JP2001321338A - Light source for endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a light source for an endoscope capable of inspecting the connection between a light guide and an endoscope with an accuracy. SOLUTION: This light source device 20 for an endoscope comprises a light guide cable 14 including a light guide fiber 15 detachably connectable to a light post at a side part of an operation part of an endoscope. Illumination light from a light source lamp 31 is supplied to the light guide fiber 15, and infrared ray from an infrared LED 41 is radiated to it, so return light reflected from the light post (a connection surface to the endoscope) is inspected by a light receiving element 42. Timing to drive the infrared ray LED 41 is synchronized with detection of the return light by the light receiving element 42 to detect the level of the return light detected, and when it is determined that the light guide cable 14 is not connected to the endoscope based on result of detection, supply of the illumination light is disconnected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope light source device used for an industrial or medical endoscope device for supplying illumination light through a light guide detachably connectable to an endoscope. About.

[0002]

2. Description of the Related Art An endoscope, which has been widely used in the medical field and the industrial field, requires a means for illuminating since a diagnostic or examination target is located inside a living body, plant, or the like. For this reason, in a general endoscope, a light source device is prepared as an external device of the endoscope, and light is guided by illumination light guiding means such as a light guide for guiding illumination light from the light source device. The test site is illuminated from the distal end side, and the illuminated optical image of the test site is captured and observed by an observation unit such as an image guide fiber.

A conventional endoscope light source device used for such an endoscope is disclosed, for example, in Japanese Patent Application Laid-Open No. 9-308607 or WO 98/08430 (PCT / US97 / 1).
As described in Japanese Patent No. 5834), there has been proposed a device that supplies illumination light from a light source lamp to an endoscope via a light guide detachably connectable to the endoscope. The endoscope light source device, in order to reduce glare when disconnecting the light guide from the endoscope, to reduce the intensity of illumination light supplied from the light source lamp by setting the light source to a standby mode It is supposed to.

However, the endoscope light source device electrically detects the connection between the endoscope and the light guide in order to detect that the light guide has been disconnected from the endoscope. Although the electric detection means is used, it is necessary to provide an electric contact to the light guide cable in the electric detection means, and therefore, a dedicated light guide cable having the electric contact is required. In such an electrical detection, noise from an electric scalpel or the like used simultaneously with the endoscope may be mixed into the electric signal, and it may be difficult to perform the detection with high accuracy.

On the other hand, Japanese Patent Application Laid-Open No. 56-833 discloses
No. 25, the endoscope light source device does not rely on electrical detection, by detecting infrared reflected light or infrared reflected light contained in illumination light from the test site, One that detects the connection between an endoscope and the light guide has been proposed.

[0006]

However, the light source device for an endoscope described in the above-mentioned Japanese Patent Application Laid-Open No. 56-83325 discloses an infrared reflected light from a portion to be examined or an infrared reflected light contained in illumination light. Therefore, it is difficult to accurately detect many unstable factors. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a light source device for an endoscope that can accurately detect a connection between a light guide and an endoscope.

[0007]

In order to achieve the above object, a light source device for an endoscope according to the present invention is detachably connectable to an endoscope and transmits illumination light generated by a light source to the endoscope. A light guide cable having a light guide provided therein, a detection light source capable of generating detection light having a wavelength different from the illumination light from the light source, and supplying the detection light to a light guide of the light guide cable; Sensor means capable of detecting the return light of the detection light from the return light from the guide, and detecting the level of the return light of the detection light, and determining the disconnection between the endoscope and the light guide based on the detection result. And control means for interrupting or reducing the supply of the illumination light when it is performed. With this configuration, an endoscope light source device that can accurately detect the connection between the light guide and the endoscope is realized.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIGS. 1 to 7 relate to a first embodiment of the present invention, and FIG. 1 is an overall configuration diagram of an endoscope apparatus according to the first embodiment of the present invention. FIG. 3 is an explanatory diagram showing a layout of a panel of the light source device for an endoscope in FIG. 1, FIG. 3 is an explanatory diagram showing a light guide detachably connected to the endoscope in FIG. 1, and FIG. FIG. 5 is a circuit block diagram showing a detection circuit of FIG. 4, FIG. 6 is a flowchart for explaining the control of the CPU of FIG. 5, and FIG. 7 is a diagram showing output light after synchronous rectification. It is a graph shown.

As shown in FIG. 1, an endoscope apparatus 1 according to the present embodiment has an elongated and rigid insertion portion 11.
1. A rigid endoscope (hereinafter simply referred to as an endoscope) 10 including an operating unit 12 also serving as a grip unit extending to the base end side of the device 1 and an eyepiece unit 13 extending above the operating unit 12. A light source device for an endoscope that supplies illumination light to the endoscope 10 via a light guide cable 14 detachably connectable to a light post described below provided on a side of the operation unit 12 of the endoscope 10 ( Hereinafter, it mainly comprises a light source device) 20.

A panel 21 is provided on the front surface of the light source device 20, and has a layout as shown in FIG. The panel 21 includes a STAND-BY unit 22 that shields a light source lamp described later when the endoscope 10 is replaced.
An AUTO-BRIGHT unit 23 for switching the brightness control of the light source lamp between automatic and manual;
A setting switch unit 24 for increasing and decreasing the brightness of the light source lamp when the mode is switched to the manual mode by the BRIGHT unit 23, and a BRIGHTNESS unit 25 for displaying the brightness of the light source lamp by LEDs 25a arranged in a line.
Are provided.

The STAND-BY section 22 is provided with a standby switch 22a and a standby LED 22b for notifying a standby state. It is a mechanism that can shield the output light from the lamp. Then, the STAND-BY state can be released by operating the standby switch 22a again. The AUTO-BRIGHT section 23 is provided with an auto switch 23a and an auto LED 23b for notifying an AUTO-BRIGHT state.
When the GHT state is set, the auto LED 23b is turned on, and a mechanism for automatically controlling the brightness of the light source lamp 31 is provided. The AUTO-BRIGHT state can be released by re-operating the auto switch 23a, and the brightness of the light source lamp 31 can be adjusted in a manual mode by manually operating the setting switch section 24.

As shown in FIG. 3, the light guide cable 14 can be detachably connected to the light post 12a of the endoscope 10, and a light guide fiber 15 is inserted through the light guide cable 14. I have. The connector 26 of the light guide cable 14 is held by a receptacle 27, and the end face 15a of the light guide fiber 15 is arranged in the light source device 20, as shown in FIG.

The light source device 20 includes a light source lamp 31 such as a metal halide lamp for generating illumination light as a light source unit.
And a lamp power supply 32 for lighting the light source lamp 31
And an infrared cut filter (hereinafter, infrared filter) 33
As a light source unit. The light source lamp 31 is provided with an elliptical reflecting mirror 34 (hereinafter referred to as a reflecting mirror) 34 having a light emitting portion such as a metal halide lamp as a first focus and an end surface 15a of the light guide fiber 15 as a second focus. The reflecting surface of the reflecting mirror 34 reflects only visible light and transmits infrared light. The infrared light of the direct light from the light source lamp 31 is cut by an infrared filter 33. In this way, no infrared rays are incident on the light guide fiber 15.

A stop 35 is disposed between the light source lamp 31 and the light guide fiber 15 to block illumination light from the light source lamp 31. The stop 35 is operated by the rotation of a stepping motor 36. Has become. The stepping motor 36 is provided with the aperture driving circuit 3
7 driven. The aperture drive circuit 37 is controlled by an aperture control circuit 38.
The aperture control circuit 38 is connected to the setting switch unit 24.
When the manual mode is set by manual operation, the aperture drive circuit 37 is operated in accordance with the operation of pressing the setting switch section 24 by the operator, so that a desired brightness can be obtained.

The end face 15 of the light guide fiber 15
At the same time as the illumination light condensed by the reflecting mirror 34 is incident, the infrared LED 4
Infrared light from 1 is also incident. This infrared LED 41 has an LE having a wavelength peak at about 950 nm.
D is generally used for infrared remote controllers. And it is arrange | positioned in the place (illumination path outside) where the illumination light of the light source lamp 31 does not hit.

The infrared light output from the infrared LED 41 enters the light guide fiber end face 15a, passes through the light guide fiber 15, and passes through the light post 12a.
(The connection surface with the endoscope 10). In the light post 12a (the connection surface with the endoscope 10), there are incident light that enters a light guide (not shown) through which the endoscope 10 is inserted, and reflected light that partially reflects from the incident surface. The reflected light returns to the light guide fiber 15 that has passed again, and returns from the light guide fiber end face 15a to the light source lamp 31 to emit the light.

This return light is detected by a light receiving element 42 as a sensor means. The light receiving element 42 is a photodiode, and may be a pin photodiode having sensitivity to infrared rays or a light receiving element 42 having an amplifier built therein. The infrared LED 41 is driven by the detection circuit 50 and the light receiving element 42
The return light detected in step (1) is subjected to signal processing by the detection circuit 50.

In this embodiment, the infrared LED 41
Is synchronized with the detection of the return light by the light receiving element 42, the level of the return light of the detection light is detected, and the disconnection between the endoscope 10 and the light guide cable 14 is determined based on the detection result. When it is determined, the supply of the illumination light is shut off.

As shown in FIG. 4, the detecting circuit 50 includes an oscillating circuit (OSC) 51 for generating an oscillating frequency, and the infrared LED 4 based on the oscillating frequency generated by the oscillating circuit 51.
1, an amplifier circuit (AMP) 53 for amplifying a light-receiving signal from the light-receiving element 42, and a light-receiving signal amplified by the amplifier circuit 53.
The synchronous rectifier circuit 54 outputs only a necessary signal component as a light receiving level in synchronization with the oscillation frequency of 1, a variable amplifier 55 that variably amplifies the light receiving level from the synchronous rectifying circuit 54, and the variable amplifier 55 An A / D converter 56 for A / D converting the amplified light receiving level;
The received light level data that has been A / D-converted by the / D converter 56 is read. The CPU 58 controls the gain by setting the amplification degree of the variable amplifier 55 and outputs a control signal to the aperture control circuit 38.

The infrared LED 41 is connected to the oscillation circuit 5
ON / OFF is repeated by the driving of the driver circuit 52 with the oscillation frequency generated in 1, and the output light modulated at this oscillation frequency is incident on the light guide fiber 15. Then, the return light from the light guide fiber 15 is received by the light receiving element 42, and the light receiving element 42 outputs a light receiving signal. The light receiving signal from the light receiving element 42 is amplified by the amplifier circuit 53, and only the necessary signal components whose timing is adjusted by the synchronous rectifier circuit 54 are output as the light receiving level.

With the synchronous rectification by the synchronous rectification circuit 54,
The light receiving component which becomes noise returning from the light guide fiber 15 is removed. Here, the light receiving component that becomes noise is return light or the like reflected from the subject via a light guide (not shown) that passes through the endoscope.

The received light level data output from the synchronous rectifier circuit 54 is variably amplified by a variable amplifier 55 whose amplification degree is set under the control of the CPU 58, and is converted into a digital signal with high precision. The CPU 58 reads the received light level data converted into a digital signal from the A / D converter 56 in accordance with a flowchart shown in FIG. 6 to be described later, adjusts the gain of the variable amplifier 55, and calculates the boundary of the light receiving level data calculated in advance. Value Vsh
(Setting threshold), the connection or disconnection between the endoscope 10 and the light guide cable 14 is determined. If the endoscope 10 and the light guide cable 14 are not connected, The aperture control circuit 3
8 is output.

Here, the control of the CPU 58 will be described with reference to the flowchart of FIG. First, GAIN is input to the D / A converter 57 as "MI
D "(intermediate value) and outputs it to the variable amplifier 55 (step S1). Next, the light receiving level data converted into a digital signal is read from the A / D converter 56 (step S2). When the received light level data read from the A is overscaled with respect to the scale of the A / D converter 56 (step S3)
The GAI is added to the D / A converter 57 as gain adjustment.
For example, N is set (set) by １ ／ and output to the variable amplifier 55 (step S4), and the process returns to step S2.

On the other hand, if the received light level data read from the A / D converter 56 is underscaled with respect to the A / D converter 56 (step S5),
As a gain adjustment, GAIN is set (set) in the D / A converter 57 by, for example, 1/4 higher and output to the variable amplifier 55 (step S6), and the process returns to step S2.

When the received light level data read from the A / D converter 56 is within the scale of the A / D converter 56, the received light level data is calculated in advance as a boundary value Vsh (set threshold).
And (Step S7). Here, as shown in FIG. 7, when the endoscope 10 and the light guide cable 14 are not connected, the light receiving level data becomes lower than Vsh.

In step 7, the light receiving level data and Vs
h, the received light level data is Vsh
If it is lower than that, it is determined that the light guide cable 14 is not connected to the endoscope 10, and a light-shielded signal is output to the aperture control circuit 38 (step S8).

On the other hand, when the received light level data is equal to or higher than Vsh, the endoscope 10 and the light guide cable 1
Assuming that No. 4 is connected, as shown in steps 9 and 10, the current light receiving level data is recalculated to correct Vsh, and the process returns to step S2 again. still,
The operation according to steps 9 and 10 is, for example, the previous 9
The average value of the received light level data up to this time and the current received light level data is calculated (step S9), and 90% of the calculated average value is taken and stored in a memory (not shown) built in the CPU 58 as the next Vsh (step S10).

As described above, when the disconnection between the endoscope 10 and the light guide cable 14 is determined under the control of the CPU 58, a light-shielding signal is output to the aperture control circuit 38.

The aperture control circuit 38 controls the standby LED 22b of the panel 21 based on the input light-shielded signal.
Is turned on, and a drive level is input to the aperture driving circuit 37 so that the aperture 35 blocks the illumination light from the light source lamp 31, and the aperture driving circuit 37 is operated. The diaphragm driving circuit 37 drives the stepping motor 36 according to the driving level from the diaphragm control circuit 38, and the diaphragm 35 blocks the illumination light from the light source lamp 31 by the rotation of the stepping motor 36. I have.

Using the endoscope apparatus 1 having the light source device 20 configured as described above, the endoscope 10 is inserted through a trocar (not shown) into an insufflated abdominal cavity (not shown) to perform endoscopic observation. Do. Then, when the endoscope 10 is once pulled out at the time of observation and replaced with an endoscope 10 having a different viewing angle, the light guide cable 14 is detached from the endoscope 10 and a replacement operation is performed.

Here, although the light emitted from the light guide cable 14 is dazzling, it is determined by the operation of the detection circuit 50 that the endoscope 10 and the light guide cable 14 are not connected. The output is blocked.
For this reason, the light emitted from the light guide cable 14 does not become dazzling, and the endoscope 10 can be replaced. Endoscope 1
After the replacement of 0, the STAND-BY switch 5 on the panel 21 is pressed down, whereby the STAND-BY is released and illumination light is supplied from the light source lamp 31 so that the original observation can be performed.

As a result, the light emission of the LED 41 is frequency-modulated, and the output signal from the light receiving element 42 is taken out as a light receiving signal in synchronization with the light emission timing of the LED 41. Thus, the conventional light guide cable 14 can be used as it is.

In this embodiment, a metal halide lamp or a xenon lamp is used as the light source lamp 31. However, the present invention is not limited to this, and various types of high-pressure discharge lamps, halogen lamps and the like can be used.

(Second Embodiment) FIGS. 8 to 12 relate to a second embodiment of the present invention, and FIG. 8 shows the inside of a light source device for an endoscope according to a second embodiment of the present invention. FIG. 9 is an explanatory diagram showing a configuration, FIG. 9 is an explanatory diagram showing a light guide detachably connected to an endoscope, FIG. 10 is a modified example of the light guide in FIG. 9, and FIG. 11 is a circuit block showing a detection circuit in FIG. FIG. 12 and FIG. 12 are graphs showing signal waveforms at various parts of the detection circuit of FIG.

In the first embodiment, the illumination light from the light source lamp 31 and the detection light from the infrared LED 41 supplied to the light guide fiber 15 are guided from the same end face 15a of the light guide fiber 15, and Similarly, the return light of the detection light from the end face 15a is configured to be detected by the light receiving element 42. However, in the second embodiment, the detection light from the infrared LED 41 and the detection light detected by the light reception element 42 are detected. It is configured to guide the return light respectively.

As shown in FIG. 8, a light source device 60 according to the second embodiment includes an infrared LED 41 on a receptacle 27 for holding the connector 26 of the light guide cable 14.
And a light receiving element 42.

The light guide fiber 15 inserted into the light guide cable 14 has a structure as shown in FIG. 9, and the light guide fiber 15 has a light guide fiber 61 facing the infrared LED 41.
a and a light guide fiber 61b facing the light receiving element 42 is provided.

The light guide fiber 15 is composed of a light guide fiber 61c constituting the light guide end face 15a on the light source side and the light guide fiber 61a.
The light guide fiber 61b is bundled together to form an end face on the endoscope 10 side.

As shown in FIG. 10, the light guide cable 1 is formed by combining two light guide members 62 on a semicircular ring.
4 may be provided. Thereby, even if the connector 26 of the light guide cable 14 rotates, the detection light from the infrared LED 41 is reliably transmitted by the light guide fiber 14 (61a to 61
c) and the light guide fiber 14
The light receiving element 42 surely receives the return light from (61a to 61c).
Light. These operations are the same even if the light guide members 62 are replaced by rotation.

A detection circuit 70 for driving the infrared LED 41 and processing the return light detected by the light receiving element 42 is constituted by a circuit block shown in FIG. The detection circuit 70 includes an oscillation circuit 51, a driver circuit 52, and an amplification circuit 53 similar to those described with reference to FIG.
An AGC circuit 71 that amplifies a light receiving signal received by the light receiving element 42 by the amplifier circuit 53 and variably amplifies the signal so as to obtain a constant amplitude.
A clamp circuit 72 for clamping the received light signal amplified by the above in synchronization with the oscillation frequency of the oscillation circuit 51; a current detection resistor R1 capable of detecting a current for charging and discharging a capacitor (not shown) in the clamp circuit 72; A voltage amplifying circuit 73 for amplifying the current detected by the current detecting resistor R1 in a detectable manner as a voltage drop; and a constant discharging direction of a capacitor (not shown) amplified by the voltage amplifying circuit 73 and discharged in the clamp circuit 72. The comparator 74 includes a comparator 74 that compares a voltage higher than the level with a reference voltage, and a CPU 75 that outputs a dimming signal based on an output result of the comparator 74.

Using the endoscope device provided with the light source device 60 configured as described above, similarly to the first embodiment, the endoscope 10 is connected to the insufflated abdominal cavity (not shown) via a trocar (not shown). And perform endoscopic observation.

When the light guide cable 14 is disconnected from the endoscope 10 during use of the endoscope 10, the output level of the light receiving element 42 in the light source device 60 decreases, and changes as shown in FIG. . The clamp current flowing through the clamp circuit 72 greatly changes due to the change in the light receiving waveform of the light receiving element 42, and the comparator 74 performs an output based on the change in the current to determine whether the light guide cable 14 is disconnected. The CPU 75 that has determined that the light guide cable 14 is not connected based on the output result of the comparator 74 outputs a dimming signal to the aperture control circuit 38. Aperture control circuit 38
Then, the dimming level is set and output to the aperture drive circuit 37. The aperture driving circuit 37 sets the luminous flux aperture to a dimming level, and supplies the illumination light at a level at which the output from the light source device 60 can be recognized. Subsequent operations are the same as in the first embodiment, and a description thereof will be omitted.

As a result, similarly to the first embodiment, since the non-connection of the light guide cable 14 is optically detected, the connection between the light guide cable 14 and the endoscope 10 can be accurately detected. .

(Third Embodiment) FIGS. 13 to 17
Fig. 13 relates to a third embodiment of the present invention, Fig. 13 is an explanatory view showing the internal configuration of a light source device for an endoscope according to a third embodiment of the present invention, and Fig. 14 is detachably attached to the endoscope. FIG. 15 is a circuit block diagram showing a detection circuit of FIG. 13, FIG. 16 is a graph showing signal waveforms of various parts of the detection circuit of FIG. 15, and FIG. 17 is a control of the CPU of FIG. It is a flowchart explaining.

In the first and second embodiments, the connection of the light guide cable 14 is optically detected. However, in the third embodiment, a detection switch is further provided. I do.

As shown in FIG. 13, a light source device 80 according to the third embodiment is a type in which a parabolic reflector is built in a light source lamp 81 called a ceramic type as a light source lamp, and a xenon gas is sealed therein. It is configured using a high-pressure discharge tube having the structure described below. The illumination light emitted from the light source lamp 81 is output as parallel light by an internal parabolic reflector, and is condensed by a condensing lens 82 to the light guide end face 15.
a.

The light receiving element 42 and the LG detection switch 83 are provided in the receptacle 27 for holding the connector 26 of the light guide cable 14. The LG detection switch 83 has a structure of a micro switch, and is turned on when the light guide cable 14 is inserted. Thereby, connection and non-connection of the light guide cable 14 can be detected.

The infrared LED 41 is arranged at a position where detection light can enter the light guide end face 15a and this detection light does not enter the light receiving element 42 provided in the receptacle 27. Thus, the light receiving element 42 can reliably receive the return light from the light guide end face 15a without being affected by the detection light emitted from the infrared LED 41.

The light guide fiber 15 inserted through the light guide cable 14 is provided with a light guide ring 84 as shown in FIG. 14, and the light of the infrared LED 41 is transmitted to the light guide fiber 15. Light guide fiber 85b that guides light and is branched from the middle
Thus, the light is guided to the light guide ring 84.

A detection circuit 90 that receives the detection signal from the LG detection switch 83, drives the infrared LED 41, and performs signal processing on the return light detected by the light receiving element 42 includes a circuit block shown in FIG. Be composed.

The detection circuit 90 includes an oscillation circuit 51, a driver circuit 52, and an amplification circuit 5 similar to those described with reference to FIG.
3 and an A / D converter 56, and the amplification circuit 53
A pulse generation circuit 91 for synchronizing the light receiving signal amplified by the A / D converter 56 with the oscillation frequency of the oscillation circuit 51 and performing sampling at the timing of A / D conversion by the A / D converter 56; And a CPU 92 for outputting a control signal of “dimming” or “warning” to the aperture control circuit 38 based on the digital signal A / D-converted by the A / D converter 56 with the pulse generated in the above. Is done. Note that the warning signal is generated from a buzzer (not shown) connected to the aperture control circuit 38 so as to generate a warning sound. The A / D converter 56 has a resolution of about 16 bits, does not require AGC (auto gain control) for the input range of the amplifier circuit 53, and has a wide dynamic range. The signal that has been A / D converted in this wide dynamic range has the number of bits of the CPU 92 set to one.
By making it 6 bits, the processing capacity is increased.

Using the endoscope device having the light source device 80 configured as described above, similarly to the first and second embodiments, the endoscope 10 is connected to the insufflation (not shown) via a trocar (not shown). Insert into the abdominal cavity, and perform endoscopic observation.

As in the first embodiment, the infrared light L
The ED 41 is driven in synchronization with the oscillation frequency of the oscillation circuit 51.
N / OFF is repeated, and output light is incident on the light guide fiber 15. The return light from the light guide fiber 15 is received by the light receiving element 42,
2 outputs a light receiving signal. The light receiving signal from the light receiving element 42 is amplified by the amplifier circuit 53, and the pulse generated by the pulse generating circuit 91 is used by the A / D converter 56 to perform A / D conversion.
The / D-converted digital signal is sampled and output as light receiving level data.

Here, as shown in FIG.
When 0 and the light guide cable 14 are not connected, the light receiving level data of the A / D converter 56 becomes lower than the average value. The light receiving level data output from the A / D converter 56 is read into the CPU 92 in accordance with a flowchart shown in FIG. 17 to be described later, and compared with the average value of the previous light receiving level data.
4 and outputs a control signal to the aperture control circuit 38.

When the light guide cable 14 is disconnected from the endoscope 10 during use of the endoscope 10, a detection signal is output from the LG detection switch 83 to the detection circuit 90, and
Upon receiving this detection signal, the CPU 92 of the detection circuit 90 operates as shown in FIG.
The program of the flowchart as shown in FIG. 7 is executed.

Next, the control of the CPU 92 will be described with reference to the flowchart of FIG. First, the presence or absence of a detection signal from the LG detection switch 83 is detected (step S11), and if not, a dimming signal is output to the aperture control circuit 38 (step S12). If there is a detection signal, the light receiving level data converted into a digital signal is read from the A / D converter 56, and the value is set as an A / D value (i) (step S13). Next, the A / D value (i) is read from this A / D value (i-10) to the previous A / D value (i-10), the value is stored (step S14), and the average value of the stored A / D value (i-10) is calculated. It is calculated (step S15). A / D value (i)
Is compared with the average of the calculated A / D values (i-10), and A
If the / D value (i) is low (step S16), A /
The value is read from the D converter 56 and the value is read as the A / D value (i
+1) (step S17). Then, similarly to the A / D value (i), the average value of the A / D value (i-10) is compared. If the A / D value (i) is low (step S18), the dimming signal and the warning signal are output. Output to the aperture control circuit 38.
If the A / D value (i) or the A / D value (i + 1) is not lower than the average value of the A / D value (i-10), the process returns to step S11. In addition, A / D value (i) or A / D
If the value (i + 1) is not lower than the average value of the A / D value (i-10), the process returns to step S11.

As described above, the warning sound is emitted simultaneously with the dimming of the light source device 80, and it informs the operator of the endoscope 10 that the light source device 80 has automatically operated. Then, when the replacement of the endoscope 10 is completed and the light guide cable 14 is connected again, detection of reconnection is performed.

The light receiving level data is read from the A / D converter 56, and the value is set as an A / D value (i + n) (step S20). The A / D value (i + n) is A / D
If the value is equal to or more than the average value (i-10) (step S2)
1), the connection of the light guide cable 14 is detected, a dimming release signal is output to the aperture control circuit 38, and the original setting is returned (step S22), and the illumination light is output from the light source device 80 in the original state. You. On the other hand, the A / D value (i + n) is A
/ D value (i-10) is less than the average value, then step S
Return to 19.

As a result, the reconnection of the light guide cable 14 can be automatically detected, so that the release operation does not have to be performed each time. In addition, by generating an “alarm” sound by an automatic operation, it is possible to notify an operator of an operation state. Moreover, similarly to the first embodiment, since the optical detection is performed, the connection between the light guide cable 14 and the endoscope 10 can be accurately detected.

The present invention is not limited to the above-described embodiment, but can be variously modified without departing from the gist of the invention.

[Supplementary Notes] (Supplementary note 1) A light guide cable which is detachably connectable to an endoscope and has a light guide internally provided with a light guide for transmitting illumination light generated by a light source to the endoscope. And a detection light source capable of supplying a detection light having a wavelength different from that of the illumination light to the light guide of the light guide cable, and a return light of the detection light can be detected from the return light from the light guide. Control means for detecting the level of return light of the detection light, and determining whether or not the endoscope and the light guide are disconnected from each other based on the detection result. And a light source device for an endoscope.

(Additional Item 2) The control means calculates a predetermined boundary value from the level of return light of the detection light when the endoscope is connected to the light guide, and detects the predetermined boundary value with respect to the boundary value. When the level of the return light of the detection light is low, it is determined that the endoscope is not connected to the light guide. When the level of the return light is higher than the boundary value, the endoscope and the light are not connected. The light source device for an endoscope according to claim 1, wherein the connection with the guide is determined.

