WO2017203581A1

WO2017203581A1 - Optical fiber scanner

Info

Publication number: WO2017203581A1
Application number: PCT/JP2016/065221
Authority: WO
Inventors: 雅史山田; 靖明葛西
Original assignee: オリンパス株式会社
Priority date: 2016-05-23
Filing date: 2016-05-23
Publication date: 2017-11-30
Also published as: JPWO2017203581A1

Abstract

According to the present invention, an optical fiber scanner (10) is provided with: an optical fiber (1); a piezoelectric element (3) fixed to the optical fiber (1); a drive line (6), the leading end of which is connected to a connecting surface (3a) of the piezoelectric element (3); a holder (4) that holds the optical fiber (1) in a cantilever state; and a wiring path (5), which is provided in the holder (4), and which guides the drive line (6) from the base end side of the holder (4) to the leading end side of the holder. In the diameter direction of the optical fiber (1), the leading end of the wiring path (5) is at a position substantially same as that of the connecting surface (3a), or at a position slightly outside of the connecting surface (3a).

Description

Fiber optic scanner

The present invention relates to an optical fiber scanner.

Conventionally, in an optical scanning endoscope, an optical fiber scanner that scans light emitted from an exit end of an optical fiber by vibration of the optical fiber is used (for example, see Patent Document 1). The optical fiber scanner of Patent Document 1 includes a mount member that supports an optical fiber in a cantilever shape, and a piezoelectric element that is fixed to the outer peripheral surface of the optical fiber on the tip side of the mount member. The tip of the optical fiber is vibrated by vibration. In order to cause the piezoelectric element to expand and contract, a voltage is applied to the piezoelectric element via a cable.

JP2015-128549A

The cable is wired from the base end of the optical fiber to the piezoelectric element via a mounting member having a diameter larger than that of the optical fiber, and the front end of the cable is joined to the piezoelectric element by a conductive adhesive. Therefore, as shown in FIG. 11 of Patent Document 1, the distal end portion of the cable is bent according to the step between the piezoelectric element and the mount member in the radial direction of the optical fiber, and is elastically restored to return to a linear shape. Force is generated at the end of the cable. This elastic restoring force causes the tip of the cable to move away from the electrode during the curing of the adhesive, and it is difficult to ensure a good electrical connection between the cable and the piezoelectric element.

The elastic restoring force can be reduced by ensuring a long projecting length of the cable projecting from the mount member to the tip side. However, in this case, a long cable lying on the piezoelectric element hinders the expansion and contraction vibration of the piezoelectric element, which may affect the vibration characteristics of the optical fiber.

The present invention has been made in view of the circumstances described above, and is an optical fiber that can ensure a good electrical connection between a drive line and a piezoelectric element without affecting the vibration characteristics of the optical fiber. An object is to provide a scanner.

In order to achieve the above object, the present invention provides the following means.
The present invention is opposite to an optical fiber that emits light from the tip, a piezoelectric element that is fixed to the optical fiber and expands and contracts in the longitudinal direction of the optical fiber by applying a driving voltage, and a surface that is fixed to the optical fiber. A driving line for supplying a driving voltage to the piezoelectric element, the optical fiber being held in a cantilever shape on the proximal side of the piezoelectric element. A holder, and a wiring path that is provided in the holder along the longitudinal direction of the optical fiber and guides the drive line from the proximal end side to the distal end side of the holder along the longitudinal direction, the distal end of the wiring path However, the present invention provides an optical fiber scanner which is positioned substantially at the same position as the connection surface of the piezoelectric element or slightly outside the connection surface in the radial direction of the optical fiber.

According to the present invention, when a driving voltage is applied to the piezoelectric element via the driving line, the piezoelectric element is deformed in the longitudinal direction of the optical fiber by the inverse piezoelectric effect, and the optical fiber to which the piezoelectric element is fixed is bent and deformed. The tip of the optical fiber is displaced in the radial direction. Thereby, the light emitted from the tip of the optical fiber can be scanned.

