JP6883474B2 - Optical device - Google Patents

Description

The present invention relates to an optical device capable of changing optical characteristics by moving a moving frame in the optical axis direction by a magnetic force.

Conventionally, as an endoscope, an endoscope having an optical device at its tip, whose optical characteristics can be changed by moving a moving frame in the optical axis direction, is known.

In this type of optical device, as an actuator for driving the moving frame, VCM (Voice Coil Motor: Voice Coil) that moves the coil and the magnet relative to each other by using the magnetic field generated in the coil according to Fleming's left-hand rule. Motor) is known.

For example, in Patent Document 1, a fixed portion (fixed frame) for holding a fixed lens group, a movable portion (moving frame) for holding a movable lens and slidable with respect to the fixed portion, and a fixed portion are arranged. An optical unit (optical device) including a coil and a magnet provided in a movable portion is disclosed.

Here, in the optical unit (optical device) disclosed in Patent Document 1, in order to realize miniaturization of the actuator and efficiently transmit the magnetic force to the magnet, the meat penetrating the fixed portion in the radial direction. A punching portion (slit) is provided, and each magnet is fixed to the moving portion so as to be arranged in the lightening portion.

International Publication No. WO2016 / 166857

However, since the optical device used at the tip of the endoscope is extremely small, when a slit is provided as in the technique disclosed in Patent Document 1 described above, the rigidity of the fixed frame is reduced and distortion occurs. Etc. may occur and the behavior of the moving frame may become unstable.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an optical device capable of efficiently transmitting a magnetic force generated in a coil to a magnet while ensuring the rigidity of a frame.

An optical device according to one aspect of the present invention has a first frame holding at least one lens, one or more magnets fixed to the outer periphery of the first frame, and the first frame along an optical axis. The first frame is fixed to the outer periphery of the second frame and the second frame, which has a tubular shape and is provided with a slit for accommodating the magnet in a movable portion, and the first frame is attached to the magnet. In a region formed between a coil that generates a magnetic field for movement and an outer peripheral surface of the second frame and an inner peripheral surface of the coil, the coil is arranged so as to avoid the slit of the second frame. In the region formed between the first adhesive for fixing the coil to the second frame, the third frame containing the coil, and the inner peripheral surface of the third frame and the outer peripheral surface of the coil, the said It has a second adhesive for fixing the coil in the third frame.

According to the optical device of the present invention, the magnetic force generated in the coil can be efficiently transmitted to the magnet while ensuring the rigidity of the frame.

Schematic configuration of the endoscope system An exploded perspective view of the optical device Sectional sectional view of the main part of the optical device along the line II-II of FIG. Cross-sectional view of the main part of the optical device along the IV-IV line of FIG. Cross-sectional view of the main part of the optical device along the VV line of FIG. Operational diagram of the optical device Operational diagram of the optical device An exploded perspective view of the optical device according to the first modification. Same as above, cross-sectional view of the main part along the optical axis direction of the optical device Same as above, cross-sectional view of other main parts along the optical axis direction of the optical device An exploded perspective view of the optical device according to the second modification. Same as above, cross-sectional view of the main part along the optical axis direction of the optical device Same as above, cross-sectional view of other main parts along the optical axis direction of the optical device An exploded perspective view of the optical device according to the third modification. Same as above, cross-sectional view of the main part along the optical axis direction of the optical device Same as above, cross-sectional view of other main parts along the optical axis direction of the optical device An exploded perspective view of the optical device according to the fourth modification. An exploded perspective view of the optical device according to the fifth modification. FIG. 6 is a cross-sectional view of a main part in a direction perpendicular to the optical axis of the optical device according to the sixth modification. A cross-sectional view of a main part in a direction perpendicular to the optical axis of the optical device according to the seventh modification.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings relate to one embodiment of the present invention, FIG. 1 is a schematic configuration diagram of an endoscopic system, FIG. 2 is an exploded perspective view of the optical device, and FIG. 3 is a main part of the optical device along lines II-II of FIG. Sectional view, FIG. 4 is a sectional view of a main part of the optical device along the IV-IV line of FIG. 3, FIG. 5 is a sectional view of a main part of the optical device along the VV line of FIG. 3, and FIGS. It is an operation explanatory drawing of.

The endoscope 1 shown in FIG. 1 has an insertion unit 2 inserted into the subject, an operation unit 3 located on the proximal end side of the insertion unit 2, and a universal cord extending from the side portion of the operation unit 3. 4 and.

