WO2020217852A1

WO2020217852A1 - Endoscope light source device and endoscope system

Info

Publication number: WO2020217852A1
Application number: PCT/JP2020/014067
Authority: WO
Inventors: 美範森本
Original assignee: 富士フイルム株式会社
Priority date: 2019-04-22
Filing date: 2020-03-27
Publication date: 2020-10-29
Also published as: JPWO2020217852A1; JP7163487B2

Abstract

Provided are an endoscope light source device and an endoscope system capable of stabilizing an illumination light amount. A light source device (13) merges illumination light from a plurality of light sources (30) by first to third DMs (51)-(53) and supplies the illumination light to a light guide (35). A first glass plate (55a) is arranged between a first LED (30a) and the first DM (51) and reflects a part of the light entering a surface to be irradiated to a first light-receiving unit (56a). The reflected light enters the first light-receiving unit (56a) through a first slit (57a). The light emission of the first LED (30a) is controlled on the basis of the incident light amount. A first attenuation filter (58a) is provided to the surface to be irradiated of the first glass plate (55a).

Description

Light source device for endoscopes and endoscope system

The present invention relates to an endoscope light source device that supplies illumination light to an endoscope light guide, and an endoscope system.

In the medical field, endoscopic diagnosis using an endoscopic system is widespread. The endoscope system includes an endoscope, a light source device for an endoscope for supplying illumination light to the endoscope, and a processor device for processing an image signal output by the endoscope. The endoscope includes, for example, a light guide made of an optical fiber, and the illumination light from the light source device for the endoscope is supplied to the light guide and irradiates the observation site (subject) via the light guide.

Conventionally, a lamp light source such as a xenon lamp or a halogen lamp that emits white light has been used as an illumination light source for an endoscope light source device, but recently, instead of a lamp light source, light of a specific color is emitted. Semiconductor light sources such as a laser diode (LD: LaserDiode) and a light emitting diode (LED: LightEmittingDiode) are being used. However, since the semiconductor light source used in the light source device for an endoscope has a high output and a large amount of self-heating, a temperature change or the like occurs in the semiconductor light source and the amount of emitted light fluctuates. Therefore, in Patent Document 1 below, a part of the illumination light is branched and irradiated to the light receiving portion, and the light emission amount of the light source is controlled (adjusted) by using the light amount of the illumination light received by the light receiving portion.

JP-A-2017-0999944

However, in the device of Patent Document 1 above, there is a limit to the stabilization of the amount of light due to the influence of the return light from the light guide. Here, the return light from the light guide is light that is supplied (irradiated) from the light source to the light guide, but is reflected by the surface of the light guide and returned to the light source, and further reflected by the surface of the light source toward the light receiving portion. Is shown. The return light from the light guide fluctuates due to individual differences in the endoscope and / or assembly errors when the endoscope and the light source device for the endoscope are connected. Therefore, the amount of light is affected by this fluctuation. Becomes unstable.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a light source device for an endoscope capable of supplying a stable amount of illumination light, and an endoscope system.

In order to achieve the above object, the light source device for an endoscope of the present invention merges the optical paths of the illumination light in the light source device for an endoscope that supplies illumination light from a plurality of light sources to the light guide of the endoscope. It has an irradiated surface that is arranged between the merging member to be combined and a specific light source and the merging member among a plurality of light sources and is irradiated with the illumination light from the specific light source, and the illumination light transmitted through the irradiated surface is merged. An optical member that emits light toward the member, a light receiving unit that receives the illumination light reflected on the irradiated surface, and a light source control unit that controls the amount of light emitted from a specific light source using the amount of illumination light received by the light receiving unit. It is provided with an attenuation filter provided on the optical member and attenuates the amount of transmitted illumination light.

A reflective attenuation filter that is arranged between the merging member and the light guide, attenuates the amount of transmitted illumination light, and reflects a certain percentage of the illumination light may be provided.

A plurality of specific light sources may be provided, and an optical member, a light receiving unit, and an attenuation filter may be provided for each specific light source.

The attenuation ratio of the illumination light may be different for each attenuation filter.

Further, the endoscope light source device of the present invention is an endoscope light source device that supplies illumination light from a plurality of light sources to the light guide of the endoscope, and includes a plurality of confluent members that merge the optical paths of the illumination light. It has an illuminated surface that is arranged between the specific light source and the merging member in the light source of the above and is irradiated with the illumination light from the specific light source, and emits the illumination light transmitted through the illuminated surface toward the merging member. An optical member, a light receiving unit that receives the illumination light reflected by the illuminated surface, a light source control unit that controls the amount of light emitted from a specific light source by using the amount of illumination light received by the light receiving unit, a merging member, and a light guide. It is provided with a reflective attenuation filter, which is arranged between the two, attenuates the amount of transmitted illumination light, and reflects a certain percentage of the illumination light.

It may be provided in the optical member and provided with an attenuation filter that attenuates the amount of transmitted illumination light.

It may be provided with a partial reflection filter provided on a part of the irradiated surface, which reflects a part of the incident illumination light toward the light receiving portion and transmits the rest.

An antireflection filter may be provided on the irradiated surface.

Further, the endoscope system of the present invention includes the above-mentioned light source device for an endoscope and an endoscope having a light guide for guiding light.

According to the present invention, it is possible to reduce the influence of the return light from the light guide and supply a stable amount of illumination light.

It is an external view of an endoscope system. It is a front view of the tip part of an endoscope. It is a block diagram which shows the electrical structure of an endoscope system. It is a graph which shows the intensity spectrum of red light, green light, blue light, and purple light. It is a graph which shows the intensity spectrum of white light. It is a figure which shows the structure of the optical path integration part. It is a graph which shows the spectral reflection characteristic of the 1st dichroic mirror. It is a graph which shows the spectral reflection characteristic of the 2nd dichroic mirror. It is a graph which shows the spectral reflection characteristic of the 3rd dichroic mirror. It is a figure which shows the structure of the optical path integration part. It is a top view which observed the irradiated surface from the light source side.

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

The endoscope system 10 can execute a normal observation mode for observing the observation site and a blood vessel emphasis observation mode for emphasizing and observing the blood vessels existing inside the mucous membrane of the observation site. The blood vessel-enhanced observation mode is a mode for visualizing a blood vessel pattern as blood vessel information and making a diagnosis such as distinguishing between good and bad tumors. In this blood vessel-enhanced observation mode, the observation site is irradiated with illumination light containing a large amount of light components in a specific wavelength band having high absorbance for 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-enhanced observation mode, a blood vessel-enhanced observation image suitable for observing a blood vessel pattern is generated as a display image.

The endoscope 11 includes, for example, an insertion unit 16 that is inserted into a living body such as in the digestive tract, an operation unit 17 provided at the base end portion of the insertion unit 16, and an endoscope 11 as a processor device 12 and a light source device. It is provided with a universal cord 18 for connecting to 13. The insertion portion 16 is composed of a tip portion 19, a curved portion 20, and a flexible tube portion 21, and is connected in this order from the tip side.

In FIG. 2, on the tip surface of the tip portion 19, an illumination window 22 for irradiating the observation portion with illumination light, an observation window 23 for capturing an image of the observation portion, and air supply / water supply for cleaning the observation window 23 are provided. An air supply / water supply nozzle 24 to be performed, and a forceps outlet 25 for projecting a treatment tool such as a forceps or an electric knife to perform various treatments are provided. An image sensor 36 and an objective optical system 45 (see FIG. 3) are built in the back of the observation window 23.

Returning to FIG. 1, the curved portion 20 is composed of a plurality of connected curved pieces, and bends in the vertical and horizontal directions in response to the operation of the angle knob 26 of the operating portion 17. By bending the curved 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 winding tube such as the esophagus or the intestine. The insertion unit 16 includes a communication cable for communicating a drive signal for driving the image sensor 36 and an image signal output by the image sensor 36, and a light guide 35 for guiding the illumination light supplied from the light source device 13 to the illumination window 22. (See FIG. 3) is inserted.

In addition to the angle knob 26, the operation unit 17 includes a forceps port 27 for inserting a treatment tool, an air supply / water supply button 28 operated when air supply / water supply is performed from the air supply / water supply nozzle 24, and a still image. A freeze button (not shown) for taking a picture of the image is provided.

A communication cable and a light guide 35 extending from the insertion portion 16 are inserted into the universal cord 18, and a connector 29 is attached to one end on the processor device 12 and the light source device 13 side. The connector 29 is a composite type connector including 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 provided on the communication connector 29a. The light source connector 29b is provided with an incident end 35a (see FIG. 3) of the light guide 35.

