JPH09280980A - Load sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To incorporate the function for establishing a two-dimensional coordinate signal by providing a sub-shaft on the upper surface of a mounting base having a cantilever beam. SOLUTION: A cantilever beam detector 23 is printed between the free end 24 and fixed end 25 of a cantilever beam 22 formed by cutting a mounting base 21, first strain detectors 29, 30 and second strain detectors 31, 32 are printed at the side of a main shaft 26, which is press fitted fixedly into the base 21 of the upper surface of the beam 22. The sub-shaft 34 is inserted into the hollow part 27 provided at the shaft 26 at the upper surface, and an operating part 33 is assembled fixedly to the lower surface from the upper direction of the shaft 26. When the upper surface of the shaft 34 is pressed by a finger toward the lower part, the shaft 34 presses the end 24 of the beam 22, and hence the detector 23 is deformed concavely to the lower surface. The resistance value of the detector 23 is raised by the deformation to detect the load applied to the shaft 34. The signal of the resistance change of the detector 23 is amplified, the signal level arriving at the threshold value to be decided as a click decided previously by a binary circuit is transmitted to provide establishing function.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load sensor used in a main operation unit of a multimedia device such as a personal computer, a portable terminal, an electronic notebook, or a controller of a game device.

[0002]

2. Description of the Related Art Recently, as a two-dimensional coordinate input device,
In addition, as a GUI (Graphical User Interface) input device for personal computers (hereinafter referred to as "PCs"), a load sensor that does not require a plane for operation, unlike a mouse, has been developed as one of pointing devices. Has been done.

A conventional load sensor is disclosed in Japanese Patent Laid-Open No. 7-24445.
The one disclosed in Japanese Patent Publication No. 59 is known.

A conventional load sensor will be described below with reference to the drawings. FIG. 5 is a perspective view of a conventional load sensor.

In the figure, reference numeral 1 is a mount made of a plate. Reference numeral 2 is a main shaft provided with a square columnar detection unit 4 provided with two pairs of strain detection elements fixed to the upper surface of the mounting base 1 and opposed to the side surfaces. Reference numeral 5 denotes a columnar operation portion provided on the upper portion of the main shaft 2.

A conventional load sensor having the following structure will be described. A force applied to the operation unit 5 by a finger or the like deforms the main shaft 2 by a component force perpendicular to the main shaft 2, and the strain detecting element 3 expands and contracts according to this deformation, and the resistance value changes. In other words, the strain detecting element 3 has a pair of pairs facing the side surface of the main shaft 2 and two pairs of strain detecting elements are arranged, so that the deformation of the main shaft 2 can be divided into two coordinates. By inserting the signals of the two coordinate axes, the arithmetic processing unit of the personal computer detects the direction and magnitude of the load applied by the finger or the like to the operation unit 5, and the pointer on the display (not shown) arrives. At that time, the position of the pointer was determined by a function (not shown) such as a switch provided separately from the load sensor.

[0007]

In the above-mentioned conventional structure, since only the direction and magnitude of the two-dimensional load parallel to the mounting base 1 can be detected, a separate function for determining the two-dimensional coordinate signal must be provided. It had the problem that it had to be done.

An object of the present invention is to solve the above conventional problems and to provide a load sensor having a function of determining a two-dimensional coordinate signal.

[0009]

In order to solve the above problems, the load sensor of the present invention has a structure in which a counter shaft is provided on the upper surface of a mount having a cantilever.

According to the present invention, a load sensor having a function of determining a two-dimensional coordinate signal can be obtained.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention has a cantilever, and a cantilever detecting element is provided between the free end and the fixed end of the cantilever. A mounting base, and a prism-shaped main shaft provided on the upper surface of the mounting base and having a hollow portion inside,
A structure including at least two strain detecting elements provided on a side surface of the main shaft, and a sub-shaft that is inserted into a hollow portion of the main shaft on an upper surface of the cantilever and protrudes from an upper surface of the main shaft. By doing so, there is an effect that it is not necessary to separately provide a function for determining a two-dimensional coordinate signal by the load sensor in a system such as a personal computer.

Further, the invention according to claim 2 is a mount having a cantilever and a cantilever detecting element provided between a free end and a fixed end of the cantilever, and A prismatic main shaft provided on the upper surface of the mounting base, at least two strain detecting elements provided on the side surface of the main shaft, and a protrusion that is fitted into the main shaft and protrudes toward the cantilever are provided. With the configuration including the auxiliary shaft, there is an effect that it is not necessary to separately provide a function for determining a two-dimensional coordinate signal by the load sensor in a system such as a personal computer.

