JPH10104493A - Lens barrel and optical equipment equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily align the optical axis of a lens barrel and the optical axis of a moving group lens with each other by moving a guide member to the lens barrel optical axis according to operation. SOLUTION: When a sleeve-side eccentric piece 8 is rotated by engaging a tool with the operation groove part of the eccentric piece 8, the rear end of a focus guide bar 7b can be moved to the lens barrel optical axis along a Y axis within a range of a specific eccentricity quantity. Consequently, a focus moving frame 5 and the optical axis of a focus lens D held by it can be moved along the Y axis. When the eccentric piece 8 is rotated by engaging the tool with the operation groove part of a U-shaped groove side eccentric piece 8, the rear end of a focus guide bar 7a can be moved to the lens barrel optical axis along an X axis within a range of a specific eccentricity quantity. Consequently, the focus moving frame 5 and the optical axis of a focus group lens D held by it can be rotated around the focus guide bar 7b along the X axis.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel for performing a zoom operation or the like by moving a lens in an optical axis direction.

[0002]

2. Description of the Related Art As a lens barrel as described above, FIG.
Are configured as shown in FIG. In this lens barrel,
Fixed group lenses A and C and movable group lenses B and D are arranged side by side in the optical axis direction. Of these lenses, the movable group lenses B and D are guide bars 16a and 1 extending in the optical axis direction.
Movement guidance is provided by 7a, 16b and 17b.

In this lens barrel, the distance between the optical axis of the lens barrel and the guide bar is such that both ends of the guide bar are fixed group lenses A and C.
Is secured by fitting into fitting holes formed in the fixing holding frames 12 and 14 and the lens barrel main body 11 with high precision.

The positions of the fitting portions of the movable holding frames 13 and 15 holding the movable group lenses B and D with the guide bars formed on the movable holding frames 13 and 15 are determined when the holding frames are held by the guide bars. It is set with high precision so that the optical axis and the optical axis of the movable holding frame substantially match.

[0005]

However, even if the position of the fitting hole for holding the end portion of the guide bar and the fitting position of the movable holding frame with the guide bar are set with high precision as described above, the fixing is performed. Due to a plurality of error factors, such as mounting play between the holding frame and the barrel main body, fitting play between the moving holding frame and the guide bar, and holding play between the moving holding frame and the moving group lens, the optical axis of the barrel and the moving group lens may be changed. It is difficult to completely match the optical axis.

Particularly, in an optical system having high sensitivity to eccentricity between lenses by increasing the number of lenses and reducing the size thereof, there is a disadvantage that a shift in the optical axis of each lens has a large effect on optical performance.

Accordingly, an object of the present invention is to provide a lens barrel in which the optical axis of the lens barrel and the optical axis of the movable lens group can be easily matched.

[0008]

In order to achieve the above object, according to the present invention, in a lens barrel provided with a guide member for guiding a lens in an optical axis direction, the guide member is moved in accordance with an operation. Guide member moving means for moving with respect to the axis is provided.

Specifically, the guide member moving means is an eccentric member having a holding portion for holding the guide member, and an outer peripheral portion eccentric to the holding portion and fitted to the lens barrel main body,
The guide member can be moved with respect to the optical axis of the lens barrel by the amount of eccentricity between the holding portion and the outer peripheral portion.

That is, in the present invention, the position of the guide member with respect to the optical axis of the lens barrel is adjusted by operating the guide member moving means, whereby the optical axis of the lens slidably fitted to the guide member and the optical axis of the lens barrel are adjusted. The shaft and the shaft can be easily and reliably aligned.

Here, the guide member moving means can be operated from the outside of the lens barrel, so that after assembling the lens barrel, the guide is confirmed while confirming subject information obtained by an image pickup device or the like attached to the lens barrel. It is desirable that the position of the member can be adjusted, that is, the optical axis of the lens can be adjusted.

Further, according to the present invention, a positioning guide member for positioning the lens with respect to the optical axis of the lens barrel (for example, positioning in the Y-axis direction with respect to the optical axis Z), and a rotation of the lens about the positioning guide member ( In a lens barrel provided with a rotation restricting guide member for restricting movement around the Y axis in the X axis direction), the maximum movement amount of the positioning guide member is smaller than the maximum movement amount of the rotation restriction guide member. doing.

That is, both the position adjustment of the positioning guide member in the Y-axis direction and the position adjustment of the rotation regulating guide member in the X-axis direction can be performed, so that the optical axis can be more precisely aligned. It is possible to prevent the adjustment amount in the Y-axis direction from being too large to make adjustment difficult, or prevent the optical axis adjustment from being too small in the X-axis direction to perform sufficient optical axis adjustment.

In this case, the eccentric member serving as the guide member moving means includes a first outer peripheral portion having a first eccentric amount with respect to the holding portion, and a first outer peripheral portion having a first eccentric amount with respect to the holding portion. A second outer peripheral portion having an eccentric amount is provided, and the first outer peripheral portion of the eccentric member holding the positioning guide member is fitted to the lens barrel main body, and the eccentric member holds the rotation regulating guide member. By fitting the second outer peripheral portion of the member to the lens barrel main body, different adjustable amounts can be set for the positioning guide member and the rotation restricting guide member by using only one kind of eccentric member. It is desirable to make.

According to the present invention, the provision of such a lens barrel makes it possible to easily and surely correct the deviation of the optical axis of the optical system, and to provide an optical device such as a camera capable of performing precise imaging. That can be realized.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIG. 1 shows a lens barrel according to a first embodiment of the present invention. In this figure, reference numeral 1 denotes a main body barrel, which holds a relay lens E on the inner periphery of the rear end. Reference numeral 2 denotes a front group fixed frame, which holds the objective lens A. Reference numeral 3 denotes a V moving frame, which holds a variable power lens B. Reference numeral 4 denotes an afocal fixing frame fixed inside the intermediate portion of the lens barrel main body 1 in the optical axis direction and the lens barrel radial direction, and holds an afocal lens C. Reference numeral 5 denotes a focus moving frame which holds the focus lens D. 6
Reference numerals a and 6b denote V guide bars for guiding the V-movable lens frame 3 in the optical axis direction. The V guide bars 6a and 6b have both ends formed inside the front portion of the lens barrel main body and the afocal fixing frame 4. It is fitted and held in the fitting hole. The V-moving lens frame 3 has a sleeve portion 3a fitted to the V guide bar 6a so as to be slidable in the axial direction, and a U-shaped groove portion 3b engaged with the V guide bar 6b. Positioning in the Y-axis direction in FIG. 2 is performed by fitting to the guide bar 6a, and X-axis direction in FIG. 2 centering on the V guide bar 6a by engaging the U-shaped groove 3b with the V guide bar 6b. Is restricted. The front group fixing frame 2 is positioned in the lens barrel radial direction by fitting to the front ends of the V guide bars 6a and 6b.

Reference numerals 7a and 7b denote focus guide bars for guiding the focus moving frame 5 in the optical axis direction. Both ends of the focus guide bars 7a and 7b are connected to the afocal fixed frame 4 and an eccentric piece 8 described later. It is fitted and held in the formed fitting hole. Focus moving frame 5
Is a sleeve portion 5a that fits into the focus guide bar 7a so as to be slidable in the axial direction.
b is engaged with the focus guide bar 7a, whereby positioning in the Y-axis direction in FIG. 2 is performed, and the U-shaped groove 5b is engaged with the focus guide bar 7a. By engaging with the focus guide bar 7b, the rotation about the focus guide bar 7a in the X-axis direction in FIG. 2 is restricted.

The guide bar 7b corresponds to a positioning guide member described in claims, and the guide bar 7a corresponds to a rotation restricting guide member described in claims.

Eccentric piece (eccentric member referred to in the claims) 8
As shown in FIG. 3, a small diameter portion 8a of φD1 and a large diameter portion 8b of φD2 eccentric to the small diameter portion 8a are configured. At the center of the end surface of the small-diameter portion 8a, an operation groove 8d cut in a cross shape is formed.
A bar fitting hole (holding portion in the claims) 8c eccentric to the large-diameter portion 8b itself and the small-diameter portion 8a is provided on an end face of the small-diameter portion 8b.
Are formed. That is, the small-diameter portion 8a is eccentric by the eccentric amount A with respect to the bar fitting hole 8c, and the large-diameter portion 8b is eccentric by the eccentric amount B.

These eccentric tops 8 are fitted into top fitting holes formed at the rear end of the lens barrel main body 1. A frame fitting hole for fitting an eccentric piece (hereinafter referred to as a U-shaped groove side eccentric piece) 8 for the focus guide bar 7a has a small-diameter loose fitting portion 1a having an inner diameter larger than the small-diameter portion 8a of the eccentric piece 8. And a large-diameter fitting portion 1b having an inner diameter substantially equal to the outer diameter of the large-diameter portion 8b. On the other hand, a frame fitting hole for fitting an eccentric piece (hereinafter, referred to as a sleeve side eccentric piece) 8 for the focus guide bar 7b has a small diameter fitting portion having substantially the same inner diameter as the small diameter portion 8a of the eccentric piece 8. 1c and a large-diameter loose fitting portion 1d having an inner diameter larger than the outer diameter of the large-diameter portion 8b. The ends of the small-diameter portions 8a of the two eccentric pieces 8 are inserted through the piece fitting holes into the lens barrel main body 1.
The back is exposed.

