JPH09244093A - Lens information transmitting device of interchangeable lens for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the diameter of an interchangeable lens small and to miniaturize the interchangeable lens by constituting a lens information transmitting device of the interchangeable lens for a camera without requiring special space around a diaphragm value setting ring. SOLUTION: When a set diaphragm value is changed by turning the diaphragm value setting ring 20, a brush base 25 is turned in the same way through the extended arm 21b of a diaphragm regulating plate 21. The diaphragm value detecting mechanisms of the brush base 25 and a code disk 24 transmit the set diaphragm value to a camera body side. When a movable lens barrel 15 is moved in an optical axis direction, the brush base 25 is moved in the optical axis direction together to change its engaging position with the extended arm 21b. The positional relation of the brush base 25 and the code disk 24 in the optical axis direction is constant. Therefore, the set lens information is surely transmitted regardless of the position of the lens barrel 15 in the optical axis direction. Since the brush base 25 is provided inside the lens barrel 15 having enough space, the outside diameter around the ring 20 is prevented from getting large.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a lens information transmission device for an interchangeable lens for a camera.

[0002]

2. Description of the Related Art In a single-lens reflex camera, a lens information transmission device for transmitting lens information set by the interchangeable lens to the camera body side through contact pins provided on the interchangeable lens and the camera body, respectively. Are known. Conventionally, the lens information is detected by a code plate provided on a fixed barrel inside the aperture value setting ring and a brush directly attached to the aperture value setting ring. However, the conventional structure in which the brush and the cord plate are directly provided around the aperture setting ring requires a radial space,
This has been an obstacle to the downsizing and downsizing of interchangeable lenses.

[0003]

SUMMARY OF THE INVENTION The present invention does not require a special space around the aperture value setting ring for detecting lens information, and therefore the diameter can be reduced.
An object of the present invention is to obtain a lens information transmission device of an interchangeable lens for a camera that can be downsized.

[0004]

SUMMARY OF THE INVENTION The present invention relates to an interchangeable lens for a camera, which transmits lens information set by an aperture value setting ring to a camera body side through a contact pin provided on a mount portion,
A movable lens barrel whose rotation is restricted and movable in the optical axis direction; a diaphragm ring supported by the movable lens barrel; a code plate provided on the movable lens barrel; and a brush that slidably contacts the code plate and is movable. A brush base supported by a lens barrel so as to be freely rotatable by restricting movement in the optical axis direction; an interlocking rotary member for transmitting the rotation of the aperture value setting ring to the brush base; lens information by the code plate and the brush And a flexible printed circuit board that transmits to the contact pins.

The brush base is constructed as a non-annular member, the interlocking rotary member is provided with an extension arm extending in a direction parallel to the optical axis, and the brush base made of the non-annular member is inserted into which the extension arm is fitted. By forming the holes, the rotation of the aperture value setting ring can be easily transmitted to the brush base. The extension arm of the interlocking rotary member can also be used as a diaphragm regulating member that engages with a stopper surface provided on the diaphragm opening / closing ring to regulate the rotation angle of the diaphragm opening / closing ring in the narrowing direction.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An interchangeable lens 10 for a single lens reflex camera shown in this embodiment has a lens mount 11 mounted on a mount on the camera body side.
1 is fixed to a mount mounting ring 12. A straight guide groove 1 parallel to the optical axis is provided on the inner circumference of the mount mounting ring 12.
The straight guide ring 13 having 3a is fixed, and the lens mount 11, the mount mounting ring 12, and the straight guide ring 13 constitute a fixed-side lens barrel.

A focus adjusting ring 14 is screwed to the front end of the linear guide ring 13 with screws 13s and 14s, and the focus adjusting ring 14 is further provided with screws 14s and 14s.
The movable lens barrel 15 is screwed and coupled at 15 s. The movable lens barrel 15 has a linear guide protrusion 15a fitted in the linear guide groove 13a.
Therefore, when the focus adjustment ring 14 is rotationally driven, the movable lens barrel 15 moves straight in the optical axis direction. The movable lens barrel 15 has, in order from the front, the first lens frame 1
The first lens L1 and the second lens L2 are fixed via 6 and the third lens L3 is fixed via the second lens frame 17.

The movable lens barrel 15 includes a second lens L2 and a third lens L2.
It is located between the lens L3 and the diaphragm support flange 15b.
Is provided integrally with the diaphragm support flange 15b.
And a diaphragm opening / closing ring 18 rotatably supported by the movable lens barrel 15.
A plurality of diaphragm blades 19 are supported between and. Each diaphragm blade 19 has a diaphragm support hole 1 formed in the diaphragm support flange 15b.
5d has a dowel 19a and a dowel 19b fitted in a diaphragm opening / closing cam hole 18a formed in the diaphragm opening / closing ring 18.
When the diaphragm opening / closing ring 18 rotates, the diaphragm opening changes in size. The shape of the diaphragm opening / closing cam hole 18a is normally the diaphragm opening / closing ring 18.
The aperture value is set to change by one step at substantially the same rotation angle. In FIG. 3, when the diaphragm opening / closing ring 18 rotates counterclockwise, the diaphragm diameter increases (F value decreases), and when it rotates clockwise, the diaphragm diameter decreases (F value increases).

A diaphragm value setting ring 20 is rotatably supported on the outer periphery of the mount mounting ring 12. On the other hand, a diaphragm restriction plate (interlocking rotary member) 21 is rotatably supported between the lens mount 11 and the mount mounting ring 12, and a radial projection 21 a provided on the diaphragm restriction plate 21 sets a diaphragm value setting. Fitted in the interlocking groove 20a in the direction parallel to the optical axis on the inner surface of the ring 20, the diaphragm restriction plate 21 always rotates in the same manner as the diaphragm value setting ring 20. The aperture restriction plate 21 also has an extension arm 21b extending forward in parallel with the optical axis. Aperture opening / closing ring 1
8 is integrally provided with a stopper surface 18b that engages with the extension arm 21b from one circumferential direction. The stopper surface 18b and the extension arm 21b have a relationship that allows the diaphragm restriction plate 21 to rotate in the narrowing direction when the diaphragm opening / closing ring 18 is held in the diaphragm opening position. In other words, the extension arm 21b engages with the stopper surface 18a of the diaphragm opening / closing ring 18 to regulate the rotation angle of the diaphragm opening / closing ring 18 in the drawing direction.

Lens mount 11 and mount mounting ring 12
A release plate 22 is also rotatably supported between the spaces. The release plate 22 has a linkage projection 22a for the camera body side and an interlocking engagement arm 22b for the diaphragm opening / closing ring 18. The interlocking engagement arm 22b engages with the engagement hole 18c (FIG. 1) formed in the diaphragm opening / closing ring 18 to give the diaphragm opening / closing ring 18 the same rotation as the release plate 22 at all times.
The linking protrusion 22a of the release plate 22 is the interchangeable lens 1
When 0 is attached to the camera body, it engages the aperture opening member on the camera body side, and when the auto mode is selected, the aperture opening / closing ring 18 is held at the aperture opening position. on the other hand,
If the diaphragm opening member on the body side escapes immediately before the shutter release, the release plate 22 can freely rotate, and the diaphragm opening / closing ring 1
Rotation in the narrowing direction by the spring force of 8 is permitted. The rotating end of the diaphragm opening / closing ring 18 is restricted by the position where the stopper surface 18b contacts the extension arm 21b, that is, by the set diaphragm value, and the opening by the plurality of diaphragm blades 19 becomes the set diaphragm value immediately before the shutter release.

A code plate 24 for detecting lens information (aperture value information) from the rotational position of the aperture value setting ring 20 is attached to the inner peripheral surface of the movable lens barrel 15, and is adjacent to the code plate 24. Thus, the brush base movement groove 15d in the circumferential direction is formed. Non-circular block-shaped brush base 2
Reference numeral 5 has a brush 25a that is in sliding contact with the code plate 24, a guide protrusion 25b that fits in the brush base movement groove 15d, and an insertion hole 25c that fits the extension arm 21b without a gap. The brush stand 25 in which the guide protrusion 25b is fitted in the brush stand moving groove 15d and the extension arm 21b is fitted in the insertion hole 25c.
The brush 25a correctly contacts the cord plate 24 with an elastic contact force, and the diaphragm restriction plate 21 (diaphragm value setting ring 2
When (0) rotates, it makes the same rotation and the cord plate 24
When the movable lens barrel 15 moves in the optical axis direction while changing the relative position with respect to the optical axis direction, the movable lens barrel 15 moves in the optical axis direction together with the movable lens barrel 15 to change the engagement position with the extension arm 21b.

As shown in FIG. 2, one end of a flexible printed circuit (FPC) 26 electrically connected to the code plate 24 is fixed to the inner peripheral surface of the movable lens barrel 15. This flexible printed circuit board 26 has a movable lens barrel 1
The inside of 5 is guided rearward through the FPC guide plate 27 and electrically connected to a plurality of contact pins 28 exposed on the mount surface of the lens mount 11. Multiple contact pins 28
Are supported by one contact pin holder 29, and are biased in the protruding direction by compression springs 30, respectively. By this urging force, contact pressure with the contact pin on the camera body side can be obtained.

As shown in FIG. 4, an in-lens electric circuit 40 is mounted in the interchangeable lens 10, and the in-lens electric circuit 40 responds to the aperture value set by the aperture value setting ring 20. The lens specific information (diaphragm-related data, AF-related data, optical system-related data) is transmitted to the body side via a plurality of contact pins 28.

In the interchangeable lens 10 having the above structure, when the aperture value setting ring 20 is rotated to change the set aperture value, the brush base 25 is also rotated in the same manner via the extension arm 21b of the aperture restriction plate 21. To do. Then, the aperture value detection mechanism formed by the brush base 25 and the code plate 24 sets the aperture value set at that time via the flexible printed board 26 and the contact pin 28.
Transmitted to the camera body side. When the movable lens barrel 15 moves in the optical axis direction for focus adjustment, both the brush bases 25 move in the optical axis direction to change the engagement position with the extension arm 21b. The positional relationship between the brush base 25 and the code plate 24 in the optical axis direction does not change. Therefore, the transmission of this setting lens information is
It can be surely performed regardless of the position of the movable lens barrel 15 in the optical axis direction. Since the brush base 25 is provided inside the movable lens barrel 15 with a sufficient space, the outer diameter around the aperture value setting ring 20 does not increase, and the interchangeable lens has a smaller diameter and a smaller size. Can be realized.

When the auto mode is selected with the interchangeable lens 10 mounted on the camera body, the aperture opening / closing ring 18 is provided with the aperture opening member and the release plate 22 on the camera body side as described above. The extended arm 21b is separated from the stopper surface 18b of the diaphragm opening / closing ring 18 except when the diaphragm aperture set by the diaphragm aperture setting ring 20 is open. Then, when the shutter is released, immediately before that, the aperture opening member on the camera body side escapes to allow the release plate 22 to freely rotate, and the aperture opening / closing ring 18 rotates in the aperture direction by the spring force. At the rotating end of the diaphragm opening / closing ring 18, the stopper surface 18b is extended arm 21b.
It is regulated by the position where it comes into contact with, that is, the set aperture value.

[0016]

According to the present invention, it is possible to construct a lens information transmission device for an interchangeable lens for a camera without requiring a special space around the aperture value setting ring. Therefore, the interchangeable lens can be downsized and downsized. Can contribute to.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a lens information transmission device for an interchangeable lens for a camera according to the present invention.

FIG. 2 is a vertical sectional view of a section different from that of FIG.

FIG. 3 is an exploded perspective view of the same main elements.

FIG. 4 is a block diagram showing a relationship between an in-camera electric circuit and contact pins.

[Explanation of symbols]

 10 interchangeable lens 15 movable lens barrel 15b diaphragm supporting flange 15c diaphragm supporting hole 15d brush base moving groove 18 diaphragm opening / closing ring 18a diaphragm opening / closing cam hole 18b stopper surface 18c engaging hole 19 diaphragm blade 20 diaphragm setting ring 21 diaphragm regulating plate (interlocking plate) Rotating member) 21b Extension arm 22 Release plate 24 Code plate 25 Brush base 25a Brush 25b Guide protrusion 25c Insertion hole 26 Flexible printed circuit board 27 FPC guide plate 28 Contact pin 29 Contact pin holder

Claims (3)

[Claims] 1. An interchangeable lens for a camera, which transmits lens information set by an aperture value setting ring to a camera body side through a contact pin provided on a mount part, is restricted in rotation and is movable in an optical axis direction. A movable lens barrel; an aperture opening / closing ring supported by the movable lens barrel; a code plate provided on the movable lens barrel; a brush slidingly contacting the code plate, and moving in the optical axis direction on the movable lens barrel. A pedestal that supports the rotation of the aperture value setting ring, and an interlocking rotary member that transmits the rotation of the aperture value setting ring to the brush base; and a flexible plate that transmits lens information by the code plate and the brush to the contact pin. A lens information transmission device for an interchangeable lens for a camera, comprising: a printed circuit board; 2. The interlocking rotary member according to claim 1, wherein the interlocking rotary member has an extension arm extending in a direction parallel to the optical axis, and the brush base made of a non-annular member has an insertion hole into which the extension arm is fitted. Information transmission device for interchangeable lenses for existing cameras. 3. The camera according to claim 2, wherein the extension arm of the interlocking rotary member engages with a stopper surface provided on the diaphragm opening / closing ring to restrict the rotation angle of the diaphragm opening / closing ring in the drawing direction. Lens information transmission device for interchangeable lenses.