Further, the invention according to claim 3 has a mount having a cantilever and a cantilever detecting element provided between a free end and a fixed end of the cantilever, and the cantilever. At least two strain detecting elements provided on the mounting base so as to face each other so as to surround the cantilever, a columnar main shaft provided on the upper surface of the mounting base and having a hollow portion therein, and the cantilever. A two-dimensional coordinate signal by a load sensor in a system such as a personal computer by being configured to be inserted into the hollow part of the main shaft on the upper surface of the main shaft and a sub shaft provided so as to project from the upper surface of the main shaft. This has the effect that there is no need to provide a separate function for this.

According to a fourth aspect of the present invention, there is provided a mount having a cantilever and a cantilever detecting element provided between a free end and a fixed end of the cantilever, and the cantilever. At least two strain detecting elements provided on the mounting base so as to be opposed to each other so as to surround the cantilever, a columnar main shaft provided on the upper surface of the mounting base, and the cantilever fitted into the main shaft. With the configuration including the auxiliary shaft provided with the protruding portion protruding toward, there is an effect that it is not necessary to separately provide a function for determining a two-dimensional coordinate signal by the load sensor in a system such as a personal computer.

The invention according to claim 5 is characterized in that the main axis of the invention according to claim 1 or 2 is a 4n prism (n is a natural number).
It consists of

(Embodiment 1) Hereinafter, a load sensor according to Embodiment 1 of the present invention will be described with reference to the drawings.

FIG. 1 is an exploded perspective view of a load sensor according to the first embodiment of the present invention. In the figure, reference numeral 21 is a mounting base having a cantilever 22 and made of a resin such as phenol or glass epoxy, or a plate-like elastic body such as ceramic. Reference numeral 23 is a cantilever detection element that is provided between the free end portion 24 and the fixed end portion 25 of the cantilever beam 22 and is composed of a strain gauge or the like. Reference numeral 26 denotes a quadrangular prism-shaped main shaft which is provided on the upper surface of the mounting base 21 and has a hollow portion 27 therein and is made of ceramic or resin. Reference numeral 28 denotes a recess provided on the lower surface of the main shaft 26 and in contact with the cantilever 22. Reference numerals 29 and 30 denote first strain detecting elements, which are provided on opposite side surfaces of the main shaft 26, and include strain gauges and the like for detecting strain in the X-axis direction. 31, 32
Is the main shaft 26 without the first strain detecting elements 29, 30.
Is a second strain detecting element including a strain gauge or the like provided on a side surface of the strain sensor for detecting strain in the Y-axis direction. Reference numeral 33 denotes an operation unit provided on the main shaft 26, in which a resin such as polybutylene phthalate or the like or a cylindrical portion (not shown) such as ceramic is covered with soft rubber or the like. 34 is in contact with the upper surface of the cantilever 22, is inserted into the hollow portion 27 of the main shaft 26, and
6 is an auxiliary shaft made of a resin such as polybutylene phthalate protruding from the upper surface of 6.

The assembling method of the load sensor having the above-described structure according to the first embodiment of the present invention will be described below.

A cantilever detecting element 23 is printed between a free end 24 and a fixed end 25 of a cantilever 22 formed by cutting the mount 21 in advance, and the first strain detecting element 2 is formed on the side surface.
The main shaft 26 provided by printing 9, 30 and the second strain detection elements 31, 32 is press-fitted and fixed to the mount 21 on the upper surface of the cantilever 22. Then, on the upper surface of the cantilever 22, the main shaft 26
The sub shaft 34 is inserted into the hollow portion 27 provided in the main shaft 26, and the operation portion 33 having the lower surface coated with the adhesive is assembled and fixed so as to be fitted from above the main shaft 26.

The operation of the load sensor according to the first embodiment of the present invention configured as described above will be described below.

A force applied to the operating portion 33 by a finger or the like deforms the main shaft 26 by a component force perpendicular to the axial direction of the main shaft 26, and in response to this deformation, the first strain detecting elements 29, 30 and the second strain detecting element 29. The strain detecting elements 31 and 32 expand and contract, and the resistance values of the first strain detecting elements 29 and 30 and the second strain detecting elements 31 and 32 change. Since the two pairs of the first strain detecting element and the second detecting element 29, 30, 31, 32 are provided so as to face each other, the deformation of the main shaft 26 can be divided into two coordinates. That is, the first strain detection element 2
The load is detected by using the voltage difference due to the resistance value change of 9 and 30 as the signal in one coordinate axis direction and the voltage difference due to the resistance value change of the second strain detection elements 31 and 32 as the signal in the other coordinate axis direction. Then, the arithmetic processing unit of the personal computer receives the signal input of the two coordinate axes, and moves the pointer on the display (not shown) according to the direction and magnitude of the load applied to the operation unit 33. Then, when the upper surface of the sub shaft 34 is pushed downward with a finger or the like, the sub shaft 34 pushes the free end portion 24 of the cantilever 22, so that the cantilever detection element 23 is deformed into a concave shape with respect to the lower surface. Due to this deformation, the resistance value of the cantilever detection element 23 becomes high, and the load applied to the counter shaft 34 can be detected. A processor (not shown) that amplifies and binarizes the signal of the resistance value change of the cantilever detection element 23, and the like to process the signal level change reaching a threshold value determined in advance as a predetermined click or more. The confirmation function can be realized by informing.

In the first embodiment, the main shaft 26 is a quadrangular prism, but it is a 4n prism (n is a natural number), and the first and second strain detecting elements 29, 30, 31, 32 are adjacent to each other. You can arrange it like this.

(Second Embodiment) A load sensor according to a second embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is an exploded perspective view of the load sensor according to the second embodiment of the present invention. In the figure, reference numeral 41 is a mounting base having a cantilever 42 and made of a resin such as phenol or glass epoxy, or a plate-like elastic body such as ceramic. Reference numeral 43 denotes a cantilever beam detection element which is provided between the free end portion 44 and the fixed end portion 45 of the cantilever beam 42 and includes a strain gauge or the like. Reference numeral 46 denotes a quadrangular prism-shaped main shaft provided on the upper surface of the mounting base 41 and made of ceramic or the like or resin or the like. Four
Reference numerals 7 and 48 denote first strain detection elements, which are provided on the opposite side surfaces of the main shaft 46 and include a strain gauge or the like for detecting strain in the X-axis direction. Reference numerals 49 and 50 denote second strain detecting elements, which are provided on the side surface of the main shaft 46 where the first strain detecting elements 47 and 48 are not provided, and which include a strain gauge for detecting strain in the Y-axis direction. Reference numeral 51 is an operating portion provided on the upper portion of the main shaft 46, in which a soft rubber or the like is covered on a cylindrical portion (not shown) made of resin or the like such as polybutylene phthalate or ceramics.
Reference numeral 52 is a sub shaft that is fitted to the main shaft 46 and is provided with a projecting portion 53 that projects toward the cantilever 42.

The assembling method of the load sensor according to the second embodiment of the present invention constructed as above will be described below.

A cantilever detecting element 43 is printed between a free end 44 and a fixed end 45 of a cantilever 42 formed by cutting the mounting base 41 in advance, and the first detecting element 4 is provided on the side surface.
The main shaft 46 provided by printing 7, 48 and the second detection elements 49, 50 is press-fitted and fixed to the mounting base 41. Then, the operation portion 51 having the lower surface coated with the adhesive is assembled and fixed so as to be fitted from above the main shaft 46. After that, the auxiliary shaft 52, which is provided in advance with the protruding portion 53 protruding to the lower portion and is in contact with the upper surface of the cantilever 42, is attached to the main shaft 46.
Fit it.

The operation of the load sensor according to the second embodiment of the present invention configured as described above will be described below.

The operation of the load sensor according to the second embodiment is the same as the operation of the auxiliary shaft 34 of the first embodiment and the auxiliary shaft 52 of the second embodiment.
The description will be omitted because it is the same as that of the protruding portion 53 having the same function.

Further, in the first embodiment, the main shaft 46 is a quadrangular prism, but it is a 4n prism (n is a natural number), and the first and second strain detecting elements 47, 48, 49, 50 are adjacent to each other. You can arrange it like this.

(Third Embodiment) A load sensor according to a third embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 is a perspective view of a load sensor according to the third embodiment of the present invention. In the figure, 61 is a cantilever beam 62.
Is a mounting base made of a plate-like elastic body such as a resin having phenol, glass epoxy, or the like, or ceramic.
Reference numeral 63 is a cantilever beam detection element that is provided between the free end portion 64 and the fixed end portion 65 of the cantilever beam 62 and is composed of a strain gauge or the like. 66 is provided on the upper surface of the mounting base 61 and has a hollow portion 6 inside.
7 is a cylindrical main shaft made of ceramic or the like having 7 or resin. 68 and 69 are provided on the upper surface of the mounting base 61 facing each other so as to surround the cantilever 62 as a center.
The first strain detection element is a strain gauge or the like that detects strain in the X-axis direction. Reference numerals 70 and 71 are, for example, strain gauges which are provided on the upper surface of the mounting base 61 on which the first strain detecting elements 68 and 69 are not provided so as to face each other so as to surround the cantilever 62, and which detect strain in the Y-axis direction. Is a second strain detecting element. 72 is the upper surface of the cantilever 62, which is a hollow portion 67 of the main shaft 66.
Is a sub-shaft made of resin such as polybutylene phthalate, which is inserted into the main shaft 66 and protrudes from the upper surface of the operation portion 73 on the upper surface of the main shaft 66.

The method of assembling the load sensor of the third embodiment differs from that of the first embodiment shown in FIG.
Is a cylindrical shape, and the first strain detecting elements 68, 69 and the second strain detecting elements 70, 71 are provided on the mounting base 61 so as to face each other so as to surround the cantilever 62 as a center.

