JPH08184738A - Lens barrel - Google Patents

Abstract

PURPOSE: To reduce the set space of a rotational amount detecting means, to miniaturize a lens barrel, and to facilitate the inspection, the adjustment, the repair and the exchange of the rotational amount detecting means. CONSTITUTION: This lens barrel 1A is provided with a fixed ring 2 and a rotating ring 3 turnably set to be coaxial with the fixed ring 2, and a gap 4 is formed between the rings 2 and 3. A belt-like aperture 31 communicating with the gap 4 is formed on the ring 3, and a cover body 33 is attachably/detachably attached to the aperture 31. The rotational amount detecting means 5 detecting the rotational amount of the ring 3 with reference to the ring 2 is set in the gap 4 near the aperture 31. The detecting means 5 is constituted of a circuit board 6, a code disk 7, a connection part 9 connecting them, and a contact member 8 having plural terminals 81 coming in contact with the code disk 7. The circuit board 6 is fixed at the outer periphery part of the ring 2 and the code disk 7 is fixed on the inner surface of the cover body 33 so as to be opposed to the circuit board 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel installed in a camera, for example.

[0002]

2. Description of the Related Art A lens barrel of a camera such as a single-lens reflex camera has a fixed ring fixedly mounted on a camera body or a main body of a lens barrel and a rotary ring rotatably mounted on the outer periphery of the fixed ring. By rotating the rotary ring with respect to the fixed ring, the follower engaging with the cam groove formed in the rotary ring and the lens to which the follower is fixed (or interlocked with the follower) are arranged in the optical axis direction. It is configured to move and focus or zoom (zoom).

In such a lens barrel, a rotation amount detecting means is installed in the gap between the fixed ring and the rotating ring in order to detect the driving amount of the lens, that is, the rotation amount of the rotating ring.

FIG. 6 is a transverse sectional view showing the structure and arrangement of the rotation amount detecting means in the conventional lens barrel 10.
As shown in the figure, the rotation amount detecting means 13 is connected to the flexible circuit board 14 on which an electronic component 15 such as an IC chip is mounted, integrally connected to the flexible circuit board 14, and has a conductive portion and an insulating portion. The flexible plate is provided on the outer peripheral surface of the fixed ring 11 located inside, which has a cord plate 16 in which parts are arranged in a predetermined pattern, and a contact member (brush) 17 having a plurality of terminals that come into contact with the cord plate 16. The circuit board 14 and the code plate 16 are fixed, and the contact member 17 is fixed so as to project inward at a position facing the code plate 16 of the rotating ring 12 located outside. Ring 12
When is rotated, the contact member 17 slides along the code plate 16, and the code of the code plate 16 provides a signal corresponding to the rotation amount of the rotary ring 12.

However, in such a conventional lens barrel 10, the flexible circuit board 14 and the code plate 16 are provided.
Has an opening angle θ ₁ of 170 to 18 on the outer peripheral surface of the fixed ring 11.
Since they are arranged in an angle range of about 0 °, there is a problem that a wide installation space is required. So, for example,
The motor and gears for transmitting the driving force have to be arranged at other places, which has been a cause of increasing the size of the lens barrel.

Further, in the conventional lens barrel 10, the rotation amount detecting means 13 must be installed before the fixed ring 11 and the rotary ring 12 are assembled, and the fixed ring 11 and the rotary ring 12 are also connected to each other. Once assembled, the rotation amount detection means 13 could not be inspected, adjusted, repaired, replaced, etc. (maintenance) unless they were disassembled, which was inconvenient.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the installation space of the rotation amount detecting means and to downsize it, and to inspect, adjust, repair, and rotate the rotation amount detecting means.
It is to provide a lens barrel that can be easily replaced.

[0008]

These objects are achieved by the present invention described in (1) to (4) below.

(1) An inner cylinder and an outer cylinder which are installed with a predetermined gap and rotate coaxially relative to each other, and an optical axis associated with the relative rotation of the inner cylinder and the outer cylinder. At least one lens that moves in a direction, and a rotation amount detection unit that detects a relative rotation amount between the inner cylindrical body and the outer cylindrical body, and the rotation amount detection unit is a circuit in which electronic components are arranged. A substrate, a code plate, and a contact member having a plurality of terminals that come into contact with the code plate, wherein the circuit board and the code plate are respectively the outer peripheral portion of the inner cylinder and the outer cylinder. A lens barrel, wherein the lens barrel is fixed to one and the other of the inner peripheral portions so as to face each other with the gap therebetween.

