JP5401295B2 - Touch panel and coordinate position detection method - Google Patents

Description

  The present invention relates to a touch panel and a coordinate position detection method.

  The touch panel is an input device that can directly input to the display, and is used by being installed on the front surface of the display. This touch panel is widely used in various applications because it can be directly input based on information visually captured by a display.

  As such a touch panel, a resistance film method is widely known. The resistive film type touch panel is installed so that each transparent conductive film is opposed to each other in the upper electrode substrate and the lower electrode substrate on which the transparent conductive film is formed, and each of the upper electrode substrates is applied with a force. The transparent conductive films are in contact with each other, and the position where the force is applied can be detected.

  Resistive touch panels can be roughly classified into 4-wire type and 5-wire type. In the four-wire system, an X-axis electrode is provided on one of the upper electrode substrate and the lower electrode substrate, and a Y-axis electrode is provided on the other. On the other hand, in the 5-wire system, both the X-axis electrode and the Y-axis electrode are provided on the lower electrode substrate, and the upper electrode substrate functions as a probe for detecting a voltage (for example, Patent Documents). 1, 2, 3).

  Specifically, a 4-wire touch panel will be described with reference to FIGS. FIG. 1 is a schematic view of a cross section of a 4-wire touch panel, and FIG. 2 is a perspective view of the 4-wire touch panel.

  The 4-wire touch panel is composed of a film 110 having a transparent conductive film 130 formed on one surface serving as an upper electrode substrate, and a glass 120 having a transparent conductive film 140 formed on one surface serving as a lower electrode substrate, The transparent conductive film 130 and the transparent conductive film 140 are disposed through the spacer 150 so as to face each other. The 4-wire touch panel is electrically connected to a host computer or the like via a cable (not shown).

  In addition, the film 110 serving as the upper electrode substrate is provided with electrodes 131 and 132 along the Y-axis direction at both ends in the X-axis direction of the surface on which the transparent conductive film 130 is formed. The glass 120 is provided with electrodes 141 and 142 along the X-axis direction at both ends in the Y-axis direction of the surface on which the transparent conductive film 140 is formed.

  In the four-wire type touch panel having such a configuration, a case where a position in contact with the touch panel is detected will be described.

First, as shown in FIG. 3, a voltage is applied to the electrode 131 and the electrode 132 in the upper electrode substrate. Specifically, the electrode 131 is grounded (0 V), and Vcc, for example, 5 V is applied to the electrode 132. In this state, if the touch pen 160 or the like is in contact at point A of the touch panel are in contact at point A and the transparent conductive film 130 and the lower electrode transparent conductive film 140 in the substrate in the upper electrode substrate. The transparent conductive film 130, the electrode 131 and the electrode 132, X-axis direction and a voltage is applied such that the potential gradient is generated in at the point A, since the transparent conductive film 130 and the transparent conductive film 140 is in contact, transparent a conductive film 140, it is possible to detect the potential at the point a. This potential is a value obtained by resistance-dividing the voltage applied at the electrodes 132 and 131 at the point A. Detection of potential is detected by the voltmeter 170 from the electrode 141 provided on the transparent conductive film 140. Thereafter, as shown in FIG. 4, the coordinate position of the X coordinate at the point A is detected based on the voltage VaVa measured by the voltmeter 170.

Next, as shown in FIG. 5, a voltage is applied to the electrode 141 and the electrode 142 in the lower electrode substrate. Specifically, the electrode 141 is grounded (0 V), and Vcc, for example, 5 V is applied to the electrode 142. Similar to the above, if in contact touch pen 160 or the like in point A of the touch panel, the transparent conductive film 140 of the lower electrode substrate and the transparent conductive film 130 in the upper electrode substrate are in contact at point A. The transparent conductive film 140, the electrode 141 and the electrode 142, Y-axis direction and a voltage is applied such that the potential gradient is generated in at the point A, since the transparent conductive film 130 and the transparent conductive film 140 is in contact, transparent a conductive film 130, it is possible to detect the potential at the point a. This potential is a value obtained by resistance division of the voltage applied to the electrode 141 and the electrode 142 at the point A. Detection of potential is detected by the voltmeter 170 from the electrode 131 provided on the transparent conductive film 130. Thereafter, as shown in FIG. 6, based on the voltage Vb measured by the voltmeter 170, the coordinate position of the Y coordinate at the point A is detected.

  As described above, the X coordinate and the Y coordinate at the point A can be obtained, and the two-dimensional position at the point A can be known.

In such a four-wire touch panel, an operation for detecting the potential of a transparent conductive film 140 of the lower electrode substrate by applying a voltage to the transparent conductive film 130 in the upper electrode substrate, the voltage to the transparent conductive film 140 of the lower electrode substrate by repeated application of the operation for detecting the potential of a transparent conductive film 130 in the upper electrode substrate alternately, it is possible to detect the continuous contact position.

  By the way, in the above-described four-wire touch panel, it is possible to detect the contact position at one point, but it is not possible to detect the position when a plurality of points touch at the same time.

  That is, as shown in FIG. 7, a state in which a voltage is applied to the electrode 131 and the electrode 132 in the upper electrode substrate, for example, the electrode 131 is grounded (0V) and Vcc, for example, 5V is applied to the electrode 132 When the touch pens 161 and 162 are in contact with each other at the points B and C, the coordinate positions at the points B and C cannot be detected.

Thus, when the contact point of the touch panel is two points point B and point C, in the transparent conductive film 140, the potential Vx is detected at the midpoint of the two points of points B and C as shown in FIG. 8 Is done. Therefore, even if the touch panel is touched at two points, the potential detected is one, and the coordinate position is detected as touching at one point. The coordinate position of each of the two points cannot be detected.

JP 2004-272722 A JP 2008-293129 A JP-A-11-353101

  The present invention has been made in view of the above, and provides a touch panel capable of detecting each contact position and a coordinate position detection method using the touch panel even when touched simultaneously at a plurality of contact positions. It is the purpose.

The present invention relates to an upper electrode substrate having an upper conductive film formed on a first substrate, a lower electrode substrate having a lower conductive film formed on a second substrate, and potential distribution in the upper conductive film. In order to generate the first electrode and the second electrode provided at both ends of the upper conductive film, a potential distribution in a direction perpendicular to the potential distribution generated in the upper conductive film is generated in the lower conductive film. For this purpose, the upper conductive film includes a third electrode and a fourth electrode provided at both ends of the lower conductive film, and the upper conductive film and the lower conductive film are arranged to face each other. A voltage having a constant value is applied to the first electrode and the second electrode to generate a potential distribution in the membrane , and either one of the third electrode and the fourth electrode is used for measurement. Apply voltage, and on the other hand, It is one that, the voltage for the measurement is characterized in that it is intended to be applied to the variable range of the voltage of the constant value.

The present invention also provides an upper electrode substrate having an upper conductive film formed on a first substrate, a lower electrode substrate having a lower conductive film formed on a second substrate, and a potential in the upper conductive film. In order to generate the distribution, a first electrode and a second electrode provided at both ends of the upper conductive film, and a potential distribution in a direction perpendicular to the potential distribution generated in the upper conductive film in the lower conductive film. In the touch panel having a third electrode and a fourth electrode provided at both ends of the lower conductive film to cause the upper conductive film and the lower conductive film to be opposed to each other, In order to generate a potential distribution in the lower conductive film , a constant voltage is applied to the third electrode and the fourth electrode, and either one of the first electrode and the second electrode is measured. Voltage on the other hand, A detects the voltage for the measurement is characterized in that it is intended to be applied to the variable range of the voltage of the constant value.

  Further, the present invention is characterized in that the voltage for the measurement is applied variably within the voltage range of the constant value.

Further, the present invention is a voltage for the measurement, an electrode having substantially the same area as the area of the region of contact Sawaten, the first electrode, the second electrode, the third electrode and It is supplied from an electrode different from the fourth electrode.

The present invention also provides an upper electrode substrate having an upper conductive film formed on a first substrate, a lower electrode substrate having a lower conductive film formed on a second substrate, and a potential in the upper conductive film. In order to generate the distribution, a first electrode and a second electrode provided at both ends of the upper conductive film, and a potential distribution in a direction perpendicular to the potential distribution generated in the upper conductive film in the lower conductive film. Coordinate positions on a touch panel having a third electrode and a fourth electrode provided at both ends of the lower conductive film for causing the upper conductive film and the lower conductive film to be opposed to each other In the detection method, in order to generate a potential distribution in the upper conductive film , a constant voltage is applied to the first electrode and the second electrode, and either the third electrode or the fourth electrode is applied. Detect initial potential from either A first potential detection step, and a second potential detection for applying a voltage for measurement to either one of the third electrode or the fourth electrode while increasing or decreasing, and detecting a potential on the other Even if the potential value for measurement is different between the step and the second potential detection step, if the potential detected on the other side is constant, it is determined that there are a plurality of contact points. And a determination step.

  In addition, according to the present invention, when it is determined that the plurality of contact points are included in the determination step, the first coordinate position is calculated based on the upper limit potential of the constant potential, and the constant potential is obtained. A coordinate position detecting step of calculating a second coordinate position based on a lower limit potential of the second coordinate position.

Further, the present invention is a case in which it is determined in the determination step that there are a plurality of contact points, and one of the plurality of contact points can be regarded as known. When the coordinate position at one contact point is X1 and the coordinate position obtained by the initial potential value is Xa, the coordinate position X2 of the other contact point is
X2 = 2 * Xa-X1
It has the coordinate position calculation process calculated by these.

In the present invention, the determination step is a first determination step, and after the first determination step, the third electrode and the fourth electrode are used to generate a potential distribution in the lower conductive film. And a third potential detecting step of detecting a second initial potential from either one of the first electrode or the second electrode, and applying the first electrode and the second electrode A voltage for measurement is applied to either one of the second electrodes while increasing or decreasing, and a potential is detected on the other, and in the fourth potential detection step, measurement is performed in the fourth potential detection step. A second determination step of determining that the contact point has a plurality of contact points when the potential detected on the other side is constant even when the potential values are different.

  In the present invention, when it is determined in the second determination step that there are a plurality of contact points, a third coordinate position is calculated based on the upper limit potential of the constant potential, and the constant A coordinate position detecting step of calculating a fourth coordinate position based on a lower limit potential of the potential.

Further, the present invention is a case in which it is determined in the determination step that there are a plurality of contact points, and one of the plurality of contact points can be regarded as known. When the coordinate position at one contact point is Y1, and the coordinate position obtained by the value of the second initial potential is Ya, the coordinate position Y2 of the other contact point is
Y2 = 2 × Ya−Y1
It has the coordinate position calculation process calculated by these.

  In the present invention, the first potential detection step, the second potential detection step, the first determination step, the third potential detection step, the fourth potential detection step, and the second determination step are sequentially repeated. It is characterized by.

  According to the present invention, it is possible to provide a touch panel capable of detecting each contact position and a coordinate position detection method using the touch panel even when a plurality of contact positions are simultaneously touched.

Cross-sectional schematic diagram of a conventional 4-wire touch panel A perspective view of a conventional 4-wire touch panel Explanatory drawing of the coordinate detection method of the X direction in the conventional 4-wire type touch panel Explanatory diagram of potential and contact position in X direction Explanatory drawing of the coordinate detection method of the Y direction in the conventional 4-wire type touch panel Explanatory diagram of potential and contact position in Y direction Explanatory drawing in the case of two-point contact in a conventional 4-wire touch panel Explanatory diagram of potential and contact position in case of two-point contact Cross-sectional schematic diagram of the touch panel in the first embodiment Explanatory drawing (1) of the touch panel in 1st Embodiment Explanatory drawing (2) of the touchscreen in 1st Embodiment Flowchart of touch panel position detection method in the first embodiment Correlation diagram of applied voltage and detection potential in case of one-point contact on touch panel in first embodiment Correlation diagram of applied voltage and detection potential in case of two-point contact on touch panel in first embodiment Subroutine of method for detecting coordinates as two points in the first embodiment Subroutine for detecting coordinates as two points in the second embodiment The perspective view of the touch panel in 3rd Embodiment

  The form for implementing this invention is demonstrated below.

[First Embodiment]
(Touch panel)
The touch panel in the first embodiment will be described. FIG. 9 is a cross-sectional view of the touch panel in the present embodiment, and FIGS. 10 and 11 are explanatory diagrams of the touch panel in the present embodiment.

  The touch panel in the present embodiment is transparent on one surface of a substantially rectangular upper electrode substrate 10 having a transparent conductive film 20 formed on one surface of the film 11 and a glass substrate 31 having substantially the same shape as the upper electrode substrate. The lower electrode substrate 30 on which the conductive film 40 is formed is configured.

  The upper electrode substrate 10 and the lower electrode substrate 30 are bonded with an adhesive or a double-sided tape through a spacer 50 or the like so that the transparent conductive film 20 in the upper electrode substrate 10 and the transparent conductive film 40 in the lower electrode substrate 30 face each other. It is joined.

  The transparent conductive film 20 in the upper electrode substrate 10 is provided with electrodes 21 and 22 extending in the Y-axis direction so that a voltage can be applied in the X-axis direction at both ends in the X-axis direction. The transparent conductive film 40 in the substrate 30 is provided with electrodes 41 and 42 extending in the X-axis direction so that a voltage can be applied in the Y-axis direction at both ends in the Y-axis direction.

  Furthermore, the touch panel according to the present embodiment is further provided with a power source 60 that can apply a variable voltage and a voltmeter 70 that can detect a potential.

  The power source 60 and the voltmeter 70 are connected to a control circuit (not shown), a host computer, and the like, and are not shown so that a predetermined voltage can be applied to the electrodes 21 and 22 and the electrodes 41 and 42. The control circuit and the switch are provided.

As a material constituting the transparent conductive film 20 and the transparent conductive film 40, ITO (Indium Tin Oxide), a material in which Al or Ga or the like is added to ZnO (zinc oxide), Sb or the like is added to SnO ₂ (tin oxide) And the like.

  Examples of the film 11 include PET (polyethylene terephthalate), PC (polycarbonate), and a transparent resin material in the visible region. Further, a resin substrate may be used in place of the glass substrate 31.