In FIG. 3, the light source device 13 is provided with a light source 30, an optical path integration unit 31, and a light source control unit 33. The light source 30 includes a first LED 30a that emits red light LR, a second LED 30b that emits green light LG, a third LED 30c that emits blue light LB, and a fourth LED 30d that emits purple light LV. In the following description, one of the first to fourth LEDs 30a to 30d, or a plurality of combinations of the first to fourth LEDs 30a to 30d may be simply referred to as a light source 30. The optical path integration unit 31 integrates (merges) the optical paths of the respective lights emitted from the first to fourth LEDs 30a to 30d. The light source control unit 33 controls the light emission of the first to fourth LEDs 30a to 30d.

As shown in FIG. 4, the red light LR has, for example, a wavelength band of 615 nm to 635 nm and a center wavelength of 620 ± 10 nm. The green light LG has, for example, a wavelength band of 500 nm to 600 nm and a center wavelength of 520 ± 10 nm. The blue light LB has, for example, a wavelength band of 440 nm to 470 nm and a center wavelength of 455 ± 10 nm. The purple light LV has, for example, a wavelength band of 395 nm to 415 nm and a central wavelength of 405 ± 10 nm.

In the normal observation mode, the light source control unit 33 turns on the first to third LEDs 30a to 30c, and turns off the fourth LED 30d. On the other hand, in the blood vessel emphasis observation mode, the light source control unit 33 turns on all the first to fourth LEDs 30a to 30d.

Further, in the normal observation mode, the optical path integration unit 31 combines the red light LR, the green light LG, and the blue light LB to generate a wide band white light LW as shown in FIG. On the other hand, in the blood vessel-enhanced observation mode, mixed light is generated by mixing white light LW with purple light LV having high absorbance for hemoglobin in blood. When the light source control unit 33 is in the blood vessel emphasis observation mode, the light source control unit 33 reduces the ratio of the amount of light of the blue light LB so that the purple light LV is more dominant than the blue light LB.

The light emitting part of the optical path integrating part 31 is arranged in the vicinity of the receptacle connector 34 to which the light source connector 29b is connected. The optical path integrating unit 31 emits the light incident from the light source 30 to the incident end 35a of the light guide 35 of the endoscope 11.

The endoscope 11 includes a light guide 35, an image sensor 36, an analog processing circuit (AFE: Analog Front End) 37, and an image control unit 38. The light guide 35 is, for example, a fiber bundle in which a plurality of optical fibers are bundled. When the light source connector 29b is connected to the light source device 13, the incident end 35a of the light guide 35 arranged in the light source connector 29b faces the exit end of the optical path integrating portion 31. The exit end of the light guide 35 located at the tip portion 19 is branched into two at the front stage of the illumination window 22 so that light is guided to each of the two illumination windows 22.

An irradiation lens 39 is arranged behind the illumination window 22. The illumination light supplied from the light source device 13 is guided to the irradiation lens 39 by the light guide 35 and is emitted from the illumination window 22 toward the observation portion. The irradiation lens 39 is a concave lens, and irradiates a wide range of the observation portion with the illumination light emitted from the light guide 35.

The objective optical system 45 and the image sensor 36 are arranged behind the observation window 23. The image of the observation portion is incident on the objective optical system 45 through the observation window 23, and is imaged on the image pickup surface 36a of the image pickup element 36 by the objective optical system 45.

The image sensor 36 is a CCD image sensor, a CMOS image sensor, or the like, and a plurality of photoelectric conversion elements (photodiodes) constituting the pixels are arranged in a matrix on the image pickup surface 36a. Further, the image pickup element 36 is a color image pickup element, and microcolor filters of three colors B, G, and R are arranged on the image pickup surface 36a on the incident side of the photoelectric conversion element for each pixel. The arrangement of this microcolor filter is, for example, the Bayer arrangement.

The image sensor 36 photoelectrically converts the light received on the image pickup surface 36a and accumulates a signal charge according to the amount of light received for each pixel. The signal charge is converted into a voltage signal and read out from the image sensor 36. The voltage signal read from the image sensor 36 is input to the AFE 37 as an image signal.

The image sensor 36 performs a storage operation of accumulating signal charges in pixels and a reading operation of reading out the accumulated signal charges within the acquisition period of one frame. The light source device 13 generates illumination light in accordance with the timing of the accumulation operation of the image sensor 36, and causes the illumination light to be incident on the light guide 35.

The AFE37 is composed of 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 a correlated double sampling process on the image signal input from the image sensor 36 to remove noise. The AGC circuit amplifies the image signal from which noise has been removed by the CDS circuit. The A / D converter converts the image signal amplified by the AGC circuit into a digital signal having a predetermined number of bits and inputs it to the processor device 12.

The image pickup control unit 38 is connected to the controller 40 in the processor device 12, and inputs a drive signal to the image pickup element 36 in synchronization with the reference clock signal input from the controller 40. The image sensor 36 inputs an image signal to the AFE 37 at a predetermined frame rate based on the drive signal from the image pickup control unit 38. This image signal is a signal in which the pixel values of the R, G, and B pixels are mixed (hereinafter referred to as RGB signals).

The processor device 12 includes a DSP (Digital Signal Processor) 41, an image processing unit 42, a frame memory 43, and a display control circuit 44, in addition to the controller 40. The controller 40 has a CPU, a ROM for storing a control program and setting data necessary for control, a RAM for loading the program and functioning as a work memory, and the like. When the CPU executes the control program, the processor device 12 Control each part.

The DSP 41 performs signal processing such as pixel interpolation processing, gamma correction, and white balance correction on a frame unit for the image signal (RGB signal) input from the AFE 37. In the pixel interpolation processing, the image signal is separated into R, G, and B image signals, and the pixel interpolation processing is performed on the image signals of each color. The DSP 41 stores an image signal that has undergone signal processing for each frame as image data in the frame memory 43.

Further, the DSP 41 has a brightness calculation unit that calculates the brightness (average brightness value) of the observation portion based on the image signal input from the AFE 37, and inputs the calculated average brightness value to the controller 40. The controller 40 generates a dimming signal which is the difference between the average brightness value input from the brightness calculation unit and the reference brightness (target value of dimming), and controls the light source of the light source device 13 with this dimming signal. Input to unit 33.

The light source control unit 33 adjusts the amount of illumination light (the amount of light emitted from the light sources 30 (first to fourth LEDs 30a to 30d)) based on the dimming signal. Specifically, when the brightness of the observation portion is insufficient (underexposure), the amount of illumination light is increased, and when the observation portion is too bright (overexposure), the amount of illumination light is decreased.

The image processing unit 42 performs predetermined image processing on the image data stored in the frame memory 43. 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-enhanced observation mode, a blood vessel-enhanced observation image is generated based on the image data, but in order to emphasize the surface blood vessel, for example, a region of the surface blood vessel in the image is extracted based on the B signal in the image data. Then, contour enhancement processing or the like is performed on the extracted surface blood vessel region. Then, the B signal subjected to the contour enhancement processing is combined with the full-color image generated based on the RGB signal. The same treatment may be performed on the mesopelagic blood vessels in addition to the superficial blood vessels. When emphasizing the mesopelagic blood vessels, the region of the mesopelagic blood vessels is extracted from the G signal containing a large amount of information on the mesopelagic vessels, and the extracted mesopelagic blood vessel region is subjected to contour enhancement processing.

The display control circuit 44 reads the image processed image data from the frame memory 43, converts it into a video signal such as a composite signal or a component signal, and outputs it to the monitor 14.

In the blood vessel enhancement observation mode, the blood vessel enhancement observation image is generated only by the BG 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 R channel of the monitor 14. Is also good.

In FIG. 6, the optical path integrating unit 31 includes the first to fourth collimator lenses (CL) 50a to 50d, the first to third dichroic mirrors (DM) 51 to 53 (merging members), and the condenser lens 54. It is configured. The first to fourth CL50a to 50d are provided corresponding to the first to fourth LEDs 30a to 30d, respectively, and collimate each light emitted from the first to fourth LEDs 30a to 30d. The first to third DMs 51 to 53 are configured by forming a dichroic filter having a predetermined transmission characteristic on a transparent glass plate, transmit light in a specific wavelength range, and reflect light in a specific wavelength range. The condensing lens 54 collects the light emitted from the optical path integrating unit 31 at the incident end 35a of the light guide 35.

The optical axis of the second LED 30b is arranged at a position where the optical axis of the second LED 30b coincides with the optical axis of the light guide 35. The first LED 30a is arranged so that its optical axis is orthogonal to the optical axis of the second LED 30b. The first DM51 is arranged at a position where the optical axes of the first LED 30a and the second LED 30b are orthogonal to each other so as to form an angle of 45 ° with each optical axis. Similarly, the third LED 30c and the fourth LED 30d are arranged so that their optical axes are orthogonal to each other. The second DM52 is arranged at a position where the optical axes of the third LED 30c and the fourth LED 30d are orthogonal to each other so as to form an angle of 45 ° with each optical axis.

The optical axis of the third LED30c is orthogonal to the optical axis of the second LED30b. The third DM53 is arranged at a position where the optical axes of the third LED 30c and the second LED 30b are orthogonal to each other so as to form an angle of 45 ° with each optical axis. The condensing lens 54 is arranged at a position where its optical axis coincides with the optical axis of the second LED 30b and faces the incident end 35a of the light guide 35.

As shown in FIG. 7, the first DM51 has a spectral reflection characteristic that reflects light in a wavelength band equal to or higher than the first threshold value λ1 (about 610 nm) and transmits light in a wavelength band lower than the first threshold value λ1. .. Most of the red light LR emitted from the first LED 30a has a wavelength band of the first threshold value λ1 or more. Most of the green light LG emitted from the second LED 30b is in the wavelength band below the first threshold value λ1. Therefore, the first DM51 reflects the red light LR and transmits the green light LG. As a result, the red light LR reflected by the first DM51 and the green light LG transmitted through the first DM51 are combined. As described above, the first DM51 functions as a merging member for merging the optical paths of the illumination light (in the present embodiment, the red light LR and the green light LG).

As shown in FIG. 8, the second DM52 has a spectral reflection characteristic that reflects light in a wavelength band lower than the second threshold value λ2 (about 430 nm) and transmits light in a wavelength band equal to or higher than the second threshold value λ2. .. Most of the blue light LB emitted from the third LED 30c has a wavelength band of the second threshold value λ2 or more. Most of the purple light LV emitted from the fourth LED 30d is in the wavelength band below the second threshold value λ2. Therefore, the second DM52 reflects the purple light LV and transmits the blue light LB. As a result, the purple light LV reflected by the second DM52 and the blue light LB transmitted through the second DM52 are combined. In this way, the second DM52 functions as a merging member that merges the optical paths of the illumination light (in this embodiment, the violet light LV and the blue light LB).

As shown in FIG. 9, the third DM53 has a spectral reflection characteristic that reflects light in a wavelength band lower than the third threshold value λ3 (about 490 nm) and transmits light in a wavelength band equal to or higher than the second threshold value λ2. .. Most of the combined wave of the red light LR and the green light LG (hereinafter referred to as the first combined wave) by the first DM51 is in the wavelength band of the third threshold value λ3 or more. Most of the combined wave of the purple light LV and the blue light LB by the second DM52 (hereinafter referred to as the second combined wave) is a wavelength band less than the third threshold value λ3. Therefore, the third DM53 reflects the second combined wave and transmits the first combined wave. As a result, the second combined wave reflected by the third DM53 and the first combined wave transmitted through the third DM53 are combined and incident on the condenser lens 54. In this way, the third DM53 functions as a merging member that merges the optical paths of the illumination light (in the present embodiment, the first merging wave and the second merging wave). In the present embodiment, all of the first to third DM51 to 53 function as the merging member of the present invention, but only one or two of the first to third DM51 to 53 function as the merging member of the present invention. It may be configured to be used.

As a result, in the blood vessel emphasis observation mode, the red light LR, the green light LG, the blue light LB, and the purple light LV emitted from the first to fourth LEDs 30a to 30d are all combined and incident on the condenser lens 54. Since the fourth LED 30d is not lit in the normal observation mode, the red light LR, the green light LG, and the blue light LB, excluding the purple light LV, are combined and incident on the condenser lens 54.

Further, as shown in FIG. 6, the first to fourth glass plates 55a to 55d (optical members) are arranged in the optical path integrating portion 31. Further, as shown in FIGS. 3 and 6, the light source device 13 is provided with the first to fourth light receiving units 56a to 56d.

The first glass plate 55a is arranged between the first CL50a and the first DM51, and reflects a part of the light incident on the irradiated surface to which the illumination light is irradiated toward the first light receiving portion 56a, and the rest is the first. It functions as an optical member that emits light toward 1DM51 (merging member). The light reflected by the first glass plate 55a is incident on the first light receiving portion 56a through the first slit 57a. The first light receiving unit 56a is a sensor that outputs a current (light receiving current) according to the light receiving amount, and the light receiving current is input to the light source control unit 33 (see FIG. 3) as light emission information indicating the light emitting amount of the first LED 30a. Will be done. In FIG. 3, the light source control unit 33 controls the light emission of the first LED 30a based on the input light emission information.

Further, the second glass plate 55b is arranged between the second CL50b and the first DM51, and a part of the light incident on the irradiated surface to be irradiated with the illumination light is reflected toward the second light receiving portion 56b, and the rest. Functions as an optical member that emits light toward the first DM51 (merging member). The light reflected by the second glass plate 55b is incident on the second light receiving portion 56b through the second slit 57b. The second light receiving unit 56b is a sensor that outputs a current (light receiving current) according to the light receiving amount, and the light receiving current is input to the light source control unit 33 (see FIG. 3) as light emission information indicating the light emitting amount of the second LED 30b. Will be done. In FIG. 3, the light source control unit 33 controls the light emission of the second LED 30b based on the input light emission information.

Similarly, the third glass plate 55c is arranged between the third CL50c and the second DM52, and a part of the light incident on the irradiated surface to be irradiated with the illumination light is reflected toward the third light receiving portion 56c. It functions as an optical member that emits the rest toward the second DM52 (merging member). The light reflected by the third glass plate 55c is incident on the third light receiving portion 56c through the third slit 57c. The third light receiving unit 56c is a sensor that outputs a current (light receiving current) according to the light receiving amount, and the light receiving current is input to the light source control unit 33 (see FIG. 3) as light emission information indicating the light emitting amount of the third LED 30c. Will be done. In FIG. 3, the light source control unit 33 controls the light emission of the third LED 30c based on the input light emission information.

Further, the fourth glass plate 55d is arranged between the fourth CL50d and the second DM52, and a part of the light incident on the irradiated surface irradiated with the illumination light is reflected toward the fourth light receiving portion 56d, and the rest. Functions as an optical member that emits light toward the second DM52 (merging member). The light reflected by the fourth glass plate 55d is incident on the fourth light receiving portion 56d through the fourth slit 57d. The fourth light receiving unit 56d is a sensor that outputs a current (light receiving current) according to the light receiving amount, and the light receiving current is input to the light source control unit 33 (see FIG. 3) as light emission information indicating the light emitting amount of the fourth LED 30d. Will be done. In FIG. 3, the light source control unit 33 controls the light emission of the fourth LED 30d based on the input light emission information. In the present embodiment, all of the first to fourth glass plates 55a to 55d function as the optical members of the present invention, but only one or two of the first to fourth glass plates 55a to 55d are present. It may be configured to function as the optical member of the present invention.

In this way, the light emission amount of the light source 30 is measured and fed back, and the light emission control of the light source 30 is performed based on this, that is, so-called automatic power control (APC: Auto Power Control) is performed to stabilize the illumination light. Supply becomes possible. However, as described above, some of the fed-back light (light incident on the first to fourth light receiving units 56a to 56d) is return light from the light guide 35 (supplied (irradiated) from the light source 30 to the light guide). However, it is reflected by the incident end 35a (surface) of the light guide 35 and returned to the light source 30, and is further reflected by the surface of the light source 30 (first to fourth LEDs 30a to 30d) to be reflected by the first to fourth light receiving portions 56a to. Light heading towards 56d) is included. Then, there is a problem that the amount of illumination light becomes unstable due to this return light.

Therefore, as shown in FIG. 6, in the present embodiment, the first to fourth glass plates 55a to 55d are provided with the first to fourth attenuation filters 58a to 58d for reducing the amount of transmitted illumination light. .. Specifically, the first attenuation filter 58a is provided on the irradiated surface of the first glass plate 55a, the second attenuation filter 58b is provided on the irradiated surface of the second glass plate 55b, and the irradiated surface of the third glass plate 55c is provided. A third attenuation filter 58c is provided in the above, and a fourth attenuation filter 58d is provided on the irradiated surface of the fourth glass plate 55d.

By providing the first to fourth attenuation filters 58a to 58d in this way, the return light can be reduced and the amount of illumination light can be stabilized. That is, the return light is first to fourth attenuated twice, going (when going from the light source 30 to the light guide) and returning (when being reflected by the surface of the light guide 35 and returning to the light source 30). It passes through any of the filters 58a to 58d. Therefore, when the first to fourth attenuation filters 58a to 58d attenuate the transmitted light amount to 70% with respect to the incident light amount of 100%, the first to fourth attenuation filters 58a to 58d exist. The return light can be reduced to 49% as compared to the state of no return light of 100%. In the present embodiment, the first to fourth attenuation filters 58a to 58d are configured by applying an ND (Neutral Density) coating to the irradiated surfaces of the glass plates (first to fourth glass plates 55a to 55d). ing.

In the first embodiment, the four light receiving portions (first to fourth light receiving portions 56a to 56d) and the glass plate (first to fourth glass plates) correspond to the four light sources (first to fourth LEDs 30a to 30d). Although the example of providing 55a to 55d), that is, the example in which all four light sources are specific light sources, the present invention is not limited thereto. Of the light sources, those to be a specific light source can be set as appropriate. Specifically, some light sources do not require or have little need for the above-mentioned feedback-based emission control (APC). For such a light source, the glass plate and the light receiving portion may be abolished so that APC is not performed.

Further, in the first embodiment described above, an example in which attenuation filters (first to fourth attenuation filters 58a to 58d) are provided on all the glass plates (first to fourth glass plates 55a to 55d) has been described. The invention is not limited to this. Depending on the type, configuration, and / or light emission mode of the light source, the influence of the return light may be small or negligible. The attenuation filter may be abolished for the glass plate corresponding to such a light source. Of course, the configuration of the attenuation filter (the rate at which the amount of transmitted light is attenuated) may be different for each light source depending on the magnitude of the influence of the return light.

Further, in the first embodiment, an example in which an attenuation filter is provided on the irradiated surface (light source (first to fourth LEDs 30a to 30d) side) of the glass plates (first to fourth glass plates 55a to 55d) has been described. However, an attenuation filter may be provided on the surface of the glass plate opposite to the irradiated surface (light guide 35 side).

[Second Embodiment]
As shown in FIG. 10, in the second embodiment, in addition to the attenuation filters (first to fourth attenuation filters 58a to 58d) described in the first embodiment, a reflection type attenuation filter 60 is provided. The reflection type attenuation filter 60 has a property of attenuating the amount of transmitted illumination light and reflecting a certain ratio of illumination light, and is arranged between the third DM53 (merging member) and the light guide 35. .. With such a configuration, the illumination light that becomes the return light passes through the reflective attenuation filter 60 twice, that is, the light that goes toward the light guide 35 and the return light that is reflected by the light guide 35. Can be reduced. A certain percentage of the illumination light from the light source 30 is reflected by the reflective attenuation filter 60 and heads toward the light source 30, but the illumination light (hereinafter referred to as the filter reflected light) is referred to by the endoscope 11. Unlike the return light, which is fluctuating light that varies depending on individual differences and / or the assembly accuracy of the light source device 13 and the endoscope 11, the individual differences of the endoscope 11 and / or the light source device 13 and the inside. It is a fixed light whose amount of light can be calculated in advance regardless of the assembly accuracy with the microscope 11. Therefore, the light source control unit 33 can control the light emission of the light source 30 in consideration of the filtered light in advance. By performing such light emission control, the amount of illumination light does not become unstable.

In the second embodiment, since the return light can be reduced by the reflective attenuation filter 60, a part or all of the first to fourth attenuation filters 58a to 58d may be abolished. Further, as shown in FIG. 11, a partial reflection filter 65 may be provided instead of the attenuation filter (any or all of the first to fourth attenuation filters 58a to 58d). In FIG. 11, the partial reflection filter 65 is provided on a part of the irradiated surface of the first to fourth glass plates 55a to 55d (in the example of FIG. 11, about 5% to 10% of the total area of the irradiated surface). It reflects some of the incident illumination light (eg, 4%) and transmits the rest (eg, 96%). Further, in the example of FIG. 11, an antireflection filter 67 formed by, for example, applying an AR (Anti Reflection) coating is provided on the entire irradiated surface, and is superposed on the antireflection filter 67 (antireflection filter 67). A partial reflection filter 65 is provided (on the light source 30 side).

Further, in the above embodiment, the fourth LED30d that emits purple light LV is provided as a semiconductor light source for acquiring blood vessel information for acquiring blood vessel information of living tissue, but instead of the fourth LED30d or in addition to the fourth LED30d. , Other semiconductor light sources for acquiring blood vessel information may be provided. For example, in order to acquire the oxygen saturation of hemoglobin in blood as blood vessel information, a semiconductor light source that emits blue light in a narrow band with a central wavelength of 473 ± 10 nm may be provided. Of course, when the blood vessel information is not observed, only the blue, green, and red semiconductor light sources may be used without providing the semiconductor light source for acquiring the blood vessel information.

Further, in the above embodiment, the LED is used as the light source, but a semiconductor light source such as LD (Laser Diode) may be used instead of the LED.

Further, in the above embodiment, in the blood vessel emphasis observation mode, the observation site is irradiated with mixed light of white light LW and purple light LV, but purple light and green light, or blue light and green light are applied to the observation site. Irradiation may be performed to obtain a blood vessel-enhanced observation image.

Further, in the above embodiment, the observation sites are simultaneously irradiated with light of a plurality of colors, but these may be sequentially irradiated to image the light of each color individually. In this case, it is preferable to use a monochrome image sensor as the image sensor 36.

