Display input device, image forming apparatus including the display input device, and method of controlling the display input device

A display input device includes a display portion for displaying screens, a touch panel portion for detecting a touch position, a recognition portion for recognizing the touch position based on an output of the touch panel portion, a plurality of piezoelectric elements disposed not to be visually recognized from outside, to form a plurality of piezoelectric element pairs each of which includes the elements opposed to each other in a short side direction of the touch panel portion, and a drive portion for supplying a drive signal having a predetermined voltage waveform to the piezoelectric elements one or more times so as to vibrate the piezoelectric elements and the touch panel portion, and so as to start to supply the drive signal to the piezoelectric element pairs at different timings.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from the corresponding Japanese Patent Application No. 2013-069909 filed Mar. 28, 2013, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

The present disclosure relates to a display input device including a display portion and a touch panel portion, a method of controlling the display input device, and an image forming apparatus including the display input device.

In recent years, equipment such as a multifunction peripheral, a copier, or a printer is equipped with an operation panel including a display portion and a touch panel portion. Using the touch panel portion, a touch position corresponding to a key or a button displayed on the display portion is recognized. A touch operation is accepted as an input of selecting a key or a button of a position corresponding to the touch position. When the input is accepted, a display on the display portion is changed (for example, the color of the button is changed). However, there is a case where the visual change is hard to recognize (particularly for a user having visual impairment). Therefore, in order to recognize that the touch is done (that the input of pressing the button is accepted) by the sense of touch, the touch panel portion may be vibrated.

There is known the following technique of vibrating the touch panel portion. Specifically, there is known an information display device including an information display surface, a transparent or translucent operation portion with a predetermined operation surface disposed on the information display surface, bidirectional functional means combined to the operation portion to be capable of converting between a mechanical action and an electric signal in a bidirectional manner, operation signal fetching means for fetching an electric signal generated from the bidirectional functional means by an operation force given to the operation surface as an operation signal, and drive control means configured to respond to the operation signal so as to send out an electric drive signal to the bidirectional functional means. By the drive signal, a mechanical reaction (vibration) generated in the bidirectional functional means is transmitted to the operation surface. With this structure, the operation surface is vibrated so that the user is provided with secure operation feeling.

As described above, by vibrating the touch panel portion, it is possible to recognize that the operation is accepted by the sense of touch.

In a cellular phone or the like, in order to vibrate the touch panel portion or a case, a vibration motor (for example, a motor with an eccentric weight attached to a rotor) may be conventionally used. However, in the case where the vibration motor is used, the vibration lasts for a relatively long period so that the operation feeling is deteriorated.

Therefore, a piezoelectric element may be used for vibrating (deforming) the touch panel portion. Utilizing characteristics of the piezoelectric element that deforms when a voltage is supplied, a voltage is supplied to the piezoelectric element as a pulse (as an impulse), for example, so as to vibrate the touch panel portion instantaneously (the vibration period of the touch panel portion is set to be shorter than in the case where the vibration motor is used). In this way, the user can be provided with operation feeling (click feeling) like that when a button or a key is pressed.

However, the display portion and the touch panel portion of the operation panel of the image forming apparatus such as the multifunction peripheral are much larger than those of the cellular phone. Therefore, in order to vibrate the touch panel portion of the image forming apparatus by the piezoelectric element, it is necessary to dispose a plurality of piezoelectric elements so that the user can be provided with operation feeling (click feeling) like that when a button or a key is pressed (so that the touch panel portion is sufficiently vibrated). For instance, the plurality of piezoelectric elements may be disposed along a long side direction of the touch panel portion or the display portion.

Here, when all the piezoelectric elements are simultaneously vibrated (when the piezoelectric elements are simultaneously deformed), vibrations of the piezoelectric elements may interfere with each other (cancel each other), and hence there may be generated a part with no vibration or a part with attenuated vibration in the touch panel portion. For instance, in a part sandwiched between the piezoelectric elements or in a part close to the piezoelectric element, vibration amount (deformation amount of the touch panel portion) is reduced. In this way, when a plurality of piezoelectric elements are used for vibrating the touch panel portion, there is a problem that the touch panel portion cannot be vibrated so as to provide the user with operation feeling (click feeling) like that when a button or a key is pressed.

Here, the technique described above is not a technique related to solution of the problem that the touch panel portion cannot be vibrated so as to provide click feeling when all the piezoelectric elements are simultaneously vibrated. Therefore, the technique described above cannot solve the above-mentioned problem.

SUMMARY OF THE INVENTION

An image forming apparatus according to a first aspect of the present disclosure includes a display portion, a touch panel portion, a recognition portion, a plurality of piezoelectric elements, and a drive portion. The display portion displays screens for operation and setting. The touch panel portion is disposed on a top surface of the display portion so as to detect a touched position. The recognition portion recognizes the touched position on the touch panel portion based on an output of the touch panel portion. The plurality of piezoelectric elements are disposed adjacent to a region that is not visually recognized from outside in the touch panel portion, and are disposed along a long side direction of the touch panel portion so as to be opposed to each other in a short side direction of the touch panel portion. There are formed a plurality of piezoelectric elements pairs, each of which includes a pair of piezoelectric elements opposed to each other in the short side direction of the touch panel portion. The drive portion supplies a drive signal having a predetermined voltage waveform to the piezoelectric elements one or more times so as to vibrate the piezoelectric elements and the touch panel portion, and does not simultaneously start to apply the drive signal to all the piezoelectric element pairs.

Further features and advantages of the present disclosure will become apparent from the description of embodiments given below.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Now, an embodiment of the present disclosure is described with reference toFIGS. 1 to 10. In the following description, a multifunction peripheral100(corresponding to the image forming apparatus) including an operation panel1(corresponding to the display input device) is exemplified. Further, the embodiment is described with reference toFIGS. 1 to 8. In addition, a variation is described with reference toFIGS. 9 and 10. However, elements such as a structure and a layout described in the embodiment are merely examples and should not be interpreted to limit the scope of the disclosure.

(General Outline of Image Forming Apparatus)

Next, with reference toFIG. 1, general outline of the multifunction peripheral100according to the embodiment is described.FIG. 1is a schematic front cross-sectional view illustrating an example of the multifunction peripheral100.

First, as illustrated inFIG. 1, on a front face of the multifunction peripheral100, there is disposed the operation panel1as illustrated by a broken line, for performing various settings and inputs of the multifunction peripheral100(details are described later). Further, an image reader2aand a document feeder2bare disposed at the upper part. In addition, the multifunction peripheral100includes a paper sheet feeder3a, a transport portion3b, an image forming portion4a, and a fixing portion4b, which are disposed in a main body.

The document feeder2bfeeds document sheets one by one from a document tray21in an automatic and continuous manner to a reading position (contact glass22for feed reading). In addition, the document feeder2bis attached to the image reader2ain an openable and closable manner upward and downward with a pivot axis at rear side of the paper plane ofFIG. 1, so as to work as a cover for pressing the contact glass (the contact glass22for feed reading and a contact glass23for place reading) of the image reader2afrom above.

The image reader2areads a document sheet passing through the contact glass22for feed reading or a document sheet placed on the contact glass23for place reading, so as to obtain image data of the document sheet. Note that the image reader2aof this embodiment can read both a color document and a black and white document. The multifunction peripheral100can print based on the image data obtained by reading (as a copy function).

The paper sheet feeder3astores a plurality of paper sheets and feeds the sheets one by one to the transport portion3b. The transport portion3bis a path for transporting the paper sheet fed from the paper sheet feeder3a. Note that the image forming portion4a, the fixing portion4b, and the like are disposed in the paper sheet transport path.

The image forming portion4aforms a toner image based on image data and transfers the toner image onto the transported paper sheet. The fixing portion4bfixes the toner image transferred onto the paper sheet. The paper sheet with the fixed toner image is discharged to a discharge tray37. In this way, image formation (printing) is performed when a copy function or a printer function is used.

Next, with reference toFIG. 2, an example of the operation panel1according to the embodiment is described.FIG. 2is a plan view illustrating an example of the operation panel1.

As illustrated inFIG. 1, the operation panel1is disposed on the upper part of the front face of the multifunction peripheral100. The operation panel1includes a display portion5for displaying menus and keys for settings and operation instructions of the multifunction peripheral100, and various images and screens for status messages and setting of the multifunction peripheral100. For instance, the display portion5is a liquid crystal display panel, an organic EL display panel, or the like.

Further, on the top surface of the display portion5, there is disposed a touch panel portion6for detecting a touched position. The touch panel portion6detects a position (coordinates) of a part touched by a user on the display portion5. Note that various types such as a resistor film type, a surface acoustic wave type, an infrared type, and a capacitive type can be used as the touch panel portion6without limiting to a particular type.

Detected coordinates using the touch panel portion6are compared with positions or coordinates of various keys displayed on the display portion5, so as to recognize a key intended to touch and press on the touch panel portion6(a key just below the touch position) among keys displayed on the display portion5. Then, the key pressed and selected by the user is specified, and the input is accepted. Thus, various settings and operation instructions in various functions such as copying and transmission of the multifunction peripheral100can be performed.

In addition, on the operation panel1, there are disposed hardware keys such as a start key11for instructing to start a job such as copying after various setting, a ten-key portion12for numerical input, and a function selection key group13for selecting a function to be used. In this way, the operation panel1is equipped with the touch panel portion6and the various hardware keys. The touch panel portion6and the various hardware keys work as portions for performing various settings and mode selections, and the like in each function of the multifunction peripheral100.

(Hardware Structure of Multifunction Peripheral100and the Like)

Next, with reference toFIG. 3, an example of a hardware structure of the multifunction peripheral100according to the embodiment is described.FIG. 3is a block diagram of an example of the hardware structure of the multifunction peripheral100.

First, in a main body of the multifunction peripheral100, there is disposed a control portion100a. The control portion100ais connected, for example, to the operation panel1, the image reader2a, the document feeder2b, the paper sheet feeder3a, the transport portion3b, the image forming portion4a, the fixing portion4b, and the like, and controls them.

The control portion100aincludes elements such as a CPU100band an ASIC100cthat is a dedicated circuit. CPU100band ASIC100cperform a process in the multifunction peripheral100. The CPU100bperforms operations and the like based on a control program that is stored in a storage device100dand is loaded, so as to control individual portions of the multifunction peripheral100. Note that it is possible to dispose a plurality of the control portions for respectively performing controls of functions such as general control, main control for image processing, engine control for image formation and turning on and off motors and the like for rotating various rollers so as to control printing, and the like. In this description, there is described the case where these control portions are integrated as the single control portion100a.

The storage device100dis connected to the control portion100a. The storage device100dis constituted by combining a ROM, a RAM, an HDD, and the like. The storage device100dcan store programs for controlling the multifunction peripheral100, and various data including data for control, set data, image data of the document sheets read by the image reader2a, and the like.

Further, the control portion100ais connected to a communication portion100eincluding various connectors, sockets, a FAX modem, and the like. The communication portion100eis connected to a plurality of external computers200(for example, personal computers or servers), and FAX devices300on the other end (only each one of them is illustrated inFIG. 3for convenience sake), via a network, a public line, and the like. For instance, the image data obtained by the image reader2acan be stored in the storage device100dor can be transmitted to the external computer200or to the FAX device300on the other end (scanner function and FAX function). In addition, it is possible to perform printing based on image data transmitted from the external computer200or the FAX device300on the other end or image data input to the multifunction peripheral100(printer function and FAX function).

In addition, the control portion100arecognizes an input to the operation panel1and controls the multifunction peripheral100so that copy or the like is performed in accordance with setting performed by the user. For instance, the paper sheet feeder3ato be used is specified and copy job is set by the operation panel1, the control portion100acontrols the specified paper sheet feeder3ato feed a paper sheet. In addition, the control portion100acontrols the communication portion100eto transmit the image data to a transmission destination specified by the operation panel1.

In addition, for example, the control portion100aincludes an image processing portion100fconfigured to perform image processing on the image data obtained by reading the document sheet by the image reader2aand the image data input to the multifunction peripheral100via the communication portion100e. The image data processed by the image processing portion100fis used for forming the toner image, for example, or is transmitted to the communication portion100eand is sent out externally.

The operation panel1of this embodiment includes a display control portion10(corresponding to the recognition portion), a memory14(corresponding to a storage portion), a driver circuit15, the display portion5, and the touch panel portion6. The display control portion10includes a circuit such as a CPU10aand an IC. The display control portion10controls a display on the display portion5and receives an output of the touch panel portion6so as to specify coordinates of a position pressed on the display portion5. Data such as a table indicating correspondence between the output of the touch panel portion6and the coordinates are stored in the memory14. The display control portion10compares coordinates of the pressed position with image data of each setting screen so as to recognize the touched position on the touch panel portion6, and hence specifies and recognizes a selected (pressed) key on the setting screen.

Specifically, in order to select a set item of each function and to set a set value of the multifunction peripheral100, it is repeated to touch the touch panel portion6so as to select a key displayed on the display portion5from a top layer display on the display portion5. Further, for each selection of key, the display control portion10changes the display on the display portion5. Further, the user finally sets a set value of the function to be selected and set. The display control portion10recognizes that this function is selected and that the setting is performed, and transmits contents thereof to the control portion100aof the main body. Thus, the control portion100acontrols the individual portions such as the image forming portion4ato perform operations on which the function selected and set by the operation panel1is reflected. Then, the user's intension is reflected on the printing, transmission, and the like (for example, density setting, enlargement or reduction, and the like).

Further, image data of screens and images displayed on the display portion5are stored in the memory14in the operation panel1. Therefore, the display control portion10reads out image data of the screen to be displayed next from the memory14every time when a key in a selection screen of a set item or each setting screen is operated. Note that image data of screens and images to be displayed on the display portion5may be stored in the storage device100dof the main body side. In this case, the operation panel1receives the image data for performing the display on the display portion5from the storage device100dvia the control portion100a.

The display control portion10instructs the driver circuit15that actually controls a display on the liquid crystal screen. Note that it is possible that a structure (CPU100bor the storage device100d) of the control portion100aperforms the functions of the display control portion10and the memory14without disposing the display control portion10and the memory14in the operation panel1.

Next, with reference toFIG. 4, a display on the operation panel1and a part to be touched for input are described.FIG. 4is an exploded perspective view illustrating a structure of the display portion5, the touch panel portion6, and the like.

As illustrated inFIG. 4, the operation panel1includes the touch panel portion6and a plurality of rectangular (band-like) piezoelectric elements7. The plurality of piezoelectric elements7are attached to contact with the touch panel portion6(on a back side of the touch panel portion6). Each piezoelectric element7is made of a material having a piezoelectric effect such as lead zirconate titanate. In addition, a lamination type can be used for each piezoelectric element7.

In addition, the display portion5is disposed on the back side of the touch panel portion6at a predetermined space with the touch panel portion6. The touch panel portion6transmits the screen and the image displayed on the display portion5. For instance, a transparent plastic plate or glass plate is used for the touch panel portion6. In addition, the piezoelectric elements7are attached to the surface of the lower side (display portion5side) of the touch panel portion6. For instance, the piezoelectric elements7are attached to the touch panel portion6with adhesive or double sided adhesive tape.

Further, a case16is disposed to cover the touch panel portion6, the piezoelectric element7, and the display portion5. A seal member17is sandwiched between the case16and the touch panel portion6for preventing dust and waste from entering. The seal member17has a rectangular loop shape and a size along a peripheral upper surface of the touch panel portion6so as to contact with the inner surface of the case16. Further, it is preferred that the touch panel portion6of this embodiment be made of low repulsion material because it is vibrated (deformed) by the piezoelectric elements7.

In addition, a part of the case16is provided with an opening16a(operation window). The opening16ahas a rectangular shape. A part of the touch panel portion6is exposed externally in the rectangular region corresponding to the opening16a. This exposed part can be visually recognized by the user (from the outside) to be a region that the user can touch (touchable region6a). The user touches a display position of a key or the like on the display portion5through the touchable region6a, and hence can set a desired function and set item. On the other hand, the piezoelectric elements7are attached to a region of the touch panel portion6that is hidden by the case16so as not to be visually recognized and cannot be touched by the user (outer peripheral region6b).

Next, with reference toFIG. 5, an example of a layout of the piezoelectric elements7in the operation panel1according to the embodiment is described.FIG. 5is an explanatory diagram illustrating an example of a layout of the piezoelectric elements7with respect to the touch panel portion6.

First, as illustrated inFIG. 5, the operation panel1of this embodiment is equipped with the six piezoelectric elements7. A plurality of the piezoelectric elements7are disposed along the long side direction of the touch panel portion6. Specifically, three piezoelectric elements7are disposed along each of the long sides of the touch panel portion6.

Further, the piezoelectric elements7are disposed to be opposed to each other in the short side direction of the touch panel portion6. Further, a pair of piezoelectric elements7opposed to each other in the short side direction of the touch panel portion6form a piezoelectric element pair8(three pairs are disposed in this embodiment). Note that when four piezoelectric elements7are disposed along the each long side direction of the touch panel portion6, there are four piezoelectric element pairs8(it is possible to dispose four or more piezoelectric element pairs8).

Here, in the following description, a piezoelectric element pair8at the left end of the touch panel portion6is referred to as a “first piezoelectric element pair81”. In addition, a piezoelectric element pair8at the middle of the touch panel portion6is referred to as a “second piezoelectric element pair82”. In addition, a piezoelectric element pair8at the right end of the touch panel portion6is referred to as a “third piezoelectric element pair83”.

A drive portion9is disposed in the operation panel1. The drive portion9supplies a drive signal S2having a predetermined voltage waveform to the piezoelectric elements7and vibrates the piezoelectric elements7, so as to vibrate the touch panel portion6contacting with the piezoelectric elements7. The drive portion9includes a plurality of drive circuits90(drive ICs), and one drive circuit90is disposed for each of the piezoelectric element pairs8.

Specifically, a first drive circuit901is disposed for the first piezoelectric element pair81. The first drive circuit901supplies the drive signal S2to the piezoelectric elements7included in the first piezoelectric element pair81simultaneously (or not simultaneously). In addition, a second drive circuit902is disposed for the second piezoelectric element pair82. The second drive circuit902supplies the drive signal S2to the piezoelectric elements7included in the second piezoelectric element pair82simultaneously (or not simultaneously). In addition, a third drive circuit903is disposed for the third piezoelectric element pair83. The third drive circuit903supplies the drive signal S2to the piezoelectric elements7included in the third piezoelectric element pair83simultaneously (or not simultaneously).

(Structure for Vibrating Touch Panel Portion6)

Next, with reference toFIG. 6, an example of a structure for vibrating the touch panel portion6of the operation panel1according to the embodiment is described.FIG. 6is a block diagram illustrating an example of a structure for vibrating the touch panel portion6of the operation panel1according to the embodiment.

In the operation panel1of this embodiment, the display control portion10recognizes that the touch panel portion6is touched based on the output of the touch panel portion6. Then, when recognizing the touch input to the touch panel portion6(when recognizing an operation to a displayed key), the display control portion10supplies the drive signal S2to the plurality of piezoelectric element pairs8, so that the touch panel portion6is vibrated (deformed). This vibration of the touch panel portion6can provide the user with operation feeling (click feeling) like that when a button or a key is pressed.

Therefore, with reference toFIG. 6, a structure for vibrating the touch panel portion6is described. Each of the first drive circuit901, the second drive circuit902, and the third drive circuit903is provided with a voltage generation circuit91and a switch portion92. Because the individual drive circuits90have the same structure, the voltage generation circuits91and the switch portions92included in the drive circuits90are denoted by the same numerals, for convenience sake.

Each voltage generation circuit91generates a voltage to be supplied to each piezoelectric element7. Each voltage generation circuit91is supplied with a voltage Vin from a power supply portion100g(seeFIG. 3) that is connected to a commercial power source and generates a voltage necessary for the multifunction peripheral. Then, the voltage generation circuit91steps up the voltage Vin and generates a voltage for applying an electric field so as to deform the piezoelectric element7.

In this embodiment, each piezoelectric element7is supplied with a voltage having a pulse waveform one or more times as the drive signal S2(having an amplitude of a few tens volts, for example). In other words, when the touch panel portion6is vibrated, the drive circuits90(the first drive circuit901, the second drive circuit902, and the third drive circuit903) supplies one or more pulses to the piezoelectric elements7. Alternatively, it is possible to supply one or more periods of sine wave voltage signal to the piezoelectric elements7as the drive signal S2. In this way, each drive circuit90applies (supplies) the voltage whose amplitude varies as the drive signal S2to each piezoelectric element7. For instance, the voltage generation circuit91generates the drive signal S2having a frequency that can vibrate each piezoelectric element7most.

Specifically, when vibrating the touch panel portion6, the display control portion10(CPU10a) gives an instruction signal S1for vibrating the piezoelectric element7to the switch portion92of the drive circuit90corresponding to the piezoelectric element pair8to be vibrated. The switch portion92that receives the instruction signal S1becomes ON state, and the switch portion92supplies the voltage generated by the voltage generation circuit91(drive signal S2) to the piezoelectric element7. Then, after a predetermined number of (one or more) pulses or periods of sine wave (drive signal S2) are supplied, the switch portion92becomes OFF state.

Note that the display control portion10can recognize a period in which the touch is continued based on the output of the touch panel portion6. Therefore, the display control portion10may give the instruction signal S1to the switch portions92of the drive portions9, which instructs to increase the number of times of the drive signal S2to be supplied to the piezoelectric element pairs8(the first piezoelectric element pair81, the second piezoelectric element pair82, and the third piezoelectric element pair83) or instructs to increase the amplitude of the voltage as the drive signal S2more, as the touch period is longer. When receiving this instruction signal S1, the drive circuits90increases the number of times of the drive signal S2to be supplied to the piezoelectric element pair8(for example, increases the number of pulses or periods of the sine wave to be input), or increases the amplitude of the voltage as the drive signal S2, as the touch period is longer.

(Vibration Control of the Touch Panel Portion6)

Next, with reference toFIGS. 7 and 8, an example of the vibration control of the touch panel portion6of the operation panel1according to the embodiment is described.FIG. 7is an explanatory diagram for explaining the piezoelectric element pair8to be vibrated in accordance with a touch position on the operation panel1according to the embodiment.FIG. 8is a flowchart illustrating an example of the vibration control flow of the touch panel portion6of the operation panel1according to the embodiment.

First, in the operation panel1of this embodiment, three piezoelectric element pairs8(total six piezoelectric elements7) are disposed. Then, the first piezoelectric element pair81, the second piezoelectric element pair82, and the third piezoelectric element pair83are supplied with the drive signal S2at the same timing so as to vibrate (contract) the piezoelectric elements7at the same timing. Then, an interference between vibrations occurs, and a part of the touch panel portion6where the vibration is weak (a curved amount or a deformed amount in the up and down direction is small) may be generated. It is known that in the case where the piezoelectric elements7are arranged like this embodiment, when the drive signal S2is supplied to all the piezoelectric element pairs8at the same time, the vibration (deformation) of the touch panel portion6is apt to be weak in the middle portion in the left and right direction (long side direction) of the touch panel portion6(in a region sandwiched between the first piezoelectric element pair81and the third piezoelectric element pair83) in the touch panel portion6.

Therefore, in the operation panel1of this embodiment, when the touch panel portion6is touched (when accepting an operation such as a selection input of a set item or a set value by touching a display position of a key or the like), the drive portion9supplies the drive signal S2to the two piezoelectric element pairs8close to the touch position recognized by the display control portion10, so as to vibrate only the two piezoelectric element pairs8close to the touch position.

Specifically, the description is made with reference toFIG. 7. First, a double-dot dashed line inFIG. 7indicates an example of the touchable region6a. For instance, when a point illustrated inFIG. 7is touched in the touchable region6a, the display control portion10gives the instruction signal S1to the first drive circuit901and the second drive circuit902in the drive portion9. As a result, the drive portion9(the first drive circuit901and the second drive circuit902) supplies the drive signal S2to the first piezoelectric element pair81and the second piezoelectric element pair82so as to vibrate the four piezoelectric elements7.

In addition, when a point b illustrated inFIG. 7is touched in the touchable region6a, the display control portion10gives the instruction signal S1to the second drive circuit902and the third drive circuit903in the drive portion9. As a result, the drive portion9(the second drive circuit902and the third drive circuit903) supplies the drive signal S2to the second piezoelectric element pair82and the third piezoelectric element pair83so as to vibrate the four piezoelectric elements7.

In this way, in this embodiment, when an input of a key selection is accepted by touching in the left half region of the touchable region6aof the touch panel portion6, the drive portion9supplies the drive signal S2to the piezoelectric elements7of the first piezoelectric element pair81and the second piezoelectric element pair82so as to vibrate the piezoelectric elements7. In addition, when the input of a key selection is accepted by touching in the right half region of the touchable region6aof the touch panel portion6, the drive portion9supplies the drive signal S2the piezoelectric elements7of the second piezoelectric element pair82and the third piezoelectric element pair83so as to vibrate the piezoelectric elements7.

Next, with reference toFIG. 8, an example of the vibration control flow of the touch panel portion6of the operation panel1according to the embodiment is described.

First, the flow ofFIG. 8starts not in a state where the operation of the touch panel portion6is stopped in a power save mode or the like but in a state where the operation panel1waits for the user to input.

Then, the display control portion10checks whether or not the display position in the input region such as a key or a button for setting input is touched, based on the output of the touch panel portion6(Step #1). In other words, the display control portion10checks whether or not the touched position is a position at which the key or the like is displayed (whether or not an operation input of selecting the key or the like is accepted), based on the output of the touch panel portion6. Note that it is possible to vibrate the piezoelectric element pairs8also when other region than the input region of a key or the like (for example, a space region) is touched.

When there is no selection input of a key or the like (No in Step #1), the flow returns to Step #1. On the other hand, when there is a selection input of a key or the like (Yes in Step #1), the display control portion10determines the piezoelectric element pair8to be supplied with the drive signal S2based on the touch position (Step #2).

In the case where eight or more piezoelectric element pairs8are disposed or other case, calculation for determining the piezoelectric element pair8to be driven based on the touch position may be complicated. Therefore, the memory14may store set data indicating the piezoelectric element pair8to be supplied with the drive signal S2in accordance with the recognized touch position. Then, the display control portion10may refer to the set data in accordance with the touch position so as to determine the piezoelectric element pair8to be driven. Thus, the drive portion9supplies the drive signal S2to the piezoelectric element pair8in accordance with the recognized touch position and the set data.

Then, the display control portion10gives the instruction signal S1to the drive circuit90(switch portion92) that supplies the drive signal S2to the two piezoelectric element pairs8out of the three piezoelectric element pairs8in accordance with the touch position (Step #3). The drive circuit90that receives the instruction signal S1supplies the drive signal S2to the connected piezoelectric elements7(Step #4). Thus, only a part of the disposed piezoelectric element pairs8are vibrated (in this embodiment, two out of three). Note that it is possible to change the number of times or the amplitude of the drive signal S2to be supplied to the piezoelectric elements7in accordance with the touch period of the touch panel portion6.

Note that the display control portion10may give the instruction signal S1simultaneously to the drive circuits90corresponding to the piezoelectric element pairs8to be driven, and the drive circuits90may start to supply the drive signal S2to the four connected piezoelectric elements7at the same timing (simultaneously). In addition, in the case where the vibration is weak so that the click feeling cannot be provided when the drive signal S2supplied simultaneously to the two piezoelectric element pairs8, the display control portion10may shift the timing to give the instruction signal S1. In other words, input start timing of the drive signal S2by the drive circuit90may be shifted for each piezoelectric element pair8.

Further, the display control portion10switches the display on the display portion5as necessary (Step #5). For instance, the display control portion10controls the display portion5to perform switching of the setting screen and switching of key display color in accordance with a key or the like selected by touching. Then, this flow is finished. This flow is performed every time when the touch panel portion6is touched.

In this way, the display input device (operation panel1) according to this embodiment includes the display portion5configured to display screens for operation and setting, the touch panel portion6disposed on the upper surface of the display portion5so as to detect a touched position, the recognition portion (display control portion10) for recognizing the touched position on the touch panel portion6based on the output of the touch panel portion6, the plurality of piezoelectric elements7adjacent to the region of the touch panel portion6that is not visually recognized from the outside, and the drive portion9configured to supply the piezoelectric elements7with the drive signal S2having the predetermined voltage waveform one or more times so as to vibrate the piezoelectric elements7and the touch panel portion6. Further, the plurality of piezoelectric elements7are disposed to be opposed to each other in the short side direction of the touch panel portion6and along the long side direction of the touch panel portion6. Further, the plurality of piezoelectric element pairs8are formed, each of which includes the pair of piezoelectric elements7opposed to each other in the short side direction of the touch panel portion6. The drive portion9does not simultaneously supply all the piezoelectric element pairs8with the drive signal S2.

Thus, it is possible to suppress reduction of the vibration amount (deformation amount) of the touch panel portion6due to interference between vibrations generated by the piezoelectric elements7, because vibration generation start timings or vibration periods of the piezoelectric element pairs8are shifted from each other. Therefore, the touch panel portion6can be sufficiently vibrated so that the operation feeling (click feeling) like that when a button or a key is pressed can be provided.

In addition, in the case where vibration generation timings of the three or more piezoelectric element pairs8arranged in the longitudinal direction of the display portion5are set to be the same, the touch panel portion6may not be sufficiently vibrated (deformation amount may become small) in a region sandwiched between piezoelectric element pairs8on both ends in the longitudinal direction of the display portion5. Therefore, when three or more piezoelectric element pairs8are disposed and the touch panel portion6is touched, the drive portion9supplies the drive signal S2to the two piezoelectric element pairs8that are first and second closest to the touch position recognized by the recognition portion (display control portion10). Thus, it is possible to suppress the reduction of the vibration amount (deformation amount) of the touch panel portion6due to the interference by inhibiting the piezoelectric element pair8away from the touch position from being driven. Therefore, it is possible to sufficiently vibrate (deform) the touch panel portion6so that the click feeling can be provided. In addition, because a part of piezoelectric element pairs8are not driven, power consumption can be reduced compared with the case where all the piezoelectric element pairs8are driven like the conventional structure.

In addition, the display input device (operation panel1) includes the storage portion (memory14) for storing the set data determining the piezoelectric element pairs8to be supplied with the drive signal S2in accordance with the recognized touch position, and the drive portion9supplies the drive signal S2to the piezoelectric element pairs8determined to supply the drive signal S2in the set data in accordance with the recognized touch position. Thus, instead of determining the piezoelectric element pairs8to be supplied with the drive signal S2by calculation from the touch position, it is possible to determine the piezoelectric element pairs8to be supplied with the drive signal S2only by referring the set data. Therefore, it is possible to determine the piezoelectric element pair8to be supplied with the drive signal S2easily and quickly.

In addition, the recognition portion (display control portion10) recognizes the period in which the touch is continued based on the output of the touch panel portion6. Further, as the touch period is longer, the drive portion9increases the number of times of the drive signal S2supplied to the piezoelectric element pair8or increase the amplitude of the voltage as the drive signal S2. Thus, it is possible to set a difference of operation feeling (click feeling) in accordance with the touch period.

In addition, when the recognition portion8(display control portion10) recognizes a touch of the touch panel portion6as an input for selecting a displayed key, the drive portion9vibrates the piezoelectric elements7(piezoelectric element pairs8) and the touch panel portion6. Thus, when the display key is operated, the touch panel portion5is instantaneously vibrated so as to provide the user with the click feeling accompanying the operation.

The display portion5is disposed on the back side of the touch panel portion6with a predetermined space to the touch panel portion6, and the piezoelectric elements7(piezoelectric element pairs8) are attached to the lower side surface of the touch panel portion6(between the display portion5and the touch panel portion6). With this layout, it is possible to effectively vibrate the touch panel portion6.

In addition, the image forming apparatus (multifunction peripheral100) according to the embodiment includes the above-mentioned display input device (operation panel1). Therefore, it is possible to sufficiently inform a user having visual or hearing impairment about that an input by touching the touch panel portion6is accepted. Therefore, it is possible to provide the image forming apparatus that is easy to use.

Next, with reference toFIGS. 9 and 10, a variation is described.FIG. 9is a block diagram illustrating an example of a structure for vibrating the touch panel portion6of the operation panel1according to the variation.FIG. 10is a flowchart illustrating an example of the vibration control flow of the touch panel portion6of the operation panel1according to the variation.

In the embodiment described above, the drive portion9supplies the drive signal S2only to the two piezoelectric element pairs8close to the touch position recognized by the display control portion10. The variation is different from the embodiment in that when the touch panel portion6is touched, all the piezoelectric element pairs8are supplied with the drive signal S2and are driven (vibrated). Specifically, the drive portion9shifts the input start timing of the drive signal S2for each piezoelectric element pair8so that a shift between the input start timing of the drive signal S2to the first piezoelectric element pair8and the input start timing of the drive signal S2to the last piezoelectric element pair8is within a predetermined time.

Other than noted in the following description, the structure is the same as the embodiment described above. Therefore, description and illustration of the same part are omitted by referring to the description and the illustration of the embodiment described above.

As illustrated inFIG. 9, when the touch panel portion6is touched (when an input key or the like is selected), in order to shift the input start timing of the drive signal S2for each piezoelectric element pair8, a timing adjustment circuit93is disposed in the first drive circuit901(corresponding to a main drive circuit) in this embodiment.

This embodiment describes an example in which when the touch panel portion6is touched, the drive signal S2is supplied to the piezoelectric element pairs8in order of the first piezoelectric element pair81, the second piezoelectric element pair82, and the third piezoelectric element pair83, but the order is not limited to this example. The timing adjustment circuit93may be disposed in one of the drive circuits90or in the drive circuit90that first supplies the drive signal S2to the piezoelectric element pair8.

First, in this embodiment, when the touch panel portion6is touched, the display control portion10gives the switch portion92of the first drive circuit901the instruction signal S1instructing to supply the first piezoelectric element pair81with the drive signal S2. When receiving the instruction signal S1, the first drive circuit901supplies the first piezoelectric element pair81(piezoelectric elements7included in the first piezoelectric element pair81) with the drive signal82. The instruction signal81is supplied also to the timing adjustment circuit93of the first drive circuit901.

Then, the timing adjustment circuit93is connected to the switch portions92of the second drive circuit902(corresponding to an auxiliary drive circuit) and the third drive circuit903(corresponding to the auxiliary drive circuit). The timing adjustment circuit93supplies the switch portions92of the second drive circuit902and the third drive circuit903with a trigger signal S3for supplying the drive signal82to the piezoelectric element7. When receiving this trigger signal S3, the second drive circuit902(the switch portion92) and the third drive circuit903(the switch portion92) supplies the connected piezoelectric element pair8(the second piezoelectric element pair82or the third piezoelectric element pair83) with the drive signal82.

