JP3857855B2 - Electronic endoscope device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic endoscope apparatus, and more particularly to a compatible processor apparatus configuration that allows an old type electronic endoscope to be used even in a new type of signal processing format.
[0002]
[Prior art]
An electronic endoscope apparatus images an object to be observed with an imaging element, for example, a CCD (Charge Coupled Device), disposed at the tip of an electronic scope (electronic endoscope), and outputs an image signal (video signal) output from the CCD. ) Is input to the processor device, and various image processes are performed by the processor device, so that the image of the object to be observed is displayed on the monitor.
[0003]
FIG. 4 shows a schematic configuration as an example of an electronic endoscope apparatus, and the electronic scope and the processor apparatus can be detachably connected by a connector. In FIG. 4, a CCD 2 is disposed on the distal end side of the electronic scope via the objective optical system 1, and a V-drive circuit 3 is connected to the CCD 2. The V-drive circuit 3 is connected to the processor device side. A drive voltage is applied to the CCD 2 based on the vertical drive pulse. Further, the horizontal drive pulse and the power are directly supplied to the CCD 2 from the processor side.
[0004]
On the other hand, as a circuit for passing an image signal from the CCD 2 through a relatively long scope insertion section, a coaxial transmission line 5, an input transistor Tr for supplying the image signal to the transmission line 5, a bias resistor R ₁ , a resistor R ₂ is provided with an output-side resistor R ₃ (R ₁ = R ₃ ) having the same resistance value as the bias resistor R _1, and the output of this transmission line 5 is CDS (Correlated Double Sampling) / AGC (Automatic gain control) is supplied to the circuit 6. The CDS / AGC circuit 6 performs correlated double sampling on an image signal by a sampling pulse and a hold pulse, and also performs automatic gain control, and the signal output (maximum range) is, for example, a ( 1.5) Amplify to V.
[0005]
An A / D converter 8 is provided on the processor device side so as to input the output of the CDS / AGC circuit 6, and a DSP (Digital Signal Processor) circuit 9 is connected to the A / D converter 8. The DSP circuit 9 digitally processes various image processing of the image signal, such as white balance, gamma correction, contour correction, and the like, thereby forming a good image.
[0006]
[Problems to be solved by the invention]
By the way, electronic devices based on new technologies have been put on the market due to remarkable technological developments in recent years. Also in electronic endoscope apparatuses, new devices such as the above DSP circuit 9 have been designed and manufactured. The
However, in such a new type (model) apparatus, the processing format of the image signal may be different from the conventional one. In such a case, there is a problem that compatibility with the old type electronic scope cannot be achieved. .
[0007]
For example, in FIG. 4, if the electronic scope is an old type and the processor device is a new type, the amplitude (maximum range of the signal portion) of the image signal output from the CDS / AGC circuit 6 on the electronic scope side is aV ( For example, the amplitude required for the signal input to the A / D converter 8 on the processor device side is bV (for example, 2V).
[0008]
That is, the image signal output voltage of the CCD 2 is halved by passing the transmission line 5 because the resistors R ₁ and R ₃ are the same, and this image signal is amplified by the CDS / AGC circuit 6 and the DSP circuit. 9, after a predetermined amplification process is performed, the final output is set to a standard amplitude (voltage), for example, about 0.7V. In the old type electronic scope, the output image signal of the CDS / AGC circuit 6 is aV. However, in the new type processor device, the processing format of the DSP circuit 9 and the like is different, so that bV (a <b) is required as the amplitude of the input signal of the A / D converter 8.
[0009]
Therefore, it is impossible to connect the old type electronic scope to the new type processor device, and rather, conventionally, a means for preventing erroneous insertion and malfunction is employed so as not to use the old type electronic scope. This hinders the use of old-type electronic scopes and prevents the spread and promotion of new devices.
[0010]
The present invention has been made in view of the above problems, and an object of the present invention is to ensure compatibility between old and new models, and an electronic endoscope that can be connected to a new type processor device even with an old type electronic endoscope. To provide an apparatus.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, an electronic endoscope having an image pickup device is detachably connected to a processor device of a type having a different signal amplitude (related) processing format from the electronic endoscope. In the electronic endoscope apparatus, the type detection means for detecting the type of the signal amplitude processing format of the electronic endoscope connected to the processor apparatus, and the type detection means disposed in the processor apparatus, based on the detection of the type detection means A switching circuit for selecting each of the input image signals of different signal amplitude processing formats, a clamp circuit for clamping an input image signal of a different type of signal amplitude processing format with an optical black pulse, and an output of this clamp circuit as a signal amplitude an amplifier circuit for amplifying for range adjustment, input signal amplitude processing format of the same type which are supplied from the switching circuit An image signal is provided and a through-line for leading to a subsequent circuit without going through the clamp circuit and an amplifier circuit, detects that the different types of the electronic endoscope of the signal amplitude processing format are connected by the type detecting means In this case, an input image signal is supplied to the clamp circuit and the amplifier circuit by the switching circuit to adjust the signal amplitude range.
