JP2008146654A - Touch panel, and position detection method for use in the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a touch panel having single-layered wiring. <P>SOLUTION: The touch panel and the position detection method therefor is provided. The touch panel includes a board and a single-layered circuit disposition formed on the board. The single-layered circuit disposition includes a plurality of conductive circuits. Each conductive circuit has an electric resistance value which gradually varies as a distance to one end thereof is varied. The touch panel has an advantage of low cost. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a structure of a touch panel, and particularly to a touch panel having a single-layer wiring and a position detection method used therefor.

  Many manufacturers now use capacitive touch sensitive devices. The greatest advantage of the capacitive touch sensitive technology is that it is very sensitive to fingers, and it is accurately sensed even if the touch panel is gently pressed. Since the capacitive touch-sensitive device has the above-described features, it is suitable for a computer pointing device.

  At present, the object applied to the capacitive sensing device is limited to a conductive object (for example, a human finger) that has a larger contact area with the touch panel and generates a large capacitance that can be detected. The capacitance resulting from very small or non-conductive objects is very small and difficult to detect. Therefore, the pen is not accurately and stably responsive, thus limiting the application of capacitive touch sensitive devices. For example, the pattern input board must be input with a pen in order to maintain the accuracy of the picture, and a capacitive touch sensitive device cannot be used.

  Referring to FIGS. 1 and 2 together, the conventional capacitive touch panel 10 includes a hard substrate (not shown) having a first surface and a second surface facing the first surface. The X-axis circuit layer 12 disposed on the first surface includes a plurality of first parallel sensitive conductive circuits 16 that are located on a plane parallel to the first surface and extend along the first direction. The Y-axis circuit layer 14 disposed on the second surface is located on a plane parallel to the second surface and extends along a second direction perpendicular to the first direction. 18 is provided. A conformable material layer (not shown) is placed on the substrate. A conductive material layer (not shown) is provided on the upper surface of the conformable material layer, and a protective layer (not shown) is provided on the upper surface of the conductive layer.

  When the surface of the capacitive touch panel sensitive device is pressed with a finger, the capacitance changes at the touch point of the touch panel. Based on the change in capacitance, the X and Y coordinates of the contact point can be calculated. Then, a command corresponding to the contact point is output from the system. As the conductive layer approaches, the capacitance measured by the sensitive device matrix increases, thus producing a contact signal. The sensitive device matrix includes an X-axis circuit layer 12 and a Y-axis circuit layer 14. The contact signal clearly indicates the position of the contact point. The first parallel sensitive conductive circuit 16 and the second parallel sensitive conductive circuit 18 are typically formed by patterning, etching circuit board materials such as copper foil, or other methods. Since copper has a lower electrical resistance, the electrical resistance at both ends of the circuit is almost zero and the energy consumption is very low.

  A first object of the present invention is to provide a touch panel having a single-layer wiring that solves the above-described problems, where the single-layer wiring is simple, and two-dimensional localization is performed using the single-layer wiring. Can be provided.

  A second object of the present invention is to solve the above problems and provide a position detection method used for a touch panel, which can achieve a two-dimensional position localization using a one-dimensional wiring detection circuit. it can.

  In order to achieve the first object, a touch panel according to the present invention includes a substrate and a single-layer circuit arrangement formed on the substrate. The single layer circuit arrangement includes a plurality of conductive circuits, and each conductive circuit has an electrical resistance value that is increased or decreased as the distance from one end thereof is changed.

  In order to achieve the first object, another touch panel according to the present invention includes a substrate and a single-layer circuit arrangement formed on the substrate. The single-layer circuit arrangement includes a plurality of conductive circuits, and each conductive circuit has an electric resistance value that is gradually changed as the distance from one end thereof is changed.

  In order to achieve the second object, a position detection method used for a touch panel according to the present invention is used to detect a contact position of a contact object on a touch panel including a plurality of conductive circuits. In these conductive circuits, the portions installed in the position detector are arranged at intervals along the first dimension direction, and the portions installed in the position detector in the conductive circuit are parallel along the second dimension direction. The unit electric resistance values of the portions extending in parallel with each other along the second dimension of the conductive circuits are changed according to the distance from one end of the conductive circuits. In the position detection method according to the present invention, first, the total of the product of the electrical resistance and the capacitance of each part of the conductive circuit is calculated, and the coordinate value in the second dimension direction of the contact position is determined based on the calculated total. .

  The touch panel according to the present invention employs a single-layer circuit arrangement in which the electric resistance value is gradually changed as the distance to one end thereof is changed, so that coordinates in a single direction or two directions are detected. It has simple wiring and low cost.

  Hereinafter, specific embodiments will be described in detail with reference to the drawings, so that the above-described object and other objects, features, and advantages of the present invention can be understood more easily.

  Please refer to Fig.3 and Fig.4 together. The touch panel 20 includes a substrate (not shown), a single layer circuit arrangement 22 and a touch panel controller 24. The single layer circuit arrangement 22 is installed on the substrate, and the touch panel controller 24 is connected to the single layer circuit arrangement 22. The single layer circuit arrangement 22 includes a plurality of conductive circuits 26 extending along a plurality of horizontal directions. Each conductive circuit 26 is composed of all n sequentially connected conductive units 28, and the first conductive unit 28 is connected to the touch panel controller 24. The electrical resistance of the conductive circuit 26 increases as the distance from the first conductive unit 28 increases. The electrical resistance for each conductive unit 28 satisfies the following relationship.

  Rn = nR (1)

  Rn represents the electrical resistance of the nth conductive unit, n is a natural number, and R is the electrical resistance of the starting conductive unit 28. The time constant of the conductive circuit 26 is expressed by the following equation.

  T = R * C + 2R * C + 3R * C + ... + (n-1) R * C + nR * C = n * (n + 1) * R * C / 2 (2)

  T is a time constant, and C is the electric capacity of the conductive circuit 26.

  When the surface of the touch panel 20 is pressed with a finger or a pen, a change in capacitance occurs at the contact position, and the single-layer circuit arrangement 22 detects the change. Therefore, the touch panel controller 24 uses the contacted conductive circuit 26 at the contact position. Detect accurately. At the same time, the time constant of the conductive circuit 26 increases correspondingly as shown in the following equation.

  T = R * C + 2R * C + 3R * C +... + IR * (C + ΔC) + (n−1) R * C + nR * C = n * (n + 1) * R * C / 2 + iR * ΔC (3)

  iR (1 ≦ i ≦ n) is the electric resistance of the conductive unit 28 of the conductive circuit 26 that is in contact, and ΔC is the electric capacity with increased fingers. When the touch panel controller 24 detects that the time constant of the conductive circuit 26 is altered, the touch panel controller 24 can accurately determine the specific position of the contact position. Therefore, the two-dimensional coordinates of the contact position where the object presses the touch panel can be accurately determined by the single-layer circuit arrangement 22.

  FIG. 5 is a diagram illustrating a structure of a touch panel according to another embodiment of the present invention. Most of the structure of the touch panel 40 is the same as that of the first embodiment. In these conductive circuits 46, the portions installed in the position detection unit (the solid line block portion indicated by number 46 in FIG. 5) are arranged along the Y-axis direction (hereinafter referred to as the first dimension direction). In these conductive circuits 46, the portion installed in the position detection unit extends in parallel along the X-axis direction (hereinafter referred to as the second dimension direction). The unit electric resistance values of the portions of these conductive circuits 46 extending in parallel along the second dimension direction are modified according to the distance from one end (right end or left end) of the conductive circuit 46. Another difference is that the beginning and end of the conductive circuit 46 are all connected to the touch panel controller 44. When operating, the conductive circuit 46 is scanned once from the beginning and once again the conductive circuit 46 is scanned from the end. Thus, position tolerances caused by pressure, contact area, humidity or other causes can be overlooked, thus reaching the purpose of accurately and stably detecting the contact position. For example, as shown in FIG. 6 and FIG. 7, the maximum detected when touching the same position (assuming that it is the second circuit unit of the second circuit of the touch panel 40) with two fingers having different dimensions separately. From the viewpoint of the electrical capacity, the first dimensional coordinates of the contact position (in this embodiment, only knowing that it is located in the second circuit) can be easily localized, and then the time constant is calculated. By this method, it is possible to know the coordinates in the second dimension direction of the contact position (in this embodiment, it can be localized to the second circuit unit).

  It should be noted that the maximum energy detected by the touch panel controller is different because the contact area is different. Therefore, the control method that only scans one end of the conductive circuit can obtain two different maximum energies in this case, and also obtain two different contact areas. However, in the control method used for the touch panel 40 according to the present embodiment, since the scanning is separately performed from both ends of the conductive circuit 46, the above problem can be effectively solved, and an accurate detection result is obtained.

  The above-described conductive circuit that increases the electrical resistance in proportion can be formed of various conductive materials, such as indium tin oxide (ITO), a flexible circuit board, a printed circuit board, or a thin film. . When the conductive circuit employs an indium tin oxide material, the electrical resistance is increased by controlling the width of each conductive unit. When the conductive circuit employs a printed circuit board, the electrical resistance is increased by applying a different electrical resistance to each conductive unit. In the same reason, the conductive circuit can have an electrical resistance that decreases proportionally.

  Since the touch panel according to the present invention employs a single-layer circuit arrangement having an electrical resistance that increases in proportion or decreases in proportion, it can detect coordinates in a single direction or in two directions. Since the touch panel according to the present invention has simple wiring, the cost is low. Note that the coordinate value in the second dimension direction of the contact position can be determined by calculating the total (time constant) of the product of the electrical resistance and the electrical capacitance at each location for each conductive circuit.

  The present invention has been specifically described above based on the embodiments. However, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the scope of the present invention. Thus, the protection scope of the present invention is determined from the following claims.

It is a top view which shows the structure of the conventional touch panel. It is sectional drawing of the touch panel shown in FIG. It is a top view which shows the structure of the touchscreen which concerns on the 1st Example of this invention. It is a figure which shows the electrical resistance of the electrically conductive circuit shown in FIG. It is a top view which shows the structure of the touchscreen which concerns on the 2nd Example of this invention. It is a figure which shows the change of energy when contacting the same position of a touch panel with a different finger. It is a figure which shows the change of energy when contacting the same position of a touch panel with a different finger.

Explanation of symbols

20, 30, 40 Touch panel 22 Single layer circuit arrangement 24, 34, 44 Touch panel controller 26, 36, 37, 46 Conductive circuit 28 Conductive unit

Claims (11)

  A single-layer circuit arrangement formed on the substrate and the substrate, the single-layer circuit arrangement includes a plurality of conductive circuits, and each conductive circuit increases as the distance from one end thereof is changed A touch panel having an electrical resistance value that is reduced or reduced.   The touch panel according to claim 1, wherein the conductive circuit has an electrical resistance that increases in proportion or decreases in proportion.   The touch panel according to claim 1, further comprising a touch panel controller connected to the single-layer circuit arrangement.   The touch panel controller according to claim 3, wherein the touch panel controller is connected to a start end and a terminal end of each conductive circuit.   The touch panel as set forth in claim 1, wherein the conductive circuit is formed of at least one of indium tin oxide, a flexible circuit board, a printed circuit board, and a thin film.   Each of the conductive circuits includes a plurality of conductive units connected in sequence, and controls the width of these conductive units or applies different electrical resistances to these conductive units to The touch panel according to claim 1, wherein the resistance is increased.   The touch panel according to claim 1, further comprising a protective layer, a conformable material layer, and a conductive layer.   The touch panel controller according to claim 3, wherein the touch panel controller detects a change in energy or a change in time constant caused by altering the electrical resistance of these conductive circuits.   The touch panel controller according to claim 3, wherein the touch panel controller detects an accurate position of the contact point based on a change in electric capacity and energy or a change in electric capacity and time constant. A position detection method used for detecting a contact position of a contact object on a touch panel including a plurality of conductive circuits, wherein a portion installed in the position detection unit in these conductive circuits is a first dimension direction In the conductive circuit, the part installed in the position detection unit extends in parallel along the second dimension direction, and extends in parallel along the second dimension direction of these conductive circuits. The unit electric resistance value is modified according to the distance from one end of these conductive circuits, and the position detection method is:
Calculating the sum of the product of electrical resistance and capacitance at various locations for each conductive circuit;
Determining a coordinate value in the second dimension direction of the contact position based on the calculated total;
A position detection method comprising: The position detection method according to claim 10, wherein a coordinate value in the second dimension direction of the contact position is determined by subtracting a scheduled value from the calculated total.

Images