In this case, since the radial step between the tip of the wiring path and the connecting surface of the piezoelectric element is slight, the tip of the drive line extending substantially linearly from the tip of the wiring path contacts the connecting surface of the piezoelectric element. Can be made. That is, the tip end portion of the drive line is brought into contact with the connection surface without generating stress at the tip end portion of the drive line without securing a long projecting length of the drive line from the tip end of the wiring path. Can be arranged. This prevents the tip of the drive line from moving alone in the process of joining the tip of the drive line to the connecting surface of the piezoelectric element with an adhesive, and provides a good electrical connection between the drive line and the piezoelectric element. Can be secured.

In the above invention, the wiring passage extends linearly in parallel to the longitudinal direction of the optical fiber from the proximal end of the holder to a middle position in the longitudinal direction of the holder, and the holder from the distal end of the linear portion An inclined portion extending obliquely with respect to the longitudinal direction of the optical fiber to the distal end of the optical fiber, and the inclined portion is inclined in a direction in which the distal end of the inclined portion is located inward in the radial direction from the proximal end, In addition, the radially inner end of the inclined portion at the tip of the inclined portion may be located on the outer side in the radial direction than the connection surface of the piezoelectric element.
By doing in this way, the front-end | tip part of a drive line protrudes diagonally toward the connection surface of a piezoelectric element from the front-end | tip of a wiring channel | path. Thereby, in the step of wiring the drive line, the tip of the drive line can be reliably and easily brought into contact with the connection surface.

In the above invention, the wiring path extends linearly from the proximal end to the distal end of the holder in parallel with the longitudinal direction of the optical fiber, and the radial direction of the wiring path at the connection surface and the distal end of the wiring path The inner ends may be located at substantially the same position in the radial direction.
By doing in this way, the front-end | tip part of the drive line which protrudes linearly in parallel with the longitudinal direction of an optical fiber from the front-end | tip of a wiring channel | path is arrange | positioned on the connection surface of a piezoelectric element. Thereby, in the step of wiring the drive line, the tip of the drive line can be reliably and easily brought into contact with the connection surface.

In the above-mentioned invention, a projection may be provided on the connection surface of the piezoelectric element and against which the tip of the drive line is abutted.
By doing in this way, the movement of the front end of the drive line that has come into contact with the protrusion is more reliably prevented by the friction between the front end of the drive line and the protrusion. Thereby, the favorable electrical connection between a drive line and a piezoelectric element can be ensured further reliably.

In the above invention, the drive line may be a flexible wiring board.
By doing in this way, a drive line can be made into a thinner structure.
In the above invention, the tip of the drive line may be joined to the connection surface of the piezoelectric element with a conductive resin or a solder material.
By doing so, it is possible to secure a better electrical connection between the drive line and the piezoelectric element.

In the above invention, the wiring passage may include a cylindrical guide pipe that accommodates the drive line. Further, the wiring passage may be provided with a groove or a hole formed in the holder in the longitudinal direction and accommodating the guide pipe.

In the said invention, the cylindrical ferrule fixed to the outer peripheral surface of the said optical fiber may be provided, and the said piezoelectric element may be fixed to the outer peripheral surface of the said ferrule.
By doing in this way, an optical fiber can be structurally reinforced with the ferrule which covers the outer peripheral surface of an optical fiber.

According to the present invention, there is an effect of securing a good electrical connection between the drive line and the piezoelectric element without affecting the vibration characteristics of the optical fiber.

1 is a side view showing an overall configuration of an optical fiber scanner according to a first embodiment of the present invention. It is the front view which looked at the optical fiber scanner of Drawing 1A from the tip side. FIG. 1B is an enlarged view of region I of the optical fiber scanner of FIG. 1A. It is a side view which shows the whole structure of the 1st modification of the optical fiber scanner of FIG. 1A. It is the front view which looked at the optical fiber scanner of Drawing 3A from the tip side. It is a side view which shows the whole structure of the 2nd modification of the optical fiber scanner of FIG. 1A. It is the front view which looked at the optical fiber scanner of Drawing 4A from the tip side. It is a side view which shows the partial structure of the 3rd modification of the optical fiber scanner of FIG. 1A. It is a side view which shows the whole structure of the optical fiber scanner which concerns on the 2nd Embodiment of this invention. It is the front view which looked at the optical fiber scanner of Drawing 6A from the tip side. FIG. 6B is an enlarged view of region VI of the optical fiber scanner of FIG. 6A. It is a side view which shows the partial structure of the optical fiber scanner which concerns on the 3rd Embodiment of this invention. It is a longitudinal cross-section which shows the structure of the guide pipe provided in the optical fiber scanner of FIG. It is a side view which shows the partial structure of the modification of the optical fiber of FIG. It is a side view which shows the whole structure of the modification of the optical fiber scanner of FIG. It is a side view which shows the whole structure of the modification of the optical fiber scanner of FIG. 1A.

