JP2019030743A - Light source device for endoscope, endoscope system, and position adjusting method - Google Patents

Abstract

To provide a light source device for an endoscope, an endoscope system, and a position adjusting method capable of reducing a change in a hue of a display image in each of endoscopic diagnoses when using a plurality of monochrome semiconductor light sources emitting a light of a plurality of colors respectively.SOLUTION: A collimator lens 75 that transmits a blue color light BL from a blue semiconductor light source 35 and a collimator lens 77 that transmits a red color light RL from a red semiconductor light source 37 are provided with adjusting mechanisms 81 and 82 respectively. The adjusting mechanisms 81 and 82 cause a focal position BFP of the blue color light BL and a focal position RFP of the red color light RL to coincide with a focal position GFP of a green color light GL by moving the collimator lenses 75 and 77 in an optical axis OA direction. The adjusting mechanisms 81 and 82 include a guide mechanism for guiding the movement of the collimator lenses 75 and 77 in the optical axis OA direction, a moving mechanism for moving the collimator lenses 75 and 77 in the optical axis OA direction, and a fixing mechanism for fixing the positions of the collimator lenses 75 and 77.SELECTED DRAWING: Figure 15

Description

  The present invention relates to an endoscope light source device that supplies illumination light to an endoscope, an endoscope system, and a position adjustment method.

  In the medical field, endoscopic diagnosis using an endoscopic system is actively performed. An endoscope system includes an endoscope, a processor device that processes an image signal output from the endoscope, an endoscope light source device that supplies illumination light to the endoscope (hereinafter simply referred to as a light source device), and It has.

  The endoscope has an insertion part to be inserted into a living body, and an illumination window for irradiating the observation target with illumination light and an observation window for imaging the observation target are arranged at the tip of the insertion part. Yes. The endoscope has a built-in light guide made of a fiber bundle in which optical fibers are bundled. The light guide guides the illumination light supplied from the light source device to the illumination window. The incident end of the light guide to which the illumination light is incident is disposed in the light source device, and the emission end of the light guide from which the illumination light is emitted is disposed at the back of the illumination window.

  An imaging sensor such as a CCD (Charge Coupled Device) image sensor is disposed behind the observation window. The imaging sensor images an observation target irradiated with illumination light and outputs an image signal. The processor device generates a display image for observation based on the image signal and displays it on the monitor.

  When the endoscope diagnosis is completed, the endoscope is removed from the processor device and the light source device, and cleaned and disinfected. Then, when starting the next endoscopic diagnosis, the processor device and the light source device are connected again. In the medical field, there are multiple endoscopes of the same model or multiple types of endoscopes with specifications according to the contents of the endoscope diagnosis. The processor device and the light source device are of the same model. A plurality of endoscopes and a plurality of types of endoscopes having different specifications can be connected in a replaceable manner.

  Conventionally, xenon lamps and halogen lamps that emit white light have been used as light sources in light source devices. Recently, however, instead of these, laser diodes (LDs) and light emitting diodes (LEDs: Light Emitting Diodes). A light source device using a semiconductor light source having a light emitting element such as the above has been proposed (see Patent Document 1).

  Patent Document 1 describes a light source device that includes blue, green, and red semiconductor light sources that emit light of three colors of blue light, green light, and red light, respectively, and that supplies the three colors of light as white light. The light source device of Patent Document 1 includes three first optical systems (first lens 26a, second lens 26b, and third lens 26c), second optical system (fourth lens 26d), and third optical system (first optical system). A dichroic mirror 25a and a second dichroic mirror 25b) are provided. The three first optical systems respectively transmit light of three colors from the blue, green, and red semiconductor light sources. The second optical system condenses three colors of light at the incident end of the light guide. The third optical system combines the optical paths of the three colors of light transmitted through the first optical system.

Japanese Patent Laying-Open No. 2015-047402

  A light source device that supplies light of a plurality of colors from a plurality of single-color semiconductor light sources as illumination light as in Patent Document 1, all of the light of a plurality of colors emitted from the second optical system is transmitted from the incident end of the light guide. To be precise, it is ideal that the focal point is formed at the incident end of the fiber bundle constituting the light guide.

  However, in the light source device of Patent Document 1, as shown in FIG. 25, the blue light BL (shown by a broken line), the green light GL (shown by a thick solid line), and the red light RL (thin) emitted from the second optical system 200. The respective focal positions BFP, GFP, and RFP (shown by solid lines) may be shifted on the optical axis OA, thereby causing a so-called color shift in which the color of the display image changes.

  Factors that shift the focal positions include assembly errors and individual differences in each part of the configuration for supplying illumination light such as blue, green, and red semiconductor light sources and the first to third optical systems. For example, when the distance between the blue semiconductor light source and the first optical system that transmits the blue light BL is shifted due to an assembly error, the focal position BFP of the blue light BL is also shifted. Alternatively, when the wavelength range or the center wavelength of the red light RL is shifted due to the individual difference of the red semiconductor light source, the refractive index of the red light RL in the first optical system and the third optical system changes. Missed.

  When each focal position shifts, a light amount waveform BW (indicated by a broken line), GW (indicated by a thick solid line), RW (indicated by a thin solid line) indicating the amount of light of the three colors of light BL, GL, and RL on the optical axis OA in FIG. As shown in FIG. 3, the light intensity peaks of the three colors of light BL, GL, and RL corresponding to the respective focal positions are also shifted on the optical axis OA. Note that the light amount waveform is a mountain-shaped waveform that peaks at the focal position and has a symmetric depression before and after the focal position. Each light quantity waveform BW, GW, RW has substantially the same shape.

  When the peaks of the respective light amount waveforms BW, GW, and RW are shifted, the light amount balance of the three colors of light BL, GL, and RL varies depending on the distance from the second optical system 200. For example, at the focal position RFP of the red light RL, the light amount of the red light RL is the highest, and then the light amount decreases in the order of the green light GL and the blue light BL. On the other hand, at the focal position BFP of the blue light BL, the light amount of the blue light BL is the highest, and then the light amount decreases in the order of the green light GL and the red light RL.

  In such a case, the light quantity balance of the three colors of light BL, GL, and RL incident on the incident end 202 varies depending on the positional relationship between the second optical system 200 and the incident end 202 of the light guide 201. As a result, the display image A color shift that changes the color tone occurs. For example, when the incident end 202B is at the focal position GFP of the green light GL as in the light guide 201B, since the amount of the green light GL is the highest, the illumination light is greenish and the entire display is greenish. An image 203G is generated. In addition, when the incident end 202A is at the focal position RFP of the red light RL as in the light guide 201A, a display image 203R that is entirely reddish is generated, and the incident end 202C is blue as in the light guide 201C. When it is at the focal position BFP of the light BL, a display image 203B that is entirely bluish is generated.

  As described above, the endoscope is detached from the light source device or connected to the light source device every time the endoscope is diagnosed. Further, when a plurality of endoscopes of the same model are shared by a single light source device, the second optical system 200 and the incident end 202 are caused by individual differences between the plurality of endoscopes although they are the same model. The positional relationship with will change. Further, when a plurality of types of endoscopes having different specifications are shared by a single light source device, some types of endoscopes have different positional relationships between the second optical system 200 and the incident end 202. Exists. For this reason, the positional relationship between the second optical system 200 and the incident end 202 is not always the same, and differs depending on the connection to the light source device, individual differences in the endoscope, and specifications. Accordingly, when there are deviations in the focal positions of light of a plurality of colors, a situation may occur in which the color of the display image changes every time an endoscopic diagnosis is made.

  Since the endoscopic diagnosis is performed based on a subtle change in color of the observation target, it is very important to reduce the change in the color of the display image at each endoscopic diagnosis. However, if a situation occurs in which the color of the display image changes every time an endoscopic diagnosis is made as described above, the operator feels uncomfortable and it is difficult to make an endoscopic diagnosis.

  The present invention relates to an endoscope light source device capable of reducing a change in color of a display image at each time of endoscopic diagnosis when using a plurality of single-color semiconductor light sources that respectively emit light of a plurality of colors. An object is to provide an endoscope system and a position adjustment method.

  To achieve the above object, the present invention provides an endoscope light source device that supplies illumination light to a light guide of an endoscope, a plurality of single-color semiconductor light sources that respectively emit light of a plurality of colors as illumination light, and at least A plurality of first optical systems configured by one optical member and transmitting a plurality of colors of light from a plurality of single-color semiconductor light sources, and a plurality of colors of light transmitted through the plurality of first optical systems are incident on a light guide. A second optical system that collects light at the end; and a position adjustment mechanism that adjusts the position of the optical member in the optical axis direction of the first optical system. The position adjustment mechanism guides the movement of the optical member in the optical axis direction. A guide mechanism; a moving mechanism that moves the optical member in the optical axis direction; and a fixing mechanism that fixes the position of the optical member.

  It is preferable that the same number of position adjusting mechanisms as the number of light of the remaining colors excluding light of one color among the light of multiple colors is provided. It is preferable to include a third optical system that is provided between the plurality of first optical systems and the second optical system and that couples optical paths of light of a plurality of colors that have passed through the plurality of first optical systems. The position adjusting mechanism is preferably provided on the monochromatic semiconductor light source side of the third optical system in the optical path from the monochromatic semiconductor light source to the second optical system.

  The plurality of monochromatic semiconductor light sources preferably have a rectangular light-emitting portion. The plurality of single-color semiconductor light sources are preferably a blue semiconductor light source, a green semiconductor light source, and a red semiconductor light source that respectively emit three colors of light of blue light, green light, and red light as illumination light. The blue semiconductor light source emits blue light with a center wavelength of 460 ± 10 nm and a half width of 25 ± 10 nm, the green semiconductor light source emits green light with a center wavelength of 550 ± 10 nm and a half width of 100 ± 10 nm, and the red semiconductor light source It is preferable to emit red light having a wavelength of 625 ± 10 nm and a half width of 20 ± 10 nm. The position adjustment mechanism preferably adjusts the position of the monochromatic semiconductor light source in the optical axis direction in addition to the optical member. The housing having a lens holder for holding the optical member is provided, and the moving mechanism moves the optical member in the lens holder in the optical axis direction by using a long hole provided in the lens holder. The guide protrusion provided in the lens holder and the guide groove formed in the housing guide the movement of the optical member in the lens holder in the optical axis direction, and the fixing mechanism fits the lens holder in the fitting hole in the housing. In this state, it is preferable to fix the position of the optical member in the lens holder by pressing the lens holder with the fixing portion.

  The present invention includes an endoscope having a light guide that guides illumination light, and an endoscope light source device that supplies illumination light to the light guide, and a plurality of the endoscopes are connected to one of the endoscopes. In an endoscope system shared by an endoscope light source device, the endoscope light source device includes a plurality of single-color semiconductor light sources that emit light of a plurality of colors as illumination light, and at least one optical member. A plurality of first optical systems that respectively transmit a plurality of colors of light from a monochromatic semiconductor light source; and a second optical system that condenses a plurality of colors of light transmitted through the plurality of first optical systems at an incident end of the light guide; A position adjusting mechanism that adjusts the position of the optical member in the optical axis direction of the first optical system, the position adjusting mechanism guiding the movement of the optical member in the optical axis direction, and the optical member on the optical axis. The moving mechanism that moves in the direction and the position of the optical member And a fixing mechanism.

  The present invention is composed of a plurality of single-color semiconductor light sources that respectively emit light of a plurality of colors as illumination light and at least one optical member, and a plurality of first colors that respectively transmit light of a plurality of colors from the plurality of single-color semiconductor light sources. An optical system and a second optical system that condenses light of a plurality of colors transmitted through the plurality of first optical systems at an incident end of a light guide of the endoscope, and is connected to a detection unit including a light guide for detection In the position adjustment method in the endoscope light source device that is possible, when the position of the incident end of the detection light guide is moved in the optical axis direction, each color light via the detection light guide with respect to the position of the incident end In order to make the peak of the light intensity waveform of each color light indicating the light intensity of each color coincide with each other by adjusting the position of the optical member and the position of the monochromatic semiconductor light source in the optical axis direction of the first optical system by the position adjusting mechanism. Position to match.

  According to the present invention, since the position adjusting mechanism for adjusting the position of at least one of the optical member and the monochromatic semiconductor light source in the optical axis direction of the first optical system is provided, a plurality of monochromatic semiconductors each emitting light of a plurality of colors. When a light source is used, it is possible to provide an endoscope light source device, an endoscope system, and a position adjustment method capable of reducing a change in color of a display image at each time of endoscopic diagnosis. .

It is an external view of an endoscope system. It is a front view of the front-end | tip part of an endoscope. It is explanatory drawing of the endoscope system which shares a some endoscope with one processor apparatus and a light source device. It is a block diagram of an endoscope system. It is sectional drawing which shows a blue semiconductor light source. It is a top view which shows a blue semiconductor light source. It is a graph which shows the emission spectrum of the blue light which a blue semiconductor light source emits. It is a graph which shows the emission spectrum of the green light which a green semiconductor light source emits. It is a graph which shows the emission spectrum of the red light which a red semiconductor light source emits. It is a graph which shows the emission spectrum of the white light comprised by blue light, green light, and red light. It is a graph which shows the spectral characteristic of the micro color filter of an image sensor. It is explanatory drawing which shows the irradiation timing of white light, and the operation timing of an image sensor. It is a figure which shows arrangement | positioning of each semiconductor light source, and the detailed structure of an optical system group. It is a disassembled perspective view of a lens holder and a housing. It is a perspective view of a lens holder, a housing, and an eccentric driver. It is explanatory drawing which shows a mode that a lens holder is moved to an optical axis direction using an eccentric driver in the state which temporarily fixed the lens holder to the housing. It is explanatory drawing which shows the change of the focus position by the movement to the optical axis direction of a collimating lens. It is a block diagram of a detection unit. It is explanatory drawing which shows the relationship between the position of the incident end of a light guide in case each focus position of blue light, green light, and red light has shifted | deviated, and a display image. It is explanatory drawing which shows the relationship between the position of the incident end of a light guide in case each focus position of blue light, green light, and red light corresponds, and a display image. It is a figure which shows the detailed structure of arrangement | positioning of each semiconductor light source, and an optical system group at the time of providing an adjustment mechanism in a blue semiconductor light source and a red semiconductor light source instead of a collimating lens. It is a figure which shows the arrangement | positioning of each semiconductor light source at the time of providing an adjustment mechanism in a blue semiconductor light source and a red semiconductor light source in addition to a collimating lens, and the detailed structure of an optical system group. It is a figure which shows the arrangement | positioning of each semiconductor light source at the time of adding a purple semiconductor light source, and the detailed structure of an optical system group. It is a graph which shows the emission spectrum of the purple light which a purple semiconductor light source emits. In the conventional light source device, it is explanatory drawing which shows the relationship between the position of the incident end of a light guide, and a display image when each focus position of blue light, green light, and red light has shifted | deviated.

  In FIG. 1, an endoscope system 10 includes an endoscope 11 that images an observation target in a living body, a processor device 12 that generates a display image for observation based on an image signal obtained by the imaging, and an observation target. And a light source device 13 that supplies illumination light to the endoscope 11. A monitor 14 for displaying a display image and an operation input unit 15 such as a keyboard or a mouse are connected to the processor device 12.

  The endoscope 11 includes an insertion portion 16 to be inserted into a living body, an operation portion 17 provided at a proximal end portion of the insertion portion 16, and a universal cord that connects the endoscope 11, the processor device 12, and the light source device 13. 18.

  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, the distal end surface of the distal end portion 19 is sent to clean the illumination window 22 for irradiating the observation target with illumination light, the observation window 23 for imaging the observation target, and the observation window 23. An air supply / water supply nozzle 24 for performing air / water supply, and a forceps outlet 25 for performing various treatments by projecting a treatment tool such as forceps and an electric knife are provided. In the back of the observation window 23, an image sensor 56 and an objective optical system 63 for image formation (both see FIG. 4) are incorporated.

  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. In FIG. 1, the upward bending operation is indicated by a broken line. As the bending portion 20 is bent, 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 56 and an image signal output from the image sensor 56, and a light guide 55 that guides illumination light supplied from the light source device 13 to the illumination window 22. Etc.) are inserted.

  In addition to the amble knob 26, the operation unit 17 includes a forceps port 27 for inserting a treatment instrument, an air / water supply button 28 that is operated when air / water is supplied from the air / water supply nozzle 24, and a still image. A release button (not shown) for photographing is provided.

  A communication cable and a light guide 55 extending from the insertion portion 16 are inserted into the universal cord 18. A connector 29 is attached to one end of the universal cord 18 on the processor device 12 and light source device 13 side. The connector 29 is a composite type connector composed of a communication connector 29A and a light source connector 29B. The communication connector 29A and the light source connector 29B are detachably connected to the processor device 12 and the light source device 13, respectively. One end of a communication cable is disposed on the communication connector 29A, and an incident end 61 (see FIG. 4) of the light guide 55 is disposed on the light source connector 29B.

  When the endoscopic diagnosis is completed, the connection of the connector 29 is released, and the endoscope 11 is removed from the processor device 12 and the light source device 13 and cleaned and disinfected. When the next endoscopic diagnosis is started, the processor device 12 and the light source device 13 are connected again.

  In FIG. 1, only one endoscope 11 is illustrated. However, as shown in FIG. 3, there are a plurality of endoscopes 11 of the same model (indicated by reference numerals 11A to 11C) A plurality of types (indicated by reference numerals 11D and 11E) having different specifications according to the contents of the endoscopic diagnosis are prepared. The processor device 12 and the light source device 13 can connect a plurality of endoscopes 11A to 11C of the same model and a plurality of types of endoscopes 11D and 11E having different specifications in an exchangeable manner.

  In FIG. 4, the light source device 13 includes a blue semiconductor light source 35, a green semiconductor light source 36, a red semiconductor light source 37, an optical system group 41, and each of the semiconductor light sources 35 to 37 that emit three lights of blue, green, and red, respectively. And a light source control unit 42 that controls driving.

  Each of the semiconductor light sources 35 to 37 includes, as light emitting elements, a blue LED 43 that emits light in a blue wavelength band (blue light BL), a green LED 44 that emits light in a green wavelength band (green light GL), and light in a red wavelength band. Each of the red LEDs 45 emits (red light RL). Each of the LEDs 43 to 45 is formed by joining a P-type semiconductor and an N-type semiconductor as is well known. When a voltage is applied, electrons and holes recombine near the PN junction near the PN junction and a current flows, and energy corresponding to the band gap is emitted as light at the time of recombination. Each of the LEDs 43 to 45 increases or decreases the amount of light emitted according to the increase or decrease of the supplied power.

  Drivers 50, 51, and 52 are connected to the LEDs 43 to 45, respectively. The light source control unit 42 controls turning on / off of the LEDs 43 to 45 and the amount of light through the drivers 50 to 52. The amount of light is controlled by changing the power supplied to the LEDs 43 to 45 based on the exposure control signal from the processor device 12.

  Each driver 50-52 lights each LED43-45 by giving a drive current to each LED43-45 continuously under control of the light source control part 42. As shown in FIG. Then, according to the exposure control signal, the power supplied to each of the LEDs 43 to 45 is changed by changing the value of the drive current to be applied, and the amount of each color light of the blue light BL, the green light GL, and the red light RL is controlled. To do. PAM (Pulse Amplitude Modulation) control that changes the amplitude of the drive current pulse, and PWM (Pulse Width Modulation) control that changes the duty ratio of the drive current pulse. May be performed.

  The optical system group 41 combines the optical paths of the blue light BL, the green light GL, and the red light RL into one optical path, and condenses each color light on the incident end 61 of the light guide 55 of the endoscope 11. Although not shown, the light source connector 29B is provided with an engaging member such as a C-ring that engages with the receptacle connector 54. The receptacle connector 54 is in contact with the outer peripheral surface of the light source connector 29B. A restricting member for restricting the amount of the light source connector 29B inserted into the receptacle connector 54 is provided. Each of the light source connector 29B and the receptacle connector 54 is provided with protective glass.

  The endoscope 11 includes a light guide 55, an imaging sensor 56, an analog processing circuit 57 (AFE: Analog Front End), and an imaging control unit 58. The light guide 55 includes a cylindrical fiber bundle 59 in which a plurality of optical fibers are bundled, and a protective tube 60 that covers the outer periphery of the fiber bundle 59. When the light source connector 29B is connected to the light source device 13, the incident end 61 of the light guide 55 (fiber bundle 59) disposed in the light source connector 29B faces the optical system group 41. The emission end of the light guide 55 located at the distal end portion 19 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 62 is disposed in the back of the illumination window 22. The illumination light supplied from the light source device 13 is guided to the irradiation lens 62 by the light guide 55 and irradiated from the illumination window 22 toward the observation target. The irradiation lens 62 is a concave lens, and widens the divergence angle of the light emitted from the light guide 55. Thereby, illumination light can be irradiated to the wide range of observation object.

  In the back of the observation window 23, an objective optical system 63 and an image sensor 56 are arranged. The image to be observed enters the objective optical system 63 through the observation window 23 and is formed on the imaging surface 56 </ b> A of the imaging sensor 56 by the objective optical system 63.

  The imaging sensor 56 includes a CCD image sensor, a CMOS (Complementary Metal-Oxide Semiconductor) image sensor, and the like. On the imaging surface 56A, a plurality of photoelectric conversion elements constituting pixels such as photodiodes are arranged in a matrix. Yes. The imaging sensor 56 photoelectrically converts the light received by the imaging surface 56A, 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 imaging sensor 56 to the AFE 57 as an image signal.

  The AFE 57 includes a correlated double sampling circuit, an automatic gain control circuit, and an analog / digital converter (all not shown). The correlated double sampling circuit performs correlated double sampling processing on the analog image signal from the image sensor 56, and removes noise caused by resetting the signal charge. The automatic gain control circuit amplifies the image signal from which noise has been removed by the correlated double sampling circuit. The analog / digital converter converts the image signal amplified by the automatic gain control circuit into a digital image signal having a gradation value corresponding to a predetermined number of bits and outputs the digital image signal to the processor device 12.

  The imaging control unit 58 is connected to the controller 65 in the processor device 12 and inputs a drive signal to the imaging sensor 56 in synchronization with a reference clock signal input from the controller 65. The imaging sensor 56 outputs an image signal to the AFE 57 at a predetermined frame rate based on the drive signal from the imaging control unit 58.

  The imaging sensor 56 is a color imaging sensor, and the imaging surface 56A is provided with three color micro color filters, a blue micro color filter (B filter), a green micro color filter (G filter), and a red micro color filter (R filter). Each filter is assigned to each pixel. The arrangement of each filter is, for example, a Bayer arrangement.

  In the following description, a pixel to which the B filter is assigned is referred to as a B pixel, a pixel to which the G filter is assigned is referred to as a G pixel, and a pixel to which the R filter is assigned is referred to as an R pixel. An image signal output from the B pixel is referred to as a B image signal, an image signal output from the G pixel is referred to as a G image signal, and an image signal output from the R pixel is referred to as an R image signal.

  In addition to the controller 65, the processor device 12 includes a DSP (Digital Signal Processor) 66, an image processing unit 67, a frame memory 68, and a display control unit 69. The controller 65 has a CPU (Central Processing Unit), a ROM (Read Only Memory) that stores control programs and setting data necessary for control, a RAM (Random Access Memory) that loads programs and functions as a working memory, and the like. The CPU controls each part of the processor device 12 by executing a control program.

  The DSP 66 acquires an image signal from the image sensor 56. The DSP 66 performs pixel interpolation processing on each of the B image signal, the G image signal, and the R image signal corresponding to each of the B pixel, the G pixel, and the R pixel. In addition, the DSP 66 performs signal processing such as gamma correction and white balance correction on the B, G, and R image signals.

  Further, the DSP 66 calculates an exposure value based on each image signal, and when the light amount of the entire image is insufficient (underexposure), the light amount of the illumination light is increased, while when the light amount is too high. In (overexposure), an exposure control signal for controlling to reduce the amount of illumination light is output to the controller 65. The controller 65 transmits an exposure control signal to the light source control unit 42 of the light source device 13.

  The frame memory 68 stores the image signal output from the DSP 66 and the processed image signal processed by the image processing unit 67. The display control unit 69 reads an image signal that has undergone image processing from the frame memory 68, converts it into a video signal such as a composite signal or a component signal, and outputs the video signal to the monitor 14.

  The image processing unit 67 generates a display image based on the B, G, and R image signals. This display image is output to the monitor 14 through the display control unit 69. The image processing unit 67 generates a display image every time the image signal in the frame memory 68 is updated.

  As shown in FIGS. 5 and 6, the blue semiconductor light source 35 includes a substrate 75 on which the blue LED 43 is mounted, a mold 77 formed on the substrate 75 and formed with a cavity 76 that accommodates the blue LED 43, and the cavity 76. And the resin 78 enclosed in the. The blue LED 43 is connected to the substrate 75 by a wiring 79. Such a mounting form of the blue semiconductor light source 35 is generally called a surface mounting type.

  The cavity 76 has a rectangular opening, and the width becomes narrower toward the substrate 75 side. Blue light BL is emitted from the rectangular opening of the cavity 76. That is, the opening of the cavity 76 functions as a light emitting part for the blue light BL. The inner surface of the cavity 76 functions as a reflector that reflects the blue light BL. The dimension of the opening of the cavity 76 is, for example, a long side of 2 mm and a short side of 1.5 mm. A diffusion material for diffusing light is dispersed in the resin 78. Since the semiconductor light sources 35 to 37 have basically the same configuration, the blue semiconductor light source 35 will be described as an example, and the description of the green and red semiconductor light sources 36 and 37 will be omitted.

