Portable telephone

Details Portable telephone Portable telephone

1999-04-28

2004-08-03

Nguyen, Lee (Department: 2682)

Telecommunications

Transmitter and receiver at same station

Radiotelephone equipment detail

C200S00600C, C200S004000, C345S161000, C379S433060

Reexamination Certificate

active

06771992

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a portable telephone, and, in particular, to a portable telephone which is provided with a multi-function key-switch unit which is operated in a manner in which a key top is inclined in a plurality of directions.
In the future, a portable telephone will have a computer function by having a browser built therein, in addition to an original radio communication function. When having a computer function, a portable telephone is provided with a multi-function key-switch unit or the like which is operated as an operator operates a personal computer. Because a portable telephone is smaller than a general personal computer, it is necessary to design a special contrivance.
2. Description of the Related Art
FIG. 1A
shows a multi-function key-switch unit
10
which is incorporated in a portable telephone in the related art. A key top
11
of the multi-function key-switch unit
10
in the related art is placed on a telephone-body assembly
12
, and is contained in an opening
14
of a portable-telephone case
13
. Pushing projections
16
are formed at four positions on the periphery on the bottom surface of the key top
11
. The telephone body
12
has a printed-circuit board
17
on the top surface thereof. A plurality of dome switches
18
-
1
and
18
-
2
(actually, four dome switches) are provided on the printed-circuit board
17
at positions at which the key top
11
is placed. Each of the dome switches
18
-
1
and
18
-
2
includes a fixed contact formed on the printed-circuit board
17
and a dome-shaped movable contact member
19
which covers the fixed contact.
For example, when the key top
11
is operated in a manner in which a position
20
on the top surface
11
a
of the key top
11
is pushed, the key top
11
inclines as shown in FIG.
1
B. As a result, the pushing projection
16
pushes the movable contact member
19
so that the dome switch
18
-
1
is turned on.
In the multi-function key-switch unit
10
in the related art, the plurality of dome switches
18
-
1
and
18
-
2
(actually, the four dome switches) are disposed, and the dome-shaped movable contact member
19
is provided in each dome switch, as mentioned above. Therefore, it is difficult to miniaturize the multi-function key-switch unit
10
. Accordingly, the multi-function key-switch unit
10
in the related art is not suitable for being incorporated in a portable telephone which is small.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a portable telephone in which the above-mentioned problem is solved.
A portable telephone according to the present invention comprises a multi-function key-switch unit in which a key top is operated in a plurality of directions. The multi-function key-switch unit comprises a stick switch which comprises a switch body and a stick projecting from the switch body, and the approximately cylindrical key top which is attached to the stick. The key top has a stopper portion provided on the bottom surface thereof, the stopper portion coming into contact with the switch body when the key top is operated to more than a predetermined degree so as to prevent the key top from inclining more than a predetermined angle.
In this arrangement, because the stopper portion is provided, when an operation is performed with a strong force, the stick switch can be protected. Further, because the stopper portion is provided on the bottom surface of the key top, it is possible to provide a mechanism, for preventing the key top from being inclined more than the predetermined angle, without increasing the size of the multi-function key-switch unit in the plan view thereof. Further, because what the stopper comes into contact with is the switch body, the multi-function key-switch unit itself can form the mechanism for preventing the key top from being inclined more than the predetermined angle. As a result, the maximum inclination angle of the key top is not affected by the variation in the accuracy with which the multi-function key-switch unit is incorporated into the portable telephone.
A portable telephone according to another aspect of the present invention comprises a multi-function key-switch unit in which a key top is operated in a plurality of directions. The multi-function key-switch unit comprises a stick switch which comprises a switch body and a stick projecting from the switch body, and the approximately cylindrical key top which is attached to the stick. The key top has a key-top body and a shaft projecting from a center of a bottom surface of the key-top body, the shaft having a nail portion which projects from an outer circumferential surface of the shaft. The stick has a pipe shape and an engagement opening in a circumference wall thereof, the nail portion engaging with the engagement opening. The stick further has a slit which extends from the engagement opening to a top end of the stick, the slit causing the pipe-shaped stick to be easily increased in a diameter thereof. The shaft of the key top is fitted into the pipe-shaped stick and the nail portion engages with the engagement opening.
In this arrangement, when a moment is developed in the key top and force of causing the shaft to slip off from the stick is developed, because the slit is provided, the pipe-shaped stick can be easily increased in the diameter thereof, and, thereby, the nail portion can easily slip out from the engagement opening. As a result, the stick switch can be protected.
A portable telephone according to another aspect of the present invention comprises a multi-function key-switch unit in which a key top is operated in a plurality of directions. The multi-function key-switch unit comprises a stick switch which comprises a switch body and a stick projecting from the switch body, and the approximately cylindrical key top which is attached to the stick. The key top has a key-top body and a shaft projecting from a center of a bottom surface of the key-top body, the shaft having a nail portion which projects from an outer circumferential surface of the shaft and a slit on a bottom-end side thereof, the slit causing the shaft to be easily reduced in a diameter thereof. The stick has a pipe shape and an engagement opening in a circumferential wall thereof, the nail portion engaging with the engagement opening. The shaft of the key top is fitted into the pipe-shaped stick and the nail portion engages with the engagement opening.
In this arrangement, because the slit is provided, the slit is narrowed and the shaft is easily reduced in the diameter thereof. As a result, the nail portion easily retreats from the engagement opening. Thereby, when the moment is developed in the key top and the force of causing the shaft to slip off from the stick is developed, the nail portion can easily slip out from the engagement opening. As a result, the stick switch can be protected.
A portable telephone according to another aspect of the present invention comprises a multi-function key-switch unit in which a key top is operated in a plurality of directions, the key top being exposed from an opening of a case of the portable telephone. The multi-function key-switch unit comprises a stick switch which comprises a switch body and a stick projecting from the switch body, and the approximately cylindrical key top which is attached to the stick. The key top has a plurality of recess portions at a periphery thereof. The case has projections on an edge of the opening. The recess portions of the key top are fitted to the projections of the case so that the key top is prevented from rotating about an axis line thereof.
A portable telephone according to another aspect of the present invention comprises a multi-function key-switch unit in which a key top is operated in a plurality of directions, the key top being exposed from an opening of a case of the portable telephone. The multi-function key-switch unit comprises a stick switch which comprises a switch body and a stick projecting from the switch body, and the approximately cy

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