JP2012231835A - Light source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device having a changeable range of irradiation with excitation light in an observed part and obtaining fluorescent images according to the regions of interest of various sizes.SOLUTION: The light source device includes a parallel light source portion 70 for emitting parallel light entering a light incident end surface 60 of a predetermined light guide member LG, and an irradiation range changing portion (e.g., dichroic mirror 56 and moving mechanism 57 thereof) for changing the range of irradiation with parallel light emitted from a light-emitting end surface of a light guide member 30g by changing the incident angle of an optical axis of the parallel light emitted from the parallel light source portion 70 relative to the optical axis of the light guide member LG.

Description

  The present invention relates to a light source device that makes parallel light incident on a light incident end face of a predetermined light guide member.

  Conventionally, endoscope systems for observing tissue in a body cavity are widely known, and a normal image is obtained by imaging a portion to be observed in a body cavity by irradiation with white light, and this normal image is displayed on a monitor screen. Electronic endoscope systems have been widely put into practical use.

  And as one of such endoscope systems, for example, to observe blood vessels running under fat and blood flow, lymphatic vessels, lymph flow, bile duct running, bile flow, etc. that do not normally appear on the image, An endoscope system has been proposed in which ICG (Indocyanine Green) is previously introduced into an observation part and an ICG fluorescence image is acquired by irradiating the observation part with excitation light of near infrared light. In addition, an endoscope system has been proposed in which autofluorescence emitted from an observed portion is detected by irradiating the observed portion with excitation light to acquire a fluorescent image.

  For example, in Patent Document 1, as described above, an endoscope system that irradiates an observed part with excitation light to capture a fluorescent image and irradiates the observed part with white light to capture a normal image. Has been proposed.

  Here, in the endoscope system in Patent Document 1, when a diagnostic image is generated by superimposing a fluorescent image and a normal image, excitation to the observed portion is performed so that these images correspond to each other. It has been proposed to match the light irradiation range with the white light irradiation range.

  More specifically, in Patent Document 1, the excitation light emitted from the lamp is reflected by a reflector to generate parallel light having a relatively wide beam width, and only the excitation light composed of this parallel light is incident. By changing the focal length of the zoom lens, the condensing angle of the excitation light to the light incident end face of the light guide that guides the excitation light is changed, thereby matching the irradiation range of the excitation light with the irradiation range of white light It has been proposed to let

JP 2002-65602 A

However, when the condensing angle of the excitation light is changed by changing the focal length of the zoom lens as in the endoscope system described in Patent Document 1, the excitation light having a relatively wide beam width is changed. Although it is possible to change the condensing angle with a significant difference, the condensing angle of excitation light emitted from a laser diode or light emitting diode with a relatively narrow beam width is changed using a zoom lens. In this case, since the original beam width is narrow, even if the focal length of the zoom lens is changed, the focusing angle cannot be changed sufficiently, and as a result, the excitation light irradiation range cannot be changed sufficiently. There's a problem.
FIG. 16 shows a graph when the condensing angle (incident angle) of laser light having a beam width w of 2 mm is changed by changing the focal length of the zoom lens. As a zoom lens, an MVL7000 manufactured by Thorlabs is used, and the focal length f is changed from 18 mm to 108 mm. At this time, the change in the condensing angle (incident angle) θ of the laser light can be expressed by θ = arctan (w / 2f), and 0.5 ° ≦ θ ≦ 3 °.
On the other hand, in an endoscope system that captures a fluorescent image as described above, for example, when the excitation light irradiation range is relatively wide and a fluorescent image with a relatively wide field of view such as the entire image of the lung or liver is to be captured, Fluorescence images of regions of interest of various sizes, such as when the excitation light irradiation range is limited to a narrow local area and high intensity illumination is used to capture high-quality fluorescent images of small structures such as lymph nodes and ducts However, the configuration of the light source device described in Patent Document 1 cannot sufficiently change the irradiation range of the excitation light in order to acquire such various fluorescent images.

  In view of the above problems, the present invention provides a light source device that can sufficiently change the irradiation range of the excitation light in the observed portion and can acquire fluorescent images corresponding to regions of interest of various sizes. The purpose is to do.

  The light source device according to the present invention includes a parallel light source unit that emits parallel light incident on a light incident end face of a predetermined light guide member, and an optical axis of the parallel light emitted from the parallel light source unit with respect to the optical axis of the light guide member. And an irradiation range changing unit that changes the irradiation range of the parallel light emitted from the light emitting end face of the light guide member by changing the incident angle.

  In the light source device of the present invention, a condensing lens that condenses the parallel light emitted from the parallel light source unit on the light incident end surface of the light guide member is provided, and the irradiation range changing unit is parallel to the condensing lens. The incident angle of the parallel light with respect to the optical axis of the light guide member can be changed by changing the incident position of the light.

  In addition, a reflection member that reflects the parallel light emitted from the parallel light source unit toward the condensing lens is provided, and the irradiation range changing unit is arranged so that the reflection member is in the optical axis direction of the condensing lens or in a direction orthogonal to the optical axis. By moving it, the incident position of the parallel light on the condenser lens can be changed.

  In addition, a reflecting member that reflects the parallel light emitted from the parallel light source unit toward the condensing lens is provided, and the irradiation range changing unit is moved in the optical axis direction of the condensing lens by moving the parallel light source unit. The incident position of the parallel light on can be changed.

  In addition to providing a plurality of parallel light source units, a reflecting member for reflecting the parallel light emitted from the plurality of parallel light source units toward the condenser lens is provided, and the plurality of parallel light source units are emitted from each parallel light source unit. The collimated parallel light is irradiated to different positions on the reflecting member, and the irradiation range changing unit switches the parallel light from each parallel light source unit to switch the parallel light to the condenser lens. The incident position can be changed.

  In addition, a light source that emits light having a wavelength band different from that of the parallel light may be provided, and the reflecting member may be disposed on the optical path of the light emitted from the light source.

  Further, a dichroic mirror that transmits light emitted from the light source and reflects parallel light can be used as the reflecting member.

  Further, a mirror member that reflects an arbitrary wavelength can be used as the reflecting member.

  In addition, the parallel light source unit is arranged in the optical axis direction of the condensing lens, and the irradiation range changing unit is parallel to the condensing lens by moving the parallel light source unit in a direction orthogonal to the optical axis of the condensing lens. The incident position of light can be changed.

  In addition, a plurality of parallel light source units are arranged in a direction perpendicular to the optical axis direction of the condensing lens, and the irradiation range changing unit switches the parallel light from each parallel light source unit to switch the parallel light to the condensing lens. The incident position can be changed.

  Further, the parallel light source unit may be provided with a laser diode or a light emitting diode.

  The parallel light source unit can emit near infrared light as parallel light.

  According to the light source device of the present invention, the parallel light emitted from the light emitting end face of the light guide member is changed by changing the incident angle of the optical axis of the parallel light emitted from the parallel light source unit with respect to the optical axis of the light guide member. Since the irradiation range can be changed, it can be changed to the irradiation range of the excitation light corresponding to the various regions of interest as described above, and fluorescence images corresponding to the regions of interest of various sizes are acquired. be able to.

Schematic configuration diagram of a rigid endoscope system using an embodiment of a light source device of the present invention Schematic configuration diagram of body cavity insertion part Schematic configuration diagram of the imaging unit The figure which shows schematic structure of the image processing apparatus and the light source device of 1st Embodiment. Illuminance distribution when excitation light is incident from a direction inclined by an incident angle of 20 ° with respect to the vertical direction of the light incident end face of the light guide, and excitation light is incident from the vertical direction on the light incident end face of the light guide. Graph showing experimental data with illuminance distribution in case The figure which shows schematic structure of the light source device of the 2nd Embodiment of this invention. The figure which shows schematic structure of the light source device of the 3rd Embodiment of this invention. The figure which shows schematic structure of the light source device of the 4th Embodiment of this invention. The figure which shows schematic structure of the light source device of the 5th Embodiment of this invention. The figure which shows schematic structure of the light source device of the 6th Embodiment of this invention. The figure which shows schematic structure at the time of providing the light-shielding member in the light source device of the 5th Embodiment of this invention. The figure which shows schematic structure of the light source device of the 7th Embodiment of this invention. The figure which shows schematic structure of the light source device of the 8th Embodiment of this invention. The figure which shows schematic structure of the light source device of the 9th Embodiment of this invention. The figure which shows schematic structure of the light source device of the 10th Embodiment of this invention. A graph showing the change of the laser beam condensing angle when the focal length of the zoom lens is changed Graph showing the change in the incident angle of the laser beam to the light guide when the incident height of the laser beam to the condenser lens is changed

  Hereinafter, a rigid endoscope system using the first embodiment of the light source device of the present invention will be described in detail with reference to the drawings. The rigid endoscope system of this embodiment is characterized by the configuration of the light source device. First, the configuration of the entire rigid endoscope system will be described. FIG. 1 is an external view showing a schematic configuration of a rigid endoscope system 1 of the present embodiment.

  As shown in FIG. 1, the rigid endoscope system 1 according to the present embodiment guides the normal light and excitation light emitted from the light source device 2 and the light source device 2 that emits white normal light and excitation light. A rigid mirror imaging apparatus that irradiates the observation unit and captures a normal image based on reflected light reflected from the observed portion by irradiation of normal light and a fluorescent image based on fluorescence emitted from the observed portion by irradiation of excitation light 10, a processor 3 that performs a predetermined process on the image signal captured by the rigid endoscope imaging device 10, and a monitor 4 that displays a normal image and a fluorescence image of the observed portion based on a display control signal generated by the processor 3. And.

  As shown in FIG. 1, the rigid endoscope imaging apparatus 10 includes a body cavity insertion unit 30 that is inserted into a body cavity, and an imaging unit 20 that captures a normal image and a fluorescence image of the observed portion guided by the body cavity insertion unit 30. And.

  Moreover, as shown in FIG. 2, the rigid-scope imaging device 10 has the body cavity insertion part 30 and the imaging unit 20 connected detachably. The body cavity insertion portion 30 includes a connection member 30a, an insertion member 30b, a cable connection portion 30c, an irradiation window 30d, and an imaging window 30e.

  The connection member 30a is provided at one end 30X of the body cavity insertion portion 30 (insertion member 30b) on the imaging unit 20 side. For example, the connection member 30a is fitted into an opening 20a formed in the imaging unit 20, thereby The body cavity insertion part 30 is detachably connected.

  The insertion member 30b is inserted into the body cavity when photographing inside the body cavity, and is formed of a hard material and has, for example, a cylindrical shape with a diameter of about 5 mm. Inside the body cavity insertion section 30, a normal image and a fluorescence image of the observed part incident from the imaging window 30e are formed, guided to one end 30X on the imaging unit 20 side of the body cavity insertion section 30, and one end thereof A relay lens 30f (see FIG. 4) that emits light from the portion 30X is provided. The normal image and the fluorescence image emitted from the relay lens 30 f are incident on the imaging unit 20.

  As shown in FIG. 2, a cable connection portion 30c is provided on the side surface of the insertion member 30b, and the light guide LG is mechanically connected to the cable connection portion 30c by a connector C. Thereby, the light source device 2 and the insertion member 30b are optically connected via the light guide LG. In the body cavity insertion portion 30, a bundled multimode optical fiber 30g (see FIG. 4) that guides normal light and excitation light emitted from the light guide LG connected to the cable connection portion 30c. The multimode optical fiber 30g is provided to guide incident normal light and excitation light to the distal end portion 30Y of the insertion member 30b and irradiate the observed portion. The multimode optical fiber 30g provided in the insertion member 30b has its tip polished to form an irradiation window 30d.

  FIG. 3 is a diagram illustrating a schematic configuration of the imaging unit 20. The imaging unit 20 includes a first imaging system that captures a fluorescence image L6 of the observed part imaged by the relay lens 30f in the body cavity insertion part 30 and generates a fluorescence image signal of the observed part, and a body cavity insertion part And a second image pickup system that generates a normal image signal by capturing a normal image L5 of the observed portion imaged by the relay lens 30f in 30. These imaging systems are divided into two optical axes orthogonal to each other by a dichroic prism 21 having a spectral characteristic that reflects the normal image L5 and transmits the fluorescent image L6.

  The first imaging system cuts light having a wavelength equal to or less than the wavelength of the excitation light reflected by the observed portion and transmitted through the dichroic prism 21 and an excitation light cut filter 22 that transmits fluorescent wavelength region illumination light, which will be described later, and a body cavity A first imaging optical system 23 that forms a fluorescent image L6 emitted from the insertion unit 30 and transmitted through the dichroic prism 21 and the excitation light cut filter 22, and a fluorescent image L6 formed by the first imaging optical system 23 And a high-sensitivity image pickup device 24 for picking up images.

  The high-sensitivity imaging element 24 detects light in the wavelength band of the fluorescent image L6 with high sensitivity, converts it into a fluorescent image signal, and outputs it. As the high sensitivity image sensor 24, for example, a monochrome image sensor can be used.

  The second imaging system includes a second imaging optical system 25 that forms a normal image L5 emitted from the body cavity insertion unit 30 and reflected by the dichroic prism 21, and a normal image formed by the second imaging optical system 25. An image sensor 26 that captures the image L5 is provided.

  The image sensor 26 detects light in the wavelength band of the normal image, converts it into a normal image signal, and outputs it. On the image pickup surface of the image pickup element 26, color filters of three primary colors red (R), green (G) and blue (B), or cyan (C), magenta (M) and yellow (Y) are arranged in a Bayer array or a honeycomb. It is provided in an array.

  In addition, the imaging unit 20 includes an imaging control unit 27. The imaging control unit 27 performs CDS / AGC (correlated double sampling / automatic gain control) processing and A / A processing on the fluorescence image signal output from the high-sensitivity imaging device 24 and the normal image signal output from the imaging device 26. A D-conversion process is performed and output to the processor 3 via the cable 5 (see FIG. 1).

  As shown in FIG. 4, the processor 3 includes a normal image input controller 41, a fluorescence image input controller 42, an image processing unit 43, a memory 44, a video output unit 45, an operation unit 46, a TG (timing generator) 47, and a CPU 48. ing.

  The normal image input controller 41 and the fluorescence image input controller 42 include a line buffer having a predetermined capacity, and the normal image input controller 41 receives a normal image signal for each frame output from the imaging control unit 27 of the imaging unit 20. The fluorescent image input controller 42 temporarily stores a fluorescent image signal. The normal image signal stored in the normal image input controller 41 and the fluorescent image signal stored in the fluorescent image input controller 42 are stored in the memory 44 via the bus.

  The image processing unit 43 receives the normal image signal and the fluorescence image signal for each frame read from the memory 44, performs predetermined image processing on these image signals, and outputs them to the bus.

  The video output unit 45 receives the normal image signal and the fluorescence image signal output from the image processing unit 43 via the bus, performs predetermined processing to generate a display control signal, and outputs the display control signal to the monitor 4. Output.

  The operation unit 46 receives input by the operator such as various operation instructions and control parameters. As will be described in detail later, in particular, in the present embodiment, a change in the irradiation range of the excitation light is accepted.

  The TG 47 outputs a drive pulse signal for driving the high-sensitivity image pickup device 24, the image pickup device 26 of the image pickup unit 20, and an LD driver 53 of the light source device 2 described later. The CPU 48 controls the entire apparatus.

  The processor 3 and the imaging unit 20 are connected via a cable 5 as shown in FIGS. 1 and 4. The cable 5 includes a signal wiring that propagates a normal image signal and a fluorescent image signal captured by the imaging unit 20, a control wiring that transmits a control signal output from the processor 3, and the like. A connector 5a and a connector 5b are provided at the tip of the cable 5. The cable 5 is detachably connected to the processor 3 via the connector 5a, and is detachably connected to the imaging unit 20 via the connector 5b. Is.

  As shown in FIG. 4, the light source device 2 includes a visible light lamp 50 that emits normal light (white light) L <b> 1 having a broadband wavelength of about 400 to 700 nm as diffused light, and a normal light emitted from the visible light lamp 50. An aspheric lens 51 that emits light L1 as substantially parallel light, a near-infrared laser diode 52 that emits excitation light L2, which is near-infrared light of 750 to 790 nm, and an LD that drives the near-infrared laser diode 52 A collimating lens 54 that receives the driver 53, the excitation light L2 emitted from the near-infrared laser diode 52 and emits it as parallel light, and the excitation light L2 emitted from the collimating lens 54 is directed to a condenser lens 55 described later. The dichroic mirror 56 that reflects normal light L1 emitted from the aspherical lens 51 and is emitted from the aspherical lens 51. Condenses and excitation light L2 reflected by the ordinary light L1 and the dichroic mirror 56, and a condenser lens 55 to be incident on the light incident end face 60 of the light guide LG as described above. In the present embodiment, a parallel light source unit 70 is configured by the near infrared laser diode 52 and the collimating lens 54.

  As the visible light lamp 50, for example, a xenon lamp is used. In this embodiment, a near infrared laser diode is used as a light source for emitting excitation light, but a near infrared light emitting diode may be used.

  As described above, the dichroic mirror 56 transmits the normal light L1 and reflects the excitation light L2, and is disposed with an inclination of 45 ° with respect to the optical axis direction of the condenser lens 55. Further, the dichroic mirror 56 is disposed on the optical path of the normal light L1 emitted from the aspheric lens 51.

  The near-infrared laser diode 52 and the collimator lens 54 are arranged so that the emission direction of the excitation light L2 is perpendicular to the optical axis of the condenser lens 55.

  Furthermore, the light source device 2 is provided with a moving mechanism 57 (irradiation range changing unit) that moves the dichroic mirror 56 in the optical axis direction (arrow A direction) of the condenser lens 55. As the moving mechanism 57, a known actuator can be used.

  Then, by moving the dichroic mirror 56 in the direction of arrow A by the moving mechanism 57, the reflection position of the excitation light L2 on the dichroic mirror 56 changes, and thereby the incident position of the excitation light L2 on the condenser lens 55 is changed. Be changed. Specifically, when the dichroic mirror 56 is positioned on the condenser lens 55 side shown in FIG. 4, the excitation light L2 is reflected by the dichroic mirror 56 and is incident on the condenser lens 55 as excitation light L3. When the mirror 56 is positioned on the visible light lamp 50 side shown in FIG. 4, the excitation light L2 is reflected by the dichroic mirror 56 and is incident on the condenser lens 55 as the excitation light L4. That is, as the dichroic mirror 56 approaches the condenser lens 55 side, the incident position of the excitation light L2 on the condenser lens 55 is changed to a position away from the optical axis of the condenser lens 55.

  As described above, when the incident position of the excitation light on the condenser lens 55 is changed, the incident angle of the optical axis of the excitation light on the light incident end surface 60 of the light guide LG is changed. Specifically, as shown in FIG. 4, the excitation light L3 has a larger incident angle with respect to the vertical direction of the light incident end face 60 than the excitation light L4.

  When the incident angle of the excitation light with respect to the light incident end surface 60 of the light guide LG is changed in this way, the irradiation range of the excitation light irradiated on the observed portion can be changed according to the magnitude of the incident angle. That is, as shown in FIG. 4, the irradiation range in the observed portion is wider in the excitation light L3 having a larger incident angle with respect to the vertical direction of the light incident end face 60 of the light guide LG than in the excitation light L4.

  Here, FIG. 5 shows experimental data indicating that the irradiation range of the excitation light is changed by changing the incident angle of the excitation light to the light incident end surface 60 of the light guide LG as described above. FIG. 5 shows the illuminance distribution when excitation light is incident from a direction inclined by an incident angle of 20 ° with respect to the vertical direction of the light incident end face 60 of the light guide LG, and the light incident end face 60 of the light guide LG. The experimental data with the illumination distribution when the excitation light is incident from the vertical direction are shown. As shown in FIG. 5, when excitation light is incident from a direction inclined by an incident angle of 20 ° with respect to the vertical direction of the light incident end face 60 of the light guide LG, it propagates in the multimode optical fiber of the light guide LG. The excitation light emitted in this way forms two illuminance distributions having peaks. A relatively wide range of illuminance distribution can be formed by distributing these two illuminance distributions with a partial overlap. However, if the incident angle is increased too much, the distance between the two illuminance distributions increases and the illuminance also decreases, making it impossible to irradiate excitation light with sufficient illuminance, so the incident angle is within a predetermined upper limit. It is desirable to set

Further, the relationship between the incident angle of the excitation light to the light incident end face 60 of the light guide LG and the irradiation range of the excitation light will be described quantitatively. First, as shown in FIG. 4, the light incident end face 60 of the light guide LG. The incident angle of the excitation light to θ _in , the exit angle of the excitation light from the multimode optical fiber 30 g _in the body cavity insertion section 30 to θ _out , and the incident height h of the excitation light to the condenser lens 55 (of the dichroic mirror 56 When the movement amount x) in the optical axis direction, these relationships satisfy the following expression. However, θ _in = θ _out is established when θ _in ≦ θ _max (= arcsin (NA)).
θ _out = θ _in = arctan (h / f) = arctan (x / f)
f: Focal length of the condenser lens 55

Accordingly, the radius r of the irradiation range of the excitation light changes so as to satisfy the following expression, depending on the incident height h of the excitation light (movement amount x of the dichroic mirror 56).
r = d · tan (θ _out ) = d · h / f = d · x / f
d: Distance between the distal end of the body cavity insertion portion 30 and the observed portion

  In FIG. 4, two incident angles are shown as incident angles to the light incident end surface 60 of the light guide LG. That is, two positions are shown as the positions of the dichroic mirror 56, but the present invention is not limited to this. The moving amount and moving direction of the dichroic mirror 56 (the condensing lens 55 side or the visible light lamp 50 side) can be arbitrarily set by the user using the operation unit 46 of the processor 3. And thereby, the irradiation range of the excitation light to a to-be-observed part is changed arbitrarily.

  A connector 61 is provided at the tip of the light guide LG on which the normal light L1 and the excitation light L3 and L4 collected by the condenser lens 55 are incident. The light guide LG is connected to the light source LG via the connector 61. The device 2 is detachably connected. The light guide LG is composed of, for example, a bundled multimode optical fiber.

  In the present embodiment, the dichroic mirror 56 is used to reflect the excitation light L2 toward the condenser lens 55. However, instead of the dichroic mirror 56, a simple mirror that reflects an arbitrary wavelength is used. It may be. In FIG. 4, the mirror is shown large in order to clearly show the change in the incident position of the excitation light to the condensing lens 55, but actually it is sufficiently small with respect to the size of the aspherical lens 51. Further, since the amount of the normal light L1 emitted from the aspherical lens 51 is sufficiently large, the vignetting of the normal light L1 by the mirror is not particularly problematic.

  In this embodiment, near-infrared light is used as excitation light. However, the present invention is not limited to this, and a narrower wavelength than normal light having a broad wavelength is used. And excitation light is not limited to the light of the said wavelength range, It determines suitably according to the kind of fluorescent pigment | dye, or the kind of biological tissue made to autofluoresce.

  Next, the operation of the rigid endoscope system of this embodiment will be described.

  First, the connector C of the light guide LG connected to the light source device 2 is connected to the cable connection portion 30c of the insertion member 30b of the body cavity insertion portion 30, and the connector 5b of the cable 5 connected to the processor 3 is connected to the imaging unit 20. Connected to.

  Next, after the light source device 2 is turned on, the user inserts the body cavity insertion part 30 into the body cavity, and the tip of the body cavity insertion part 30 is installed in the vicinity of the observed part.

Then, the normal light L 1 is emitted from the visible light lamp 50 of the light source device 2, and the normal light L 1 is made substantially parallel light by the aspherical lens 51 and then incident on the condensing lens 55. The light is incident on the light incident end surface 60 of LG. On the other hand, excitation light L2 is emitted from the near-infrared laser diode 52 of the light source device 2, and the excitation light L2 passes through the collimator lens 54 and then enters the dichroic mirror 56.

  It is assumed that the dichroic mirror 56 at this time is arranged by the moving mechanism 57 at a position corresponding to the excitation light irradiation range set and input by the user in the operation unit 46.

  The excitation light L2 incident on the dichroic mirror 56 is reflected toward the condensing lens 55 and then incident on the condensing lens 55. The condensing lens 55 sets the excitation light L2 with respect to the light incident end surface 60 of the light guide LG. It is incident with an incident angle corresponding to the irradiated range.

  Then, the normal light L1 and the excitation light L2 incident on the light incident end surface 60 of the light guide LG as described above are guided by the light guide LG and incident on the multimode optical fiber 30g in the body cavity insertion portion 30. The normal light L1 and the excitation light L3 or the excitation light L4 incident from the end face and guided by the multimode optical fiber 30g are irradiated from the distal end of the body cavity insertion portion 30 toward the observed portion.

  And the normal image based on the reflected light reflected from the observed part by the irradiation of the normal light L1 as described above is picked up, and the fluorescence based on the fluorescence emitted from the observed part by the irradiation of the excitation light L3 or L4. An image is taken. It should be noted that ICG is administered to the observed part in advance, and fluorescence emitted from the ICG is imaged.

  Specifically, when the normal image is captured, the normal image L5 based on the reflected light reflected from the observed portion by the irradiation of the normal light L1 is incident from the distal end portion 30Y of the insertion member 30b, and the inside of the insertion member 30b. Are guided by the relay lens 30 f and emitted toward the imaging unit 20.

  The normal image L5 incident on the imaging unit 20 is reflected by the dichroic prism 21 toward the imaging element 26 in a right angle direction, and is imaged on the imaging surface of the imaging element 26 by the second imaging optical system 25. 26 sequentially captures images at a predetermined frame rate.

  The normal image signals sequentially output from the image sensor 26 are subjected to CDS / AGC (correlated double sampling / automatic gain control) processing and A / D conversion processing in the imaging control unit 27, and then the processor via the cable 5. 3 are sequentially output.

  The normal image signal input to the processor 3 is temporarily stored in the normal image input controller 41 and then stored in the memory 44. Then, the normal image signal for each frame read from the memory 44 is subjected to gradation correction processing and sharpness correction processing in the image processing unit 43 and then sequentially output to the video output unit 45.

  Then, the video output unit 45 performs a predetermined process on the input normal image signal to generate a display control signal, and sequentially outputs the display control signal for each frame to the monitor 4. The monitor 4 displays a normal image based on the input display control signal.

  On the other hand, when the fluorescent image is picked up, a fluorescent image L6 based on the fluorescence emitted from the observed portion by irradiation with the excitation light L3 or L4 enters from the distal end portion 30Y of the insertion member 30b, and the relay in the insertion member 30b. The light is guided by the lens 30 f and emitted toward the imaging unit 20.

  The fluorescent image L6 incident on the imaging unit 20 passes through the dichroic prism 21 and the excitation light cut filter 22, and is then imaged on the imaging surface of the high-sensitivity imaging element 24 by the first imaging optical system 23, and has high sensitivity. Images are taken at a predetermined frame rate by the image sensor 24.

  The fluorescent image signals sequentially output from the high-sensitivity image sensor 24 are subjected to CDS / AGC (correlated double sampling / automatic gain control) processing and A / D conversion processing in the imaging control unit 27, and then passed through the cable 5. Are sequentially output to the processor 3.

  The fluorescence image signal input to the processor 3 is temporarily stored in the fluorescence image input controller 42 and then stored in the memory 44. Then, the fluorescence image signal for each frame read from the memory 44 is subjected to predetermined image processing in the image processing unit 43 and then sequentially output to the video output unit 45.

  Then, the video output unit 45 performs a predetermined process on the input fluorescent image signal to generate a display control signal, and sequentially outputs the display control signal for each frame to the monitor 4. The monitor 4 displays a fluorescent image based on the input display control signal.

  Then, after the fluorescent image is displayed once as described above, when the user wants to change the excitation light irradiation range, an instruction to change the excitation light irradiation range by the user is input in the operation unit 46. Is done.

  Then, the dichroic mirror 56 is moved in the direction of arrow A by the moving mechanism 57 according to the irradiation range of the excitation light set and input in the operation unit 46, whereby the incident angle of the excitation light to the light incident end face 60 of the light guide LG. Is changed, the irradiation range of the excitation light to the observed portion is changed.

According to the rigid endoscope system of the above embodiment, the irradiation range of the excitation light emitted from the light emitting end face of the body cavity insertion unit 30 can be changed by changing the incident angle of the excitation light with respect to the optical axis of the light guide LG. Therefore, it can be changed to the irradiation range of the excitation light according to the region of interest of various sizes such as lungs and liver, or lymph nodes and ducts, and the fluorescence image corresponding to the region of interest of various sizes is acquired can do.
FIG. 17 is a graph for illustrating the difference in the operational effect from the method using the conventional zoom lens. Specifically, FIG. 17 shows a change in the incident angle of the laser light on the light guide LG when the incident position (incident height h) of the laser light having a beam width of 2 mm on the condenser lens 55 is changed. Is. As the condenser lens 55, 66315-L manufactured by Edmund is used, and its focal length f is 37.5 mm and its diameter is 50 mm. The change in the incident angle θin of the laser beam to the light guide LG at this time can be expressed by θin = arctan (h / f), and 0 <θin ≦ 30 °.

  Next, rigid endoscope systems using the light source devices of the second to tenth embodiments of the present invention will be described below. Since the rigid endoscope system using the light source device of the second to tenth embodiments is different from the rigid endoscope system of the first embodiment only in the configuration of the light source device, only the configuration of the light source device will be described.

  In the light source device 2 of the first embodiment, the dichroic mirror 56 is moved in the direction of the optical axis of the condenser lens 55. On the other hand, the light source device 6 of the second embodiment is shown in FIG. As shown, the dichroic mirror 56 is moved in a direction (arrow B direction) orthogonal to the optical axis direction of the condenser lens 55. Even when the dichroic mirror 56 is moved in the direction of the arrow B as described above, the incident position of the excitation light to the condenser lens 55 can be changed as in the light source device 2 of the first embodiment. The incident angle of the optical axis of the excitation light to the light incident end surface 60 of the light guide LG can be changed, and thereby the irradiation range of the excitation light to the observed part can be changed.

  Next, a light source device according to a third embodiment of the present invention will be described. In the light source device 2 of the first and second embodiments, the incident position of the excitation light to the condensing lens 55 is changed by moving the dichroic mirror 56, but this is the third embodiment. 7, the dichroic mirror 56 is kept fixed at a predetermined position as shown in FIG. 7, and the parallel light source unit 70 including the near infrared laser diode 52 and the collimating lens 54 is condensed by the moving mechanism 58. The lens 55 is moved in the optical axis direction (arrow C direction).

  Even when the near-infrared laser diode 52 and the collimating lens 54 are moved in the direction of the arrow C as described above, the reflection position of the excitation light on the dichroic mirror 56 can be changed. Similarly to the light source device 2 of the embodiment, the incident position of the excitation light to the condenser lens 55 can be changed, thereby changing the incident angle of the optical axis of the excitation light to the light incident end face 60 of the light guide LG. Thus, the irradiation range of the excitation light to the observed part can be changed.

  Next, a light source device according to a fourth embodiment of the present invention will be described. In the light source device 7 according to the third embodiment, the reflection position of the excitation light on the dichroic mirror 56 is changed by moving the parallel light source unit 70 including the near-infrared laser diode 52 and the collimator lens 554. In contrast, the light source device 8 of the fourth embodiment, as shown in FIG. 8, includes a first parallel light source unit 70a including a near-infrared laser diode 52a and a collimator lens 54a, A second parallel light source unit 70b having an infrared laser diode 52b and a collimating lens 54b is arranged in the optical axis direction of the condenser lens 55, and the near infrared laser diode 52a is arranged by the LD driver 53 (irradiation range changing unit). The pumping light L2 is emitted from the near infrared laser diode 52b and the pumping light L2 ′ is emitted from the near infrared laser diode 52b.

  Even when the emission of the excitation light L2 from the near-infrared laser diode 52a and the emission of the excitation light L2 ′ from the near-infrared laser diode 52b are switched as described above, the light source device of the third embodiment is also provided. 7, since the reflection position of the excitation light on the dichroic mirror 56 can be changed, the incident position of the excitation light to the condenser lens 55 can be changed, and thereby the light incident end face of the light guide LG. By changing the incident angle of the optical axis of the excitation light to 60, the irradiation range of the excitation light to the observed part can be changed. In the light source device 8 of the fourth embodiment shown in FIG. 8, two parallel light source units are provided. However, when switching the irradiation range of the excitation light to the observation unit in three or more stages, The number of parallel light source units may be increased according to the number of steps in the irradiation range, and these may be arranged in the optical axis direction of the condenser lens 55.

  Next, a light source device according to a fifth embodiment of the present invention will be described. In the light source devices of the first to fourth embodiments, the excitation light emitted from the near-infrared laser diode is reflected by the dichroic mirror 56 at a right angle so as to enter the condenser lens 55. On the other hand, in the light source device 9 of the fifth embodiment, as shown in FIG. 9, the dichroic mirror 56 is not provided, and the parallel light source unit 70 including the near-infrared laser diode 52 and the collimating lens 54 is collected. It is arranged on a straight line parallel to the optical axis of the optical lens 55 and on the optical path of the normal light L1 transmitted through the aspherical lens 51. Further, the parallel light source unit 70 arranged as described above is moved by the moving mechanism 58 in a direction (arrow D direction) orthogonal to the optical axis of the condenser lens 55.

  Even when the parallel light source unit 70 is moved by the moving mechanism 58 in this way, the incident position of the excitation light to the condenser lens 55 is changed as in the light source devices of the first to fourth embodiments. Accordingly, the incident angle of the optical axis of the excitation light to the light incident end surface 60 of the light guide LG can be changed to change the irradiation range of the excitation light to the observed portion.

  Next, a light source device according to a sixth embodiment of the present invention will be described. In the light source device 9 of the fifth embodiment, the incident position of the excitation light to the condenser lens 55 is changed by moving the parallel light source unit 70, but the sixth embodiment is different from this. As shown in FIG. 10, the light source device 11 includes a first parallel light source unit 70a including a near infrared laser diode 52a and a collimating lens 54a, a near infrared laser diode 52b, and a collimating lens 54b. The second parallel light source unit 70b is arranged in a direction orthogonal to the optical axis of the condenser lens 55, and the LD driver 53 emits the excitation light L2 from the near infrared laser diode 52a and the near infrared laser diode 52b. The emission of the excitation light L2 ′ is switched.

  Even when the emission of the excitation light L2 from the near-infrared laser diode 52a and the emission of the excitation light L2 ′ from the near-infrared laser diode 52b are switched as described above, the light source device of the fifth embodiment is also provided. 9, the incident position of the excitation light to the condensing lens 55 can be changed, so that the incident angle of the optical axis of the excitation light to the light incident end surface 60 of the light guide LG can be changed thereby exciting the excitation light. The irradiation range to the observed part can be changed. In the light source device 11 of the sixth embodiment shown in FIG. 10, two parallel light source units are provided. However, when switching the irradiation range of the excitation light to the observed unit in three or more stages, The number of parallel light source units may be increased in accordance with the number of stages in the irradiation range, and these may be arranged in a direction perpendicular to the optical axis of the condenser lens 55.

  Even if the near-infrared laser diode and the collimating lens are provided on the optical path of the normal light L1 as in the light source devices 9 and 11 of the fifth and sixth embodiments, the light amount of the normal light L1 is as follows. It can be made sufficiently large, and since there is a diffraction effect, a diffusion effect, etc., a shadow that causes a problem does not appear in the observed portion.

  For the vignetting of the normal light L1 by the near-infrared laser diode, for example, an Edmund precision aspheric lens having a lens diameter of 50 mm is used as the aspheric lens 51, and the diameter of the near-infrared laser diode is 5.6 mm. When an Edmund laser diode is used, the transmission efficiency is 1- (5.6 / 50) = 99%, so there is no particular problem.

  However, in the fifth and sixth embodiments, the near-infrared laser diode is provided on the optical path of the ordinary light L1 as described above, and therefore the near-infrared laser diode is irradiated with the ordinary light L1. As a result, the near-infrared laser diode may generate heat and break down.

  Therefore, for example, as shown in FIG. 11, a light shielding member 51a that prevents the near-infrared laser diode 52 from being irradiated with the normal light L1 is provided on a part of the surface of the aspheric lens 51 on the visible light lamp 50 side. It may be. As the light shielding member 51a, a member that reflects the normal light L1 may be used, or a member that absorbs the normal light L1 may be used. When a member that reflects the normal light L1 is used as the light shielding member 51a, it is desirable that the direction in which the normal light L1 is reflected be a direction other than the visible light lamp 50 direction.

  In the above description, the light blocking member 51a is provided on the surface of the aspherical lens 51 on the visible light lamp 50 side. However, the present invention is not limited to this, and is provided on the surface of the aspherical lens 51 on the near infrared laser diode 52 side. Alternatively, it may be provided separately from the aspherical lens 51.

  Alternatively, a reflection member that reflects the normal light L1 may be provided on the visible light lamp 50 side of the near-infrared laser diode. This reflecting member is also preferably configured such that the direction in which the normal light L1 is reflected is a direction other than the visible light lamp 50 direction. Or you may make it provide a heat insulation member with respect to a near-infrared laser diode instead of a reflection member. A known material can be used as the material of the heat insulating member. Moreover, you may make it provide both a heat insulation member and a reflection member with respect to a near-infrared laser diode.

  Next, a light source device according to a seventh embodiment of the present invention will be described. In the light source devices of the first to fourth embodiments, the visible light lamp 50 and the aspherical lens 51 are arranged in the optical axis direction of the condenser lens 55, and the near-infrared laser diode 52 and the collimating lens 54 are provided. The parallel light source unit 70 provided is arranged in a direction perpendicular to the optical axis direction. On the other hand, the light source device 12 of the seventh embodiment collects the parallel light source unit 70 as shown in FIG. In addition to being arranged in the optical axis direction of the optical lens 55, the visible light lamp 50 and the aspherical lens 51 are arranged in a direction perpendicular to the optical axis direction. The dichroic mirror 59 in the light source device 12 shown in FIG. 12 reflects the normal light L1 emitted from the visible light lamp 50 and transmitted through the aspheric lens 51 toward the condenser lens 55, and near-infrared laser diode 52. The excitation light L2 that has been emitted from the laser beam and transmitted through the collimator lens 54 is transmitted.

  Further, in the light source device 12 of the seventh embodiment, the parallel light source unit 70 arranged as described above is moved by the moving mechanism 58 in a direction perpendicular to the optical axis of the condenser lens 55 (arrow E direction). It is what you do.

  Even when the parallel light source unit 70 is moved by the moving mechanism 58 in this way, the incident position of the excitation light to the condenser lens 55 is changed as in the light source devices of the first to fourth embodiments. Accordingly, the incident angle of the optical axis of the excitation light to the light incident end surface 60 of the light guide LG can be changed to change the irradiation range of the excitation light to the observed portion.

  Next, a light source device according to an eighth embodiment of the present invention will be described. In the light source device 12 of the seventh embodiment, the incident position of the excitation light to the condensing lens 55 is changed by moving the parallel light source unit 70. On the other hand, the eighth embodiment As shown in FIG. 13, the light source device 13 includes a first parallel light source unit 70a including a near infrared laser diode 52a and a collimating lens 54a, a near infrared laser diode 52b, and a collimating lens 54b. The second parallel light source unit 70b is arranged in a direction orthogonal to the optical axis of the condenser lens 55, and the LD driver 53 emits the excitation light L2 from the near infrared laser diode 52a and the near infrared laser diode 52b. The emission of the excitation light L2 ′ is switched.

  Even when the emission of the excitation light L2 from the near-infrared laser diode 52a and the emission of the excitation light L2 ′ from the near-infrared laser diode 52b are switched as described above, the light source device of the seventh embodiment is also provided. 12, the incident position of the excitation light to the condenser lens 55 can be changed, so that the incident angle of the optical axis of the excitation light to the light incident end surface 60 of the light guide LG is changed thereby The irradiation range to the observed part can be changed. In the light source device 13 of the eighth embodiment shown in FIG. 13, two parallel light source units are provided. However, when switching the irradiation range of the excitation light to the observed unit at three or more levels, The number of parallel light source units may be increased in accordance with the number of stages in the irradiation range, and these may be arranged in a direction perpendicular to the optical axis of the condenser lens 55.

  Next, a light source device according to a ninth embodiment of the present invention will be described. In the light source devices of the first to eighth embodiments, the excitation light emitted from the near-infrared laser diode is condensed and incident on the light incident end surface 60 of the light guide LG by the condenser lens 55. On the other hand, as shown in FIG. 14, the light source device 14 of the ninth embodiment directly applies the excitation light L3 or L4 emitted from the parallel light source unit 70 to the light guide LG without providing the condenser lens 55. The light is incident on the light incident end face 60. Note that the normal light L1 emitted from the visible light lamp 50 is collected by the condenser lens 65 and is incident on the light incident end surface 60 of the light guide LG.

