JP2012042721A - Scanning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To acquire an image which does not have blurring and distortion or the like while preventing permanent distortion of a mount which supports a fork member to perform a confocal scanning.SOLUTION: In a scanning device of a scanning type confocal endoscope including the fork member having a point light source functioning as a confocal pin hole, a magnet for applying a bias magnetic field to the fork member, the mount for supporting the fork member, and a coil for magnetizing a base end of the fork member, an electromagnet opposite to the base end of the fork member is provided, and control means is also provided which controls energization to the coil and the electromagnet to vibrate the fork member.

Description

  The present invention relates to a scanning device, and more particularly to a scanning device in a scanning confocal endoscope.

  In recent years, examinations using a scanning confocal endoscope using scanning by a confocal laser are performed as one means for a doctor to observe the inside of a body cavity of a patient. An example of such a conventional scanning confocal endoscope is disclosed in Patent Document 1. FIG. 7A is a schematic diagram of the scanning device 200 at the distal end portion of the conventional scanning confocal endoscope. FIG. 7B shows a schematic diagram of the tuning fork 201 in FIG. FIGS. 7A and 7B show a case where the scanning device 200 is in a resting state in which scanning is not performed. For convenience, as shown in FIG. 7A, the Z-axis with the front end side as the positive direction along the longitudinal direction of the scanning device 200, and the upper direction perpendicular to the longitudinal direction of the scanning device 200 and the upper side of the paper surface as the positive direction. A Y-axis and an X-axis that is perpendicular to the longitudinal direction and that has a positive direction on the back side of the drawing are set. The same applies to the following description.

  The scanning device 200 has a tuning fork 201 having two teeth, an X drive coil 202 for X scanning that vibrates the teeth of the tuning fork 201, a Y drive coil 203 for Y scan, and a tuning fork 201. The mount 204 is provided. One tooth portion of the tuning fork 201 is provided with an optical fiber (not shown) that guides the illumination light from the light source along the longitudinal direction. The optical fiber extends to the tip of the tooth portion. The outgoing light from the optical fiber travels to the lens unit 205 provided on the tip side of the tuning fork 201.

  Further, a bias magnet 206 made of a permanent magnet is provided on the tooth portion of the tuning fork 201 as a magnet for applying a bias magnetic field to the tuning fork 201. A driving force in the X-axis direction of the tooth portion is generated by the interaction of the magnetic fields generated by the X drive coil 202 and the bias magnet 206, respectively. The position of the bias magnet 206 on the tooth portion of the tuning fork 201 can be arbitrarily adjusted, and the tooth portion can be vibrated at a desired frequency by changing the position of the bias magnet 206. As shown in FIG. 7B, the bias magnet 206 is provided so that the S pole side is in contact with the tooth portion of the tuning fork 201 for convenience. For this reason, the installation surface of the bias magnet 206 with respect to the tuning fork 201 is magnetized to the N pole. Therefore, the base end of the tuning fork 201 is magnetized to the south pole. A permanent magnet 207 used for Y-scan is provided at the rear end of the fork. For convenience, the permanent magnet 207 is provided such that the S pole is arranged on the Y axis positive direction side and the N pole is arranged on the Y axis negative direction side. As shown in FIG. 7A, when the scanning device 200 is in a resting state, the base end of the tuning fork 201 is magnetized to the south pole by the bias magnet 206, so the base end of the tuning fork 201 is the permanent magnet 207. It is still in a state of being drawn toward the N pole side.

FIGS. 8A to 8C show the driving state of the scanning device 200 at times 0, t ₁ , t ₂ , t ₃ , and t ₄ , respectively. FIG. 9 shows a current input state to the Y drive coil 205 when the scanning device 200 is driven.

