JP6523237B2 - Endoscope system - Google Patents

Description

  The present invention relates to an endoscope system.

  Generally, an endoscope system is used to observe a living tissue in a body cavity. The endoscope system irradiates white light as illumination light to a portion to be observed in a body cavity, and captures an optical image by light reflected from the portion to be observed using a predetermined imaging element capable of capturing a two-dimensional image And display the obtained two-dimensional image on the monitor screen. Techniques related to control of illumination light of such an endoscope system are shown, for example, in Patent Documents 1 to 3.

  Patent Document 1 discloses a technique for always obtaining illumination light of appropriate light quantity and chromaticity. Specifically, it is proposed to change the drive current to be supplied to the light source in a pulse form and to control the number of pulses, the pulse width, and the pulse amplitude for this pulse.

  Patent Document 2 discloses a technique for supplying illumination light to a diseased part while suppressing heating of the endoscope scope tip. Specifically, it is proposed to control on / off of the light source in a pulse shape and to adjust the lighting time of the light source and the amplitude (intensity) of the pulse.

  Patent Document 3 discloses a technique for making it possible to select only an observation mode corresponding to a connected endoscope in an endoscope apparatus corresponding to a plurality of observation modes. Here, the observation mode is a division such as normal light observation, fluorescence observation, narrow band light observation, infrared light observation and the like.

  By the way, a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal-Oxide Semiconductor) image sensor is known as an imaging element that can be used to capture a two-dimensional image by the endoscope system. Further, as is well known, the CCD image sensor and the CMOS image sensor have different signal readout systems due to their structural differences, and shutter control at the time of photographing is different.

  For example, in the case of an interline CCD image sensor, a light receiving unit, a vertical transfer unit, a horizontal transfer unit, an amplifier, etc. are provided, and a vertical transfer unit capable of holding electric charge for all pixels in the light receiving unit . Therefore, after the exposure is completed, the charges accumulated in each pixel can be transferred to the vertical transfer unit at the same timing. Therefore, the timing to start the charge accumulation at each pixel position of the light receiving unit and the timing to end the charge accumulation are simultaneous for all pixels. That is, when capturing a two-dimensional image, the shutter can be simultaneously released for the entire one frame of the two-dimensional image only by the control on the image sensor side. Such shutter control is called a global shutter system.

  On the other hand, in the case of a general CMOS image sensor, charge is read out row by row sequentially from each pixel position of the light receiving part of the two-dimensional array of N rows and M columns, and the accumulated charge is initialized. Therefore, the timing at which the charge accumulation starts at each pixel position of the light receiving unit and the timing at which the charge accumulation ends are slightly shifted for each row. That is, when capturing a two-dimensional image, the timing of releasing the shutter is shifted for each row of the two-dimensional image only by the control on the image sensor side, and the shutter can not be released simultaneously for the entire one frame. Such shutter control is called a rolling shutter system.

  Therefore, in the case of an endoscope system adopting a general CMOS image sensor, the timing of the charge accumulation period (the time when the shutter is substantially open) of each position of the light receiving unit is shifted for each scanning line. . Therefore, when the lighting start timing of the light source is adjusted for light control of the illumination, a difference in the illumination light amount occurs for each scanning line of the two-dimensional image, and uneven brightness occurs in the image.

  When controlling only the amplitude (emission intensity) of the current supplied to the light source, the illumination light amount is not affected by the timing deviation of signal readout etc. Therefore, an endoscope system adopting a general CMOS image sensor Even in the case of the above, unevenness in luminance does not occur for each scanning line. However, an endoscope system generally requires a light quantity dynamic range of 1: 9000 or more. In order to realize such a wide light quantity dynamic range, it can not cope with only the amplitude control of the current supplied to the light source.

  On the other hand, in the case of an endoscope system employing a CCD image sensor, the timing for reading out the signal does not shift for each scanning line, so the lighting start timing of the light source etc. should be adjusted for light control of the illumination. Is also possible. In addition, in the case of an endoscope system adopting a CCD image sensor, there is a period in which the shutter is closed simultaneously for all pixels, so during this period unnecessary heat is turned off to suppress heat generation. Help. However, in the case of an endoscope system employing a general CMOS image sensor, since the period during which the shutter is closed is shifted for each scanning line, the illumination can not be turned off during a specific period.

JP, 2009-56248, A JP, 2007-222251, A JP, 2005-6974, A

  As described above, the optimal control of the illumination light differs depending on the type of the imaging device mounted in the endoscope to be used, but it is possible to optimally control the emitted light amount of the illumination light according to the type of the imaging device It has not been done.

  Therefore, an object of the present invention is to provide an endoscope system capable of appropriately controlling the light quantity of the illumination light in a wide dynamic range according to the type of the imaging device mounted in the endoscope.

The present invention has the following constitution. An endoscope having an illumination optical system for irradiating light from a light source to a subject, and an imaging optical system including an imaging device for imaging the subject; and a control device to which the endoscope is detachably connected. An endoscope system comprising:
The imaging device is an imaging device controlled by a rolling shutter system,
The control device includes the light source and light source control means for driving the light source to emit light continuously by a pulse-like light source drive signal to control the intensity of emitted light of the light source.
The light source control unit controls the light source drive signal by combining and controlling pulse amplitude modulation control for controlling pulse amplitude, pulse density control for controlling pulse interval, and pulse width modulation control for controlling pulse width. Endoscope system to generate.

  Since the endoscope system of the present invention switches the control pattern of the illumination light according to the type of the imaging device mounted on the connected endoscope, appropriate light control of illumination is performed according to the type of the imaging device It is possible to realize light quantity control of a wide dynamic range.

It is a block diagram showing an example of composition of the principal part about the whole endoscope system of an embodiment. It is a perspective view which shows the external appearance of the endoscope system shown in FIG. It is a longitudinal cross-sectional view showing the structure of the vicinity of an endoscope front-end | tip part. It is a block diagram which shows the specific structural example of a light source driver. It is a time chart which shows the example of control timing in the case of being controlled by a global shutter method. It is a time chart which shows an example of control timing in a case of being controlled by a rolling shutter method. It is a graph which shows the characteristic example of the control pattern used by a global shutter system. It is a graph which shows the characteristic example of the control pattern used by a rolling shutter system. It is a graph which shows the specific example of the spectrum regarding illumination light. It is a front view which shows the structure of the endoscope front-end | tip part in a 1st modification. It is a block diagram which shows the structure of the light source device in a 1st modification. It is a block diagram which shows the structure of the light source device in a 2nd modification. It is a front view which shows the structure of the endoscope front-end | tip part in a 3rd modification. It is a block diagram which shows the structure of the light source device in a 3rd modification.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
An example of the configuration of the main part of the entire endoscope system of this embodiment is shown in FIG. Also, the appearance of the endoscope system shown in FIG. 1 is shown in FIG.

  As shown in FIGS. 1 and 2, the endoscope system 100 includes an endoscope 11, a control device 13 which is an external control device to which the endoscope 11 is connected, and image information connected to the control device 13. And a display unit 15 for displaying the The controller 13 is connected to an input unit 17 that receives an input operation.

  The endoscope 11 is an electronic endoscope, and includes an illumination unit 11a (illumination optical system), an imaging element 11b (imaging optical system), and a scope information memory 11c, as shown in FIG. The illumination unit 11a emits illumination light from the tip of the endoscope insertion unit 19 shown in FIG. The imaging element 11b is a two-dimensional imaging means, and can image a region to be observed such as a living body through a predetermined objective lens unit to obtain a two-dimensional image. As a specific example of the imaging element 11 b, a two-dimensional charge coupled device (CCD) image sensor or a two-dimensional complementary metal-oxide semiconductor (CMOS) image sensor is used.

  In addition, since it is usually necessary to reproduce a color image in the endoscope system 100, in the actual imaging element 11b, a color filter composed of a plurality of color segments (for example, RGB primary color filters in Bayer arrangement, CMYG , And CMY complementary color filters) are used.

  The scope information memory 11 c holds information unique to the endoscope 11 in advance. The information held by the scope information memory 11c also includes information on the shutter method of the imaging device 11b.

  As shown in FIG. 2, the endoscope 11 includes an endoscope insertion portion 19, an operation portion 25, a universal cord 27, and connector portions 29A and 29B. The endoscope insertion portion 19 is formed in an elongated shape, and its distal end side is inserted into the subject. Further, the endoscope insertion portion 19 is configured of a flexible portion 31 having flexibility, a bending portion 33, and a distal end (hereinafter also referred to as an endoscope distal end). The operation unit 25 is connected to the proximal end of the endoscope insertion unit 19 and is used when performing an operation for bending the tip of the endoscope insertion unit 19 or observation. The universal cord 27 is extended from the operation unit 25. The connector portions 29A and 29B are provided at the tip of the universal cord 27 and detachably connect the endoscope 11 to the control device 13.

  The bending portion 33 is provided between the flexible portion 31 and the endoscope distal end portion 35, and is bendable by the turning operation of the angle knob 41 disposed in the operation portion 25. The curved portion 33 can be curved in any direction and at any angle depending on the region of the subject in which the endoscope 11 is used, and the observation of the illumination port of the illumination at the distal end portion 35 of the endoscope and the imaging device The direction can be directed to the desired observation site.

  The configuration in the vicinity of the endoscope tip 35 is shown in FIG. As shown in FIG. 3, the endoscope distal end portion 35 is provided with an illumination unit 11 a for irradiating illumination light to a region to be observed and an imaging element 11 b for photographing an image of the region to be observed .

  The illumination unit 11 a includes a multimode optical fiber 71 and a fluorescent body 72. As the multimode optical fiber 71, for example, a thin fiber having a core diameter of 105 μm, a cladding diameter of 125 μm, and a diameter of 0.3 mm to 0.5 mm including a protective layer serving as an outer shell can be used.

  The multi-mode optical fiber 71 guides the blue light emitted from the light source 45 a in the light source device 45 to the vicinity of the fluorescent body 72 of the endoscope tip portion 35. The phosphor 72 absorbs and excites part of the energy of the blue light guided by the multimode optical fiber 71, and emits visible light in the green to yellow wavelength band. The phosphor 72 is formed of a plurality of types of phosphors, and is formed, for example, including a phosphor such as a YAG-based phosphor or BAM (BaMgAl10O17).

  As shown in FIG. 3, a cylindrical sleeve member 73 is provided so as to cover the outer periphery of the phosphor 72. A ferrule 74 holding the multimode optical fiber 71 as a central axis is inserted into the sleeve member 73. Further, in the multimode optical fiber 71 extended from the rear end side (the side opposite to the front end side) of the ferrule 74, a flexible sleeve 75 covering the outer cover is inserted between the multimode optical fiber 71 and the sleeve member 73.

  Luminescent light generated in the fluorescent substance 72 by excitation and a part of blue light guided by the multi-mode optical fiber 71 and transmitted through the fluorescent substance 72 are synthesized and observed as illumination light of a near white spectrum from the irradiation port 35a It is emitted towards the area. In the vicinity of the irradiation port 35a, an irradiation lens 76 for irradiating illumination light is provided.

  As shown in FIG. 3, the imaging device 11 b is disposed on a substrate 61 fixed inside the endoscope distal end portion 35. Further, one end face 62a of the prism 62 is connected to the light receiving surface of the imaging element 11b. In addition, the objective lens unit 63 is connected to another end face 62b which is different from the end face 62a by 90 degrees. The objective lens unit 63 guides the light to the light receiving surface of the imaging element 11b via the prism 62 so that an image of the observation area can be photographed from the observation window 35b facing the observation area. The signal cable 64 electrically connects the imaging device 11 b on the substrate 61 to the control device 13.

  Referring back to FIG. 1 again, the control unit 13 comprises a video processor 45 and a light source unit 43. The light source device 43 generates illumination light to be supplied to the irradiation port of the endoscope distal end portion 35. The video processor 45 functions as a light source control unit that performs image processing on an image signal output from the imaging element 11 b and controls the light amount of illumination. The video processor 45 and the light source device 43 are connected to the endoscope 11 via the connector portions 29A and 29B as shown in FIG.

  Further, the display unit 15 and the input unit 17 described above are connected to the video processor 45. The video processor 45 performs image processing on the imaging signal transmitted from the endoscope 11 based on an instruction from the operation unit 25 or the input unit 17 of the endoscope 11 and generates a display image to the display unit 15. Supply.

Next, signal processing of the endoscope system will be described.
As shown in FIG. 1, the video processor 45 includes an amplifier (AMP) 51, a correlated double sampling / programmable gain amplifier (hereinafter referred to as CDS / PGA) 52, an A / D converter 53, an image processing unit 54, and a light amount. A measurement unit 55, a storage unit 56, a microcomputer (CPU) 57, a timing generator (TG) 58, and an imaging device driver 59 are provided.

