JPH07151948A - Lens barrel - Google Patents

Abstract

PURPOSE:To unnecessitate a holding plate for mounting a flexible printed board, to improve mounting position accuracy and to reduce the product cost in a lens barrel in which the flexible printed board mounting an electrical element is attached. CONSTITUTION:This lens barrel has a resin fixed barrel 3 obtained by integrally molding plural groups so as to be a polygon shape when two or more plate-like projecting parts 3c forming a part of a plate whose end surface 3d is in parallel with an axial line are at least made as a group, and the flexible printed board 15 being bent in the polygon shape and where the electrical element is mounted at a planar part 15g; and the flexible printed board is attached to the fixed barrel 3 by making the planar part 15g of the flexible printed board 15 to be along the planar part 47 where the end surface 3d of the plate-like projecting part 3c forms a part of it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel for cameras, video cameras and the like, and more particularly to a lens barrel to which a flexible printed circuit board (flexible wiring board) on which electric elements are mounted is attached.

[0002]

2. Description of the Related Art Conventionally, in order to arrange electric parts in a lens barrel of a video camera, etc., electric elements are densely mounted on a doughnut-shaped hard substrate having a hole through which a light beam passes. This hard substrate is attached near the mount of the fixed cylinder. Further, in a lens barrel having a large mounting scale such as a large-diameter lens and a high-magnification zoom, a flexible printed circuit board on which electric elements are mounted is bent in a polygonal shape and wound around a fixed cylinder to be mounted.

In order to mount the flexible printed circuit board on a cylindrical fixed cylinder, a thin metal plate is bent at several places, and a flexible printed board having electric elements mounted on a polygonal holding plate having a plurality of flat portions. After the substrate is attached with double-sided tape or the like, this holding plate is attached to the outer periphery of the fixed cylinder and fixed with screws or the like. At that time, the flexible printed circuit board is arranged such that the surface on which the electronic element is mounted matches the flat surface portion of the holding plate.

In Japanese Utility Model Application Laid-Open No. 63-107431, a flexible printed circuit board is provided with a flat surface on a protruding portion of a frame body so that a pad for writing information is brought into contact therewith. The holding plate for keeping the flat surface is abolished.

Further, in the one disclosed in Japanese Utility Model Laid-Open No. 63-109912, when a flexible printed board is bent, a protruding dowel provided on a frame is used for positioning, and the flexible printed board is attached to the dowel. The fitting hole is caught so that the bent state can be maintained to some extent.

[0006]

However, in the conventional example in which the flexible printed circuit board is wound around and fixed to the outer periphery of the fixed cylinder, in order to maintain the state in which the flexible printed circuit board is bent in a polygonal shape having a plane portion, It is necessary to fix it to a metal holding plate bent in a polygonal shape. This metal plate becomes more expensive as the number of times of bending increases, and recently, the number of electric elements required due to multifunctional functions such as power zoom and camera shake correction increases, and the mounting area tends to increase.

Therefore, the holding plate needs to have a large mounting area, and not only the cost of the holding plate itself but also the die cost for making the holding plate is high, and the cost of the product itself using the holding plate is high. There was a problem that it became something like that.

Further, in the conventional example in which the flat surface is provided on the protruding portion of the frame body on which the flexible printed circuit board is arranged, the position where the flat surface is provided is limited. There is a problem in that only a flat area having a small area can be formed with respect to the area of the plane section, and the holding of the flexible printed circuit board becomes unstable.

Further, in the conventional example in which the flexible printed circuit board is maintained in the bent state by the dowel provided on the frame, the flexible printed circuit board is stably maintained due to the difference in diameter between the fitting hole of the flexible printed circuit board and the dowel. Therefore, it is difficult to arrange electric components in high density, and when moving parts are in the vicinity, problems such as interference may occur.

An object of the present invention is to obtain a lens barrel that solves the above problems.

[0011]

According to the invention of claim 1, the end face has a polygonal shape with at least two plate-like protrusions forming a part of a plane parallel to the axis. A flat portion in which a plurality of groups are integrally molded and made of a resin, and a flexible printed circuit board that is bent in a polygonal shape and an electric element is mounted on the flat portion, and the end face of the plate-like protruding portion forms a part Since the flexible printed circuit board is attached to the fixed cylinder along the plane portion of the flexible printed circuit board, no holding plate for holding the flexible printed circuit board is required. Therefore, the product cost can be reduced. In addition, since the flexible printed circuit board is supported by the plate-shaped protruding part, it is possible to support the flat part of the flexible printed circuit board in an appropriate place without worrying about the wall thickness of the molded component, thus improving the stability of support. To do.

According to the second aspect of the present invention, the flexible printed circuit board has a connection means for electrically connecting the components of the control circuit and / or an adjustment means for adjusting the control characteristic. By arranging the connecting means and the adjusting means on the end face of the plate-like protrusion, even if an external force is applied to the flexible printed circuit board by connecting the connector or adjusting the semi-fixed resistor in the assembly process, Since the end face of the plate-like projecting portion as a force receiving member is located in the lower portion thereof, the flexible printed circuit board is not damaged.

According to the third aspect of the present invention, a protrusion for mounting and positioning the flexible printed circuit board is formed on the end face of the plate-shaped protruding portion, and the flexible printed circuit board is attached to the fixed cylinder or the plate-shaped protruding portion. By forming the locking means for stopping, it is possible to prevent the flexible printed circuit board from peeling and falling due to the repulsive force.

[0014]

【Example】

Example 1. Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show Embodiment 1 of the present invention. FIG. 1 is a cross-sectional view of a lens barrel and a cross-sectional view taken along the line AA of FIG.

In FIGS. 1 and 2, reference numeral 1 is an outer cylinder,
A mount 2 for mounting on a camera body (not shown) is fixed to the end surface of the outer casing 1 with screws 41.
Reference numeral 3 denotes a fixed cylinder fitted inside the outer cylinder 1,
It is fixed to the flange portion of the with screws 42. Reference numeral 4 denotes a first group lens barrel holding the optical lens L1, and the first group lens barrel is screwed and fixed to a screw 3i on the inner side of the front end of the fixed barrel 3 by a screw 4a.

Reference numeral 5 denotes a third group lens barrel holding an optical lens L3, and this third group lens barrel 5 is a flange portion 3j of the fixed barrel 3.
It is fixed by screws 44. Reference numeral 6 denotes a cam barrel which is rotatably held on the outer circumference of the fixed barrel 3, and cam grooves 6a are arranged in the cam barrel 6 at three equal portions in the circumferential direction. Reference numeral 7 denotes a second group lens barrel which holds the optical lens L2, and the second group lens barrel 7 has three rollers 7a in the outer circumferential direction.
I have it in my place.

The roller 7a is formed in the cam groove 6 of the cam barrel 6.
a, and the fixed barrel 3 is engaged with the straight-moving grooves 3a provided at three equal portions in the optical axis direction. As a result, by rotating the cam barrel 6, the second group lens barrel 7 moves in the optical axis direction, and focus adjustment is performed. In FIG. 1, the upper side of the center line O is an infinite position, and the lower side is the closest position.
Shows the state of movement.

Reference numeral 8 denotes a focus adjusting motor. The motor 8 is fixed to a gear base plate 9 with screws (not shown), and the gear base plate 9 is fixed to the fixed barrel 3 with screws 45. 10 is a gear train for transmitting the torque of the motor 8,
The gear 10a at the final stage meshes with a gear portion 6b provided on the outer periphery of the rear portion of the cam barrel 6.

Reference numeral 11 denotes a focus ring rotatably held by the fixed barrel 3 and the outer barrel 1, and 12 a switch for switching between automatic focus adjustment and manual focus adjustment. This switch 12 is movable in the optical axis direction. The clutch plate 13 is held by the outer cylinder 1, and the clutch plate 13 is screwed inside the outer cylinder 1.
It is fixed at.

The front end of the clutch plate 13 is the gear 10 described above.
a is held freely rotatable and immovable in the optical axis direction, and by switching the switch 12, the gear 10a is moved in the optical axis direction, the cam barrel 6 is engaged with the gear train 10, and automatic focus adjustment by a motor is performed. Or a manual focus adjustment is performed by engaging the cam barrel 6 with a gear portion 11a provided on the inner circumference of the focus ring 11.

Reference numeral 14 is a known electromagnetic diaphragm unit fixed to the fixed barrel 3 by screws (not shown), and 15 is a flexible printed circuit board. The flexible printed circuit board 15 has the focus adjusting motor 8 and the electromagnetic diaphragm unit 14 described above. The control circuit and the electric element 15a are arranged. The flexible printed circuit board 15 has a connection part 1 at the rear part.
5b is extended, and the tip of the connecting portion 15b is electrically connected to the contact part 16 fixed to the mount 2.

Then, the contact part 16 and the connecting portion 15b.
Communication with the camera body and power supply from the camera body are performed via the. Further, the lead wire 8a of the focus adjusting motor 8 is electrically connected to the control circuit on the flexible printed circuit board 15 by soldering 43, as shown in FIG.

A connection terminal 14a for a flexible printed board 15 is attached to the electromagnetic diaphragm unit 14,
It is guided to the rear side of the camera body via the notch 3b of the fixed barrel 3. The connecting terminal 14a is attached to the guide component 17 attached to the fixed barrel 3 with the screw 48 with a double-sided tape to prevent interference with other moving components, and its tip is mounted on the flexible printed circuit board 15. It is connected to 15c.

FIGS. 3 and 4 are perspective views showing the structure of the flexible printed circuit board mounting portion of the fixed barrel 3, and the small diameter portion of the fixed barrel 3 formed of a polycarbonate resin that fits inside the exterior barrel 1. The outer peripheral surface of 3-1 includes a plurality of ribs 3c, which are at least two plate-like protrusions whose end faces form a part of a plane parallel to the axis O, and have a polygonal shape (see FIG. In the example shown, 4 groups) are integrally molded.

End face 3d of rib 3c forming each of the above groups
Are in the same plane, and the ribs 3c of each group are
On the plane 47 formed by the end face 3d of the electronic device 1
The plane portion 15g of the flexible printed circuit board 15 on which 5a is mounted is bent in a polygonal shape and attached.

At the time of this attachment, first, the rib end surface 3d
The fitting holes 15d of the flexible printed circuit board 15 and the long holes 1 are formed in the dowels 3e and 3f as positioning protrusions provided on the
Positioning is performed through 5e, and one flat surface portion 15g is attached and fixed to the flat surface 47 with a double-sided tape. Next, the flexible printed board 15 is wound while being pulled, and the plane portions 15g are sequentially attached to the plane 47.

Finally, as shown in FIG. 4, the slope 3 of the claw 3g as a locking means provided between the ribs 3c of the fixed barrel 3.
The engaging hole 15f of the flexible printed circuit board 15 is hooked on h and fixed with double-sided tape. At this time, the resin claw 3
Using the restoring force generated when g is deformed, claw 3g
By pulling the flexible printed circuit board 15 with, it is possible to prevent the printed circuit board from peeling off from the fixed cylinder 3.

Generally, when the fixed barrel 3 is molded with resin, a straight groove, a cam groove, a roller mounting seat, etc. are often formed at three equally spaced positions on the outer periphery, and the mold structure is divided in the optical axis direction. In addition to the die, a die that divides into three or six diametrical directions, a so-called outer diameter slide die, is often used.

The fixed cylinder 3 in this embodiment includes ribs 3c,
Both the dowel 3e and the claw 3g can be integrally molded with the fixed cylinder 3 by an outer diameter slide type. Further, by using this fixed cylinder 3, there is no need for a metal holding plate or a member for preventing peeling, and the flexible printed circuit board can be reliably held with an inexpensive structure.

Further, a land for connecting the lead wire 8a of the focus adjusting motor 8 and a connector 15c for connecting the connection terminal 14a of the electromagnetic diaphragm unit 14 are arranged at positions where they abut on the end surface 3d of the rib 3c. As a result (see FIG. 1), the rib 3c can receive the force applied to the flexible printed circuit board 15 due to the soldering or the connector connection during the assembly work, and the deformation or damage of the flexible printed circuit board 15 can be prevented.

Example 2. FIG. 5 shows the second embodiment of the present invention and is an exploded perspective view showing only the fixed cylinder 30 and the flexible printed circuit board 31 including the control circuit. A rib 30a extending in the circumferential direction and a rib 3 extending in the optical axis direction connecting the ribs to the small diameter portion 30-1 of the resin-molded fixed cylinder 30.
0b and 30c are integrally molded, and these ribs 30a
A flat surface portion 30d is formed by the end faces of 3c.
A dowel 30e for positioning the flexible printed board 31 is provided on an end surface of the rib 30a, and a fitting hole 31a is provided in the flexible printed board 31.

In the second embodiment having the above-mentioned structure, after the dowels 30e are fitted in the fitting holes 31a, both ends of the flat surface of the flexible printed circuit board are bent.
It is fixed by a screw 32 to a mounting wall 30f provided on the rib 30b. Therefore, the attachment and the fixing are reliable. In addition, a connector 3 for connecting the electromagnetic diaphragm unit 14
3 is arranged so as to come on the rib 30c to receive an external force at the time of connection.

[0033]

As described above, according to the first aspect of the invention, at least two or more plate-like protrusions whose end faces form part of a plane parallel to the axis line are formed on the outer periphery of the resin-made fixed cylinder. Groups are formed integrally with each other so as to form a polygonal shape, and the flat portion of each group is arranged so that the flat portion of the flexible printed circuit board is arranged along the flat portion of the flexible printed circuit board. Since a holding plate for holding the flexible printed circuit board is not necessary, it is possible to improve the mounting position accuracy of the flexible printed circuit board and reduce the product cost. In addition, since the flexible printed circuit board is supported by the end of the plate-shaped protruding portion, it is possible to support the flexible printed circuit board at a suitable position on the flat surface portion without worrying about the wall thickness of the molded component, and stable support is achieved. You can improve the property.

According to the second aspect of the present invention, the flexible printed circuit board has a connecting means for electrically connecting the components of the control circuit and / or an adjusting means for adjusting the control characteristic. Since the means and the adjusting means are positioned on the end face of the plate-like protrusion, even if an external force is applied to the flexible printed circuit board such as connecting the connector or adjusting the semi-fixed resistor in the assembly process, the force is not The flexible printed circuit board is not damaged because it is received by the end face of the plate-like protrusion.

According to the third aspect of the present invention, a protrusion for mounting and positioning the flexible printed circuit board is provided on the end face of the plate-like protrusion formed on the outer periphery of the fixed cylinder, and the fixed cylinder or the plate-like protrusion has the above-mentioned protrusion. Since the locking means for locking the flexible printed circuit board is provided, the assembling property is improved, and the flexible printed circuit board can be prevented from coming off due to the repulsive force caused by bending.

[Brief description of drawings]

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

2 is a cross-sectional view taken along the line AA of FIG.

FIG. 3 is a perspective view of a fixed cylinder for explaining attachment of the flexible printed circuit board.

FIG. 4 is an enlarged perspective view of a main part of a fixed cylinder showing a mounting end portion of a flexible printed circuit board.

FIG. 5 is an enlarged perspective view of a main part of a fixed barrel showing a second embodiment of the present invention.

[Explanation of symbols]

 3 Fixed Tube 3c Plate-like Projection 3e, 3f Mounting Positioning Protrusion 3g Locking Means 15 Flexible Printed Circuit Board (Flexible Wiring Board) 15a Electric Element 15g Flat Surface 47 Flat Surface

Claims (3)

[Claims] 1. A fixed cylinder made of resin integrally formed with a group of at least two plate-like projecting portions whose end faces form a part of a plane parallel to the axis and which has a polygonal shape. A flexible printed circuit board that is bent in a polygonal shape and has an electric element mounted on a flat surface portion, and the flat surface portion of the flexible printed circuit board is arranged along the flat surface portion where the end face of the plate-like protrusion forms a part. A lens barrel, wherein a flexible printed circuit board is attached to the fixed barrel. 2. The flexible printed circuit board has a connecting means for electrically connecting the components of the control circuit and / or an adjusting means for adjusting the control characteristics, and the connecting means and the adjusting means are provided. The lens barrel according to claim 1, wherein the lens barrel is located on an end surface of the plate-like protrusion. 3. A protrusion for mounting and positioning the flexible printed circuit board is formed on an end surface of the plate-shaped protrusion, and a locking means for locking the flexible printed circuit board is formed on the fixed cylinder or the plate-shaped protrusion. The lens barrel according to claim 1, wherein: