JP2011187087A - Input device and control method for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an input device reduced in cost and size. <P>SOLUTION: The input device includes: a touch sensor 11 detecting touch input; a piezoelectric element 12 mounted on the touch sensor 11; and a control part 14 detecting a pressing load to a touch surface 11a of the touch sensor 11 based on an output signal of the piezoelectric element 12, and driving the piezoelectric element 12 to feed back tactile sensation to the pressing object that presses the touch surface 11a when the detected pressing load meets a reference for feeding back tactile sensation. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an input device including a touch sensor and a method for controlling the input device.

  In recent years, a mobile terminal such as a mobile phone, an information device such as a calculator and a ticket vending machine, a home appliance such as a microwave oven, a television, and a lighting fixture, an industrial device (FA device), etc. As input devices such as switches, input devices including touch sensors such as touch panels and touch switches are widely used.

  As such a touch sensor, various systems such as a resistive film system, a capacitance system, and an optical system are known. However, any type of touch sensor accepts a touch input by a finger or a stylus pen, and the touch sensor itself is not physically displaced like a push button switch even when touched.

  As described above, even if the touch sensor is touched, the touch sensor itself is not physically displaced, so that the operator cannot obtain feedback for the input even if the touch input is accepted. For this reason, the operator is likely to repeatedly input such as touching the same position many times, and may stress the operator.

  In order to prevent such repeated input, for example, a touch input is received and a sound is produced, or a display color of an input object such as an input button displayed on the display unit corresponding to the input position is displayed. There are known ones in which the input operation can be confirmed by hearing or vision by changing the display mode such as changing.

  However, in the case of a feedback method that works on hearing, it is difficult to confirm in a noisy environment, and if the device used is in a silent state such as manner mode, it cannot be handled. In the feedback method that works visually, if the size of the input object displayed on the display unit is small, especially in the case of finger input, the input object is hidden under the finger and the display mode changes. There are cases where it is not possible.

  Also, a feedback method has been proposed in which when the touch sensor accepts an input regardless of hearing or sight, the touch sensor is vibrated to generate a tactile sensation at the fingertip of the operator (for example, Patent Document 1). 2).

JP 2003-288158 A JP 2008-130055 A

  However, the techniques disclosed in Patent Documents 1 and 2 merely vibrate the touch sensor when the touch sensor receives an input. For this reason, especially when a button switch such as a push button switch (push-type button switch) is drawn on the top of the touch sensor, when the threshold value for accepting input from the touch sensor is low, a finger or the like touches the touch sensor lightly. A tactile sensation is presented just by touching. As a result, an erroneous operation is induced in response to an unintended operation (touch) before the operator pushes, or a sense of incongruity due to an unintended operation (touch) before the operator pushes is given. Here, the threshold value for accepting an input by touch of the touch sensor is a threshold value at which the touch sensor reacts. For example, in the resistive film method, the threshold value is a threshold value of the pressing force with which the upper conductive film contacts the lower conductive film. In the method, it is a detection threshold value of an electrical signal due to contact.

  In order to solve such an inconvenience, the present applicant detects a pressing load due to a touch on the touch surface of the touch sensor, and when the detected load reaches a predetermined threshold value that presents a tactile sensation, Is developing an input device that vibrates and presents a tactile sensation to a pressed object such as a finger.

  According to this input device, when the operator pushes the touch surface and the pressing load reaches a predetermined threshold value, a tactile sensation is presented, so that an erroneous operation due to the unintended touch described above is induced or uncomfortable. It is possible to reliably prevent the operator from recognizing that the input is accepted by the operator as a tactile sensation.

  By the way, in order to configure such an input device, in addition to the basic configuration of the touch sensor and its control unit, a load sensor that detects a pressing load on the touch sensor and an actuator that vibrates the touch sensor are required. For this reason, the number of parts increases and the cost is increased, and it is necessary to secure a space for installing the parts, resulting in an increase in the size of the apparatus. Therefore, in realizing the input device described above, there is room for further improvement in terms of cost and miniaturization.