  An imaging signal obtained by imaging of the imaging device 11 b is input to the input of the amplifier 51. The imaging signal is amplified by the amplifier 51 having a constant gain, and then input to the CDS / PGA 52. The CDS / PGA 52 inputs the imaging signal amplified by the amplifier 51, and corresponds to the accumulated charge amount of each photoelectric conversion cell of the imaging element 11b for each color of R (red), G (green), B (blue) It is output as an analog image signal representing a level.

  An analog image signal output from the CDS / PGA 52 is input to an A / D converter 53 and converted into digital image data. The image processing unit 54 performs various types of image processing on the digital image data output from the A / D converter 53, and generates information of an image to be displayed on the screen of the display unit 15. Therefore, the display unit 15 displays an image captured by the imaging element 11 b in the endoscope 11, that is, a two-dimensional image of the observation region of the living body.

  An output of the imaging device driver 59 is connected to a control input terminal for controlling imaging and signal readout of the imaging device 11b. The output of the timing generator 58 is connected to the input of the imaging device driver 59. The imaging device driver 59 controls various timings in photographing of the imaging device 11 b using various timing signals (clock pulses) input from the timing generator 58. That is, the timing of reading out the signal charge accumulated in the area of each cell by photographing, the shutter speed of the electronic shutter, and the like are controlled. The timing generator 58 also generates a timing signal to be supplied to the light source driver 43b.

  In the video processor 45 of this configuration example, a desired imaging operation is performed even when the connected endoscope 11 is equipped with either a CCD image sensor or a CMOS image sensor as the imaging device 11 b. The timing generator 58 is configured to be able to output the timing signals necessary for the above. Switching between control for the CCD image sensor and control for the CMOS image sensor is performed by an instruction inputted from the microcomputer 57 to the timing generator 58.

  In the case of a global shutter type CCD image sensor, the exposure operation for each cell of all pixels is performed at the same timing, while in the case of a general rolling shutter type CMOS image sensor, every scanning line (every row) Since it is necessary to shift the timing to sequentially perform exposure and signal readout, it is configured to be able to selectively cope with both methods. The CMOS image sensor also includes an element of a global shutter system, and in this case, it is handled in the same manner as the global shutter system of a CCD image sensor.

  The light amount measurement unit 55 measures the light amount based on the digital image data output from the A / D converter 53. For example, by detecting the maximum brightness, the minimum brightness, the average brightness, and the like of the entire area from digital image data obtained by shooting, it is possible to grasp whether an image having a desired brightness can be shot.

  In the storage unit 56, various control patterns representing the relationship between the light amount instruction value instructed to the light source driver 43b for light control and the control output value to the light source 43a are recorded. In accordance with the type of scope, that is, interlocking with the shutter operation of the imaging element 11b of the endoscope 11, that is, depending on whether it is a CCD image sensor or a rolling shutter type CMOS image sensor, the corresponding control pattern is taken out Is transmitted to the light source driver 43b. The light source driver 43b may store this control pattern.

  The microcomputer 57 executes a prepared program to control the entire endoscope system 100. A typical process performed by the control of the microcomputer 57 is as follows.

1. The information of the endoscope 11 is read from the scope information memory 11 c of the endoscope 11 connected to the control device 13. The information includes the shutter operation of the image pickup device 11b of the endoscope 11, that is, the content indicating whether the electronic shutter control method is the global shutter method or the rolling shutter method.

2. In accordance with the above-mentioned read information, the timing generator 58 is instructed to drive the image sensor 11 b by the global shutter system or the rolling shutter system.

3. In response to an instruction such as a shutter speed input from the input unit 17 by the operation of the user, the timing generator 58 is instructed to drive the imaging element 11b at the designated shutter speed.

4. According to the read information, one of the plurality of control patterns stored in the storage unit 56 is automatically selected. Thereby, different control patterns are selected in the case of the global shutter system and the case of the rolling shutter system.

5. A light source device such that the light source device 43 controls the light amount in accordance with the light amount instruction value for illumination control determined by the light amount measured by the light amount measurement unit 55, the designated value input from the input unit 17, etc. Give instructions to 43.

  As shown in FIG. 1, the light source device 43 includes a light source 43a, a light source driver 43b, and a condenser lens 43c. The light source 43a emits light by being energized by the control of the light source driver 43b and the light is emitted. This light is collected by the collecting lens 43 c and introduced into the optical fiber 71. Then, it travels through the optical fiber 71 and is guided to the illumination unit 11a.

In the present embodiment, as the light source 43a, a blue LED (light emitting diode) or D (laser diode) having an oscillation wavelength of 405 nm or 445 nm, for example, a broad area type InGaN based laser diode, InGaNAs based laser diode, ,
A GaNAs based laser diode or the like is used.

  The light source driver 43 b is connected to the timing generator 58 of the video processor 45 and the microcomputer 57. The light source driver 43 b supplies a pulse-like drive current to the light source 43 a based on the instruction given from the microcomputer 57 and the timing of the signal inputted from the timing generator 58. The contents of control of the light source driver 43b are automatically switched between the case of the global shutter system and the case of the rolling shutter system as described later.

  A specific configuration example of the light source driver 43b is shown in FIG. In the example shown in the figure, the light source driver 43 b includes an LUT (look-up table) 101, a timer circuit 102, and a constant current circuit 103.

  The light source driver 43b combines the pulse number modulation (PNM) control, the pulse width modulation (PWM) control, the pulse amplitude modulation (PAM) control, and the pulse density modulation (PDM) control as needed, and generates a light source 43a. A light source drive signal can be generated to control the current of the light source. The contents of each control of PAM, PWM, PDM, and PNM will be described later.

A plurality of combinations of control values of PAM, PWM, PDM, and PNM with respect to designated light amounts are registered in the LUT 101 as control patterns. Each of the plurality of control patterns corresponds to the pulse number modulation (PNM) control, the pulse width modulation (PWM) control, the pulse amplitude modulation (PAM) control, and the pulse density modulation (PDM) control for the light amount instruction value. The emitted light intensity of the light source is defined as the sum of any one control part or a plurality of two or more control parts. By controlling the light source by combining a plurality of controls, the dynamic range of the emitted light amount of the light source can be expanded.
The LUT 101 may store each control amount as a table, or may obtain each control amount by an arithmetic expression.

  The timer circuit 102 blinks for supplying a pulse-like drive current to the light source 43a based on each control value of PWM, PDM, PNM inputted from the LUT 101 and the timing of the signal inputted from the timing generator 58. The constant current circuit 103 is supplied.

  The constant current circuit 103 generates a light source drive signal for controlling the current of the light source 43a based on the amplitude signal corresponding to the control value of PAM input from the LUT 101 and the blinking signal output from the timer circuit 102. Do.

  Control when the charge accumulation period of the photoelectric conversion unit of the imaging device is controlled by the electronic shutter of the global shutter system as in the case where the imaging device 11b of the endoscope 11 connected to the control device 13 is a CCD type image sensor An example of the timing is shown in FIG.

  In FIG. 5, a vertical scanning signal VD for controlling the scanning of the imaging element 11b, an electronic shutter pulse, and a driving signal SLD (shown in FIG. 4) of the laser diode LD which is a light source for illumination (43a in FIG. 1). (Corresponding to a light source drive signal) is shown. Further, a period between one pulse and the next pulse in the vertical scanning signal VD shown in FIG. 5 represents a period of one screen (one frame).

  Then, during the ON period (Ta) of the electronic shutter pulse, in the area of the cell corresponding to each pixel of the photoelectric conversion unit of the imaging device 11b, the light receiving intensity and the exposure time (corresponding to Ta) by a photodiode or the like. Corresponding charges are generated and accumulated. In this case, since the global shutter system is used, charges are accumulated at the same timing for all pixels. That is, in any of the plurality of pixels, charge accumulation starts at time t1 shown in FIG. 5 and ends at time t2 when the period Ta of the electronic shutter has elapsed.

  The illumination in this case has no influence on the captured image except when the electronic shutter is open, so the light source drive signal SLD for controlling the illumination light is the charge accumulation timing (t1 of the imaging element 11b). The light source is controlled to be turned on at the same timing so as to be synchronized with t2).

  In the example shown in FIG. 5, it is assumed that the light quantity of illumination is controlled by combining pulse number modulation (PNM) control, pulse width modulation (PWM) control, and pulse amplitude modulation (PAM) control. .

  That is, the length of the lighting period Tb is adjusted by changing the time t11 at which the light source drive signal SLD shown in FIG. 5 is switched from off (low level) to lighting (high level) before and after time t1 opening the electronic shutter. Control the amount of light. About time t12 which changes light source drive signal SLD from lighting to extinguishing, it fixes to the same timing as time t2. The lighting period Tb is controlled as an integral multiple of the lighting period Tc of the following PWM control. This is PNM control. The lighting period Tb is set to a predetermined ratio or more with respect to the charge accumulation period Ta per frame. For example, if the predetermined ratio is set to 1/2, the sense of discontinuity at the time of moving image reproduction can be eliminated and the occurrence of flicker can also be prevented.

  Also, even during the lighting period Tb from time t11 to t12 shown in FIG. 5, the on / off of the light source drive signal SLD is controlled at a very short constant lighting cycle Tc (for example, about 1/100 of Tb). Turn on and off alternately. Then, in each period of the lighting cycle Tc, the width of a pulse that represents the time for which the lamp is actually turned on is adjusted. Thus, the light amount (flashing ratio) is controlled. This is PWM control.

  Further, by making the amplitude of the pulse (from t11 to t12) of the light source drive signal SLD variable, the magnitude (instantaneous value) of the current supplied to the light source can be changed to adjust the lighting intensity of the light source. This is PAM control.

  An example of control timing when the imaging device 11b of the endoscope 11 connected to the control device 13 is a CMOS image sensor and the charge accumulation period of the photoelectric conversion unit of the imaging device is controlled by a rolling shutter electronic shutter It is shown in FIG.

  In FIG. 6, a vertical scanning signal VD for controlling the scanning of the imaging element 11b, an electronic shutter pulse applied to each of a large number of scanning lines, and a laser diode as a light source for illumination (43a in FIG. 1). A drive signal SLD of the LD (corresponding to the light source drive signal shown in FIG. 4) is shown. A period between one pulse and the next pulse in the vertical scanning signal VD shown in FIG. 6 represents a period of one screen (one frame).

  In the case of a general CMOS-type image sensor, there are no elements that simultaneously hold signal charges generated at each pixel position of the photoelectric conversion unit of the imaging device for all pixels, so a large number is arranged in the row direction and column direction It is necessary to sequentially perform charge storage and readout of signal charges for each row of the pixel group. Therefore, in this case, it is controlled by the rolling shutter type electronic shutter.

  In this case, as shown in FIG. 6, the timing of the electronic shutter pulse applied to the imaging element 11b is slightly shifted for each scanning line (for each row of pixel groups). For example, while the electronic shutter pulse is open at time t11 for the first scanning line L1 and closed at time t21, the electronic shutter pulse is open at time t1 n for the nth scanning line Ln. The shutter is closed at time t2n. That is, the timing t1n for opening the shutter of the n-th scanning line Ln and the timing t2n for opening the shutter become timings later than the first scanning line L1 by time Tc1 and time Tc2, respectively. The period between the opening and closing of the electronic shutter (for example, "Tc1 + Tb" in FIG. 6), that is, the length of the charge accumulation period at each pixel position is the same for all scanning lines.

  For example, as shown in FIG. 6, when the charge accumulation period of each pixel position is equivalent to the period of one frame of the image (the interval of the pulses of the vertical scanning signal VD), the light source of illumination is used at any timing. Is turned off, the influence appears as a change in charge storage amount at each pixel position of the imaging element 11b. Moreover, since the timing of the charge accumulation period is shifted for each row, the rows of the imaging element 11b have different effects according to the timing when the light source of the illumination is turned off.

  Therefore, in the example shown in FIG. 6, the drive signal SLD of the laser diode LD for illumination is controlled so as to light the light source substantially continuously. Therefore, although the pulse number modulation (PNM) control described above is not performed in the example shown in FIG. 6, pulse width modulation (PWM) control, pulse amplitude modulation (PAM) control, and pulse density modulation (PDM) control are performed. ing.

