JP6099586B2 - Endoscope light source device and endoscope system - Google Patents

Description

  The present invention relates to an endoscope light source device and an endoscope system having an excitation light source and a phosphor.

  In recent medical treatments, diagnosis and the like using an endoscope system including an endoscope light source device, an electronic endoscope, and a processor device are widely performed. The endoscope light source device generates illumination light and irradiates the sample. The electronic endoscope generates an imaging signal by imaging an inside of a specimen irradiated with illumination light with an imaging element. The processor device performs image processing on the imaging signal generated by the electronic endoscope, and generates an observation image to be displayed on the monitor.

  Conventionally, in an endoscope light source device, a lamp light source such as a xenon lamp or a halogen lamp that emits white light as illumination light has been used, but recently, a light of a specific color is emitted instead of the lamp light source. Semiconductor light sources such as laser diodes (LDs) and light emitting diodes (LEDs) are being used.

  In addition, in order to increase the brightness of illumination light, an excitation light source (blue LD) that emits excitation light (blue light), a phosphor that emits fluorescence (green light) upon incidence of the excitation light, and fluorescence that reflects excitation light An endoscope light source device provided with a dichroic mirror for transmission is known (see Patent Document 1). In this endoscope light source device, the excitation light emitted from the excitation light source is reflected by the dichroic mirror and applied to the phosphor. The phosphor emits fluorescence (green light) toward the dichroic mirror in response to the excitation light irradiation. This fluorescence is emitted through the dichroic mirror.

  In the endoscope light source device described in Patent Document 1, in order to generate blue light, red light, and violet light in addition to green light, a blue light source (blue LED), a red light source (red LED), and a purple light source are generated. (Purple LED) is provided. Further, in order to integrate the optical path of these lights with the optical path of the fluorescence (green light) from the phosphor, one dichroic mirror is provided for each light source. Of these lights, violet light is narrow-band light and is used in a blood vessel enhancement observation mode for enhancing blood vessels on the surface of a living tissue.

JP 2013-215435 A

  However, in the endoscope light source device described in Patent Document 1, since one dichroic mirror is provided for each of the excitation light source, the blue light source, the red light source, and the violet light source, the number of dichroic mirrors is large. For this reason, there is a problem that the cost is increased and the apparatus size is increased.

  Further, in the endoscope light source device described in Patent Document 1, a purple light source used only in the blood vessel enhancement observation mode and a dichroic mirror provided for the purple light source are provided on the most downstream side of the optical path. . For this reason, fluorescence (green light), blue light, and red light (normal light) generated in the normal observation mode always pass through the dichroic mirror provided for the violet light source. Since the dichroic mirror absorbs and scatters light slightly by transmission or reflection, there is a concern about attenuation of normal light.

  The present invention relates to an endoscope light source device and an endoscope system having an excitation light source and a phosphor, which can reduce the number of dichroic mirrors and suppress attenuation of normal light. An object is to provide an apparatus and an endoscope system.

  In order to achieve the above object, an endoscope light source device according to the present invention includes a first light source that emits excitation light, and fluorescence that emits first light having a longer peak wavelength than the excitation light when irradiated with the excitation light. A second light source that emits a second light whose peak wavelength is shorter than the first light, a third light source that emits a third light whose peak wavelength is shorter than the second light, and a second light A first dichroic mirror that generates one of reflection and transmission and the other of reflection and transmission with respect to the third light, and reflection and excitation with respect to the excitation light, the second light, and the third light. A second dichroic mirror that generates one of the transmissions and generates the other of the reflection and transmission of the first light, and the phosphor is excited from the first light source via the second dichroic mirror. When the light enters, the second dichroic mirror The first dichroic mirror emits the first light toward the first, the second dichroic mirror integrates the optical paths of the second and third lights, and the second dichroic mirror includes the second and third lights integrated with the first dichroic mirror. The optical path with the first light incident from the phosphor is integrated. A dichroic mirror is synonymous with a dichroic filter.

  The fourth light source that emits the fourth light whose peak wavelength is longer than the first light and the first to third light whose optical paths are integrated by the second dichroic mirror cause one of reflection and transmission. It is preferable to include a third dichroic mirror that generates the other of reflection and transmission with respect to the fourth light and integrates the optical paths of the first to fourth lights.

The first light is green light, and the peak wavelength of the first light is preferably less than 560 nm .

  The third dichroic mirror may cause the other of reflection and transmission with respect to light having a specific wavelength within a range of 560 to 590 nm.

  You may provide the long wavelength cut filter which cuts the light beyond the specific wavelength within the range of 560-590 nm. In this case, it is preferable to include a filter insertion / removal unit that inserts / removes the long wavelength cut filter onto / from the optical path of the first light.

  A notch filter that attenuates light in the wavelength range of 560 to 590 nm may be provided. In this case, it is preferable to include a filter insertion / removal unit that inserts / removes the notch filter onto / from the optical path integrated by the third dichroic mirror.

  The phosphor is preferably a rotating phosphor that is driven to rotate and the irradiation position of the excitation light on the phosphor moves in accordance with the rotation.