  In the touch panel in the present embodiment, the transparent conductive film 20 in the upper electrode substrate 10 and the transparent conductive film 40 in the lower electrode substrate 30 are in contact with each other by pressing the upper electrode substrate 10 with a touch pen, a finger, or the like. By detecting the voltage at the position, it is possible to detect the contact position between the upper electrode substrate 10 and the lower electrode substrate 30, that is, the position where the upper electrode substrate 10 is pressed by the touch pen 81 or 82, a finger or the like. is there.

(Coordinate position detection method)
Next, a coordinate detection method in the present embodiment will be described based on FIG.

First, in step 102 (S102), an initial potential in the X direction is measured (first potential detection step). Specifically, as shown in FIG. 10, a voltage of 5V is applied to the electrode 22 in the upper electrode substrate 10 and a voltage of 0V is applied to the electrode 21. Thus, the transparent conductive film 20, causing a potential gradient in the X direction. In this state, the potential is measured by the voltmeter 70 connected to the electrode 41. In this step, the power source 60 is not connected to the electrode 42, or even if the power source 60 is connected to the electrode 42, the voltage is not applied to the electrode 42. . The potential measured in this state is a potential for specifying the position coordinates of one contact position when the touch position on the touch panel is one point. Further, when there are two contact positions on the touch panel, the potential corresponds to the position coordinates of a position that is approximately the middle point of the two contact positions.

  Next, in step 104 (S104), the applied voltage is changed and the potential in the X direction is measured (second potential detecting step). Specifically, in a state where the power source 60 is connected to the electrode 42 and voltage can be applied to the electrode 42 by the power source 60, the power source 60 applies voltage to the electrode 42 while increasing the voltage sequentially, and connects to the electrode 41. The potential corresponding to the voltage applied by the applied voltmeter 70 is measured.

  Here, when the touch position on the touch panel is one point, as shown in FIG. 13, when the voltage value applied by the power supply 60 is sequentially changed to 1V, 2V, 3V, 4V, and 5V, the voltmeter 70 The detected potential rises sequentially. Here, when the initial potential value is 3V and the voltage applied by the power supply 60 is 3V, the potential detected by the voltmeter 70 is approximately 3V.

  On the other hand, when the touch positions on the touch panel are two points, as shown in FIG. 14, when the voltage value applied by the power source 60 is sequentially changed to 1V, 2V, 3V, 4V, 5V, the voltmeter 70 There is an applied voltage region where the detected potential is constant. For example, as shown in FIG. 10, when the touch pens 81 and 82 are in contact with the touch panel at two points D and E, as shown in FIG. Even if it is changed to 2V, 3V, 4V, and 5V, there is a region where the potential detected by the voltmeter 70 is substantially constant at 3V. As described above, even if the voltage value applied by the power supply 60 is changed, the touch to the touch panel is one point or two points depending on whether or not the potential detected by the voltmeter 70 may be constant. Can be determined. Note that the range of the voltage applied by the power source 60 is a range from the value of the voltage applied to the electrode 21 to the value of the voltage applied to the electrode 22, and in this embodiment, 0 V to 5 V. is there.

  14 shows a state where the touch panel is in contact with two points, that is, in the case where the potential detected by the voltmeter 70 is in contact with one point with the point D at which the potential detected by the voltmeter 70 is approximately 4V. An experiment in which the voltage value was measured by the voltmeter 70 while changing the applied voltage value by the power supply 60 in a state where the potential detected by the voltmeter 70 is in contact with the E point which is a position of about 2V. It is a result.

  As shown in FIG. 14, when the potential is measured by the voltmeter 70 while changing the applied voltage by the power supply 60, the potential detected by the voltmeter 70 increases when the applied voltage by the power supply 60 is from 0V to 2V. . Further, when the voltage applied by the power source 60 is 2V to 4V, the potential detected by the voltmeter 70 is substantially constant at about 3V, although it varies slightly. Furthermore, the potential detected by the voltmeter 70 rises when the voltage applied by the power supply 60 is 4V to 5V.

  From this experimental result, the inventor corresponds to the two contact points that the applied voltage value at which the potential detected by the voltmeter 70 starts to become constant and the applied voltage value at which the potential starts to rise again after becoming constant. It was found to be a voltage value. In other words, the voltage value at which the applied voltage starts to become substantially constant and the voltage detected by the voltmeter 70 is 2V indicates the potential corresponding to the point E which is one of the two contact positions. It has been found that a voltage value of 4V applied voltage that starts to increase after the detected voltage starts increasing after a substantially constant value indicates a potential corresponding to point D which is the other contact position of the two contact positions. .

  Next, in step 106, it is determined whether or not there is an applied voltage range in which the initial potential value and the applied voltage value are different (first determination step). Specifically, in the case where the touch position on the touch panel is one point, when the same voltage value as the initial potential is applied by the power source 60, the voltmeter 70 measures the same voltage value as the initial potential, but a voltage different from the initial potential. When a value is applied, the voltmeter 70 measures a voltage value different from the initial potential. However, when the touch position on the touch panel is two points, when the same voltage value as the initial potential is applied by the power supply 60, the voltmeter 70 measures the same voltage value as the initial potential, but the voltage value different from the initial potential is Even if it is applied, the same voltage value as the initial potential may be measured. Therefore, even when a voltage different from the initial potential is applied by the power supply 60, it is determined whether the touch panel is touched at one point or two points depending on whether the same voltage value as the initial potential value is detected. It can be performed.

  Therefore, when a voltage value different from the initial potential value is applied by the power supply 60, if there is a case where the voltage value detected by the voltmeter 70 is the same value as the initial potential value, the process proceeds to step 110. On the other hand, when a voltage value different from the initial potential value is applied by the power source 60, if there is no case where the voltage value detected by the voltmeter 70 is the same value as the initial potential value, the process proceeds to step 108. .

  Next, in step 108 (S108), the position of the X coordinate at the contact position is calculated based on the value of the initial potential. Specifically, since the contact position is determined to be one point, the voltage value measured by the voltmeter 70 in a state where no voltage is applied by the power supply 60 by a control circuit and a calculation circuit (not shown). Based on (initial voltage value), the X coordinate is calculated. In this embodiment, in addition to the case where the touch position on the touch panel is one point, two points are touched, and the X coordinate value at these two points is also detected in the same manner. In this case, as will be described later, it is possible to determine whether the contact position is one point or two points by detecting the coordinate position of the Y coordinate.

  Next, in step 110 (S110), the X coordinate at the contact position is calculated based on the initial potential value and the voltage value measured by the voltmeter 70 when the applied voltage value is changed in the power supply 60. Specifically, a range of the applied voltage by the power source 60 in which the potential value detected by the voltmeter 70 is the same potential as the initial potential value is obtained by a control circuit and a calculation circuit (not shown). Based on the upper limit voltage value and the lower limit voltage value, the X coordinates (first coordinate position, second coordinate position) of the two contact positions are calculated. For example, in the case shown in FIG. 14, since the upper limit of the range of the applied voltage is 4V and the lower limit is 2V, the voltage value detected by the voltmeter 70 corresponds to the X coordinate corresponding to 4V and 2V, that is, E The X coordinates of point and point D are calculated. Thereby, the value of each X coordinate in the case where the contact position is two points of E point and D point can be obtained.

  Step 110 will be described in more detail based on the subroutine shown in FIG.

  First, in step 202 (S202), a range of applied voltage that is the same potential as the initial potential value is obtained. Specifically, the voltage applied by the power supply 60 is sequentially increased by a control circuit and a calculation circuit (not shown), and the potential value detected by the voltmeter 70 becomes the same potential as the initial potential value. Is stored in a memory (not shown) or the like to obtain a range of voltage applied by the power source 60 in which the potential value detected by the voltmeter 70 is the same as the initial potential value.

  Next, in step 204 (S204), the coordinate position is calculated based on the upper limit value of the applied voltage range obtained in step 202. Specifically, the voltage applied by the power source 70 is within the range of the voltage applied by the power source 60 where the potential value detected by the voltmeter 70 stored in a memory (not shown) is the same as the initial potential value. The highest voltage value (upper limit value) is extracted, and the coordinate position is calculated based on this value.

  Next, in step 206 (S206), the coordinate position is calculated based on the lower limit value of the range of the applied voltage obtained in step 202. Specifically, the voltage applied by the power source 70 is within the range of the voltage applied by the power source 60 where the potential value detected by the voltmeter 70 stored in a memory (not shown) is the same as the initial potential value. The lowest voltage value (lower limit value) is extracted, and the coordinate position is calculated based on this value.

  As described above, the respective contact positions when there are two contact positions, that is, the X coordinates of the points E and D are calculated, and thereafter, the process returns to the main routine.

Next, in step 112 (S112), an initial potential in the Y direction is measured (third potential detection step). Specifically, as shown in FIG. 11, a voltage of 5 V is applied to the electrode 42 in the lower electrode substrate 40, and a voltage of 0 V is applied to the electrode 41. Thus, the transparent conductive film 40, causing a potential gradient in the Y direction. In this state, the potential is measured by the voltmeter 70 connected to the electrode 21. In this step, the power source 60 is not connected to the electrode 22, or even if the power source 60 is connected to the electrode 22, the voltage is not applied to the electrode 22. . The potential measured in this state is a potential for specifying the position coordinates of the touch position when the touch position on the touch panel is one point. Further, when there are two contact positions on the touch panel, the potential corresponds to the position coordinates of a position that is approximately the middle point of the two contact positions.

