JP6226730B2 - Optical scanning device and optical scanning observation device - Google Patents

Description

  The present invention relates to an optical scanning device and an optical scanning observation device using the same.

  There have been proposed optical scanning devices that vibrate the tip of a fiber using a piezoelectric element and scan an object with illumination light so as to draw a predetermined locus (for example, Patent Document 1 and Non-Patent Document 1). reference). In such an apparatus, a plurality of piezoelectric elements are arranged around a holding member that cantilever-supports the tip of the fiber for fiber scanning. Then, the fiber is driven at a desired frequency by alternately applying positive and negative voltages so as to expand and contract the piezoelectric element in the direction along the fiber.

  In particular, by forming the holding member in a rectangular parallelepiped shape that is long in the direction along the optical axis of the fiber and disposing the piezoelectric elements on the four side surfaces, the emission end of the illumination light of the fiber can be scanned two-dimensionally. . Accordingly, by controlling the waveform of the voltage applied to the piezoelectric element, it is possible to perform scanning with various scanning patterns such as spiral scanning, raster scanning, and Lissajous scanning. Here, when the fiber is vibrated in the vicinity of the resonance frequency at the tip of the fiber, it is easy to obtain a larger amplitude. Therefore, vibration driving in at least one direction is performed at a frequency near the resonance frequency.

Special table 2008-525844

Quinn. YJ Smithwick et al. "A Nonlinear State-Space Model of a Resonating Single Fiber Scanner for Tracking Control: Theory and Experiment", ASME J Dyn. Syst., Meas., Control, 126 (1), pp. 88- 101, 2004

  By the way, in order to increase the amplitude of the fiber, it is desirable to expand and contract the piezoelectric element as much as possible in the direction along the optical axis of the fiber on the holding member. This is because if the expansion and contraction of the piezoelectric element is large, the tip of the fiber is tilted more greatly. The amount of expansion / contraction of the piezoelectric element increases as the length of the piezoelectric element increases. However, in order to lengthen the piezoelectric element, it is necessary to increase the length of the holding member on which the piezoelectric element is disposed. However, if the length of the holding member is increased, as a result, the combined length of the holding member and the fiber tip is increased. As a result, it becomes difficult to reduce the size of the optical scanning device. In particular, when this optical scanning apparatus is applied to an endoscope, the distal end has a long rigid length, which is preferable from the viewpoint that the insertable luminal organs are limited and the insertion procedure becomes difficult. Absent.

  Therefore, the object of the present invention, which has been made by paying attention to these points, has made it possible to increase the amplitude of the fiber tip without increasing the combined length (that is, the hard length) of the fiber holding member and the fiber tip. An object of the present invention is to provide an optical scanning device and an optical scanning observation device using the same.

The invention of an optical scanning device that achieves the above object is as follows.
A fiber that emits illumination light from a light source toward an object;
A rectangular parallelepiped fiber holding member that is inserted through the fiber and supports the tip of the fiber so as to be swingable;
A piezoelectric element disposed on each side of the fiber holding member;
And a recess is provided at an end of the fiber holding member that supports the tip of the fiber.

  The concave portion of the fiber holding member may have an anisotropic shape around the optical axis of the fiber.

Preferably, before Symbol piezoelectric element is fixed so as to expand and contract in the extending direction of the front Symbol fiber.

Further, the invention of the optical scanning observation apparatus that achieves the above object is
A fiber that emits illumination light from a light source toward an object;
A rectangular parallelepiped fiber holding member that is inserted through the fiber and supports the tip of the fiber so as to be swingable;
A piezoelectric element disposed on each side of the fiber holding member;
A detector for detecting signal light obtained from the object by irradiation of the illumination light ;
And a recess is provided at an end of the fiber holding member that supports the tip of the fiber.

  According to the present invention, since the concave portion is provided in the end portion of the fiber holding member that supports the tip portion of the fiber, the tip of the fiber can be obtained without increasing the combined length (hard length) of the fiber holding member and the fiber tip portion. The amplitude of the part can be increased.

