JP2003241055A - Lens barrel - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] To fix a magnetic sensor section in a lens barrel, use a self-tapping screw member, and make a center axis of the self-tapping screw member and a fastening hole parallel. Reduce the number of components when fixing the magnetic sensor unit and adjusting the gap and parallel state between the magnet and the magnetic sensor unit to be constant. A frame portion on which the magnetic sensor portion is attached and a fastening hole are formed on a housing side, and an elastic body is arranged between the fastening hole and the magnetic sensor portion on the frame portion. From the mounting hole to the fastening hole, a screw member having a threaded guide portion, a self-tap screw portion, and a head portion is inserted therethrough, and the self-tap screw portion is screwed into the fastening hole so as to be magnetic sensor portion. By attaching the self-tapping screw member, the magnetic sensor unit is fixed with the center axis of the self-tapping screw member and the fastening hole parallel to each other, and the gap between the magnet and the magnetic sensor unit and Adjust the parallel state to make it constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel used in, for example, a video camera or the like and provided with a magnetic sensor section for detecting lens movement.

[0002]

2. Description of the Related Art A magnetic sensor unit used in a video camera or the like detects magnetism magnetized in a magnet provided on a moving body such as a lens frame. The output value changes due to the gap. For example, in some MR sensors, even if the gap between the magnetic sensor unit and the magnet changes by about several tens of μm, the output value thereof may change greatly, and in order to ensure accurate detection, , It is necessary to make this gap constant.

Further, when the magnetic sensor portion and the magnet are not parallel to each other, when the magnet or the magnetic sensor portion moves, the gap between them cannot be kept constant. Therefore, it is necessary to keep the gap and the parallel state constant between the magnetic sensor unit and the magnet.

Therefore, FIGS. 10 to 12 show three conventional techniques in which a magnetic sensor portion is provided inside the lens barrel. It should be noted that components having the same function will be described with the same reference numerals.

In the first prior art shown in FIG. 10, the guide shafts 61a and 61b and the lens frame 62 are arranged in a housing 64 which constitutes a lens barrel, and the lens frame 6 is provided.
The reference numeral 2 moves in parallel along the two guide shafts 61a and 61b. A magnet 63 is attached to the lens frame 62, and a magnetic sensor 66 is arranged close to the magnet 63.
Has a configuration in which it is directly fixed to the housing 64 via a screw member 65.

The second prior art shown in FIG. 11 has substantially the same structure as the first conventional example, and the different parts are that the magnetic sensor part 66 is fixed to the housing 64. Holding table 67 and compression coil spring 68
The point is that they are fixed by the M screw member 69 and the bolt 70 via. The gap between the magnet 63 and the magnetic sensor unit 66 and the parallel state can be temporarily adjusted via the holding table 67 and the compression coil spring 68.

In the third prior art shown in FIG. 12, the magnetic sensor portion 66 is fixed to the housing 64 via a leaf spring 71 and a screw 72, and the magnet 63 attached to the moving body is magnetic. It is configured to move substantially parallel to the sensor unit 66. Therefore, the gap between the magnet 63 and the magnetic sensor portion 66 can be temporarily adjusted via the leaf spring 71 and the screw 72.

[0008]

However, in the first prior art, the magnetic sensor unit 66 is provided in the housing 6.
Since it is directly fixed to No. 4, the gap between the magnet 63 and the magnetic sensor unit 66 and the parallel state cannot be adjusted, so that it is difficult to make the output value of the magnetism detected in each lens barrel constant, which makes the product function. There is a disadvantage that variations occur.

In the second prior art, although the gap between the magnet 63 and the magnetic sensor portion 66 and the parallel state can be adjusted, a screw member 69, a holding base 67, a compression coil spring 68, an M screw member 69 and Since the number of parts is increased by using the bolts 70 and the like, it is difficult to manage the parts, and the cost of the parts and the number of assembling steps at the time of manufacturing increase, which causes a problem that the size cannot be reduced.

In the third prior art, although the gap between the magnet 63 and the magnetic sensor portion 66 can be adjusted, the lower portion of the magnetic sensor portion 66 is fixed, and the leaf spring 71 and the screw 72 provided on the upper portion. Since the gap is adjusted by, it is impossible to adjust the front and rear and left and right parallel states with respect to the moving direction of the magnet 63.
Therefore, it is difficult to make the output value of the detected magnetism constant, and further, there is a problem that the magnet 63 and the magnetic sensor unit 66 collide when the parallel state before and after this is not correctly maintained. . Further, since the gap is adjusted by the leaf spring 71 and the screw 72, the range in which the gap can be adjusted is small and it is difficult to reduce the size.

Further, in recent years, the housing of the lens barrel is often made of synthetic resin such as PC for the purpose of weight reduction and cost reduction. Therefore, it is used as a screw member for fixing the magnetic sensor portion. It is preferable to use a screw member having a tap function with less slack, that is, a so-called self-tap screw member. However, in a conventional self-tap screw member, a fastening hole without a screw thread for screwing the screw member is used. It was difficult to screw on the line of the central axis in parallel with the central axis.

Therefore, in the prior art, it is possible to properly adjust the gap and parallel state between the magnet and the magnetic sensor portion, reduce the number of parts to prevent cost increase, and self-tap screw. When a member is used, there is a problem to be solved in that the center axis of the self-tapping screw member and the fastening hole are parallel to each other and the magnetic sensor unit is accurately fixed.

[0013]

The invention according to the present invention as a concrete means for solving the above-mentioned problems of the prior art is at least a pair of guide shafts attached to a casing and guided by the guide shafts. A lens barrel having a lens attached to a moving lens frame and a magnet, and a magnetic sensor unit attached to a housing that detects the magnetism of the magnet, wherein the magnetic sensor unit is plate-shaped,
A reference seating surface in which a mounting hole is formed and a sensing surface are provided, and a frame part to which the magnetic sensor part is mounted and a fastening hole are formed on the housing side, and an elastic body is provided between the frame and the fastening hole. And installing the magnetic sensor part in the frame part, from the mounting hole to the fastening hole, insert a screw member having a guide part without thread, a self-tapping screw part and a head part, and the self-tapping screw The present invention provides a lens barrel characterized in that a magnetic sensor part is attached by screwing the part into a fastening hole.

In the present invention, the frame portion is provided with a positioning protrusion according to the width of the magnetic sensor portion;
The fastening hole is provided with a guide hole portion corresponding to a non-threaded guide portion of the screw member on the bottom side; the magnetic sensor portion has the reference seat surface on the back side of the head portion of the screw member. It is always attached to the surface by an elastic body in a crimped state;

In the lens barrel according to the present invention, a plate-shaped magnetic sensor unit is attached to the housing of the lens barrel, and the magnetic sensor unit has a reference seat surface having a mounting hole and a sensing surface. A frame part to which the magnetic sensor part is attached and a fastening hole are formed on the housing side, and an elastic body is arranged between the magnetic sensor part and the fastening hole to form the frame part in the frame part. A magnetic sensor part is installed, and a screw member having a non-threaded guide part, a self-tapping screw part, and a head part is inserted from the mounting hole to the fastening hole, and the self-tapping screw part is screwed into the fastening hole. By using a self-tapping screw member having a guide portion without a screw thread, the central axis of the self-tapping screw member and the fastening hole are made parallel to each other. Fix the part Bets can be, moreover, it is possible to adjust the gap and parallel state between the magnet and the magnetic sensor unit is also to reduce the number of parts easily and constant.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in detail based on specific embodiments. FIG. 1 shows a schematic side view of a lens barrel 1 according to an embodiment of the present invention.
In this lens barrel 1, a plurality of optical lenses are arranged inside, and the magnetic sensor unit 2 is attached to the housing 7 by a screw member 4, and the magnetic sensor unit 2 is It is for detecting the position of movement of one movable lens incorporated inside.

The structure and arrangement of the magnetic sensor unit 2 and members related thereto will be described with reference to FIG.
The magnetic sensor unit 2 has a substantially rectangular plate shape,
The mounting hole 2a is formed near one side, and the mounting hole 2a is formed.
A reference seating surface 2b is formed with a slight step around a, and a sensing surface 2 is provided on a lower surface facing the opposite side.

The screw member 4 is provided with a self-tapping portion 4a having a tap function, a guide portion 4b having no thread, and a neck portion 4e. The head portion 4f of the screw member 4 is fitted with a screwdriver or the like. Then, a bit hole 4c for turning the screw member 4 is provided. The housing 7 is provided with a fastening hole 5 into which the screw member 4 is screwed.

A pair of guide shafts 6a and 6b for moving the lens is fixed to the housing 7 of the lens barrel 1, and a lens frame 3 for holding the lens 8 is a sleeve formed on the lens frame 3. Guide shafts 6a, 6 via 9a, 9b
supported by b. The lens frame 3 includes guide shafts 6a and 6a.
It is possible to move in the front-back direction parallel to the guide shafts 6a and 6b along b, whereby the lens 8 can move along with the lens frame 3. Also, the lens frame 3
The magnet 10 is fixed to the sleeve 9a of the above, and moves together with the lens frame 3.

A frame portion 12 for mounting the magnetic sensor portion 2 is formed on the housing 7, and a positioning projection portion 12a is formed on the frame portion 12 in accordance with the width of the magnetic sensor portion 2. . An opening 13 is formed in the portion surrounded by the frame.

When the magnetic sensor portion 2 is attached to the housing 7, when the magnetic sensor portion 2 is set in the frame portion 12, an elastic body such as a coil spring is provided at a position where the attachment hole 2a and the fastening hole 5 are aligned with each other. 11 is provided and the screw member 4 is attached to the mounting hole 2a.
3 through 4, the magnetic sensor unit 2 is inserted into the fastening hole 5 and forcedly screwed.
Is fixed to the housing 7, and the sensing surface 2c provided in the magnetic sensor unit 2 is brought into a state of being close to the magnet 10 through the opening 13, and the magnetism of the magnet 10 can be read.

In this mounting operation, even if the screw member 4 is rotated to be screwed into the fastening hole 5, the magnetic sensor portion 2 is inadvertently rotated due to the presence of the positioning projection 12a provided on the frame portion 12. Can be prevented.

As shown in FIG. 4b, the fastening hole 5 into which the screw member 4 is screwed is composed of a tap screwing portion 5a and a guide hole portion 5b provided on the bottom side thereof. ,
These are the guide portions 4b without threads in the screw member 4.
Is formed to have a diameter substantially the same as the diameter. In this way, when the tap screw attachment portion 5a and the guide hole portion 5b have the same diameter,
The shape of the fastening hole 5 can be easily formed.

When a screw member is forcibly screwed into the fastening hole 5, the threadless guide portion 4b at the tip portion descends along the tap screwing portion 5a, and then the self-tapping portion 4a is removed. Move forward while engraving the thread on the tap threaded portion 5a,
The magnetic sensor unit 2 is fixed or fixed in the set state, and the reference seat surface 2b of the magnetic sensor unit 2 is the back surface 4 of the head portion 4f of the screw member 4 by the elastic body 11.
It is always attached to d by crimping.

Guide portion 4b of the screw member 4 without threads
Are formed substantially parallel to the axis 14a passing through the center of the screw member 4, and the fastening hole 5 and the guide hole 5b are also formed substantially parallel to the axis 14b passing through the center of the fastening hole 5. Therefore, when the screw member 4 is inserted into and screwed into the fastening hole 5, the axis 14a of the screw member 4 and the axis 14b of the fastening hole 5 are inevitably aligned with each other, and the screw member 4 is tightened. It stands upright from.

The back side surface 4d of the head portion 4f of the screw member 4 is formed horizontally in a direction orthogonal to the axis 14a of the screw member 4, and the attached magnetic sensor portion 2 is horizontal by the screw member 4. It is positioned in the state.

Further, the guide shafts 6a, 6b and the fastening hole 5
The angle formed with the axis line 14b passing through the center of the magnet is a right angle, and the magnetic sensor unit 2 and the magnet 10 are positioned substantially in parallel by arranging the guide shafts 6a and 6b horizontally.

Therefore, the magnet 1 is moved along with the lens frame 3.
Even if 0 moves, the magnetic sensor unit 2 and the magnet 10 can be placed in a substantially parallel state, and the magnetic flux of the magnet 10 can be received by the sensing surface 2c in a stable state. Stable output can be obtained.

By providing the magnetic sensor part 2 and the casing 7 with counterbore parts 15 and 16 for accommodating a part of the elastic body 11, the elastic body is provided when the magnetic sensor part 2 is arranged in the casing 7. The work of disposing 11 is further facilitated.

The drive unit for moving the lens in the lens barrel 1 drives the magnetic field generated by the yokes 17a and 17b and the linear magnet 18 by passing a current through the coil 19 arranged in the lens frame 3. A flexible printed wiring board (not shown) is attached to the coil 19 for generating force, and power is supplied to the coil 19 from the other end attached to the casing of the flexible printed wiring board. ing.

