JP2010287148A - Operation input device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect an input regardless of an operating body (even when a thick glove is worn) in a method for detecting a touch input to a panel surface through a change in capacitance. <P>SOLUTION: In the operation input device, when a dielectric sheet of a switch part 13 is touched and pressed with a finger or the like, the dielectric sheet is deformed down nearer to an electrode of a sensor 135 to cause a change in capacitance, on the basis of which an oscillation circuit part 136g constituting an RC oscillation circuit outputs an oscillation signal, with the result that the operation input causes a change in voltage V output from a frequency-voltage conversion part 136c. In a control part 17, an operation input determination part 171 in the control part determines whether or not the switch part 13 is turned on in accordance with the conversion voltage V from the frequency-voltage conversion part 136c, and generates a detection signal indicating whether there is an ON operation in accordance with the determination. The ON operation determination is based on whether or not the input voltage V exceeds a predetermined threshold determinative of an ON operation (based on a voltage in the absence of touches). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an operation input device that gives instructions such as start, stop, and operating conditions to an apparatus or device having an information processing function. More specifically, the present invention relates to an operation input device that touches a dielectric surface (for example, a panel surface by a finger). The present invention relates to an operation input device that detects an operation input from a change in an output signal generated in a sensor electrode by capacitive coupling depending on whether or not the operation is performed.

An apparatus or device having an information processing function includes, for example, an operation panel having an LCD (Liquid Crystal Display) as a user interface. By touching (pressing) a button displayed on the screen according to an operation guide of the LCD screen A detection circuit works and can give instructions such as starting, stopping, operating conditions, etc., and an operation input device having no mechanical operation unit has been put into practical use and is called a so-called touch panel.
As such an operation input device, in recent years, an electrode is attached to the inside of a panel such as glass or acrylic that is touched by an operator, and a capacitance change that detects a change in the capacitance caused by the contact of a finger or the like is detected. A type of device has been proposed. The operation input device having such a configuration is easy to realize the design and waterproof structure of the product by flattening the surface of the operation panel.
However, for example, when a thick glove or a prosthetic finger is used, since the change in capacitance is small and contact cannot be detected, as shown in Patent Document 1, a part touching the touch panel as a touch panel operating glove A conductor has been proposed that can be input reliably in any situation.

However, in the method using the touch panel operation glove described above, it takes time and effort to wear the glove every time an input is made.
The present invention has been made in view of the above-described problems of the prior art. The object of the present invention is to detect the presence or absence of an operation input based on a change in capacitance, as long as an operation for touching a predetermined position of the panel is possible. In other words, it is possible to detect the operation body without questioning, that is, even when a finger or a thick glove is used.

  The present invention is an apparatus for performing an operation input, and is a sensor that is disposed so as to face a sheet-like dielectric that is elastically deformed by contact of an operating body, and a sheet surface opposite to a surface that contacts the operating body of the dielectric. An electrode, signal detection means for detecting an output signal generated at the sensor electrode by capacitive coupling, and the presence or absence of an operation input based on a signal detected by the signal detection means when the operating body is not in contact A threshold value determining means for determining the threshold value of the signal, and an operation presence / absence determining means for comparing the magnitude of the signal detected by the signal detection means with the threshold value and determining the presence / absence of an operation input based on whether or not the threshold value is exceeded. It is characterized by that.

  According to the present invention, an output signal having a required magnitude can be generated by a contact operation regardless of the operation body (for example, even when wearing thick gloves), and the contact of the operation body can be reliably detected.

1 is an external view showing a schematic configuration of an operation input device according to an embodiment of the present invention. It is sectional drawing which shows schematic structure of the switch part in an operation input device (FIG. 1). It is a block diagram which shows schematic structure of the processing system which concerns on the detection of the presence or absence of the operation input to the switch part in an operation input device (FIGS. 1, 2). It is a figure which shows the processing flow of the operation input detection which the processing system of FIG. 3 performs.

