endoscope imaging system, comprising: (Additional Item 2) When the camera head is connected to the video signal processing device, a frequency-divided clock divided by the second frequency dividing circuit is used. 2. The endoscope imaging system according to claim 1, wherein a switching circuit for using the frequency-divided clock divided by the first frequency dividing circuit is provided in the video signal processing device. As described above, according to the present invention, even when the camera head is not connected to the CCU, a color bar or the like can be displayed on the monitor, and the CCU can be controlled. In addition, there is an effect that there is no need to manage the phase of the divided clock between the patient and the secondary circuit.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram showing a configuration of an endoscope apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram showing a configuration of a preprocessing circuit and a video processing circuit in FIG. [Description of Signs] 1 ... Endoscope device 2 ... Optical endoscope 3 ... TV camera 4 ... TV camera external endoscope 5 ... Light source device 6 ... CCU 7 ... TV monitor 21 ... Camera head 25 ... CCD 28 ... Preprocessing circuit 29 ... Video processing circuit 130 ... Preamplifier 131 ... TG 132 ... First frequency dividing circuit 133 ... Scope detection level output unit 135 ... Floating circuit 136 ... Secondary circuit 137 ... CDS circuit 138 ... A / D conversion Circuit 139 Second divider circuit 140 A / D converter circuits 141, 156, 157, 158, 159, 160 ...
P. C 142 color separation circuit 143 enhancement circuit 144 color difference signal synchronization circuit 145 RGB matrix circuit 146 detection circuit 147 paint W / B circuits 148a, 148b, 148c gamma circuit 149 mask circuit 150 color bar Superimposing circuit 151 D / A conversion circuit 152 Encoder 153 CPU 154 SSG circuit 155 Oscillator 161 Switching circuit 162 Connection detection circuit

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H04N 5/225 H04N 5/225 C 5/335 5/335 Z 7/18 7/18 MF term (reference) 4C061 CC06 DD01 LL03 MM05 NN01 SS05 SS30 5B047 AA17 AB04 BA03 BB04 BC05 BC08 BC11 BC14 BC21 CA04 CA23 CB17 5C022 AA09 AB15 AB64 AC69 5C024 BX02 CY44 EX54 GY01 HX02 5C054 AA01 CC07 EA01 EA03 EA05 EC06 ED05

Claims (1)

Claims: 1. An image pickup unit having an image pickup device for picking up an image of an object, a readout signal generating means for generating a readout signal for reading out an image pickup signal of the image pickup device, and a detachable image pickup unit. A signal processing unit having an imaging signal processing unit connected thereto and capable of processing an imaging signal from the imaging element; a clock generation unit provided in the signal processing unit, for generating a reference clock signal; and provided in the imaging unit. A first frequency divider for dividing the reference clock signal generated by the clock generator and outputting the divided signal to the read signal generator; and a first frequency divider provided in the signal processing unit and generated by the clock generator. A second frequency dividing means for dividing the reference clock signal, wherein the second frequency dividing means is provided in the signal processing unit; Switching means for switching between the frequency-divided signal from the second frequency-dividing means and the frequency-divided signal from the second frequency-dividing means; and generating a timing signal capable of controlling the imaging signal processing means based on the frequency-divided signal from the switching means. And a timing signal generating means provided in the signal processing unit.