JPH04217216A - 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. CONSTITUTION:A focus adjusting member 8 is disposed so as to rotate at a certain position with regard to a fixed cylinder 1 which is an element of a lens barrel, lens holding members 10, 9, 11 which interlock with the rotation of the focus adjusting member to travel in an axial direction are provided at the inside of the fixed cylinder 1, a driving means 14 and a gear means 15 which interlocks with the driving 14 are disposed at a part of the lens holding members 10, 9, 11, and a part of the gear means 15 is engaged with a gear part 15f which is formed at a part of the focus adjusting member 8.

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

[Prior Art] Conventionally, in the lens barrel of a photographic lens (interchangeable lens) that is attached to a camera body, main mounting parts such as a motor as a driving means for a focusing lens, a gear train, and electrical components are mounted on the camera body. It was attached to a part of the fixed tube that was connected to the For example, the drive of the motor is controlled by a focusing signal (electrical signal) from a focus detection device installed on the camera body, and the driving force at this time moves the focusing lens straight on the optical axis to achieve focusing. ing.

0003

In a conventional lens barrel, each element such as a motor, a gear train, and a main mounting component (board) is mounted in a fixed barrel near a mount that is connected to a camera body. For this reason, when the focusing lens is moved along the optical axis by a focusing operation, the aperture unit and the electromagnetic motor that drives the aperture unit also move straight on the optical axis. The problem was that the electrical wiring had to be connected using a flexible printed circuit board, making each component complicated.

[0004] The present invention provides a flexible printed circuit board for wiring between the electromagnetic motor for driving the aperture and the main mounting components by appropriately arranging the motor, gear train, main mounting components, etc. provided in the lens barrel. It is an object of the present invention to provide a lens barrel that can be configured without using a lens barrel, which simplifies the entire device and facilitates assembly and assembly adjustment.

[0005]

[Means for Solving the Problems] The lens barrel of the present invention includes:
A focusing member is arranged to rotate in a fixed position relative to the fixed barrel, and a lens holding member is provided inside the fixed barrel and moves in the optical axis direction in conjunction with the rotation of the focusing member, and the lens holding member is provided. It is characterized in that a drive means and a gear means interlocked with the drive means are disposed in a part of the member, and a part of the gear means is meshed with a gear part formed in a part of the focus adjustment member.

[0006]

[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 constituting a part of the second lens holding member, and a key part 9c for straight movement is provided on a part of the outer peripheral surface, and the key groove 1g is provided with the key part 9c in the fixed cylinder 1. It is embedded in 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 constituting a part of the second lens holding member, which holds the rear lens group of the photographing lens, has a bayonet claw 11a, and has a bayonet groove provided in the middle barrel 9. 9a and bayonet are fixed. The middle barrel 9 and the rear lens barrel 11 constitute a second lens holding member. The front lens barrel 10, the middle barrel 9, and the rear lens barrel 11 constitute a lens holding member that moves straight on the optical axis.

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.

At this time, the cam surface 9b and the cam surface 10
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 adjustment 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 opening is controlled by a known electromagnetic motor 12a. 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 (board), which incorporates electrical components, and is fixed to the inner tube 9 with screws. Electromagnetic motor 12a for driving the aperture unit 12
A coil terminal 12b extending from the main mounting component 13 is directly soldered to the main mounting component 13.

Reference numeral 14 denotes an electromagnetic motor, which drives a lens holding member consisting of a front lens barrel 10, a middle barrel 9, and a rear lens barrel 11, and a motor mounting portion 9d provided on the outer periphery of the middle barrel 9. It is fixed with screws.

Reference numeral 15 denotes a gear train as a gear means, which transmits the rotational torque of the electromagnetic motor 14, and each gear is connected to a gear shaft (gear train shaft) 9e integrally molded on the inner cylinder 9.
The final stage gear is configured to mesh with an inner gear (gear portion) 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 front lens barrel 10, the middle barrel 9, the rear lens barrel 11, and the motor on the outer periphery of the middle barrel 9 can be adjusted. Each element, such as the electromagnetic motor 14 incorporated in the mounting part 9d, the gear train 15 fitted into the gear shaft integrally molded in the middle tube 9, and the main mounting component 13 fixed to the middle tube 9, is integrally mounted parallel to the optical axis. The focus is adjusted by moving the camera in the direction.

[0028]

According to the present invention, by configuring each element constituting the lens barrel as described above, in particular, the coil terminal from the aperture drive motor of the aperture unit can be extended to the main mounting component, and direct soldering is possible. As a result, each element can be constructed without using a flexible printed circuit board, and as a result, the lens barrel structure can be simplified, assembly and assembly adjustment can be facilitated, and a lens barrel with improved economic efficiency can be achieved. can.

[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;

[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 (1)

[Claims] 1. A focus adjustment member is arranged to rotate in a fixed position relative to a fixed barrel, and a lens holding member that moves in the optical axis direction in conjunction with the rotation of the focus adjustment member is disposed inside the fixed barrel. At the same time, a drive means and a gear means interlocked with the drive means are disposed in a part of the lens holding member, and a part of the gear means is meshed with a gear part formed in a part of the focus adjustment member. A lens barrel featuring: