JP2013043027A - Light source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To assure safety of eyes to excitation light while efficiently entering both excitation light and white light to a light guide.SOLUTION: The light source device is configured such that a second light (e.g., excitation light) is diffusively or convergently entered to an optical system 56 to which first and second lights differed in wavelength band are entered and which causes the first and second lights incident on an incident end surface 60 of a light guide portion LG, with the first light (e.g., white light) being collectively entered into the area of the incident end surface of the light guide portion LG by the optical system 56, whereby the second light transmitted by the optical system 56 is prevented from being converged to one point on the incident end surface 60 of the light guide portion LG, and the second light is collectively entered into the area of the incident end surface 60 of the light guide portion LG.

Description

  The present invention relates to a light source device that makes light of a first wavelength band and light of a second wavelength band different from the first wavelength band incident on a light incident end face of a predetermined light guide unit.

  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.

  As one of such endoscope systems, for example, in order to observe blood vessels under fat and blood flow, lymph vessels, lymph flow, bile duct runs, bile flow and the like that do not normally appear on an image, An endoscope system has been proposed in which ICG (Indocyanine Green) is introduced into an observation unit, and a fluorescence image of ICG is acquired by irradiating the observation unit with near-infrared excitation 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, an endoscope system that captures both a normal image and a fluorescent image as described in Patent Document 1 includes a light source device that emits white light and excitation light, white light emitted from the light source device, and The endoscope includes a light guide to which excitation light is incident.

  And in patent document 1, while making the excitation light radiate | emitted from the light source device enter into the light guide of an endoscope, without causing loss, it is uneven in the excitation light irradiated to a to-be-observed part from the front-end | tip of an endoscope. Therefore, the diameter of the excitation light and the light guide light incidence can be reduced by moving the condensing lens that collects the excitation light on the light incident end face of the light guide of the endoscope in the direction of the optical axis. It has been proposed to match the diameter of the end face.

  On the other hand, Patent Document 2 also proposes an endoscope system that includes a light source device that emits white light and excitation light, and an endoscope that includes a light guide that receives the white light and excitation light. ing.

  And in the endoscope system of patent document 2, in order to make both white light and excitation light inject efficiently with respect to the light guide of an endoscope, a light guide is made to the point where white light converges with a condensing lens. In consideration of the fact that the point at which the excitation light converges due to the chromatic aberration of the condenser lens deviates from the light incidence end surface, the excitation light is further collected after being converted into diffused light by the light flux adjuster. It has been proposed that the point where the excitation light is incident on the light lens and thereby the excitation light converges is located on the light incident end face.

JP 2006-181061 A JP 2002-228842 A

  However, when the diameter of the excitation light is changed by moving the condenser lens as in the endoscope system described in Patent Document 1, the diameter of the excitation light matches the diameter of the white light. Although there is no particular problem, for example, when the diameter of white light is larger than the diameter of the excitation light, when the diameter of the excitation light is adjusted to the diameter of the light incident end face of the light guide, Since it becomes larger than the diameter of the light incident end face of the light guide, a loss occurs in the amount of white light incident on the ride guide.

  Further, as in the endoscope system described in Patent Document 2, when the convergence point of the excitation light is positioned on the light incident end face of the light guide, for example, when the light guide is configured by a bundle fiber. In this case, the incident area of the excitation light at the light incident end face of the bundle fiber is reduced, and the emission area of the excitation light at the distal end of the endoscope is thereby reduced, so that a high bright spot is formed. Therefore, for the excitation light emitted from such a high luminescent spot, it is necessary to take some safety measures when entering the eye.

  In view of the above problems, the present invention provides a light source device capable of efficiently making both excitation light and white light incident on a light guide and ensuring eye safety against excitation light. For the purpose.

  The light source device of the present invention is a first light source that emits first light having a first wavelength band that is incident on a light guide unit that guides light to the observed portion and irradiates the observed portion with light. , A second light source unit that emits second light having a second wavelength band different from the first wavelength band and is incident on the light guide unit, and the first and second lights are incident And an optical system for causing the first and second light to enter the incident end face of the light guide section, and the second light source section is within the range of the incident end face of the light guide section by the optical system. When the second light is diffused or converged and is incident on the optical system in a state where the light is condensed and incident on the light, the second light transmitted through the optical system is incident on the incident end face 1 of the light guide unit. The second light is condensed and incident within the range of the incident end face of the light guide unit. Characterized in that it is one that is configured urchin.

  In the light source device of the present invention, the optical system is configured to collect the first and second lights incident thereon and collect the incident first and second lights on the incident end face of the light guide unit. It can be equipped with a lens.

  Further, the second light source unit may be provided with a concave lens that diffuses the second light or a convex lens that converges the second light.

  In addition, the second light source unit can be configured to change the incident range of the second light to the optical system.