  Next, in step 114 (S114), the applied voltage is changed and the potential in the Y direction is measured (fourth potential detecting step). Specifically, in a state where the power source 60 is connected to the electrode 22 and a voltage can be applied to the electrode 22 by the power source 60, the power source 60 applies the voltage to the electrode 22 while increasing the voltage sequentially and connects to the electrode 21. The electric potential is measured by the voltmeter 70. The range of the voltage applied by the power source 60 is the range of the voltage applied to the electrode 22 from the voltage applied to the electrode 21, that is, 0V to 5V in the present embodiment. In this step, the same operation as that performed in the case of the X coordinate in step 104 is also performed for the Y coordinate.

  Next, in step 116 (S116), it is determined whether or not there is an applied voltage range in which the initial potential value and the applied voltage value are different (second determining step). That is, even when a voltage value different from the initial potential value is applied by the power supply 60, if the voltage value detected by the voltmeter 70 may be the same value as the initial potential value, the process proceeds to step 120. . On the other hand, when a voltage value different from the initial potential value is applied by the power supply 60, if there is no case where the voltage value detected by the voltmeter 70 is the same value as the initial potential value, the process proceeds to step 118. .

  Next, in step 118 (S118), the position of the Y coordinate at the contact position is calculated based on the value of the initial potential. Specifically, since it is determined that the contact position is a single point, a voltage value (measured by the voltmeter 70 in a state in which no voltage is applied by the power supply 60 by a control circuit and a calculation circuit (not shown)) ( The Y coordinate is calculated based on the initial voltage value. In this embodiment, as will be described later, in addition to the case where the touch position on the touch panel is one point, the case where the Y coordinate values at the two touch positions are equal is also detected. In this case, since it is determined in step 106 that the two points are in contact, the Y coordinate values of the contact positions at the two points are equal.

  Next, in step 120 (S120), the Y coordinate at the contact position is calculated based on the initial potential value and the voltage value measured by the voltmeter 70 when the applied voltage value is changed in the power supply 60. Specifically, a range of the applied voltage by the power source 60 in which the potential value detected by the voltmeter 70 is the same potential as the initial potential value is obtained by a control circuit and a calculation circuit (not shown). Based on the upper limit voltage value and the lower limit voltage value, the Y coordinate of the two contact positions is calculated. Specifically, the Y coordinate (third coordinate position, fourth coordinate position) of the two contact positions is calculated by performing a subroutine shown in FIG. From the above, the first coordinate position and the second coordinate position that are the X coordinates of the two points obtained in step 110, the third coordinate position that is the Y coordinate of the two points obtained in step 120, and the fourth coordinate position. From the coordinate position, the XY coordinates at the two contact positions can be obtained.

  As described above, even if it is determined in step 106 that the contact position is one point, it may be determined in step 116 that the contact position is two points. In this case, the touch positions on the touch panel are two points, the X coordinate positions at the two points are equal, and the Y coordinate positions are different.

  Even if it is determined in step 106 that the contact position is two points, it may be determined in step 116 that the contact position is one point. In this case, the touch positions on the touch panel are two points, the Y coordinate positions at the two points are equal, and the X coordinate positions are different.

  As described above, the coordinate position at the contact position on the touch panel in the present embodiment is detected. Further, by repeatedly performing step 102 to step 120, it is possible to detect the movement of the touch position on the touch panel.

  Moreover, in the position detection method in the touch panel in this Embodiment, it is possible to detect the position coordinate of each contact position, even if there are a plurality of contact positions, without dividing the touch panel.

[Second Embodiment]
Next, a second embodiment will be described. In the present embodiment, the processes in steps 110 and 120 in the first embodiment are different from those in the first embodiment. That is, the subroutine for detecting the coordinate position at two points is different.

  The subroutine in the present embodiment will be described based on FIG.

  First, in step 302 (S302), it is determined whether or not the previous touch position (the touch position detected when the main routine shown in FIG. 12 was executed last time) on the touch panel is one point. In the present embodiment, the coordinate position of the previous contact position is stored in a memory (not shown) or the like. If it is determined that the previous contact position is one point, the process proceeds to step 310. On the other hand, if it is determined that the previous contact position is not one point, the process proceeds to step 304.

  Next, in step 304 (S304), the range of the applied voltage that is the same potential as the initial potential value is obtained. Specifically, the voltage applied by the power supply 60 is sequentially increased by a control circuit and a calculation circuit (not shown), and the potential value detected by the voltmeter 70 becomes the same potential as the initial potential value. Is stored in a memory (not shown) or the like to obtain a range of voltage applied by the power source 60 in which the potential value detected by the voltmeter 70 is the same as the initial potential value.

  Next, in step 306 (S306), the coordinate position is calculated based on the upper limit value of the range of applied voltage obtained in step 304. Specifically, the voltage applied by the power source 70 is within the range of the voltage applied by the power source 60 where the potential value detected by the voltmeter 70 stored in a memory (not shown) is the same as the initial potential value. The highest voltage value (upper limit value) is extracted, and the coordinate position is calculated based on this value.

  Next, in step 308 (S308), the coordinate position is calculated based on the lower limit value of the applied voltage range obtained in step 304. Specifically, the voltage applied by the power source 70 is within the range of the voltage applied by the power source 60 where the potential value detected by the voltmeter 70 stored in a memory (not shown) is the same as the initial potential value. The lowest voltage value (lower limit value) is extracted, and the coordinate position is calculated based on this value.

  Next, in step 310 (S310), a coordinate position is calculated based on the previous contact position and the initial potential. Specifically, when the repetition cycle from step 102 to step 120 is short, it is assumed that the contact point (one contact point) hardly moves during this cycle, and the position coordinate of one contact point is the previous time. It is possible to easily detect the position coordinate on the other side by assuming that the coordinate position is the same.

  That is, since the initial potential value indicates the potential at the midpoint between the two contact positions, if the X coordinate of one of the two contact positions is known, the X coordinate is solved. The X coordinate of the other contact position can be obtained from the X coordinate of the one contact position and the value of the initial potential. Specifically, if the X coordinate of one contact position whose X coordinate is known is X1, the coordinate position calculated from the initial potential value is Xa, and the X coordinate of the other contact position is X2, the other contact position The coordinate position X2 of the X coordinate can be obtained by equation (1).

  X2 = 2 × Xa−X1 (1)

  If the Y coordinate of one contact position where the Y coordinate is known is Y1, the coordinate position calculated from the initial potential value is Ya, and the Y coordinate of the other contact position is Y2, the other Y coordinate The coordinate position Y2 can be obtained by equation (2).

  Y2 = 2 × Ya−Y1 (2)

  In this way, when one point is touched in the previous coordinate position detection, this one point is regarded as one contact position, and the position coordinate of the other contact position can be calculated assuming that the coordinate position is known. Is possible.

  As described above, the position coordinates of each contact position when there are two contact positions can be calculated. After the completion of this subroutine, the process returns to the main routine in the first embodiment.

[Third Embodiment]
Next, a third embodiment will be described. In the present embodiment, the connection position of the power source connected to the touch panel is different from that of the first embodiment.

  Specifically, in the present embodiment, as shown in FIG. 17, when detecting the coordinate position in the X direction, the electrode 43 having an area substantially equal to the contact region at the point D and the point E is provided on the lower electrode substrate 30. The voltage is changed by the power supply 60 from the electrode 43 and applied. By making the size of the electrode connected to the power source 60 substantially equal to the contact area at the point D and the point E, it is possible to appropriately control the influence of the potential supplied from the power source 60 and to accurately The coordinates of the contact position can be detected. Further, a transparent conductive film removal region 44 obtained by removing a part of the transparent conductive film 40 may be provided around the electrode 43. Furthermore, instead of the electrode 43, an electrode 45 having a size substantially equal to the contact area at the point D and the point E may be provided at a part of the four corners of the lower electrode substrate 30.

  Similarly, when detecting the coordinate position in the Y direction, the upper electrode substrate 10 is provided with the electrode 23 having a size substantially equal to the contact area at the point D and the point E, and connected to the power source of the power source 60 from the electrode 23. Apply with varying voltage. By making the size of the electrode connected to the power source 60 substantially equal to the contact area at the point D and the point E, it is possible to appropriately control the influence of the potential supplied from the power source 60 and to accurately The coordinates of the contact position can be detected. Further, a transparent conductive film removal region 24 from which a part of the transparent conductive film 20 is removed may be provided around the electrode 23.

  The contents other than the above are the same as in the first embodiment.

  As mentioned above, although the form which concerns on implementation of this invention was demonstrated, the said content does not limit the content of invention.

  The present invention can be applied to a 4-wire resistive touch panel, and is useful when the display of various information processing devices is configured with a 4-wire resistive touch panel. Examples of information processing devices in this case include a mobile phone, a personal digital assistant (PDA), a portable music player, a portable image player, a portable browser, a one-segment tuner, an electronic dictionary, a car navigation system, a computer, a POS terminal, and an inventory management terminal. ATM and various multimedia terminals.

DESCRIPTION OF SYMBOLS 10 Upper electrode substrate 11 Film 20 Transparent conductive film 21 Electrode 22 Electrode 30 Lower electrode substrate 31 Glass 40 Transparent conductive film 41 Electrode 42 Electrode 50 Spacer 60 Power supply 70 Voltmeter 81 Touch pen 82 Touch pen

Claims (10)

An upper electrode substrate having an upper conductive film formed on the first substrate;
A lower electrode substrate having a lower conductive film formed on a second substrate;
A first electrode and a second electrode provided at both ends of the upper conductive film to generate a potential distribution in the upper conductive film;
A third electrode and a fourth electrode provided at both ends of the lower conductive film in order to generate a potential distribution in a direction perpendicular to a potential distribution generated in the upper conductive film in the lower conductive film;
In the touch panel in which the upper conductive film and the lower conductive film are arranged to face each other,
In order to generate a potential distribution in the upper conductive film , a voltage having a constant value is applied to the first electrode and the second electrode, and measurement is performed on one of the third electrode and the fourth electrode. For detecting the potential on the other side ,
The touch panel is characterized in that the voltage for the measurement is applied variably within the voltage range of the constant value . An upper electrode substrate having an upper conductive film formed on the first substrate;
A lower electrode substrate having a lower conductive film formed on a second substrate;
A first electrode and a second electrode provided at both ends of the upper conductive film to generate a potential distribution in the upper conductive film;
A third electrode and a fourth electrode provided at both ends of the lower conductive film in order to generate a potential distribution in a direction perpendicular to a potential distribution generated in the upper conductive film in the lower conductive film;
In the touch panel in which the upper conductive film and the lower conductive film are arranged to face each other,
In order to generate a potential distribution in the lower conductive film , a voltage having a constant value is applied to the third electrode and the fourth electrode, and measurement is performed on one of the first electrode and the second electrode. For detecting the potential on the other side ,
The touch panel is characterized in that the voltage for the measurement is applied variably within the voltage range of the constant value . Voltage for the measurement, and an electrode having substantially the same area as the area of the region of contact Sawaten, said first electrode, said second electrode, said third electrode and said fourth electrode the touch panel according to claim 1 or 2, characterized in that supplied from different electrode. An upper electrode substrate having an upper conductive film formed on the first substrate;
A lower electrode substrate having a lower conductive film formed on a second substrate;
A first electrode and a second electrode provided at both ends of the upper conductive film to generate a potential distribution in the upper conductive film;
A third electrode and a fourth electrode provided at both ends of the lower conductive film in order to generate a potential distribution in a direction perpendicular to a potential distribution generated in the upper conductive film in the lower conductive film;
In the coordinate position detection method in the touch panel in which the upper conductive film and the lower conductive film are arranged to face each other,
In order to generate a potential distribution in the upper conductive film , a voltage having a certain value is applied to the first electrode and the second electrode, and the initial value is higher than either the third electrode or the fourth electrode. A first potential detection step of detecting a potential;
A second potential detection step of applying a measurement voltage to either one of the third electrode and the fourth electrode while increasing or decreasing, and detecting a potential on the other;
In the second potential detection step, even when the potential value for measurement is different, if the potential detected on the other side is constant, a determination step for determining that the second potential detection step has a plurality of contact points; ,
A coordinate position detection method characterized by comprising: If it is determined in the determination step that the contact point has a plurality of contact points, a first coordinate position is calculated based on the upper limit potential of the constant potential, and based on the lower limit potential of the constant potential. The coordinate position detection method according to claim 4 , further comprising a coordinate position detection step of calculating a second coordinate position. In the case where it is determined in the determination step that it has a plurality of contact points, and one of the plurality of contact points can be regarded as known,
When the coordinate position at one contact point is X1 and the coordinate position obtained by the initial potential value is Xa, the coordinate position X2 of the other contact point is:
X2 = 2 * Xa-X1
The coordinate position detection method according to claim 4 , further comprising a coordinate position calculation step calculated by: The determination step is a first determination step,
After the first determination step, a constant voltage is applied to the third electrode and the fourth electrode in order to generate a potential distribution in the lower conductive film , and the first electrode or the first electrode A third potential detection step of detecting a second initial potential from one of the two electrodes;
A fourth potential detection step of applying a measurement voltage to either one of the first electrode and the second electrode while increasing or decreasing the voltage and detecting a potential on the other;
In the fourth potential detection step, even if the potential value for measurement is different, the second potential is determined to have a plurality of contact points if the potential detected on the other side is constant. A decision process;
The coordinate position detection method according to claim 4, comprising : If it is determined in the second determination step that the contact point has a plurality of contact points, a third coordinate position is calculated based on the upper limit potential of the constant potential, and the lower limit of the constant potential is determined. The coordinate position detection method according to claim 7 , further comprising a coordinate position detection step of calculating a fourth coordinate position based on the potential. In the case where it is determined in the determination step that it has a plurality of contact points, and one of the plurality of contact points can be regarded as known,
When the coordinate position at one contact point is Y1, and the coordinate position obtained by the value of the second initial potential is Ya, the coordinate position Y2 of the other contact point is
Y2 = 2 × Ya−Y1
The coordinate position detection method according to claim 7 , further comprising a coordinate position calculation step calculated by: The first potential detection step, the second potential detection step, the first determination step, the third potential detection step, the fourth potential detection step, and the second determination step are sequentially repeated. The coordinate position detection method according to any one of 7 to 9 .

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