Hereinafter, an embodiment of an operation input device according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 is an external view showing a schematic configuration of the operation input device according to this embodiment.
1, the operation input device 10 has a liquid crystal display unit 12, a switch unit 13, a buzzer 15, and a power switch 16 as elements constituting the device, and these are incorporated in the acrylic panel unit 11 and illustrated. It is attached to the body of an apparatus or device (hereinafter simply referred to as “device”) having an information processing function.
The operation input device 10 shown in FIG. 1 is a means for notifying information for notifying the user of the device of the state (status) of the device and a means for the user to give instructions such as start, stop, operating conditions, etc. Provide a function as a user interface. The notification of the status of the device is performed through the liquid crystal display unit 12 and the buzzer 15, and the user's instruction is performed through the switch unit 13 and the power switch 16. The liquid crystal display unit 12 displays the status of the device and guides how the user should perform an operation in order to instruct the operation requested by the user in the displayed status. By performing operation input of the switch unit 13 in accordance with this guidance, an instruction requested by the user is transmitted to the device.

“Basic configuration of the switch”
FIG. 2 is a cross-sectional view showing a schematic configuration of a switch unit in the operation input device (FIG. 1) of this embodiment.
In FIG. 2, the switch unit 13 is configured so that the operating body is directly connected as a constituent element in order from the surface pressed by the operating body such as the operator's finger (the surface marked with an arrow F in the figure indicating the direction of the pressing operation). The dielectric sheet 131 that comes into contact, the spacer 132 that secures a space when the dielectric sheet 131 is pressed and deformed (dented), the acrylic panel 133 that serves as the base of the spacer 132, and a screen for operation input can be displayed. A display 135, a sensor 135 having a sensor electrode for detecting an output signal generated by capacitive coupling, and a capacitance detection circuit board 136 for detecting a signal generated in the sensor 135.

The dielectric sheet 131 is formed of a ferroelectric thin film such as lead zirconate titanate (PZT) or barium titanate (BTO) on a material that is relatively soft and has a relatively high visible light transmittance, such as an OHP film. Apply things. As a method of forming a ferroelectric thin film, a sputtering method or a vacuum evaporation method can be used. In addition, by using a material having a high transmittance, a high dielectric constant, and a flexibility, the dielectric sheet may be composed of only the material.
The spacer 132 is preferably an elastic body that has a high visible light transmittance and is flexible.
For both the dielectric sheet 131 and the spacer 132, a substance having a high visible light transmittance is used because the screen displayed by the next display unit 134 is displayed from the surface of the switch unit 13 (surface with arrow F). This is to ensure visibility when viewing.

In addition to using liquid crystal, the display unit 134 uses a display device such as electronic paper or an organic EL (Electronic Luminescent) that does not require a backlight. By using such a display device that does not require a backlight, the overall thickness can be reduced and the space can be saved when the switch unit 13 is configured using the elements shown in FIG. Enable. Note that variable display means using electronic paper or organic EL can be implemented by applying existing technology.
The display unit 134 employs a display that can change the display of the screen by changing the display program, and displays a screen corresponding to the content of the instruction given by the user's operation input (particularly, a plurality of sensors 135 are provided). In the example described later, it becomes possible to deal with various input methods).

In the switch section 13 of FIG. 2, the dielectric sheet 131 is deformed (recessed) by performing an operation of pressing the surface of the switch section 13 from the direction of the arrow F shown in FIG. When the distance between the dielectric sheet 131 and the electrode of the sensor 135 is reduced and the capacitance is increased, the output signal generated at the sensor electrode changes, and the presence or absence of an operation input is determined from the output signal. It can be detected (details are described later).
According to this detection principle, the output signal generated at the sensor electrode changes corresponding to the local deformation of a portion of the dielectric sheet 131 where the sensor electrode is present.

Therefore, even if a plurality of sensor electrodes are provided for the common dielectric sheet 131, if the plurality of sensor electrodes are not pressed at the same time, the change in output caused by the deformation of the dielectric sheet 131 by the operation is caused by any of the plurality of sensors. By detecting whether or not it has occurred, it is possible to identify the operation location and detect the presence or absence of the operation. In this embodiment, an operation input device having a switch unit having a plurality of sensors is also one of the embodiments.
The method of providing a plurality of sensors is not shown in the configuration of the switch unit 13 in FIG. 2 showing an example in which only one sensor is implemented, but each sensor is a dielectric like the sensor 135 in FIG. It is provided so as to face the sheet surface of the body sheet 131 and to arrange the sensors at a predetermined interval. With such an arrangement, it is possible to reduce the influence of sensor outputs provided at other positions when the dielectric sheet 131 corresponding to one sensor position is pressed, and prevent erroneous detection. In addition, it is necessary to configure a sensor output detection circuit so that the outputs of a plurality of sensors can be individually identified and detected. Incidentally, regarding a circuit and a processing process for detecting an operation input based on the sensor output, This will be described in detail in the following “operation input detection process” and “control flow for operation input detection”.

"Operation input detection process"
The detection process of presence / absence of an operation input for detecting whether or not the switch unit is turned on based on a change generated in the output signal of the sensor 135 due to the operation input to the switch unit 13 having the above configuration will be described in detail.
FIG. 3 is a block diagram showing a schematic configuration of a processing system related to detection of presence / absence of an operation input to the switch unit. Note that the processing system shown in FIG. 3 shows a system configured by related elements with a focus on the detection operation of the operation input of the switch unit 13 of the operation input device 10 (see FIGS. 1 and 2). Elements common to FIGS. 1 and 2 are given the same reference numerals.
The processing system of FIG. 3 includes a control unit 17 including a CPU (Central Processing Unit) 172 and the like, a switch unit 13 that operates under the control of the control unit 17, a liquid crystal display unit 12, and a process related to detection of presence / absence of an operation input. Including a program (software) used for control by the control unit 17, a ROM (Read Only Memory) 19 for storing data, etc., data related to the processing being executed (display data used in the liquid crystal display unit 12, detection of presence / absence of operation input) Each component includes a RAM (Random Access Memory) 18 or the like for storing a threshold value used in

  When the control function of the control unit 17 (including an operation input determination unit 171 described later) is realized by software, a program for causing a computer including the CPU 172, the RAM 18, the ROM 19 and the like to function as the control unit 17 Can be realized. The CPU 172 reads a control / processing program or the like recorded (stored) in the ROM 19 at the time of execution of the process into the RAM 18 as a work memory, and drives the program to cause the CPU (computer) 172 to execute the process. Can function as. The medium for recording the program is not limited to the ROM, and a computer-readable recording medium such as an HDD, a CD (Compact Disk) -ROM, an MO (Magnet Optical Disk), a DVD (Digital Versatile Disk), or the like is used. be able to. In addition, when a device (not shown) on which the operation input device 10 is mounted is connected to a network such as the Internet, the program may be acquired by downloading via the network.

The switch unit 13 shown in FIG. 3 includes a switching unit provided in a capacitance detection circuit board 136 (see FIG. 2) for detecting an output signal from the sensor 135 in addition to the display unit 134 and the sensor 135 shown in FIG. A circuit unit 136s, an oscillation circuit unit 136g, and a frequency / voltage conversion unit 136c that converts a frequency into a voltage are included. In addition, the switch part 13 in this embodiment mounts the above-mentioned multiple sensors as the sensor 135.
The switching circuit unit 136s is a circuit that sequentially scans each sensor by switching the connection between the oscillation circuit unit 136g and a plurality of sensors 135 one by one in a time-sharing manner according to a signal from the control unit 17. In this time-division switching operation, the output of a plurality of sensors can be individually identified and detected by associating the switching timing with each sensor on a one-to-one basis.

