JP5403905B2 - Resistive touch panel - Google Patents

Description

  The present invention relates to a touch panel, and more particularly to a resistive touch panel that can simultaneously detect two points on a touch panel.

  The touch panel is widely used as an input device by being overlapped with a display device. Various methods such as a resistance method and a capacitive coupling method are known as a position detection method when touching the touch panel with a finger or the like, but the resistance method has the simplest structure, and a dedicated pen, etc. It is superior in that it does not require a device.

  6A and 6B are schematic views of a conventional resistive touch panel. As shown in FIG. 6A, the touch panel 100 overlaps the X-side resistance film 1 and the Y-side resistance film 2 with a minute gap provided so that the side on which the resistance film is formed is opposed. A first X electrode terminal 3 and a second X electrode terminal 4 are provided on opposite sides of the X-side resistance film 1, and voltages Vcc and 0 V are applied thereto, respectively. Similarly, a first Y electrode terminal 5 and a second Y electrode terminal 6 are provided on opposite sides of the Y-side resistance film 2, and these are provided on a side orthogonal to the side on which the X electrode terminal is provided. ing. A position detection method when one point on the touch panel 100 is pressed will be described. When a certain point on the X-side resistance film 1 is pressed with a pen 7 or the like, the contact with the contact 8 on the Y-side resistance film 2 is made, and the potential at the contact 8 is set using the voltmeter 11 connected to the Y-side resistance film 2. taking measurement. The potential at this time is a value obtained by dividing Vcc by the first X-side resistor 9 and the second X-side resistor 10 on the X-side resistor film 1. If the sheet resistance of the resistance film is uniform in the plane, the pressed position on the X electrode film can be known from the measured potential.

  On the other hand, the voltages 0V and Vcc are also applied to the first Y electrode terminal 5 and the second Y electrode terminal 6 provided on opposite sides of the Y-side resistance film 2, respectively. A voltmeter 11 is also provided on the X-side resistance film 1, and a voltage obtained by dividing Vcc by the first Y-side resistance 13 and the second Y-side resistance 14 of the Y-side resistance film 2 is measured. From this measurement result, the position on the Y electrode film can be known. A similar measurement method is disclosed in Patent Document 1.

JP-A-8-161099

  However, the conventional resistive touch panel has a problem that the position cannot be detected when two points on the touch panel are pressed by simply measuring the voltage. This problem will be described with reference to FIG. As shown in the figure, when two points on the touch panel, for example, both ends of the resistance film, are pressed using the pens 71 and 72, the detected voltage becomes a voltage near the midpoint, and the voltage measurement result indicates It was difficult to obtain the coordinates of two points.

  The resistive touch panel according to the present invention is a resistive touch panel including two flat plates in which two planar conductive layers including electrodes are opposed to each other on opposite sides, and the first point where the two flat plates are in contact with each other. First point position detecting means for detecting the position of the eye, storage means for storing the position of the first point, and second point detecting means for detecting the second point where the two flat plates contact each other A point-to-point distance calculating means for calculating a distance between the first point and the second point, and detecting a middle point coordinate between the first point and the second point Point coordinate detection means; and second point position calculation means for calculating the position of the second point based on the position of the first point, the distance between the two points, and the midpoint coordinates. It is characterized by.

  In the resistance touch panel of the present invention, the second point detection means may include interelectrode resistance measurement means.

  In the resistance touch panel of the present invention, the distance calculation means between the two points may use a measured resistance value.

  The resistive touch panel according to the present invention may further include a change rate detection means for detecting a temporal change in the distance between two points.

  The resistive touch panel according to the present invention may further include an output unit that outputs a midpoint coordinate between two points together with a temporal change rate of the distance between the two points.

  According to the present invention, a distance between two points can be easily calculated by measuring an inter-electrode resistance in a resistance touch panel, and can correspond to application software for pressing two points on the touch panel.

  Hereinafter, a resistive touch panel according to the present invention will be described with reference to the drawings. However, it should be noted that the technical scope of the present invention is not limited to these embodiments, but extends to the invention described in the claims and equivalents thereof.

<Overall measurement sequence>
FIG. 1 is a flowchart showing a driving sequence of a touch panel according to the present invention. First, in step 101, it is determined whether or not the first point is pressed. When one point on the touch panel is pressed and the X-side resistance film 1 and the Y-side resistance film 2 come into contact with each other, the X-side electrode terminal and the Y-side electrode terminal change in potential. Can be detected. Here, the detection method when two points on the touch panel are pressed will be described. However, it is impossible that two points are simultaneously pressed, and the timing of pressing the first point and the second point is always Therefore, even if two points are pressed, only the first point is initially pressed. Further, the coordinates of the position of the first point are detected from the detected potential. Since the detection method is the same as the conventional detection method described above, detailed description thereof is omitted. If the first point is not pressed, the process enters a waiting state.

  Next, when the first point is pressed, in step 102, the detected coordinates of the first point are stored in the storage means. This is because the coordinate data of the first point is used when calculating the coordinates of the second point.

  Next, in step 103, it is determined whether or not the second point has been pressed. Details of the contents of this determination step will be described later. If it is detected that the second point has been pressed, the process proceeds to a step of calculating the coordinates of the second point. If the second point is not detected, the process returns to step 101 and waits until the first point is detected.

  When the second point is detected, the resistance value is measured in steps 104 to 106, and the distance between the first point and the second point is calculated from the resistance value. The calculation method will be described later. Next, in step 107, the coordinates of the midpoint are calculated. The coordinates of the midpoint are determined by measuring the voltage with two points pressed. Next, in step 108, the coordinates of the second point are calculated from the distance between the two points and the coordinates of the middle point.

<Configuration of Touch Panel of the Present Invention>
As shown in FIG. 2A, the touch panel of the present invention has an X-side resistance film 1 formed of a planar conductive layer having a first X electrode terminal 3 and a second X electrode terminal 4 on two opposite sides. The flat plate and the Y-side flat plate in which the Y-side resistive film 2 made of a planar conductive layer having the first Y electrode terminal 5 and the second Y electrode terminal 6 is opposed to two opposite sides orthogonal to the X electrode terminal are opposed to each other. Are provided with two flat plates. Vcc and OV are applied to the first X electrode terminal 3 and the second X electrode terminal 4, respectively, and an electrometer (not shown) is provided on at least one of the electrodes. Similarly, the first Y electrode terminal 5 and Vcc and OV are applied to the second Y electrode terminal 6, respectively, and at least one electrode is provided with an electrometer (not shown), and two flat plates are in contact with each other based on the measured values of these electrometers. First point position detecting means for detecting the position of the first point is provided. In addition, storage means for storing the position of the first point is provided outside the touch panel. Further, as shown in FIG. 2A, a resistance measuring device 12 is provided between the first X electrode terminal 3 and the second X electrode terminal 4, and similarly, the first Y electrode terminal 5 and the second Y electrode terminal 6 Between them, a resistance measuring device (not shown) is provided, and these constitute second point detecting means for detecting the second point where the two flat plates contact. Instead of this resistance measuring device, an ammeter may be arranged in series with the resistance layer, and the resistance may be calculated from the current value. Further, a two-point distance calculation means for calculating a distance between two points from the measured resistance value is provided outside the touch panel. Further, the midpoint coordinates between the two points can be detected from the potential when the two points are pressed, and the electrometer constitutes the midpoint coordinate detection means. Further, a second point position calculating unit is provided outside the touch panel for calculating the position of the second point based on the distance between the two points and the midpoint coordinates.

<Second point detection determination step>
Next, each step will be described in detail.
In order to detect that the second point is pressed while one point on the touch panel is pressed, the resistance value of the X-side resistance film 1 is measured. First, for comparison, the resistance in a state where one point of the X-side resistance film 1 is pressed will be described with reference to FIGS. The resistance is measured by using a resistance measuring instrument 12 installed between the first X electrode terminal 3 and the second X electrode terminal 4 of the X-side resistance film 1. As shown in FIG. 2A, it is assumed that when one point at a substantially central portion of the X-side resistance film 1 is pressed by the pen 7, the Y-side resistance film 2 is in contact with the contact 8. At this time, the resistance of the X-side resistance film 1 is the sum of the first X-side resistance 9 and the second X-side resistance 10, and does not change even when the X-side resistance film 1 is pressed. This is because the Y-side resistance film 2 does not contribute to the change in resistance value. As is apparent from the equivalent circuit shown in FIG. 5B, the first Y-side resistor 14 and the second Y-side resistor 15 of the Y-side resistor film 2 are opened, and the Y-side resistor film 2 changes its resistance value. It turns out that it does not contribute to. For example, if the first X-side resistor 9 and the second X-side resistor 10 are both 100Ω, the measured resistance value is 200Ω.

Next, a case where two points of the central portion and the end portion of the X-side resistance film 1 are pressed will be described with reference to FIGS. The substantially central portion of the X-side resistance film 1 is pressed with the pen 71 and the end portion is pressed with the pen 72. At this time, the contact point 13 of the X-side resistance film 1 and the contact point 8 of the Y-side resistance film 2 come into contact with the pen 71, and the contact point 16 between the X-side resistance film 1 and the contact point of the Y-side resistance film 2 with the pen 72. 17 is in contact, and the contact resistance between these two sets of contacts is assumed to be negligibly small. The equivalent circuit when the resistance measuring instrument 12 is installed between the first X electrode terminal 3 and the second X electrode terminal 4 of the X-side resistance film 1 is shown in FIG. The second X-side resistor 10 and the second Y-side resistor 15 are connected in parallel. If the second X-side resistor 10 and the second Y-side resistor 15 have substantially the same resistance value, the value of the parallel resistor is It becomes about half of the value of the 2X side resistor 10. For example, if the first X-side resistor 9 and the second X-side resistor 10 are both 100Ω, the measured resistance value is 150Ω.
In this way, it is possible to detect that the second point has been pressed by measuring the resistance value and detecting that the size has decreased.

<Detection of distance between two points>
After detecting that the second point is pressed, the distance between the two points is calculated from the measured resistance value. As described above, when the X-side resistance film 1 and the Y-side resistance film 2 contact at two points, the resistance value between the first X electrode terminal 3 and the second X electrode terminal 4 of the X-side resistance film 1 decreases. However, the decreasing resistance value is approximately proportional to the distance between the two touching points. However, since the X-side resistance film 1 and the Y-side resistance film 2 have a finite size, the resistance value may be different depending on the position on the plane. Further, it is desirable that the contact resistance between the X-side resistance film 1 and the Y-side resistance film 2 is negligible, but there may be variations in pressing for each user, and the contact resistance may need to be taken into consideration.
Therefore, it is desirable to obtain a relationship between the position of the two points to be pressed and the resistance value in advance, create a table, and perform calibration based on the created table. For example, as shown in FIGS. 4A and 4B, consider a case where the vicinity of both ends of the X-side resistance film 1 is pressed. At this time, the contact point 18 of the X-side resistive film 1 and the contact point 19 of the Y-side resistive film 2 are brought into contact with the pen 71, and the contact 16 of the X-side resistive film 1 and the contact point 17 of the Y-side resistive film 2 are similarly brought into contact with each other. Assume that. The equivalent circuit when the resistor 12 is installed between the first X electrode terminal 3 and the second X electrode terminal 4 of the X-side resistance film 1 is shown in FIG. The first X-side resistor 9 and the second X-side resistor 10 are connected in parallel with the first Y-side resistor 14 and the second Y-side resistor 15. Here, assuming that the first X-side resistor 9, the second X-side resistor 10, the first Y-side resistor 14, and the second Y-side resistor 15 are all 100Ω, the resistance value of the resistance measuring instrument 12 is 100Ω.

As already shown in FIGS. 2 to 4, the measured resistance value is determined by the distance between the two pressed points, so that the distance between the two points can be obtained from the measured resistance value. When the relationship between the measured resistance value and the distance between two points is generalized and graphed, the relationship is as shown in FIG. That is, when the distance between the two points is very small, it is considered equivalent to the case where only one point is pressed, and the resistance value between the X electrode terminals is R which is the maximum value. On the other hand, if the distance between the two points is a distance equal to the distance L of one side of the resistive film, the resistance value between the X electrode terminals is ½ · R, which is half the maximum value. Similarly, other points are plotted as shown in FIG.
Based on this graph, the distance between two points can be calculated from the resistance value. In this case, the distance between the two points may be obtained from the measured resistance value by a calculation formula, or may be obtained by referring to a calibration table.

<Detection of midpoint coordinates>
The detection of the midpoint coordinates is executed in step 107 in FIG. The coordinates of the midpoint use the characteristic that the voltage detected when the two points are pressed becomes equal to the voltage when the midpoint between the two points is pressed. The coordinates of this midpoint are used when calculating the coordinates of the second point.

  Further, in the case of moving while the two points are in contact, the coordinates of the midpoint are used to calculate the center. For example, when applied to application software that designates an arbitrary point on an image such as a map via a touch panel, two points are selected across an area to be enlarged, and the distance between the two points is increased. Applications that expand are conceivable. In this case, the area to be enlarged can be set at the midpoint between the two points.

<When changing the distance between two points over time>
An application to application software that changes the distance between two points in time and links the operation with enlargement / reduction of an image will be described. To know the variation of the distance between two points, calculates the distance d (t _i) between two points at a certain time t _i, the stored advance, predetermined time from t _i only past time t _i Compared with the distance d (t _i-1 ) in _-1 . Here, if the change Δd = d (t _i ) −d (t _i−1 ) detected by the change rate detecting means for detecting the temporal change in the distance between the two points is positive, the distance between the two points is increased. If it is negative, it can be determined that the distance between the two points is reduced.
Specifically, in step 104 in FIG. 1, in order to set an initial value of the distance between two points, an initial value d (t ₀ ) of the distance between two points is calculated with i = 0. Next, in step 105, i is incremented by 1 in order to define the distance between two points after a predetermined time has elapsed. Next, a distance d (t _i ) between the two points is calculated, and a change Δd = d (t _i ) −d (t _i−1 ) is calculated. For example, when i = 1, Δd = d (t ₁ ) −d (t ₀ ). Here, Δt = t _i −t _i−1 can be an arbitrary value. By calculating Δd, it is possible to determine whether the distance between the two points is increasing or decreasing. Furthermore, by calculating Δd / Δt over time, the acceleration can be calculated. Application to various application software becomes possible.

  Thus, in application software that enlarges / reduces an image in response to a change in the distance between two points, the center between the two points and the enlargement / reduction of the distance between the two points are important information. The coordinates of the two points are not significant. In the present invention, the distance between two points can be directly calculated from the resistance value, and the coordinates of the midpoint can be calculated from the potential of the electrode terminal when the two points are pressed. can do.

It is a flowchart showing the drive sequence of the resistance-type touch panel of this invention. An example of resistance measurement when one point of the resistance touch panel is pressed is shown. An example of resistance measurement when one point of the resistance touch panel is pressed is shown. An example of resistance measurement when two points of the center and end of the resistance touch panel are pressed is shown. It is a graph showing the relationship between the distance between two points on the resistance touch panel according to the embodiment of the present invention and the resistance measurement value. An example of potential measurement when one point of a resistive touch panel is pressed by a known technique will be described. An example of potential measurement when two points on a resistive touch panel are pressed by a known technique will be described.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 X side resistance film 2 Y side resistance film 3 1st X electrode terminal 4 2nd X electrode terminal 5 1st Y electrode terminal 6 2nd Y electrode terminal 7 Pen 71 Pen 72 Pen 8 Contact 9 1X side resistance 10 2nd X side resistance 11 Voltage Total 12 Resistance measuring instrument 13 Contact 14 1st Y side resistance 15 2nd Y side resistance 16 Contact 17 Contact 18 Contact

Claims (2)

A resistive touch panel provided with two flat plates each having a planar conductive layer provided with electrodes on two opposite sides,
First point position detecting means for detecting a position of a first point where the two planar conductive layers contact each other;
Second point detection means for detecting contact of the planar conductive layer at a second point different from the first point;
Midpoint coordinate detecting means for detecting midpoint coordinates between the first point and the second point;
Second point position calculating means for calculating the position of the second point based on the position of the first point and the middle point coordinates;
An interelectrode resistance measuring means for measuring a resistance value between the electrodes;
A point-to-point distance calculating means for calculating a distance between two points using the resistance value measured by the inter-electrode resistance measuring means;
A change rate detecting means for detecting a temporal change rate of the distance between two points;
And a potential detecting means for detecting a potential between the electrodes,
The first point position detection unit and the middle point coordinate detection unit detect the first point position and the middle point coordinate based on the interelectrode potential detected by the potential detection unit.
A resistive touch panel. With temporal variation of the distance between two points, further comprising output means for outputting the midpoint coordinates of the two points, resistive touch panel according to claim 1.

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