JP2011081980A - Elastic spacer for force transmission between omnidirectional pressure sensor and key top - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an elastic spacer for force transmission arranged between a key top and an omnidirectional pressure sensor capable of correctly controlling a gap between the key top and a sensor. <P>SOLUTION: The elastic spacer for force transmission, arranged between the omnidirectional pressure sensor and the key top, includes: a ring-shaped thick supporting part supported in relation to the omnidirectional pressure sensor; a circular thick central part contacting a lower surface of the key top; a ring-shaped thin middle part arranged to keep the gap between the sensor and the key top by elastically supporting the middle part from the supporting part so that the middle part faces upward; and a protruded part arranged on the lower surface of the middle part to face a pressure-sensing part of the sensor. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to an elastic spacer for force transmission between an omnidirectional pressure sensor and a key top.

A sensor capable of detecting a 360-degree direction such as a joystick by the pressure from above and giving strength to a specific direction by a pressing pressure is referred to as an omnidirectional pressure sensor. For example, Upside Co., Ltd .: VECTOR-PAD (vector pad) of 4-10-7 Tomiyama Building 4F Nihonbashi Honcho, Chuo-ku, Tokyo is an example.

The omnidirectional pressure sensor 10 (hereinafter sometimes simply referred to as a sensor) has a thin coin shape. As shown in the cross-sectional view of FIG. 1, the substrate 12, the silicon rubber 14, the conductive rubber 16, and the copper electrode 18 are used. It is configured. In FIG. 1, the sensor obtains 360-degree direction data and an analog current output corresponding to the pressure intensity by applying pressure from the top of the silicon rubber 14. The current output is converted into digital data by a dedicated IC (not shown). The sensor 10 has a diameter of about 10 mm and a thickness of about 1.1 mm, and an air layer of about 0.2 mm is interposed between the conductive rubber 16 and the copper electrode 18. When pressure is applied from the upper part of the sensor 10, the air layer is deformed. At this time, the change in electrostatic capacitance using the conductive rubber 16 and the copper electrode 18 as both electrodes of the capacitor is captured two-dimensionally.

  The change in capacitance is output as a change in current and converted into a digital voltage output by a dedicated IC. As a result, an output as shown in FIG. 2 is obtained. The characteristic of such an omnidirectional pressure sensor is that a pressure from about 0.3 N can be detected. That is, a highly sensitive sensor can be realized. Utilizing such characteristics, omnidirectional pressure sensors have been used in input devices for mobile phones, digital cameras, and car navigation systems. This sensor is particularly suitable for computer input devices such as a mouse which is a pointing device. However, the present invention is not limited to computer input devices.

  Such an omnidirectional pressure sensor is characterized by extremely high pressure detection sensitivity. For this reason, it is impossible to directly attach the key top, which is a part that is directly touched by a finger to apply pressure to the sensor, to the sensor.

That is, the size of the sensor is about 10 mm in diameter, and the finger is too large to transmit pressure directly to the sensor.
The sensor can detect from 0.3N, that is, a load of about 30 g, and the key top load itself is offset.
The pressure sensing part of the sensor is due to impact, wear, weak durability, and the like.
A gap of about 50 to 300 micrometers was required between the sensor and the key top.

  That is, with reference to FIG. 3, the key top 20 disposed in the opening of the upper case 22 must be supported with a gap from the upper surface of the silicon rubber 14 of the sensor 10.

  In the conventional example, the key top 20 is supported by the upper case 22 as shown in FIG. That is, the key top 20 is supported by the spring 26 attached to the upper case 22. Therefore, when one of the circumferential portions of the key top 20 is pushed with an index finger, as shown in FIG. 5, the spring 26 is bent, and the pushed portion moves downward and is provided on the silicon rubber 14 of the sensor 10. The pressure sensor 14a (not shown in FIGS. 1 to 3 for the sake of explanation and illustration) is pressed down to detect the pressure.

The spring 26 used here is made of stainless steel in a spiral shape or made of thin plastic.

  However, in the configuration of the conventional example described above, due to dimensional errors between the lower case that fixes the sensor and the upper case that supports the key top during mass production, the lower part of the key top and the sensor The gap with the top surface could not be managed accurately. If this gap cannot be managed, the sensitivity may be felt differently when a pressure output of 360 degrees is obtained with a finger.

  The present invention is an elastic spacer for force transmission disposed between an omnidirectional pressure sensor and a key top, and includes a ring-shaped thick support portion supported in association with the omnidirectional pressure sensor and a lower surface of the key top. A circular thick central portion that abuts, and a thin ring-shaped intermediate portion for elastically supporting the central portion upward from the support portion to provide a gap between the sancer and the key top And a protruding portion provided on the lower surface of the intermediate portion so as to face the pressure sensing portion of the sensor.

  According to the present invention, it is possible to obtain an elastic spacer for force transmission that is disposed between an omnidirectional pressure sensor and a key top that cannot accurately manage a gap between the key top and the sensor.

It is a schematic sectional drawing of an omnidirectional pressure sensor. It is a graph which shows the relationship between the force applied to an omnidirectional pressure sensor, and an output. It is a schematic sectional drawing which shows arrangement | positioning of an omnidirectional pressure sensor and a keytop. It is a schematic sectional drawing which shows the structure of the prior art example which supports a keytop in an upper case. It is a schematic sectional drawing which shows the operation state of the prior art example shown in FIG. It is a schematic sectional drawing which shows the elastic spacer for force transmission of this invention with an omnidirectional pressure sensor and a keytop. It is a figure which shows the elastic spacer for force transmission of this invention, FIG. 7a is the top view, and FIG. 7b is the side view. It is a schematic sectional drawing which shows the operation state of the elastic spacer for force transmission of this invention.

The present invention is an elastic spacer for force transmission disposed between an omnidirectional pressure sensor and a key top. In the present invention, the elastic spacer for transmitting force includes a ring-shaped thick support portion supported in association with the omnidirectional pressure sensor, a circular thick central portion that contacts the lower surface of the key top, and the support portion to the center. A ring-shaped thin intermediate portion for elastically supporting the portion upward and providing a gap between the sensor and the key top, and the intermediate portion facing the pressure sensing portion of the sensor And a projecting portion provided on the lower surface.

  FIG. 6 is a view showing an elastic spacer for force transmission according to the present invention together with an omnidirectional pressure sensor and a key top. FIG. 6 shows the sensor 10 described with reference to FIG. 1 and the key top 20 described with reference to FIG. In the present invention, a force transmission elastic spacer 30 (hereinafter also referred to simply as a spacer) is provided between the sensor 10 and the key top 20 to transmit the force applied to the key top to the sensor 10. Yes. The spacer 30 is made of silicon rubber, and silicon rubber having a hardness of about 60 degrees to 40 degrees is used. The key top 20 is simply placed on the spacer 30 or is integrated with the spacer 30 with an adhesive or adhesive tape.

The spacer 30 is deformed in the direction of the applied force when the force from the key top is applied, and the circular thick central portion 30a that hardly deforms when the force from the key top is applied, and extending outward from the central portion 30a. A ring-shaped extremely thin intermediate portion 30b, a ring-shaped thick support portion 30c that extends further outward from the intermediate portion and hardly deforms when a force from the key top is applied, and a lower surface of the central portion 30a. The ring-shaped projecting portion 30d. Here, the thin portion, that is, the intermediate portion 30b has a thickness of 50 to 200 microns, and the thick portion, that is, the central portion 30a and the support portion 30c may have a thickness of about 150 to 400 microns.

The support portion 30c is disposed on the plate 10a to which the sensor 10 is attached. The intermediate portion 30b flexibly exerts a force upward on the central portion 30a so that the central portion 30a is in contact with the lower surface of the key top 20. Due to this structure, a certain gap can be maintained between the sensor 10 and the key top 20. This is because in the conventional example, as described above, the distance between the sensor and the key top is determined by the distance between the upper case and the lower case. It can be managed much more accurately. Further, the protruding portion 30 d of the spacer 30 is formed at a position facing the pressure sensing portion 14 a of the sensor 10.

  In FIG. 7, each part of the spacer is shown in order to better understand the shape of the spacer. Note that the protrusion is not shown because it is formed inside the spacer.

Next, as shown in FIG. 8, when the finger 28 presses one circumferential portion of the key top 20, the thin intermediate portion 30b of the spacer 30 corresponding to the pressed portion of the key top 20 is deformed downward. Then, the protruding portion 30d pushes the pressure sensing portion 14 of the sensor 10. As a result, the pressure is detected and extracted as a signal including the direction. When the intermediate portion 30b is formed thick, only the desired corresponding portion is not pressed, that is, the adjacent portions are also pressed, and the pressure is not correctly detected.

DESCRIPTION OF SYMBOLS 10 Omnidirectional pressure sensor 10a Plate which has attached the omnidirectional pressure sensor 12 Board | substrate 14 Silicon rubber 14a Silicon rubber pressure sensing part 16 Conductive rubber 18 Copper electrode 20 Key top 22 Upper case 26 Spring 28 Finger 30 Elastic spacer for force transmission 30a Central portion 30b of the force transmission elastic spacer 30b Intermediate portion 30c of the force transmission elastic spacer Support portion 30d of the force transmission elastic spacer Projection portion of the force transmission elastic spacer

Claims (3)

  An elastic spacer for force transmission arranged between the omnidirectional pressure sensor and the key top, which is a ring-shaped thick support portion supported in association with the omnidirectional pressure sensor, and a circular shape abutting on the lower surface of the key top A thick central portion, a ring-shaped thin intermediate portion for elastically supporting the central portion from the support portion so as to face upward, and providing a gap between the sensor and the key top; An elastic spacer for force transmission, comprising: a protruding portion provided on a lower surface of the intermediate portion so as to face the pressure sensing portion.   2. The force transmission elastic spacer according to claim 1, wherein the spacer is made of silicon rubber.   2. The force transmission elastic spacer according to claim 1, wherein the key top is placed on the spacer, or the key top is integrated with the spacer by adhesion or adhesive tape. Elastic spacer for use.