Keyboard input device

Details Keyboard input device Keyboard input device

2000-02-15

2003-12-16

Edwards, Timothy (Department: 2735)

Coded data generation or conversion

Bodily actuated code generator

Including keyboard or keypad

C200S302100, C200S515000

Reexamination Certificate

active

06664901

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to low-profile keyboard input devices preferably used in notebook personal computers and the like.
2. Description of the Related Art
Hitherto, personal computers such as notebook computers to be used as portable terminal devices have been improved regarding miniaturization and weight-reduction.
A typical configuration of a keyboard input device used in such a notebook personal computer is described below with reference to FIG.
8
.
A metallic plate
21
is provided with a film substrate
22
. The film substrate
22
is provided thereon with a plurality of conducting patterns
23
, which are electrically conductive, each conducting pattern
23
having a pair of fixed contact parts
23
a
and
23
b
. The fixed contact parts
23
a
and
23
b
are disposed opposing each other across a gap
23
c
therebetween.
A plurality of hollow domed elastic spring members
24
of an elastically-deformable material such as rubber are provided covering the fixed contact parts
23
a
and
23
b
. Each elastic spring member
24
includes a mounting flange
24
a
formed at the bottom thereof. A plurality of air-passage grooves
24
b
having predetermined width and depth are formed at the bottom of the mounting flange
24
a
opposing the film substrate
22
and the conducting pattern
23
.
The elastic spring members
24
are bonded by an adhesive
25
to the film substrate
22
including the conducting patterns
23
.
Each of the hollow elastic spring members
24
is provided with a protrusion
24
c
downwardly protruding from the inner top thereof. The protrusion
24
c
includes a movable conductive-contact part
24
d
formed at the end thereof.
Each of the domed elastic spring members
24
is provided with a key-receiving part
24
e
upwardly protruding from the outer top thereof.
The key-receiving part
24
e
receives a key-top
26
brought into contact therewith at the inner surface
26
a
of the key-top
26
. The key-top
26
moves vertically while supported by a lifting mechanism (not shown) mounted on the metallic plate
21
.
Mounting holes (not shown) are formed in the metallic plate
21
for mounting the lifting mechanism (not shown). The metallic plate
21
is provided with a sealing sheet
27
for sealing the mounting holes, laminated on the bottom surface of the metallic plate
21
.
A known keyboard thus arranged operates in a manner such that air in the hollow elastic spring members
24
is discharged by the deformation of the hollow domed elastic spring members
24
pressed by the key-tops
26
through the air-passage grooves
24
b
provided at the mounting flanges
24
a
, whereby the key-tops
26
can smoothly move vertically with a light touch, thereby providing superior feeling in the key operation.
By pressing each key-top
26
, the movable contact part
24
d
comes in contact with the fixed contact parts
23
a
and
23
b
, whereby the pair of the fixed contact parts
23
a
and
23
b
are electrically connected to each other through the movable contact part
24
d.
Such known keyboard devices are mounted in notebook personal computers used as portable terminal devices. At present, the notebook personal computers are often used outdoors even in wet weather, therefore, the need for waterproof keyboard devices is increasing.
However, the known keyboard device has a problem when used outdoors in wet weather in that there is a risk of discoloration and corrosion of the fixed contact parts
23
a
and
23
b
by water droplets adhering on the film substrate
22
and the conducting patterns
23
penetrating into the hollow elastic spring members
24
through the air-passage grooves
24
b
of the mounting flanges
24
a
. The problem is that there is a risk of defective conduction between the pair of the fixed contact parts
23
a
and
23
b
and the movable contact part
24
b
in contact therewith, which is caused by the discoloration or corrosion of the fixed contact parts
23
a
and
23
b
. Also, there is a risk of disconnection of the conducting patterns
23
by corrosion when water droplets remain on the conducting patterns
23
, a portion of which is disposed at the outside of the elastic spring members
24
.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a waterproof keyboard device in which water droplets of rain or the like are prevented from penetrating into elastic spring members when the keyboard device is used outdoors in wet weather.
In accordance with an aspect of the present invention, a keyboard input device is provided which comprises a flexible film substrate; a conducting pattern provided on the film substrate, including a pair of fixed contact parts opposing each other; a hollow domed elastic spring member including a movable contact part provided on the ceiling thereof, the movable contact part being vertically movable; and a key-top for pressing the top of the elastic spring member. The elastic spring member is mounted on the film substrate so that the movable contact part is disposed over the pair of the fixed contact parts. An air-passage hole is provided in the ceiling having the movable contact part, the air-passage hole being formed in the vertically moving direction of the movable contact part. Also, air-passage grooves communicating with the air-passage hole are formed in a direction perpendicular to the axis of the air-passage hole, the air-passage grooves being provided at least in one of the positions in the key-top at a portion thereof to be in contact with the top of the elastic spring member and in the elastic spring member at the top thereof. With this arrangement, the air in the hollow elastic spring member is discharged, when the key-top is pressed to deform the elastic spring member, to the outside of the elastic spring member through the air-passage hole and the air-passage grooves.
The keyboard input device according to the present invention may be provided with an insulating overcoat, which is moisture-resistant and water-repellent, disposed on the film substrate including the conducting pattern with the pair of the fixed contact parts being exposed, and may be provided with the elastic spring member bonded to the overcoat by an adhesive.
In the keyboard input device according to the invention, the film substrate may be provided with a hole between the pair of the fixed contact parts which oppose each other across the hole therebetween.
According to another aspect of the present invention, a keyboard input device is provided which comprises a metallic plate; a flexible film substrate disposed on the metallic plate; a conducting pattern including a pair of fixed contact parts formed thereon opposing each other; a hollow domed elastic spring member including a movable contact part provided on the ceiling thereof, the movable contact part being vertically movable; and a key-top for depressing the top of the elastic spring member. A first hole is formed in the film substrate in the vicinity of the fixed contact parts, and an air-passage hole is formed in the metallic plate at a position in which the first hole is disposed, in the moving direction of the movable contact part. With this arrangement, the air in the hollow elastic spring member is discharged, when the key-top is pressed to deform the elastic spring member, to the lower part of the metallic plate through the first hole and the air-passage hole.
The keyboard input device according to the invention may be provided with an insulating overcoat, which is moisture-resistant and water-repellent, disposed on the film substrate including the conducting pattern with the pair of the fixed contact parts being exposed, and the elastic spring member is bonded to the overcoat by an adhesive.
In the keyboard input device according to the invention, the first hole in the film substrate may be disposed in a position flanked by the pair of the fixed contact parts.
In the keyboard input device according to the invention, the film substrate may be bonded to the metallic plate, and the first

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