JP2012231910A - Optical scan type observation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical scan type observation device for acquiring image information with brightness nonuniformity suppressed therein.SOLUTION: The optical scan type observation device includes: a distal end 10a of an insertion part 10 for emitting laser beams from a light source 22 to a celomic inner wall S; an illumination fiber 11 for scanning the laser beams to be emitted from the distal end 10a of the insertion part 10 on the celomic inner wall S; a detection fiber 17 for receiving reflection light from the celomic inner wall S where the laser beams are scanned by the illumination fiber 11; a storage part 26 for storing intake efficiency information which indicates the distribution of intake efficiency of the reflection light to be taken in for each scan position by the detection fiber 17; and a light amount adjustment part 28 for adjusting the light amount of the laser beams thereby to allow the light amount of the laser beams so as to be proportional to the inverse number of a function of the intake efficiency with respect to the scan position, on the basis of the intake efficiency information stored in the storage part 26.

Description

  The present invention relates to an optical scanning observation apparatus.

  Conventionally, illumination light emitted from the distal end of the endoscope insertion portion is scanned by applying a drive signal to the illumination fiber that transmits the illumination light to the distal end of the endoscope insertion portion and continuously displacing the distal end of the illumination fiber. An optical scanning endoscope apparatus is known (see, for example, Patent Document 1). In the optical scanning endoscope apparatus described in Patent Document 1, a plurality of detection fibers are arranged around an illumination fiber, and return light from an observation target irradiated with illumination light is captured and detected by these detection fibers. Thus, an image to be observed is constructed.

Special table 2008-511112 gazette

  However, since the direction in which the illumination light is irradiated by the illumination fiber varies depending on the position on the observation target, the intensity of the scattered light from each irradiation position also varies depending on the scattering direction. In addition, even if the prospective angle of the detection fiber with respect to each irradiation position on the observation target is different, the efficiency of capturing scattered light is the same if the irradiation positions are within the predetermined area. The efficiency of capturing scattered light by the detection fiber differs from the irradiation position. Therefore, even if each irradiation position on the observation target originally has the same brightness information, the detected light amount captured and detected by the detection fiber differs depending on the irradiation position, and the image of the observation target to be constructed There is a problem that uneven brightness occurs.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an optical scanning observation apparatus that can acquire image information in which uneven brightness is suppressed.

In order to solve the above problems, the present invention employs the following means.
The present invention includes an emission unit that emits illumination light emitted from a light source toward an observation target site, a scanning unit that scans the illumination light emitted by the emission unit on the observation target site, and the scanning unit. A light receiving unit that receives the return light from the scanning position of the observation target site scanned by the illumination light, and a capture efficiency that indicates a distribution of the capture efficiency of the return light that can be captured at each scanning position by the light receiving unit. Based on the storage efficiency information stored in the storage section and the storage efficiency information stored in the storage section, the amount of the illumination light is proportional to the reciprocal of the capture efficiency function with respect to the scanning position. An optical scanning observation apparatus including a light amount adjusting unit that adjusts a light amount is provided.

  According to the present invention, since the irradiation direction of the illumination light emitted from the emission unit is different for each illumination light irradiation position in the observation target region, the intensity of the return light varies depending on the return direction. Further, according to the positional relationship between the irradiation position of the illumination light emitted from the emission unit and the region where the return light can be received by the light receiving unit, the capture efficiency of the return light received by the light receiving unit is also different.

  In this case, since the capture efficiency information stored in the storage unit indicates the capture efficiency of the return light that can be captured by the light receiving unit with respect to the scanning position of the illumination light, the light amount adjustment unit determines the illumination light based on the capture efficiency information. By adjusting the amount of illumination light so that the amount of light is proportional to the inverse of the function of the capture efficiency of the light receiving unit with respect to the scanning position, the amount of return light received at each scanning position received by the light receiving unit It can be maintained at a ratio substantially equal to the ratio of the original return light intensity. Therefore, by detecting the return light received by the light receiving unit, it is possible to acquire image information in which brightness unevenness due to the influence of the positional relationship between the emitting unit and the light receiving unit is suppressed.

In the above invention, the light amount adjustment unit may control the output of the light source.
With this configuration, the light amount adjusting unit generates illumination light by increasing or decreasing the light amount from the light source for each scanning position based on the capturing efficiency information, and the inverse of the function of the capturing efficiency by the light receiving unit with respect to the scanning position. Illumination light with a light quantity proportional to is irradiated onto the observation target part. As a result, the amount of the return light can be increased or decreased for each scanning position, and the influence of the difference in the return light capture efficiency for each scanning position in the light receiving unit can be reduced. Therefore, the amount of the return light received at each scanning position received by the light receiving unit can be maintained at a ratio approximately equal to the original ratio of the return light intensity at each scanning position.

Moreover, in the said invention, the said light quantity adjustment part is good also as controlling the scanning density on the said observation object site | part of the said illumination light by the said scanning part.
With this configuration, the light intensity adjusting unit improves or reduces the scanning density by the scanning unit for each scanning position based on the capturing efficiency information, and the amount of illumination light is proportional to the reciprocal of the function of capturing efficiency with respect to the scanning position. Is irradiated to the site to be observed. This increases or decreases the amount of return light for each scanning position, reduces the influence of the difference in return light capture efficiency for each scanning position in the light receiving unit, and reduces the return light for each scanning position received by the light receiving unit. The amount of received light can be maintained at a ratio approximately equal to the ratio of the original intensity of the return light at each scanning position.

  Further, in the above invention, a transmission member having a variable transmittance disposed on an optical axis of the illumination light between the observation target site and the scanning unit is provided, and the light amount adjustment unit transmits the transmission of the transmission member. The rate may be controlled.

  With this configuration, the light amount adjusting unit improves or reduces the transmittance of the transmission member for each scanning position based on the capturing efficiency information, and the illumination light proportional to the inverse of the capturing efficiency function with respect to the scanning position is observed. The target site is irradiated. This increases or decreases the amount of return light for each scanning position, reduces the influence of the difference in return light capture efficiency for each scanning position in the light receiving unit, and reduces the return light for each scanning position received by the light receiving unit. The amount of received light can be maintained at a ratio approximately equal to the ratio of the original intensity of the return light at each scanning position.

  In the above invention, the light amount adjustment unit is disposed on the optical axis of the illumination light between the observation target part and the scanning unit, and is proportional to the inverse of the function of the capturing efficiency with respect to the scanning position. It may be a transmittance adjusting member having a transmittance distribution.

  With this configuration, the transmittance adjustment member transmits illumination light with a high transmittance or a low transmittance for each range corresponding to each scanning position based on the capturing efficiency information, and a function of the capturing efficiency with respect to the scanning position. Illumination light having a light quantity proportional to the reciprocal of is irradiated onto the observation target region.

Moreover, in the said invention, it is good also as providing the image construction part which detects the said return light received by the said light-receiving part, and constructs | assembles the image of the said observation object site | part.
With this configuration, the image construction unit can acquire an image without uneven brightness due to the influence of the positional relationship between the emitting unit and the light receiving unit.

  According to the present invention, it is possible to acquire image information in which uneven brightness is suppressed.

1 is a longitudinal sectional view of an optical scanning endoscope apparatus according to a first embodiment of the present invention. It is a schematic structure of the illumination fiber of FIG. It is a figure which shows the relationship between the irradiation range of the laser beam by the optical scanning endoscope apparatus of FIG. 1, and the light reception range of the reflected light by a detection fiber. It is a figure which shows the brightness nonuniformity of the image information at the time of irradiating a laser beam with a fixed light quantity. It is a figure which shows the relationship between the drive signal of a piezoelectric element, and the light quantity of a light source. It is a longitudinal cross-sectional view of an insertion part at the time of bundling a some detection fiber to one and comprising a bundle fiber. It is a figure which shows the relationship between the drive signal value given to a piezoelectric element, and time. It is a figure which shows the scanning density of a laser beam. It is a figure which shows the positional relationship of the body cavity inner wall at the time of near point observation, and a scanning optical system. It is a figure which shows the brightness nonuniformity of the image information at the time of irradiating a laser beam with a fixed light quantity in near point observation. It is a longitudinal cross-sectional view of the insertion part which shows the structure of the insertion part in the case of employ | adopting Michelson interferometry as a measurement-refusal method. It is a longitudinal cross-sectional view of the insertion part of the optical scanning endoscope apparatus which concerns on the 2nd Embodiment of this invention. It is the top view which looked at the optical element of FIG. 12 in the thickness direction. It is a longitudinal cross-sectional view of the insertion part at the time of replacing with the optical element of FIG. 12, and providing the coating member. It is a figure which shows the structure which resonates an illumination fiber by electrical control using an electro-optic crystal as a scanning part, and scans a laser beam. It is a figure which shows the structure which scans a laser beam by an electromagnetic drive using a permanent magnet and a coil as a scanning part. It is a figure which shows a mode that a magnetic field generate | occur | produces in the illumination fiber of FIG. It is a figure which shows a mode that the illumination fiber of FIG. 16 curves.

[First Embodiment]
An optical scanning observation apparatus according to a first embodiment of the present invention will be described below with reference to the drawings.
In the present embodiment, an optical scanning endoscope apparatus will be described as an example of the optical scanning observation apparatus. As shown in FIG. 1, the optical scanning endoscope apparatus 100 according to the present embodiment has an elongated insertion portion 10 to be inserted into a body cavity and a laser beam emitted from a distal end portion 10 a of the insertion portion 10 ( And a light source 22 that emits (illuminating light).

  The insertion portion 10 can introduce laser light emitted from the light source 22 from the proximal end portion 10b and emit it from the distal end portion 10a. The insertion portion 10 includes an illumination fiber 11 that guides laser light introduced from the base end portion 10b to the distal end portion 10a, and a laser light guided by the illumination fiber 11 to an observation target site (for example, an inner wall of a body cavity) ) A scanning optical system (emitter) 13 that emits toward S, and a plurality of light beams that receive reflected light (return light) scattered at the scanning position of the body cavity inner wall S by being irradiated with laser light from the scanning optical system 3 A detection fiber (light receiving unit) 17 is provided.

  The illumination fiber 11 is a cylindrical member that can be elastically deformed, and is disposed along the longitudinal direction of the insertion portion 10. As shown in FIG. 2, the illumination fiber 11 is inserted into and held by a cylindrical piezoelectric element 15. In FIG. 2, let the longitudinal direction of the illumination fiber 11 be a Z-axis direction.

  The piezoelectric element 15 has two pairs of electrodes that are respectively disposed opposite to each other at four positions in the circumferential direction. The directions in which the electrodes face each other are defined as an X-axis direction and a Y-axis direction, respectively. The piezoelectric element 15 can resonate the illumination fiber 11 in the X-axis direction and the Y-axis direction when a drive signal is given. Further, by linearly changing the amplitude of the drive signal applied to the piezoelectric element 15 so as to gradually increase, the tip of the illumination fiber 11 can be displaced spirally from the center outward in the radial direction. It has become. Thereby, the illumination fiber 11 can scan the laser beam emitted by the scanning optical system 13 in a spiral manner on the inner wall S of the body cavity.

The scanning optical system 13 is provided in the vicinity of the distal end portion 10 a of the insertion portion 10, and is arranged at a predetermined interval in the longitudinal direction of the insertion portion 10 with respect to the distal end of the illumination fiber 11.
The detection fibers 17 are arranged at predetermined intervals in the circumferential direction along the outer periphery of the insertion portion 10 so as to surround the insertion portion 10 concentrically. Similar to the illumination fiber 11, the detection fiber 17 is provided along the longitudinal direction of the insertion portion 10, and one end is disposed around the distal end portion 10 a of the insertion portion 10. The detection fiber 17 is set to NA = 0.5, for example.

  Further, the optical scanning endoscope apparatus 100 takes in each scanning position by an image construction unit 24 such as a CCD for constructing a two-dimensional image by detecting reflected light received by the detection fiber 17 and the detection fiber 17. A storage unit 26 for storing capture efficiency information indicating a distribution of capture efficiency of reflected light, a light amount adjustment unit 28 for adjusting the light amount of laser light based on the capture efficiency information stored in the storage unit 26, And a drive unit (not shown) that outputs a drive signal for causing the illumination fiber 11 to resonate.