  Further, the second light source unit may include a concave lens that diffuses the second light or a convex lens that converges the second light, and a moving mechanism that moves the concave lens or the convex lens in the optical axis direction.

  Further, the first light source unit may be provided with a visible light source that emits the first light.

  In addition, the first light source unit may include a parallel optical system that causes the first light to enter the optical system as parallel light.

  Further, the second light source unit may be provided with a semiconductor light source that emits second light.

  A semiconductor laser light source can be used as the semiconductor light source.

  Further, the second light source unit can emit near infrared light as the second light.

  Further, the first and second lights can be incident on the light guide portion provided in the endoscope.

  According to the light source device of the present invention, the first light is diffused or converged in the state in which the first light is collected and incident within the range of the incident end face of the light guide by the optical system, and the optical By making the light incident on the system, the second light transmitted through the optical system is prevented from converging to one point on the incident end surface of the light guide unit, and the second light is within the range of the incident end surface of the light guide unit. For example, when white light is used as the first light and excitation light is used as the second light, both the excitation light and the white light are efficiently used as the light guide. And the safety of the eyes against the excitation light can be ensured.

  Further, when the second light incident range to the optical system is configured to be changeable, for example, a plurality of types of light guides having different areas of the second light incident end face are attached to the light source device. Even if the second light is incident, the second light is incident on the optical system in accordance with the size of the incident end face of the second light of the light guide attached and the distance between the optical system of the light source device and the incident end face of the light guide. By changing the incident range, it is possible to optimize the incident area of the second light on the incident end face of the light guide.

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 other embodiment of the light source device of this invention. The figure which shows schematic structure of other embodiment of the light source device of this invention. The figure which shows schematic structure of other embodiment of the light source device of this invention. The figure which shows schematic structure of other embodiment of the light source device of this invention. The figure which shows schematic structure of other embodiment of the light source device of this invention. The figure which shows schematic structure of other embodiment of the light source device of this invention.

  Hereinafter, a rigid endoscope system using an embodiment of a 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.

  A connector 61 (see FIG. 4) is provided at the tip of the light guide LG, and the light guide LG is detachably connected to the light source device 2 via the connector 61. The light guide LG is composed of, for example, a bundled multimode optical fiber.

  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 the fluorescence image L4 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 the body cavity insertion part And a second imaging system that generates a normal image signal by capturing a normal image L3 of the observed portion imaged by the relay lens 30f within 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 L3 and transmits the fluorescent image L4.

  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 L4 emitted from the insertion unit 30 and transmitted through the dichroic prism 21 and the excitation light cut filter 22, and a fluorescent image L4 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 L4 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 L3 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 L3 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 exit angle of excitation light or normal 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 light source 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 light source 52 The driver 53, the concave lens 54 that diffuses and emits the excitation light L2 emitted from the near-infrared laser light source 52, and the excitation light emitted from the concave lens 54 while transmitting the normal light L1 emitted from the aspherical lens 51. A dichroic mirror 55 that reflects the light L2 toward a condenser lens 56 to be described later, and a normal light L1 that passes through the dichroic mirror 55 and the dichroic mirror 55. It reflected the excitation light L2 is condensed and a light guide LG of condenser lens is incident on the light incident end face 60 56.

  As the visible light lamp 50, for example, a xenon lamp is used. In this embodiment, white light is used as the normal light L1 (visible light). However, the present invention is not limited to this, and other light may be used as long as it has a visible wavelength.

  The near-infrared laser light source 52 is driven by the LD driver 53 and emits near-infrared laser diode 52a that emits near-infrared light as excitation light L2, and the excitation light L2 emitted from the near-infrared laser diode 52a is substantially parallel. And a collimator lens 52b for light. In the present embodiment, a near infrared laser light source is used as a light source for emitting excitation light. However, the present invention is not limited to this, and a near infrared light emitting diode may be used.

  The concave lens 54 diffuses the excitation light L2 emitted from the near-infrared laser light source 52 and makes it incident on the dichroic mirror 55 as described above, and the excitation light L2 reflected by the dichroic mirror 55 is diffused as this. The light enters the condenser lens 56.

  As described above, the dichroic mirror 55 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 56.

  As described above, the condenser lens 56 receives the normal light L1 that has been made substantially parallel light by the aspheric lens 51, and condenses the normal light L1 on the light incident end surface 60 of the light guide LG. However, it is arranged at a position where the normal light L1 falls within the range of the light incident end face 60 of the light guide LG.

  Further, the normal light L1 and the excitation light L2 that has been diffused by the concave lens 54 as described above are incident on the condensing lens 56, and the excitation light L2 is substantially parallel light like the normal light L1. Therefore, the excitation light L2 converged by the condensing lens 56 is incident on the light incident end surface 60 of the light guide LG without converging.

