JPH0824669B2 - Electronic endoscopic device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electronic endoscope apparatus in which a plurality of electronic endoscopes having different lengths can be interchangeably used by the same video processor.

[Prior Art] In recent years, various electronic endoscope apparatuses using a solid-state imaging device such as a charge coupled device (CCD) as an imaging means have been proposed.

This electronic endoscope apparatus has advantages such as higher resolution than a fiberscope, easy image recording and reproduction, and easy image processing such as image enlargement and comparison of two screens. Have.

FIG. 4 is an explanatory diagram showing a configuration of a conventional electronic endoscope apparatus.

In this figure, reference numeral 1 is the tip of the insertion portion of the electronic endoscope. An objective lens system 2 and a light distribution lens system 3 are disposed on the tip side of the tip portion 1. A solid-state image sensor 4 is arranged at the image forming position of the objective lens system 2. Further, on the rear end side of the light distribution lens system 3, a light guide 5 inserted in the insertion portion is continuously provided.

This electronic endoscope is used by being connected to a video processor 7 which processes a signal from the electronic endoscope through a connector 6. A pulse generation circuit 8 is provided in the video processor 7, and the drive pulse φ ₀ as shown in FIG. 5A is output from the pulse generation circuit 8. The drive pulse φ ₀ is applied to the solid-state image sensor 4 in the tip portion 1 through the signal line 9 in the electronic endoscope. When the drive pulse at the terminal of the solid-state image sensor 4 is φ ₁ , the drive pulse φ ₁ is
Due to the length of the signal line 9, as shown in FIG.
The drive pulse φ _{0 is} delayed by a time t ₁ proportional to the length of the signal line 9.

The solid-state image sensor 4 outputs a video signal V ₀ as shown in FIG. 5C in synchronization with the drive pulse φ ₁ .
The video signal V ₀ passes through the signal line 10 in the electronic endoscope, and the sample hold circuit in the video processor 7
Entered in 11. Assuming that the video signal input to the sample-hold circuit 11 is V ₁ , the video signal V ₁ is, with respect to the video signal V ₀ , the signal line 10 as shown in FIG. 5D. Is delayed by a time t ₁ proportional to the length of.

By the way, the video signal V ₁ is composed of a clock component and a video component, as shown in FIG. 5 (d). Since only the video component is necessary to obtain an image, the sample hold circuit 11 is used to extract the video component from the video signal V ₁ by removing the clock component.
The video component extracted by the sample hold circuit 11 is video signal processed by the video signal processing circuit 12 and input to the monitor 15 so that the subject is displayed.

It is necessary to supply a sample hold pulse SH indicating the sampling timing to the sample hold circuit 11, and this sample hold pulse SH is, as shown in FIG. 5 (e), the image of the video signal V ₁ It must be output at the timing that matches the component. That is,
The drive pulse φ ₀ should be output with a delay time t ₂ including the delay times t ₁ and t ₁ due to the signal lines 9 and 10. However, if the lengths of the electronic endoscopes connected to the video processor 7 are different, the signal lines 9 and 10 are different.
Is different, and the delay time t ₁ due to the signal lines 9 and 10 is also different. Therefore, the delay time t ₂ also differs depending on the length of the electronic endoscope.

To deal with this, conventionally, a plurality of sample hold pulse generating circuits 13 are prepared as shown in FIG.
Each sample hold pulse generation circuit 13 is triggered by the trigger pulse TG output from the pulse generation circuit 8 at the same time, and outputs sample hold pulses SH _{1 to} SH _n at different timings. The trigger pulse TG is always output in a constant timing relationship with the drive pulse φ ₀ . In addition, the sample hold pulses SH _{1 to} SH _n output from each sample hold pulse generation circuit 13 are output at the optimum timing for each of the n types of electronic endoscopes to be used. It is set.