(First embodiment)
Hereinafter, an optical fiber scanner 10 according to a first embodiment of the present invention will be described with reference to FIGS. 1A to 5.
As shown in FIG. 1A, the optical fiber scanner 10 according to this embodiment is fixed to the optical fiber 1, the cylindrical ferrule 2 that covers the outer peripheral surface of the optical fiber 1, and the outer peripheral surface of the ferrule 2. The piezoelectric element 3, a holder 4 that holds the optical fiber 1 and the ferrule 2 in a cantilever shape, a wiring path 5 provided in the holder 4, and a drive line 6 connected to the piezoelectric element 3 are provided. .

The optical fiber 1 is connected to a light source (not shown) at the proximal end, guides light incident on the proximal end from the light source to the distal end, and exits from the distal end.
The ferrule 2 is a square cylindrical member made of a conductive elastic material. The ferrule 2 has a through hole penetrating in the longitudinal direction along the central axis, and the optical fiber 1 is inserted into the through hole. The ferrule 2 is fixed to the outer peripheral surface of the optical fiber 1 at a position spaced from the distal end of the optical fiber 1 to the proximal end side, and the distal end portion of the optical fiber 1 protrudes from the opening on the distal end side of the through hole.
In addition, the shape of the ferrule 2 is not limited to a rectangular tube shape, and may be another polygonal tube shape or a cylindrical shape, for example.

The piezoelectric element 3 is a rectangular flat plate made of a piezoelectric ceramic material such as lead zirconate titanate (PZT). Each piezoelectric element 3 has electrodes formed on the front surface 3b and the back surface 3c facing each other in the thickness direction, and is polarized in the thickness direction. One piezoelectric element 3 is fixed to each of the four outer surfaces of the ferrule 2 by a conductive adhesive so that the thickness direction coincides with the radial direction of the optical fiber 1. Thus, the piezoelectric element 3 is fixed to the outer peripheral surface of the optical fiber 1 via the ferrule 2. Of the front surface 3b and the back surface 3c of the piezoelectric element 3, the surface opposite to the surface fixed to the optical fiber 1 via the ferrule 2 is a connection surface 3a to which the tip of the drive line 6 is connected.

The holder 4 is a cylindrical member made of a conductive material, and has a central hole 4a penetrating in the longitudinal direction as shown in FIG. 1B. The holder 4 is provided on the base end side with respect to the piezoelectric element 3, and is fixed to the outer peripheral surface of the ferrule 2 with a conductive adhesive in a state where the ferrule 2 is fitted in the central hole 4a. A part of the holder 4 in the longitudinal direction is provided with a large diameter part 4b having a larger diameter than the other parts, and the large diameter part 4b is fixed to the inner wall of a frame (not shown) that accommodates the entire optical fiber scanner 10. . Thereby, the ferrule 2 and the optical fiber 1 are supported by the holder 4 in the shape of a cantilever having the tip as a free end.

The wiring passage 5 includes a hole formed in the holder 4 in the longitudinal direction and penetrating from the base end surface to the front end surface. The wiring passages 5 are provided at intervals in the circumferential direction of the holder 4 so as to be aligned with the respective piezoelectric elements 3 along the longitudinal direction of the optical fiber 1. Each wiring path 5 is composed of a straight portion 5a and an inclined portion 5b in this order from the base end side.

The straight portion 5 a extends linearly in parallel with the longitudinal direction of the optical fiber 1 from the base end of the holder 4 to a midway position in the longitudinal direction of the holder 4. Further, the straight portion 5 a is formed by a groove opened on the outer peripheral surface of the holder 4. The straight portion 5 a may be a hole closed in the circumferential direction without opening in the outer peripheral surface of the holder 4.
As shown in FIG. 2, the inclined portion 5b extends from the tip of the straight portion 5a to the tip of the holder 4 while being inclined with respect to the longitudinal direction of the optical fiber 1, and the tip of the inclined portion 5b is more than the base end of the inclined portion 5b. The optical fiber 1 is tilted in the direction positioned on the inner side in the radial direction. The radially inner end of the opening 5c of the inclined portion 5b on the tip surface of the holder 4 is located slightly outside the piezoelectric element 3 in the radial direction.

The drive line 6 is accommodated one by one along the longitudinal direction in each wiring passage 5. The distal end portion of the drive line 6 protrudes obliquely with respect to the longitudinal direction of the optical fiber 1 from the inclination of the inclined portion 5b of the wiring passage 5 according to the opening 5c. The connection surface 3a is joined. The adhesive A used here is preferably a resin adhesive or solder.

The base end of each drive line 6 is connected to a power supply (not shown), and the drive voltage supplied from the power supply is transmitted to the electrodes on the connection surface 3a of the piezoelectric element 3. When an alternating voltage is applied as a drive voltage to the electrode on the connection surface 3a, the piezoelectric element 3 expands and contracts in the longitudinal direction of the optical fiber 1, and the tip of the ferrule 2 and the optical fiber 1 to which the piezoelectric element 3 is fixed. Bending vibration is excited in the portion, and the tip of the optical fiber 1 vibrates. Thereby, the light emitted from the tip of the optical fiber 1 can be scanned. Further, the scanning trajectory of light can be controlled by controlling the amplitude and phase of the alternating voltage applied to each piezoelectric element 3. Here, the holder 4 connected to the electrodes on the ferrule 2 side of the four piezoelectric elements 3 via the ferrule 2 functions as a common ground.

In the manufacturing process of such an optical fiber scanner 10, the drive line 6 is wired as follows.
The drive line 6 is inserted into the wiring path 5 from the base end side of the holder 4, and the drive line 6 is pushed into the wiring path 5 until the tip of the drive line 6 contacts the connection surface 3 a of the piezoelectric element 3. Next, the adhesive A is applied to the tip of the drive line 6, and the adhesive A is cured to join the tip of the drive line 6 to the connection surface 3 a of the piezoelectric element 3.

In this case, according to the present embodiment, the distal end portion of the drive line 6 protrudes obliquely from the opening 5c of the wiring passage 5 toward the connection surface 3a of the piezoelectric element 3, so that the distal end portion of the drive line 6 is a straight line. The tip of the drive line 6 is in contact with the connection surface 3a. That is, the drive line 6 can be arranged so that the tip of the drive line 6 is in contact with the connection surface 3 a without generating stress at the tip of the drive line 6. Therefore, after positioning the tip of the drive line 6 on the connection surface 3a, the tip of the drive line 6 does not move alone due to elastic restoring force or the like. As a result, the adhesive A can be cured while maintaining the contact between the tip of the drive line 6 and the connection surface 3 a of the piezoelectric element 3, and the connection between the drive line 6 and the connection surface 3 a of the piezoelectric element 3. There is an advantage that a good electrical connection can be ensured.

Furthermore, a step in the radial direction between the connection surface 3a and the opening 5c of the wiring passage 5 is defined as a step D (see FIG. 1B). Since this step D is slight, the tip of the drive line 6 protruding from the opening 5c is shortened. Thereby, the drive line 6 positioned on the piezoelectric element 3 does not hinder the stretching vibration of the piezoelectric element 3, and the wiring line of the drive line 6 can be prevented from affecting the vibration characteristics of the optical fiber 1. There is.

In the present embodiment, the inclined portion 5b of the wiring passage 5 is formed of a hole formed in the holder 4 and closed in the circumferential direction. Instead, as shown in FIGS. 3A and 3B. Similarly to the straight portion 5a, a groove opened on the outer peripheral surface of the holder 4 may be used. Even if it does in this way, there can exist the effect mentioned above.

In the present embodiment, the drive wire 6 is exemplified by a covered wire in which an electric wire is covered with an insulating material. However, as shown in FIG. 4A, a flexible wiring board 61 in which an electrode pattern is formed on the surface of a thin-film flexible substrate. May be used as a drive line. The electrode pattern is formed on the surface of the flexible wiring board 61 on the piezoelectric element 3 side so as to be in direct contact with the connection surface 3 a of the piezoelectric element 3. The cross section of the wiring path 5 of the holder 4 is formed in an elongated rectangular shape corresponding to the cross sectional shape of the flexible wiring board 61 as shown in FIG. 4B. Even if it does in this way, there can exist the effect mentioned above.

In the present embodiment, as shown in FIG. 5, a protrusion 7 may be further provided on the connection surface 3 a of the piezoelectric element 3 so that the tip of the drive line 6 abuts. The protrusion 7 is made of, for example, resin or solder. The protrusion 7 is provided on the distal end side of the contact position so that the distal end of the drive line 6 projecting obliquely from the opening 5c is adjacent to the contact position that contacts the connection surface 3a. In the process of wiring the drive line 6, the drive line 6 is pushed into the wiring path 5 to a position where the tip of the drive line 6 abuts against the protrusion 7. In a state in which the tip of the drive line 6 hits the protrusion 7, the movement of the tip of the drive line 6 is further reliably prevented by the friction between the tip of the drive line 6 and the protrusion 7. Therefore, according to the present modification, a good connection between the drive line 6 and the piezoelectric element 3 can be further ensured.

(Second Embodiment)
Next, an optical fiber scanner 20 according to a second embodiment of the present invention will be described with reference to FIGS. 6A to 7. In the present embodiment, the configuration different from the first embodiment will be mainly described, and the configuration common to the first embodiment will be denoted by the same reference numerals and the description thereof will be omitted.
The optical fiber scanner 20 according to the present embodiment is different from the first embodiment in the shape and position of the wiring passage 51.

In this embodiment, as shown in FIG. 6A, the wiring passage 51 is formed of a hole that is linearly formed in parallel to the longitudinal direction of the optical fiber 1 from the proximal end surface to the distal end surface of the holder 4. As shown in FIGS. 6B and 7, the radial positions of the connection surface 3 a of the piezoelectric element 3 and the radially inner end of the opening 51 c of the wiring passage 51 on the tip surface of the holder 4 are substantially the same. It has become.

In the manufacturing process of such an optical fiber scanner 20, the drive line 6 is wired as follows.
The drive line 6 is inserted into the wiring path 51 from the base end side of the holder 4, and the drive line 6 is pushed into the wiring path 51 until the tip of the drive line 6 is positioned on the connection surface 3 a of the piezoelectric element 3. Next, the adhesive A is applied to the tip of the drive line 6, and the adhesive A is cured to join the tip of the drive line 6 to the connection surface 3 a of the piezoelectric element 3.

In this case, according to the present embodiment, the tip end portion of the drive line 6 protrudes linearly from the opening 51c of the wiring passage 51 in parallel with the longitudinal direction of the optical fiber 1. Here, since there is no or almost no radial step between the connection surface 3 a and the opening 51 c of the wiring passage 51, the drive line 6 contacts the connection surface 3 a of the piezoelectric element 3. That is, the drive line 6 can be arranged so that the tip of the drive line 6 is in contact with the connection surface 3 a without generating stress at the tip of the drive line 6. Therefore, after positioning the tip of the drive line 6 on the connection surface 3a, the tip of the drive line 6 does not move alone due to elastic restoring force or the like. As a result, the adhesive A can be cured while maintaining the contact between the tip of the drive line 6 and the connection surface 3 a of the piezoelectric element 3, and the connection between the drive line 6 and the connection surface 3 a of the piezoelectric element 3. There is an advantage that a good electrical connection can be ensured.

Furthermore, the tip portion of the drive line 6 protruding from the opening 51c can be shortened. Thereby, the drive line 6 positioned on the piezoelectric element 3 does not hinder the stretching vibration of the piezoelectric element 3, and the wiring line of the drive line 6 can be prevented from affecting the vibration characteristics of the optical fiber 1. There is.
In the present embodiment, the modifications of FIGS. 3A to 5 described in the first embodiment may be combined as appropriate. That is, the wiring passage 51 may be configured by a groove opened on the outer peripheral surface of the holder 4. Further, a flexible wiring board 61 may be used instead of the drive line 6. Moreover, the protrusion part 7 may be provided in the connection surface 3a.

(Third embodiment)
Next, an optical fiber scanner according to a third embodiment of the present invention will be described with reference to FIGS. In the present embodiment, configurations different from those in the first and second embodiments will be mainly described, and configurations common to the first and second embodiments will be denoted by the same reference numerals and description thereof will be omitted.
As shown in FIG. 8, the optical fiber scanner according to the present embodiment has a cylindrical guide pipe (wiring path) that accommodates the drive line 6 instead of the

wiring paths

5 and 51 that are holes formed in the holder 4. ) 8 differs from the first and second embodiments in that 8 is provided on the holder 4.

As shown in FIG. 9, the guide pipe 8 is composed of a linear portion 8a extending linearly in order from the base end side, and an inclined portion 8b inclined with respect to the longitudinal direction of the linear portion 8a. The guide pipe 8 is made of a hard tube made of, for example, metal or resin, and has higher rigidity than the drive line 6.

As shown in FIG. 8, the holder 4 is formed with a passage (wiring passage) 4c like the wiring passage 5 in the first embodiment, and the guide pipe 8 is accommodated in the passage 4c. The passage 4c may be constituted by a groove opened on the outer peripheral surface of the holder 4 or may be constituted by a hole closed in the circumferential direction. In the guide pipe 8, the inclined portion 8b is inclined with respect to the longitudinal direction of the optical fiber 1 in the direction in which the distal end is positioned inward in the radial direction with respect to the proximal end of the inclined portion 8b, and the distal end surface of the inclined portion 8b Is held in the passage 4c so that the opening 8c is located slightly outside the connecting surface 3a of the piezoelectric element 3 in the radial direction.

In the manufacturing process of such an optical fiber scanner, the drive line 6 is wired as follows.
The drive line 6 is inserted into the guide pipe 8 attached in the passage 4 c of the holder 4 from the proximal end side of the guide pipe 8, and the drive line 6 is driven until the distal end of the drive line 6 contacts the connection surface 3 a of the piezoelectric element 3. 6 is pushed into the guide pipe 8. Next, the adhesive A is applied to the tip of the drive line 6, and the adhesive A is cured to join the tip of the drive line 6 to the connection surface 3 a of the piezoelectric element 3.

In this case, according to the present embodiment, the tip portion of the drive line 6 protrudes obliquely from the opening 8c of the guide pipe 8 toward the connection surface 3a of the piezoelectric element 3, so that the tip portion of the drive line 6 is a straight line. The tip of the drive line 6 is in contact with the connection surface 3a. That is, the drive line 6 can be arranged so that the tip of the drive line 6 is in contact with the connection surface 3 a without generating stress at the tip of the drive line 6. Therefore, after positioning the tip of the drive line 6 on the connection surface 3a, the tip of the drive line 6 does not move alone due to elastic restoring force or the like. As a result, the adhesive A can be cured while maintaining the contact between the tip of the drive line 6 and the connection surface 3 a of the piezoelectric element 3, and the connection between the drive line 6 and the connection surface 3 a of the piezoelectric element 3. There is an advantage that a good electrical connection can be ensured.

In the present embodiment, the guide pipe 8 is composed of the straight portion 8a and the inclined portion 8b. Instead of this, as shown in FIG. Similarly to the wiring passage 51 in the embodiment, the holder 4 may extend linearly over the entire length. Even if it does in this way, there can exist the effect mentioned above.

In the present embodiment, the guide pipe 8 is provided in the passage 4 c of the holder 4, but instead, as shown in FIG. 11, the passage 4 c is omitted and the guide pipe 8 is attached to the outer periphery of the holder 4. It may be fixed directly to the surface. Even if it does in this way, there can exist the effect mentioned above.
In the present embodiment, the modifications of FIGS. 4A to 5 described in the first embodiment may be combined as appropriate. That is, the flexible wiring board 61 may be used instead of the drive line 6. Moreover, the protrusion part 7 may be provided in the connection surface 3a.

In the first to third embodiments described above, the piezoelectric element 3 is fixed to the optical fiber 1 via the ferrule 2, but instead of this, as shown in FIG. The piezoelectric element 3 may be directly fixed to the outer peripheral surface of the optical fiber 1 by omitting it. In this case, the optical fiber 1 is directly held by the holder 4. FIG. 12 shows a modification of the optical fiber scanner 10 of the first embodiment as an example, but the ferrule 2 can be omitted also in the optical fiber scanners of the second and third embodiments.

DESCRIPTION OF SYMBOLS 1 Optical fiber 2 Ferrule 3 Piezoelectric element 3a Connection surface 4 Holder 4a Center hole 4b Large diameter part 4c Path (wiring path)
5, 51 Wiring path 5a Straight line portion 5b

Inclined portion

5c, 51c Opening 6 Drive line 61 Flexible wiring board (drive line)
7 Protrusion 8 Guide pipe (wiring path)
8a Linear portion 8b Inclined

portion

10, 20 Optical fiber scanner

Claims

An optical fiber that emits light from the tip;
A piezoelectric element that is fixed to the optical fiber and expands and contracts in the longitudinal direction of the optical fiber by application of a driving voltage;
A driving line for supplying a driving voltage to the piezoelectric element having a tip connected to a connecting surface of the piezoelectric element that is a surface opposite to a surface fixed to the optical fiber;
A holder for holding the optical fiber in a cantilever shape on the proximal side from the piezoelectric element;
A wiring path provided in the holder along the longitudinal direction of the optical fiber and guiding the drive line from the proximal end side to the distal end side of the holder along the longitudinal direction;
An optical fiber scanner in which a leading end of the wiring passage is positioned substantially at the same position as the connection surface of the piezoelectric element or slightly outside the connection surface in the radial direction of the optical fiber.
The wiring path is
A linear portion extending linearly in parallel to the longitudinal direction of the optical fiber from the base end of the holder to a midway position in the longitudinal direction of the holder;
An inclined portion extending from the front end of the straight portion to the front end of the holder with an inclination with respect to the longitudinal direction of the optical fiber,
The inclined portion is inclined in a direction in which the distal end of the inclined portion is positioned inward in the radial direction from the base end, and the radially inner end of the inclined portion at the distal end of the inclined portion is the piezoelectric element. The optical fiber scanner according to claim 1, wherein the optical fiber scanner is located outside of the connection surface in the radial direction.
The wiring path extends linearly in parallel to the longitudinal direction of the optical fiber from the proximal end to the distal end of the holder,
2. The optical fiber scanner according to claim 1, wherein the radially inner end of the wiring passage at the connection surface and the tip of the wiring passage is located at substantially the same position in the radial direction.
The optical fiber scanner according to any one of claims 1 to 3, further comprising a protrusion provided on the connection surface of the piezoelectric element and against which a tip of the drive line is abutted.
The optical fiber scanner according to any one of claims 1 to 4, wherein the drive line is a flexible wiring board.
The optical fiber scanner according to any one of claims 1 to 5, wherein a tip end of the drive line is joined to a connection surface of the piezoelectric element by a conductive resin or a solder material.
The optical fiber scanner according to any one of claims 1 to 6, wherein the wiring passage includes a cylindrical guide pipe that accommodates the drive line.
The optical fiber scanner according to claim 7, wherein the wiring passage includes a groove or a hole formed in the holder in the longitudinal direction and accommodating the guide pipe.
A cylindrical ferrule fixed to the outer peripheral surface of the optical fiber,
The optical fiber scanner according to any one of claims 1 to 8, wherein the piezoelectric element is fixed to an outer peripheral surface of the ferrule.