JPH04217214A - Lens barrel - Google Patents

Abstract

PURPOSE:To provide a lens barrel for camera with a simple structure, and easy assembly and assembling adjustment by appropriately setting respective elements which constitute a lens barrel, and reducing the use of flexible print board with traveling and absorption functions. CONSTITUTION:A focus adjusting member 8 is rotatably held on the inner peripheral surface of a fixed cylinder 1 which is an element of a lens barrel, and lens holding members (10, 9, 11) which interlock with the rotational motion of the focus adjusting member 8 to travel in an optical axis direction through a cam mechanism on the inside of the fixed cylinder 1 are provided. Besides, a motor for lens driving 14 which rotates the focus adjusting member 8, a diaphragm unit 12, an electromagnetic motor 12a for diaphragm driving which drives the diaphragm unit 12, and an electric circuit substrate 13 which driving- controls the motor for lens driving and the electro-magnetic motor for diaphragm driving are disposed at a part of the lens holding members (10, 9, 11).

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a lens barrel for a photographic lens (interchangeable lens) used in a 35 mm film photographic camera, video camera, etc., and in particular to appropriately setting each element constituting the lens barrel. This invention relates to a lens barrel that simplifies the entire lens barrel and facilitates assembly and assembly adjustment.

0002

2. Description of the Related Art Various types of lens barrels for photographing lenses (interchangeable lenses) to be mounted on camera bodies have been proposed.

FIG. 4 is a sectional view of a main part of a lens barrel proposed in Japanese Utility Model Application Publication No. Sho 62-140512. In the figure, reference numeral 41 indicates a fixed tube, and a bayonet mount 41A coupled to the camera body (not shown) is attached to one end of the fixed tube on the side of the camera body. 42 is a first moving ring, and 44 is a second moving ring, each of which has focusing lenses L4 to L6.
, L1 to L3. A fitting portion 4 that fits into the inner diameter portion 42a of the first moving ring 42 is provided on the outer peripheral surface of the second moving ring 44.
4a and a fixing means for fixing the second movable ring 44 to the first movable ring 42. The fixing means includes a plurality of protrusions 44b, 44b protruding from the outer periphery of the second movable ring 44.
An engaging portion 42b provided on the inner diameter surface of the first movable ring 42
, 42b....

Reference numeral 46 indicates a motor held by the fixed cylinder 41, and yokes 46a1 and 46a2 fixed to the fixed cylinder 41.
, a stator consisting of a permanent magnet (not shown), etc., and a roller consisting of a coil, a rotating shaft 46b, etc. G1～
Gn indicates a gear group constituting a gear mechanism that increases/decreases the rotation speed in conjunction with the rotating shaft 46b, and this gear group is pivotally supported by a base plate 48 fixed to the fixed cylinder 41.

Reference numeral 50 denotes a rotating ring that rotates at a fixed position of the fixed cylinder 41, and the inner diameter of the rotating ring 50 is provided with a helicoid portion 50a that screws into the helicoid portion 42c formed on the outer periphery of the first movable ring 42. Further, a V-shaped ball race groove 50b for receiving the bearing ball 52 is formed on the outer periphery of the rotating ring 50.

The bearing balls 52 are arranged in the ball race groove 50b of the rotary ring 50 by a ball spacer 54 so as to be continuous with each other or at regular intervals by the spacer 54, and are fitted into the inner periphery of the fixed cylinder 41 and have an inclined surface at one end. It is held by a first ball receiving ring 56 provided and a second ball receiving ring 58 that is threadedly engaged with the threaded portion 41a on the inner surface of the fixed cylinder 41.

Reference numeral 60 denotes a plate-shaped spacer provided between the first ball receiving ring 56 and the fixed cylinder 41, and the pressure of the ball 52 is adjusted by changing the thickness of the spacer. 62 is a position detector such as an encoder disposed within the gear mechanism.

A part of the outer periphery of the rotary ring 50 has a small diameter, and a gear ring 64 is fixed to the outer periphery of the small diameter part 50c, and the gear ring 64 is threadedly engaged with the output gears of the gears G1 to Gn. There is.

In the above structure, a space is formed between the movable ring 42 and the fixed cylinder 41 so that the motor 46 and the gear mechanisms G1 to Gn can be accommodated, and this space is formed between the fixed cylinder 41 and the movable ring 42. This is maintained by bearing components 50, 56, 58 of balls 52, 52, .

D represents the inner peripheral surface of the moving ring 42 and the small diameter wall surface 42.
Aperture unit fixed to e, EMD is aperture unit D
The motor EMD is fixed to the aperture unit D.

70 is a hard printed board, and the motor 46
It is equipped with an electric circuit that drives and controls the , EMD, etc. The motor 46 and the rigid printed board 70 are connected by a flexible printed board (not shown). The rigid printed board 70 is disposed in the gap between the first movable ring 42 and the mount portion 41A, and is fixed to the fixed cylinder 41.

