Input apparatus and input method

A disclosed input apparatus includes an operating part pressed by a user; a first resistance film and a second resistance film facing each other; a measuring unit configured to measure a difference between a first electric potential of a first end of a contact resistance and a second electric potential of a second end of the contact resistance; and a detecting unit configured to obtain pressure information indicative of a pressure load caused by the pressing of the operating part based on the difference in electric potential.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2010-279715 filed on Dec. 15, 2010 the entire contents of which are incorporated herein by reference.

FIELD

The embodiments discussed herein relates to an input apparatus and an input method.

BACKGROUND

Various input apparatuses such as a touch panel have been known to exist. According to a technique disclosed in Japanese Unexamined Patent Application Publication No. 2006-106841, a touch panel having a function of preventing an erroneous touching operation (touching a wrong place) is provided.

SUMMARY

However, the touch panel of Patent Document 1 has a problem that a production cost and an apparatus scale become great.

According to an aspect of the embodiment, an input apparatus includes an operating part pressed by a user; a first resistance film and a second resistance film facing each other; a measuring unit configured to measure a difference in electric potential between a first electric potential of a first end of a contact resistance and a second electric potential of a second end of the contact resistance; and a detecting unit configured to obtain pressure information indicative of a pressure load caused by the pressing of the operating part based on the difference in electric potential.

DESCRIPTION OF EMBODIMENTS

A description is given below, with reference toFIG. 1throughFIG. 14of the embodiments of the present invention. The same reference symbols are attached to elements having the same functions and steps carrying out the same processes, and descriptions of these overlapping portions are omitted.

[a] First Embodiment

In the following description, a five wire analog resistive touch panel is applied to an input apparatus of the First Embodiment. However, any resistive touch panel may be applicable to the First Embodiment.FIG. 1is an exploded perspective view of a touch panel80of the First Embodiment.FIG. 2is a cross-sectional view of the touch panel80. Referring toFIG. 3, a block chart of the input apparatus of the First Embodiment is illustrated.

Referring toFIG. 3, the input apparatus of the First Embodiment can be broadly classified into a touch panel80and a controlling unit82. The touch panel80includes a first substrate52and a second substrate56. The controlling unit82includes a measuring unit66, a coordinate detecting unit64, an electrode controlling unit62, an electrode controlling unit62, a CPU70, a displaying unit68, a communicating unit72and a memory unit.

Referring toFIG. 1andFIG. 2, the first substrate52and the second substrate56are arranged so as to face each other. On four sides of the second substrate56, a first electrode111, a second electrode112, a third electrode113and a fourth electrode114are arranged. The first electrode111and the second electrode112are arranged so as to face each other, and the third electrode113and the fourth electrode114are arranged so as to face each other.

Referring toFIG. 2, resistance films are respectively formed on surfaces of the first substrate52and the second substrate56which are facing each other. A first resistance film50is formed on a resistance film forming surface of the first substrate52. A second resistance film54is formed on a resistance film forming surface of the second substrate56. The materials of the first resistance film50and the second resistance film54are, for example, indium tin oxide (ITO).

The surface opposite to the resistance film forming surface of the first substrate52functions as operating part58to be pressed by a user. The user presses the operating part for an operation. This action of pressing may also be expressed as “touching”. Referring toFIG. 2, plural dot spacers60are provided between the first substrate52and the second substrate56. If the operating part58is not pressed by the user, the first resistance film50is placed so as not to touch the second resistance film54.

Referring toFIG. 2(B), a method of detecting the coordinate of a position G on the operating unit pressed by the user is described. Hereinafter, a mode of detecting the coordinate of the pressed position G is referred to as a coordinate detecting mode. If the user presses the operating part58, the first substrate52is warped, and the first resistance film50contacts the second resistance film54. Then the coordinate detecting unit64(seeFIG. 3) detects the position where the first resistance film50contacts the second resistance film54(pressed position) G (seeFIG. 1). In the above description, the X-coordinate of the contact position G is referred to as Px1and the Y-coordinate of the contact position G is referred to as Py1.

