JP2020073047A - Light source device for endoscope and endoscope system - Google Patents

Abstract

To provide a light source device for an endoscope and an endoscope system capable of ensuring compatibility and continuity with diagnostics constructed based on images.SOLUTION: A rotation filter control unit 54, in the case of a normal mode, by sequentially inserting a B1 filter, G1 filter, and R1 filter of a normal filter in an optical path of a semiconductor light source unit, sequentially emits normal blue light, normal green light, and normal red light, and in the case of a first blood vessel emphasizing mode, by sequentially inserting a B2 filter and a G2 filter of a first blood vessel emphasizing filter in the optical path of the semiconductor light source unit, sequentially emits a blue narrow band light and a first green narrow band light. A light quantity ratio of light of a plurality of colors is changed for each mode by a switching operation by a mode switching unit.SELECTED DRAWING: Figure 9

Description

  The present invention relates to an endoscope light source device and an endoscope system including a plurality of semiconductor light sources that emit light of a plurality of colors.

  2. Description of the Related Art In recent medical care, diagnosis and the like are performed by an endoscope system including a light source device for an endoscope (hereinafter referred to as a light source device), an electronic endoscope (hereinafter referred to as an endoscope), and a processor device. .. The light source device emits illumination light for illuminating the observation site. The endoscope has an image sensor, images the observation site illuminated by the illumination light, and outputs an image signal. The processor device generates an image from the image signal and causes the monitor to display the image.

  As a light source device, conventionally, a lamp light source such as a xenon lamp which emits white light and three color filters capable of transmitting the respective wavelength ranges of blue (B), green (G) and red (R) are surrounded. A device including a rotary filter provided along the direction is known (Patent Document 1). By rotating the rotary filter and sequentially inserting the color filters of each color into the optical path of white light, blue light, green light, and red light are sequentially emitted as illumination light. When imaging an observation site that is sequentially illuminated with illumination light of each color, an endoscope having a monochrome image sensor is used, and an image is captured by the monochrome image sensor each time the observation site is illuminated with illumination light of each color. ..

  Further, in Patent Document 2, in a light source device including a lamp light source and a rotation filter, in order to obtain tissue information of a desired depth of a biological tissue, light in a wavelength range narrower than a wavelength range of white light (hereinafter, narrow range) It is described that it enables narrow band light observation using band light). The rotary filter is provided with two narrow band color filters capable of respectively transmitting a part of the wavelength band of blue light and a part of the wavelength band of green light for observing narrow band light. Further, in order to increase the amount of narrow band light, a semiconductor light source that emits narrow band light, such as a laser diode (LD: Laser diode) or a light emitting diode (LED: Light emitting diode), is provided in addition to the lamp light source. There is.

  In order not to impair the accuracy of diagnosis, the light source device is required to have stability such as the tint of illumination light. For this reason, when the color of illumination light changes, the light source needs to be replaced. In the case of the lamp light source used in the conventional apparatus as disclosed in Patent Documents 1 and 2, there arises a problem that frequent replacement is required every 100 hours. On the other hand, in recent years, instead of the lamp light source and the rotary filter, a light source device including a semiconductor light source having a long life has become widespread (Patent Document 3). Since the semiconductor light source has a longer life than the lamp light source, the number of times of replacement can be reduced. The semiconductor light source emits light of a plurality of colors such as blue light, green light, and red light. The lights of the plurality of colors are combined by a combining member, for example, a dichroic mirror (also referred to as a dichroic filter), and emitted as illumination light. When imaging an observation site illuminated with illumination light obtained by combining lights of a plurality of colors, an endoscope having a color image sensor provided with a BGR color filter is used.

JP, 2003-126031, A JP2012-55391A International Publication No. 2015/159676

  The light source device provided with the semiconductor light source has an advantage that the tint or the like of the illumination light is unlikely to change due to its long life, that is, the tint or the like of the image is unlikely to change. Useful in building. However, a light source device including a semiconductor light source may have a wavelength range of illumination light different from that of a conventional light source device including a lamp light source and a rotary filter. Even in such a case, the conventional light source device is also included. It is required to ensure compatibility and continuity with the diagnostics that have been constructed based on the images obtained in.

  An object of the present invention is to provide a light source device for an endoscope and an endoscope system capable of ensuring compatibility and continuity with diagnostics constructed based on images.

  A light source device for an endoscope of the present invention has a blue light source that emits blue light, a green light source that emits green light, and a red light source that emits red light, and a semiconductor light source unit that emits light of a plurality of colors, and a semiconductor light source unit. And a light source control unit that emits light of a plurality of colors, and a normal filter and a first blood vessel emphasizing filter. The normal filter or the first blood vessel emphasizing filter is sequentially provided in the optical path of the semiconductor light source unit. A filter unit that is inserted and sequentially emits light having different wavelength ranges, a mode switching unit that is used for switching operation between the normal mode and the first blood vessel enhancement mode, and a B1 filter and a G1 filter that are normal filters in the normal mode. , And R1 filters are sequentially inserted into the optical path of the semiconductor light source unit to sequentially emit normal blue light, normal green light, and normal red light, and in the case of the first blood vessel emphasizing mode, the first blood vessel. The B2 filter and the G2 filter of the tuning filter are sequentially inserted into the optical path of the semiconductor light source unit to include a rotary filter control unit that sequentially emits the blue narrowband light and the first green narrowband light. The light quantity ratio of light of a plurality of colors is changed for each mode by a switching operation by the mode switching unit.

  It is preferable that the light source control unit make the light intensity of the blue light emitted from the blue light source in the first blood vessel enhancement mode higher than the light intensity of the blue light emitted from the blue light source in the normal mode. The light source controller emits blue light and green light at the same time when the B1 filter is inserted in the optical path, emits blue light, green light and red light at the same time when the G1 filter is inserted in the optical path, and emits light to the optical path. It is preferable to emit green light and red light at the same time when the R1 filter is inserted. It is preferable that the light source controller emits blue light when the B2 filter is inserted in the optical path and emits green light when the G2 filter is inserted in the optical path.

  The light source control unit sequentially emits blue light and green light when the B1 filter is inserted in the optical path, and sequentially emits blue light, green light, and red light when the G1 filter is inserted in the optical path, It is preferable to sequentially emit green light and red light when the R1 filter is inserted in the optical path. It is preferable that the filter portion has a disc shape and is a rotary filter in which a plurality of filters are provided along the circumferential direction.

  The endoscope system of the present invention has a blue light source that emits blue light, a green light source that emits green light, and a red light source that emits red light, and controls the semiconductor light source unit that emits light of a plurality of colors and the semiconductor light source unit. However, it has a light source control unit for emitting light of a plurality of colors, a normal filter and a first blood vessel emphasizing filter, and the ordinary filter or the first blood vessel emphasizing filter is sequentially inserted in the optical path of the semiconductor light source unit. , A filter unit that sequentially emits light having different wavelength ranges, a mode switching unit that uses a switching operation between the normal mode and the first blood vessel enhancement mode, and a B1 filter, a G1 filter, and a normal filter in the normal mode, By sequentially inserting the R1 filter into the optical path of the semiconductor light source unit, the normal blue light, the normal green light, and the normal red light are sequentially emitted, and in the first blood vessel enhancement mode, the first blood vessel intensity is increased. The B2 filter and the G2 filter of the filter for light are sequentially inserted into the optical path of the semiconductor light source unit, so that the blue narrowband light and the first green narrowband light are sequentially emitted, and the filter unit is sequentially emitted. An endoscope having a monochrome image sensor that captures an image each time the observation site is illuminated with light, and a processor device that generates an image based on a plurality of image signals output each time the monochrome image sensor captures an image, The light source control unit changes the light amount ratio of the light of a plurality of colors for each mode by the switching operation by the mode switching unit.

  According to the light source device for an endoscope, the method for operating the same, and the endoscope system of the present invention, compatibility and continuity with diagnostics constructed based on images can be ensured.

It is an external view of an endoscope system. It is a block diagram which shows the electric constitution of an endoscope system. It is a figure which shows the structure of a semiconductor light source part. It is a figure which shows the light intensity spectrum of blue light, green light, and red light. It is a figure which shows the structure of a rotary filter. It is a figure which shows the transmission characteristic of a filter for normal use. It is a figure which shows the transmission characteristic of the 1st blood vessel emphasis filter. It is a flow chart explaining an operation of an endoscope system. It is a figure explaining control of the light quantity ratio at the time of normal mode. It is a figure explaining control of the light quantity ratio in the 1st blood vessel emphasis mode. It is a figure explaining the control which makes the light intensity of blue light large in the 1st blood vessel emphasis mode. It is a figure explaining control which lights up a plurality of LED light sources one by one. It is a figure which shows the structure of the semiconductor light source part of 3rd Embodiment. It is a figure which shows the light intensity spectrum of violet light, blue light, green light, and red light. It is a figure which shows the relationship between the wavelength range of purple light and the transmission characteristic of a filter for normal use. It is a figure which shows the relationship between the wavelength range of purple light and the transmission characteristic of the 1st blood vessel emphasis filter. It is a figure explaining the lighting control at the time of the normal mode of 3rd Embodiment. It is a figure explaining the lighting control at the time of the 1st blood vessel emphasis mode of 3rd Embodiment. It is a figure explaining control which turns on a blue LED light source and a purple LED light source one by one in the 1st blood vessel emphasis mode of a 3rd embodiment. It is a figure explaining control which lights up a blue LED light source and a purple LED light source simultaneously at the time of the 1st blood vessel emphasis mode of a 3rd embodiment. It is a figure explaining the control which turns on each LED light source one by one in the normal mode of 3rd Embodiment. It is a figure explaining the lighting control of the 1st blood vessel emphasis mode using the filter for normal. It is a figure which shows the structure of the rotary filter of 4th Embodiment. It is a figure which shows the transmission characteristic of the 2nd blood vessel emphasis filter. It is a figure explaining the lighting control at the time of the 2nd blood vessel emphasis mode of 4th Embodiment. It is a figure explaining the control which makes a green LED light source and a red LED light source light up one by one in the 2nd blood vessel emphasis mode of a 4th embodiment. It is a figure which shows the semiconductor light source part of 5th Embodiment. It is a figure which shows a multi-chip LED light source. It is a figure which shows the internal structural example of the front-end | tip part of an endoscope.

[First Embodiment]
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 subject, and an image of the observation site based on an image signal obtained by the imaging. , A light source device 13 for endoscope (hereinafter, simply referred to as a light source device) that supplies illumination light that illuminates an observation site to the endoscope 11, and a monitor 14 as a display unit that displays an image. It has and. An operation input unit 15 such as a keyboard and a mouse is connected to the processor device 12.

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

  The bending portion 20 has a structure in which a plurality of bending pieces are connected, and bends in the vertical and horizontal directions according to the operation of the angle knob 17 a of the operation portion 17. By bending the bending portion 20, the tip 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. In the insertion portion 16, a drive signal for driving the image pickup device 35, a signal cable 112 (see FIG. 29) for transmitting an image signal output from the image pickup device 35, and illumination light emitted from the light source device 13 are supplied to the tip portion 19. A light guide 32 (see FIG. 2) that guides light up to is inserted.

  In addition to the angle knob 17a, the operation unit 17 is provided with a mode switching unit 17b used for an observation mode switching operation. In this embodiment, the observation mode includes a normal mode and a first blood vessel emphasis mode. The normal mode is an observation mode in which the monitor 14 displays a normal image obtained by capturing an image of an observation region illuminated with broadband illumination light having a high color rendering property. In the first blood vessel emphasizing mode, a first blood vessel emphasizing image obtained by imaging an observation site illuminated with narrow band light containing a large amount of light components in a specific wavelength range having high absorbance for blood hemoglobin is displayed on the monitor 14. It is an observation mode.

  A signal cable 112 (see FIG. 29) and a light guide 32 (see FIG. 2) extending from the insertion portion 16 are inserted into the universal cord 18, and one end on the processor device 12 and the light source device 13 side is A connector 29 is attached. The connector 29 is a composite type connector including a communication connector 29a and a light source connector 29b. The communication connector 29a is detachably connected to the processor device 12. One end of the signal cable 112 is arranged in the communication connector 29a. The light source connector 29b is detachably connected to the light source device 13. An incident end 32a (see FIG. 2) of the light guide 32 is arranged on the light source connector 29b.

  In FIG. 2, the endoscope 11 includes a light guide 32, an illumination optical system 33, an objective optical system 34, an image pickup device 35, an image pickup drive unit 36, and a CDS / AGC (Correlated Double Sampling / Automatic Gain Control). It has a circuit 37 and an A / D (Analog to Digital) conversion circuit 38.

  The light guide 32 is a fiber bundle that bundles a plurality of optical fibers. The incident end 32 a of the light guide 32 faces the emitting end of the semiconductor light source unit 50 when the light source connector 29 b is connected to the light source device 13. The exit end of the light guide 32 guides the illumination light to the tip portion 19.

  The illumination optical system 33 is arranged at the tip portion 19 and the incident surface faces the exit end of the light guide 32. The illumination light guided through the light guide 32 is emitted from the tip portion 19 via the illumination optical system 33 and illuminates the observation site. The illumination optical system 33 is a concave lens and is capable of illuminating a wide range of an observation site.

  The objective optical system 34 is arranged at the tip portion 19. The exit surface of the objective optical system 34 faces the imaging surface of the imaging element 35. The return light (light image) from the observation site is incident on the image pickup surface of the image pickup device 35 via the objective optical system 34. The objective optical system 34 includes, for example, an objective lens and a zoom lens.

  The image pickup device 35 is a monochrome image sensor having no color filter on the image pickup surface side, and picks up an image of the observed region and outputs an image signal. As the image sensor 35, a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal-Oxide Semiconductor) image sensor can be used. On the image pickup surface of the image pickup device 35, a plurality of pixels that generate an image signal by photoelectric conversion are two-dimensionally arranged in a matrix. The image pickup device 35 is driven by the image pickup drive unit 36, and receives the return light from the observation region by a plurality of pixels and outputs an image signal.

  Although the image sensor 35 is a monochrome image sensor in this embodiment, it may be a color image sensor provided with a color filter array. The color filter array has a blue (B) filter, a green (G) filter, and a red (R) filter. The B filter has a high light transmittance in the wavelength range of 380 nm to 560 nm, for example. The G filter has a high light transmittance for a wavelength range of 450 nm to 630 nm, for example. The R filter has a high light transmittance in the wavelength range of 580 nm to 760 nm, for example. Any one of these filters is arranged on each pixel. The color array of the color filter array is, for example, a Bayer array, in which G filters are arranged in a checkered pattern every other pixel, and B filters and R filters are arranged in a square lattice pattern on the remaining pixels. Has been done. Instead of the primary color filter array as described above, a complementary color filter array may be provided.

  The CDS / AGC circuit 37 performs correlated double sampling and automatic gain control on the analog image signal received from the image sensor 35. The A / D conversion circuit 38 converts the analog image signal passed through the CDS / AGC circuit 37 into a digital image signal. The A / D conversion circuit 38 inputs the digital image signal after A / D conversion to the processor device 12.

  The processor device 12 includes a controller 40, a DSP (Digital Signal Processor) 41, a frame memory 42, an image processing unit 43, and a display control unit 44.

  The controller 40 has a CPU (Central Processing Unit), a ROM (Read only memory) for storing a control program and setting data necessary for control, a RAM (Random access memory) as a working memory for loading the control program, and the like. The controller 40 controls each unit of the processor device 12 by the CPU executing the control program.

  The controller 40 controls to synchronize the operation of the light source controller 55 and the operation of the image pickup driving unit 36. Specifically, the controller 40 causes the image sensor 35 to sequentially output image signals by driving the image sensor 35 periodically (every one frame period) in accordance with the rotation of the rotary filter 53 described later.

  The DSP 41 performs signal processing such as pixel interpolation processing, gamma correction, white balance correction, and synchronization processing on the image signal sequentially output for each frame by the image sensor 35 via the communication connector 29a. The DSP 41 stores the image-processed image signals in the frame memory 42 as image data.

  The image processing unit 43 reads out the image data from the frame memory 42 and subjects the image data to predetermined image processing to generate an image. 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.

  The light source device 13 includes a semiconductor light source unit 50, a diaphragm 51, a diaphragm control unit 52, a rotation filter 53, a rotation filter control unit 54, a light source control unit 55, and a condenser lens 56. The semiconductor light source unit 50 emits light under the control of the light source control unit 55. The light emitted from the semiconductor light source unit 50 sequentially passes through the diaphragm 51, the rotary filter 53, and the condenser lens 56, and is incident on the incident end 32 a of the light guide 32. The rotary filter corresponds to the "filter unit" described in the claims.

  In FIG. 3, the semiconductor light source unit 50 includes a blue LED (Light Emitting Diode) light source 60, a green LED light source 61, a red LED light source 62, an LED drive unit 63, and a condensing optical system 64. ..

  The blue LED light source 60 is an LED light source having a single chip structure in which one blue LED 60b is mounted on one substrate 60a. The green LED light source 61 is an LED light source having a single chip structure in which one green LED 61b is mounted on one substrate 61a. The red LED light source 62 is an LED light source having a single chip structure in which one red LED 62b is mounted on one substrate 62a. The blue LED light source 60 emits blue light LB. The green LED light source 61 emits green light LG. The red LED light source 62 emits red light LR. Therefore, the semiconductor light source unit 50 is capable of emitting light of multiple colors.

  As shown in FIG. 4, the blue light LB has, for example, a wavelength range of 420 nm to 500 nm and a center wavelength of 460 nm. The wavelength range of the green light LG is, for example, 480 nm to 600 nm. The red light LR has, for example, a wavelength range of 600 nm to 650 nm and a center wavelength of 620 nm to 630 nm. The central wavelength of the blue light LB is on the shorter wavelength side than the wavelength range of the green light LG. The center wavelength of the red light LR is on the longer wavelength side than the wavelength range of the green light LG. The light of each color may have the same center wavelength or the same peak wavelength, or may have different peak wavelengths.

  The green LED light source 61 includes, for example, a blue LED for excitation (not shown) as an excitation light emitting element and a green phosphor (not shown). The excitation blue LED emits excitation blue light having a wavelength range of 450 nm to 460 nm, for example. The green phosphor emits broad-band green fluorescence when excited with blue light for excitation.

  Based on the control of the light source control unit 55, the LED driving unit 63 independently applies a driving current to the blue LED light source 60, the green LED light source 61, and the red LED light source 62 to turn on the LED light sources 60 to 62. .. The set value and the application time of the drive current are set by the light source control unit 55 for each of the LED light sources 60 to 62. Therefore, the blue LED light source 60, the green LED light source 61, and the red LED light source 62 emit light with a light intensity according to the set value of the drive current, and also emit during the light emission period according to the application time of the drive current.

  The condensing optical system 64 has first to third collimator lenses 65 to 67, a first combining member 68, and a second combining member 69.

  The first collimator lens 65 collects the blue light LB emitted from the blue LED light source 60 and emits it as parallel light. The second collimator lens 66 collects the green light LG emitted from the green LED light source 61 and emits it as parallel light. The third collimator lens 67 collects the red light LR emitted from the red LED light source 62 and emits it as parallel light. The light that the first to third collimator lenses 65 to 67 collimate does not have to be perfectly parallel light, and may be any light that can be regarded as substantially parallel light.

  The optical path of the blue light LB emitted from the first collimator lens 65 and the optical path of the green light LG emitted from the second collimator lens 66 are orthogonal to each other, and a first multiplexing member 68 is provided at this intersection. .. The first multiplexing member 68 is, for example, a dichroic mirror, and the blue light LB is incident on one surface at an angle of 45 ° and the green light LG is incident on the other surface at an angle of 45 °. The first multiplexing member 68 transmits the blue light LB and reflects the green light LG, thereby integrating the optical path of the blue light LB and the optical path of the green light LG.

  The optical path integrated by the first combining member 68 and the optical path of the red light LR emitted from the third collimator lens 67 are orthogonal to each other, and the second combining member 69 is arranged at this intersection. The second multiplexing member 69 is, for example, a dichroic mirror, and the blue light LB and the green light LG are incident on one surface at an angle of 45 °, and the red light LR is incident on the other surface at an angle of 45 °. To do. The second combining member 69 transmits the blue light LB and the green light LG and reflects the red light LR to integrate the optical path integrated by the first combining member 68 and the optical path of the red light LR. To do. As a result, the blue light LB, the green light LG, and the red light LR are combined by the second combining member 69. The light combined by the second combining member 69 is emitted from the semiconductor light source unit 50.

  The diaphragm 51 is controlled by the diaphragm controller 52 and adjusts the light emitted from the semiconductor light source unit 50 to a predetermined amount. The diaphragm control unit 52 drives a diaphragm motor (not shown) of the diaphragm 51 based on the control of the light source control unit 55, and adjusts the diaphragm amount of the diaphragm 51 so that a predetermined amount of light enters the rotary filter 53. Control.

  In FIG. 5, the rotary filter 53 has a disc shape, and includes a normal filter 70 on the outer side and a first blood vessel emphasizing filter 72 on the inner side. The normal filter 70 and the first blood vessel emphasizing filter 72 have different wavelength ranges that can be transmitted. The normal filter 70 has a B1 filter 70a, a G1 filter 70b, and an R1 filter 70c along the circumferential direction. The first blood vessel emphasis filter 72 has two B2 filters 72a and one G2 filter 72b along the circumferential direction.

  The B1 filter 70a corresponds to the "broadband blue filter" recited in the claims. The G1 filter 70b corresponds to the "wide band green filter" recited in the claims. The R1 filter 70c corresponds to the "broadband red filter" recited in the claims. The B2 filter 72a corresponds to the "blue filter for narrow band" described in the claims. The G2 filter 72b corresponds to the "narrow band first green filter" recited in the claims.

  As shown in FIG. 6, in the normal-use filter 70, the B1 filter 70a includes the entire wavelength range of the blue light LB and the short wavelength side of the wavelength range of the green light LG in the light emitted from the semiconductor light source unit 50. Allows transmission of light including some. Of the light emitted from the semiconductor light source unit 50, the G1 filter 70b includes the entire wavelength range of the green light LG, a part of the wavelength range of the blue light LB on the long wavelength side, and the short wavelength range of the wavelength range of the red light LR. The light including a part of the side is transmitted. Of the light emitted from the semiconductor light source unit 50, the R1 filter 70c transmits light including the entire wavelength range of the red light LR and a part of the wavelength range of the green light LG on the long wavelength side. Hereinafter, the light transmitted through the B1 filter 70a is referred to as "normal blue light", the light transmitted through the G1 filter 70b is referred to as "normal green light", and the light transmitted through the R1 filter 70c is "normal red light". These are collectively referred to as "normal illumination light".

  As shown in FIG. 7, in the first blood vessel emphasizing filter 72, the B2 filter 72a transmits a part of the wavelength range of the blue light LB of the light emitted from the semiconductor light source unit 50. Specifically, the short wavelength component of the blue light LB is transmitted. More specifically, the B2 filter 72a transmits light having a wavelength range of 390 nm to 460 nm. The G2 filter 72b transmits a part of the wavelength range of the green light LG in the light emitted from the semiconductor light source unit 50. Specifically, the G2 filter 72b transmits light having a wavelength range of 530 nm to 550 nm. Hereinafter, the light transmitted through the B2 filter 72a is referred to as "blue narrowband light", the light transmitted through the G2 filter 72b is referred to as "first green narrowband light", and these are collectively referred to as "first illumination for blood vessel enhancement". Light.

  The blue narrow band light is light in a wavelength range optimum for observing superficial blood vessels located at a shallow position from the mucous membrane surface. On the other hand, the first green narrowband light is light in a wavelength range optimum for observing the middle-layer blood vessels located deeper than the surface blood vessels. The long-wavelength component of the blue light LB reduces the contrast between the mucous membrane and the blood vessel, but does not pass through the B2 filter 72a, so that it is prevented from entering the light guide 32.

  The center of the rotary filter 53 is attached to the rotary shaft of a rotary motor (not shown), and can be rotationally driven. An encoder (not shown) is attached to the rotation shaft of the rotation motor, and the rotation of the rotation motor, that is, the rotation of the rotation filter 53 can be detected by this encoder. The encoder detects, for example, a reference point that is a rotation start position of the rotary filter 53, and inputs a detection signal to the light source controller 55 via the rotary filter controller 54. The light source control unit 55 obtains the rotation speed and the rotation position of the rotation filter 53 based on the detection signal and inputs the rotation speed and the rotation position to the controller 40. As a result, the filters inserted in the optical path of the semiconductor light source unit 50 can be detected, and the image signal is sequentially output from the image sensor 35 each time each filter is sequentially inserted.

  The rotary filter control unit 54 moves the rotary filter 53 in the radial direction according to the switching operation of the mode switching unit 17b. Specifically, when the mode switching unit 17b switches to the normal mode, the rotation filter control unit 54 inserts the normal filter 70 into the optical path of the semiconductor light source unit 50. On the other hand, when the mode switching unit 17b switches to the first blood vessel emphasizing mode, the rotation filter control unit 54 inserts the first blood vessel emphasizing filter 72 into the optical path of the semiconductor light source unit 50.

  Further, the rotation filter control unit 54 drives the rotation motor to rotate the rotation filter 53 at a constant rotation speed under the control of the light source control unit 55. Therefore, in the normal mode, the B1 filter 70a, the G1 filter 70b, and the R1 filter 70c of the normal filter 70 are sequentially inserted in the optical path of the semiconductor light source unit 50, and the normal blue light, the normal green light, and the normal light are emitted. Red light is emitted sequentially. On the other hand, in the first blood vessel emphasizing mode, the B2 filter 72a and the G2 filter 72b of the first blood vessel emphasizing filter 72 are sequentially inserted in the optical path of the semiconductor light source unit 50, and the blue narrow band light and the first green narrow band light are sequentially arranged. Is ejected. That is, the rotary filter 53 sequentially emits illumination light having different wavelength ranges.

  The light source control unit 55 controls the LED driving unit 63, and controls the turning on and off of the blue LED light source 60, the green LED light source 61, and the red LED light source 62. In the present embodiment, the light source control unit 55 always turns on all of the blue LED light source 60, the green LED light source 61, and the red LED light source 62 in both the normal mode and the first blood vessel emphasizing mode. That is, the light source control unit 55 controls the semiconductor light source unit 50 to emit light of a plurality of colors. As a result, a wide band light including the blue light LB, the green light LG, and the red light LR is emitted from the semiconductor light source unit 50, so that the white light emitted by the conventional light source device including the lamp light source such as the xenon lamp and the rotary filter is emitted. Color rendering with light is maintained.

  In addition, the light source control unit 55 independently controls the light intensity, the light emission period, and the light emission timing of the blue LED light source 60, the green LED light source 61, and the red LED light source 62, so that the light amount of each of the LED light sources 60 to 62 and Control the light intensity ratio. In the present embodiment, the light source control unit 55 sets the light amount of the blue LED light source 60, the light amount of the green LED light source 61, and the light amount of the red LED light source 62 to the same light amount between the normal mode and the first blood vessel emphasizing mode. And As a result, the light source control unit 55 maintains the LED light sources 60 to 62 at a specific light amount ratio between the normal mode and the first blood vessel emphasizing mode. At least, the light amounts of the LED light sources 60 to 62 are controlled so that the light amount ratio does not change during the normal mode or the first blood vessel emphasizing mode. The "same light amount" does not have to be completely the same, and may have a certain width. For example, it means that the difference in the light amount of a specific LED light source between the two observation modes is 10% or less.

  The light source control unit 55 stores, in a memory (not shown), a lookup table showing the relationship between the set value of the drive current applied to each of the LED light sources 60 to 62, the application time of the drive current, and the light amount, for example. Therefore, the light amount of each of the LED light sources 60 to 62 is controlled by driving the LED drive unit 63 with the set value and the application time of the drive current read from the lookup table. Instead of the look-up table, a light amount sensor for measuring the light amount of each of the blue LED light source 60, the green LED light source 61, and the red LED light source 62 is provided, and each LED light source 60 is based on the measurement value of the light amount sensor. You may control the light quantity of -62.

  In the present embodiment, the light source control unit 55 adjusts the set value of the drive current in order to control the light amount of each of the LED light sources 60 to 62. Thereby, the light intensity of the blue light LB, the light intensity of the green light LG, and the light intensity of the red light LR are set to the same light intensity between the normal mode and the first blood vessel emphasizing mode. The “same light intensity” does not have to be completely the same, and may have a certain width. For example, with respect to the light emitted from a specific LED light source between the two observation modes, the difference in light intensity is 10% or less.

  In order to maintain the color rendering property with the white light of the wide band emitted by the conventional light source device including the lamp light source such as a xenon lamp and the rotary filter, the light source control unit 55 controls the light quantity ratio of the light emitted from the semiconductor light source unit 50. It is preferable that the light amount ratio of the white light emitted by the conventional light source device is substantially the same. The "same" of the light quantity ratio does not have to be completely the same, and even if it is slightly different, it is considered the same if the color rendering property with the white light emitted from the conventional light source device can be maintained to some extent. As a result, the hue and brightness of white light emitted by the conventional light source device can be maintained.

  The condenser lens 56 is arranged in the vicinity of the incident end 32a of the light guide 32, condenses the illumination light emitted from the rotary filter 53, and makes it incident on the incident end 32a of the light guide 32.

  Next, the operation of the endoscope system 10 will be described with reference to the flowchart shown in FIG. When the endoscope system 10 is activated for the user such as a doctor to perform an endoscopic diagnosis, the light source control unit 55 of the light source device 13 controls the semiconductor light source unit 50, whereby the blue LED light source 60, All of the green LED light source 61 and the red LED light source 62 are turned on (S11). As a result, the semiconductor light source unit 50 emits light that combines the blue light LB, the green light LG, and the red light LR.

  When the normal mode is set (YES in S12), the rotary filter control unit 54 moves the rotary filter 53 and inserts the normal filter 70 into the optical path of the semiconductor light source unit 50 (S13). Further, the rotation filter control unit 54 rotates the rotation filter 53 to sequentially insert the B1 filter 70a, the G1 filter 70b, and the R1 filter 70c of the normal filter 70 into the optical path of the semiconductor light source unit 50. As a result, the light emitted from the semiconductor light source unit 50 (that is, the light obtained by combining the blue light LB, the green light LG, and the red light LR) sequentially enters the B1 filter 70a, the G1 filter 70b, and the R1 filter 70c. As a result, the normal blue light, the normal green light, and the normal red light are sequentially emitted from the rotary filter 53 and enter the light guide 32.

  In the endoscope 11, the imaging element 35 images the observation site each time the observation site is sequentially illuminated with the normal blue light, the normal green light, and the normal red light (normal illumination light) (S14). ). As a result, the B1 image signal, the G1 image signal, and the R1 image signal are output from the image sensor 35 in different frames. Each image signal is subjected to various signal processing by the DSP 41 and stored in the frame memory 42 as image data.

  In the processor device 12, the image processing unit 43 performs predetermined image processing on the image data stored in the frame memory 42 to generate an image, and the display control unit 44 outputs the image to the monitor 14 to display the image. Is displayed (S15). As the image processing in the normal mode, the image processing unit 43 sequentially performs, for example, color conversion processing, color enhancement processing, and structure enhancement processing. In the color conversion processing, 3 × 3 matrix processing, gradation conversion processing, three-dimensional LUT (lookup table) processing, and the like are performed on the image signal. The color enhancement processing is performed on the image signal that has undergone the color conversion processing. The structure emphasizing process is, for example, a process of emphasizing the structure of an observation site such as a blood vessel or a pit pattern (gland duct), and is performed on the image signal after the color emphasizing process. A normal image is generated using the image signal that has undergone various image processes as described above, and is displayed on the monitor 14. During the normal mode, step S14 and step S15 are repeated.

  On the other hand, when the first blood vessel emphasis mode is set (NO in S12), the rotation filter control unit 54 moves the rotation filter 53 and inserts the first blood vessel emphasis filter 72 into the optical path of the semiconductor light source unit 50 (S16). ). The rotation filter control unit 54 rotates the rotation filter 53 to sequentially insert the B2 filter 72a and the G2 filter 72b of the first blood vessel emphasizing filter 72 into the optical path of the semiconductor light source unit 50. As a result, the light emitted from the semiconductor light source unit 50 (that is, the light obtained by combining the blue light LB, the green light LG, and the red light LR) sequentially enters the B2 filter 72a and the G2 filter 72b. As a result, the blue narrowband light and the first green narrowband light are sequentially emitted from the rotary filter 53 and enter the light guide 32. Since the first blood vessel emphasizing filter 72 is provided with two B2 filters 72a, blue narrow band light is sequentially emitted each time each B2 filter 72a is inserted into the optical path of the semiconductor light source unit 50. . That is, in the first blood vessel emphasizing mode, the rotary filter 53 sequentially emits the blue narrowband light, the blue narrowband light, and the first green narrowband light.

  In the endoscope 11, the imaging device 35 changes the observing region every time the observing region is sequentially illuminated with the blue narrow band light, the blue narrow band light, and the first green narrow band light (first illumination light for blood vessel enhancement). Imaging is performed (S17). As a result, the B2 image signal, the B2 image signal, and the G2 image signal are output from the image sensor 35 in different frames. Each image signal is subjected to various signal processing by the DSP 41 and stored in the frame memory 42 as image data.

  In the processor device 12, the image processing unit 43 performs predetermined image processing on the image data stored in the frame memory 42 to generate an image, and the display control unit 44 outputs the image to the monitor 14 to display the image. Is displayed (S15). As the image processing in the first blood vessel enhancement mode, the image processing unit 43 generates an added B2 image signal by performing an addition process of aligning and adding each B2 image signal output in different frames, for example. .. Then, the image processing unit 43 sequentially performs the color conversion process, the color enhancement process, and the structure enhancement process on the added B2 image signal and the G2 image signal, as in the normal mode. The first blood vessel emphasized image is generated using the image signal that has been subjected to various image processing as described above, and is displayed on the monitor 14. During the first blood vessel emphasizing mode, step S17 and step S15 are repeated.

  As described above, in the light source device 13 of the present invention, since the blue light LB, the green light LG, and the red light LR emitted from the semiconductor light source unit 50 are incident on the rotary filter 53, a lamp light source such as a xenon lamp and a rotary filter. The wavelength range of the illumination light is almost the same as that of the conventional light source device having the above. Therefore, the light source device 13 ensures compatibility and continuity with the diagnostics constructed based on the image obtained using the conventional light source device.

  Further, since the light source device 13 can be used by connecting the endoscope 11 having a monochrome image sensor as the image pickup device 35, it is possible to use an endoscope 11 having a monochrome image sensor corresponding to a conventional light source device. An endoscope can be connected and used. That is, the light source device 13 is compatible with the conventional endoscope.

[Second Embodiment]
In the first embodiment, the light source controller 55 maintains the blue LED light source 60, the green LED light source 61, and the red LED light source 62 at a specific light quantity ratio between the normal mode and the first blood vessel emphasizing mode. However, in the second embodiment, the light amount ratio is changed when the observation mode is switched. That is, the light amount ratios of the LED light sources 60 to 62 are changed for each of the normal filter 70 and the first blood vessel emphasizing filter 72. Note that, in the second and subsequent embodiments, description of the same members and controls as those in the first embodiment will be omitted.

  The light source control unit 55, for example, turns on the LED light source that emits light that can pass through the filter being inserted in the optical path of the semiconductor light source unit 50 among the blue LED light source 60, the green LED light source 61, and the red LED light source 62, The LED light source that emits light that does not pass through the filter that is inserted in the optical path of the semiconductor light source unit 50 is turned off.

  Specifically, as shown in FIG. 9, the light source control unit 55 controls the red LED light source 62 during the B1 filter period T1a in which the B1 filter 70a of the normal filter 70 is inserted in the optical path of the semiconductor light source unit 50. Is turned off (OFF), and the blue LED light source 60 and the green LED light source 61 are turned on (ON) at the same time. Further, the light source control unit 55 turns off the blue LED light source 60 during the R1 filter period T1c in which the R1 filter 70c is inserted in the optical path of the semiconductor light source unit 50, and the green LED light source 61 and the red LED light source 62 are simultaneously turned on. Turn on the light. Note that the light source control unit 55 turns on all the blue LED light source 60, the green LED light source 61, and the red LED light source 62 during the G1 filter period T1b in which the G1 filter 70b is inserted in the optical path of the semiconductor light source unit 50. When the R1 filter period T1c ends, the B1 filter period T1a starts again, and thereafter, the respective periods T1a to T1c are repeated until the normal mode ends.

  As shown in FIG. 10, the light source control unit 55 includes a first B2 filter 72a in which one of the two B2 filters 72a of the first blood vessel emphasizing filter 72 is inserted in the optical path of the semiconductor light source unit 50. In the period T2a, the green LED light source 61 and the red LED light source 62 are turned off, and the blue LED light source 60 is turned on. The same applies to the second B2 filter period T2b in which the other B2 filter 72a is inserted in the optical path of the semiconductor light source unit 50. Further, the light source control unit 55 turns off the blue LED light source 60 and the red LED light source 62 and turns on the green LED light source 61 during the G2 filter period T2c in which the G2 filter 72b is inserted in the optical path of the semiconductor light source unit 50. Let When the G2 filter period T2c ends, the first B2 filter period T2a starts again, and thereafter, the respective periods T2a to T2c are repeated until the normal mode ends.

  As described above, by turning off the LED light source that emits light that does not pass through the filter that is inserted in the optical path of the semiconductor light source unit 50, it is possible to suppress the generation of Joule heat. Further, in the normal mode, since at least two colors of the blue light LB, the green light LG, and the red light LR are simultaneously emitted, the color rendering property with the white light emitted from the conventional light source device is maintained. ..

  Note that the light source control unit 55 inserts the B2 filter 72a of the first blood vessel emphasizing filter 72 into the optical path of the semiconductor light source unit 50 in order to brighten the first blood vessel emphasizing image obtained in the first blood vessel emphasizing mode. Alternatively, the light amount of the blue LED light source 60 may be increased.

  Specifically, the light source control unit 55 sets the set value of the drive current applied to the blue LED light source 60 in the first blood vessel emphasis mode and the set value of the drive current applied to the blue LED light source 60 in the normal mode. Bigger than. Accordingly, as shown in FIG. 11, the light source control unit 55 causes the blue LED light source 60 to emit light in the first blood vessel emphasizing mode rather than the light intensity of the blue light LBa emitted from the blue LED light source 60 in the normal mode. The light intensity of the blue light LBb is increased.

  Further, the light source control unit 55, during the period in which the normal filter 70 or the first blood vessel emphasizing filter 72 is inserted in the optical path of the semiconductor light source unit 50, the blue LED light source 60, the green LED light source 61, and the red LED light source. The light amount ratio of each of the LED light sources 60 to 62 may be changed by sequentially lighting 62.

For example, as shown in FIG. 12, in the normal mode, in the B1 filter period T1a, the light source control unit 55 turns on the blue LED light source 60 at time T ₁ . Next, the light source control unit 55, at time _{T 2,} after time _{T 1,} and turns on the green LED light source 61 with turns off the blue LED light source 60. Then, the light source control unit 55 turns off at time _{T 3} later than time _{T 2,} the green LED light source 61. In the present embodiment, time T ₁ is the start timing of the B1 filter period T1a, and time T ₃ is the end timing of the B1 filter period T1a.

In G1 filter period T1b, the light source control unit 55 lights the blue LED light source 60 at time _{T 3.} The light source control unit 55 lights the green LED light source 61 with turns off the blue LED light source 60 at time _{T 4} after time _{T 3.} Next, the light source control unit 55 turns off the green LED light source 61 and turns on the red LED light source 62 at time T ₅ after time T ₄ . Then, the light source control unit 55 turns off the red LED light source 62 at time _{T 6} after time _{T 5.} In the present embodiment, B1 and time _{T 3} which is the end timing of the filter period T1a and the start timing of the G1 filter period T1b, has a time _{T 6} and the end timing of the G1 filter period T1b.

In R1 filter period T1c, the light source control unit 55 lights the green LED light source 61 at time _{T 6.} The light source control unit 55 lights the red LED light source 62 with turns off the green LED light source 61 at time _{T 7} after time _{T 6.} The light source control unit 55 turns off the red LED light source 62 at time _{T 8} after time _{T 7.} In the present embodiment, the G1 time _{T 6} is the end timing of the filter period T1b the start timing of the R1 filter period T1c, the time _{T 8} is the end timing of the R1 filter period T1c.

  As described above, in each of the periods T1a to T1c, it is possible to suppress the generation of Joule heat by sequentially lighting the plurality of LED light sources without lighting them simultaneously. Also in this case, at least two colors of the blue light LB, the green light LG, and the red light LR enter the filters, so that the color rendering properties with the conventional light source device are maintained.

[Third Embodiment]
In the first and second embodiments, the semiconductor light source unit 50 is provided with the three-color LED light sources of the blue LED light source 60, the green LED light source 61, and the red LED light source 62, but in the third embodiment, the semiconductor light source is used. Instead of the light source unit 50, a semiconductor light source unit 80 provided with LED light sources of four colors is used (see FIG. 13).

  As shown in FIG. 13, the semiconductor light source unit 80 is provided with a blue LED light source 60, a green LED light source 61, and a red LED light source 62, and a purple LED light source 82 that emits purple light LV. The purple LED light source 82 is a single-chip LED light source in which one purple LED 82b is mounted on one substrate 82a.

  As shown in FIG. 14, the purple light LV has a wavelength range of 395 nm to 415 nm and a center wavelength of 405 nm, for example. The purple light LV is light in a wavelength range optimum for observing the extreme surface blood vessels at a position shallower than the surface blood vessels.

  In addition, the semiconductor light source unit 80 includes a condensing optical system 84 instead of the condensing optical system 64 of the first and second embodiments. The condensing optical system 84 has a fourth collimator lens 86 and a third combining member 88 in addition to the members of the condensing optical system 64.

  The fourth collimator lens 86 collects the violet light LV emitted from the violet LED light source 82 and emits it as parallel light. The light collimated by the fourth collimator lens 86 does not have to be completely parallel light, and may be any light that can be regarded as substantially parallel light.

  The optical path of the purple light LV emitted from the fourth collimator lens 86 is orthogonal to the optical path integrated by the second combining member 69, and the third combining member 88 is arranged at this intersection. The third combining member 88 is, for example, a dichroic mirror, and the blue light LB, the green light LG, and the red light LR combined by the second combining member 69 are incident on one surface at an angle of 45 °. Then, the purple light LV is incident on the other surface at an angle of 45 °. The third combining member 88 transmits the blue light LB, the green light LG, and the red light LR and reflects the violet light LV, thereby integrating the optical path of the violet light LV with the second combining member 69. Integrate with the optical path. As a result, the purple light LV, the blue light LB, the green light LG, and the red light LR are combined by the third combining member 88, and the combined light is emitted from the semiconductor light source unit 80.

  The purple light LV, the blue light LB, the green light LG, and the red light LR emitted from the semiconductor light source unit 80 enter the rotary filter 53 via the diaphragm 51. As shown in FIG. 15, the B1 filter 70a of the normal filter 70 transmits the entire wavelength range of the purple light LV. Further, as shown in FIG. 16, the B2 filter 72a of the first blood vessel emphasis filter 72 transmits a part of the wavelength range of the purple light LV.

  The light source control unit 55 controls the LED driving unit 63 to independently turn on or off the blue LED light source 60, the green LED light source 61, the red LED light source 62, and the purple LED light source 82. For example, the light source control unit 55 turns off the LED light source that emits light that does not pass through the filter being inserted in the optical path of the semiconductor light source unit 50 as in the second embodiment.

  Specifically, as shown in FIG. 17, in the normal mode, the light source control unit 55 turns off the purple LED light source 82 in the G1 filter period T1b and the R1 filter period T1c, while it is in the blue state in the B1 filter period T1a. In addition to the LED light source 60 and the green LED light source 61, the purple LED light source 82 is turned on at the same time. As a result, in the B1 filter period T1a, the blue light LB, the green light LG, and the purple light LV are simultaneously emitted. In the third embodiment, the normal blue light that is the light transmitted through the B1 filter 70a includes the entire wavelength range of the purple light LV, the entire wavelength range of the blue light LB, and the wavelength range of the green light LG. Including a part on the short wavelength side.

  On the other hand, as shown in FIG. 18, in the first blood vessel emphasizing mode, the light source control unit 55 turns on only the purple LED light source 82 in the first B2 filter period T2a, and the blue LED light source 60 and the green LED light source. 61 and the red LED light source 62 are turned off. Further, the light source control unit 55 turns on only the blue LED light source 60 during the second B2 filter period T2b, and turns on only the green LED light source 61 during the G2 filter period T2c.

  In this way, by performing lighting control of the blue LED light source 60, the green LED light source 61, the red LED light source 62, and the purple LED light source 82, it is possible to increase the blood vessel contrast of the normal image in the normal mode. Further, in the first blood vessel emphasizing mode, a first blood vessel emphasizing image in which not only superficial blood vessels but also extreme superficial blood vessels are highlighted is obtained.

  In the first blood vessel emphasizing mode, the light source control unit 55 may sequentially turn on the blue LED light source 60 and the purple LED light source 82 during the first B2 filter period T2a and the second B2 filter period T2b. good.

For example, as shown in FIG. 19, in the first B2 filter period T2a, the light source control unit 55 turns on the purple LED light source 82 from time T ₁ to time T ₂ and turns the blue LED light source 60 from time T ₂ to time T _2. up to T ₃ to light. Then, in the second B2 filter period T2b, to light the violet LED light source 82 from the time _{T 3} to time _{T 4,} to light the blue LED light source 60 from the time _{T 4} to time _{T 5.} In this case, time T ₁ is the start timing of the first B2 filter period T2a, time T ₃ is the end timing of the first B2 filter period T2a and the start timing of the second B2 filter period T2b, and time T ₅ Is the end timing of the second B2 filter period T2b.

  Further, as shown in FIG. 20, the light source control unit 55 may simultaneously turn on the blue LED light source 60 and the purple LED light source 82 during the first B2 filter period T2a and the second B2 filter period T2b. In this case, a brighter first blood vessel emphasized image is obtained.

  Further, the light source control unit 55 sequentially supplies the blue LED light source 60, the green LED light source 61, the red LED light source 62, and the violet LED light source 82 during the period in which the normal filter 70 is inserted in the optical path of the semiconductor light source unit 50. It may be turned on.

For example, as shown in FIG. 21, in the B1 filter period T1a, the light source controller 55 turns on the purple LED light source 82 from time T ₁ to time T ₂ and turns the blue LED light source 60 from time T ₂ to time T _3. The green LED light source 61 is turned on and is turned on from time T ₃ to time T ₄ . In this case, time T ₁ is the start timing of the B1 filter period T1a, and time T ₄ is the end timing of the B1 filter period T1a.

In the G1 filter period T1b, the light source control unit 55 turns on the blue LED light source 60 from time T ₄ to time T ₅ , turns on the green LED light source 61 from time T ₅ to time T _6, and turns on the red LED light source 62 at time. The light is turned on from T ₆ to time T ₇ . Further, the R1 filter period T1c, the light source control unit 55, a green LED light source 61 from the time _{T 7} to time _{T 8} is turned to turn on the red LED light source 62 from the time _{T 8} to time _{T 9.} In this case, the time T ₄ which is the end timing of the B1 filter period T1a is set as the start timing of the G1 filter period T1b, the time T ₇ is set as the end timing of the G1 filter period T1b and the start timing of the R1 filter period T1c, and time T _{9 is set.} Is the end timing of the R1 filter period T1c.

  In the case of the semiconductor light source unit 80 capable of emitting the purple light LV in addition to the blue light LB, the green light LG, and the red light LR, the lighting control of the light source control unit 55 causes the first blood vessel to be used by using the normal filter 70. It is possible to acquire an emphasized image.

Specifically, as shown in FIG. 22, in the B1 filter period T1a, the light source control unit 55 turns on the purple LED light source 82 from time T ₁ to time T ₂ . Next, the light source control unit 55 turns on the blue LED light source 60 from time T ₂ to time T ₃ . In this case, time T ₁ is the start timing of the B1 filter period T1a, and time T ₃ is the end timing of the B1 filter period T1a. In the B1 filter period T1a, the light source control unit 55 simultaneously turns on the purple LED light source 82 and the blue LED light source 60 instead of turning on the purple LED light source 82 and the blue LED light source 60 as described above. It may be done.

  Further, the light source control unit 55 turns on only the green LED light source 61 in the G1 filter period T1b. The light source control unit 55 turns off all the LED light sources 60 to 62 and 82 in the R1 filter period T1c.

  As a result, similarly to each of the above-described embodiments, the B1 image signal and the G1 image signal are sequentially output from the image sensor 35, and thus it is possible to generate the first blood vessel emphasized image using these image signals. Therefore, in the case of the semiconductor light source unit 80, when the semiconductor light source unit 80 is used in combination with the rotary filter provided with only the normal filter 70 without providing the first blood vessel enhancement filter 72, not only the normal mode but also the first blood vessel enhancement The mode is also executable.

[Fourth Embodiment]
In each of the above embodiments, the observation mode includes the normal mode and the first blood vessel emphasizing mode, but in the fourth embodiment, instead of the first blood vessel emphasizing mode, a relatively deep position from the mucous membrane surface, for example, , Has a second blood vessel enhancement mode suitable for observing a deep blood vessel at a position deeper than the middle blood vessel. The second blood vessel emphasizing mode can be switched by the switching operation of the mode switching unit 17b, as in the above embodiments.

  As shown in FIG. 23, in the fourth embodiment, a rotary filter 90 is used instead of the rotary filter 53 of each of the above embodiments. The rotary filter 90 includes a second blood vessel emphasizing filter 92 inside. The second blood vessel emphasis filter 92 has a λ1 filter 92a, a λ2 filter 92b, and a λ3 filter 92c along the circumferential direction. A normal filter 70 similar to that in each of the above embodiments is provided outside the rotary filter 90. The λ1 filter 92a corresponds to the “narrowband second green filter” recited in the claims, and the λ2 filter 92b corresponds to the “narrowband first red filter” recited in the claims, The λ3 filter 92c corresponds to the “narrowband second red filter” recited in the claims.

  As shown in FIG. 24, the λ1 filter 92a transmits a part of the wavelength range of the green light LG. For example, the λ1 filter 92a transmits light having a wavelength range of 520 nm to 560 nm. The λ2 filter 92b transmits a part of the wavelength range of the green light LG that is on the longer wavelength side than the wavelength range that transmits the λ1 filter 92a and a part of the wavelength range of the red light LR that is on the short wavelength side. For example, the λ2 filter 92b transmits light having a wavelength range of 580 nm to 620 nm. The λ3 filter 92c transmits a part of the wavelength range of the red light LR on the longer wavelength side than the wavelength range of the λ2 filter 92b. For example, the λ3 filter 92c transmits light having a wavelength range of 610 nm to 650 nm. Hereinafter, the light transmitted through the λ1 filter 92a is referred to as "second green narrowband light", the light transmitted through the λ2 filter 92b is referred to as "first red narrowband light", and the light transmitted through the λ3 filter 92c is referred to as "second". "2 red narrow band light" and these are collectively referred to as "second blood vessel enhancing illumination light".

  The second green narrow band light is light suitable for observing the middle layer blood vessel. The first red narrowband light is light that reaches the vicinity of the deep blood vessel. The second red narrow band light is light that reaches a position slightly deeper than the deep blood vessel. By using the first red narrow band light and the third illumination light, it is possible to highlight deep blood vessels. The middle-layer blood vessels can also be displayed by the second green narrow band light.

  The rotation filter control unit 54 inserts the second blood vessel emphasizing filter 92 into the optical path of the semiconductor light source unit 50 when the second blood vessel emphasizing mode is set.

  In the second blood vessel emphasizing mode, the light source controller 55 turns on the green LED light source 61 and the red LED light source 62.

  Specifically, as shown in FIG. 25, the light source control unit 55 turns on the green LED light source 61 and turns on the blue LED light source in the λ1 filter period T3a in which the λ1 filter 92a is inserted in the optical path of the semiconductor light source unit 50. 60 and the red LED light source 62 are turned off. The light source control unit 55 turns on the green LED light source 61 and the red LED light source 62 at the same time and turns off the blue LED light source 60 during the λ2 filter period T3b in which the λ2 filter 92b is inserted in the optical path of the semiconductor light source unit 50. The light source control unit 55 turns on the red LED light source 62 and turns off the blue LED light source 60 and the green LED light source 61 during the λ3 filter period T3c in which the λ3 filter 92c is inserted in the optical path of the semiconductor light source unit 50.

  In the endoscope 11, the imaging device 35 is illuminated each time the observation site is sequentially illuminated with the second green narrowband light, the first red narrowband light, and the second red narrowband light (second blood vessel enhancing illumination light). Captures an image of the observation site. As a result, the image sensor 35 outputs the λ1 image signal, the λ2 image signal, and the λ3 image signal in different frames.

  In the processor device 12, the image processing unit 43 generates an image by performing predetermined image processing. For example, the image processing unit 43 generates a second blood vessel emphasized image having a plurality of output channels. Specifically, the image processing unit 43 allocates the λ1 image signal to the luminance channel Y, obtains the difference between the λ2 image signal and the λ3 image signal as a difference signal, and outputs the difference signal to the two color difference channels Cr and Cb. assign. When the difference signal is assigned to the color difference channels Cr and Cb, each may be multiplied by a specific coefficient. Then, the image processing unit 43 uses the ITU-R. According to the inverse transformation of 601, the RGB second blood vessel emphasized image is generated. The second blood vessel emphasized image is displayed on the monitor 14 by the display control unit 44. Deep blood vessels are highlighted in the second blood vessel emphasized image. Further, the middle-layer blood vessels are also displayed in the second blood vessel emphasized image.

  The generation and display of the second blood vessel emphasized image is not limited to the above method. For example, the image processing unit 43 corrects the λ2 image signal by multiplying the λ2 image signal by the ratio or difference between the λ2 image signal and the λ3 image signal, and allocates the corrected λ2 image signal to the G channel of the monitor 14. , Λ1 image signal may be assigned to the B channel of the monitor 14, and λ3 image signal may be assigned to the R channel of the monitor 14.

As shown in FIG. 26, the light source control unit 55 may sequentially turn on the green LED light source 61 and the red LED light source 62 during the λ2 filter period T3b. For example, the light source control unit 55 turns on the green LED light source 61 from time T ₁ to time T ₂ and turns on the red LED light source 62 from time T ₂ to time T _{3 in} the λ2 filter period T3b. In this case, time T ₁ is the start timing of the λ2 filter period T3b, and time T ₃ is the end timing of the λ2 filter period T3b.

  As described above, in the fourth embodiment, the deep blood vessels can be observed by making the green light LG and the red light LR emitted from the semiconductor light source unit 50 incident on the second blood vessel emphasis filter 92.

  In the fourth embodiment, the second blood vessel emphasizing mode is provided instead of the first blood vessel emphasizing mode of the first to third embodiments, but the normal mode, the first blood vessel emphasizing mode, and the second blood vessel It may have an emphasis mode. In this case, for example, a rotation filter provided with a second blood vessel emphasizing filter 92, a first blood vessel emphasizing filter 72, and a normal filter 70 in order from the inside is used, and each observation mode is switchable.

[Fifth Embodiment]
In each of the above embodiments, a plurality of single-chip LED light sources are used, but in the fifth embodiment, a multi-chip LED light source having a plurality of LEDs mounted on one substrate is used.

  As shown in FIG. 27, the semiconductor light source unit 100 of the fifth embodiment has a multi-chip LED light source 102 and a collimator lens 104 in addition to the LED driving unit 63.

  As shown in FIG. 28, in the multi-chip LED light source 102, a blue LED 60b, a green LED 61b, a red LED 62b, and a purple LED 82b are mounted on one substrate 102a. The substrate 102a has, for example, a rectangular shape and holds the LEDs 60b, 61b, 62b, and 82b. On the substrate 102a, the blue LEDs 60b, the green LEDs 61b, the red LEDs 62b, and the purple LEDs 82b are arranged in a square, the blue LEDs 60b and the green LEDs 61b are arranged in one diagonal, and the red LEDs 62b and purple are arranged in the other diagonal. The LEDs 82b are arranged respectively. The green LED 61b, the red LED 62b, and the purple LED 82b are independently controlled by the light source control unit 55 via the LED driving unit 63.

  The collimator lens 104 collects the blue light LB, the green light LG, the red light LR, and the violet light LV emitted from the blue LED 60b, the green LED 61b, the red LED 62b, and the violet LED 82b, and emits them as parallel light. The light collimated by the collimator lens 104 does not have to be completely parallel light, and may be any light that can be regarded as substantially parallel light. As a result, the blue light LB, the green light LG, the red light LR, and the purple light LV are emitted from the semiconductor light source unit 100.

  As described above, in the fifth embodiment, light of multiple colors can be emitted from the semiconductor light source unit 100 without using a multiplexing member such as a dichroic mirror. Therefore, the semiconductor light source unit 100 can be made compact.

  In addition, in the fifth embodiment, four LEDs of the blue LED 60b, the green LED 61b, the red LED 62b, and the purple LED 82b are used as the LEDs mounted on the multi-chip LED light source 102, but the LEDs are not limited thereto. For example, two different multi-chip LED light sources may be configured by mounting two different LEDs among the four LEDs. In this case, the optical paths of the multi-chip LED light sources are combined by the combining member.

  Also, the LED mounted by the multi-chip LED light source may be the excitation blue LED (blue LED 60b or purple LED 82b). In this case, a phosphor that emits green and red fluorescence by being excited by the exciting blue light emitted from the exciting blue LED is used. As a result, broadband light in which the excitation blue light, the green fluorescence, and the red fluorescence are combined is emitted from the multi-chip LED light source.

  In addition to this, for example, a multi-chip LED light source in which a blue LED for excitation is mounted, a phosphor that excites and emits green fluorescence by blue light for excitation, and a red LED that emits red light are provided. The red light may be combined with the light combined with the green fluorescence by using a combining member. The red LED in this case preferably emits narrow band red light.

  In each of the above embodiments, the light source control unit 55 is in the normal mode, that is, in the optical path of the semiconductor light source unit 50, any one of the B1 filter 70a, the G1 filter 70b, and the R1 filter 70c of the normal filter 70 is used. When at least two colors are inserted, at least two colors of light are emitted, but instead of this, only one color of light may be emitted. For example, the light source controller 55 turns on only the blue LED light source 60 during the B1 filter period T1a, turns on only the green LED light source 61 during the G1 filter period T1b, and turns on only the red LED light source 62 during the R1 filter period T1c. Such lighting control is effective when an endoscope having a color image sensor is connected to the light source device 13 for use. That is, in the case of a color image sensor, so-called color mixing occurs when light of a plurality of colors is received, but the occurrence of color mixing is suppressed by performing lighting control for sequentially emitting light of one color as described above. A high-quality image with good color reproducibility can be displayed on the monitor.

  In each of the above-described embodiments, the light emitted from the objective optical system 34 is directly incident on the image pickup surface of the image pickup device 35 at the distal end portion 19 of the endoscope 11, but the present invention is not limited to this. The light emitted from may be incident on the image pickup surface of the image pickup device 35 by reflection. An example of the configuration will be described below.

  As shown in FIG. 29, at the tip portion 19, in addition to the objective optical system 34 and the image pickup device 35, a lens barrel 110 having the objective optical system 34, a signal cable 112 electrically connected to the image pickup device 35, A prism 114, a cover glass 116, and a holding frame 118 are provided. Note that the light guide 32, the illumination optical system 33, and the like are omitted in FIG.

  The lens barrel 110, the prism 114, the cover glass 116, and the image sensor 35 are integrally held by a holding frame 118. The signal cable 112 is soldered to the image pickup device 35, and transmits a signal between the image pickup device 35, the CDS / AGC circuit 37, and the image pickup drive unit 36. In addition, the signal cable 112 electrically connects the endoscope 11 and the processor device 12.

  The prism 114 is arranged on the base end side of the lens barrel 110, and is fixed to the image pickup device 35 with an optical adhesive via the cover glass 116. The entrance surface of the prism 114 faces the exit surface of the objective optical system 34, and the exit surface of the prism 114 faces the imaging surface of the image sensor 35. The prism 114 has, for example, an entrance surface and an exit surface orthogonal to each other, and has a reflecting surface facing each surface. Therefore, the light emitted from the objective optical system 34 enters the prism 114, is then reflected by the reflecting surface inside the prism 114, and enters the imaging element 35. The prism 114, the cover glass 116, and the image sensor 35 may not be in close contact with each other, and for example, a space may be provided by a spacer or the like.

  In each of the above embodiments, the semiconductor light source unit emits at least the blue light LB, the green light LG, and the red light LR, but two colors of the blue light LB, the green light LG, and the red light LR are used. It is sufficient to emit light of a plurality of colors including at least the above light. Even in this case, the light source control unit 55 enables the lights of the respective colors to be independently emitted. Of course, in addition to the above two colors of light, light of a plurality of colors such as violet light LV may be emitted. Further, the LED light source provided in the semiconductor light source unit is not limited to the blue, green, red, and purple LEDs. For example, an orange LED emitting a narrow band orange light having a wavelength range of 580 nm to 620 nm and a center wavelength of 600 nm may be used.

  In each of the above-described embodiments, the light source control unit 55 adjusts the set value of the drive current in order to control the light amount of each LED light source, but instead of or in addition to this, the application time of the drive current is adjusted. May be adjusted. Since the light emission period of each LED light source is controlled by adjusting the application time of the drive current, the light amount of each LED light source can be adjusted.

  The light source control unit 55 may control the light emission of each LED light source independently or may control the light emission depending on a certain light source. For example, the light source control unit 55 may turn on the respective LED light sources at the same time, and cause the LED light sources to emit light at a prescribed maximum light amount while maintaining a specific light amount ratio. The light amount control in this case is performed by the diaphragm 51. An ND (Neutral Density) filter may be provided in place of the diaphragm 51, and the light amount may be controlled by adjusting the light reduction amount.

  Further, in each of the above-described embodiments, the dichroic mirror is used as the multiplexing member for multiplexing the lights of the respective colors emitted by the LED light sources, but a half mirror may be used instead. When the half mirror is used, a part of the wavelength range is not cut off unlike the dichroic mirror, so that the light in the wavelength range with high continuity can be emitted from the semiconductor light source unit.

10 Endoscope System 11 Endoscope 12 Processor Device 13 Light Source Device 14 Monitor 15 Operation Input Section 16 Insertion Section 17 Operation Section 17a Angle Knob 17b Mode Switching Section 18 Universal Code 19 Tip Section 20 Bending Section 21 Flexible Tube Section 29 Connector 29a Communication connector 29b Light source connector 32 Light guide 32a Incident end 33 Illumination optical system 34 Objective optical system 35 Imaging device 36 Imaging drive unit 37 CDS / AGC circuit 38 A / D conversion circuit 40 Controller 41 DSP
42 frame memory 43 image processing unit 44 display control unit 50 semiconductor light source unit 51 diaphragm 52 diaphragm control unit 53 rotation filter 54 rotation filter control unit 55 light source control unit 56 condensing lens 60 blue LED source 61 green LED light source 62 red LED light source 63 LED drive unit 64 Condensing optical system 60a Substrate 60b Blue LED
61a Substrate 61b Green LED
62a Substrate 62b Red LED
65 1st collimator lens 66 2nd collimator lens 67 3rd collimator lens 68 1st multiplexing member 69 2nd multiplexing member 70 Normal filter 70a B1 filter 70b G1 filter 70c R1 filter 72 1st blood vessel emphasis filter 72a B2 filter 72b G2 filter 80 Semiconductor light source unit 82 Purple LED light source 82a Substrate 82b Purple LED
84 Condensing Optical System 86 Fourth Collimator Lens 88 Third Multiplexing Member 90 Rotation Filter 92 Second Blood Vessel Enhancement Filter 92a λ1 Filter 92b λ2 Filter 92c λ3 Filter 100 Semiconductor Light Source 102 Multi-Chip LED Light Source 102a Substrate 104 Collimator Lens 110 lens barrel 112 signal cable 114 prism 116 cover glass 118 holding frame LB blue light LG green light LR red light LV purple light

Claims (7)

A blue light source that emits blue light, a green light source that emits green light, and a red light source that emits red light, and a semiconductor light source unit that emits light of a plurality of colors,
A light source control unit that controls the semiconductor light source unit to emit light of the plurality of colors;
A filter that includes a normal filter and a first blood vessel emphasizing filter, and sequentially inserts the multiple normal filter or the first blood vessel emphasizing filter into the optical path of the semiconductor light source unit to sequentially emit light having different wavelength ranges. Department,
A mode switching unit for switching between the normal mode and the first blood vessel emphasizing mode,
In the normal mode, by sequentially inserting the B1 filter, G1 filter, and R1 filter of the normal filter into the optical path of the semiconductor light source unit, normal blue light, normal green light, and normal red light are obtained. Emits light sequentially,
In the case of the first blood vessel emphasizing mode, the B2 filter and the G2 filter of the first blood vessel emphasizing filter are sequentially inserted in the optical path of the semiconductor light source unit, whereby blue narrow band light and first green narrow band light are obtained. And a rotary filter control unit for sequentially ejecting,
The light source control unit is an endoscope light source device that changes the light amount ratio of the light of the plurality of colors for each mode by the switching operation by the mode switching unit.   The light source control unit increases the light intensity of the blue light emitted from the blue light source in the first blood vessel enhancement mode to be higher than the light intensity of the blue light emitted from the blue light source in the normal mode. Item 2. The light source device for an endoscope according to Item 1. The light source control unit,
When the B1 filter is inserted in the optical path, the blue light and the green light are simultaneously emitted,
When the G1 filter is inserted in the optical path, the blue light, the green light, and the red light are simultaneously emitted.
The light source device for an endoscope according to claim 1, wherein the green light and the red light are simultaneously emitted when the R1 filter is inserted in the optical path. The light source control unit,
Emits the blue light when the B2 filter is inserted in the optical path,
The light source device for an endoscope according to claim 1, wherein the green light is emitted when the G2 filter is inserted in the optical path. The light source control unit,
When the B1 filter is inserted in the optical path, the blue light and the green light are sequentially emitted.
When the G1 filter is inserted in the optical path, the blue light, the green light, and the red light are sequentially emitted.
The light source device for an endoscope according to claim 1, wherein the green light and the red light are sequentially emitted when the R1 filter is inserted in the optical path.   The light source device for an endoscope according to any one of claims 1 to 5, wherein the filter portion has a disc shape and is a rotary filter provided with the plurality of filters along a circumferential direction. A blue light source that emits blue light, a green light source that emits green light, and a red light source that emits red light, and a semiconductor light source unit that emits light of a plurality of colors,
A light source control unit that controls the semiconductor light source unit to emit light of the plurality of colors;
A filter unit having a normal filter and a first blood vessel emphasizing filter, in which the normal filter or the first blood vessel emphasizing filter is sequentially inserted in the optical path of the semiconductor light source unit to sequentially emit light having different wavelength ranges. When,
A mode switching unit for switching between the normal mode and the first blood vessel emphasizing mode,
In the normal mode, by sequentially inserting the B1 filter, G1 filter, and R1 filter of the normal filter into the optical path of the semiconductor light source unit, normal blue light, normal green light, and normal red light are obtained. Emits light sequentially,
In the case of the first blood vessel emphasizing mode, the B2 filter and the G2 filter of the first blood vessel emphasizing filter are sequentially inserted in the optical path of the semiconductor light source unit, whereby blue narrow band light and first green narrow band light are obtained. A rotary filter control unit for sequentially ejecting,
An endoscope having a monochrome image sensor that captures an image each time an observation region is illuminated with light sequentially emitted from the filter unit,
And a processor device that generates an image based on a plurality of image signals output each time the monochrome image sensor performs the imaging,
The endoscope system in which the light source control unit changes the light amount ratio of the light of the plurality of colors for each mode by the switching operation by the mode switching unit.

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