The insertion portion 2 includes a tip portion 10 disposed at the tip, a bendable curved portion 11 disposed on the proximal end side of the distal end portion 10, and an operation portion 3 disposed on the proximal end side of the curved portion 11. It is configured to have a flexible tube portion 12 having flexibility connected to the tip end side of the above.

As will be described in detail later, the tip portion 10 is provided with an optical device 20 for forming an image of a subject on an image pickup device (not shown). Further, the operation unit 3 is provided with an angle operation knob 13 for bending the curved portion 11, and further provided with a zoom lever 14 for changing the optical characteristics of the optical device 20.

An endoscope connector 15 connected to an external device 17 is provided at the base end of the universal cord 4. The external device 17 to which the endoscope connector 15 is connected is connected to an image display unit 18 such as a monitor via a cable.

Further, the endoscope 1 is an optical fiber bundle (shown) that transmits illumination light from a universal cord 4, an operation unit 3, a composite cable 16 inserted into the insertion unit 2, and a light source unit provided in an external device 17. Do not have).

The composite cable 16 is configured to electrically connect the endoscope connector 15 and the image pickup element. Further, by connecting the endoscope connector 15 to the external device 17, the image sensor is electrically connected to the external device 17 via the composite cable 16. As a result, power is supplied from the external device 17 to the image sensor and communication between the external device 17 and the image sensor is performed via the composite cable 16.

The external device 17 is provided with an image processing unit. This image processing unit generates a video signal based on the image sensor output signal output from the image sensor, and outputs the video signal to the image display unit 18. That is, in the present embodiment, the optical image (endoscope image) captured by the image sensor is displayed on the image display unit 18 as an image.

Further, the optical fiber bundle is configured to transmit the light emitted from the light source portion of the external device 17 to the illumination window of the tip portion 10. The light source unit may be arranged on the operation unit 3 or the tip portion 10 of the endoscope 1.

Next, the configuration of the optical device 20 in this embodiment will be described in detail below.

As shown in FIGS. 2 to 5, the optical device 20 includes a front group lens unit 25, a rear group lens unit 26 connected to the proximal end side of the front group lens unit 25, the front group lens unit 25, and the front group lens unit 25. It has a moving group lens unit 27 arranged on the optical axis (imaging optical axis) O of the rear group lens unit 26, and an actuator unit 28 for moving the moving group lens unit 27 forward and backward in the optical axis O direction. It is composed of.

The front group lens unit 25 includes a front group lens frame 30 which is a fixed lens frame, and a front group lens 31 held by the front group lens frame 30. Here, the front group lens 31 in the present embodiment refers to a "group lens" in a broad sense including a lens having two or more lenses and a lens consisting of a single lens. To do. As shown in FIGS. 4 and 5, the front lens group lens 31 of the present embodiment is composed of a single lens.

The front group lens frame 30 is composed of a substantially cylindrical frame body. A front group lens 31 is fixed to the inner circumference of the tip portion of the front group lens frame 30 via an adhesive 32. Here, the front group lens frame 30 of the present embodiment also functions as an exterior frame of the optical device 20, and the moving group lens unit 27 and the actuator unit 28 are placed closer to the proximal end side than the front group lens 31. It is possible to accommodate it. As a result, the front group lens frame 30 has a function as a third frame including the coil 46 (described later) provided in the actuator unit 28.

The rear group lens unit 26 includes a rear group lens frame 35 which is a fixed lens frame, and a rear group lens 36 held by the rear group lens frame 35. Here, the rear group lens 36 in the present embodiment refers to a "group lens" in a broad sense including a lens having two or more lenses and a lens consisting of a single lens. To do. As shown in FIGS. 4 and 5, the rear group lens 36 of the present embodiment is composed of two lenses 36a.

The rear group lens frame 35 is formed of a substantially ring-shaped frame body, and the rear group lens 36 is fixed to the inner circumference of the rear group lens frame 35 via an adhesive or the like. Here, the rear group lens frame 35 of the present embodiment also functions as a holding frame for holding an imaging unit (not shown). That is, in the rear group lens frame 35, for example, the image sensor holding frame can be fitted on the outer periphery on the base end side, and the image sensor is held on the base end surface via a cover glass or the like. Is possible.

The rear group lens frame 35 is internally fitted to the proximal end side of the front group lens frame 30 after accommodating the moving group lens unit 27 and the actuator unit 28. Then, the rear group lens frame 35 is positioned in the image pickup optical axis O direction with respect to the front group lens frame 30 while checking the image captured by the image pickup element held on the proximal end surface, for example. After that, the rear group lens frame 35 is fixed to the front group lens frame 30 via an adhesive or the like.

The moving group lens unit 27 includes a moving group lens frame 40 as a first frame and a moving group lens 41 held by the moving group lens frame 40. Here, the moving group lens 41 in the present embodiment refers to a "group lens" in a broad sense including a lens having two or more lenses and a lens having a single lens. To do. As shown in FIGS. 4 and 5, the moving group lens 41 of the present embodiment is composed of a single lens.

The moving group lens frame 40 is formed of a substantially cylindrical frame body, and a moving group lens 41 is fixed to the inner circumference of the moving group lens frame 40 via an adhesive or the like.

Further, a plurality of magnets 42 are fixed on the outer circumference of the moving group lens frame 40.

Specifically, on the outer circumference of the moving group lens frame 40 of the present embodiment, a plurality of (for example, four) concave grooves 40a extending in the optical axis O direction are rotated by 90 degrees around the optical axis O. It is provided for each position. A magnet 42 is held in each of the concave grooves 40a.

In this case, for example, as shown in FIGS. 2 and 3, each magnet 42 is arranged so that a part thereof protrudes outward in the radial direction of the moving group lens frame 40 from each concave groove 40a.

Further, each magnet 42 is magnetized so as to have polarity in the thickness direction. Each magnet 42 in the present embodiment is arranged in the concave groove 40a so that the radial outer side of the moving group lens frame 40 is the S pole and the radial inner side of the moving group lens frame 40 is the N pole, and an adhesive or the like is applied. It is fixed through.

The actuator unit 28 includes a coil holding frame 45 as a second frame and a coil 46 provided on the outer periphery of the coil holding frame 45.

The coil holding frame 45 is formed of a tubular (more specifically, substantially cylindrical) frame that includes the moving group lens frame 40 so as to be movable along the optical axis O.

The wall portion of the coil holding frame 45 is provided with, for example, a slit 45a extending in the optical axis O direction at each 90-degree rotation position corresponding to each magnet 42 held in the moving group lens frame 40. There is. The width of each slit 45a is set wider than the width of each magnet 42, so that each slit 45a can accommodate each magnet 42 protruding from the outer peripheral surface of the moving group lens frame 40.

The coil 46 is configured by, for example, a plurality of conductors insulated by a coating film being wound around the outer periphery of the coil holding frame 45. The coil 46 is fixed to the inner surface of the coil 46 and the outer periphery of the coil holding frame 45 by an adhesive 48 as a second adhesive applied so as to avoid the slit 45a.

Here, the coil 46 is basically formed in a substantially cylindrical shape, but in order to bring it as close as possible to each magnet 42 accommodated in the slit 45a, for example, it is shown in FIGS. As described above, it is desirable that the portion corresponding to the slit 45a is shaped flat.

Excitation currents in different directions are supplied to the coil 46, for example, depending on the operating condition of the zoom lever 14.

For example, when the zoom lever 14 is operated in the preset first direction, the coil 46 is supplied with an exciting current for setting the tip end side to the north pole and the proximal end side to the south pole. In response to the magnetic field generated by the coil 46 by this exciting current, the magnet 42 is attracted to the tip side along the optical axis O direction, whereby the moving group lens frame 40 (moving group lens unit 27) moves to the wide side. (See FIG. 6).

Further, for example, when the zoom lever 14 is operated in a preset second direction, an exciting current for setting the tip end side to the S pole and the proximal end side to the N pole is supplied to the coil 46. .. In response to the magnetic field generated by the coil 46 by this exciting current, the magnet 42 is attracted to the proximal end side along the optical axis O direction, whereby the moving group lens frame 40 (moving group lens unit 27) moves to the tele side. (See FIG. 7).

Here, in the optical device 20 of the present embodiment, the coil 46 of the actuator unit 28 is used as the first adhesive in order to compensate for the decrease in rigidity due to the provision of the slit 45a in the coil holding frame 45 as described above. It is fixed to the front group lens frame 30 via the adhesive 47 of the above.

Specifically, for example, as shown in FIGS. 3 and 5, an adhesive is applied to a region (small gap) formed between the inner peripheral surface of the front lens frame 30 and the outer peripheral surface of the coil 46. 47 is arranged, and the coil 46 is fixed to the front group lens frame 30 via the adhesive 47. Since the coil 46 and the coil holding frame 45 are fixed by the adhesive 48, the front group lens frame 30 and the coil holding frame 45 are integrated via the coil 46.

According to such an embodiment, the moving group lens frame 40 holding the moving group lens 41, the magnet 42 fixed to the outer periphery of the moving group lens frame 40, and the moving group lens frame 40 are placed along the optical axis O. A coil holding frame 45 having a tubular shape that is movablely contained and having a slit 45a for accommodating the magnet 42 provided on the wall portion and a coil holding frame 45 provided on the outer periphery of the coil holding frame 45, and a moving group lens with respect to the magnet 42. A region formed between the coil 46 that generates a magnetic field for moving the frame 40, the front group lens frame 30 that includes the coil 46, and the inner peripheral surface of the front group lens frame 30 and the outer peripheral surface of the coil 46. In the above, by forming the optical device 20 with the adhesive 47 for fixing the coil 46 to the front group lens frame 30, the magnetic force generated in the coil 46 is efficiently utilized while ensuring the rigidity of the coil holding frame 45. It can be transmitted well to the magnet 42.

That is, by providing the coil holding frame 45 with the slit 45a and accommodating the magnet 42 fixed to the moving group lens frame 40 in the slit 45a, the magnet 42 can be brought closer to the coil 46, which is generated in the coil 46. The magnetic force can be efficiently transmitted to the magnet 42.

On the other hand, the optical device 20 arranged at the tip portion 10 of the endoscope 1 generally has a diameter of only about several millimeters, and the frame such as the coil holding frame 45 is also formed to be extremely thin. When the slit 45a is provided in the coil holding frame 45, a decrease in rigidity is unavoidable. However, such a decrease in rigidity is caused by applying the coil 46 and the adhesive 48 to the front group lens frame 30 via the adhesive 47. By supplementing by fixing the coil holding frame 45 through the coil holding frame 45, it is possible to prevent distortion from occurring in the coil holding frame 45 and the like, and it is possible to ensure good behavior of the moving group lens frame 40.

Here, for example, as shown in FIGS. 8 to 10, magnets 42 forming a pair of front and rear are arranged in each concave groove 40a provided in the moving group lens frame 40, and a pair of front and rear are placed on the outer periphery of the coil holding frame 45. It is also possible to fix the eggplant coil 46.

In this case, each magnet 42 is arranged so that a part thereof protrudes from each concave groove 40a in the outer diameter direction of the moving group lens frame 40. Further, each magnet 42 is arranged so that its polarity is reversed in the front-rear direction. For example, of the pair of front and rear magnets 42, the magnet 42 located in the front has a concave groove 40a so that the radially outer side of the moving group lens frame 40 has an S pole and the radial inner side of the moving group lens frame 40 has an N pole. On the contrary, the magnet 42 located at the rear is arranged in the concave groove 40a so that the radial outside of the moving group lens frame 40 is the north pole and the radial inside of the moving group lens frame 40 is the south pole. ..

Further, the pair of coils 46 fixed to the coil holding frame 45 are supplied with an exciting current so as to be excited with different polarities.

For example, when the zoom lever 14 is operated in a preset first direction, the coil 46 arranged on the tip side in the optical axis O direction has an north pole on the tip side and an S pole on the base end side. The exciting current is supplied. On the contrary, the coil 46 arranged on the proximal end side is supplied with an exciting current so that the distal end side has an S pole and the proximal end side has an N pole.

Further, for example, when the zoom lever 14 is operated in a preset second direction, the coil 46 arranged on the tip end side in the optical axis O direction has an S pole on the tip end side and N on the base end side. An exciting current is supplied to make the pole. On the contrary, the coil 46 arranged on the proximal end side is supplied with an exciting current for having the distal end side as the north pole and the proximal end side as the south pole.

According to such a configuration, the magnetic field generated by each coil 46 can be applied to each magnet 42 more effectively.

As a method of preventing the adhesive 47 from wrapping around the unnecessary portion, the adhesive 47 is arranged in the slit 45a by arranging the adhesive range between the coil 46 and the front group lens frame 30 so as to avoid the slit 45a. It is possible to prevent wraparound and the like, and it is possible to stably realize the forward / backward movement of the moving group lens frame 40 in the optical axis O direction.

Further, for example, as shown in FIGS. 11 to 13, a metal ring member 50 can be interposed between the coils 42 arranged in pairs on the outer circumference of the coil holding frame 45.

Further, for example, as shown in FIGS. 14 to 16, the ring member 50 can be integrally formed with the coil holding frame 45.