1 is a block diagram showing a schematic configuration of an optical scanning endoscope apparatus according to a first embodiment. FIG. 2 is an overview diagram schematically showing the scope of FIG. 1. It is a figure which expands and shows the inside of the front-end | tip part of the scope of FIG. It is a figure which shows schematic structure of the light source unit of the optical scanning type endoscope apparatus of FIG. It is a figure which shows schematic structure of the detection unit of the optical scanning endoscope apparatus of FIG. FIG. 6A is an enlarged view of the scanning unit of FIG. 3, FIG. 6A is a cross-sectional view taken along the optical axis direction of the optical fiber of the scanning unit, and FIG. 6B is a front view seen from the emission end side of the optical fiber. FIG. It is sectional drawing of the scanning part using the piezoelectric element by a prior art. It is a perspective view of the scanning part of the optical scanning endoscope which concerns on 2nd Embodiment. It is a general-view figure which shows roughly the scope of the optical scanning type microscopic endoscope which concerns on 3rd Embodiment. It is a figure which expands and shows the inside of the front-end | tip part of FIG. It is a figure which shows schematic structure of the light source and the detection unit of the optical scanning type microscopic endoscope which concerns on 3rd Embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing a schematic configuration of an optical scanning endoscope apparatus 10 according to the first embodiment. The optical scanning endoscope apparatus 10 includes a scope 20, a light source unit 30 (light source), a detection unit 40 (detection unit), a computer 50, and a display device 58. The light source unit 30 and the scope 20 are optically connected by an SMF (single mode fiber) 11, and the detection unit 40 and the scope 20 are optically connected by a plurality of MMF (multimode fiber) 12. Yes. A wiring cable 13 is connected between the computer 50 and the scope 20.

  FIG. 2 is a schematic view schematically showing the scope 20 of FIG. The scope 20 includes an operation unit 24 and an insertion unit 25. The operation unit 24 is connected to the SMF 11 from the light source unit 30, the MMF 12 from the detection unit 40, and the wiring cable 13 from the computer 50. The SMF 11, the MMF 12, and the wiring cable 13 are inserted into the insertion unit. 25 is led to the distal end portion 26 of the insertion portion 25.

  FIG. 3 is an enlarged view showing the inside of the distal end portion 26 of the scope 20 of FIG. The SMF 11 is disposed so as to pass through the central portion of the tube-shaped distal end portion 26, and the MMF 12 is disposed so as to pass through the outer peripheral portion of the distal end portion 26. The SMF 11 inserted through the scope 20 passes through a hole provided in an actuator holder 61 and a rectangular parallelepiped ferrule 62 (fiber holding member) whose end is fixed to the actuator holder 61. The fiber tip portion 11a protruding from is supported in a swingable manner. A lens 64 is disposed at the tip of the emission end of the fiber tip 11 a of the SMF 11, and the laser light (illumination light) output from the SMF 11 is configured to form a small spot on the observation object 100. In FIG. 3, the lens 64 is a single lens, but it may be composed of a plurality of lenses.

  On the other hand, the incident end of the MMF 12 faces the side on which the observation object 100 is disposed, and the light obtained by irradiating the observation object 100 with the laser light output from the SMF 11 is incident as signal light. It is configured. Here, the light obtained by irradiating the observation object is reflected light or scattered light of the laser light output from the SMF 11, fluorescent light generated by the laser light irradiation, or the like.

  Further, thin plate-like piezoelectric elements 63 a to 63 d are fixed in contact with the four side surfaces of the ferrule 62. By applying an oscillating voltage to the piezoelectric elements 63 a to 63 d via the wiring cable 13, the SMF 11 is driven to vibrate via the ferrule 62.

  FIG. 4 is a diagram showing a schematic configuration of the light source unit 30 of the optical scanning endoscope apparatus 10 of FIG. The light source unit 30 includes LD (semiconductor laser) 31R, DPSS (semiconductor excitation solid-state laser) 31G, LD31B, and dichroic mirrors 32a, 32b that emit CW (continuous oscillation) laser light of the three primary colors red, green, and blue, respectively. The lens 33 is provided.

