JPH0695994B2 - Endoscope device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an endoscope apparatus having an improved transmission method of a video signal obtained by an external camera attached to a fiberscope.

[Prior Art] Recently, an electronic endoscope (hereinafter referred to as an electronic endoscope) using a solid-state imaging device such as a charge-coupled device (hereinafter abbreviated as CCD) instead of an image guide for transmitting an optical image. Or, abbreviated as electronic scope.) Has been put into practical use, and it is now possible to display a captured endoscopic image on a TV monitor.

In addition, an external TV with a built-in image pickup means such as a solid-state image pickup device in the eyepiece part of an optical endoscope using a conventional image guide.
It has also become possible to attach a camera and display it on a TV monitor.

FIG. 10 shows a conventional example of an endoscope apparatus equipped with the above-mentioned external TV camera.

In FIG. 10, in the fiberscope 1, the image of the subject is transmitted to the endoscope operation section 3 by the image guide 2, and the illumination light is directed to the subject by the light guide 6 inserted through the universal cable 5 connected to the light source device 4. Is transmitted. An optical image obtained by the image guide 2 is formed on an image pickup surface of a solid-state image pickup device (hereinafter abbreviated as CCD) 9 by an image forming optical system in an external TV camera 8 attached to an eyepiece 7 of the fiberscope 1. Form an image. The optical image formed on the CCD 9 is photoelectrically converted, input to the signal processing circuit 11, processed as a signal and output as an image signal. The image signal is transmitted through the signal cable 10 through a plurality of transmission lines. It is transmitted by 12 to the camera control unit 13. In addition, the camera control unit is included in the signal cable 10.
A plurality of power lines (not shown) capable of supplying power from the 13 side to the external TV camera 8 are also inserted.

The camera control unit 13 converts the image signal into, for example, an NTC composite video signal, and the NTC composite video signal is transmitted to the TV.
It is input to the monitor 14 and the subject image is displayed on the screen.

Further, Japanese Patent Laid-Open No. 50-69054 discloses that an image signal output from an imaging device mounted on a fiberscope used with a high-frequency treatment device has a frequency band different from that of the high-frequency component contained in the high-frequency current. A technique is disclosed in which the modulated image signal is modulated so that the modulated image signal is transmitted to a monitor.

[Problems to be Solved by the Invention] As shown in FIG. 10, an external TV camera 8 is used in the above-mentioned conventional example.
The signal cable 10 in which the transmission line 12 for transmitting the image signal is inserted is connected to the camera control unit 13.
Furthermore, a universal cable 5 in which a light guide 6 and an air supply pipe or forceps pipe (not shown) are inserted from the endoscope operation section 3
Are connected to the light source device 4. In this way, since the two cables, the signal cable 10 and the universal cable 5, are connected, the universal cable 5 and the signal cable 10 may be twisted during operation of the endoscope, or the weight of the cable may be heavy. There is a problem that the operability of the endoscope is significantly reduced.

[Object of the Invention] The present invention has been made in view of the above circumstances, and an object thereof is to provide an endoscope apparatus in which the operability of the endoscope apparatus is significantly improved by omitting a signal cable. .

[Means for Solving the Problems] An endoscope apparatus according to the present invention is inserted into a universal cable extending from an optical endoscope together with a light guide, and is attached to an eyepiece of the optical endoscope. It is provided with a signal line capable of transmitting a video signal obtained by the attached image pickup means to the signal processing unit.

[Operation] In the present invention, the output of the solid-state imaging device is superimposed on the burst signal, the horizontal signal, and the vertical synchronization signal in the imaging means mounted on the eyepiece of the optical endoscope, and is inserted into the universal cable. Is transmitted to the signal processing unit by the signal line.

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

1 to 8 relate to a first embodiment of the present invention.
FIG. 4 is a block diagram of the entire endoscope apparatus, FIG. 2 is an explanatory diagram showing the influence of noise on frequency, FIG. 3 is a circuit diagram of a high-frequency emphasis circuit, and FIG. 4 is an explanatory diagram of the output of a mixer. Figure 5 shows
6 is an explanatory diagram of the CCD output, FIG. 6 is a frequency spectrum diagram of the output of the CDS (correlated double sampling) circuit, FIG. 7 is an explanatory diagram showing the phase relationship between the detection signal and the CCD output, and FIG. 8 is the PLL.
It is an explanatory view of a (phase synchronization control loop) circuit.

As shown in FIG. 1, the endoscope apparatus 21 of the present embodiment is provided with a fiberscope 22, an external TV camera 23 mounted on the fiberscope 22, and an illumination light connected to the fiberscope 22. Video signal processing unit 25 for processing the image signals transmitted from the light source unit 24 and the external TV camera 23.
And a TV monitor 27 for displaying a video signal output from the control device 26.

The fiberscope 22 includes an elongated insertion portion 28, a large-diameter operation portion 29 continuously provided behind the insertion portion 28, and a universal cable 31 extending from a side portion of the large-diameter operation portion 29. I have it.

In the insertion part 28 and the universal cable 31,
The light guide 32 formed by the fiber bundle that transmits the illumination light is inserted, and this universal cable is inserted.
By connecting the connector portion 33 provided at the tip of the light source portion 24 to the light source portion 24, white light emitted from the light source lamp 34 such as a xenon lamp is condensed and emitted to the incident end surface of the light guide 32 by the condenser lens 36. It has become so. The light guide 32 allows the illumination light to enter the insertion portion 28.
Is transmitted to the emission end face on the front end side and is emitted to the object side via the light distribution lens 37. The object illuminated by the illumination light is imaged by the objective lens 38 on the incident end face of the image guide 39 formed by the fiber bundle inserted through the insertion portion 28. The exit end surface of the image guide 39 is an imaging lens of the external TV camera 23 detachably attached to an eyepiece section 41 provided on the rear end side of the operation section 29.
The optical image transmitted by the image forming lens 42 is arranged so as to face the image forming lens 42, and is formed on the image pickup surface of a solid-state image pickup device (hereinafter abbreviated as CCD) 43 as an image pickup means. ing. An R, G, B mosaic filter 45, for example, is arranged on the image pickup surface of the CCD 43.

The CCD 43 outputs an image signal (video signal) photoelectrically converted by applying a drive signal from a CCD drive circuit 44 in the external TV camera 23, and this image signal is input to a CDS (correlated double sampling) circuit 46. Then, the 1 / f noise and the like generated from the CCD 43 due to the double sampling are suppressed.

FIG. 6 is a frequency spectrum diagram of the output of the CDS circuit 46, and the luminance signal 48 has a frequency component of about 3 MHz. The carrier wave 51 of the carrier color signal 49 is 8 MHz, and the carrier color signal 49 is 8M.
It has a band of ± 500 KHz.

The output of the CDS circuit 46 is input to the high-frequency emphasis circuit 47, the high-frequency component of the frequency is emphasized, and then input to the balanced modulator 63. In this balanced modulator 63, the output of the high frequency emphasis circuit 47 is set to R, B,
The color difference signals R-Y and B-Y are generated by separating them into the G signal, and the color difference signals R-Y and B-Y are modulated by the color carrier and superposed on the luminance signal Y. The superimposed signal is sent to the transmission line 53 via the mixer 52. This transmission line 53 is connected to a transmission line 56 inserted through the inside of the universal cable 31 by a terminal 54. Further, the transmission line 56 is connected to each circuit provided in the control device 26 by a terminal 57.

By the way, a xenon lamp, for example, is used as the endoscope light source lamp 34. This lamp 34 is a discharge tube in principle, and a large amount of noise is generated. In addition, since various electric circuits are configured in the light source unit 24, it has a great source of noise. Both noises are superimposed on the transmission lines 53 and 56, and as a result, the S / N ratio of the video signal obtained by the CCD 43 is significantly deteriorated. In FIG. 2, generally, the noise 58 that jumps into the transmission lines 53 and 56 from the air becomes easier to jump in as the frequency becomes higher. Therefore, in order to avoid the influence of this noise, the high frequency component of the signal to be transmitted should be raised by the frequency characteristic similar to the characteristic of FIG. A high-frequency emphasis circuit 47 is provided for that purpose. In FIG. 2, numeral 59 indicates a frequency band higher than the actual noise-mixed frequency characteristic in order to positively suppress the noise fog on the transmission lines 53 and 56. The high frequency emphasizing circuit 47 is composed of a high pass filter as shown in FIG.

The CCD drive circuit 44 receives the pulses of the vertical synchronizing signal φV, the horizontal synchronizing signal φH, the reset signal φR, etc. generated by the timing pulse generating circuit 61, amplifies them, and applies them to the CCD 43. The basic clock signal output from the crystal oscillator 62 is supplied to the timing pulse generation circuit 61. The output of the timing pulse generator 61, the horizontal synchronizing signal, and the charge transfer signal are also output to the signal shaper 64. FIG. 4A shows a signal shaper 64.
(B) is a charge transfer signal, which coincides with the charge transfer cycle of the unit pixel. FIG. 6C is a burst signal triggered by a horizontal synchronizing signal, which is a charge transfer signal generated in a burst form by being gated by a gate signal (not shown). The burst signal (c) and the horizontal synchronizing signal (a) are mixed and the waveform shown in FIG. FIG. 6E shows the output waveform of the mixer 52, and the burst signal generation region is the video signal generation period.
66 is avoided, for example, during the horizontal blanking period.
On the other hand, 67 is a chrominance carrier generated by being superimposed on the luminance signal.

FIG. 5 shows in detail the operation waveform of the charge transfer signal shown in FIG. 4 (b). The cycle of the charge transfer signal is CCD.
It matches the one pixel cycle of the output.

The video information signal output from the mixer 52 is input from the terminal 57 to the sync signal separator 68, the low pass filter 69, the band pass filter 71, and the burst signal separator 72. The low-pass filter 69 separates and extracts the luminance signal 48 shown in FIG. 6, and the band-pass filter 71 separates and extracts the carrier color signal 49 shown in FIG.
The luminance signal Y separated by the low-pass filter 69 is FM.
It is input to the modulator 73.

The burst signal separation circuit 72 separates and extracts the burst signal shown in FIG. 4 (c), and the burst signal of the charge transfer signal thus separated and extracted is a PLL (phase synchronization control loop) circuit 7.
Entered in 4. The PLL circuit 74 converts the input burst signal into a continuous signal. PLL circuit 7
The output of 4 is input to the R / B detection pulse generation circuit 75 and becomes a clock signal.

FIG. 8 shows a concrete example of the PLL circuit 74, and the output of the burst signal separation circuit 72 is one input of the phase comparator 76. The comparison output of the phase comparator 76 controls the oscillation frequency of the voltage control oscillator (hereinafter abbreviated as VCO) 77, and the output of the VCO 77 is input from the other input terminal of the phase comparator 76. ing. As a result, a continuous signal phase-synchronized with the burst signal is obtained at the output of the VCO 77, and the burst signal shown in FIG. 4 (c) is reproduced.

The R / B detection pulse generation circuit 75 generates and inputs the R detection signal and the B detection signal to a color separation circuit 78 for extracting a color difference signal from the carrier color signal separated by the bandpass filter 71. It is supposed to do.

FIG. 7 is a diagram showing the phase relationship between the R / B detection signal and the CCD output. Since the color signals R and B are alternately generated for every pixel with respect to the luminance signal in the CCD output, the R / B detection signal is perfectly in phase with the charge transfer signal, and the R detection signal is the CCD output. It coincides with the center of R signal generation period, and the detection signal for B is CC
It coincides with the center of the B signal generation period of the D output.

The output of the color separation circuit 78 is a line-sequential signal in which an R signal and a B signal are generated for each horizontal scanning line, and the line-sequential signal is input to a subtractor 79. Y is input, and the luminance signal Y causes the color difference signal R-
Y, BY are generated. The color difference signals RY and BY are input to the FM modulator 81. FM modulator 73,81
The frequency band of the input video signal is 1MHz to 10MHz. This modulated video signal is an isolation transformer for separating the patient side circuit and the secondary side circuit.
It is designed to be input to the primary side of 82.

Note that the transmission band of the isolation transformer 82 is an AC component, and a DC component is impossible. On the contrary,
The video signal has a component close to DC (20Hz), so the video signal cannot be transmitted. In order to solve this, the FM modulators 73 and 81 make the frequency band of the video signal 1 MHz to 10 MHz to enable transmission.

FM demodulators 83 and 84 are provided on the secondary side of the isolation transformer 82, respectively, and a luminance signal Y and a color difference signal R are provided.
-Y, BY line-sequential signals are demodulated. This luminance signal Y
Is input to the mixer 86, and the line-sequential signal is input to the color difference synchronization circuit 87. The color difference synchronizing circuit 87 synchronizes the line-sequential color difference signals to generate color difference signals RY and BY. The color difference signals RY and BY are input to the color encoder circuit 88, converted into chroma signals, and input to the mixer 86. The mixer 86 superimposes the chroma signal, the luminance signal Y, and the sync signal input from the sync signal separator 68, and outputs the composite signal as an NTSC composite signal to the TV monitor 27. There is.

When outputting the three primary color signals R, G, B, an inverse matrix circuit or the like is provided, and the luminance signal Y and the color difference signals RY, BY are input to this inverse matrix circuit.

The horizontal sync signal may be a composite sync signal including a vertical sync signal.