The oscillation circuit unit 136g is coupled with the capacitance generated between the dielectric sheet 131 and the sensor electrode detected by the sensor 135 scanned by the switching circuit unit 136s, and outputs a signal having a frequency corresponding to the capacitance. In this example, the RC oscillation circuit is configured to output an oscillation signal corresponding to a change in the capacitance C caused by deformation of the dielectric sheet 131.
The frequency / voltage conversion unit 136c receives the oscillation signal generated by the oscillation circuit unit 136g, converts it to a voltage signal corresponding to the oscillation frequency, and outputs the converted detection voltage to the control unit 17.
In this embodiment, the frequency / voltage converter 136c generates a lower voltage as the oscillation frequency of the signal oscillated by the oscillation circuit section 136g is higher, and generates a higher voltage as the oscillation frequency is lower. The circuit is configured so as to have a conversion characteristic that is inversely proportional to the subsequent voltage.

The operation when an operation input to the switch unit 13 is performed is as follows.
When the user touches and presses the dielectric sheet 131 with a finger or the like as an operation input operation, the dielectric sheet 131 is recessed (elastically deformed). By this operation, the equivalent electrostatic capacitance at the electrode of the sensor 135 changes as the distance between the dielectric sheet 131 and the electrode of the sensor 135 approaches.
If the equivalent capacitance at the electrode of the sensor 135 is C, the capacitance C can be expressed by an equivalent expression of “C = ε * S / d”. In this equation, ε is the relative dielectric constant (approximate value) of the ferroelectric, S is the area of the dielectric sheet, and d is the distance between the dielectric sheet and the sensor.
When the operation input is performed, the dielectric sheet 131 is strongly pressed with a finger or the like, so that the amount of deformation is increased and the distance d between the dielectric sheet 131 and the sensor 135 is decreased. As a result of lowering the frequency, the voltage V output from the frequency / voltage converter 136c increases.

As described above, the voltage V output from the frequency / voltage conversion unit 136c changes in response to pressing of the dielectric sheet 131 when an operation is input.
The voltage V detected by the sensor 135 of the switch unit 13 and converted by the frequency / voltage conversion unit 136c is output from the switch unit 13 to the control unit 17, and the control unit 17 uses the operation input determination unit 171 in the control unit. It is determined whether or not the switch unit 13 is turned on based on the voltage V, and a detection signal indicating whether or not the switch is turned on (ON / OFF) is generated according to the determination result.
The determination of the ON operation is performed by comparing the voltage V input as a value inversely proportional to the distance between the dielectric sheet 131 and the sensor 135 with a threshold value that is set in advance as a reference for determining the ON operation, and the voltage V exceeds the threshold value. It is determined whether or not an ON operation has been performed.

Further, the following method is adopted as a threshold value determining method. That is, for example, when the dielectric sheet 131 is not pressed by a finger or the like at the timing before operation input is performed at the time of power-on or initialization (when not in contact), the sensor 135 of the switch unit 13 The voltage V detected and converted by the frequency / voltage conversion unit 136c is detected, and a value obtained by considering a predetermined margin in the detected value is determined as a threshold value.
In addition, when this method is applied to a switch unit equipped with a plurality of sensors, the non-contact voltage V is detected for each of the plurality of sensors, and the respective threshold values are determined. By adopting this method, the distortion of the dielectric sheet 131 and the dielectric constant unevenness can be corrected. In addition, since the distortion and dielectric constant unevenness of the dielectric sheet 131 can be allowed to some extent, the cost of the dielectric sheet can be reduced.
In this way, for example, the threshold value (voltage value) determined for each sensor at the time of power-on or initialization is stored in the RAM 18 in association with each sensor by the number of sensors 135 via the control unit 17. The stored voltage value is used as a threshold value Vh for determining an ON operation for the output of each sensor.
In the above, an example is shown in which the process for determining the threshold value used to determine the ON operation is performed at the time of power-on or initialization, but this threshold value changes over time due to factors such as environmental (eg, temperature) changes. In this case, for example, the re-determination process may be performed after a predetermined time has elapsed since the previous threshold was determined.