  The dichroic mirror 32a has an optical characteristic of transmitting light in the red wavelength band and reflecting light in the green wavelength band. The dichroic mirror 32a has red laser light emitted from the laser light source 31R and green light emitted from the laser light source 31G. The laser beam is combined. The dichroic mirror 32b has an optical characteristic of transmitting light in the red wavelength band and light in the green wavelength band and reflecting light in the blue wavelength band, and laser light combined by the dichroic mirror 32a. Are combined with the blue laser light emitted from the laser light source 31B.

  In this way, laser beams of the three primary colors of red, green, and blue emitted from the laser light sources 31R, 31G, and 31B are combined to become white laser light, which is incident on the incident end of the SMF 11 by the lens 33. Is done. The arrangement of the laser light sources 31R, 31G, and 31B and the dichroic mirrors 32a and 32b is not limited to this. For example, after combining green and blue laser beams, the red laser beams are combined. Also good.

  FIG. 5 is a diagram showing a schematic configuration of the detection unit 40 of the optical scanning endoscope apparatus 10 of FIG. The detection unit 40 includes PDs 41 </ b> R, 41 </ b> G, 41 </ b> B, dichroic mirrors 42 a, 42 b, and a lens 43, which are photodiodes for detecting light corresponding to each color of red, green, and blue. A plurality of MMFs 12 are bundled and connected to the detection unit 40.

  The signal light reflected by the observation object 100 by the irradiation of the laser light or generated at the observation object 100 and emitted from the emission end through the MMF 12 becomes a substantially parallel light beam by the lens 43. Dichroic mirrors 42a and 42b are arranged on the optical path of the signal light that has become a substantially parallel light beam. The dichroic mirror 42b has an optical characteristic of reflecting light in the blue wavelength band and transmitting light in the red and green wavelength bands, and separates the blue signal light from the signal light that has become a parallel light flux by the lens 43. . The separated blue signal light is detected by the PD 41B and converted into an electrical signal. The dichroic mirror 42a has an optical characteristic of reflecting light in the green wavelength band and transmitting light in the red wavelength band, and separates the signal light transmitted through the dichroic mirror 42b into red and green signal lights. To do. The separated red and green signal lights are detected and converted into electric signals by the PD 41R and PD 41G, respectively.

  The PDs 41R, 41G, and 41B are electrically connected to a detection control unit 52 and a signal processing unit 54 of the computer 50 in FIG. Further, the arrangement of the PDs 41R, 41G, and 41B and the dichroic mirrors 42a and 42b is not limited to this. For example, after separating the red light from the signal light, the green and blue signal lights are further separated. Also good.

  1 controls driving of the scanning unit 23, the light source unit 30, and the detection unit 40 of the scope 20, and processes electric signals output from the detection unit 40 to synthesize images and display them on the display device 60. To do. Therefore, the computer 50 includes a light source control unit 51, a detection control unit 52, a scanning control unit 53, a signal processing unit 54, a control unit 55, a storage unit 56, and an input unit 57.

  The detection control unit 52 can control the detection timing, detection time, and detection sensitivity of signal light by the PDs 41R, 41G, and 41B of the detection unit 40. Further, the scanning control unit 53 drives and controls the scanning unit 23 of the scope 20 to scan the spot of the laser light emitted from the SMF 11 along a desired locus on the observation target. Furthermore, the signal processing unit 54 generates image data corresponding to each point of the observation object 100 based on the electrical signals output from the PDs 41R, 41G, and 41B of the detection unit 40, and as corresponding pixel data, Store in the storage unit 56.

  The control unit 55 controls the whole of the light source control unit 51, the detection control unit 52, the scanning control unit 53, and the signal processing unit 54 of the optical scanning endoscope apparatus 10 by the laser light from the light source unit 30. The observation object 100 is scanned, the detection unit 40 converts the signal light obtained from the observation object 100 into an electrical signal at a predetermined timing, and the signal processing unit 54 generates image data.

  Next, the configuration of the scanning unit 23 will be described in more detail. 6 is an enlarged view of the scanning unit 23 of FIG. 3, FIG. 6 (a) is a cross-sectional view taken along the optical axis direction of the optical fiber of the scanning unit, and FIG. 6 (b) is a diagram of the fiber tip 11a. It is the front view seen from the outgoing end side. The ferrule 62 is a member made of, for example, a nickel material and having a quadrangular prism shape whose section perpendicular to the optical axis of the SMF 11 is substantially square. One end of the rectangular column in the longitudinal direction is fixed to an actuator holder 61 fixed inside the scope 20. A conical recess 65 is provided at the other end of the ferrule 62, that is, the end on the exit end side that swingably supports the fiber tip 11 a of the SMF 11. The SMF 11 is inserted into a hole that passes through the central portion of the actuator holder 61 and the ferrule 62, and is fixed by an adhesive 66 at a concave portion 65 on the fiber tip portion 11a side. The recess 65 may be formed in a columnar shape instead of a conical shape.

  As shown in FIG. 6 (b), the piezoelectric elements 63a to 63d include a pair of piezoelectric elements 63a and 63c and a pair of piezoelectric elements 63b and 63d arranged to face each other with the SMF 11 interposed therebetween. By applying voltages in opposite directions to the piezoelectric elements 63a to 63d in the set, the piezoelectric elements 63a to 63d expand and contract in different directions from the piezoelectric elements facing the optical axis direction of the SMF 11. As a result, the SMF 11 can be tilted in two directions, the Y-axis direction orthogonal to the optical axis of the SMF 11 and the X-axis direction orthogonal to both the optical axis and the Y-axis direction of the SMF 11.

  As shown in FIG. 6A, each of the piezoelectric elements 63a to 63d extends from one end of the ferrule 62 to the other end along the SMF 11 on each side surface extending in the optical axis direction of the SMF 11 of the ferrule 62. One end is attached so as to contact the actuator holder 61. By doing in this way, the amplitude of piezoelectric element 63a-63d in the fiber front-end | tip part 11a side can be enlarged. If the amplitude of the piezoelectric elements 63a to 63d is increased, the amplitude of the fiber tip portion 11a is necessarily increased.

  For comparison, FIG. 7 shows a cross-sectional view of a scanning unit (comparative example) using a piezoelectric element according to the prior art. In FIG. 7, each component is given a number obtained by adding 100 to the number of each corresponding component in FIG. According to FIG. 7, the surface of the ferrule 162 on the side of the fiber tip 111a is a flat surface, and the SMF 111 inserted through the ferrule 162 is fixed by applying an adhesive 166 thereon. In this case, it is difficult to apply the adhesive 166 around the fiber in a balanced manner. The piezoelectric elements 163a to 163d (only 163a and 163c are shown) are not provided over the entire length in the direction along the SMF 111 on the side surface of the ferrule 162.

  Comparing the scanning unit 23 of the present invention shown in FIG. 6 (a) with the scanning unit 123 of the comparative example of FIG. Without shortening the length, the length of the ferrule 62 is increased, and accordingly, the lengths of the piezoelectric elements 63a to 63d are increased. As a result, the amplitude of the fiber tip portion 11a can be increased without changing the resonance frequency of the fiber tip portion 11a of the SMF 11 from the case of FIG.

  As described above, according to the present embodiment, since the recess 65 is provided at the end of the ferrule 62 that supports the fiber tip 11a, the tip of the fiber is not changed without changing the length of the fiber tip 11a. The amplitude of 11a can be increased. As a result, the fiber tip 11a can be driven to vibrate with high energy efficiency and high amplitude without changing the resonance frequency. Further, since the rigid length of the fiber tip portion 11a and the ferrule 62 is not changed, when applied to a scanning endoscope, the insertable luminal organs are limited or the operability is deteriorated. There is no. Furthermore, since the scanning unit 23 is configured by arranging the thin plate-like piezoelectric elements 63a to 63d along the rectangular parallelepiped ferrule 62, the diameter of the tip of the scope 20 can be reduced.

  Moreover, since the adhesive 66 is applied to the recess 65 to fix the support portion of the fiber 11, the adhesive 66 is easily filled, and the adhesive does not flow and become non-uniform.

  Furthermore, the piezoelectric elements 63a to 63d are attached so as to be in contact with the actuator holder 61, whereby the elongation of the piezoelectric elements 63a to 63d on the fiber tip end 11a side is increased. Further, since the piezoelectric elements 63a to 63d extend from one end to the other end of the side surface of the ferrule 62 in the direction along the SMF 11, the same applied voltage as compared with the case where the piezoelectric elements are partially provided in the longitudinal direction of the ferrule. Can increase the amplitude of the piezoelectric element.

(Second Embodiment)
FIG. 8 is a perspective view of a scanning unit of the optical scanning endoscope according to the second embodiment. In this figure, only the fiber tip 11a, ferrule 62 and piezoelectric elements 63a to 63d of the SMF 11 are shown. Unlike the first embodiment, the recess 64 of the ferrule 62 has a shape in which a cross section perpendicular to the optical axis of the SMF 11 is an ellipse having a long axis in the X-axis direction and a short axis in the Y-axis direction. Yes. That is, the concave portion 64 has an anisotropic shape around the optical axis (that is, the Z axis) of the SMF 11. Other configurations of the second embodiment are the same as those of the first embodiment.

  By providing the anisotropic concave portion 64 as described above, when the concave portion 64 is filled with the adhesive 65 and the SMF 11 is fixed, the elasticity of the adhesive 65 holding the SMF 11 allows the fiber tip 11 a of the SMF 11. The resonance frequency varies depending on the vibration direction. In the elliptical concave portion 64 of FIG. 8, since the resonance frequency is different between the X-axis direction and the Y-axis direction, vibration in the Y-axis direction occurs when the scanning unit is driven to vibrate near the resonance frequency in the X-axis direction. Thus, generation of an undesired elliptical orbit can be avoided. The concave section 64 having an elliptical cross section is particularly suitable for a scanning method that vibrates the fiber tip 11a of the SMF 11 in one direction at a resonance frequency, for example, raster scanning or Lissajous scanning.

(Third embodiment)
In the third embodiment, the optical scanning device of the present invention is applied to an optical scanning microscope endoscope, and FIG. 9 is a schematic view schematically showing the scope. FIG. 10 is an enlarged view showing the inside of the distal end portion 26 of the scope 20 of FIG. Unlike the optical scanning endoscope according to the first embodiment, this optical scanning microscopic endoscope does not include an MMF for collecting and transmitting signal light obtained from the observation object 100, and is an observation target. The SMF 11 used for illuminating the object 100 is also used for collecting and transmitting signal light.

  In the first embodiment, the light source unit and the detection unit are provided, whereas in the present embodiment, the light source / detection unit 70 in which these components are combined into one is provided. FIG. 11 is a diagram showing a schematic configuration of the light source / detection unit 70 of the optical scanning microscope endoscope. The light source / detection unit 70 includes an LD 71 that is a blue light source, a dichroic mirror 72, a lens 73, and a PMT (photomultiplier tube) 74. The laser light emitted from the LD 71 is configured to pass through the dichroic mirror 72 and enter the SMF 11 through the lens 73. The signal light that has passed through the SMF 11 becomes a substantially parallel light beam by the lens 73, is reflected by the dichroic mirror 72, and is detected by the PMT 74. For this reason, the dichroic mirror 72 has a wavelength characteristic that transmits the wavelength of light emitted from the LD 71 and reflects signal light. For example, when a sample stained with fluorescein is fluorescently observed with an optical scanning microscope, a semiconductor laser with a wavelength of 494 nm is used as the LD 71, and the dichroic mirror that transmits this wavelength and reflects the fluorescence with a wavelength of 520 nm. 72 can be used.

  The scanning unit 23 is configured similarly to the scanning unit of the first embodiment described with reference to FIGS. Since other configurations are the same as those of the first embodiment, the same or corresponding components are denoted by the same reference numerals and description thereof is omitted.

  With the configuration as described above, the laser light emitted from the LD 71 passes through the SMF 11 and is collected from the tip of the scope 20 by the lens 64 and irradiated onto the observation object 100. At that time, the distal end portion 11 a of the SMF 11 is driven to vibrate by the scanning unit 23. Signal light such as fluorescent light obtained from the observation object 100 by scanning with the laser light is incident on the SMF 11 from the emission end of the fiber tip 11a of the SMF 11 by the lens 64. This signal light is guided through the SMF 11 to the light source / detection unit 70 and detected by the PMT 74. The control of the LD 71 and the piezoelectric elements 63a to 63d and the processing of the image data obtained from the PMT 74 are the same as in the first embodiment.

  According to the present embodiment, since the scanning unit similar to that shown in FIGS. 3 and 6 of the first embodiment is used in the optical scanning microscope endoscope, the same effect as that of the first embodiment is used. Is obtained. Although the scope type of FIG. 9 is assumed in the present embodiment, a probe type that is used by being inserted into a forceps hole of another scope may be used. By doing so, it is possible to simultaneously perform microscopic observation by inserting a probe-type scanning microscopic endoscope into the forceps hole of the scope while performing endoscopic observation with another scope.

  In addition, this invention is not limited only to the said embodiment, Many deformation | transformation or a change is possible. For example, the light source unit, detection unit, and computer of the first embodiment may be stored in the same housing. Alternatively, a light receiving element for receiving signal light may be arranged at the distal end of the scope, and an electric signal output from the light receiving element may be input to the computer via a cable. Further, the use of the optical scanning device of the present invention is not limited to the optical scanning endoscope and the optical scanning microscope endoscope, and can be applied to an image projection device or the like.

10 Optical Scanning Endoscope Device 11 SMF (Single Mode Fiber)
11a Fiber tip 12 MMF (multimode fiber)
DESCRIPTION OF SYMBOLS 13 Wiring cable 20 Scope 23 Scanning part 24 Operation part 25 Insertion part 26 Tip part 30 Light source unit 31R, 31B LD (semiconductor laser)
31G DPSS laser (semiconductor pumped solid-state laser)
32a, 32b Dichroic mirror 33 Lens 40 Detection unit 41R, 41G, 41B PD (photodiode)
42a, 42b Dichroic mirror 43 Lens 50 Computer 51 Light source control unit 52 Detection control unit 53 Scan control unit 54 Signal processing unit 55 Control unit 56 Storage unit 58 Display device 61 Actuator holder 62 Ferrule (fiber holding member)
63a to 63d Piezoelectric element 64 Lens 65 Recess 66 Adhesive 71 LD (semiconductor laser)
72 Dichroic mirror 73 Lens 74 PMT (Photomultiplier tube)
100 Observation object

Claims (4)

A fiber that emits illumination light from a light source toward an object;
A rectangular parallelepiped fiber holding member that is inserted through the fiber and supports the tip of the fiber so as to be swingable;
A piezoelectric element disposed on each side of the fiber holding member;
And a recess is provided at an end of the fiber holding member that supports the tip of the fiber.   The optical scanning device according to claim 1, wherein the concave portion of the fiber holding member has an anisotropic shape around an optical axis of the fiber. The piezoelectric element includes an optical scanning device according to claim 1 or 2, characterized in that it is fixed so as to stretch the extending direction before Symbol fiber. A fiber that emits illumination light from a light source toward an object;
A rectangular parallelepiped fiber holding member that is inserted through the fiber and supports the tip of the fiber so as to be swingable;
A piezoelectric element disposed on each side of the fiber holding member;
A detector for detecting signal light obtained from the object by irradiation of the illumination light ;
And a recess is provided at an end of the fiber holding member that supports the tip of the fiber.

Images