JP2002169076A - Contacting and separating mechanism and lens moving mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a contacting and separating mechanism in which the disadvantage of the conventional end surface cam mechanism is eliminated with a simple configuration. SOLUTION: The contacting and separating mechanism has a first annular body and a second annular body in which relative turning is enabled and at least either can directly advance in an axial direction, a contacting and separating cam surface formed on the end surface of the first annular body opposed to the second annular body and inclined in a circumferential direction, a follower projection formed on the second annular body to engage with the contact and separation cam surface, and a means to give relative turning to the first and the second annular bodies. In the contacting and separating mechanism which forms a shape to contact and separate the first and the second annular bodies in the axial direction by the relative turning of the first and the second annular bodies, the contacting the separating cam surface and the follower projection form an annular rib which is located in the outer peripheral side, covers the follower projection of the second annular body, and is extended from the contacting and separating cam surface to the second annular body side on the peripheral surface of the first annular body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism for moving an annular body toward and away from a lens and a lens moving mechanism, and more particularly, to a mechanism for moving an annular body or a lens using a cam surface having an end cam shape.

[0002]

2. Description of the Related Art As a mechanism for moving an annular body such as a lens frame, a cam surface inclined with respect to the circumferential direction is formed on one end surface of a pair of relatively rotatable annular bodies, and the other side. There is a so-called end cam (face cam) provided with a follower projection which engages with the contact / separation cam surface on the annular body. The use of such an end face cam has the advantage that the structure of the moving mechanism can be simplified, but on the strength side, it is more advantageous to form the end face of the annular body into a completely cylindrical shape without forming an end face cam. . Further, when the annular body moved by the end surface cam is used as a lens frame, it is necessary to prevent light leakage from a portion where the cam surface is formed. However, separately providing a strength member and a light shielding member is not desirable in terms of space and manufacturing cost.

[0003] For example, a zoom lens system proposed by the applicant of the present invention that can be reduced in size while having a high zoom ratio (Japanese Patent Application No. Hei 1 (1994)).
No. 1-79572) has a plurality of movable zoom lens groups that change the focal length; at least one zoom lens group has two sub-groups, one of which is a sub-group of the other. A switching group that is a movable sub-group that is selectively positioned at one of the two moving ends in the optical axis direction in relation to the sub-group; a short focal length side zooming region from the short focal length end to the intermediate focal length And the movable sub-group in the switching group is located at one of the moving ends different from each other between the intermediate focal length and the long focal length side zooming region from the long focal length end; The basic trajectory of the zooming of the lens group is discontinuous at the intermediate focal length, and is determined so as to form an image on a predetermined image plane according to the position of the movable sub-group. When mechanically constructing a lens barrel that satisfies such a zoom lens system, it is preferable to use the above-described end face cam mechanism because the structure of the lens moving mechanism can be simplified. It is desirable to ensure the property.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lens moving mechanism and a contact / separation moving mechanism which are simple in structure and excellent in strength and light shielding properties.

[0005]

SUMMARY OF THE INVENTION The present invention is directed to a first annular body and a second annular body which are relatively rotatable and at least one of which is capable of linearly moving in the axial direction; the first annular body being opposed to the second annular body. Contact / separation cam surface formed on the end surface which is inclined with respect to the circumferential direction;
A follower projection formed on the annular body and engaging with the contact / separation cam surface; and means for imparting relative rotation to the first and second annular bodies; 1st, 2nd
In the contact / separation moving mechanism having a shape for bringing the first and second annular bodies into and out of contact with each other in the axial direction by the relative rotation of the annular body, the contacting / separating mechanism is provided on the peripheral surface of the first annular body and on the outer peripheral side of the contact / separation cam surface Position to,
An annular rib is formed to cover the follower projection of the second annular body and extend toward the second annular body. According to this configuration, the strength around the contact / separation cam surface of the annular body can be increased with a simple configuration in which the annular rib is provided.

In this contact / separation moving mechanism, it is desirable that the inner peripheral surface of the annular rib of the first annular member and a part of the outer surface of the second annular member slidably contact each other. With this configuration, it is possible to increase the stability of the first and second annular members during movement.

[0007] The follower projection is formed on an end face of the second annular body facing the first annular body, and is located on the peripheral surface of the second annular body on the inner peripheral side of the follower projection. First
It is preferable that an annular rib different from the above-described annular rib provided on the first annular body is formed so as to extend toward the annular body. According to this configuration, the strength around the follower protrusion can be increased also on the second annular body side.

The above-mentioned contact / separation moving mechanism comprises a first lens for supporting the first and second annular bodies at first and second sub-lens groups which respectively function optically at an approach position and a separation position. It can be applied as a group frame and a second lens group frame.

In the above-mentioned contact / separation moving mechanism, one of the first and second annular members is a focus lens supporting member that supports a focus lens group, which is movably supported in a straight line.
The other of the first and second annular bodies is a drive ring that is rotatable relative to the focus lens support member, and the focus lens support member is moved by the contact / separation cam surface and the follower protrusion in accordance with the rotation of the drive ring. It can be applied to move straight. In this case, furthermore, the first lens group frame which supports the first and second sub-lens groups which function optically at the approach position and the separation position, respectively, and which is capable of relative rotation and linear movement, is further provided. And the second lens group frame.

The present invention also provides a first lens group frame which supports first and second sub-lens groups which function optically at an approach position and a separation position, respectively, and which is capable of relative rotation and linear movement. A second lens group frame; a contact / separation cam surface formed on an end face of the first lens group frame facing the second lens group frame and inclined with respect to the circumferential direction; a contact / separation formed on the second lens group frame A follower projection that engages with the cam surface; and a drive ring that imparts relative rotation to the first lens group frame and the second lens group frame. The contact and separation cam surface and the follower projection have first and second lenses. In a lens moving mechanism configured to move the first and second lens group frames to an approach position and a separation position by relative rotation of the group frame, a peripheral surface of the first lens group frame is provided outside the contact / separation cam surface. Side, and covers the follower projection of the second lens group frame. It is characterized by the formation of the annular rib extending. According to this lens moving mechanism, the strength around the contact / separation cam surface of the lens group frame can be increased with a simple configuration in which the annular rib is provided, and the light shielding property can be enhanced by the annular rib.

In this lens moving mechanism, it is preferable that the inner peripheral surface of the annular rib of the first lens group frame and a part of the outer surface of the second lens group frame slidably contact with each other. With this configuration,
It is possible to increase the stability of the first lens group frame and the second lens group frame during movement.

The follower projection is provided on the first lens group frame.
The first lens group frame is formed on an end surface facing the lens group frame, and is located on the peripheral surface of the second lens group frame on the inner peripheral side of the follower protrusion and extends toward the first lens group frame. It is preferable to form an annular rib different from the above-described annular rib provided in the above. According to this configuration, it is possible to increase the strength around the follower protrusion and the light shielding property even on the second lens group frame side.

In the above-described lens moving mechanism, the first and second sub-lens groups constitute one lens group of a plurality of zoom lens groups of a zoom lens system that moves in the optical axis direction during a zooming operation. The first and second sub-lens groups respectively function as focus lens groups at the approach position and the separation position, and the first and second sub-lens groups are located at the approach position and the separation position.
It is possible to provide a focusing mechanism for moving the lens group frame and the second lens group frame in the optical axis direction while maintaining the distance therebetween.

In the above-mentioned focus mechanism, the first lens group frame is supported so as to be capable of rectilinear movement in the optical axis direction while restricting the rotation, and the second lens group frame is capable of reciprocating rotation within a certain angle range. A support cylinder that restricts the rotation at both rotation ends corresponding to the approach position and the separation position and supports the linear movement in the optical axis direction; when the first lens group frame and the second lens group frame come and go, A focus cam surface formed on an end surface of the drive ring that gives relative rotation to both lens group frames and facing the second lens group frame and inclined with respect to the circumferential direction; and provided on the second lens group frame. A second follower projection, which is different from the first follower projection engaged with the contact / separation cam surface of the first lens unit frame, when the focus cam surface of the drive ring is engaged at the two rotation ends;
And the focus cam surface and the second follower projection of the second lens group frame can be formed by forming the second lens group frame to move straight by rotating the drive ring. According to this configuration, in addition to the contact / separation mechanism for each lens group frame, a focus mechanism for integrally moving both lens group frames is preferable because it can have a simple structure using the end surface cam.

In the case where the focusing mechanism is configured as described above, the second lens group frame is located on the peripheral surface of the drive ring on the outer peripheral side of the focus cam surface and covers the second follower projection of the second lens group frame.
It is preferable to form an annular rib different from the above-described annular rib provided on the first (and second) lens group frame side in a manner extending to the lens group frame side. With this annular rib, it is possible to improve the strong light shielding property around the focus cam surface of the drive ring.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Explanation of a zoom lens system having a switching group to which the present invention can be applied] In the following embodiments, the present invention is applied to a lens barrel described later. This lens barrel is suitable for use in a zoom lens system proposed by the present applicant in Japanese Patent Application No. 11-79572. First, each aspect of a zoom lens system having a switching group proposed by the present applicant in Japanese Patent Application No. 11-79572 will be described with reference to FIGS. Note that IM in FIGS. 1 to 9 indicates an image plane such as a film plane, and the image plane IM does not move. FIG. 1 shows a first mode of a zoom lens system using a switching group. The zoom lens system includes, in order from the object side, a first variable power lens group 10 having a positive power as a whole,
As a whole, the second variable power lens group 20 has a negative power. The first variable power lens group 10 includes, in order from the object side, a first lens group L1 (a first sub group S1) having a negative power and a positive power. The second variable power lens group 20 comprises a third lens group L3 having a negative power. The second sub group S2 in the first variable power lens group 10 is fixed to the first group frame 11, and the movable sub group frame 12 of the first sub group S1 has a guide groove formed in the first group frame 11. The movable member 13 can be moved by a certain distance in the optical axis direction.
The first sub-group S1 selects one of two positions, a moving end on the object side where the movable sub-group frame 12 contacts the front end of the guide groove 13 and a moving end on the image plane where it contacts the rear end. Take. The third lens group L3 is fixed to the second group frame 21.

The basic locus of zooming of the zoom lens system includes the movement of the first variable power lens group 10 (first group frame 11) and the second variable power lens group 20 (second group frame 21), and the guide groove 13 Are set as follows with the movement of the first group frame 12 (the first sub-group S1) within the camera. When zooming,
The diaphragm D moves together with the first variable power lens group 10 (first group frame 11).

A: short focal length end fw to intermediate focal length f
In the short focal length side zooming area Zw up to m, the first sub-unit S1 holds an interval (first interval, wide interval) d1 apart from the second sub-unit S2. Then, the first variable power lens group 10 (first group frame 11) and the second variable power lens group 20 (second group frame 21) both move toward the object side while changing the air gap between them.

B: At the intermediate focal length fm, the first zoom lens group 10 (first group frame 11) and the second zoom lens group 20
The (second group frame 21) moves to the image plane side from the position at the long focal length end in the short focal length zooming area Zw.
The first sub-group S1 is provided with the guide groove 13 of the first group frame 11.
In this case, an interval (second interval, narrow interval) d2 is reached, which reaches the moving end on the image plane side and approaches the second sub-group S2.

C: intermediate focal length fm to long focal length end f
In the long focal length side zooming zone Zt up to t, the first sub-group S1 is closer to the second sub-group S2 (second
D2) is held. Then, the first variable power lens group 1
0 (the first group frame 11) and the second variable power lens group 20 (the second group frame 21) set the air gap between each other based on the position after the movement to the image plane side at the intermediate focal length fm. Both move to the object side while changing.

The drawing is a simplified one, and the basic zooming locus of the first variable power lens group 10 (first group frame 11) and the second variable power lens group 20 (second group frame 21) is drawn by a straight line. But
It is not always a straight line.

In focusing, the first sub-unit S1 and the second sub-unit S2 are moved integrally in all variable focal length ranges (that is, the first variable power lens group 10 (the first group frame 1).
1) is moved).

FIG. 2 shows a second embodiment of a zoom lens system having a switching group. The zoom lens system includes, in order from the object side, a first variable power lens group 10 having a positive power, a second variable power lens group 20 having a positive power as a whole, and a third variable power lens group 30 having a negative power. ing. The first variable power lens group 10 includes a first lens group L1 having a positive power, and the second variable power lens group 20 includes, in order from the object side, a second lens group L2 having a negative power (first sub group S1). And a third lens unit L3 (second sub-unit S2) having a positive power, and the third variable power lens unit 30 includes a fourth lens unit L4 having a negative power. The first lens unit L1 includes a first variable power lens unit frame 1
Fixed to 1. The second sub group S2 in the second variable power lens group 20 is fixed to the second group frame 21, and the movable sub group frame 22 of the first sub group S1 has a guide groove formed in the second group frame 21. It is possible to move within the optical axis 23 by a certain distance in the optical axis direction.
The first sub-group S1 selects one of two positions, a moving end on the object side where the movable sub-group frame 22 contacts the front end of the guide groove 23 and a moving end on the image plane side where it contacts the rear end. Take. The fourth lens unit L4 is fixed to the third group frame 31.

The zooming basic locus of the zoom lens system according to the second embodiment is represented by a first variable power lens group 10 (first group frame 1).
1), second variable power lens group 20 (second group frame 21) and third
With the movement of the variable power lens group 30 (third group frame 31) and the movement of the second group frame 22 (first sub group S1) in the guide groove 23, the following settings are made. At the time of zooming, the aperture D is set to the second variable power lens group 20 (the second group frame 21).
To move with.

A: short focal length end fw to intermediate focal length f
In the short focal length side zooming area Zw up to m, the first sub-unit S1 holds an interval (first interval, wide interval) d1 apart from the second sub-unit S2. Then, the first zoom lens group 10 (first group frame 11), the second zoom lens group 20 (second group frame 21), and the third zoom lens group 30 (third group frame 3)
1) both move toward the object side while changing the air gap between each other.

B: At the intermediate focal length fm, the first zoom lens group 10 (first group frame 11) and the second zoom lens group 20
The (second group frame 21) and the third variable power lens group 30 (third group frame 31) move to the image plane side from the position at the long focal length end in the short focal length side zooming area Zw. Further, the first sub-group S1 reaches the moving end on the image plane side in the guide groove 23 of the second group frame 21 and is close to the second sub-group S2 (second interval, narrow interval) d2. Take.

C: intermediate focal length fm to long focal length end f
In the long focal length side zooming zone Zt up to t, the first sub-group S1 is closer to the second sub-group S2 (second
D2) is held. Then, the first variable power lens group 1
0 (first group frame 11), second variable power lens group 20 (second group frame 21), and third variable power lens group 30 (third group frame 31)
Moves to the object side while changing the air gap between them, based on the position after the movement to the image plane side at the intermediate focal length fm.

The figure is a simplified one, in which a first zoom lens group 10 (first group frame 11), a second zoom lens group 20 (second group frame 21) and a third zoom lens group 30 ( Although the zooming basic locus of the third group frame 31) is drawn by a straight line, it is not always a straight line.

In focusing, the first sub-unit S1 and the second sub-unit S2 are moved integrally in all variable focal length ranges (that is, the second variable power lens group 20 (the second group frame 2)).
1) is moved).

The zooming basic locus of the zoom lens system described above is discontinuous at the intermediate focal length fm, as in the first embodiment, but at the short focal length end fw, the intermediate focal length fm.
(Discontinuous point) and first lens unit L at long focal length end ft
1. By appropriately setting the positions of the first sub-group S1 (second lens group L2), the second sub-group S2 (third lens group L3) and the fourth lens group L4, an image is always correctly formed on the image plane. Such a solution exists. According to such a basic zooming locus, a compact zoom lens system can be obtained while having a high zoom ratio.

FIG. 3 shows a third embodiment of a zoom lens system having a switching group. This embodiment is the same as the second embodiment except that the most object side positive lens unit L1 in the second embodiment is replaced by the negative lens unit L1.

FIG. 4 shows a fourth embodiment of a zoom lens system having a switching group. The zoom lens system includes, in order from the object side, a first variable power lens group 10 having a positive power as a whole and a second variable power lens group 20 having a negative power as a whole.
The first variable power lens unit 10 includes, in order from the object side, a first lens unit L1 having a negative power (a first sub group S1).
1) and the second lens unit L2 having positive power (the second sub-unit S
2), and the second variable power lens group 20 includes, in order from the object side, the third lens group L3 (the third sub group S
3) and the fourth lens unit L4 having negative power (the fourth sub-unit S
4).

The second sub group S2 in the first variable power lens group 10
Is fixed to the first group frame 11, and the movable sub group frame 12 supporting the first sub group S1 is movable within the guide groove 13 formed in the first group frame 11 by a fixed distance in the optical axis direction. is there.
The first sub-group S1 selects one of two positions, a moving end on the object side where the movable sub-group frame 12 contacts the front end of the guide groove 13 and a moving end on the image plane where it contacts the rear end. Take. Similarly, the fourth sub-group S4 in the second variable power lens group 20 includes the second group frame 2
The movable sub-group frame 22 fixed to 1 and supporting the third sub-group S3 is movable within the guide groove 23 formed in the second group frame 21 by a fixed distance in the optical axis direction. Third subgroup S3
Is selected from two positions: a moving end on the object side where the movable sub-group frame 22 contacts the front end of the guide groove 23, and a moving end on the image plane side where it contacts the rear end.

The basic locus of zooming of the zoom lens system includes the movement of the first variable power lens group 10 (first group frame 11) and the second variable power lens group 20 (second group frame 21), and the guide groove 13 With the movement of the first group frame 11 (first sub-group S1) and the second group frame 21 (third sub-group S3) within and, 23 are set as follows. During zooming, the stop D moves together with the first variable power lens group 10 (first group frame 11).

A: short focal length end fw to intermediate focal length f
In the short focal length side zooming area Zw up to m, the first sub-group S1 holds an interval (first interval, wide interval) d1 apart from the second sub-group S2, and the third sub-group S3 has the Intervals separated from 4 subgroups S4 (first interval, wide interval)
Take d3. Then, the first variable power lens group 10 (first group frame 11) and the second variable power lens group 20 (second group frame 21) both move toward the object side while changing the air gap between them.

B: At the intermediate focal length fm, the first zoom lens group 10 (first group frame 11) and the second zoom lens group 20
The (second group frame 21) moves to the image plane side from the position at the long focal length end in the short focal length zooming area Zw.
The first sub-group S1 is provided with the guide groove 13 of the first group frame 11.
, Reaches the moving end on the image plane side, takes an interval (second interval, narrow interval) d2 close to the second sub-unit S2, and the third sub-unit S3 approaches the fourth sub-unit S4. Interval (second
, D4).

C: intermediate focal length fm to long focal length end f
In the long focal length side zooming zone Zt up to t, the first sub-group S1 holds an interval (narrow interval) d2 close to the second sub-group S2, and the third sub-group S3 holds the fourth sub-group S4. Is maintained at an interval (narrow interval) d4 that is close to. The first variable power lens group 10 (first group frame 11) and the second variable power lens group 20 (second group frame 21) are based on the position after the movement to the image plane side at the intermediate focal length fm. Then, both are moved to the object side while changing the air gap between them.

In the drawing, for the sake of convenience, the first variable power lens group 10
(First group frame 11) and second variable power lens group 20 (second group frame 2)
Although the zooming basic trajectory of 1) is drawn by a straight line, it is not always a straight line.

In focusing, the first sub-unit S1 and the second sub-unit S2 are moved integrally in all variable focal length ranges (that is, the first variable power lens group 10 (the first group frame 1).
1) is moved).

The basic trajectory of the zooming of the zoom lens system described above is the same as the first to third embodiments, and the intermediate focal length f
m, the first at the short focal length end fw, the intermediate focal length fm (discontinuous point), and the first at the long focal length end ft.
Sub group S1 (first lens group L1), second sub group S2 (second lens group L2), third sub group S3 (third lens group L)
By appropriately setting the position of 3) and the fourth sub-group S4 (fourth lens group L4), there is a solution that always forms a correct image on the image plane. According to such a basic zooming locus, a compact zoom lens system can be obtained while having a high zoom ratio.

FIG. 5 shows a fifth embodiment of a zoom lens system having a switching group. The zoom lens system includes, in order from the object side, a first variable power lens group 10 having a positive power as a whole and a second variable power lens group 20 having a negative power as a whole.
The first variable power lens unit 10 includes, in order from the object side, a first lens unit L1 having a negative power (a first sub group S1).
1) and the second lens unit L2 having positive power (the second sub-unit S
2), and the second variable power lens group 20 includes, in order from the object side, the third lens group L3 (the third sub group S
3) and the fourth lens unit L4 having negative power (the fourth sub-unit S
4).

The second sub group S2 in the first variable power lens group 10
Is fixed to the first group frame 11, and the movable sub group frame 12 supporting the first sub group S1 is movable within the guide groove 13 formed in the first group frame 11 by a fixed distance in the optical axis direction. is there.
The first sub-group S1 selects one of two positions, a moving end on the object side where the movable sub-group frame 12 contacts the front end of the guide groove 13 and a moving end on the image plane where it contacts the rear end. Take. Similarly, the fourth sub-group S4 in the second variable power lens group 20 includes the second group frame 2
The movable sub-group frame 22 fixed to 1 and supporting the third sub-group S3 is movable within the guide groove 23 formed in the second group frame 21 by a fixed distance in the optical axis direction. Third subgroup S3
Is selected from two positions: a moving end on the object side where the movable sub-group frame 22 contacts the front end of the guide groove 23, and a moving end on the image plane side where it contacts the rear end.

The basic locus of zooming of the zoom lens system includes the movement of the first variable power lens group 10 (first group frame 11) and the second variable power lens group 20 (second group frame 21), and the guide groove 13 With the movement of the first group frame 11 (first sub-group S1) and the second group frame 21 (third sub-group S3) within and, 23 are set as follows. During zooming, the stop D moves together with the first variable power lens group 10 (first group frame 11).

A: In the short focal length side zooming zone Zw from the short focal length end fw to the first intermediate focal length fm1,
The first sub-group S1 holds an interval (first interval, wide interval) d1 that is separated from the second sub-group S2, and the third sub-group S3
Is an interval apart from the fourth subgroup S4 (first interval,
(Wide interval) d3 is taken. Then, the first variable power lens group 10
(First group frame 11) and second variable power lens group 20 (second group frame 2)
1) both move toward the object side while changing the air gap between each other.

B: At the intermediate focal length fm1, the first zoom lens group 10 (first group frame 11) and the second zoom lens group 20 (second group frame 21) are in the short focal length side zooming zone Z.
It moves to the image plane side from the position at the end of the long focal length in w. Further, the first sub-group S1 reaches the moving end on the image plane side in the guide groove 13 of the first group frame 11 and is close to the second sub-group S2 (second interval, narrow interval) d2. Take.

C: In the intermediate zooming zone Zm from the first intermediate focal length fm1 to the second intermediate focal length fm2,
The first sub-group S1 holds an interval (second interval, narrow interval) d2 close to the second sub-group S2, and the third sub-group S3
Is an interval apart from the fourth subgroup S4 (first interval,
(Wide interval) d3 is held. Then, the first variable power lens group 1
0 (the first group frame 11) and the second variable power lens group 20 (the second group frame 21) are based on the position after the movement to the image plane side at the first intermediate focal length fm1. Both move to the object side while changing the air gap.

D: At the second intermediate focal length fm2,
The first variable power lens group 10 (first group frame 11) and the second variable power lens group 20 (second group frame 21) have an intermediate zooming area Zm.
It moves to the image plane side from the position at the long focal point side end portion. Further, the third sub-group S3 reaches the moving end on the image plane side in the guide groove 23 of the second group frame 21 and is close to the fourth sub-group S4 (second interval, narrow interval) d4. Take.

E: In the long focal length side zooming zone Zt from the second intermediate focal length fm2 to the long focal length end ft,
The first sub-group S1 holds an interval (narrow interval) d2 close to the second sub-group S2, and the third sub-group S3 sets an interval (narrow interval) d4 close to the fourth sub-group S4. Hold. Then, the first zoom lens group 10 (first group frame 11) and the second zoom lens group 20 (second group frame 21) move to the image plane side at the second intermediate focal length fm2. Based on the position, they move toward the object side while changing the air gap between them.

The figure is a simplified one, and the basic zooming locus of the first variable power lens group 10 (first group frame 11) and the second variable power lens group 20 (second group frame 21) is drawn by a straight line. But
It is not always a straight line.

In focusing, the first sub-unit S1 and the second sub-unit S2 are moved integrally in all the variable focal length regions (that is, the first variable power lens unit 10 (the first group frame 1).
1) is moved).

The basic zooming locus of the zoom lens system described above has the intermediate focal length f, as in the first to fourth embodiments.
m, but at the short focal length end fw, the first,
The first sub-group S1 (the first lens group L) at the second intermediate focal lengths fm1, fm2 (discontinuous points) and the long focal length end ft
1), a second sub-group S2 (second lens group L2), a third sub-group S3 (third lens group L3), and a fourth sub-group S4 (fourth
By appropriately determining the position of the lens unit L4), there is a solution that always forms a correct image on the image plane. According to such a basic zooming locus, a compact zoom lens system can be obtained while having a high zoom ratio.

FIG. 6 shows a sixth embodiment of the zoom lens system having a switching group. The zoom lens system includes, in order from the object side, a first variable power lens group 10 having a positive power as a whole and a second variable power lens group 20 having a negative power as a whole.
The first variable power lens unit 10 includes, in order from the object side, a first lens unit L1 having a negative power (a first sub group S1).
1) and the second lens unit L2 having positive power (the second sub-unit S
2), and the second variable power lens group 20 includes, in order from the object side, the third lens group L3 (the third sub group S
3) and the fourth lens unit L4 having negative power (the fourth sub-unit S
4).

The second sub group S2 in the first variable power lens group 10
Is fixed to the first group frame 11, and the movable sub group frame 12 supporting the first sub group S1 is movable within the guide groove 13 formed in the first group frame 11 by a fixed distance in the optical axis direction. is there.
The first sub-group S1 selects one of two positions, a moving end on the object side where the movable sub-group frame 12 contacts the front end of the guide groove 13 and a moving end on the image plane where it contacts the rear end. Take. Similarly, the fourth sub-group S4 in the second variable power lens group 20 includes the second group frame 2
The movable sub-group frame 22 fixed to 1 and supporting the third sub-group S3 is movable within the guide groove 23 formed in the second group frame 21 by a fixed distance in the optical axis direction. Third subgroup S3
Is selected from two positions: a moving end on the object side where the movable sub-group frame 22 contacts the front end of the guide groove 23, and a moving end on the image plane side where it contacts the rear end.

The basic locus of zooming of the zoom lens system is based on the movement between the first variable power lens group 10 (first group frame 11) and the second variable power lens group 20 (second group frame 21), and the guide groove 13 With the movement of the first group frame 11 (first sub-group S1) and the second group frame 21 (third sub-group S3) within and, 23 are set as follows. During zooming, the stop D moves together with the first variable power lens group 10 (first group frame 11).

A: In the short focal length side zooming zone Zw from the short focal length end fw to the first intermediate focal length fm1,
The first sub-group S1 holds an interval (first interval, wide interval) d1 that is separated from the second sub-group S2, and the third sub-group S3
Is an interval apart from the fourth subgroup S4 (first interval,
(Wide interval) d3 is taken. Then, the first variable power lens group 10
(First group frame 11) and second variable power lens group 20 (second group frame 2)
1) both move toward the object side while changing the air gap between each other.

B: At the intermediate focal length fm1, the first zoom lens group 10 (first group frame 11) and the second zoom lens group 20 (second group frame 21) are in the short focal length side zooming zone Z.
It moves to the image plane side from the position at the end of the long focal length in w. Further, the third sub-group S3 reaches the moving end on the image plane side in the guide groove 23 of the second group frame 21 and is close to the fourth sub-group S4 (second interval, narrow interval) d4. Take.

C: In the intermediate zooming zone Zm from the first intermediate focal length fm1 to the second intermediate focal length fm2,
The first sub-group S1 holds an interval (first interval, wide interval) d1 separated from the second sub-group S2, and the third sub-group S3
Is the distance close to the fourth subgroup S4 (the second distance,
(Narrow interval) d4 is maintained. Then, the first variable power lens group 1
0 (the first group frame 11) and the second variable power lens group 20 (the second group frame 21) are based on the position after the movement to the image plane side at the first intermediate focal length fm1. Both move to the object side while changing the air gap.

D: At the second intermediate focal length fm2,
The first variable power lens group 10 (first group frame 11) and the second variable power lens group 20 (second group frame 21) have an intermediate zooming area Zm.
It moves to the image plane side from the position at the long focal point side end portion. Further, the first sub-group S1 reaches the moving end on the image plane side in the guide groove 13 of the first group frame 11 and is close to the second sub-group S2 (second interval, narrow interval) d2. Take.

E: In the long focal length side zooming zone Zt from the second intermediate focal length fm2 to the long focal length end ft,
The first sub-group S1 holds an interval (narrow interval) d2 close to the second sub-group S2, and the third sub-group S3 sets an interval (narrow interval) d4 close to the fourth sub-group S4. Hold. Then, the first zoom lens group 10 (first group frame 11) and the second zoom lens group 20 (second group frame 21) move to the image plane side at the second intermediate focal length fm2. Based on the position, they move toward the object side while changing the air gap between them.

The drawing is a simple one, and the basic zooming locus of the first variable power lens group 10 (first group frame 11) and the second variable power lens group 20 (second group frame 21) is drawn by a straight line. But
It is not always a straight line.

In focusing, the first sub-unit S1 and the second sub-unit S2 are moved integrally in all variable focal length ranges (that is, the first variable power lens unit 10 (the first group frame 1)).
1) is moved).

The basic trajectory for zooming of the zoom lens system described above is the same as the first to fifth embodiments, and the intermediate focal length f
m, but at the short focal length end fw, the first,
The first sub-group S1 (the first lens group L) at the second intermediate focal lengths fm1, fm2 (discontinuous points) and the long focal length end ft
1), a second sub-group S2 (second lens group L2), a third sub-group S3 (third lens group L3), and a fourth sub-group S4 (fourth
By appropriately determining the position of the lens unit L4), there is a solution that always forms a correct image on the image plane. According to such a basic zooming locus, a compact zoom lens system can be obtained while having a high zoom ratio.

FIG. 7 shows a seventh embodiment of the zoom lens system having a switching group. The zoom lens system includes, in order from the object side, a first variable power lens group 10 having a positive power as a whole and a second variable power lens group 20 having a negative power. The first variable power lens unit 10 includes, in order from the object side, a first lens L1 having a positive power (first sub group S1), a second lens group L2 having a negative power (second sub group S2), and a positive lens. A third lens unit L3 (third sub-unit S3) having a power,
The second variable power lens unit 20 is a fourth lens unit L4 having a negative power.
Consists of First sub group S of the first variable power lens group 10
The first and third sub-groups S3 are fixed to the first group frame 11, and the movable sub-group frame 12 supporting the second sub-group S2 has an optical axis within a guide groove 13 formed in the first group frame 11. It can move a certain distance in the direction. The second sub-group S2 selects one of two positions, a moving end on the object side where the movable sub-group frame 12 contacts the front end of the guide groove 13 and a moving end on the image plane where the movable sub-group frame 12 contacts the rear end. Take. The fourth lens unit L4 is fixed to the second group frame 21.

The zooming basic locus of this zoom lens system is based on the movement of the first variable power lens group 10 (first group frame 11) and the second variable power lens group 20 (second group frame 21), and the guide groove 13 Are set as follows with the movement of the first group frame 11 (the second sub-group S2) within the camera. When zooming,
The diaphragm D moves together with the first variable power lens group 10 (first group frame 11).

A: short focal length end fw to intermediate focal length f
In the short focal length side zooming area Zw up to m, the second sub-unit S2 has a narrow distance close to the first sub-unit S1,
The wide distance apart from the sub-group S3 is maintained. Then, the first variable power lens group 10 (first group frame 11) and the second variable power lens group 20 (second group frame 21) both move toward the object side while changing the air gap between them.

B: At the intermediate focal length fm, the first variable power lens group 10 (first group frame 11) and the second variable power lens group 20
The (second group frame 21) moves to the image plane side from the position at the long focal length end in the short focal length zooming area Zw.
Further, the second sub-group S2 includes the guide groove 13 of the first group frame 11.
In this case, the moving end on the image plane side is reached, and a wide interval is set apart from the first sub-unit S1, and a narrow interval is set close to the third sub-unit S3.

C: intermediate focal length fm to long focal length end f
In the long focal length side zooming zone Zt up to t, the second sub-group S2 keeps a wide interval apart from the first sub-group S1, and a narrow interval close to the third sub-group S3. The first variable power lens group 10 (first group frame 11) and the second variable power lens group 20 (second group frame 21) are based on the position after the movement to the image plane side at the intermediate focal length fm. Then, both are moved to the object side while changing the air gap between them.

The drawing is a simple one, and the basic zooming locus of the first variable power lens group 10 (first group frame 11) and the second variable power lens group 20 (second group frame 21) is drawn by a straight line. But
It is not always a straight line.

In focusing, the first sub-group S1 to the third sub-group S3 are moved integrally (ie, the first zoom lens group 10 (first group frame 11) is moved in all variable focal length regions). Do).

The zooming basic locus of the zoom lens system described above has an intermediate focal length f, as in the first to sixth embodiments.
m, the first at the short focal length end fw, the intermediate focal length fm (discontinuous point), and the first at the long focal length end ft.
Sub group S1 (first lens group L1), second sub group S2 (second lens group L2), third sub group S3 (third lens group L)
By appropriately setting the position of the third lens unit L4 and the fourth lens unit L4, there is a solution that always forms an image on the image plane correctly.
According to such a basic zooming locus, a compact zoom lens system can be obtained while having a high zoom ratio.

As described above, the zoom lens system having the above-described switching group is practically used as a photographing lens system of a camera having a photographing lens system and a finder optical system having different optical axes. The stop position during zooming of each lens group during shooting is preferably determined stepwise on the basic zooming locus, that is, a plurality of focal length steps. FIGS. 8 and 9 show an example in which the stop position of each lens group during zooming is stepwise. In this example, the first embodiment of FIG. 1 is used as an example, and the same components as those of FIG. 1 are denoted by the same reference numerals. The basic zooming locus is indicated by a broken line, and the stop positions of the first group frame 11 and the second group frame 21 at the time of zooming during shooting are indicated by black circles on the zooming locus indicated by the broken line. FIG. 9 is a drawing in which the moving trajectory connecting the black circles in FIG. 8 with smooth curves is drawn by a solid line. In an actual mechanical configuration, the first group frame 11 and the second group frame 21 are moved in this manner. be able to.

In each of the above embodiments, for convenience, each lens group is illustrated as a single lens, but these can of course be composed of a plurality of lenses.

[Description of Overall Structure of Zoom Lens Barrel Having Switching Group] In each of the above embodiments, FIGS.
The first variable power lens group 10 of the mode of FIG. 4, the second variable power lens group 20 of the mode of FIG. 2, the second variable lens group 20 of the mode of FIG. 3, the first variable lens group 10 of the mode of FIG. The first variable power lens group 10 in the mode of FIG. 5, the first variable power lens group 10 in the mode of FIG. 6,
And the first variable power lens group 10 (first lens L
1 and the third lens L3) are switching groups, and function as focus lens groups in the entire focal length range.

The following description relates to a lens barrel adaptable to the above-mentioned switching group. Hereinafter, the first variable-magnification lens group (switching group) 10 and the second variable-magnification in the embodiments shown in FIGS. 1, 8, and 9 will be described. An embodiment applied to a zoom lens barrel having a lens group 20 will be described. In the zoom lens barrel (system) of the embodiment shown in FIG. 10 and subsequent figures, one of the first sub-groups S1 and S2 constituting the switching group 10 is fixed to the first group frame 11, FIGS.
Is different from the first zoom lens system, the first sub-groups S1 and S2
Are movable in the optical axis direction with respect to the switching group frame. In this mode, the movement trajectory given to the switching group frame during the zooming operation and the first sub-group S1 and the second sub-group S2 in the switching group frame
, The combined trajectory with the moving trajectory given in FIG. At the time of focusing, the first sub-group S1 and the second sub-group S2 are integrally moved in the optical axis direction within the switching group frame. The actual operation is based on the focal length information set by the operator and the detected subject distance information, before the shutter release starts, the movement of the switching group frame and the first sub-frame in the switching group frame. The first sub-group S1 and the second sub-group S2 may be located at predetermined positions in the optical axis direction by the movement of the group S1 and the second sub-group S2.

As shown in FIG. 10, the fixed cylinder 42 fixed to the camera body 41 has a female helicoid 43 formed on the inner peripheral surface thereof. A male helicoid 45 formed around the rear end of the cam ring 44 is screwed into the female helicoid 43. On the other hand, a pinion 47 driven by a zooming motor 46 is positioned outside the fixed cylinder 42, and a male helicoid 45 is attached to the pinion 47.
And a gear (not shown) formed on the outer periphery of the cam ring 44 by being inclined in the same direction as the lead of the male helicoid 45 is engaged. Therefore, when the cam ring 44 is given forward and reverse rotational motions via the zooming motor 46, the cam ring 44 advances and retreats in the optical axis direction according to the female helicoid 43 and the male helicoid 45. The rotational position of the cam ring 44 by the zooming motor 46 is detected by a focal length detecting means 46C composed of, for example, a code plate and a brush.

The cam ring 44 supports a rectilinear guide ring 48 that can rotate relative to the cam ring 44 and move together in the optical axis direction (cannot move relative to the optical axis direction).
The rectilinear guide ring 48 is supported by the camera body 41 so as to permit only rectilinear movement in the optical axis direction. Inside the cam ring 44, in order from the front, the first variable power lens group 10
The switching group frame 50 having the (first sub-group S1 and the second sub-group S2) and the rear group lens frame 49 to which the second variable power lens group 20 is fixed are located. The group lens frame 49 is guided linearly in the optical axis direction by a linear guide ring 48.

On the inner peripheral surface of the cam ring 44, there are formed bottomed cam grooves 44f and 44r for the switching group frame 50 and the rear group lens frame 49. FIG. 11 shows the bottomed cam grooves 44f and 44r.
3 shows the developed shape of the. Three sets of the bottomed cam grooves 44f and 44r are formed at equal angular intervals in the circumferential direction, and the switching group frame 50 and the rear group lens frame 49 have follower pins 50p fitted into these bottomed cam grooves 44f and 44r. And 49p
Are formed so as to protrude in the radial direction.

The bottomed cam grooves 44f, 44r are respectively provided with the follower pins 50p, 49p introduction positions 44f-a, 44p.
ra, zoom lens system storage positions 44fr, 44r
-R, wide end positions 44f-w, 44r-w, and tele end positions 44ft, 44rt. From the introduction positions 44f-a, 44r-a to the storage positions 44fr, 44
Rotation angle to rr is θ1, storage positions 44fr, 44r
The rotation angle from −r to the wide end positions 44fw and 44r−w is θ2, and the rotation angle from the wide end positions 44fw and 44r−w to the tele end positions 44ft and 44rt is θ3. A rotation angle θ4 exceeding the tele end positions 44ft and 44rt is a rotation angle for assembly. The cam groove 44r for the rear lens group frame 49 has an intermediate discontinuous position fm corresponding to the basic zooming locus of the second variable power lens group 20 in the modes shown in FIGS.

On the other hand, the cam groove 44f for the first variable power lens group 10 changes its shape smoothly from the wide end position 44fw to the tele end position 44ft, and apparently has There is no discontinuous position. This is because, in the present embodiment, the switching group frame 50 is arranged so that the position of the sub-group S2 is not discontinuous in the short focal length zooming zone Zw and the long focal length zooming zone Zt sandwiching the intermediate focal length fm in FIG. And that the sub-group S2 is moved. A connection line CC schematically shown in FIG. 1 includes a short focal length side zooming area Zw and a long focal length side zooming area Zt sandwiching the intermediate focal length fm.
The cam groove 44f
Corresponds to the basic zooming locus connected by the connection line CC. Follower pin 50p is connected to this connection line C
While moving in the section corresponding to C, the sub-group S1 moves from the front moving end to the rear moving end. The section of the cam groove 44f corresponding to the connection line CC is controlled not to be used for photographing (not to stop the cam ring 44) as an actual zooming area. Of course, like the cam groove 44r,
It is also possible to provide discontinuous parts.

When the pinion 47 is rotationally driven forward and reverse via the zooming motor 46, the zoom lens barrel having the above-described structure moves forward and backward in the optical axis direction while rotating the cam ring 44.
The switching group frame 50 (first variable-magnification lens group 10) and the rear group lens frame 49 (second variable-magnification lens group 20), which are guided straight in the optical axis direction in the cam ring 44, have a cam groove 44f with a bottom. It moves straight in the optical axis direction along a predetermined locus according to 44r.

A zoom lens barrel that gives the switching group frame 50 and the rear group lens frame 49 the above operation is well known.
The above is an example. The feature of the present embodiment lies in the support structure of the first sub-group S1 and the second sub-group S2 with respect to the switching group frame 50 and the driving structure thereof. Switching group frame 50
The specific structure in FIG.

In the switching group frame 50, a front shutter holding ring 51, a rear shutter holding ring 52, a front sub group frame 53, a rear sub group frame 54, a drive ring 55, and a gear holding ring 56 are located. The front shutter holding ring 51, the rear shutter holding ring 52, and the gear holding ring 56 constitute a part of the switching group frame 50. The first sub-group S1 is fixed to a front sub-group frame (first lens group frame, holding ring) 53, and the second sub-group S2 is a rear sub-group frame (second lens group frame, holding ring) 54.
Fixed to. Front sub-group frame 53, rear sub-group frame 5
4 and a drive ring 55 are movable members for performing a contact / separation switching operation and a focusing operation of the front sub-group frame 53 and the rear sub-group frame 54 (the first sub-group S1 and the second sub-group S2). It is fitted in the center opening 51p of the holding frame 51. The drive ring 55 is provided with a thrust surface 52a of the rear shutter holding ring 52 (see FIGS. 13, 15, and 1).
The rear end position is regulated by 6), and is rotatably supported between the front and rear shutter holding rings 51, 52. The drive ring 55 is a drive member that performs a contact / separation switching operation and a focusing operation between the first sub-unit S1 and the second sub-unit S2 by the forward / reverse rotation. A gear holding ring 56 is fixed in front of the front shutter holding ring 51, and the rear shutter holding ring 52 includes a lens shutter 57 and a diaphragm mechanism 58.
(FIGS. 12, 15, and 16).

The front sub-group frame 53 has a cylindrical shape, and is provided with linear guide ribs 53a at two locations outside in the diameter direction. A guide hole 5 formed in the straight guide rib 53a
3b, a rectilinear guide rod 59 is loosely inserted (loosely fitted), the rear end of the rectilinear guide rod 59 is fixed to a fixing hole 56q at the bottom of the gear holding ring 56, and the front end is a fixing bracket. It is fixed to the front end surface of the gear holding ring 56 via a fixing screw 61 and a fixing screw 61. A compression coil spring 62, which is located between the fixed bracket 60 and the linear guide rib 53a and urges the front sub-group frame 53 toward the rear sub-group frame 54, is fitted on the outer periphery of the linear guide rod 59. The gear holding ring 56 is formed with a U-shaped recess 56r for accommodating the linear guide rod 59 and the compression coil spring 62 (see FIGS. 25 to 27). The storage recess 56r communicates with the center opening 51p of the front shutter holding ring 51. The rotation direction of the front sub-group frame 53 is 1
At two positions inverted by 80 °, the straight guide ribs 53a
Can be assembled with the straight guide rod 59 of the front shutter holding ring 51.

In the front sub-group frame 53, four sets of contact / separation lead surfaces (contact / separation cam surfaces) 53c are formed at equal angular intervals in the circumferential direction in the form of an end surface cam having a rear end surface opened.
An annular light-shielding reinforcing rib 53d is formed so as to cover the outside of the open end of the contact / separation lead surface 53c. FIG.
Is an enlarged development view of the contact / separation lead surface 53c. The contact / separation lead surface 53c is formed into a straight line inclined at an inclination angle α with respect to the circumferential direction, and the contact / separation lead surface 53c is deepened into a shallow V-shape at both ends. Follower stabilizing recesses 53e and 53f are formed. The follower stabilizing recess 53e regulates the wide-side separation position of the front sub-group frame 53 and the rear sub-group frame 54 (the first sub-group S1 and the second sub-group S2), and the follower stabilizing recess 53f adjusts the tele-side approach position. regulate.

On the outer peripheral surface of the rear sub-group frame 54, four sets of follower projections 54a are formed corresponding to the four sets of contact / separation lead surfaces 53c of the front sub-group frame 53. The follower protrusion 54a is the most proximate lead surface 5 of the inclined surface 54b corresponding to the proximate lead surface 53c of the front sub-group frame 53.
It is provided at the tip of the portion located on the 3c side. The tip of the follower projection 54a has a substantially semicircular shape that is symmetrical to the left and right, and the follower stabilizing recesses 53e and 53f correspond to the tip of the follower projection 54a. The follower protrusion 54a and the inclined surface 54b
An annular light-shielding reinforcing rib 54c is formed on the inner side of the inner wall. The contact / separation lead surface 53c formed on the front sub-group frame 53 and the follower projection 54 formed on the rear sub-group frame 54
a constitutes a contact / separation cam mechanism for bringing the lens group frames 53 and 54 into and out of contact with each other. Four sets of contact / separation lead surfaces 53c of the front sub-group frame 53 and four follower protrusions 54a of the rear sub-group frame 54
Are formed at equal angular intervals as described above.
It can be engaged at different relative rotational positions every 0 °. The number (N, 4 in the embodiment) of the contact / separation lead surface 53c and the follower protrusion 54a is determined by the linear guide rib 53 of the front sub-group frame 53.
As for a and the number (M, 2 in the embodiment) of the straight guide rods 59 of the front shutter holding ring 51, M is a multiple of N and N is a divisor of M. According to this relationship, selective assemblability in the rotation direction is obtained, and for example, an assembling position at which the most preferable optical performance is obtained can be selected.

The rear sub-group frame 54 also has, on its outer peripheral surface, the same circumferential position as the two diametrically opposed follower projections 54a of the four follower projections 54a.
A rectilinear guide protrusion 54d is formed so as to protrude behind the follower protrusion 54a in the optical axis direction. Further, a straight guide protrusion 54d is provided on the outer peripheral surface of the rear sub-group frame 54.
Three driven projections 54e are formed so as to be further rearward in the optical axis direction at equal angular intervals. This driven projection 5
4e is a pair of parallel circumferentially separated driven surfaces N1 and N2 that are circumferentially separated from each other, and connects the driven surfaces N1 and N2, and has a smooth cylindrical surface having its rotation axis in a direction perpendicular to the optical axis ( N3), and has a symmetrical shape with respect to a line (center line) passing through the centers of the driven surfaces N1 and N2 in the circumferential direction and parallel to the optical axis.

The rotation range of the rear sub-group frame 54 with respect to the non-rotating front shutter holding ring 51 is provided on the inner peripheral surface of the front shutter holding ring 51 so as to correspond to each linear guide protrusion 54 d of the rear sub-group frame 54. A pair of rotation regulating surfaces 5 for defining
1a and 51b are formed (see FIG. 24). That is, the rotation restricting surfaces 51a and 51b are
When the rotary member 4 rotates in the forward and reverse directions, it engages with the circumferential separation stopper surfaces M1 and M2 of the linear guide protrusion 54d to regulate the rotation end. The rotation restricting surface 51a is
A wide-side straight guide groove 51d is formed between the stopper surface M2 and the guide surface 51c engaged with the stopper surface M2, and the rotation restricting surface 51b
Constitutes a tele-side rectilinear guide groove 51f between the stopper surface M1 of the rectilinear guide projection 54d and the engaging guide surface 51e. That is, the circumferential width of the wide-side straight guide groove 51d and the tele-side straight guide groove 51f corresponds to the width of the straight guide protrusion 54d in the same direction, and the guide protrusion 54d is engaged with substantially no gap. . The clearance between the wide-side or tele-side straight guide grooves 51d and 51f and the straight guide protrusion 54d is set smaller (stricter) than the clearance between the guide hole 53b of the front sub-group frame 53 and the straight guide rod 59. The straight guide projection 54 of the rear sub-group frame 54
d is located at a diametrically opposed position, and the rectilinear guide grooves 51d and 51f of the front shutter holding ring 51 select the rotational position of the two rectilinear guide protrusions 54d (that is, determine the rotational position of the rear sub-group frame 54. A pair is provided so that they can be fitted (inverted 180 °).

The drive ring 55 has, on its front end face, three sets of control recesses 55a corresponding to the three driven projections 54e of the rear sub-group frame 54 (see FIG. 22). The control concave portion 55a has a symmetrical shape with respect to a center line c in a direction parallel to the optical axis, and has a pair of rotation imparting surfaces 55 that engage with the circumferentially separated driven surfaces N1 and N2 of the driven projection 54e.
b and 55c, and telephoto and wide-side focus lead surfaces (focus cam surfaces) 55d and 55e that come into contact with the cylindrical surface N3 of the driven projection 54e. The tele-side focus lead surface 55d and the wide-side focus lead surface 55e are formed between the rotation imparting surfaces 55b and 55c in the form of an end surface cam having an open front end surface. , The absolute values are the same. The outer peripheral side front of the control concave portion 55a of the drive ring 55 is covered with an annular light shielding reinforcing rib 55f. This drive ring 55
The focus lead surfaces 55d and 55e and the driven protrusion 54e formed on the rear sub-group frame 54 constitute a focus cam mechanism. Three driven projections 54e of the rear sub-group frame 54
The three control concave portions 55a of the drive ring 55 are provided at equal angular intervals as described above, and can be engaged at different relative rotation positions every 120 °.

The cylindrical surface N3 of the driven projection 54e is
Focus lead surfaces 55d, 5 having tilt directions opposite to each other.
Due to the contact with 5e, each focus lead surface 55d,
It is formed in a cylindrical shape in order to avoid interference with 55e and perform reliable power transmission. Conversely, the circumferentially separated driven surfaces N1 and N2 of the driven protrusion 54e are parallel planes, but the rotation transmission from the rotation imparting surfaces 55b and 55c can be performed without using such a parallel plane. For example, this driven surface N
Instead of 1 and N2, the contact portion with the rotation imparting surfaces 55b and 55c may be a cylindrical surface similar to the cylindrical surface N3 (continuous with the cylindrical surface N3). That is, the entire outer peripheral surface of the driven projection (at least the focus lead surface 5
5d, 55e, and the rotation imparting surfaces 55b,
5c) may be formed in a cylindrical shape.

The above-mentioned compression coil spring 62 for pressing and urging the front sub-group frame 53 backward is provided with a contact / separation lead surface 53c of the front sub-group frame 53 and a follower projection 54 of the rear sub-group frame 54.
a, the driven protrusion 54e of the rear sub-group frame 54 (the cylindrical surface N
3) The focus lead surfaces 55d and 55e on the tele side or the wide side of the drive ring 55 are always in contact with each other. As described above, the drive ring 55 has its rear end surface abutting on the thrust surface 52a of the rear shutter holding ring 52, and the front sub-group frame 53,
The contact relationship between the rear sub-group frame 54, the drive ring 55, and the rear shutter holding ring 52 (thrust surface 52a) is maintained. In these contact states, the tip of the rear sub-group frame 54 enters the inner periphery of the front sub-group frame 53 and the drive ring 55 is positioned on the outer periphery of the rear sub-group frame 54, as is apparent from FIGS. are doing.

FIGS. 21A to 21H show the front sub-group frame 5 formed by the rotation applying surfaces 55b and 55c of the drive ring 55.
3 and the rear subgroup frame 54 (the first subgroup S1 and the second subgroup S
2) shows the switching operation between the tele side approach state and the wide side separation state of 2). In FIG. 21, the solid arrow indicates the rotation direction of the drive ring 55. The state (A) shown in the upper left end of FIG. 21 is the rotation applying surface 55b of the drive ring 55.
Are in contact with the driven protrusion 54e, and the rectilinear guide protrusion 54d of the rear sub-group frame 54 is separated from the wide rectilinear guide groove 51d. In this state, the drive ring 55
Moves to the right in the figure (rotates clockwise), the rotation applying surface 55b is moved by the driven surface N1 of the driven protrusion 54e.
Is pressed to rotate the rear sub-group frame 54 in the same direction, and then the straight guide projection 54d is brought into contact with the rotation regulating surface 51b.
That is, the state is shifted from (A) to (C) in FIG.
During this time, the front sub-group frame 53 (first sub-group S1) includes the contact / separation lead surface 53c and the follower projections 54 of the rear sub-group frame 54.
a, the rear sub-group frame 54 (the second sub-group S2) approaches (FIG. 21B), and finally the follower protrusion 54
a is engaged with the follower stabilizing recess 53f to be in a stable state (FIG. 21C). Since four follower projections 54a and four follower stabilizing recesses 53f are formed at equal angular intervals in the circumferential direction, all of them are engaged with each other.
The eccentricity of the front sub-group frame 53 and the rear sub-group frame 54 is eliminated. As described above, the switching from the wide-side separation state to the tele-side approach state is completed, and the first sub-group S1 is in a state of approaching the second sub-group S2 (approaching movement end). No further rotation of the drive ring 55 in the same direction is possible.

When the switching to the tele-side approach state is completed, the drive ring 55 rotates in the reverse direction. Then, the driven projection 54
e (rear sub-group frame 54) is the tele-side focus lead surface 5
In order to move backward according to 5d, the straight guide projection 54d
Can enter only the tele-side straight guide groove 51f and can only move straight in the optical axis direction. By the integral movement of the rear sub-group frame 54 and the front sub-group frame 53 at the approach movement end by the tele-side focus lead surface 55, focusing on the tele side from the intermediate focal length to the long focal length end is performed (FIG. 21).
(D)).

Then, the rotation applying surface 55c is
When the drive ring 55 rotates until it abuts on the driven surface N2 of e, the rectilinear guide protrusion 54d of the rear sub-group frame 54 comes off from the tele-side rectilinear guide groove 51f (FIG. 21E).

In this state, when the driving ring 55 reverses the rotation direction and moves leftward (rotates counterclockwise) in the figure, the rotation imparting surface 55c moves to the driven surface N2 of the driven projection 54e.
Is pressed to rotate the rear sub-group frame 54 in the same direction, and the stopper surface M1 of the straight guide protrusion 54d is eventually turned to the rotation restricting surface 51.
a. That is, the state changes from (E) to (G) in FIG. During this time, the front sub-group frame 53 includes the contact / separation lead surface 53c and the follower projections 54a of the rear sub-group frame 54.
From the rear sub-group frame 54 (FIG. 21).
(F)) Finally, the follower protrusion 54a is engaged with the follower stabilizing concave portion 53e to be in a stable state (FIG. 21).
(G)). Follower protrusion 54a and follower stable recess 53
Since four e are formed at equal angular intervals in the circumferential direction, eccentricity of the front sub-group frame 53 and the rear sub-group frame 54 is eliminated by engaging all of them. Thus, the switching from the tele-side approach state to the wide-side separation state is completed, and the first sub group S1 is separated from the second sub group S2 (separation movement end). No further rotation of the drive ring 55 in the same direction is possible.

When the switching to the wide-side separation state is completed, the drive ring 55 rotates in the reverse direction. Then, the driven projection 54
e (rear sub-group frame 54) moves rearward in accordance with the wide-side focus lead surface 55e, so that the linear guide protrusion 54
d enters the wide-side straight guide groove 51d and allows only the straight movement in the optical axis direction. This tele-side focus lead surface 5
By the integral movement of the rear sub-group frame 54 and the front sub-group frame 53 at the separated moving end by 5d, focusing on the wide side from the intermediate focal length to the short focal length end is performed (FIG. 21).
(H)).

Then, the rotation applying surface 55c is
When the drive ring 55 rotates until it comes into contact with the driven surface N1 of e, the rectilinear guide protrusion 54d of the rear sub-group frame 54 comes off the tele-side rectilinear guide groove 51d, and returns to the beginning of the description (FIG. 2).
1 (A)).

FIG. 22 shows the tele-side focus lead surface 55d and the wide-side focus lead surface 55d of the drive ring 55.
The focus principle by e is shown. Rear subgroup frame 5
When the drive ring 55 rotates within its tele-side focus area pt (from the infinity shooting position ∞ to the shortest shooting position n) with the cylindrical surface N3 of the driven projection 54e of No. 4 abutting on the telescopic focus lead surface 55d. , Straight guide groove 5 on the tele side
The rear sub-group frame 54 (and the front sub-group frame 53 (the first sub-group S1 and the second sub-group S2)) whose rotation is restrained by the engagement between 1f and the linear guide lug 54d integrally advance and retreat in the optical axis direction. Focusing is performed. Similarly, with the cylindrical surface N3 of the driven projection 54e in contact with the wide-side focus lead surface 55e, the drive ring 55 rotates within its wide-side focus area pw (from the infinity shooting position ∞ to the shortest shooting position n). Then, the rear sub-group frame 54 (and the front sub-group frame 53 (the first sub-group S1 and the second sub-group S2) whose rotation is restricted by the engagement of the wide-side straight guide groove 51d and the straight guide protrusion 54d. Are integrally moved in the optical axis direction to perform focusing.

More specifically, focusing on the tele side and the wide side is performed at a position where the rectilinear guide protrusion 54d of the rear sub-group frame 54 abuts the rotation restricting surface 51a or 51b (a position where the rotation direction of the drive ring 55 is reversed). ) Is controlled by controlling the number of pulses counted by the pulsar of the drive system that drives the drive ring. For example, the number of pulses of the drive system for moving the focus lens group (sub-groups S1 and S2) from this reference position to the shortest imaging position n, the infinity imaging position ∞, and an arbitrary subject distance is determined by the focus lead surfaces 55d and 55e. Can be known in advance in consideration of the lead angle, etc., and by controlling the number of these pulses, it is possible to perform focusing according to the subject distance information. In the illustrated embodiment, the tele-side focus lead surface 55d and the wide-side focus lead surface 55e of the drive ring 55 have opposite inclinations with respect to the circumferential direction and have the same absolute value, and the driven protrusion 54e has a pair of circumferentially spaced apart. The driven surfaces N1, N2 are symmetrical with respect to the center in the circumferential direction. For this reason, focusing on the tele side and the wide side can be performed on the same basis, and there is an advantage that control is facilitated.

FIG. 17 shows a state in which the front sub-group frame 53 (the first sub-group S1) and the rear sub-group frame 54 (the second sub-group S2) are focused on infinity in the wide-angle state, and FIG. 19 shows a focusing state at the shortest photographing distance in the separated state, FIG. 19 shows a focusing state at infinity in the close state on the telephoto side, and FIG. The positional relationship between the sub group frame 54, the drive ring 55, and the front shutter holding ring 51) is shown. (A) of each drawing is a drawing in which these components are separated in the optical axis direction, and (B) is a drawing of an actual operation state.

A gear 55g is formed all around the rear end outer peripheral surface of the drive ring 55. As shown in FIGS. 12, 29, and 30, the gear 55g is meshed with the reduction gear train 63a for switching and focusing, and is driven to rotate forward and reverse by a forward / reverse drive motor 64 having a pulsar (encoder) 64p. The reduction gear train 63a for switching and focusing includes a front shutter holding ring 51 and a gear holding ring 5.
6, the forward / reverse drive motor 64 is held by the rear shutter holding ring 52. Drive ring 55
Since the gear 55g is formed on the entire circumference, the three sets of control recesses 55a and the three driven projections 54e of the rear sub-group frame 54 are engaged at different relative rotation positions every 120 °. Becomes easier.

The lens shutter 57 and the aperture mechanism 58 are mounted on the rear shutter holding ring 52. That is, as shown in FIG. 12, FIG. 15, and FIG.
7 includes a shutter sector support plate 57a, three shutter sectors 57b, and a shutter drive ring 57c for driving the shutter sector 57b to open and close. The diaphragm mechanism 58 includes a diaphragm sector support plate 58a and three diaphragm sectors 5.
8b and an aperture drive ring 58c for opening and closing the aperture sector 58b.
7d, it is supported by the rear shutter holding ring 52. As is well known, the shutter sector 57b and the aperture sector 58b have a pair of dowels, one of which is a support plate 57b.
a, 58a rotatably supported, and the other is
7c and 58c are rotatably fitted. The lens shutter 57 opens and closes the opening of the shutter sector 57b by reciprocating rotation of the shutter drive ring 57c, and the aperture mechanism 58 adjusts the size of the aperture formed by the aperture sector 58b by the rotation of the aperture drive ring 58c. Change.

A sector gear 57g is formed on a part of the outer periphery of the shutter drive ring 57c, and this sector gear 57g meshes with a shutter drive reduction gear train 63b from a shutter drive motor 57m (FIG. 1).
2). When the shutter drive motor 57m is driven to rotate in the forward and reverse directions, the opening closed by the shutter sector 57b opens momentarily and closes again. In the present zoom lens barrel, the shutter sector 57b is a blade that has both a variable aperture function for determining an arbitrary aperture value and a shutter function, and an opening amount (aperture) of the shutter sector 57b according to the exposure value at the time of shutter release. Value) and the opening time (shutter speed) change.
7 m is controlled. The aperture driving ring 58c has a driven projection 58g on its outer periphery, and the driven projection 58g is engaged with an aperture control cam groove 48s formed on the inner peripheral surface of the linear guide ring 48 (FIG. 10). For zooming, the straight guide ring 48 and the rear shutter holding ring 52 (aperture drive ring 58c)
Moves relatively in the optical axis direction. Then, the aperture control cam groove 48
The driven projection 58g is moved in the circumferential direction according to s, the aperture driving ring 58 is rotated by a predetermined angle, and the size of the opening formed by the aperture sector 58b is changed. The aperture sector 58b is provided in order to regulate the maximum value of the photographing aperture diameter particularly at the wide-side photographing distance, and the opening amount is mechanically (forced) opened according to the extended state of the entire zoom lens barrel. Changes.

The zooming motor 4 for driving the cam ring 44
6. The forward / reverse drive motor 64 for driving the drive ring 55 and the shutter drive motor 57m of the lens shutter 57 are controlled by a control circuit 66 as shown in FIG.
The control circuit 66 includes focal length information 67 set by the operator via a zoom switch or the like, subject distance information 68 detected by distance measuring means or photometric means, subject luminance information 69, and a cam by the focal length detecting means 46C. The rotational position information of the ring 44 and the rotational position information of the motor 64 by the pulsar 64p are input, and the zooming motor 46 and the positive motor 46 are adjusted so that exposure is performed under the correct exposure condition with the set focal length according to the information. The reverse drive motor 64 and the shutter drive motor 57m are controlled. In the illustrated embodiment, the shutter sector 57b doubles as a shutter and a variable aperture, and the aperture sector 58b performs only the restriction of the photographing aperture diameter at the time of wide-angle photographing. The variable aperture mechanism may be of a type that can freely change the size of the aperture. In this case, the aperture drive ring 58c may be rotated by an independent motor or manual operation.

In the present embodiment, the focal length detecting means (rotating position detecting means of the cam ring 44) 46C detects the rotating position of the cam groove 44f corresponding to the connection line CC (FIG. 1), and the control circuit 66 In this section, the cam ring 44 is not stopped. In the step zoom mode, the stop position of the cam ring 44 is controlled stepwise. As described above, the drive corresponding to the set focal length, the subject distance, the subject brightness, and the like of the zoom lens barrel (photographing optical system) having the above-described switching group is completed immediately before the shutter release is performed. The focal length set by the operator may be confirmed at least by a finder optical system (not shown) separate from the photographing optical system.

In the zoom lens barrel using the above-described lens barrel for the switching group, the stop positions of the switching group frame, the first sub-group frame, and the second sub-group frame at the time of photographing are set in steps on the basic zooming locus. It is practical to be wise.

The mechanical structure of the above lens barrel is shown in FIG.
This is applied to the first variable power lens group 10 in the mode of FIGS. 8 and 9, but is applied to the second variable power lens group 2 in the mode of FIG.
0, the second zoom lens group 20 in the embodiment of FIG. 3, the first zoom lens group 10 in the embodiment of FIG. 4, the first zoom lens group 10 in the embodiment of FIG. 5, and the first zoom lens in the embodiment of FIG. The present invention can also be applied to the lens group 10 and the first variable power lens group 10 of the embodiment of FIG. 7 (the first lens L1 and the third lens L3 are integrated).

[0107]

DESCRIPTION OF THE FEATURES OF THE INVENTION In the zoom lens barrel described above, the switching group 10 is moved between the wide-side separation position and the tele-side approach position, and the switching group 10 is moved between the approach position and the separation position. In order to operate focusing,
A so-called end cam is used. Specifically, a contact / separation lead surface (contact / separation cam surface) 53c formed on the rear end surface side of the front sub-group frame (first annular body, first lens group frame) 53;
The follower projection (first follower projection) 54a of the rear sub-group frame (second annular body, second lens group frame) 54 that engages with the contact / separation lead surface 53c is the first sub-group (sub-lens group). ) Functions as a contact / separation cam mechanism for moving S1 and the second sub-group (sub-lens group) S2 to the approach position and the separation position.
Also, a tele-side focus lead surface (contact / separation cam surface, focus cam surface) 55d and a wide-side focus lead surface (contact / separation cam surface, focus cam surface) formed on the front end surface side of the drive ring (first annular body) 55 ) 55e and a driven sub-projection (follower projection, second follower projection) 54e on the side of the rear sub-group frame (second annular body, second lens group frame) 54 are in the approach position and the separation position. S1 and the second subgroup S
2 functions as a focus mechanism for moving straight while maintaining the interval.

As shown in FIG. 13, the lens barrel according to the present embodiment comprises an annular light-shielding reinforcing rib (annular rib) 53d in a drive ring 55 and a front sub-group frame 53 having a lead surface formed in an end surface cam shape. , 55f are formed. The annular light-shielding reinforcing ribs 53d and 55f are respectively provided with a contact / separation lead surface 53c and a focus lead surface 55.
d, 55e, and are formed so as to extend to the rear sub-group frame 54 side, covering the follower projection 54a and the driven projection 54e with which these lead surfaces are engaged. Further, with respect to the rear sub-group frame 54, the front follower projection 54 a is provided with the contact / separation lead surface 5 on the front sub-group frame 53 side.
It has an end face follower shape formed at a position facing 3c. An annular light-shielding reinforcing rib (annular rib) 54c located on the inner peripheral side of the follower projection 54a and extending toward the front sub-group frame 53 is formed on the rear sub-group frame 54. The function and advantage of providing such an annular light-shielding reinforcing rib are described below.
The following description focuses on the relationship between and the rear subgroup frame 54. In the illustrated embodiment, the annular light-shielding reinforcing rib 53d of the front sub-group frame 53 is formed on two outer peripheral sides of the four contact / separation lead surfaces 53c, but all of the four contact / separation lead surfaces 53c are provided. Can also be provided on the outer peripheral surface side of.

First, as shown in FIGS. 17 to 20, by providing an annular light-shielding reinforcing rib 53d,
The peripheral portion near the rear end of the front sub-group frame 53 is widened, and the strength of the front sub-group frame 53 is improved. Similarly, by providing the annular light shielding reinforcing rib 54c, the rear sub-group frame 54 is provided.
Is extended, and the strength of the rear sub-group frame 54 is improved.

The front sub-group frame 53 and the rear sub-group frame 5
Reference numerals 4 denote optical systems (a first sub group S1 and a second sub group S
2) The annular light-shielding reinforcing rib 53
In the portion provided with d and 54c, the outer peripheral side of the front sub-group frame 53 and the inner peripheral side of the rear sub-group frame 54 are respectively covered, so that the light shielding property can be improved. Specifically, in both the separated state of the front sub-group frame 53 and the rear sub-group frame 54 shown in FIGS. 17 and 18 and the close state shown in FIGS. Are overlapped with each other, and light leakage from a gap between the contact / separation lead surface 53c on the front sub-group frame 53 side and the inclined surface 54b on the rear sub-group frame 54 side can be prevented.

As shown in FIGS. 15 and 16, the inner peripheral surface of the annular light-shielding reinforcing rib 53d is in contact with a part of the outer surface of the rear sub-group frame 54. The group frame 54 functions as a guide when relatively moving between the wide-side separation position and the tele-side approach position. Further, the outer peripheral surface of the annular light shielding reinforcing rib 54c is in contact with a part of the inner peripheral surface of the front sub-group frame 53, and functions as a similar guide. Therefore, the stability of the front sub-group frame 53 and the rear sub-group frame 54 when moving can be enhanced, and it is possible to prevent the sub-groups S1 and S2 from falling down.

The annular light-shielding reinforcing rib 55f of the drive ring 55
Basically, the above annular light-shielding reinforcing ribs 53d, 54
It has the same effect as c. That is, the annular light shielding reinforcing rib 5
By forming 5f, the peripheral surface near the front end of the drive ring 55 is widened, so that the strength near the rib 55f can be increased.

Also, as shown in FIGS. 17 to 20,
Since the annular light-shielding reinforcing rib 55f is located at a position covering a part of the outer peripheral surface of the second sub-group frame 54 that supports the optical system, the function of preventing harmful light from entering inside the second sub-group frame 54 is provided. Is provided.

Further, as shown in FIGS. 15 and 16,
The second sub-group frame 5 is provided on the inner peripheral surface of the annular light shielding reinforcing rib 55f.
4 is in contact with the projecting end surface of the driven projection 54e, and when the second sub-group frame 54 moves with respect to the drive ring 55, the driven projection 54e contacts the inner peripheral surface of the annular light shielding reinforcing rib 55f.
The projecting end of e is slid to maintain the contact state. Since the driven projections 54e are provided in three positions at different positions in the circumferential direction, each driven projection 54e is formed of an annular light shielding reinforcing rib 55f.
The contact of the second sub-group frame 54 is restricted. That is, the annular light-shielding reinforcing rib 55f also functions as a guide for stably moving the second sub-group frame 54.

As described above, in the lens barrel of the present embodiment, since the annular body such as the lens frame is formed so as to extend to cover the end cam mechanism portion, the annular body is improved in strength. Can be. If the annular body is a lens frame that supports the optical system, the light-shielding property can be improved by the annular rib. Furthermore, by making the inner peripheral surface of the annular rib slidably contact the outer surface of the annular body having the follower protrusion, the annular rib can have a function of a contact / separation movement guide.

However, the present invention is not limited to the illustrated embodiment. For example, the present invention is particularly preferable when applied to a lens barrel having a switching group as in the embodiment, since many advantages are obtained as described above. However, the present invention is preferably applied to an annular body contact / separation mechanism other than the lens barrel. It is also possible.

[0117]

As is apparent from the above description, according to the present invention, the lens moving mechanism and the contact / separation moving mechanism which have a simple structure using the end face cam mechanism and have excellent strength and light shielding properties are provided. Obtainable.

[Brief description of the drawings]

FIG. 1 is a diagram showing a basic zooming locus of a first embodiment of a zoom lens system having a switching group.

FIG. 2 is a diagram illustrating a basic zooming locus of a second embodiment of a zoom lens system having a switching group.

FIG. 3 is a diagram illustrating a basic zooming locus of a third embodiment of a zoom lens system having a switching group.

FIG. 4 is a diagram showing a basic zooming locus of a fourth embodiment of a zoom lens system having a switching group.

FIG. 5 is a diagram showing a basic zooming locus of a fifth embodiment of the zoom lens system having a switching group.

FIG. 6 is a diagram showing a basic zooming locus of a sixth embodiment of the zoom lens system having a switching group.

FIG. 7 is a diagram showing a basic zooming locus of a seventh embodiment of the zoom lens system having a switching group.

