JP2003038433A - Electronic endoscope device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic endoscope capable of stably operating a CCD at the distal end of an insert part regardless of the length and fine-line of a signal cable disposed in a scope unit. SOLUTION: A detecting means for detecting substrate voltage of the CCD and a timing control means capable of controlling the timing of the power supply voltage and the other driving signals input to the CCD are provided in the scope unit. The timing control means controls to supply the other driving signal when the substrate voltage detected by the detecting means reaches a designated threshold or more after the power supply voltage is supplied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic endoscope apparatus, and more particularly, to drive control of an image pickup element arranged at the tip of an insertion portion of an electronic endoscope apparatus.

[0002]

2. Description of the Related Art Generally, an electronic endoscope apparatus has a scope unit having an insertion portion to be inserted into a body cavity or the like, and a scope unit detachably attachable to supply illumination light to the scope unit. And a processor unit that receives and processes an image signal from the unit to generate a video signal of a predetermined standard. An image sensor (CCD; Charge Cou) is attached to the tip of the insertion part of the scope unit.
pled device), the image of the subject captured at the tip of the insertion unit is transmitted via the signal cable provided in the scope unit, and then signal processed at the base end of the scope unit and inside the processor. A standard video signal is output from the processor to the monitor device. Further, the signal for driving the CCD at the tip of the insertion section is generated by the signal generation circuit in the base section of the scope unit or the processor unit, and reaches the tip of the insertion section via the signal cable arranged in the scope unit. Is transmitted.

As described above, the scope unit has a CCD
It is necessary to dispose a drive signal input to the device, a power supply, and a signal cable for transmitting an image signal output from the CCD, while the electronic endoscope apparatus used for medical use imposes a burden on the patient. In order to reduce the number, it is required to reduce the diameter of the insertion part. Therefore, it is required to reduce the number of signal cables arranged in the scope unit or to thin the signal cables.

On the other hand, the CCD is being miniaturized by reducing the unit cell size (size per pixel) or reducing the types of external power supply, and the CCD thus miniaturized is viewed electronically. Use in a mirror device is advantageous for reducing the diameter of the insertion portion of the electronic endoscope device. For example, if the voltage applied to the CCD substrate is
A CCD of the type that is internally generated from the power supply voltage inside the device has also been proposed. In such a CCD, it is not necessary to externally supply the substrate voltage, and the number of signal cables arranged in the scope unit can be reduced.

[0005]

By the way, a signal cable is arranged in the scope unit to operate the CCD, but since the total length of the scope unit reaches several meters, the signal cable is not Due to the delay and waveform distortion caused by the increase in resistance and capacitance, the signal generated at the predetermined rising timing at the base end,
A situation may occur in which the tip portion does not arrive at a predetermined rising timing. Such a situation is concerned especially when the signal cable is thinned. In particular, when the signals for operating the CCD do not reach the CCD at predetermined timings, the CCD may malfunction and a normal image signal may not be obtained.

The present invention has been made in view of such circumstances. That is, the present invention provides an electronic endoscope apparatus in which the malfunction of the CCD due to the length of the signal cable and the thinning of the signal cable can be avoided in the electronic endoscope apparatus in which the diameter of the insertion portion is further reduced. With the goal.

[0007]

Therefore, the invention according to claim 1 is an electronic endoscope apparatus in which a CCD is provided at the tip of the insertion portion and a predetermined video signal is generated based on an output signal from the CCD. A detection means for detecting the substrate voltage of the CCD, and a timing control means for controlling the timing of supplying a plurality of drive signals for driving the CCD to the CCD. In this case, the timing control means applies the predetermined power supply voltage of the plurality of drive signals to CC.
When the substrate voltage detected by the detecting means becomes equal to or higher than a predetermined threshold after being supplied to D, control is performed so that a drive signal other than the predetermined power supply voltage is supplied. The timing control in which the drive signal is applied after the power supply voltage and the substrate voltage have stabilized can be reliably realized without being affected by signal distortion or the like.

Here, the CCD may have a voltage generating circuit for internally generating a substrate voltage from a predetermined power supply voltage supplied (claim 2).

According to a third aspect of the present invention, an electronic endoscope which has an insertion portion and a base end portion which is a connection portion to the processor unit, and which obtains an image signal of a subject from a CCD arranged at the tip end of the insertion portion. The scope unit for the apparatus includes a detection means for detecting the substrate voltage of the CCD and a timing control means for controlling the timing of supplying a plurality of drive signals for driving the CCD to the CCD. In this case, the timing control means supplies the predetermined power supply voltage of the plurality of drive signals to the CCD, and then, when the substrate voltage detected by the detection means becomes equal to or higher than the predetermined threshold value, the predetermined power supply Control is performed so that a drive signal other than voltage is supplied. The timing control in which the drive signal is applied after the power supply voltage and the substrate voltage have stabilized can be reliably realized without being affected by signal distortion or the like.

Here, the CCD may have a voltage generating circuit for internally generating a substrate voltage from a predetermined power supply voltage supplied (claim 4).

[0011]

1 is a block diagram showing the overall configuration of a control system of an electronic endoscope apparatus 100 as an embodiment of the present invention. The electronic endoscope apparatus 100 supplies a scope unit 10 with an insertion portion 10a and a base end portion 10b to be inserted into a body cavity, supplies illumination light to the scope unit 10, and processes a signal obtained from the scope unit 10. Unit 50 for generating a video signal
It consists of and. The scope unit 10 is configured to be attachable to and detachable from the processor unit 50. In addition,
The image generated by the processor unit 50 is displayed on an external monitor (not shown) connected to the processor unit 50 via a connection cable.

In FIG. 1, the illumination light from the light source section 40 is inserted through the light guide 7 disposed inside the scope unit 10 into the insertion section 10a of the scope unit 10.
The subject is illuminated from the tip of the. An optical image of an illuminated object formed by an objective lens (not shown) provided at the tip of the insertion unit 10a of the scope unit 10 is received on the light receiving surface of a CCD (Charge Coupled Device) 2 and accumulated as an electric charge. And converted into an electric signal. The CCD 2 is an interline color C
It shall be a CD.

The CCD 2 accumulates the light received by the light receiving surface as an electric charge and outputs an electric signal corresponding to the accumulated light quantity. The power supply voltage (Vdd) and other drive signals for operating the CCD 2 are supplied from the CCD control unit 9 to the CCD 2
Is supplied via a signal cable. The image signal output from the CCD 2 under the control of the CCD control unit 9 is subjected to predetermined processing such as amplification and gamma correction in the CCD control unit 9 and then input to the video signal processing circuit 20 in the processor unit 50. It

In the processor unit 50, the CCD
The signal from the control unit 9 includes a Y (luminance) component, RY (red-).
(Luminance) component and BY (blue-luminance) component digital signals, and the data of these components are Y memory 21, (RY) memory 22, and (B) which are image memories corresponding to the respective signals. -Y) 23 Once stored in memory.

The microcomputer 30 uses the timing signal generated by the timing circuit 31 to use the scope unit 10
Data communication with the side, control of the image memories 21-23, processing of input from a keyboard (not shown), and the like.

The data stored in the image memories 21-23 are read out at a predetermined timing under the control of the microcomputer 30 and input to the video processing circuit 25. The video processing circuit 25 synthesizes the image data of each component input from the image memories 21-23 to generate, for example, an NTSC standard composite video signal 26, an RGB separate signal 27, or the like. These video signals are sent to the monitor device. The power supply unit 45 supplies power such as the power supply voltage of the CCD 2 to the scope unit 10 side.

The aperture adjustment circuit 42 is a video signal processing circuit 2
Based on the signal of the brightness component generated by 0, the aperture of the diaphragm 41 is adjusted so that the brightness level of the image becomes a desired level.

FIG. 2 shows the CC inside the scope unit 10.
3 is a block diagram showing a detailed configuration of D2 and a CCD control unit 9. FIG. Details of the CCD2 control will be described with reference to FIG.
It should be noted that the CCD 2 here has a power supply voltage VDD of 15
It is a type of CCD that requires V and also requires a negative power supply such as a -8V power supply.

The power supply circuit 64 includes a processor unit 50.
Positive power supply and negative power supply (+15
V, -8V) is supplied to the CCD 2 according to the control timing from the microcomputer 67. The CCD vertical clock driver 61 receives a vertical drive signal generated by a DSP (digital signal processor) 65 and CC
The vertical clock is output to D2. The CCD horizontal clock driver 62 also receives a horizontal drive signal generated by the DSP 65 and outputs a horizontal clock to the CCD 2. In addition, positive power supply and negative power supply (+ 15V, -8
V), the vertical drive signal, and the horizontal drive signal supply timing control, the microcomputer 67 controls the power supply circuit 64 and the DSP 6.
Run through 5.

The microcomputer 67 uses D to adjust the color spectral characteristics of the CCD and the spectral characteristics of the light guide 7.
The white balance of the image signal generated in SP65 is adjusted. The data applied for the adjustment is stored in the memory (ROM) 66. As a result, the spectral characteristics of each scope unit are kept constant without variation. Further, the microcomputer 67 is the processor unit 50.
It is also connected to the side microcomputer 30 and has a function of performing data communication with the side microcomputer 30.

The image signal output from the CCD 2 is A /
The DSP 6 converts the digital signal by the D converter 63.
Input to 5. The DSP 65 subjects the input digital image signal to camera process processing such as blanking, clamping, white balance adjustment, and gamma correction, and outputs the image signal in the Y signal and C signal format to the processor unit 50 side. Output to.

FIG. 3 shows the structure (cross-sectional view) of a general pixel portion of an interline CCD used for the CCD 2. In the CCD 2 shown in FIG. 3, the voltage Vsub applied to the N substrate (substrate) portion is internally generated using the power supply voltage VDD (+ 15V) and set to a positive voltage. As a result, a potential well is formed in the charge storage section 2a and stable operation is obtained. From the structure of the CCD 2 as described above, the CCD
In order to operate Stable 2 stably, the horizontal and vertical drive signals must be supplied after the power supply voltage VDD (+ 15V) is supplied and the substrate voltage Vsub that rises following it is increased to a predetermined voltage. I have to. For that reason,
A monitoring circuit 68 for monitoring the voltage of the substrate terminal 81 of the CCD 2 is provided in the scope unit 10.

The substrate terminal 81 is a CCD
2 is connected to the N substrate inside. Therefore, by monitoring the voltage at the substrate terminal 81,
The voltage of the N substrate portion can be monitored.

The monitoring circuit 68 (FIG. 2) is, for example, an A / D converter for converting the voltage of the substrate terminal 81 (FIG. 2) into a digital value, and compares the digitally converted voltage value with a predetermined threshold value. Then, it can be configured by a comparison circuit that outputs a comparison result. The monitoring circuit 68 determines whether the substrate terminal 81 has exceeded a predetermined threshold value by the microcomputer 67.
Tell (Fig. 2). The charges stored in the charge storage unit 2a (FIG. 3) are then transferred to the vertical CCD register unit 2b.
(FIG. 3) and further to a horizontal CCD register section (not shown), and a signal line 71 (FIG. 2) as an image signal via the signal output terminal 82 (FIG. 2) of the CCD 2.
Is output to.

FIG. 4 is a flowchart showing the control of the supply timing of the power supply voltage VDD (+15 V) to the CCD 2 and other drive signals (horizontal and vertical drive signals) by the microcomputer 67. When the electronic endoscope apparatus 100 is activated, power is supplied to the microcomputer 67, and the microcomputer 67 starts operating, the microcomputer 67 operates for a certain time (for example, 100
After waiting for 10 ms, the power source +15 V is supplied to the CCD 2 (S11).

Next, by checking the signal from the monitoring circuit 68, it is measured whether or not the voltage of the substrate terminal 81 has reached a predetermined threshold value (for example, 10 V) or more (S1).
2). If the substrate terminal 81 voltage is equal to or higher than the predetermined threshold value (S13: YES), the DSP 65
Horizontal and vertical drive signals are generated with respect to (S1
5). On the other hand, when the voltage of the substrate terminal 81 is not equal to or higher than the predetermined threshold value (S13: NO), the signal from the monitoring circuit 68 is checked again after a lapse of a fixed time (for example, 100 ms) to measure the voltage of the substrate terminal 81. Is performed (S14).

By performing control as in the flow chart shown in FIG. 4, the timing relationship between +15 V input to the CCD 2 and other drive signals can be controlled as shown in FIG. In FIG. 5, reference numeral 91 indicates the transition of the power supply + 15V input to the CCD 2, reference numeral 92 indicates the transition of the substrate voltage generated inside the CCD 2 by the input power supply + 15V, and reference numeral 94 indicates the horizontal and vertical inputs to the CCD 2. The transition of the drive signal is shown respectively. Figure 5
As shown in FIG. 5, there is a delay or rounding in the rise of the power supply + 15V input to the CCD 2 due to the resistance value and the capacitance according to the length of the signal cable, and the substrate voltage rises following this rise of the power supply + 15V. Then, after the substrate voltage rises above a predetermined threshold voltage, the supply of horizontal and vertical drive signals is started.
Although not included in the flowchart of FIG. 4, CC
Regarding the -8V power supply input to D2, the substrate voltage is set to a predetermined threshold voltage as indicated by reference numeral 93 in FIG. It is also possible to input after it stands up above.

[0028]

As described above, according to the present invention,
Even when the insertion portion of the electronic endoscope apparatus has a small diameter or the insertion portion has a long length, it is possible to control each timing of turning on the power to the CCD and starting the supply of the drive signal to a desired timing. Therefore, the CCD at the tip of the insertion portion can be stably operated.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of a control system of an electronic endoscope apparatus of the present invention.

FIG. 2 is a block diagram showing details of a control system in a scope unit of the electronic endoscope apparatus of the present invention.

3 is a cross-sectional view schematically showing a general configuration of a pixel portion of a CCD arranged at the tip of the insertion portion of the scope unit shown in FIG.

FIG. 4 is a flow chart showing control of the power supply timing to the CCD in the scope unit of FIG. 2 and the control timing of other drive signals.

5 is a timing chart showing the timing of turning on the power supply of the CCD and other drive signals, which is realized by the control of FIG.

[Explanation of symbols]

2 CCD 10 Scope unit 50 processor units 64 power supply circuit 65 DSP 66 memory 67 Microcomputer 68 Supervisory circuit 81 Substrate terminal 100 electronic endoscope system

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4C061 CC06 LL02 SS05                 5C022 AA09 AB31 AC42 AC69 AC75                 5C024 BX02 CX00 DX01 EX03 GY04                       HX01

Claims (4)

[Claims] 1. An electronic endoscope apparatus having a CCD at the tip of an insertion portion and generating a predetermined video signal based on an output signal from the CCD, a detection means for detecting a substrate voltage of the CCD, A plurality of driving signals for driving a CCD are supplied to the CC.
Timing control means for controlling the timing of supplying to the D. The timing control means supplies a predetermined power supply voltage of the plurality of drive signals to the CCD, and then the sub-detector detected by the detection means. An electronic endoscope apparatus, characterized in that, when the straight voltage becomes equal to or higher than a predetermined threshold value, control is performed so as to supply a drive signal other than the predetermined power supply voltage. 2. The electronic endoscope apparatus according to claim 1, wherein the CCD has a voltage generation circuit that internally generates a substrate voltage from the supplied predetermined power supply voltage. 3. A C having an insertion portion and a base end portion which is a connection portion to the processor unit and arranged at the tip of the insertion portion.
In a scope unit for an electronic endoscope apparatus that obtains an image signal of a subject from a CD, a detection unit that detects a substrate voltage of the CCD, and a plurality of drive signals for driving the CCD are provided in the CC.
Timing control means for controlling the timing of supplying to the D. The timing control means supplies a predetermined power supply voltage of the plurality of drive signals to the CCD, and then the sub-detector detected by the detection means. A scope unit, wherein when the straight voltage exceeds a predetermined threshold value, control is performed so as to supply a drive signal other than the predetermined power supply voltage. 4. The scope unit according to claim 3, wherein the CCD has a voltage generating circuit that internally generates a substrate voltage from the supplied predetermined power supply voltage.