  SUMMARY An advantage of some aspects of the invention is that it provides an input device and a control method for the input device which are appropriately configured so as to reduce cost and size.

The invention of an input device that achieves the above object is as follows.
A touch sensor for detecting touch input;
A piezoelectric element attached to the touch sensor;
A pressing target that presses the touch surface when the pressing load on the touch surface of the touch sensor is detected based on an output signal of the piezoelectric element and the detected pressing load satisfies a criterion for presenting a tactile sensation A control unit for driving the piezoelectric element so as to present a tactile sensation with respect to
It is characterized by providing.

Furthermore, the invention of the control method of the input device that achieves the above object is as follows:
A touch sensor for detecting touch input;
A method of controlling an input device comprising: a piezoelectric element attached to the touch sensor;
A pressing target that presses the touch surface when the pressing load on the touch surface of the touch sensor is detected based on an output signal of the piezoelectric element and the detected pressing load satisfies a criterion for presenting a tactile sensation Driving the piezoelectric element to present a tactile sensation to
It is characterized by this.

  In the present invention, the piezoelectric element is used as a load sensor that detects a pressing load on the touch surface of the touch sensor and an actuator that vibrates the touch surface by using the piezoelectric positive effect and the piezoelectric reverse effect of the piezoelectric element. Shared. Therefore, the number of parts can be reduced and the cost can be reduced, and the installation space for the parts can be reduced and the apparatus can be downsized.

It is a functional block diagram which shows schematic structure of the input device which concerns on one embodiment of this invention. FIG. 2 is a cross-sectional view and a main part plan view of a main part showing a schematic configuration example of a mounting structure of a touch sensor, a piezoelectric element, and a display unit shown in FIG. It is a flowchart which shows schematic operation | movement of the input device shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a functional block diagram showing a schematic configuration of an input device according to an embodiment of the present invention. The input device includes a touch sensor 11, a piezoelectric element 12, a display unit 13, and a control unit 14 that controls the operation of each unit.

  The touch sensor 11 detects a touch input by a pressing target such as a finger on the touch surface of the touch sensor 11 under the control of the control unit 14, and supplies position information of the touch position to the control unit 14. The touch sensor 11 is formed of a known type such as a resistive film type, a capacitance type, or an optical type, and is disposed on the display unit 13.

  The piezoelectric element 12 is attached to the touch sensor 11. The piezoelectric element 12 is controlled by the control unit 14 by using a piezoelectric positive effect, a load detection mode for detecting a pressing load on the touch surface of the touch sensor 11, and a touch sensor using a piezoelectric reverse effect. 11 is operated in any one of tactile sensation presentation modes in which the touch surface is vibrated. In the load detection mode, an output signal corresponding to the pressing load on the touch surface of the touch sensor 11 is supplied to the control unit 14. Further, in the tactile sensation presentation mode, the touch surface of the touch sensor 11 is vibrated according to the drive signal supplied from the control unit 14, and a predetermined tactile sensation according to the drive signal is presented to the pressing target pressing the touch surface. To do.

  The display unit 13 displays an input object such as an input button such as a push button switch (push button switch) under the control of the control unit 14. For example, the display unit 13 is a liquid crystal display panel or an organic EL display panel. Etc. are used. The touch input to the input object displayed on the display unit 13 is detected by the control unit 14 based on the position information output from the touch sensor 11.

  The control unit 14 includes, for example, a CPU and the like, and is based on position information from the touch sensor 11, display information on the display unit 13, an output signal corresponding to a pressing load obtained from the piezoelectric element 12 in the load detection mode, and the like. To control the operation.

  2 shows a schematic configuration example of the mounting structure of the touch sensor 11, the piezoelectric element 12, and the display unit 13 shown in FIG. 1, FIG. 2 (a) is a cross-sectional view of the main part, and FIG. FIG. The display unit 13 is housed and held in the housing 21. The touch sensor 11 is held on the display unit 13 via an insulator 22 made of an elastic member. In the present embodiment, the touch sensor 11 is held on the display unit 13 via the insulators 22 arranged at the four corners deviated from the display area A of the display unit 13 indicated by virtual lines in FIG. To do.

  Further, the housing 21 is provided with an upper cover 23 so as to cover the surface area of the touch sensor 11 deviated from the display area of the display unit 13, and is made of an elastic member between the upper cover 23 and the touch sensor 11. A dustproof insulator 24 is disposed.

  In the touch sensor 11 shown in FIG. 2, the surface member having the touch surface 11 a is made of, for example, a transparent film or glass, the back member is made of glass or acrylic, and the touch surface 11 a is pressed via the insulator 24. Then, a structure is used in which the pressing portion is bent (distorted) by a small amount in accordance with the pressing force, and the entire touch sensor 11 including the back member is bent by a small amount.

  The touch sensor 11 detects a pressing load on the touch surface 11a of the touch sensor 11 in the vicinity of one side or a plurality of sides covered with the upper cover 23, in this case, in the vicinity of the three sides, on the back surface. Are respectively attached to the piezoelectric elements 12 for presenting a tactile sensation to the pressing target pressing the touch surface 11a. The outputs of these three piezoelectric elements 12 are supplied to the control unit 14 in parallel. In FIG. 2B, the casing 21, the upper cover 23, and the insulator 24 shown in FIG. 2A are not shown.

  FIG. 3 is a flowchart showing a schematic operation of the input apparatus according to the present embodiment. The control unit 14 always monitors the output signals of the three piezoelectric elements 12 in the load detection mode (step S301). Further, the control unit 14 monitors the output of the touch sensor 11, and the position information of the touch input by the pressing target (pressed object) such as a finger obtained from the touch sensor 11 is displayed on the display unit 13. It is detected whether or not the position is an input to the position (step S302). When the position information from the touch sensor 11 is an input to the position for the input object displayed on the display unit 13 (in the case of Yes), the display mode of the input object in the display unit 13 is changed. The color is changed or the like is changed (step S303).

  Further, the control unit 14 calculates a pressing load on the touch sensor 11 based on the outputs of the three piezoelectric elements 12, and detects whether or not the pressing load satisfies a reference (eg, 1N) for presenting a tactile sensation. (Step S304). As a result, when it is detected that the pressing load satisfies the standard (in the case of Yes), the three piezoelectric elements 12 are switched from the load detection mode to the tactile sensation presentation mode (step S305). Then, the control unit 14 supplies (applies) predetermined drive signals to the three piezoelectric elements 12 to drive the three piezoelectric elements 12, thereby vibrating the touch sensor 11 and touching them. A tactile sensation is presented to the pressed object touching the surface 11a (step S306). Thereafter, the control unit 14 returns the three piezoelectric elements 12 to the load detection mode (step S307), and calculates the pressing load on the touch sensor 11.

  Here, in step S304, the pressure load calculated based on the outputs of the three piezoelectric elements 12 is preferably a pressure sensation (sensation such as the hardness or softness of an object) felt by the operator at each position on the touch surface 11a. For example, the calculation is performed based on the average value of the outputs of the three piezoelectric elements, the weighted addition value, or the like so that substantially the same calculation result can be obtained. Similarly, in step S306, the drive signals applied to the three piezoelectric elements 12 are preferably the same tactile sensation (sensation such as touch of an object) by the operator at almost the same pressure sensation at each position on the touch surface 11a. In other words, the amplitude, the phase, and the like are appropriately changed according to the position and location of the touch surface 11a so that substantially the same tactile sensation in which the pressure sense and the tactile sense are combined is obtained.

  Further, in step S304, the reference of the pressing load that presents the tactile sensation can be appropriately set according to the load characteristic when the push button switch to be expressed is pressed, for example. For example, this reference may be set to the same load as the touch sensor 11 reacts to the touch input (the touch input reaction of the touch sensor 11 and the timing to present the tactile sensation are set the same), or the touch sensor 11 A load higher than the load that reacts to the touch input may be set (a setting that delays the timing of presenting the tactile sensation than the response of the touch input of the touch sensor 11). For example, in the case where the input device according to the present embodiment is applied to a mobile terminal, it is preferable that the touch sensor 11 be equal to or more than a load that reacts to a touch input (timing to present a tactile sensation rather than a touch input response of the touch sensor 11). Set to slow down). In addition, this load setting can also be set freely by the user so that the elderly user can set it heavier (slower) and the user who frequently emails can set it lighter (faster). .

  Further, the tactile sensation presented in step S306 can be appropriately set by a drive signal applied to the piezoelectric element 12. For example, in the case of presenting a click tactile sensation that is felt as “cuckling” obtained when a push button switch used in a mobile terminal is pressed, for example, when the above reference load is applied, for example, 100 Hz to 200 Hz, Preferably, one cycle of a sine wave having a constant frequency of 170 Hz is applied to the piezoelectric element 12 as a drive signal, and the touch surface 11a is vibrated by about 15 μm with a reference pressing load applied. Accordingly, it is possible to present the operator with a real click feeling through the pressing object (pressing object) pressing the touch surface 11a of the touch sensor 11 and to recognize that the input operation is completed. Similarly, in the case of presenting a click tactile sensation that is harder than “kachi”, a sine wave signal or a rectangular wave signal of about 200 Hz to 500 Hz is applied for one cycle as a drive signal.

  In this way, pressure is stimulated until the load applied to the touch sensor 11 calculated based on the output of the piezoelectric element 12 satisfies a reference (for example, 1N) that provides tactile sensation. The element 12 is driven with a predetermined drive signal to vibrate the touch surface 11a to stimulate the sense of touch. As a result, a tactile sensation is presented to the operator to recognize that the input operation has been completed. Therefore, even if a button switch such as a push button switch (push-type button switch) is drawn on the upper part of the touch sensor, the operator can realistically feel the click feeling similar to the case where the touch button is operated on the touch sensor 11. The input operation can be performed while obtaining, so there is no sense of incongruity. Further, since the input operation can be performed in conjunction with the consciousness of “pressing” the touch sensor 11, an input error due to simple pressing can be prevented.

  In addition, when the reference pressing load for presenting the tactile sensation is set higher than the load that the touch sensor 11 reacts to touch input (the timing at which the tactile sensation is presented is slower than the touch input reaction of the touch sensor 11), touch The input position is determined in accordance with the touch operation on the surface 11 a, the display mode of the input object at the corresponding portion of the display unit 13 is changed, and then the touch surface 11 a detected based on the output of the piezoelectric element 12. When the pressing load on the head satisfies a criterion for presenting a tactile sensation, the piezoelectric element 12 is driven to present a tactile sensation, and the input position is determined and predetermined processing (for example, execution of a program corresponding to the object) Processing) can be executed. In this case, the operator can confirm the selection of the input object by changing the display mode of the input object displayed on the display unit 13, and the selection is performed by pressing the touch surface 11 a to present a click feeling. It can be recognized that the input object is determined (executed). Thereby, it is possible to prevent erroneous input by a so-called lost finger.

  When presenting the click sensation of the push button switch in this way, after the return to the load detection mode in step S307, even at the time of release, the three piezoelectric elements 12 when the pressing load falls below a predetermined reference. Is switched to the tactile sensation presentation mode, and the three piezoelectric elements 12 are driven by the same drive signal as when pressed to present the same click tactile sensation (in this case, release tactile sensation). In this way, it is possible to present a more realistic click tactile sensation that can be felt as “cut” when pressed and “click” when released. Of course, the release tactile sensation is not necessarily the same drive signal as the click tactile sensation.

  Here, the load standard for presenting the release tactile sensation can be set the same as the above-described load standard for presenting the click tactile sensation at the time of pressing, but preferably 50% to the load standard for presenting the click tactile sensation at the time of pressing. Set to 80% lower value. In this way, when the same position (input object) is continuously input (sequentially hit), the sequential input and the tactile sensation presentation timing match, and a realistic click tactile sensation without discomfort can be presented. In other words, by making the standard load that presents a tactile sensation at the time of release smaller than the standard load that presents a tactile sensation at the time of pressing, the reference load that presents a tactile sensation at the time of release is pressed. Occasionally, the operability during continuous input can be significantly improved by setting the load to be approximately 50% or more of the reference load that sometimes presents a tactile sensation. In addition, by making the reference load that presents a tactile sensation at the time of release approximately 80% or less of the reference load that presents a tactile sensation when pressed, it is possible to cope with minute load changes in the hold state during continuous input.