Next, a second embodiment will be described with reference to FIG. Also in the second embodiment, the magnetic sensor unit is attached to the housing by using the screw member, and the configurations of the screw member and the fastening holes are changed. Since it is the same as the first embodiment and the description thereof is redundant, its illustration and detailed description are omitted.

In this second embodiment, FIG.
As shown in (a), in the screw member 24, the neck portion 24e between the self-tapping portion 24a and the head portion 24f is formed to be slightly longer, and the self-tapping portion 24a and the guide portion 24b having no thread are slightly formed. It has a small diameter.

Further, as shown in FIG. 5B, the housing 7
The fastening hole 25 provided on the side is a series of guide hole portions 25b formed on the bottom side of the tap screwing portion 25a, as in the first embodiment. The second guide hole portion 25c having a slightly larger diameter is provided between the 16 and the tap screwing portion 25a.

When the magnetic sensor part 2 is attached using the screw member 24 formed in this way, the neck part 24e becomes the second part.
Of the guide hole portion 25c, and the guide portion 24b having no thread is inserted into the guide hole portion 25b. When the screw member 24 is screwed in this state, both guide hole portions 25b, The screw member 24 has a fastening hole 25 at 25c.
Located vertically along the axis 14b of the self-tapping portion 2
4a moves vertically while tapping the tap screwing portion 25a, so that the magnetic sensor portion 2 can be fixed in an appropriate state.

FIGS. 6A and 6B show a third embodiment. The third embodiment shows only the main part as in the second embodiment, and the structures of the screw member and the fastening hole are changed. Therefore, the other configuration is the same as that of the first embodiment, and the details thereof are omitted.

In the third embodiment, the screw member 34 has a threaded guide portion 34 formed on the distal end side.
The diameter of b is formed to be slightly smaller than the diameter of the self-tapping portion 34a. The neck portion 34e is formed with a slight constriction on the self-tapping portion 34a side.

As shown in FIG. 6B, the fastening hole 35 formed on the side of the housing 7 has the guide hole portion 35b formed on the bottom side of the tap screwing portion 35a, and is formed by the screw member. 34
The hole is formed to have a slightly smaller diameter corresponding to the diameter of the guide portion 34b.

When the magnetic sensor portion 2 is attached using the screw member 34 thus formed, first, the tip of the guide portion 34b is fitted into the guide hole portion 35b, and the screw member 34 is vertically attached along the axis 14b. If the screw member 34 is screwed in that state, the self-tapping portion 34
It is possible for a to move vertically while tapping the tap screwing portion 35a to fix the magnetic sensor unit 2 in an appropriate state.

The fourth embodiment is shown in FIGS. 7 (a) and 7 (b). Also in the fourth embodiment, the second and third
Similar to the embodiment described above, only the main part is shown, and the configurations of the screw member and the fastening hole are changed. Therefore, the other configuration is the same as that of the first embodiment, and the details thereof are omitted.

The screw member 44 according to the fourth embodiment
Forms a neck portion 44e between the self-tapping portion 44a and the head portion 44f to be slightly longer, to form the self-tapping portion 44a to have a slightly smaller diameter, and to form a guide portion 44b having no thread at the tip portion to have a smaller diameter. Then, it is formed in three steps.

As shown in FIG. 7B, the fastening hole 45 provided on the housing 7 side corresponds to the three-stage screw member 44, and the second guide hole portion 45c and tap. Threaded part 4
5a and the guide hole 45b are successively formed in three steps in a small diameter.

When the magnetic sensor portion 2 is attached using the screw member 44 formed in this way, the neck portion 44e fits into the second guide hole portion 45c and the non-threaded guide portion 44b becomes the guide hole portion 45b. When the screw member 44 is screwed in this state, the screw member 44 is screwed into the guide hole portions 45b and 45c.
Is maintained vertically along with the self-tapping portion 44a advancing vertically while tapping the tap screwing portion 45a,
The magnetic sensor unit 2 can be fixed in an appropriate state.

The fifth embodiment is shown in FIGS. 8 (a) and 8 (b). Also in this fifth embodiment, the second,
Similar to the third and fourth embodiments, only the main parts are shown, and the configurations of the screw member and the fastening hole are changed. Therefore, the other configuration is the same as that of the first embodiment, and the details thereof are omitted.

The screw member 54 according to the fifth embodiment
The neck portion 54e between the self-tapping portion 54a and the head portion 54f is formed to have a slightly longer length, and the self-tapping portion 54a having a slightly smaller diameter is formed at the end portion of the neck portion 54e. The guide part without threads is not formed on the.

The fastening hole 55 provided on the housing 7 side is provided with a guide hole portion 55c in which the neck portion 54e fits, corresponding to the shape of the screw member 54, and the guide hole portion 5 is provided.
A tap screwing portion 55a having a diameter smaller than 5c is formed.

When the magnetic sensor unit 2 is attached using the screw member 54, the neck portion 54e is fitted in the second guide hole 55c, and the screw member 54 is screwed in this state. , The screw member 54 is maintained vertically along the axis 14b in the guide hole 55c, and the self-tapping portion 54a moves vertically while tapping the tap screwing portion 55a to bring the magnetic sensor unit 2 into an appropriate state. Can be fixed.

As described above, in any of the embodiments shown in FIG. 5 to FIG. 8, by forming the thread-free guide portion and the guide hole portion in the screw member and the fastening hole, When the screw member is screwed, the axis line 14a passing through the center of the screw member and the axis line 14 passing through the center of the fastening hole.
Since there is no inconvenience that the screw member is tilted and screwed when b matches, the magnetic sensor unit can always be attached in an appropriate state. Further, the fastening member of the present invention is not limited to these.

Further, in any of the embodiments shown in FIGS. 5 to 8, the counterbore portions 15 and 16 are provided so that the elastic body 11 is provided when the magnetic sensor portion 2 is disposed in the housing 7. Although the work of arranging the countersinks is facilitated, it is not always necessary to form these countersink portions 15 and 16.

Further, a side view of the yoke of the driving portion in the lens barrel 1 is shown in FIG. 9 (a), and a plan view of the flat plate yoke 17b is shown in FIG. 9 (b). The yoke of the drive unit is composed of a U-shaped yoke 17a and a flat plate yoke 17b. If the accuracy of the parallelism and flatness between the U-shaped yoke 17a and the flat plate yoke 17b is poor, or if the flatness of the flat plate yoke 17b is poor, the U-shaped yoke 17a is moved when the lens frame 3 is moved, resulting in a contact noise. Occurs.

At this time, as shown in FIG. 9 (b), chamfers 20a, 20b, 20c are formed at three places so that the U-shaped yoke 17a is supported by the three contact surfaces 21a, 21b, 21c. Thus, it is possible to reduce rattling and prevent generation of unpleasant noise due to contact between metals when the lens frame 3 moves due to rattling.

[0051]

As described above, in the lens barrel according to the present invention, at least a pair of guide shafts attached to the housing, a lens attached to the lens frame that is moved by being guided by the guide shafts, and A lens barrel including a magnet and a magnetic sensor unit attached to a housing that detects the magnetism of the magnet, wherein the magnetic sensor unit is plate-shaped, and a reference seat surface having an attachment hole formed therein. A sensing surface, a frame portion to which the magnetic sensor portion is attached and a fastening hole are formed on the housing side, and an elastic body is arranged between the fastening hole and the magnetic field in the frame portion. Install the sensor part, insert a screw member having a non-threaded guide part, a self-tapping screw part, and a head part from the mounting hole to the fastening hole, and screw the self-tapping screw part into the fastening hole. Magnetic sensor part By installing it, it can be installed in a state where it coincides with the axis of the screw member and the fastening hole, and the reference seat surface of the screw member can be accurately positioned in the direction orthogonal to the axis. The magnetic sensor portion, which is disposed on the surface in a pressed state via an elastic body, is positioned parallel to the magnet, and moreover, the tightening state of the screw member can be arbitrarily set, whereby the magnet and the magnetic sensor portion can be set. It has an excellent effect that the gap between and can be adjusted to be constant.

[Brief description of drawings]

FIG. 1 is a schematic side view of a lens barrel according to a first embodiment of the present invention.

FIG. 2 is a perspective view schematically showing an exploded view of a peripheral configuration of a magnetic sensor portion and a lens frame, which are main portions of the lens barrel, in an enlarged manner.

FIG. 3 is a schematic plan view showing, in an enlarged manner, an attached state of a magnetic sensor portion of a main portion of the lens barrel.

4A is a schematic enlarged cross-sectional view taken along the line AA in FIG. 3, and FIG. 4B is a cross-sectional view of the fastening hole in FIG. 4A.

FIG. 5 shows a second lens barrel according to the present invention,
FIG. 6A is a schematic cross-sectional view showing a fixed state with a screw member which is a fastening member of a main part and a fastening hole, and FIG.
The figure is a cross-sectional view of the fastening hole in FIG.

FIG. 6 shows a third lens barrel according to the present invention,
FIG. 6A is a schematic cross-sectional view showing a fixed state with a screw member which is a fastening member of a main part and a fastening hole, and FIG.
The figure is a cross-sectional view of the fastening hole in FIG.

FIG. 7 shows a fourth lens barrel according to the present invention,
FIG. 6A is a schematic cross-sectional view showing a fixed state with a screw member which is a fastening member of a main part and a fastening hole, and FIG.
The figure is a cross-sectional view of the fastening hole in FIG.

FIG. 8 shows a fifth lens barrel according to the present invention,
FIG. 6A is a schematic cross-sectional view showing a fixed state with a screw member which is a fastening member of a main part and a fastening hole, and FIG.
The figure is a cross-sectional view of the fastening hole in FIG.

FIG. 9A is a side view of the yoke of the drive unit of the lens barrel. FIG. 6B is a plan view of the flat plate yoke of FIG.

FIG. 10 is a cross-sectional view showing a peripheral configuration of a magnetic sensor portion and a lens frame, which are main portions of a lens barrel according to a first conventional example.

FIG. 11 is a cross-sectional view showing a peripheral configuration of a magnetic sensor portion and a lens frame, which are main portions of a lens barrel according to a second conventional example.

FIG. 12 is a perspective view showing a configuration around a magnetic sensor unit that is a main part of a lens barrel according to a third conventional example.

[Explanation of symbols]

1 Lens barrel; 2 Magnetic sensor part; 2a Mounting hole 2b Reference seat surface; 2c Sensing surface; 3 Lens frame 4, 24, 34, 44, 54 Screw member 4a, 24a, 34a, 44a, 54a Self-tapping part 4b, 24b, 34b, 44b Guide part 4c with no screw thread 4c Bit hole; 4d Back side surfaces 4e, 24e, 34e, 44e, 54e Neck part 4f Head part; 5, 25, 35, 45, 55 Fastening holes 5a, 25a, 35a, 45a, 55a Tap screw attachment parts 5b, 25b, 25c, 35b, 45b, 45c, 55
c Guide Holes 6a, 6b Guide Shaft; 7 Housing; 8 Lenses 9a, 9b Sleeve; 10 Magnet; 11
Elastic body 12 Positioning projection portion; 13 Opening portion; 14a,
14b Central shafts 15 and 16 counterbore part; 17a U-shaped yoke; 17
b flat plate yoke 18 linear magnet; 19 coil; 20a,
20b, 20c Chamfering 21a, 21b, 21c Contact surface

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masanori Hayashi             2170 Omigawa, Omigawa-cho, Katori-gun, Chiba Prefecture             Knee Component Chiba Co., Ltd. (72) Inventor Fujio Kanai             6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Soni             -Inside the corporation F-term (reference) 2H044 AE06 BD11 BE18

Claims (4)

[Claims] 1. A pair of guide shafts mounted on a housing, a lens and a magnet mounted on a lens frame which is guided and moved by the guide shaft, and a housing for detecting magnetism of the magnet. A magnetic lens section having a magnetic sensor section provided therein, wherein the magnetic sensor section has a plate shape, and includes a reference seat surface having a mounting hole and a sensing surface, and the magnetic field is provided on the housing side. A frame portion to which the sensor portion is attached and a fastening hole are formed, an elastic body is arranged between the fastening hole and the magnetic sensor portion is installed in the frame portion, and the mounting hole to the fastening hole are provided. A lens barrel characterized in that a magnetic sensor unit is attached by inserting a screw member having a non-threaded guide unit, a self-tapping screw unit and a head unit, and screwing the self-tapping screw unit into a fastening hole. . 2. The lens barrel according to claim 1, wherein the frame portion is provided with a positioning protrusion in accordance with the width of the magnetic sensor portion. 3. The lens barrel according to claim 1, wherein the fastening hole is provided with a guide hole corresponding to a non-threaded guide of a screw member on the bottom side. 4. The lens barrel according to claim 1, wherein in the magnetic sensor portion, the reference seat surface is always attached to the back side surface of the head portion of the screw member by an elastic body in a pressure-bonded state. .