According to a second aspect of the present invention, there is provided an electronic endoscope apparatus in which an electronic endoscope having an image pickup device is detachably connected to a processor apparatus of a type different in signal amplitude processing format from the electronic endoscope. Type detection means for detecting the type of signal amplitude processing format of the connected electronic endoscope, a clamp circuit that is disposed in the processor device and clamps an input image signal from the electronic endoscope with an optical black pulse; Input the output of this clamp circuit, select the amplification factor for adjusting the signal amplitude range for image signals of different signal amplitude processing formats, and select the signal amplitude range for image signals of the same signal amplitude processing format. An amplification circuit that selects an amplification factor that is not adjusted is connected to an electronic endoscope of a different type of signal amplitude processing format by the type detection means. When it is detected that, to control switching of the amplification factor in the amplification circuit, and executes the adjustment of the signal amplitude range.
[0012]
According to the first aspect of the present invention, for example, when it is detected that an old type electronic endoscope is connected to a new type processor device, the clamp circuit and the amplifier circuit are selected by the switching circuit. According to this clamp circuit, an image signal in which the DC component of the image signal is cut to make the black level coincide with 0V is formed, and this image signal is amplified with a predetermined amplification factor by the amplification circuit, thereby providing a new type. The signal amplitude is adapted to the processing format. On the other hand, when a new type of electronic endoscope is connected to the new type of processor device, the switching circuit does not select the amplification circuit, and the input image signal from the electronic endoscope is A / D as it is. It is supplied to the digital signal processing circuit via the converter.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a main configuration of an electronic endoscope apparatus according to an embodiment, which is obtained by connecting a new type processor apparatus to an old type electronic scope (electronic endoscope). 1, the CDS (correlated double sampling) / AGC (automatic gain control) circuit 6 described in FIG. 4 is arranged on the electronic scope side, and the amplitude of the output image signal of the CDS / AGC circuit 6 is a ( For example, 1.5) V.
[0014]
On the other hand, the new type processor device is provided with a DC clamp circuit 13 and a 3 dB amplification (corresponding to b / a times) via a switching circuit 12 in the previous stage of the A / D converter 11 and has a level shift function of 2V. The DC clamp circuit 13 clamps the image signal based on the reference voltage of the reference voltage setting circuit 15 and OBP (Optical Black Pulse) input from the timing generator. The switching circuit 12 is connected to a through line L to the input portion of the A / D converter 11 so that the switching circuit 12 can select any of the through line L, the clamp circuit 13 and the amplifier 14. It has become.
[0015]
Further, a microcomputer 16 is provided in the processor device, and the microcomputer 16 determines whether the connected electronic scope is an old type or a new type. This determination can be performed by detecting the identification information supplied from the electronic scope at the time of connection, or detecting the amplitude (aV) of the image signal input from the CDS / AGC circuit 6. Based on this determination, the microcomputer 16 controls the switching circuit 12 to be switched.
[0016]
The embodiment is configured as described above, and its operation will be described with reference to FIG. First, when an electronic scope is connected to a new type of processor device, the microcomputer 16 detects and determines the type of the electronic scope, and when it is detected that the old type is the old type, the switching circuit 12 causes a DC clamp circuit. 13 and the amplifier 14 are selected. Here, an image signal having the maximum aV amplitude shown in FIG. 2A is supplied from the CDS / AGC circuit 6 on the old type electronic scope side. This image signal is level-shifted by 2V from the position of 0V. Signal.
[0017]
When this image signal is supplied to the DC clamp circuit 13, its black level portion is clamped by the OBP shown in FIG. 2B, and as shown in FIG. 2C, the black level portion is set to 0V. Is converted to a matched signal. Next, by passing through the amplifier 14, as shown in FIG. 2D, the signal amplitude is amplified to about 3 dB (b / a times), for example, and then a level shift of 2V is performed. Therefore, according to this clamping and amplification, a signal having a maximum amplitude of bV and raised by 2V from the 0 potential level is formed, and an image signal suitable for a new type of processing format is obtained.
[0018]
This image signal is a signal with high color reproducibility, which is different from a signal obtained by simply amplifying (b / a times) the output of the CDS / AGC circuit 6 in FIG. That is, the output of the CDS / AGC circuit 6 in FIG. 2A is a signal that is raised by 2V from 0V. If this signal is amplified as it is, the black level voltage is also amplified and the reference position is distorted. The color reproducibility of the output deteriorates. However, in the present invention, the black level of the image signal is once lowered to 0 potential by the DC clamp circuit 13 and this image signal is amplified, whereby the color information of the image signal can be linearly and accurately amplified. And high color reproducibility can be obtained.