"Control flow for operation input detection"
Next, the flow of processing executed when the control unit 17 detects an operation input to the switch unit 13 and accepts the input will be described with reference to the control flow of FIG.
The control flow of this embodiment shown in FIG. 4 is started when the power switch 16 of the operation input device 10 is pressed and the power to the device is turned on.
When this control flow is started when the power is turned on, processing for determining a threshold value Vh used for determining whether or not there is an operation input is performed as an initialization procedure. During the initialization procedure described below, it is assumed that no operation input to the switch unit 13 is performed. For example, a method of displaying a message for waiting for an operation input on the screen of the liquid crystal display unit 12 or a buzzer 15 The user is notified of the prohibition of operation input (pressing of the switch unit 13) by one or both of the methods of sounding the sound, and the necessary conditions are adjusted.

  As an initialization procedure, first, the switching circuit unit 136s is operated, and the oscillation circuit unit 136g is connected to the sensor electrode so that a predetermined sensor electrode in the sensor 135 and the oscillation circuit unit 136g are capacitively coupled ( Step S101). In this embodiment, a plurality of sensors (electrodes) are mounted as the sensor 135, and each threshold value Vh is determined for each of the plurality of sensors. While switching the connection, the determined threshold value Vh is recorded in the RAM 18 (step S103 to be described later), and is used when determining whether or not there is an operation input when the operation input is actually performed. Therefore, this initialization procedure (steps S101 to S103) is performed by the number of sensors (electrodes).

Next, the oscillation circuit unit 136g is switched by the switching circuit unit 136s, capacitively coupled to the connected sensor electrode, and oscillates at a frequency according to the capacitance value when there is no operation input, that is, no contact. The oscillated signal is output to the frequency / voltage converter 136c (step S102).
Next, the frequency / voltage conversion unit 136 c receives the signal oscillated by the oscillation circuit unit 136 g in the previous step, converts the oscillation frequency of the input signal into a voltage, and sends the obtained voltage value to the control unit 17. Further, the control unit 17 determines the threshold value Vh based on the voltage value sent from the frequency / voltage conversion unit 136c of the switch unit 13 as the voltage value corresponding to the capacitance detected when there is no contact. The threshold value Vh is recorded in the RAM 18 (step S103). At this time, the determined threshold value Vh is stored in the RAM 18 corresponding to the number of sensors 135 in association with each sensor.
The initialization procedure is thus completed, and the process proceeds to the operation input actually performed.

After the initialization, for the operation input actually performed, the switching circuit unit 136s is operated, and a plurality of sensors (electrodes) mounted as the sensors 135 are scanned one by one in a predetermined order according to a predetermined order. The connection is switched so that the oscillation circuit unit 136g is capacitively coupled to each sensor (step S104).
The oscillation circuit unit 136g oscillates at a frequency according to the capacitance value of the connected sensor (electrode) by switching the previous step, and outputs the oscillated signal to the frequency / voltage conversion unit 136c (step S105). .
Next, the frequency / voltage conversion unit 136c receives the signal oscillated by the oscillation circuit unit 136g in the previous step, converts the oscillation frequency of the input signal into a voltage, and sends the obtained voltage value to the control unit 17 ( Step S106).

Next, the control unit 17 uses a voltage value sent from the frequency / voltage conversion unit 136c of the switch unit 13 as a voltage value corresponding to the capacitance detected by the sensor (electrode) connected this time. A process for detecting the presence or absence of an operation input is performed. That is, the operation input determination unit 171 of the control unit 17 determines the voltage value sent as the voltage value corresponding to the capacitance of the sensor (electrode) detected this time and the threshold value of the sensor (electrode) in the previous step S103. Is compared with the value Vh determined as follows to determine whether or not the current voltage value is larger than the threshold value Vh (step S107).
If it is determined that the current voltage value is greater than the threshold value Vh (step S107—YES), it is determined that there is an operation input, and the control unit 17 is configured by the sensor in response to the result. This acceptance process is executed by recognizing the switch-on operation (step S108). In addition, this reception process is recognized as an operation input that the control unit 17 responds to the user with, for example, “Yes / No” or a selection instruction with respect to the guidance and menu shown through the screen of the liquid crystal display unit 12. It is processing to do.
Further, the control unit 17 operates the buzzer 15 to notify the user that the operation input has been performed effectively (step S109).

On the other hand, when it is determined that the current voltage value does not exceed the threshold value Vh (NO in step S107), it is determined that there is no operation input, the processing in steps S108 and S109 is skipped, and the process proceeds to step S110.
In addition, the process sequence of step S104-S109 demonstrated above is a process of one sensor which the switching circuit part 136s connected among the some sensors (electrode) which the switch part 13 has, and with respect to a some sensor Then, while switching the connection to the sensor on a time basis, the processing of steps S104 to S109 for detecting the presence or absence of an operation input for each sensor is continued until the power is turned off. Therefore, the procedure up to the end after step S104 is continuously repeated except for the period during which operation input is prohibited.

However, in this embodiment, in addition to the above, detection of presence / absence of operation input that is continuously performed may be interrupted. This is because a processing step for re-determining the threshold value Vh determined when the power is turned on is provided in order to prevent a decrease in accuracy of detecting the presence or absence of an operation input.
The reason for providing this processing step is that the threshold value Vh is assumed to fluctuate over time due to factors such as changes in the environment (for example, temperature). In this embodiment, the threshold value Vh that affects the detection accuracy is The time when fluctuation is assumed not to occur is set as the threshold expiration date in advance, and when this threshold expiration date is exceeded, control to re-determine the threshold Vh is performed.
As a processing flow, after determining whether or not there is an operation input (step S109 / step S107-NO), it is confirmed whether or not an instruction to shut down the processing system for determining the presence or absence of an operation input is given (step S109). S110) If shutdown is instructed (step S110-YES), this control flow is terminated.
On the other hand, when the shutdown is not instructed (step S110-NO), it is confirmed whether or not the elapsed time since the process of determining the previous threshold is within the predetermined threshold expiration date (step S111).
Here, when the elapsed time since the process of determining the previous threshold exceeds the predetermined threshold expiration date (step S111-NO), the process returns to step S101 to re-determine the threshold Vh. .
Also, if the elapsed time since the process of determining the previous threshold value does not exceed the predetermined threshold expiration date (step S111-YES), the threshold value thus far is determined without re-determining the threshold value Vh. While continuing to use Vh, the process returns to step S104 to continue the processing flow for determining whether or not there is an operation input.

  10..Operation input device, 12 .... Liquid crystal display unit, 13..Switch unit, 131..Dielectric sheet, 132..Spacer, 133..Acrylic panel, 134..Display unit, 135..Sensor, 136 ..Capacitance detection circuit board 136g Oscillator circuit 136c Frequency / voltage converter 136s Switching circuit 15 Buzzer 16 Power switch 17 Control unit 171 .. Operation input determination unit, 172... CPU, 18.

JP 2008-81896 A

Claims (5)

A sheet-like dielectric that is elastically deformed by the contact of the operating body;
A sensor electrode disposed opposite to the sheet surface opposite to the surface with which the operating body of the dielectric is in contact;
Signal detection means for detecting an output signal generated at the sensor electrode by capacitive coupling;
Threshold determination means for determining a threshold for determining the presence or absence of an operation input based on a signal detected by the signal detection means when the operating body is not in contact;
An operation input device comprising: an operation presence / absence determination unit that compares the magnitude of a signal detected by the signal detection unit with the threshold and determines whether or not there is an operation input based on whether or not the threshold is exceeded. The operation input device according to claim 1,
The sensor electrode is composed of a plurality of electrodes arranged with a predetermined interval between the electrodes,
The threshold value determining means is a means for determining a threshold value for each of the plurality of sensor electrodes,
The operation input device is characterized in that the operation presence / absence determining means is a means for determining presence / absence of an operation input by a threshold value determined for each sensor electrode for each of a plurality of sensor electrodes. In the operation input device according to claim 1 or 2,
The sheet-like dielectric uses a material having a high visible light transmittance,
A flat display portion for displaying an input screen is provided between the sheet-like dielectric and the substrate on which the sensor electrode is placed, and these are combined to form a panel. Operation input device. The operation input device according to claim 3,
The operation input device, wherein the display unit is electronic paper. The operation input device according to claim 3,
The operation input device, wherein the display unit is an organic EL.

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