The image construction unit 24 is connected to the other end of the detection fiber 17.
The capture efficiency information stored in the storage unit 26 is, for example, reflected light received by the detection fiber 17 at each scanning position on the specimen by scanning the laser light on the specimen with uniform brightness over the entire surface. It may be created by measuring the capture efficiency of light, or may be created based on the relationship between the scanning position predicted by simulation and the capture efficiency of reflected light received by the detection fiber 17.

  The light amount adjustment unit 28 reads the capture efficiency information from the storage unit 26, and the light source 22 of each light source 22 is scanned for each laser light scanning position so that the light amount of the laser light is proportional to the inverse of the function of the capture efficiency of the detection fiber 17 with respect to the scanning position. The output is controlled. For example, the light amount adjusting unit 28 controls the light source 22 so as to increase the light amount of the illumination light irradiated to other scanning positions with reference to the light amount of the illumination light irradiated to the scanning position having the highest capturing efficiency by the detection fiber 17. It is supposed to be. The light amount adjusting unit 28 and the driving unit are electrically connected to each other.

Next, the operation of the optical scanning endoscope apparatus 100 configured as described above will be described below.
In order to acquire image information of the body cavity inner wall S by the optical scanning endoscope apparatus 100 according to the present embodiment, the insertion part 10 is inserted into the body cavity of the living body, and the distal end part 10a is opposed to the body cavity inner wall S. Laser light is generated by the light source 22.

  Laser light emitted from the light source 22 is introduced into the insertion portion 10, guided by the illumination fiber 11, and emitted toward the body cavity inner wall S by the scanning optical system 13. At this time, a drive signal is given to the piezoelectric element 15 by the operation of the drive unit, and the illumination fiber 11 is resonated. Then, the tip of the illumination fiber 11 is displaced in a spiral shape from the center outward in the radial direction, whereby the laser light is scanned on the body cavity inner wall S in a spiral manner via the scanning optical system 13.

  The reflected light scattered at each scanning position on the body cavity inner wall S by being irradiated with the laser light is received by the plurality of detection fibers 17 and guided to the image construction unit 24. Thereby, reflected light is detected by the image construction unit 24, and a two-dimensional image of the body cavity inner wall S is constructed.

  Here, as shown in FIG. 3, the irradiation direction of the laser light emitted from the scanning optical system 13 is different for each irradiation position (for example, detection points A, B, C, D) of the inner wall S of the body cavity. Therefore, the intensity varies depending on the direction in which the reflected light also returns. Further, the reflection received by the detection fiber 17 in accordance with the positional relationship between the irradiation position (detection points A to D) of the laser light emitted by the scanning optical system 13 and the region where the reflected light can be received by the detection fiber 17. The light capture efficiency is also different.

  In the present embodiment, by the operation of the light amount adjusting unit 28, the light source 22 is configured so that the light amount of the laser light is proportional to the reciprocal of the function of the capturing efficiency with respect to the scanning position based on the capturing efficiency information stored in the storage unit 26. Output is controlled.

  For example, when there is a detection unevenness such that when the laser beam is irradiated with a constant light amount, the detection efficiency of the reflected light by the image construction unit 24 becomes darker toward the periphery of the angle of view with respect to the center of the angle of view as shown in FIG. As shown in FIG. 5, the light source 22 is controlled so as to gradually increase the output of the light source 22 in synchronization with the drive signal given to the piezoelectric element 15 of the illumination fiber 11 by the drive unit. In FIG. 4, a symbol P indicates a two-dimensional image constructed by the image construction unit 24.

  By doing so, the amount of illumination light emitted gradually increases from the center of the scanning range toward the outside in the radial direction, and the amount of reflected light reflected at each scanning position is also increased from the center of the scanning range to the radius. It gradually increases toward the outside of the direction. As a result, the influence of the difference in the reflected light capturing efficiency at each scanning position by the detection fiber 17 is reduced, and the amount of reflected light received at each scanning position received by the detection fiber 17 is changed to the original reflected light at each scanning position. It is possible to maintain a ratio substantially equal to the ratio of the strength.

  Therefore, according to the optical scanning endoscope apparatus 100 according to this embodiment, the detection unevenness of the reflected light detected by the image construction unit 24 is reduced, and the influence of the positional relationship between the scanning optical system 13 and the detection fiber 17 is reduced. It is possible to acquire image information in which uneven brightness is suppressed.

  In the present embodiment, the light amount of the illumination light applied to the scanning position where the capturing efficiency by the detection fiber 17 is low is increased. However, the light amount adjusting unit 28 causes the light amount of the laser light to be captured by the detecting fiber 17 with respect to the scanning position. For example, the amount of illumination light may be increased or decreased for each scanning position in accordance with the capture efficiency of the detection fiber 17.

  In the present embodiment, the plurality of detection fibers 17 are arranged along the outer periphery of the insertion portion 10. Instead of this, for example, as shown in FIG. The bundle fiber may be bundled together to form a bundle fiber, and the bundle fiber may be disposed at a position shifted in the radial direction with respect to the illumination fiber 11 inside the insertion portion 10.

  Also in this case, the capture efficiency information indicating the distribution of the capture efficiency of the reflected light that can be captured for each scanning position by the detection fiber 17 is measured in advance and stored in the storage unit 26, and the light amount adjustment unit 28 is processed in the same manner. Thus, by adjusting the output of the light source 22, it is possible to acquire image information in which brightness unevenness due to the influence of the positional relationship between the scanning optical system 13 and the detection fiber 17 is suppressed.

This embodiment can be modified as follows.
In the present embodiment, the light amount adjusting unit 28 controls the output of the light source 22. However, as a first modification, the light amount adjusting unit 28 scans the scanning density of the laser light on the body cavity inner wall S by the illumination fiber 11. It is good also as controlling. In this case, based on the capture efficiency information, the light intensity adjusting unit 28 irradiates the body cavity inner wall S with a light amount proportional to the reciprocal of the capture efficiency function with respect to the scan position. It is only necessary to adjust the scanning density of the laser beam.

  For example, when there is a detection unevenness such that when the laser beam is irradiated with a constant light amount, the detection efficiency of the reflected light by the image construction unit 24 becomes darker toward the periphery of the angle of view with respect to the center of the angle of view as shown in FIG. By the operation of the light amount adjusting unit 28, the rate of change of the amplitude of the drive signal applied to the piezoelectric element 15 of the illumination fiber 11 is gradually reduced as shown in FIG. 7, and scanning by the illumination fiber 11 is performed as shown in FIG. The density may be gradually increased from the center of the scanning range toward the outside in the radial direction. FIG. 7 shows the relationship between the drive signal value given to the piezoelectric element 15 and time, and FIG. 8 shows the scanning density of the laser beam.

  By doing so, the amount of reflected light increases from the center of the scanning range toward the outside in the radial direction, and the influence due to the difference in the return light capturing efficiency at each scanning position by the detection fiber 17 can be reduced. . As a result, the amount of return light received at each scanning position received by the detection fiber 17 is maintained at a ratio approximately equal to the ratio of the original return light intensity at each scanning position, and the detection unevenness of the reflected light is reduced. be able to.

  As a second modification, the distance between the body cavity inner wall S and the scanning optical system 13 is measured, and the light amount adjustment unit 28 determines the light amount of the laser light based on the capture efficiency information according to the distance. The amount of laser light may be adjusted so as to be proportional to the inverse of the function of the capture efficiency with respect to. In this case, the capture efficiency information of the detection fiber 17 may be stored in advance in the storage unit 26 in association with the distance between the subject (observation target site) and the scanning optical system 13.

  For example, when the distance between the body cavity inner wall S and the scanning optical system 13 is made closer to the far point observation as shown in FIG. 1 (in the case of near point observation), as shown in FIG. The efficiency of capturing reflected light from the vicinity of the center of the range may decrease, and the detection efficiency of reflected light from the vicinity of the center of the scanning range may decrease as in the two-dimensional image P illustrated in FIG. In such a case, according to the distance between the body cavity inner wall S and the scanning optical system 13, the light amount adjusting unit 28 increases the light amount of the laser light irradiated near the center of the scanning range as compared with the far-point observation. In addition, the output of the light source 22 may be controlled.

  As the distance measuring means, for example, a method in which the scanning optical system 13 irradiates the subject with laser light and measures the distance between the subject and the scanning optical system 13 using laser Doppler interferometry, For example, a Michelson interferometry method is used in which reflected light from a subject when the illumination fiber 11 is positioned at the center of the insertion portion 10 in the radial direction and an interference signal is measured. When the Michelson interferometry is adopted, for example, as shown in FIG. 11, the laser beam is transmitted on the optical axis between the tip of the illumination fiber 11 and the scanning optical system 13, and the reflected light is reflected. A half mirror 31 is disposed, and a reference mirror 33 that reflects the reflected light reflected by the half mirror 31 and a light receiver 35 that receives the reflected light reflected by the reference mirror 33 are provided on the inner surface of the insertion portion 10. That's fine.

[Second Embodiment]
Next, an optical scanning observation apparatus according to a second embodiment of the present invention will be described with reference to the drawings.
An optical scanning endoscope apparatus (optical scanning observation apparatus) 200 according to the present embodiment is arranged between the tip of the illumination fiber 11 and the scanning optical system 13 instead of the light amount adjustment unit 28 as shown in FIG. This embodiment is different from the first embodiment in that a disc-shaped optical element (transmittance adjusting member) 126 disposed on the optical axis is adopted.
In the following, portions having the same configuration as those of the optical scanning endoscope apparatus 100 according to the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  The optical element 128 has a transmittance distribution that is proportional to the reciprocal of the function of the capture efficiency by the detection fiber 17 with respect to the scanning position of the laser light. For example, when laser light is irradiated with a certain amount of light, as shown in FIG. 4, a subject in which detection unevenness occurs such that the detection efficiency of reflected light by the image construction unit 24 becomes darker toward the periphery of the field angle than the center of the field angle. On the other hand, as shown in FIG. 13, an optical element 128 having a transmittance distribution in which the transmittance is lower toward the center and the transmittance is increased toward the outer side in the radial direction may be used.

  According to the optical scanning endoscope apparatus 200 according to the present embodiment, the optical element 128 transmits light with a high transmittance or a low transmittance for each range corresponding to each scanning position, and a function of the capture efficiency with respect to the scanning position. Illumination light having a light quantity proportional to the reciprocal of is irradiated onto the subject. As a result, the amount of reflected light increases or decreases at each scanning position, and the amount of reflected light received at each scanning position received by the detection fiber 17 is substantially equal to the ratio of the original reflected light intensity at each scanning position. Therefore, it is possible to reduce unevenness in detection of reflected light. Therefore, it is possible to acquire image information without uneven brightness without changing the output of the light source 22.

  In the present embodiment, the optical element 128 has been described as an example of the light amount adjustment unit. However, as shown in FIG. 14, a coating member 129 coated on the surface of the scanning optical system 13 is employed as the light amount adjustment unit. It is good as well. In this case, similarly to the optical element 128, the coating member 129 may have a transmittance distribution proportional to the inverse of the function of the capturing efficiency by the detection fiber 17 with respect to the scanning position of the laser light.

Further, the present embodiment can be modified as follows.
In the present embodiment, the optical element 128 and the coating member 127 are described as examples of the light amount adjustment unit. However, for example, on the optical axis between the light amount adjustment unit 28 and the tip of the illumination fiber 11 and the scanning optical system 13. It is also possible to employ a transmission member (not shown) having a variable transmittance disposed in the window, and to change the transmittance of the transmission member by electrical control by the light amount adjustment unit 28. As the transmissive member, for example, an electrochromic element or a liquid crystal can be employed. For example, a transmission member may be disposed at the position of the optical element 128 in FIG. 12 and the transmission member and the light amount adjustment unit 28 may be electrically connected.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the specific structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included. For example, in each of the above-described embodiments, the optical scanning endoscope apparatus 100 has been described as an example of the optical scanning observation apparatus. However, an objective lens (an emitting unit) that irradiates a subject with laser light emitted from a light source; A scanning unit such as a galvanometer mirror that scans the laser light emitted from the objective lens on the subject, an optical system (light receiving unit) that receives reflected light from the subject, a storage unit, and a light amount adjustment unit. A normal optical scanning microscope apparatus may be used.

  Further, in each of the above-described embodiments, the configuration in which the illumination fiber 11 is resonated by the piezoelectric element 15 and the laser beam is scanned as the scanning unit has been described as an example. However, instead of this, as the scanning unit, for example, scanning A configuration in which the laser light emitted from the optical system 13 is allowed to pass through the electro-optic crystal and the laser light is scanned by electrical control may be employed.

