JP2006034330A - Light source device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow two kinds of light emitted from different light sources to pass a same optical path and be incident on an illumination optical system. <P>SOLUTION: This light source device is provided with a first light source 31 emitting a while light L1, a second light source 32 emitting an excitation light L2, and a polarizing beam splitter 40. The white light L1 emitted from the first light source 31 and the excitation light L2 emitted from the second light source are incident on the polarizing beam splitter 40 with mutual optical paths intersected with each other. The polarizing beam splitter 40 splits the while light L1 into a p-polarized transmitted light and a s-polarized reflected light. Alternatively, the polarizing beam splitter 40 splits the excitation light L2 into the p-polarized transmitted light where the optical path conforms with the reflected light of the white light and the s-polarized reflected light where the optical path conforms with the transmitted light of the white light. The white light and excitation light emitted from the polarizing beam splitter to conform the optical paths are incident on the light guides 15 and 16. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light source device for causing light emitted from two light sources to enter an illumination optical system, for example, an endoscope light source device.

  2. Description of the Related Art Conventionally, there has been known an autofluorescence observation endoscope system that detects an abnormality occurring in a living body by using in-vivo autofluorescence. In this system, when excitation light is irradiated onto a tissue in a living body, autofluorescence is excited in the tissue in the living body, and an abnormality in the tissue in the living body is found due to the difference in the autofluorescence.

  In this endoscope system, when trying to observe the autofluorescence and the normal reflected light image in the living body at the same time, or when performing arithmetic processing using two images of the autofluorescent image and the normal reflected light image, Excitation light and normal light (visible light) are irradiated. Therefore, the light source device of this system includes a white light source that emits white light and an excitation light source that emits excitation light to excite autofluorescence, and the white light emitted by these two light sources is the same as the excitation light. The light is repeatedly irradiated into the living body through the light guide.

Therefore, conventionally, as described in Patent Document 1 and Patent Document 2, it is known that light is incident on the same light guide by matching the optical paths of light emitted from two light sources. In these patent documents, a dichroic mirror or a prism is disposed at a position where the optical path of white light and the optical path of excitation light intersect, and the excitation light is reflected by this dichroic mirror or the like and white light is transmitted. The optical paths of the two lights are matched.
JP 2003-61909 A JP 2002-65602 A

  Since the dichroic mirrors and the like described in Patent Documents 1 and 2 reflect and transmit light according to the wavelength, for example, transmit light having a specific wavelength or more (white light) and reflect light having a specific wavelength or less. Thus, the optical paths of the two lights are matched.

  However, for example, when the excitation light is light including visible light, if all of the excitation light is reflected by the dichroic mirror, visible light in the vicinity of the excitation light included in white light is reflected by the dichroic mirror. Since the subject cannot be irradiated, the color reproducibility of the observation image when white light is irradiated deteriorates.

  Therefore, the present invention has been made in view of such problems, and an object thereof is to provide a light source device that can appropriately irradiate an observation image with light emitted from two light sources.

  A first light source device according to the present invention includes a first light source that emits one first light of excitation light and visible light that excites autofluorescence, and excitation light and visible light that excite autofluorescence. The second light source that emits the other second light and the optical path of the first and second light are provided at a position where the first and second light are incident so that the first and second light are incident. Are separated into a first transmitted light and a first reflected light having the same spectral distribution and emitted, and the second light is a second reflected light whose optical path matches the first transmitted light. A beam splitter that emits light having a spectral distribution equally separated from the second transmitted light whose optical path coincides with the first reflected light, and an illumination optical system that receives the light emitted from the beam splitter. Features.

  The illumination optical system includes a first condenser lens group on which the first transmitted light and the second reflected light are incident, and a first condenser on which the second transmitted light and the first reflected light are incident. It is preferable to have a second condenser lens group having an optical axis different from that of the lens group. In this case, each of the first and second condenser lens groups may be composed of a single lens or may be composed of two or more lenses.

  Further, the first transmitted light and the second reflected light, and the first reflected light and the second transmitted light may be incident on the same condenser lens group having the same optical axis. In this case, each condensing lens group may be constituted by a single lens or may be constituted by two or more lenses.

  Preferably, the beam splitter is either a polarizing beam splitter or a half mirror, and the first and second lights are a rotating wheel or a light source disposed between the first or second light source and the beam splitter. Are alternately incident on the beam splitter by a method such as current control.

  In the case where the beam splitter is a polarization beam splitter, among the first light, the light polarized in one direction is transmitted and emitted as the first transmitted light, and the light polarized in the direction perpendicular to the one direction is reflected and reflected. In addition to being emitted as one reflected light, among the second light, light polarized in one direction is transmitted and emitted as second transmitted light, and light polarized in the vertical direction is reflected and emitted as second reflected light. Let At this time, the first light is preferably uniform polarized light. Also, the second light is preferably uniform polarized light. Uniformly polarized light refers to light characterized in that the polarization components in the parallel direction and the perpendicular direction are substantially uniform with respect to the incident surface of the splitting surface of the polarization beam splitter, for example, p / s polarized light. Say. Accordingly, in this specification, light such as natural light, random polarization, circular polarization, and elliptical light (however, light having an appropriate axis) is included in light of uniform polarization. Here, the incident surface of the dividing surface means a plane formed by the light beam and the normal of the dividing surface.

  The second light source device according to the present invention can emit the first incident light by separating the first incident light into the first reflected light and the first transmitted light having the same spectral distribution, and intersects the first incident light. The second incident light incident on the light beam is separated into the second reflected light having the same optical path as that of the first transmitted light and the second transmitted light having the same optical path as that of the first reflected light. A beam splitter that can emit light, a first light source that makes one of excitation light and visible light that excites autofluorescence enter the beam splitter as first incident light, and autofluorescence. A second light source that causes the other second light of the excitation light and visible light to be excited to enter the beam splitter as second incident light, and illumination optics that is disposed on the optical path of the first transmitted light The beam splitter includes at least one of the first lights. By transmitting light, it causes emitted as a first transmitted light, and reflects at least a portion of the light of the second light, and wherein the emit as a second reflected light.

  The third light source device according to the present invention includes a first light source that emits one first light of excitation light and visible light that excites autofluorescence, and excitation light and visible light that excite autofluorescence. The second light source that emits the other second light and the optical path of the first and second light are arranged so that the first and second light are incident, and the first light source is incident on the first light source. The light that is polarized in one direction is transmitted and emitted as transmitted light, and the light that is polarized in the direction perpendicular to this one direction is reflected in the second light, so that the transmitted light matches the optical path. A polarization beam splitter that emits the reflected light, and an illumination optical system that receives the reflected light and transmitted light.

  In the third light source device, the first light is preferably light polarized in one direction, and the second light is preferably light polarized in the vertical direction. Further, the first and second lights are preferably incident on the beam splitter alternately.

  According to the present invention, visible light and excitation light emitted from different light sources can be incident on the illumination optical system through the same optical path without impairing a specific wavelength range.

  A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram schematically illustrating an endoscope system according to the first embodiment. The endoscope system in this embodiment includes an electronic endoscope 10, a processor (light source device) 20, and a TV monitor 22. The electronic endoscope 10 includes an insertion portion 11 for insertion into a body cavity, an operation portion 12 for a user to hold and operate the electronic endoscope 10, and a connection portion 13 for connection to the processor 20. And have.

  The electronic endoscope 10 is provided with first and second light guides 15 and 16 made of an optical fiber bundle so as to be along each other. The first and second light guides 15 and 16 are inserted from the connection portion 13 through the operation portion 12 to the distal end portion 11a of the insertion portion 11, respectively. The connecting portion 13 is connected to the processor 20, whereby the end portions of the first and second light guides 15 and 16 are disposed in the processor 20. First and second light sources 31 and 32 (see FIG. 2) are provided in the processor 20, and light emitted from the first and second light sources 31 and 32 is connected to the light guides 15 and 16 at their ends. Incident from the part. The incident light is emitted from the other ends of the light guides 15 and 16 to the observation object in the body cavity, for example, via the first and second light distribution lenses 17 and 18, respectively.

  The illumination light incident on the light guides 15 and 16 is white light (visible light) and excitation light, and the white light and the excitation light are alternately irradiated on the observation target for each field. Here, when the observation object is irradiated with white light, the observation object reflects white light, and the reflected light is incident on an imaging element (not shown). In the image sensor, an image corresponding to the incident reflected light is formed, and an image signal corresponding to the image is input to the processor 20. The image signal is subjected to predetermined image processing in the processor 20 and then output to the TV monitor 22 as a normal observation image.

  On the other hand, when the observation object is irradiated with excitation light, auto-fluorescence is excited in the observation object, and the auto-fluorescence enters the image sensor. In the image sensor, an image corresponding to the incident autofluorescence is formed, and an image signal corresponding to the image is input to the processor 20. The image signal is subjected to predetermined image processing in the processor 20 and then output to the TV monitor 22 as an autofluorescence observation image.

  FIG. 2 is a configuration diagram schematically showing the inside of the processor 20 of the present embodiment. The processor 20 includes a first light source 31 having a lamp 34 and a reflector 35, a laser light source 39, an optical fiber 36 connected to the light source, and a second light source 32 having a plano-convex lens 37. The first light source 31 emits parallel light (white light) L <b> 1 by reflecting the white light emitted from the lamp 34 by the reflector 35. The second light source 32 emits parallel light (excitation light) L <b> 2 by refracting the excitation light (diffused light) emitted from the optical fiber 36 by the plano-convex lens 37. The white light L1 is emitted from the left side to the right side in FIG. 2, and the excitation light L2 is emitted from the upper side to the lower side in FIG. 2, whereby the optical paths of the white light L1 and the excitation light L2 are orthogonal.

  A polarizing beam splitter 40 is provided at a position where the optical paths of the white light L1 and the excitation light L2 intersect. The polarization beam splitter 40 is a beam splitter in which the inclined surfaces of the first and second right-angle prisms 41 and 42 are bonded together. That is, the polarization beam splitter 40 is formed in a cube as shown in FIG. 2, and the left surface R1 and the lower surface R2 in the drawing are two surfaces sandwiching the side facing the inclined surface of the first right-angle prism 41, and the upper surface in the drawing. R3 and the right surface R4 are two surfaces sandwiching a side facing the slope of the second right-angle prism 42.

  The slope of the first and second right-angle prisms 41 and 42 to which the first and second right-angle prisms 41 and 42 are bonded is coated with a multilayer film 43. The multilayer film 43 reflects s-polarized light and transmits p-polarized light. Therefore, the polarization beam splitter 40 reflects the s-polarized light of the incident light in the direction orthogonal to the incident light and emits it as reflected light, and transmits the p-polarized light of the incident light to transmit the transmitted light. To be emitted.

  The white light L1 is uniformly polarized light (p / s polarized light), and is incident on the polarization beam splitter 40 from the left surface R1. Here, the p-polarized light of the white light L1 passes through the multilayer film 43 and is emitted from the right surface R4 as transmitted light, and the s-polarized light of the white light L1 is reflected by the multilayer film 43 and is reflected as reflected light. The light is emitted from the lower surface R2. That is, the white light L1 is separated from the p-polarized transmitted light and the s-polarized reflected light by about ½ each and is emitted from the right surface R4 and the lower surface R2, respectively.

  The excitation light L2 is uniformly polarized light (p / s polarized light), and is incident on the polarization beam splitter 40 from the upper surface R3. Therefore, the p-polarized light of the excitation light L2 is transmitted through the multilayer film 43 and emitted from the lower surface R2 as transmitted light, and the s-polarized light of the excitation light L2 is reflected by the multilayer film 43 and is reflected as reflected light. The light is emitted from the right surface R4. That is, the excitation light L2 is separated from the p-polarized transmitted light and the s-polarized reflected light by about ½ each and is emitted from the lower surface R2 and the right surface R4.

  Here, since the white light L1 and the excitation light L2 incident on the polarization beam splitter 40 are incident perpendicularly to the left surface R1 and the upper surface R2, respectively, the light emitted from the lower surface R2 and the right surface R4 is lower surface R2. And perpendicular to the right surface R4. Therefore, the optical paths of the reflected light (s-polarized light) of the excitation light L2 emitted from the right surface R4 and the transmitted light (p-polarized light) of the white light L1 coincide. Similarly, the optical paths of the reflected light (s-polarized light) of the white light L1 emitted from the lower surface R2 and the transmitted light (p-polarized light) of the excitation light L2 also coincide.

  A first condenser lens 51 is provided on the optical path of the transmitted light of the white light L1, and the transmitted light (p-polarized light) of the white light L1 and the reflected light (s-polarized light) of the excitation light L2 are supplied to the condenser lens 51. Incident. On the optical path of the transmitted light (p-polarized light) of the excitation light L2, a reflection mirror 45 is provided on which the transmitted light is incident at an angle of 45 °. The reflection mirror 45 totally reflects the transmitted light (p-polarized light) of the excitation L2 and the reflected light (s-polarized light) of the white light L1 so as to travel in the same direction as the transmitted light of the white light L1. The totally reflected light is incident on a second condensing lens 52 that is positioned on the optical path and arranged in parallel with the first condensing lens 51. The light incident on the first and second condenser lenses 51 and 52 is condensed by the lenses 51 and 52 and is incident on the first and second light guides 15 and 16, respectively.

  Accordingly, when white light is emitted from the first light source 31, the white light is divided by the polarization beam splitter 40, and the divided p-polarized white light and s-polarized white light are respectively the first and second light. The light guides 15 and 16 are incident. Since the amount of light of p-polarized white light and s-polarized white light is substantially the same, each of the first light guide 15 and the second light guide 16 emits substantially the same amount of white light toward the living body. Exit. Similarly, when the excitation light is emitted from the second light source 32, the first light guide 15 and the second light guide 16 emit substantially the same amount of excitation light toward the living body.

  Here, the white light and the excitation light enter the first and second light guides 15 and 16 through the same optical path. Therefore, the light distribution characteristics of the white light emitted from the first and second light guides 15 and 16 are the same as the light distribution characteristics of the excitation light. Thereby, in this embodiment, a normal observation image and an autofluorescence observation image are obtained with light having the same light distribution characteristic, and the comparison of these images becomes accurate. Moreover, since the polarization beam splitter 40 can separate light without wavelength dependency, the color reproducibility of the observation image does not deteriorate.

  In the present embodiment, a rotating wheel (not shown) is provided between the first and second light sources 31 and 32 and the polarizing beam splitter 40, and excitation light and white light are controlled by controlling the rotating wheel. Are alternately incident on the polarization beam splitter 40. However, at least one of the white light and the excitation light may be incident on the polarization beam splitter 40 by controlling the current of the light source instead of controlling the rotating wheel.

  Also, instead of providing a rotating wheel, a polarizing plate is provided on the optical path of the excitation light and white light emitted from the beam splitter, and white light and excitation light are incident on the condenser lenses 51 and 52 alternately by controlling this polarizing plate. You may let them.

  A second embodiment of the present invention will be described with reference to FIG. Also in this embodiment, as in the first embodiment, the white light and the excitation light are divided by the polarization beam splitter 40, and both the white light transmitted light and the excitation light reflected light are emitted from the right surface R4. These optical paths coincide. Further, both the reflected light of the white light and the transmitted light of the excitation light are emitted from the lower surface R2, and their optical paths also coincide. Further, similarly to the first embodiment, the reflected light of the white light and the transmitted light of the excitation light are reflected by the reflection mirror 45, and these optical paths are parallel to the optical path of the transmitted light of the white light L1.

  In the present embodiment, these light beams whose optical paths are parallel are all incident on the same condenser lens 65. That is, in the first embodiment, the optical paths of the transmitted light of the white light and the transmitted light of the excitation light pass through the first and second condenser lenses, respectively, but in the present embodiment, the white light L1 The optical path of the transmitted light and the optical path of the transmitted light of the excitation light L2 all pass through one condenser lens 65. Thus, in the present embodiment, the transmitted light and reflected light of the white light L1 and the transmitted light and reflected light of the excitation light L2 are all incident on the same condenser lens 65 and then applied to the same light guide 66. Incident.

  The optical path of the transmitted light of the white light L1 and the optical path of the transmitted light of the excitation light L2 do not pass through the center of the condenser lens 65, and the centers of these optical paths sandwich the center of the condenser lens 65. , Located at the same distance from the center of the condenser lens 65.

  As described above, also in the present embodiment, the divided white light and the excitation light are incident on the condenser lens 65 through the same optical path. Therefore, the light distribution characteristic of the white light emitted from the light guide 66 is It becomes the same as the light distribution characteristic of the excitation light. Moreover, since the center of each optical path of white light transmitted light and reflected light is located at the same distance from the center of the condenser lens 65, the white light is irradiated into the living body with a good light distribution balance. Furthermore, the transmitted light and reflected light of the excitation light are similarly irradiated into the living body with a good light distribution balance.

  A third embodiment according to the present invention will be described with reference to FIG. In the first and second embodiments, the transmitted light and the reflected light of the white light and the excitation light are incident on the light guide. In the present embodiment, the transmitted light of the white light and the reflection of the excitation light are reflected. Only light is incident on the light guide. Hereinafter, the third embodiment will be described in detail.

  In the third embodiment, the first light source 31 includes a lamp 34 and a reflector 35, and emits unpolarized parallel light (white light) L1 as in the first embodiment. On the other hand, the second light source 32 includes a semiconductor laser 72 and a plano-convex lens 73. Since the semiconductor laser 72 emits s-polarized excitation light, the second light source 32 emits s-polarized parallel light (excitation light). ) L2 is emitted.

  The white light L1 emitted from the first light source 31 is divided into about ½ each of p-polarized transmitted light and s-polarized reflected light, and emitted from the right surface R4 and the lower surface R2, respectively. On the other hand, since the excitation light L2 emitted from the second light source 32 is s-polarized light, it is reflected by the polarization beam splitter 40 and emitted from the right surface R4. The reflected light of the excitation light L2 emitted from the right surface R4 has an optical path that matches the optical path of the transmitted light of the white light L2 emitted from the right surface R4.

  A condenser lens 81 is disposed on the optical path of the white light transmitted light. Therefore, the reflected light of the excitation light L2 and the transmitted light of the white light L2 emitted from the polarization beam splitter 40 are incident on the condensing lens 81 and collected by the condensing lens 81, and then the end of the light guide 85. Is incident on.

  As described above, also in the present embodiment, since the white light and the excitation light pass through the same optical path and enter the light guide 85, the light distribution characteristics of the white light and the excitation light emitted from the light guide 85 are as follows. Are the same. Thereby, in this embodiment, a normal observation image and an autofluorescence observation image are obtained with light having the same light distribution characteristic, and the comparison of these images becomes accurate.

  In the third embodiment, of the white light emitted from the first light source 31, s-polarized light is reflected by the polarization beam splitter 40 and emitted from the lower surface R2 as reflected light. In the embodiment, it is not used as illumination light.

  In the third embodiment, the polarized light emitted from the second light source 32 is polarized excitation light, but it may be non-polarized light. However, in order to effectively use the excitation light, polarized light is preferable.

  Further, the excitation light emitted from the second light source 32 may be p-polarized light. In this case, the excitation light is transmitted by the second beam splitter 40, and the optical path of the transmitted light matches the optical path of the reflected light of the white light. Therefore, in this case, light can be made incident on the light guide by providing a condensing lens on the optical path. Furthermore, in the third embodiment, the white light emitted from the first light source 31 may be polarized. When the excitation light is s-polarized light, the white light is p-polarized light, and the excitation light When is p-polarized light, the white light becomes s-polarized light.

  In the first and second embodiments according to the present invention, the polarization beam splitter 41 may be another beam splitter as long as the spectral distribution is equal and separates light, and may be a half mirror, for example. In this case, the half mirror is disposed at a position where the multilayer film 43 is disposed.