The operation of the load sensor of the third embodiment is the same as that of the first and second strain detecting elements 29, 3 of the first embodiment.
Since it has the same operation as 0, 31, 32, the description thereof will be omitted.

(Embodiment 4) Hereinafter, a load sensor according to Embodiment 4 of the present invention will be described with reference to the drawings.

FIG. 4 is an exploded perspective view of the load sensor according to the fourth embodiment of the present invention. In the figure, reference numeral 81 is a mounting base having a cantilever 82 and made of a resin such as phenol or glass epoxy, or a plate-like elastic body such as ceramic. Reference numeral 83 denotes a cantilever beam detection element including a strain gauge or the like provided between the free end portion 84 and the fixed end portion 85 of the cantilever beam 82. Reference numeral 86 denotes a cylindrical main shaft provided on the upper surface of the mounting base 81 and made of ceramic or the like or resin or the like. 87,
Reference numeral 88 denotes a first strain detecting element, which is provided on the mounting base 81 so as to be opposed to each other so as to surround the cantilever 82 as a center, and includes a strain gauge or the like for detecting strain in the X-axis direction. 89, 90
Is the cantilever 82, and the first can face the cantilever 82 so as to surround it.
Is a second strain detecting element including a strain gauge or the like provided on the upper surface of the mounting base 81 on which the strain detecting elements 87 and 88 are not provided and which detects strain in the Y-axis direction. Reference numeral 91 denotes an operating portion provided on the upper portion of the main shaft 86, in which a soft rubber or the like is covered on a cylindrical portion (not shown) made of resin or the like such as polybutylene phthalate or ceramics. Reference numeral 92 denotes a sub-shaft which is fitted on the main shaft 86 on the upper surface of the cantilever 82 and which is provided with a projecting portion 93 which projects toward the cantilever 82.

The operation of the load sensor according to the fourth embodiment is the same as that of the second embodiment with respect to the first and second strain detecting elements 47 and 4.
Since it has the same operation as 8, 49, 50, the description thereof will be omitted.

[0037]

As described above, according to the present invention, the mounting base is provided with the cantilever beam having the cantilever beam strain detecting element between the fixed end portion and the free end portion, and the auxiliary shaft faces the upper surface of the cantilever beam. Since the configuration is provided as described above, it is possible to provide a load sensor in a system such as a personal computer in which a function for determining a two-dimensional coordinate signal by the load sensor is added.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a load sensor according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of a load sensor according to a second embodiment of the present invention.

FIG. 3 is a perspective view of a load sensor according to a third embodiment of the present invention.

FIG. 4 is an exploded perspective view of a load sensor according to a fourth embodiment of the present invention.

FIG. 5 is a perspective view of a conventional load sensor.

[Explanation of symbols]

 21 mounting base 22 cantilever 23 cantilever detection element 24 free end 25 fixed end 26 main shaft 27 hollow portion 29, 30 first strain detection element 31, 32 second strain detection element 34 counter shaft

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Katsuhiko Omoto 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] 1. A mount having a cantilever and a cantilever detection element provided between a free end and a fixed end of the cantilever, and an internal mount provided on the upper surface of the mount. A prismatic main shaft having a hollow portion, at least two strain detecting elements provided on the side surface of the main shaft, and an upper surface of the cantilever that is inserted into the hollow portion of the main shaft and protrudes from the upper surface of the main shaft. Load sensor consisting of a counter shaft provided so as to do so. 2. A mount having a cantilever and a cantilever detecting element provided between a free end and a fixed end of the cantilever, and a corner provided on an upper surface of the mount. A load sensor comprising a columnar main shaft, at least two strain detecting elements provided on a side surface of the main shaft, and a sub shaft provided with a protruding portion that is fitted into the main shaft and protrudes toward the cantilever. 3. A mount having a cantilever and a cantilever detection element provided between a free end and a fixed end of the cantilever, and a mounting base surrounding the cantilever. At least two strain sensing elements that are provided on the mounting base oppositely to each other, a columnar main shaft that is provided on the upper surface of the mounting base and has a hollow portion inside, and a hollow portion of the main shaft on the upper surface of the cantilever. And a counter shaft that is inserted into the main shaft and that projects from the upper surface of the main shaft. 4. A mount having a cantilever and a cantilever detecting element provided between a free end and a fixed end of the cantilever, and a mounting base surrounding the cantilever. At least two strain detecting elements that are provided on the mounting base oppositely to each other, a columnar main shaft provided on the upper surface of the mounting base, and a protrusion that is fitted into the main shaft and protrudes toward the cantilever. A load sensor consisting of an auxiliary shaft provided. 5. The load sensor according to claim 1, wherein the main shaft is a 4n prism (n is a natural number).