JPH04217212A - Lens barrel - Google Patents

Abstract

PURPOSE:To provide a lens barrel for camera with a simple structure, and easy assembly, disassembly and assembling adjustment by appropriately setting respective elements which constitute the lens barrel of a replacement lens. CONSTITUTION:There are provided a plural projection parts 11a on the outer peripheral surface of a lens holding member 11 at prescribed intervals and plural projection parts 11e with barrels at positions whose optical axis directions are different from those of the projection parts 11a, and an abutting surface 9j coming into contact with plural gap parts 9i at which the projection parts 11a are inserted in a cylinder holding member 9 where the lens holding member 11 is installed, engaging stepped parts 9g where the projection parts 11a are installed, and the abutting projection parts 11e.

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, disassembly, and assembly adjustment.

0002

[Prior Art] Conventionally, a lens holding member that holds a lens as a constituent member of a lens barrel of a photographic lens (interchangeable lens) attached to a camera body, and a cylindrical holder with different outer diameter dimensions to which the lens holding member is attached. There are parts. At this time, the lens holding member and the cylindrical holding member having different outer diameters are attached by screwing or adhesive, as proposed in, for example, Japanese Patent Laid-Open No. 58-78132.

0003

[Problems to be Solved by the Invention] In conventional lens barrels, when fixing the lens holding member and the cylinder holding member, they were fixed with screws or adhesive, so there was a lot of assembly, disassembly, and assembly adjustment. There are problems in that it takes time and costs are high.

The present invention simplifies the entire lens barrel and facilitates assembly and assembly adjustment by appropriately setting the structure of the lens holding member, which is one element of the lens barrel, and the cylindrical holding member to which it is attached. The objective is to provide a lens barrel with a

[0005]

[Means for Solving the Problems] The lens barrel of the present invention includes:
A cylindrical holding member to which the lens holding member is attached, wherein a plurality of protrusions are provided at predetermined intervals on the outer peripheral surface of the lens holding member, and a plurality of barreled protrusions are provided at predetermined intervals at positions different from the protrusions in the optical axis direction. The present invention is characterized in that a plurality of voids into which the protrusion is inserted, an engaging step portion into which the protrusion is engaged, and a body attachment surface which abuts the body attachment protrusion are provided.

In particular, in the present invention, the plurality of protrusions provided on the lens holding member and the engaging step portion of the cylindrical holding member are bayonet coupled, and the lens holding member has a plurality of caulking feet on the outer periphery. It is characterized in that a plurality of lens mounting parts are provided for positioning the lens in the optical axis direction of the lens held in a part of the inner peripheral part.

[0007]

[Embodiment] Fig. 1 is a sectional view of a main part of an embodiment of the present invention, Fig. 2
, 3 and 4 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. A key portion 9c is implanted on the outer circumferential surface of the middle tube 9 as a cylindrical holding member constituting a part of a second lens holding member which will be described later. It is installed in a direction parallel to the optical axis in order to fit into 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 cylinder 1 to prevent dirt, dust, etc. from entering the inside from the rear side of the fixed cylinder 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 as a cylinder holding member, which is disposed between a front group lens barrel 10 and a rear group lens barrel 11, which will be described later.

First, the mutual relationship between the middle barrel 9, the front lens barrel 10 which is a member in front of the middle barrel 9, and the focus adjustment member 8 will be explained with reference to FIG.

The middle cylinder 9 has a key part 9 for straight movement on a part of its outer peripheral surface.
A key groove 1g in which the key portion 9c is provided in the fixed cylinder 1.
It is embedded in This holds the middle tube 9 so that it can move 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 photographing 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 designates a rear lens barrel as a lens holding member to be described later, which holds the rear lens group 41 of the photographing lens, has a bayonet claw 11a, and has a bayonet groove 9a provided in the middle barrel 9 and a bayonet. Fixed. The middle barrel 9 and the rear lens barrel 11 constitute a second 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.

[0020]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 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.

Next, the mutual relationship between the middle cylinder 9 and the rear group lens barrel 11, which is a rear member of the middle cylinder 9, will be explained using FIG.

The rear lens barrel 11, which serves as a lens holding member, is molded from synthetic resin. Reference numeral 11f represents a fitting portion, into which the rear lens group 41 is fitted. Reference numeral 11b denotes barrel attachment parts, which are provided at three locations at approximately equal angles on the inner circumference of the rear group lens barrel 11.
The rear lens group 41 is in contact with it. Reference numeral 11c denotes a caulking foot portion, which is provided at a position facing the body attachment portion 11b, and fixes the rear lens group 41 by thermal caulking. 11a is a protrusion (
bayonet portion), and are provided at three locations on the outer periphery of the rear group lens barrel 11. 11a' is an engagement surface, and the protrusion 11a
The engagement stepped part (bayonet part) 9 of the middle cylinder 9
It is engaged with g. Reference numeral 11e designates projecting portions attached to the barrel, which are provided at three approximately equal angles at positions angularly shifted from the projecting portion 11a on the outer periphery of the rear group lens barrel 11. Reference numeral 11e' denotes a barrel attachment surface, which is made up of one surface of the protruding portion 11e and is similar to the barrel attachment surface 9 of the middle tube 9.
j, thereby positioning the rear group lens barrel 11 in the optical axis direction.

The engaging surface 11a' of the protrusion 11a of the rear group lens barrel 11 which is bayonet-coupled with the engagement step 9g of the middle tube 9, and the barreled protrusion of the rear group lens barrel 11 which is attached to the middle tube 9. The distance dimension of the optical axis direction between 11e and the barrel mounting surface 11e' is maintained with high accuracy.

The engagement step portions 9g are provided at three locations at approximately equal angles on the inner circumference of the middle cylinder 9, and the protruding portion (bayonet portion) 11a of the rear group lens barrel 11 engages with the engagement step portions 9g. are combined. Locking projections 9h are provided at three locations adjacent to the engagement step 9g, and are locked when the projection 11a of the rear group lens barrel 11 is engaged. 9i is a cavity, which is provided at three locations adjacent to the engagement step 9g, and is located in the rear group lens barrel 1.
This is for inserting the first protrusion 11a. Reference numeral 9j denotes a barrel attachment surface, with which the barrel attachment surface 11e' of the barrel attachment projection 11e of the rear group lens barrel 11 comes into contact.

Next, the assembly operation of the rear lens group 41, the rear group lens barrel 11, and the middle barrel 9 will be explained using FIG.

First, the rear lens group 41 is fitted into the fitting part 11f of the rear lens barrel 11, and with a part of the rear lens group 41 in contact with the barrel part 11b, it is thermally swaged using the swaging foot 11c. Fix it.

Next, the protrusion 11a of the rear lens barrel 11 is inserted into the middle barrel 9.
By inserting it into the gap 9i and rotating the rear group lens barrel 11 clockwise, the protrusion 11a slides on the locking protrusion 9h of the middle barrel 9 and falls into the engagement step 9g. The rear group lens barrel 11 is attached to the middle barrel 9. At this time, the rear group lens barrel 11
The position in the optical axis direction is the barrel attachment surface 11e' of the barrel attachment protrusion 11e.
The dimensions of the rear group lens barrel 11 are set so that it is held by the elastic force caused by the deformation of the protrusion 11a, as determined by the engagement of the barrel attachment surface 9j of the middle barrel 9 with the rear lens barrel 11.

Returning to FIG. 1, reference numeral 12 denotes an aperture unit, and the aperture aperture is driven and 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 the front lens barrel 10, the middle barrel 9, and the rear lens barrel 11, and is fixed to the motor mounting portion 9d provided on the outer periphery of the middle barrel 9 with screws. There is.

Numeral 15 is a gear train, which transmits the rotational torque of the electromagnetic motor 14. Each gear is fitted into a gear shaft (gear train shaft) 9e integrally formed in the middle cylinder 9, and is connected to the final 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 due to 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.

[0038]

According to the present invention, by configuring the lens holding member and cylinder holding member that constitute a part of the lens barrel as described above, the lens barrel structure is simplified, and assembly, disassembly, and assembly adjustment are facilitated. A lens barrel with improved economic efficiency 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 perspective view of a portion of FIG. 1;

[Explanation of symbols]

1 Fixed tube
9g Engagement stepped portion 2 Reinforcement ring
9h Locking protrusion 3 Mount lid member 9j Trunk attachment surface 4 Changeover switch 11a Protrusion (bayonet claw) 5 Switch spring 11
b Body attachment part 7 nameplate
11c Caulking foot 8 Focus adjustment member 11e Trunked protrusion 9 Middle tube
41 Rear lens group 10 Front group barrel 11 Rear group 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 follower

Claims (3)

[Claims] 1. A plurality of protrusions are provided at predetermined intervals on the outer peripheral surface of a lens holding member, and a plurality of barreled protrusions are provided at predetermined intervals at positions different from the protrusions in the optical axis direction, and the lens holding member is removed. A lens characterized in that a cylindrical holding member to be worn is provided with a plurality of cavities into which the protrusion is inserted, an engagement step portion into which the protrusion engages, and a barrel attachment surface that comes into contact with the barrel attachment projection. lens barrel. 2. The lens barrel according to claim 1, wherein the plurality of protrusions provided on the lens holding member and the engaging stepped portion of the cylindrical holding member are bayonet coupled. 3. A plurality of caulking feet are provided on the outer circumference of the lens holding member, and a plurality of lens body mounting portions are provided on a part of the inner circumference for positioning the lens held in the optical axis direction. The lens barrel according to claim 1, wherein: