JP2017049094A - Capacitance type input device - Google Patents

Abstract

Capacitance capable of detecting the proximity of an operating body to a surface plate and detecting whether the operating body has pressed the surface plate without adding a new member such as an infrared sensor. A formula input device is provided. A plate-like substrate, a conductive and flexible surface plate disposed opposite to the substrate, and a non-conductive layer disposed between the substrate and the surface plate. A first detection state in which the surface plate is not grounded and a second detection state in which the surface plate is grounded, the first detection state comprising a spacer and one or more detection electrodes provided on the substrate; In the detection state, the proximity of the operating body to the surface plate is detected, and in the second detection state, it is detected whether or not the surface plate is pressed by the operating body. [Selection] Figure 2

Description

  The present invention relates to a capacitance type input device that detects the degree of proximity of an operating body to a surface plate and detects whether or not the operating body has pressed the surface plate.

  The load sensor described in Patent Literature 1 includes a plate-like fixed substrate made of a metal material, and a movable substrate made of a flexible metal material disposed so as to face the fixed substrate, and the fixed substrate and the movable substrate. Between the two, a metal spacer sandwiched between two sealing members made of an insulating material is disposed. In this load sensor, it is possible to detect a load applied to the movable substrate by the operating body based on a change in capacitance between the fixed substrate and the movable substrate, which is generated when the movable substrate is bent by the pressing of the operating body. it can.

Japanese Utility Model Publication No. 2-5038

  In recent years, when a load sensor is applied to various devices, the function of illuminating the movable substrate or emitting the movable substrate when the operating body approaches the load sensor for the purpose of clearly indicating the position of the load sensor, etc. Is being sought. However, in the load sensor described in Patent Document 1, it is necessary to newly provide an electrode for proximity detection, an infrared sensor, and the like in order to detect that the operating body is approaching. There was a risk of inducing.

  Therefore, the present invention provides a static detection capable of detecting the proximity of the operating body to the surface plate and detecting whether or not the operating body has pressed the surface plate without adding a new member such as an infrared sensor. An object of the present invention is to provide a capacitive input device.

In order to solve the above-described problems, a capacitance-type input device according to the present invention includes a plate-like base material, a surface plate having conductivity and flexibility, disposed opposite to the base material, and a base material. A first detection state and a surface plate, wherein the surface plate is not grounded, and includes a non-conductive spacer disposed between the surface plate and the surface plate, and one or more detection electrodes provided on the substrate. Whether the operating body is close to the surface plate in the first detection state, and whether the surface plate is pressed by the operating body in the second detection state. It is characterized by detecting this.
Thereby, it becomes possible to perform both the detection of the approach of the operating body to the surface plate and the detection of whether or not the surface plate is pressed by the operating body without adding a new member such as a sensor.

In the capacitance-type input device of the present invention, it is preferable to include a controller that switches between the first detection state and the second detection state.
As a result, the two detection states can be quickly switched at an appropriate timing.

In the first aspect of the capacitive input device of the present invention, the control unit performs the second detection when the proximity of the operating body and the surface plate is equal to or less than the first threshold value in the first detection state. It is preferable to switch to the state.
Thereby, when the operating body is sufficiently close to the display board, the first detection state for detecting the proximity degree is switched to the second detection state for detecting the pressing operation by the operating body. The detection state can be smoothly switched for each of the press detections while reducing detection omissions.

In the first aspect of the capacitive input device of the present invention, the control unit switches to the second detection state when the proximity of the operating body and the surface plate is equal to or less than the first threshold value in the first detection state. After being set, it is preferable to switch the first detection state and the second detection state to each other at regular intervals.
Accordingly, it is possible to reliably detect that the operator who has performed the pressing operation has removed the finger or the like from the surface plate, thereby accurately performing the subsequent detection of the proximity degree and the detection of the pressing operation. Can do.

In the first aspect of the capacitive input device of the present invention, when the control unit switches from the second detection state to the first detection state, the degree of proximity between the operating body and the surface plate is first. When it is larger than the threshold value, it is preferable to hold the first detection state until it becomes equal to or lower than the first threshold value.
As a result, it is possible to avoid a situation in which the operating body returns to the second detection state even though the operating body has moved away from the surface plate, and when the operating body separated from the surface plate approaches the surface plate again. In addition, the proximity degree can be detected.

In the second aspect of the capacitive input device of the present invention, the control unit switches between the first detection state and the second detection state at regular intervals regardless of the output signal from the detection electrode. It is preferable.
Thereby, both the approach detection of the operating body with respect to a surface plate and the detection of the presence or absence of the press of the surface plate by an operating body can be performed reliably.

In the third aspect of the capacitance-type input device of the present invention, the second detection state is a state in which the second detection state is grounded via the operation body in contact with the surface plate, and the operation body separated from the surface plate is represented. Switching from the first detection state to the second detection state by contacting the face plate, and switching from the second detection state to the first detection state by moving the operating body that has been in contact with the surface plate away from the surface plate. It is preferable.
Thereby, since the switching process by a control part can be abbreviate | omitted, both the approach detection of the operation body with respect to a surface plate and the detection of the presence or absence of the press with the operation body with respect to a surface plate can be performed in the form which suppressed cost.

In the capacitance-type input device of the present invention, the base material is provided with one or more drive electrodes, and in the first detection state, a drive voltage is applied to each of the drive electrodes, and each of the detection electrodes It is preferable that it is detected that the operating body is close to the surface plate based on the current change at.
By using the mutual capacitance detected in this way, it is possible to accurately detect both the approach of the operating body to the surface plate and the detection of the presence or absence of pressing by the operating body on the surface plate.

In the capacitance-type input device of the present invention, it is preferable that in the first detection state, it is detected that the operating body is close to the surface plate based on a current change in the detection electrode.
By using the self-capacitance detected in this manner, both the approach detection of the operating body to the surface plate and the detection of whether or not the surface plate is pressed by the operating body can be executed with a compact configuration.

In the capacitance-type input device of the present invention, it is preferable that the control unit causes the light emitting unit to emit light when the proximity of the operating body and the surface plate is equal to or less than the second threshold value in the first detection state.
Accordingly, the position of the sensor unit or the operation area can be clearly shown to the operator, which can contribute to the convenience of the operator.

  According to the present invention, without adding a new member such as an infrared sensor, it is possible to accurately detect the proximity of the operating body to the surface plate and detect whether the surface plate is pressed by the operating body. it can.

It is sectional drawing which shows the structure of the sensor part of the electrostatic capacitance type input device which concerns on embodiment of this invention. It is a functional block diagram of the electrostatic capacitance type input device which concerns on embodiment of this invention. It is sectional drawing which shows the basic composition of the sensor part of the electrostatic capacitance type input device which concerns on a modification.

  Hereinafter, a capacitive input device according to an embodiment of the present invention will be described in detail with reference to the drawings. The capacitive input device of this embodiment can be applied to mobile phones and other portable information terminals, home appliances, in-vehicle electronic devices, and the like. In each figure, XYZ coordinates are shown as reference coordinates. The Z direction is along the vertical direction of the sensor unit, and the XY plane is a plane orthogonal to the Z direction. In the following description, the state viewed from the Z direction may be referred to as a plan view. In the following description, the operating body is an operator's finger or hand that operates the capacitive input device.

FIG. 1 is a cross-sectional view illustrating a configuration of a sensor unit 10 of the capacitive input device according to the present embodiment. FIG. 2 is a functional block diagram of the capacitive input device according to the present embodiment.
As shown in FIG. 1, the sensor unit 10 in the capacitive input device according to the present embodiment includes a plate-like base material 11 and a surface plate arranged to face the base material 11 in the vertical direction (Z direction). 12 and a spacer 13 disposed between the substrate 11 and the surface plate 12. In the sensor unit 10, a pair of drive electrodes 14 and detection electrodes 15 are provided.

  The substrate 11 is made of a non-conductive material, such as plastic or glass, and is fixed to a device to which the capacitive input device is applied, such as a liquid crystal panel. The base material 11 can be selected from either a light transmissive (light transmissive) material or a non-light transmissive material depending on the specifications of the device to be applied.

  The surface plate 12 is configured using a flexible plate-like material so that at least the entire operation area 17 (input area) of the upper surface 12a has conductivity. Here, as shown in FIG. 1, the operation area 17 is an area inside the area corresponding to the spacer 13 in the XY plane, and the area corresponding to the spacer 13 outside the operation area 17 is a non-operation area 18. ing.

For the surface plate 12, either a light transmissive material or a non-light transmissive material can be selected according to the specifications of the device to be applied. In the case where the surface plate 12 is made of a light transmissive material, for example, the entire surface corresponding to the operation region 17 on the upper surface of the flexible plastic plate having flexibility is formed by ITO ( A transparent conductive material such as Indium Tin Oxide), SnO ₂ , or ZnO is formed. On the other hand, when the surface plate 12 is made of a non-translucent material, for example, it is made of a flexible metal plate and corresponds to the operation region 17 on the upper surface of the flexible and non-conductive plate-like material. A non-translucent conductive thin film or conductive nanowire is formed over the entire area. Here, the conductive nanowire is fixed to the upper surface of the plate-like material by a binder. Examples of conductive nanowires include metal nanowires such as silver nanowires and carbon nanotubes.

  As shown in FIG. 2, a switch 22 for switching between a first detection state that is not grounded and a second detection state that is grounded is connected to the surface plate 12, and this switch is connected to the control unit 21. The operation is controlled by.

  The spacer 13 is provided in a frame shape on the outer peripheral portion of the upper surface 11 a of the base material 11. The spacer 13 is formed of a non-conductive material, for example, an adhesive made non-translucent by containing a pigment, and the base material 11 and the surface plate 12 are fixed by the spacer 13 so as to face each other. .

As shown in FIG. 1, a space 16 surrounded by the base material 11, the surface plate 12, and the spacer 13 is formed in the sensor unit 10. In this space 16, the drive electrode 14 and the detection electrode 15 are provided on the upper surface 11 a of the substrate 11. The drive electrode 14 and the detection electrode 15 are formed in a predetermined planar shape, for example, a rectangle by a transparent conductive material such as ITO, SnO ₂ , or ZnO by a thin film forming method such as sputtering or vapor deposition.

  The drive electrode 14 and the detection electrode 15 are formed to have a predetermined distance L1 between the surface plate 12 in the vertical direction. Thereby, even when the surface plate 12 is pressed downward and bent when the operator makes a finger contact with the surface plate 12 within the range of the operation region 17, the driving electrode 14 and the detection electrode 15 The state of being separated from the surface plate 12 is maintained.

  As shown in FIG. 2, a light emitting unit 23 is connected to the control unit 21. The light emitting unit 23 is, for example, a light emitting diode, and is provided on the inner wall of the space 16 of the sensor unit 10, the lower surface of the substrate 11, the surface plate 12, or the like so as to illuminate the entire surface plate 12 or the operation region 17 or a specific range. Be placed. In accordance with the instruction signal from the control unit 21, the light emitting unit 23 starts to emit light when the degree of proximity between the operating tool and the surface plate 12 becomes equal to or less than the second threshold value. The light emission of the light emitting unit 23 is stopped by the control of the control unit 21 when, for example, the first detection state is switched to the second detection state.

  The control unit 21 operates the switch 22 based on the output from the detection circuit 25 to connect the front plate 12 to the GND, that is, the first detection state in which the front plate 12 is not connected to the GND, and the front plate 12 to the GND. Switch to the grounded second detection state. In the initial state where the capacitive input device is activated, detection is performed as the first detection state, and the degree of proximity between the operating tool and the surface plate 12 is equal to or less than the first threshold value by the output from the detection circuit 25. When it is determined that the control has been performed, the control unit 21 outputs an instruction signal to the switch 22 so as to switch from the first detection state to the second detection state. Here, the proximity degree is a numerical value that changes corresponding to the distance between the operating body and the surface plate 12, and is calculated by the control unit 21 based on the detection value output from the detection circuit 25. When the distance between and is large, a large value is assumed. The first threshold is a value indicating the degree of proximity corresponding to 1 mm, for example, and is preferably larger than 0.

  Further, the detection circuit 25 performs an operation of subtracting a predetermined offset value from the measurement value output from the detection electrode 15. This offset value is determined by calibration performed at the time of shipment of the capacitive input device or at the time of startup after shipment, and is stored in a storage unit (not shown) included in the control unit 21. By using such an offset value, depending on the physical properties of the surface plate 12, the detection characteristics of the detection electrode 15, the environment in which the capacitive input device is installed, etc., the surface plate 12 when there is no pressing by the operating body. And the influence of noise components entering the detection electrode 15 can be suppressed, and proximity detection and pressure detection can be performed with higher accuracy.

  In the first detection state, the control unit 21 controls the drive circuit 24 so as to apply a predetermined drive voltage, for example, a rectangular wave with a constant period, to the drive electrode 14. In the first detection state, when the operating body approaches the operation area 17 of the surface plate 12 that is not grounded, the capacitance between the operating body and the surface plate 12 increases according to the degree of proximity. . In accordance with the increase in capacitance, the current flowing from the drive electrode 14 through the surface plate 12 to the detection electrode 15 decreases, and the capacitance (mutual capacitance) between the drive electrode 14 and the detection electrode 15 decreases. Therefore, the control unit 21 can detect the degree of proximity between the operating tool and the surface plate 12 based on the output signal from the detection electrode 15.

  Further, the control unit 21 outputs an instruction signal to the light emitting unit 23 to start light emission of the light emitting unit 23 when the degree of proximity between the operating body and the surface plate 12 is equal to or less than the second threshold. Further, the control unit 21 outputs an instruction signal to the switch 22 so that the surface plate 12 is grounded when the degree of proximity between the operating body and the surface plate 12 is equal to or less than the first threshold value which is smaller than the second threshold value. Then, when the surface plate 12 is grounded by the operation of the switch 22, the state is switched to the second detection state. Here, for example, when the first threshold value is a value indicating the proximity degree corresponding to 1 mm, the second threshold value is set to a value indicating the proximity degree corresponding to 1 cm, for example, as a larger value. The light emission of the light emitting unit 23 is preferably stopped by the control of the control unit 21 when switching from the first detection state to the second detection state, but is automatically stopped after a certain time from the start of light emission. Alternatively, it may be stopped when it is detected that the surface plate 12 is pressed in the second detection state.

  In the second detection state, the control unit 21 controls the drive circuit 24 so as to apply a predetermined drive voltage, for example, a rectangular wave with a constant period, to the drive electrode 14. In this state, when the operating body pushes down the surface plate 12 toward the base material 11, the distance between the surface plate 12 and the drive electrode 14 and the distance between the surface plate 12 and the detection electrode 15 are reduced. While the capacitance between the electrode 14 and the capacitance between the surface plate 12 and the detection electrode 15 increases, the capacitance (mutual capacitance) between the drive electrode 14 and the detection electrode 15 decreases. . The current flowing from the drive electrode 14 to the detection electrode 15 decreases according to the change in capacitance. Thereby, it is detected that the operating body has pressed the surface plate 12, and further, the degree of proximity between the surface plate 12 and the detection electrode 15 in the vertical direction.

  Here, since the surface plate 12 is grounded in the second detection state, even if the operating body is in contact with the surface plate 12, if the surface plate 12 does not bend toward the base material 11 side, The electrostatic capacitance between the detection electrode 15 does not decrease. For this reason, when an operator accidentally touches the surface plate 12 or when moisture adheres to the upper surface 12a of the surface plate 12, it is possible to prevent erroneous detection. In the second detection state, since a decrease in capacitance between the drive electrode 14 and the detection electrode 15 caused by the deflection of the surface plate 12 is detected, a non-conductive operating body, for example, a glove is used. It is possible to detect the pressing operation performed with the hand.

  After switching from the first detection state to the second detection state, the control unit alternates between the first detection state and the second detection state at regular intervals regardless of the output signal from the detection electrode 15. It is preferable to switch to. Here, the fixed time is, for example, 10 ms. By such switching, when the operator interrupts or ends the pressing operation in the second detection state, it is reliably detected in the first detection state that the operating body has left the surface plate 12. Will be able to. In the process of alternately switching between the first detection state and the second detection state as described above, the control unit also returns to the first detection state and detects that the operating body is separated from the surface plate 12. 21 determines whether the proximity degree of the operating body and the surface plate 12 exceeds the first threshold value. In this determination, when the degree of proximity between the operating tool and the surface plate 12 is larger than the first threshold value, the first detection state is maintained until the first threshold value is less than or equal to the first threshold value. Sometimes switch to the second detection state. By performing such control, it is possible to avoid a situation in which the operating body returns to the second detection state even though the operating body has moved away from the surface plate 12. When the operating body approaches the surface plate 12 again, the proximity degree can be detected in the first detection state, and when the operation body approaches the second threshold value, the light emitting unit 23 can reliably emit light.

  As described above, according to the above-described embodiment, the proximity of the operating body to the surface plate is detected and the operating body presses the surface plate without adding a new member such as an infrared sensor. It is possible to accurately perform both the detection of whether or not.

  Further, when the proximity of the operating body and the surface plate 12 becomes equal to or less than the first threshold, that is, when the operating body is sufficiently close to the display board, the pressing operation is performed from the first detection state in which the proximity is detected. Since it switches to the 2nd detection state to detect, it can switch a detection state smoothly, reducing detection omission about each of proximity detection and press detection.

  Furthermore, the light emitting unit 23 is caused to emit light when the degree of proximity between the operating body and the surface plate 12 is equal to or less than the second threshold value in the first detection state. The position and the like can be clearly shown, which can contribute to the convenience of the operator. For example, when the capacitive input device according to the present embodiment is used as a control switch for home appliances or the like, when the operator brings a finger close to the surface plate 12, the degree of proximity between the operation body and the surface plate 12 becomes the first. Since the light emitting unit 23 emits light when the threshold value is 2 or less, the operation area 17 and the like are illuminated as a range to be pressed by the control switch. When the operator further moves the finger closer to the surface plate 12 from this state, the first detection state is switched to the second detection state. When the operator presses the surface plate 12, the control unit 21 detects this, The defined signal is output to the home appliance side. Furthermore, it is possible to use a plurality of such capacitive input devices arranged side by side. In this case, the light emission forms of the light emitting units 23 included in the respective capacitive input devices, for example, colors, images, etc., are mutually connected. If they are different, the operator can easily discriminate between a plurality of capacitive input devices as control switches.

A modification will be described below.
(1) In the above-described embodiment, the proximity of the operating body is detected using the mutual capacitance. However, as in the capacitive input device 50 shown in FIG. The self-capacitance may be detected as a configuration in which only the detection electrode 55 is provided on the base material 11 in the space 16 surrounded by the spacer 13. Here, FIG. 3 is a cross-sectional view showing the basic configuration of the sensor unit of the capacitive input device according to the modification. Similar to the drive electrode 14 and the detection electrode 15 of the above-described embodiment, the detection electrode 55 is formed to have a predetermined interval L1 between the detection electrode 55 and the surface plate 12 in the vertical direction. In the capacitance type input device 50, in the first detection state, stray capacitance (self-capacitance) in the detection electrode 55 is detected based on a current change in the detection electrode 55, and this is used to display the operating body. The proximity to the face plate 12 is detected.

(2) In the above-described embodiment, when the degree of proximity between the operating tool and the surface plate 12 is equal to or lower than the first threshold value in the first detection state, the second detection state is switched. Thus, the two detection states may be switched every predetermined time regardless of the degree of proximity between the operating body and the surface plate 12, that is, regardless of the output signal from the detection electrode 15. Also in this case, the switching of the two detection states is controlled by the control unit 21, and each detection state is switched, for example, every 10 ms. Further, the time until switching may be different between the first detection state and the second detection state. Thereby, both the approach detection of the operating body with respect to the surface plate 12 and the detection of the presence or absence of the press of the operating body with respect to the surface plate 12 can be performed reliably.

(3) In the above-described embodiment and the above-described modification, the first detection state and the second detection state are switched to each other by the control of the control unit 21, but instead of this, the operator as an operation body The first detection state and the second detection state may be switched to each other depending on whether or not a finger or hand touches the surface plate 12. Even in this case, in the first detection state, the proximity degree between the operating body and the surface plate 12 is detected, and when the proximity degree is equal to or less than the second threshold value, the control unit 21 causes the light emitting unit 23 to emit light. Be controlled. Further, when a finger or the like as a conductor comes into contact with the surface plate 12, the surface plate 12 is in a grounded state. When the operating body pushes down the surface plate 12 in this state, the surface plate 12 and the detection electrode 15 Capacitance corresponding to the degree of proximity is detected.
Although the present invention has been described with reference to the above embodiment, the present invention is not limited to the above embodiment, and can be improved or changed within the scope of the purpose of the improvement or the idea of the present invention.

  As described above, the capacitive input device according to the present invention has both a simple configuration for detecting the proximity of the operating body to the surface plate and detecting whether the operating body has pressed the surface plate. Useful in that it can be implemented.

DESCRIPTION OF SYMBOLS 10 Sensor part 11 Base material 12 Surface plate 13 Spacer 14 Drive electrode 15 Detection electrode 17 Operation area 18 Non-operation area 21 Control part 22 Switch 23 Light emission part 24 Drive circuit 25 Detection circuit 50 Sensor part 55 Detection electrode

Claims (10)

A plate-like substrate;
An electrically conductive and flexible surface plate disposed opposite the substrate;
A non-conductive spacer disposed between the substrate and the surface plate;
One or more detection electrodes provided on the base material,
A first detection state in which the surface plate is not grounded and a second detection state in which the surface plate is grounded;
Detecting the degree of proximity that the operating body approaches the surface plate in the first detection state, and detecting whether or not the surface plate is pressed by the operating body in the second detection state. Capacitance type input device.   The capacitive input device according to claim 1, further comprising a control unit that switches between the first detection state and the second detection state.   The said control part is switched to a said 2nd detection state, when the said proximity degree of the said operation body and the said surface plate becomes below a 1st threshold value in a said 1st detection state. 2. The capacitive input device according to 2.   In the first detection state, the control unit is configured to change the proximity degree between the operating body and the surface plate to the second detection state at a certain time after the degree of proximity is equal to or less than the first threshold value. The capacitance type input device according to claim 3, wherein the first detection state and the second detection state are switched with each other.   When the control unit is switched from the second detection state to the first detection state, the degree of proximity between the operating body and the surface plate is larger than the first threshold value, The capacitance type input device according to claim 4, wherein the first detection state is held until the first threshold value or less.   The electrostatic control according to claim 2, wherein the control unit switches between the first detection state and the second detection state at regular intervals regardless of an output signal from the detection electrode. Capacitive input device. The second detection state is a state in which the second detection state is grounded through the operation body in contact with the surface plate,
The operation body that has been separated from the surface plate is switched from the first detection state to the second detection state by contacting the surface plate,
2. The capacitance type according to claim 1, wherein the operation body that is in contact with the surface plate is switched from the second detection state to the first detection state by being separated from the surface plate. Input device. The substrate is provided with one or more drive electrodes,
In the first detection state, a drive voltage is applied to each of the drive electrodes, and it is detected that the operating body has approached the surface plate based on a current change in each of the detection electrodes. The capacitance-type input device according to claim 1, wherein:   8. The method according to claim 1, wherein in the first detection state, it is detected that the operating body is close to the surface plate based on a current change in the detection electrode. Capacitance type input device described in 1.   The said control part makes a light emission part light-emit, when the said proximity degree of the said operation body and the said surface plate becomes below a 2nd threshold value in a said 1st detection state. Item 10. The capacitance-type input device according to any one of Item 9.

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