JP2003083819A - Force detection device using variable resistance element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the power consumption. SOLUTION: A flat resistor RR comprising carbon is formed on a substrate 110. A circular cavity region is provided on the center part of the resistor RR, and semicircular contact electrodes S1, S2 are formed. An elastically deformable body 121 to be deformed downward by function of an external force is arranged over the substrate 110, and a hemispheric contact conductor C comprising conductive rubber is mounted on the under surface thereof. The conduction state between terminals T3, T4 is monitored, and, only when the contact electrodes S1, S2 are conducted, a prescribed voltage is applied between terminals T1, T2, and a resistance value between two points sandwiching the resistor RR is measured. When a great external force functions, the contact conductor C is pressed downward to enlarge the contact area to the resistor RR. By utilizing reduction of the resistance value between the two points sandwiching the resistor RR resulting therefrom, the magnitude of the external force is detected based on the measured resistance value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a force detecting device using a variable resistance element, and more particularly to an electronic device such as a mobile phone or a game playing device which executes a predetermined process based on a predetermined program. The present invention relates to a force detection device suitable for use as an input device or the like for performing an operation input indicating a predetermined operation amount.

[0002]

2. Description of the Related Art Electronic devices such as mobile phones and game playing devices receive a predetermined operation input by a user, and a program proceeds based on the operation input. Usually, this kind of operation input is often performed while looking at the cursor and other indicators displayed on the display screen, and it is required to input in four directions, up, down, left and right, or in eight directions including diagonal directions. Is common. In order to perform such directional input, a so-called joystick type device is used. This type of device usually has a built-in two-dimensional force detection device, and detects the X-axis direction component and the Y-axis direction component of the applied force separately to determine the direction of the applied operation input. The operation amount and will be detected. For example, an operation input in which the X-axis direction component is +5 indicates an operation amount of 5 to the right, and an operation input in which the Y-axis direction component is −8 indicates an operation amount of 8 in the downward direction. It will be. Of course, it is also possible to detect an operation input applied in an oblique direction by performing an operation that combines the X-axis direction component and the Y-axis direction component.

In addition, electronic devices such as mobile phones and game play devices require click inputs in addition to the directional operation inputs described above. This click input is basically an input indicating a binary state of ON / OFF, but it is important to give the operator a feeling of clicking (so-called click feeling).
It is necessary to secure a certain amount of stroke and apply a reaction force to the pressing force applied from the fingertip. As a switch suitable for performing ON / OFF input with such a click feeling, a switch using elasticity of an elastic material such as rubber or metal is generally used,
A force detection device having a function of performing an operation input in a predetermined direction together with a click input is in practical use.

For an input device for a relatively inexpensive electronic device such as a mobile phone or a game playing device, it is desirable to use an inexpensive force detection device having a structure as simple as possible. As such a force detection device, Japanese Patent Application No. 2000-13201
Japanese Patent No. 2 discloses a force detection device using a variable resistance element. This device uses a variable resistance element whose resistance value changes according to the applied pressure, and by detecting the change in the resistance value of this variable resistance element, the applied external force can be detected. it can. The variable resistance element can be configured by, for example, a plate-shaped resistor and a contact conductor that can contact the resistor. If the contact area of the contact conductor with the resistor changes depending on the magnitude of the external force applied, the electrical resistance between two predetermined points of the resistor changes depending on the size of this contact area. It will be. Therefore, it is possible to detect the magnitude of the applied external force based on the change in the electric resistance. Since both the resistor and the contact conductor are extremely simple electric circuit elements, the force detection device based on such a principle has an advantage that the structure is very simple and the manufacturing cost can be reduced.

[0005]

In the force detecting device using the variable resistance element described above, it is essential to measure the electric resistance of the resistor in order to obtain the detected value of the applied force. However, in order to measure the electric resistance of the resistor, it is necessary to pass a current through the resistor, so that power consumption cannot be avoided to some extent during measurement. Therefore, when the force detection device using the variable resistance element described above is incorporated into various electronic devices, there has been a problem that power consumption is increased as a whole. In particular, in electronic devices such as mobile phones and game play devices that operate on a built-in battery, a design that minimizes battery consumption is desired. Although it has a great advantage in terms of power consumption, it has a great disadvantage in terms of power consumption.

Of course, it is possible to employ a method of intermittently operating an electric resistance measuring circuit that consumes a large amount of power to reduce the overall power consumption. For example, if the circuit is operated for 20 msec,
200 that the circuit will be stopped for the next 180 msec
If the intermittent operation of the msec cycle is performed, the measurement can be performed 5 times per second, and the power consumption can be reduced to about 1/5. However, even if such a method is adopted, it is not possible to completely suppress wasteful power consumption. Considering the actual usage of mobile phones, etc., the time during which the input operation for moving the cursor is performed is very limited, and the power consumption is high while the operator does not perform any operation input. Operating the circuit is not efficient.

Therefore, an object of the present invention is to provide a force detection device using a variable resistance element capable of efficiently suppressing power consumption.

[0008]

[Means for Solving the Problems] (1) A first aspect of the present invention is a force detection device using a variable resistance element having a function of detecting the magnitude of an applied external force. An elastic deformable body that is disposed at a position facing the substrate, at least a portion of which is made of a material that elastically deforms, and that is displaced with respect to the substrate by elastic deformation based on the action of an external force; A variable resistance element having a property of changing the resistance value between two predetermined points according to the pressure applied by the displacement of the elastic deformable body, and a pair of contact electrodes. When the external force of a predetermined magnitude or more acts on the elastically deformable body while maintaining the electrically insulating state between the working electrodes, the elastically deformable body is deformed to electrically connect the pair of contact electrodes. A switching element that performs a simple switching function, A detection circuit that detects a resistance value between two points of the variable resistance element as an electric signal is provided, and the detection circuit can perform a detection function of outputting the resistance value between the two points as an electric signal, and It is configured so that it is possible to select two modes, a standby mode that cannot perform the detection function but consumes less power than the detection mode, and that can maintain a standby state for shifting to the detection mode. The electrical state between the contact electrodes is
In the insulated state, the standby mode is selected, and in the conductive state, the detection mode is selected.

(2) A second aspect of the present invention is the above-mentioned first aspect.
In the force detection device using the variable resistance element according to the aspect, the pair of contact electrodes included in the switching element include a contact fixed electrode formed on the substrate and a contact displacement electrode formed on the elastic deformable body side. And a structure in which the displacement electrode for contact physically contacts the fixed electrode for contact due to the deformation of the elastic deformable body when an external force of a predetermined magnitude or more is applied to the elastic deformable body. Is.

(3) A third aspect of the present invention is the above-mentioned first aspect.
In the force detection device using the variable resistance element according to the aspect, the switching element is in contact with both of the pair of contact electrodes formed on the substrate and the pair of contact electrodes at the same time, so that the pair of contact electrodes is formed. And an intermediary electrode capable of conducting electric current between the intermediary electrode and the intermediary electrode, which normally does not contact either of the pair of contact electrodes, or maintains contact with only one of them. However, when an external force of a predetermined magnitude or more is applied to the elastically deformable body, the elastically deformable body is deformed so as to be in contact with both of the pair of contact electrodes at the same time.

(4) The fourth aspect of the present invention is the above-mentioned third aspect.
In the force detection device using the variable resistance element according to the above aspect, the intermediary electrode is formed at a position where displacement of the elastically deformable body occurs.

(5) A fifth aspect of the present invention relates to the above-mentioned fourth aspect.
In the force detecting device using the variable resistance element according to the first aspect, the pair of contact electrodes includes a ring-shaped first electrode and the first electrode.
An annular second electrode disposed adjacent to the outer side of the electrode, and the intermediary electrode is formed at a position where both the first electrode and the second electrode can be simultaneously contacted at any position. is there.

(6) A sixth aspect of the present invention relates to the above-mentioned fourth aspect.
In the force detecting device using the variable resistance element according to the aspect, a plurality of N electrodes belonging to the first group and a plurality of N electrodes belonging to the second group are arranged on the substrate,
The i-th (1 ≦ i ≦ N) electrode belonging to the first group and the i-th electrode belonging to the second group are adjacent to each other, and belong to the first group arranged adjacent to each other. A pair of contact electrodes are configured by the electrodes to be connected and the electrodes belonging to the second group, and the total number of electrodes is N.
The pair of contact electrodes is formed as a set.

(7) A seventh aspect of the present invention is based on the above-mentioned sixth aspect.
In the force detection device using the variable resistance element according to the aspect, the electrodes belonging to the first group and the electrodes belonging to the second group are alternately arranged along the circumference defined on the substrate, and the mediation is performed. The electrodes are formed along the "circumference facing the above circumference" on the elastically deformable body side.

(8) An eighth aspect of the present invention relates to the above-mentioned first aspect.
~ In the force detecting device using the variable resistance element according to the seventh aspect, the variable resistance element is a conductive body for contact arranged in a position facing the resistance body arranged on the substrate and the resistance body of the elastic deformation body. The contact conductor is made of a material that elastically deforms, and at least the contact surface for the resistor has conductivity, and the contact conductor resists the pressure applied by the displacement of the elastic deformable body. The shape of the contact surface with respect to the body is changed, and the resistance value between two points sandwiching the "contact position of the contact conductor" on the resistor is changed according to the change of the area of the contact surface. It was done like this.

(9) A ninth aspect of the present invention is the above-mentioned eighth aspect.
In the force detection device using the variable resistance element according to the aspect, the contact conductor is made of conductive rubber.

(10) According to a tenth aspect of the present invention, in the force detecting device using the variable resistance element according to the above-mentioned first to seventh aspects, the variable resistance element is a first resistor, First
A second resistor arranged at a position facing the resistor of
The surface portion of at least one of the first resistor and the second resistor facing the other has a concavo-convex structure that causes elastic deformation, and the surface portion of the first resistor and the second resistor has The area of the contact surface between the first resistor and the second resistor is changed, and a predetermined point connected to the first resistor side and the second resistor are connected according to the change of the area of the contact surface. The resistance value between a predetermined point connected to the resistor side is changed.

(11) According to an eleventh aspect of the present invention, in the force detecting device using the variable resistance element according to the tenth aspect, the first resistor and the second resistor are connected to each other by a pressure-sensitive conductive element. It is composed of a sexual ink.

(12) According to a twelfth aspect of the present invention, in the force detecting device using the variable resistance element according to the above-mentioned third aspect, the variable resistance element is arranged on the substrate, and a void region is provided in the central portion. And a contact conductor disposed at a position facing the resistor of the elastically deformable body, the contact conductor being made of an elastically deformable material, and at least the resistor. The contact surface with respect to is conductive and has a shape in which the area of the contact surface with respect to the resistor changes according to the pressure applied by the displacement of the elastic deformable body. The resistance value between two points sandwiching the "contact position of the contact conductor" on the resistor is changed, and a pair of contact electrodes forming a switching element are formed in the central portion of the resistor. Placed in the void area, the contact conductor switches It is obtained by configured to function as an intermediary electrode constituting the elements.

(13) A thirteenth aspect of the present invention is a force detecting device using the variable resistance element according to the twelfth aspect, wherein the resistance value is sufficiently larger than the resistance value between two points of the resistor. A resistance element with a resistance element is provided, and a circuit for detecting a conduction state between a pair of contact electrodes forming a switching element and a circuit for detecting a resistance value between these two points are isolated from each other via the resistance element. It was done like this.

(14) According to a fourteenth aspect of the present invention, in the force detecting device using the variable resistance element according to the above-mentioned first to thirteenth aspects, a voltage is applied between two points of the resistor in the detection circuit. A circuit for detecting the resistance value between the two points by applying the voltage is prepared, and the voltage is applied in the detection mode and the voltage is not applied in the standby mode.

(15) According to a fifteenth aspect of the present invention, in the force detecting device using the variable resistance element according to the fourteenth aspect, the conduction / insulation state of the pair of contact electrodes forming the switching element is set. It is used as an ON / OFF switch so that a voltage is applied between two points of the resistor.

(16) According to a sixteenth aspect of the present invention, in the force detecting device using the variable resistance element according to the above-mentioned first to fifteenth aspects, an operation panel made of a rigid material is attached to an elastically deformable body, The elastically deformable body is displaced based on an operation input applied to the operation panel.

(17) According to a seventeenth aspect of the present invention, in the force detecting device using the variable resistance element according to the above-mentioned first to sixteenth aspects, the elastic deformable body is made substantially parallel to the upper surface of the substrate. And a side wall portion for fixing the periphery of the film-like portion to the upper surface of the substrate, and columnar protrusions extending downward from a predetermined plurality of locations on the lower surface of the film-like portion. However, at least a part of the film-shaped portion and the columnar protrusions are made of an elastic material.

(18) According to an eighteenth aspect of the present invention, in the force detecting device using the variable resistance element according to the seventeenth aspect, the elastically deformable body is made of integrally molded rubber. .

(19) A nineteenth aspect of the present invention is for an electronic device for performing an operation input indicating an operation amount in a predetermined direction to an electronic device that executes a predetermined process based on a predetermined program. In the input device, the force detection device using the variable resistance element according to the above-described first to eighteenth aspects is incorporated,
The external force detected by this force detection device can be handled as an operation amount.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on illustrated embodiments.

§1. Of force detector using variable resistance element
Basic Structure The present invention relates to a force detection device using a variable resistance element,
The present invention provides a novel method for efficiently suppressing power consumption. Therefore, here, the basic structure of the force detection device using the variable resistance element to which the present invention is applied will be described by presenting an example. The example described here is a force detection device disclosed as a basic embodiment in the above-mentioned Japanese Patent Application No. 2000-132012.

FIG. 1 is a side sectional view showing the structure of a force detecting device using this variable resistance element. This force detection device
The X-axis direction of the external force acting in the XYZ three-dimensional coordinate system,
It has a function of independently detecting each component in the Y-axis direction and the Z-axis direction, and main components are the substrate 110, the elastic deformable body 120, and the fixing member 130 as shown in the drawing. Here, for convenience of description, the origin O of the XYZ three-dimensional coordinate system is defined at a substantially central position on the upper surface of the substrate 110.
It is assumed that the upper surface of the substrate 110 is arranged along the XY plane. In the coordinate system shown in FIG. 1, the X axis is to the right of the figure,
The Z axis is defined in the upper direction of the figure, and the Y axis is defined in the lower direction perpendicular to the paper surface.

As described above, the substrate 110 is a plate-shaped rigid substrate having an upper surface along the XY plane,
In this force detecting device, a glass epoxy substrate is used. Of course, the material of the substrate 110 is not particularly limited, and any substrate may be used as long as it is a substrate having sufficient rigidity so as not to be deformed by the action of a force described later. However, since it is necessary to form a plurality of resistors that are electrically independent from each other on the upper surface, it is necessary that at least the surface on which the resistors are formed have an insulating property. Therefore, for practical use, it is preferable to use a glass epoxy substrate, a polyimide substrate, a glass substrate or the like made of an insulating material. Of course, a metal plate can be used as the substrate 110, but in this case, it is necessary to form an insulating film on at least the resistor forming portion on the upper surface.

FIG. 2 is a top view of the substrate 110,
The dashed-dotted rectangle is the elastic deformable body 12 arranged on this.
The position of 0 is shown. The substrate 110 shown in FIG.
2 is a cross section obtained by cutting the substrate 110 shown in FIG. 2 along the X axis. The upper surface of the substrate 110 is included in the XY plane of the XYZ three-dimensional coordinate system, and the origin O is defined at the center thereof. As shown in the figure, six resistors R1 to R6 are formed on the upper surface of the substrate 110. These resistors R
In the case of this force detection device, 1 to R6 are all resistors made of flat plate carbon. The resistor used in the present invention may be of any material as long as it is a material having a resistance value suitable for the measurement described below, and may have any shape, In practice, it is preferable to use a plate-like resistor that can be formed on the upper surface of the substrate 110 by printing using a material such as carbon.

Here, an important point is that these resistors R1 to R1
It is the arrangement of R6. As shown in the figure, the first resistor R1 is arranged in the X-axis positive region on the upper surface of the substrate 110, and
Is placed in the X-axis negative region of the upper surface of the substrate 110, the third resistor R3 is placed in the Y-axis positive region of the upper surface of the substrate 110, and the fourth resistor R4 is the substrate. 11
It is arranged in the Y-axis negative region on the upper surface of 0. Each of these four resistors R1 to R4 has a rectangular shape with the same size, and is arranged so as to be line-symmetric with respect to the X axis or the Y axis. In addition, the origin O and each resistor R
The distances from 1 to R4 are also the same.
As will be described later, the first resistor R1 and the second resistor R2 are used to detect the X-axis direction component of the applied external force, and the third resistor R3 and the fourth resistor R4 operate. It is used to detect the Y-axis direction component of the applied external force.

On the other hand, the fifth resistor R5 and the sixth resistor R6 are square plate-shaped resistors having the same size as each other. Here, the fifth resistor R5 is arranged so that the center point thereof is located at the position of the origin O, while the sixth resistor R6 is arranged around the lower right part of these resistor groups. Has been done. As will be described later, the fifth resistor R5 and the sixth resistor R6 are used to detect the Z-axis direction component of the applied external force. However, the original detection value of the Z-axis direction component is obtained from the fifth resistor R5, and the sixth resistor R6 is merely used as a reference for the standard resistance value. Therefore, here, the fifth resistor R
5 is called a "Z-axis resistor", and the sixth resistor R6 is called a "reference resistor". Z-axis resistor R5 is
In principle, it may be arranged at any position on the upper surface of the substrate 110, but in order to improve the detection sensitivity, it is preferably arranged at the position of the origin O (the position intersecting the Z axis). This is due to the structure of the elastically deformable body 120 according to the force detecting device,
This is because the displacement in the central portion (the portion intersecting the Z axis) becomes the largest. On the other hand, since the reference resistor R6 is a resistor used only for referring to the resistance value, it may be arranged at any position on the substrate 110.

On the other hand, the elastically deformable body 120 has the substrate 11
It is a member arranged on the upper surface of 0. This elastic deformable body 12
A top view of No. 0 is shown in FIG. 3, and a bottom view thereof is shown in FIG. A cross section obtained by cutting the elastically deformable body 120 shown in FIGS. 3 and 4 along the X axis is shown in FIG. As shown in FIG. 1, the elastically deformable body 120 includes a disk-shaped acting portion 121 located inside and a flexible portion 122 around the acting portion 121.
And an outer fixing portion 123, and further, the acting portion 12
At the center of the upper surface of No. 1, a cylindrical operation rod 125 having the Z axis as the central axis is formed. As shown in the side sectional view of FIG. 1, the action portion 12 is provided on the upper surface of the elastic deformable body 120.
1, a flexible structure 122 and a fixed part 123 form a step structure, and a cavity V is formed on the lower surface. The upper surface of the elastically deformable body 120 does not necessarily have to have such a step structure, but in the case of the illustrated example, the step structure between the action portion 121 and the flexible portion 122 has a wall thickness of the flexible portion 122. Contributing to make it thinner. That is, the acting portion 121
By setting the thickness of the flexible portion 122 smaller than the thickness of the flexible portion 122, the flexible portion 122 is provided with flexibility. In addition, the step structure between the flexible portion 122 and the fixed portion 123 is
This is a convenience for fixing the fixing portion 123 with the fixing member 130.

Elastic deformable body 120 in this force detecting device
In this way, the operating portion 121, the flexible portion 122, and the fixed portion 123 are provided in this manner. Here, the acting portion 121 may be basically of any form as long as it is arranged above the substrate 110 and has a structure that causes displacement by the action of an external force. Since it is necessary to attach a plurality of contact conductors to a predetermined position (a position facing each resistor) on the lower surface thereof, it is preferable to adopt a plate-like form having a lower surface suitable for attaching the contact conductors. . The action part 121 does not need to be a completely rigid body, but it is preferable that the action part 121 has a certain degree of rigidity as compared with the flexible part 122. In this force detection device, the action part 121 has a thickness larger than that of the flexible part 122. By increasing the wall thickness of 121, a certain degree of rigidity is provided.

The fixing portion 123 is a portion for fixing the elastic deformation body 120 to the substrate 110, and in the illustrated example, the lower surface of the fixing portion 123 is in direct contact with the upper surface of the substrate 110. The fixing member 130 is a member that has a function of fixing the fixing portion 123 to the substrate 110.
0 and the elastically deformable body 120 are surrounded from the outer peripheral portion thereof, and the state in which the upper surface of the fixed portion 123 and the lower surface of the substrate 110 are sandwiched is maintained. Note that the fixing portion 123 does not necessarily have to be directly fixed to the substrate 110, and the fixing portion 123
It may be fixed indirectly between the substrate and the substrate 110 through some intermediate member.

The flexible portion 122 includes the working portion 121 and the fixed portion 1.
It is a flexible portion formed between 23 and 23. Since the flexible portion 122 has flexibility, the action portion 12
When an external force acts on 1, the flexible portion 122 is bent, and the acting portion 121 is displaced with respect to the substrate 110. The external force is actually applied to the operating rod 125. For example, if you use this force detection device as a part of a joystick for computer games,
The external force applied by the operator operating the operating rod 125 is transmitted from the operating rod 125 to the flexible portion 122 via the acting portion 121, and the flexible portion 122 causes a flexure in accordance with the external force to act. The part 121 will be displaced. The degree of flexibility of the flexible portion 122 is a parameter that defines the relationship between the magnitude of the force applied by the operator and the magnitude of the displacement generated in the acting portion 121. In the illustrated example, the outer shape of the cavity V is rectangular, but the outer shape of the cavity V may be circular. In this case, the flexible portion 122 has an annular shape (donut shape).
become.

In this force detecting device, the elastic deformable body 120 is entirely formed by integrally molding insulating silicon rubber, and the acting portion 121, the flexible portion 122, and the fixing portion 1 are formed.
23 and operating rod 125 are both made of insulating silicone rubber. Of course, since at least the flexible portion 122 of the elastic deformable body 120 in this force detecting device needs to be flexible, each part of the elastic deformable body 120 can be made of a different material. However,
In order to reduce the manufacturing cost, it is preferable that the entire elastic deformable body 120 is formed as an integrally molded product made of the same material such as insulating silicon rubber.

The portion shown by the broken line in the top view of FIG. 3 is a cavity V formed on the lower surface of the elastically deformable body 120. As shown in the bottom view of FIG. 4, five contact conductors C1 to C5 are housed inside the cavity V. The contact conductors C1 to C5 are all bowl-shaped (more accurately, the contact conductors C1 to C4 are hemispherical, and the contact conductor C5 is semi-ellipsoidal), and elastically deform. It is made of a conductive material. Here, conductive silicon rubber is used as the conductive material that elastically deforms, and the contact conductors C1 to C5 are all formed of conductive silicon rubber into a bowl shape and bonded to the lower surface of the elastic deformable body 120. It was done. Here, the arrangement of these contact conductors C1 to C5 is important. That is, the contact conductors C1 to C5 are arranged at positions facing the resistors R1 to R5, respectively. Each of the contact conductors C1 to C5 is made of a material that elastically deforms, at least the contact surface with respect to the resistors R1 to R5 has conductivity, and the elastic deformable body 12 is included.
Depending on the pressure applied by the displacement of 0, the resistors R1 to R
5 must have a shape in which the area of the contact surface changes. In the side sectional view of FIG. 1, the contact conductors C1 and C are shown.
It is clearly shown that 2 and C5 are arranged at positions facing the resistors R1, R2 and R5, respectively. In this force detection device, in the state where no external force acts, the contact conductors C1 to C5 are
The distance between the resistors R1 to R5 is set so that the resistors R1 to R5 almost come into point contact with each other. No contact conductor is provided at a position facing the reference resistor R6. This is because the reference resistor R6 is a resistor used for referring to the resistance value, as described above.

As described above, when an external force acts on the operating rod 125, the flexible portion 122 is bent, and the lower surface of the acting portion 121 is displaced with respect to the upper surface of the substrate 110. When such displacement occurs, the contact state of each contact conductor with each resistor changes. More specifically, the area of the contact surface of each contact conductor with respect to each resistor changes. The basic principle of the force detection device according to the present invention is
The point is that the area of such a contact surface is detected as a change in the resistance value of the resistor and the magnitude of the applied external force is obtained. Hereinafter, the basic principle of detecting the component of the applied external force in each coordinate axis will be described.

§2. Of force detector using variable resistance element
Operating Principle Now, as shown in the side sectional view of FIG. 5A, one resistor R is formed on the upper surface of the substrate 110, and the action portion 12
It is assumed that hemispherical contact conductor C is formed on the lower surface of 1. At this time, it is assumed that the contact conductor C is in a point contact with the center of the resistor R at its lower end point. FIG. 5B is a top view of the resistor R at this time, and the black circle S shown in the center position indicates the contact surface of the contact conductor C. As described above, in the state where the lower end point of the contact conductor C is substantially in point contact with the surface of the resistor R, the contact surface S is a minute circle close to the point.

Now, as shown in FIG. 5 (b), wirings are drawn from the left and right ends of the resistor R, terminals T1 and T2 are connected to the ends of these wirings, and both terminals T1 and T2 are connected.
Suppose you measure the resistance between them. In other words, the resistance value between two points on both sides of the “contact position (contact surface S) of the contact conductor C” on the resistor R is measured. in this case,
Since the contact surface S is a minute circle close to a point, the contact conductor C has almost no effect on the measured resistance value, and the resistance value obtained by the measurement is the original resistance value of the resistor R. This is a value close to the resistance value. Figure 5 (c)
Is an equivalent circuit of such a measurement system. The arrow extending downward from the contact conductor C is only in contact with the center point of the resistor R, and the resistor R is provided between both terminals T1 and T2.
Only the original resistance value of appears.

On the other hand, as shown in the side sectional view of FIG. 6A, the downward force −Fz (force in the −Z axis direction) of the drawing is applied to the action portion 121. Consider the case of joining. In this case, the lower surface of the action portion 121 is displaced downward, and a pressing force in the −Z axis direction is applied to the contact conductor C. Since the contacting conductor C is made of a conductive material that is elastically deformable (conductive silicone rubber in this example), it is crushed by the pressing force as shown in the figure, and the contacting member C is pressed against the resistor R. The contact state changes.
Since the shape of the contact conductor C is such that the area of the contact surface changes (hemispherical in this example) based on such a change in the contact state, as shown in the figure, the contact conductor C When C is crushed in the vertical direction, the area of the contact surface increases. FIG. 6B is a top view of the resistor R at this time, and the circle S shows the contact surface of the contact conductor C. The concentric circle drawn inside this circle S is the resistor R
3 is an isobar showing the pressure distribution applied to the surface of the. That is, the contact pressure increases toward the center of the circle S.

When the contact surface of the contact conductor C becomes large in this way, the resistance value between the terminals T1 and T2 changes. That is, since the contact conductor C is a conductor and has a property of allowing a current to flow much more easily than the resistor R, the current flowing between the terminals T1 and T2 is at the contact surface portion indicated by the circle S. Does not pass through the resistor R, but bypasses the inside of the contact conductor C. FIG. 6 (c) is an equivalent circuit of such a measurement system.
Two arrows extending downward from the contact conductor C are resistors R
Are contacted with each other, and the electric current is diverted to the contacting conductor C side at these two positions. The distance between the two arrows becomes wider according to the size of the contact surface of the contact conductor C. After all, the larger the area of the contact surface of the contact conductor C with respect to the resistor R, the smaller the resistance value between the terminals T1 and T2.

In this way, the larger the external force -Fz acting on the acting portion 121, the larger the area of the contact surface of the conductor C for contact, and the smaller the resistance value between the terminals T1 and T2. A linear relationship does not always hold between the applied external force and the resistance value between both terminals, but if a monovalent functional relationship holds between them and the resistance value between both terminals can be measured, The magnitude of the applied external force can be calculated. This is the basic principle of force detection in the force detection device using the variable resistance element.

Then, by the force detection device described in §1,
The reason why the X-axis, Y-axis, and Z-axis direction components of the applied external force can be detected will be described. First, consider a case where an external force F in the diagonally lower right direction acts on the operating rod 125 in the force detection device shown in FIG. When the force detecting device is used as a joystick, the operator operates the operating rod 125.
If you perform an operation that tilts diagonally to the right, such an external force F
Will work. The side sectional view of FIG. 7 shows the displacement state of the action portion 121 when such an external force F acts. When an external force F is applied, the flexible portion 12 having flexibility
2 causes bending, but since the external force F is a force in the diagonally lower right direction, as shown in the drawing, the disk-shaped acting portion 12
1 is displaced so as to incline in the lower right direction. When the external force F is decomposed into force components in each coordinate axis direction, the downward force −Fz
It can be divided into (force in the −Z axis direction) and force to the right in the figure + Fx (force in the + X axis direction). Here, the principle of detecting the component + Fx in the + X-axis direction among these components will be described.

When the external force F is regarded as a force acting on the origin O of the coordinate system, in reality, the force component in the + X-axis direction +
Fx is the moment around the Y-axis,
If we consider it as the force given to the operating rod 125 by the operator,
The force component + Fx in the X-axis direction is a force directed in the + X-axis direction. As described above, the force and the moment indicate substantially the same physical quantity, and in the present specification, hereinafter, a unified description will be given to the way of thinking as the force.

Now, when an external force F including a component + Fx in the + X axis direction is applied, the disc-shaped acting portion 121 is displaced so as to be inclined in the lower right direction, as shown in FIG. Therefore, when the contact conductors C1 and C2 arranged on the X axis are compared with each other in the degree of collapse, the degree of collapse of C1 is larger than that of C2. Therefore, R1 of C1
The contact area for C2 is larger than the contact area for C2 for R2. Therefore, for example, if the resistance values at both ends of the resistors R1 and R2 in FIG. 7 are measured, the resistance value for the resistor R1 is smaller than the resistance value for the resistor R2. The greater the difference between the two resistance values, the greater the X-axis direction component of the applied external force.

Contrary to the above example, the operator operates the operation rod 125.
When the operation of inclining to the lower left is performed, the downward force −Fz (force in the −Z-axis direction) and the downward force −Fx (− in the figure)
The external force F that is a combination of the force (in the X-axis direction) acts, and the disk-shaped acting portion 121 is displaced so as to incline in the lower left direction. Therefore, the contact area of C2 with R2 is
It is larger than the contact area of C1 with R1. As a result, the resistance value of the resistor R2 becomes smaller than the resistance value of the resistor R1. After all, the resistance value between two points sandwiching the “contact position of the first contact conductor C1” for the first resistor R1 arranged in the X-axis positive region and the first resistor R1 arranged in the X-axis negative region. It is possible to detect the X-axis direction component of the applied external force by comparing the resistance value between two points sandwiching the "contact position of the second contact conductor C2" for the second resistor R2. become. That is, the direction of the force (whether in the + X axis direction or the −X axis direction) can be recognized based on the magnitude relationship between the two resistance values, and the magnitude of the force can be recognized based on the difference between the two resistance values.

The principle of detecting the Y-axis direction component of the applied external force is exactly the same as the above-described principle of detecting the X-axis direction component. As shown in FIG. 2, six resistors R1 to R6 are arranged on the substrate 110. To detect the X-axis direction component, as described above, the first resistor R1 arranged in the X-axis positive region and the second resistor R2 arranged in the X-axis negative region.
And a first contact conductor C1 and a second contact conductor C2 arranged at positions facing these. On the other hand, in order to detect the Y-axis direction component, the third resistor R3 arranged in the Y-axis positive region, the fourth resistor R4 arranged in the Y-axis negative region, and the position facing them. Third contact conductor C3 and fourth contact conductor C4 arranged in
And can be used.

On the other hand, the principle of detecting the Z-axis direction component of the applied external force is slightly different from the above-described principle of detecting the X-axis direction component and the Y-axis direction component. In order to detect the X-axis direction and the Y-axis direction, it was necessary to compare the resistance values of a pair of resistors arranged on both sides of the origin O, whereas the Z-axis direction is detected. It is also possible to do this simply by measuring the resistance value of a single resistor. The arrangement of the resistors used for detection in the Z-axis direction is not limited to a specific position, and the Z-axis direction component of the force exerted by the resistors arranged at any position on the upper surface of the substrate 110. Can be detected. For example, in FIG. 7, the external force F
The principle of detecting the X-axis direction component + Fx of the above has been described, but this external force F also includes the Z-axis direction component −Fz, and the force for crushing the contact conductor C1 in the vertical direction is the Z-axis direction. It is nothing but the action of component-Fz. In other words, the resistor C1
The direct reason that the resistance value of the resistor C1 is decreased is that the Z-axis direction component −Fz acts, and the decrease amount of the resistance value of the resistor C1 is primarily applied to the resistor C1. This indicates the magnitude of the force of the Z-axis direction component. It was possible to detect the X-axis direction component + Fx by the above-described principle because the contact conductors C arranged on the left and right sides of the figure.
This is because the Z-axis force applied to C1 and C2 is unbalanced between left and right.

As a result, it is also possible to detect the force component in the Z-axis direction based on the resistance value of the resistor R1. Similarly, the force component in the Z-axis direction can be detected by using any of the resistors R2, R3, R4. However, in practice, it is preferable to dispose a dedicated resistor for detecting the force component in the Z-axis direction at a position where the most efficient detection can be performed. Therefore, in this force detecting device, as shown in the top view of FIG. 2, the fifth resistor R5 arranged on the origin O is used as the Z-axis resistor, and Z is placed above it. The shaft contact conductor C5 is arranged. That is, both the Z-axis resistor R5 and the Z-axis contact conductor C5 are arranged on the Z-axis. In FIG. 1, when a force −Fz in the −Z-axis direction is applied to the operating rod 125, the Z-axis contact conductor C5 is arranged so as to make point contact with the Z-axis resistor R5.
Are crushed, and the contact state changes. That is, as shown in FIG. 6A, the contact area increases.
Here, “Z-axis contact conductor C on the Z-axis resistor R5 is used.
If the resistance value between two points sandwiching the "5 contact position" is measured, the measured resistance value has a relationship that decreases as the contact area of the Z-axis contact conductor C5 increases. Based on the value, the acting force −Fz in the −Z axis direction can be obtained.

When the force detecting device is used for a joystick or the like, the force in the Z-axis direction generated by the operation applied to the operating rod 125 by the operator is usually the force in the -Z-axis direction -Fz (in FIG. 1). (Downward force), so +
It is not necessary to measure the force + Fz (force in the upward direction in FIG. 1) in the Z-axis direction. However, when this force detector is used in an environment where a force pulling the operating rod 125 upward is applied, it is necessary to have a configuration capable of measuring the force + Fz in the + Z axis direction. In fact, with the configuration shown in FIG.
The force + Fz in the + Z axis direction cannot be measured. As already described in §1, in the force detection device shown in FIG. 1, in the state where no external force acts, the contact conductors C1 to C1.
The distance between the two is set so that C5 is in a state in which it almost comes into point contact with the upper surfaces of the resistors R1 to R5 at the lower end point. In such a configuration, the operating rod 1
When a force that pulls 25 upward is applied, the contact conductors C1 to C5 are lifted from the upper surfaces of the resistors R1 to R5 and are in a non-contact state. Therefore, even if the force + Fz in the + Z-axis direction acts, each resistor R1
There will be no change in the resistance value of ~ R5.

Even if a force + Fz in the + Z-axis direction is applied, the contact conductors C1 to C5 can be detected even if no external force acts so that the force can be detected. It suffices that the resistors R1 to R5 are brought into surface contact with each other with a certain pressing force. With such a configuration, when the force + Fz in the + Z-axis direction acts, the contact area with the resistor decreases, and the force acting in the form of an increase in the resistance value of the resistor is detected. Will be able to.

As described above, the Z-axis direction component can be detected by using only the single Z-axis resistor R5, but in practice, the detection is performed by using the reference resistor R6. Is preferred. The reason is that a general resistor has a property that its resistance value changes due to various environmental factors. For example, if the chemical composition changes due to aging, the resistance value changes. Practically, the most important environmental factor is temperature. The resistance value of a general resistor changes depending on the temperature. Therefore, when the Z-axis direction component of the applied force is detected based on only the resistance value of the Z-axis resistor R5, the detected value is likely to be affected by temperature.
It becomes impossible to obtain an accurate detection result. X mentioned above
In the case of the axial direction component or the Y-axis direction component, detection is performed based on the difference between the resistance values of the pair of resistors, so the influence of such temperature is offset. Therefore, even when the Z-axis direction component is detected, if the detection is performed with reference to the resistance value of the reference resistor R6, the influence of the temperature can be canceled.

In the case of the example shown in FIG. 2, the Z-axis resistor R5 and the reference resistor R6 are resistors having geometrically congruent shapes, and the change of the resistance value due to the environment such as temperature. Are equivalent. The only difference between the two is whether or not the resistance value changes due to the action of external force. That is, the Z-axis resistor R5 is a resistor in which the resistance value between predetermined two points (two points sandwiching the contact position of the Z-axis contact conductor C5) is changed by the action of an external force. , Reference resistor R6
Indicates that the resistance value between the two specified points is constant without being affected by external force (this means that the resistance value does not change with respect to the effect of external force, and of course with respect to the effect of temperature, etc. Is a resistor. Therefore, if the difference between the two resistance values is detected, this difference will be
Only factors based on the action of external forces will be included and environmental factors such as temperature can be excluded.

The principle of detecting the directional components of the X-axis, Y-axis, and Z-axis of the external force F acting on the operating rod 125 in the force detecting device shown in FIG. 1 has been described above. As described above, the force detection device shown in FIG. 1 is a three-dimensional force detection device capable of detecting the force of each three-dimensional coordinate axis direction component. In this three-dimensional force detection device, each of the resistors R1 to R6 shown in FIG. 2 and each of the contact conductors C1 to C5 shown in FIG. That is, the resistors R1 and R2 and the contact conductor C
1, C2 is responsible for detecting the X-axis direction component, and the resistor R
3, R4 and the contact conductors C3, C4 take charge of the detection of the Y-axis direction component, and the Z-axis resistor R5 and the reference resistor R
The Z-axis contact conductor C5 is responsible for detecting the Z-axis direction component.

Therefore, the two-dimensional force detecting device capable of detecting the force of the two-dimensional coordinate axis direction component and the one-dimensional force detecting device capable of detecting the force of the one-dimensional coordinate axis direction component are constituted. If so, it is necessary to use only the resistors and the contact conductors described above that are necessary for detection. For example, it is sufficient to use the resistors R1 and R2 and the contact conductors C1 and C2 to realize a one-dimensional force detection device that detects the force of the X-axis direction component. Also,
In order to realize a two-dimensional force detection device that detects the X-axis direction component and the Y-axis direction component, the resistors R1, R2, R3 and R4 and the contact conductors C1, C2, C3 and C4 are prepared. In order to realize a two-dimensional force detection device that is sufficient and detects the X-axis direction component and the Z-axis direction component, the resistors R1, R2, R
It is sufficient to prepare 5, R6 and the contact conductors C1, C2, C5.

§3. Sensing for use as a force sensing device
Circuit So far, the configuration and operating principle of the basic form of the force detection device using the variable resistance element have been described. A predetermined detection circuit is required in order to extract an externally applied external force as an electric signal by such a force detection device. Here, an example suitable for practical use of such a detection circuit will be described. FIGS. 8A, 8B and 8C are circuit diagrams showing an example of such a detection circuit.

First, in the circuit shown in FIG. 8A, the resistor R
1 and R2 is a detection circuit that outputs a detection value of a component of the force in the X-axis direction to an output terminal Tx. In this detection circuit, the X-axis detection resistor is formed by connecting the first resistor R1 and the second resistor R2 in series at the X-axis detection connection point Jx. First resistor R1 or second
As shown in Fig. 5 (b), the two ends of the resistor R2 are the central points on the left and right short sides of the rectangular resistor, so that the current flows in the left and right directions in the figure. I have to. Of course, the two end points of each resistor R may be any end points as long as they are two points sandwiching the contact position of the contact conductor C, and therefore, for example, FIG.
In, the current may flow in the vertical direction of the figure by taking the center points on both upper and lower long sides of the rectangular resistor.

In the circuit of FIG. 8 (a), the X-axis detection resistor constituted by the first resistor R1 and the second resistor R2 connected in series has the upper end connected to the power supply Vcc and the lower end. Is grounded, and a constant power supply voltage Vcc is applied to both ends. Here, the voltage output to the output terminal Tx is the voltage at the connection point Jx for X-axis detection, and the power supply voltage Vcc is the resistance value for the first resistor R1 and the resistance for the second resistor R2. Equivalent to the value divided by the value. As described in §2, + force in X-axis direction +
When Fx is added, the resistance value of the first resistor R1 decreases as compared with the resistance value of the second resistor R2. Therefore, the voltage output to the output terminal Tx increases. On the contrary, when the force −Fx in the −X axis direction is applied, the voltage output to the output terminal Tx drops. After all, the output terminal T with no external force applied
When this voltage value rises with reference to the voltage value output to x (theoretically Vcc / 2), the + X-axis direction force + F having a magnitude corresponding to this increase width.
When x is applied and this voltage value is decreased, a force −Fx in the −X axis direction having a magnitude corresponding to the width of the decrease is applied. In this way, FIG. 8 (a)
If the detection circuit of is used, it is possible to detect the component of the applied external force in the X-axis direction based on the output voltage of the output terminal Tx.

Next, the circuit shown in FIG. 8B has a resistor R
3 and R4 is a detection circuit that outputs the detection value of the Y-axis direction component of the force to the output terminal Ty. In this detection circuit, the Y-axis detection resistor is formed by connecting the third resistor R3 and the fourth resistor R4 in series at the Y-axis detection connection point Jy. First resistor R1 or second
The two end points of the resistor R2 may be any end points as long as they are two points sandwiching the contact position of the contact conductor C. In the circuit of FIG. 8 (b) as well, the third
The Y-axis detection resistor formed by connecting the resistor R3 and the fourth resistor R4 in series has the upper end connected to the power supply Vcc, the lower end grounded, and a constant power supply voltage Vcc at both ends. It is in the applied state. Based on the output voltage of the output terminal Ty in this detection circuit, the principle that the component of the applied external force in the Y-axis direction can be detected is shown in FIG.
This is the same as the principle of detection of the X-axis direction component by the detection circuit of.

On the other hand, the circuit shown in FIG.
5 and R6 is a detection circuit that outputs the detection value of the Z-axis direction component of the force to the output terminal Tz. In this detection circuit, Z
The Z-axis detection resistor is formed by connecting the axis resistor R5 and the reference resistor R6 in series at the Z-axis detection connection point Jz. The endpoints of the Z-axis resistor R5 may be any endpoints as long as they are two points sandwiching the contact position of the Z-axis contact conductor C5.
Further, the end points of the reference resistor R6 may be located at the same positions as the end points of the Z-axis resistor R5.

Also in the circuit of FIG. 8 (c), the Z-axis detecting resistor formed by connecting the Z-axis resistor R5 and the reference resistor R6 in series has the upper end connected to the power supply Vcc, The lower end is grounded, and a constant power supply voltage Vc is applied to both ends.
c is being applied. Here, the output terminal T
The voltage output to z is the voltage at the connection point Jz for Z-axis detection, and is a value obtained by proportionally dividing the power supply voltage Vcc by the resistance value for the Z-axis resistor R5 and the resistance value for the reference resistor R6. Equivalent to. As described in §2, the resistance value of the Z-axis resistor R5 increases or decreases due to the action of force in the Z-axis direction. On the other hand, the resistance value of the reference resistor R6 is constant irrespective of the action of force (although it changes due to the influence of temperature or the like, this change also applies to the Z-axis resistor R5. And is offset). For example, when a force -Fz in the -Z axis direction is applied, the contact area of the Z-axis contact conductor C5 increases, and the resistance value of the Z-axis resistor R5 decreases. As a result, the output voltage of the output terminal Tz rises. In addition, + Z axis force + F
If a force detector having a configuration capable of detecting z is also used, when a force + Fz in the + Z-axis direction is applied, the contact area of the Z-axis contact conductor C5 decreases, and the Z-axis resistor R5 is reduced. The resistance value of will increase. As a result, the output voltage of the output terminal Tz drops. As described above, by using the detection circuit shown in FIG. 8C, the Z-axis direction component of the applied external force can be detected based on the output voltage of the output terminal Tz.

As described above, if the detection circuit shown in FIGS. 8 (a), (b), and (c) is added to the three-dimensional force detecting device described in §1, the external force acting in the XYZ three-dimensional coordinate system is added. X of F
It is possible to configure a three-dimensional force sensor having a function of independently detecting each directional component of the axis, the Y axis, and the Z axis. Of course, when constructing a one-dimensional force sensor or a two-dimensional force sensor, only the detection circuit necessary according to the detection component may be used from the three detection circuits shown in FIG.

In any case, in the force detecting device using the variable resistance element described above, it is essential to measure the electric resistance of the resistor to obtain the detected value of the applied force.
However, in order to measure the electric resistance of the resistor,
As shown in the detection circuit in FIG. 8, it is necessary to pass a current through the resistor, and power consumption cannot be avoided to some extent during measurement. In fact, in order to detect a three-dimensional force using the circuit shown in FIG. 8, it is necessary to pass a current through all the six resistors R1 to R6. Therefore, when the force detection device using the variable resistance element described above is incorporated in various electronic devices, the problem that the power consumption as a whole increases is as described above. This is a great disadvantage especially when used in electronic devices such as mobile phones and game playing devices that operate on a built-in battery.

An object of the present invention is to efficiently suppress the power consumption of the force detection device using the variable resistance element described above. The basic principle is that an electric current is passed through the resistor to perform the measurement only when it is necessary to measure the electrical resistance of the resistor. For example, the side sectional view of FIG. 1 shows a state where no external force is applied to the force detection device. In such a state, since there is no external force to be detected, it is not necessary to actually perform an operation for detection. Therefore, when the force detection device is in the state as shown in FIG. 1, the power supply voltage Vcc may not be supplied in the detection circuit shown in FIG. 8 to suppress power consumption. On the other hand, the side sectional view of FIG. 7 shows a state when an external force to be detected acts on this force detection device. In such a state, it is necessary to actually perform an operation for detection. Therefore, if the power supply voltage Vcc is supplied in the detection circuit shown in FIG. 8 so that the resistance value can be measured. Good.

Actually, a detection mode in which the detection circuit can perform a detection function of outputting a resistance value between two predetermined points of the resistor as an electric signal, and such a detection function cannot be performed. It is configured such that two modes, that is, a standby mode in which a standby state for shifting to the detection mode can be maintained with less power consumption than that in the detection mode, can be selected, and as shown in FIG. If no external force is applied, the standby mode is selected,
As shown in FIG. 7, when an external force to be detected is applied, the detection mode may be selected. In the present invention, a switching element is added to perform such mode switching. This switching element has a pair of contact electrodes. Normally, the pair of contact electrodes maintain an electrically insulating state, and when an external force of a predetermined magnitude or more acts on the elastic deformable body 120. The elastic deformation body 120 is a component that performs a switching function so that the pair of contact electrodes are electrically connected by the deformation of the elastic deformation body 120 (detailed configuration will be described in §4 and later). Then, using this switching element, the standby mode is selected when the electrical state between the pair of contact electrodes forming the switching element is the insulating state, and the detection is performed when the electrical state is the conducting state. The mode may be selected.

§4. Basic implementation of the force detection device according to the present invention
Embodiment FIG. 9 is a side sectional view showing a basic embodiment of a force detection device using a variable resistance element according to the present invention. The embodiment shown in FIG. 9 can be realized by slightly modifying the force detection device shown in FIG.

First, the first modification is that, instead of the elastically deformable body 120 in FIG. 1, an elastically deformable body 120A is used in the apparatus shown in FIG. Elastic deformable body 120
A is a member arranged on the upper surface of the substrate 110, and is a disk-shaped acting portion 121 located inside, a flexible portion 122 around it, an outer fixing portion 123A, and a columnar operating rod 1.
25, and is a member having the same function as the elastically deformable body 120 of FIG. Further, the material is also integrally formed of insulating silicon rubber similarly to the elastically deformable body 120. However, the portion of the fixing portion 123A that functions as a pedestal is the fixing portion 12 shown in FIG.
It is slightly higher than 3. Therefore, the shape of the fixing member 130A is also slightly different from that of the fixing member 130 shown in FIG.

In this way, the fixing portion 1 functioning as a pedestal
The height of 23A is made higher by making the cavity portion VV higher, so that the contact conductors C1 to C5 and the resistor RR1 in a normal state (a state where no external force acts).
This is because it is in a non-contact state with ~ RR5. That is, in the force detection device shown in FIG. 1, the lower ends of the contact conductors C1 to C5 are in point contact with the resistors R1 to R5 even when no external force is applied. In the force detection device shown in FIG.
A gap is formed between C5 and the resistors RR1 to RR5 and is in a non-contact state.

The second modification is that instead of the resistors R1 to R6 (see the top view of the substrate 110 shown in FIG. 2) in the device of FIG. 1, the resistors RR1 to R of the device of FIG. 9 are used.
That is, R6 is used. These resistors RR1 to R
The structure of R6 is clearly shown in FIG. This Figure 1
0 is a top view of the substrate 110 of the apparatus shown in FIG.
The position of A is shown. The substrate 110 shown in FIG.
The cross section is a cross section obtained by cutting the substrate 110 shown in FIG. 10 along the X axis. Also in this case, the XY plane is taken on the upper surface of the substrate 110 to define the XYZ three-dimensional coordinate system. Figure 10
The resistor RR6 shown in is a component identical to that of the resistor R6 shown in FIG. 2, and the arrangement position on the substrate 110 is also identical (here, different reference numerals are used for convenience of description). On the other hand, the resistors RR1 to RR5 shown in FIG.
Is also a component close to the resistors R1 to R5 shown in FIG. Specifically, the resistors RR1 to RR5 shown in FIG.
The outer contour line of is the same rectangle as the outer contour lines of the resistors R1 to R5 shown in FIG. 2, the overall shape is also flat, and the arrangement position on the substrate 110 is also the same. However, a circular void region is formed in each of the central portions of the resistors RR1 to RR5, and a pair of semicircular contact electrodes are arranged in the circular void region.

FIG. 11 (a) is an enlarged top view for more clearly showing the structure of the resistors RR1 to RR5 (hatching indicates a portion where a flat plate-shaped structure exists, Not intended to show a cross section). This FIG.
The resistor RR shown in (a) is one resistor representing the resistors RR1 to RR4. In addition, the resistor RR5
Has a square outer shape, the basic structure is the same as that of the resistor RR shown in FIG. 11 (a). As shown in the figure, the resistor RR is a rectangular flat plate resistor having a circular void region in the center, and in this embodiment, it is formed on the substrate 110 by using carbon as a material by a printing method. Then, in the circular void region formed in the center of the resistor RR, a pair of semi-circular contact electrodes S for contact is formed.
1, S2 are arranged. A pair of contact electrodes S1, S
Reference numeral 2 denotes a plate-shaped electrode having the same height as the resistor RR, and in this embodiment, it is formed on the substrate 110 by a printing method using a metal such as copper as a material.

Although the same hatching is shown in FIG. 11A, the resistor RR is a constituent element made of a material having electrical resistance (carbon in this example).
The pair of contact electrodes S1 and S2 are constituent elements made of a conductive material (copper in this example), and are arranged at positions physically separated from each other, and are electrically isolated from each other. There is. Although the wiring pattern is not shown in FIG. 10, wiring is actually provided to the resistor RR and the contact electrodes S1 and S2. Terminals T1 to T4 shown in FIG. 11 (a) are terminals electrically connected to each part by this wiring. As described above, the electric resistance of the resistor RR is measured as the electric resistance between the terminals T1 and T2. The wiring shown in FIG. 11 (a) does not show an actual wiring path. The actual wiring path is formed using the upper surface of the substrate 110 or the lower surface of the substrate 110 via a through hole formed in the substrate 110 as necessary. For example, the contact electrodes S1 and S2 are surrounded by the resistor RR.
Since it is completely surrounded by the terminal T
The wiring path between 3 and T4 needs to be formed by utilizing the through hole formed in the substrate 110.

FIG. 11B is a side sectional view in the vicinity of the resistor RR formed on the substrate 110 (illustration of wiring is omitted). The side cross section of the resistor RR shown in FIG. 11 (b) corresponds to the cross section of the resistor RR shown in FIG. 11 (a) taken along the line connecting the terminals T1 and T2. As described above, in the force detection device shown in FIG. 9, the fixed portion 1 that functions as a pedestal
Since the height of 23A is increased, in a normal state where no external force is applied, the contact conductor C formed on the lower surface of the acting portion 121 has a resistance RR or a contact as shown in FIG. 11 (b). The physical contact with the working electrodes S1 and S2 is maintained. However, when an external force including the force component −Fz in the negative direction of the Z axis (for example, the diagonal force F shown in FIG. 7) acts, as shown in the side sectional view of FIG.
Is displaced downward, and the lower end of the contact conductor C comes into contact with the contact electrodes S1 and S2. When the magnitude of the external force is further increased, as shown in FIG. 13, the contact conductor C made of an elastically deformable material is deformed by the pressure applied by the downward displacement of the acting portion 121, and the resistor R
It also comes into contact with R.

The area of the contact surface of the conductor C for contact with the resistor RR depends on the pressure applied by the displacement of the acting portion 121,
That is, the fact that it changes depending on the magnitude of the applied external force is as described above. Since the resistor RR has a circular void region in the central portion, when the external force applied is gradually increased, the area change of the contact surface of the conductor C for contact is changed by the device shown in FIG. This is slightly different from the area change of the rectangular resistor used.
However, there is no change in the basic property that the contact surface of the contact conductor C increases as the external force increases, and the resistance value between the two points of the resistor RR depends on the magnitude of the external force. It becomes a fixed amount. Therefore, the force detection device shown in FIG. 9 can fulfill the function of performing XYZ three-dimensional force detection on the completely same principle as the force detection device shown in FIG. Moreover, the force detection device shown in FIG. 9 is provided with a pair of contact electrodes S1 and S2 that can be used as switching elements, and the detection circuit is detected by detecting the conduction state of the contact electrodes S1 and S2. Two modes, namely
It becomes possible to perform switching processing between the detection mode and the standby mode.

Now, by the contact electrodes S1 and S2, O
Consider a case where the N / OFF switch SW is configured.
In this case, the equivalent circuit of the resistor RR and the pair of contact electrodes S1 and S2 shown in FIG. 11A is as shown in FIG. Terminals T1 to T4 in each circuit diagram of FIG.
Corresponds to the terminals T1 to T4 shown in FIG. 11 (a), and the switch SW is a switch which is turned off when the contact electrodes S1 and S2 are non-contact and is turned on when they are contacted. Further, in FIG. 14A, as shown in the side sectional view of FIG. 11B, the contact conductor C does not contact the resistor RR and the contact electrodes S1 and S2. FIG. 14 (b) is an equivalent circuit of the state, and as shown in the side sectional view of FIG.
1 (c) is an equivalent circuit in the state of being in contact with S1 and S2.
Is an equivalent circuit in the state where the contact conductor C is in contact with both the resistor RR and the contact electrodes S1 and S2, as shown in the side sectional view of FIG.

Since the switch SW is turned on when the contact conductor C contacts the contact electrodes S1 and S2, it is in the off state in the equivalent circuit of FIG. 14 (a).
The equivalent circuits of (b) and (c) are turned on. Also, FIG.
In the equivalent circuits of 4 (a) and 4 (b), since the contacting conductor C is not in contact with the resistor RR, there is no change in the resistance value between the terminals T1 and T2. In the equivalent circuit of c), since the contacting conductor C is in contact with the resistor RR,
The resistance value between both terminals T1 and T2 will change according to a contact area (namely, according to the magnitude of the applied external force). After all, in the configuration shown in FIG. 11B, the contact conductor C functions as a conductor that changes the resistance value of the resistor RR, and at the same time, the pair of contact electrodes S1 and S2.
By simultaneously contacting both of them, they also function as an intermediary electrode capable of conducting them. Focusing on the function of the contact conductor C as an intermediary electrode, switching is performed by a pair of contact electrodes S1 and S2 formed on the substrate 110 and the contact conductor C that functions as an intermediary electrode. The element is configured. This switching element normally maintains an electrically insulated state between the pair of contact electrodes S1 and S2 (when no external force to be detected is applied), and the elastic deformation body 120 has a predetermined size or more. It can be said that, when the external force is applied, the elastically deformable body 120 is deformed to perform a switching function so that the pair of contact electrodes S1 and S2 are electrically connected.

If the pair of contact electrodes S1 and S2 constituting such a switching element are used as ON / OFF switches and the voltage application between the two points of the resistor RR is controlled, power consumption is reduced. It becomes possible to suppress efficiently. That is, a switch SW that turns on / off depending on the conduction / insulation state of the pair of contact electrodes S1 and S2 is formed,
When the switch SW is OFF, the detection circuit is set to the standby mode so that no voltage is applied between the two points of the resistor RR, and when the switch SW is ON, the detection circuit is set to the detection mode and the two points of the resistor RR are connected. The control is such that a voltage is applied. With this control,
In the equivalent circuit of 4 (a), since the switch SW is in the OFF state, the detection circuit is in the standby mode and the terminal T
Since no voltage is applied between 1 and T2 and no current flows through the resistor RR, power consumption can be suppressed. However, in the equivalent circuits of FIGS. 14 (b) and 14 (c), the switch SW
Turns on and the detection circuit enters the detection mode. Therefore, a voltage is applied between the terminals T1 and T2, and the resistor R
By passing a current through R, the resistance value between the terminals T1 and T2 is measured. In other words, as shown in FIG. 11 (b), when the external force to be detected is not acting,
A current does not flow through the resistor RR and unnecessary power consumption is suppressed, and when an external force of a certain amount acts, as shown in FIGS. 12 and 13, a current flows through the resistor RR, and the external force acting is detected. Will be possible. As described above, if the current is supplied to the resistor RR only when it is necessary for the detection, it is possible to significantly reduce the power as a whole.

In the embodiment shown in FIG. 9, all the contact conductors C1 to C5 (mediation electrodes) are in contact with the contact electrodes S1 and S2 in a normal state where no external force is applied.
However, in a normal state in which no external force is applied, the intermediary electrode may be in contact with only one of the pair of contact electrodes. . For example, in FIG. 11 (b), the contact conductor C includes only the contact electrode S1 (or the contact electrode S2).
Even when the contact electrodes S1 and S2 are in contact with each other, the insulating state is maintained between the pair of contact electrodes S1 and S2. Therefore, for example, the positions of the resistor RR and the pair of contact electrodes S1 and S2 in FIG. 11B are slightly shifted to the right so that the contact electrode S1 is located immediately below the center of the contact conductor C. In addition, in a normal state in which no external force is applied, the central portion of the contact conductor C is the contact electrode S.
It does not matter if only point 1 is in point contact. In short, the intermediary electrode (contact conductor C) normally does not contact either of the pair of contact electrodes S1 and S2 (when no external force to be detected is acting), or It suffices to maintain the state of being in contact with only one of them, and when the external force of a predetermined magnitude or more acts, it is possible to fulfill the function of being in the state of being in contact with both of the pair of contact electrodes S1 and S2 at the same time. .

§5. Specific of the force detection device according to the present invention
Detection Circuits Here, some specific detection circuits used in the force detection device shown in FIG. 9 are illustrated. FIG. 15 is a circuit diagram showing a first example of such a detection circuit, and has a function substantially equivalent to that of the detection circuit shown in FIG. 8 described above. That is, RR1
~ RR6 are the resistors shown in FIG.
It functions as a resistance element having both ends between a predetermined two points. The contact conductors C1 to C1 are respectively connected to the resistors RR1 to RR5.
Since C5 contacts and the resistance value changes depending on the contact area, in the circuit diagram of FIG.
RR5 is depicted as a variable resistance element. On the other hand, since the resistor RR6 functions as a reference resistance element,
In the circuit diagram of No. 5, it is drawn as a constant resistance element. The five switches SW1 to SW5 are resistors RR1 to RR1, respectively.
A switch composed of a pair of contact electrodes S1 and S2 in a void region formed in the central portion of RR5, which is OFF when the contact electrodes S1 and S2 are in an insulating state and ON when the contact electrodes are in a conducting state. .

After all, the detection circuit shown in FIG.
It is nothing but the one in which five switches SW1 to SW5 connected in parallel are inserted in the supply path of the power supply voltage Vcc in the detection circuit shown in FIG. Therefore, the five switches SW1
~ If all of SW5 are OFF, each resistor RR
No current flows through 1 to RR6, but if any one of the switches is in the ON state, each resistor RR1 to RR6
Then, a current for detecting the resistance value is supplied. The detection principle for each coordinate axis direction component of the external force is exactly the same as the detection principle in the detection circuit shown in FIG.

FIG. 16 is a circuit diagram showing a second example of the detection circuit that can be used in the force detection device shown in FIG.
The difference from the detection circuit shown in FIG. 15 is that a circuit for detecting an external force in the X-axis direction (FIG. 16 (a)), a circuit for detecting an external force in the Y-axis direction (FIG. 16 (b)), and a circuit in the Z-axis direction. The point is that the control of the current supply to the circuit for detecting the external force (FIG. 16 (c)) is separately performed. In this detection circuit, an external force including a component in the X-axis direction is applied, and a switch SW1 (a switch including a pair of contact electrodes S1 and S2 formed in the void region of the resistor RR1) or a switch SW2 (a void of the resistor RR2). When any one of a pair of contact electrodes S1 and S2 formed in the area) is turned on, a current is passed through the resistors RR1 and RR2 necessary for detecting the external force of the X-axis direction component. . Further, an external force including a Y-axis direction component is applied, and the switch SW3
(Switch composed of a pair of contact electrodes S1, S2 formed in the void region of the resistor RR3) or switch S
Any one of W4 (switch formed of a pair of contact electrodes S1 and S2 formed in the void region of the resistor RR4) is O
When it becomes N, a current is passed through the resistors RR3 and RR4 necessary for detecting the external force of the Y-axis direction component. Furthermore, an external force including a Z-axis direction component is applied, and the switch SW5 (resistor R
A pair of contact electrodes S1 formed in the void region of R5
When the switch S2) is turned on, a current is passed through the resistors RR5 and RR6 necessary for detecting the external force of the Z-axis direction component. As described above, the detection circuit shown in FIG. 16 enables fine control in consideration of the direction of the applied external force.

FIG. 17 is a circuit diagram showing a third example of the detection circuit that can be used in the force detection device shown in FIG.
This detection circuit is composed of a signal processing circuit provided with an input terminal for analog signals. The input analog signal is converted into a digital signal, and a predetermined operation is performed on the digital signal internally to obtain a digital signal. Output is obtained. The signal processing circuit shown in FIG. 17 is configured as a one-chip integrated circuit. The analog input terminals T11 to T15 shown on the right side of the drawing respectively have resistors RR.
Analog voltage values corresponding to the resistance values of 1 to RR5 are input. One end (lower end in the figure) of each of the resistors RR1 to RR5 is grounded, and the other end (upper end in the figure) is connected to each of the analog input terminals T11 to T15, and the switches SW11 to SW15 and the reference resistor are respectively connected. Body RR6
It is connected to the power supply Vcc through 1 to RR65. Here, RR61 to RR65 are reference resistors similar to RR6 shown in FIG. 10, and in this circuit, five sets of reference resistors RR61 to RR65 are formed on the substrate 110 in place of RR6. I am trying to use it.

When each of the switches SW11 to SW15 is turned on, a voltage is applied from the power supply Vcc to each of the resistors RR1 to RR5, and the analog input terminals T11 to T15 correspond to the resistance values of each of the resistors RR1 to RR5. A partial pressure will be applied. For example, at the analog input terminal T11, the voltage of the power supply Vcc is applied to the resistance value of the resistor RR1 (variable resistance element whose resistance value changes according to the magnitude of the applied external force) and the reference resistor RR61 (constant resistance element). ), And a partial pressure proportionally divided by the resistance value is added. This analog divided voltage value is converted into a digital signal inside the signal processing circuit, and a digital value corresponding to the resistance value of the resistor RR1 is obtained. Similarly, the voltage divisions of the resistors RR2 to RR5 are applied to the analog input terminals T12 to T15 and digitized inside the signal processing circuit to obtain digital values corresponding to the respective resistance values. As described above, the component of the applied external force in the direction of each coordinate axis can be obtained based on these digital values. That is, the X-axis direction component can be obtained as the difference between the resistance value of the resistor RR1 and the resistance value of the resistor RR2, and the Y-axis direction component is the resistor R.
It can be obtained as the difference between the resistance value of R3 and the resistance value of the resistor RR4, and the Z-axis direction component can be obtained as the resistance value of the resistor RR5. If the signal processing circuit shown in FIG. 17 is used, each component of the applied external force in the coordinate axis direction can be output as a digital signal, so that it can be used in an electronic device such as a mobile phone input device or a game input device. Is convenient.

The switches SW11 to SW15 are switches for controlling the voltage supply to each resistor. That is, when all of the switches SW11 to SW15 maintain the OFF state, the voltage of the power supply Vcc is not applied to each resistor, and no current flows through each resistor. Therefore,
Power consumption by the resistor will not occur, but of course,
Since the partial pressure to be measured is not applied to the analog input terminals T11 to T15, the resistance value of each resistor cannot be detected. This indicates that the signal processing circuit is in the standby mode. On the other hand, when any of the switches SW11 to SW15 is turned on, the voltage of the power supply Vcc is applied to the resistor connected to the switch turned on, and a current flows through the resistor. Therefore, power is consumed by the resistor, and as described above, the digital value corresponding to the resistance value of the resistor is detected. This indicates that the signal processing circuit is in the detection mode state.

ON / OF of the switches SW11 to SW15
The F control is performed by the control signals S21 to S25 output from the control terminals T21 to T25. In reality, the switches SW11 to SW15 are composed of semiconductor switches such as logic elements, and control signals S21 to S25 are used.
Becomes a digital logic signal. The signal processing circuit includes a CPU and a program for operating the CPU, and control signals S21 to S21 are executed by the logical operation of the CPU.
25 logical values are determined.

Input terminals T01 to T01 shown on the left side of FIG.
The power supply voltage Vcc or the ground voltage is applied to T03 depending on the ON / OFF state of the switches SW1 to SW5. That is, when each of the switches SW1 to SW5 is in the OFF state, the resistance element R0 is connected to each of the input terminals T01 to T03.
The power supply voltage Vcc is applied via 1 to R03, but when at least one of the switches SW1 and SW2 is turned on, the input terminal T01 becomes the ground potential, and at least one of the switches SW3 and SW4 becomes O.
When in the N state, the input terminal T02 is at the ground potential, and when the switch SW5 is in the ON state, the input terminal T03 is at the ground potential. Therefore, the signal processing circuit, based on the potentials of the input terminals T01 to T03, switches SW1 to SW1.
The ON / OFF state of SW5 can be grasped.

The switches SW1 to SW5 are the switches S shown in the circuit diagram of FIG. 15 and the circuit diagram of FIG.
It is the same switch as W1 to SW5, and is a switch composed of a pair of contact electrodes S1 and S2 in the void region formed in the central portions of the resistors RR1 to RR5, respectively. Therefore, with respect to the force detection device shown in FIG.
When an external force of a certain magnitude including the axial component is applied,
When the switch SW1 or SW2 is turned on and an external force of a predetermined magnitude including the Y-axis direction component is applied, the switch SW3 or SW4 is turned on and an external force of a predetermined magnitude including the Z-axis direction component is applied. Then, the switch SW5 is turned on.

Therefore, in the signal processing circuit shown in FIG. 17, when the potential of the input terminal T01 is the power supply voltage Vcc (when the switches SW1 and SW2 are in the OFF state),
From the control terminals T21 and T22, the switches SW11 and S are connected.
When the control signals S21 and S22 for turning off W12 are output and the potential of the input terminal T01 is the ground potential (when at least one of the switches SW1 and SW2 is on), the control terminals T21 and T22 are Switch S
Control signals S21 and S for turning on W11 and SW12
The control so that 22 is output is performed.
As a result, a current flows through the resistors RR1 and RR2 only when an external force of a predetermined magnitude including the X-axis direction component is applied, and the X-axis direction component of the external force can be detected. Similarly, when the potential of the input terminal T02 is the power supply voltage Vcc (when the switches SW3 and SW4 are in the OFF state),
From the control terminals T23 and T24, the switches SW13 and S
When the control signals S23 and S24 for turning off W14 are output and the potential of the input terminal T02 is the ground potential (when at least one of the switches SW3 and SW4 is on), the control terminals T23 and T24 are Switch S
Control signals S23 and S for turning on W13 and SW14
The control so that 24 is output is performed.
As a result, a current flows through the resistors RR3 and RR4 only when an external force of a predetermined magnitude including the Y-axis direction component is applied, and the Y-axis direction component of the external force can be detected. Also,
When the potential of the input terminal T03 is the power supply voltage Vcc (when the switch SW5 is in the OFF state), the control signal S for turning the switch SW15 into the OFF state is output from the control terminal T25.
25, and when the potential of the input terminal T03 is the ground potential (when the switch SW5 is in the ON state), the control terminal T03
From 25, control is performed to output a control signal S25 for turning on the switch SW15. As a result, a current flows through the resistor RR5 only when an external force of a predetermined magnitude including the Z-axis direction component is applied, and the Z-axis direction component of the external force can be detected.

Of course, it is also possible to perform finer control by the signal processing circuit. For example, the ON / OFF states of the five switches SW1 to SW5 are independently detected, and when the switch SW1 is in the ON state, only the switch SW11 is turned ON, and when the switch SW2 is in the ON state, only the switch SW12 is turned ON.
It is also possible to control the five systems independently, such as N, and when the switch SW3 is in the ON state, only the switch SW13 is turned on, and so on. On the contrary, it is also possible to perform a rough control. For example, all five switches SW1 to SW5 are connected in parallel, and one of
When one switch is turned on, five switches S
Comprehensive control such as turning on all of W11 to SW15 may be performed.

As mentioned above, some detection circuits which can be used in the force detection device shown in FIG. 9 have been shown. However, in any case, until one of the switches SW1 to SW5 is turned on, eventually,
The detection circuit maintains a standby mode in which the original detection function cannot be performed, and power consumption is suppressed. In other words, unless an external force large enough to turn on one of the switches SW1 to SW5 is applied, the detection output of the external force cannot be obtained from the detection circuit, and the detection sensitivity has a dead zone region. It will be provided. Then, any of the switches SW1 to SW5 is turned on.
When an external force of such a magnitude is applied, the detection circuit shifts to the detection mode and performs the original detection function.

The three specific examples of the specific detection circuits used in the force detection device shown in FIG. 9 have been described above. In each circuit diagram of these detection circuits, the switches SW1 to SW5 and the resistors RR1 to RR5 are drawn as completely separate circuit elements, and as long as the circuit diagram is seen, no interference occurs between them. looks like. However, in the case of the force detection device shown in FIG. 9, the contact conductors C1 to C5 are the resistor RR1.
~ Because it is a constituent element that fulfills both functions of contacting RR5 to change the resistance value and functioning as an intermediary electrode contacting the pair of contact electrodes S1, S2,
The operation of the switches SW1 to SW5 is performed by the resistors RR1 to RR.
5 will have an effect on the resistance value.

For example, consider a circuit as shown in FIG. This circuit shows a state in which predetermined wiring is provided to the resistor RR and the pair of contact electrodes S1 and S2 formed in the void region at the center thereof. Contact electrode S
1 is grounded via a terminal T3, and the contact electrode S2 is connected to a power supply Vcc via a terminal T4 and a resistance element R01. With this configuration, when the contact conductor C is in the non-contact state (the switch SW is in the OFF state), the terminal T
The potential of 4 becomes the power supply voltage Vcc, but when the contact conductor C is in contact with both of the pair of contact electrodes S1 and S2 at the same time (the switch SW is in the ON state), the electrodes S1 and S are in contact.
The two are electrically connected, and the potential of the terminal T4 becomes the ground potential. Therefore, for example, if the terminal T4 is connected to the input terminal T01 of the signal processing circuit shown in FIG.
The PU can recognize the ON / OFF state of the switch SW.

However, considering the case where the contact conductor C is also in contact with the resistor RR as shown in the side sectional view of FIG. 13, the resistor RR and the electrode S are considered.
The overall contact surface of the contacting conductor C with respect to 1, S2 is
The contact surface S is shown by the broken line in FIG. That is,
The contact conductor C contacts both the electrodes S1 and S2, and also contacts the peripheral portion of the circular void region in the central portion of the resistor RR. In such a state, the electrode S
Since the contact conductor C is also at the ground potential along with S1 and S2, the portion inside the contact surface S of the resistor RR is also at the ground potential.
Therefore, the equivalent circuit for the resistor RR at this time is as shown in FIG. That is, when the resistor RR is considered as a resistance element, its central portion is grounded. Therefore, when the resistance value of the resistor RR is measured by applying a predetermined voltage between the terminals T1 and T2, the measurement can be performed in principle, but the measurement sensitivity is lowered.

As described above, in order to prevent the circuit for detecting the conduction state of the pair of contact electrodes S1, S2 constituting the switching element from interfering with the circuit for detecting the resistance value between the two points of the resistor RR. It is preferable to prepare a resistance element having a resistance value sufficiently larger than the resistance value between the two points of the resistor RR, and use this resistance element to isolate both circuits. Figure 20
Is a circuit for detecting the conduction state of the contact electrodes S1, S2 in the circuit shown in FIG. 18 and a circuit for detecting the resistance value between two points of the resistor RR, which are isolated by a resistance element having a large resistance value. It is a circuit diagram showing an example. This example is a circuit configuration example in the case where the resistance value between the left and right two points of the resistor RR (that is, the resistance value between the terminals T1 and T2) when the contact conductor C is not in contact is 10 kΩ. is there. As shown in the figure, the terminal T4 connected to the contact electrode S2 is 10
The terminal T3 connected to the power supply voltage Vcc via the resistance element R01 of MΩ and connected to the contact electrode S1 is 1
It is grounded via a resistance element R04 of MΩ. Therefore, the contact electrodes S1 and S2 that form the switch SW
Is isolated from the power supply system by a resistance element R01 having a resistance of 10 MΩ and a resistance element R04 having a resistance of 1 MΩ (both having a resistance value sufficiently larger than a resistance value 10 kΩ between two points of the resistor RR). It is in a state of Therefore, even if a current is supplied from the same power supply system in order to measure the resistance value of the resistor RR, the switch SW is turned ON / OF.
The interference with the resistance value of the resistor RR due to the F operation is considerably suppressed.

FIG. 21 is an equivalent circuit when the switch SW is in the ON state in the circuit shown in FIG.
When the resistor RR is considered as a resistance element, its central portion is in contact with the contact conductor C, but the potential of the contact conductor C corresponds to the potential of the node TT in the circuit diagram of FIG. To do. The node TT is isolated from the power supply line Vcc by a resistance element R01 of 10 MΩ,
Since it is isolated from the ground line Gnd by a resistance element R04 of 1 MΩ, even if the node TT is connected near the center of the resistance element RR, the resistance element has a resistance value of at most about 10 kΩ. There is no great influence on the measurement of the resistance value of the RR. The resistance element R01 is 10 MΩ and the resistance element R04 is 1 MΩ.
The resistance value of both resistance elements is set to about 10 times,
This is a consideration for clearly detecting the ON / OFF state of the switch SW. That is, in FIG. 20, when the contact electrodes S1 and S2 are in the insulated state (the switch SW is in the OFF state), the terminal T4 becomes the power supply voltage Vcc, and the contact electrodes S1 and S2 are in the conductive state (the switch SW is in the ON state). In the case of, the terminal T4 is almost at the ground voltage (Vcc × 1/11), so that the ON / OFF state of the switch SW can be detected by directly capturing the potential of the terminal T4 as a digital value.

§6. Using the variable resistance element according to the present invention
Another embodiment of the force detection device The present invention relates to a plate-shaped substrate, an elastic deformable body arranged to face the substrate, and an elastic deformable body arranged between the substrate and the elastic deformable body, and the It is widely applicable to a force detection device having a variable resistance element whose resistance value between two predetermined points changes, and a detection circuit which detects the resistance value of this variable resistance element as an electric signal, and its application target is: It is not limited to the force detection device described in §1. So here,
Regarding the force detection device different from the force detection device described in §1,
An embodiment to which the present invention is applied will be described.

FIG. 22 is an exploded side sectional view showing the components by disassembling the force detection device according to this another embodiment. As shown in the figure, this force detection device is provided with a control panel 210,
Elastic deformation body 220, dome-shaped structure 230, substrate 240
It is composed by. In practice, this force detecting device arranges the dome-shaped structure 230 on the substrate 240,
It is constructed by covering the upper part thereof with an elastic deformable body 220 and further attaching the operation panel 210 thereon. This force detection device is suitable for use as an input device for an electronic device that executes a predetermined process based on a predetermined program, such as a mobile phone or a game playing device,
ON / O in addition to the operation input indicating the operation amount in the predetermined direction
A switch input indicating the FF state can be performed. Here, the force detection device will be described on the assumption that it is used as an input device for such an electronic device.

The operation panel 210 is disposed on the upper surface of the elastically deformable body 220, and has a function of transmitting a force applied based on the operation of the operator to the elastically deformable body 220 to cause the elastically deformable body 220 to elastically deform. have. Here, the operation input to the operation panel 210 by the operator corresponds to the external force to be detected by the force detection device. Therefore, the operation panel 210 is
Based on the action of this external force, the elastically deformable body 220 is elastically deformed and a part of the elastically deformable body 220 is displaced with respect to the substrate 240.

FIG. 23 is a top view of the operation panel 210, and FIG. 24 is a bottom view of the operation panel 210. As shown in the figure, the operation panel 210 has a disk shape as a whole, and in this embodiment, it is made of resin such as plastic. As described above, the operation panel 210 includes the elastically deformable body 2
Any shape may be used as long as it can perform the function of transmitting a force to 20, but a disk-shaped one is suitable for inputting the operation amount in various directions. Further, the elastic deformable body 220 is surely operated by the operator.
In order to transmit the electric field to the metal, it is preferable to use a rigid material such as resin or metal. In the case of the illustrated embodiment, the operation panel 210 is composed of an operation portion 211, a bank portion 212, and an outer peripheral portion 213 as shown in FIG. 23, and the lower surface thereof is as shown in FIG. A cylindrical pressing rod 214 is projected to the inside. The operation portion 211 is a smooth hollow portion formed inside the bank portion 212 so as to fit the operator's finger, and the outer peripheral portion 213.
Is a taper portion formed on the outside of the bank portion 212. In addition, the pressing rod 214 is turned on / off as described later.
This is for effectively performing a switch input indicating the FF state, and has a function of effectively transmitting a vertically downward force from the operator to the vicinity of the apex of the dome-shaped structure 230.

In the case of this embodiment, the elastically deformable body 220 is made of integrally molded silicone rubber. FIG. 25 is a top view of this elastic deformable body 220, and FIG.
FIG. 4 is a bottom view of this elastically deformable body 220. As shown, the elastic deformable body 220 has a substantially square shape in plan view. The basic components thereof are, as shown in the side sectional view of FIG. 22, an inner membranous portion 221 and an annular raised portion 2.
22, outer film portion 223, side wall portion 224, fixed leg portion 22
5, columnar protrusions P1 to P3. As shown in FIG.
The inner film-shaped portion 221 and the outer film-shaped portion 223 are film-shaped structures that form the entire square-shaped upper surface of the elastic deformable body 220, but here, for convenience of description, the annular raised portion 2
The inner portion of 22 is referred to as the inner membrane portion 221, and the outer portion thereof is referred to as the outer membrane portion 223. This film part 22
1 and 223 are arranged substantially parallel to the upper surface of the substrate 240 with the dome-shaped structure 230 interposed therebetween. The annular raised portion 222 is an annular raised portion formed on the upper surface of this film-shaped portion, and the inner film-shaped portion 221.
The upper surface portion of is surrounded by the annular raised portion 222. In this embodiment, the annular raised portion 222 has a washer-like structure having a rectangular cross section, which is the operation panel 21 arranged on the upper surface thereof.
This is a consideration so that the force from 0 can be received efficiently.

On the other hand, the side wall portion 224 has the outer film portion 223.
Has a function of fixing the surrounding area to the upper surface of the substrate 240. The square-shaped film-shaped portions 221 and 223 are supported by the side wall portions 224 on their four sides, and are kept substantially parallel to the upper surface of the substrate 240. As shown in the bottom view of FIG. 26, columnar fixed leg portions 225 extend downward at the four corners of the lower surface of the elastically deformable body 220. The four fixing legs 225 are formed on the substrate 240.
It is inserted into the fixing hole portions 241 (see FIG. 22) formed at four places on the upper surface of the. Thus, the elastically deformable body 220 is fixed at a predetermined position on the substrate 240.

Further, as shown in FIG. 26, a large number of columnar projections P1 to P3 extending downward are formed on the lower surfaces of the film portions 221 and 223. FIG. 27 shows the positions of the columnar projections P1 to P3 in order to clarify the positions thereof.
Concentric circles with dashed lines are added to the bottom view of. As illustrated, if three concentric circles K1, K2, and K3 are defined around the center of the elastically deformable body 220, the columnar protrusions P1 to P3 are arranged on the circumference of any concentric circle. I understand. That is, a total of four columnar projections P1 are arranged on the circumference of the inner concentric circle K1 at a circumferential angle of 90 °, and a total of four columnar projections P2 are arranged on the circumference of the reference concentric circle K2 at a circumferential angle of 22.5 °. A total of 16 are arranged, and the columnar protrusions P3 have a circumferential angle of 4 on the circumference of the outer concentric circle K3.
A total of eight are arranged at intervals of 5 °.

The side surface shape of each of the columnar protrusions P1 to P3 is shown in FIG.
2 is clearly shown in a side sectional view. Note that, in the side sectional view of FIG. 22, in order to avoid complication of the drawing, only the columnar projections P1 to P3 that are located on the cut surface are drawn, but actually, FIG. 26 and FIG. As shown in the bottom view of FIG. 1, a larger number of columnar projections extend downward from the lower surface of the film-shaped portion. Here, comparing the lengths and shapes of the columnar projections P1, P2, P3 shown in FIG. 22, each has a unique length and shape. This is because each of them has different main functions.

That is, the main function of the columnar protrusion P1 is
It has a function as the contact conductor C in the force detection device described in §1 and functions to change the resistance value of the resistor by contacting the surface of the resistor formed on the substrate 240. Therefore, the columnar protrusion P1 has a length and a shape suitable for fulfilling such a function as a contact conductor. Therefore, here, the columnar protrusions P1 are referred to as “columnar protrusions” or “contact conductors” as necessary.

On the other hand, the main function of the columnar projections P3 is that the inner film-shaped portion 221 and the outer film-shaped portion 223 are placed on the upper surface of the substrate 240 in a state where no input from the operator is applied to the operation panel 210. The columnar protrusion P3 is set to have a length suitable for performing such a supporting function. Therefore, here, the columnar protrusions P3 are referred to as "supporting columnar protrusions".

On the other hand, the main function of the columnar projections P2 is, as will be described later, the function of causing a change in the electrically conductive state by coming into contact with an electrode formed on the upper surface side of the substrate 240. . Therefore, here, the columnar protrusion P
2 will be referred to as "columnar protrusions for electrodes". The length of the electrode columnar projections P2 is set shorter than the lengths of the supporting columnar projections P1 and the contact conductors P3 in the state where no input from the operator is applied to the operation panel 210. In order to keep the lower end of the electrode columnar projection P2 in a suspended state, the electrode columnar projection P2 is kept in a state of not being in physical contact with the electrode formed on the upper surface of the substrate 240.

The contact conductor P1, the supporting columnar protrusion P3, and the electrode columnar protrusion P2 are not limited to the length,
The side shape is also different. Specifically, the lower ends of the contact conductor P1 and the supporting columnar projections P3 are slightly rounded, while the electrode columnar projections P2 are disk-shaped protrusions whose lower ends are flat. . Such a difference in shape is also based on the above-mentioned difference in function. That is, the lower ends of the contact conductor P1 and the supporting columnar protrusion P3 contact the upper surface of the substrate 240 to change the contact surface,
It has a shape suitable for supporting the membrane part,
The lower end portion of the electrode columnar projection P2 is in contact with the electrode formed on the upper surface of the substrate 240, and has a shape suitable for ensuring electrical conduction.

As in the embodiment shown here, the operation panel 21
When 0 is composed of a disc-shaped rigid member, it is considered that the force applied by the operator is transmitted along a concentric circle centered on the central axis of the operation panel 210, and therefore, as shown in FIGS. It is preferable that each of the columnar protrusions P1 to P3 is also arranged along a predetermined circumference. Particularly, in the illustrated embodiment, when an operation input indicating a predetermined direction is applied to the operation panel 210, the applied force is the same as the operation panel 2 does.
From the peripheral portion of 10 to the annular ridge 222. Therefore, here, the reference concentric circle K2 shown in FIG.
Is a circle corresponding to the center position of the annular ridge 222, and the electrode columnar projection P2 is arranged at a predetermined position (16 places) directly below the annular ridge 222. Further, the reference concentric circle An inner concentric circle K1 is defined inside K2, and a contact conductor P1 is arranged on the circumference of the inner concentric circle K1.
An outer concentric circle K3 is defined on the outer side of 2, and supporting columnar protrusions P3 are arranged on the circumference thereof.

As a component of this elastically deformable body 220,
Another important component is the displacement conductive layer 226 formed in a predetermined area on the lower surface of the film portion. FIG. 28 shows the elastically deformable body 22 for showing the formation region of the displacement conductive layer 226.
It is a bottom view of 0. Displacement conductive layer 226 is formed in the area within the circle shown by hatching in the drawing (the hatching in FIG. 28 is not for showing a cross section but for showing an area). As mentioned above,
Although a large number of columnar protrusions are formed on the lower surface of the elastic deformable body 220, the displacement conductive layer 226 is formed on the lower surface of the elastic deformable body 220 including the surfaces of these columnar protrusions. Therefore, the displacement conductive layer 226 is also formed on the surface portions of the columnar protrusions (contact conductors) P1 and the electrode columnar protrusions P2 located in the hatched areas in FIG. Since the columnar protrusion P1 functions as a conductor for contact with the resistor, at least the contact surface portion with respect to the resistor needs to have conductivity. The displacement conductive layer 226 formed on the surface of the columnar protrusion P1 becomes necessary to fulfill such a function as a contact conductor. Further, since the electrode columnar protrusion P2 functions as an intermediary electrode that contacts a pair of contact electrodes formed on the substrate 240, as will be described later, at least the contact surface portion has conductivity. Need to be Displacement conductive layer 226 formed on the surface of the electrode columnar projection P2
Are necessary to fulfill such a function as an intermediary electrode. On the other hand, the supporting columnar projections P3 need only have a physical supporting function and are not required to have an electrical function. Therefore, in the embodiment shown here, the displacement conductive layer 226 is formed on the surface thereof. Not not.

The displacement conductive layer 226 is, specifically,
It can be configured by a layer made of a conductive material applied to the lower surface of the elastic deformable body 220. As described above, in this embodiment, the elastically deformable body 220 is made of integrally molded silicon rubber. The displacement conductive layer 226 can be formed by applying a conductive coating material to a partial area (area inside the hatched circle in FIG. 28) and drying it. The thickness of the displacement conductive layer 226 is equal to that of the elastic deformable body 220.
The displacement conductive layer 226 is not shown in the side cross-sectional view because the displacement conductive layer 226 is smaller than the thickness of each part.

On the other hand, the dome-shaped structure 230, as shown in the side sectional view of FIG. 22, is a structure in the shape of a flat cup, and is arranged so as to be flat near the center of the upper surface of the substrate 240. To be done. FIG. 29 is a top view of the dome-shaped structure 230. The shape of the dome-shaped structure 230 is not particularly limited, but if the dome-shaped structure 230 having a circular planar shape is used as shown in the figure, the operation input in each direction can be smoothly performed. It is possible to do so, which is preferable. In addition, the dome-shaped structure 230 has a property that, when a downward pressing force of a predetermined amount or more is applied to the vicinity of the apex, the vicinity of the apex is elastically deformed to be convex downward so that the shape is inverted. have. FIG. 30 is a side sectional view showing such a state of shape reversal. Figure 30
(a) shows a state in which no external force is applied, and FIG.
In (b), a downward pressing force F is applied to the vicinity of the apex,
The state in which the shape is inverted so that the vicinity of the apex is elastically deformed to be convex downward is shown. Of course, since this shape reversal is elastic deformation, when the pressing force F disappears, the dome-shaped structure 230 returns to the original state shown in FIG. 30 (a).

The shape inversion of this dome-shaped structure 230 is
It is used for switch input by the operator. Therefore, at least the lower surface portion of the dome-shaped structure 230 near the apex needs to form the conductive contact surface 231. That is, as shown in FIG. 30 (b), when the shape inversion occurs near the apex, the conductive contact surface 231 contacts with the electrode provided on the substrate 240 side to detect the switch input. Like In this embodiment, a metal dome is used as the dome-shaped structure 230. Generally, if a dome-shaped structure is made of a metal material,
Although the shape inversion as described above occurs and the dome having the conductive contact surface 231 can be realized, the dome-shaped structure 230 does not necessarily have to be made of metal. For example, the conductive contact surface 231 may be realized by forming a dome-shaped structure made of resin or the like and forming a conductive material film near the center of the lower surface thereof.

Next, the structure of the substrate 240 will be described. The basic functions of the substrate 240 are a function of mounting and supporting the above-mentioned constituent elements and a function of providing a reference surface for forming each resistor and each electrode. FIG. 31 shows a top view of the substrate 240. As described above, the four fixing holes 241 shown in the figure are holes dug in the upper surface of the substrate 240 in order to insert the fixing legs 225 of the elastically deformable body 220.

As shown in the figure, four fan-shaped resistors R11 to R14 and four circular or annular electrodes E15 to E18 are formed on the upper surface of the substrate 240. Here, based on the position where each electrode is arranged, the two annular electrodes E15 and E16 arranged outside the four resistors R11 to R14 are called outer electrodes, and the circular electrodes arranged inside are arranged. The electrode E17 and the annular electrode E18 will be referred to as inner electrodes. In FIG. 31, in order to clearly show the shapes of the resistors and the electrodes, the individual resistors and the electrodes are hatched. Therefore, FIG.
The hatching at does not indicate a cross section. Further, in the drawing, two types of hatching patterns are used, but this is to show the resistor and the electrode separately.
In this embodiment, the resistors R11 to R14 are made of flat plate carbon, and the electrodes E15 to E18 are made of metal such as copper. Both are formed by printing a predetermined pattern on the substrate 240.

The outer ring-shaped outer electrode E formed on the outermost side
Reference numeral 15 is formed in an outer peripheral facing portion (a portion of the upper surface of the substrate where the outer contour line of the operating panel 210 is projected on the substrate 240) facing the outer peripheral portion of the operating panel 210. In the case of this embodiment, since the operation panel 210 has a disc shape, the outer peripheral facing portion facing the outer peripheral circle is also a circular portion, and the outer electrode E15 faces the outer peripheral circle of the operation panel 210 as shown in the figure. It is an annular (washer-like) electrode arranged at a position. The outer electrode E16 is an annular (washer-shaped) electrode disposed slightly inside the outer electrode E15. To describe the more accurate position, the boundary portion between the outer electrode E15 and the outer electrode E16 is located on the circumference opposite to the reference concentric circle K2 shown in FIG. 27, and the outer contour of the outer electrode E15 is located. The distance between the outer contour and the inner contour of the outer electrode E16 is designed to be substantially equal to the diameter of the electrode columnar projection P2. Therefore, the two outer electrodes E15 and E16 are arranged directly below the electrode columnar projections P2.

The role of the outer electrodes E15 and E16 is to serve as the lower surface of the electrode columnar projection P2 when the elastic deformation body 220 is deformed by an operation input from the operator to the operation panel 210 in a predetermined direction. By contacting the displacement conductive layer 226 formed in the above, it is to detect that the applied operation input has a predetermined magnitude or more. That is, the elastically deformable body 220 is deformed by the operation input of the operator, and the displacement conductive layer 226 formed on the lower surface of any one of the electrode columnar projections P2 has the outer electrodes E15 and E1.
When both of the outer electrodes E15 and E16 are in contact with each other at the same time, the outer electrodes E15 and E16 are brought into conduction through the contacting displacement conductive layer 226. Therefore, the outer electrodes E15 and E16
By electrically detecting the conduction state between them, it is possible to recognize whether or not an operation input having a predetermined magnitude or more is applied. After all, the outer electrodes E15 and E16 function as a pair of contact electrodes, and the displacement conductive layer 226 formed on the lower surface of each electrode columnar projection P2 functions as an intermediary electrode, and the two constitute a switching element. Will be. A pair of contact electrodes E15 that constitute this switching element,
E16 normally maintains an electrically insulated state (while an operation input of a predetermined size or more is not applied to the operation panel 210), but an operation input of a predetermined size or more is supplied to the operation panel 210. When added, the mediating electrodes come into contact with each other at the same time due to the deformation of the elastically deformable body 220, and the mediating electrodes are brought into an electrically conducting state.

Four fan-shaped resistors R11 to R14
Are resistors R1 to R4 in the force detection device described in §1.
It has a function equivalent to that of (1) and is arranged at a position suitable for detecting a directional operation input applied by the operator. Since the force detection device described in §1 had the function of detecting the XYZ triaxial components of the external force, five resistors R1 to R5 (other reference resistors R6) were formed on the substrate. However, in the force detection device shown here, the operation amount is X
Since it has only the function of detecting the Y biaxial direction component, it is sufficient to form the four resistors R11 to R14 (the external force in the Z axis direction is a switch as will be described later). Only binary states of ON / OFF are detected as inputs).

Here, the origin O (not shown) is located at the center position of the upper surface of the substrate 240 shown in FIG. 31, the X axis is on the right side of the drawing, and the Y axis is on the upper side of the drawing. The upper surface of the substrate is included in the XY plane. If the XYZ three-dimensional coordinate system is defined as described above, the resistor R11 is located in the X-axis positive region, the resistor R12 is located in the X-axis negative region,
Resistor R13 in the Y-axis positive area, resistor R in the Y-axis negative area
14 is formed. Then, above the four resistors R11 to R14, columnar protrusions P1 (displacement conductive layer 2 on the lower surface) functioning as contact conductors, respectively.
26 are formed). Each resistor R
11 to R14 and the contacting conductor P arranged above them
A variable resistance element is constituted by 1 and the operation panel 210.
When an operation input of a predetermined size is applied to the contact, the elastic body 220 is deformed so that the contact conductor P1 moves to the resistor R11.
As described above, the resistance value between the two predetermined points of the resistors R11 to R14 changes according to the contact area at this time. Therefore, §1
Detecting the X-axis direction component and the Y-axis direction component of the applied operation input by using the resistors R11 to R14 by the same principle as that using the resistors R1 to R4 in the force detection device described in 1. Will be possible.

As shown in FIG. 31, resistors R11 to R1 are provided.
Two inner electrodes E17 and E18 are formed on the inner side of 4, that is, near the center of the substrate 240. The role of the pair of inner electrodes E17 and E18 is to detect the switch input applied to the operation panel 210 by the operator, that is, the pressing force in the vertically downward direction. The inner electrode E17 is a disc-shaped electrode arranged in the center of the substrate, and its diameter is set smaller than that of the circle forming the bottom peripheral surface (edge portion of the bottom) of the dome-shaped structure 230. On the other hand, the inner electrode E18 is a washer-shaped electrode, and its outer diameter is
The diameter is set to be approximately equal to the diameter of the circle forming the bottom peripheral surface of the dome-shaped structure 230, and the dome-shaped structure 230 is placed on the washer-shaped inner electrode E18. Figure 3
2 in the center of the upper surface of the substrate 240 shown in FIG.
It is a top view which shows the state which has arrange | positioned the dome-shaped structure 230 shown in FIG. In practice, the dome-shaped structure 230 is fixed to the upper surface of the substrate 240 by using an adhesive agent or an adhesive tape.

As shown in FIG. 30B, when a pressing force F vertically downward is applied to the vicinity of the apex of the dome-shaped structure 230, the shape of the dome-shaped structure 230 is inverted, but At this time, the electrode E17 is the dome-shaped structure 23.
0 has a shape suitable for contacting the conductive contact surface 231 on the lower surface. In this embodiment, the dome-shaped structure 23
0 is composed entirely of metal, so Fig. 30 (a)
In the state shown in Fig. 30, the dome-shaped structure 230 is in contact with only the washer-shaped inner electrode E18, but in the state shown in Fig. 30 (b), the vicinity of the inverted vertex becomes the inner electrode E17. Also comes into contact with each other, and has a function of electrically connecting the pair of inner electrodes E17 and E18 to each other.
That is, the inner electrodes E17 and E18 are composed of a pair of physically separated electrodes, but when the metal dome-shaped structure 230 is inverted, the dome-shaped structure 23 is formed.
The bottom peripheral surface of 0 is in contact with the inner electrode E18, and the lower surface near the apex thereof is in contact with the inner electrode E17, and the dome-shaped structure 230 made of a conductive material is attached to both inner electrodes E18.
By simultaneously contacting 17 and E18, the two become conductive with each other. After all, these pair of inner electrodes E1
By electrically detecting the conduction state between 7 and E18, the ON / OFF state related to the switch input by the operator can be detected. Note that the dome-shaped structure 230 does not necessarily have to be entirely made of a conductive material, and at least a portion extending from the inner side surface (the lower surface in the state of being laid down) to the bottom peripheral surface forms a conductive contact surface. Then, both inner electrodes E17 and E18 can be electrically connected.

As described above, on the upper surface of the substrate 240, a pair of outer electrodes E15 and E16 (contact electrodes), four resistors R11 to R14, and a pair of inner electrodes E17 and E18.
Although the flat plate-like constituent elements (contact electrodes) are formed, the respective constituent elements are arranged in the following positions in consideration of their respective functions. First, as described above, the inner electrode E18 is arranged at a position in contact with the bottom peripheral surface of the dome-shaped structure 230.
Is the shape of the dome-shaped structure 230,
It is arranged at a position where it can come into contact with the conductive contact surface 231 corresponding to the lower surface near the apex. Further, the pair of outer electrodes E15, E16 are arranged in the outer peripheral facing portion (the portion facing the reference concentric circle K2 in FIG. 27) on the substrate 240 facing the outer peripheral portion of the operation panel 210. On the other hand, the resistor R11
To R14 are the “dome-shaped structure 23 on the upper surface of the substrate 240.
It is arranged at a predetermined position in the "intermediate region portion, which is located outside the arrangement region of 0 and inside the outer peripheral facing portion".
In the present embodiment, the substrate 240 is composed of a printed circuit board for mounting an electronic circuit, and each electrode is composed of a printed pattern such as copper formed on the printed circuit board.
Each resistor is composed of a carbon print pattern formed on this printed board. in this way,
If the substrate 240 is composed of a printed circuit board for a circuit, various wirings can be provided on the substrate 240 by a printed pattern, which is convenient for practical use.

The details of the structure of each component shown in FIG. 22 have been described above, but an actual force detecting device is constructed by stacking these components. That is, the substrate 2
A dome-shaped structure 230 is placed in the center of 40, and an elastic deformable body 220 is placed so as to cover it (fixing leg 225 is inserted into fixing hole 241 to be fixed), and operation panel 210 is placed thereon. 33 is bonded to form a force detecting device as shown in the side cross-sectional view of FIG.

§7. Using the variable resistance element according to the present invention
Operation of Another Embodiment of Force Detection Device Subsequently, the operation of the force detection device shown in FIG. 33 will be described. Here, for the sake of convenience, the origin O is located at the center position of the upper surface of the substrate 240 shown in FIG. 31, the X axis is in the right direction of the drawing, and the Y axis is in the upper direction of the drawing, so that the upper surface of the substrate is included in the XY plane.
A three-dimensional coordinate system will be defined and the following description will be given. In FIG. 33, the X axis is on the right side of the figure and the Z axis is on the upper side of the figure.
Axis, Y axis is defined in the direction perpendicular to the plane of the drawing.

As described above, this force detecting device is provided with a switch input (so-called click input) indicating an ON / OFF state and an operation input indicating an operation amount in a predetermined direction, with respect to an arbitrary electronic device. It is a device with the function of performing.
Here, the operator will perform these inputs to the operation panel 210. Basically, when performing switch input, the operator touches the center portion of the operation panel 210 with his / her finger to move downward (Z When performing the operation of pushing in the negative direction of the axis and performing the operation input in the predetermined direction, the operation of pushing the operation panel 210 diagonally downward is performed.

FIG. 34 is a side sectional view (a side view of the dome-shaped structure 230) showing a deformed state of each part when the operator inputs a switch. When a downward pressing force (referred to as −Fz in the sense of a force in the negative direction of the Z axis) is applied to the operation panel 210, the pressing force −Fz causes the pressing rod 214 to be displaced downward, Inner membrane part 221
A downward force is applied to the apex of the dome-shaped structure 230. The dome-shaped structure 230 has a property that when a downward pressing force of a predetermined amount or more is applied to the vicinity of the apex, the shape is inverted so that the vicinity of the apex elastically deforms and becomes convex downward. Therefore, when the magnitude of the pressing force −Fz exceeds a predetermined critical value, the shape inversion occurs near the apex of the dome-shaped structure 230 as illustrated. That is, when the operator gradually increases the downward pressing force −Fz, the dome-shaped structure 230 suddenly collapses and enters the state shown in the figure, and a click feeling is transmitted to the fingertips of the operator.
At this time, the columnar protrusions P1, which are made of an elastic material,
P3 is elastically deformed and slightly crushed in the vertical direction.
However, the electrode-shaped columnar projection P2 remains suspended.

When the shape of the dome-shaped structure 230 is inverted, the inner electrode E17 shown in FIG.
The conductive contact surface 231 on the lower surface of the dome-shaped structure 230 is
Are in contact with each other, so that the inner electrode E17 and the inner electrode E18 are electrically connected. When the operator stops the pressing operation, the dome-shaped structure 230 returns to the original state,
The device will return to the state of FIG. In this state,
The inner electrode E17 and the inner electrode E18 are insulated.
After all, by detecting the electrical connection state between the inner electrode E17 and the inner electrode E18, the switch input indicating the ON / OFF state can be detected, and so-called click input can be detected.

Next, consider a case where the operator inputs an operation indicating the operation amount in a predetermined direction. Such an operation input is normally given as an input indicating an operation amount in four directions including up, down, left and right, or in eight directions including oblique directions. In the embodiment shown here, the four resistors R11 to R11 shown in FIG.
R14 and a contact conductor (a columnar protrusion P1 whose surface is covered with the displacement conductive layer 226) arranged above the R14,
Thus, a total of four sets of variable resistance elements are formed, and the operation amount in each direction can be detected based on the resistance values of the four sets of variable resistance elements.

For example, it is assumed that the operator performs an operation for applying a downward force including a force in the negative direction of the X axis to the operation panel 210. Here, the force applied by such an operation is referred to as -Fx. In FIG. 35, the operator has such an operation force −Fx (not necessarily the operation panel 210
It is not necessary to add it to the center position of the, but it is actually added to the part displaced slightly to the left as shown in the drawing). Is a side view). Operating force-Fx is
Since the force component is obliquely downward, it also includes a downward force component (negative Z-axis component) in the figure, but this downward force component is the pressing force by the above-mentioned click operation.
Since it is smaller than Fz, sufficient force for reversing the shape is not applied to the dome-shaped structure 30. Therefore, the operation panel 210 inclines so that the left side is lowered and the right side is raised in FIG. In other words, the dome-shaped structure 23
A value of 0 causes shape reversal with respect to a vertically downward pressing force applied as a switch input, and does not cause shape reversal with respect to an oblique downward pressing force applied as an operation input in a predetermined direction. A structure having such deformation characteristics may be used. Note that the same phenomenon occurs when a vertically downward operation force -FFx is applied to the position near the left end of the operation panel 210 in the figure instead of the obliquely downward operation force -Fx shown in FIG. In the present embodiment, “X
When the operation input indicating the operation amount in the negative direction of the axis is referred to, not only the operation input in the oblique downward direction like the operation force-Fx but also the displacement in the negative direction of the X axis like the operation force-FFx. It also includes an operation input that pushes the position vertically downwards,
The operation force-FFx is an operation input equivalent to the operation force-Fx.

Now, as shown in FIG. 35, the operation panel 210
Force to tilt the left side to -Fx (or -FFx,
The same applies hereinafter), the columnar protrusion P in the left half of the figure
1 and P3 are elastically deformed and crushed in the vertical direction.
On the other hand, the columnar protrusions P1 and P3 in the right half of the figure are in a state of being lifted from the upper surface of the substrate 240, as shown. Eventually, when an operating force −Fx having a magnitude larger than a certain level is applied, as shown in FIG. 35, the columnar protrusion P at the left end of the figure is obtained.
The lower end surface of 2 (displacement conductive layer functioning as an intermediary electrode) is brought into contact with both outer electrodes E15 and E16, the outer electrodes E15 and E16 conduct, and the entire displacement conductive layer 226 forms outer electrodes E15 and E16. It becomes the same potential as.
If the operating force -Fx is further increased from this state, as shown in FIG. 36, the columnar protrusions P1 and P on the left half of the figure are shown.
3 is elastically deformed so as to be further crushed, and the columnar protrusion P2 is also slightly elastically deformed to be in a crushed state. And finally,
As shown in FIG. 37, the columnar protrusions P1, P2 on the left side of the figure
All of P3 is completely collapsed.

From the state shown in FIG. 33, to FIG.
Considering how the resistance value between predetermined two points of each of the resistors R11 to R14 changes when transitioning to the state shown in FIGS. 36 and 37, the resistors shown on the left side of the figure are shown. R1
2, the contact surface of the columnar protrusion P1 (contact conductor) arranged above the contact protrusion gradually increases, so that the resistor R1
While the resistance value between the two predetermined points of 2 gradually decreases, the columnar protrusion P2 (contact conductor) is not in contact with the resistor R11 shown on the right side of the drawing. , The resistance value does not change. On the contrary, when the operation force + Fx in the positive direction of the X axis is applied, the operation panel 210 is inclined to the right side, so the left-right relationship is reversed as compared with the case described above, and the resistance is increased. The resistance value between the two predetermined points of the body R11 gradually decreases. After all, resistor R11
By measuring the resistance value of R12 and R12, the operation amount applied as the operation force −Fx, + Fx in the X-axis direction can be detected (for example, the difference between both resistance values may be obtained). By measuring the resistance values of the resistors R13 and R14 arranged on the Y-axis according to exactly the same principle, it is possible to detect the operation amount applied as the operation force −Fy, + Fy in the Y-axis direction.

Such an operation amount in the X-axis direction or the Y-axis direction is an operation amount which can be input by the operator by inclining the operation panel 210 in four directions of up, down, left and right.
By performing predetermined arithmetic processing, it is possible to detect the operation amount in more directions. For example, the total operation amount in eight directions including the oblique 45 ° direction can be obtained as a combined component of the operation amount in the X-axis direction and the operation amount in the Y-axis direction. Specifically, for example, the operation amount x in the X-axis direction
And the operation amount y in the Y-axis direction are obtained, the route (x
It is possible to treat the operation amount having a size of ² + y ² ) as acting on the oblique 45 ° direction (which direction can be determined by the combination of the signs of the operation amounts x and y). Of course, the force in any direction can be detected, and in this case, the magnitude of the operation amount is the route (x ²
+ Y ² ), and the direction is tan ⁻¹ (y / x).

By the way, in order to measure the resistance values of the resistors R11 to R14, it is necessary to apply a voltage between two predetermined points of each resistor to cause a current to flow through the resistors. An object of the present invention is to efficiently suppress power consumption in a force detection device using such a variable resistance element.
The force detection device shown in FIG. 3 also has a function of efficiently suppressing power consumption. That is, until the operation input applied to the operation panel 210 exceeds a predetermined magnitude, the detection circuit is kept in the standby mode in which no current is applied to the resistor, and the operation input above the predetermined magnitude is applied. At this time, the detection circuit may be set to the detection mode so that the resistance is measured by applying a current to the resistor. Specifically, in the force detection device shown in FIG. 33, the outer electrodes E15 and E16 (a pair of contact electrodes) formed on the substrate 240 and the columnar protrusion P2 arranged above the outer electrodes E15 and E16.
And the displacement conductive layer 226 (intermediate electrode) formed on the surface thereof constitute a switching element. When the outer electrodes E15 and E16 are electrically insulated, the standby mode is set, and when the outer electrodes E15 and E16 are electrically connected, detection is performed. The mode can be switched.

FIG. 38 is a circuit diagram showing an example of a detection circuit that can be used in the force detection device shown in FIG. Like the detection circuit shown in FIG. 17, this detection circuit is composed of a signal processing circuit having an input terminal for an analog signal. The input analog signal is converted into a digital signal, and a predetermined digital signal is internally generated. Is calculated and an output as a digital signal is obtained. This FIG.
The signal processing circuit shown in is also configured as a one-chip integrated circuit, and has an analog input terminal T1 shown on the right side of the drawing.
Analog voltage values corresponding to the resistance values of the resistors R11 to R14 are input to 1 to T14, respectively. Each resistor R
One end (lower end in the drawing) of 11 to R14 is grounded, and the other end (upper end in the drawing) is connected to each of the analog input terminals T11 to T.
14 and switches SW11
-SW14 and resistance elements R05-R08 are connected to the power supply Vcc.

When each of the switches SW11 to SW14 is turned on, a voltage is applied from the power supply Vcc to each of the resistors R11 to R14, and the analog input terminals T11 to T14 correspond to the resistance values of each of the resistors R11 to R14. Similar to the circuit shown in FIG. 17, the voltage division is applied to obtain a digital value corresponding to each resistance value. The added operation amount in the X-axis direction can be obtained based on the resistance value of the resistor R11 or R12 (or the difference between the two), and the added Y
The operation amount in the axial direction can be obtained based on the resistance value of the resistor R13 or R14 (or the difference between the two).

The switches SW11 to SW14 are switches for controlling the voltage supply to each resistor, and when all the switches SW11 to SW14 maintain the OFF state, the voltage of the power supply Vcc changes to each resistor. Is not applied to
No current flows through each resistor. This indicates that this signal processing circuit is in the standby mode. On the other hand, when any of the switches SW11 to SW14 is turned on, the voltage of the power supply Vcc is applied to the resistor connected to the switch turned on, and a current flows through the resistor. Therefore, as described above, the digital value corresponding to the resistance value of the resistor is detected. This indicates that this signal processing circuit is in the detection mode state.

ON / OF of the switches SW11 to SW14
The F control is performed by the control signals S21 to S24 output from the control terminals T21 to T24. In reality, the switches SW11 to SW14 are composed of semiconductor switches such as logic elements, and control signals S21 to S24 are used.
Becomes a digital logic signal. The signal processing circuit includes a CPU and a program for operating the CPU, and control signals S21 to S21 are executed by the logical operation of the CPU.
Twenty-four logical values are determined.

A power supply voltage Vcc or a ground voltage is applied to the input terminal T01 shown on the left side of FIG. 38 depending on the ON / OFF state of the switch SW1. That is, when the switch SW1 is in the OFF state, the power supply voltage Vcc is applied to the input terminal T01 via the resistance element R01, but when the switch SW1 is in the ON state,
The input terminal T01 has the ground potential. Therefore, the signal processing circuit can grasp the ON / OFF state of the switch SW1 based on the potential of the input terminal T01.

The switch SW1 is actually a switch constituted by the outer electrodes E15 and E16 (a pair of contact electrodes) formed on the substrate 240 in the force detecting device shown in FIG. OFF when E16 is in an insulating state, O when E16 is in a conducting state
Become N. Therefore, for example, in the state shown in FIG. 33 or FIG.
In the state where the axial operation amount is not applied), switch S
Although W1 is in the OFF state, in the state shown in FIG. 35, FIG. 36, and FIG. 37 (the state in which the X-axis direction operation amount or the Y-axis direction operation amount of a predetermined size or more is added), switch SW1
Is turned on.

Therefore, in the signal processing circuit shown in FIG. 38, when the potential of the input terminal T01 is the power supply voltage Vcc (when the switch SW1 is in the OFF state), the control terminal T2 is used.
From 1 to T24, switch SW11 to SW14 OF
When the control signals S21 to S24 for setting the F state are output and the potential of the input terminal T01 is the ground potential (the switch SW1 is O
In the case of N state), from the control terminals T21 to T24,
The control is performed so as to output the control signals S21 to S24 for turning on the switches SW11 to SW14. As a result, a current flows through the resistors R11 to R14 and detection can be performed only when an operation amount of a predetermined size including the X-axis or Y-axis direction component is applied. After all, until the switch SW1 is turned on, the detection circuit maintains the standby mode in which the original detection function cannot be performed, and power consumption is suppressed.

On the other hand, the input terminal T shown on the left side of FIG.
00 depends on the ON / OFF state of the switch SW0,
The power supply voltage Vcc or the ground voltage is applied. That is, when the switch SW0 is in the OFF state, the input terminal T0
The power supply voltage Vcc is applied to 0 through the resistance element R00, but when the switch SW0 is turned on, the input terminal T00 becomes the ground potential. Therefore, the signal processing circuit can grasp the ON / OFF state of the switch SW0 based on the potential of the input terminal T00. This switch SW0 is actually the inner electrode E1 formed on the substrate 240 in the force detection device shown in FIG.
7 and E18, which are OFF when the inner electrodes E17 and E18 are in an insulating state, and ON when they are in a conducting state. Therefore, the ON / OFF state of the switch SW0 indicates a switch input by the operator (click input by inverting the shape of the dome-shaped structure 230).

In the embodiment shown here, as shown in the bottom view of FIG. 28, a single displacement conductive layer 226 (hatched portion in the figure) is provided on the bottom surface of the elastic deformable body 220.
And a conductive layer (a part of the displacement conductive layer 226) formed on the lower surface of each columnar protrusion P1 (contact conductor).
And the conductive layer formed on the lower surface of each columnar projection P2 (another part of the displacement conductive layer 226) are electrically connected to each other, and therefore when the detection circuit shown in FIG.
When 1 is in the ON state, the entire displacement conductive layer 226 is grounded, which affects the resistance value measurement of the resistors R11 to R14. Of course, even if there is such an influence, the resistance value can be measured, but in order to perform more efficient measurement, the resistance value is sufficiently larger than the resistance values of the resistors R11 to R14. A resistance element may be prepared, and a circuit that detects the conduction state of the contact electrodes E15 and E16 and a circuit that detects the resistance values of the resistors R11 to R14 may be isolated by using the prepared resistance element. . Specifically, in the detection circuit shown in FIG. 38, the resistance element R01 is composed of a resistance element having a large resistance value of about 10 MΩ, and 1 MΩ is provided between the electrode E16 and the ground level Gnd.
A resistance element having a large resistance value may be inserted. Alternatively, instead of forming the displacement conductive layer 226 as a single conductive layer, electrically isolated island-shaped conductive layers are formed on the lower surface of each columnar projection P1 and the lower surface of each columnar projection P2. May be.

§8. Using the variable resistance element according to the present invention
Modification of Force Detection Device As described above, the force detection device using the variable resistance element according to the present invention has been described with respect to some embodiments.
Further, some modified examples will be described.

(1) Modified Example of Form of Contact Electrodes In the embodiment shown in FIG. 31, a pair of annular contact electrodes (that is, outer electrodes E15 and E16) and a bottom surface of the electrode columnar projection P2 are formed. Although the switching element is composed of the displaced conductive layer 226 that has been formed, the pair of contact electrodes used as the switching element need not necessarily be annular. For example, a pair of contact electrodes E partially shown in FIG.
15A and E16A are outer electrodes E15 and E shown in FIG.
The annular electrode is formed at substantially the same position as 16, but tooth-shaped protrusions are formed on each electrode, and these electrodes are in mesh with each other (the hatching in FIG. 39 is for clarifying the shape of the electrode). It does not show a cross section). The displacement conductive layer 226 functioning as an intermediary electrode is
Although it is necessary to simultaneously contact both of the pair of contact electrodes, a pair of contact electrodes E15A, E as shown in FIG.
If 16A is used, such simultaneous contact becomes easier.

A contact electrode group E, a part of which is shown in FIG.
15B and E16B (the hatching in FIG. 40 is for clarifying the shape of the electrode and not for showing the cross section), and the plurality of N electrodes E15B belonging to the first group are shown.
And a plurality of N electrodes E16B belonging to the second group are alternately arranged along the circumference defined on the substrate 240 (outer electrodes E15 and E16 shown in FIG. 31).
It is located in almost the same position). This makes the first
The electrode E15B belonging to the group and the electrode E16B belonging to the second group are arranged adjacent to each other, and the electrode E15B and the electrode E16B arranged adjacent to each other form a pair of contact electrodes. In addition, a pair of contact electrodes composed of N sets in total is formed. In the embodiment shown in FIG. 31, a pair of contact electrodes E1
Although only 5, 5 and E16 were provided, the example shown in FIG. 40 is a modification in which a plurality of pairs of contact electrodes are provided. In this modification, it is necessary to perform wiring for each of the N electrodes E15B and the N electrodes E16B, which makes the wiring complicated in practice.

(2) Modification of Pair of Contact Electrodes In the embodiments described so far, the pair of contact electrodes included in the switching element are both formed on the substrate, and both of the pair of contact electrodes are formed. Although the technique of bringing the pair of contact electrodes into conduction by simultaneously contacting the intermediary electrode with the pair of electrodes has been adopted, it is not always necessary to provide the pair of contact electrodes on the substrate side in carrying out the present invention. It is not always necessary to use the intermediary electrode. For example, a fixed electrode for contact formed on the substrate and a displacement electrode for contact formed on the elastic deformable body side constitute a pair of contact electrodes, and an external force of a predetermined magnitude or more is applied to the elastic deformable body. When a force acts, the fixed electrode for contact formed on the substrate and the displacement electrode for contact formed on the elastic deformable body are brought into physical contact by the deformation of the elastic deformable body. It doesn't matter.

However, in order to electrically detect whether or not the fixed electrode for contact formed on the substrate and the displacement electrode for contact formed on the elastically deformable body side physically contact with each other in this way. Therefore, it is necessary to wire each electrode. In practice, it is not preferable to provide wiring on the elastic deformable body side. Therefore, in practice, it is preferable to adopt a method in which a pair of contact electrodes are provided on the substrate and the electrodes are electrically connected using the intermediary electrode, as in the embodiments described above. If you take such a method,
Since wiring is not required on the side of the intermediary electrode, it is not necessary to provide wiring on the side of the elastically deformable body by wiring only on the side of the substrate.

(3) Modified Example of Variable Resistance Element In the embodiments described so far, the resistor arranged on the substrate and the contact conductor provided on the elastic deformable body side so as to face the resistor. , The variable resistance element used in the present invention is arranged between the substrate and the elastic deformable body, and the variable resistance element is provided between two predetermined points according to the pressure applied by the displacement of the elastic deformable body. As long as the constituent element has the property of changing the resistance value, it is not always necessary to form it by combining the resistor and the contact conductor.

FIG. 41 shows a variable resistance element 30 having a form different from that of the variable resistance element used in the above embodiments.
It is a sectional side view which shows the structure of 0. The variable resistance element 300 shown here includes a first sheet 310 and a second sheet 320.
It has a structure in which and are laminated so as to be vertically symmetrical. First
Sheet 310 of first film 31 as shown.
1 and the first conductive layer 312 formed thereon and the first resistor 313 formed thereon, the second sheet 320 is formed into the second
Film 321, a second conductive layer 322 formed thereunder, and a second resistor 323 formed therebelow,
It is composed by. However, here, the first and second modifiers are attached to the individual constituents for the sake of convenience to distinguish the two, and the actual structure is the first sheet 310. And the second sheet 3
20 is exactly the same sheet, and the variable resistance element 300 is obtained by turning one of the two same sheets upside down and stacking them on the other. Practically, it is preferable to bond both sheets by some method so as not to shift both sheets.

First resistor 313 and second resistor 3
Each of 23 is made of a material that elastically deforms, and is arranged at a position facing each other. Moreover, the upper surface of the first resistor 313 and the lower surface of the second resistor 323 each have a corrugated structure having a corrugated cross-section, and the first resistor 313 and the second resistor 313 are formed in accordance with the pressure applied in the vertical direction in the drawing. The area of the contact surface with the resistor 323 is changed. That is, in the state where the vertical pressure is not applied to the variable resistance element 300, as shown in FIG. 41, the apex portions of the corrugated concavo-convex structure of the resistors 313 and 323 are in point contact with each other. Although the area of the contact surface is extremely small, when a downward external force −Fz as shown in FIG. 42 acts on the variable resistance element 300, as shown in the figure, the waveforms of the resistors 313, 323 are generated. The uneven structure portion is deformed by the pressure, and the contact area between the both increases.

The first conductive layer 312 is connected to the lower surface of the first resistor 313, and the second conductive layer 322 is connected to the upper surface of the second resistor 323. When the resistance value between the terminal T31 connected to the conductive layer 312 and the terminal T32 connected to the second conductive layer 322 is measured, the resistance value changes depending on the contact area between the two. Therefore, based on this resistance value, it becomes possible to detect the vertical external force applied to the variable resistance element 300. That is, the two sheets 310 and 320 are
It functions as the variable resistance element 300 having the property that the resistance value between two predetermined points changes according to the applied pressure. Practically, the following method may be used to create the first sheet 310, for example. First, FPC (Fl
A first film 311 made of an exible print circuit film or the like is prepared, and a first conductive layer 312 is formed by forming a layer of copper or the like on the upper surface of the first film 311. continue,
The pressure sensitive conductive ink may be applied to the upper surface of the first conductive layer 312, and the surface of the pressure sensitive conductive ink may be processed into a corrugated structure having a wavy cross section to form the first resistor 313. Of course, the second sheet 320 can be created by the same method. In the illustrated example, the corrugated uneven structure having a corrugated cross section is formed on each of the upper surface of the first resistor 313 and the lower surface of the second resistor 323, but such an uneven structure is not necessarily formed on both of them. It is not necessary to form it, and the variable resistance element can be configured as long as it is formed on at least one surface portion. In short, the first resistor 313
A surface portion of at least one of the second resistor 323 and the second resistor 323 has a concavo-convex structure that causes elastic deformation, and the area of the contact surface between the two varies depending on the pressure applied between the two. It only has to be configured.

The variable resistance element 300 shown in FIG. 41 is
For example, it can be used in place of the variable resistance element constituted by the "resistor and the contact conductor" in the force detection device shown in FIG. In this case, the substrate 240
The variable resistance element 300 described above may be used instead of the four resistors R11 to R14 formed above. Specifically, four variable resistance elements 300-1 to 300-1 having a fan-shaped planar shape like the resistors R11 to R14 of FIG. 32 and having a side sectional structure as shown in FIG.
If 300-4 are prepared, and each of them is adhered to a predetermined position on the substrate 240, that is, a position where the resistors R11 to R14 of FIG. 32 are arranged (the lower surface of the first film 311 is attached to the substrate 240). Should be adhered to the upper surface of
The four variable resistance elements 300-1 to 300-4 have the same functions as the four resistors R11 to R14. However, the applied external force is detected based on the resistance value between the terminals T31 and T32 shown in FIG. 41 for each variable resistance element 300.

Since each variable resistance element 300 can be actually made as a very thin sheet member, four variable resistors R11 to R14 are replaced with four variable resistance elements 300-1 to 300-. The side sectional structure of the force detecting device replaced with No. 4 is almost the same as the force detecting device shown in FIG.
However, in the case of the force detection device shown in FIG. 33, four resistors R
11 to R14, the columnar protrusion P1 arranged above it, and the conductive layer formed on the lower surface thereof (displacement conductive layer 226).
While the variable resistance element is configured by the combination of and, the variable resistance element 300 shown in FIG. 41 functions by itself as a variable resistance element. P1 only needs to function as a protrusion for applying pressure, and the columnar protrusion P1
It is not necessary to form the displacement conductive layer 226 on the lower surface of the.

When the columnar protrusion P1 shown in FIG. 33 is made to function as a protrusion for applying pressure, the pressure is concentrated near the central portion of the upper surface of the variable resistance element 300 shown in FIG. , 323 are unevenly distributed in the vicinity of the central portion, and efficient detection sensitivity cannot be obtained. Therefore, as shown in FIG. 42, the resistors 313, 32
In order to uniformly generate the deformation of No. 3 and improve the detection sensitivity, instead of the elastic deformable body 220 shown in FIG.
An elastic deformable body 220A whose bottom view is shown in FIG. 43 may be used. The elastically deformable body 22 shown in FIG.
0A is obtained by replacing the four columnar protrusions P1 in the elastically deformable body 220 shown in FIG. 26 with four plate-like protrusions P4. The planar shape of each plate-like protrusion P4 is fan-shaped, and is the same as that of the four variable resistance elements 300-1 to 300-4 formed on the substrate 240. Will be placed in the position. Note that it is not necessary to form a conductive layer on the lower surface of each plate-shaped projection P4. FIG. 44 shows four resistance elements R11 to R14 in the force detection device shown in FIG.
FIG. 44 is a side sectional view showing a modified example in which the elastic deformable body 220 is replaced with the elastic deformable body 220A shown in FIG. 43 while being replaced with 00-4. Each variable resistance element 300-1 to 300
-4 all have the same cross-sectional structure as the variable resistance element 300 shown in FIG. 41, and pressure is applied to the entire surface by the plate-like projection P4 arranged above it. Therefore, more efficient detection sensitivity can be obtained.

Although FIG. 43 shows an example in which four fan-shaped plate-like projections P4 are formed, they are connected to each other to form one washer-like plate-like projection. It doesn't matter if you do so. In addition, each variable resistance element 3
In 00-1 to 300-4, for example, the portions of the film 311 or the film 321 are connected to each other, and four sets of fan-shaped conductive layers and resistors are formed on a single washer-shaped film. It may be structured. Furthermore, in the above description, the entire variable resistance element 300 is referred to as the substrate 2.
Although fixed to the 40 side, of the variable resistance element 300,
The first sheet 310 is fixed to the substrate 240 side (the first film 311 is bonded to the upper surface of the substrate 240), and the second sheet 320 is fixed to the plate-like protrusion P4 side (elastic deformable body 220A side) (second). The film 321 may be adhered to the lower surface of the plate-like protrusion P4.

(4) Application to One-Dimensional Force Detection Device The force detection device according to the embodiment shown in FIG.
Although it is a three-dimensional force detection device having a function of detecting a Z three-dimensional force direction component, if the resistors R5 and R6 and the contact conductor C5 are omitted, the force components in the X-axis direction and the Y-axis direction are detected. It is possible to configure a two-dimensional force detection device having a function to do so. Also, the resistors R1 and R2 and the contact conductor C
By disposing only C1 and C2, it is possible to configure a one-dimensional force detection device having a function of detecting only the force component in the X-axis direction. Similarly, the force detection device according to the embodiment shown in FIG. 33 is a two-dimensional force detection device having a function of detecting an XY two-dimensional force direction component (manipulation amount), but a resistor and a contact conductor. Can be used as a three-dimensional force detecting device, or can be used as a one-dimensional force detecting device by removing unnecessary resistors and contact conductors. As described above, the present invention can be applied to any one-dimensional, two-dimensional, or three-dimensional force detection device.

(5) Other Modifications In the embodiments described above, some detection circuits were described by showing circuit diagrams. However, the detection circuits used in implementing the present invention use these circuits. However, the detection circuit is not limited to the above, and any circuit may be used as long as it has a function of outputting the resistance value of the variable resistance element as an electric signal. The detection circuit used in the present invention is
It operates in two modes, a standby mode and a detection mode. In the standby mode, the circuit does not necessarily have to perform any operation, and the transition to the detection mode is made based on the state transition of the switching element. If the state is possible, the circuit may be completely stopped. For example, a method may be adopted in which the state in which the power supply to the detection circuit is completely stopped is set to the standby mode, and when the state transition of the switching element occurs, the power supply is started to shift to the detection mode. In addition, the switching element in the present invention is a component capable of changing the conduction state between the pair of contact electrodes in order to switch from the standby mode to the detection mode or from the detection mode to the standby mode described above. So long as it has any configuration.

The use of the force detection device according to the present invention is as follows.
The present invention is not limited to the input device for electronic equipment, but can be applied to a detection device used for controlling robots and industrial machines. Further, it is also possible to use it as an acceleration detecting device by attaching a weight body to the elastically deformable body and detecting the force acting on the weight body based on the acceleration. In this case, the detection circuit is in the standby mode unless acceleration of a predetermined magnitude or more is applied, so that power consumption can be saved.

[0160]

As described above, according to the present invention, it is possible to realize a force detecting device using a variable resistance element capable of efficiently suppressing power consumption.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a structure of a force detection device using a variable resistance element to which the present invention is applied.

2 is a top view of a substrate 110 in the force detection device shown in FIG. 1, and a cross section of the substrate 110 taken along the X axis is shown in FIG.

3 is an elastic deformable body 12 in the force detection device shown in FIG.
0 is a top view of the elastic deformable body 120, and a cross section of the elastic deformable body 120 taken along the X axis is shown in FIG. 1.

4 is an elastic deformation body 12 in the force detection device shown in FIG.
1 is a bottom view of No. 0, and FIG. 1 shows a cross section of the elastically deformable body 120 taken along the X axis.

FIG. 5 is a side sectional view (a), a plan view (b), and an equivalent circuit diagram (c) showing a contact state between a resistor R and a contact conductor C in a state where an external force is not applied.

FIG. 6 is a side cross-sectional view (a) showing a contact state between the resistor R and the contact conductor C in a state where an external force is applied, (a), a plan view
(b) is an equivalent circuit diagram (c).

FIG. 7 is a side cross-sectional view showing a state when an external force F in a diagonally lower right direction is applied to the force detection device shown in FIG.

8 is a circuit diagram showing an example of a detection circuit used in the force detection device shown in FIG.

FIG. 9 is a side sectional view showing the structure of a force detection device using a variable resistance element according to a basic embodiment of the present invention.

10 is a top view of the substrate 110 in the force detection device shown in FIG. 9, and a cross section of the substrate 110 taken along the X axis is shown in FIG.

11 (a) is a resistor RR shown in FIG.
1 is an enlarged view of 1 to RR4 and a wiring diagram thereof. Hatching is for clarifying the shape of the plate-shaped structure,
It is not intended to show a cross section. FIG. 2B is a side sectional view showing the positional relationship between the resistor RR shown in FIG. 1A and the contact conductor C disposed above the resistor RR in the state where no external force is applied.

FIG. 12 is a resistor R in a state where an external force −Fz is applied.
FIG. 6 is a side sectional view showing a contact state between R and a contact conductor C arranged above the R.

FIG. 13 is a side cross-sectional view showing a contact state between the resistor RR and the contact conductor C arranged above the resistor RR in the state where a larger external force −Fz is applied.

FIG. 14 shows a resistor RR shown in FIGS. 11 to 13, a contact conductor C disposed above the resistor RR, and a pair of contact electrodes S.
It is an equivalent circuit in various states of the switch SW constituted by 1 and S2.

15 is a circuit diagram showing a first example of a detection circuit used in the force detection device shown in FIG.

16 is a circuit diagram showing a second example of a detection circuit used in the force detection device shown in FIG.

17 is a circuit diagram showing a third example of a detection circuit used in the force detection device shown in FIG.

FIG. 18 is a wiring diagram showing a circuit for detecting an ON / OFF state of a switch composed of a pair of contact electrodes S1 and S2 formed in the central void region of the resistor RR.

19 is an equivalent circuit diagram of the wiring shown in FIG.

20 is a wiring diagram for enabling efficient resistance value measurement by further adding a resistance element to the wiring shown in FIG.

FIG. 21 is an equivalent circuit diagram for the wiring shown in FIG.

FIG. 22 is an exploded side sectional view of a force detection device according to another embodiment of the present invention.

23 is a top view of the operation panel 210 shown in FIG. 22. FIG.
FIG. 22 shows a side cross section of this operation panel 210 cut at the center.

FIG. 24 is a bottom view of the operation panel 210 shown in FIG. 22.
FIG. 22 shows a side cross section of this operation panel 210 cut at the center.

25 is a top view of the elastically deformable body 220 shown in FIG. A side cross section of the elastically deformable body 220 cut at the center is shown in FIG.

FIG. 26 is a bottom view of the elastically deformable body 220 shown in FIG. A side cross section of the elastically deformable body 220 cut at the center is shown in FIG.

27 is a bottom view for explaining the arrangement of the columnar protrusions formed on the bottom surface of the elastically deformable body 220 shown in FIG.

28 is a bottom view showing a displacement conductive layer 226 formed on the bottom surface of the elastically deformable body 220 shown in FIG. 26 (hatching does not show a cross section).

FIG. 29 is a top view of the dome-shaped structure 230 shown in FIG. 22. A side cross section of the dome-shaped structure 230 cut at the center is shown in FIG.

30 is a side sectional view illustrating a shape reversing operation of the dome-shaped structure 230 shown in FIG.

FIG. 31 is a top view of the substrate 240 shown in FIG. A side cross section of the substrate 240 cut at the center (XZ plane) is shown in FIG. 22 (hatching does not indicate the cross section).

32 is a top view showing a state in which a dome-shaped structure 230 is arranged on the substrate 240 shown in FIG.

FIG. 33 is a side sectional view of a force detection device configured by assembling the components shown in FIG. 22. However,
A portion of the dome-shaped structure 230 is shown on the side surface, not on the cross section. Further, each of the columnar protrusions P1 to P3 is depicted only in a cross-sectional portion, and the columnar protrusions located in the back are not shown.

34 is a side sectional view showing a state when switch input (click input) is performed in the force detection device shown in FIG. 33. However, the dome-shaped structure 230 is shown not on the cross section but on the side surface. In addition, each columnar protrusion P1
Only the cross-sectional portion of each of P3 to P3 is depicted, and the columnar protrusions located at the back are not shown.

FIG. 35 is a diagram illustrating an X in the electronic device input device shown in FIG. 33;
It is a side sectional view showing the 1st state when the operation input to the axis negative direction is performed. However, the dome-shaped structure 230 is shown not on the cross section but on the side surface. Further, each of the columnar protrusions P1 to P3 is depicted only in a cross-sectional portion, and the columnar protrusions located in the back are not shown.

FIG. 36 is a diagram showing an X in the electronic device input device shown in FIG. 33;
It is a side sectional view showing the 2nd state when the operation input to the axis negative direction is performed. However, the dome-shaped structure 230 is shown not on the cross section but on the side surface. Further, each of the columnar protrusions P1 to P3 is depicted only in a cross-sectional portion, and the columnar protrusions located in the back are not shown.

FIG. 37 is a diagram showing an X in the electronic device input device shown in FIG. 33;
It is a sectional side view which shows the 3rd state when the operation input to a shaft negative direction is performed. However, the dome-shaped structure 230 is shown not on the cross section but on the side surface. Further, each of the columnar protrusions P1 to P3 is depicted only in a cross-sectional portion, and the columnar protrusions located in the back are not shown.

38 is a circuit diagram showing an example of a detection circuit used in the force detection device shown in FIG. 33.

39 is a top view showing a modified example of the pair of contact electrodes shown in FIG. 31. FIG.

FIG. 40 is a top view showing another modification of the pair of contact electrodes shown in FIG. 31.

FIG. 41 is a pair of resistors 3 having a wavy uneven surface structure.
13 is a side sectional view showing an example in which the variable resistance element 300 is configured using 13,323. FIG.

FIG. 42 is a pressure-F applied to the variable resistance element 300 shown in FIG.
It is a sectional side view which shows the deformation state when z acts.

43 is a bottom view of an elastically deformable body 220A suitable when the variable resistance element 300 shown in FIG. 41 is used.

44 is a variable resistance element 300 shown in FIG. 41 and FIG.
FIG. 4 is a side sectional view of a force detection device configured using the elastically deformable body 220A shown in FIG.

[Explanation of symbols]

110 ... Substrate 120, 120A ... Elastic deformable body 121 ... Working part 122 ... Flexible part 123, 123A ... Fixing part 125 ... Operating rod 130, 130A ... Fixing member 210 ... Operation panel 211 ... Operation part 212 ... Bank part 213 ... Outer periphery Portion 214 ... Pressing bar 220, 220A ... Elastic deformable body 221 ... Inner film portion 222 ... Annular ridge portion 223 ... Outer film portion 224 ... Side wall portion 225 ... Fixed leg portion 226 ... Displacement conductive layer 230 ... Dome structure 231 ... Conductive contact surface 240 ... Substrate 241 ... Fixing hole portion 300 ... Variable resistance element 310 ... First sheet 311 ... First film 312 ... First conductive layer 313 ... First resistor 320 ... Second Sheet 321 ... Second film 322 ... Second conductive layer 323 ... Second resistor C, C1-C5 ... Contact conductor E15-E18 ... Electrodes E15A, E15B, E1 A, E16B ... Electrode F ... External force + Fx ... + X-axis direction component of external force-Fx, -FFx ...- X-axis direction component of external force-Fz ...- Z-axis direction component of external force Gnd ... Ground point Jx, Jy, Jz ... Connection Point K1 ... Inner concentric circle K2 ... Reference concentric circle K3 ... Outer concentric circle O ... Coordinate system origin P1 to P3 ... Columnar projection P4 ... Plate-shaped projections R, R1 to R6, RR, RR1 to RR6, R11 to R1
4 ... Resistors R100, R200 ... Resistors R00-R08 ... Resistor elements S ... Contact surfaces S1, S2 ... Contact electrodes S21-S25 ... Control signals SW, SW0-SW5 ... Switches SW11-SW15 consisting of a pair of contact electrodes ... Semiconductor switches T1 to T4, T00 to T03, T11 to T15, T21
-T25, T31, T32 ... Terminal TT ... Nodes Tx, Ty, Tz ... Detected value output terminals V, VV ... Cavity Vcc ... Power supply voltage X, Y, Z ... Coordinate axes of three-dimensional coordinate system

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2F051 AA21 AB07 BA07 DA03                 5B087 BB15 BC12 BC33 CC36                 5E030 AA20 BA29

Claims (19)

[Claims] 1. A force detection device having a function of detecting the magnitude of an applied external force by using a variable resistance element, the plate-shaped substrate and at least one arranged at a position facing the substrate. An elastic deformable body, a part of which is elastically deformable, having a structure that is displaced with respect to the substrate by elastic deformation based on the action of an external force, and the elastic deformable body is disposed between the substrate and the elastic deformable body. It has a variable resistance element having the property that the resistance value between two predetermined points changes according to the pressure applied by the displacement of the body, and a pair of contact electrodes, and normally there is an electrical connection between the pair of contact electrodes. A switching function is maintained such that the insulating state is maintained and, when an external force of a predetermined magnitude or more is applied to the elastic deformable body, the elastic deformable body is deformed to electrically connect the pair of contact electrodes. The switching element to fulfill, A detection circuit that detects a resistance value between the two points of the variable resistance element as an electric signal; and the detection circuit can perform a detection function of outputting the resistance value between the two points as an electric signal. Detection mode,
It is configured to be able to select two modes: a standby mode that cannot perform the detection function, but consumes less power than the detection mode, and that can maintain a standby state for shifting to the detection mode. The standby mode is selected when the electrical state between the pair of contact electrodes is an insulating state, and the detection mode is selected when the electrical state is a conductive state. A force detection device using a variable resistance element. 2. The force detecting device according to claim 1, wherein the pair of contact electrodes included in the switching element includes a contact fixed electrode formed on the substrate and a contact displacement formed on the elastic deformable body side. When an external force of a predetermined magnitude or more is applied to the elastic deformable body, the contact displacement electrode physically contacts the contact fixed electrode due to the deformation of the elastic deformable body. A force detection device using a variable resistance element, which is configured as described above. 3. The force detection device according to claim 1, wherein the switching element includes a pair of contact electrodes formed on the substrate,
And an intermediary electrode capable of electrically connecting between the pair of contact electrodes by simultaneously contacting both of the pair of contact electrodes, wherein the intermediary electrode is usually one of the pair of contact electrodes. When the external force of a predetermined magnitude or more is applied to the elastically deformable body while maintaining the state where the elastically deformable body is not in contact with only one of them, A force detection device using a variable resistance element, wherein the force detection device is arranged so as to be in contact with both of the contact electrodes at the same time. 4. The force detection device according to claim 3, wherein the intermediary electrode is formed at a position where displacement of the elastically deformable body occurs. 5. The force detection device according to claim 4, wherein the pair of contact electrodes is composed of a ring-shaped first electrode and a ring-shaped second electrode adjacent to the outside of the first electrode. Then, an intermediary electrode is provided on both the first electrode and the second electrode,
A force detecting device using a variable resistance element, characterized in that the force detecting device is formed at a position where it can be simultaneously contacted at any place. 6. The force detection device according to claim 4, wherein a plurality of N electrodes belonging to the first group and a second electrode are provided on the substrate.
A plurality of N electrodes belonging to a group are arranged, and an i-th (1 ≦ i ≦ N) electrode belonging to the first group and an i-th electrode belonging to the second group are respectively arranged. The electrodes belonging to the first group and the electrodes belonging to the second group, which are adjacent to each other and are arranged adjacent to each other, constitute a pair of contact electrodes, and a total of N pairs of contact electrodes are formed. A force detecting device using a variable resistance element, characterized in that a contact electrode is formed. 7. The force detecting device according to claim 6, wherein the electrodes belonging to the first group and the electrodes belonging to the second group are alternately arranged along a circumference defined on the substrate, A force detecting device using a variable resistance element, wherein the intermediary electrode is formed along the "circumference facing the circumference" on the elastically deformable body side. 8. The force detection device according to claim 1, wherein the variable resistance element is arranged at a position opposite to the resistance body arranged on the substrate and the elastic deformation body. And a contact conductor, wherein the contact conductor is made of an elastically deformable material,
At least the contact surface for the resistor has conductivity, and has a shape in which the area of the contact surface for the resistor changes according to the pressure applied by the displacement of the elastic deformation body, A variable resistance element characterized in that the resistance value between two points sandwiching the “contact position of the contact conductor” on the resistor is changed according to the change of the surface area. Force detection device used. 9. The force detecting device according to claim 8, wherein the contact conductor is made of conductive rubber. 10. The force detection device according to claim 1, wherein the variable resistance element includes a first resistor and a second resistor arranged at a position facing the first resistor. A surface of the first resistor and the second resistor facing the other of the first resistor and the second resistor has a concavo-convex structure that causes elastic deformation. The area of the contact surface between the first resistor and the second resistor is changed according to the applied pressure, and the area of the contact surface is changed to the first resistor side. A force detecting device using a variable resistance element, wherein a resistance value between a predetermined point connected and a predetermined point connected to the second resistor side is changed. 11. The force detection device according to claim 10, wherein the first resistor and the second resistor are made of pressure-sensitive conductive ink. apparatus. 12. The force detection device according to claim 3, wherein the variable resistance element is arranged on the substrate and has a flat plate-like resistance body having a void region in a central portion, and the resistance body of the elastically deformable body is opposed to the resistance body. And a contact conductor arranged at a position, wherein the contact conductor is made of an elastically deformable material,
At least the contact surface for the resistor has conductivity, and has a shape in which the area of the contact surface for the resistor changes according to the pressure applied by the displacement of the elastic deformation body, A pair of contact electrodes, which are configured so that a resistance value between two points on both sides of the “contact position of the contact conductor” on the resistor changes according to a change in surface area, and which constitute a switching element. Is arranged in a void region formed in the central portion of the resistor, and the contact conductor is configured to function as an intermediary electrode constituting a switching element. Force detection device. 13. The force detecting device according to claim 12, wherein a resistance element having a resistance value sufficiently larger than a resistance value between two points of the resistance body is prepared, and a pair of contact elements constituting a switching element are provided. A force detection device using a variable resistance element, characterized in that a circuit for detecting a conduction state between electrodes and a circuit for detecting a resistance value between the two points are isolated from each other via the resistance element. . 14. The force detection device according to claim 1, wherein the detection circuit detects a resistance value between the two points by applying a voltage between the two points of the resistor. A force detection device using a variable resistance element, wherein control is performed such that the voltage is applied in the detection mode and the voltage is not applied in the standby mode. 15. The force detection device according to claim 14, wherein the conduction / insulation state of the pair of contact electrodes forming the switching element is used as an ON / OFF switch, and a voltage is applied between two points of the resistor. A force detection device using a variable resistance element, characterized in that 16. The force detection device according to claim 1, wherein an operation panel made of a rigid material is attached to the elastically deformable body, and the elastically deformable body is attached to the elastically deformable body based on an operation input applied to the operation panel. A force detecting device using a variable resistance element characterized in that displacement is generated. 17. The force detecting device according to claim 1, wherein the elastic deformable body is arranged so as to be substantially parallel to the upper surface of the substrate, and the film-like portion of the film-like portion. A side wall portion for fixing the periphery to the upper surface of the substrate, and a columnar protrusion extending downward from a predetermined plurality of locations on the lower surface of the film-like portion, and at least a part of the film-like portion and the columnar protrusion. A force detecting device using a variable resistance element, characterized in that: is made of an elastic material. 18. The force detecting device according to claim 17, wherein the elastically deformable body is made of integrally molded rubber. 19. An electronic device input device for inputting an operation indicating an operation amount in a predetermined direction to an electronic device that executes a predetermined process based on a predetermined program, 18. An input device for electronic equipment, comprising the force detection device according to any one of 18, and handling an external force detected by the force detection device as an operation amount.