JP2002350702A - Lens barrel, optical adjustment method for the same and optical equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the following problem; a shape part for facilitating the eccentricity adjustment of a lens and the positional adjustment of the lens in an optical axis direction is not formed on a lens frame, etc., then, it is difficult to perform the optical adjustment in the case of performing the eccentricity adjustment of each lens and the positional adjustment of each lens in the optical axis direction for every lens barrel. SOLUTION: As for the lens barrel provided with the lens frame 9 for holding the lens 2 and a holding member 7 for holding the lens frame, the holding member is provided with the shape parts for adjustment 7c to 7e for performing the eccentricity adjustment of the lens frame in a direction orthogonal to the optical axis with reference to the holding member and the stepwise positional adjustment in the optical axis direction while the lens frame is brought into contact with the shapes from the optical axis direction.

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 for an optical device such as a photographing device and an observation device.

[0002]

2. Description of the Related Art As a reciprocating mechanism for zooming and focusing in a lens barrel, a mechanism for reciprocating in the optical axis direction by a helicoid screw or a rod-shaped guide member is known. Also, various proposals have been made for a lens barrel that moves the lens lens frame in the optical axis direction by using an inner cam provided on a cam ring or the like, a guide groove, and a cam follower provided on the lens frame.

As the latter lens barrel, for example, there is a lens barrel shown in FIGS. FIG. 5 shows a collapsed state of the lens barrel, and FIG. 6 shows a wide photographing state of the lens barrel.

[0004] In these figures, reference numeral 101 denotes the whole of the lens barrel.
A lens barrel main body 11a is provided, 102 is a first moving lens, 103 is a second moving lens, 104 is a third moving lens, and 105 is a fourth moving lens.

Reference numeral 106 denotes a fixed frame fixed to the lens barrel main body 101, 107 denotes a rotatably fitted outer periphery of the fixed frame 106,
A cam ring (cam cylinder) in which the inner diameter rib 107a is interposed between the abutting portion 106a and the protruding portion 106b of the fixed frame 106, and is prevented from moving in the optical axis direction.

Reference numeral 108 denotes a first lens holding cylinder for holding the first moving lens 102, and the first lens holding cylinder 10
Reference numeral 8 is arranged between the lens barrel main body 101 and the cam ring 106. At the rear end of the first lens holding barrel 108, a cam groove 107 formed on the outer periphery of the cam ring 107 while being engaged with a rectilinear groove 101 a formed on the barrel main body 101.
A tapered roller 109 that also engages with c is attached.

[0007] Reference numerals 111, 112, 113, and 114 denote guide bars fixed at both ends to the barrel main body 101 and the fixed frame 106, and held substantially parallel to the optical axis.

Reference numeral 115 denotes a second lens frame for holding the second lens 103, and the sleeve portion 115a is
11 and the U-shaped groove 115 b is fitted to the guide bar 112. Accordingly, the second lens frame 115 is guided by the guide bar 111 to move in the optical axis direction, and the guide bar 112 prevents rotation about the guide bar 111.

[0010] 116 is fixed to the second lens frame 115,
The tapered roller engages with a cam groove 107d formed on the inner periphery of the cam ring 107. 117 is a cylindrical roller.
The cylindrical roller 116 is located between the grooves 107f formed on the outer periphery of the cam ring 107 in the collapsed state shown in FIG. 5, and is substantially aligned with the optical axis on the outer peripheral side of the cam ring 107 in the zoom region shown in FIG. It is arranged with a slight gap from the vertical surface 107g.

Reference numeral 118 denotes a third lens frame for holding the third movable lens 104. The sleeve portion 118a is fitted on the guide bar 113, and the U groove portion 118b is connected to the guide bar 114.
Is fitted. Thus, the third lens frame 118 is guided by the guide bar 113 to move in the optical axis direction, and the guide bar 114 prevents rotation about the guide bar 113.

Reference numeral 123 denotes a fourth lens frame which sandwiches and holds the fourth movable lens 105 together with the lens holding plate 124. The sleeve portion 123a is fitted to the guide bar 113, and the U groove portion 123b is fitted to the guide bar 114. ing. As a result, the fourth lens frame 123 is
3 guides the movement in the optical axis direction, and the guide bar 114 prevents rotation about the guide bar 113.