Reference numeral 71 denotes a contact block, one of which exchanges electrical signals with the camera body (not shown), and the other connected to the hard printed board 70 by soldering 71a.

69 is the back cover, and the bayonet mount 4
It fits into the inner diameter of 1A. The flexible printed board 72 connects to the EMD through the hole 4 of the first movable ring 42 from the connecting portion 72a.
2d and exits to the camera body side, and is bent along the outer periphery of the first movable ring 42 toward the lens entrance. A flexible printed board 72 bent toward the entrance port is bent toward the camera body between it and the fixed tube 41, and one end 72c of the flexible printed board 72 is soldered to a part of the rigid printed board 70.

In the configuration shown in FIG. 4, the motor 46 rotates based on a signal related to lens drive transmitted from the camera body side. The rotational torque of the motor 46 is transmitted to the rotating ring 50 via the gear mechanisms G1 to Gn, thereby rotating the rotating ring 50 in a fixed position. rotating ring 50
As a result of the rotation, the first movable ring 42 is restricted from rotating through a key means (not shown), and is moved in the optical axis direction by the helicoid portion 42c. When the first moving ring 42 moves, the second moving ring 44 also moves, thereby causing the lenses L1 to L
6 is moved in the optical axis direction.

In such a moving mechanism, the fixed cylinder 41
and the first moving ring 42 .
The position of the bent portion 72b changes with the movement, and at this time, the flexible printed board 72 follows the movement of the first moving ring 42.

[0016]

[Problems to be Solved by the Invention] In the conventional lens barrel, the flexible printed board 72 is parallel to the optical axis direction and has a parallel portion along the fixed barrel 41 and the first movable ring 42, and a parallel portion along the fixed barrel 41 and the first movable ring 42. The bent portion 72a between the movable ring 42 and the bent portion 72a follows the relative movement between the fixed cylinder 41 and the first movable ring 42.

For this reason, when the first movable ring 42 is rotationally driven with respect to the optical axis, the flexible printed board may be twisted and cut. I couldn't do it.

The flexible printed board is moved to the first moving ring 42
In order to follow the rotational direction as well, it is necessary to take out only the movement in the rotational direction and configure a portion that follows the rotational direction, and as a result, the configuration tends to become complicated.

By appropriately setting each element constituting the lens barrel, the present invention reduces the use of a conventional flexible printed board with a movement absorption mechanism, and reduces the need for a lens drive motor and an aperture drive electromagnetic motor. To provide a lens barrel that can connect between the camera and an electric circuit board, simplifies the entire lens barrel, and facilitates assembly and assembly adjustment.

[0020]

[Means for Solving the Problems] The lens barrel of the present invention includes:
A lens holding member is fitted inside the fixed cylinder so as to be movable in the optical axis direction, and a lens driving motor that drives a focusing member in a part of the lens holding member, an aperture unit,
It is characterized by disposing an aperture driving electromagnetic motor that drives the aperture unit, and an electric circuit board that drives and controls the lens driving motor and the aperture driving electromagnetic motor.

In particular, the present invention is characterized in that the electric circuit board and the lens drive motor and/or the aperture drive electromagnetic motor are connected by a flexible printed board or coil terminal without a movement absorption mechanism.

[0022]

[Embodiment] Fig. 1 is a sectional view of a main part of an embodiment of the present invention, Fig. 2
, 3 are perspective views of a portion of FIG. 1, respectively.

In the figure, reference numeral 1 denotes a fixed cylinder, which is molded from resin such as plastic. At the rear end of the fixed barrel 1, there is a bayonet claw 1a as a mount member for bayonet connection to the camera body (not shown), and on the inner peripheral surface of the tip end there is a holding member for bayonet connection to the reinforcing ring 2. A bayonet claw 1c and a groove 1d are provided. A plurality of key grooves 1g are provided on the inner circumferential surface of the cylindrical portion 1b of the fixed tube 1 in order to fit into key portions 9c implanted on the outer circumferential surface of the middle tube 9 that constitutes a part of the second lens holding member, which will be described later. It is provided in a direction parallel to the optical axis.

The reinforcing ring 2 is made of a metal material and is used to prevent the fixed cylinder 1 from deforming (deflecting). The reinforcing ring 2 has a groove 2a on its outer circumferential surface that engages with a bayonet claw 1c provided on the inner circumferential surface of the fixed cylinder 1, and a bayonet claw 8a of a focus adjustment member 8, which will be described later, is fitted into its inner circumferential surface. A groove 2b is provided. After fitting the reinforcing ring 2 into the inner circumference of the fixed cylinder 1, it is rotated around the optical axis so that the side surface 2a1 of the groove 2a of the reinforcing ring 2 comes into contact with the stopper part 1h provided on the fixed cylinder 1. ing. This allows positioning in the optical axis direction and fixation to the fixed barrel 1 by frictional force with the inner circumferential surface of the fixed barrel 1.

Reference numeral 3 denotes a mount lid member, which is fixed to the rear side of the fixed tube 1 to prevent dirt, dust, etc. from entering the inside from the rear side of the fixed tube 1. A plurality of engagement claws 3b are integrally molded with resin on the outer periphery of the disk portion 3a of the mount lid member 3 so as to protrude from the outer periphery. This mount lid member 3 is integrated with the fixed cylinder 1 by fitting and fixing the engaging claw 3b into an engaging groove or hole provided in the fixed cylinder 1 using the elastic force of the resin.

4 is a changeover switch, and a focus adjustment member 8
Switching between automatic focus adjustment and manual focus adjustment is performed, and a switch spring 5 is attached to the protrusion 4a at one end with a screw 6.
is fixed. The changeover switch 4 is mounted in a groove 7a provided in the nameplate 7 so as to be movable in a direction parallel to the optical axis (in the direction of arrow 4b) by the elastic force of a switch spring 5. The nameplate 7 is fixed to the nameplate fixing surface 1f of the fixed tube 1 in such a manner that the protrusion 4a of the changeover switch 4 and the switch spring 5 are movable within the hole 1e provided in the fixed tube 1.

Reference numeral 8 denotes a focus adjustment member (focus adjustment ring), which is rotated around the optical axis manually or electrically by a driving force from an electromagnetic motor 14, which will be described later. A bayonet claw 8a is provided on a part of the outer peripheral surface of the focus adjustment member 8, and is held rotatably around the optical axis by fitting into a groove 2b provided in the inner peripheral surface of the reinforcing ring 2. There is.

Further, a plurality of protruding sliding surfaces 8b are provided on a part of the outer peripheral surface of the focus adjustment member 8, and the sliding surfaces 8b rotate in a fixed position while sliding on the inner peripheral surface of the reinforcing ring 2. That's what I do.

Reference numeral 9 denotes a middle cylinder, and a key part 9c for straight movement is provided on a part of the outer peripheral surface, and the key part 9c is fitted into a keyway 1g provided in the fixed cylinder 1. Thereby, the middle tube 9 is held so as to be movable in a direction parallel to the optical axis.

Reference numeral 10 denotes a front lens barrel, which constitutes a first lens holding member that holds the front lens group of the photographic lens. The middle tube 9 has an engagement hole 9f on its outer peripheral surface, and is fixed by fitting into a plurality of engagement claws 10c integrally formed on the front group lens barrel 10.

Reference numeral 11 denotes a rear lens barrel, which holds the rear lens group of the photographing lens, and has a bayonet claw 11a.
The bayonet is fixed to a bayonet groove 9a provided in the middle cylinder 9. The middle barrel 9 and the rear lens barrel 11 constitute a second lens holding member. The first lens holding member and the second lens holding member constitute a lens holding member.

A cam surface 9b is provided at the front end of the middle tube 9, and a cam surface 10b is provided at the rear side of the front group lens barrel 10 to face the cam surface 9b of the middle tube 9. And the middle barrel 9 and the front lens barrel 10
By fixing the two cam surfaces 9b and 10b facing each other, the two cam surfaces 9b and 10b
A parallel cam groove space is formed that faces each other.

[0033]The cam surface 9b and the cam surface 10 at this time
A cam follower portion 8c extending from the focusing member 8 is fitted into the cam groove space formed by b, thereby forming a cam structure.

In this embodiment, by rotating the focus adjusting member 8 around the optical axis, the front group lens barrel 10, the rear group lens barrel 11, and the middle tube 9 integrated therewith are connected via the cam follower 8c.
and are moved in a direction parallel to the optical axis.

Reference numeral 12 denotes an aperture unit, and the aperture aperture is driven and controlled by a known electromagnetic motor 12a for driving the aperture. The diaphragm unit 12 is fixed by fitting an engaging claw protruding from the middle cylinder 9 into the front disk surface of the diaphragm unit 12.

Reference numeral 13 denotes a main mounting component (electric circuit board), which incorporates electrical components and is fixed to the inner tube 9 with screws. An electromagnetic motor 12a for driving the aperture unit 12 is directly soldered to the main mounting component 13 using a flexible printed board 12b without a movement absorption mechanism.

Reference numeral 14 denotes a lens driving electromagnetic motor, which drives the front lens barrel 10, the middle barrel 9, and the rear lens barrel 11. Fixed.

14a is a coil terminal, which extends from the lens driving electromagnetic motor 14, and is connected to the main mounting component 13.
It is connected by direct soldering.

Reference numeral 15 denotes a gear train, which transmits the rotational torque of the lens driving electromagnetic motor 14. Each gear is fitted into a gear shaft (gear train shaft) 9e integrally formed in the inner cylinder 9, and the final The stage gear is configured to mesh with an inner gear 15f provided on a part of the inner peripheral surface of the focus adjustment member 8.

Next, the operation of the lens barrel of this embodiment will be explained. First, the lens barrel of this example is attached to the camera body. In the automatic focus detection mode, the electromagnetic motor 14 is driven based on a signal obtained by an automatic focus detection device provided on the camera body side. The rotational torque of the electromagnetic motor 14 is transmitted to the inner gear 15f provided on the inner peripheral surface of the focus adjustment member 8 via the gear train 15.
is rotated around the optical axis with respect to the fixed barrel 1.

At this time, the cam follower portion 8a of the focus adjustment member 8 is fitted into the cam groove space formed by the cam surface 9b of the middle tube 9 and the cam surface 10b of the front lens barrel 10 fixed to the middle tube 9. There is. Furthermore, the middle tube 9 is movable relative to the fixed tube 1 in a direction parallel to the optical axis by a key structure consisting of a key portion 9c and a keyway 1g.

Therefore, as the focus adjustment member 8 rotates, the front lens barrel 10 and the middle barrel 9 move in the optical axis direction via the cam follower 8a. Further, the rear group lens barrel 11, which is bayonet-coupled to the middle tube 9, also moves integrally with the middle tube 9 in the optical axis direction at the same time.

In addition, for manual focus adjustment, selector switch 4
By switching to the manual mode, a part of the gear train 15 is separated so that the rotational torque from the electromagnetic motor 14 is not transmitted to the focusing member 8. At this time, the same operation as described above is performed by manually rotating the focus adjustment member 8.

In this embodiment, by rotating the focus adjustment member 8 around the optical axis, the focus adjusting member 8 can be attached to the front group lens barrel 10, the middle tube 9, the rear group lens barrel 11, and further to the outer periphery of the middle tube 9. an electromagnetic motor 12a for driving the diaphragm, an electromagnetic motor 14 for driving the lens built into the motor mounting part 9d, a gear train 15 fitted into a gear shaft integrally formed in the middle tube 9, and a main mounting component 13 fixed to the middle tube 9. Focus adjustment is performed by integrally moving each element such as in a direction parallel to the optical axis.

[0045]

According to the present invention, by configuring each element constituting a part of the lens barrel as described above, the number of flexible printed boards with a movement absorption mechanism can be reduced, and the electric circuit board and electromagnetic motor can be reduced. can be directly wired, and the electrical circuits other than the mount contacts can be moved integrally, simplifying the lens barrel structure, making assembly and assembly adjustment easier, and improving economic efficiency. tube can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of an embodiment of the present invention.

FIG. 2 is a perspective view of a portion of FIG. 1;

FIG. 3 is a perspective view of a portion of FIG. 1;

FIG. 4 is a sectional view of a main part of a conventional lens barrel.

[Explanation of symbols]

1 Fixed cylinder 2 Reinforcement ring 3 Mount lid member 4 Selector switch 5 Switch spring 7 Nameplate 8 Focus adjustment member 9 Middle tube 10 Front group lens barrel 11 Rear group lens barrel 12 Aperture unit 12a Electromagnetic motor 13 Main mounted parts 14 Electromagnetic motor 15 Gear train 1c bayonet claw 1d groove 1g keyway 8a Bayonet claw 8b Sliding surface 8c Cam follow part

Claims (3)

[Claims] 1. A lens holding member is fitted inside a fixed cylinder so as to be movable in the optical axis direction, and a lens driving motor for driving a focusing member in a part of the lens holding member, an aperture unit, and an aperture unit. A lens barrel characterized in that an aperture driving electromagnetic motor that drives an aperture unit, and an electric circuit board that drives and controls the lens driving motor and the aperture driving electromagnetic motor are arranged. 2. The electric circuit board and the lens drive motor and/or the diaphragm drive electromagnetic motor are connected to each other by a flexible printed board or a coil terminal without a movement absorption mechanism. lens barrel. 3. A focus adjustment member is rotatably held on the inner circumferential surface of the fixed barrel, and is moved in the optical axis direction via a cam mechanism in conjunction with the rotation of the focus adjustment member inside the fixed barrel. a lens holding member for rotating the focusing member, a lens driving motor for rotating the focusing member, an aperture unit, an aperture driving electromagnetic motor for driving the aperture unit, and the lens driving motor and the lens holding member. A lens barrel characterized in that an electric circuit board for driving and controlling an electromagnetic motor for driving an aperture is arranged.