  The tactile sensation presented by the piezoelectric element 12 is not limited to the click tactile sensation, and various tactile sensations can be presented by changing the drive signal. For example, when presenting a soft tactile sensation that can be felt as “bull” or “buni”, a sine wave signal of about 200 Hz to 500 Hz is applied for two to three periods as a drive signal. Alternatively, in the case of presenting a tactile sensation that can be perceived as a vibration felt as “bull”, a sine wave signal of about 200 Hz to 500 Hz is applied as a drive signal for four cycles or more. It is preferable that the drive signal information presenting these various tactile sensations is stored in a storage unit (not shown) so that the user can appropriately set a drive signal presenting a desired tactile sensation.

  According to the input device according to the present embodiment, since the piezoelectric element 12 is shared as a load sensor that detects a pressing load on the touch surface 11a of the touch sensor 11 and an actuator that vibrates the touch surface 11a, the number of components is reduced. This can reduce costs. Moreover, since the number of parts can be reduced, the installation space for the parts can be reduced, and the apparatus can be miniaturized.

  In addition, this invention is not limited only to the said embodiment, Many deformation | transformation or a change is possible. For example, the number of piezoelectric elements 12 is not limited to three and can be any number. Also, the structure of the piezoelectric element can be a known structure such as a monomorph, a unimorph, a bimorph, a laminated type, or the like according to the area of the touch sensor 11, the vibration amplitude, or the like.

  The present invention can also be effectively applied to an input device that functions as a touch switch in which a touch sensor performs an on / off operation. Furthermore, the input device according to the present invention presents a tactile sensation sequentially with different standards (loads) in the middle of pressing against the touch sensor, and a tactile sensation of a multi-stage switch such as a two-stage switch (pressed and then pushed further). Can also be presented. Accordingly, for example, when applied to a release button of a camera, it is possible to present a tactile sensation between focus lock (1 step push) and release (2 step push). Further, when combined with the display unit, the display of the menu screen hierarchy and the like can be variously changed according to the number of push-in steps. Furthermore, when presenting the tactile sensation of the multi-stage switch as described above, it is possible to change the drive signal for vibrating the touch surface at each stage and present a different tactile sensation at each stage.

  Further, the input device according to the present invention drives the piezoelectric element when the pressing load detected based on the output of the piezoelectric element satisfies a criterion for presenting tactile sensation. Here, the case where the pressing load detected based on the output of the piezoelectric element satisfies the standard for presenting tactile sensation may be the time when the detected pressing load reaches a reference value for presenting tactile sensation. The detected pressing load may exceed a reference value that provides tactile sensation, or may be detected when a reference value that provides tactile sensation is detected based on the output of the piezoelectric element.

DESCRIPTION OF SYMBOLS 11 Touch sensor 11a Touch surface 12 Piezoelectric element 13 Display part 14 Control part 21 Case 22 Insulator 23 Upper cover 24 Insulator

Claims (2)

A touch sensor for detecting touch input;
A piezoelectric element attached to the touch sensor;
A pressing target that presses the touch surface when the pressing load on the touch surface of the touch sensor is detected based on an output signal of the piezoelectric element and the detected pressing load satisfies a criterion for presenting a tactile sensation A control unit for driving the piezoelectric element so as to present a tactile sensation with respect to
An input device comprising: A touch sensor for detecting touch input;
A method of controlling an input device comprising: a piezoelectric element attached to the touch sensor;
A pressing target that presses the touch surface when the pressing load on the touch surface of the touch sensor is detected based on an output signal of the piezoelectric element and the detected pressing load satisfies a criterion for presenting a tactile sensation Driving the piezoelectric element to present a tactile sensation to
A control method for an input device.

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