The sample and hold pulses SH _{1 to} SH _n are input to the multiplexer 14. The address inputs X ₁ , X ₂ , X ₃ of this multiplexer 14 are connected to pull-up resistors R ₁ , R ₂ , R _{3 respectively.}
The power supply is connected via. The connector 6, which is a part of the electronic endoscope, has four pins P ₁ , P ₂ ,
P ₃ and P _G are provided. Corresponding to the pins P ₁ , P ₂ , P ₃ , P _G , on the video processor 7 side, when the connector 6 is connected to the video processor 7, the pins P ₁ , P ₂ , P ₂ and P ₃ are the multiplexers, respectively.
It is wired so as to be connected between each of the address input terminals X ₁ , X ₂ , X _{3 of} 14 and the resistors R ₁ , R ₂ , R ₃ . Further, the pin P _G is wired so as to be connected to the ground. Therefore, when the pins P ₁ , P ₂ , P ₃ are all open (no wiring is made), all of the address input terminals X ₁ , X ₂ , X ₃ of the multiplexer 14 are at H level. Level is applied.
Further, for example, when only the pin P ₁ is connected to the pin P _G on the electronic endoscope side, the L level is applied to the address input end X ₁ and the H level is applied to the address input ends X ₂ and X _3. To be done. As described above, 2 ³ = 8 addresses can be designated to the multiplexer 14 depending on the connection method between the pins P ₁ , P ₂ , P ₃ and the pin P _G. The multiplexer 14 selects one of the sample and hold pulses SH _{1 to} SH _n according to the address designated by the pins P ₁ , P ₂ , P ₃ , and P _G and sends it to the sample and hold circuit 11. To do. In addition,
In the illustrated example, the number (n) of the sample hold pulse generation circuits 13 is eight.

For each length of the electronic endoscope, if the connection between the pins P ₁ , P ₂ , P ₃ and the pin P _G is determined so that the multiplexer 14 selects the optimum sample hold pulse, each electronic A sample hold pulse with an optimal timing can be used for each endoscope.

[Problems to be Solved by the Invention] However, in the conventional electronic endoscope apparatus, the sample and hold pulse generation circuit 13 that outputs the sample and hold pulse at different timings is different for each length of the electronic endoscope to be used. Therefore, there is a problem that the video processor 7 becomes large and costly. When a mono-multivibrator circuit or the like is used for each of the sample and hold pulse generation circuits 13, a semi-fixed resistor or the like must be adjusted for each circuit in order to prevent output pulse variations due to variations in component constants. However, there is a problem that the number of manufacturing steps increases.

[Object of the Invention] The present invention has been made in view of the above circumstances, and can simplify the circuit configuration of a video processor that can be connected to a plurality of electronic endoscopes having different lengths. It is an object of the present invention to provide an electronic endoscope device that can eliminate the need for adjustment.

[Means and Actions for Solving Problems] An electronic endoscope apparatus according to the present invention has a drive pulse for driving a solid-state image pickup device in a video processor connected to the electronic endoscope, and a drive pulse synchronized with the drive pulse. A pulse generation circuit for generating a reference sample and hold pulse, and a plurality of taps for delaying the reference sample and hold pulse generated by the pulse generation circuit with a plurality of different delay amounts and outputting a pulse of a different delay amount from each of the plurality of taps. With a delay line and a pulse with a different delay amount from each tap of the delay line with a plurality of taps, and selects a pulse with a delay amount according to the length of the signal line of the electronic endoscope from among these pulses. Then, a multiplexer for transmitting the sample-hold pulse to the sample-hold circuit is provided.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 relate to an embodiment of the present invention.
FIG. 1 is an explanatory view showing the structure of the electronic endoscope apparatus, FIG. 2 is a side view showing the entire electronic endoscope apparatus, and FIG. 3 is an explanatory view showing the structure of a delay line.

As shown in FIG. 2, the electronic endoscope apparatus 21 includes an electronic endoscope 22, a video processor 24 connected to the electronic endoscope 22 via a connector 23, and a video processor 24 connected to the video processor 24. And a monitor 25 as a display means.

The electronic endoscope 22 has an elongated and flexible insertion portion 26, for example.
A large-diameter operation portion 27 is connected to the rear end of the rear portion. The operation unit
A flexible cable 28 extends laterally from the rear end of the cable 27, and the connector 23 is provided at the tip of the cable 28.

A rigid tip portion 29 and a bending portion 30 adjacent to the tip portion 29 and capable of bending to the rear side are sequentially provided on the tip end side of the insertion portion 26. Further, by rotating the bending operation knob 31 provided on the operation portion 27, the bending portion 30
Can be bent in the left-right direction and / or the up-down direction. Further, the operation section 27 is provided with an insertion port 32 that communicates with a forceps channel provided in the insertion section 26.

As shown in FIG. 1, on the tip side inside the tip portion 29,
An objective lens system 35 and a light distribution lens system 36 are arranged.
A solid-state image sensor 37 is arranged at the image forming position of the objective lens system 35. Further, on the rear end side of the light distribution lens system 36, a light guide 38 inserted in the insertion portion 26 is continuously provided. The light guide 38 is connected to a light source device (not shown) provided in the video processor 24 via the cable 28 and the connector 23.

On the other hand, a pulse generation circuit 40 is provided in the video processor 24, and the drive pulse φ ₀ as shown in FIG. 5A is output from the pulse generation circuit 40. The drive pulse φ ₀ is applied to the solid-state image pickup device 37 in the distal end portion 29 through the cable 28 of the electronic endoscope 22, the operation portion 27, and the signal line 41 inserted in the insertion portion 26. . If the drive pulse at the terminal of the solid-state image pickup device 37 is φ ₁ , the drive pulse φ ₁ is different from the drive pulse φ _{0 as} shown in FIG. 5B because of the length of the signal line 41. Then, it is delayed by a time t ₁ proportional to the length of the signal line 41.

The solid-state image sensor 37 outputs a video signal V ₀ as shown in FIG. 5C in synchronization with the drive pulse φ ₁ .
The video signal V ₀ passes through the insertion section 26 of the electronic endoscope 22, the operation section 27, and the signal line 42 inserted through the cable 28, and then the sample hold circuit in the video processor 24.
Entered in 43. Assuming that the video signal input to the sample hold circuit 43 is V ₁ , the video signal V ₁ is longer than the video signal V ₀ by the length of the signal line 42 as shown in FIG. 5 (d). Delays by a time t ₁ proportional to that.

The video signal V ₁ is composed of a clock component and a video component, as shown in FIG. 5 (d). This video signal
The video component of V ₁ is extracted by the sample hold circuit 43 except for the clock component. Then, this video component is subjected to video signal processing by the video signal processing circuit 44, input to the monitor 25, and the subject is displayed.

In this embodiment, the pulse generation circuit 40 outputs the reference sample hold pulse SH ₀ . The reference sample hold pulse SH ₀ is always output in a fixed timing relationship with the drive pulse φ ₀ . The reference sample hold pulse SH ₀ is input to the delay line 45 having a plurality of taps. The delay line 45 includes, for example, as shown in FIG. 3, an input end IN provided at one end of the coil and a plurality of taps T _{1 to} T _n (n = 20 in the illustrated example) provided in the middle of the coil. ), A grounding GND terminal, and an impedance matching resistor R connected between the other end of the coil and the grounding GND terminal. Input terminal IN
The reference sample-and-hold pulse SH ₀ input to is delayed by a slightly different delay amount and output from the taps T _{1 to} T _{n as} sample and hold pulses SH _{1 to} SH _n . In addition, as this delay line 45,
SDL100N500 (made by JPC Co., Ltd.) or the like can be used. Further, the delay line 45 may be a distributed constant type using a coil as shown in FIG. But good.

Sample-and-hold pulse SH ₁ ~SH _n output from the taps T ₁ through T _n is input to the multiplexer 46.
The multiplexer 46 is connected to the sample hold pulse.
One of SH _{1 to} SH _n is selected and sent as a sample hold pulse SH to the sample hold circuit 43. A power supply is connected to each address input terminal X ₁ , X ₂ , X ₃ of the multiplexer 46 via pull-up resistors R ₁ , R ₂ , R ₃ .

