JP2000339079A - Keyboard - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a keyboard having a depression part of a plastic sheet and having a comfortable click action function with respect to a sheet keyboard using an emboss sheet as a thinning means instead of key tops and actuators. SOLUTION: The keyboard has a membrane switch 1 provided with a plurality of switch elements 13 and an emboss sheet 4 stuck to the surface of the switch 1, the sheet 4 has a plurality of depression parts 41 formed by emboss working on positions opposed to respective switch elements 13 and each depression part 41 has at least one projection 42 projected to the switch element side on its center.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet keyboard using an embossed sheet in place of a key top or an actuator as means for thinning, and in particular, a keyboard having a click action function for feeding back a switch operation to an operator's finger. About.

As a keyboard pursuing the maximum thickness, there is a sheet keyboard in which a mechanism such as a key top and an actuator is omitted, and a dome-shaped pressing portion is generally formed as a means for feeding back a switch operation at the time of key operation to an operator. Have been.

[0003] The dome-shaped pressing portion reverses its convex direction in the process of being pressed, and the load changes before and after the pressing, causing a click action. The click action is transmitted to the operator's finger, and the switch operation at the time of operation is fed back to the operator.

In key switches and the like, a dome-shaped actuator made of metal is used to generate a click action. In a sheet keyboard, a dome-shaped actuator made of metal is used to generate a click action.

For example, a plurality of dome-shaped actuators are formed by embossing a plastic sheet into a dome shape and mounting a dome-shaped actuator made of metal therein, or by omitting the plastic sheet and directly embossing the metal sheet. Is done.

However, a sheet keyboard using a dome-shaped actuator made of metal may be expensive and have a short keying life. Therefore, there is a demand for the development of a keyboard in which the pressing portion is made of a plastic sheet and has a good click action function.

[0007]

2. Description of the Related Art FIG. 6 is a perspective view showing the structure of a conventional keyboard, FIG. 7 is a sectional side view for explaining the operation of the conventional keyboard, and FIG. 8 is a diagram showing an example of operating characteristics.

In FIG. 6, the conventional keyboard has a membrane switch 1 and an embossed sheet 2 adhered to the membrane switch 1.
The back surface is supported by the support panel 3 so as not to bend during operation.

The membrane switch 1 includes a plurality of switch elements 13 each having a pair of contact electrodes 11 and 12 opposed to each other with a gap therebetween. The embossed sheet 2 made of a plastic sheet has a plurality of switch elements 13 at positions opposed to the switch elements 13. It has a dome-shaped pressing part 21.

[0010] The embossed sheet 2 having a plurality of dome-shaped pressing portions 21 heats the upper mold and the lower mold formed so that the concavities and convexities are opposite to each other. It is formed by a method called embossing in which the material is sandwiched and pressed.

The embossed sheet 2 is adhered on the membrane switch 1 via a spacer 14 made of a plastic film or the like. A window 15 that is not subject to interference during the operation.

The spacer 14 interposed between the membrane switch 1 and the embossed sheet 2 does not always need to be formed exclusively, but is interposed as a base material between, for example, a double-sided adhesive used for sticking. Plastic film.

Before the pressing part 21 is pressed as shown in FIG. 7A, the contact electrodes 11 and 12 of the membrane switch 1 are opposed to each other with a gap therebetween. As shown in (2), the pressing section 21 is inverted, the switch element 13 is pressed, and the space between the contact electrodes 11 and 12 is closed.

FIG. 8 (a) shows a detailed description of the click action function when the pressing portion is pressed on such a keyboard. As shown in FIG. The load required for pushing down gradually increases.

When the stroke is further increased, the load, which has been increased with the change of the stroke, passes through a point where the load is reduced at once. This phenomenon means that the pressed portion, which has been maintaining the upwardly convex state, is reversed and has shifted to the downwardly convex state.

When the stroke is further increased, a point at which the load which has been reduced with the change in the stroke becomes heavier is reached. This phenomenon means that the pressing part presses the membrane switch, the space between the pair of contact electrodes closes, and the switch element operates.

[0017]

However, when a force for closing the contact electrodes is applied to the membrane switch when the depressed portion is reversed, the switch element operates, but if the repulsive force of the emboss sheet is weak, the membrane switch can be sufficiently operated. It cannot be pressed and the space between the contact electrodes does not close as shown in FIG.

If the distance between the switch elements is large, the diameter and height of the pressed part can be set to values sufficient for pressing the switch element. However, as the distance between the switch elements is reduced, the diameter and height of the pressed part are reduced. Is difficult to set to a value sufficient to press the switch element.

As a result, even if the pressing portion is reversed, the pressing of the membrane switch is insufficient as shown in FIG. 7 (c) and a gap is interposed between the contact electrodes, and as shown in FIG. Even after the inversion is detected, the space between the contact electrodes cannot be closed unless the pressing portion is continuously pressed.

Therefore, even if the pressed portion is reversed and the click action is transmitted to the operator, the switch does not always operate, and there is a problem that the operator may make a mistouch unless the operation is confirmed by means other than the click action. .

[0021] It is an object of the present invention to provide a keyboard in which the pressing portion is made of a plastic sheet and has a good click action function.

[0022]

FIG. 1 is a perspective view showing a keyboard according to the present invention. The same object is denoted by the same symbol throughout the drawings.

The above problem has a membrane switch 1 provided with a plurality of switch elements 13 and an embossed sheet 4 stuck on the membrane switch 1, and the embossed sheet 4 is located at a position facing the switch elements 13. This is achieved by the keyboard of the present invention which has a plurality of pressing portions 41 formed by embossing, and each of the pressing portions 41 has at least one projection 42 projecting toward the switch element 13 at the center.

By forming at least one projection protruding toward the switch element at the center of each depressed portion, the repulsive force of the embossed sheet when the depressed portion is inverted is applied to the membrane switch via the projection. It is possible to apply the voltage intensively.

As a result, even when the repulsive force of the embossed sheet is weak, the membrane switch is sufficiently depressed to close the gap between the contact electrodes, and the diameter and height of the depressed portion do not reach values sufficient for depressing the switch element. However, the space between the contact electrodes can be closed.

That is, it is possible to realize a keyboard in which the pressing portion is made of a plastic sheet and has a good click action function.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 2 is a plan view showing the shape of the pressed portion of the keyboard according to the present invention, FIG. 3 is a perspective view showing the cross-sectional shape of the pressed portion, FIG. 4 is a side sectional view for explaining the operation of the keyboard according to the present invention, and FIG. FIG. 9 is a view showing another embodiment of the keyboard according to the present invention.

As shown in FIG. 1, the keyboard according to the present invention comprises an embossed sheet 4 which is superimposed and adhered on the membrane switch 1.
The back surface is supported by the support panel 3 so as not to bend during operation.

The membrane switch 1 includes a plurality of switch elements 13 each having a pair of contact electrodes 11 and 12 opposed to each other with a gap therebetween. The embossed sheet 4 is connected to the membrane switch 1 via a spacer 14 made of a plastic film or the like. It is stuck on top.

The spacer 14 interposed between the membrane switch 1 and the embossed sheet 4 does not necessarily need to be specially formed. For example, the spacer 14 is interposed as a base material in the middle of a double-sided adhesive used for sticking. Plastic film.

The embossed sheet 4 made of a plastic sheet has a plurality of pressing portions 41 formed at positions facing the switch elements 13, and each pressing portion 41 has a pressing portion at the center.
1 that protrudes toward the switch element 13 when forming 41
The protrusions 42 are provided.

In general, the interval between the pressing portions of the keyboard is generally wide in the width direction and narrow in the depth direction in consideration of the movement of the hand, and the conventional dome-shaped pressing portion 21 having a circular shape has a sufficient diameter. Then, as shown in FIG. 2 (a), the adjacent pressed parts partially overlap.

As a result, even if the diameter of the depressed portion is a value sufficient for depressing the switch element, the repulsion force is weakened even if the depressed portion is inverted with the depression, and the inverted depressed portion causes the switch element of the membrane switch to be turned off. Since it cannot be pressed sufficiently, it causes mistouch.

Therefore, in the keyboard according to the present invention, as shown in FIG. 2B, the keyboard is wide in the width direction and narrow in the depth direction so that the pressed portions do not partially overlap each other even if it is arranged wide in the width direction and narrow in the depth direction. A plurality of oblong pressing portions 41 are arranged and formed on the embossed sheet.

By making the pressed portion oval as described above, there is no portion overlapping with the adjacent pressed portion and the repulsive force at the time of reversal is increased. However, when this is formed in a dome shape, the width in the depth direction is narrow, so that the diameter is small. The switch element cannot be sufficiently pressed down as in the case of the small pressing section.

In the keyboard according to the present invention, as shown in FIG. 3, the pressing portion 41 formed on the embossed sheet 4 has a substantially trapezoidal cross section, and the substantially trapezoidal pressing portion 41 has a base 43 rising from the embossed sheet 4. And the flat upper surface 44 are sloped
Connected by 45.

The shape of the slope 45 may be a surface whose height changes linearly as it approaches the upper surface portion 44 from the base portion 43 as shown in FIG. 3A, or as shown in FIG. 3B. As described above, the curved surface may have a curved shape whose height changes in a curved manner as it approaches the upper surface portion 44 from the base portion 43.

The embossed sheet 4 having the substantially trapezoidal pressing portion 41 is heated after heating the upper mold and the lower mold formed so that the concavities and convexities are opposite to each other. It is formed by a method called embossing in which the material is sandwiched and pressed.

As shown in FIG. 4A, the spacer 14 interposed between the embossed sheet 4 and the membrane switch 1 has an oval window 16, and the oval window 16 is opposed to the oval pressing portion 41. And does not interfere when the switch element 13 is pressed.

When the pressing portion 41 is pressed, the pressing portion 41 is inverted as shown in FIG. 4 (b), and the tip of the projection 42 projecting to the center pushes the switch element 13, and the tip of the projection 42
By pressing the button, the space between the contact electrodes 11 and 12 facing each other via the gap is closed.

When the pressure applied to maintain the inverted state is removed, the pressed section 41 that has been pressed and inverted is restored by the repulsive force. With the restoration of the pushed section 41, the switch element 13 is also switched as shown in FIG. The state shown in a) is restored and the space between the contact electrodes 11 and 12 that have been closed is opened.

In another embodiment of the keyboard according to the present invention, as shown in FIG.
When the pressing portion 41 is pressed and inverted, the tip of the plurality of projections 42 presses the switch element 13 to close the contact electrodes 11 and 12.

In the manufacturing process of a keyboard or the like, foreign matter which causes a trouble during assembly is prevented as much as possible from entering between members.
As shown in (b), the insulating foreign matter 17 may adhere to the contact electrode 11 or the contact electrode 12.

In the case where only one protrusion 42 is formed at the center of the pressing portion 41 as in the above embodiment, when the insulating foreign matter 17 is located immediately below the protrusion 42, the pressing portion 41 is inverted and the tip of the protrusion 42 is Even when the switch element 13 is depressed, the insulating foreign matter 17 is interposed therebetween and the space between the contact electrodes 11, 12 is not closed.

However, by forming a plurality of protrusions 42 at the center of the pressing portion 41, the pressing portion 41 is inverted and the protrusion 42
When the button 13 is depressed, as shown in FIG. 5 (c), even if the insulating foreign matter 17 is interposed therebetween, the portion between the contact electrodes 11 and 12 pressed by the other projections 42 is closed.

By forming at least one projection protruding toward the switch element at the center of each depressed portion, the repulsive force of the embossed sheet when the depressed portion is reversed is applied to the membrane switch via the projection. It is possible to apply the voltage intensively.

As a result, even when the repulsive force of the embossed sheet is weak, the membrane switch is sufficiently depressed to close the gap between the contact electrodes, and the diameter and height of the depressed portion do not reach values sufficient for depressing the switch element. However, the space between the contact electrodes can be closed.

That is, it is possible to realize a keyboard in which the pressing portion is made of a plastic sheet and has a good click action function.

[0049]

As described above, according to the present invention, it is possible to provide a keyboard having a good click action function in which the pressing portion is made of a plastic sheet.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a keyboard according to the present invention.

FIG. 2 is a plan view showing the shape of a pressed portion of the keyboard according to the present invention.

FIG. 3 is a perspective view illustrating a cross-sectional shape of a pressing unit.

FIG. 4 is a side sectional view for explaining the operation of the keyboard according to the present invention.

FIG. 5 is a diagram showing another embodiment of the keyboard according to the present invention.

FIG. 6 is a perspective view showing a configuration of a conventional keyboard.

FIG. 7 is a side sectional view for explaining the operation of a conventional keyboard.

FIG. 8 is a diagram illustrating an example of an operation characteristic.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Membrane switch 4 Embossed sheet 3 Support panel 11, 12 Contact electrode 13 Switch element 14 Spacer 16 Window 17 Insulating foreign matter 41 Pressed part 42 Projection 43 Base 44 Top surface 45 Slope

Claims (3)

[Claims] 1. A switch comprising: a membrane switch having a plurality of switch elements; and an embossed sheet stuck on the membrane switch, wherein the embossed sheet is formed by embossing at a position facing the switch element. A plurality of depressed portions, each of which has at least one protrusion protruding toward the switch element at the center. 2. The keyboard according to claim 1, wherein the pressing portion has an oval shape when the embossed sheet is viewed from the front. 3. The pressing unit has a substantially trapezoidal cross section in which a base rising from a sheet and a flat upper surface are connected by a slope, and the slope is closer to the upper surface from the base. 2. The keyboard according to claim 1, wherein the keyboard has a surface whose height changes linearly, or a curved surface whose height changes in a curve as it approaches the upper surface from the base.