[0019]
On the other hand, when the microcomputer 16 detects that the connected electronic scope is the same new type as the processor device, the through circuit L is selected by the switching circuit 12. In this case, an image signal having an amplitude bV is output from the CDS / AGC circuit 6 of the new type electronic scope, and this image signal is supplied to the DSP circuit via the A / D converter 11 as it is.
[0020]
FIG. 3 shows another embodiment, in which the amplification factor of the amplifier circuit can be switched. That is, an amplifier circuit (with a 2V level shift function) 18 connected to the subsequent stage of the DC clamp circuit 13 includes an amplifier unit 19 to which resistors R ₄ and R ₅ that change amplification factors are connected and the resistors R ₄ and R ₅ . The switching circuit 20 is configured to switch, and when the resistor R ₄ is selected, 0 dB amplification is obtained, and when the resistor R ₅ is selected, 3 dB signal amplification is obtained.
[0021]
Thus, in this example, the switching control of the switching circuit 20 based on the microcomputer 16 selects the resistor R ₅ when electronic scope of the old type is connected, the output of the DC clamp circuit 13 by b / a times amplification, An image signal having an amplitude bV can be obtained. On the other hand, when a new type electronic scope is connected, the clamped image signal is output to the A / D converter 11 without being amplified by selecting the resistor R ₄ . This also ensures compatibility with old and new electronic scopes.
[0022]
Also, a plurality of amplification factors can be set using the circuit of FIG. 3 to ensure compatibility with a plurality of types of electronic scopes. That is, n resistors R _n for changing the amplification factor including the resistors R ₄ and R ₅ in the amplifier circuit 18 of FIG. These resistors R _n By switching between, the output amplitudes of a plurality of electronic scopes can be adjusted to a new type of format. Further, by using the amplifier circuit 18 of FIG. 3 in the configuration of FIG. 1, compatibility with a plurality of types of electronic scopes can be maintained.
[0023]
【The invention's effect】
As described above, according to the present invention, an amplifier circuit that can be selected by a clamp circuit and a switching circuit is provided in a new type processor device, and an image signal is clamped when an old type electronic endoscope is connected. Since the signal amplitude range is adjusted after amplification, compatibility between the old and new models is ensured, and the old type electronic endoscope can be connected to the new type processor device and used. .
[Brief description of the drawings]
FIG. 1 is a block diagram showing a main configuration of an electronic endoscope apparatus according to an embodiment of the present invention.
FIG. 2 is a waveform diagram showing signal processing according to the embodiment.
FIG. 3 is a block circuit diagram showing a configuration of another example of the embodiment.
FIG. 4 is a block circuit diagram showing a configuration of a conventional electronic endoscope apparatus.
[Explanation of symbols]
2 ... CCD,
6: CDS (correlated double sampling) / AGC (automatic gain control) circuit,
9 ... DSP (Digital Signal Processor),
12, 20 ... switching circuit,
13 ... DC clamp circuit,
14 ... Amplifier, 16 ... Microcomputer,
18 ... Amplifier circuit,
R _{1 to} R ₅ , R _n ... Resistance.

Claims (2)

In the electronic endoscope apparatus detachably connected to different types of processing units of the signal amplitude processing format electronic endoscope with the electronic endoscope having an image pickup element,
Type detecting means for detecting the type of signal amplitude processing format of the electronic endoscope connected to the processor device;
A switching circuit disposed in the processor device for selecting each of the input image signals of different signal amplitude processing formats based on the detection of the type detection means;
A clamp circuit that clamps an input image signal of a different type of signal amplitude processing format with an optical black pulse;
An amplification circuit for amplifying the output of the clamp circuit for signal amplitude range adjustment;
A through line for guiding an input image signal of the same signal amplitude processing format supplied from the switching circuit to a subsequent circuit without passing through the clamp circuit and the amplifier circuit;
When the type detection means detects that an electronic endoscope of a different type of signal amplitude processing is connected, the input image signal is supplied to the clamp circuit and the amplifier circuit by the switching circuit, and the signal amplitude range is adjusted. An electronic endoscope apparatus characterized by executing In an electronic endoscope apparatus in which an electronic endoscope having an image pickup device is detachably connected to a processor apparatus of a type different in signal amplitude processing format from the electronic endoscope,
Type detecting means for detecting the type of signal amplitude processing format of the electronic endoscope connected to the processor device;
A clamp circuit disposed in the processor device and configured to clamp an input image signal from the electronic endoscope with an optical black pulse;
Input the output of this clamp circuit, select the amplification factor to adjust the signal amplitude range for image signal types with different signal amplitude processing formats, and adjust the signal amplitude range for image signals with the same signal amplitude processing format An amplification circuit that selects an amplification factor that is not
When the type detection means detects that an electronic endoscope of a different type of signal amplitude processing is connected, the amplification factor in the amplifier circuit is switched and the signal amplitude range is adjusted. An electronic endoscope apparatus.

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