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Claims  |
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What is claimed is:
1. A switching device comprising:
a decision switch for deciding an operational instruction;
a selection switch, disposed adjacent to said decision switch, for
selecting an operational instruction;
a key top having a central portion disposed over said decision switch;
a guide disposed around said key top, wherein said key top and said guide
are separate from one another and define an interstice therebetween such
that when a force is applied to said key top in a direction toward a
center of said decision switch this force is not transmitted to said
guide, such that when a force is applied to a central portion of said key
top this force is transmitted to said decision switch, and when a tilting
force is applied to said key top this tilting force is transmitted to said
selection switch through said guide; and
a key base disposed between said key top and said decision switch and said
selection switch, with said key top and said guide being independently
fixed to said key base;
wherein a part of said key base that is between a portion of said key base
that corresponds to an upper portion of said decision switch and a portion
of said key base that corresponds to an upper portion of said selection
switch is weaker than other parts of said key base, and
wherein when the force is applied to the central portion of said key top
this force is transmitted to said decision switch through said key base,
and when the tilting force is applied to said key top this tilting force
is transmitted to said selection switch through said key base.
2. The switching device according to claim 1, wherein said part of said key
base that is between the portion of said key base that corresponds to the
upper portion of said decision switch and the portion of said key base
that corresponds to the upper portion of said selection switch is weaker
than the other parts of said key base by having a through hole therein.
3. The switching device according to claim 2, wherein said key base is
integral with a key base of a numeric key.
4. The switching device according to claim 1, wherein said key base is
integral with a key base of a numeric key.
5. A switching device comprising:
a decision switch for deciding an operational instruction;
a selection switch, disposed adjacent to said decision switch, for
selecting an operational instruction;
a key top having a central portion disposed over said decision switch;
a guide disposed around said key top, wherein said key top and said guide
are separate from one another and define an interstice therebetween such
that when a force is applied to said key top in a direction toward a
center of said decision switch this force is not transmitted to said
guide, such that when a force is applied to a central portion of said key
top this force is transmitted to said decision switch, and when a tilting
force is applied to said key top this tilting force is transmitted to said
selection switch through said guide;
three additional selection switches adjacent to said decision switch such
that said three additional selection switches and said selection switch
define four selection switches that are disposed around said decision
switch at regular intervals in a cross shape;
a cylindrical boss coaxial with said key top and extending from said
central portion of said key top toward said decision switch; and
a key base disposed between said key top and said decision switch and said
four selection switches such that when the force is applied to the central
portion of said key top this force is transmitted to said decision switch
through said key base, and when the tilting force is applied to said key
top this tilting force is transmitted to said selection switch through
said key base,
wherein said guide includes a central cylindrical opening receiving said
cylindrical boss, said central cylindrical opening being positioned
opposite to the center of said decision switch with four ribs extending
from said central cylindrical opening in a cross shape toward respective
ones of said four selection switches,
wherein said four ribs are integrally fixed to said key base at positions
that are opposite to central portions of said four selection switches,
respectively, with a concave/convex relationship being defined at one of
said positions for positioning said guide relative to said key base,
wherein an end portion of said cylindrical boss is integrally fixed to said
key base, with a concave/convex relationship being defined between said
cylindrical boss and said key base for positioning said key top relative
to said key base and for preventing rotation of said key top relative to
said key base,
wherein each of said four selection switches comprises a dome-shaped layer
of material, and said decision switch comprises superposed dome-shaped
layers of said material such that said dome-shaped decision switch and
said four dome-shaped selection switches are to control a flow of
electricity between isolated conductive terminals by receiving respective
forces from a curved protruded elastic material,
wherein each of said four selection switches and said key base are adjacent
to one another while an interstice is defined between said decision switch
and said key base,
wherein through holes are provided in respective parts of said key base
that are between a portion of said key base that corresponds to an upper
portion of said decision switch and respective portions of said key base
that corresponds to respective upper portions of said four selection
switches such that said respective parts are weaker than other parts of
said key base, and
wherein said key base is integral with a key base of a numeric key.
6. A switching device comprising:
a dome-shaped decision switch for deciding an operational instruction;
dome-shaped selection switches, disposed around said decision switch, each
for selecting an operational instruction; and
a key top having a central portion disposed over said dome-shaped decision
switch,
such that when a force is applied to a central portion of said key top this
force is transmitted to said dome-shaped decision switch, and when a
tilting force is applied to said key top this tilting force is transmitted
to one of said dome-shaped selection switches, whereby said dome-shaped
decision switch and said dome-shaped selection switches are to control a
flow of electricity between isolated conductive terminals by receiving
respective forces from a curved protruded elastic material,
wherein each of said dome-shaped selection switches comprises a dome-shaped
layer of material, and said dome-shaped decision switch comprises
superposed dome-shaped layers of said material.
7. The switching device according to claim 6, wherein each of said
dome-shaped selection switches is similar in construction to each other of
said dome-shaped selection switches.
8. The switching device according to claim 7, further comprising a guide
that is constructed and arranged to transmit the tilting force from said
key top to said dome-shaped selection switches.
9. The switching device according to claim 7, further comprising:
a key base disposed between said key top and said decision switch and said
selection switches; and
a guide, with said key top and said guide being independently fixed to said
key base,
wherein parts of said key base that are respectively between a portion of
said key base that corresponds to an upper portion of said dome-shaped
decision switch and portions of said key base that correspond to
respective upper portions of said dome-shaped selection switches are
weaker than other parts of said key base, and
wherein when the force is applied to the central portion of said key top
this force is transmitted to said dome-shaped decision switch through said
key base, and when the tilting force is applied to said key top this
tilting force is transmitted to said one of said dome-shaped selection
switches through said key base.
10. The switching device according to claim 9, wherein said parts of said
key base that are respectively between the portion of said key base that
corresponds to the upper portion of said dome-shaped decision switch and
the portions of said key base that correspond to the respective upper
portions of said dome-shaped selection switches are weaker than the other
parts of said key base by having respective through holes therein.
11. The switching device according to claim 10, wherein said key base is
integral with a key base of a numeric key.
12. The switching device according to claim 9, wherein said key base is
integral with a key base of a numeric key.
13. A switching device comprising:
a decision switch for deciding an operational instruction;
a selection switch, disposed adjacent to said decision switch, for
selecting an operational instruction;
a key top having a central portion disposed over said decision switch; and
a key base disposed between said key top and said decision switch and said
selection switch, wherein said selection switch and said key base are
adjacent to one another while an interstice is defined between said
decision switch and said key base, and wherein said key top is fixed to
said key base such that said key top is supported by said key base,
such that when a force is applied to a central portion of said key top this
force is transmitted to said decision switch through said key base, and
when a tilting force is applied to said key top this tilting force is
transmitted to said selection switch through said key base.
14. The switching device according to claim 13, further comprising a guide,
with said key top and said guide being independently fixed to said key
base, and wherein a part of said key base that is between a portion of
said key base that corresponds to an upper portion of said decision switch
and a portion of said key base that corresponds to an upper portion of
said selection switch is weaker than other parts of said key base.
15. The switching device according to claim 14, wherein said part of said
key base that is between the portion of said key base that corresponds to
the upper portion of said decision switch and the portion of said key base
that corresponds to the upper portion of said selection switch is weaker
than the other parts of said key base by having a through hole therein.
16. The switching device according to claim 15, wherein said key base is
integral with a key base of a numeric key.
17. The switching device according to claim 14, wherein said key base is
integral with a key base of a numeric key.
18. The switching device according to claim 13, wherein said key base is
integral with a key base of a numeric key.
19. A portable terminal device including a switching device, said switching
device comprising:
a dome-shaped decision switch for deciding an operational instruction;
dome-shaped selection switches, disposed around said decision switch, each
for selecting an operational instruction; and
a key top having a central portion disposed over said dome-shaped decision
switch,
such that when a force is applied to a central portion of said key top this
force is transmitted to said dome-shaped decision switch, and when a
tilting force is applied to said key top this tilting force is transmitted
to one of said dome-shaped selection switches, whereby said dome-shaped
decision switch and said dome-shaped selection switches are to control a
flow of electricity between isolated conductive terminals by receiving
respective forces from a curved protruded elastic material,
wherein each of said dome-shaped selection switches comprises a dome-shaped
layer of material, and said dome-shaped decision switch comprises
superposed dome-shaped layers of said material.
20. The portable terminal device according to claim 19, wherein each of
said dome-shaped selection switches is similar in construction to each
other of said dome-shaped selection switches.
21. The portable terminal device according to claim 20, further comprising
a guide that is constructed and arranged to transmit the tilting force
from said key top to said dome-shaped selection switches.
22. A portable terminal device including a switching device, said switching
device comprising:
a decision switch for deciding an operational instruction;
a selection switch, disposed adjacent to said decision switch, for
selecting an operational instruction;
a key top having a central portion disposed over said decision switch; and
a key base disposed between said key top and said decision switch and said
selection switch, wherein said selection switch and said key base are
adjacent to one another while an interstice is defined between said
decision switch and said key base, and wherein said key top is fixed to
said key base such that said key top is supported by said key base,
such that when a force is applied to a central portion of said key top this
force is transmitted to said decision switch through said key base, and
when a tilting force is applied to said key top this tilting force is
transmitted to said selection switch through said key base.
23. A switching device comprising:
a decision switch for deciding an operational instruction;
a selection switch, disposed adjacent to said decision switch, for
selecting an operational instruction;
an elastic key base;
a key top having a central portion disposed over said decision switch; and
a guide disposed around said key top,
wherein said key top and said guide are separate from one another and
define an interstice therebetween, and
wherein said key top and said guide are independently fixed to said elastic
key base such that said key top and said guide are independently supported
by said elastic key base. |
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Claims |
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Description |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a switching device for selecting an
operational instruction and deciding the operational instruction, and more
particularly to a switching device that exhibits a decrease in
malfunctions.
2. Description of the Related Art
For example, in a portable telephone system, key operation becomes
disadvantageously complicated with recent progress of soft function, and
moreover, density of keys in accordance with downsizing of the body as
well as miniaturization of the key itself further make the operation
complicated. In order to cope with these problems, various techniques of a
switch have been proposed, such as a switch in a combination of a function
key and a numeric key, using a jog dial, using a cross key, and using a
stick switch.
For example, in the case of using a stick switch, one key operation enables
a shift of a cursor for retrieving an operational instruction and
executing the retrieved operational instruction, thereby improving the
operational performance remarkably compared with the case of pressing a
numeric key many times. In the structure of separately mounting a stick
switch (for example, a purchase), however, since volume for the body of
the stick switch itself and area for soldering it are required, in
advancing downsizing and thinning of the portable telephone system, the
size of a stick switch may be disadvantageously limited and a malfunction
may easily occur.
In place of this stick switch, for example, Japanese Patent Application
Laid-Open Publication No. 11-126126 discloses a scroll switch device for a
portable telephone, comprising a decision switch for deciding an
operational instruction of a portable telephone and a plurality of
selection switches for shifting a cursor on an information display. This
scroll switch device, however, does not sufficiently prevent a malfunction
from occurring.
As mentioned in the above conventional example, even a scroll switch device
having a much greater possibility of being downsized, relative to a stick
switch, is defective in preventing a malfunction from occurring.
Therefore, a switch that is capable of surely preventing a malfunction is
highly desired.
SUMMARY OF THE INVENTION
In order to solve the above conventional problem, the present invention
aims to provide a switching device that decreases the possibility of a
malfunction occurring when selecting an operational instruction by a
selection switch and deciding the operational instruction by a decision
switch.
In order to achieve the above object, a switching device according to the
present invention comprises a decision switch for deciding an operational
instruction, a selection switch disposed around the decision switch for
selecting an operational instruction, a key top whose central portion is
disposed over the decision switch, and a guide disposed around the key
top. The switching device is constructed such that pressure applied to a
central portion of the key top is transmitted to the decision switch, and
a force resulting from tilting of the key top away from a central axis is
transmitted to the selection switch through the guide. Also, the key top
and the guide are separately formed with an interstice provided
therebetween.
Accordingly, since the interstice is provided between the key top and the
guide, the pressure applied to the central portion of the key can be
prevented from being transmitted to the selection switch when this
pressure is to be transmitted only to the decision switch, even when the
key top is slightly tilted. Accordingly, such a malfunction in which the
selection switch is also operated during operation of the decision switch
is prevented.
A switching device according to the present invention comprises a decision
switch for deciding an operational instruction, a selection switch
disposed around the decision switch for selecting an operational
instruction, and a key top whose central portion is disposed over the
decision switch. The switching device is constructed such that pressure
applied to the central portion of the key top is transmitted to the
decision switch, and a force resulting from tilting of the key top away
from a central axis is transmitted to the selection switch. The decision
switch and the selection switch are each formed as a domed switch for
switching, through conducting electricity, between isolated conductive
terminals in response to pressure applied to a curved protruded elastic
material. Also, the decision switch is formed as a domed switch of more
layers than the selection switch.
Accordingly, since the decision switch is formed as a domed switch having
more layers than the selection switch, the decision switch becomes
difficult to be pushed down as compared to the selection switch.
Therefore, even if a force in the downward direction (that is, in the
direction of the decision switch) is produced when the force resulting
from tilting of the key top away from the central axis is transmitted to
the selection switch, the decision switch can be prevented from being
depressed. In other words, such a malfunction in which the decision switch
is also depressed when the selection switch is depressed, can be
prevented.
Additionally to the above structure, a switching device according to the
present invention further comprises a key base disposed between both
switches (namely, the decision switch and the selection switch) and the
key top. This switching device is constructed such that pressure applied
to the central portion of the key top is transmitted to the decision
switch through the key base, and the force resulting from tilting of the
key top away from the central axis is transmitted to the selection switch
through the key base. Also, a through hole is provided in a part of the
key base between the portion corresponding to the upper portion of the
decision switch and the portion corresponding to the upper portion of the
selection switch, thereby making this part weaker than other portions of
the key base.
Accordingly, since the part of the key base between the portion
corresponding to the upper portion of the decision switch and the portion
corresponding to the upper portion of the selection switch is weaker than
other portions of the key base, the pressure applied to the central
portion of the key top becomes difficult to be transmitted to the
selection switch, and the force resulting from tilting of the key top away
from the central axis becomes difficult to be transmitted to the decision
switch, thereby preventing such a malfunction in which the other of the
decision switch and selection switch is also operated during operation of
a selected one of the decision switch and the selection switch.
A switching device according to the present invention comprises a decision
switch for deciding an operational instruction, a selection switch
disposed around the decision switch for selecting an operational
instruction, a key top whose central portion is disposed over the decision
switch, and a key base disposed between both switches (namely, the
decision switch and the selection switch) and the key top. This switching
device is constructed such that pressure applied to the central portion of
the key top is transmitted to the decision switch through the key base,
and the force resulting from tilting of the key top toward a central axis
is transmitted to the selection switch through the key base. Also, the
selection switch and the key base are adjacently provided, while an
interstice is provided between the decision switch and the key base.
Accordingly, since the selection switch and the key base are adjacently
provided and an interstice is provided between the decision switch and the
key base, the decision switch becomes more difficult to be operated than
the selection switch while the force resulting from tilting of the key top
is being applied, thereby preventing such a malfunction in which the
decision switch is also operated during operation of the selection switch.
Additionally to the above structure, a switching device according to the
present invention is constructed such that the part of the key base
between the portion corresponding to the upper portion of the decision
switch and the portion corresponding the upper portion of the selection
switch is weaker than other portions of the key base. Especially, a
switching device according to the present invention is preferably
constructed such that a through hole is provided in the key base between
the portion corresponding to the upper portion of the decision switch and
the portion corresponding to the upper portion of the selection switch,
thereby making this part weaker than the other portions of the key base.
Accordingly, since the part of the key base between the portion
corresponding to the upper portion of the decision switch and the portion
corresponding to the upper portion of the selection switch is weaker than
the other portions of the key base, the pressure applied to the central
portion of the key top becomes difficult to be transmitted to the
selection switch, and the force resulting from tilting of the key top away
from the central axis becomes difficult to be transmitted to the decision
switch, thereby preventing such a malfunction in which the other of the
decision switch and selection switch is also operated during operation of
a selected one of the decision switch and selection switch.
Additionally to the above structure, a switching device of the present
invention is constructed such that the decision switch and the selection
switch are formed on a key sheet, and this key sheet and the key base are
integrally formed with the key sheet and the key base of each numeric key.
Accordingly, since the both switches (namely, the decision switch and the
selection switch) and the numeric key use the key sheet and the key base
in common, a reduction in the number of the parts along with a reduction
in cost, and downsizing and thinning of the switching device can be
realized.
Further, a portable terminal device provided with one of the
above-mentioned various switching devices can be provided.
The portable terminal device provided with a switching device capable of
selecting an operational instruction and deciding an operational
instruction, as mentioned above, can prevent a malfunction during
operation of the switching device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of a scroll switch device provided in a portable
telephone system in accordance with one embodiment of the present
invention.
FIG. 2 is a sectional view taken along the line 2--2 of the scroll switch
device and its vicinity provided in the portable telephone system
according to the embodiment of the present invention.
FIG. 3 is an enlarged view of the portion A.
FIG. 4 is a sectional view of the scroll switch device and its vicinity
when the key top is pressed.
FIG. 5 is a sectional view of the scroll switch device and its vicinity
when the key top is slightly tilted.
FIG. 6 is a sectional view of the scroll switch device and its vicinity
when the key top is tilted.
FIG. 7 is a sectional view of the scroll switch device and its vicinity
when the key top is tilted.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the present invention will be described with
reference to the drawings.
In this embodiment, the structure and the operation of a scroll switch
device, which is an example of the switching device according to the
present invention, will be fully described together with the description
of the structure and the operation of a portable telephone system, which
is an example of a portable terminal according to the present invention.
FIG. 1 is a plan view of a scroll switch device provided in the portable
telephone system of this embodiment, FIG. 2 is a sectional view taken
along the line 2--2 of the scroll switch device and its vicinity provided
in the portable telephone system of this embodiment, and FIG. 3 is an
enlarged view of the A portion indicated by a dotted line in FIG. 2. In
these figures, the same reference numerals are attached to the same
components.
With reference to FIGS. 1 to 3, the structure of the portable telephone
system of this embodiment and the structure of the scroll switch device of
this embodiment, provided in the same portable telephone system, will be
described.
The portable telephone system of this embodiment is formed by covering a
circuit (not illustrated) having a wireless communication function, a
scroll switch device, a numeric key 15, an information display (not
illustrated) and the like with a casing. For example, a casing 1 on the
rear side and a casing 16 on the front side are shown in FIG. 2.
On the upper portion of the casing 1 on the rear side, a printed circuit
board 2 is supported by a projected portion of the casing 1, and the
scroll switch device of this embodiment is provided on the printed circuit
board 2. Here, the upper portion means the front side.
More specifically, for example, a thin key sheet 3 made of PET is provided
on the printed circuit board 2, one decision switch 4 formed in a domed
shape is stuck on the key sheet 3, and four selection switches 5a to 5d
formed similarly in a domed shape are also stuck on the key sheet 3.
Here, the four selection switches 5a to 5d are positioned at regular
intervals in a shape of a cross around the decision switch 4. The
respective selection switches 5a to 5d have a function of selecting an
operational instruction, while moving a cursor displayed on the
information display, such as a liquid crystal display screen provided on
the portable telephone system of the embodiment, in a respective inherent
direction.
The decision switch 4 has a function of deciding the operational
instruction selected by the above-mentioned cursor so as to make the
portable telephone system execute the same operation.
As an operating method of these switches 4, 5a to 5d, for example, one of
the selection switches 5a to 5d is turned on, so to move the cursor to
select one of various operational instructions of the portable telephone
system and turned off, and the decision switch 4 is turned on, thereby to
decide the same operational instruction.
The domed switch is formed by two isolated conductive terminals (conductive
pattern), provided on an elastic material formed in a curved shape and the
printed circuit board 2, and a conductive portion provided on the elastic
material, by way of example. The domed switch is constituted such that
pressure applied to the elastic material bends and deforms the elastic
material, so as to put the conductive portion of the elastic material into
contact with the two conductive terminals, hence to conduct electricity
between the two conductive terminals and thereby turn on (or off) the
switch. The elastic material also returns to its original curved shape,
hence to electrically isolate the two conductive terminals and thereby
turn off (or on) the switch. In the embodiment, a metal is used as the
elastic material, and the domed switch is formed as a domed metal click
plate.
In the embodiment, for example, as illustrated in FIG. 3, the respective
selection switches 5a to 5d are formed from a single layer of material,
and the decision switch 4 is formed by overlaying two layers of the same
material that forms the respective selection switches 5a to 5d.
A key base 6 formed from a rubber such as a soft rubber is provided on the
upper portion of the decision switch 4 and the selection switches 5a to
5d. The key base 6 is provided with a conical convex portion 7a opposite
to the central portion of the decision switch 4, four conical convex
portions 7b to 7e opposite to the respective central portions of the
respective selection switches 5a to 5d, and four through holes 8a to 8d
positioned respectively between portions of the decision switch 4 that are
adjacent to respective portions of the selection switches 5a to 5d. A
predetermined interstice is provided between the decision switch 4 and the
conical convex portion 7a opposed to it, and the respective selection
switches 5a to 5d are provided in contact with the conical convex portions
7b to 7e opposed thereto, respectively. These conical convex portions 7a
to 7e are designed to directly press the switches 4, 5a to 5d,
respectively, by pushing the key base 6 downwardly.
A guide 9 formed by, for example, a mold and a key top 12 formed by, for
example, a mold or a hard rubber, are independently provided on the upper
portion of the key base 6.
As illustrated in FIG. 1, the guide 9 is in a shape of a cross, with a
central portion thereof being positioned at an upper portion corresponding
to the central portion of the decision switch 4, and four ribs extended
from the central portion toward the respective selection switches 5a to 5d
like a cross.
These four ribs adhere to the key base 6 to be integrally fixed thereto at
upper portions that are opposed to the respective central portions of the
respective selection switches 5a to 5d. Cylindrical concave/convex
portions 10a and 10b for mutually positioning the guide 9 and the key base
6 are provided at one of the thusly fixed plural positions (in this
embodiment, two of the four positions). The respective concave/convex
portions 10a and 10b are formed by engaging a concave portion formed in
one of the guide 9 and the key base 6 with a convex portion formed on the
other of the guide 9 and key base 6. In this embodiment, the convex
portion is provided on the key base 6, while the concave portion is
provided on the guide 9.
A cylindrical hole 11 for receiving a boss 13 of a key top 12, described
later, is provided in the central portion of the guide 9. For example, as
illustrated in FIG. 3, a predetermined interstice is provided between the
guide 9 and the boss 13 of the key top 12. The guide 9 is positioned
around the key top 12 for providing a function of transmitting to the key
base 6, power when the peripheral portion of the key top 12 is inclined
away from a central axis so as to press the guide 9.
The central portion of the key top 12 is positioned opposite to the upper
portion of the central portion of the decision switch 4. The cylindrical
boss 13, with its central portion regarded as an axis, is protruded toward
the decision switch 4 from the central portion of the key top 12. The end
portion of the boss 13 adheres to the key base 6 and is integrally fixed
thereto. A quadrangular concave/convex portion 14 for mutually positioning
the key top 12 and the key base 6, and mutually stopping rotation of the
key top 12, is provided at the fixed portion.
The concave/convex portion 14 is formed by engaging a concave portion
formed in one of the key base 6 and the boss 13 of the key top 12 with a
convex portion formed in the other of the key base 6 and the boss 13. In
this embodiment, a quadrangular convex portion is provided in the key base
6 and a concave portion corresponding to this quadrangular portion is
provided in the boss 13 of the key top 12. Further, the concave/convex
portion may be formed of a polygonal shape, an elliptical shape, or the
like so as to prevent rotation of the key top 12. In other words, the
concave/convex portion must have a shape other than cylindrical.
In the embodiment, the key sheet 3 and the key base 6 of the scroll switch
device are integrally formed with the key sheet and the key base of each
numeric key switch. More specifically, a domed switch 15a for a numeric
key is also provided on the key sheet 3 of the embodiment, and the numeric
key 15 is provided on the key base 6 at a position that opposes the
central portion of the domed switch 15a. Further, through holes 8e to 8g
having the same function as the above-mentioned through holes 8a to 8d are
provided in the key base 6 of the embodiment between portions of the
selection switches 5b to 5d that are adjacent to portions of the domed
switch 15a.
The casing 16 on the front side is formed so as to expose the top of the
key top 12 which is operated by a user, the top of the numeric key 15
which is operated by a user, and the information display seen by a user,
outwardly of the front side, and is also formed so as to accommodate the
key top 12, the numeric key 15, and the information display therein. More
specifically, a skirt portion formed on the key top 12 and a protruded
portion formed on the numeric key are lodged within the casing 16 on the
front side so as not to be removable from within the casing 16.
In the scroll switch device provided in the portable telephone system of
the embodiment constituted as described above, a user operates the
peripheral portion of the key top 12 so as to tilt the key top 12 away
from its central axis. Therefore, the tilt force is transmitted to one of
the selection switches 5a to 5d through the guide 9 and the key base 6, so
as to press the corresponding selection switch of 5a to 5d. Then, a cursor
on the information display is shifted in the direction corresponding to
the pressed selection switch of 5a to 5d, where an operational instruction
can be selected. Further, a user operates the central portion of the key
top 12 so as to press the central portion of the key top 12, whereby the
pressure is transmitted to the decision switch 4 through the key base 6 so
as to press the decision switch 4, thereby deciding the operational
instruction selected by a cursor.
Some operational states of the scroll switch device of the embodiment
provided in the portable telephone system of the embodiment will be
described with reference to FIGS. 4 to 7.
FIG. 4 shows a sectional example of the scroll switch device and its
vicinity according to the embodiment in the state where the central
portion of the key top 12 is depressed 0.25 mm. In this state, the
decision switch 4 is pressed and deformed through the key base 6 by
pressing down the key top 12, thereby performing the deciding operation of
the operational instruction. Here, since the decision switch 4 of the
embodiment is formed by overlaying two metal domed switches so as to get a
stronger force of inversion, the decision switch 4 would not operate
unless a user presses the central portion of the key top 12 on purpose.
FIG. 5 shows a sectional example of the scroll switch device and its
vicinity according to the embodiment in the state where the key top 12 is
tilted slightly vertically (for example, at most .+-.5.degree.) away from
its central axis. In this embodiment, since the predetermined interstice
is provided between the boss 13 of the key top 12 and the through hole 11
of the guide 9, the tilt force is not directly transmitted to the guide 9
even in the state as shown in this figure, thereby preventing the
selection switches 5a to 5d from easily being depressed.
FIGS. 6 and 7 each show a sectional example of the scroll switch device and
its vicinity according to the embodiment in the state where the key top 12
is further tilted (in this example, about .+-.8.degree.) as compared with
the case as shown in FIG. 5. In this state, the boss 13 of the key top 12
is adjacent to the through hole 11 of the guide 9 so as to press the guide
9 in order to tilt the guide 9. Therefore, the selection switch of 5a to
5d corresponding to the direction of this tilt is depressed, thereby
selecting an operational instruction (for example, a scroll operation).
As mentioned above, the scroll switch device of the embodiment provided in
the portable telephone system of the embodiment can perform the operation
of both the decision switch 4 and the selection switches 5a to 5d which
are provided separately, by manipulating a single key (key top 12),
thereby decreasing the number of operation keys that are required. A user
can obtain a necessary function (various functions provided in the
portable telephone system) easily by operating only one key (key top 12)
according to the instruction while looking at the information display.
Further, in the scroll switch device of the embodiment provided in the
portable telephone system of the embodiment, since the key top 12 and the
guide 9 are separately constituted, and a predetermined interstice is
provided between the key top 12 and the guide 9, force is not easily
transmitted to the guide 9, within a predetermined range, only by a slight
tilt of the key top 12. Accordingly, a malfunction of the selection
switches 5a to 5d is prevented. In other words, only when a user tilts the
key top 12 on purpose to try to operate the selection switches 5a to 5d,
will the selection switches 5a to 5d operate. As the size of this
interstice, various sizes may be considered so long as the selected size
can prevent from the above malfunction.
Further, in the scroll switch device of the embodiment provided in the
portable telephone system of the embodiment, since the respective
selection switches 5a to 5d are formed from a single layered domed click
plate, and the decision switch 4 is formed by overlaying two layers of the
domed click plate, the load against deformation of the decision switch 4
is much more than the selection switches 5a to 5d, thereby preventing a
malfunction from easily occurring in the decision switch 4 during the
operation of the selection switches 5a to 5d. As a method of increasing
the load against deformation of the domed switch, for example, the
diameter of the dome is increased. This method is not suitable for
downsizing, and the structure of this embodiment is more preferable.
In the scroll switch device of the embodiment provided in the portable
telephone system of the embodiment, since the convex portions 7b to 7e of
the key base 6 are in contact with the respective selection switches 5a to
5d, and the convex portion 7a of the key base 6 is separated from the
decision switch 4 by a predetermined interstice, it is possible to prevent
a malfunction from easily occurring in the decision switch 4 when the
selection switches 5a to 5d are operated. As the size of this interstice,
various sizes may be considered so long as the selected size can prevent
the above malfunction.
In the scroll switch device of the embodiment provided in the portable
telephone system of the embodiment, the through holes 8a to 8d are
provided in parts of the key base respectively between the portion
corresponding to the upper portion of the decision switch 4 and the
portions corresponding to the upper portions of the respective selection
switches 5a to 5d. These parts are thus weaker than other portions of the
key base. Therefore, when the key top 12 is pressed so as to operate the
decision switch 4, and when the key top 12 is tilted so as to operate the
selection switches 5a to 5d, it is possible to decrease the degree to
which force is transmitted to other of the switches, e.g. between the
decision switch 4 and the respective selection switches 5a to 5d, through
the key base 6. It is also possible to relieve the load resistance of the
key base 6 itself, thereby enabling assured and smooth operation of the
respective switches 4, 5a to 5d.
Since the distance between the decision switch 4 and the respective
selection switches 5a to 5d, and the mutual distance between the selection
switches 5a to 5d become very small, with the advance of miniaturization
of a scroll switch device, there arises a problem of interaction between
the respective switches 4, 5a to 5d caused by the resistance of the key
base 6 in pressing down and tilting the key top 12. In the structure of
the embodiment, however, since the force is dispersed by the through holes
8a to 8d provided between the respective switches 4, 5a to 5d, in order to
solve this problem, it is possible to prevent a malfunction of the
decision switch 4 and the selection switches 5a to 5d. As the size of this
through hole, various sizes may be considered so long as the holes prevent
this malfunction.