Further, for example, as shown in FIG. 17, at least one end (for example, the base end) of the slit 45a provided in the coil support frame 45 is released, and the key 40b that is in sliding contact with the released slit 45a is moved. It can also be provided at one end of the group lens frame 40. With this configuration, it is possible to prevent the optical device 20 from being displaced around the optical axis O and to realize good optical characteristics.

Alternatively, for example, as shown in FIG. 18, instead of one end of the moving group lens frame 40, a key 40b that is in sliding contact with the released slit 45a can be provided between the pair of front and rear magnets 42.

Further, for example, as shown in FIG. 19, it is also possible to form a groove portion 30a extending along the direction of the optical axis O on the inner surface of the front group lens frame 30 to hold the adhesive 47. .. With this configuration, the actuator unit 28 is inserted into the front lens frame 30 even if the region formed between the inner peripheral surface of the front lens frame 30 and the outer peripheral surface of the coil 46 is minute. In this case, it is possible to prevent problems such as the adhesive 47 applied to the outer peripheral surface of the coil 46 being pushed out by the front lens frame 30, and the coil 46 is securely adhered to the front lens frame 30. be able to.

Further, for example, as shown in FIG. 20, a plurality of through holes 30b penetrating in the radial direction are provided on the wall portion of the front group lens frame 30, and the inner circumference of the front group lens frame 30 is provided through the through holes 30b. It is also possible to inject the adhesive 47 into the region formed between the surface and the outer peripheral surface of the coil 46. With this configuration, it is possible to reliably bond the parts that need to be bonded while preventing problems such as the adhesive 47 wrapping around the unnecessary parts.

The present invention is not limited to the above-described embodiments, and various modifications and changes can be made, which are also within the technical scope of the present invention. For example, it goes without saying that the configuration of the above-described embodiment and the configuration of each modification may be appropriately combined.

1 ... Endoscope 2 ... Insertion part 3 ... Operation part 4 ... Universal cord 10 ... Tip part 11 ... Curved part 12 ... Flexible tube part 13 ... Angle operation knob 14 ... Zoom lever 15 ... Endoscope connector 16 ... Composite cable 17 ... External device 18 ... Image display unit 20 ... Optical device 25 ... Front group lens unit 26 ... Rear group lens unit 27 ... Moving group lens unit 28 ... Actuator unit 30 ... Front group lens frame (third frame)
30a ... Groove 30b ... Through hole 31 ... Front group lens 32 ... Adhesive 35 ... Rear group lens frame 36 ... Rear group lens 36a ... Lens 40 ... Moving group lens frame (first frame)
40a ... Concave groove 40b ... Key 41 ... Moving group lens 42 ... Magnet 42 ... Coil 45 ... Coil holding frame (second frame)
45a ... Slit 46 ... Coil 47 ... Adhesive (first adhesive)
48 ... Adhesive (second adhesive)
50 ... Ring member O ... Optical axis

Claims (6)

A first frame that holds at least one lens,
With one or more magnets fixed to the outer circumference of the first frame,
A second frame having a tubular shape that includes the first frame so as to be movable along the optical axis, and a slit for accommodating the magnet on the wall portion.
A coil fixed to the outer circumference of the second frame and generating a magnetic field for moving the first frame with respect to the magnet.
In the region formed between the outer peripheral surface of the second frame and the inner peripheral surface of the coil, the first frame is arranged so as to avoid the slit of the second frame and the coil is fixed to the second frame. With adhesive,
The third frame containing the coil and
An optical device comprising, in a region formed between the inner peripheral surface of the third frame and the outer peripheral surface of the coil, a second adhesive for fixing the coil to the third frame. The second adhesive is arranged in a region formed between the inner peripheral surface of the third frame and the outer peripheral surface of the coil so as to avoid the slit of the second frame, and is arranged in the third frame. The optical device according to claim 1, wherein the coil is fixed. The first or second aspect of the third frame, wherein a groove extending along the direction of the optical axis and holding the first adhesive is formed on the inner surface of the third frame. Optical device. The first or second aspect of the present invention, wherein the wall portion of the third frame is provided with a through hole that penetrates in the radial direction and for injecting the first adhesive into the region. Optical device. The optical device according to claim 1 or 2, wherein a plurality of sets of the magnets paired in the direction of the optical axis are fixed to the outer periphery of the first frame. The optical device according to claim 5, wherein the plurality of sets of the magnets are fixed to the outer periphery of the first frame at equal rotation angles about the optical axis.

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