Specifically, the timing adjustment circuit93outputs the trigger signal S3so that the input start timings of the drive signal S2to the piezoelectric element pair8(the first piezoelectric element pair81, the second piezoelectric element pair82, and the third piezoelectric element pair83) are shifted for each piezoelectric element pair8(so that a phase difference is generated).

In this case, the timing adjustment circuit93outputs the trigger signal S3so that a shift between the input start timing of the drive signal S2to the first piezoelectric element pair8(the first piezoelectric element pair81in this embodiment) and the input start timing of the drive signal S2to the last piezoelectric element pair8(the third piezoelectric element pair83in this embodiment) is within a predetermined time. It is because that there is a case where the touch panel portion6cannot be vibrated (deformed) so as to provide the operation feeling (click feeling) like that when a button or a key is pressed (a deformation speed of the touch panel portion6becomes mild) when the shift is too large.

The “predetermined time” can be arbitrarily determined. However, it is preferred to determine a shift time range that can provide the operation feeling (click feeling) like that when a button or a key is pressed by experiment or the like in advance, and to determine the “predetermined time” within the determined time range.

Next, with reference toFIG. 10, there is described an example of the vibration control flow of the touch panel portion6of the operation panel1according to the variation.

First, similarly to the case ofFIG. 8, the flow ofFIG. 10also starts not in a state where the operation of the touch panel portion6is stopped in a power save mode or the like but in a state where the operation panel1waits for the user to input.

Then, the display control portion10checks whether or not the display position in the input region such as a key or a button for setting input is touched, based on the output of the touch panel portion6(Step #21).

When there is no selection input of a key or the like (No in Step #21), the flow returns to Step #21. On the other hand, when there is a selection input of a key or the like (Yes in Step #21), the display control portion10supplies the first drive circuit901with the instruction signal S1instructing to supply the drive signal S2to the first piezoelectric element pair81connected to the first drive circuit901(Step #22). The first drive circuit901supplies the first piezoelectric element pair81with the drive signal S2in accordance with the instruction signal S1(Step #23).

Then, the timing adjustment circuit93(first drive circuit901) supplies the trigger signal S3to the second drive circuit902and the third drive circuit903in a predetermined order so that the input start timings of the drive signal S2to the piezoelectric element pairs8are shifted (Step #24).

Further, in accordance with the trigger signal S3, the second drive circuit902and the third drive circuit903supply the drive signal S2to the second piezoelectric element pair82and the third piezoelectric element pair83at shifted timings (Step #25). Then, the display control portion10switches the display on the display portion5as necessary (Step #26). Then, this flow is finished. This flow is performed every time when the touch panel portion6is touched.

In this way, in the display input device (operation panel1) according to this embodiment, when the touch panel portion6is touched, the drive portion9supplies the drive signal S2to the piezoelectric elements7by shifting the input start timing of the drive signal S2for each piezoelectric element pair8, so that a shift between the input start timing of the drive signal S2to the first piezoelectric element pair8and the input start timing of the drive signal S2to the last piezoelectric element pair8is within a predetermined time. Thus, the vibration generation timings or the vibration periods from the piezoelectric element pairs8are shifted, and hence reduction of the vibration amount (deformation amount) of the touch panel portion6due to interference can be suppressed. Therefore, it is possible to sufficiently vibrate (deform) the touch panel portion6so that the click feeling can be provided.

In addition, the drive portion9is disposed for each of the piezoelectric element pairs8, is connected to the piezoelectric element7of the piezoelectric element pair8, and includes the drive circuits90(the first drive circuit901, the second drive circuit902, and the third drive circuit903) for supplying the drive signal S2to the piezoelectric elements7. Among the plurality of drive circuits90, one drive circuit90as the main drive circuit (first drive circuit901) is connected to the auxiliary drive circuits (the second drive circuit902and the third drive circuit903) that are the drive circuits90other than the main drive circuit (first drive circuit901). The main drive circuit supplies the connected piezoelectric elements7with the drive signal S2, and gives the auxiliary drive circuits with the trigger signal S3for supplying the drive signal S2to the piezoelectric elements7so that the vibration start timings of the piezoelectric element pairs8are shifted. When receiving the trigger signal S3, the auxiliary drive circuit supplies the connected piezoelectric elements7with the drive signal S2. Thus, using the drive circuit90(first drive circuit901) as a master, it is possible to shift the input start timings of the drive signal S2to the piezoelectric element pairs8by the other drive circuits90(the second drive circuit902and the third drive circuit903). Therefore, only by shifting the timing of the trigger signal S3from the drive circuit90as one master, it is possible to control the input start timing of the drive signal S2to the piezoelectric element pairs8so as to suppress the reduction of the vibration amount (deformation amount) of the touch panel portion6due to interference.

The present disclosure can be supplied to a method.

Although the embodiment of the present disclosure is described above, the scope of the present disclosure is not limited to this. It is possible to add various modifications for embodiments without deviating from the spirit of the disclosure.