FIG. 8 is a diagram illustrating an example of a stop position during photographing of a constituent lens group of a zoom lens system having a switching group.

FIG. 9 is a diagram illustrating an example of the stop position and an example of an actual movement locus of the lens group.

FIG. 10 is a cross-sectional view showing an embodiment of a zoom lens barrel embodying the zoom lens system having the switching group shown in FIGS. 1, 8, and 9;

11 is a developed view of an inner surface of the cam ring, showing an example of a cam groove shape of the cam ring of the zoom lens barrel in FIG. 10;

FIG. 12 is an exploded perspective view around a switching group frame.

FIG. 13 is an exploded perspective view of a part around a switching group frame.

FIG. 14 is a perspective view of a part around the switching group frame in a different assembled state.

FIG. 15 is an upper half cross-sectional view of a first sub-group and a second sub-group of the switching group frame in a state of being separated on the wide side.

FIG. 16 is an upper half sectional view in the tele side approaching state.

FIG. 17 is a developed view (A) showing the positional relationship between the first and second sub-groups in the infinity in-focus state in the wide-side separation state, with the respective components separated in the optical axis direction. FIG. 7B is a developed view (B) of the actual engagement state.

FIG. 18 is a development view (A) showing the positional relationship between the first and second sub-groups in the state of focusing on the shortest photographing distance in the wide-side separation state, with the respective components being separated in the optical axis direction. (B) is a developed view (B) of an actual engagement state.

FIG. 19 illustrates a positional relationship between components of the first sub-unit and the second sub-unit in an infinity in-focus condition in a telephoto-side approaching condition.
FIG. 3A is a developed view (A) in which each component is separated in the optical axis direction, and FIG.

FIG. 20 is a developed view (A) showing the positional relationship between the first and second sub-groups in a focusing state at the shortest photographing distance in the tele-side approaching state, with the respective components separated in the optical axis direction. )
FIG. 7B is a developed view (B) of the actual engagement state.

FIG. 21 is a development view illustrating switching between a tele-side approach state and a wide-side separation state by forward and reverse rotation of a drive ring.

FIG. 22 is an explanatory diagram of focusing by a drive ring.

FIG. 23 is an enlarged development view of the face cam of the front sub-group frame.

FIG. 24 is a front sub-group frame with respect to a front shutter holding ring,
It is a development expansion view showing a relation between a rear subgroup frame and a drive ring.

FIG. 25 is a front view showing a relationship between a front sub-group frame and a front shutter holding ring as viewed from a line XXV-XXV in FIG. 14;

26 is an enlarged view of a part XXVI of FIG. 25.

FIG. 27 is a front view showing the relationship between the rear sub-group frame and the front shutter retaining ring as viewed from the direction of the line XXVII-XXVII in FIG. 14;

FIG. 28 is an enlarged view of a part XXVIII of FIG. 27;

FIG. 29 is a front view showing a reduction gear arrangement of a drive ring driving system held between a front shutter holding ring and a gear holding ring.

FIG. 30 is a developed plan view of FIG. 29.

FIG. 31 is a block diagram showing a control system of the zoom lens barrel shown in FIG.

[Explanation of symbols]

 L1 First lens group L2 Second lens group L3 Third lens group L4 Fourth lens group S1 First sub group S2 Second sub group S3 Third sub group S4 Fourth sub group 10 First variable power lens group 11 First Group frame 12 Movable sub group frame 13 Guide groove 20 Second variable power lens group 21 Second group frame 22 Movable sub group frame 23 Guide groove 41 Camera body 42 Fixed cylinder 43 Female helicoid 44 Cam ring 45 Male helicoid 46 Zooming motor 46C Focal length detection means 47 Pinion 48 Straight guide ring 49 Rear lens group frame 50 Switching group frame 51 Front shutter holding ring 51a 51b Rotation regulating surface 51d Wide side straight guide groove 51f Tele side straight guide groove 51p Center opening 52 Rear shutter holding ring 52a Thrust surface 53 Front sub-group frame 53a Straight guide rib 53b Guide hole 53c Contact / separation lead surface 3d annular light-shielding reinforcing rib 53e 53f follower stabilizing recess 54 rear sub-group frame 54a follower protrusion 54b inclined surface 54c annular light-shielding reinforcing rib 54d rectilinear guide protrusion 54e driven protrusion 55 drive ring 55a control recess 55b 55c rotation applying surface 55d tele-side focus lead Surface 55e Wide-side focus lead surface 55f Annular light-shielding reinforcing rib 55g Gear 56 Gear press ring 56q Fixing hole 56r Storage recess 57 Lens shutter 57a Shutter sector support plate 57b Shutter sector 57c Shutter drive ring 57d Sector press ring 57g Sector gear 57m Shutter drive motor 58 Squeezing mechanism 58a Squeezed sector support plate 58b Squeezed sector 58c Squeezing drive ring 58g Driven protrusion 59 Straight guide rod 60 Fixing bracket 61 Fixing screw 62 Compression coil spring 63a Reduction gear train for switching and focusing 63b Shutter drive reduction gear train 64 Forward / reverse drive motor 66 Control circuit 67 Set focal length information 68 Subject distance information 69 Subject brightness information

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazunori Ishizuka 2-36-9 Maenocho, Itabashi-ku, Tokyo Inside Asahiko Gaku Kogyo Co., Ltd. (72) Maiko Takashima 2-36, Maenocho, Itabashi-ku, Tokyo No. 9 F-term in Asahiko Gaku Kogyo Co., Ltd. (reference) 2H044 BD07 BD09 EF03

Claims (12)

[Claims] A first annular body and a second annular body which are relatively rotatable and at least one of which is capable of linearly moving in the axial direction;
Formed on the end face of the annular body facing the second annular body,
A contact / separation cam surface inclined with respect to the circumferential direction; a follower projection formed on the second annular body and engaging with the contact / separation cam surface; and a means for imparting relative rotation to the first and second annular bodies A contact / separation moving mechanism having a shape in which the contact / separation cam surface and the follower protrusion are configured to contact / separate the first and second annular members in the axial direction by relative rotation of the first and second annular members. In the second annular body, the outer circumferential surface of the first annular body is located on the outer circumferential side from the contact / separation cam surface and covers the follower projection of the second annular body.
A contact / separation moving mechanism, wherein an annular rib extending toward the annular body is formed. 2. The moving mechanism according to claim 1, wherein
A contact / separation moving mechanism in which an inner peripheral surface of an annular rib of the first annular member and a part of an outer surface of the second annular member abut slidably. 3. The moving mechanism according to claim 1, wherein the follower projection is formed on an end surface of the second annular body facing the first annular body, and the follower projection is formed on an end surface of the second annular body. A contact / separation moving mechanism having an annular rib formed on an inner peripheral side of the follower projection and extending to the first annular body side from the follower projection, the annular rib being different from the annular rib on the first annular body side. 4. The moving mechanism according to claim 1, wherein the first and second annular members optically function at an approach position and a separation position, respectively. 2
A first lens group frame and a second lens group frame that respectively support the sub lens groups. 5. The focus moving mechanism according to claim 1, wherein one of said first and second annular bodies is supported so as to be able to move straight and supports a focus lens group. The other of the first and second annular bodies is a lens support member,
A drive ring rotatable relative to the focus lens support member, wherein the rotation of the drive ring causes the focus lens support member to move linearly by the contact / separation cam surface and the follower protrusion; 6. The moving mechanism according to claim 5, wherein
The focus lens support member supports first and second sub-lens groups that function optically at an approach position and a separation position, respectively, and includes a first lens group frame capable of relative rotation and linear movement, and a second lens group frame. A contact / separation moving mechanism consisting of a lens group frame. 7. A first lens group frame and a second lens which support first and second sub-lens groups optically functioning at an approach position and a separation position, respectively, and are capable of relative rotation and linear movement. Group frame; a contact / separation cam surface formed on an end face of the first lens group frame facing the second lens group frame and inclined with respect to the circumferential direction; the contact / separation cam surface formed on the second lens group frame A drive ring for providing relative rotation between the first lens group frame and the second lens group frame; and the contact / separation cam surface and the follower projection are provided for the first and second lens group frames. A lens movement mechanism configured to move the first and second lens group frames to the approach position and the separation position by relative rotation of the first lens group frame. The second lens group which is located on the outer peripheral side and covers the follower projection of the second lens group frame; A lens moving mechanism having an annular rib extending toward the group frame. 8. The lens moving mechanism according to claim 7, wherein the inner peripheral surface of the annular rib of the first lens group frame and a part of the outer surface of the second lens group frame are slidably contacted. mechanism. 9. The lens moving mechanism according to claim 7, wherein the follower projection is formed on an end surface of the second lens group frame facing the first lens group frame, and the follower projection is formed around the second lens group frame. A lens moving mechanism having, on a surface thereof, an annular rib different from the annular rib on the first lens group frame side, the annular rib being located on the inner peripheral side of the follower protrusion and extending toward the first lens group frame. 10. The lens moving mechanism according to claim 7, wherein said first and second sub-lens groups include a plurality of zoom lens systems moving in an optical axis direction during a zooming operation. A first lens group frame of the magnification lens group and functioning as a focus lens group at the approach position and the separation position, respectively; a first lens group frame and a second lens group frame at the approach position and the separation position Lens moving mechanism having a focus mechanism for moving the lens in the optical axis direction while maintaining the distance. 11. The lens moving mechanism according to claim 10, wherein the focus mechanism supports the first lens group frame such that the first lens group frame is capable of linearly moving in the optical axis direction while restricting rotation. A support cylinder that is capable of reciprocating rotation within a certain angle range, restricts rotation at both rotation ends corresponding to the approach position and the separation position, and supports the linear movement in the optical axis direction; A focus cam surface formed on an end surface opposed to the second lens group frame and inclined with respect to the circumferential direction; and the focus cam surface provided on the second lens group frame when at the two rotation ends. A second follower projection different from the first follower projection that engages with the contact / separation cam surface of the first lens group frame;
A lens moving mechanism in which the focus cam surface and the second follower protrusion of the second lens group frame are configured to move the second lens group frame straight by rotation of a drive ring. 12. The lens moving mechanism according to claim 11, wherein the second lens group frame is located on the outer peripheral side of the focus cam surface on the peripheral surface of the drive ring and covers the second follower projection of the second lens group frame. A lens moving mechanism that forms an annular rib different from the annular rib on the lens group frame side that extends toward the lens group frame side.