Printed circuit board

A camera having a printed circuit board with edge portions which are folded for a predetermined length between support members. One of the folded portions contacts a contact portion of the camera to provide additional support for the printed circuit board.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a printed circuit board which can be 
formed three-dimensionally. 
2. Related Background Art 
Since a printed circuit board comprises a thin plate, it may be bent when a 
depression switch mounted thereon is actuated, so that secure on-off 
operation cannot be assured. Also such board bending may lead to damage to 
the electronic component mounted on the circuit board, by eventual contact 
with other components, detachment of terminals of such electronic 
component, or breakage of the wirings formed on the circuit board. 
Breakage of the circuit board itself may occur. 
For this reason, the board bending has conventionally been reduced by the 
reinforcement of the board itself, for example by change of the board 
material or increase in the board thickness. Also attempts have been made 
to reduce the board bending by increasing the supporting positions of the 
board or the supporting area thereof. 
However, the change in the material or thickness of the circuit board 
itself is not too effective if the size of the circuit board is large, and 
may lead to an increase in the weight and cost of the board. 
Also, the increase in the number of supporting positions of the board or in 
the supporting area thereof is encountered by the following difficulties. 
In the equipment employing the printed circuit board, the supporting parts 
may not necessarily be provided at desired positions because of spatial 
limitation. 
Also, the board designing becomes difficult, in order to provide the 
supporting parts in suitable positions. 
Furthermore, the increased number of supporting parts on the printed 
circuit board is against space saving, and is disadvantageous for 
component mounting, since such electronic components or wirings cannot be 
placed on such supporting parts. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide a printed circuit board 
capable of preventing the bending thereof by an external force, without 
changing the material or thickness of the board. 
According to the present invention, the bending of the printed circuit 
board itself by the external force can be prevented by folding the edge of 
the board.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 shows, in a camera, the location of the printed circuit board 
embodying the present invention. 
A camera member 3 supports an electronic flash, an auto focus/finder block 
a lens barrel etc. On the camera member 3 there are provided pins 3a to 3d 
for supporting the printed circuit board. 
The printed circuit board 1 is provided thereon with conductive wiring 
patterns (not shown), and various electronic components such as resistors, 
capacitors, IC's, etc., are fixed thereon by soldering. The printed 
circuit board 1 is supported on the pins 3a to 3d, by means of holes 1a to 
1d formed on the board 1 and screws 2a to 2d. 
FIGS. 2A and 2B are respectively a lateral view, seen from a shorter side 
of the board 1, and a plan view, showing the details of the printed 
circuit board 1 shown in FIG. 1. 
As shown in FIG. 2A, the printed circuit board 1 is provided with folded 
portions 1e, 1f, formed by folding the longitudinal edges of the board 1 
by 90.degree.. The edge of the folded portion if is so positioned as to 
contact a portion 3e of the camera member 3 shown in FIG. 1, and such 
contact further reduces the board bending. The folded portion 1e is 
extended somewhat longer, as it does not contact other members. 
Referring to FIG. 2B, the printed circuit board 1 receives the force of a 
switch 5, to be explained later (and shown in FIG. 3), in an area 1. 
The folded portion 1e is formed continuously and longer than a section m 
between the holes 1a and 1c (or between the supporting pins 3a and 3d). 
Also the folded portion 1f is likewise formed continuously and longer than 
a section n between the holes 1b and 1d (or between the supporting pins 3b 
and 3d). This is because the folded portion 1e or 1f can prevent bending 
if the length of the folded portion 1e or 1f is at least slightly shorter 
than the section m or n, but it can no longer prevent the bending if the 
respective length thereof is significantly shorter than said section m or 
n. The length of the folded portion 1e or 1f needs only to be 
substantially equal to the length of the section m or n. Consequently, 
such folded portions 1e, 1f need not be provided outside the area 1, 
namely in the area 2. 
The folded portion 1e is formed parallel to the line connecting the 
supporting pins 3a and 3c, but such parallel configuration is not 
limitative. The same applies also to the folded portion 1f. 
FIG. 3 shows a switch 5 which is provided on the printed circuit board 1 
shown in FIG. 1 and is turned on and off by depression. 
Referring to FIG. 3, the switch 5 is comprises a rubber member 5a and a 
conductive rubber member 5b, and, when the rubber member 5a is depressed, 
the switch is turned on by the contact of the conductive rubber member 5b 
with an exposed conductive pattern (not shown) on the printed circuit 
board 1. 
An external cover 6, covering the camera member 3, is provided with a hole 
through which the rubber member 5 protrudes externally for enabling the 
depressing operation for turning on and off the switch 5. 
The switch 5 is provided in the vicinity of the folded portion 1e or 1f 
within the area 1 shown in FIG. 2B, because the switch 5 is affected by 
the board bending in the shorter direction thereof if it is positioned at 
the center of the board. 
The folded portions 1e, if on the printed circuit board 1 ensure the secure 
switching operation of the switch 5, because the board 1 is bent little by 
the depression on the switch 5. 
As explained above, the presence of the folded portions 1e, if on the board 
1 allows for a reduction in the number of supporting pins for the board 
and the supporting area thereof, thereby increasing the effective space of 
the camera member 3 and achieving compactness and lighter weight. Also, 
the designing of the board 1 can be facilitated. 
Also, in the printed circuit board 1 itself, the reduced supporting areas 
provide a larger effective space, as in the case of the camera member 3, 
thereby facilitating the designing and achieving compactness and lighter 
weight. 
Thus, the folded portions 1e, 1f can reinforce the printed circuit board 
against the bending thereof in the longitudinal direction. Naturally, the 
reinforcement in the shorter direction is also possible by forming similar 
folded portions in the shorter ends. It is also possible to provide only 
one folded portion, or to provide a folded portion in each of the 
longitudinal end and the shorter end. 
Furthermore, though the folded portions 1e, 1f of the foregoing embodiment 
do not have enough areas for mounting electronic components, they may be 
expanded in areas to mount such components thereon. 
As explained in the foregoing, the present invention allows for an increase 
in the rigidity of the printed circuit board against external forces, 
without varying the thickness or material of the board itself. Such 
increased rigidity allows for a reduction in the number of the supporting 
parts of the printed circuit board and supporting areas thereof, thereby 
contributing to space saving and weight reduction in the camera.