JPH01145612A - Lens barrel for macrolens - Google Patents

Abstract

PURPOSE:To enable fast driving and to reduce a difference between a forward and a backward driving speed by fitting an accessory fitting member to an intermediate straight moving cylinder and employing the rolling coupling of sphere bodies as the coupling between the intermediate straight moving cylinder and an intermediate moving rotary cylinder. CONSTITUTION:The intermediate straight moving cylinder 6 is held by the intermediate moving rotary cylinder 2 with the sphere bodies 6a. A straight moving body 6b is screwed to the intermediate straight moving cylinder 6 and fitted in a straight movement groove 1b provided to a fixed member 1. The accessory fitting member 6c is fixed to the intermediate straight moving cylinder 6 with a screw. Consequently, the torque load at the time of accessory fitting is reduced and there is the rolling bearing of the spherical bodies between the intermediate straight moving cylinder 6 and intermediate moving rotary cylinder 2, so the torque load is reduced. Consequently, the driving speed is increased and even when the lens barrel is used while an expanding/contracting direction is almost perpendicular, the driving speed has no forward/backward difference.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a macro lens barrel that employs a multiplex configuration, and is particularly applicable to reducing the load when expanding and contracting with a limited force using an actuator such as an electromagnetic motor. The present invention relates to a macro lens barrel that achieves the following.

[Prior Art] A conventional macro lens barrel is configured such that a mounting portion for an accessory such as a macro strobe is provided on a tip end of the extensible barrel that is exposed on the periphery.

[Problems to be Solved by the Invention] In the conventional macro lens barrel described above, the attached accessories require a large amount of effort, that is, when a relatively heavy accessory such as a macro strobe is attached, However, there are problems in that the load on the actuator is large, the driving speed is slow, and if the actuator is used in a state where the direction of expansion and contraction is close to vertical, there will be a difference in the driving speed between reciprocations.

The present invention attempts to solve these problems.

[Means for Solving the Problems] A rotary cylinder including a lens system having at least two mutually movable lens groups and rotationally driven by a lens drive motor held by a fixed member; An intermediate movable rotary cylinder held so as to be rotatable and movable in the optical axis direction, and the fixed member rotatably coupled to the intermediate movable rotary cylinder by a rolling sphere and movable only in the optical axis direction. an intermediate movable linear cylinder to which an accessory mounting member is fixed; Light is transmitted between the first lens barrel, which is movable only in the optical axis direction and holds the first lens group, and the fixed member, which is held by the intermediate moving rotary barrel so as to be rotatable and movable in the optical axis direction. The second lens group lens barrel is capable of moving only in the axial direction and holds a second lens group.

[Function]According to the present invention, since the accessory mounting member is provided on the intermediate moving linear cylinder rather than on the tip where the amount of feeding is large, the torque load when installing the accessory is reduced, and the attachment of the accessory is made easier. Since the connection between the intermediate moving linear cylinder and the intermediate moving rotating cylinder, which are sometimes subjected to weight loads, is not a sliding movement due to fitting, but a rolling bearing using a spherical body, the torque load is reduced, and furthermore, the torque load is reduced.
Since the second group lens barrel located at the intermediate U-turn portion of the flexible printed board is of the straight-moving type, the rotation angle of the rotary barrel near infinity can be increased.

[Embodiment] The drawings show an embodiment of the present invention. Figure 1 shows the state when shooting at infinity, Figure 2 shows the state when shooting at the closest distance, Figure 3 shows the state of the flexible printed board at the closest distance, and Figure 4 shows the light of each lens group. The movement relationships in the axial direction are shown respectively.

In FIGS. 1 to 3, reference numeral 1 denotes a fixed member that connects an intermediate moving rotary cylinder 2 and a helicoid threaded portion 1a (see FIGS. 1 and 2).
(see figure). Further, Ib and lc shown in FIG. 1 or 2 are straight grooves provided in the fixing member 1.

3a shown in FIGS. 1 and 2 is the stator of the ultrasonic motor, which generates vibration waves using electrical signals.
This itself does not rotate.