According to this embodiment as described above, the universal cable
Since the video information signal is transmitted to the transmission line 56 which is inserted through the inside 31, the transmission line for transmitting the video information signal to the external TV camera 23 is not required, and the universal cable 31 is simply connected to the control device 26. Imaging can be performed, and since the transmission line is only the universal cable 31, the operability can be improved as compared with the case where the operator has a plurality of cables.

In this embodiment, the light source unit 24 and the video signal processing unit 25 are provided in the control device 26, but it is also possible to connect a light source device that has already been sold by separately providing the light source unit 24 and the video signal processing unit 25. You can measure the decline.

FIG. 9 is a block diagram of the entire endoscope apparatus according to the second embodiment of the present invention.

The endoscope device 91 of the present embodiment is connected to the fiberscope 22, an external TV camera 92 provided on the eyepiece 41 of the fiberscope 22, and a universal cable 93 connected to the fiberscope 22. A light source device 94, a control device 96 that is electrically connected to the light source device 94 and performs signal processing, and a TV monitor 27 that receives a composite video signal generated by the control device 96 and displays a subject image. There is.

A video processor 97 and an external power supply 98 are provided in the control device 96. The output of the external power supply 98 is passed through the resistor 99 and the changeover switch 101 provided in the light source device 94.
Is connected to one terminal. This changeover switch 101
The other terminal of the internal power supply 102 is provided in the light source device 94.
The external power supply 98 and the internal power supply 102 can be selected by manually operating the switch unit 103, for example. The power selected by the changeover switch 101 is supplied to the regulator 106 via the transmission line 104 inserted in the universal cable 93. The electric power stabilized by the regulator 106 is supplied to the video processor 107 composed of a CCD drive circuit, CCD, or the like. In this video processor 107, the subject obtained by the fiberscope 22 is photoelectrically converted by a CCD and output as a video information signal. This video information signal is input to the transistor 108, and the current flowing through the transistor 108 is modulated by the video information signal. When the current modulated by the video information signal flows through the transistor 108, a voltage drop occurs at the output terminal of the resistor 99 in the control device 96, which means that the video information is transmitted. This video information is input to the video processor 97, converted into an NTSC composite signal or RGB signal, and output to the TV monitor 27.

In this embodiment, since the video information is transmitted to the transmission line 104 which is inserted through the universal cable 93 and supplies electric power, the endoscope device 91 does not require a transmission line for transmitting the video information signal. The operability of can be improved.

Other configurations, operations and effects are similar to those of the first embodiment.

[Effects of the Invention] As described above, according to the present invention, the signal cable can be omitted by transmitting the video signal by the transmission line inserted through the universal cable, and the operability of the endoscope apparatus is improved. Can be greatly improved.

[Brief description of drawings]

1 to 8 relate to a first embodiment of the present invention.
FIG. 4 is a block diagram of the entire endoscope apparatus, FIG. 2 is an explanatory diagram showing the influence of noise on frequency, FIG. 3 is a circuit diagram of a high-frequency emphasis circuit, and FIG. 4 is an explanatory diagram of the output of a mixer. , FIG. 5 is an explanatory diagram of CCD output, FIG. 6 is a frequency spectrum diagram of the output of the CDS (correlated double sampling) circuit, FIG. 7 is an explanatory diagram showing the phase relationship between the detection signal and the CCD output, and FIG. The illustration shows the PLL
FIG. 9 is an explanatory diagram of a (phase synchronization control loop) circuit, FIG. 9 is a block diagram of the entire endoscope apparatus according to the second embodiment of the present invention, and FIG. 10 is an endoscope equipped with an external TV camera. It is explanatory drawing which shows one conventional example of an apparatus. 21 …… Endoscope device 22 …… Fiberscope 23 …… External TV camera 24 …… Light source unit 25 …… Video signal processing unit 26 …… Control device 27 …… TV monitor 31 …… Universal cable 56 …… Transmission line

Claims (1)

[Claims] 1. An optical endoscope, an external TV camera detachably attached to an eyepiece of the optical endoscope, and having an image pickup means; and the optical endoscope. A universal cable that extends and passes through a light guide that supplies illumination light, a light source unit that is connected to the optical endoscope by the universal cable, and a signal that processes the video signal obtained by the imaging means. In an endoscope apparatus including a processing unit, a unit for emphasizing a high frequency component of a video signal obtained by the image capturing unit and a signal with the high frequency component emphasized are inserted into the universal cable together with a light guide. And a means for transmitting a signal to the signal processing unit via the signal line.