(2) The outer cylinder has an opening communicating with the gap, and a lid detachably installed so as to close the opening, and one of the circuit board and the code plate is The lens barrel according to (1) above, which is fixed to the inner surface of the lid.

(3) The lens barrel according to (1) or (2), wherein the circuit board and the code plate are connected via a flexible connecting portion.

(4) The lens barrel according to any one of (1) to (3), wherein the contact member is provided on the circuit board at a position facing the code plate.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The lens barrel of the present invention will be described below in detail with reference to the preferred embodiments shown in the accompanying drawings.

1 and 2 are a horizontal sectional view and a vertical sectional view, respectively, showing a first embodiment of a lens barrel of the present invention.
FIG. 3 is a development view showing the configuration of the rotation amount detecting means, and FIG.
It is a perspective view which shows the structure by the side of the inner surface of a cover body.

As shown in FIGS. 1 and 2, the lens barrel 1A of the present invention includes a lens barrel body 18, a fixed ring (inner cylinder body) 2 fixedly installed in the lens barrel body 18, The fixed ring 2
And a rotating ring (outer cylinder body) 3 rotatably and coaxially installed.

As shown in FIG. 2, inside the fixed ring 2,
The lens 29 is supported so as to be movable in the optical axis direction. That is, the lens 29 is supported and fixed to the lens support member 28, the lens support member 28 is inserted inside the annular member 25 via the helicoid 27, and further, the base end side of the annular member 25 (see FIG. 2 in the right side) is inserted inside the fixed ring 2 via the helicoid 26.

A guide member 251 is formed on the outer peripheral portion of the tip end side (left side in FIG. 2) of the annular member 25, and the guide member 251 is formed in the inner peripheral portion of the rotary ring 3 and is a straight guide groove 3.
It is inserted in 7.

A guide member 24 is fixed to the base end side of the lens support member 28, and the guide member 24 is inserted into a straight guide groove 23 formed on the base end side of the fixed ring 2.

The lens barrel body 18 is provided with a gear block (shown by a chain double-dashed line in FIG. 2) 19 for transmitting the rotational force of a motor (not shown) to the rotary ring 3, and the gear block 19 is provided.
The rack gear 38 of the rotary ring 3 meshes with the output-side gear of the gears constituting the.

When the gear of the gear block 19 is rotationally driven, the rotary ring 3 rotates in a predetermined direction, and the annular member 25 also rotates in the same direction accordingly. The annular member 25 moves in the optical axis direction of the lens 29 with the rotation due to the action of the helicoid 26. The movement of the annular member 25 is transmitted to the lens support member 28 via the helicoid 27. Since the movement direction of the support member 28 is regulated by the straight guide groove 23, the lens support member 28 and the lens 29 supported thereby are moved by the movement of the annular member 25.
It moves in the optical axis direction.

As shown in FIG. 1, a predetermined gap 4 is formed between the fixed ring 2 and the rotary ring 3. In addition, at a predetermined portion of the rotary ring 3, along the circumferential direction thereof, the gap 4 is formed.
A strip-shaped opening 31 that communicates with is formed. A lid 33, which is formed in substantially the same shape as the opening 31 so as to close the opening 31, is detachably attached to the opening 31.

A step portion 32 is formed at each of both ends of the opening 31, while a lid portion 33 is provided at each of both ends thereof.
Locking portions 34 that lock with the step portions 32 are formed respectively. The lid 33 is inserted into the opening 31, and the corresponding step portion 32 and the engaging portion 34 are engaged with each other, and this portion is fixed from the outer peripheral surface side of the rotary ring 3 by a fixture such as a screw (not shown). .

A rotation amount detecting means 5 for detecting the rotation amount of the rotary ring 3 with respect to the fixed ring 2 is installed in the gap 4 near the opening 31.

The rotation amount detecting means 5 is, as shown in FIG.
A flexible circuit board (FPC) 6, a code plate 7 for carrying predetermined information, and a contact provided on the circuit board 6 and having three terminals 81 contacting the code plate 7 formed at the tips thereof. And a member (brush) 8. In this case, the circuit board 6 and the code plate 7 are integrally formed via the thin plate-shaped connecting portion 9. The connecting portion 9 has flexibility and can be easily bent and deformed into, for example, a semicircular arc shape.

Electronic components such as an IC chip 61, a diode 62, and a resistor / capacitor 63 are mounted on the circuit board 6 in a desired arrangement.

The code plate 7 has a conductive portion 71 and an insulating portion 72.
Are formed in a predetermined arrangement, and when each terminal 81 of the contact member 8 slides along the longitudinal direction of the code plate 7, each terminal 81 is electrically connected to the code plate 7 depending on its position. State or non-conduction state.

The rotation amount detecting means 5 is arranged as shown in FIG. That is, a pair of flatly shaped fixing surfaces 21 and 22 are formed on the outer peripheral portion of the fixed ring 2 at a position facing the opening 31, and the circuit board 6 has one end side and the other end side fixed, respectively. Surface 21,
It is adhesively fixed to both fixing surfaces 21 and 22 so as to be located on 22.

On the other hand, the code plate 7 is detachably fixed to the inner surface (back surface) of the lid 33 in a state of being folded back 180 °. That is, as shown in FIG. 4, a pair of claw portions 35 facing each other is formed at one end portion on the inner surface side of the lid 33, and the base end portion (on the connection portion 9 side) of the cord plate 7 is
It is sandwiched by both claws 35, and the tip of the code plate 7 is fixed to the inner surface of the lid 33 by a pin 36. As a result, when the lid 33 is mounted in the opening 31, the circuit board 6 and the code plate 7 face each other with the gap 4 interposed therebetween.

The contact member 8 installed on the circuit board 6 is
The cord 81 faces the cord plate 7 fixed to the inner surface of the lid 33, and each terminal 81 thereof is pressed by the cord plate 7 and is in contact with the cord 81 by being biased by a spring part in the middle. Further, the connecting portion 9 that connects the circuit board and the code plate 7 crosses the gap 4 while being curved in a semi-circular shape.

As shown in FIG. 1, the rotation amount detecting means 5 is
In the gap 4 between the fixed ring 2 and the rotary ring 3, the opening angle θ ₂ is within an angle range of, for example, about 90 to 110 °, and compared with the conventional lens barrel 10, the installation space for the rotation amount detecting means 5 is set. Can be reduced.

In the lens barrel 1A, when the rotary ring 3 is rotated in a predetermined direction, the terminals 81 of the contact member 8 slide along the longitudinal direction of the code plate 7 in accordance with the rotation of the rotary ring 3 and the terminals 81 and the cord. The position of the contact member 8 on the code plate 7, that is, the rotation amount of the rotary ring 3 is detected by a combination of conduction and non-conduction with the plate 7. At this time, with the rotation of the rotary ring 3, the connecting portion 9 maintains a curved and deformed state,
The state shown by the one-dot chain line in FIG. 1 is displaced to the state shown by the solid line.

To assemble the lens barrel 1A, first, the fixed ring 2 and the rotary ring 3 are assembled, then the rotation amount detecting means 5 is inserted through the opening 31, and the circuit board 6 is fixed to the fixed surface 21 of the fixed ring 2. , 22 and attach the code plate 6 to 18
The process is performed by folding back at 0 ° and fixing to the inner surface of the lid 33, and finally attaching the lid 33 to the opening 31 and fixing with a screw or the like.

Also, when inspecting, adjusting, repairing, or replacing (maintenance) the rotation amount detecting means 5 at various places, the fixed ring 2 and the rotating ring 3 are not disassembled. The lid 33 may be removed.

FIG. 5 is a cross sectional view showing a second embodiment of the lens barrel of the present invention. The lens barrel 1B shown in FIG.
The lens barrel 1A is the same as the lens barrel 1A except that the configuration of the rotation amount detecting means 5 and the structure of the lid 33 on the inner surface side are different.

That is, in the rotation amount detecting means 5 in the lens barrel 1B, the circuit board 6 and the code plate 7 are separated (without the connecting portion 9), and the circuit board 6 is the outer circumference of the fixed ring 2. The cord plate 7 is adhesively fixed to the fixing surfaces 21 and 22 formed on the portion, and the code plate 7 is adhesively fixed to the inner surface of the lid 33. Then, each terminal 81 of the contact member 8 installed on the circuit board 6 is pressed against and in contact with the code plate 7.
Since the code plate 7 is fixed to the inner surface of the lid 33 by adhesion, the claw portion 35 and the pin 36 are not provided on the inner surface of the lid 33.