In the lens barrel configured as described above, when the tool is engaged with the operation groove 8d of the eccentric piece 8 on the sleeve side and the eccentric piece 8 is rotated, the focus guide is kept within the range of the eccentric amount A. The rear end of the bar 7b can be moved in the Y-axis direction with respect to the optical axis of the lens barrel (the optical axis of the afocal lens C in this embodiment). Thereby, the optical axes of the focus moving frame 5 and the focus lens D held by the focus moving frame 5 can be moved in the Y-axis direction. On the other hand, when the tool is engaged with the operation groove 8d of the U-shaped groove side eccentric piece 8 and the eccentric piece 8 is rotated, the rear end of the focus guide bar 7a is moved within the range of the eccentric amount B to the lens barrel optical axis. Can be moved in the X-axis direction. Thereby, the optical axes of the focus moving frame 5 and the focus group lens D held by the focus moving frame 5 are
It can be rotated in the X-axis direction about the focus guide bar 7b.

Here, the eccentric amount of the eccentric piece 8 on the sleeve side becomes the maximum adjustment amount of the optical axis as it is, but the U-shaped groove side rotates about the focus guide bar 7b. Approximately half of the eccentric amount is the maximum adjustment amount of the optical axis. When one kind of eccentric amount that satisfies the required adjustment amount is given to the eccentric piece 8, the maximum adjustment amount is too large on the sleeve side as a result, the adjustment sensitivity becomes large, and it is difficult to adjust.
The problem that adjustment takes too long occurs. On the other hand, if eccentric pieces having different eccentric amounts are used on the sleeve side and the U-shaped groove side, two kinds of molds for the eccentric pieces are required, which causes an increase in cost.

For this reason, in this embodiment, one kind of eccentric piece is used by using eccentric pieces having the same amount of eccentricity (ie, the same shape) on the sleeve side and the U-shaped groove side. And the sleeve side eccentric pieces 8 and U
By changing the fitting portion (small-diameter portion 8a or large-diameter portion 8b) of the groove-side eccentric piece 8 to the lens barrel main body 1, different guide bar adjustment amounts are obtained on the sleeve side and the U-shaped groove side.

When the lens barrel of the present embodiment is used, an image sensor such as a CCD is attached to the rear end of the barrel body 1, and a monitor screen on which a chart or the like is photographed through the lens barrel is checked. It is possible to perform an adjustment operation for making the optical axis of the lens barrel coincide with the optical axis of the focus lens D.

In particular, in the lens barrel of the present embodiment, the sensitivity of the afocal lens C and the focus lens D to eccentricity is higher than that of the other lenses.
The predetermined optical performance can be satisfied by matching the optical axes of the lens and the focus lens D.

(Second Embodiment) FIG. 4 shows a lens barrel according to a second embodiment of the present invention. Note that the main parts of the present lens barrel are the same as those of the lens barrel of the first embodiment, and the common parts are denoted by the same reference numerals as in the first embodiment, and description thereof will be omitted.

In FIG. 4, the small diameter portion 8 of the eccentric piece 8 '
A gear G1 is formed on the outer periphery of the a ′, and the large diameter portion 8 is formed.
A gear G2 is formed on the outer periphery of b '. Further, a gear insertion opening 1b 'opened on the side surface of the lens barrel main body 1 is formed in a portion of the lens barrel main body 1 facing the gear G1 of the sleeve-side eccentric piece 8', and has a U-shaped groove side offset. A gear insertion opening 1 a ′ opened on the side surface of the lens barrel main body 1 is formed in a portion of the core piece 8 ′ facing the gear G 2.

In the lens barrel of the present embodiment, the respective eccentric pieces 8 'are rotated from the side surfaces of the lens barrel using the adjustment gears 9a and 9b, so that each focus guide bar similar to that of the first embodiment is provided. Adjustment of 7a and 7b can be performed. For this reason, the optical axis can be adjusted in the back projection inspection, the MTF measurement inspection process, and the like without attaching an imaging device such as a CCD to the rear end of the lens barrel.

In each of the above embodiments, the case where the optical axis of the afocal lens and the optical axis of the focus lens are adjusted has been described. However, the present invention can be applied to the optical axis adjustment of other lenses. it can.

Further, in each of the above embodiments, the case where the position of the guide bar is adjusted using the eccentric piece has been described. However, in the present invention, the guide member moving means other than the eccentric piece,
For example, the position of the guide bar may be adjusted using a screw.

