JP2002023037A - Lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lens barrel realizing the improvement of the impact resistance of the magnetic circuit of the zoom lens or the like of a video camera device. SOLUTION: In this zoom lens mechanism equipped with the magnetic circuit linearly movable in an optical axis direction along a guide shaft, the magnetic circuit is constituted of an inside yoke 30 supported by a lens barrel body 1, an outside yoke 31 facing to the yoke 30, a side part yoke 32 assembled between the yokes 30 and 31 and constituted to be a closed loop, an electromagnetic coil 33 supported by the lens frame 11 of a zoom unit 10 and movably inserted and attached to the yoke 30, and a magnet 35 attracted and fixed on the yoke 31 so as to face to the coil 33. The yoke 32 is assembled in the yoke 30 and also a pair of presser members 36 and 36 are supported, and the magnet 35 is held by pressing pieces 37 and 37 formed by bending the members 36 and 36, then the magnet 35 is prevented from being peeled from the yoke 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel suitable for use in a video camera device, and more particularly, to a magnetic circuit having excellent impact resistance of a movable lens such as a zoom lens or a focus lens, and The present invention relates to an optical filter mechanism that can easily be assembled.

[0002]

2. Description of the Related Art Conventionally, there is a video camera apparatus in which, for example, a zooming operation of a zoom lens is linearly driven by using a magnetic drive circuit. In this drive circuit, a magnet is arranged so as to face the electromagnetic coil, and the magnet is fixed to the zoom yoke only by the magnetic force of the magnet itself.

On the other hand, in a video camera device, an optical filter such as an infrared cut filter or a low-pass filter is provided in front of a CCD image pickup device so as to be able to be taken in and out. In this type, the optical filter is held by, for example, a U-shaped filter frame, and a method of fitting and holding a frame member of another member from the opening end side of the filter frame, or fixing the frame frame by heat caulking or bonding is used. Widely adopted.

[0004]

By the way, in the above-described magnetic circuit, in the fixing method in which the magnet is magnetically attracted to the zoom yoke, when the video camera device receives a large impact due to dropping or the like, the magnet is moved to the zoom yoke. It is assumed that they fall off from

Further, the conventional optical filter has a problem that the number of parts is increased, and as a result, the number of assembling steps is increased, and the work becomes complicated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has improved the impact resistance of a magnetic circuit of a movable lens, reduced the number of parts of an optical filter, and improved assemblability. It is an object of the present invention to obtain a lens barrel capable of achieving the following.

[0007]

In order to achieve the above object, a lens barrel according to the present invention holds a magnet fixed to a second yoke by its own magnetic attraction force with a holding member made of sheet metal. In addition, the magnet is prevented from peeling off due to an impact.

According to the lens barrel described above, even if the magnet receives a stress in a direction in which it is peeled off from the second yoke by the impact, the magnet is held by the holding member, so that the magnet can be moved from the second yoke to the magnet. Peeling can be avoided.

Further, the lens barrel according to the present invention is formed in a U-shape from a resin material, the open end side of which is a holder frame for inserting an optical filter, and the inner side of each frame side of the holder frame. It comprises a formed rib-shaped guide side plate and a projection provided on the inner surface end of the insertion portion of the holder frame.

According to the optical filter mechanism configured as described above, by inserting the optical filter into the holder frame from the insertion port on the open end side, the insertion port is pushed open and the optical filter is inserted into the holder frame. Be worn. The optical filter in the inserted state is held by the guide side plate, and is not locked out by the protrusion.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a lens barrel according to the present invention will be described below with reference to the drawings, taking a lens barrel of a video camera device as an example.

FIG. 1 is a cross-sectional plan view of the entire lens barrel. The front of the lens barrel 1 has a front barrel 2, and the rear of the lens barrel 1 has a rear barrel 3. A pair of guide shafts 4 and 5 penetrates through the lens barrel 1 in parallel with the optical axis L. One end of the guide shafts 4 and 5 is press-fitted and fixed to the front barrel 2 and the guide shaft 4 is fixed. , 5 are press-fitted and fixed to the rear lens barrel 3.

The front lens barrel 2 has three convex lenses 6, 7, 8
Is attached.

Behind the front lens group 9, a zoom unit 10 is arranged movably on the optical axis L along guide shafts 4 and 5. The zoom lens frame 11 is provided with three zoom lenses 12, 13, and 14. The zoom lens frame 11 has a guide cylinder 15 provided at one end thereof supported by one guide shaft 4 and provided at the other end. The support 16 is supported by the other guide shaft 5.