3b is a rotor of the ultrasonic motor, which is rotated by the vibration waves of the stator 3a. The rotary cylinder 4 is then rotated via the damper 3c. 4a is a spherical body, which is a steel ball in this embodiment, and holds the rotation of the rotary cylinder 4 with respect to the fixed member 1 with little friction. Reference numeral 4b denotes a distance scale plate, which is glued to the outer periphery of the rotary tube 4, and the distance can be read through the distance window 5. 4c is a straight groove provided on the inner surface of the rotary cylinder 4. Reference numeral 2a denotes a rotation key, which is fixed to the intermediate moving rotary cylinder 2 with a screw and is fitted into a straight groove 4c of the rotary cylinder 4.

Reference numeral 6 denotes an intermediate moving linear cylinder, which is held on the intermediate moving rotary cylinder 2 by a plurality of spheres (steel balls in this embodiment) 6a. Reference numeral 6b denotes a linear key which is screwed to the intermediate translation cylinder 6 and fitted into a linear groove 1b provided in the fixed member 1. Reference numeral 6c denotes an accessory attachment member, which is fixed to the intermediate moving linear cylinder 6 with a screw. 6d is a rectilinear groove provided on the inner surface of the intermediate movable rectilinear cylinder 6.

Reference numeral 7 designates a first group lens barrel (first lens group I), which is engaged with a helicoid screw 2b provided on the intermediate movable rotating barrel 2 by a helicoid screw 7a.

Reference numeral 7b denotes a straight forward key, which is fixed to the first group lens barrel 7 with a screw and is fitted into a straight forward groove 6d provided in the intermediate moving straight forward barrel 6.

Reference numeral 8 denotes a known electromagnetic diaphragm unit, which is fixed to the first group lens barrel 7.

Reference numeral 9 denotes a second group lens barrel (second lens group TI), which has a helicoid screw 9a on its outer periphery, and is engaged with a helicoid screw 2c of the intermediate movable rotating barrel 2.

9b is a straight forward key screwed to the second group lens barrel 9;
It fits into a straight groove 10 provided in the fixed member 1.

Reference numeral 10 denotes a known bayonet mount, which is fixed to the fixing member 1 with screws.

Reference numeral 11 denotes a third group lens barrel (third lens group m 2 ), which is fixed to the bayonet mount 10 with screws.

Reference numeral 12 denotes an exterior cylinder, which is fixed to the fixing member 1 with screws.

Reference numeral 13 shown in FIG. 3 is a flexible printed board, which transmits electrical signals between the electromagnetic diaphragm unit 8 and the main mounting board 17. 14 is a guide plate of the front end 13a of the flexible printed board 13 screwed to the first group lens barrel 7; 15 is an intermediate portion 13b and 13c of the flexible printed board 13 screwed to the second group lens barrel 9; At the same time, the intermediate bent portion 13 of the flexible printed board 13 is
d is fixed. Reference numeral 16 denotes a stand for the main mounting board 17, which is fixed to the fixing member 1 with screws, and the U-turn part 13e of the flexible printed board 13 at the inner peripheral part 16a.
It serves as a guide plate, and also fixes the rear end portion 13f of the flexible printed board 13 at the portion 16b. In addition, a flexible printed board 1 is attached to the second group lens barrel 9.
A hole 9c that is slightly thicker than the width of the flexible printed board 13 is provided so that the flexible printed board 13 can pass through the hole 9c.

In the macro lens barrel having the configuration explained in FIGS. 1 to 3, when an electric signal is sent to the stator 3a,
The rotor 3b rotates due to the vibration waves and rotates via the damper 3c. Then, the intermediate moving rotary cylinder 2 rotates via the rotary key 2a fitted in the straight groove 4c of the rotary cylinder 4, and at the same time, it is rotated against the fixed member 1 by the helicoid screw 1a provided on the fixed member 1. do. At this time, the second
Since the straight-advance key 9b fixed with a screw is fitted into the straight-advance groove 1C provided in the fixed member 1, the group lens barrel 9 is restricted from rotating and extends straight. In addition, the relationship with the intermediate moving rotating barrel 2 is as follows: The vericoid screw 2 provided on the intermediate moving rotating barrel 2
c and the helicoid screw 9a provided in the second group lens barrel 9, the relative position changes.

Next, the intermediate movable linear cylinder 6 is extended in the same way as the intermediate movable rotary cylinder 2 by the spherical body 6a made of a steel ball, but since the linear key 6b is restricted from rotating by the rectilinear groove 1b provided in the fixed member 1, Make a straight forward feed. The first group lens barrel 7 is rotationally regulated by the engagement of a straight key 7b fixed thereto with a screw and a straight groove 6d provided in the intermediate moving straight barrel 6, and moves straight. Also, the first group lens barrel 7 is extended by the intermediate moving rotating barrel 2.
rotates, the intermediary movable rotary barrel 2 is fed out to the intermediate movable rotary barrel 2 by the engagement between the vericoid screw 2b provided on the intermediate movable rotary barrel 2 and the vericoid screw 7a provided in the first group lens barrel 7.

Next, the flexible printed board 13 at the closest time
The movement of the flexible printed board 13 when changing from the state shown in FIG. On the other hand, since it moves backward, the U-turn portion 13a of the flexible printed board 13 moves backward along the inner peripheral portion 16a of the stand 16, and the support of the main board 17 moves backward. At the same time, another U-turn portion 13b of the flexible printed board 13 is attached to the guide plate 15 because the front end portion 13a fixed to the electromagnetic diaphragm unit 8 moves rearward with respect to the second group lens barrel 9. It moves backwards along. At infinity, another U-turn portion 13b is inscribed just inside the U-turn portion 13e.

FIG. 4 shows the movement of each lens group in the optical axis direction. In FIG. 4, ■ indicates the first lens group, 11 indicates the second lens group, and III indicates the third lens group.

In the macro lens barrel configured as shown,
It has the following effects.

First, the accessory mounting member 6 is attached to the intermediate moving linear cylinder 6 that moves in a straight line.
By providing C, the lens barrel load torque for rotating the rotating barrel 4 is approximately 200 gr-cm when a light strobe of approximately 120 gr is attached, compared to when it is provided in the first lens barrel group. I was able to reduce it.

Second, because the intermediate movable rotary barrel 2 and the intermediate movable linear barrel 6 are coupled by rolling, the rotary barrel is more stable when a ring light strobe of approximately 120gr is attached, compared to the case where this is normally done by fitting. The lens barrel load torque for turning 4 was reduced by approximately 200 gr-cm.

Thirdly, by operating the second group lens barrel 9 in a straight line, the notch angle of the hole 9C for passing the flexible printed board 13 is smaller than that when the second group lens barrel 9 rotates. Because of this, the lead pitch of the part necessary for feeding out can be reduced, so the lens barrel load torque for rotating the rotary barrel 4 can be reduced by about 30%.

[Effects of the Invention] As explained above, according to the present invention, the accessory mounting member is attached to the intermediate translational cylinder, and the connection between the intermediate translational cylinder and the intermediate rotational cylinder is achieved by rolling by a spherical body. Because it is a coupling, the load torque is significantly reduced,
Therefore, even in an autofocus macro lens with a large extension amount, high-speed driving is possible, and even when the lens is used in a state in which the direction of expansion and contraction is close to vertical, the difference in reciprocating driving speed can be reduced.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention. Figure 1 is a cross-sectional view of the interchangeable lens in the infinity shooting state, Figure 2 is a cross-sectional view of the closest macro photography, and Figure 3 is the closest micro photography. Sectional view of the flexible printed board in the state, No. 4
The figure is an explanatory diagram of movement of each lens group in the optical axis direction. 1... Fixed member, 2... Intermediate moving rotating cylinder, 4
...Rotating cylinder, 6...Intermediate moving linear cylinder, 6a
... Sphere, 7... First group lens barrel, 9... Second
Group barrel, ■...1st lens group, ■! ...Second lens group, Hl...Third lens group.

Claims (1)

[Claims] A rotating barrel that includes a lens system having at least two mutually movable lens groups and that is rotatably driven by a lens drive motor held in a fixed member, and that is rotatable and movable in the optical axis direction within the fixed member. An accessory mounting member is fixed between an intermediate movable rotary cylinder held by the intermediate movable rotary cylinder and the fixing member which is rotatably coupled to the intermediate movable rotary cylinder by a rolling sphere and can only be moved in the optical axis direction. and an intermediate moving translational barrel which is rotatably held by the intermediate moving rotation barrel and movable in the optical axis direction, and is only movable in the optical axis direction between the intermediate moving translational barrel and the intermediate moving translational barrel. A second lens barrel that is movable only in the optical axis direction between a first group lens barrel that holds one lens group and the fixed member that is held rotatably and movably in the optical axis direction by the intermediate movable rotary barrel. A macro lens barrel comprising a second group barrel holding a lens group.