That is, even during a period (full period) in which the light source is on, the drive signal SLD is controlled so that the light source blinks periodically by periodically turning on and off in a very short cycle. That is, the on / off control of the light source drive signal SLD is performed during the lighting cycle Td from time t31 to t32 shown in FIG. 6 to perform lighting and extinguishing, and the width of the pulse representing the actual lighting time is adjusted. Thus, the light amount (flashing ratio) is controlled. This is PWM control.
Further, the lighting cycle Td used in PWM control is not constant but variable. Control for adjusting the lighting cycle Td is PDM control. That is, even if the pulse width (lighting period Te) in the lighting cycle Td is constant, the light quantity of the illumination decreases if the lighting cycle Td becomes long, and the light quantity of the illumination increases if the lighting cycle Td becomes short. Further, by making the amplitude of the pulse of the light source drive signal SLD variable, it is possible to change the magnitude (instantaneous value) of the current supplied to the light source and adjust the lighting intensity of the light source. This is PAM control.

  In the example shown in FIG. 6, the light source drive signal SLD is controlled so as to continuously turn on the light source for illumination, but for example, the illumination is turned on only for the timing of the period Tb shown in FIG. It may be changed to turn off at the timing. That is, the light source is turned on at a timing other than the timing (during each period of Tc1 and Tc2) of switching the row in the rolling shutter control of the imaging element 11b. In this case, even in the rolling shutter control, the length of the actual exposure time (charge accumulation period) of each row can be made to coincide, and the above-mentioned pulse number modulation (PNM) control can also be performed. That is, the light amount control of the illumination can be performed without being aware of the timing of row switching in rolling shutter control.

  As described above, the microcomputer 57 shown in FIG. 1 reads the information of the endoscope 11 from the scope information memory 11 c of the endoscope 11 connected to the control device 13, and the imaging device 11 b of the endoscope 11. Functions as a type identification unit that distinguishes whether the electronic shutter control system is the global shutter system or the rolling shutter system. The microcomputer 57 interlocks the light control table used to control the light source 43a for illumination with the electronic shutter operation of the imaging device, that is, automatically according to the distinction between the global shutter system and the rolling shutter system. Switch.

  The light adjustment table indicates the relationship between the light amount instruction value for controlling the light amount of the light source 43a and the control output value, and is arranged, for example, on the LUT 101 shown in FIG. The control output value of the dimming table is configured as any one or a combination of a control value for PAM control, a control value for PNM control, a control value for PWM control, and a control value for PDM control. In order to make it possible to selectively switch the relationship between the light amount instruction value and the control output value from among a plurality of types of control patterns, a plurality of light adjustment tables are prepared in advance. The microcomputer 57 selects one of the plurality of light adjustment tables according to the situation, that is, according to the distinction between the global shutter system or the rolling shutter system of the imaging device 11b of the endoscope 11 and other imaging conditions. Automatically select and enable one dimming table.

  The characteristics of the dimming tables of different control patterns are shown in FIG. 7 and FIG. The control pattern shown in FIG. 7 is used when performing control of the global shutter system, and the control pattern shown in FIG. 8 is used when performing control of the rolling shutter system.

  Referring to FIG. 7, this control pattern is composed of three combinations of the control characteristic of PNM control, the control characteristic of PWM control, and the control characteristic of PAM control. In the case of the control pattern of FIG. 7, in the range of 0 to 10 of the light amount command value, a constant PAM control value of the minimum amplitude is output, and at the same time, the PNM control changes to increase the light amount with the increase of the light amount command value. The value is output. When the light amount command value exceeds 10, the PAM control value increases as the command value increases, and the PNM control value becomes a constant value. The PWM control value changes so as to increase the light amount as the light amount command value increases over the entire range of 0 to 1000 of the light amount command value. That is, when the control pattern shown in FIG. 7 is adopted, the current flowing through the light source, that is, the light amount is determined by the combination of PNM control, PWM control, and control output of PAM control.

  Referring to FIG. 8, this control pattern is composed of three combinations of control characteristics of PDM control, control characteristics of PWM control, and control characteristics of PAM control. In the case of the control pattern of FIG. 8, in the range of 0 to 10 of the light amount command value, a constant PAM control value of the minimum amplitude is output, and at the same time, the PDM control changes to increase the light amount with the increase of the light amount command value. The value is output. When the light amount command value exceeds 10, the PAM control value increases as the command value increases, and the PDM control value becomes the maximum value (constant value). The PWM control value changes so as to increase the light amount as the light amount command value increases over the entire range of 0 to 1000 of the light amount command value. That is, when the control pattern shown in FIG. 8 is adopted, the current flowing through the light source, that is, the light amount is determined by the combination of the PDM control, the PWM control, and the control output of the PAM control.

  When the microcomputer 57 recognizes that the image pickup device 11b of the endoscope 11 is a global shutter type CCD image sensor, it automatically selects a light control table of a control pattern as shown in FIG. 7, for example. . Therefore, in this case, the light amount of the light source is controlled by the combination of PAM control, PNM control, and PWM control. Although PDM control can be further combined, in the case of the global shutter system, PDM control needs to be limited to only the shutter open period (corresponding to the range of Tb in FIG. 6).

  When the microcomputer 57 recognizes that the image pickup device 11b of the endoscope 11 is a rolling shutter type CMOS image sensor, it automatically selects a light control table of a control pattern as shown in FIG. 8, for example. . Therefore, in this case, the light amount of the light source is controlled by the combination of PAM control, PDM control, and PWM control.

  When the imaging element 11b of the endoscope 11 is a global shutter system, the timing at which the electronic shutter is open is common to all pixels. In addition, the illumination light when the electronic shutter is closed is not only used for photographing, but also leads to an increase in heat generation at the tip of the endoscope 11 and the portion to be observed. Therefore, in such a situation, it is desirable to perform at least PNM control and turn off the light source for illumination when the electronic shutter is closed, and continuously turn on the light source regardless of the timing of opening and closing the electronic shutter. PDM control is not suitable.

  On the other hand, when the imaging device 11b of the endoscope 11 is a rolling shutter system, the timing at which the electronic shutter is opened is slightly shifted for each row of pixel groups. Therefore, in this case, it is necessary to cause the light source for illumination to emit light continuously so that the amount of illumination light does not change for each row. That is, PNM control is not suitable, and it is desirable to adjust the light amount using PDM control.

  In the above-described endoscope system 100, the microcomputer 57 of the control device 13 detects the type of the imaging device 11b of the connected endoscope 11 and automatically adjusts the light control method of illumination according to the difference. Switch. Accordingly, appropriate light adjustment control can be performed even in the endoscope 11 mounted with the imaging device 11b of either the global shutter method or the rolling shutter method.

  Further, in the endoscope system 100 described above, the light source driver 43b of the control device 13 integrally controls the lighting light amount, lighting ratio, lighting time, and lighting density of the light source 43a. Thereby, an appropriate illumination mode can be provided according to the type of imaging element 11b and the imaging mode. Moreover, the dynamic range of light control can be expanded by combining several control.

  An example of the spectrum of light used for illumination by the endoscope system 100 described above is shown in FIG. The spectrum S1 shown in FIG. 9 represents the intensity distribution for each wavelength of the illumination light irradiated from the endoscope tip portion 35 to the observation portion such as a living body when the laser light source having a center wavelength of 405 nm is adopted as the light source 43a. ing. Further, the spectrum S2 represents the intensity distribution of each wavelength of the illumination light irradiated from the endoscope tip portion 35 to the observation portion such as a living body when the laser light source having a central wavelength of 445 nm is adopted as the light source 43a. .

  For example, the laser light of 445 nm which is blue light is emitted by the light source 43 a, and the blue light is guided to the illumination unit 11 a of the endoscope 11 and irradiated to the fluorescent substance 72. In this case, part of the energy of the blue light is absorbed by the phosphor 72, whereby the phosphor 72 is excited to emit light. The emission light of the phosphor 72 is visible light in a green to yellow wavelength band. Then, the remaining energy component of the blue light transmitted without being absorbed by the phosphor 72 is added to the light emitted by the excitation of the phosphor 72, and the white of the wavelength distribution as shown in the spectrum S2 shown in FIG. The illumination light is emitted from the endoscope tip portion 35 to the observed portion.

  Similarly, when a laser beam of 405 nm is emitted by the light source 43a and this laser beam is guided to the illumination unit 11a of the endoscope 11 and irradiated to the fluorescent substance 72, a wavelength such as the spectrum S1 shown in FIG. As illumination light of distribution, it irradiates to a to-be-observed part from the endoscope front-end | tip part 35. As shown in FIG.

Next, a modification of the illumination light of the endoscope system 100 will be described.
FIG. 10 shows a state in which the end face of the distal end side of the endoscope distal end portion 35 is viewed from the side of the observation portion in the configuration of the endoscope distal end portion 35 in the first modified example. The configuration of the light source device 43 in the first modification is shown in FIG.

  In the example shown in FIG. 10, the endoscope distal end portion 35 is provided with one observation window 201 and two illumination windows 202 and 203 disposed on both sides thereof. As described above, by arranging the illumination windows 202 and 203 on both sides of the observation window 201 and emitting illumination light from the illumination windows 202 and 203, illumination unevenness is less likely to occur in the observation image, and the treatment tool in the forceps hole When it is inserted from the tip of the endoscope to protrude from the tip of the endoscope, it is possible to prevent the shadow of the treatment tool from being generated in the observation image, and a sufficient amount of light can be obtained over a wide range.

  In the case of using the endoscope 11 shown in FIG. 10, a light source device 43A having a configuration as shown in FIG. 11 is used as the light source device 43, for example. A light source device 41A shown in FIG. 11 includes a laser light source LD1 having a central wavelength of 445 nm and a laser light source LD2 having a central wavelength of 405 nm.

  The two laser light sources LD1 and LD2 are connected to independent light source drivers 43b1 and 43b2, respectively, and the emitted light amount is controlled individually. The output lights of the two laser light sources LD1 and LD2 are multiplexed by the combiner 211, branched into a plurality of optical paths by the coupler 212, and irradiated to the phosphors 213 and 214 disposed at the light emitting end of each optical path .

  If only the laser light source LD1 of the two laser light sources LD1 and LD2 is turned on, white illumination light for normal observation is emitted as illumination light. That is, the emission light of the phosphors 213 and 214 generated by the excitation of the phosphors 213 and 214 irradiated with the laser light having the central wavelength 445 nm and the laser light having the central wavelength 445 nm transmitted through the phosphors 213 and 214 are added. Illumination light having a spectrum close to white is obtained.

  In addition, when the two laser light sources LD1: LD2 are simultaneously turned on at a light amount ratio of about 1: 7, an observation image in which fine blood vessels in the surface layer of the tissue are emphasized can be obtained with illumination light for narrowband light observation. Furthermore, hybrid illumination light of white light and narrow band light can be obtained by simultaneously turning on the two laser light sources LD1: LD2 at a light amount ratio of about 4: 1. According to this, it is possible to obtain an observation image in which information on fine blood vessels in the surface layer of the tissue is superimposed on a normal observation image.

  By using two laser light sources LD1 and LD2, illumination light such as spectra S1 and S2 shown in FIG. 9 can be obtained. In the case of simultaneously emitting and combining blue laser light having a central wavelength of 445 nm and violet laser light having a central wavelength of 405 nm, wavelength bands of light in the vicinity of 460 to 470 nm which are insufficient for blue laser light having a central wavelength of 445 nm are It is compensated by the light of the same band emitted from the purple laser light having a central wavelength of 405 nm, and the color tone (color rendering) of white light is improved.

  The configuration of the light source device 43 in the second modification is shown in FIG. When illumination light can be emitted from illumination windows of a plurality of systems as shown in FIG. 10, for example, light having different spectra is emitted from the illumination windows of a plurality of systems using the light source device 43B shown in FIG. Also good.

  Similar to the light source device 43A, the light source device 43B shown in FIG. 12 includes the laser light source LD1 having a central wavelength of 445 nm and the laser light source LD2 having a central wavelength of 405 nm. The output light of the laser light sources LD1 and LD2 is not multiplexed or demultiplexed, and the output light of the laser light source LD1 is irradiated to the phosphor 215 as it is, and the output light of the laser light source LD2 is illuminated through the diffusion member 216. Lead to In this case, since the narrow band light can be used as illumination light, and an image with little noise can be obtained when performing fluorescence observation with an endoscope, etc., since the laser light with a central wavelength of 405 nm can be irradiated without passing through the phosphor. .

  FIG. 13 shows the configuration of the endoscope tip portion 35 in the third modified example, in which the end face of the tip portion 35 of the endoscope tip portion 35 is viewed from the observation portion side. The configuration of the light source device 43 in the third modification is shown in FIG.