As shown in FIG. 8B, at time 0, the tuning fork 201 is not magnetized by the Y drive coil 205, but as explained in FIG. Since the base end is magnetized to the south pole, the base end of the tuning fork 201 is drawn toward the north pole side of the permanent magnet 207, and the base end of the tuning fork 201 moves from the neutral position to the north pole side with respect to the permanent magnet 207. It is in a shifted position. From time 0 toward t _1, plus the current flowing through the Y drive coils 205 is increased, the proximal end of the tuning fork 201 is gradually being magnetized more strongly N-pole. At time t _1, as shown in FIG. 8 (a), the proximal end of the tuning fork 201 are attracted to S pole of the permanent magnet 207, the tip of the tuning fork 201 is in a state inclined in the Y axis negative direction. From the time _{t 1} toward _{t 2,} positive current flowing in the Y drive coils 205 gradually decreases at time _{t 2,} the current flowing through the Y drive coils 205 becomes 0. At time t ₂ , as in time 0, as shown in FIG. 8B, the tuning fork 201 is not magnetized by the Y drive coil 205, and the base end of the tuning fork 201 is in a neutral position with respect to the permanent magnet 207. To a position shifted from the N pole side.

From time t ₂ to t ₃ , the negative current flowing through the Y drive coil 205 increases, and the base end of the tuning fork 201 is more strongly magnetized to the south pole. At time t ₃ , as shown in FIG. 8C, the base end of the tuning fork 201 is drawn toward the north pole side of the permanent magnet 207, and the tip of the tuning fork 201 is inclined in the positive direction of the Y axis. From time _{t 3} toward _{t 4,} the negative current flowing in the Y drive coils 205 is reduced. Then, at time _{t 4,} current flowing in the Y drive coils 205 is the same as the state of the result time 0, _{t 2} to 0. Then, by repeating the state from time zero to t ₄ periodically tuning fork 201 periodically vibrate in the Y-axis direction.

  Therefore, the observation object is scanned with the illumination light when the tuning fork 201 vibrates in the X-axis direction and the Y-axis direction. The light reflected from the observation object enters the objective lens of the lens unit 205 and returns to the optical fiber, and an observation image is generated via a subsequent photodetector or the like.

JP 2008-514970 A

  In the conventional scanning confocal endoscope scanning device as described above, the base end of the tuning fork that faces the Y-scan permanent magnet is permanent from the neutral position in the resting state as shown in FIG. The state of being attracted to one magnetic pole of the magnet or the state of being repelled from the other magnetic pole continues. For this reason, when the scanning device is in a resting state, a permanent deformation of the mount may occur due to the deformation force constantly applied from the tuning fork to the mount that holds the tuning fork. Further, when the scanning device is in a driving state, when the value of the current flowing through the Y drive coil becomes 0 A, the position of the base end of the tuning fork with respect to the permanent magnet deviates from the neutral position, and the acquired image is blurred. Distortion may occur.

  The present invention has been made in view of the above circumstances. An object of the present invention is to provide a scanning device that can acquire an image free from blurring and distortion while preventing permanent distortion of a mount that supports a tuning fork.

  A scanning device according to an embodiment of the present invention that solves the above problems includes a fork member having a point light source that functions as a confocal pinhole, a magnet that applies a bias magnetic field to the fork member, and a support for the fork member. And a scanning confocal endoscope scanning device having a coil for magnetizing the base end of the fork member, and an electromagnet facing the base end of the fork member is provided to energize the coil and the electromagnet. Control means for controlling and vibrating the fork member is provided. Therefore, when the scanning device is in a resting state, the current value flowing through the electromagnet that generates vibration of the fork member is set to 0 A, and the fork member is stopped at the neutral position with respect to the electromagnet, which has been a concern in the past. Can be prevented. Even when the scanning device is in a driving state, when the current value flowing through the coil is set to 0 A and the fork member moves to the neutral position, the current value flowing through the electromagnet also becomes zero, and the fork member may deviate from the neutral position. Therefore, it is possible to prevent image blurring and distortion.

  More preferably, the control means controls the energization to the coil and the electromagnet to turn off the energization to the coil and the electromagnet at a predetermined timing, while the magnetic poles alternately alternate between the base end of the fork member and the electromagnet. Magnetize so as to reverse, and magnetize the other so that the magnetic pole does not reverse.

  According to the scanning device of the present invention, it is possible to acquire an image free from blurring or distortion while preventing permanent deformation of the mount that supports the fork member.

FIG. 1A is a schematic view showing a confocal optical unit having a scanning device according to an embodiment of the present invention, and FIG. 1B is a perspective view showing an outline of the internal configuration of the scanning device. FIG. 2 is a schematic cross-sectional view of a scanning device according to an embodiment of the present invention. 3A to 3C are schematic cross-sectional views illustrating the driving state of the scanning device according to the first embodiment of the present invention. 4A and 4B are graphs showing the energization state of the Y drive coil and the electromagnet of the scanning device according to the first embodiment of the present invention. FIGS. 5A to 5C are schematic cross-sectional views illustrating a driving state of the scanning device according to the second embodiment of the present invention. FIGS. 6A and 6B are graphs showing the energization state of the Y drive coil and the electromagnet of the scanning device according to the second embodiment of the present invention. FIG. 7A is a schematic sectional view of a conventional scanning device, and FIG. 7B is a diagram showing a tuning fork in the conventional scanning device. 8A to 8C are schematic cross-sectional views showing a driving state of a conventional scanning device. FIG. 9 is a graph showing the energization state of the Y drive coil of the conventional scanning device.

  Hereinafter, a scanning device according to an embodiment of the present invention will be described with reference to the drawings. In addition, the same number is attached | subjected, when showing the same member over several figures.

  FIG. 1A is a schematic diagram showing a confocal optical unit 10 having a scanning device 100 according to an embodiment of the present invention. Hereinafter, in describing the configuration of the confocal optical unit 10, for convenience, the Z axis is defined in the longitudinal direction of the confocal optical unit 10, and two axes orthogonal to the Z axis and orthogonal to each other are defined as the X axis and the Y axis. Axis. As shown in FIG. 1 (a), the endoscope front side is defined as the positive direction of the Z axis, the upward direction on the paper is defined as the positive direction of the Y axis, and the front side of the paper is defined as the positive direction of the X axis. In FIG. 1A, only the inner cylinder 102, the optical fiber 103, and the shape memory alloy 104 among the components of the scanning device 100 are shown.

  The confocal optical unit 10 is provided at the distal end portion of the scanning confocal endoscope. As shown to Fig.1 (a), the confocal optical unit 10 has the metal outer cylinder 101 which accommodates each component of a unit. The outer cylinder 101 holds an inner cylinder 102 having an outer wall surface shape corresponding to the inner wall surface shape of the outer cylinder 101 so as to be coaxial and slidable in the Z-axis direction. The exit end of the optical fiber 103 is supported inside the inner cylinder 102 through openings formed in the base end surfaces of the outer cylinder 101 and the inner cylinder 102. The output end of the optical fiber 103 can be regarded as a point light source that functions as a confocal pinhole.

  The confocal optical unit 10 includes a compression coil spring 105 between the proximal end surface of the inner cylinder 102 and the inner wall surface of the outer cylinder 101. An arbitrary elastic material can be used instead of the compression coil spring 105. The compression coil spring 105 is sandwiched between the base end face of the inner cylinder 102 and the inner wall surface of the outer cylinder 101 in an initially compressed state from the natural length in the Z-axis direction.

  The confocal optical unit 10 has a shape memory alloy 104 as a guide member made of a shape memory material that expands and contracts in the Z-axis direction. The shape memory alloy 104 has one end fixed to the base end surface of the inner cylinder 102 and the other end fixed to the inner wall surface of the outer cylinder 101. The shape memory alloy 104 has a property of deforming when an external force is applied at room temperature and restoring a predetermined shape by a shape memory effect when heated to a certain temperature or more by energization.

  The shape memory alloy 104 extends in the Z-axis direction by applying a restoring force of the compression coil spring 105 at room temperature. The shape memory alloy 104 is designed such that the restoring force due to the shape memory effect is larger than the restoring force of the compression coil spring 105.

  The shape of the shape memory alloy 104 is controlled by heating the shape memory alloy 104 itself by energizing the shape memory alloy 104. Specifically, when the shape memory alloy 104 is heated by energization, the shape memory alloy 104 contracts in the Z-axis direction against the restoring force of the compression coil spring 105. As the shape memory alloy 104 contracts, the inner cylinder 102 fixed to one end of the shape memory alloy 104 moves backward in the Z-axis direction along with the optical fiber 103 supported by the inner cylinder 102. The amount of contraction of the shape memory alloy 104 is precisely controlled by the amount of current supplied to the shape memory alloy 104. This energization amount (that is, the amount of movement of the optical fiber 103 in the Z-axis direction) varies according to, for example, an operator's operation for adjusting the Z-axis movement amount in the operation portion of the endoscope.

  The shape memory alloy 104 loses or weakens its restoring force due to the shape memory effect when energization stops and returns to room temperature, or when the temperature decreases due to a decrease in the energization amount. And it extends in the Z-axis direction by the restoring force of the compression coil spring 105. The proximal end surface of the inner cylinder 102 is pushed by the restoring force of the compression coil spring 105, and moves forward in the Z-axis direction together with the optical fiber 103 in the outer cylinder 101.

  Laser light emitted from the exit end of the optical fiber 103 is focused on the surface or surface layer of the subject via the lens unit of the scanning device 100. This focal position is displaced in the Z-axis direction according to the advance and retreat of the exit end of the optical fiber 103 that functions as a point light source. That is, the confocal optical unit 10 moves in the biaxial direction (X-axis direction and Y-axis direction) of the exit end of the optical fiber 103, and the uniaxial direction (Z-axis) of the exit end by the compression coil spring 105 and the shape memory alloy 104. The object is three-dimensionally scanned.

  Light incident on the exit end of the optical fiber 103 propagates through the optical fiber 103. The light propagating through the optical fiber 103 is sent to a video processor (not shown) to which an endoscope is connected, and is detected by a photodetector. The video processor, for example, separates light from the optical fiber 103 from light from the light source by a photocoupler incorporated in a connection connector connected to the scanning confocal endoscope. This detection signal is input to the image generation circuit, and the image generation circuit assigns a pixel address to the point image represented by each detection signal according to the detection timing of the detection signals sequentially input. The image generation circuit buffers an image signal composed of a spatial arrangement of each point image in the frame memory in units of frames according to the assigned pixel address. The buffered signal is swept from the frame memory at a predetermined timing, and converted into a video signal conforming to a predetermined standard such as NTSC or PAL. By sequentially inputting the converted video signals to the monitor, a three-dimensional confocal image of the subject with high magnification and high resolution is displayed on the monitor.

  FIG. 1B is a perspective view showing the internal configuration of the scanning device 100. The scanning device 100 includes a tuning fork 111 that is a fork member having two tooth portions, an X drive coil 112 for X scan that vibrates the tooth portions of the tuning fork 111, a Y drive coil 113 for Y scan, and a tuning fork 111. It has a mount 114 made of an elastic material such as urethane that is penetrated and gripped. One tooth portion of the tuning fork 111 is provided with an optical fiber 103 that guides illumination light from the light source along the longitudinal direction. The optical fiber 103 extends to the tip of the tooth portion. Light emitted from the optical fiber 103 travels to the lens unit 115 provided on the tip side of the tuning fork 111.

  The tuning fork 111 is made of a material having magnetic permeability such as an electromagnetic steel plate. In addition, a bias magnet 116 made of a permanent magnet is provided on a tooth portion of the tuning fork 111, and a driving force of the tooth portion is generated by the interaction of magnetic fields generated by the X drive coil 112 and the bias magnet 116, respectively. The position of the bias magnet 116 on the tooth portion of the tuning fork 111 can be arbitrarily adjusted, and the tooth portion can be vibrated at a desired frequency by changing the position of the bias magnet 116.