Further, in the above 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. Further, the present invention is an endoscope system using a fiber scope that guides the reflected light of an observation portion of illumination light with an image guide, and an ultrasonic endoscope having an imaging element and an ultrasonic transducer built in at the tip. , And the light source device for endoscopes used for it.

10 Endoscope system 11 Endoscope 12 Processor device 13 Light source device (Light source device for endoscope)
14 Monitor 15 Operation input unit 16 Insertion unit 17 Operation unit 18 Universal cord 19 Tip part 20 Curved part 21 Flexible tube part 22 Lighting window 23 Observation window 24 Air supply / water supply nozzle 25 Forceps outlet 26 Angle knob 27 Forceps port 28 Air supply・ Water supply button 29 connector 29a Communication connector 29b Light source connector 30 Light source 30a to 30d 1st to 4th LEDs
31 Optical path integration unit 33 Light source control unit 34 Receptacle connector 35 Light guide 35a Incident end 36 Image sensor 37 AFE
38 Imaging control unit 39 Illumination lens 40 Controller 41 DSP
42 Image processing unit 43 Frame memory 44 Display control circuit 45 Objective optical system 50a to 50d 1st to 4th collimator lenses 51 to 53 1st to 3rd dichroic mirrors (merging members)
54 Condensing lens 55a to 55d 1st to 4th glass plates (optical members)
56a to 56d 1st to 4th light receiving parts 57a to 57d 1st to 4th slits 58a to 58d 1st to 4th attenuation filter 60 Reflection type attenuation filter 65 Partial reflection filter 67 Antireflection filter LR Red light LG Green light LB Blue Light LV Purple light λ1 First threshold λ2 Second threshold λ3 Third threshold

Claims

In an endoscope light source device that supplies illumination light from a plurality of light sources to the light guide of the endoscope.
With the merging member that merges the optical paths of the illumination light,
It has an irradiated surface that is arranged between the specific light source in the plurality of light sources and the merging member and is irradiated with the illumination light from the specific light source, and the illumination light transmitted through the irradiated surface is merged. An optical member that emits light toward the member,
A light receiving unit that receives the illumination light reflected by the irradiated surface and
A light source control unit that controls the amount of light emitted from the specific light source by using the amount of illumination light received by the light receiving unit.
A light source device for an endoscope provided on the optical member and provided with an attenuation filter for attenuating the amount of transmitted illumination light.
The endoscope according to claim 1, further comprising a reflective attenuation filter that is arranged between the merging member and the light guide, attenuates the amount of transmitted illumination light, and reflects a certain proportion of the illumination light. Light source device.
A plurality of the specific light sources are provided,
The light source device for an endoscope according to claim 1 or 2, wherein the optical member, the light receiving portion, and the attenuation filter are provided for each specific light source.
The light source device for an endoscope according to claim 3, wherein the attenuation ratio of the illumination light is different for each attenuation filter.
In an endoscope light source device that supplies illumination light from a plurality of light sources to the light guide of the endoscope.
With the merging member that merges the optical paths of the illumination light,
It has an irradiated surface that is arranged between the specific light source in the plurality of light sources and the merging member and is irradiated with the illumination light from the specific light source, and the illumination light transmitted through the irradiated surface is merged. An optical member that emits light toward the member,
A light receiving unit that receives the illumination light reflected by the irradiated surface and
A light source control unit that controls the amount of light emitted from the specific light source by using the amount of illumination light received by the light receiving unit.
A light source device for an endoscope, which is arranged between the merging member and the light guide, and includes a reflective attenuation filter that attenuates the amount of transmitted illumination light and reflects a certain proportion of the illumination light.
The light source device for an endoscope according to claim 5, which is provided on the optical member and includes an attenuation filter for attenuating the amount of transmitted illumination light.
A plurality of the specific light sources are provided,
The light source device for an endoscope according to claim 6, wherein the optical member, the light receiving portion, and the attenuation filter are provided for each specific light source.
The light source device for an endoscope according to claim 7, wherein the attenuation ratio of the illumination light is different for each attenuation filter.
The invention according to any one of claims 1 to 8, further comprising a partial reflection filter provided on a part of the irradiated surface, which reflects a part of the incident illumination light toward the light receiving portion and transmits the rest. Light source device for endoscopes.
The light source device for an endoscope according to any one of claims 1 to 9, wherein an antireflection filter is provided on the irradiated surface.
The light source device for an endoscope according to any one of claims 1 to 10.
An endoscope system including an endoscope having a light guide that guides light.