In the lens barrel 1B, the curved connecting portion 9
Does not require a space for moving, the installation space of the rotation amount detecting means 5 is further reduced. Further, also in such a lens barrel 1B, assembling and maintenance can be easily performed in the same manner as described above.

In the lens barrels 1A and 1B, the purpose of detecting the rotation amount of the rotary ring 3 by the rotation amount detecting means 5 is:
There is no particular limitation, and examples thereof include detection of the lens drive amount for focusing, detection of the zoom lens drive amount during zooming, and the like.

The lens barrel of the present invention has been described above based on the illustrated embodiments, but the present invention is not limited to these.

For example, in each of the above embodiments, the inner tubular body is the fixed ring and the outer tubular body is the rotary ring, but conversely, the inner tubular body may be the rotary ring and the outer tubular body may be the fixed ring. Further, the circuit board may be fixed to the inner peripheral surface of the outer cylindrical body, and the code plate may be fixed to the outer peripheral surface of the inner cylindrical body.

[0040]

As described above, according to the lens barrel of the present invention, it is possible to reduce the installation space of the rotation amount detecting means, and as a result, the installation space of other parts such as the motor and gear. This can be ensured, and the lens barrel can be downsized.

In particular, when a lid which is detachably attached to the opening formed in the outer cylindrical body is provided, the lens barrel is assembled, the rotation amount detecting means is inspected, adjusted and repaired.
Exchange and the like can be easily performed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of a lens barrel of the present invention.

FIG. 2 is a longitudinal sectional view showing a first embodiment of the lens barrel of the present invention.

FIG. 3 is a development view showing a configuration of a rotation amount detecting means in the present invention.

FIG. 4 is a perspective view showing a configuration of an inner surface side of a lid according to the present invention.

FIG. 5 is a cross-sectional view showing a second embodiment of the lens barrel of the present invention.

FIG. 6 is a cross-sectional view showing the configuration of a conventional lens barrel.

[Explanation of symbols]

 1A, 1B Lens barrel 18 Lens barrel main body 19 Gear block 2 Fixed ring (inner cylinder) 21, 22 Fixed surface 23 Straight guide groove 24 Guide member 25 Annular member 251 Guide member 26, 27 Helicoid 28 Lens support member 29 Lens 3 Rotating ring (outer cylinder) 31 Opening 32 Step portion 33 Lid body 34 Locking portion 35 Claw portion 36 Pin 37 Straight guide groove 38 Rack gear 4 Gap 5 Rotation amount detecting means 6 Circuit board 61 IC chip 62 Diode 63 Resistance / capacitor 7 Code plate 71 Conductive part 72 Insulating part 8 Contact member 81 Terminal 9 Connection part 10 Lens barrel 11 Fixed ring 12 Rotating ring 13 Rotation amount detecting means 14 Flexible circuit board 15 Electronic component 16 Code plate 17 Contact member

Claims (4)

[Claims] 1. An inner cylindrical body and an outer cylindrical body, which are installed with a predetermined gap and rotate relative to each other coaxially, and an optical axis direction with relative rotation of the inner cylindrical body and the outer cylindrical body. At least one lens that moves to the inner side, and a rotation amount detection unit that detects a relative rotation amount between the inner cylindrical body and the outer cylindrical body. The rotation amount detection unit is a circuit board on which electronic components are arranged. And a code plate, and a contact member having a plurality of terminals that come into contact with the code plate, wherein the circuit board and the code plate are inside the outer peripheral portion of the inner cylindrical body and the outer cylindrical body, respectively. A lens barrel, wherein the lens barrel is fixed to one and the other of the peripheral portions so as to face each other with the gap therebetween. 2. The outer cylindrical body has an opening communicating with the gap, and a lid body detachably installed so as to close the opening, and one of the circuit board and the code plate is
The lens barrel according to claim 1, which is fixed to an inner surface of the lid. 3. The lens barrel according to claim 1, wherein the circuit board and the code plate are connected via a flexible connecting portion. 4. The lens barrel according to claim 1, wherein the contact member is provided on the circuit board at a position facing the code plate.