(Appendix 3) A light guide cable which is detachably connectable to an endoscope and has a light guide internally provided with a light guide for transmitting illumination light generated by a light source to the endoscope, and an inner light guide cable. A light guide for detecting light for transmitting detection light other than the illumination light, and a detection light having a wavelength different from that of the illumination light from the light source, and the detection light is used as a light for detection light of the light guide cable. A detection light source that can be supplied to the guide, a detection light reflection portion provided at a light guide cable connection portion of the endoscope, and the detection from a return light from the detection light reflection portion provided at the light guide cable connection portion. Sensor means capable of detecting return light of light, detecting the level of return light of the detection light, and when it is determined that the endoscope and the light guide are not connected based on the detection result, A light source device for an endoscope, comprising: control means for interrupting or decreasing supply.

(Additional Item 4) The control means calculates a predetermined boundary value from the level of return light of the detection light when the endoscope is connected to the light guide, and detects the boundary value with respect to the boundary value. When the level of the return light of the detection light is low, it is determined that the endoscope is not connected to the light guide. When the level of the return light is higher than the boundary value, the endoscope and the light are not connected. The light source device for an endoscope according to claim 3, wherein the connection with the guide is determined.

(Additional Item 5) The light source device for an endoscope according to additional item 1 or 3, further comprising light guiding means for guiding return light of the detection light to the sensor means.

[0066]

As described above, according to the present invention, it is possible to realize an endoscope light source device capable of detecting the connection between the light guide and the endoscope with high accuracy.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an endoscope apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a panel layout of the light source device for an endoscope in FIG. 1;

FIG. 3 is an explanatory view showing a light guide detachably connected to the endoscope of FIG. 1;

FIG. 4 is an explanatory diagram showing the internal configuration of the endoscope light source device of FIG. 1;

FIG. 5 is a circuit block diagram showing a detection circuit of FIG. 4;

FIG. 6 is a flowchart illustrating control of the CPU in FIG. 5;

FIG. 7 is a graph showing output light after synchronous rectification.

FIG. 8 is an explanatory diagram showing an internal configuration of a light source device for an endoscope according to a second embodiment of the present invention.

FIG. 9 is an explanatory view showing a light guide detachably connected to the endoscope.

FIG. 10 is a modified example of the light guide of FIG. 9;

FIG. 11 is a circuit block diagram illustrating the detection circuit of FIG. 8;

FIG. 12 is a graph showing signal waveforms at various parts of the detection circuit of FIG. 11;

FIG. 13 is an explanatory diagram showing an internal configuration of a light source device for an endoscope according to a third embodiment of the present invention.

FIG. 14 is an explanatory view showing a light guide detachably connected to the endoscope.

15 is a circuit block diagram showing the detection circuit of FIG.

16 is a graph showing the signal waveform of each part of the detection circuit of FIG.

17 is a flowchart illustrating control of the CPU in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Endoscope apparatus 10 ... Endoscope 14 ... Light guide cable 15 ... Light guide fiber 20 ... Light source device (light source device for endoscope) 31 ... Light source lamp 35 ... Stop 36 ... Stepping motor 37 ... Stop drive circuit 38 ... Aperture control circuit 41... Infrared LED (detection light source) 42... Light receiving element (sensor) 50. Amplifier 56 A / D converter (A / D) 57 D / A converter (D / A) 58 CPU

Claims (2)

[Claims] 1. A light guide cable which is detachably connectable to an endoscope and has a light guide provided therein for transmitting illumination light generated by a light source to the endoscope, and is different from illumination light from the light source. A detection light source capable of generating detection light of a wavelength and supplying the detection light to a light guide of the light guide cable; a sensor unit capable of detecting return light of the detection light from return light from the light guide; Control means for detecting the level of return light of the detection light, and for interrupting or reducing the supply of the illumination light when the disconnection between the endoscope and the light guide is determined based on the detection result. A light source device for an endoscope, comprising: 2. The control means calculates a predetermined boundary value from a level of return light of detection light when the endoscope is connected to the light guide, and calculates a predetermined boundary value of the detection light with respect to the boundary value. When the level of the return light is low, it is determined that the endoscope is not connected to the light guide. When the level of the return light is high with respect to the boundary value, the connection between the endoscope and the light guide is determined. The light source device for an endoscope according to claim 1, wherein connection is determined.