KR20180130437A - Pressure sensing apparatus - Google Patents

Abstract

The present invention is to provide a force sensing apparatus capable of sensing a force parallel to a sensor surface acting on a sensor surface without requiring a complicated configuration. A force sensing apparatus according to the present invention includes three or more electrodes, a force sensor formed on three or more electrodes and having a sensor layer made of a pressure-reducing material, and a sensing part for sensing an electrical resistance value between two or more pairs of electrodes among three or more electrodes of the force sensor.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a force detecting device having a sensor layer made of a pressure-reducing material.

A pressure detecting device is known in which small-sized pressure sensor elements are arranged in a two-dimensional array shape and pressure distribution measurement is possible (see, for example, Non-Patent Document 1 and Patent Document 1). In this pressure detecting device, the pressure sensor element outputs a signal voltage corresponding to the pressure externally applied. Further, in many cases, it is assumed that the pressure detecting device performs active matrix control of the pressure sensor element by using a thin film transistor (TFT: Thin Film Transistor) as in the pixel driving on the image display panel 1).

In the active matrix type two-dimensional pressure sensor, for example, two-dimensional pressure distribution data is acquired by sequentially changing the pressure sensor elements that read and switch active gate wirings using a shift resist. By continuing this operation at all times, it is possible to acquire the two-dimensional data of the pressure varying with time.

On the other hand, as a sensor device for measuring the contact pressure and the shearing force, there is known a four-gauge bridge circuit including a contact pressure measuring part and a shear force measuring part (see Patent document 2). In the sensor device described in Patent Document 2, the shear-force measuring unit is provided with a comb-like electrode on the one surface electrode and a comb-tooth electrode on the surface-facing electrode facing each other, Respectively.

Further, there is known a technique for measuring pressure by a strain sensor by a fiber Bragg grating (see Patent Document 3). Further, a technology for measuring a shear force and a pressure by using an X-axis sensor, a Y-axis sensor and a Z-axis sensor made of a piezo resistance cantilever in combination is known (see Patent Document 4).

Patent Document 1: JP-A-10-070278 Patent Document 2: Japanese Patent Publication No. 5688792 Patent Document 3: Japanese Patent Application Laid-Open No. 2007-263937 Patent Document 4: Japanese Patent Publication No. 5561674

Non-Patent Document 1: NanotechJapan Bulletin Vol.6, No.3, 2013, pp.6-7

The above-described two-dimensional pressure sensor is expected to be applied as a sensor for detecting tactile information and the like in, for example, a fingertip of a robot imitating a human being. However, in the conventional two-dimensional pressure sensor, it is possible to detect the force perpendicular to the sensor surface from the force acting on the sensor surface, which is the contact surface on which the force acts, but the force parallel to the sensor surface can not be detected.

For example, when an object touching the sensor surface is dragged or slid sideways, forces parallel to the sensor surface, such as shear force and frictional force, act on the sensor surface. In the conventional two-dimensional pressure sensor, a force parallel to the sensor surface could not be detected. Therefore, even if a tactile sensor is constructed using a conventional two-dimensional pressure sensor, it is considered difficult to detect an operation of dragging or sliding an object contacting the sensor surface sideways.

Information about the direction and size of the force parallel to the contact surface, such as shear force, is important information in, for example, a scene where the fingertip of the robot grasps an object. For example, if the finger tip of the robot tries to escape the object to be grasped, it is determined whether the gripping force is strong or weak or is to be maintained if it can be known whether the direction of departure is the direction of gravity or the direction opposite thereto, or the direction perpendicular to gravity direction. can do.

On the other hand, in the sensor device described in Patent Document 1, it is considered that it is not easy to precisely align the positions of the two comb-shaped electrodes facing each other. It is considered that the use of an optical fiber as a sensor device as in the technique described in Patent Document 3 is not suitable for miniaturization of a device. Moreover, using a sensor corresponding to the orthogonal three-axis directions of the X-axis sensor, the Y-axis sensor and the Z-axis sensor as in the technique described in Patent Document 4 is considered to be complicated in construction and increase in manufacturing cost.

An object of the present invention is to provide a force detecting device capable of detecting a force parallel to a sensor surface acting on a sensor surface without requiring a complicated configuration.

According to one aspect of the present invention, there is provided a force sensor comprising three or more electrodes, a force sensor formed on the three or more electrodes and having a sensor layer made of a pressure-reducing material, And a detection unit for detecting an electric resistance value of the electric power source.

According to the present invention, a force parallel to the sensor surface acting on the sensor surface can be detected without requiring a complicated configuration.

1 is a schematic view showing the entire structure of a force detection device according to a first embodiment of the present invention.
2 is a plan view showing a structure of a cell array including sensor cells in the force detection device according to the first embodiment of the present invention.
3 is a plan view for explaining the electric resistance value of the sensor cell in the force detecting device according to the first embodiment of the present invention.
4 is a diagram showing the relationship between magnitude and magnitude of each electric resistance value of the sensor cell and the direction of force in the force detecting device according to the first embodiment of the present invention.
5 is a plan view showing a structure of a cell array including sensor cells in a force detection device according to a second embodiment of the present invention.
6 is a plan view showing a structure of a cell array including sensor cells of a two-dimensional pressure sensor according to the background art.
7 is a plan view for explaining the electric resistance value of the sensor cell of the two-dimensional pressure sensor according to the background art.

≪ First Embodiment >

A force detecting apparatus according to a first embodiment of the present invention will be described with reference to Figs. 1 to 4. Fig. 1 is a schematic view showing the entire structure of a force detecting device according to the present embodiment. 2 is a plan view showing a structure of a cell array including sensor cells in the force detecting device according to the present embodiment. 3 is a plan view for explaining the electric resistance value of the sensor cell in the force detecting device according to the present embodiment. Fig. 4 is a diagram showing the relationship between the magnitude and magnitude of the electric resistance values of the sensor cell and the direction of the force in the force detection device according to the present embodiment.

The force detecting device according to the present embodiment is provided with a touch panel such as a liquid crystal display device, an OLED (Organic Light Emitting Diode) display device, and the like, and a force .

1 and 2, the force detection device 100 according to the present embodiment includes a sensor array 10, a gate line drive circuit 20, a detection circuit 30, a power line drive circuit 40, And a control unit 50, as shown in FIG.

The sensor array 10 includes a plurality of sensor cells 60 arranged two-dimensionally over a plurality of rows (for example, m rows) and a plurality of columns (for example, n columns). Each of m and n is an integer of 2 or more. In the sensor array 10, the plurality of sensor cells 60 are arranged in a rectangular lattice shape, such as a tetragonal lattice pattern.

Each sensor cell 60 includes two selection transistors M1 and M2, which are a first active element and a second active element, respectively, and a force sensor S using a decompression material. The selection transistors M1 and M2 are each formed of, for example, a thin film transistor. The force detection device 100 according to the present embodiment is an active matrix drive type sensor device in which the selection transistors M1 and M2 are active elements.

The force sensor S has four electrodes 62A, 62B, 62C and 62D and a sensor layer 64 made of a decompression material formed on the four electrodes 62A, 62B, 62C and 62D.

The electrodes 62A, 62B, 62C, and 62D constitute a first electrode, a second electrode, a third electrode, and a fourth electrode that are independent of each other. The electrodes 62A, 62B, 62C, and 62D are formed on the substrate with an insulating layer interposed therebetween. The sensor layer 64 is formed on the insulating layer on which the openings 66A, 66B, 66C and 66D for exposing the electrodes 62A, 62B, 62C and 62D are formed, and the openings 66A, 66B, 66C and 66D 62B, 62C, and 62D through the electrodes 62A, 62B, 62C, and 62D. The substrate includes a sheet-like member and a film-like member in addition to the substrate-like member, and any material can be used as the material. Further, the substrate may be flexible with flexibility or hard with no flexibility.

The sensor layer 64 is made of a decompression material whose electrical resistance value changes with a change in pressure, for example. More specifically, as the pressure-reducing material constituting the sensor layer 64, a pressure-sensitive conductive material including an insulating resin and a conductive filler dispersed in an insulating resin is exemplified. In such a pressure-sensitive conductive material, the number of contacts of the conductive filler changes in accordance with the magnitude of the applied pressure, so that the electric resistance value changes depending on the magnitude of the applied pressure. As the decompression material constituting the sensor layer 64, a pressure-sensitive conductive material in which fine irregularities are formed on the contact surface with the electrode may be used for the electrode having the minute irregularities. In such a pressure-sensitive conductive material, the contact area with the electrode changes due to the fine irregularities depending on the magnitude of the applied pressure, so that the electric resistance value changes depending on the magnitude of the applied pressure.

The sensor layer 64 has, for example, a substantially rectangular planar shape having two pairs of sides along the row direction and the column direction. The planar shape of the sensor layer 64 is not particularly limited, and various shapes can be employed.

On the other hand, the electrodes 62A, 62B, 62C and 62D have the same planar shape as each other and have a smaller planar shape than the sensor layer 64. [ The electrodes 62A, 62B, 62C, and 62D have a substantially rectangular planar shape having two pairs of sides along the row direction and the column direction, for example. The planar shape of the electrodes 62A, 62B, 62C, and 62D is not particularly limited, and various shapes can be employed.

The electrodes 62A, 62B, 62C, and 62D are two-dimensionally arranged at regular intervals.

The electrodes 62A, 62B, 62C and 62D are arranged at four corners of the sensor layer 64. [ 2 shows a case in which the electrodes 62A, 62B, 62C and 62D are arranged at the left upper corner of the paper surface of the sensor layer 64, the upper right corner of the paper, the lower left corner of the paper, have.

The surface on the side of the electrodes 62A, 62B, 62C and 62D on which the sensor layer 64 is formed becomes the sensor surface 70 which is a force detecting surface for detecting the force acting by the contacted object have. A plurality of sensor layers 64 may be exposed on the sensor surface 70 and a protective layer (not shown) formed of a resin material or the like for protecting the sensor surface 70 including the plurality of sensor layers 64 may be formed .

Each of the rows of the sensor array 10 includes a plurality of first gate lines GL1a, GL2a, ..., GLma (first gate lines) GL1a, GL2a, ..., GLma . Each of the rows of the sensor array 10 is provided with a plurality of second gate lines GL1b, GL2b, ... GL2b, GL2b, ... GL2b, GL2b, ... GL2b, GL2b, GLmb) are arranged. The second gate lines GL1b, GL2b, ..., GLmb are arranged corresponding to the first gate lines GL1a, GL2a, ..., GLma, respectively. The first gate lines GL1a, GL2a, ..., GLma and the second gate lines GL1b, GL2b, ..., GLmb are connected to the gate line driving circuit 20. [ In the following description, the first gate line is appropriately represented as the 'first gate line GLia', and the second gate line is appropriately represented as the 'second gate line GLib'. Here, i is an integer satisfying 1? I? M.

Data lines DL1, DL2, ..., DLn, which are output signal lines, are arranged in each column of the sensor array 10 in the column direction. The data lines DL1, DL2, ..., and DLn are connected to one end of a resistor R included in the detection circuit 30, respectively. The other end of the resistor R is connected to the ground voltage line of the ground voltage VS. An input terminal side of the A / D converter 68 included in the detection circuit 30 is connected to a connection node between the data lines DL1, DL2, ..., DLn and one end of the resistor R. The configuration for connecting the data lines DL1, DL2, ..., DLn to the A / D converter is not limited to the configuration shown in Fig. 2, but various configurations can be employed. For example, a configuration in which the data lines DL1, DL2, ..., DLn are connected to the inputs of a single A / D converter through a multiplexer. Hereinafter, the data line is appropriately represented as a "data line DLj". Here, j is an integer satisfying 1? J? N.

The first power supply lines VL1a, VL2a, ..., VLna extend in the column direction in each column of the sensor array 10. [ VLnb (VL1b, VL2b, ..., VLnb) corresponding to the first power source lines (VL1a, VL2a, ..., VLna) extend in the column direction in each column of the sensor array . The first power supply lines VL1a, VL2a, ..., VLna and the second power supply lines VL1b, VL2b, ..., VLnb are connected to the power supply line driving circuit 40. [ Hereinafter, the first power line is appropriately indicated as a 'first power line VLja', and the second power line is appropriately represented as a 'second power line VLjb'. Here, j is an integer satisfying 1? J? N.

The electrodes 62A, 62B, 62C and 62D of the force sensor S in the sensor cell 60 located in the ith row and the jth column and the selection transistors M1 and M2 are connected as follows.

That is, the gate electrode of the selection transistor Ml is connected to the corresponding first gate line GLia in the ith row. The source electrode of the selection transistor Ml is connected to the corresponding data line DLj in the j-th column. The drain electrode of the selection transistor Ml is connected to the electrode 62A.

The gate electrode of the selection transistor M2 is connected to the corresponding second gate line GLib in the ith row. The source electrode of the selection transistor M2 is connected to the corresponding data line DLj in the j-th column. The drain electrode of the selection transistor M2 is connected to the electrode 62D.

The electrode 62C is connected to the first power source line VLja in the corresponding j-th column. The electrode 62B is connected to the corresponding second power supply line VLjb in the j-th column.

The gate line driving circuit 20 is composed of a decoder and a shift register. The gate line driving circuit 20 supplies the driving signal Pia to the first gate line GLia. The gate line driving circuit 20 supplies the driving signal Pib to the second gate line GLib. The driving signal Pia is a driving signal of the selection transistor Ml connected to the first gate line GLia. The driving signal Pib is a driving signal of the selection transistor M2 connected to the second gate line GLib. Thus, the gate line driving circuit 20 is a driving circuit for driving the selection transistors M1 and M2. For example, when the selection transistors M1 and M2 are N-type transistors, when the driving signals Pia and Pib are at the high level, the selection transistors M1 and M2 of the corresponding ith row are turned on. When the driving signals Pia and Pib are at the low level, the corresponding selection transistors M1 and M2 of the ith row are turned off.

The detection circuit 30 is a circuit that detects the voltage of the data line DLj and functions as a detection section for detecting the output of the electric resistance value between the electrodes in the force sensor S as described later, A resistor R, an A / D converter 68, and the like. It is possible to obtain the direction and magnitude of the force detected by the force sensor S based on the output of the electric resistance value between the electrodes in the force sensor S detected by the detection circuit 30. [

The power line driving circuit 40 supplies the power supply voltage VD to the first power supply line VLja to turn on the first power supply line VLja and the first power supply line VLja to the high impedance And is turned off. The power line driving circuit 40 supplies the power supply voltage VD to the second power supply line VLjb to turn on the second power supply line VLjb and turns on the second power supply line VLjb to the high impedance And is turned off.

The control unit 50 is connected to the gate line drive circuit 20, the detection circuit 30, and the power line drive circuit 40. The control unit 50 has a CPU (Central Processing Unit) that performs various operations such as calculation, control, and determination. The control unit 50 also has a ROM (Read Only Memory) for storing various programs executed by the CPU, a database to be referred to by the CPU, and the like. The control unit 50 also has a RAM (Random Access Memory) for temporarily storing data being processed and input data by the CPU. Further, the control unit 50 may be integrally incorporated in the force detection device 100, or may be realized by a separate independent computer device.

The control unit 50 controls the operations of the gate line driving circuit 20, the detection circuit 30, and the power line driving circuit 40 and their timings through a control circuit or the like . The control unit 50 also controls the operation of the force sensing device 100 based on the output of the electric resistance value of the force sensor S detected by the detection circuit 30 And functions as a processing section for obtaining the direction and magnitude of the force.

A force parallel to the sensor surface 70 may be applied to the sensor surface 70 of the force detecting device 100 due to the contact of the object. A force parallel to the sensor surface 70 acting on the sensor surface 70 includes a component parallel to the sensor surface 70 in a force acting in an inclined direction with respect to the sensor surface 70. [ Specifically, the force parallel to the sensor surface 70 acting on the sensor surface 70 includes, for example, a shearing force, a frictional force, and the like.

In a force sensor S having a plurality of electrodes 62A, 62B, 62C, and 62D in contact with a common sensor layer 64 when a force parallel to the sensor surface 70 acts, 70 may occur in the pressure acting on the sensor layer 64 by the direction of the force parallel to the sensor layer 64. Therefore, the relative magnitude of the electrical resistance value between the plurality of electrodes 62A, 62B, 62C, and 62D may occur. The magnitude of the electric resistance value in the force sensor S can be made to correspond to the direction of the force parallel to the sensor surface 70. [ Further, the magnitude of the force parallel to the sensor surface 70 can be obtained based on the electric resistance value between the electrodes 62A, 62B, 62C, and 62D.

3, in the force sensor S, the electric resistance value R _AB between the electrode 62A and the electrode 62B, the electric resistance value R between the electrode 62A and the electrode 62C _AC , the electrical resistance value R _BD between the electrode 62B and the electrode 62D, and the electrical resistance value R _CD between the electrode 62C and the electrode 62D. Relative magnitude relations occur in the values of the electric resistance values (R _AB , R _AC , R _BD , R _CD ) in accordance with the direction of the force parallel to the sensor surface (70).

The electric resistance values (R _AB , R _AC , R _BD , R R, R R, R R, R R, R R, R R, R _CD ) are the same as those shown in Fig. The symbol '~' indicates that the electric resistance values on both sides are approximately equal.

That is, the lower side from the upper side of the floor with respect to the sensor surface 70, when the vertically directed force is applied, the relative magnitude relationship between the electric resistance (R _AB, R _AC, R _BD, R _CD) is, R _CD < R _AC ~ R _BD < R _AB .

The relative magnitude of the electrical resistance values (R _AB , R _AC , R _BD , and R _CD ) in the case where a force vertically directed from the lower side to the upper side of the paper surface acts on the sensor surface 70 is R _AB < R _AC ~ R _BD < R _CD .

Further, when the right side from the left side of the paper with respect to the sensor surface 70, is parallel to the heading force is applied, the relative magnitude relationship between the electric resistance (R _AB, R _AC, R _BD, R _CD) is, R _BD < R _AB ~ R _CD <R _AC .

In addition, in the case where to the left from the right side with respect to the sensor surface 70, is parallel to the heading force is applied, the relative magnitude relationship between the electric resistance (R _AB, R _AC, R _BD, R _CD) is, R _AC < R _AB ~ R _CD <R _BD .

The relative magnitude of the electrical resistance values (R _AB , R _AC , R _BD , and R _CD ) when the force directed to the diagonal line of 45 degrees from the upper left side to the lower right side of the paper surface acts on the sensor surface 70 , R _BD ~ R _CD <R _AB ~ R _AC .

The relative magnitude of the electrical resistance values (R _AB , R _AC , R _BD , and R _CD ) when the force directed to the diagonal line of 45 degrees from the lower right to the upper left of the paper surface acts on the sensor surface 70 , R _AB ~ R _AC <R _BD ~ R _CD .

The relative magnitude of the electrical resistance values (R _AB , R _AC , R _BD , and R _CD ) in the case where a force directed to the diagonal line of 45 degrees acts from the upper right side to the lower left side of the paper surface with respect to the sensor surface 70 , R _AC ~ R _CD <R _AB ~ R _BD .

The relative magnitude of the electrical resistance values (R _AB , R _AC , R _BD , and R _CD ) when the force directed to the diagonal line of 45 degrees from the lower left end to the upper right end of the paper surface acts on the sensor surface 70 , R _AB ~ R _BD <R _AC ~ R _CD .

The direction of the force parallel to the sensor surface 70 can be obtained based on the electric resistance value between the electrodes 62A, 62B, 62C and 62D in each force sensor S, 70) can also be obtained. The relative magnitude of the electrical resistance value between the electrodes differs depending on the structure and shape of the sensor layer 64 and the pressure-reducing material constituting the sensor layer 64, and therefore, it can be acquired by experiment or simulation beforehand.

The force detection device 100 according to the present embodiment can acquire the electric resistance values R _AB , R _AC , R _BD , and R _CD in the following manner and obtain the relative magnitude of the electric resistance values R _AB , R _AC , R _BD , and R _CD . Hereinafter, the operation sequence of the force detecting device 100 according to the present embodiment will be described.

A force parallel to the sensor surface 70 acts on an object surface of the sensor surface 70 of the force detecting device 100 according to the present embodiment.

First, the gate line driving circuit 20 supplies the driving signal Pia to the first gate line GLia in the i-th row to turn on the first gate line GLia in the i-th row. As a result, the selection transistor M1 connected to the first gate line GLia in the i-th row is turned on for each row. On the other hand, the other first gate line and the second gate line are set to the OFF state in which no drive signal is supplied.

The first gate line GLia of the i-th row is turned on and the power supply line driving circuit 40 supplies the power supply voltage VL1a, VD are supplied to turn on the first power supply lines VL1a, VL2a, ..., VLna. On the other hand, the power line driving circuit 40 turns the second power lines VL1b, VL2b, ..., VLnb into the OFF state by making the second power lines VL1b, VL2b, ..., VLnb high impedance, do.

As described above, the first gate line GLia in the i-th row is turned on, the other first gate line and the second gate line are turned off, and the first power lines VL1a, VL2a, ..., VLna are turned on State, and the second power supply lines VL1b, VL2b, ..., VLnb are turned off. The electric resistance between the electrode 62A of the force sensor S and the electrode 62C in the corresponding sensor cell 60 in the i-th row is set to the data line DL1, DL2, A voltage corresponding to the value R _AC is output. The detection circuit 30 detects a voltage in accordance with the electric resistance value R _AC output to the data lines DL1, DL2, ..., DLn. Thus, the detection circuit 30 functioning as the detection unit can detect the electric resistance value R _AC for each sensor cell 60 in the i-th row.

Next, the ON and OFF states of the first power source line and the second power source line are switched while maintaining the ON state of the first gate line GLia in the ith row and the OFF state of the other first gate line and the second gate line. The first power supply lines VL1a, VL2a, ..., VLna are turned off by setting the first power supply lines VL1a, VL2a, ..., VLna to high impedance by the power line driving circuit 40, . On the other hand, the power source line driving circuit 40 supplies the power source voltage VD to the second power source lines VL1b, VL2b, ..., VLnb to turn on the second power lines VL1b, VL2b, ..., VLnb Is turned on.

As described above, the first gate line GLia of the i-th row is turned on, the other first gate line and the second gate line are turned off, and the first power lines VL1a, VL2a, ..., VLna are turned off State, and the second power supply lines VL1b, VL2b, ..., VLnb are turned on. The electric resistance between the electrode 62A and the electrode 62B of the force sensor S in the corresponding sensor cell 60 in the i-th row is set to the data lines DL1, DL2, ..., A voltage corresponding to the value R _AB is output. The detection circuit 30 detects a voltage in accordance with the electric resistance value R _AB output to the data lines DL1, DL2, ..., DLn. Thus, the detection circuit 30 functioning as the detection unit can detect the electric resistance value R _AB for each sensor cell 60 in the i-th row.

Next, the drive signal Pib is supplied from the gate line drive circuit 20 to the second gate line GLib in the i-th row to turn on the second gate line GLib in the i-th row. Thus, the selection transistor M2 connected to the second gate line GLib in the i-th row is turned on for each row. On the other hand, the other first gate line and the second gate line are set to the OFF state in which no drive signal is supplied.

The second gate line GLib of the i-th row is turned on and the power supply line driving circuit 40 drives the first power supply lines VL1a, VL2a, VLna, VD are supplied to turn on the first power supply lines VL1a, VL2a, ... VLna. On the other hand, the power line driving circuit 40 turns the second power lines VL1b, VL2b, ..., VLnb into the OFF state by making the second power lines VL1b, VL2b, ..., VLnb high impedance, do.

As described above, the second gate line GLib in the i-th row is turned on, the other first gate line and the second gate line are turned off, and the first power lines VL1a, VL2a, ..., VLna are turned on State, and the second power supply lines VL1b, VL2b, ..., VLnb are turned off. The electric resistance between the electrode 62C and the electrode 62D of the force sensor S in the corresponding sensor cell 60 in the i-th row is set to the data line DL1, DL2, ..., DLn, The voltage corresponding to the value R _CD is output. The detection circuit 30 detects a voltage corresponding to the electric resistance value R _CD output to the data lines DL1, DL2, ..., DLn. In this way, the detection circuit 30 serving as the detection section can detect the electric resistance value R _CD for each sensor cell 60 in the i-th row.

Next, the ON and OFF states of the first power source line and the second power source line are switched while maintaining the ON state of the second gate line GLib in the i-th row and the OFF state of the other first gate line and the second gate line. The first power supply lines VL1a, VL2a, ..., VLna are turned off by setting the first power supply lines VL1a, VL2a, ..., VLna to high impedance by the power line driving circuit 40, . On the other hand, the power source line driving circuit 40 supplies the power source voltage VD to the second power source lines VL1b, VL2b, ..., VLnb to turn on the second power lines VL1b, VL2b, ..., VLnb Is turned on.

As described above, the second gate line GLib in the i-th row is turned on, the other first gate line and the second gate line are turned off, and the first power lines VL1a, VL2a, ..., VLna are turned off State, and the second power supply lines VL1b, VL2b, ... VLnb are turned on. The electric resistance between the electrode 62B of the force sensor S and the electrode 62D in the corresponding sensor cell 60 in the i-th row is set to the data line DL1, DL2, The voltage corresponding to the value (R _BD ) is output. The detection circuit 30 detects a voltage corresponding to the electric resistance value R _BD output to the data lines DL1, DL2, ..., DLn. Thus, the detection circuit 30 serving as the detection unit can detect the electrical resistance value (R _BD ) for each sensor cell 60 in the i-th row.

The detection circuit 30 functioning as the detection unit is provided for each of the sensor cells 60 in the sensor array 10 by sequentially performing the above-described operations for the first to the m-th rows, R _AB , R _AC , R _BD , and R _CD ) are separately detected and acquired. The controller 50, for each sensor cell 60, and the obtained electric resistance (R _AB, R _AC, R _BD, R _CD), the sensor surface (70 acting with respect to the sensor surface 70, on the basis of The direction and magnitude of the force parallel to the direction of the force. That is, based on the relative magnitude of the acquired electrical resistance values (R _AB , R _AC , R _BD , and R _CD ) for each sensor cell 60, The direction of the force parallel to the acting sensor surface 70 is obtained. In addition, the controller 50, for each sensor cell 60, on the basis of the obtained electric resistance (R _AB, R _AC, R _BD, R _CD), a sensing surface that operate on the sensor surface 70 ( 70) is obtained.

For example, the control unit 50 determines the relative magnitude of the electrical resistance values (R _AB , R _AC , R _BD , R _CD ) and the magnitude of the force In the memory device. The controller 50 can refer to such a database to obtain the direction of the force parallel to the sensor surface 70 acting on the sensor surface 70 with respect to each sensor cell 60. [

The control unit 50 also calculates the relationship between the electric resistance values R _AB , R _AC , R _BD and R _CD and the magnitude of the force parallel to the sensor surface 70 acting on the sensor surface 70 And the base is held in the memory device. The control unit 50 can refer to such a database and obtain the magnitude of the force parallel to the sensor surface 70 acting on the sensor surface 70 with respect to each sensor cell 60. [

The control unit 50 further performs statistical processing on the plurality of sensor cells 60 in the vicinity using the detection result of the direction and magnitude of the force parallel to the sensor surface 70 acting on the sensor surface 70 . As a result, the error in the detection result of the force parallel to the sensor surface (70) acting on the sensor surface (70) can be reduced. For example, the detection results of the direction and magnitude of the force parallel to the sensor surface 70 are averaged for a plurality of sensor cells 60 such as 2 x 2 and 3 x 3 in the row direction and the column direction, Can be reduced.

As described above, according to the present embodiment, the force sensor S having the plurality of electrodes 62A, 62B, 62C, and 62D and the sensor layer 64 made of the decompression material acts on the sensor surface 70 A force parallel to the sensor surface 70 is detected. Therefore, according to the present embodiment, a force parallel to the sensor surface 70 acting on the sensor surface 70 can be detected without requiring a complicated configuration.

On the other hand, unlike the force detection device 100 according to the above-described embodiment, a two-dimensional pressure sensor according to the background art can not detect a force parallel to the sensor surface acting on the sensor surface. Hereinafter, this point will be described with reference to FIG. 6 and FIG. 6 is a plan view showing a structure of a cell array including sensor cells of a two-dimensional pressure sensor according to the background art. 7 is a plan view for explaining the electric resistance value of the sensor cell of the two-dimensional pressure sensor according to the background art.

6, the sensor array 310 of the two-dimensional pressure sensor 300 is arranged in two dimensions (for example, m rows) and a plurality of columns (for example, n columns) And a plurality of sensor cells 360 arranged.

Each of the sensor cells 360 includes one selection transistor M and a pressure sensor Sb using a pressure-reducing material. The pressure sensor Sb has two electrodes 362A and 362B and a sensor layer 364 made of a decompression material formed on the two electrodes 362A and 362B. The sensor layer 364 is made of the same pressure-sensitive conductive material as the sensor layer 64. [

The electrodes 362A and 362B are formed on the substrate with an insulating layer interposed therebetween. The sensor layer 364 is formed on the insulating layer on which the openings 366 for exposing the electrodes 362A and 362B are formed and is in contact with the electrodes 362A and 362B through the openings 366. [ The surface on the side of the electrodes 362A and 362B on which the sensor layer 64 is formed is a sensor surface 370 which is a pressure detecting surface for detecting the pressure acting on the contacted object.

In each row of the sensor array 310, a plurality of gate lines GL1, GL2, ..., and GLm that extend in the row direction and are drive signal lines are disposed. Data lines DL1, DL2, ..., DLn, which are output signal lines, are arranged in each column of the sensor array 310 in the column direction. The data lines DL1, DL2, ..., DLn are connected to one end of a resistor Rb included in the detection circuit, respectively. The other end of the resistor Rb is connected to the ground voltage line of the ground voltage VS. An input terminal of the A / D converter 368 included in the detection circuit is connected to a connection node between the data lines DL1, DL2, ..., DLn and one end of the resistor Rb.

The electrodes 362A and 362B of the sensor cell 360 located in the ith row and the jth column and the selection transistor M are connected as follows. That is, the gate electrode of the selection transistor M is connected to the corresponding gate line GLi in the ith row. The source electrode of the selection transistor M is connected to the corresponding data line DLj in the j-th column. The drain electrode of the selection transistor M is connected to the electrode 362A. The electrode 362B is connected to a common power supply line to which the power supply voltage VD is supplied.

In the case of the two-dimensional pressure sensor 300 configured as described above, the pressure sensor Sb only has two electrodes 362A and 362B. Therefore, the two-dimensional pressure sensor 300 can detect only the electric resistance value R _AC between the electrode 362A and the electrode 362B as shown in Fig. As a result, unlike the force detecting apparatus 100 according to the present embodiment, the two-dimensional pressure sensor 300 can detect the force acting on the sensor surface 370 perpendicular to the sensor surface 370, The force acting in parallel with the sensor surface 370 can not be detected.

&Lt; Second Embodiment >

A force detecting apparatus according to a second embodiment of the present invention will be described with reference to Fig. 5 is a plan view showing the structure of a cell array including sensor cells in the force detection device according to the present embodiment. The same components as those of the force detection device according to the first embodiment are denoted by the same reference numerals and will not be described or briefly described.

The basic configuration of the force detection device according to the present embodiment is substantially the same as that of the force detection device 100 according to the first embodiment shown in Figs. The force detection device according to the present embodiment is configured such that the connection of the selection transistors M1 and M2 to the first and second gate lines and the connection of the electrodes to the first and second power supply lines But differs from the first embodiment in part.

The force sensor 200 according to the present embodiment is configured such that the same sensor cell 60a as that of the sensor cell 60 of the first embodiment and the sensor cell 60 of the first embodiment are provided in the sensor array 10, The sensor cells 60b are arranged alternately in the row direction and the column direction.

When the sensor cell 60b having a different connection from the sensor cell 60 of the first embodiment is located in the x-th row and the y-th column, the electrodes 62A and 62B of the force sensor S in the sensor cell 60b, 62B, 62C and 62D and the selection transistors M1 and M2 are connected as follows. X is an integer satisfying 1? X? M, and y is an integer satisfying 1? Y? N.

That is, the gate electrode of the selection transistor M1 is connected to the first gate line GLxa in the corresponding x-th row. The source electrode of the selection transistor Ml is connected to the data line DLy in the corresponding y-th column. The drain electrode of the selection transistor Ml is connected to the electrode 62B.

The gate electrode of the selection transistor M2 is connected to the second gate line GLxb of the corresponding x-th row. The source electrode of the selection transistor M2 is connected to the data line DLy in the corresponding y-th column. The drain electrode of the selection transistor M2 is connected to the electrode 62C.

Further, the electrode 62A is connected to the first power source line VLya in the corresponding y-th column. The electrode 62D is connected to the second power source line VLyb in the corresponding y-th column.

In this embodiment mode, the ON / OFF state of the first and second gate lines can be switched and the ON / OFF state of the first and second power source lines can be switched in the same manner as in the first embodiment. Thus, the electrical resistance values (R _AB , R _AC , R _BD , and R _CD ) can be individually acquired for each sensor cell 60 in the sensor array 10. Further, in this embodiment, the correspondence relationship between the operation sequence and the obtained electric resistance value is different from the correspondence relationship in the above-described first embodiment.

<Modified Embodiment>

The present invention is not limited to the above-described embodiment, and various modifications are possible.

For example, in the above embodiment, the case where each of the force sensors S has four electrodes 62A, 62B, 62C and 62D has been described as an example, but the present invention is not limited thereto. The force sensor S may have three or more electrodes. In this case, each sensor cell 60 needs to have active elements such as two or more plural selection transistors. By having three or more electrodes, it is possible to acquire the electric resistance value between two or more pairs of electrodes. Based on the relative magnitude of the electric resistance values, the direction of the force parallel to the sensor surface Can be obtained.

In the above embodiment, the selection transistors M1 and M2 such as thin film transistors are used as active elements, but the present invention is not limited thereto. Other active elements such as a metal insulator metal (MIM) diode may be used in place of the selection transistor M. [ Each sensor cell may be provided with a device having memory property. The detection circuit 30 may obtain the outputs of the data lines DL1, DL2, ..., DLn by a method other than the current equal voltage, for example.

In the above embodiment, the N-type thin film transistor is applied to the selection transistors M1 and M2, but the present invention is not limited thereto. The P-type thin film transistor may be applied to the selection transistors M1 and M2. In the case of applying the P-type thin film transistor, the logic of the gate driving signal is opposite to that of the above embodiment, and the power source potential and the ground potential to be supplied to the sensor cell are opposite.

Further, in the above embodiment, the case where the plurality of sensor cells 60 are arranged in a rectangular lattice pattern in the sensor array 10 has been described as an example, but the present invention is not limited thereto. The plurality of sensor cells 60 can be arranged two-dimensionally regularly or irregularly.

10: Sensor array
20: gate line driving circuit
30: Detection circuit
40: Power line driving circuit
50:
60, 60a, 60b: sensor cell
62A, 62B, 62C, 62D: electrodes
64: sensor layer
70: Sensor face
100, 200: force detection device
S: Force sensor
M1, M2: Select transistor
GLia: first gate line
GLib: Second gate line
VLja: first power line
VLjb: the second power line
DLj: data line

Claims (11)

A force sensor having three or more electrodes, a force sensor formed on the three or more electrodes and having a sensor layer made of a pressure-
And a detecting section for detecting an electrical resistance value between two or more pairs of electrodes among the three or more electrodes of the force sensor.
The method according to claim 1,
And each of the force sensors includes a plurality of sensor cells arranged two-dimensionally.
3. The method of claim 2,
Wherein each of the plurality of sensor cells includes a plurality of active elements.
The method of claim 3,
Wherein the active element is a thin film transistor.
The method of claim 3,
Wherein the three or more electrodes include a first electrode, a second electrode, a third electrode, and a fourth electrode,
The active element includes a first active element connected to the first electrode and a second active element connected to the fourth electrode.
6. The method of claim 5,
A first driving signal line connected to the first active element for driving the first active element,
And a second driving signal line connected to the second active element for driving the second active element.
6. The method of claim 5,
A first power line connected to the second electrode for supplying a power source voltage,
And a second power supply line connected to the third electrode for supplying a power supply voltage.
6. The method of claim 5,
And an output signal line connected to the first active element and the second active element.
6. The method of claim 5,
Wherein the first electrode, the second electrode, the third electrode, and the fourth electrode are disposed at four corners of the sensor layer,
Wherein the detecting unit detects an electrical resistance between the first electrode and the second electrode, between the first electrode and the third electrode, between the second electrode and the fourth electrode, and between the third electrode and the fourth electrode Value detecting means.
9. The method according to any one of claims 1 to 8,
Wherein the three or more electrodes have the same planar shape as each other.
9. The method according to any one of claims 1 to 8,
Wherein the three or more electrodes are two-dimensionally arranged at regular intervals.

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