FIG. 4andFIG. 5are block charts of important portions of the input apparatus of the First Embodiment. Referring toFIG. 4andFIG. 5, a method of detecting a coordinate with the coordinate detecting unit64is briefly described. When the X-coordinate is detected, the electrode controlling unit62applies voltage to the first electrode111to thereby generate a difference in the electric potential in X-axis directions. Referring toFIG. 4, electric potential of the first electrode111is Vcc, and electric potential of the second electrode112is ground potential Vcc. In this case, the third electrode113and the fourth electrode114are opened without being applied with voltage. Then, the difference in the electric potential occurs between the first electrode111and the second electrode112. After the coordinate detecting unit64detects the electric potential Vx1of the contact position G (Px1) in the X-axis directions, the X-coordinate (Px1) can be detected.

Provided that a resistance value between the first electrode111and the second electrode112is designated as Rx, and a resistance value between the contact position Px1and the second electrode112(the ground) is designated as Rx1, Vx1is represented by the following formula:
Vx1=(Vcc/Rx)·Rx1

When the Y-coordinate (Py1) is detected, the electrode controlling unit62applies a voltage to the third electrode113to thereby generate a difference in an electric potential in Y-axis directions. Referring toFIG. 5, the electric potential of the third electrode113is designated as Vcc and the electric potential of the fourth electrode114is designated as a ground potential (GND). In this case, the first electrode111and the second electrode112are opened by a switching part200. Then, a difference in an electric potential occurs between the third electrode113and the fourth electrode114in parallel with the Y-axis. The coordinate detecting unit64detects the Y coordinate (Py1) by detecting the electric potential in the Y-axis directions of the contact position G.

Provided that a resistance value between the third electrode113and the fourth electrode114is designated as Ry, and a resistance value between the contact position Py1and the fourth electrode114(the ground) is designated as Ry1, Vy1is represented by the following formula:
Vy1=(Vcc/Ry)·Ry1

With this, the coordinate detecting unit64detects the X coordinate and the Y coordinate of the contact position G and send these to the CPU70. The CPU70sends the X coordinate and the Y coordinate to the host computer84via the communicating unit72. The host computer84carries out processes corresponding to the sent X coordinate and the Y coordinate.

Next, a structure of obtaining the pressure information of the input apparatus of the First Embodiment is described. The pressure information of the First Embodiment indicates a pressure load applied by the user to the operating part58. For example, it is possible to render the pressure information to be (i) information indicative of whether the pressure load is great or small. Further, it is possible to render the pressure information to be (ii) information indicative of a value of the pressure load.

In the following description, erroneously pressing the operating part58is refereed to as “erroneous press”. The erroneous press may also be referred to as “touching a wrong place”. A “correct press” is carried out when the operating part58is voluntarily pressed by the user. If the pressure information indicates whether the pressure load is “great” or “small”, the input apparatus of the First Embodiment can determine whether the press by the user is “the erroneous press” or “the correct press”.

The user may draw characters, marks, drawings or the like on the operating part58. In this case, if the pressure load applied by the user is “great”, the input apparatus of the First Embodiment determines that a writing pressure of the user is great and a line reproduced and depicted on the displaying unit68is made thicker. If the pressure load applied by the user is “small”, the input apparatus of the First Embodiment determines that the writing pressure of the user is small and a line reproduced and depicted on the displaying unit68is made thin.

If the pressure information is (ii) the information indicative of the value of the pressure load, the host computer70carries out the process corresponding to the value of the pressure load. Then, the input apparatus becomes easy to be used.

In the following description, the pressure information is the information indicative of whether the pressure load is “great” or “small” and the “correct press” or the “erroneous press” is determined. Referring toFIG. 4, the structure of obtaining the pressure information is described. Referring toFIG. 6, a process flow of the input apparatus of the First Embodiment is described. Referring toFIG. 4, the measuring part661of the First Embodiment includes a first measuring part20, a first converting part22, a second measuring part24, a second converting part26, and a calculating part28.

Referring toFIG. 6, the user presses the operating part58in step S2. At this time, it is not known whether the press is a correct press or an erroneous press. As illustrated inFIG. 2B, the first resistance film50contacts the second resistance film54. The CPU70recognizes the contact to thereby recognize the press of the operating part58with the user.

Referring toFIG. 4, when the first resistance film50contacts the second resistance film54, the contact resistance102is determined. With the Ohm's law, the difference Vm in electric potential between both ends Pc1and Pc2of the contact resistance102and the contact resistance value Rc of the contact resistance102are in proportion (Vm∝Rc). The contact resistance value Rc is inversely proportional to a contact area S (see (B) ofFIG. 2) between the first resistance film50and the second resistance film54(Rc∝ (1/s)). The pressure load F applied by the user is proportional to the contact area S (F∝S). Therefore, referring toFIG. 7, the pressure load F can be summarized to be inversely proportional to the difference Vm in electric potential (Vm∝(1/F)). The input apparatus is operated under a concept A that “the pressure load F is inversely proportional to the difference Vm in the electric potential.

If the CPU70recognizes that the first resistance film50contacts the second resistance film54, a mode of measuring a difference in electric potential is set up. There are various methods of setting a mode of measuring the difference in the electric potential. Referring toFIG. 4, the mode of measuring the difference in the electric potential is selected by switching over the switch106. In the mode of measuring the difference in the electric potential, an electric potential (a first electric potential) of one end Pc1of the contact resistance102and an electric potential (a second electric potential) of the other end Pc2and the difference Vm in the electric potential are measured.

Referring toFIG. 4, the switch106is an ordinary switch. Said differently, when the switch106is turned on, a movable end1062contacts a fixed end1064, and the mode changes to a mode of measuring the difference in the electric potential. Meanwhile, when the switch106is turned off, the electric contact between the movable end1062and the fixed end1064is released, the mode of measuring the difference in the electric potential is switched to the coordinate detecting mode described above.

When the switch106is turned on, an electric current from a power source Vcc to which the first electrode111is connected flows via Pc2, the contact resistance102, Pc1, the switch106which has been turned on, and the reference resistance104to the GND108, in this order. As described, the reference resistance104is provided to lead the electric current from the power source Vcc to the GND108.

When the switch106is turned on, the first measuring part20measures an analog value (hereinafter, “a first analog value V1”) of a first electric potential V1of the one end Pct of the contact resistance102. The second measuring part24measures an analog value (hereinafter, “a second analog value V2”) of a second electric potential V2of the other end Pc2of the contact resistance102.

The first analog value V1and the second analog value V2can be represented as follows.
V1=(Vcc/(Rx2+Rc+Rd))×Rd
V2=(Vcc/(Rx2+Rc+Rd))×(Rc+Rd)

The Rx2is a resistance value between the first electrode111and the Pc2. The Rc is a resistance value of the contact resistance102, and the Rd is a resistance value of the reference resistance104.

In order to make certainly measure the second electric potential V2with the second measuring part24, the second electrode112may contact the switching part200. The switching part200includes a movable end202, a first fixed end204and a second fixed end206. The first fixed end is connected to a GND (grounded), and the second fixed end206is connected to the second measuring part24. When the CPU70switches the mode to the mode of measuring the difference in electric potential, the movable end202is electrically connected to the first fixed end204or the second fixed end206with a short time interval. By changing over the switching part200, the second measuring part24can certainly measure an analog value of the second electric potential V2.

The analog value V1of the first electric potential measured by the first measuring part20is input into the first converting part22. The second analog value V2of the second electric potential measured by the second measuring part24is input into the second converting part26.

The first converting part22converts the first analog value V1of the first electric potential to a digital value (hereinafter, referred to as “a first digital value V1′”). The second converting part26converts the second analog value V2of the second electric potential to a digital value (hereinafter, referred to as “a second digital value V2′”). The first converting part22and the second converting part26may be known A/D converter.

The first digital value V1′from the first converting part and the second digital value V2′ from the second converting part26may be input into the calculating part28. The calculating part28obtains a difference between the first digital value V1′ and the second digital value V2′ and outputs the difference as the difference in the electric potential (hereinafter, referred to as “a digital value difference Vm′”). The digital value difference Vm′″ is obtainable by the following formula:
Vm′=|V1′−V2′|

The difference Vm′ in the electric potential output from the calculating part28is input in the detecting unit702of the CPU70.

The detecting unit702obtains the pressure information (the information indicative of whether the pressure load is “great” or “small”) based on the measured difference Vm′ in the electric potential. In a case where the user carries out a correct press of the operating part (the press voluntarily carried out by the user), the pressure load caused by the press becomes great to a certain extent. On the contrary thereto, if the user erroneously presses the operating part58(the erroneous press involuntarily carried out by the user), the pressure load become small to a certain extent. Because of the above concept that the pressure load F is inversely proportional to the difference Vm in the electric potential (referring toFIG. 7), the pressure load F is determined to be small, and the detecting unit702determines that the press by the user is the an erroneous press. On the contrary thereto, if the difference in electric potential Vm′ is smaller than the threshold value α, the pressure load is determined to be great. Then, the detecting unit702determines that the press by the user is a correct press.

If the detecting unit702determines that the press by the user is the erroneous press, information such as “erroneously touched” may be displayed on the displaying unit68. By displaying as described above, the user can recognize the erroneous touch.

Further, if the user erroneously presses the touch panel80, the coordinate detecting unit64detects the coordinate of the erroneously pressed position and the host computer84performs a process corresponding to the coordinate. Thus, the process is involuntarily carried out. Therefore, if the detecting unit702determines that the press by the user is the erroneous press, the coordinate detecting unit64(CPU70) may not send the coordinate of the erroneously pressed position to the host computer84. With this, even if the user erroneously presses, the erroneous process may be prevented from being carried out.

When the detecting unit702determines that the pressure load is “great”, the thickness of the line depicted by the user on the operating part58is displayed so that the thickness of the line depicted on the operating part58becomes thick. When the detecting unit702determines that the pressure load is “small”, the thickness of the line depicted by the user on the operating part58is displayed so that the thickness of the line depicted on the operating part58becomes thin.

Next, the other pressure information is described. As described above, the pressure information indicates whether the press on the operating part58is the erroneous press. Other pressure information may indicate the value of the pressure load F having a unit of N or the like. For example, when the user presses the operating part58, it is possible to obtain the value of the pressure load F. Two ways of obtaining the pressure load are described.

The first way of obtaining the pressure load F is described. As described above, the pressure load F can be summarized to be inversely proportional to the difference Vm in the electric potential. Said differently, a relationship between the pressure load F and the difference Vm in the electric potential are as follows:

where β is a constant experimentally determined in advance. Therefore, if the difference Vm in the electric potential is input in the detecting unit702by the measuring unit66, the detecting unit702substitutes the difference Vm in the electric potential for Vm in Formula 1 to thereby obtain the pressure load F. Formula 1 may be memorized in the memory unit74in advance.

The second way of obtaining the pressure load F is described. As described above, the pressure load F can be summarized to be inversely proportional to the difference Vm in the electric potential. Then, a table illustrated inFIG. 8may be prepared to associate the difference Vm in the electric potential and the pressure load F. Referring toFIG. 8, if the difference in the electric potential is Vm1the pressure load is F1, and if the difference in electric potential is Vmn, the pressure load is Fn.

When the difference in the electric potential Vm is input in the detecting unit702, the detecting unit702refers to the table and obtains the input difference Vm in the electric potential and the corresponding to the pressure load F and outputs these. When the value of the difference Vm in the electric potential input in the detecting unit702is the value of the difference in the electric potential which does not exist in the table, a pressure load corresponding to the value of the difference in the electric potential is obtained and output.