  Further, in the first to third embodiments according to the present invention, the polarization beam splitter 40 may be any as long as it can separate light into two lights that are polarized in a perpendicular direction, and reflects p-polarized light. Alternatively, a beam splitter that transmits s-polarized light may be used.

It is the schematic diagram which showed the electronic endoscope system. It is the block diagram which showed typically the illuminating device of 1st Embodiment. It is the block diagram which showed typically the illuminating device of 2nd Embodiment. It is the block diagram which showed typically the illuminating device of 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Electronic endoscope 15 1st light guide 16 2nd light guide 20 Light source device (processor)
31 First light source 32 Second light source 40 Polarizing beam splitter 51 First condensing lens 52 Second condensing lens 65, 81 Condensing lens 66, 85 Light guide L1 White light (visible light)
L2 excitation light

Claims (13)

A first light source that emits one first light of excitation light and visible light that excites autofluorescence;
A second light source that emits the other second light of the excitation light and visible light that excites autofluorescence;
The first and second light beams are provided at positions where the optical paths of the first and second light beams intersect so that the first and second light beams are incident on the first light beam. The first reflected light is separated and emitted, and the second light is divided into the second reflected light whose optical path matches the first transmitted light, and the first reflected light matches the optical path. A beam splitter that diverges the second transmitted light equally and emits the same, and
An illumination optical system into which light emitted from the beam splitter is incident.   In the illumination optical system, the first condenser lens group into which the first transmitted light and the second reflected light are incident, and the second transmitted light and the first reflected light are incident. The light source device according to claim 1, further comprising: a second condenser lens group having an optical axis different from that of the first condenser lens group.   The first transmitted light and the second reflected light, and the first reflected light and the second transmitted light are incident on the same condenser lens group having the same optical axis. Item 2. The light source device according to Item 1.   4. The light source device according to claim 1, wherein the first light and the second light are alternately incident on the beam splitter. 5.   5. The light source device according to claim 1, wherein the beam splitter is one of a polarization beam splitter and a half mirror.   The beam splitter is a polarization beam splitter, and transmits light that is polarized in one direction out of the first light, is emitted as the first transmitted light, and is polarized in a direction perpendicular to the one direction. Of the second light, the light polarized in the one direction is transmitted and emitted as the second transmitted light, and the light polarized in the vertical direction is reflected. The light source device according to claim 5, wherein the light source device is reflected and emitted as the second reflected light.   The light source device according to claim 1, wherein the first light is uniform polarized light.   The light source device according to claim 1, wherein the second light is uniform polarized light. The second incident light that can be emitted by separating the first incident light into the first reflected light and the first transmitted light having the same spectral distribution, and is incident so as to intersect the first incident light. A beam splitter capable of emitting the second reflected light having the same optical path as that of the first transmitted light and the second transmitted light having the same optical path as that of the first reflected light. When,
A first light source that makes one of the excitation light and the visible light that excite autofluorescence enter the beam splitter as the first incident light;
A second light source that causes the other second light of the excitation light and the visible light to excite autofluorescence to enter the beam splitter as the second incident light;
An illumination optical system disposed on the optical path of the first transmitted light,
The beam splitter transmits at least part of the first light and emits the first transmitted light, reflects at least part of the second light, and A light source device that emits light as reflected light 2. A first light source that emits one first light of excitation light and visible light that excites autofluorescence;
A second light source that emits the other second light of the excitation light and visible light that excites autofluorescence;
The first and second light beams are arranged at positions where the optical paths of the first and second light beams intersect so that the first and second light beams are incident, and transmit light polarized in one direction among the first light beams. A polarizing beam splitter that emits light as transmitted light, reflects light polarized in a direction perpendicular to the one direction out of the second light, and emits light as reflected light whose optical path coincides with the transmitted light;
An illumination optical system to which the reflected light and transmitted light are incident.   The light source device according to claim 10, wherein the first light is light polarized in the one direction.   12. The light source device according to claim 10, wherein the second light is light polarized in a direction perpendicular to the one direction. The light source device according to claim 10, wherein the first light and the second light are alternately incident on the beam splitter.

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