  In the example shown in FIG. 13, the endoscope distal end portion 35 is provided with one observation window 231 and two pairs of illumination windows (232, 233, 234, 235) disposed on both sides thereof. In the example shown in FIG. 13, the illumination window 232 and the illumination window 235 form a pair, and the illumination window 233 and the illumination window 234 form a pair. Then, the illumination light of the same type is configured to be emitted from the two illumination windows forming a pair. By using two pairs of illumination windows, light of different spectra can be emitted simultaneously. That is, the illumination light of the first spectrum is emitted from one pair of illumination windows, and the illumination light of the second spectrum is emitted from the other pair of illumination windows.

  With regard to the two pairs of illumination windows provided on both sides of the observation window, a straight line passing through the center point of the observation window and bisecting the distal end surface of the distal end of the insertion section is defined as a boundary line P, and each pair of illuminations The windows are arranged across the boundary line P, and the pair of first illumination windows (232 and 235) are illumination windows for emitting white light, and the pair of second illumination windows (233 and 234) are white. It is configured to be an illumination window that emits narrow band light that is narrower than light.

  When the endoscope 11 shown in FIG. 13 is used, a light source device 43C having a configuration as shown in FIG. 14 is used as the light source device 43, for example. A light source device 43C shown in FIG. 14 includes a laser light source LD1 having a central wavelength of 445 nm, a laser light source LD2 having a central wavelength of 405 nm, a laser light source LD3 having a central wavelength of 472 nm, and a laser light source LD4 having a central wavelength of 780 nm.

  The four laser light sources LD1, LD2, LD3, and LD4 are connected to independent light source drivers 43b1, 43b2, 43b3, and 43b4, and the emitted light amounts are individually controlled. The output lights of the two laser light sources LD1 and LD2 are multiplexed by the combiner 221, branched into two optical paths by the coupler 222, and irradiated to the phosphors 225 and 226 disposed at the light emitting end of each optical path. . Further, the output lights of the other two laser light sources LD3 and LD4 are multiplexed by the combiner 223, are branched into two optical paths by the coupler 224, and the diffusion members 227 and 228 disposed at the light emitting end of each optical path. Led to the lighting window.

  In the third modified example of the configuration shown in FIG. 13 and FIG. 14, information on oxygen saturation can be extracted from the observation image by sequentially turning on and imaging the LDs with center wavelengths 405 nm, 445 nm and 472 nm. Specifically, among hemoglobin contained in red blood cells, the difference between the absorption spectra of oxygenated hemoglobin HbO2 and reduced hemoglobin Hb after oxygen release is used to determine the oxygen saturation and blood vessel depth of the observation region. It can be asked. Oxidized hemoglobin HbO2 and reduced hemoglobin Hb have substantially the same absorbance near wavelength 405 nm, reduced hemoglobin Hb has a higher absorbance than oxidized hemoglobin HbO2 near wavelength 445 nm, and oxygenated hemoglobin HbO2 absorbance than reduced hemoglobin Hb near wavelength 472 nm It's getting higher. Further, the depth of penetration of the laser light from the surface of the mucous membrane tissue has a characteristic that it becomes shallower as the wavelength of the laser light becomes shorter. Using these characteristics, the oxygen saturation of the observation area and the blood vessel depth displayed in the observation area are determined.

  The laser beam having a central wavelength of 785 nm is suitably used to observe blood vessel information in the deep mucous membrane tissue, and infrared light observation and blood vessel navigation using ICG (indocyanine green) can be performed. This ICG is in a state of being bound to a protein in blood, and absorbs near infrared light having a wavelength of 750 to 850 nm, for example, having a maximum absorption wavelength of 805 nm, and generates near infrared fluorescence.

  According to this illumination pattern, since near-infrared light can be irradiated in addition to white light, it is possible to extract blood vessel information of the mucous membrane deep layer which is difficult to obtain especially by visible light. For example, in the case of applying this light projection unit to an endoscope navigation system for obtaining positional information of blood vessels in the vicinity of a bronchus, laser light with a central wavelength of 785 nm is emitted toward ICG injected into the blood vessels. Then, since fluorescence having a broad spectral characteristic at a peak wavelength of 830 nm is generated in the portion where blood and ICG have reacted, by making the generated fluorescence a mark, accurate treatment can be performed with high positional accuracy. Furthermore, since a plurality of light emitting units are used, the light from each light emitting unit can be combined to allow high intensity light irradiation.

  Furthermore, as the laser light sources LD3 and LD4, one emitting laser light with a central wavelength of 375 nm, 405 nm, 445 nm, etc. may be used. The laser beam having a wavelength of 375 nm is excitation light in the case of performing fluorescence observation using "fluorescent drug" "luciferase". In addition, since laser light with a wavelength of 405 nm and 445 nm can be irradiated without passing through a phosphor, narrow band light can be irradiated.

  Thus, the present invention is not limited to the embodiments described above, but changes and applications of those skilled in the art are also intended by the present invention based on the description of the specification and well-known techniques. Is included in the range for which

As described above, the following matters are disclosed in the present specification.
(1) An endoscope having an illumination optical system for irradiating a subject with light from a light source and an imaging optical system including an imaging element for imaging the subject, and a control device to which the endoscope is detachably connected An endoscope system comprising:
A light source control unit configured to control the intensity of the light emitted from the light source in accordance with a light amount instruction value input from the control device;
Type identification means for identifying the type of the imaging device mounted on the endoscope connected to the control device;
Have
The light source control means comprises a plurality of control patterns representing the relationship between the light amount indication value and the control output value to the light source, and switches to any of the control patterns based on the identification result by the type identification means The endoscope system which controls the emitted light intensity of the said light source based on the switched control pattern.

  According to this endoscope system, even if the endoscope connected to the control device is equipped with any kind of image pickup element, the endoscope pattern is switched to the control pattern corresponding to the image pickup element. Optimal light source control can be performed. This enables light quantity control of a wide dynamic range.

(2) The endoscope system of (1),
An endoscope system, wherein the light source control means switches the control pattern in conjunction with a shutter operation of the imaging device.

  According to this endoscope system, by switching the control pattern in conjunction with the shutter operation of the imaging device, it is possible to perform emitted light control optimal for the shutter operation.

(3) The endoscope system according to (1) or (2), wherein
The endoscope system which identifies whether the said classification identification means is an imaging device controlled by a global shutter system, or an imaging device controlled by a rolling shutter system as classification of the said imaging device.