  The endoscope system of the present invention includes a light source device, an endoscope, and a control unit. The light source device includes a first light source that emits excitation light, a phosphor that emits first light having a longer peak wavelength than the excitation light by irradiation of the excitation light, and a first wavelength that has a shorter peak wavelength than the first light. A second light source that emits two lights, a third light source that emits third light having a shorter peak wavelength than the second light, and one of reflection and transmission with respect to the second light. A first dichroic mirror that generates the other of the reflection and transmission of light, and one of reflection and transmission of the excitation light, the second light, and the third light, and the first light A second dichroic mirror that generates the other of reflection and transmission, and the phosphor enters the second dichroic mirror when excitation light is incident from the first light source via the second dichroic mirror. 1 light, 1st dichroic The optical path of the second light and the third light is integrated, and the second dichroic mirror is the optical path of the second light and the third light whose optical paths are integrated by the first dichroic mirror and the first light incident from the phosphor To integrate. The endoscope includes an image sensor that images reflected light from an observation site irradiated with at least one of the first to third lights. The control unit controls the first to third light sources and the image sensor.

  The light source device reflects and transmits the fourth light source that emits the fourth light whose peak wavelength is longer than the first light, and the first to third lights whose optical paths are integrated by the second dichroic mirror. It is preferable to include a third dichroic mirror that generates one and generates the other of reflection and transmission with respect to the fourth light and integrates the optical paths of the first to fourth lights.

  In the normal observation mode, the control unit emits the first light, the second light, and the fourth light simultaneously or individually, and in the blood vessel enhancement observation mode, the control unit has a first observation mode and a blood vessel enhancement observation mode. It is preferable to emit light and third light simultaneously or separately.

  According to the present invention, the phosphor emits the first light toward the second dichroic mirror when the excitation light enters from the first light source via the second dichroic mirror, and the first dichroic mirror And the second dichroic mirror integrates the optical path of the second light and the third light integrated by the first dichroic mirror and the first light incident from the phosphor. The number of dichroic mirrors can be reduced, and normal light attenuation can be suppressed. For example, the excitation light is blue laser light, the first light is green light, the second light is blue light, and the third light is violet light.

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 a block diagram which shows the electric constitution of an endoscope system. It is a figure which shows the structure of a color filter array. It is a figure which shows the structure of a light source part. It is a graph which shows the wavelength spectrum of illumination light. It is a graph which shows the light transmittance of a 1st dichroic mirror. It is a figure which shows the structure of a rotation fluorescent substance. It is a figure which shows the structure of a blue laser diode. It is a graph which shows the light transmittance of a 2nd dichroic mirror. It is a graph which shows the light transmittance of a 3rd dichroic mirror. It is a graph which shows the modification of a 2nd dichroic mirror. It is a figure which shows the structure of the light source part using the 2nd dichroic mirror of the characteristic shown in FIG. It is a graph which shows the modification of a 1st dichroic mirror. It is a figure which shows the structure of the light source part using the 1st dichroic mirror shown in FIG. It is a graph which shows the modification of a 3rd dichroic mirror. It is a figure which shows the structure of the light source part using the 3rd dichroic mirror shown in FIG. It is a table | surface explaining the deformation | transformation pattern of a light source part. It is a figure explaining the field sequential method at the time of normal observation mode. It is a figure explaining the field sequential method at the time of blood-vessel emphasis observation mode. It is a graph which shows the modification of the 2nd dichroic mirror for cutting the long wavelength component of green light. It is a figure which shows the structure of the light source part which provided the long wavelength cut filter. It is a figure which shows the structure of the light source part which provided the notch filter. It is a graph which shows the light transmittance of a notch filter.

  In FIG. 1, an endoscope system 10 includes an electronic endoscope (hereinafter simply referred to as an endoscope) 11 that images an observation site in a living body as a specimen, and an observation site based on an imaging signal obtained by imaging. A processor device 12 that generates a display image, an endoscope light source device (hereinafter simply referred to as a light source device) 13 that supplies illumination light for irradiating an observation site to the endoscope 11, and a monitor 14 that displays the display image It has. An operation input unit 15 such as a keyboard or a mouse is connected to the processor device 12.

  The endoscope system 10 includes a normal observation mode for observing an observation site with normal light (white light) and a blood vessel enhancement observation mode for observing a blood vessel existing inside the mucous membrane of the observation site with special light. And have. These observation modes can be selected by the operation input unit 15 or the like.

  The blood vessel enhancement observation mode is a mode for visualizing a blood vessel pattern as blood vessel information and performing a diagnosis such as tumor quality discrimination. In this blood vessel enhancement observation mode, the observation site is irradiated with special light containing a large amount of light components in a specific wavelength band with high absorbance to hemoglobin in blood.

  In the normal observation mode, a normal observation image suitable for observing the entire observation site is generated as a display image. In the blood vessel enhancement observation mode, a blood vessel enhancement observation image suitable for observation of a blood vessel pattern is generated as a display image.

  The endoscope 11 connects the insertion unit 16 inserted into the digestive tract of a living body, the operation unit 17 provided at the proximal end portion of the insertion unit 16, and the endoscope 11 to the processor device 12 and the light source device 13. And a universal cord 18 for the purpose. The insertion portion 16 includes a distal end portion 19, a bending portion 20, and a flexible tube portion 21, and is connected in this order from the distal end side.

  As shown in FIG. 2, an illumination window 22 that irradiates the observation site with illumination light, an observation window 23 for capturing an image of the observation site, and an observation window 23 are washed on the distal end surface of the distal end portion 19. An air supply / water supply nozzle 24 for supplying air and water and a forceps outlet 25 for performing various treatments by projecting a treatment tool such as a forceps or an electric knife are provided. An imaging element 33 (see FIG. 3) is built in the back of the observation window 23.

  The bending portion 20 is composed of a plurality of connected bending pieces, and bends in the vertical and horizontal directions according to the operation of the angle knob 26 of the operation portion 17. By curving the bending portion 20, the distal end portion 19 is directed in a desired direction. The flexible tube portion 21 has flexibility and can be inserted into a tortuous tube passage such as an esophagus or an intestine. The insertion unit 16 guides the drive signal for driving the image sensor 33, the signal cable for transmitting the image signal output from the image sensor 33, and the illumination light supplied from the light source device 13 to the illumination window 22. A light guide 32 (see FIG. 3) is inserted.

  In addition to the angle 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, a still image. A freeze button (not shown) or the like is provided for photographing the image.

  A communication cable and a light guide 32 extending from the insertion portion 16 are inserted into the universal cord 18, and a connector 29 is attached to one end of the processor device 12 and the light source device 13. 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. An incident end 32a (see FIG. 3) of the light guide 32 is disposed on the light source connector 29b.

  In FIG. 3, the light source device 13 includes a light source unit 30 and a light source control unit 31. The light source unit 30 outputs one of normal light and special light as illumination light based on the control of the light source control unit 31. The illumination light output from the light source unit 30 enters the incident end 32 a of the light guide 32 of the endoscope 11.

  The endoscope 11 includes a light guide 32, an imaging device 33, an imaging drive unit 34, an analog processing circuit (AFE: Analog Front End) 35, an irradiation lens 36, and an objective optical system 37. . The light guide 32 is a fiber bundle obtained by bundling a plurality of optical fibers. When the light source connector 29 b is connected to the light source device 13, the incident end 32 a of the light guide 32 disposed on the light source connector 29 b faces the emission end of the light source unit 30. The exit end of the light guide 32 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 respectively.

  An irradiation lens 36 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 36 by the light guide 32 and irradiated from the illumination window 22 toward the observation site. The irradiation lens 36 is a concave lens, and irradiates the illumination light emitted from the light guide 32 to a wide range of the observation site.

  An imaging element 33 is disposed behind the observation window 23 via an objective optical system 37. The image (reflected light) of the observation site is incident on the objective optical system 37 through the observation window 23, and is formed on the imaging surface 33 a of the image sensor 33 by the objective optical system 37.

  The imaging element 33 is a single-plate color CCD image sensor or CMOS image sensor, and a plurality of pixels that generate pixel signals by photoelectric conversion are formed on the imaging surface 33a. A color filter array 38 shown in FIG. 4 is provided on the imaging surface 33a. The color filter array 38 includes a red (R) filter 38a, a green (G) filter 38b, and a blue (B) filter 38c. Each filter 38a, 38b, 38c is disposed on the light incident side corresponding to one pixel. The color array of the color filter array 38 is called a Bayer array. Further, microlenses (not shown) are provided on the color filter array 38 corresponding to the respective pixels.

  The image pickup device 33 is driven by the image pickup drive unit 34, picks up an image formed on the image pickup surface 33a with a plurality of pixels via the color filter array 38, and outputs an image pickup signal. The imaging signal has one of R, G, and B color signals (R signal, G signal, and B signal) for each pixel.

  The AFE 35 includes a correlated double sampling (CDS) circuit, an automatic gain control (AGC) circuit, an analog / digital (A / D) converter, and the like. The CDS circuit performs correlated double sampling processing on the imaging signal input from the imaging element 33 to remove noise. The AGC circuit amplifies the imaging signal from which noise has been removed by the CDS circuit. The A / D converter converts the imaging signal amplified by the AGC circuit into a digital signal having a predetermined number of bits and inputs the digital signal to the processor device 12.

  The processor device 12 includes a controller 40 as a control unit, a DSP (Digital Signal Processor) 41, a frame memory 42, an image processing unit 43, and a display control unit 44. The controller 40 includes a CPU, a ROM that stores a control program and setting data necessary for control, a RAM as a working memory for loading the control program, and the like. Each part, the light source control part 31, and the imaging drive part 34 are controlled.

  The DSP 41 performs signal processing such as pixel interpolation processing, gamma correction, and white balance correction on the imaging signal input from the AFE 35 via the communication connector 29a. In the pixel interpolation processing, pixel interpolation processing is performed for each of the R signal, the G signal, and the B signal. The DSP 41 causes the frame memory 42 to store the imaged signal subjected to signal processing as image data for each frame period.

  The image processing unit 43 reads image data from the frame memory 42 and performs predetermined image processing. Specifically, in the normal observation mode, a normal observation image is generated based on the image data. On the other hand, in the blood vessel enhancement observation mode, a blood vessel enhancement observation image is generated based on the image data. In order to enhance the surface blood vessels, for example, the region of the surface blood vessels in the image is extracted based on the B signal in the image data. Then, an edge enhancement process or the like is performed on the extracted surface blood vessel region. Then, the B signal that has been subjected to the contour enhancement process is combined with a full-color image generated based on the RGB signal. The same processing may be performed for the middle- and deep-layer blood vessels in addition to the surface blood vessels. In the case of emphasizing the intermediate deep blood vessel, the region of the intermediate deep blood vessel is extracted from the G signal containing a lot of information on the intermediate deep blood vessel, and the contour enhancement processing is performed on the extracted region of the intermediate deep blood vessel.

  The display control unit 44 converts the image generated by the image processing unit 43 into a video signal such as a composite signal or a component signal and outputs the video signal to the monitor 14. In the blood vessel enhancement observation mode, a blood vessel enhancement observation image is generated using only the B signal and the G signal without using the R signal, the B signal is assigned to the B channel and the G channel of the monitor 14, and the G signal is assigned to the monitor 14. It may be assigned to the R channel.

  In FIG. 5, the light source unit 30 includes a blue LED (B-LED) 50a, a purple LED (V-LED) 50b, a red LED (R-LED) 50c, an LED driving unit 51, and first to third. Dichroic mirrors (DM) 52a to 52c, first to sixth lenses 53a to 53f, a blue laser diode (B-LD) 54, an LD driving unit 55, a rotating phosphor 56, a rotating motor 57, and a motor And a drive unit 58.

  As shown in FIG. 6, the B-LED 50a emits blue light LB having a wavelength band of about 430 nm to 480 nm and a peak wavelength of about 455 nm. The V-LED 50b emits purple light LV having a wavelength band of about 395 nm to 415 nm and a peak wavelength of about 405 nm. The R-LED 50c emits red light LR having a wavelength band of about 580 nm to 640 nm and a peak wavelength of about 620 nm. Among these, the purple light LV is narrow band light having high absorbance to blood hemoglobin.

  The LED drive unit 51 generates an LED drive signal (drive current or drive voltage) for driving each of the B-LED 50a, the V-LED 50b, and the R-LED 50c based on the control of the light source control unit 31, and each LED 50a. To ~ 50c.

  The first lens 53a is disposed on the optical path of the blue light LB emitted from the B-LED 50a, and condenses the blue light LB. The second lens 53b is disposed on the optical path of the purple light LV emitted from the V-LED 50b, and collects the purple light LV. The optical path of the blue light LB emitted from the first lens 53a and the optical path of the violet light LV emitted from the second lens 53b are orthogonal to each other, and the first DM 52a is disposed at this intersection. The blue light LB is incident on one surface of the first DM 52a at an angle of 45 °, and the violet light LV is incident on the other surface at an angle of 45 °.

  As shown in FIG. 7, the first DM 52a has a threshold λ1 at about 420 nm, reflects light having a wavelength less than or equal to the threshold λ1, and transmits light having a wavelength greater than the threshold λ1. That is, the first DM 52a transmits the blue light LB incident from the first lens 53a and reflects the violet light LV incident from the second lens 53b by 90 °. Thereby, each optical path of blue light LB and purple light LV is integrated.

  The rotating phosphor 56 includes a disc-shaped wheel plate 60 and a phosphor layer 61 provided on one surface of the wheel plate 60. The wheel plate 60 is made of a metal such as copper, aluminum, or stainless steel.

As shown in FIG. 8, the phosphor layer 61 is embedded in a recess 62 formed on one surface of the wheel plate 60. The recess 62 is formed in a circumferential shape centering on the rotation shaft 63 of the wheel plate 60. The phosphor layer 61 is formed of a phosphor that emits green fluorescence (green light LG) by excitation light LE emitted from the B-LD 54 as an excitation light source. Examples of this phosphor include BAM (BaMgAl ₁₀ O ₁₇ ), β-SiAlON (β-Si _6-x Al _x O _x N _{8 -x} ), YAG (Y ₃ A ₁₅ O ₂ ), and the like. As shown in FIG. 6, the green light LG has a wavelength band of about 500 nm to 600 nm and a peak wavelength of about 540 nm.

  The LD drive unit 55 generates an LD drive signal (drive current or drive voltage) for driving the B-LD 53 based on the control of the light source control unit 31 and supplies the LD drive signal to the B-LD 53. As shown in FIG. 9, the B-LD 53 has a plurality of LD elements 55a arranged in a two-dimensional array. As shown in FIG. 6, the B-LD 53 emits blue laser light having a wavelength band of about 450 nm to 460 nm and a peak wavelength of about 455 nm as the excitation light LE.

  The fourth lens 53d is disposed on the optical path of the excitation light LE emitted from the B-LD 54, and condenses the excitation light LE. The second DM 52b is disposed at the intersection of the optical path of the excitation light LE emitted from the fourth lens 53d and the optical path of the blue light LB and the purple light LV integrated by the first DM 52a. The excitation light LE is incident on one surface of the second DM 52b at an angle of 45 °, and the blue light LB and the violet light LV are incident on the other surface at an angle of 45 °.

  As shown in FIG. 10, the second DM 52b is a long-pass filter having a threshold λ2 at about 490 nm, reflects light having a wavelength equal to or smaller than the threshold λ2, and transmits light having a wavelength larger than the threshold λ2. That is, the second DM 52b reflects the excitation light LE incident from the fourth lens 53d and deflects it by 90 °, and reflects the blue light LB and violet light LV incident from the first DM 52a and deflects them by 90 °.

  The fifth lens 53e is disposed on the optical path of the excitation light LE reflected by the second DM 52b, and condenses the excitation light LE. The excitation light LE condensed by the fifth lens 53e is applied to the phosphor layer 61 of the rotating phosphor 56.

  The rotation motor 57 rotates the wheel plate 60 around the rotation shaft 63. The motor drive unit 58 generates a rotation drive signal based on the control of the light source control unit 31 and supplies the rotation drive signal to the rotation motor 57. The rotation motor 57 rotates the wheel plate 60 according to the rotation drive signal. The excitation light LE is continuously applied to a part of the phosphor layer 61 in a state where the wheel plate 60 is rotationally driven. Therefore, the irradiation position 64 of the excitation light LE on the phosphor layer 61 moves as the wheel plate 60 rotates.

  The green light LG is generated from the irradiation position 64 of the phosphor layer 61 by the irradiation of the excitation light LE. As shown in FIG. 6, the green light LG has a wavelength band of about 500 nm to 600 nm and a peak wavelength of about 540 nm. The green light LG is collected by the fifth lens 53e and emitted toward the second DM 52b. Since the second DM 52b has the optical characteristics described above, the green light LG is transmitted through the second DM 52b. Therefore, the second DM 52b integrates the optical path of the blue light LB and the purple light LV and the optical path of the green light LG.

  The third lens 53c is disposed on the optical path of the red light LR emitted from the R-LED 50c, and condenses the red light LR. The optical path of the red light LR emitted from the third lens 53c and the optical paths of the purple light LV, the blue light LB, and the green light LG integrated by the second DM 52b are orthogonal to each other, and the third DM 52c is disposed at this intersection. ing. The red light LR is incident on one surface of the third DM 52c at an angle of 45 °, and the violet light LV, the blue light LB, and the green light LG are incident on the other surface at an angle of 45 °.

  As shown in FIG. 11, the third DM 52c has a threshold λ3 at about 580 nm, reflects light having a wavelength equal to or greater than the threshold λ3, and transmits light having a wavelength smaller than the threshold λ3. In other words, the third DM 52c reflects the red light LR incident from the third lens 53c and deflects it by 90 °, and transmits the violet light LV, blue light LB, and green light LG incident from the second DM 52b. Thereby, each optical path of purple light LV, blue light LB, green light LG, and red light LR is integrated.

  The fifth lens 53f is disposed on the optical path of the violet light LV, the blue light LB, the green light LG, and the red light LR emitted from the third DM 52c. The fifth lens 53f is disposed in the vicinity of the light source connector 29b, collects the incident light, and makes it incident on the incident end 32a of the light guide 32.

  In the normal observation mode, the B-LED 50a, the R-LED 50c, and the B-LD 54 are driven, and the mixed light obtained by combining the blue light LB, the green light LG, and the red light LR is supplied to the light guide 32 as normal light. The In one blood vessel enhancement observation mode, the V-LED 50b and the B-LD 54 are driven, and the mixed light of the purple light LV and the green light LG is supplied to the light guide 32 as special light.

  The blue light LB and the purple light LV are imaged by a pixel provided with a B filter 38c. The green light LG is imaged by the pixel provided with the G filter 38b. The red light LR is imaged by a pixel provided with an R filter 38a.

  As described above, in the light source unit 30, the optical paths of the blue light LB, the purple light LV, the green light LG, and the red light LR are integrated in order from the short wavelength side by the first to third DMs 52a to 52c. The violet light LV used in the blood vessel enhancement observation mode is optically integrated by the first DM 52a, and among the blue light LB, the green light LG, and the red light LR constituting the normal light, only the blue light LB is the first DM 52a. Pass through. For this reason, in this embodiment, attenuation of normal light due to passing through the dichroic mirror for integrating the purple light LV is reduced.

  In the present embodiment, the excitation light LE is guided to the rotating phosphor 56, and the second DM 52b for emitting the green light LG from the rotating phosphor 56 is used to make the purple light LV, the blue light LB, and the green light. Since the optical paths of the light LG are integrated, the number of dichroic mirrors can be reduced from the number of sources (four).

  Next, the operation of the endoscope system 10 will be described. When performing an endoscopic diagnosis, the endoscope 11 is connected to the processor device 12 and the light source device 13, and the processor device 12 and the light source device 13 are powered on. When the endoscope system 10 is activated, the operation input unit 15 is operated to select the normal observation mode.

  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 B-LED 50a, the R-LED 50c, and the B-LD 54 are driven based on the control of the controller 40. As a result, blue light LB, red light LR, and green light LG are generated from the light source unit 30, and normal light in which these are mixed is supplied to the light guide 32 as illumination light.

  In the endoscope 11, illumination light is guided to the illumination window 22 through the light guide 32 and is irradiated from the illumination window 22 to the observation site. The reflected light from the observation site enters the image sensor 33 from the observation window 23 via the objective optical system 37. The image sensor 33 photoelectrically converts incident light every frame period to generate an image signal. This image signal is processed by the AFE 35 such as CDS, AGC, A / D conversion, and the like, and is input to the DSP 41 of the processor device 12 as a digital signal.

  The DSP 41 performs signal processing such as pixel interpolation processing, gamma correction, and white balance correction on the digital imaging signal input from the endoscope 11 in units of frames to obtain image data, and this image data is stored in the frame memory. 42 is stored. The image processing unit 43 performs predetermined image processing on the image data stored in the frame memory 42 to generate a normal observation image. The normal observation image is displayed on the monitor 14 via the display control unit 44. The normal observation image displayed on the monitor 14 is updated every frame.

  Next, when a lesion and a suspicious observation site are found in the normal observation mode, the normal observation mode is switched to the blood vessel enhancement observation mode. In this blood vessel enhancement observation mode, the V-LED 50b and the B-LD 54 are driven based on the control of the controller 40. As a result, purple light LV and green light LG are generated from the light source unit 30, and special light in which these are mixed is supplied to the light guide 32 as illumination light.

  In the endoscope 11, the reflected light from the observation site is imaged in the same manner as in the normal observation mode, and the imaging signal is input to the processor device 12. The processor device 12 is the same as in the normal observation mode except that the blood vessel enhancement observation image is generated by the image processing unit 43 and the blood vessel enhancement observation image is displayed on the monitor 14 by the display control unit 44.

  In the above embodiment, the second DM 52b reflects light having a wavelength less than or equal to the threshold value λ2 and transmits light having a wavelength greater than the threshold value λ2. However, as shown in FIG. May be reflected, and light having a wavelength smaller than the threshold λ2 may be transmitted. In this case, the B-LD 54, the rotating phosphor 56, the B-LED 50a, and the V-LED 50b are arranged as shown in FIG. 13 with respect to the second DM 52b, and the blue light LB and the purple light LV transmitted through the second DM 52b. The optical path and the optical path of the green light LG reflected by the second DM 52b are integrated.

  In the above embodiment, the first DM 52a reflects light having a wavelength less than or equal to the threshold λ1 and transmits light having a wavelength greater than the threshold λ1, but as shown in FIG. 14, reflects light having a wavelength greater than or equal to the threshold λ1. It is also possible to transmit light having a wavelength smaller than the threshold λ1. In this case, as shown in FIG. 15, the optical path of the violet light LV transmitted through the first DM 52a and the optical path of the blue light LB reflected by the first DM 52a are integrated.

  In the above embodiment, the third DM 52c reflects light having a wavelength of the threshold value λ3 or more and transmits light having a wavelength smaller than the threshold value λ3. However, as shown in FIG. It is also possible to transmit light having a wavelength larger than the threshold λ3. In this case, as shown in FIG. 17, the optical path of the red light LR transmitted through the third DM 52c and the optical paths of the purple light LV, the blue light LB, and the green light LG reflected by the third DM 52c are integrated.

  Accordingly, each of the first to third DMs 52a to 52c generates one of reflection and transmission for light having a wavelength equal to or greater than the threshold, and generates the other of reflection and transmission for light having a wavelength smaller than the threshold. Therefore, as shown in FIG. 18, the combination of the optical characteristics (reflection or transmission) of the first to third DMs 52a to 52c can be eight patterns including the above embodiment. The configuration shown in FIG. 5 corresponds to the first pattern, and the configuration shown in FIG. 13 corresponds to the second pattern.

  In the above embodiment, the R-LED 50c and the third DM 52c are provided in the light source unit 30, but the R-LED 50c and the third DM 52c are not provided, and yellow light including green and red wavelength bands is generated from the rotating phosphor 56. You may let them.

  In the above embodiment, blue laser light is used as the excitation light LE. However, violet laser light or the like may be used as the excitation light LE instead.

  In the above embodiment, the primary color filter array 38 is used, but a complementary color filter array may be used instead.

  Further, instead of the single-plate color image sensor 33, a monochrome image sensor may be used. In this case, the B-LED 50a, the V-LED 50b, the R-LED 50c, and the B-LD 54 in the light source device 13 are individually driven, and each of the red light LR, the green light LG, the blue light LB, and the purple light LV. Are individually emitted, and the reflected light from the observation site illuminated by each light is individually imaged by the imaging device. This imaging method is called a frame sequential method.

  Specifically, in the normal observation mode, as shown in FIG. 19, the red light LR, the green light LG, and the blue light LB are sequentially emitted through the extinguishing period. In one blood vessel enhancement observation mode, as shown in FIG. 20, the purple light LV and the green light LG are alternately emitted over the lamp period. The image sensor is exposed by reflected light from the observation site irradiated with each light, and signal readout is performed during the extinguishing period. The method of providing the light extinction period in this way is preferable when the image sensor is a CMOS image sensor. This is because a CMOS image sensor basically cannot read signals during exposure. Since the CCD image sensor can read out the signal during exposure, it is not necessary to provide a light-off period.

  In the case of this frame sequential method, the wavelength bands of the red light LR, the green light LG, and the blue light LB are brought close to the wavelength bands obtained by the conventional xenon light source and the wavelength selection filter. From the viewpoint of affinity. In particular, since the green light LG is fluorescent and has a large spread on the long wavelength side, it is preferable to cut the long wavelength side component. Specifically, it is preferable to cut light having a specific wavelength or longer within the range of 560 to 590 nm of the green light LG.

  For this purpose, for example, in the above embodiment, the threshold λ3 of the third DM 52c may be set in the range of 560 to 590 nm. In this case, the green light LG is guided and cut out of the optical path by reflecting the wavelength component equal to or greater than the threshold λ3 without passing through the third DM 52c.

  In addition, as shown in FIG. 21, the second DM 52b is provided with a second threshold λ4 in addition to the first threshold λ2, and the green light LG is between the first threshold λ2 and the second threshold λ4. A band-pass filter that transmits only light of a wavelength component may be used. Even in this case, the reflection and transmission of the second DM 52b can be reversed.

  Further, as shown in FIG. 22, a long wavelength cut filter 70 that cuts light having a specific wavelength within the range of 560 to 590 nm may be provided on the optical path of the green light LG from the rotating phosphor 56 to the third DM 52c. good. The long wavelength cut filter 70 is inserted into and removed from the optical path of the green light LG by the filter insertion / removal unit 71. The filter insertion / removal unit 71 inserts the long wavelength cut filter 70 on the optical path of the green light LG when the imaging method is the frame sequential method.

  Moreover, as shown in FIG. 23, you may provide the notch filter 80 which attenuates the light of a specific wavelength range. The notch filter 80 is disposed on the optical path integrated by the third DM 52c. As shown in FIG. 24, the notch filter 80 reflects or absorbs light in the wavelength range of 560 to 590 nm and transmits light of other wavelengths, and partially transmits green light LG and red light LR, respectively. Dimmed.

  The notch filter 80 is inserted into and removed from the optical path integrated by the third DM 52 c by the filter insertion / removal unit 81. When the imaging method is the frame sequential method, the filter insertion / removal unit 81 inserts the notch filter 80 on the optical path to reduce light in the wavelength range of 560 to 590 nm from the green light LG and the red light LR. Note that the attenuation rate in the wavelength range of 560 to 590 nm may not be 100%.

  Moreover, in the said embodiment, although the fluorescent substance is made into the rotation fluorescent substance 56 driven rotationally, the fluorescent substance does not need to be rotationally driven and is a reflection type which emits fluorescence in the direction opposite to the incident direction of the excitation light LE. If it is a thing.

  In the above-described embodiment, the light source device and the processor device are separately configured, but the light source device and the processor device may be configured as one device.

  The first to fourth light sources described in the claims correspond to the B-LD 54, the B-LED 50a, the V-LED 50b, and the R-LED 50c, respectively, in the embodiment. The first to fourth lights described in the claims correspond to green light LG, blue light LB, purple light LV, and red light LR, respectively.

  The configuration described in claim 1 of the claims includes patterns 1 to 8 shown in FIG. 18, and additional items 1 to 4 obtained by disassembling the patterns are described below. The supplementary item 1 corresponds to the patterns 1 and 5. Additional item 2 corresponds to patterns 2 and 6. The supplementary item 3 corresponds to the patterns 3 and 7. The supplementary item 4 corresponds to the patterns 4 and 8.

[Additional Item 1]
A first light source that emits excitation light;
A phosphor that emits first light having a peak wavelength longer than that of the excitation light by irradiation of the excitation light;
A second light source that emits second light having a shorter peak wavelength than the first light;
A third light source that emits third light having a shorter peak wavelength than the second light;
A first dichroic mirror that transmits the second light and reflects the third light;
A second dichroic mirror that reflects the excitation light, the second light, and the third light and transmits the first light;
The phosphor emits the first light toward the second dichroic mirror when the excitation light is incident from the first light source via the second dichroic mirror,
The first dichroic mirror integrates the optical paths of the second and third lights, and the second dichroic mirror integrates the second and third lights whose optical paths are integrated by the first dichroic mirror, and the phosphor. An endoscope light source device characterized by integrating an optical path with the first light incident from the endoscope.
[Additional Item 2]
A first light source that emits excitation light;
A phosphor that emits first light having a peak wavelength longer than that of the excitation light by irradiation of the excitation light;
A second light source that emits second light having a shorter peak wavelength than the first light;
A third light source that emits third light having a shorter peak wavelength than the second light;
A first dichroic mirror that transmits the second light and reflects the third light;
A second dichroic mirror that transmits the excitation light, the second light, and the third light and reflects the first light;
The phosphor emits the first light toward the second dichroic mirror when the excitation light is incident from the first light source via the second dichroic mirror,
The first dichroic mirror integrates the optical paths of the second and third lights, and the second dichroic mirror integrates the second and third lights whose optical paths are integrated by the first dichroic mirror, and the phosphor. An endoscope light source device characterized by integrating an optical path with the first light incident from the endoscope.
[Additional Item 3]
A first light source that emits excitation light;
A phosphor that emits first light having a peak wavelength longer than that of the excitation light by irradiation of the excitation light;
A second light source that emits second light having a shorter peak wavelength than the first light;
A third light source that emits third light having a shorter peak wavelength than the second light;
A first dichroic mirror that reflects the second light and transmits the third light;
A second dichroic mirror that reflects the excitation light, the second light, and the third light and transmits the first light;
The phosphor emits the first light toward the second dichroic mirror when the excitation light is incident from the first light source via the second dichroic mirror,
The first dichroic mirror integrates the optical paths of the second and third lights, and the second dichroic mirror integrates the second and third lights whose optical paths are integrated by the first dichroic mirror, and the phosphor. An endoscope light source device characterized by integrating an optical path with the first light incident from the endoscope.
[Additional Item 4]
A first light source that emits excitation light;
A phosphor that emits first light having a peak wavelength longer than that of the excitation light by irradiation of the excitation light;
A second light source that emits second light having a shorter peak wavelength than the first light;
A third light source that emits third light having a shorter peak wavelength than the second light;
A first dichroic mirror that reflects the second light and transmits the third light;
A second dichroic mirror that transmits the excitation light, the second light, and the third light and reflects the first light;
The phosphor emits the first light toward the second dichroic mirror when the excitation light is incident from the first light source via the second dichroic mirror,
The first dichroic mirror integrates the optical paths of the second and third lights, and the second dichroic mirror integrates the second and third lights whose optical paths are integrated by the first dichroic mirror, and the phosphor. An endoscope light source device characterized by integrating an optical path with the first light incident from the endoscope.

  As described above, the first dichroic mirror integrates the optical paths of the second and third lights, and the second dichroic mirror integrates the second and third lights with the optical paths integrated by the first dichroic mirror, and the first light. And integrate the light path. Therefore, when the first to third light sources are simultaneously driven and the first to third lights are emitted at the same time, the first to third lights are combined by the first and second dichroic mirrors.

DESCRIPTION OF SYMBOLS 10 Endoscope system 11 Endoscope 12 Processor apparatus 13 Light source apparatus 30 Light source part 33 Image pick-up element 38 Color filter array 40 Controller 52a-52c 1st-3rd dichroic mirror 56 Rotary fluorescent substance 60 Wheel board 61 Phosphor layer 70 Length Wavelength cut filter

Claims (12)

A first light source that emits excitation light;
A phosphor that emits first light having a peak wavelength longer than that of the excitation light by irradiation of the excitation light;
A second light source that emits second light having a shorter peak wavelength than the first light;
A third light source that emits third light having a shorter peak wavelength than the second light;
A first dichroic mirror that produces one of reflection and transmission for the second light and the other of reflection and transmission for the third light;
A second dichroic mirror that generates one of reflection and transmission for the excitation light, the second light, and the third light, and generates the other of reflection and transmission for the first light; With
The phosphor emits the first light toward the second dichroic mirror when the excitation light is incident from the first light source via the second dichroic mirror,
The first dichroic mirror integrates the optical paths of the second and third lights, and the second dichroic mirror integrates the second and third lights whose optical paths are integrated by the first dichroic mirror, and the phosphor. An endoscope light source device characterized by integrating an optical path with the first light incident from the endoscope. A fourth light source that emits fourth light having a longer peak wavelength than the first light;
One of reflection and transmission is generated for the first to third lights whose optical paths are integrated by the second dichroic mirror, and the other of reflection and transmission is generated for the fourth light. A third dichroic mirror that integrates the optical paths of the first to fourth lights,
The endoscope light source device according to claim 1, comprising: The endoscope light source device according to claim 2, wherein the first light is green light, and a peak wavelength of the first light is less than 560 nm . The light source for an endoscope according to claim 3 , wherein the third dichroic mirror generates the other one of reflection and transmission with respect to light having a specific wavelength within a range of 560 to 590 nm. apparatus. 4. The endoscope light source device according to claim 3 , further comprising a long wavelength cut filter that cuts light having a specific wavelength within a range of 560 to 590 nm.   The endoscope light source device according to claim 5, further comprising a filter insertion / removal unit that inserts / removes the long wavelength cut filter into / from the optical path of the first light. 4. The endoscope light source device according to claim 3 , further comprising a notch filter that attenuates light in a wavelength range of 560 to 590 nm.   The light source device for endoscope according to claim 7, further comprising a filter insertion / removal unit that inserts / removes the notch filter into / from the optical path integrated by the third dichroic mirror.   9. The phosphor according to claim 1, wherein the phosphor is a rotary phosphor that is driven to rotate and an irradiation position of the excitation light on the phosphor moves in accordance with the rotation. Endoscope light source device. A first light source that emits excitation light;
A phosphor that emits first light having a peak wavelength longer than that of the excitation light by irradiation of the excitation light;
A second light source that emits second light having a shorter peak wavelength than the first light;
A third light source that emits third light having a shorter peak wavelength than the second light;
A first dichroic mirror that produces one of reflection and transmission for the second light and the other of reflection and transmission for the third light;
A second dichroic mirror that generates one of reflection and transmission for the excitation light, the second light, and the third light, and generates the other of reflection and transmission for the first light; With
The phosphor emits the first light toward the second dichroic mirror when the excitation light is incident from the first light source via the second dichroic mirror,
The first dichroic mirror integrates the optical paths of the second and third lights, and the second dichroic mirror integrates the second and third lights with the optical paths integrated by the first dichroic mirror, and the phosphor. A light source device that integrates an optical path with the first light incident from
An endoscope having an image sensor that images reflected light from an observation site irradiated with at least one of the first to third lights;
A control unit that controls the first to third light sources and the image sensor;
An endoscope system comprising: The light source device is
A fourth light source that emits fourth light having a longer peak wavelength than the first light;
One of reflection and transmission is generated for the first to third lights whose optical paths are integrated by the second dichroic mirror, and the other of reflection and transmission is generated for the fourth light. A third dichroic mirror that integrates the optical paths of the first to fourth lights,
The endoscope system according to claim 10, further comprising: It has a normal observation mode and a blood vessel enhancement observation mode,
The control unit emits the first light, the second light, and the fourth light simultaneously or individually in the normal observation mode, and the first light and the third light in the blood vessel enhancement observation mode. The endoscope system according to claim 11, wherein light is emitted simultaneously or individually.

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