Electricity: electrical systems and devices – Housing or mounting assemblies with diverse electrical... – For electronic systems and devices
Reexamination Certificate
1998-07-29
2001-01-09
Picard, Leo P. (Department: 2835)
Electricity: electrical systems and devices
Housing or mounting assemblies with diverse electrical...
For electronic systems and devices
C361S689000, C361S689000, C200S344000, C200S345000
Reexamination Certificate
active
06172868
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a keyboard device suitable for use in, for example, a notebook personal computer which needs to be thin. In addition, the present invention relates to a personal computer employing the aforementioned keyboard device.
2. Description of the Related Art
One type of personal computer includes a rotatable cover above the computer body. A keyboard device is incorporated in the computer body, and a display device is incorporated in the rotatable cover. When the personal computer is in use, the cover with a display device incorporated therein is opened, whereas when the personal computer is not in use, the cover is closed so that the keyboard device is covered from above it. In the personal computer of the type described above, in order to make the keyboard device thinner, the key switches of the keyboard device are formed, as shown in
FIGS. 10 and 11
.
Each key switch has a boat-shaped key top
58
, two retainer portions
58
disposed at the back side of each key top
58
, two retainer portions
58
c
each with a slide groove
58
b
, and a key top supporting structure L disposed below each key top
58
. Each key top supporting structure L comprises a first lever portion
56
and a second lever portion
57
, with the first lever portion and the second lever portion being combined so as to form a cross. One end of each first lever portion
56
is rotatably retained by the retainer portions
58
a
of the key top
58
associated thereto. One end of each second lever portion
57
is slidably inserted into the slide grooves
58
b
in the retainer portions
58
c
of the key top
58
associated thereto.
Below the key top supporting structures L is disposed a key top supporting member
55
with a slide groove
55
b
for slidably retaining the other end of the first lever portions
56
, and a retainer portion
55
a
for rotatably retaining the other end of the second lever portions.
A membrane switch
54
is disposed below the key top supporting member
55
so as to be slidable on a flat supporting substrate
60
and between the key top supporting member
55
and the supporting substrate
60
. The membrane switch
54
is a laminated structure including, from bottom to top, a protective sheet
54
a
, a stationary contact sheet
54
b
, a spacer sheet
54
c
, a movable contact sheet
54
d
, and a protective sheet
54
e
. These sheets are integrally bonded together. At a hole
54
f
in the spacer sheet
54
c
, a contact
54
g
on the sheet
54
d
and a contact
54
h
on the sheet
54
d
oppose each other.
A dome-shaped resilient member
59
with a protrusion
59
a
used for operating a switch is provided below each key top supporting structure L, such that the top portion thereof opposes its associated key top supporting structure L and the bottom portion is mounted to the membrane sheet
54
.
Accordingly, the keyboard device is constructed as described above.
As shown in
FIGS. 12 and 13
, the personal computer includes a cam projection
515
a
and a spring member
517
. The cam projection
515
a
is provided at the front side of the cover
515
with a display device (not shown). The spring member
517
is disposed between the membrane switch
54
of the keyboard device mounted within a body
513
and a side wall
516
of the body
513
.
In addition, when the personal computer having the above-described structure is ordinarily used by opening the cover
515
and operating the keyboard device
512
, the key top supporting structures L are raised and supported by their corresponding resilient members
59
at their highest positions, as shown in FIG.
10
. When an operator pushes a dome-shaped key top
58
downward against the resilient force of the resilient member
59
associated thereto, the inwardly projecting portion
59
a
of the associated resilient member
59
pushes the protective sheet
54
e
and the sheet
54
d
of the membrane switch
54
, causing the contact
54
h
to come into contact with the contact
54
g
, whereby the switch is set in an on state.
Thereafter, releasing the key top
58
causes the resilient member
59
to return back to its original state due to its resiliency, and the associated supporting structure L and key top
58
to be restored back to its original state, causing the contact
54
h
to separate from the contact
54
g
, whereby the switch is set in an off state.
Accordingly, contact switching is performed.
As shown in
FIGS. 11 and 13
, lowering the cover
515
onto the keyboard device
512
causes the cam projection
515
a
to engage the left end of the membrane switch
54
of the keyboard device, causing the membrane switch
54
to move to the right against the spring force of the spring member
517
. This causes the membrane switch
54
to slide in sliding contact between the supporting substrate
60
and the key top supporting member
55
, and the resilient members
59
to move in the same direction and move out from below their corresponding key top supporting structures L. Disengagement of the resilient members
59
from below their corresponding key top supporting structure L causes the key top supporting structures L to be lowered due to its own weight, causing the key tops
58
to be lowered downward. This reduces the thickness of the entire keyboard device
512
.
When the cover
515
is opened, the cam projection
515
a
disengages the membrane switch
54
, whereby the spring member
517
causes the membrane switch
54
to slide in sliding contact between the supporting substrate
60
and the key top supporting member
55
, and move back to its original position. Since, as a result of the sliding movement of the membrane switch
54
, the resilient members
59
slide back to the bottom portion of their corresponding key top supporting structures L in sliding contact therewith, the key top supporting structures L are pushed back upward by their respective resilient members
59
, which in turn causes the corresponding key tops
58
to rise upward and horizontally in order to be supported at their highest positions.
Thereafter, operations, such as those described above, are repeated to perform contact switching.
In such conventional keyboard devices and personal computers employing the aforementioned conventional keyboard devices, since the membrane switch
54
is slid, the electrical connecting structure between the electrical circuit in the personal computer and the sliding membrane switch
54
is complicated, which not only leads to high costs but also to lack of electrical reliability.
In addition, since the resilient member
59
is slid along its associated key top supporting structure L, the resilient member
59
has a shorter life. Moreover, since the resilient member cannot move smoothly, it cannot be operated with ease.
SUMMARY OF THE INVENTION
In order to overcome the above-described problems, according to a first aspect of the present invention, there is provided a keyboard device comprising: a key top; a first lever portion having one end slidably retained by a housing member and the other end rotatably retained at a back side of the key top; a second lever portion having one end rotatably retained by a supporting member disposed below the housing member and the other end slidably retained at the back side of the key top; and a membrane switch disposed between the housing member and the supporting member; wherein the first lever portion and the second lever portion are combined through a shaft member into the shape of a cross; wherein the supporting member and the membrane switch are affixed together; and wherein the housing member is slidably retained, with the sliding movement of the housing member causing the first lever portion and the second lever portion combined into the shape of a cross to be raised and lowered.
Although not exclusive, the keyboard device may further comprise a switch operating resilient member provided at a back surface of the key top.
Although not exclusive, the keyboard device may further comprise a spring member for pushing the o
Alps Electric Co. ,Ltd.
Brinks Hofer Gilson & Lione
Duong Hung Van
Picard Leo P.
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