  The concave lens 54 is disposed at a position such that the excitation light L1 converged by the condenser lens 56 falls within the range of the light incident end surface 60 of the light guide LG. The concave lens 54 is desirably arranged so that the diameter of the cross section of the light beam of the excitation light L2 substantially matches the diameter of the light incident end surface 60 of the light guide LG.

  In the present embodiment, near-infrared light is used as the excitation light. However, the present invention is not limited to this, and other wavelengths narrower than normal light having a wide-band wavelength can be used. And excitation light is not limited to the light of the said wavelength range, It determines suitably by 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, then enters the condenser lens 56, and is condensed by the condenser lens 56. Then, the light is incident on the light incident end face 60 of the light guide LG.

  On the other hand, the excitation light L2 is emitted from the near-infrared laser diode 52a of the light source device 2, and the excitation light L2 is transmitted through the collimator lens 52b, then is diffused by the concave lens 54 and is incident on the dichroic mirror 55.

  The excitation light L2 incident on the dichroic mirror 55 is reflected toward the condenser lens 56 and is incident on the condenser lens 56 as diffused light. Then, the excitation light L2 is converged by the condenser lens 56 and is incident on the light incident end surface 60 of the light guide LG.

  Next, 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 L2 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 fluorescent image based on the fluorescence emitted from the observed part by the irradiation of the excitation light L2 is obtained. Imaged. 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 L3 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 L3 incident on the imaging unit 20 is reflected by the dichroic prism 21 in the direction perpendicular to the imaging element 26, 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 capturing a fluorescent image, a fluorescent image L4 based on the fluorescence emitted from the observed portion by irradiation with the excitation light L2 is incident from the distal end portion 30Y of the insertion member 30b, and the relay lens 30f in the insertion member 30b. Is guided toward the image pickup unit 20.

  The fluorescent image L4 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.

  According to the rigid endoscope system of the above-described embodiment, the normal light L1 is condensed within the range of the light incident end surface 60 of the light guide LG by the condenser lens 56, and the excitation light L2 is diffused. By making it enter into the condensing lens 56, the excitation light L2 which permeate | transmitted the condensing lens 56 is made not to converge on one point of the light-incidence end surface 60 of the light guide LG, and excitation light L2 is light incidence of the light guide LG. Since the light is condensed and incident within the range of the end surface 60, both the normal light L1 and the excitation light L2 can be efficiently incident on the light guide LG, and the safety of the eyes with respect to the excitation light L2 Sex can be secured.

  In the light source device 2 of the rigid endoscope system of the above embodiment, the visible light lamp 50 and the aspherical lens 51 are arranged in the optical axis direction of the condenser lens 56, and the near-infrared laser light source 52 and the concave lens 54 are condensed. In contrast to this, the visible light lamp 50 and the aspherical lens 51 are arranged on the condensing lens 56 as in the light source device 6 shown in FIG. The near-infrared laser light source 52 and the concave lens 54 may be disposed in the direction of the optical axis of the condenser lens 56 in a direction orthogonal to the optical axis direction. In this case, a dichroic mirror 55 that transmits near-infrared light and reflects white light is used.

  Further, in the light source device 2 of the rigid endoscope system of the above embodiment, as shown in FIG. 6, a moving mechanism 62 that moves the concave lens 54 in the optical axis direction (arrow A direction) may be further provided. By moving the concave lens 54 by the moving mechanism 62, the incident range of the excitation light L2 incident on the condenser lens 56 can be changed, whereby the incidence of the excitation light L2 on the light incident end surface 60 of the light guide LG. The area can be adjusted. Therefore, for example, even when a plurality of types of rigid mirror imaging devices 10 having different areas of the incident end face of the excitation light L2 are attached to the light source device 2, the incident end face (light) of the excitation light of the attached rigid mirror imaging device 10 The concave lens 54 is moved in accordance with the size of the light incident end surface 60) of the guide LG and the distance between the condensing lens 56 of the light source device 2 and the light incident end surface 60 of the light guide LG, whereby the light incident end surface 60 of the light guide LG. The incident area of the excitation light L2 at can be optimized. That is, the incident area of the excitation light L2 can be within the range of the light incident end face 60 of the light guide LG, and the excitation light L2 converged by the condensing lens 56 is light incident end face 60 of the light guide LG. It is possible not to converge to one point. As the moving mechanism 62, a known actuator can be used. Also, in the light source device 6 shown in FIG. 5, the concave lens 54 may be configured to be movable.

  Moreover, in the light source device 2 of the rigid endoscope system of the above embodiment, the near infrared laser light source 52 provided with the collimator lens 52b is used. For example, as in the light source device 7 shown in FIG. Only the near-infrared laser diode 57 may be used. In this case, since the near-infrared light emitted from the near-infrared laser diode 57 is diffused light, the concave lens 54 like the light source device 2 of the above embodiment is used. Can be omitted. Further, a near infrared light emitting diode may be used instead of the near infrared laser diode 57.