Behind the zoom unit 10, a fixed lens 17 is supported by a lens frame 18 integrally formed from the lens barrel 1.

A focus unit 19 is disposed behind the fixed lens 17 so as to be movable on the optical axis L along the guide shafts 4 and 5. Three focus lenses 21, 22, 23 are attached to the focus lens frame 20, and the support portion 24 provided at one end of the focus lens frame 20 is supported by one guide shaft 4 and provided at the other end. A guide cylinder 25 is supported by the other guide shaft 5.

The infrared cut filter 26 can be moved in and out of the optical axis L behind the focus unit 19.
And a low-pass filter 27, and a CCD image pickup device 28 is disposed behind the low-pass filter 27.

The above-mentioned zoom unit 10 and focus unit 19 are driven linearly by an electromagnetic circuit.

FIG. 2 is a perspective view of the lens barrel 1 as viewed from the housing portion 29 in which the electromagnetic circuit of the zoom unit 10 is stored. FIG. 3 is a perspective view of the zoom unit 10 and the electromagnetic circuit in a set state. Is a sectional view of the set state, and FIG. 5 is a perspective view of the separated state of the yoke and the magnet of the electromagnetic circuit.

The yoke of the electromagnetic circuit of the zoom unit 10 is a plate-shaped inner yoke 30, a plate-shaped outer yoke 31 facing the inner yoke 30, and side portions interposed at both ends of the yokes 30, 31. Consisting of yokes 32, 32,
The whole is configured as a box-shaped closed loop. More specifically, U-shaped grooves 30a, 30a and 31 are provided at both ends of the inner yoke 30 and the outer yoke 31, respectively.
a, 31a are formed, and are assembled by engaging the pieces 32a, 32a of the side yoke 32 formed in a cross shape with these grooves.

An electromagnetic coil 33 is movably inserted into the inner yoke 30 in a non-contact state, and the electromagnetic coil 33 is supported by the lens frame 11. Note that a control current is applied to the electromagnetic coil 33 from the flexible board 34.

A magnet 35 is provided on the back surface of the outer yoke 31.
Is attracted, and faces the above-described electromagnetic coil 33 with a predetermined gap therebetween. Here, the magnet 35 is attracted and fixed to the outer yoke 31 by its own magnetic force.
A pair of holding members 36, 36 so as not to peel off from
Is held by

As shown in FIG. 5, the holding members 36, 36 are formed in a cross shape using a sheet metal material so as to match the shape of the side yoke 32 described above, and each of the holding members 36, 36 is formed at right angles. The holding pieces 37 are formed by bending. These two holding members 36, 36 are holding pieces 3
The pieces on the opposite side of the inner and outer yokes 30 and 30 are formed as supporting pieces 38 and 38 so that the supporting pieces 38 and 38 overlap the inner surfaces of the side yokes 32 and 32.
a. Thereby, the holding pieces 37, 37 of the holding members 36, 36 are in contact with the magnet 35.

With such a configuration, the magnet 35 is fixed by suction to the outer yoke 31 and
Since the camera device is held by the holding pieces 37, 37 of the holding members 36, 36, for example, the camera device receives an impact due to dropping or the like.
Even if a stress is generated in the direction in which the magnet 35 separates from the outer yoke 31, the magnet 35 is received by the holding pieces 37, 37, so that the magnet 35 can be prevented from peeling off, and the impact resistance can be improved. It becomes a high magnetic circuit.

Since the holding member 36 is made of a magnetic material, the holding member 36 is attracted to the side yoke 32.
The holding member 36 is magnetically integrated with the side yoke 32, so that the workability of the assembly can be improved.

On the other hand, FIG. 6 is a perspective view of the lens barrel 1 viewed from the housing portion 39 of the focus unit 19 in which the electromagnetic circuit is housed, FIG. 7 is a perspective view of the focus unit 19 and the electromagnetic circuit in a set state, FIG. 8 is a perspective view of a separated state of the yoke and the magnet of the electromagnetic circuit.

As in the case of the yoke of the zoom unit 10, the yoke of the focus unit 19 also has a plate-shaped inner yoke 40, a plate-shaped outer yoke 41 facing the inner yoke 40, and both ends of both yokes 40, 41. It is composed of side yokes 42, 42 interposed in the portion, and the whole is configured in a box shape. Here, a part different from the yoke of the zoom unit 10 is that one end of the inner yoke 40 is a U-shaped groove 40a.
On the other hand, the other end is an engagement hole 40b, and one end of the outer yoke 41 is an engagement hole 41b.
The other end is a U-shaped groove 41a. The pieces 42a and 42 of the side yoke 42 formed in a cross shape in these grooves and holes.
a is engaged to form a box.

An electromagnetic coil 43 is movably inserted into the inner yoke 40 in a non-contact state, and the electromagnetic coil 43 is supported by the lens frame 20. Note that a control current is applied to the electromagnetic coil 43 from a flexible board 44.

A magnet 45 is provided on the back surface of the outer yoke 41.
Is attracted, and faces the above-described electromagnetic coil 43 with a predetermined gap therebetween. Like the above-described zoom unit 10, the magnet 45 is held by the bending pieces 47, 47 of the pair of holding members 46, 46 in the same manner as the above-described zoom unit 10 so that the magnet 45 does not separate from the outer yoke 31.

Next, the structure of the holder frame of the infrared cut filter 26 (hereinafter simply referred to as the filter 26) will be described. FIG. 9 is a perspective view of the holder frame and the filter, and FIG. 10 is a longitudinal sectional view of the holder frame.

The holder frame 48 is integrally formed from a plastic material and has a substantially U-shape as a whole.
And the side frame 51, and the opening side of the holder frame 48 becomes the insertion port 52 of the filter 26 having a square shape. Guide side plates 49 parallel to the inner surfaces of the upper frame 49 and the lower frame 50 are provided.
a, 49a and 50a, 50a are formed to face each other. Further, parallel guide side plates 51a, 51a are also formed on the inner surface side of the side frame 51. these,
Guide side plates 49a, 49a, 50a, 50a and 51
The filter 26 is held between the a and 51a without rattling.

The upper frame 49 and the lower frame 50 on the side of the insertion port 52 are provided.
On the inner surface side of the end portion, protrusions 53, 53 having tapered surfaces 53a, 53a are formed to face each other.

Reference numeral 54 denotes a support for the holder frame 48. The support 54 is supported by a support shaft (not shown) so as to be vertically inserted into and removed from the optical axis L. Reference numeral 55 denotes guide side plates 49a, 49a, 50.
a, 50a and core holes for injection molding 51a, 51a.

The operation of inserting the filter 26 into the holder frame 48 constructed as described above is performed by pressing the filter 26 from the insertion opening 52 with the insertion side end thereof pressed against the tapered surfaces 53a, 53a of the projections 53, 53. As a result, the upper frame 49 and the lower frame 50 are elastically deformed and expanded in the vertical direction, and the upper and lower sides of the filter 26 ride on the projections 53, 53 and are inserted between the guide side plates 49a, 49a, 50a, 50a. . Then, the filter 26 has the protrusion 53,
After passing through 53 and being completely inserted into the holder frame 48,
The upper frame 49 and the lower frame 50 are restored to their original positions, and the filter 26 is restored.
Is completed. As a result, the filter 26 inserted into the holder frame 48 does not come out of the insertion port 52 by abutting on the projections 53, 53.

By using the holder frame as described above, the filter can be securely held by the holder frame composed of one part, and the number of parts can be reduced.
The filter can be assembled with just one touch.

Further, since the filter 26 is formed in a square shape, the insertion direction of the filter 26 into the holder frame 48 is not specified, so that the workability of assembling the filter can be improved.

FIG. 11 is a perspective view of another embodiment of the holder frame, and FIG. 12 is a longitudinal sectional view of the same. The same components as those of the holder frame 48 shown in FIG.

In the holder frame 48 of this embodiment, the guide side plates formed on the inner surfaces of the upper frame 49, the lower frame 50, and the side frame 51 are alternately arranged as guide side plates 56. Are the same.

Even if the guide side plate 56 is arranged in this manner, the filter 26 inserted in the holder frame 48 can be used.
Can be held without rattling. In this case, the holder frame 48 is not formed with a core hole, and can be manufactured with a simple molding die.

The present invention is not limited to the embodiment described above and shown in the drawings, and various modifications can be made without departing from the scope of the invention.

In this embodiment, the magnetic circuit of the zoom mechanism and the focus mechanism driven linearly in the video camera apparatus has been described. However, the magnetic circuit of the zoom mechanism and the focus mechanism in the case of an ordinary still camera or digital camera is also widely used. Applicable.

In addition to the holder frame of the infrared cut filter 26, the present invention can be applied to the holder frame of the low-pass filter 27.

[0043]

As described above, the lens barrel of the present invention is configured such that the magnet fixed to the second yoke by its own magnetic attraction force is held by the holding member made of sheet metal. In addition, the magnet can be prevented from being separated from the outer yoke in response to an impact, and a magnetic circuit having high impact resistance and high reliability can be obtained.

Further, by forming the holding member from a magnetic material, the holding member is attracted to the side yoke, whereby the holding member is magnetically integrated with the side yoke, thereby assembling the magnetic circuit. Workability can be improved.

In the lens barrel according to the present invention, a U-shaped open end formed of a resin material serves as an insertion port for an optical filter, and an inner surface of each side of the holder frame. With the rib-shaped guide side plate formed and the projection provided at the inner surface end of the insertion opening of the holder frame, the optical filter is securely held by the holder frame composed of one component. The number of parts can be reduced, and the filter can be assembled with one touch.

[Brief description of the drawings]

FIG. 1 is an overall sectional view of a lens barrel according to the present invention.

FIG. 2 is a perspective view of a lens barrel seen from a housing portion side of the zoom unit where a magnetic circuit is housed.

FIG. 3 is a perspective view of a set state of a zoom unit and a magnetic circuit thereof.

FIG. 4 is a sectional view of the zoom unit and its magnetic circuit in a set state.

FIG. 5 is a perspective view showing a state where a magnetic circuit of the zoom unit is separated.

FIG. 6 is a perspective view of a lens barrel seen from a housing unit side of the focus unit in which a magnetic circuit is housed.

FIG. 7 is a perspective view of a set state of a focus unit and a magnetic circuit thereof.

FIG. 8 is a perspective view showing a state where a magnetic circuit of the focus unit is separated.

FIG. 9 is a perspective view of an infrared cut filter and a holder frame.

FIG. 10 is a sectional view of the holder frame.

FIG. 11 is a perspective view of another embodiment of the holder frame.

FIG. 12 is a sectional view of the holder frame.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Lens barrel, 4, 5 ... Guide shaft, 9 ... Front lens group, 10 ... Zoom unit, 11 ... Lens frame of zoom lens, 19 ... Focus unit, 20 ... Lens frame of focus unit, 26 ... Infrared Cut filter, 2
8 CCD image sensor, 30 inner yoke, 31 outer yoke, 32 side yoke, 33 electromagnetic coil, 35 magnet, 36 holding member, 37 holding piece, 40 inner yoke, 41 outer yoke , 42 ... side yoke, 45 ...
Magnet, 46 ... holding member, 47 ... holding piece, 48 ... holder frame, 49 ... upper frame, 50 ... lower frame, 51 ... side frame, 49
a, 50a, 51a ... guide side plate, 53 ... protrusion, 56
… Guide side plate

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) G02B 7/04 D (72) Inventor Ryoichi Suemori 9-15-22, Hongo-cho, Minokamo-shi, Gifu Sony Minokamo Co., Ltd. F-term (reference) 2H044 AE10 BD10 BD12 BE02 BE06 BE10 BE20 DA01 DA02 DB02 EF04 EF08 EF10 5C022 AA11 AB43 AB44 AB66 AC54 AC78

Claims (3)

[Claims] A first yoke supported by a lens barrel main body, the lens barrel having a magnetic circuit supported by a lens frame and having a magnetic circuit capable of linearly moving in an optical axis direction along a guide axis; A second yoke facing the first yoke, a yoke side plate assembled between the first yoke and the second yoke and configured as a box-shaped closed loop, and the lens frame A magnetic circuit is constituted by an electromagnetic coil supported on the first yoke and movably inserted into the first yoke, and a magnet attracted and fixed to the second yoke so as to face the electromagnetic coil; A lens barrel, comprising: a holding member that is held together with the yoke side plate to a first yoke and made of a sheet metal material to prevent the magnet from peeling off from the second yoke. 2. The lens barrel according to claim 1, wherein said holding member is made of a magnetic material. 3. A lens barrel provided with an optical filter mechanism in which an optical filter is held in a holder frame, wherein the holder is formed in a U-shape from a resin material, and an open end side of the lens barrel serves as an insertion port of the optical filter. A frame, a rib-shaped guide side plate formed on the inner surface side of each frame side of the holder frame, and holding the optical filter; and a filter stopper provided at an inner surface end of the insertion portion of the holder frame. The optical filter is inserted by pushing open the insertion opening of the holder frame, is held by the guide side plate, and is prevented from being removed by the projection. A lens barrel comprising an optical filter mechanism.