JP5780653B2 - Light source device and endoscope system - Google Patents

Description

  The present invention relates to a light source device for supplying light to an endoscope, and an endoscope system using the light source device.

  In the medical field, endoscopic diagnosis using an endoscopic system is widespread. An endoscope system includes an endoscope having an insertion portion that is inserted into a living body and has an imaging element and an illumination window disposed at a distal end thereof, a light source device that supplies light to the endoscope, and an image signal output by the imaging element. And a processor unit for processing. The endoscope has a built-in light guide composed of a plurality of optical fibers, and light supplied from the light source device is guided to the illumination window by the light guide and irradiated to the observation site.

  In recent endoscopic diagnosis, special observation using special light limited to a specific wavelength is used in addition to normal observation of observing the overall properties of the surface of living tissue under normal light, which is white light. Light observation is also performed. There are various types of special light observations. For example, by utilizing the optical characteristics of living tissue that the depth of penetration from the surface of the mucosa varies depending on the wavelength, the superficial blood vessels that exist near the mucosal surface and the surface blood vessels There is known blood vessel enhancement observation in which middle and deep blood vessels in the deep layer are highlighted and displayed (see, for example, Patent Document 1 and Patent Document 2). In abnormal tissues such as cancer that occurs in living tissue, the state of blood vessels is different from that in normal tissues, so that blood vessel enhancement observation has been found useful for early cancer detection.

  The extinction coefficient of blood hemoglobin has a wavelength dependence, and increases rapidly in the region where the wavelength is about 450 nm or less, and has a peak in the blue region near 405 nm. Moreover, although it is a low value compared with the wavelength of 450 nm or less, it has a peak even when the wavelength in the green region is about 530 nm to 560 nm. When the observation site is irradiated with light having a wavelength with a large extinction coefficient, the blood vessel has a large absorption, so that an image with high contrast between the blood vessel and the other portion can be obtained. Therefore, in the endoscope system of Patent Document 1, blue light in the wavelength region having a wavelength of about 390 to 445 nm is used for surface blood vessel enhancement, and green light in the wavelength region of about 530 to 550 nm is used for medium and deep blood vessel enhancement. Utilizing this, a blood vessel emphasizing image for emphasizing each of the superficial blood vessel and the middle-deep blood vessel is acquired.

  In the light source device described in Patent Document 1, a blue light and a green light are generated by combining a white light source such as a xenon lamp and a rotating filter having optical transparency with respect to the blue and green wavelength regions. Patent Document 1 discloses a technique for performing color tone calibration by photographing a color reference object with an endoscope and adjusting the gain of an image signal for each obtained color (paragraph 0035). , 0036). If such calibration is performed for each endoscope, an image with an appropriate color tone can be obtained regardless of the model even when there is a difference in transmission characteristics of the optical system depending on the model of the endoscope.

  In the light source device described in Patent Document 2, a semiconductor light source such as a laser diode (LD) or an LED is used as a light source that emits blue light or green light. The greater the amount of blue light or green light, the higher the blood vessel contrast. If a semiconductor light source is used, a high output can be obtained as compared with the xenon lamp disclosed in Patent Document 1, so that a high-contrast image can be easily obtained.

JP-A-2005-131130 JP 2011-041758 A

  However, when the light transmission characteristics of the light guide of the existing endoscope were examined, as shown in FIG. 16, the light transmittance in the short wavelength region is lower than that in the long wavelength region, and in particular, the wavelength is about 430 nm or less. It was found that the light transmittance dropped drastically in the blue region. If the light guide has a low light transmittance, the amount of emitted light that is guided by the light guide and emitted to the observation site also decreases, making it difficult to utilize the performance of the semiconductor light source. Therefore, development of an improved endoscope having a light guide with improved light transmittance in the blue region is being studied.

  Even when developing an improved endoscope, considering the convenience of users who have existing endoscopes (operators performing endoscopy), the improved endoscope and existing endoscopes It is desirable to ensure the compatibility of both in the light source device so that both can be used.

  However, if the light transmission characteristics of the light guide are different, the amount of emitted light varies depending on the type of endoscope. In normal observation, there is little effect because the brightness of a part of the wide wavelength range from blue to red is reduced, but in the case of blood vessel enhancement observation, since monochromatic light such as blue light and green light is used, The decrease in the light transmittance of blue light has a great effect because it causes a decrease in the contrast of the superficial blood vessel that is the main observation target.

  Therefore, taking advantage of the semiconductor light source that can control only the blue light output independently, when an existing endoscope is used, increase the output of the blue light source only, It is conceivable to make the ratio of the emitted light quantity the same as the ratio of the emitted light quantity in the improved endoscope.

  However, when the output of the blue light source is increased, as a matter of course, the output adjustment range up to the upper limit is narrower than in the case of using the improved endoscope. This means that in an existing endoscope, the adjustment range in which exposure control can be performed while maintaining the ratio of the emitted light quantity of blue light and green light at a predetermined ratio is narrowed. In an existing endoscope, even after the output of the blue light source reaches the upper limit value, the exposure can be controlled because there is a margin in the adjustment range of the output of the green light source. However, in this case, the ratio of the amount of emitted light also changes.

  When the ratio of the amount of emitted light changes, only the contrast of the superficial blood vessels is reduced in the observation image. Even in this case, since the contrast of the middle- and deep-layer blood vessels is maintained, it is difficult for the user to notice the decrease in the contrast of the surface blood vessels, and it is difficult to determine how reliable the state of the surface blood vessels drawn in the observation image is. Therefore, there arises a problem that it is difficult to use the existing endoscope with peace of mind.

  Patent Documents 1 and 2 do not clearly indicate or suggest such problems or solutions. The calibration according to the model described in Patent Document 1 corrects the color tone and does not solve the above problem.

  The present invention has been made in view of the above problems, and an object thereof is a light source device incorporating a plurality of semiconductor light sources for observing blood vessel information, and using a plurality of types of endoscopes having different light guide optical characteristics. In some cases, the user can use a plurality of types of endoscopes with peace of mind while maintaining the exposure control adjustment range for brightness correction regardless of the type of endoscope.

The light source device of the present invention is a first and second light guide for guiding illumination light that illuminates an observation site in a living body, and is used for blood vessel information observation. A connection part for connecting the first and second endoscopes, each having a difference in light transmittance with respect to at least one of them, each having a built-in first and second light guide, and an inner part connected to the connection part An endoscope identifying unit for identifying whether the type of endoscope is the first or the second endoscope, a first and a second semiconductor light source for emitting first and second light, respectively, The ratio of the emitted light amounts of the first and second lights that are guided by one of the second light guides and emitted toward the observation site is maintained at a predetermined ratio regardless of the type of the endoscope. An output system for controlling the outputs of the first and second semiconductor light sources according to the type of endoscope A section, after one of the outputs of the first and second semiconductor light sources has reached the upper limit value above, of the first and second semiconductor light source, increasing the light amount of the semiconductor light sources does not reach the upper limit value An output control unit that corrects the brightness of an observation image, and a notification unit that performs a notification process for notifying the fact when the ratio of the amount of emitted light cannot be maintained by exposure control. And

  It is preferable that the notification unit performs the notification process only when an endoscope having a lower light transmittance is connected between the first and second endoscopes.