If the whole key base is soft, the portion corresponding to the upper
portion of the decision switch 4 and the portions corresponding to the
upper portions of the selection switches 5a to 5d must also be soft, and
the switching operation may work poorly. Use of the above structure of the
embodiment, however, can allow the portion of the key base 6 corresponding
to the upper portion of the decision switch 4 and the portions
corresponding to the upper portions of the selection switches 5a to 5d to
be hard to some degree, and make it difficult to transmit the force to
another switch at a time of pushing one of the decision switch 4 and the
selection switches 5a to 5d.
In the scroll switch device of the embodiment provided in the portable
telephone system of the embodiment, since the key sheet and the key base
of the scroll switch device are formed integrally with the key sheet and
the key base of the numeric key 15, and not separately therefrom, the
number of the parts and the cost can be decreased, thereby realizing
further downsizing and thinning of the scroll switch device.
In the scroll switch device of the embodiment provided in the portable
telephone system of the embodiment, since the key base 6, the guide 9, and
the key top 12 are integrally formed in their relative positions, it is
possible to realize the assured operation of the respective central
portions of the domed switches respectively forming the decision switch 4
and the selection switches 5a to 5d, by manipulating the key top 12.
The structure of the switching device and the portable terminal according
to the present invention is not restricted to the above-mentioned
structure, but various structures maybe used.
As one example, although in the embodiment the four selection switches 5a
to 5d are provided around the decision switch 4 in a shape of a cross at
regular intervals, various structures may be used for the number of the
selection switches and the arrangement thereof.
Though the embodiment is constituted in that an interstice is provided
between the key top 12 and the guide 9, the key top 12 and the guide 9 may
be separately contacted with each other in a slidable manner. In this
slidable structure, even when the key top 12 is pressed down to operate
the decision switch 4, a malfunction of the selection switches 5a to 5d
can be prevented because the pressure is not transmitted to the guide 9.
More specifically, the force of pressing down the central portion of the
key top 12 is not transmitted to the selection switches 5a to 5d, while it
is transmitted to the decision switch 4, thereby preventing such a
malfunction in which the selection switches 5a to 5d are operated by
mistake during operation of the decision switch 4.
Though the domed switch is formed by a metallic elastic material in the
embodiment, an elastic rubber or a spring may be used as the elastic
material, so long as it can be deformed by a force and returned to its
original shape by removing the force. Further, the domed switch is not
restricted to the structure shown in the embodiment, but various
structures may be used so long as it can be switched on and off by
pressing the curved protruded portion.
Though the selection switches 5a to 5d are formed as one-layered domed
switches and the decision switch 4 is formed as a two-layered domed switch
in the embodiment, another structure is possible so long as the decision
switch is stronger than the selection switches, e.g. by overlapping many
more layers of the domed switches.
Though the through holes 8a to 8d are provided respectively between the
parts of the key base 6 corresponding to the upper portion of the decision
switch 4 and the portions corresponding to the upper portions of the
respective selection switches 5a to 5d (hereinafter, referred to as
portion B), thereby making these parts weaker than other portions of the
switches, in the embodiment, it is also possible to make the portion B
weaker than the other portions by forming only the portion B of the key
base 6 from a soft material, or having only the portion B be thin.
Though the embodiment has been described in the case where the portable
terminal of the present invention is adopted to a portable telephone
system, the portable terminal of the present invention may be adopted to
various portable terminal systems, such as a PHS, so long as the selecting
processing of an operational instruction and the deciding processing of
the operational instruction can be performed.
The selecting processing of an operational instruction and the deciding
processing of the operational instruction performed by the switching
device of the present invention, and the portable terminal of the present
invention may be controlled by a processor running a control program
stored in a ROM, in a hardware resource provided with, for example, a
processor or a memory, or they may be arranged as a hardware circuit of
each independent function for executing the respective processing.
As set forth hereinabove, the switching device of the present invention
comprises a decision switch for deciding an operational instruction, a
selection switch disposed around the decision switch for selecting an
operational instruction, a key top whose central portion is disposed over
the decision switch, and a guide disposed around the key top. The
switching device is constructed such that pressure on the central portion
of the key top is transmitted to the decision switch, and a force
resulting from tilting of the key top away from a central axis is
transmitted to the selection switch through the guide. Also, the key top
and the guide are separately formed with an interstice provided
therebetween, thereby preventing such a malfunction in which the selection
switch is also operated during operation of t | | |
