JP5273865B2 - Endoscope light source device - Google Patents

Description

  The present invention relates to an endoscope light source device capable of supplying blinking illumination light.

  In general, an electronic endoscope system for diagnosing or treating the inside of a body cavity of a patient is generated by an electronic endoscope that images the inside of the body cavity with an image pickup device such as a CCD provided at a distal end portion, and an electronic endoscope. A video processor that processes the output image signal and outputs the processed image signal to a monitor, and a light source device that supplies light for illuminating the observation site in the body cavity to the electronic endoscope. Some video processors incorporate a light source device. In such an electronic endoscope system, illumination light from the light source device is irradiated from the front end of the electronic endoscope into the body cavity, and reflected light reflected by the body cavity wall is photoelectrically converted by the CCD. The electric charge generated by the photoelectric conversion is read as an image signal, transferred to a video processor, and output to a monitor.

  In addition, in a conventional electronic endoscope system, a method for shortening an exposure time in each frame photographed by a CCD is known in order to clearly capture a moving subject. Patent Document 1 includes an optical chopper (hereinafter referred to as “chopper”) for flickering illumination light between an endoscope light guide and a light source in order to adjust the exposure time. An endoscope light source device is also described. The chopper described in Patent Document 1 has a rotating disk composed of an opening and a light shielding part, and the rotating disk is arranged so as to cross the optical path of illumination light. Then, when the rotating disk rotates at a constant rotation speed, the state where the illumination light passes through the opening and the state where the illumination light is blocked by the light shielding unit are alternately repeated, and the light passing through the rotating disk is periodically It enters the light guide as intermittent illumination light (hereinafter referred to as “flickering light”) that repeats blinking. Further, the exposure time in the CCD can be adjusted by adjusting the ratio of the opening or the light shielding part in the rotating disk. Further, the rotation of the chopper's turntable is controlled so that the passing light blinks in synchronization with the image transfer signal of the endoscope. Thus, the exposure time in each frame is adjusted to a certain time.

Japanese Patent Publication No. 6-38134

  By the way, in recent years, an increase in the number of pixels of an image sensor used in an electronic endoscope system, more specifically, an increase in megapixels has been progressing. In such an image sensor with a high pixel count, it takes a long time to store charges during imaging, and the field rate of the image sensor decreases accordingly. For example, the field rate in an image sensor with 1.2 million pixels suitable for use in an electronic endoscope is about 30 Hz. When imaging with blinking light using an electronic endoscope equipped with such a high-pixel-number imaging device, the chopper provided in the light source device synchronizes the passing light with the image transfer signal at the field rate. The rotation speed is controlled so as to blink at a frequency of about 30 Hz.

  Usually, the blinking light by the chopper as described above is irradiated toward the body cavity wall in a state where the electronic endoscope is inserted into the body cavity, so that it is not assumed to enter the eyes of the operator or the patient. However, in practice, an electronic endoscope that emits blinking light before and after the examination may be placed in the examination room, and the blinking light may enter the eyes of an operator or other person in the examination room. . In addition, the illumination light from the light source device is used for direct observation, such as when the illumination light of an electronic endoscope is used as illumination when observing a lesion removed from the body cavity or inside the oral cavity before the examination. In this case, a blinking light will enter the eyes of the surgeon.

  Here, in general, the frequency of light that humans recognize as continuous light is 50 Hz or more. Therefore, when using an electronic endoscope that performs imaging at a field rate of 50 Hz or more, even if the blinking light emitted by the electronic endoscope directly enters the eyes of an operator or the like, it is recognized as continuous light. However, when using an electronic endoscope that performs imaging at a field rate of 30 Hz as described above, the blinking light of 30 Hz emitted from the electronic endoscope is also perceived as blinking light by the human eye. In particular, the inside of the examination room during and before and after the examination of the electronic endoscope may be darkened in advance, so that flickering light is easily detected. For this reason, there is a problem that an operator who sees the flickering light feels uncomfortable due to the flickering of light or cannot perform appropriate direct observation.

  Therefore, the present invention has been made in view of the above circumstances, and in a situation where blinking light enters the eyes of an operator or the like, it is possible to switch the frequency at which the illumination light blinks to a frequency range in which flicker does not feel. An object of the present invention is to provide an endoscope light source device.

  In order to solve the above problems, according to the present invention, an endoscope light source device for supplying illumination light to an endoscope is disposed between and passes through a light source and a light guide of the endoscope. Illumination light blinking means for periodically blinking the illumination light, control means for controlling the illumination light blinking means to blink the illumination light at a first frequency based on a signal from the endoscope, and irradiation from the endoscope Illuminating light detection means for detecting the illuminating light to be emitted, and the control means illuminates at a second frequency higher than the first frequency when the illuminating light is detected by the illuminating light detecting means. An endoscope light source device is provided that controls illumination light blinking means so as to blink.

  In this case, the second frequency may be set to an integer multiple of the first frequency. The second frequency is preferably 50 Hz or more. With such a configuration, when the illumination light emitted from the endoscope is detected by the illumination light detection means, that is, the endoscope is not inserted into the patient's body and the operator or the person in the examination room In the case of direct eye contact, switching the frequency of the blinking light can prevent the operator from feeling uncomfortable due to the light flickering.

  Further, the signal from the endoscope may be a vertical synchronization signal. With this configuration, the exposure time in each field can be adjusted to a certain time.

  The illumination light detection means may include a photo sensor that detects light that illuminates the outside of the body cavity and outside the endoscope light source device. Further, the illumination light detecting means detects the illumination light emitted from the endoscope when the blinking of the light detected by the photosensor is synchronized with the blinking of the illumination light that is blinked by the first frequency. It may be determined that it has been done. With this configuration, it is possible to appropriately detect whether or not the flickering light is scattered in the examination room.

  Therefore, according to the present invention, it is possible to provide an endoscope light source device capable of switching the frequency at which the illumination light flickers to a frequency range in which the flickering light does not feel an unpleasant flicker when the blinking light enters the eyes of an operator or the like. can do.

1 is a schematic configuration diagram of an electronic endoscope system in an embodiment of the present invention. It is (a) enlarged front view and (b) enlarged side view of a turntable in an embodiment of the present invention. It is a figure which shows the structure of the motor control part in embodiment of this invention. It is a flowchart which shows the frequency switching process in embodiment of this invention. It is a block diagram which shows the structure of the blinking light detection circuit in embodiment of this invention. It is a flowchart which shows the blinking light detection process in embodiment of this invention. It is a figure for demonstrating the blinking light detection process in embodiment of this invention.

  Hereinafter, an electronic endoscope system 1 using an endoscope light source device according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of an electronic endoscope system 1 of the present embodiment. The electronic endoscope system 1 is a medical observation system for an operator to observe and diagnose the inside of a patient's body cavity. The electronic endoscope system 1 includes an electronic endoscope 10 for taking an image of a body cavity, a processor 20 including the endoscope light source device of the present invention, and a monitor 30.

  The electronic endoscope 10 includes an insertion portion 10a that is a long flexible tube that is inserted into a patient's body, and a connection portion 10c that is electrically and optically connected to the processor 20. A light guide 101 for propagating light supplied from the processor 20 extends from the connection portion 10c of the electronic endoscope 10 to the distal end of the insertion portion 10a. In addition, a light distribution lens 102 for emitting light propagated by the light guide 101 to the observation site is formed at the distal end of the insertion portion 10a, and light reflected from the observation site is imaged on the light receiving surface of the image sensor. Objective lens 103, and CCD 104, which is a solid-state imaging device that generates an image signal based on the subject image formed on the light receiving surface.

  In addition, the connection unit 10c of the electronic endoscope 10 stores drive control of the CCD 104, a drive / processing circuit 105 that performs image processing on an image signal generated by the CCD 104, model information of the electronic endoscope 10, and the like. An EEPROM 106 is provided.

  The processor 20 has a system controller 201 and a timing controller 202 for driving and synchronizing the entire electronic endoscope system 1, and a video signal output from the electronic endoscope 10 in a format suitable for display on the monitor 30. A video signal processing circuit 203 for conversion, a front panel 204 provided with various operation buttons including a main power switch, and a light source unit 205 for supplying illumination light to the electronic endoscope 10 are provided. The light source unit 205 includes a light source 251 formed of a high-intensity lamp such as a halogen lamp or a xenon lamp, and a motor control unit 252 that configures an optical chopper for blinking light emitted from the light source 251, a motor driver 253, a motor 254, an encoder 255, a turntable 256, and a photo interrupter 257.

  Further, a transparent cover 208a is provided in the vicinity of the front panel 204 of the processor 20 of the present embodiment. Further, a photo sensor 208 is disposed behind the transparent cover 208a. The photosensor 208 is made up of a phototransistor, a CDS element, and the like, and is a sensor for detecting light in the examination room where the processor 20 is disposed via the transparent cover 208a. Further, the processor 20 includes a blinking light detection circuit 206 that performs a blinking light detection process described later based on the detection result of the photosensor 208. The monitor 30 is a display device having a general image receiving function for displaying an image based on the video signal processed by the video signal processing circuit 203.

  In-body cavity observation in the electronic endoscope system 1 having the above-described configuration is performed as follows. First, when the power of the processor 20 is turned on, the light source 251 is driven and irradiated with illumination light. Then, the operator inserts the insertion portion 10a of the electronic endoscope 10 into the patient's body. The continuous light emitted from the light source 251 is converted into flickering light by a turntable 256 disposed in the optical path. Until the switch (not shown) on the front panel 204 is pressed, the rotating disk is controlled to stop in a light passing state, and continuous light is emitted from the tip of the electronic endoscope 10. FIG. 2 is an enlarged view of the rotating disk 256. FIG. 2A is a front view of the turntable 256, and FIG. 2B is a side view of the turntable 256. The rotating disk 256 has a disk shape centered on the rotating shaft 256a. The turntable 256 has an opening 256b and a light shielding portion 256c.

  A motor 254 and an encoder 255 are attached to the rotating shaft 256 a of the rotating disk 256. The motor 254 is driven according to the drive signal supplied from the motor driver 253, and rotates the rotating disk 256 at a predetermined speed. The encoder 255 is interlocked with the rotating shaft 256a, and outputs an index pulse signal every time the rotating disk 256 makes one rotation. Further, the motor driver 253 drives the motor 254 in accordance with a control signal output from the motor control unit 252. The processing in the motor control unit 252 will be described in detail later.

  The continuous light emitted from the light source 251 enters one end of the light guide 101 when the opening 256b of the turntable 256 is in its optical path. On the other hand, when the light shielding portion 256c of the turntable 256 is in the optical path, light cannot be passed through the turntable 256 because the light is blocked by the light shielding portion 256c. That is, when the rotating plate 256 is rotated by the motor 254, the continuous light emitted from the light source 251 can be converted into blinking light.

  A photo interrupter 257 is attached to the turntable 256. The photo interrupter 257 includes a light emitting unit made of a light emitting diode or the like and a light receiving unit made of a phototransistor or the like, and is arranged so that the light emitting unit and the light receiving unit face each other with the rotating disk 256 interposed therebetween. The photo interrupter 257 is disposed on the same radial line centered on the rotation axis 256a with the light beam position of the light source 251. When the photo interrupter 257 is located at the opening 256b of the turntable 256, the light from the light emitting portion reaches the light receiving portion. When the photointerrupter 257 is located at the light shielding portion 256c of the turntable 256, the light shielding portion 256c causes the light emitting portion. The light from is blocked. As a result, an output signal synchronized with the blinking light incident on the light guide 101 (hereinafter referred to as “flickering light signal”) is generated by the photo interrupter 257.

  The blinking light that has entered the light guide 101 of the electronic endoscope 10 is propagated through the light guide 101 and is emitted from the distal end of the insertion portion 10 a through the light distribution lens 102. Then, the light reflected by the biological tissue in the body cavity is imaged on the light receiving surface of the CCD 104 via the objective lens 103. In the present embodiment, a single-plate simultaneous type is applied as a color imaging method, and yellow (Ye), cyan (Cy), magenta (Mg), and green (G) color elements are checked on the light receiving surface of the CCD 104. Complementary color filters (not shown) arranged in a line are arranged corresponding to each pixel on the light receiving surface. In the CCD 104, an image signal corresponding to the intensity of light transmitted through the complementary color filter is generated by photoelectric conversion, and an image signal for one field is sequentially read by a color difference line sequential method at predetermined time intervals based on the field rate. And sent to the driving / processing circuit 105.

  In the driving / processing circuit 105, predetermined processing is performed on the image signal, and a video signal including the luminance signal Y and the color difference signals RY and BY is generated. The predetermined processing here includes, for example, clipping processing that limits the dynamic range of the image signal to a predetermined range, and gamma that corrects the γ (gamma) characteristics so that the gradation characteristics and color reproducibility of luminance are appropriate. Correction processing and the like are included. The video signal generated by the driving / processing circuit 105 is output to the video signal processing circuit 203 of the processor 20. The drive / processing circuit 105 outputs a drive signal to the CCD 104 as a CCD driver for driving the CCD 104.

  In the video signal processing circuit 203, the luminance signal component in the received video signal is subjected to noise reduction processing or the like, and the luminance signal, the color difference signal, and the decoding synchronization signal with reduced noise are multiplexed, such as an NTSC composite video signal. A video signal is generated. Then, the generated video signal is output from the processor 20 to the monitor 30, and a subject image based on the video signal is displayed on the monitor 30. Thereby, the surgeon and the diagnostician can observe the state in the body cavity of the patient from the subject image displayed on the monitor 30.

  Next, rotation control of the turntable 256 in the motor control unit 252 will be described. FIG. 3 is a diagram illustrating a schematic configuration of the motor control unit 252. As shown in FIG. 3, the motor control unit 252 includes a phase comparator 2521 and a frequency divider 2523. The phase comparator 2521 receives the synchronization signal transmitted from the electronic endoscope 10 and the index pulse signal from the encoder 255 converted by the frequency divider 2523. The synchronization signal here is a signal synchronized with a vertical synchronization signal at the time of image transfer in the electronic endoscope 10. The phase comparator 2521 compares the input synchronization signal with the phase of the index pulse signal, and controls the motor 254 so as to eliminate the phase difference, thereby rotating the rotating disk 256.

  The frequency divider 2523 converts the frequency of the index pulse signal output from the encoder 255 into a 1 / N frequency. The frequency division number N in the frequency divider 2523 is set to 1 or 2 based on the result of the blinking light detection process by the blinking light detection circuit 206. Here, when the frequency division number N is set to 1, the frequency of the index pulse signal from the encoder 255 is output to the phase comparator 2521 without being changed. As a result, the motor 254 rotates the turntable 256 at a speed that causes the continuous light from the light source 251 to blink at the same frequency as the synchronization signal of the electronic endoscope 10. On the other hand, when the frequency division number N is set to 2, the frequency of the index pulse signal from the encoder 255 is converted to 1/2 and output to the phase comparator 2521. As a result, the motor 254 rotates the turntable 256 at such a speed (that is, double speed) that the continuous light from the light source 251 blinks at a frequency twice that of the synchronization signal of the electronic endoscope 10.

  Next, the blinking light frequency switching process in this embodiment will be described. As described above, in the present embodiment, the frequency of the blinking light is switched by switching the value of the frequency division number N in the frequency divider 2523. Further, in the present embodiment, the frequency of the blinking light when the blinking light is emitted from the tip of the electronic endoscope 10 is placed in the examination room, that is, when the blinking light is scattered in the examination room. Is switched to 50 Hz or higher. FIG. 4 is a flowchart showing the flow of frequency switching processing in the present embodiment. This process starts when the electronic endoscope 10 is connected to the processor 20 under the control of the system controller 201 and the front panel 204 or the like is operated to start the emission of blinking light.

  In this process, first, the frequency division number N in the frequency divider 2523 of the motor control unit 252 is set to 1 which is an initial value (S1). Subsequently, it is determined whether or not the field rate of the electronic endoscope 10 connected to the processor 20 is 50 Hz or more (S2). Specifically, when the electronic endoscope 10 is connected to the processor 20, model information stored in the EEPROM 106 of the electronic endoscope 10 is transmitted to the processor 20. The system controller 201 determines the field rate of the electronic endoscope 10 based on the transmitted model information.

  If the field rate of the electronic endoscope 10 is 50 Hz or higher (S2: Yes), the frequency division number N remains 1 (S6) and the process returns to S2. Here, as described above, the frequency of light that humans generally recognize as continuous light is 50 Hz or more. For this reason, when synchronized with a vertical synchronization signal of an electronic endoscope that is driven at a field rate of 50 Hz or higher, light that blinks at 50 Hz or higher is emitted, and thus humans recognize it as continuous light. Therefore, when the field rate of the connected electronic endoscope 10 is 50 Hz or higher, the frequency division number N is set to 1, and the rotation of the turntable 256 is controlled.

  On the other hand, if the field rate of the electronic endoscope 10 is not 50 Hz or higher (S2: No), then a blinking light detection process is performed (S3). In the blinking light detection process, based on the detection result by the photosensor 208, it is determined whether or not the blinking light emitted from the tip of the electronic endoscope 10 is scattered in the examination room. The blinking light detection process will be described with reference to FIGS. FIG. 5 is a block diagram showing a schematic configuration of the blinking light detection circuit 206, and FIG. 6 is a flowchart of the blinking light detection process.

  In the blinking light detection process, first, the light outside the processor 20 (that is, the examination room) is detected by the photosensor 208, and the detection result is acquired as an output signal (S31). The acquired output signal is output to the band limiting circuit 261 of the blinking light detection circuit 206. In the band limiting circuit 261, the band of the output signal of the photosensor 208 is limited, and the noise component is cut (S32). The band-limited output signal is output to the amplifier circuit 262 and amplified by the amplifier circuit 262 (S33). The amplified signal is input to the waveform shaping circuit 263, and the waveform is shaped so as to be a rectangular wave for comparison to be described later (S34). Then, the signal shaped into a rectangular wave is output to the phase / speed comparator 264.

  The phase / velocity comparator 264 compares the phase and frequency of the output signal from the photosensor 208 and the blinking light signal output from the photointerrupter 257 (S35). FIG. 7 is a diagram for explaining phase and frequency comparison in the phase / speed comparator 264. In each waveform of FIG. 7, the horizontal axis represents time, and the vertical axis represents the output value of the signal. 7A shows a blinking light signal output from the photo interrupter 257, and FIG. 7B shows an output signal from the photosensor 208 shaped by the waveform shaping circuit 263. The phase / velocity comparator 264 determines how much the frequency and phase of the output signal shown in FIG. 7B are deviated from the frequency and phase of the blinking optical signal shown in FIG. It detects and outputs a signal as shown in FIG. 7C according to the deviation.

  Here, when the blinking light emitted from the electronic endoscope 10 is detected by the photosensor 208, the output signal from the photosensor 208 and the blinking light signal from the photo interrupter 257 are substantially synchronized. On the other hand, when only the light other than the blinking light emitted from the electronic endoscope 10 is detected by the photosensor 208, for example, the light from the display screen of the monitor 30 or the leakage light from outside the examination room, the photosensor 208 The output signal is not synchronized with the blinking light signal from the photo interrupter 257, and a signal corresponding to the phase and frequency deviation is output by the phase / speed comparator 264.

  Subsequently, a signal is output from the phase / speed comparator 264 to the ripple removal circuit 265. In the ripple removing circuit 265, the signal output from the phase / speed comparator 264 is averaged and converted into a signal as shown in FIG. 7D (S36). As shown in FIG. 7D, in the signal after ripple removal, in the periods P1 and P4 in which the blinking light signal from the photo interrupter 257 and the output signal from the photo sensor 208 are synchronized, the output value Becomes 1/2 Vcc. On the other hand, the output value becomes 0 in the period P2 in which the output signal from the photosensor 208 is advanced with respect to the blinking light signal from the photo interrupter 257. Furthermore, the output value becomes Vcc during the period P3 in which the output signal from the photosensor 208 is delayed with respect to the blinking light signal from the photo interrupter 257. Note that the ripple removing circuit 265 of this embodiment includes a low-pass filter having a time constant of several seconds. By using the ripple removing circuit 265 to perform averaging based on a signal for several seconds output from the phase / speed comparator 264, it is possible to reduce the influence of noise.

  Subsequently, it is determined whether or not the output signal from the ripple removing circuit 265 is 1/2 Vcc (S37). Here, when the output signal from the ripple removing circuit 265 is 1/2 Vcc (S37: Yes), it is determined that the blinking light is detected by the photosensor 208 (S38). On the other hand, when the output signal from the ripple removing circuit 265 is not ½ Vcc (S37: No), it is determined that the flickering light is not detected by the photosensor 208 (S39). After the processes of S38 and S39, the blinking light detection process is terminated, and the process returns to the frequency switching process of FIG.

  Returning to FIG. 4, in subsequent S <b> 4, a determination is made on the result of the blinking light detection process. Here, if it is determined that the blinking light is detected in the blinking light detection process (S4: Yes), the frequency division number N in the frequency divider 2523 is set to 2 (S5). As a result, the frequency of the index pulse signal from the encoder 255 is converted to 1/2 by the frequency divider 2523 in the motor control unit 252 and output to the phase comparator 2521. As a result, for example, when the frequency (field rate) of the synchronization signal of the electronic endoscope 10 is 30 Hz, the turntable 256 is set so that the continuous light from the light source 251 blinks at 60 Hz, which is twice that frequency. The rotation is controlled at double speed. Thereby, the frequency of the blinking light radiated into the examination room becomes 60 Hz, which is recognized as continuous light by an operator or the like.

  On the other hand, if it is determined that the blinking light is not detected in the blinking light detection process (S3: No), the frequency division number N is set to 1 (S6). In this case, since it is considered that the electronic endoscope 10 is not directly in the eyes of the operator or the like because it is inserted into the patient's body, the continuous light from the light source 251 is synchronized with the electronic endoscope 10. The turntable 256 is rotationally controlled so as to blink in synchronization with the frequency of the signal (for example, 30 Hz).

  After the processes of S5 and S6, the process returns to the process of S2, and the frequency division number N is switched based on the field rate of the electronic endoscope 10 connected to the processor 20 and the detection result of the blinking light by the photosensor 208. It is done. For example, if the frequency division number N is set to 2 in S5 and the blinking light has a frequency twice that of the synchronization signal, and the electronic endoscope 10 remains in the examination room, the blinking light detection in S3 is performed. In the process, it is determined that the blinking light is detected again. This is because the blinking light signal from the photo interrupter 257 and the output signal from the photo sensor 208 are both synchronized at a double frequency, as shown in the period P4 in FIG. In this case, the frequency division number N is continuously set to 2, and the turntable 256 is controlled so that the blinking light has a frequency twice that of the synchronization signal.

  On the other hand, if the electronic endoscope 10 is inserted into the patient's body for in-vivo observation after the frequency division number N is set to 2 in S5 and flickering light having a frequency twice that of the synchronization signal is supplied, S3 In the blinking light detection process, it is determined that no blinking light is detected, and the frequency division number N is switched to 1. Thereby, the rotational speed of the turntable 256 is automatically controlled so that the blinking light is synchronized with the synchronization signal.

  As described above, the processor 20 in this embodiment determines whether or not the blinking light emitted from the electronic endoscope 10 is scattered in the examination room by the blinking light detection circuit 206 based on the detection result of the photosensor 208. to decide. When it is determined that the blinking light is detected by the blinking light detection circuit 206, the frequency division number N is set so that the continuous light from the light source 251 blinks at a frequency of 50 Hz or more. It is the structure to control. With this configuration, when the insertion portion 10a of the electronic endoscope 10 is taken out from the patient's body and the blinking light directly enters the eyes of an operator or the like, the human recognizes the continuous light as 50 Hz or more. A flickering light that flickers at a frequency is supplied. Thereby, even when flickering light directly enters the human eye, discomfort can be prevented without detecting flicker. Furthermore, when the illumination light from the light source device is used for direct observation, such as when the illumination light of an electronic endoscope is used as illumination when observing a lesion removed from the body cavity or inside the oral cavity before the examination However, appropriate direct observation can be performed with illumination light without flicker.

  Further, when the blinking light is no longer detected by the blinking light detection circuit 206, the frequency division number N is set so that the continuous light from the light source 251 is synchronized with the synchronization signal of the electronic endoscope 10. 256 is controlled. With this configuration, when the electronic endoscope 10 is inserted into the patient's body, that is, when observing the endoscope with the electronic endoscope 10, blinking light suitable for imaging inside the body cavity is supplied. .

  Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments and can be modified in various ranges. For example, in the above-described embodiment, as a means for converting continuous light into blinking light, a rotary disk type optical chopper is used, but for example, a reflective type having a rotating mirror, a liquid crystal cell, a car cell, etc. A shutter using an electro-optical effect or a shutter using a magneto-optical effect such as a Faraday effect or a magnetic Kerr effect may be used as a means for blinking illumination light.

  In the above-described embodiment, the frequency dividing number in frequency divider 2523 is set to either 1 or 2. However, the present invention is not limited to this, and an arbitrary integer is set. It is good also as a structure. As a result, the frequency of the blinking light can be set to an integral multiple of the synchronization signal from the electronic endoscope 10, and a wide range of electronic endoscopes (for example, low-field-rate (20 Hz, etc.) electronic endoscopes). Can also be supported.

  Furthermore, in the above-described embodiment, the photo sensor 208 is provided in the vicinity of the front panel 204 of the processor 20, but for example, the photo sensor may be provided in the grip portion of the electronic endoscope 10. In this case, the signal detected by the photo sensor of the electronic endoscope 10 is transmitted to the blinking light detection circuit 206 of the processor 20 to perform the blinking light detection process. With this configuration, even when the processor 20 and the electronic endoscope 10 are located at a distance from each other, it is possible to appropriately detect the blinking light.

DESCRIPTION OF SYMBOLS 1 Electronic endoscope system 10 Electronic endoscope 20 Processor 30 Monitor 205 Light source part 251 Light source 252 Motor control part 253 Motor driver 254 Motor 255 Encoder 256 Turntable 257 Photo interrupter 206 Blink light detection circuit 208 Photo sensor

Claims (6)

An endoscope light source device for supplying illumination light to an endoscope,
Illumination light blinking means that is arranged between a light source and a light guide of the endoscope and periodically blinks the illumination light passing therethrough,
Control means for controlling the illumination light blinking means to blink illumination light at a first frequency based on a signal from the endoscope;
Illumination light detection means for detecting illumination light emitted from the endoscope,
The control means controls the illumination light blinking means to blink the illumination light at a second frequency higher than the first frequency when the illumination light is detected by the illumination light detection means. An endoscope light source device characterized by the above.   The endoscope light source device according to claim 1, wherein the second frequency is 50 Hz or more.   The endoscope light source device according to claim 1, wherein the second frequency is an integral multiple of the first frequency.   The light source device for an endoscope according to any one of claims 1 to 3, wherein the signal from the endoscope is a vertical synchronization signal.   The said illumination light detection means includes the photo sensor which detects the light which is the exterior of the said light source device for endoscopes, and illuminates the body cavity outside, The one of Claims 1-4 characterized by the above-mentioned. The light source device for endoscopes described in 1.   The illumination light detection unit is configured to detect illumination light emitted from the endoscope when the blinking of light detected by the photosensor is synchronized with the blinking of illumination light that is blinked by the first frequency. The endoscope light source device according to claim 5, wherein the endoscope light source device is determined to be detected.

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