  Specifically, as shown in FIG. 15, laser light is incident on two electro-optic crystals 115 that are deflected in directions orthogonal to each other, and a voltage is applied to the electro-optic crystals 115 to generate a refractive index distribution inside. Thus, the laser light may be scanned by deflecting the laser light passing through the electro-optic crystal 115. FIG. 15 shows only the electro-optic crystal 115 in one direction (for example, the Y-axis direction), but the same applies to the electro-optic crystal in a direction orthogonal to the one (for example, the X-axis direction).

  Moreover, as a scanning part, it is good also as employ | adopting the structure which resonates the illumination fiber 11 by an electromagnetic drive with a permanent magnet and a coil, and scans a laser beam, for example. Specifically, as shown in FIG. 16, the illumination fiber 11 is inserted into the permanent magnet 116 to hold the illumination fiber 11 in a cantilever shape, and the inner surface of the insertion portion 10 is spaced in the radial direction of the permanent magnet 116. An X-axis driving tilted coil 117 and a Y-axis driving tilted coil 118 are arranged, and the illumination fiber 11 is caused to resonate by electromagnetic driving by causing a current to flow through these coils 17 and 118 to scan the laser light. It is good. In this case, the X-axis driving tilted coil 117 and the Y-axis driving tilted coil 118 may be disposed so as to be inclined in different directions with respect to the longitudinal direction of the insertion portion 10.

In such a configuration, for example, when a current is passed through the Y-axis driving tilted coil 118, a magnetic field is generated in the Y-axis direction intersecting the longitudinal direction of the illumination fiber 11, as shown in FIG. As shown in FIG. 18, the illumination fiber 11 is bent so that the magnetic moment of the permanent magnet 116 follows the magnetic field. Thereby, the laser beam can be scanned in the Y-axis direction. Similarly, when an electric current is passed through the tilted coil 117 for driving the X axis, the illumination fiber 11 can be bent in the X axis direction, and the laser beam can be scanned in the X axis direction. Therefore, the tip of the illumination fiber 11 is spirally displaced by two-dimensionally applying laser light to the X-axis driving tilted coil 117 and the Y-axis driving tilted coil 118 by alternately shifting the phase of the driving signal by 90 °. Can be scanned automatically.
Moreover, a galvanometer mirror may be employed as the scanning unit.

11 Illumination fiber (scanning part)
13 Scanning optical system (emitter)
17 Detection fiber (light receiving part)
24 Image construction unit 26 Storage unit 28 Light amount adjustment unit 100, 200 Optical scanning endoscope apparatus (optical scanning observation apparatus)

Claims (6)

An emission unit that emits illumination light emitted from a light source toward an observation target site;
A scanning unit that scans the observation target region with the illumination light emitted by the emitting unit;
A light receiving unit that receives return light from a scanning position of the observation target region scanned with the illumination light by the scanning unit;
A storage unit for storing capture efficiency information indicating a distribution of the capture efficiency of the return light that can be captured at each scanning position by the light receiving unit;
A light amount adjusting unit that adjusts the light amount of the illumination light based on the capture efficiency information stored in the storage unit so that the light amount of the illumination light is proportional to the inverse of the function of the capture efficiency with respect to the scanning position; An optical scanning observation apparatus.   The optical scanning observation apparatus according to claim 1, wherein the light amount adjustment unit controls an output of the light source.   The optical scanning observation apparatus according to claim 1, wherein the light amount adjustment unit controls a scanning density of the illumination light on the observation target portion by the scanning unit. A transmission member with variable transmittance disposed on the optical axis of the illumination light between the observation target site and the scanning unit;
The optical scanning observation apparatus according to claim 1, wherein the light amount adjusting unit controls the transmittance of the transmissive member.   The light amount adjusting unit is disposed on the optical axis of the illumination light between the observation target site and the scanning unit, and has a transmittance distribution proportional to the inverse of the function of the capturing efficiency with respect to the scanning position. The optical scanning observation apparatus according to claim 1, wherein the optical scanning observation apparatus is an adjustment member.   The optical scanning observation apparatus according to claim 1, further comprising an image constructing unit configured to construct an image of the observation target part by detecting the return light received by the light receiving unit.

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