  Further, in the light source devices 2, 6, and 7 of the rigid endoscope system of the above embodiment, the concave lens 54 is used as means for causing the excitation light L2 to enter the condenser lens 56 as diffused light. Like the light source device 8 shown in FIG. 8, a convex lens 58 that converges the excitation light L2 emitted from the near-infrared laser light source 52 is provided, and the excitation light L2 is once converged by the convex lens 58 and then diffused. You may make it make the excitation light L2 as diffused light enter into the condensing lens 56. FIG.

  8 is further provided with a moving mechanism for moving the convex lens 58 in the optical axis direction, and the convex lens 58 is moved in accordance with the rigid mirror imaging device 10 attached to the light source device 8. Thus, the incident area of the excitation light L2 on the light incident end face 60 of the light guide LG may be optimized.

  Further, in the light source devices 2, 6, 7, and 8 of the rigid endoscope system according to the above embodiment, the dichroic mirror 55 is used. However, as shown in the light source device 9 shown in FIG. Alternatively, a triangular prism 63 having a mirror surface 63a may be used. In the light source device 9 shown in FIG. 9, the excitation light L2 emitted from the near-infrared laser diode 52a is collimated by the collimator lens 52b and then enters the condenser lens 59. Then, the excitation light L2 converged by the condensing lens 59 is incident on the triangular prism 63, reflected by the mirror surface 63a of the triangular prism 63 in a right angle direction, and the excitation light L2 reflected by the mirror surface 63a is the condensing lens 56. And is incident on the light incident end surface 60 of the light guide LG. Even in this case, the excitation light L2 is incident on the light incident end face 60 of the light guide LG without being converged. On the other hand, the normal light L1 emitted from the visible light lamp 50 is converted into parallel light by the aspherical lens 51, and a part of the normal light L1 is reflected by the mirror surface 63a of the triangular prism 63, resulting in loss. After being converted into parallel light, it is incident on the condensing lens 56, and is condensed by the condensing lens 56 within the range of the light incident end surface 60 of the light guide LG.

  In the above embodiment, the fluorescent image is captured by the first imaging system. However, the present invention is not limited to this, and an image based on the light absorption characteristics of the observed part by irradiating special light to the observed part is captured. You may make it do.

  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 Light source device 2, 6, 7, 8 Light source device 3 Processor 4 Monitor 5 Cable 10 Rigid mirror imaging device 20 Imaging unit 24 High sensitivity imaging device 26 Imaging device 30 Body cavity insertion part 30g Multimode optical fiber 50 Visible light Lamp 51 Aspherical lens 52 Near infrared laser light source 52a Near infrared laser diode 52b Collimator lens 54 Concave lens 55 Dichroic mirror 56 Condensing lens 57 Near infrared laser diode 58 Convex lens 60 Light incident end face 61 Connector 62 Moving mechanism

Claims (11)

A first light source that emits first light having a first wavelength band that is incident on a light guide that guides light to the observed part and irradiates the observed part with the light;
A second light source unit that emits second light having a second wavelength band different from the first wavelength band, which is incident on the light guide unit;
An optical system that receives the first and second lights and makes the first and second lights incident on an incident end face of the light guide unit;
The second light source unit diffuses or converges the second light in a state where the first light is collected and incident within a range of an incident end surface of the light guide unit by the optical system. The second light transmitted through the optical system is not converged to one point on the incident end surface of the light guide unit by being incident on the optical system. Is configured to be focused and incident within the range of the incident end face of the light guide section.   The optical system includes a condensing lens that receives the first and second light beams and collects the incident first and second light beams on an incident end surface of the light guide unit. The light source device according to claim 1.   The light source device according to claim 1, wherein the second light source unit includes a concave lens that diffuses the second light or a convex lens that converges the second light.   4. The light source device according to claim 1, wherein the second light source unit is configured to change an incident range of the second light to the optical system. 5.   The second light source unit includes a concave lens that diffuses the second light or a convex lens that converges the second light, and a moving mechanism that moves the concave lens or the convex lens in the optical axis direction. The light source device according to claim 4.   6. The light source device according to claim 1, wherein the first light source unit includes a visible light source that emits the first light.   7. The light source device according to claim 1, wherein the first light source unit includes a parallel optical system that causes the first light to enter the optical system as parallel light. .   The light source device according to claim 1, wherein the second light source unit includes a semiconductor light source that emits the second light.   9. The light source device according to claim 8, wherein the semiconductor light source is a semiconductor laser light source.   The light source device according to claim 1, wherein the second light source unit emits near infrared light as the second light.   The light source device according to any one of claims 1 to 10, wherein the first and second lights are incident on the light guide portion provided in an endoscope.

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