On the other hand, the connector 23 of the electronic endoscope 22 has, for example, 4
Book pins P ₁ , P ₂ , P ₃ , P _G are provided. This pin P ₁ ,
On the video processor 24 side corresponding to P ₂ , P ₃ , and P _G, when the connector 23 is connected to the video processor 24, the pins P ₁ , P ₂ , and P ₃ respectively correspond to the multiplexer 46. It is wired so as to be connected between the address input terminals X ₁ , X ₂ , X ₃ and the resistors R ₁ , R ₂ , R ₃ . Further, the pin P _G is wired so as to be connected to the ground. Therefore, the pin
It is possible to specify 2 ³ = 8 addresses in the multiplexer 46 depending on how P ₁ , P ₂ , P ₃ are connected to the pin P _G.

The electronic endoscope 22 has the pins P ₁ , P ₂ , P ₃ and the pin P _G for each length, that is, for each length of the signal lines 41, 42.
, And the multiplexer 46 is
According to the address designated by the pins P ₁ , P ₂ , P ₃ , and P _G , the sample hold pulse SH with the optimum timing is selected for each electronic endoscope 22 from among the sample hold pulses SH _{1 to} SH _n. And sends it to the sample hold circuit 43. That is, as shown in FIG. 5 (e), the sample hold pulse SH is delayed by the delay times t ₁ and t ₁ by the signal lines 41 and 42 with respect to the drive pulse φ ₀ .
With a delay time of t ₂ including, the signal is output at a timing that matches the video component of the video signal V ₁ .

In the present embodiment configured as described above, a plurality of types of electronic endoscopes 22 can be exchangeably connected to the video processor 24 by the connector 23. Illumination light from a light source device (not shown) in the video processor 24 is emitted from the tip of the light distribution lens system 36 through the light guide 38 to illuminate the subject. On the other hand, the output drive pulses phi ₀ from the pulse generating circuit 40, the drive pulse phi ₀ is passed through the cable 28, the operation unit 27 signal line 41 and is inserted into the insertion portion 26, of the electronic endoscope 22 Solid-state image sensor 37 in the tip 29
Is applied to The drive pulse φ _{1 at} the terminal of the solid-state image pickup device 37 is the length of the signal line 41, so that it is shown in FIG.
As shown in, the drive pulse φ _{0 is} delayed by a time t ₁ proportional to the length of the signal line 41.

A signal corresponding to each pixel of the solid-state image sensor 37 is read by the drive pulse φ ₁ and
37 outputs a video signal V ₀ as shown in FIG. 5 (c) in synchronization with the drive pulse φ ₁ . This video signal V ₀ is
The insertion section 26, the operation section 27, and the cable 28 of the electronic endoscope 22.
It is inputted to the sample hold circuit 43 in the video processor 24 through the signal line 42 inserted therein. The video signal V ₁ input to the sample hold circuit 43 is
As shown in FIG. 7D, the video signal V _{0 is} delayed by a time t ₁ proportional to the length of the signal line 42.

On the other hand, the pulse generation circuit 40 outputs a reference sample hold pulse SH ₀ . The reference sample hold pulse SH ₀ is always output in a constant timing relationship with the drive pulse φ ₀ . The reference sample hold pulse SH ₀ is a delay line 4 with multiple taps.
Entered in 5.

The reference sample hold pulse SH ₀ input to the delay line 45 is delayed by a slightly different delay amount and output from the taps as sample hold pulses SH _{1 to} SH _n . These sample and hold pulses SH _{1 to} SH _n are
It is input to the multiplexer 46.

The multiplexer 46, for each electronic endoscope 22 from among the sample hold pulse SH ₁ ~ SH _n according to the address specified by the pins P ₁ , P ₂ , P ₃ , P _G provided in the connector 23. The optimum timing, that is, the signal line with respect to the drive pulse φ ₀ as shown in FIG.
41, 42 has a delay time of t ₂ including the delay time t ₁ , t ₁ ,
A sample hold pulse SH having a timing matching the video component of the video signal V ₁ is selected and sent to the sample hold circuit 43.