  As shown in FIG. 7, the blue semiconductor light source 35 has, for example, a wavelength component in the vicinity of 420 nm to 500 nm which is a blue wavelength band, and emits blue light BL having a center wavelength of 460 ± 10 nm and a half width of 25 ± 10 nm. As shown in FIG. 8, the green semiconductor light source 36 emits green light GL having a wavelength component in the vicinity of 480 nm to 600 nm, which is a green wavelength band, for example, with a center wavelength of 550 ± 10 nm and a half-value width of 100 ± 10 nm. To do. Further, as shown in FIG. 9, the red semiconductor light source 37 has, for example, a wavelength component in the vicinity of 600 nm to 650 nm which is a red wavelength band, and emits red light RL having a center wavelength of 625 ± 10 nm and a half width of 20 ± 10 nm. . The center wavelength indicates the center wavelength of the emission spectrum width of each color light, and the half-value width is a wavelength range indicating half of the peak of the emission spectrum of each color light.

  FIG. 10 shows an emission spectrum of the mixed light of the blue light BL, the green light GL, and the red light RL, the optical paths of which are combined by the optical system group 41. This mixed light is used as white light WL which is illumination light. In order to maintain the color rendering property equivalent to that of white light emitted from a xenon light source, the white light WL is configured not to generate a wavelength band having no light intensity component in its emission spectrum.

  FIG. 11 is a graph illustrating spectral characteristics of the B filter, the G filter, and the R filter provided on the imaging surface 56A of the imaging sensor 56. The B pixel to which the B filter is assigned is sensitive to light in the wavelength band of about 380 nm to 560 nm, and the G pixel to which the G filter is assigned is sensitive to light in the wavelength band of about 450 nm to 630 nm. The R pixel to which the R filter is assigned is sensitive to light in the wavelength band of about 580 nm to 800 nm. The blue light BL, green light GL, and red light RL that constitute the white light WL are mainly reflected by the B pixel for reflected light corresponding to the blue light BL, and mainly reflected by the G pixel and red light RL for the green light GL. The reflected light is received mainly by the R pixel.

  In FIG. 12, the imaging sensor 56 performs an accumulation operation for accumulating signal charges in pixels and a read operation for reading the accumulated signal charges within an acquisition period of an image signal of one frame. In accordance with the timing of the accumulation operation of the image sensor 56, the respective semiconductor light sources 35 to 37 are turned on, and white light WL (BL + GL + RL) composed of mixed light of blue light BL, green light GL, and red light RL is irradiated to the observation target. The reflected light is incident on the image sensor 56. The image sensor 56 separates the reflected light of the white light WL by each filter. The B pixel receives reflected light corresponding to the blue light BL, the G pixel receives reflected light corresponding to the green light GL, and the R pixel receives reflected light corresponding to the red light RL. The imaging sensor 56 sequentially outputs image signals for one frame according to the frame rate in accordance with the readout timing.

  In FIG. 13, the optical system group 41 includes collimator lenses 75, 76, and 77 that guide the color lights from the semiconductor light sources 35 to 37 to the incident end 61, and the colors that have passed through the collimator lenses 75 to 77. It is composed of dichroic mirrors 78 and 79 for coupling light paths of light, and a condensing lens 80 for condensing each color light at the incident end 61.

  The collimating lenses 75 to 77 transmit the respective color lights from the respective semiconductor light sources 35 to 37 to make the respective color lights substantially parallel. The collimating lenses 75 to 77 constitute a plurality of first optical systems and correspond to optical members constituting the first optical system. The dichroic mirrors 78 and 79 are optical members in which a dichroic filter having a predetermined transmission characteristic is formed on a transparent glass plate. The dichroic mirrors 78 and 79 are provided between the collimating lenses 75 to 77 and the condenser lens 80. The dichroic mirrors 78 and 79 constitute a third optical system. The condensing lens 80 constitutes a second optical system.

  The green semiconductor light source 36 is disposed at a position where its optical axis coincides with the optical axis of the light guide 55. The green semiconductor light source 36 and the red semiconductor light source 37 are arranged so that their optical axes are orthogonal to each other. A dichroic mirror 78 is provided at a position where the optical axes of the green semiconductor light source 36 and the red semiconductor light source 37 are orthogonal to each other. Similarly, the blue semiconductor light source 35 is also arranged to be orthogonal to the optical axis of the green semiconductor light source 36, and a dichroic mirror 79 is provided at a position where these optical axes are orthogonal.

  The dichroic mirror 78 is disposed with an inclination of 45 ° with respect to the optical axis of the green semiconductor light source 36 and the optical axis of the red semiconductor light source 37. Further, the dichroic mirror 79 is disposed in an attitude inclined by 45 ° with respect to the optical axis of the blue semiconductor light source 35 and the optical axis of the green semiconductor light source 36.

  The dichroic filter of the dichroic mirror 78 has a characteristic of reflecting light in the red wavelength band of about 600 nm or more and transmitting light in the blue and green wavelength bands of less than about 600 nm, for example. The dichroic mirror 78 transmits the green light GL from the green semiconductor light source 36 downstream and reflects the red light RL from the red semiconductor light source 37. As a result, the optical paths of the green light GL and the red light RL are combined.

  On the other hand, the dichroic filter of the dichroic mirror 79 has a characteristic of reflecting light in a blue wavelength band of less than about 480 nm, for example, and transmitting light in green and red wavelength bands of about 480 nm or more. For this reason, the dichroic mirror 79 transmits the green light GL transmitted through the dichroic mirror 78 and the red light RL reflected by the dichroic mirror 78. Further, the dichroic mirror 79 reflects the blue light BL from the blue semiconductor light source 35. By the action of the dichroic mirror 79, all the optical paths of the blue light BL, the green light GL, and the red light RL are combined to generate white light WL.

  Among the collimating lenses 75 to 77, the collimating lens 75 facing the blue semiconductor light source 35 excluding the collimating lens 76 facing the green semiconductor light source 36 and the collimating lens 77 facing the red semiconductor light source 37 are provided with a position adjusting mechanism (hereinafter referred to as a position adjusting mechanism). 81, 82). The adjustment mechanisms 81 and 82 adjust the focal positions of the blue light BL and the red light RL emitted from the condenser lens 80 by adjusting the positions of the collimating lenses 75 and 77 in the optical axis direction, and thereby adjust the blue light BL. , Green light GL and red light RL are mechanisms for matching the focal positions of the respective color lights. More specifically, the adjustment mechanisms 81 and 82 move the collimating lenses 75 and 77 in the optical axis direction, thereby matching the focal positions of the respective color lights.

  In the light source device having a plurality of single-color semiconductor light sources such as the light source device 13 having the blue semiconductor light source 35, the green semiconductor light source 36, and the red semiconductor light source 37 of the present embodiment, as described with reference to FIG. The focal positions BFP, GFP, and RFP of the blue light BL, green light GL, and red light RL emitted from the lens 80 may be shifted on the optical axis OA. The adjustment mechanisms 81 and 82 eliminate the color shift in which the color of the display image changes due to the shift of the respective focus positions, and the focus positions BFP and red of the blue light BL emitted from the condenser lens 80. The focal position RFP of the light RL is matched with the focal position GFP of the green light GL. That is, in the present embodiment, the green light GL corresponds to one color of light, and the blue light BL and the red light RL correspond to the remaining colors of light.

  14 and 15 showing a specific configuration of the adjusting mechanism 81, the collimating lens 75 is held by a cylindrical lens holder 90 and attached to the housing 91 of the optical system group 41. A long hole 92 is provided in the upper part of the lens holder 90, and a guide protrusion 93 is provided in the lower part opposite to the long hole 92. The long hole 92 is formed along a direction perpendicular to the optical axis OA. Further, the long hole 92 is formed so that its center coincides with the optical axis OA when viewed from above and is symmetrical with respect to the optical axis OA. The long hole 92 functions as a moving mechanism that moves the lens holder 90, that is, the collimating lens 75 in the direction of the optical axis OA. The guide protrusion 93 is formed over the entire width of the lens holder 90 along a direction parallel to the optical axis OA.

  A fitting hole 95 into which the lens holder 90 is fitted is formed in the housing 91. A notch 96 is provided in the upper part of the fitting hole 95, and a guide groove 97 is provided in the lower part facing the notch 96. The notch 96 is provided to expose the upper portion of the lens holder 90 provided with the elongated hole 92 when the lens holder 90 is fitted into the fitting hole 95. The guide groove 97 is formed over the entire width of the insertion hole 95 along the direction parallel to the optical axis OA, like the guide protrusion 93.

  The guide groove 97 receives the guide protrusion 93 when the lens holder 90 is fitted into the fitting hole 95. The guide protrusion 93 and the guide groove 97 guide the movement of the lens holder 90, that is, the collimator lens 75 in the optical axis OA direction. That is, the guide protrusion 93 and the guide groove 97 function as a guide mechanism.

  A bearing portion 98 is provided on the upper portion of the notch 96. The bearing portion 98 is provided at a position facing the upper portion of the lens holder 90 exposed by the notch 96. A bearing hole 99 is formed in the bearing portion 98.

  After the lens holder 90 is fitted into the fitting hole 95, the fixture 100 is attached to the housing 91. The fixture 100 includes a main body 101 having a shape that follows the upper portion of the lens holder 90 exposed by the notch 96, and attachment portions 102 that protrude from both ends of the main body 101. An insertion hole 104 is formed in the attachment portion 102. A screw 105 is inserted into the insertion hole 104. The screw 105 is screwed into a screw hole 106 formed on the upper surface of the housing 91.

  When the fixing tool 100 is fastened and fixed to the housing 91 with the screw 105, the main body 101 comes into close contact with the upper part of the lens holder 90 exposed by the notch 96, and presses the lens holder 90 from the upper part. Thereby, the movement of the lens holder 90 in the direction of the optical axis OA is restricted, and the position of the lens holder 90, that is, the collimating lens 75 is fixed. The fixing tool 100, the screw 105, and the screw hole 106 function as a fixing mechanism.

  FIG. 15 shows a temporarily fixed state before the lens holder 90 is fitted into the fitting hole 95 and the fixture 100 is attached to the housing 91. In this temporarily fixed state, it is possible to move the lens holder 90, that is, the collimating lens 75 in the direction of the optical axis OA using the eccentric driver 110.

  The eccentric driver 110 includes a grip 111 gripped by an operator, a rotating shaft 112 protruding from the lower portion of the grip 111, and an eccentric shaft 113 protruding from the lower portion of the rotating shaft 112. The grip 111, the rotation shaft 112, and the eccentric shaft 113 are all cylindrical. The centers of the grip 111 and the rotating shaft 112 coincide with each other. The radius of the eccentric shaft 113 is ½ of the radius of the rotating shaft 112. Further, the center of the eccentric shaft 113 is shifted from the center of the rotating shaft 112 by the radius of the eccentric shaft 113. The rotating shaft 112 is inserted into the bearing hole 99, and the eccentric shaft 113 is fitted into the elongated hole 92 (see also FIG. 16).

  FIG. 16 shows how the lens holder 90 is moved in the direction of the optical axis OA using the eccentric driver 110. When the eccentric shaft 110 is rotated 180 degrees from the state shown in FIG. 16A in which the eccentric shaft 113 is positioned at the center of the long hole 92 and the front surface of the lens holder 90 and the housing 91 coincide with each other, FIG. As shown, the eccentric shaft 113 rotates 180 ° along the elongated hole 92. As the eccentric shaft 113 rotates, the lens holder 90 approaches the front surface of the housing 91 by the diameter of the eccentric shaft 113.

  As indicated by the arrows in both directions, the lens holder 90 can transition between the state shown in FIG. 16A and the state shown in FIG. 16B, and is eccentric with respect to the optical axis OA direction. There is an adjustment allowance for 113 diameters.

  The adjustment mechanism 81 includes a guide protrusion 93 that functions as a guide mechanism, a guide groove 97, a long hole 92 that functions as a moving mechanism, a fixture 100 that functions as a fixing mechanism, a screw 105, and a screw hole 106. The adjustment mechanism 82 has the same configuration as the adjustment mechanism 81 except that the adjustment target is changed from the collimating lens 75 to the collimating lens 77, and thus illustration and description thereof are omitted.

  In FIG. 17, when the collimating lens 75 is moved in the direction of the optical axis OA by the adjusting mechanism 81, the focal position BFP of the blue light BL emitted from the condenser lens 80 changes. Specifically, when the collimator lens 75 moves toward the blue semiconductor light source 35 along the optical axis OA from the state shown in FIG. 17A, the light is emitted from the condenser lens 80 as shown in FIG. The focal length of the blue light BL to be increased becomes longer, and the focal position BFP is moved away from the condenser lens 80. Conversely, when the collimating lens 75 moves from the state shown in FIG. 17A to the side opposite to the blue semiconductor light source 35 along the optical axis OA, the light is emitted from the condenser lens 80 as shown in FIG. The focal length of the blue light BL becomes shorter and the focal position BFP approaches the condenser lens 80. In the present embodiment, using such optical properties, the adjustment mechanism 81 moves the collimator lens 75 in the direction of the optical axis OA, thereby adjusting the focal position BFP of the blue light BL emitted from the condenser lens 80. . In FIG. 17, the dichroic mirror 79 is not shown in order to avoid complication. The change in the focal position RFP of the red light RL by the adjustment mechanism 82 is the same as in FIG.

  In FIG. 18, the adjustment of the focal position BFP of the blue light BL and the focal position RFP of the red light RL by the adjustment mechanisms 81 and 82 is performed using the detection unit 120 before shipment of the light source device 13.

  The detection unit 120 includes a detection light guide 121, an incident end scanning device 122, a light amount waveform detection device 123, and a light amount waveform monitor 124. The detection light guide 121 has the same specifications as the light guide 55 mounted on the endoscope 11. A connector 126 similar to the light source connector 29B of the endoscope 11 is provided at the incident end 125 of the detection light guide 121. The connector 126 is connected to the receptacle connector 54 of the light source device 13.

  The incident end scanning device 122 reciprocates the incident end 125 of the light guide for detection 121 in the direction of the optical axis OA at a predetermined scan width and time interval, so that the condensing lens 80 in the light source device 13 and the incident end 125 are moved. The positional relationship is changed periodically. For example, the tolerance of the distance between the condensing lens 80 and the incident end 61 of the light guide 55 in the plurality of endoscopes 11A to 11C of the same model is set as the scan width.

  The light amount waveform detection device 123 detects the light amount of each color light of the blue light BL, the green light GL, and the red light RL emitted from the emission end of the detection light guide 121 at a predetermined timing, and detects each color light in the optical axis OA direction. A light intensity waveform indicating the light intensity is output.

  The light amount waveform monitor 124 displays the light amount waveform of each color light output from the light amount waveform detection device 123 (the light amount waveform GW of the green light GL in FIG. 18).

  A position on the optical axis OA is assigned to the horizontal axis of the light amount waveform, and a light intensity is assigned to the vertical axis. “0” on the horizontal axis indicates the center position of the scan width of the incident end 125 by the incident end scanning device 122. The horizontal axis indicates the position away from the condenser lens 80 as it goes to the negative side on the left side.

  In FIG. 18, the tolerance of the distance between the condensing lens 80 and the incident end 61 of the light guide 55 in a plurality of endoscopes 11A to 11C of the same model is 1.5 mm, for example, and the incident end 125 by the incident end scanning device 122 is shown. The scan width is set to -1.5 mm to 1.5 mm.

  Hereinafter, the operation of the above configuration will be described. First, assembly work of the light source device 13 such as fitting the lens holder 90 into the fitting hole 95 is performed. After the assembling operation, the focal positions of the blue light BL and red light RL emitted from the condenser lens 80 are adjusted, and the color misregistration is solved so that the focal positions of the blue light BL, green light GL, and red light RL are matched. Final inspection before shipment including work is performed.

  In the color misregistration elimination work, first, the connector 126 provided at the incident end 125 of the detection light guide 121 of the detection unit 120 is connected to the receptacle connector 54 of the light source device 13.

  Then, the incident end scanning device 122, the light amount waveform detecting device 123, and the light amount waveform monitor 124 of the detection unit 120 are driven. Thereby, the incident end 125 of the detection light guide 121 is reciprocated in the direction of the optical axis OA at a predetermined scan width and time interval by the incident end scanning device 122. Further, the light amount waveform detection device 123 detects the light amount of the light emitted from the emission end of the detection light guide 121 at a predetermined timing, and the light amount waveform as the detection result is displayed on the light amount waveform monitor 124.

  The operator observes the light amount waveform displayed on the light amount waveform monitor 124, the peak of the light amount waveform GW indicating the focal position BFP of the blue light BL, the peak of the light amount waveform GW indicating the focal position GFP of the green light GL, The adjustment mechanisms 81 and 82 adjust the positions of the collimating lenses 75 and 77 on the optical axis OA so that the peaks of the light amount waveform RW indicating the focal position RFP of the red light RL coincide. More specifically, after the rotation shaft 112 of the eccentric driver 110 is inserted into the bearing hole 99 and the eccentric shaft 113 is fitted into the elongated hole 92, the eccentric driver 110 is rotated, so that the collimating lenses 75 and 77 are moved to the optical axis. Move in the OA direction.

