Touch panel apparatus and electronic apparatus providing tactile feedback to an operator

A touch panel apparatus is provided with a strain gauge sensor (16), a piezoelectric element (17), and a control unit (1). The strain gauge sensor (16) detects the pressing force to be applied to a touch panel (12) when a select-execute function key (18) is operated. The piezoelectric element (17) makes the touch panel (12) vibrate. The control unit (1) changes the function to be selected with the operation of the select-execute function key (18), in accordance with the pressing force detected by a pressing force detection unit (20), and when an arbitrary function is continued to be selected for a prescribed period of time (T0), the function that is continued to be selected is executed. The control unit also makes, each time the function is changed, the touch panel (12) vibrate with a first vibration pattern by controlling the piezoelectric element (17), and makes, when a function is to be executed, the touch panel (12) vibrate with a second vibration pattern that is different from the first vibration pattern by controlling the piezoelectric element (17).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. National Phase under 35. U.S.C. §371 of International Application PCT/JP2013/050694, filed Jan. 16, 2013, which claims priority to Japanese Patent Application No. 2012-014294, filed Jan. 26, 2012. The disclosures of the above-described applications are hereby incorporated by reference in their entirety. The International Application was published under PCT Article 21(2) in a language other than English.

TECHNICAL FIELD

The present invention relates to a touch panel apparatus with a touch panel being provided on a display unit, and more specifically to a touch panel apparatus having a function of providing tactile feedback to an operator by vibrating the touch panel and an electronic apparatus provided with the touch panel apparatus.

BACKGROUND ART

In recent years, for a touch panel apparatus with a touch panel being provided on a display unit, a technology called forced feedback that provides tactile feedback from an operation key being pressed to an operator has been proposed (see for example Patent Document 1). In Patent Document 1, a piezoelectric element is provided on the touch panel. In the technology disclosed in Patent Document 1, tactile feedback is provided to an operator by vibrating the touch panel as a result of contractive deformation of the piezoelectric element by applying voltage to the piezoelectric element in response to the operator's touch on an operation face of the touch panel.

A technology that detects a pressing force applied on an operation key by a pressure sensor for selection and execution of a particular function, as well as adjustment and change of properties of functions according to the pressing force thus detected has also been proposed (see for example Patent Document 2). In the technology disclosed in Patent Document 2, an operator is notified of a selected function or properties thereof by means of vibration generated every time the pressing force exceeds a preset threshold.

DISCLOSURE OF THE INVENTION

Problems to be Solved by the Invention

Also for a touch panel apparatus, selection and execution of a function according to a pressing force being applied have been considered. However, it is difficult to employ the technology of Patent Document 1 and the technology of Patent Document 2 simultaneously. In other words, in a case in which the technology of forced feedback of Patent Document 1 is employed, it is difficult for an operator to distinguish whether the vibration of the touch panel is for providing a touch sensation of the operation key to the operator or for notifying the operator of execution of a function.

The objective of the present invention is to provide a touch panel apparatus that allows an operator to distinguish between vibration for providing a touch sensation of the operation key to the operator and vibration for notifying the operator of execution of a function being selected.

Means for Solving the Problems

The touch panel apparatus according to the present invention is provided with a display unit, a touch panel, a pressing force detection unit, a vibration driving unit, and a control unit. The display unit displays the select-execute function key accepting selection and execution of a plurality of functions. The touch panel is disposed on a display face of the display unit and accepts an operation with respect to the select-execute function key. The pressing force detection unit detects a pressing force with respect to the touch panel upon operation of the select-execute function key. The vibration driving unit vibrates the touch panel. The display unit changes a function to be selected by the operation of the select-execute function key depending on the pressing force detected by the pressing force detection unit and, in a case in which an arbitrary function is continuously selected for a preset period of time, executes the continuously selected function. The control unit vibrates the touch panel in the first vibration pattern by controlling the vibration driving unit every time the function is changed, and vibrates the touch panel in a second vibration pattern that is different from the first vibration pattern by controlling the vibration driving unit when the function is executed.

Effects of the Invention

The present invention is configured to: change a function according to a pressing force of an operation of the select-execute function key; if a function is continuously selected for a preset period of time, execute the selected function; vibrate the touch panel in the first vibration pattern every time a function is changed; and vibrate the touch panel in the second vibration pattern that is different from the first vibration pattern by controlling a vibration driving means when a function is executed. As a result, the present invention can provide a tactile sensation of pressure of an operation key in the first vibration pattern, and, at a moment where the tactile sensation of pressure of an operation key is not required, notification of execution of a selected function in the second vibration pattern. Given this, the present invention provides an effect of allowing distinction between the tactile sensation of pressure of an operation key and vibration for notification of execution of a selected function.

EXPLANATION OF REFERENCE NUMERALS

PREFERRED MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention is described specifically with reference to the drawings. An image forming apparatus100provided with a touch panel apparatus10according to the present embodiment is a copy machine. With reference toFIG. 1, the image forming apparatus100includes an original reading unit120, an original feeding unit130, and a recording unit140. The original reading unit120is disposed above the recording unit140. The original feeding unit130is disposed above the original reading unit120. The image forming apparatus100is described herein as a copy machine; however, the image forming apparatus100also includes a scanner, a multifunction peripheral, and the like.

The touch panel apparatus10that makes settings and an operation instruction of the image forming apparatus100is provided on a front face side (front side inFIG. 1) of the image forming apparatus100. As shown inFIGS. 2 and 3, the touch panel apparatus10includes a display unit11and a touch panel12. The display unit11displays various operation keys that accept an operation input. The touch panel12is provided on a display face of the display unit11. The touch panel12accepts an operation with respect to an operation key displayed on the display unit11by detecting an input by pressing with an operator's fingertip, a stylus pen, or the like, and outputting a signal corresponding to a position where the input is detected. For example, a liquid crystal display panel can be used as the display unit11. For example, a touch panel of a resistance film type or a capacitance type can be used as the touch panel12. In the present embodiment, a touch panel having a structure that is bent (strained) to a slight degree according to the pressing force of pressing is employed.

As shown inFIG. 3, the display unit11is arranged and supported in a housing13. The touch panel12is supported on the display unit11through an elastic member14. An upper cover for covering the display unit11and a peripheral region of the touch panel12is provided in the housing13. An elastic member15is provided between the upper cover and the touch panel12. A strain gauge sensor16is adhered to a surface of the touch panel12in a region covered by the upper cover of the housing13. A belt-like piezoelectric element17is adhered to a back face of the touch panel12. The strain gauge sensor16functions as the pressing force detection unit that detects a pressing force applied to the touch panel12. The piezoelectric element17functions as the vibration driving unit that vibrates the touch panel12.

As shown inFIG. 2, the touch panel apparatus10includes a permanent operation key, the select-execute function key18, and a function-classified operation key display area19. The permanent operation key includes numerical keys, a reset key, a stop key, a start key, and the like. The numerical keys are keys allowing input of a numerical value such as the number of copies. The reset key is a key allowing input of an instruction for initializing setting information. The stop key is a key for stopping a copy operation or for clearing a numerical value being input. The start key is a key allowing input of an output instruction for starting a printing operation. The select-execute function key18switches between function modes according to a pressing force applied to the touch panel12. A function-classified operation key corresponding to the function mode switched by the select-execute function key18is displayed in the function-classified operation key display area19.

As shown inFIG. 1, the original reading unit120includes a scanner121, a platen glass122, and an original reading slit123. The scanner121is composed of an exposure lamp, a CCD (Charge Coupled Device) sensor and the like, and movable along a conveying direction of an original MS in the original feeding unit130. The platen glass122is a platen composed of a transparent member such as glass. The original reading slit123includes a slit that extends in a direction orthogonal to the conveying direction of the original MS in the original feeding unit130.

In a case of reading the original MS placed on the platen glass122, the scanner121is moved to a position facing the platen glass122. The scanner121reads the original MS by scanning the original MS placed on the platen glass122, to thereby obtain image data. The scanner121outputs the image data thus obtained to the recording unit140. On the other hand, in a case of reading the original MS being fed by the original feeding unit130, the scanner121is moved to a position facing the original reading slit123. The scanner121reads the original MS through the original reading slit123, in sync with the conveying operation of the original MS by the original feeding unit130, to thereby obtain image data. The scanner121outputs the image data thus obtained to the recording unit140.

The original feeding unit130includes an original mounting unit131, an original discharge portion132, and an original conveying mechanism133. The original conveying mechanism133feeds the original MS placed on the original mounting unit131sheet by sheet. The original MS being fed by the original conveying mechanism133is conveyed to a position facing the original reading slit123on the original reading unit120, and then discharged to the original discharge portion132. A front side of the original feeding unit130can be lifted upward. By lifting the front side of the original feeding unit130, an upper face of the platen glass122can be exposed.

The recording unit140includes, in addition to an image forming unit150, a paper feeding unit160, a paper path170, a conveyance roller181, a discharging roller182, and a discharging tray190.

The paper feeding unit160includes a plurality of paper feeding cassettes161ato161dand a paper feeding roller162. Printing paper P is housed in the paper feeding cassettes161ato161d. The paper feeding roller162feeds the printing paper P sheet by sheet from the paper feeding cassettes161ato161dto the paper path170. The paper feeding roller162, the conveyance roller181, and the discharging roller182function as the conveying unit. The printing paper P is conveyed by the conveying unit. The printing paper P that is fed by the paper feeding roller162to the paper path170is conveyed by the conveyance roller181to the image forming unit150. The printing paper P with the image data being recorded by the image forming unit150is discharged to the outside of the apparatus by the discharging roller182. The printing paper P with the image data being recorded is guided by the discharging roller182and discharged to the discharging tray190.

The image forming unit150includes a photosensitive drum151, a charging unit152, an exposure unit153, a developing unit154, a transfer unit155, a cleaning unit156, and a fixing unit157. The exposure unit153is an optical unit provided with a laser device, a mirror, and the like. The exposure unit153outputs a laser beam based on the image data and exposes a surface of the photosensitive drum151. The surface of the photosensitive drum151is electrically charged by the charging unit152prior to exposure. Therefore, an electrostatic latent image is formed on the surface of the photosensitive drum151being exposed. The developing unit154is a developing unit that develops the electrostatic latent image formed on the surface of the photosensitive drum151using a toner. A toner image based on the electrostatic latent image is formed on the photosensitive drum151by the developing unit154. The transfer unit155transfers the toner image formed on the photosensitive drum151by the developing unit154onto the printing paper P. The fixing unit157fixes the toner image onto the printing paper P by heating the printing paper P onto which the toner image has been transferred by the transfer unit155.

Next, a control system of the image forming apparatus100is described with reference toFIG. 4. In the image forming apparatus100, the touch panel apparatus10, the original reading unit120, the original feeding unit130, the image forming unit150, and the conveyance unit (the paper feeding roller162, the conveyance roller181, and the discharging roller182) are connected to the control unit1and operation thereof is controlled by the control unit1. In addition, a storage unit2and an image processing unit3are also connected to the control unit1.

The control unit1is an image processing unit such as a microcomputer provided with ROM (Read Only Memory), RAM (Random Access Memory), and the like. A control program for control of operation of the image forming apparatus100is stored in the ROM. The control unit1reads the control program stored in the ROM and develops the control program to the RAM, to thereby control the entire apparatus according to predetermined instruction information and the like being input from the touch panel apparatus10.

The storage unit2is composed of semiconductor memory, a HDD (Hard Disk Drive), or the like. The image data obtained by reading the original by the original reading unit120is stored in the storage unit2.

The image processing unit3performs predetermined image processes with respect to the image data. For example, a zooming process, and image improvement processes such as density adjustment, tone adjustment, and the like are performed by the image processing unit3.

As shown inFIG. 4, the touch panel apparatus10includes a pressing force detection unit20and a vibration driving unit21. The pressing force detection unit20detects a pressing force applied to the touch panel12based on an output (an average output value of the four strain gauge sensors16) from the strain gauge sensor16and outputs the pressing force thus detected to the control unit1. Detection of the pressing force by the pressing force detection unit20is always in operation. The control unit1monitors temporal change of the pressing force applied to the touch panel12. The vibration driving unit21applies a voltage signal to the piezoelectric element17based on control by the control unit1, to thereby vibrate the touch panel12.

Next, operation of the touch panel apparatus10according to the present embodiment is described in detail with reference toFIGS. 5A to 7. The image forming apparatus100is configured to operate in four function modes: “Copy”; “Send/Fax”, “Document Box”, and “Status Check”. The function mode is switched by the select-execute function key18. As shown inFIG. 2, the permanent operation keys such as the numerical keys, the reset key, the stop key, the start key, and the like that are used in any of the function modes, are assigned to the touch panel apparatus10. The function-classified operation key display area19, in which function-classified operation keys corresponding to the function mode are displayed, is also assigned to the touch panel apparatus10. Since the permanent operation keys are used more often than the function-classified operation keys, an operation sensation is required. For this reason, in many cases, physical keys are used for the permanent operation keys. On the contrary, in the present embodiment, the permanent operation keys are assigned to the touch panel12. In a case of accepting an operation to a region on the touch panel12in which the permanent operation keys are assigned, the control unit1controls the vibration driving unit21to vibrate the touch panel12. The tactile sensation from the vibration of the touch panel12is fed back to the operator. In a case of vibration in response to an operation to the region of the permanent operation keys, the vibration driving unit21applies a voltage signal of 1 pulse to the piezoelectric element17. As a result, as shown inFIG. 5A, the touch panel12vibrates in such a way that the operation face side thereof is elevated once (hereinafter referred to as a first vibration pattern). The operator can thus receive a tactile sensation as if a physical key is being used. In the present embodiment, in a case of accepting an operation to the region of the function-classified operation keys displayed in the function-classified operation key display area19, the control unit1does not vibrate the touch panel12. Operation sensation is thus differentiated between the permanent operation keys and the function-classified operation keys. Alternatively, in a case of accepting an operation to the region of the function-classified operation keys, the touch panel12can vibrate in a vibration pattern that is different from the first vibration pattern in response to an operation to the permanent operation keys.

In a case of accepting an operation to the region of the permanent function keys, the touch panel12is vibrated in the first vibration pattern upon acceptance of the operation. On the other hand, in a case of accepting an operation to the region of the select-execute function key18, the touch panel12is vibrated in the first vibration pattern every time the function mode is changed. More specifically, every time the pressing force exceeds a preset threshold, in other words every time the function mode is changed by the operation to the select-execute function key18, the touch panel12is vibrated in the first vibration pattern. In the present embodiment, as shown inFIG. 6, four thresholds P1 to P4 are defined for the four function modes. The function modes are assigned to the pressing force of the operation to the select-execute function key18(in other words, a pressing force accepted by the region of the touch panel12in which the select-execute function key18is assigned). In the present embodiment, a range of the accepted pressing force between the thresholds P0 and P1 is assigned to “Copy”, a range between the thresholds P1 and P2 is assigned to “Send/Fax”, a range between the thresholds P2 and P3 is assigned to “Document Box”, and a range between the thresholds P3 and P4 is assigned to “Status Check”.

A selection operation of the function mode is described with reference toFIG. 6. When an operator presses the select-execute function key18, the operation is accepted as the pressing force reaches the threshold P0. Positional information of the select-execute function key18is notified from the touch panel12to the control unit1. The control unit1controls the vibration driving unit21to vibrate the touch panel12in the first vibration pattern. Here, the control unit1monitors the pressing force detected by the pressing force detection unit20. Given this, the control unit1controls the vibration driving unit21every time the pressing force exceeds the thresholds P0, P1, P2, and P3 to vibrate the touch panel12in the first vibration pattern. As a result, the operator can understand the function mode being selected, based on the number of vibrations in the first vibration pattern. More specifically, the operator can understand that, after pressing the select-execute function key18: “Copy” is selected if the touch panel12vibrates once in the first vibration pattern; “Send/Fax” is selected if the touch panel12vibrates twice; “Document Box” is selected if the touch panel12vibrates three times; and “Status Check” is selected if the touch panel12vibrates four times. As described above, the touch panel12vibrates in the first vibration pattern every time the function mode is selected, and the operator can receive a tactile sensation as if using a multi-stage switch.

Next, a function execution operation that executes switching of the function modes is described with reference toFIG. 7. The control unit1monitors the pressing force detected by the pressing force detection unit20. Given this, in a case in which the same function mode is continuously selected for a preset period of time T0, the control unit1executes switching to the function mode. For example, as shown by a solid line inFIG. 7, in a case in which the preset period of time T0 elapses while the operator presses the select-execute function key18and maintains the pressing force between the threshold P2 and P3 (while “Document Box” is selected), the control unit1executes switching to the function mode “Document Box”. In addition, when the function mode is switched, the control unit1vibrates the touch panel12in the second vibration pattern that is different from the first vibration pattern by controlling the vibration driving unit21. The control unit1thus notifies the operator of the switching of the function mode. A plurality of short-period vibrations is used as the second vibration pattern. More specifically, the vibration driving unit21applies a voltage signal of multiple pulses that is weaker than that of the first vibration pattern to the piezoelectric element17. As a result, as shown inFIG. 5B, the touch panel12vibrates in such a way that the operation face side thereof is elevated successively for a plurality of times. Here, a vibration period T2 of one vibration in the second vibration pattern is shorter than a vibration period T1 of the first vibration pattern. As a result, from the vibration in response to switching of the function modes, the operator can perceive a tactile sensation that is different from that of the operation of the select-execute function key18.

A range of the pressing force of pressure of the select-execute function key18above the threshold P4 is assigned to “Reset”. In other words, a range beyond the range of the pressing force to which selections of the function modes are assigned is assigned to “Reset”, which cancels switching of the function mode. Given this, as shown by a dashed-dotted line inFIG. 7, if the select-execute function key18is further pressed after execution of switching to the function mode “Document Box” and the pressing force exceeds the threshold P4, the control unit1cancels the switching to the function mode “Document Box” and resets the function mode to an initial function mode (for example, “Copy”). As a result, even in a case in which the function mode is erroneously switched to an undesired function mode, the operator can easily cancel the switching of the function mode by further pressing the select-execute function key18.

In the present embodiment, switching of the function mode is performed by an operation of the select-execute function key18. However, functions to be selected and executed by an operation of the select-execute function key18are not limited. For example, the select-execute function key18can also be used as a key for instructing switching to a sleep mode. In such a case, a range of a weaker pressing force on the select-execute function key18can be assigned to light sleep and a range of a stronger pressing force can be assigned to deep sleep.

As described above, the present embodiment includes the display unit11, the touch panel12, the pressing force detection unit20(the strain gauge sensors16), the vibration driving unit21(the piezoelectric element17), and the control unit1. The display unit11displays the select-execute function key18accepting selection and execution of a plurality of functions. The touch panel is disposed on a display face of the display unit11and accepts an operation with respect to the select-execute function key18. The pressing force detection unit20detects a pressing force with respect to the touch panel12upon operation of the select-execute function key18. The vibration driving unit21vibrates the touch panel12. The display unit11changes a function to be selected by the operation of the select-execute function key18depending on the pressing force detected by the pressing force detection unit20and, in a case in which an arbitrary function is continuously selected for a preset period of time T0, executes the continuously selected function. The control unit1vibrates the touch panel12in the first vibration pattern by controlling the vibration driving unit21every time the function is changed, and vibrates the touch panel12in a second vibration pattern that is different from the first vibration pattern by controlling the vibration driving unit21when the function is executed. Since the present embodiment can thus notify the operator of execution of a selected function at a moment where the tactile sensation of pressure of an operation key is not required, an effect of allowing the operator to distinguish between the vibration for providing a tactile sensation of pressure of the operation key and the vibration for notifying execution of the selected operation can be provided.

In addition, in the present embodiment, the vibration driving unit21, in the first vibration pattern, vibrates the touch panel12in such a way that an operation face side of the touch panel12is elevated once, and, in the second vibration pattern, vibrates the touch panel in such a way that the operation face side of the touch panel12is elevated for a plurality of times. As a result, the present embodiment provides an effect of providing the tactile sensation of pressure of an operation key to the operator through the first vibration pattern, and notifying the operator of execution of a selected function through the second vibration pattern.

Furthermore, in the present embodiment, in a case in which the pressing force detected by the pressing force detection unit20exceeds a range to which the plurality of functions is assigned, the control unit1cancels execution of the plurality of functions. As a result, even in a case in which an undesired function is executed, the operator can easily cancel the execution of the function.

It should be noted that, in the present Specification, the touch panel apparatus10according to the present invention is applied as a constituent feature of the image forming apparatus100and performs setting and operation instructions for the image forming apparatus100. However, the use of the touch panel apparatus10according to the present invention is not limited to the image forming apparatus100. For example, the present invention can be widely applied to various electronic devices such as a mobile phone, a smart phone, a tablet terminal, and the like. In addition, the present invention is not limited to the above described embodiment and can be modified as appropriate within a scope of technical idea of the present invention. Moreover, the number, positions, shapes and the like of the above described constituent features are not limited to the embodiment, and the number, positions, shapes and the like that are preferable for practicing the present invention can be selected. It should be noted that, in the drawings, the same constituent feature is referred by the same reference symbol.