  Further, in the light source device 14 of the ninth embodiment, the optical axis of the parallel light source unit 70 arranged as described above is inclined at a plurality of angles with respect to the vertical direction of the light incident end surface 60 of the light guide LG. In addition, the parallel light source unit 70 is moved in the direction of arrow F (circumferential direction of a circle centered on the center of the light incident end surface 60 of the light guide LG) by the moving mechanism 58.

  As described above, even when the parallel light source unit 70 is moved by the moving mechanism 58, the optical axis of the excitation light to the light incident end surface 60 of the light guide LG, as in the light source devices of the first to eighth embodiments. Can be changed, and thereby the irradiation range of the excitation light to the observed portion can be changed.

  Next, a light source device according to a tenth embodiment of the present invention will be described. In the light source device of the ninth embodiment, the incident angle of the optical axis of the excitation light to the light incident end surface 60 of the light guide LG is changed by moving the parallel light source unit 70. On the other hand, as shown in FIG. 15, the light source device 15 of the tenth embodiment includes a first parallel light source unit 70a including a near infrared laser diode 52a and a collimating lens 54a, a near infrared laser diode 52b, and a collimator. A second parallel light source unit 70b including a lens 54b is disposed along the direction of the arrow F described above, and the LD driver 53 emits the excitation light L2 from the near-infrared laser diode 52a and the near-infrared laser diode 52b. The excitation light L2 ′ from the emission is switched.

  Thus, even when the emission of the excitation light L2 from the near-infrared laser diode 52a and the emission of the excitation light L2 ′ from the near-infrared laser diode 52b are switched, the light source device of the ninth embodiment is used. 14, the incident angle of the optical axis of the excitation light to the light incident end surface 60 of the light guide LG can be changed, so that the irradiation range of the excitation light to the observed part can be changed. In the light source device 15 of the tenth embodiment shown in FIG. 15, two parallel light source units are provided. However, when switching the irradiation range of the excitation light to the observation unit in three stages or more, The number of parallel light source units may be increased in accordance with the number of steps in the irradiation range, and these may be arranged in the direction of arrow F described above.

  In the above-described embodiment, the fluorescent image is captured by the first imaging system. However, the present invention is not limited to this, and other special light composed of parallel light is irradiated to the observed portion. You may make it image the image based on the light absorption characteristic of a to-be-observed part.

  Moreover, although the said embodiment applies the light source device of this invention to a rigid endoscope system, you may apply not only to this but a flexible endoscope system, for example.

DESCRIPTION OF SYMBOLS 1 Rigid endoscope system 2, 6-9, 11-15 Light source device 3 Processor 4 Monitor 10 Rigid endoscope imaging device 20 Imaging unit 24 High-sensitivity imaging device 26 Imaging device 30 Body cavity insertion part 30f Relay lens 30g Multimode optical fiber 50 Visible light Lamp 51 Aspherical lens 51a Light shielding member 52, 52a, 52b Near infrared laser diode 54, 54a, 54b Collimator lens 55 Condensing lens 56 Dichroic mirror 57 Moving mechanism 58 Moving mechanism 59 Dichroic mirror 60 Light incident end face 65 Condensing lens 70 Parallel light source unit 70a First parallel light source unit 70b Second parallel light source unit

Claims (12)

A parallel light source unit that emits parallel light incident on a light incident end face of a predetermined light guide member;
The irradiation range of the parallel light emitted from the light emitting end surface of the light guide member is changed by changing the incident angle of the optical axis of the parallel light emitted from the parallel light source unit with respect to the optical axis of the light guide member. A light source device comprising an irradiation range changing unit. A condensing lens that condenses parallel light emitted from the parallel light source unit on a light incident end surface of the light guide member;
The irradiation range changing unit changes an incident angle of the parallel light with respect to an optical axis of the light guide member by changing an incident position of the parallel light on the condenser lens. Item 2. The light source device according to Item 1. A reflective member that reflects the parallel light emitted from the parallel light source unit toward the condenser lens;
The irradiation range changing unit changes the incident position of the parallel light on the condenser lens by moving the reflecting member in the optical axis direction of the condenser lens or in a direction perpendicular to the optical axis. The light source device according to claim 2. A reflective member that reflects the parallel light emitted from the parallel light source unit toward the condenser lens;
The irradiation range changing unit changes the incident position of the parallel light to the condenser lens by moving the parallel light source unit in an optical axis direction of the condenser lens. 2. The light source device according to 2. A plurality of the parallel light source units, and a reflecting member that reflects the parallel light emitted from the plurality of parallel light source units toward the condenser lens,
The plurality of parallel light source units are arranged such that parallel light emitted from the parallel light source units is irradiated to different positions on the reflecting member,
The said irradiation range change part changes the incident position of the said parallel light to the said condensing lens by switching the injection | emission of the parallel light from each said parallel light source part. Light source device. A light source that emits light having a wavelength band different from that of the parallel light;
The light source device according to claim 3, wherein the reflection member is disposed on an optical path of light emitted from the light source.   The light source device according to claim 6, wherein the reflection member is a dichroic mirror that transmits the light emitted from the light source and reflects the parallel light.   The light source device according to claim 3, wherein the reflecting member is a mirror member that reflects an arbitrary wavelength. The parallel light source unit is arranged in the optical axis direction of the condenser lens,
The irradiation range changing unit changes the incident position of the parallel light to the condenser lens by moving the parallel light source unit in a direction orthogonal to the optical axis of the condenser lens. The light source device according to claim 2. A plurality of the parallel light source sections are arranged in a direction perpendicular to the optical axis direction of the condenser lens;
The said irradiation range change part changes the incident position of the said parallel light to the said condensing lens by switching the injection | emission of the parallel light from each said parallel light source part. Light source device.   The light source apparatus according to claim 1, wherein the parallel light source unit includes a laser diode or a light emitting diode.   The light source device according to claim 1, wherein the parallel light source unit emits near infrared light as the parallel light.

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