  According to this endoscope system, the control pattern is changed in accordance with the shutter method of the imaging device to be used, so that optimal control can be performed on each imaging device. For example, in the global shutter system, it is preferable to set control so that the exposure time of each pixel is simultaneously set in all the pixels, and to turn off the light in order to avoid heat generation when the shutter is closed. Further, in the rolling shutter system, since the exposure time of each pixel is different for each scanning line, continuous light emission of the light source is required. Therefore, control is preferable in which the actual exposure time of each line is equal. Optimal control can be performed according to the type of such an imaging element.

(4) The endoscope system of (3),
The control pattern corresponds to the light amount instruction value.
Control part by pulse number modulation control to change the lighting time of the light source,
Control part by pulse width modulation control which changes the duty ratio of lighting and extinguishing,
Control part by pulse amplitude modulation control which changes lighting intensity,
An endoscope system, wherein the emitted light intensity of the light source is defined by a total of at least three control portions among control portions by pulse density modulation control which changes a lighting interval.

  According to this endoscope system, each control part by control including at least three of pulse number modulation control, pulse width modulation control, pulse amplitude modulation control, and pulse density modulation control corresponding to the designated light amount indication value Is calculated from the preset value curve of each control set in advance, and the control amount of each control is summed to define the emitted light intensity of the light source, whereby the combination from each control method to the low output to the high output The outgoing light intensity can be set while maintaining high continuity within the wide dynamic range.

(5) It is an endoscope system of (4),
When the type identification unit identifies the imaging device as a global shutter imaging device,
An endoscope system in which the light source control means controls the light source with a control pattern combining three of the pulse number modulation control, the pulse width modulation control, and the pulse amplitude modulation control.

  According to this endoscope system, in the case of an imaging device of the global shutter system, the shutter is particularly closed by controlling the light source with a control pattern combining pulse number modulation control, pulse width modulation control and pulse amplitude modulation control. In some cases, the light source can be turned off by adjusting the lighting time by pulse number modulation control, and unnecessary heat generation can be prevented when the shutter is closed.

(6) The endoscope system of (4),
When the type identification unit identifies the imaging device as a rolling shutter imaging device,
An endoscope system in which the light source control means controls the light source with a control pattern combining three of the pulse density modulation control, the pulse width modulation control, and the pulse amplitude modulation control.

  According to this endoscope system, in the case of a rolling shutter type imaging device, in particular, by controlling the light source with a control pattern in which pulse density modulation control, pulse width modulation control, and pulse amplitude modulation control are combined, By changing the lighting cycle by density modulation control, light source control can be performed in which the actual exposure time of each line is equalized.

(7) The endoscope system according to any one of (1) to (6), wherein
The endoscope includes an identification information storage unit that stores type information of an imaging device mounted on the endoscope.
The endoscope system, wherein the type identification unit reads out type information of the imaging element from the identification information storage unit of the endoscope connected to the control device, and identifies the type of the imaging element.

  According to this endoscope system, the type of the imaging device can be easily and reliably determined by reading out the type information of the imaging device from the identification information storage unit.

(8) The endoscope system according to any one of (1) to (7), wherein
The illumination optical system includes an optical fiber for guiding light emitted from the light source, and a phosphor disposed in front of the light path of the light emitting end of the optical fiber and excited by the emitted light to emit light. An endoscope system that generates illumination light by mixing the light emitted from the light source and the light emitted from the phosphor.

  According to this endoscope system, the light emitted from the light source and the light emitted from the phosphor are mixed to generate the illumination light. Therefore, for example, blue excitation light and fluorescence excited and emitted thereby are used. Illumination light of any color can be easily generated, such as generating white light.

(9) The endoscope system according to any one of (1) to (8),
The endoscope system, wherein the illumination optical system emits emitted light from a plurality of light sources, and the light source control unit drives the plurality of light sources individually.

  According to this endoscope system, by individually controlling, a plurality of types of light can be emitted from the same illumination optical system, and the endoscope tip can be configured to be more advantageous for downsizing.

(10) The endoscope system according to any one of (1) to (9), wherein
An endoscope system in which the light source is a semiconductor light emitting element.
According to this endoscope system, illumination light can be generated with high responsiveness and high efficiency.

11 endoscope 11a illumination unit 11b imaging device 11c scope information memory 13 control unit 15 display unit 17 input unit 19 endoscope insertion unit 35 endoscope tip unit 43 light source device 45 video processor 61 substrate 62 prism 63 objective lens unit 72 Phosphor 100 Endoscope system

Claims (8)

An endoscope having an illumination optical system for irradiating light from a light source to a subject, and an imaging optical system including an imaging device for imaging the subject; and a control device to which the endoscope is detachably connected. An endoscope system comprising:
The imaging device is an imaging device controlled by a rolling shutter system,
The control device includes the light source and light source control means for driving the light source to emit light continuously by a pulse-like light source drive signal to control the intensity of emitted light of the light source.
The light source control unit controls the light source drive signal by combining and controlling pulse amplitude modulation control for controlling pulse amplitude, pulse density control for controlling pulse interval, and pulse width modulation control for controlling pulse width. Endoscope system to generate. The endoscope system according to claim 1 , wherein
The endoscope system, wherein the light source control means generates the light source drive signal based on a light amount instruction value obtained using an imaging signal of the subject. The endoscope system according to claim 2 , wherein
The light source control means controls the amplitude value of the pulse amplitude variable to a constant value when the light amount instruction value is in a constant low light amount range, and when the light amount instruction value is larger than the low light amount range. The endoscope system which increases the said amplitude value with the increase in light quantity instruction value. The endoscope system according to any one of claims 1 to 3 , wherein
The illumination optical system includes an optical fiber for guiding light emitted from the light source, and a phosphor disposed in front of the light path of the light emitting end of the optical fiber and excited by the emitted light to emit light. An endoscope system that generates illumination light by mixing the light emitted from the light source and the light emitted from the phosphor. The endoscope system according to any one of claims 1 to 4 , wherein
The illumination optical system emits light emitted from a plurality of light sources,
The endoscope system, wherein the light source control means drives the plurality of light sources individually. The endoscope system according to any one of claims 1 to 5 , wherein
The endoscope system in which the light source is a semiconductor light emitting element. The endoscope system according to claim 6 , wherein
The endoscope system, wherein the light source is a laser diode. The endoscope system according to claim 6 , wherein
The endoscope system, wherein the light source is a light emitting diode.

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