[0012]

In the lens barrel constructed as described above, the eccentricity adjustment of each lens and the optical control for each lens barrel are performed due to individual manufacturing errors of the lens frame and other lens barrel constituting members. Optical adjustment such as axial position adjustment is required.

However, in the above-mentioned lens barrel, there is a problem that optical adjustment is difficult because the lens frame or the like is not provided with a shape portion for easily adjusting the eccentricity of the lens and adjusting the position in the optical axis direction.

In the lens barrel constructed as described above, the optical adjustment cannot be performed even when the position of the first movable lens 102 having relatively low optical sensitivity is adjusted during optical adjustment. Adjustable third moving lens 10
It must be adjusted with the fourth or fourth moving lens 105 or the like.

In this case, since optical adjustment cannot be performed when the lens is completed, a dummy lens equivalent to the first moving lens 102 and the second moving lens 103 is prepared, and the third moving lens 104 and the fourth moving lens are prepared. It is known that the eccentricity or inclination of 105 is adjusted to obtain a desired optical performance.

However, when the optical adjustment is performed by using the dummy lens, the optical adjustment including the manufacturing error of at least the first movable lens 102 and the second movable lens 103 cannot be performed. Therefore, there is a problem that it is difficult to obtain desired optical performance.

[0017]

According to a first aspect of the present invention, there is provided a lens barrel having a lens frame for holding a lens and a holding member for holding the lens frame. An adjustment shape for causing the lens frame to abut against the member from the optical axis direction and performing eccentricity adjustment of the lens frame with respect to the holding member in the direction orthogonal to the optical axis and stepwise position adjustment in the optical axis direction. Part is provided.

In the second invention of the present application, a first lens frame for holding a first lens, a second lens frame for holding the first lens frame and holding a second lens, In a lens barrel having a holding member for holding the second lens frame, the first lens frame is abutted against the second lens frame from the optical axis direction, and the first lens frame with respect to the second lens frame. An adjustment shape part for performing eccentricity adjustment of the lens frame in the direction orthogonal to the optical axis and stepwise position adjustment in the optical axis direction is provided, and the second lens frame is provided on the holding member in the optical axis direction. And an adjustment shape portion for performing eccentricity adjustment of the second lens frame with respect to the holding member in the direction orthogonal to the optical axis and stepwise adjustment of the position in the direction of the optical axis.

According to these inventions, the eccentricity of the lens frame can be adjusted using the adjustment shape portion as a reference surface, and each adjustment surface can be formed in a step shape so that each step surface can be adjusted to the optical axis of the lens frame. It can be used as a positioning reference plane in the direction. Therefore, the eccentricity adjustment of the lens and the position adjustment in the optical axis direction can be easily performed in each lens barrel.

It is preferable that the adjusting shape portion has, for example, a stair-like shape having a width that allows the eccentricity adjustment of the lens frame in the direction orthogonal to the optical axis and continuing in the circumferential direction and moving back and forth in the optical axis direction. As a result, it is possible to easily correct the holding member provided with the adjustment shape portion and the mold for molding the lens frame, and as a result, the lens is tilted, and the optical performance of the lens barrel is guaranteed. Will be.

In the first and second aspects of the present invention, the lens optically adjusted by the adjustment shape portion or the lens group including the first and second lenses is replaced with a plurality of lenses or lenses constituting a photographic optical system. By making the lens or lens group that can be adjusted and operated from the outside of the lens barrel, the optical performance, infinity focus and predetermined close distance for each lens barrel Is guaranteed.

[0022]

1 to 4 show a lens barrel for a digital still camera according to an embodiment of the present invention.

FIG. 4 is an exploded view of the lens barrel, and FIG. 1 is a collapsed state of the lens barrel. FIG. 2 shows a wide zoom state of the lens barrel, and FIG. 3 shows a tele-zoom state of the lens barrel.

In these figures, reference numeral 1 denotes a CCD holder which supports the entire lens barrel and has a CCD mounting portion 1a;
2 is a first lens (first lens in claims) 2a
And a second lens (a second lens in the claims) 2b, a first moving lens group 3, a second moving lens 4, and a third moving lens 4. Reference numeral 5 denotes a guide tube fixed to the CCD holder 1.

The CCD holder 1 and the guide tube 5 constitute a lens barrel main body according to the present invention.

Reference numeral 6 denotes a cam ring rotatably fitted on the outer periphery of the guide cylinder 5. The cam ring 6 is prevented from moving in the optical axis direction by the bayonet connection of the inner diameter rib 6a to the butting portion 5a and the protruding portion 5b of the guide cylinder 5.

Reference numeral 8 denotes a first lens frame for holding the first lens 2a (first lens frame in claims), and reference numeral 9 denotes a second lens frame for holding the second lens 2b (second lens frame in claims).
Lens frame).

Reference numeral 7 denotes a first lens frame 8 and a second lens frame 9
(I.e., a first lens holding cylinder (holding member) that holds the first movable lens group 2). A tapered roller (cam follower) that fits into a guide groove 5c formed in the guide tube 5 and engages with a cam groove 6b formed in the inner periphery of the cam ring 6 is formed on the outer periphery of the first lens holding tube 7. ) 10 is fixed.

Reference numeral 11 denotes a decorative ring fixed to the first lens holding cylinder 7, and reference numeral 12 denotes a sheet displaying the name of the lens fixed to the decorative ring 11, and the like.

Reference numerals 13 and 14 are guide bars extending substantially in the optical axis direction. The front ends of the guide bars 13 and 14 in the optical axis direction are fixed to the one-end support portions 7a and 7b provided in the first lens holding tube 7, and the rear ends of the guide bars 13 and 14 are the rear end of the first lens holding tube 7. Are fixed to a metal plate 15 integrally connected to the metal plate 15. The metal plate 15 is positioned by a positioning dowel (not shown) provided at the rear end of the first lens holding cylinder 7.

Reference numeral 16 denotes a second movable lens frame for holding the second movable lens 3. The sleeve 16 a provided on the second movable lens frame 16 is fitted to the guide bar 14, and the U-groove 16 b is engaged with the guide bar 13. As a result, the second movable lens frame 16 is guided to move in the optical axis direction by fitting the sleeve portion 16a and the guide bar 14, and is centered on the guide bar 14 by the engagement between the U groove portion 16b and the guide bar 13. Rotation is blocked.

17 is fixed to the second movable lens frame 16,
The tapered roller engages with a cam groove 6c formed on the inner periphery of the cam ring 6.

Reference numerals 19 and 20 are guide bars extending in the optical axis direction. These guide bars 19 and 20 have their rear ends in the optical axis direction fixed to the one-end supports 1a and 1b provided in the CCD holder 1, and their front ends are integrally connected to the front end of the CCD holder 1. It is fixed to the metal plate 21. The metal plate 21 is positioned by a positioning dowel 1c provided at the front end of the CCD holder 1.

Reference numeral 18 denotes a third moving lens frame for holding the third moving lens 4. The sleeve portion 18 a provided on the third movable lens frame 18 is fitted on the guide bar 19, and the U groove portion 18 b is engaged with the guide bar 20. Thereby, the third movable lens frame 18 is guided to move in the optical axis direction by fitting the sleeve portion 18a and the guide bar 19, and
The engagement of the U-groove 18b and the guide bar 20 prevents rotation about the guide bar 19.

An aperture device 22 is attached to the second movable lens frame 16 and moves integrally with the second movable lens frame 16 in the optical axis direction. An aperture motor 23 drives the aperture device 22; A diaphragm FPC (flexible printed circuit board) that transmits a drive signal to the diaphragm 23 and moves the bending portion 24a in the optical axis direction as the diaphragm device 22 moves.
It is.

Reference numeral 25 denotes an FPC pressing plate which is attached to the guide cylinder 5 (the attaching portion is not shown) and assists the U-turn movement of the bent portion 24a of the aperture FPC 24 in the optical axis direction.

Reference numeral 26 denotes a rack attached to the third movable lens frame 18, and 27 denotes a stepping motor for moving the third movable lens 4 in the optical axis direction. The rack is mounted on a feed screw 28 provided as an output shaft thereof. 26 are engaged. Therefore, when the stepping motor 27 rotates, the third moving lens 4 is driven in the optical axis direction by the engagement between the feed screw 28 and the rack 26.

Reference numeral 29 denotes a motor holding member for holding the feed screw 28. The motor holding member 29a disposed near the drive unit of the stepping motor 27 is used to move the motor CC from the optical axis direction.
It is fixed to the D holder 1. The drive of the stepping motor 27 is controlled by a drive signal transmitted from a control circuit (not shown) via the FPC.

As a method of incorporating the stepping motor 27, the third movable lens frame 18 with the rack 26 attached thereto is used.
Guide bars 19 and 20 attached to CCD holder 1
Then, the rack 26 is fitted into the feed screw 28, the motor fixing portion 29a is attached to the CCD holder 1, and the metal plate 21 is attached to the CCD holder 1.

As described above, it can be configured as one unit together with the FPC for the stepping motor 27 (not shown).

On the other hand, with respect to the front unit, a diaphragm FPC 24 soldered to a diaphragm motor 23 is incorporated into an FPC holding plate 25 at a predetermined length position, and the diaphragm device 22 as one unit is attached with a tapered roller 17. Guide bars 13 and 14 are attached to the first movable lens frame 7 attached to the second movable lens frame 16 and the tapered roller 10 attached.
And the metal plate 15.

The tapered roller 10 is provided in the guide groove 5 of the guide cylinder 5.
c and the cam ring 6 is inserted into the cam groove 6b.

Since the tapered roller 10 has a metal plate 15 having a higher strength coupled to the first lens holding cylinder 7 made of plastic, as shown in FIG. 2 or FIG. Even if an impact or a large external force is applied to the first lens holding cylinder 7 from the directions B and C, the first lens holding cylinder 7 does not deform (bend), and the tapered roller 10 does not come off the cam groove 6b. Absent.

The tapered roller 17 is inserted into the guide groove 5d of the guide cylinder 5 and the cam groove 6c of the cam ring 6.

Since the tapered roller 17 integrally has the flange portion (stopper portion) 17a shown in FIG. 1, as shown in FIG. 2 or FIG. When a shock or large external force is applied to
Since the flange portion 17a abuts on the inner peripheral surface of the guide cylinder 5 to maintain the tapered roller 17 in the inserted state in the cam groove portion 6c (prevents a skewing movement), the tapered roller 17 comes off the cam groove portion 6c. There is no.

The inner diameter rib 6a of the cam ring 6 is
Of the FPC holding plate 25
Are attached to the guide tube 5 and are configured as one unit.

A rear unit including the CCD holder 1;
The front unit including the first lens holding cylinder 7 has a screw hole 5e provided in the guide cylinder 5 with the aperture FPC 24 inserted in the notch 1e provided in the CCD holder 1 and C.
A screw connection is made using a hole 1f provided in the CD holder 1. The cam ring 6 is prevented from rotating beyond a predetermined angle by a notch 6e provided in the cam ring 6 and a projection 1d provided in the CCD holder 1.

After the front and rear units are connected to the first lens frame 8 and the second lens frame 9, a minute optical adjustment is performed in a lens photographing state. Specifically, a projection 8a is provided at a rear portion of the first lens frame 8, and this projection 8a
Are provided in steps so as to be continuous with the second lens frame 9 in the circumferential direction, and are provided as stepped surfaces 9b, 9c, 9d as adjustment shape portions.
The distance adjustment (position adjustment in the optical axis direction) between the first lens 2a and the second lens 2b is performed so as to achieve the best optical adjustment state.

The eccentricity of the first lens frame 8 can be adjusted in a direction perpendicular to the optical axis with the projection 8a abutting on one of the step surfaces 9b, 9c, and 9d (that is, each step surface is the first step). It has a width in the direction perpendicular to the optical axis that allows the eccentricity adjustment of one lens frame 8), and the eccentricity adjustment is performed so as to be in the best optical adjustment state in accordance with the above-described spacing adjustment. After the adjustment, the first lens frame 8 and the second lens frame 9 are joined by bonding or the like.

A projection 9a is provided at the rear of the second lens frame 9.
The projection 9a is abutted against any one of stepped surfaces 7c, 7d, and 7e as adjustment shape portions provided in a stepwise shape so as to be continuous with the first lens holding cylinder 7 in the circumferential direction. Thus, the focus shift caused by the manufacturing error of the lens and the lens barrel part is canceled. As the method, a step surface on which the projection 9a is abutted is determined so that the third movable lens frame 18 can obtain an infinite focus and a predetermined close distance in a predetermined moving range.

Further, the eccentricity can be adjusted in a direction perpendicular to the optical axis with the projection 8a of the second lens frame 9 abutting on one of the step surfaces 7c, 7d, and 7e (that is, each step surface is the first step surface). It has a width in the direction perpendicular to the optical axis that allows eccentricity adjustment of the two lens frames 9). After the adjustment, the second lens frame 9 and the first lens holding cylinder 7 are joined by bonding or the like.

Reference numeral 30 denotes a stepping motor having a speed reduction mechanism built in the BOX. This stepping motor 30
Is mounted on the CCD holder 1, and the output gear is engaged with the large gear portion 6 a of the cam ring 6. The drive of the stepping motor 30 is controlled by a drive signal transmitted from a control circuit (not shown) via the FPC.

Next, the operation of the lens barrel configured as described above will be described. When a drive signal is transmitted to the stepping motor 30 to change from the collapsed (retracted) state in FIG. 1 to the wide state in FIG. 2, the stepping motor 30 rotates, and the output of the stepping motor 30 is the large gear of the cam ring 6. It is transmitted to the unit 6d. The rotation of the cam ring 6 prevents the rotation of the first lens holding cylinder 7 by the engagement between the tapered roller 10 and the guide groove 5c. 2 to project from the retracted state to the front of the guide tube 5 as shown in FIG.

At this time, the second lens frame 16 is driven in the optical axis direction by the engagement between the cam groove 6c and the tapered roller 17 while being guided and prevented from rotating by the guide bars 13 and 14.

At the same time, a drive signal is also transmitted to the stepping motor 27 to move the third moving lens frame 18 to the wide state shown in FIG.

To change from the wide state to the telephoto state shown in FIG. 3, similarly, the stepping motor 30 is driven to extend the first lens holding cylinder 7 and the second movable lens frame 16, and the stepping motor 27 is driven. Then, the third moving lens frame 18 is driven to the telephoto state in FIG.

In the present embodiment, the first lens holding cylinder 7 has been described as a holding member according to claim 1 or claim 4.
The invention described in claim 1 is realized even when the second movable lens frame 9 is used as a holding member.

In this embodiment, the lens barrel used in the digital still camera has been described. However, the present invention is not limited to the lens barrel of another photographing apparatus such as a video camera or a film camera, or an observation apparatus such as a binocular or a telescope. Can also be applied to the lens barrel.

[0059]

As described above, according to the first and second aspects of the present invention, the eccentricity of the lens frame can be adjusted using the adjustment shape portion as the reference plane, and the adjustment shape portion can be stepwise shaped. By forming, etc., each step surface can be used as a positioning reference surface in the optical axis direction of the lens frame. Therefore, the eccentricity adjustment of the lens and the position adjustment in the optical axis direction can be performed.
This can be easily performed in each lens barrel.

Here, if the adjustment shape portion has, for example, a staircase shape having a width that allows eccentricity adjustment of the lens frame in the direction orthogonal to the optical axis and continuing in the circumferential direction and moving back and forth in the optical axis direction, Since the holding member provided with the shape portion and the mold for molding the lens frame can be easily corrected, as a result, the falling of the lens is guaranteed, and the optical performance of the lens barrel is guaranteed.

In the first and second aspects of the present invention, the lens optically adjusted by the adjusting shape portion or the lens group including the first and second lenses is replaced with a plurality of lenses or lenses constituting a photographic optical system. If a lens or a lens group that can be adjusted from the outside of the lens barrel, that is, a lens or a lens group that can be adjusted from the outside of the lens barrel, is provided with optical performance, infinity focus, and a predetermined close distance for each lens barrel. Can be guaranteed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a collapsed state of a lens barrel according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a wide state of the lens barrel according to the first embodiment.