  For example, the first and second light guides have different first light transmittance differences for the first light and different second light transmittance differences for the second light.

  This is a driving condition for controlling the outputs of the first and second semiconductor light sources, and a first condition for maintaining the ratio of the quantity of emitted light at a predetermined ratio according to the respective light transmittances of the first and second light guides. It is preferable that the storage unit stores the first and second driving conditions in advance, and the output control unit controls the outputs of the first and second light sources based on the first and second driving conditions.

  The light guide is, for example, a fiber bundle in which optical fibers are bundled. A relatively large difference in light transmittance is, for example, the second light, and the second light is, for example, blue light having a wavelength of about 430 nm or less. Blue light has a wavelength of about 410 ± 10 nm, for example. The first light includes green light having a wavelength range of about 530 nm to 560 nm, for example.

  The first semiconductor light source that emits the first light includes, for example, a light emitting element that emits excitation light having a wavelength of about 440 ± 10 nm, and a phosphor that emits fluorescence including the green light by the excitation light.

An endoscope system according to the present invention is an endoscope system including first and second endoscopes, and a light source device to which the first and second endoscopes are interchangeably connected. 2 endoscopes are first and second light guides for guiding illumination light for illuminating an observation site in a living body, and are used for blood vessel information observation. First and second light guides each having a difference in light transmittance with respect to at least one of them are built-in, and the light source device is connected to a connection unit that connects the first and second endoscopes in a replaceable manner. An endoscope identification unit for identifying whether the type of endoscope connected to the unit is the first or second endoscope, and first and second semiconductors that emit first and second light, respectively Light is guided by one of the light source and the first and second light guides and emitted toward the observation site. The output of the first and second semiconductor light sources is controlled according to the type of endoscope so that the ratio of the emitted light quantity of the first and second lights is maintained at a predetermined ratio regardless of the type of endoscope. After one of the outputs of the first and second semiconductor light sources reaches the upper limit first , the light quantity of the semiconductor light source that has not reached the upper limit among the first and second semiconductor light sources is set. And an output control unit that corrects the brightness of the observation image by raising and a notification unit that executes a notification process for notifying the fact when the ratio of the amount of emitted light cannot be maintained by exposure control. It is preferable.

  According to the present invention, when a plurality of types of endoscopes having different optical characteristics of a light guide are used in a light source device incorporating a plurality of semiconductor light sources for blood vessel information observation, one of the outputs of the plurality of semiconductor light sources is After reaching the upper limit first, the exposure control is prioritized over the ratio of the emitted light quantity and the other output is raised to correct the brightness of the observation image, and when the ratio of the emitted light quantity can no longer be maintained, Since the fact is notified, it is possible to maintain the exposure control adjustment range even when the model is changed, and to use it with peace of mind.

It is an external view of the endoscope system of the present invention. It is a front view of the front-end | tip part of an endoscope. It is a block diagram which shows the electric constitution of an endoscope system. It is a graph which shows the spectrum of illumination light. It is a graph which shows the absorption spectrum of hemoglobin. It is a graph which shows the scattering coefficient of a biological tissue. It is a graph which shows the spectral characteristic of the color microfilter of an image pick-up element. It is explanatory drawing which shows the irradiation timing and imaging timing of illumination light. It is explanatory drawing which shows the image processing procedure in normal observation mode and blood vessel emphasis observation mode. It is a block diagram of a light source control part. It is a graph which shows the light transmission characteristic of a light guide. It is a graph which shows the relationship between a drive current value and emitted light quantity. It is a graph which shows the relationship between an exposure control value and a drive current value. It is a flowchart which shows the light source control procedure in the blood vessel emphasis observation mode. It is explanatory drawing which shows another aspect of the light for blood vessel emphasis. It is a graph which shows the light transmission characteristic of the conventional light guide.

  As shown in FIG. 1, an endoscope system 10 according to a first embodiment of the present invention includes an endoscope 11 that images an observation site in a living body, and an observation image of the observation site based on a signal obtained by the imaging. , A light source device 13 that supplies light to irradiate the observation site to the endoscope 11, and a monitor 14 that displays an observation image. The processor device 12 is provided with a console 15 that is an operation input unit such as a keyboard and a mouse.

  The endoscope system 10 includes a normal observation mode for observing an observation site under white light, and a blood vessel enhancement observation mode for highlighting blood vessels existing in the observation site using special light. The blood vessel enhancement observation mode is a special light observation mode for diagnosing the quality of blood vessels, etc., and making a diagnosis such as tumor quality. Special light has a wavelength range with high absorbance to hemoglobin in the blood. Narrow band light is used.

  The endoscope 11 includes an insertion portion 16 to be inserted into a subject's digestive tract, an operation portion 17 provided at a proximal end portion of the insertion portion 16, an operation portion 17, a processor device 12, and a light source device 13. And a universal cord 18 for connecting the two.

  The insertion portion 16 includes a distal end portion 19, a bending portion 20, and a flexible tube portion 21 that are continuously provided from the distal end. As shown in FIG. 2, on the distal end surface of the distal end portion 19, the illumination window 22 that irradiates the observation site with illumination light, the observation window 23 that receives the image light reflected by the observation site, and the observation window 23 are washed. An air supply / water supply nozzle 24 for performing air supply / water supply, a forceps outlet 25 for projecting a treatment instrument such as forceps and an electric knife, and the like are provided. An imaging element 44 (see FIG. 3) and an imaging optical system are built in the back of the observation window 23.

  The bending portion 20 includes a plurality of connected bending pieces, and is bent in the vertical and horizontal directions by operating the angle knob 26 of the operation portion 17. By bending the bending portion 20, the direction of the distal end portion 19 is directed in a desired direction. The flexible tube portion 21 is flexible so that it can be inserted into a tortuous duct such as the esophagus or the intestine. The insertion unit 16 includes a communication cable that communicates a drive signal for driving the image sensor 44 and an image signal output from the image sensor 44, and a light guide 43 that guides illumination light supplied from the light source device 13 to the illumination window 22. (See FIG. 3) is inserted.

  In addition to the angle knob 26, the operation unit 17 is provided with a forceps port 27 for inserting a treatment instrument, an air / water supply button for performing air / water supply operation, a release button for photographing a still image, and the like. Yes.

  A communication cable and a light guide 43 extending from the insertion portion 16 are inserted into the universal cord 18, and a connector 28 is attached to one end of the processor unit 12 and the light source device 13. The connector 28 is a composite type connector composed of a communication connector 28a and a light source connector 28b. One end of a communication cable is disposed on the communication connector 28a, and the communication connector 28a is detachably connected to a receptacle connector 42a (see FIG. 3) of the processor device 12. The light source connector 28b is provided with an incident end of the light guide 43, and the light source connector 28b is detachably connected to the receptacle connector 42b (see FIG. 3) of the light source device 13.

  As shown in FIG. 3, the light source device 13 includes two types of first and second light source modules 31 and 32 having different emission wavelengths, and a light source control unit 34 that drives and controls them. The light source control unit 34 controls drive timing and synchronization timing of each unit of the light source device 13.

  The first and second light source modules 31 and 32 have laser diodes LD1 and LD2 that emit narrowband light in a specific wavelength range, respectively. As shown in FIG. 4, the laser diode LD1 emits narrowband light N1 having a wavelength region limited to 440 ± 10 nm and a center wavelength of 445 nm in the blue region. In the blue region, the laser diode LD2 emits narrowband light N2, which is a narrowband light whose wavelength range is limited to 410 ± 10 nm and whose center wavelength is 405 nm, for example. As the laser diodes LD1 and LD2, those of InGaN, InGaNAs, and GaNAs can be used. Further, as the laser diodes LD1 and LD2, a broad area type laser diode having a wide stripe width (waveguide width) capable of increasing output is preferable.

The first light source module 31 is a light source that emits white light for normal observation. The first light source module 31 includes a phosphor 36 in addition to the laser diode LD1. As shown in FIG. 4, the phosphor 36 is excited by the 445 nm blue-band narrow-band light N1 emitted from the laser diode LD1, and emits fluorescence FL in a wavelength region extending from the green region to the red region. The phosphor 36 absorbs a part of the narrowband light N1 to emit fluorescence FL and transmits the remaining narrowband light N1. The narrowband light N1 that passes through the phosphor 36 is diffused by the phosphor 36. White light is generated by the transmitted narrow-band light N1 and the excited fluorescence FL. As the phosphor 36, for example, a YAG-based or BAM (BgMgAl ₁₀ O ₁₇ ) -based phosphor is used. Two first light source modules 31 are provided so that the amount of white light increases.

  The second light source module 32 is a light source for surface blood vessel enhancement. In FIG. 5 showing the absorption spectrum of blood hemoglobin, the absorption coefficient μa of blood hemoglobin has a wavelength dependence, increases rapidly in the region where the wavelength is 450 nm or less, and has a peak in the vicinity of 405 nm. Yes. Moreover, although it is a low value compared with the wavelength of 450 nm or less, it also has a peak at wavelengths of 530 nm to 560 nm. When the observation site is irradiated with light having a wavelength having a large extinction coefficient μa, the blood vessel has a large absorption, so that an image having a large contrast between the blood vessel and the other portion is obtained. In FIG. 5, an absorption spectrum Hb indicates an absorption spectrum of reduced hemoglobin not bonded to oxygen, and an absorption spectrum HbO2 indicates an absorption spectrum of oxidized hemoglobin bonded to oxygen.

  Further, as shown in FIG. 6, the light scattering characteristics of the living tissue also have wavelength dependence, and the scattering coefficient μS increases as the wavelength becomes shorter. Scattering affects the depth of light penetration into living tissue. That is, the greater the scattering, the more light that is reflected near the mucosal surface layer of the biological tissue and the less light that reaches the mid-depth layer. Therefore, the shorter the wavelength, the lower the depth of penetration, and the longer the wavelength, the higher the depth of penetration. In view of such light absorption characteristics of hemoglobin and light scattering characteristics of living tissue, the wavelength of light for blood vessel enhancement is selected.

  The 405 nm narrow-band light N2 emitted from the second light source module 32 has a low depth of penetration, and is therefore absorbed by the surface blood vessels, and is therefore used as light for emphasizing the surface blood vessels. By using the narrowband light N2, the superficial blood vessel can be depicted with high contrast in the observation image. Further, the green component of white light emitted from the first light source module 31 is used as the light for emphasizing the middle deep blood vessel. In the absorption spectrum shown in FIG. 5, the absorption coefficient gradually changes in the green region of 530 nm to 560 nm as compared with the blue region of 450 nm or less. It is not required to be. Therefore, as described later, a green component color-separated from white light by the G-color micro color filter of the image sensor 44 is used.

  The light source control unit 34 controls turning on / off of the laser diodes LD <b> 1 and LD <b> 2 and the amount of light through the driver 37. Specifically, the light source control unit 34 turns on the laser diodes LD1 and LD2 by applying a drive pulse. Then, by performing PWM control for controlling the duty ratio of the drive pulse, the output (light emission amount) is controlled by changing the drive current value. The control of the drive current value may be PAM control for changing the amplitude of the drive pulse.

  A branched light guide 41 is provided on the downstream side of the optical path of the first and second light source modules 31 and 32. The branched light guide 41 is an optical path integration unit that integrates the optical paths of the first and second light source modules 31 and 32 into one optical path. Since the light guide 43 of the endoscope 11 has one incident end, each module is provided in a stage before the light from the first and second light source modules 31 and 32 is supplied to the endoscope 11 by the branched light guide 41. The optical paths 31 and 32 are integrated. The branched light guide 41 has branch portions 41a to 41c whose incident ends are branched into a plurality of portions, and emits light incident from the respective branch portions 41a to 41c from one output end 41e.

  The two first light source modules 31 are disposed so as to face the incident surfaces of the branch portions 41a and 41b of the branch light guide 41, respectively, and the second light source module 32 faces the incident surface of the branch portion 41c. Be placed.

  The exit end 41e of the branched light guide 41 is disposed near the receptacle connector 42b to which the connector 28b of the endoscope 11 is connected. The exit end 41e is provided with a homogenizer 50 for making the light quantity distribution in the cross section of the light beam uniform, and the light from the first and second light source modules 31 and 32 incident on the branched light guide 41 is the homogenizer 50. Is supplied to the light guide 43 of the endoscope 11 disposed in the connector 28b.

  The endoscope 11 includes a light guide 43, an imaging element 44, an analog processing circuit 45 (AFE: Analog Front End), and an imaging control unit 46. The light guide 43 is a fiber bundle in which a plurality of optical fibers are bundled. When the connector 28 is connected to the light source device 13, the incident end of the light guide 43 faces the emission end of the homogenizer 50 of the light source device 13. . The exit end of the light guide 43 branches into two at the front stage of the illumination window 22 so that light is guided to the two illumination windows 22.

  An irradiation lens 48 is disposed behind the illumination window 22. The light supplied from the light source device 13 is guided to the irradiation lens 48 by the light guide 43 and irradiated from the illumination window 22 toward the observation site. The irradiation lens 48 is a concave lens, and widens the divergence angle of the light emitted from the light guide 43. Thereby, illumination light is irradiated to the wide range of an observation site | part.

  In the back of the observation window 23, an objective optical system 51 and an image sensor 44 are arranged. The image light reflected by the observation site enters the objective optical system 51 through the observation window 23 and is imaged on the imaging surface 44 a of the imaging element 44 by the objective optical system 51.

  The imaging element 44 is composed of a CCD image sensor, a CMOS image sensor, or the like, and has an imaging surface 44a in which a plurality of photoelectric conversion elements constituting pixels such as photodiodes are arranged in a matrix. The image sensor 44 photoelectrically converts the light received by the imaging surface 44a and accumulates signal charges corresponding to the amount of received light in each pixel. The signal charge is converted into a voltage signal by an amplifier and read out. The voltage signal is output from the image sensor 44 as an image signal, and the image signal is sent to the AFE 45.

  The image pickup device 44 is a color image pickup device, and micro-color filters of three colors B, G, and R having spectral characteristics as shown in FIG. 7 are assigned to each pixel on the image pickup surface 44a. The white light emitted from the first light source module 31 is split into three colors B, G, and R by the micro color filter. The arrangement of the micro color filter is, for example, a Bayer arrangement.

  As shown in FIG. 8, in the normal observation mode, the image sensor 44 performs an accumulation operation for accumulating signal charges and a read operation for reading the accumulated signal charges within an acquisition period of one frame. As shown in FIG. 8A, in the normal observation mode, the laser diode LD1 is turned on in accordance with the accumulation timing, and the observation site is irradiated with white light composed of the narrowband light N1 and the fluorescence FL as illumination light. The reflected light enters the image sensor 44. In the image sensor 44, the white light is color-separated by a micro color filter, the B pixel receives reflected light corresponding to the narrowband light N1, the G pixel in the fluorescent FL, the G pixel in the fluorescent FL, The R pixel receives reflected light corresponding to the R component. The image sensor 44 sequentially outputs the image signals B, G, and R for one frame in which the pixel values of the B, G, and R pixels are mixed according to the frame rate in accordance with the readout timing. Such an imaging operation is repeated while the normal observation mode is set.

  In the blood vessel enhancement observation mode, as shown in FIG. 8B, the second light source module 32 is turned on in addition to the first light source module 31 in accordance with the accumulation timing. When the first light source module 31 is turned on, similarly to the normal observation mode, the observation site is irradiated with white light (N1 + FL) composed of the narrowband light N1 and the fluorescence FL as illumination light. When the second light source module 32 is turned on, the narrowband light N2 is added to the white light (N1 + FL), and these are irradiated to the observation site as illumination light.

  As in the normal observation mode, the illumination light in which the narrow-band light N2 is added to the white light is split by the B, G, and R micro color filters of the image sensor 44. In the image sensor 44, the B pixel receives the narrowband light N2 in addition to the narrowband light N1. The G pixel receives the G component of the fluorescence FL. The R pixel receives the R component of the fluorescence FL. Even in the blood vessel enhancement observation mode, the image sensor 44 sequentially outputs the image signals B, G, and R according to the frame rate in accordance with the readout timing. Such an imaging operation is repeated while the blood vessel enhancement observation mode is set.

  In FIG. 3, the AFE 45 includes a correlated double sampling circuit (CDS), an automatic gain control circuit (AGC), and an analog / digital converter (A / D) (all not shown). The CDS performs a correlated double sampling process on the analog image signal from the image sensor 44, and removes noise caused by resetting the signal charge. AGC amplifies an image signal from which noise has been removed by CDS. The A / D converts the image signal amplified by AGC into a digital image signal having a gradation value corresponding to a predetermined number of bits and inputs the digital image signal to the processor device 12.

  The imaging control unit 46 is connected to a controller 56 in the processor device 12 and inputs a drive signal to the imaging element 44 in synchronization with a base clock signal input from the controller 56. The imaging element 44 outputs an image signal to the AFE 45 at a predetermined frame rate based on the drive signal from the imaging control unit 46.

  The ID memory 47 is a storage unit that stores an endoscope ID that is identification information for identifying the model and the individual of the endoscope 11, and includes, for example, a nonvolatile memory such as an EEPROM or a flash memory. The endoscope ID is output to the processor device 12 through the connector 28a. Of course, as the ID memory 47, an RFID tag capable of wirelessly transmitting information may be used.

  In addition to the controller 56, the processor device 12 includes a DSP (Digital Signal Processor) 57, an image processing unit 58, a frame memory 59, and a display control circuit 60. The controller 56 includes a CPU, a ROM that stores a control program and setting data necessary for control, a RAM that loads the program and functions as a work memory, and the like. To control.

  The DSP 57 acquires an image signal output from the image sensor 44. The DSP 57 separates an image signal in which signals corresponding to B, G, and R pixels are mixed into B, G, and R image signals, and performs pixel interpolation processing on the image signals of the respective colors. In addition, the DSP 57 performs signal processing such as gamma correction and white balance correction on each of the B, G, and R image signals.

  Further, the DSP 57 calculates the exposure value based on the image signals B, G, and R, and the light amount is increased so that the light amount of the illumination light is increased when the light amount of the entire image is insufficient (underexposure). If it is too high (overexposure), an exposure control signal is transmitted to the light source device 13 via the controller 56 so as to reduce the amount of illumination light (see FIG. 10).

  The frame memory 59 stores image data output by the DSP 57 and processed data processed by the image processing unit 58. The display control circuit 60 reads the image processed image data from the frame memory 59, converts it into a video signal such as a composite signal or a component signal, and outputs it to the monitor 14.

  As shown in FIG. 9A, in the normal observation mode, the image processing unit 58 performs normal observation based on the image signals B, G, and R color-separated into B, G, and R colors by the DSP 57. Display image (observation image P) is generated. The generated observation image P is output to the monitor 14. The image processing unit 58 updates the display image every time the image signals B, G, and R in the frame memory 59 are updated. In the observation image P, the entire properties of the observation site such as the mucous membrane, the superficial blood vessel 61, and the intermediate deep blood vessel 62 are displayed in full color.

  As shown in FIG. 9B, in the blood vessel enhancement observation mode, the image processing unit 58 generates a display image for blood vessel enhancement observation based on the image signals B, G, and R. The image signal B in the blood vessel enhancement observation mode includes information on the narrow band light N2 in addition to the B component of white light (including a part of the narrow band light N1 and the fluorescence FL). It is drawn with high contrast. In lesions such as cancer, there is a tendency to increase the density of superficial blood vessels compared to normal tissues, so there is a feature in the blood vessel pattern, so in blood vessel enhancement observation for the purpose of tumor discrimination, It is preferable that the superficial blood vessel is clearly depicted. Further, since the image signal G contains a lot of information on the middle-deep blood vessels, the image signal G is subjected to contour enhancement processing and the like to emphasize the middle-deep blood vessels.

  The display image for blood vessel enhancement observation is generated based on the three color image signals B, G, and R in the same way as for normal observation, so that the observation site can be displayed in full color. The image signal B in the mode has a higher blue density than the image signal B in the normal observation mode. For this reason, when a display image for blood vessel enhancement observation is generated, color correction is performed so that the same color as that of the display image for normal observation is obtained. The image processing unit 58 generates a display image (observation image PE) for blood vessel enhancement observation every time the image signals B, G, and R in the frame memory 59 are updated. In the observation image PE, the observation site is displayed in full color as in the observation image P. However, as compared with the observation image P, the superficial blood vessel 61 and the middle-deep blood vessel 62 are drawn with high contrast and highlighted.

  As a method for generating a display image for blood vessel enhancement observation, the image signal B is generated using only two colors of the image signals B and G without using the image signal R, and the image signal B is generated by the B channel and G channel of the monitor 14. In addition, a method of displaying the observation region in a pseudo color, such as a method of assigning a signal corresponding to the image signal G to the R channel of the monitor 14, may be employed.

  In FIG. 10, the endoscope system 10 can use a plurality of types of endoscopes 11A and 11B. The endoscope 11B is an existing endoscope having a light guide 43B, and the endoscope 11A is an improved endoscope having a light guide 43A with improved light transmission characteristics with respect to the light guide 43B. is there.

  As shown in FIG. 11, the light transmission characteristic B of the light guide 43B has a light transmittance that drops in a blue region having a wavelength of 430 nm or less, particularly in the vicinity of about 400 nm. On the other hand, the light transmission characteristic A of the light guide 43A has an improved light transmittance mainly in the blue region as compared with the light guide 43B.

  Comparing the light transmission characteristics A and B, the difference d2 between the light transmittances TA2 and TB2 in the blue region is large, and the difference d1 between the light transmittances TA1 and TB1 in the green region having a longer wavelength than the blue region is small. Therefore, the output of light supplied from the light source device 13 to the endoscopes 11A and 11B and the light guides 43A and 43B of the endoscopes 11A and 11B are guided and emitted from the respective illumination windows 22 to the observation site. The relationship with the amount of emitted light is as shown in FIG.

  In FIG. 12, the drive current value is a current value for driving the laser diodes LD1 and LD2, and corresponds to the light output of each of the first light source modules 31 and 32. Graphs GA and GB are the relationship between the output of the G component of the white light emitted by the first light source module 31 and the amount of emitted light when the endoscopes 11A and 11B are used. The graphs N2A and N2B are the second This is the relationship between the output of the light source module 32 and the amount of emitted light. When the drive current value exceeds the bias current value, the outputs of the laser diodes LD1 and LD2 increase corresponding to the increase of the drive current value.

  As shown in the graphs GA and GB, for the G component of the white light emitted from the first light source module 31, the difference Δ1 between the light transmittances TA1 and TB1 of the light guides 43A and 43B corresponding thereto is small, so the first light source When the output of the module 31 is the same, the difference in the amount of emitted light is also small. On the other hand, as shown in the graphs N2A and N2B, for the narrowband light N2 emitted from the second light source module 32, the difference Δ1 between the light transmittances TA2 and TB2 of the light guides 43A and 43B is large. When the output of the module 32 is the same, the difference in emitted light quantity is also large. Since the light transmittance TB2 of the light guide 43B is about half of the light transmittance TA2 of the light guide 43A, the amount of emitted light also falls to about half.

  In FIG. 10, the light source control unit 34 includes a drive current control unit 66, an endoscope identification unit 67, and a basic drive condition table (TBL) 68. The drive current control unit 66 receives an exposure control signal for correcting the brightness of the entire image, which is transmitted from the DSP 58 of the processor device 12, and controls the outputs of the first and second light source modules 31 and 32. .

  The endoscope identification unit 67 identifies whether the connected endoscope 11 is the endoscope 11A or 11B based on the endoscope ID transmitted via the processor device 12. The endoscope identification unit 67 is provided with a model table (TBL) 67a that stores a correspondence relationship between the endoscope ID and model information representing one of the endoscopes 11A and 11B. The endoscope identification unit 67 transmits the model information identified with reference to the model table 67 a to the drive current control unit 66.

  The drive current control unit 66 reads the basic drive condition from the basic drive condition table 68 based on the received model information. The basic drive condition is to determine the ratio of the drive current values of the first light source modules 31 and 32 in the blood vessel enhancement observation mode. Since the ratio of the emitted light quantity of the white light (N1 + FL) and the narrow-band light N2 emitted from the illumination window 22 (the emitted light quantity ratio) affects the balance between the contrast of the surface blood vessels and the contrast of the middle-deep blood vessels in the observation image. In the case of performing exposure control, in principle, the emitted light amount ratio is maintained at a predetermined ratio. Further, in either case of the endoscope 11A and the endoscope 11B having different light transmission characteristics of the light guides 43A and 43B, the basic driving condition is changed so that the ratio of the emitted light quantity of illumination light is the same. The basic drive condition table 68 stores a condition A for the endoscope 11A and a condition B for the endoscope 11B.

  In FIG. 13, the horizontal axis is a target exposure control value designated by the exposure control signal received by the light source control unit 34 from the processor device 12, and the vertical axis is necessary to obtain the target exposure control value. This is the drive current value of the laser diodes LD1 and LD2. As the target exposure control value is higher, the required drive current value is also increased, and the outputs of the laser diodes LD1 and LD2 are increased. The graph G-LD2A corresponds to the condition A, and shows the relationship between the exposure control value and the drive current value of the laser diode LD2 when the endoscope 11A is used, and the graph G-LD2B corresponds to the condition B. Therefore, the relationship between the exposure control value and the drive current value of the laser diode LD2 when the endoscope 11B is used is shown. A graph G-LD1 is common to the conditions A and B, and shows the relationship between the exposure control value and the drive current value of the laser diode LD1.

  As shown in FIG. 13, in the condition A for the endoscope 11A, for example, when the drive current value of the laser diode LD1 of the first light source module 31 is “1” (see G-LD1), the second light source module 32 is used. The drive current value of the laser diode LD2 is set to “5” (see G-LD2A), and the ratio of the drive current value of the LD2 to the LD1 is 1: 5. Exposure control when the endoscope 11A is used is performed while maintaining the ratio of condition A.

  For example, when the distance from the distal end portion 19 of the insertion portion 16 to the observation target is long and the reflected light from the observation target is small, or when the shutter speed of the imaging device 44 is set short, the amount of light received by the imaging device 44 Is insufficient and underexposed. In this case, an exposure control signal requesting that the outputs of the laser diodes LD1 and LD2 be increased is sent from the processor device 12 to the light source device 13. The light source device 13 increases the drive current values of the laser diodes LD1 and LD2 while maintaining the ratio of condition A according to the exposure control value specified by the exposure control signal. On the other hand, in the case of overexposure, the outputs of the laser diodes LD1 and LD2 are lowered while maintaining the ratio of condition A.

  On the other hand, for the condition B for the endoscope 11B, for example, when the drive current value of the laser diode LD1 is “1” (see G-LD1), the drive current value of the laser diode LD2 is “10” (G -Refer to LD2B), and the ratio of the drive current value of LD2 to LD1 is 1:10. The condition B is a value determined in consideration of the difference Δ2 between the light transmittances T2A and T2B in the light guides 43A and 43B shown in FIG. 11. Compared with the condition A, the drive current value of the laser diode LD2 The ratio of is high. Thereby, the output of the 2nd light source module 32 goes up, and the fall part of the light transmittance of the blue region of the light guide 43B of the endoscope 11B is compensated. Exposure control when the endoscope 11B is used is performed while maintaining the ratio of condition B until the drive current value of the laser diode LD2 reaches the upper limit (max).

  As described above, the drive current control unit 66 changes the basic drive condition according to whether the endoscope connected to the light source device 13 is the endoscope 11A or the endoscope 11B, thereby changing the endoscope 11A. The emitted light quantity ratio is the same when used and when the endoscope 11B is used. However, as is apparent from the graph of FIG. 13, the adjustment range in which the exposure control can be performed while maintaining the emission light amount ratio at a predetermined ratio is up to the exposure control value E2 in the case of the endoscope 11A. On the other hand, in the case of the endoscope 11B, the endoscope 11B is narrower up to the exposure control value E1, which is a value lower than the exposure control value E2.

If the adjustment range of the exposure control is different, even when the endoscope 11B is used in the same situation as the endoscope 11A (for example, the observation site and the observation distance are the same), in the range of the exposure control values E1 to E2, The brightness of the observation images of the endoscope 11A and the endoscope 11B is different. More specifically, the screen brightness of the endoscope 11A is secured by exposure control, whereas the screen of the endoscope 11B becomes dark because exposure control cannot be performed.

  If there is a difference in screen brightness depending on the type of endoscope, it is not convenient for the surgeon who is the user. A dark screen is also undesirable because it affects operability such as checking the position of the tip 19. Therefore, in order to ensure the brightness of the screen when the endoscope 11B is used, the drive current control unit 66 gives priority to the exposure control over the maintenance of the emission light quantity ratio. Specifically, in the range of the exposure control values E1 to E2, only the drive current value of the laser diode LD1 is increased and the output is increased regardless of the basic drive condition specified by the condition B. This ensures the brightness of the screen.

  However, in this case, naturally, the emission light quantity ratio cannot be maintained at a predetermined ratio, and the light quantity of the narrowband light N1 is relatively lowered, so that the contrast of the surface blood vessels in the observation image PE (see FIG. 9) is lowered. The decrease in the contrast of the superficial blood vessel 61 affects the balance between the superficial blood vessel contrast and the mid-deep blood vessel contrast in the observation image PE, and, for example, a blood vessel that should be rendered if the output light quantity ratio is maintained at a predetermined ratio. Affects the appearance of blood vessels, such as However, even if the contrast of the superficial blood vessel is reduced in the observation image PE, the contrast of the mid-deep blood vessel is maintained, so that the operator is difficult to notice that the contrast of the superficial blood vessel has been reduced.

  Therefore, the drive current control unit 66 executes the notification process when the ratio specified by the condition B cannot be maintained in the range of the exposure control values E1 to E2. In the notification process, the drive current control unit 66 transmits a notification command to the processor device 12 so as to notify that the illumination condition (emitted light quantity ratio) has been changed. When receiving the notification command, the controller 56 of the processor device 12 displays a message indicating that the illumination condition has been changed on the monitor 14. As shown in FIG. 10, for example, a message such as “the illumination condition has been changed” is displayed together with the observation image. Of course, as the message, more specifically, it may be displayed that the ratio of the amount of emitted light has been changed, and that the contrast of the surface blood vessels has decreased. With such a message, it is possible to alert the operator that the lighting conditions have been changed and that this point should be noted when performing image diagnosis.

  In this example, the monitor 14 is used as a message display means. However, an indicator such as a lamp may be used, or a speaker that emits sound may be used.

  Hereinafter, the operation of the above configuration will be described with reference to the flowchart of FIG. When performing endoscopic diagnosis, the endoscope 11 is connected to the processor device 12 and the light source device 13 with the connector 28, the processor device 12 and the light source device 13 are turned on, and the electronic endoscope system 10 is activated. To do.

  The insertion part 16 of the endoscope 11 is inserted into the subject's digestive tract, and observation in the digestive tract is started. In the normal observation mode, the first light source module 31 is turned on as shown in FIG. White light in which narrowband light N1 emitted from the laser diode LD1 and fluorescence FL emitted from the phosphor 36 are mixed is supplied to the endoscope 11. The supplied light is guided to the illumination window 22 through the light guide 43 and irradiated to the observation site. In the normal observation mode, the first light source module 31 is driven under the same driving conditions regardless of the connected endoscopes 11A and 11B. Further, the drive current control unit 66 controls the output of the first light source module 31 based on the exposure control signal transmitted from the processor device 12.

  As shown in FIGS. 8A and 9A, the observation site is imaged by the imaging device 44 during the irradiation with white light (N1 + FL), and B, G, and R image signals are generated by the DSP 57. . In the normal observation mode, the image processing unit 58 generates a display image for normal observation based on the B, G, and R image signals. The display control circuit 60 converts the generated display image into a video signal and displays the observation image P on the monitor 14. Such processing is repeated in the normal observation mode.

  In the normal observation mode, only white light emitted from the first light source module 31 is used as illumination light. Regarding the light transmittance of white light, the difference is small in both the light guide 43A of the endoscope 11A and the light guide 43B of the endoscope 11B, so that either the endoscope 11A or the endoscope 11B is used. Even in this case, a similar observation image can be obtained. Therefore, the operator can use either the endoscope 11A or the endoscope 11B without any problem.

  When performing blood vessel enhancement observation, a mode switching operation is performed by the console 15, and the processor device 12 is set to the blood vessel enhancement observation mode. As shown in FIG. 14, in the blood vessel enhancement observation mode, first, the light source control unit 34 acquires an endoscope ID from the ID memory 47 of the endoscope 11 via the processor device 12 (S101). The endoscope identifying unit 67 identifies whether the connected endoscope 11 is the endoscope 11A or the endoscope 11B based on the acquired endoscope ID (S102). Information is transmitted to the drive current control unit 66.

  The drive current control unit 66 reads the basic drive condition corresponding to the received model information from the basic drive condition table 68, and determines the basic drive condition (S103). Condition A is selected when the endoscope 11A is connected, and condition B is selected when the endoscope 11B is connected. The drive current control unit 66 starts driving the laser diode LD1 of the first light source module 31 and the laser diode LD2 of the second light source module 32 under the determined basic drive condition (S104).

  The white light (N1 + FL) emitted from the first light source module 31 and the narrow band light N2 emitted from the second light source module 32 are supplied to the endoscope 11 and guided to the illumination window 22 through the light guide 43 to be observed. Is irradiated.

  As shown in FIGS. 8B and 9B, the observation site is imaged by the imaging device 44 during irradiation with white light (N1 + FL) and narrowband light N2, and images of B, G, and R are obtained by the DSP 57. A signal is generated. In the blood vessel enhancement observation mode, as in the normal observation mode, the image processing unit 58 generates a display image for blood vessel enhancement observation based on the B, G, and R image signals. The display control circuit 60 converts the generated display image into a video signal and displays the observation image PE on the monitor 14. Such processing is repeated in the blood vessel enhancement observation mode. In the blood vessel enhancement observation mode, the narrow-band light N2 is included in the image signal B in addition to the B component of white light, so that the superficial blood vessels are depicted with high contrast in the observation image PE.

  In the blood vessel enhancement observation mode, the light source control unit 34 controls the outputs of the first light source module 31 and the second light source module 32 based on the exposure control signal from the processor device 12 (S105). The drive current control unit 66 controls the outputs of the laser diodes LD1 and LD2 of the modules 31 and 32 while maintaining the ratio specified by the condition A when the endoscope 11A is connected. On the other hand, when the endoscope 11B is connected, the outputs of the laser diodes LD1 and LD2 are controlled while maintaining the ratio specified in the condition B.

  Regardless of which of the endoscopes 11A and 11B is connected, the drive current control unit 66 has white light (N1) based on the condition A or the condition B in the range up to the exposure control value E1 (see FIG. 13). , FL) and the narrow-band light N2 are subjected to exposure control in a state where the ratio of the emitted light quantity is maintained at a predetermined ratio. Therefore, in the range up to the exposure control value E1, there is no difference in the contrast of the superficial blood vessels drawn in the observation image PE regardless of which of the endoscopes 11A and 11B is used.

  However, when the endoscope 11B is connected, when the amount of light received by the image sensor 44 is insufficient and an exposure control signal with an exposure control value exceeding E1 is received from the processor device 12, the output of the laser diode LD2 is output. Has reached the upper limit value, the laser diode LD2 cannot further increase its output (S106). In this case, the drive current control unit 66 prioritizes securing the brightness of the observation image PE over maintaining the emitted light amount ratio, and changes only the output specified by the condition B to increase only the output of the laser diode LD1. Thereby, although the emitted light quantity ratio is changed (S107), the adjustment range of exposure control for brightness correction can be maintained.

  When only the output of white light (N1 + FL) increases due to the increase in the output of only the laser diode LD1, the ratio of the narrowband light N2 decreases, so that the contrast of the surface blood vessels relatively decreases in the observation image PE. The drive current control unit 66 executes notification processing for transmitting a notification command to the processor device 12 when the emission light amount ratio is changed. The controller of the processor device 12 displays a message indicating that the illumination condition has been changed on the monitor 14 based on the notification command. With this message, the surgeon can grasp that the lighting condition has been changed, and can perform appropriate image diagnosis with that in mind. Therefore, the endoscope 11B can be used with confidence. The above process is repeated until the blood vessel enhancement observation mode ends (S109).

  In the embodiment described above, the notification process is performed only when the endoscope 11B is connected. However, the notification process may be performed when the endoscope 11A is connected. For example, as shown in FIG. 13, in the range exceeding the exposure control value E2, the output of the laser diode LD2 reaches the upper limit value even in the case of the endoscope 11A. At this time, if only the output of the laser diode LD1 is increased with priority given to the brightness correction over the maintenance of the emitted light quantity ratio, the contrast of the superficial blood vessels in the observation image PE is reduced as in the above example. In this case, the drive current control unit 66 executes a notification process.

  However, in the exposure control value E2, when the laser diode LD1 has also reached the upper limit value, there is no room to increase the output any more, so the emission light quantity ratio may be changed because the endoscope 11B Only when is connected. In this case, as in the above example, it is sufficient to execute the notification process only when the endoscope 11B having a relatively low light transmission characteristic of the light guide is connected to the endoscope 11A. .

  In the above embodiment, it is determined based on the drive current value whether or not the emission light amount ratio of the two types of light, the narrow band light N2 and the white light, has been changed, but whether or not the emission light amount ratio has been changed. The determination method may be, for example, a method of determining by measuring the amount of light received by the image sensor. In this case, the amount of received light is measured based on the image signal output from the image sensor. However, when measuring the amount of received light, there is a concern about the complexity of the configuration due to the addition of measurement errors and measurement processing, so the method of determining based on the drive current value as in the above embodiment is accurate and simple. It is advantageous in terms of sex.

  In the above embodiment, as a light source in the blood vessel enhancement observation mode, a light source (second light source module 32) that emits narrow-band light N2 having a wavelength of 405 nm and a white light source (first light source module 31) are used. However, as shown in FIG. 15, instead of or in addition to the white light source, the narrow-band light N2 is used for emphasizing the mid-depth blood vessel. A light source that emits narrowband light N3 (green narrowband light having a wavelength of about 530 to 560 nm) may be used.

  In addition, as a white light source, a light source composed of a light emitting element that emits blue excitation light and a phosphor that emits yellow fluorescence has been described as an example, but as a white light source, a light emitting element that emits blue excitation light and a red light emission The light emitting element may be composed of two light emitting elements and a phosphor emitting green fluorescence, or may be composed of light emitting elements of three colors of blue, green, and red without using the phosphor.

  In the above-described embodiment, blood vessel enhancement observation has been described as an example of blood vessel information observation. However, blood vessel information observation includes, in addition to blood vessel enhancement observation, oxygen saturation of blood, which is imaged and observed. There is saturation observation. The present invention can also be applied to oxygen saturation observation.

  Illumination light in oxygen saturation observation is, for example, light having a difference in extinction coefficient between oxyhemoglobin and reduced hemoglobin, such as light having a wavelength of 445 nm or 473 nm, and reduction from oxyhemoglobin, such as light having a wavelength of 405 nm. The light of the isosbestic point having the same extinction coefficient of hemoglobin is used. Then, an oxygen saturation is calculated by performing an operation between a plurality of images acquired at each wavelength. When performing oxygen saturation observation, it is necessary to maintain the ratio of the amount of emitted light of each wavelength at a predetermined ratio in order to ensure the reliability of the calculation between images. Of course, exposure control for correcting the brightness of the image is also performed. Therefore, also in the oxygen saturation observation, when using a plurality of endoscopes having different light transmission characteristics of the light guide, such as the endoscopes 11A and 11B, the same problem as in the blood vessel enhancement observation occurs. May be applied to oxygen saturation observation.

  In addition, in oxygen saturation observation, three or more types of light having different wavelengths are used as an example, but in blood vessel enhancement observation, in addition to blue light and green light, the wavelength is increased to emphasize deeper blood vessels. In some cases, three or more types of light are used, such as using long red light. The present invention may be applied when three or more types of light are used.

  In the above embodiment, as an example of a plurality of types of endoscopes, an existing endoscope and an improved endoscope with improved light transmission characteristics of the light guide in the blue region have been described as an example. The improved endoscope is an example. However, the present invention is not limited to this, and the endoscopes of a plurality of models are a plurality of endoscopes in which light guides having different light transmittances for at least one of two types of light for blood vessel information observation are incorporated. Good.

  In the above embodiment, the laser diode is described as an example of the semiconductor light source, but another semiconductor light source such as an LED may be used.

  In the above-described embodiment, an example of a simultaneous method in which white light is color-separated by a micro color filter and a plurality of color images are simultaneously acquired using a color image sensor provided with B, G, and R micro color filters is described. However, the present invention may be applied to a frame sequential method in which images of respective colors are sequentially acquired using a monochrome imaging element not provided with a color filter.

  In the above embodiment, the example in which the light source device and the processor device are configured separately is described, but the two devices may be configured integrally. In addition, the present invention can be applied to other types of endoscope systems such as a system including an ultrasonic endoscope in which an imaging element and an ultrasonic transducer are built in a distal end portion and a processor device that performs image processing. it can.

DESCRIPTION OF SYMBOLS 10 Endoscope system 11, 11A, 11B Endoscope 12 Processor apparatus 13 Light source apparatus 28 Connector 31 1st light source module 32 2nd light source module 34 Light source control part 42a, 42b Receptacle connector (connection part)
43, 43A, 43B Light guides 47, 47A, 47B ID memory 66 Drive current control unit 67 Endoscope identification unit 68 Basic drive condition table LD1, LD2 Laser diode

Claims (10)

Light for at least one of first and second lights having different wavelengths, which are first and second light guides for guiding illumination light for illuminating an observation site in a living body and used for blood vessel information observation A connection unit for connecting the first and second endoscopes, each having a difference in transmittance, in which the first and second light guides are incorporated, respectively;
An endoscope identification unit for identifying whether the type of endoscope connected to the connection unit is the first or second endoscope;
First and second semiconductor light sources emitting the first and second lights, respectively;
The ratio of the amount of emitted light of the first and second lights guided by one of the first and second light guides and emitted toward the observation site is predetermined regardless of the type of the endoscope. An output control unit that controls the outputs of the first and second semiconductor light sources according to the type of the endoscope so that the ratio is maintained, and one of the outputs of the first and second semiconductor light sources is the first. After reaching the upper limit, an output control unit that corrects the brightness of the observation image by increasing the light amount of the semiconductor light source that does not reach the upper limit among the first and second semiconductor light sources, and
A light source device comprising: a notification unit that executes a notification process for notifying that when the ratio of the amount of emitted light cannot be maintained by the exposure control.   The said notification part performs the said alerting | reporting process only when the endoscope with the said lower light transmittance is connected among the said 1st and 2nd endoscopes. Light source device.   2. The first and second light guides according to claim 1, wherein the difference between the first light transmittances for the first light and the difference between the second light transmittances for the second light are different. 2. The light source device according to 2. It is a driving condition for controlling the outputs of the first and second semiconductor light sources, and the ratio of the emitted light quantity is maintained at the predetermined ratio according to the light transmittance of each of the first and second light guides. A storage unit that stores in advance the first and second drive conditions for
4. The light source device according to claim 1, wherein the output control unit controls outputs of the first and second light sources based on the first and second driving conditions. 5. .   The light source device according to claim 1, wherein the light guide is a fiber bundle in which optical fibers are bundled. It is the second light that has a relatively large difference in the light transmittance among the first and second lights,
The light source device according to claim 5, wherein the second light is blue light having a wavelength of about 430 nm or less.   The light source device according to claim 6, wherein the blue light has a wavelength of about 410 ± 10 nm.   The light source device according to claim 6, wherein the first light includes green light having a wavelength range of about 530 nm to 560 nm.   The first semiconductor light source that emits the first light includes a light emitting element that emits excitation light having a wavelength of about 440 ± 10 nm, and a phosphor that emits fluorescence including the green light by the excitation light. The light source device according to claim 8. In an endoscope system including first and second endoscopes, and a light source device to which the first and second endoscopes are exchangeably connected,
The first and second endoscopes are:
Light transmission for at least one of first and second lights having different wavelengths, which are first and second light guides for guiding illumination light for illuminating an observation site in a living body and used for blood vessel information observation The first and second light guides with different rates are built in,
The light source device
A connecting portion for connecting the first and second endoscopes in a replaceable manner;
An endoscope identification unit for identifying whether the type of endoscope connected to the connection unit is the first or second endoscope;
First and second semiconductor light sources emitting the first and second lights, respectively;
The ratio of the amount of emitted light of the first and second lights guided by one of the first and second light guides and emitted toward the observation site is predetermined regardless of the type of the endoscope. An output control unit that controls the outputs of the first and second semiconductor light sources according to the type of the endoscope so that the ratio is maintained, and one of the outputs of the first and second semiconductor light sources is the first. After reaching the upper limit, an output control unit that corrects the brightness of the observation image by increasing the light amount of the semiconductor light source that does not reach the upper limit among the first and second semiconductor light sources, and
An endoscope system comprising: a notifying unit that executes a notification process for notifying that the ratio of the amount of emitted light is changed when the ratio of the amount of emitted light cannot be maintained.

Images