  Further, the scanning device 100 includes an electromagnet 117 provided at a position facing the base end of the tuning fork 111. The electromagnet 117 is magnetized to the N pole or the S pole or transitions to a state having no magnetic pole based on energization control by a controller or the like provided as a control means provided in the video processor. Therefore, conventionally, when the shape memory alloy is deformed by energizing the shape memory alloy, thermal demagnetization of the permanent magnet occurs due to the heat generation of the shape memory alloy, which affects the scanning operation of the scanning device. Although there is a possibility, in the present invention, by controlling the energization of the electromagnet while considering the heat generation of the shape memory alloy 104 due to the energization of the shape memory alloy 104, the scanning device can be used without worrying about thermal demagnetization. A scanning operation can also be performed. Specific energization control of the electromagnet 117 will be described later.

  Hereinafter, two examples in the embodiment of the present invention will be described.

  FIG. 2 is a side sectional view of the scanning device 100 in the resting state in which scanning is not performed in the first embodiment. As shown in FIG. 2, in the resting state, since the energization to the electromagnet 117 is stopped, no magnetic pole is generated in the electromagnet 117. A bias magnet 116 is provided so that the S pole side is in contact with the tooth portion of the tuning fork 111. For this reason, the installation surface of the bias magnet 116 with respect to the tuning fork 111 is magnetized to the N pole. Therefore, the base end of the tuning fork 111 is magnetized to the south pole. However, since no magnetic pole is generated in the electromagnet 117, the proximal end of the tuning fork 111 is stationary at a neutral position with respect to the electromagnet 117. For this reason, in the present invention, since the stationary position of the tuning fork 111 does not deviate from the neutral position when the scanning device 100 is in the resting state, permanent deformation of the mount 114 can be prevented.

FIGS. 3A to 3C show states when the scanning device 100 is driven at times 0, t ₁ , t ₂ , t ₃ , and t ₄ in the first embodiment. FIGS. 4A and 4B show temporal changes in current input states to the Y drive coil 113 and the electromagnet 117 when the scanning device 100 is driven. For convenience, as can be seen from FIGS. 3 (a), 3 (c) and 4 (b), when a positive current is passed through the electromagnet 117, the electromagnet 117 has an N pole on the Y axis negative direction side and a positive Y axis. Assume that the south pole is generated on the direction side. Hereinafter, a description will be given with reference to FIGS. 3A to 3C and FIGS. 4A and 4B.

At time 0, as shown in FIGS. 4A and 4B, the currents flowing through the Y drive coil 113 and the electromagnet 117 are 0, respectively. 3B, the base end of the tuning fork 111 is in a neutral position with respect to the electromagnet 117. From time 0 toward t _1, positive current increases flowing through the Y drive coils 113 and the electromagnet 117, with the proximal end of the tuning fork 111 will be magnetized more strongly N-pole, becomes stronger pole occurring electromagnet 117 Go. At time t _1, as shown in FIG. 3 (a), the proximal end of the tuning fork 111 are attracted to the S pole side caused by the electromagnet 117, the tip of the tuning fork 111 is in a state inclined in the Y axis negative direction.

From time t ₁ to time t ₂ , the positive current flowing through the Y drive coil 113 and the electromagnet 117 gradually decreases, and the magnetic force generated at the base end of the tuning fork 111 and the electromagnet 117 gradually decreases. At time t ₂ , both currents flowing in the Y drive coil 113 and the electromagnet 117 become zero. At time t ₂ , as in time 0, as shown in FIG. 3B, the tuning fork 111 is not magnetized by the Y drive coil 113, and the proximal end of the tuning fork 111 is in a neutral position with respect to the electromagnet 117. Moving.

From time t ₂ to t ₃ , a large negative current gradually flows in the Y drive coil 113, and a large positive current gradually flows in the electromagnet 117. Therefore, the base end of the tuning fork 111 is more strongly magnetized to the south pole, and the magnetic pole generated in the electromagnet 117 becomes stronger. At time t ₃ , as shown in FIG. 3C, the base end of the tuning fork 111 is drawn toward the N pole side of the electromagnet 117, and the tip of the tuning fork 111 is tilted in the Y-axis positive direction.

From time t ₃ to t ₄ , the negative current flowing through the Y drive coil 113 decreases, and the positive current flowing through the electromagnet 117 also decreases. Then, at time _{t 4,} current flowing in the Y drive coils 113 and the electromagnet 117 are both 0. At time t ₄ , similarly to times 0 and t ₂ , as shown in FIG. 3B, the tuning fork 111 is not magnetized by the Y drive coil 113, and the base end of the tuning fork 111 is in contact with the electromagnet 117. Move to neutral position. Then, by repeating the state from time zero to t ₄ periodically tuning fork 111 is periodically vibrated in the Y-axis direction.

In the first embodiment, no magnetic pole is generated in the electromagnet 117 at times 0, t ₂ and t ₄ . Therefore, regardless of whether the base end of the tuning fork 111 is magnetized to the N pole or the S pole by the bias magnet 116, the tuning fork 111 is not attracted in the positive or negative Y-axis direction from the neutral position as in the prior art. Move to position. As described above, since the base end of the tuning fork 111 does not deviate from the neutral position, no blur or distortion occurs in the image acquired by the optical fiber 103.

  Next, a second embodiment of the present invention will be described. Since the second embodiment is the same as the first embodiment except that the energization states of the tuning fork 111 and the electromagnet 117 are different, the description of each component of the scanning device 100 is omitted. Further, in the second embodiment, the scanning device 100 in a resting state in which scanning is not performed is the same as that in FIG.

FIGS. 5A to 5C show the driving state of the scanning device 100 at times 0, t ₁ , t ₂ , t ₃ , and t ₄ in the _second embodiment. FIGS. 6A and 6B show temporal changes in the input state of current to the Y drive coil 113 and the electromagnet 117 when the scanning device 100 is driven. For convenience, as shown in FIG. 5A, when a positive current is passed through the electromagnet 117, the electromagnet 117 has an N pole on the Y axis negative direction side and an S pole on the Y axis positive direction side. To do. Hereinafter, a description will be given with reference to FIGS. 5A to 5C and FIGS. 6A and 6B.

At time 0, as shown in FIGS. 6A and 6B, the currents flowing through the Y drive coil 113 and the electromagnet 117 are 0, respectively. 5B, the base end of the tuning fork 111 is in a neutral position with respect to the electromagnet 117. From time 0 toward t _1, positive current increases flowing through the Y drive coils 113 and the electromagnet 117, with the proximal end of the tuning fork 111 will be magnetized more strongly N-pole, becomes stronger pole occurring electromagnet 117 Go. At time t _1, as shown in FIG. 5 (a), the proximal end of the tuning fork 111 are attracted to the S pole side caused by the electromagnet 117, the tip of the tuning fork 111 is in a state inclined in the Y axis negative direction.

From time t ₁ to time t ₂ , the positive current flowing through the Y drive coil 113 and the electromagnet 117 gradually decreases, and the magnetic force generated at the base end of the tuning fork 111 and the electromagnet 117 gradually decreases. At time t ₂ , both currents flowing in the Y drive coil 113 and the electromagnet 117 become zero. At time t ₂ , as in time 0, as shown in FIG. 5B, the tuning fork 111 is not magnetized by the Y drive coil 113, and the proximal end of the tuning fork 111 is in a neutral position with respect to the electromagnet 117. Moving.

From the time t ₂ over the t _3, progressively larger positive current flows in the Y drive coils 113, as shown in FIG. 6 (a), is gradually larger negative current to the electromagnet 117 as shown in FIG. 6 (b) Flows. Therefore, the base end of the tuning fork 111 is more strongly magnetized to the north pole, and the magnetic pole generated in the electromagnet 117 is stronger. Since a negative current flows through the electromagnet 117, the electromagnet 117 generates an S pole on the Y axis negative direction side and an N pole on the Y axis positive direction side, as shown in FIG. At time t ₃ , as shown in FIG. 5C, the base end of the tuning fork 111 is drawn toward the S pole side of the electromagnet 117, and the tip of the tuning fork 111 is inclined in the positive direction of the Y axis.

From time _{t 3} toward _{t 4,} plus the current flowing through the Y drive coils 113 is reduced, also decreases the negative current flowing in the electromagnet 117. Then, at time _{t 4,} current flowing in the Y drive coils 113 and the electromagnet 117 are both 0. At time t ₄ , similarly to times 0 and t ₂ , as shown in FIG. 6B, the tuning fork 111 is not magnetized by the Y drive coil 113, and the base end of the tuning fork 111 is not connected to the electromagnet 117. Move to neutral position. Then, by repeating the state from time zero to t ₄ periodically tuning fork 111 is periodically vibrated in the Y-axis direction.

As in the first embodiment, in the second embodiment, no magnetic pole is generated in the electromagnet 117 at times 0, t ₂ , and t ₄ . Therefore, even if the base end of the tuning fork 111 is magnetized to the south pole by the bias magnet 116, it is not attracted in the positive or negative Y-axis direction from the neutral position as in the prior art, and moves to the neutral position. As described above, since the base end of the tuning fork 111 does not deviate from the neutral position, no blur or distortion occurs in the image acquired by the optical fiber 103.

  As shown in the first and second embodiments, in the present invention, the effects of the present invention can be achieved even if the input waveforms of the current applied to the tuning fork and the electromagnet are interchanged. That is, in the first embodiment, the Y drive coil 113 is energized as before, and the magnetic pole at the base end of the tuning fork 111 is alternately switched between the N pole and the S pole, while the electromagnet 117 does not switch the magnetic pole. By energizing to control only the magnetic force, the tuning fork 111 is periodically vibrated to vibrate in the Y-axis direction. In contrast, in the second embodiment, the Y drive coil 113 is energized to control only the magnetic force without switching the base magnetic pole of the tuning fork 111 while alternately switching the magnetic pole of the electromagnet 117 between the N pole and the S pole. Then, the tuning fork 111 is vibrated periodically to vibrate in the Y-axis direction. In any of the embodiments, the phenomenon in which the base end of the tuning fork 111 is continuously attracted in the positive or negative Y-axis direction from the neutral position when the scanning device 100 is in a resting state can be avoided to prevent permanent distortion. . Further, during the drive control of the scanning device 100, even when the tuning fork 111 moves to the neutral position during vibration (FIGS. 3B and 5B), the base end of the tuning fork 111 is positive or negative from the neutral position. Since there is no shift in any of the Y-axis directions, a captured image without blurring or distortion can be acquired.

  The above is the description of the embodiment of the present invention, but the present invention is not limited to the above-described configuration, and various modifications can be made within the scope of the technical idea of the present invention. For example, in the above description, the base end of the tuning fork is magnetized to the south pole by the bias magnet. However, even when the polarity of the bias magnet is reversed and the base end of the tuning fork is magnetized to the north pole, As described, the effect of the present invention can be achieved by controlling the energization of the Y drive coil and the electromagnet.

100 Scanning Device 104 Shape Memory Alloy 111 Tuning Fork 113 Y Drive Coil 114 Mount 116 Bias Magnet 117 Electromagnet

Claims (2)

Scanning having a fork member having a point light source that functions as a confocal pinhole, a magnet that applies a bias magnetic field to the fork member, a mount that supports the fork member, and a coil that magnetizes the proximal end of the fork member In a confocal endoscope scanning device,
An electromagnet is provided opposite the proximal end of the fork member;
Control means for controlling energization to the coil and the electromagnet to vibrate the fork member;
A scanning device characterized by that.   The control means controls energization to the coil and the electromagnet to turn off the energization to the coil and the electromagnet at a predetermined timing, and sets one of the base end of the fork member and the electromagnet as a magnetic pole. The scanning device according to claim 1, wherein the magnet is magnetized so as to be reversed alternately, and the other is magnetized so that the magnetic pole is not reversed.

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