In each of the above embodiments, the integrated lens barrel has been described. However, the present invention is directed to a Monaca barrel formed by dividing the barrel along a plane parallel to the optical axis, or an optical lens barrel. The present invention is also applicable to a lens barrel or the like divided in the axial direction.

[0032]

As described above, in the present invention, since the position of the guide member with respect to the optical axis of the lens barrel can be adjusted by operating the guide member moving means, the guide member is slidably fitted to the guide member. The optical axis of the lens and the optical axis of the lens barrel can be easily and reliably matched.

Further, if the guide member moving means can be operated from the outside of the lens barrel, after assembling the lens barrel, the guide member can be moved while confirming subject information obtained by an image pickup device or the like attached to the lens barrel. Position adjustment, that is, alignment of the optical axis of the lens can be performed.

In the present invention, a positioning guide member for positioning the lens with respect to the optical axis of the lens barrel, and a rotation restricting guide member for restricting rotation of the lens around the positioning guide member are provided. In this case, since the maximum movement amount of the positioning guide member is smaller than the maximum movement amount of the rotation restricting guide member, both the position adjustment of the positioning guide member and the position adjustment of the rotation restricting guide member are performed. In addition to being able to perform more strict optical axis alignment, the positioning guide member where the eccentric amount of the eccentric member as the guide member moving means is the maximum moving amount is excessively moved or the eccentric member It is possible to prevent the movement amount of the rotation regulating guide member, in which about half of the eccentricity amount becomes the maximum movement amount, from being insufficient, so that it becomes difficult to align the optical axis.

Further, in the present invention, the eccentric member has a first outer peripheral portion having a first eccentric amount with respect to the holding portion for holding the guide member, and a first eccentric amount larger than the first eccentric amount with respect to the holding portion. A second outer peripheral portion having a second eccentric amount is provided, the first outer peripheral portion of the eccentric member for the positioning guide member is fitted to the lens barrel main body, and the eccentric member for the rotation regulating guide member is provided. Since the second outer peripheral portion is fitted to the lens barrel main body, the maximum movement amount of both guide members can be made different only by using one kind of eccentric member, and the manufacturing cost of the eccentric member can be reduced. Can be suppressed.

In the present invention, the provision of such a lens barrel makes it possible to easily and surely correct the deviation of the optical axis of the optical system, and to provide an optical device such as a camera capable of performing precise imaging and the like. Can be realized.

[Brief description of the drawings]

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

FIG. 2 is a rear view of the lens barrel.

FIG. 3 is a detailed view of the eccentric coma of the lens barrel.

FIG. 4 is a sectional view of a lens barrel according to a second embodiment of the present invention.

FIG. 5 is a sectional view of a conventional lens barrel.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Lens barrel main body 2 ... Front group fixed frame 3 ... V moving frame 4 ... Afocal fixed frame 5 ... Focus moving frame 3a, 5a ... Sleeve part 3b, 5b ... U-shaped groove part 6a, 6a ... V
Guide bar 7a, 7b Focus guide bar 8 Eccentric frame 9a, 9b Adjustment gear A Objective lens B Variable magnification lens C Afocal lens D Focus lens E Relay lens G1, G2 Adjustment gear

Claims (6)

[Claims] 1. A lens barrel having a guide member for guiding a lens in an optical axis direction, comprising a guide member moving means for moving the guide member with respect to the optical axis of the lens barrel in accordance with an operation. Lens barrel. 2. The lens barrel according to claim 1, wherein the guide member moving unit moves the guide member in response to an operation from outside the lens barrel. 3. A positioning guide member for positioning the lens with respect to the barrel optical axis, and a rotation restricting guide member for restricting rotation of the lens around the positioning guide member. 3. The lens barrel according to claim 1, wherein a maximum movement amount of the positioning guide member by the guide member moving means is smaller than a maximum movement amount of the rotation regulating guide member. 4. The guide member moving means is an eccentric member having a holding portion for holding the guide member and an outer peripheral portion which is eccentric with respect to the holding portion and which fits into a lens barrel main body. The lens barrel according to any one of claims 1 to 3, wherein: 5. The eccentric member has a first outer peripheral portion having a first eccentric amount with respect to the holding portion, and a second eccentric amount larger than the first eccentric amount with respect to the holding portion. A first outer peripheral portion of the eccentric member that holds the positioning guide member is fitted to the lens barrel main body, and the eccentric member holds the rotation restricting guide member. The lens barrel according to claim 4, wherein a second outer peripheral portion of the core member is fitted to the barrel body. 6. An optical apparatus comprising the lens barrel according to claim 1.