FIG. 3 is a sectional view showing a telephoto state of the lens barrel according to the first embodiment.

FIG. 4 is an exploded perspective view showing a configuration of the lens barrel.

FIG. 5 is a sectional view showing a collapsed state of a conventional lens barrel.

FIG. 6 is a cross-sectional view showing a wide state of a conventional lens barrel.

[Explanation of symbols]

 Reference Signs List 1 CCD holder 2 First moving lens group 3 Second moving lens 4 Third moving lens 5 Guide cylinder 6 Cam ring 7 First lens holding cylinder 8 First lens frame 9 Second lens frame 7c to 7e, 9b to 7d Step surface 10, 17 Cam follower 13, 14, 19, 20 Guide bar 15, 21 Metal plate 27, 30 Stepping motor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/225 G02B 7/08 B // G02B 7/08 7/04 D

Claims (11)

[Claims] 1. A lens barrel comprising: a lens frame for holding a lens; and a holding member for holding the lens frame, wherein the lens frame is abutted against the holding member from an optical axis direction. A lens barrel provided with an adjusting shape part for performing eccentricity adjustment of the lens frame with respect to a holding member in a direction orthogonal to an optical axis and stepwise adjustment in a direction of an optical axis. 2. The adjusting shape portion has a width that allows eccentricity adjustment of the lens frame in a direction orthogonal to the optical axis, and has a stepped shape that is continuous with the circumferential direction of the holding member and that moves back and forth in the optical axis direction. The lens barrel according to claim 1, wherein: 3. The lens barrel according to claim 1, wherein the lens is a lens disposed closest to the object side among a plurality of lenses constituting a photographing optical system. 4. A first lens frame holding a first lens, a second lens frame holding the first lens frame and holding a second lens, and a second lens frame holding the first lens frame. A lens barrel having a holding member for holding, wherein the first lens frame is abutted against the second lens frame from an optical axis direction, and the first lens with respect to the second lens frame. An adjustment shape portion for performing eccentricity adjustment of the frame in the direction orthogonal to the optical axis and stepwise position adjustment in the optical axis direction is provided, and the second lens frame is provided on the holding member in the optical axis direction. And an adjustment shape part for performing eccentricity adjustment of the second lens frame with respect to the holding member in the direction orthogonal to the optical axis and stepwise position adjustment in the direction of the optical axis. A lens barrel characterized by the following. 5. The adjustment shape portion provided on the second lens frame has a width allowing eccentricity adjustment of the first lens frame in a direction orthogonal to the optical axis, and the adjustment shape portion of the second lens frame. The adjustment shape portion provided on the holding member has a width allowing the eccentricity adjustment of the second lens frame in the direction orthogonal to the optical axis. 5. The lens barrel according to claim 4, wherein the lens barrel has a stepped shape that extends in the circumferential direction of the holding member and moves back and forth in the optical axis direction. 6. The lens barrel according to claim 4, wherein the first and second lenses form a single lens group. 7. The lens system according to claim 4, wherein the first and second lenses form a single lens group that moves in the optical axis direction together with the holding member with respect to the lens barrel main body.
Or the lens barrel according to 5. 8. The apparatus according to claim 4, wherein said first and second lenses form a lens group disposed closest to the object side among a plurality of lens groups forming a photographic optical system. The lens barrel according to any one of the above. 9. An optical apparatus comprising the lens barrel according to claim 1. Description: 10. The method for optically adjusting a lens barrel according to claim 4, wherein the first lens frame holding the first lens is held by the second lens. The eccentricity adjustment and the stepwise position adjustment in the optical axis direction of the second lens frame are performed by abutting the adjusted shape portion of the second lens frame, and the second lens frame holding the first lens frame is adjusted. 2 lens frame,
This second part is brought into contact with the adjustment shape part of the holding member.
An eccentricity adjustment of the lens frame and a stepwise adjustment of the position in the optical axis direction. 11. An optical adjustment method for a lens barrel according to claim 10, wherein an infinity focus of the entire lens barrel and a predetermined close distance are obtained.