The ways of obtaining the pressure load are not limited to the “first way” and “second way” and may be any other way.

The input apparatus of the First Embodiment obtains the difference in the electric potential between the both ends of the contact resistance102corresponding to the contact area between the first resistance film50and the second resistance film54. Therefore, the production cost can be reduced and the input apparatus can be made compact.

[b] Second Embodiment

An input apparatus of the Second Embodiment is described next. Referring toFIG. 9, a block chart of the input apparatus of the Second Embodiment is illustrated. The input apparatus of the Second Embodiment differs from the input apparatus of the First Embodiment at a point that the measuring part661of the input apparatus of the First Embodiment is substituted by a measuring part662. The measuring part662includes a change-over unit120, a measuring part30, a converting part32and a calculating part28.

The measuring part30measures a first analog value V1of a first electric potential and a second analog value V2of a second electric potential. The converting part32converts the first analog value V1to the first digital value V1′and also converts the second analog value V2to the second digital value V2′. The change-over unit120includes a movable end1202, a first fixed end1204and a second fixed end1206. If the movable end1202electrically contacts the first fixed end1204, the measuring part30can measure the first analog value V1of the first electric potential. If the movable end1202electrically contacts the second fixed end1206, the measuring part30can measure the first analog value V2of the second electric potential.

If the operating part58is operated and the first resistance film50contacts the second resistance film54, the CPU70turns on the switch106to change over the mode to the mode of measuring the difference in the electric potential. At the same time, the CPU70electrically connects the movable end1202of the change-over unit120alternately to the first fixed end1204or the second fixed end1206at short time intervals. Therefore, the measuring part30may measure the first analog value V1of the first electric potential and the second analog value V2of the second electric potential at short time intervals.

The measured first analog value V1and the second analog value V2are input in the converting part32. The converting part32converts the first analog value V1to the first digital value V1′ and also converts the second analog value V2to the second digital value V2′.

The converted first digital value V1′and the converted second digital value V2′ are input in the calculating part28. The calculating part28calculates |V1′-V2′| to obtain the difference Vm′ in the electric potential (the digital value difference) and outputs the difference Vm′ in the electric potential.

With the input apparatus of the Second Embodiment, the number of the measuring parts and the number of the converting parts may be respectively one. Therefore, the size of the input apparatus can further be made compact.

The calculating parts28of the measuring parts661and662of the First and Second Embodiments may be provided in the CPU70.

An input apparatus of the Third Embodiment is described next. Referring toFIG. 10, a block chart of the input apparatus of the Third Embodiment is illustrated. The input apparatus of the Third Embodiment differs from the input apparatus of the First Embodiment at a point that the measuring part661of the input apparatus of the First Embodiment is substituted by a measuring part663. The measuring part663includes a differential circuit400and a converting part46. The differential circuit400includes a first measuring part20, a second measuring part24and a calculating part44.

When the CPU70changes the mode to the mode of measuring the difference in the electric potential mode, the first measuring part20measures the first analog value V1of the first electric potential. The second measuring part24measures the second analog value V2of the second electric potential. The calculating part44calculates an analog value difference Vm by calculating |V1−V2|. The calculated analog value Vm is input into the converting part46.

The converting part46converts the input analog difference Vm to the digital value difference Vm′ and outputs the converted input analog difference Vm to a digital value difference Vm′ and outputs the converted digital value difference Vm' as the difference in the electric potential.

With the Third Embodiment, the number of the converting parts can be made one. Therefore, the size of the input apparatus can be made compact.

[Mode of Setting a Threshold Value α]

If the pressure information indicates whether the pressure load applied by the user is great or small, the detecting unit702uses the threshold value α to determine whether the press is great or small. The values of the loads of the correct presses are differently applied by the users. Therefore, it is necessary to setup the threshold values α for the users respectively. Therefore, the mode of setting the threshold value α is described.

