JPH05152701A - Connection structure of flexible printed wiring board - Google Patents

Abstract

PURPOSE:To realize connector connection excellent in assembling workability at a low cost without necessitating a reinforcing sheet, by a method wherein a pattern part for connector connection is folded back and the insertion part of a flexible printed board into the connector is made double. CONSTITUTION:A plurality of terminal patterns 9 for connector connection are formed on one end side of a flexible printed board 8 of connection side. A stretched part 8a is formed on the further end side of the terminal patterns 9. At the time of connector connection, the stretched parpt 8a is folded back on the side opposite to the surface on which the terminal patterns 9 are formed, and the printed board is connected with a connector. Thereby necessary contact pressure can be ensured without sticking a reinforcing sheet serving as a spacer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible printed wiring board connection structure, and more particularly to a connection structure between a flexible printed wiring board and a connector.

[0002]

2. Description of the Related Art In recent years, miniaturization and multi-functionalization have progressed also in the field of electronic equipment, and accordingly, it has become an important issue to efficiently connect many internal wirings in a small space. ..

As a measure against this problem, a method of connecting printed circuit boards to each other using a connector is generally known.

The connection method using a connector has a large merit in size reduction and efficiency improvement because the area of the connection portion occupying the printed wiring board is smaller and the work is easier than the connection method using soldering.

8 and 9 are drawings showing a general conventional example, FIG. 8 is a perspective view of a flexible printed wiring board on a connection side, and FIGS. 9A and 9B show a connection method and a connection state. FIG. In the figure, reference numeral 1 is a flexible printed wiring board on the connection side, and a plurality of terminal patterns 2 for connector connection are formed on one end side thereof. Further, the terminal pattern 2 in the flexible printed wiring board 1
The reinforcing plate 3 is attached to the surface opposite to the surface on which is formed. Reference numeral 4 denotes a printed wiring board on the connected side, on which a connector including a housing 5, a contact piece 6 and a slider 7 is mounted. In the connection method having the above-described structure, first, the slider 7 is pulled out from the housing 5 (see FIG.
In (a), the flexible printed wiring board 1 is inserted into the housing 5 of the connector, and then the slider 7 is attached to the housing 5.
By pushing in, the plurality of terminal patterns 2 are pressed against the plurality of corresponding contact pieces 6 and are electrically connected. At this time, the reinforcing plate 3 is connected to the terminal pattern 2 and the contact piece 6.
It plays the role of a spacer to secure the contact pressure with.

On the other hand, as another conventional example of such a connection structure, there is one as shown in the drawings.
1 will be described. 10 and 11 are views showing a conventional lens barrel, FIG. 10 is a part of a vertical cross section of the lens barrel, and FIG. 11 is a diagram showing an outer shape of a printed wiring board.

Reference numeral 21 is a claw portion 2 for connecting to the camera body.
1a is a mount, and 22 is a main body (fixed cylinder) fixed to the mount 21 by screws 23, which extends to the front of the lens and forms a fixed portion for a zoom mechanism or a focus mechanism (not shown). Reference numeral 24 denotes a contact member for making electrical communication between the camera body and the lens by contacting the electrical contact protruding from the camera body when the mount 21 is mounted on the camera body.
It is fixed by screws 25. Reference numeral 26 is a ring-shaped hard printed wiring board on which a microcomputer 27 and other electric parts (not shown) are mounted to form an electric circuit, which is sandwiched between the mount 21 and the main body 22 and is orthogonal to the optical axis. It is located in a position. A flexible printed board 28 serves to electrically connect the contact member 24 and the hard printed wiring board 26.

A connector 29 is mounted on the surface of the rigid printed wiring board on the mount 21 side. Reference numeral 30 denotes a flexible printed board, one end of which is inserted into a connector, and the other end of which is pasted on the outer periphery of the fixed cylinder 22 beyond the hard printed wiring board 26 in an arc shape, and focal length detection together with signal generating means (not shown). Configure the device.

Reference numeral 31 is an exterior ring, which is held by sandwiching a convex portion 31a protruding inwardly between the mount 21 and the main body 22. On the back surface of the flexible printed board 30, a reinforcing plate 30a is attached, which has a function of reinforcing the connector when inserting the connector and also having a role of making the thickness necessary to secure the contact pressure of the connector contact piece. Reference numeral 32 denotes a back lid, which is fixed by elastically engaging the claw portion 32a with the mount 21.
Reference numeral 33 denotes an autofocus drive unit that constitutes an autofocus mechanism, and is arranged so as to occupy a part of the phase around the optical axis of the lens barrel.

The substrate area S in this conventional example is π (B ²
It is -A ^2). (However, B is the outer radius of the substrate, and A is the inner radius.) As another conventional example, there is a lens barrel configured as disclosed in, for example, JP-A-1-66991.

[0011]

However, in the conventional example shown in FIGS. 8 and 9, (i) since a reinforcing plate as a spacer is required to secure the contact pressure, the manufacturing process of the flexible printed wiring board is complicated. And the cost will be high.

(Ii) Since the contact piece and the terminal pattern are only on one side and need to be connected in a state of facing each other, the shape of the flexible printed wiring board becomes complicated in order to match the front and back sides of the flexible printed wiring board. However, there are problems such as an increase in cost and a decrease in assembly workability.

Further, in the conventional example shown in FIGS. 10 and 11, since electric components are mounted on one rigid printed wiring board,
There is a limitation on the mounting area, and there are the following problems.

(A) That is, since the outer diameter of the annular disk is regulated by the inner diameter of the fixed cylinder and the inner diameter is regulated by the outer diameter of the back cover, the diameter of the fixed cylinder is increased if the mounting area is increased. It is immediately linked to the enlargement of the lens by increasing the diameter and the reduction of the peripheral light amount or the reduction of the diameter by decreasing the diameter of the back cover.

(B) Further, since the difference between the inner and outer diameters is limited, the size of a relatively large component such as a microcomputer is also limited, which is a great limitation in improving the camera function.

(C) There are restrictions on the components to be mounted on the mount side surface of the rigid printed wiring board 26. In other words, when arranging parts on the mount side surface, it is necessary to arrange them in a position that avoids interference with the mount (close to the inner diameter side), and mount relatively large parts such as a microcomputer. It is impossible to do so, which leads to deterioration of wiring efficiency. Further, even if the connector is arranged, the flexible printed board is forcibly bent in the immediate vicinity of the insertion port, so that the boundary between the part where the reinforcing plate 10a is attached and the part where it is not attached is markedly different in strength. Since stress is concentrated and the pattern is easily broken, there is a problem in reliability. If the whole unit is easily shifted away from the mount in order to solve these problems, the space for the art focus drive unit will be pressed.

Accordingly, it is an object of the present invention to provide an improved flexible printed wiring board connection structure capable of solving the above-mentioned problems of the conventional example.

[0018]

In order to achieve the above object, a flexible printed wiring board connecting structure according to the present invention is a flexible printed wiring board-connector connecting structure, wherein a connector is connected to a tip of the flexible printed wiring board. And a connector pattern portion is provided, and the connector connection pattern portion is folded back to double the insertion portion of the flexible printed wiring board into the connector. A connector connection pattern portion is provided at the tip of the flexible printed wiring board for fixing the connector to a printed wiring board that is inclined with respect to the plane orthogonal to the axis and has an opening for shooting light, and is connected to the connector. Is provided, and the connector connecting pattern portion is folded and inserted into the connector.

When the present invention is applied to a lens barrel, a printed wiring board on which electric parts are mounted and which forms an electric circuit is arranged so as to be inclined with respect to a plane perpendicular to the optical axis, and the shape is such that a light beam is avoided. By arranging in such a manner, the problems in the conventional lens barrel can be solved. Therefore, according to the present invention, it is possible to provide a lens barrel which is inexpensive, has a good assembling workability, can be downsized while improving the system, and is highly reliable.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 are drawings showing a first embodiment of a connection structure according to the present invention. FIGS. 1 (a) and 1 (b) are perspective views of a connection side flexible printed wiring board, and FIG. 2 is a connection state. Are shown respectively.

Reference numeral 8 is a flexible printed board on the connection side, and a plurality of terminal patterns 9 for connecting the connector are formed on one end side thereof. Further, an extension portion 8a is provided on the further end side of the terminal pattern 9, and when connecting to the connector, the extension portion 8a should be folded back and connected to the side opposite to the surface on which the terminal pattern 9 is provided. Therefore, it is possible to secure the necessary contact pressure without attaching a reinforcing plate that functions as a spacer.

FIG. 3 is a view showing a second embodiment of the connection structure according to the present invention. In the figure, 10 is a flexible printed wiring board, and 11 is a terminal pattern. The reinforcing pattern 1 is provided on the extension 10a of the flexible printed wiring board 10.
0b is formed, which is effective in preventing deformation when folded back and inserted into the connector.

FIGS. 4 and 5 are views showing a third embodiment of the connection structure according to the present invention, and FIGS. 4 (a) to 4 (c).
5 is a perspective view of the connection side flexible printed wiring board, and FIG. 5 shows an example of a connected state. In the figure, 12 is a flexible printed wiring board on the connection side, 12a is an extension of the flexible printed wiring board 12, and in addition to the first terminal pattern 13, there is a second terminal pattern 14 formed on the extension 12a. is doing. When the extension 12a of the flexible printed wiring board 12 is folded back, the first terminal pattern 13 and the second terminal pattern 14 are located on the front and back sides, respectively. Therefore, in addition to the connection state shown in FIG. The connection status is also possible. Therefore, it is possible to connect the flexible printed wiring board 12 regardless of the front and back sides, and it is not necessary to form a complicated shape to match the front and back sides of the flexible printed wiring board 12 and to perform complicated routing, thus improving the assembly workability. be able to. In addition, when diversion of parts to other models, it is possible to reduce restrictions on arrangement.

Although the first and second terminal patterns are provided in this embodiment, it is of course possible to form only the second terminal pattern if not necessary.

Next, with reference to FIGS. 6 and 7, an embodiment in which the present invention is applied to mounting electric parts in a lens barrel of a camera will be described.

FIG. 6 is a part of a vertical cross section of a lens barrel to which the connection structure of the present invention is applied, and FIG. 7 is an external view of a printed wiring board. The same parts as those of the conventional example shown in FIG. 10 are designated by the same reference numerals, and the description thereof will be omitted.

Reference numeral 34 denotes a hard printed wiring board on which a microcomputer 27 and other electric parts (not shown) are mounted to form an electric circuit, and the wiring board 34 forms an angle θ with respect to a plane perpendicular to the optical axis. It is arranged so as to be inclined so as to form an inclined surface. 35 is a flexible printed board,
One end is inserted into the connector, and the other end is pasted on the outer periphery of the fixed cylinder 2 over the hard printed wiring board 34 in an arc shape, and constitutes a focal length detection device together with signal generating means (not shown). On the back surface of the flexible printed board 15, a reinforcing plate 15a is attached, which has a function of reinforcing the connector when it is inserted and having a thickness required to secure the contact pressure of the connector contact piece. The substrate in this embodiment has a shape surrounded by a double ellipse. The long piece of the inner ellipse is C, the short piece is D, the long piece of the outer ellipse is E, the short piece is F, and the optical axis of the substrate. The area is as follows, where θ is the angle of inclination with the plane perpendicular to. (However, it is assumed that the diameter of the fixed cylinder and the back cover are the same as the conventional example.)

[0029]

[Equation 1]

Therefore, the area S'is

[0031]

[Equation 2]

It is The substrate area S in the conventional example is S = π (B ² −A ² ).

[0033]

[Equation 3]

It is In the case of this embodiment, since 0 <θ <90 °,

[0035]

[Equation 4]

It is Therefore, S ′> S, and the substrate area increases in accordance with the tilt angle θ as compared with the conventional example.

Also,

[0038]

[Equation 5]

Therefore, the difference in the inner and outer diameters of the substrate can be partially increased as compared with the conventional example.

With the above structure, the following effects can be obtained as compared with the first conventional example.

(1) Since the mounting area can be widened even with the same lens barrel outer diameter and the same lens structure, it is possible to prevent the lens from becoming large, the amount of peripheral light from decreasing, and the aperture from becoming small.

(2) Since the difference between the inner diameter and the outer diameter can be partly large, the restriction on the size of a relatively large component such as a microcomputer can be relaxed. Therefore, the system can be improved. Alternatively, if the same system is used, the lens barrel can be made smaller.

(3) Since the space on the mount side of the printed wiring board, especially the space in the thrust direction, can be partly increased, the restrictions on the components mounted on the mount side can be greatly relaxed. For example, since it is possible to arrange components on the outer diameter side of the substrate and relatively large components such as a microcomputer, which has been impossible in the past, wiring efficiency can be significantly improved. In addition, even when the connector is placed, it is not necessary to forcibly bend the flexible printed board in the immediate vicinity of the insertion port, so stress concentration at the boundary between the affixed part and the affixed part with a significant strength difference occurs. Can be prevented. Therefore, it is possible to manufacture a highly reliable product without the occurrence of pattern disconnection.

When the present invention is applied to the wiring connection in the lens barrel, for example, it is possible to use a hard printed board which is cheaper than the flexible printed board in comparison with the conventional lens barrel. Therefore, there is a cost advantage.

(2) There is an advantage that assembly workability is very good because complicated work such as bending is not required at the time of assembly.

[0046]

As described above, according to the present invention, in a structure in which a flexible printed wiring board and another printed wiring board are connected via a connector, the connector insertion terminal portion of the flexible printed wiring board is extended. A connection method of the connector which is inexpensive and has good assembling workability can be realized by being configured to be folded back and then connected to the connector, and by providing a reinforcing pattern or a terminal pattern in the extension portion as necessary.

When the present invention is applied to the wiring connection of the lens barrel, the printed wiring board on which the electric parts are mounted and which forms the electric circuit is arranged while being inclined with respect to the plane perpendicular to the optical axis. By arranging the lens barrel so as to avoid the light flux, it is possible to provide a lens barrel which is inexpensive, has good assembly workability, can be downsized while improving the system, and is highly reliable. In the description of the embodiment shown in FIG. 6, the hard printed wiring board was described, but there is no problem even if a flexible printed wiring board is used, and there is no change in the essential effect.

[Brief description of drawings]

FIG. 1 is a perspective view of a tip portion of a flexible printed wiring board according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a connection structure between the flexible printed wiring board and the connector of FIG.

FIG. 3 is a perspective view of a flexible printed wiring board according to a second embodiment of the present invention.

FIG. 4 is a perspective view of a flexible printed wiring board according to a third embodiment of the present invention.

5 is a vertical cross-sectional view of the connection structure between the wiring board and the connector of FIG.

FIG. 6 is a vertical sectional view of a lens barrel having a connection structure to which the present invention is applied.

FIG. 7 is a front view of one component in the structure of FIG.

8 is a perspective view of a conventional example corresponding to the flexible printed wiring board of FIG.

9 is a vertical cross-sectional view of the connection structure between the flexible printed wiring board and the connector of FIG.

10 is a vertical cross-sectional view of a lens barrel having a connection structure using the flexible printed wiring board of FIG.

11 is a front view of one component in the structure shown in FIG.

[Explanation of symbols]

1,8,10,12 ... Flexible printed wiring board 2,9,11,13,14 ... Terminal pattern 3 ... Reinforcement board 4 ... Connected side printed wiring board 5 ... (Connector) housing 6 ... Contact piece 7 ... Slider 8a, 10a, 12a ... Extension part 21 ... Mount 22 ... Main body 24 ... Contact member 26 ... Hard printed wiring board 27 ... Microcomputer 28 ... Flexible printed board 29 ... Connector

Claims (2)

[Claims] 1. In a connection structure between a flexible printed wiring board and a connector, a connector connection pattern portion is provided at a tip of the flexible printed wiring board, and the connector connection pattern portion is folded back to provide the flexible connection to the connector. A connection structure for a flexible printed wiring board, wherein the insertion portion of the printed wiring board is doubled. 2. A flexible printed wiring for connecting a connector to a printed wiring board, which is arranged to be inclined with respect to a plane orthogonal to the optical axis of the lens barrel and has an opening for photographing light, and is connected to the connector. A connection structure for a flexible printed wiring board, characterized in that a connector connection pattern portion is provided at a tip of the board, and the connector connection pattern portion is folded and inserted into the connector.