  Here, “matching the focal positions of the respective color lights” naturally includes the case where the focal positions of the respective color lights are completely matched, but also includes the case where the focal positions of the respective color lights are within a predetermined range. This predetermined range is displayed by a line segment indicated by reference numeral 128 in FIG. The operator preferably completes the peaks of the light amount waveforms GW, BW, and RW of each color light so that the peaks of the light amount waveforms GW, BW, and RW of each color light are at least within the predetermined range indicated by the line segment 128. Adjust to match.

  In the position adjustment, while observing the light amount waveform displayed on the light amount waveform monitor 124, the eccentric driver 110 is rotated so that the peaks of the light amount waveforms BW and RW coincide with the peak of the light amount waveform GW, and the collimating lenses 75 and 77 are moved along the optical axis. It is only necessary to move in the OA direction, and the focal positions of the respective color lights of the blue light BL, the green light GL, and the red light RL can be matched very easily.

  The adjustment mechanisms 81 and 82 are provided only on the collimating lenses 75 and 77, and the focal position BFP of the blue light BL and the focal position RFP of the red light RL are set to the focal position of the green light GL with reference to the focal position GFP of the green light GL. Since each of the collimating lenses 75 to 77 is made to coincide with the GFP, adjustment work can be saved as compared with the case of providing an adjusting mechanism for each of the collimating lenses 75 to 77 and adjusting the focal positions of the three colors of light.

  Of course, the collimator lens 76 may be provided with the same adjustment mechanism as the adjustment mechanisms 81 and 82. When the adjustment mechanism is also provided in the collimating lens 76, in the color misregistration elimination work, first, the position of one of the collimating lenses 75 to 77, for example, the collimating lens 76 is adjusted, and the peak of the light amount waveform GW is maximized. The position of the collimating lens 76 is searched. Then, after fixing the collimating lens 76 at the searched position, the positions of the collimating lenses 75 and 77 may be adjusted.

  The adjustment mechanisms 81 and 82 have a simple configuration including a guide protrusion 93 as a guide mechanism, a guide groove 97, a long hole 92 as a moving mechanism, and a fixture 100, a screw 105, and a screw hole 106 as a fixing mechanism. Therefore, the increase in size and cost of the light source device 13 due to the provision of the adjustment mechanisms 81 and 82 can be minimized.

  After the collimating lenses 75 and 77 are moved in the direction of the optical axis OA and the focal positions of the respective color lights of the blue light BL, the green light GL, and the red light RL are matched, the operator screws the screw 105 into the screw hole 106. The fixing tool 100 is fastened and fixed to the housing 91, and the positions of the collimating lenses 75 and 77 are fixed. This completes the color misregistration elimination work.

  After the final inspection including the color misregistration elimination work is completed, the light source device 13 is shipped to the customer.

  When performing an endoscopic diagnosis at a medical site, the endoscope 11 is connected to the processor device 12 and the light source device 13, the processor device 12 and the light source device 13 are turned on, and the endoscope system 10 is activated. .

  The insertion part 16 of the endoscope 11 is inserted into the living body, and in-vivo observation is started. The light source control part 42 sets the drive current value given to each LED 43-45, and starts lighting of each semiconductor light source 35-37. Then, the light amount control is performed while maintaining the target emission spectrum.

  Each of the semiconductor light sources 35 to 37 emits blue light BL, green light GL, and red light RL from the LEDs 43 to 45, respectively. The blue light BL, the green light GL, and the red light RL are incident on the collimating lenses 75 to 77 of the optical system group 41, respectively.

  The blue light BL is reflected by the dichroic mirror 79. The green light GL passes through the dichroic mirrors 78 and 79. The red light RL is reflected by the dichroic mirror 78 and passes through the dichroic mirror 79. The optical paths of the blue light BL, the green light GL, and the red light RL are coupled by the dichroic mirrors 78 and 79. These blue light BL, green light GL, and red light RL are incident on the condenser lens 80. Thereby, white light WL composed of mixed light of blue light BL, green light GL, and red light RL is generated. The condensing lens 80 condenses the white light WL on the incident end 61 of the light guide 55 of the endoscope 11 and supplies the white light WL to the endoscope 11.

  In the endoscope 11, the white light WL is guided to the illumination window 22 through the light guide 55 and irradiated from the illumination window 22 to the observation target. The reflected light of the white light WL reflected by the observation target enters the image sensor 56 from the observation window 23. The imaging sensor 56 outputs the B image signal, the G image signal, and the R image signal to the DSP 66 of the processor device 12. The DSP 66 color-separates each image signal and inputs it to the image processing unit 67. The imaging operation by the imaging sensor 56 is repeated at a predetermined frame rate. The image processing unit 67 generates a display image based on each input image signal. The display image is output to the monitor 14 through the display control unit 69. The display image is updated according to the frame rate of the image sensor 56.

  The DSP 66 calculates an exposure value based on each image signal, and transmits an exposure control signal corresponding to the calculated exposure value to the light source control unit 42 of the light source device 13. Based on the received exposure control signal, the light source control unit 42 determines the drive current value of each of the semiconductor light sources 35 to 37 so that the ratio of the light amount of each color light becomes constant (so that the target emission spectrum does not change). . And each semiconductor light source 35-37 is driven with the determined drive current value. Thereby, the light quantities of the blue light BL, the green light GL, and the red light RL constituting the white light WL by the respective semiconductor light sources 35 to 37 can be kept constant at a ratio suitable for observation.

  As shown in FIG. 19, if the color misregistration elimination work is not performed and the light source device 13 is shipped with the focus positions BFP, GFP, and RFP being misaligned as in FIG. As described above, the color of the display image changes. For example, in the endoscopes 11A to 11C of the same model, the positional relationship between the condenser lens 80 and the incident end 61 changes depending on individual differences. When the incident end 61A is at the focal position RFP of the red light RL as in the light guide 55A of the endoscope 11A, a display image 130R that is entirely reddish is generated. Further, when the incident end 61B is at the focal position GFP of the green light GL as in the light guide 55B of the endoscope 11B, a display image 130G that is entirely green is generated, and the light of the endoscope 11C is generated. When the incident end 61C is at the focal position BFP of the blue light BL as in the guide 55C, a display image 130B having a bluish color as a whole is generated. In addition, although illustration is abbreviate | omitted, also about multiple types of endoscope 11D, 11E from which specification differs, when the positional relationship of the condensing lens 80 and the incident end 61 differs mutually, endoscope 11D and endoscope 11E. Will change the color of the display image.

  On the other hand, in the present embodiment, as shown in FIG. 20, the focal positions BFP, GFP, and RFP of the blue light BL, the green light GL, and the red light RL are matched by the color misregistration work. In the endoscopes 11A to 11C, even if the positional relationship between the condenser lens 80 and the incident ends 61A, 61B, and 61C changes due to individual differences, the light quantity balance of each color light incident on the incident ends 61A, 61B, and 61C varies. As a result, a display image 130 whose color does not change is generated. Although illustration is omitted, the same applies to the case of using a plurality of types of endoscopes 11D and 11E having different specifications. Therefore, a situation in which the color of the display image changes every time an endoscopic diagnosis is performed does not occur, and the operator can smoothly perform an endoscopic diagnosis without feeling uncomfortable.

  When the semiconductor light sources 35 to 37 are used, since the semiconductor light sources 35 to 37 having a rectangular light emitting unit are used, the condensed image of each color light emitted from the condenser lens 80 is also rectangular. In such a case, using a semiconductor light source having a circular light emitting portion, the condensed image is more likely to protrude from the incident end 61 than when the condensed image of each color light is circular. For this reason, the adjustment mechanisms 81 and 82 of the present invention are particularly useful in the light source device 13 including the semiconductor light sources 35 to 37 having such a rectangular light emitting section.

  In the above-described embodiment, the adjustment mechanisms 81 and 82 are provided in the collimating lenses 75 and 77. However, the adjustment mechanism is more than the dichroic mirrors 78 and 79 in the optical path from the semiconductor light sources 35 to 37 to the condenser lens 80. What is necessary is just to be provided in the semiconductor light sources 35-37 side. For example, as shown in FIGS. 21 and 22, adjustment mechanisms 131 and 132 may be provided in the blue semiconductor light source 35 and the red semiconductor light source 37 instead of or in addition to the collimating lenses 75 and 77. In this case, the adjustment mechanisms 131 and 132 move the blue semiconductor light source 35 and the red semiconductor light source 37 in the direction of the optical axis OA. As shown in FIG. 22, when the blue semiconductor light source 35 and the red semiconductor light source 37 are provided with an adjusting mechanism in addition to the collimating lenses 75 and 77, only the collimating lenses 75 and 77 or the blue semiconductor light source 35 and the red semiconductor light source 35 shown in FIG. The adjustment allowance can be earned more than the case of the semiconductor light source 37 alone.

  However, unlike the collimating lens, the semiconductor light source is connected to a member such as a wiring that is likely to hinder movement in the direction of the optical axis OA. It is preferable that an adjustment mechanism is provided only in the collimating lens and the collimating lens is moved in the direction of the optical axis OA so that the focal positions of the respective color lights coincide with each other.

  In the above embodiment, an example in which the first optical system is configured by one collimating lens 75 to 77 has been described, but the first optical system may be configured by a plurality of optical members. Similarly, the second optical system may be constituted by a plurality of optical members instead of the single condensing lens 80 exemplified in the above embodiment. When the first optical system is composed of a plurality of optical members, an adjustment mechanism may be provided on at least one of the plurality of optical members.

  In the above embodiment, the focal position BFP of the blue light BL and the focal position RFP of the red light RL are made to coincide with the focal position GFP of the green light GL with reference to the focal position GFP of the green light GL. The focal position BFP of the red light RL or the focal position RFP of the red light RL may be used as a reference. When the focal position BFP of the blue light BL is used as a reference, the collimating lenses 76 and 77 are provided with an adjusting mechanism, but the collimating lens 75 may or may not be provided with an adjusting mechanism. When the focal position RFP of the red light RL is used as a reference, the collimating lenses 75 and 76 are provided with an adjusting mechanism, but the collimating lens 77 may or may not be provided with an adjusting mechanism.

  In the above-described embodiment, it has been described that the color misregistration eliminating work is performed at the time of the final inspection before the light source device 13 is shipped, but the timing of performing the color misregistration eliminating work is not particularly limited. For example, after the light source device 13 is shipped, the worker may go to the customer with the detection unit 120 to perform the color misregistration elimination work in response to a customer request.

  The adjustment mechanism is not limited to the configuration exemplified in the above embodiment. For example, the guide mechanism can be configured by the lens holder 90 and the fitting hole 95 itself without providing the guide protrusion 93 and the guide groove 97 of the above embodiment. Further, as the moving mechanism, a known moving mechanism that converts a rotational motion into a straight motion, such as a ball screw, a push-pull bolt, or an eccentric cam, may be used instead of the elongated hole 92 of the above-described embodiment. Furthermore, the fixing mechanism may also be constituted by a pair of C-rings that sandwich the lens holder 90 from both sides, and screws that fasten and fix the pair of C-rings. In short, any mechanism can be used as long as it can guide the movement of the optical member such as the collimating lens 75 in the optical axis OA direction, move the optical member in the optical axis direction, and fix the position of the optical member. Good.

  In the above embodiment, the three semiconductor light sources 35 to 37 of blue, green, and red are illustrated as the monochromatic semiconductor light sources. However, as shown in FIG. 23, a purple wavelength band for observing with emphasis on the surface blood vessels. A purple semiconductor light source 135 that emits light (purple light VL) may be added.

  In FIG. 23, the purple semiconductor light source 135 has a purple LED (not shown) that emits purple light VL as a light emitting element. The specific structure of the purple semiconductor light source 135 is the same as that of the blue semiconductor light source 35 shown in FIGS. As shown in FIG. 24, the purple semiconductor light source 135 has a wavelength component in the vicinity of 380 nm to 420 nm, for example, a purple wavelength band, and emits purple light VL having a center wavelength of 405 ± 10 nm and a half width of 20 ± 10 nm.

  The optical system group 136 includes a collimating lens 137 that transmits the violet light VL and makes it substantially parallel to the optical system group 41 of the above embodiment, and a dichroic mirror 138 that couples the optical paths of the blue light BL and the violet light VL. This is an added configuration. The blue semiconductor light source 35 and the violet semiconductor light source 135 are arranged so that their optical axes are orthogonal to each other, and a dichroic mirror 138 is provided at a position where these optical axes are orthogonal. The dichroic mirror 138 is arranged at an angle of 45 ° with respect to the optical axes of the blue semiconductor light source 35 and the violet semiconductor light source 135.

  The dichroic filter of the dichroic mirror 138 has a characteristic of reflecting light in a violet wavelength band of, for example, less than about 430 nm and transmitting light in blue, green, and red wavelength bands higher than that. The dichroic mirror 138 transmits the blue light BL from the blue semiconductor light source 35 downstream, and reflects the violet light VL from the violet semiconductor light source 135. As a result, the optical paths of the blue light BL and the purple light VL are combined. The violet light VL reflected by the dichroic mirror 138 has the characteristic that the dichroic mirror 79 reflects light in the blue wavelength band of less than about 480 nm as described above, and is reflected by the dichroic mirror 79 toward the condenser lens 80. . As a result, the optical paths of all of the blue light BL, green light GL, red light RL, and purple light VL are combined.

  The collimating lens 137 is provided with an adjusting mechanism 139 as with the collimating lenses 75 and 77 of the above embodiment. The adjustment mechanism 139 moves the collimator lens 137 in the direction of the optical axis OA so that the focal position of the purple light VL coincides with the focal positions of the blue light BL, the green light GL, and the red light RL.

  As is well known, the reflectance of the superficial blood vessel greatly decreases in the wavelength band below 450 nm, and decreases most in the vicinity of 405 nm. When the observation target is irradiated with light having a wavelength band with low reflectivity, the blood vessel absorbs a large amount, so that a display image having a difference in contrast between the blood vessel and the other portion can be obtained.

  In addition, the light scattering characteristics of biological tissue also have wavelength dependence, and the scattering coefficient increases as the wavelength becomes shorter. Scattering affects the depth of light penetration into living tissue. In other words, the greater the scattering, the more light is reflected near the mucosal surface layer of the biological tissue and the less light reaches the mid-deep layer. Therefore, the shorter the wavelength, the lower the depth of penetration, and the longer the wavelength, the higher the depth of penetration.

  The violet light VL having a central wavelength of 405 ± 10 nm emitted from the violet semiconductor light source 135 has a relatively short wavelength and a low depth of penetration. Therefore, the purple light VL can be used as special light for emphasizing the surface blood vessels. By using the purple light VL, it is possible to obtain a display image in which the surface blood vessels are depicted with high contrast.

  When highlighting the superficial blood vessels, the purple semiconductor light source 135 is turned on in addition to the semiconductor light sources 35 to 37 in accordance with the timing of the accumulation operation of the image sensor 56. When each of the semiconductor light sources 35 to 37 and 135 is turned on, the purple light VL is added to the white light WL of the above-described embodiment, and the mixed light (WL + VL) is irradiated onto the observation target as illumination light.

  The illumination light in which the purple light VL is added to the white light WL is split by the micro color filter of the image sensor 56. The B pixel receives reflected light corresponding to the purple light VL in addition to the reflected light corresponding to the blue light BL. The G pixel and the R pixel receive the reflected light corresponding to the green light GL and the reflected light corresponding to the red light RL, respectively, as in the above embodiment. The imaging sensor 56 sequentially outputs the B, G, and R image signals according to the frame rate in accordance with the readout timing.

  In this case, the B image signal includes a reflected light component corresponding to the violet light VL in addition to a reflected light component corresponding to the blue light BL constituting the white light WL. It is drawn with contrast. In lesions such as cancer, surface blood vessels tend to be denser than normal tissues, and the surface blood vessels have a characteristic pattern. Therefore, when purple semiconductor light source 135 is added, surface blood vessels are clearly depicted. This is preferable because it makes it easier to identify the lesion.

  In the above embodiment, the light amount control of each color light is performed by changing the drive current value applied to each of the LEDs 43 to 45 based on the exposure control signal from the processor device 12. Due to the influence of the semiconductor light source, the output light amount with respect to the drive current value may fluctuate. Therefore, a light quantity measurement sensor that measures the light quantity of each color light is provided in the optical system group, and based on the light quantity measurement signal output from the light quantity measurement sensor, it is monitored whether or not the light quantity of each color light has reached the target value. May be.

  In this case, the light source control unit compares the light quantity measurement signal with the target light quantity, and gives to each of the semiconductor light sources 35 to 37 set in the exposure control so that the light quantity becomes a target value based on the comparison result. Fine-tune the drive current value. In this way, the light quantity of each color light is constantly monitored by the light quantity measurement sensor, and the light quantity can be controlled to always follow the target value by finely adjusting the drive current value given based on the measurement result of the light quantity. For this reason, the illumination light of the target emission spectrum can be obtained more stably.

  In the above embodiment, a semiconductor light source composed of only LEDs is cited. For example, a green semiconductor light source is excited by a blue excitation light LED that emits blue excitation light in a purple to blue wavelength band, and blue excitation light. Alternatively, a fluorescent semiconductor light source composed of a green phosphor emitting green light in the green wavelength band may be used. Also, instead of or in addition to the green semiconductor light source, the red semiconductor light source is replaced with a blue excitation light LED that emits blue excitation light in the purple to blue wavelength band, and red fluorescence in the red wavelength band excited by the blue excitation light. You may comprise with the red fluorescent substance which emits. When the red semiconductor light source is composed of a fluorescent semiconductor light source, the excitation light LED is not limited to the blue excitation light emitting element that emits blue excitation light in the purple to blue wavelength band, but green that emits green excitation light in the green wavelength band. An excitation light emitting element may be used. In this case, a fluorescent semiconductor light source is configured by encapsulating a phosphor in the cavity 76 shown in FIGS. 5 and 6 instead of the resin 78.

  Further, the LED mounting form shown in FIGS. 5 and 6 is one example, and other forms may be adopted. For example, a microlens for adjusting the divergence angle may be provided on the light exit surface of the resin 78, or the LED may be housed in a shell-type case in which the microlens is formed instead of the surface mount type. In addition, when a fluorescent semiconductor light source is used as a green semiconductor light source or a red semiconductor light source, the fluorescent semiconductor light source is not limited to one in which the excitation light LED and the phosphor are integrally provided, and may be provided separately. . In this case, a light guide member such as a lens or an optical fiber is added between the excitation light LED and the phosphor, and the excitation light of the excitation light LED is guided to the phosphor through the light guide member.

  Furthermore, an organic EL (Electro-Luminescence) element may be used as the light emitting element instead of the LED.

  The configuration of the optical system group in the above embodiment is an example, and various modifications can be made. For example, as an optical member constituting the third optical system, a dichroic mirror in which a dichroic filter is formed on a transparent glass plate is used, but instead, a dichroic prism in which a dichroic filter is formed on a prism may be used. Further, instead of an optical member formed with a dichroic filter, such as a dichroic mirror or a dichroic prism, for example, a plurality of incident ends facing each semiconductor light source and one exit end facing an incident end of an endoscope light guide The optical path may be coupled using a branched light guide having The branched light guide is obtained by dividing a predetermined number of optical fibers at one end into a plurality and splitting an incident end into a plurality. In this case, each semiconductor light source is arranged corresponding to each branched incident end.

  In the above embodiment, the light source device 13 having the three single-color semiconductor light sources 35 to 37 or the four single-color semiconductor light sources 35 to 37 and 135 has been exemplified, but the blue semiconductor light source and the green semiconductor light source, and the green semiconductor light source and the purple semiconductor light source. The present invention is also applicable to a light source device having two monochromatic semiconductor light sources. The display light based on the green light GL may be obtained by irradiating the observation target with mixed light of the blue light BL and the green light GL or mixed light of the green light GL and the purple light VL.

  In the above embodiment, the image sensor 56 is exemplified by a color image sensor that separates illumination light by B, G, and R micro color filters, and B, G, and R image signals are simultaneously acquired by the color image sensor. The simultaneous endoscope system and the light source device used therefor have been described as an example. However, each image signal of B, G, and R is obtained by sequentially irradiating each color light of blue, green, and red with a monochrome imaging sensor. The present invention may be applied to a field-sequential endoscope system that obtains images sequentially and a light source device used therefor.

  In the above embodiment, the example in which the light source device and the processor device are configured separately has been described, but these devices may be configured integrally. In addition, the present invention provides an endoscope system using a fiberscope that guides reflected light of an observation target of illumination light with an image guide, and an ultrasonic endoscope in which an imaging sensor and an ultrasonic transducer are built in a distal end portion. It can also be applied to a light source device used therefor.

DESCRIPTION OF SYMBOLS 10 Endoscope system 11, 11A-11E Endoscope 13 Light source device 35 Blue semiconductor light source 36 Green semiconductor light source 37 Red semiconductor light source 55, 55A-55C Light guide 61, 61A-61C Incident end 75-77, 137 Collimating lens ( First optical system, optical member)
78, 79, 138 Dichroic mirror (third optical system)
80 condenser lens (second optical system)
81, 82, 139 Adjustment mechanism 92 Long hole 93 Guide protrusion 97 Guide groove 100 Fixing tool 105 Screw 106 Screw hole 110 Eccentric driver 120 Detection unit 135 Purple semiconductor light source BL Blue light GL Green light RL Red light WL White light VL Purple light BFP Blue light focal position GFP Green light focal position RFP Red light focal position BW Blue light intensity waveform GW Green light intensity waveform RW Red light intensity waveform

Claims (11)

In an endoscope light source device for supplying illumination light to a light guide of an endoscope,
A plurality of single-color semiconductor light sources that respectively emit light of a plurality of colors as the illumination light;
A plurality of first optical systems configured by at least one optical member and transmitting the plurality of colors of light from the plurality of single-color semiconductor light sources;
A second optical system for condensing the light of the plurality of colors transmitted through the plurality of first optical systems at an incident end of the light guide;
A position adjusting mechanism for adjusting the position of the optical member in the optical axis direction of the first optical system;
The position adjustment mechanism includes a guide mechanism for guiding movement of the optical member in the optical axis direction;
A moving mechanism for moving the optical member in the optical axis direction;
An endoscope light source device having a fixing mechanism for fixing a position of the optical member.   2. The endoscope light source device according to claim 1, wherein the number of the position adjustment mechanisms is the same as the number of light of the remaining colors excluding the light of one color among the light of the plurality of colors. .   A third optical system is provided between the plurality of first optical systems and the second optical system, and couples optical paths of the light of the plurality of colors transmitted through the plurality of first optical systems. The endoscope light source device according to claim 1.   4. The inside of claim 3, wherein the position adjusting mechanism is provided closer to the monochromatic semiconductor light source than the third optical system in an optical path from the monochromatic semiconductor light source to the second optical system. Endoscopic light source device.   5. The endoscope light source device according to claim 1, wherein the plurality of single-color semiconductor light sources includes a rectangular light-emitting portion. 6.   The plurality of monochromatic semiconductor light sources are a blue semiconductor light source, a green semiconductor light source, and a red semiconductor light source that respectively emit three colors of light of blue light, green light, and red light as the illumination light. The endoscope light source device according to any one of 5. The blue semiconductor light source emits the blue light having a center wavelength of 460 ± 10 nm and a half width of 25 ± 10 nm,
The green semiconductor light source emits the green light having a center wavelength of 550 ± 10 nm and a half width of 100 ± 10 nm.
7. The endoscope light source device according to claim 6, wherein the red semiconductor light source emits the red light having a center wavelength of 625 ± 10 nm and a half width of 20 ± 10 nm.   The endoscope light source according to claim 1, wherein the position adjusting mechanism adjusts the position of the monochromatic semiconductor light source in the optical axis direction in addition to the optical member. apparatus. A housing provided with a lens holder for holding the optical member;
The moving mechanism moves the optical member in the lens holder in the optical axis direction by using a long hole provided in the lens holder,
The guide mechanism guides movement of the optical member in the lens holder in the optical axis direction by a guide protrusion provided on the lens holder and a guide groove formed on the housing.
The fixing mechanism fixes a position of the optical member in the lens holder by pressing the lens holder with a fixing portion in a state where the lens holder is fitted in a fitting hole in the housing. The endoscope light source device according to any one of 1 to 8. An endoscope having a light guide for guiding illumination light;
An endoscope light source device for supplying the illumination light to the light guide,
In an endoscope system in which a plurality of the endoscopes are shared by one endoscope light source device,
The endoscope light source device is:
A plurality of single-color semiconductor light sources that respectively emit light of a plurality of colors as the illumination light;
A plurality of first optical systems configured by at least one optical member and transmitting the plurality of colors of light from the plurality of single-color semiconductor light sources, respectively;
A second optical system for condensing the light of the plurality of colors transmitted through the plurality of first optical systems at an incident end of the light guide;
A position adjusting mechanism for adjusting the position of the optical member in the optical axis direction of the first optical system;
The position adjustment mechanism includes a guide mechanism for guiding movement of the optical member in the optical axis direction;
A moving mechanism for moving the optical member in the optical axis direction;
An endoscope system having a fixing mechanism for fixing a position of the optical member. A plurality of first optical systems configured by a plurality of single-color semiconductor light sources that emit light of a plurality of colors as illumination light and at least one optical member, respectively, that transmit the plurality of colors of light from the plurality of single-color semiconductor light sources, respectively. And a second optical system that condenses the light of the plurality of colors transmitted through the plurality of first optical systems at an incident end of a light guide of the endoscope, and is connected to a detection unit including a light guide for detection In the position adjustment method in the endoscope light source device that is possible,
When the position of the incident end of the light guide for detection is moved in the optical axis direction, the peak of the light amount waveform of each color light indicating the amount of light of each color light through the light guide for detection with respect to the position of the incident end. In order to make them coincide, the position of the optical member and the position of the monochromatic semiconductor light source are adjusted in the optical axis direction of the first optical system by a position adjusting mechanism, so that the focal positions of the respective color lights are made to coincide. How to adjust the position.

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