FIG. 11illustrates a flow of setting the threshold value α. The CPU20makes the display unit (seeFIG. 3) display information P prompting selection whether the threshold value α is actually measured. The information P is, for example, a message such as “Do you actually measure the threshold value α?” When the user observes the information P, the user selects whether the threshold value α is actually measured in order to newly determine the threshold value α. In a case where a threshold value α for a user X is not set or the threshold value α for the user X is requested to be changed, the user X selects the actual measurement in Yes of step S12ofFIG. 11.

Meanwhile, if the threshold value α is set for the user X and it is determined that the threshold value α need not to be changed, the user may select that the actual measurement is not carried out by selecting No in step S12.

When Yes is selected in step S12, the process goes to step S14. In step S14, the threshold value α is actually measured. Detailed way for actually measuring the threshold value α is described in detail later.

When the actually measuring process of the threshold value α (the process of step S14) ends or the threshold value is not actually measured in step S12, the process goes to step S16. In step S16, the threshold value α is actually adjusted. The CPU70makes the displaying unit68display the threshold value α actually measured in step S14or a preset threshold value α. Then, the user may finely adjust the displayed threshold value α. For example, if the threshold value α is made slightly greater, the threshold value α is increased when the user pushes down a threshold value increasing button (not illustrated). For example, if the threshold value α is made slightly smaller, the threshold value α is decreased when the user pushes down a threshold value decreasing button (not illustrated).

After completing the threshold value adjusting process in step S16, the process goes to step S18. In step S18, the threshold value α is actually confirmed. The CPU70displays information Q of prompting a determination whether the threshold value α is appropriate on the displaying unit68. For example, the information Q is a message such as “is the adjusted threshold value α is appropriate?”. The user may confirm the threshold value α after observing the information Q. Specifically, the user presses the operating part58to confirm the threshold value α. The displaying unit68displays whether the pressing is the erroneous press based on the threshold value α finely adjusted in step S16. The operating part58repeats pressing the operating part58and displaying whether it is the erroneous press by plural times to thereby determine whether the finely adjusted threshold value α is appropriate. Specifically, if the erroneous press is not displayed when the user presses the operating part58with the correct press or if the erroneous press is displayed when the user presses the operating part58with the erroneous press, the finely adjusted threshold value α becomes the appropriate threshold value. Specifically, if the erroneous press is not displayed when the user presses the operating part58with the erroneous press or if the erroneous press is displayed when the user presses the operating part58with the correct press, the finely adjusted threshold value α is not the appropriate threshold value. After completing the threshold value confirming process, the process goes to step S20.

In step S20, the user determines whether the threshold value α is appropriate. The CPU70makes the displaying unit68display information R thereby enabling the user to determine whether the threshold value α is appropriate. The information R is a message such as “Is the threshold value α is OK?”. If the threshold value α is appropriate in the threshold value confirming process of step S18, the user presses an OK button (not illustrated) and the setup unit704(seeFIG. 3) sets the threshold value α in Yes of step S20. If the threshold value a is not appropriate in the confirming process of step S18, the user presses a NG button (not illustrated) and goes back to step S12. As described, the threshold value α is determined based on the processing flow ofFIG. 11.

Next, a detailed process of actually measuring the threshold value α in step S14is described. In the following description, the process of actually measuring the threshold value α using the input apparatus of the First Embodiment is exemplified. However, the input apparatuses of the Second and Third Embodiments may be used.FIG. 12illustrates a flow of actually measuring the threshold value α. Briefly explaining, in the actual measurement of the threshold value α, the user presses the operating part58with a pressure load of the erroneous press by N times (N is a natural number. Hereinafter, the press of the operating portion58for actually measuring the threshold value is specifically called “a provisional press”. The differences Vm in the electric potential are obtained by each provisional press and an average value of the differences Vm in the electric potential of the N times is acquired. The acquired average value is set as the threshold value α.

In a case where the actually measuring process is carried out, the CPU70causes the display portion68to display information S such as “Please press the operating part58with a pressure load of the erroneous press” to prompt the user to erroneously press the operating part58.

Then, the CPU70determines whether the first analog value V1and the second analog value V2are accurately measured. For example, the determination is carried out by determining whether V2is in the GND level (the electric potential of V2is zero). If V2is in the GND level, the first analog value V1and the second analog value V2are determined not to be accurately measured.

If the first analog value V1or the second analog value V2is not accurately measured, the process returns to step S24. If the first analog value V1and the second analog value V2are accurately measured, the process goes to step S28.

With step S28, the first converting part22and the second converting part26convert the first analog value V1and the second analog value V2to the first digital value V1′ and the second digital value V2′, respectively. The calculating part28obtains a difference Vm′ in the electric potential between the first digital value V1′ and the second digital value V2′ in step S28. The obtained difference in the electric potential Vm′ is stored in the memory unit74.

The CPU70determines whether the number n of the provisional presses reaches N. If the number n reaches N in Yes of step S30, the process goes to step S32. If the number n does not reach N, the number n is incremented in step S34and the process returns to step S24. The process is repeated to acquire the difference Vm′ in the electric potential until the number n reaches N. The obtained difference Vm′ in the electric potential is stored in the memory unit74. When the number n reaches N, the difference Vm′ in the electric potential is stored in the memory unit74.

In step S32, the CPU70calculates an average value of the differences Vm′ in the electric potentials, the number of which is N. The calculated average value is a threshold value α. The average value may be calculated as an average value of the differences Vm′ in the electric potential as many as N. Further, the average value may be obtained from the differences Vm′ in the electric potential as many as (N-2) excluding the maximum difference and the minimum difference.

With the process flow illustrated inFIG. 11andFIG. 12, the threshold value α corresponding to the user may be obtained. As described, the setup unit704sets up the threshold value α based on the differences Vm′ in the electric potential measured by the measuring part66when the operating part58is provisionally pressed. Further, if the value of the threshold value α is not appropriate for the user in steps S18and S20after the user directly observes the value of the threshold value α, the threshold value α is preferably changeable.

Further, if the users and the threshold values a appropriate for the users are associated and then stored, it is possible to make the threshold values a corresponding to the users use to facilitate usability.FIG. 13illustrates a table associating the users and the threshold values α. In an example ofFIG. 13, the threshold value α1is used for the user X. The table illustrated inFIG. 13is stored in the memory unit74. Before the user presses the operating part58of the input apparatus of the Third Embodiment, the user may input his or her name to the input apparatus. Then, the CPU70refers to the table illustrated inFIG. 13and uses the threshold value corresponding to the input name. With the structure, it is possible to accurately carry out the detection of the erroneous press or the like in association with the users.

(1) InFIG. 4,FIG. 9andFIG. 10, the voltage is applied between the first electrode111and the second electrode112, the third electrode113and the fourth electrode114are opened, and the difference in the electric potential of both ends of the contact resistance102is measured. Otherwise, when the voltage is applied between the third electrode113and the fourth electrode114, and the first electrode111and the second electrode112are opened, the difference in the electric potential of both ends of the contact resistance102may be measured.

(2) InFIG. 6, step S8(the coordinate detecting process) is carried out after step S4(the mode of measuring the difference in the electric potential) and step S6(obtaining the pressure information). Otherwise, after step S8, step S4and step S6may be carried out.

(3)FIG. 14is an exploded perspective view of a touch panel to which plural positions can be input. The first substrate52is divided into plural areas. The input apparatuses of the embodiments can use this type of the touch panel.

(4) As described above, the input apparatuses of the embodiments use the five wire analog resistive touch panel. However, as long as a resistive film type touch display is used, another method (e.g., a four wire analog resistive touch panel) may be used.

Effect of the Invention

According to the input apparatus and the input method of the present invention, a manufacturing cost can be reduced, compactness of the device can be realized, and pressure information indicative of a pressure load can be obtained.