From the video signal V ₁ , the video component is extracted by the sample hold circuit 43 except for the clock component. Then, this video component is subjected to video signal processing by the video signal processing circuit 44, input to the monitor 25, and the subject is displayed.

In the delay line 45 shown in FIG. 3, assuming that the maximum delay amount is 200 nsec, sample hold pulses SH _{1 to} SH ₂₀ having a delay amount of, for example, 10 nsec are obtained from the taps T _{1 to} T ₂₀ . Generally, the time required for an electric signal to reciprocate every time the length of the electronic endoscope 22 increases by 1 m increases by about 10 nsec. Therefore, this delay line
By using 45, a plurality of electronic endoscopes 22 of arbitrary length (in units of about 1 m) are selected from the electronic endoscopes 22 having a difference between the shortest length and the longest length of about 20 m, and eight types are selected in the illustrated example. And can be used in combination with the same video processor 24.

Thus, according to this embodiment, one pulse generation circuit
Since 40 and one delay line 45 with a plurality of taps can output a plurality of sample and hold pulses at different timings, it is not necessary to provide a plurality of sample and hold pulse generation circuits, and a plurality of electronic signals of different lengths can be used. The circuit configuration of the video processor 24 that can be connected to the endoscope 22 can be simplified, and the size and cost can be reduced accordingly.

Further, since the delay amount of the delay line 45 is highly accurate, it is not necessary to adjust the timing of the sample hold pulse.

Further, by using the delay line 45 having a large number of taps, even when the electronic endoscope 22 having a new length is used, the tap having the optimum delay amount can be selected from the taps. Thus, it is possible to deal with the situation without replacing the sample hold pulse generating circuit.

The present invention is not limited to the above-mentioned embodiment, and for example,
The number of taps of the delay line 45 with a plurality of taps, the delay amount interval between the taps, and the like can be set arbitrarily. Further, the address setting of the multiplexer 46 is not limited to using the pins provided on the connector 23, but may be using the setting means provided on the video processor 24 side.

[Effects of the Invention] As described above, according to the present invention, the circuit configuration of the video processor connectable to a plurality of electronic endoscopes having different lengths can be simplified, and the timing adjustment of the sample hold pulse is unnecessary. There is an effect that can be.

[Brief description of drawings]

1 to 3 relate to an embodiment of the present invention, FIG. 1 is an explanatory view showing the configuration of an electronic endoscope apparatus, and FIG. 2 is a side view showing the whole electronic endoscope apparatus. FIG. 3 is an explanatory diagram showing a configuration of a delay line, FIG. 4 is an explanatory diagram showing a configuration of a conventional electronic endoscope apparatus, and FIG. 5 is a driving pulse of a solid-state image pickup device, a video signal, and a sample hold pulse. It is a waveform diagram. 21 …… Electron endoscope device, 22 …… Electronic endoscope 23 …… Connector 24 …… Video processor 37 …… Solid-state image sensor, 40 …… Pulse generation circuit 41,42 …… Signal line 43 …… Sample hold Circuit 44 …… Video signal processing circuit 45 …… Delay line with multiple taps 46 …… Multiplexer

Claims (1)

[Claims] 1. An electronic endoscope capable of deriving an output signal of a solid-state image pickup device provided as an image pickup means at a distal end portion of an insertion portion through a signal line inserted in the insertion portion, and the electronic endoscope. And a video processor for extracting a video component at the timing of a sample hold pulse from the output signal of the solid-state image sensor input via the signal line using a sample hold circuit and processing the video signal. In the endoscope apparatus, a drive pulse for driving the solid-state imaging device and a pulse generation circuit for generating a reference sample hold pulse synchronized with the drive pulse in the video processor, and the reference generated by the pulse generation circuit. The sample-and-hold pulse is delayed by a plurality of different delay amounts, and a pulse with a different delay amount is output from each of the taps. The delay line with taps and the pulse with the different delay amount from each tap of the delay line with multiple taps are input, and the pulse with the delay amount according to the length of the signal line of the electronic endoscope is selected from among these pulses. A multiplexer that selects and sends the sample-hold pulse to the sample-hold circuit as a sample-hold pulse.