A single-layer capacitive touch screen

Abstract

The present invention is a single-layer capacitive touch screen, which includes two groups of parallel wires arranged along the X and Y directions on a substrate, M wires R arranged along the X direction, each wire R goes from left to right along the X direction and then goes back in the opposite direction from right to left along the X direction, and so on, until the M wires R are spaced in the X direction according to a first set distance, any group of continuous m wires R along the X direction are different; along the Y direction, they are the same, and each m×n intersection is an effective touch position during positioning. The present invention repeatedly removes the wires, resulting in fewer wire ends and lower costs.

Description

Technical Field

[0001] The present invention relates to the field of capacitive touch devices, and in particular to a single-layer capacitive touch screen. Background Art

[0002] Touch devices mainly include touch screens TP and touch whiteboards. Their main function is to locate the touch point or track. They are a type of computer input device. Generally, a transparent touch device installed in front of a display screen is called a touch screen, and a touch whiteboard is installed in an electronic board. At present, touch devices mainly include infrared touch devices, resistive touch screens, and capacitive touch screens based on the method of locating touch points or touch tracks. At present, infrared touch positioning is mainly used on electronic whiteboards, while resistive positioning and capacitive positioning methods are mainly used on touch screens. With the development of science and technology, resistive positioning and capacitive positioning methods are also used on electronic whiteboards.

[0003] At present, capacitive electronic whiteboards and touch screens are the main touch devices. Figure 1 As shown, a first protective layer 01 including glass or transparent PCT is formed, and a first conductive circuit layer 02 formed by etching a transparent ITO or the like is formed under the first protective layer. A dielectric layer 03 filled with transparent adhesive is formed under the first conductive circuit layer 02. A second conductive circuit layer 04 having the same basic composition as the first conductive circuit layer 02 is formed under the dielectric layer 03. A second protective layer 05 is formed under the second conductive circuit layer 04 or is directly attached to the display screen. In practice, the first conductive circuit layer 02 and the second conductive layer 04 are etched to form the following. Figure 2 The crisscross lines shown are generally horizontal lines (T, X direction) and vertical lines (R, Y direction). Since there is a dielectric layer 03 composed of insulating transparent glue between the first conductive line layer 02 and the second conductive line layer 04, the intersections of T and R are not in contact with each other (insulated). Therefore, there is a certain capacitance. When a pulse signal is emitted from T, a corresponding pulse signal will be received on R due to capacitance induction. If a human hand or other touch pen touches a certain intersection at this time, since there is also capacitance between the human hand or other touch pen and T or R, some energy will be induced. In this way, R will receive a pulse signal with a lower amplitude than normal. Figure 2 As shown in the figure, when the hand or touch pen touches the intersection of Tj and Ri, the Ri line will receive a pulse signal with a lower amplitude than the normal amplitude, so that the intersection of TjRi can be located as the touch point, which is an absolute positioning method. At this time, T and R can be copper wires or other solid metal wires, or transparent silver wires or transparent conductive films (most touch screens currently use transparent wires).

[0004] On a touch device such as a capacitive touch screen or a touch electronic whiteboard, the first conductive circuit layer 02 and the second conductive circuit layer 04 are both called sensing layers. The cost of the sensing layer accounts for a large proportion of the entire touch screen. Therefore, in order to reduce the cost, various methods are used in the art to reduce the laying of laminated materials. However, it is difficult to reduce the cost of two such sensing layers. For example, Chinese patent document CN103902092B discloses a touch screen with a double-layer conductive circuit layer. Summary of the invention

[0005] The present invention aims to solve the problem of high wiring cost on current capacitive touch screens or touch electronic whiteboards and other touch devices, and provides a single-layer capacitive touch screen.

[0006] The technical scheme of the present invention is: a single-layer capacitive touch screen, comprising a conductive circuit layer and a touch positioning device, characterized in that: on the conductive circuit layer, a first group of conductive wires T1, T2, T3 ... Tn and a second group of conductive wires R1, R2, R3 ... Rn are extended along a first direction, and the first group of conductive wires T1, T2, T3 ... Tn and the second group of conductive wires R1, R2, R3 ... Rn are arranged at intervals; and further comprising a signal transmitting device T and a signal receiving device R, wherein the signal transmitting device T is respectively composed of the first group of conductive wires T1, T2, T3 ... Tn and the second group of conductive wires R1, R2, R3 ... Rn. The starting end sends a set electrical signal, and the signal receiving device R receives electrical signals from the second group of conductive wires R1, R2, R3...Rn respectively; the signal receiving device R is also provided with a detection device for detecting the phase delay between the received signal and the set electrical signal; the touch positioning device determines the position of the touch point in the first direction according to the sequence number of the second group of conductive wires R1, R2, R3...Rn of which the signal receiving device R receives the signal, and determines the position of the touch point in the direction perpendicular to the first direction according to the phase delay of the signal received by the signal receiving device R.

[0007] Furthermore, in the above-mentioned single-layer capacitive touch screen: each conductive wire in the first group of conductive wires T1, T2, T3...Tn is arranged in parallel.

[0008] Furthermore, in the above-mentioned single-layer capacitive touch screen: the resistance per unit length of each conductive wire in the first group of conductive wires T1, T2, T3...Tn and the second group of conductive wires R1, R2, R3...Rn is linearly related to its length.

[0009] Furthermore, in the above-mentioned single-layer capacitive touch screen: the signal transmitting device T and the signal receiving device T are respectively arranged at the same end of the first group of conductive wires T1, T2, T3...Tn and the second group of conductive wires R1, R2, R3...Rn.

[0010] Furthermore, in the above-mentioned single-layer capacitive touch screen: the set electrical signal emitted by the signal emitting device T is a periodic square wave signal.

[0011] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural diagram of a touch screen in the prior art.

[0013] Figure 2 4 is a distribution diagram of the wires T and R in the touch screen according to the first embodiment of the present invention.

[0014] Figure 3 4 is a distribution diagram of the wires T and R in the touch screen according to the second embodiment of the present invention. DETAILED DESCRIPTION

[0015] This embodiment is a capacitive touch screen with only one conductive circuit layer. Figure 2 As shown, on this conductive circuit layer, two groups of conductive wires are arranged in parallel, including a first group of conductive wires T1, T2, T3...Tn and a second group of conductive wires R1, R2, R3...Rn, which are insulated from each other. The 2n conductive wires are arranged in parallel along the horizontal direction of the touch screen. A conductive wire Tj in the first group of conductive wires T1, T2, T3...Tn and a conductive wire Rj in the second group of conductive wires R1, R2, R3...Rn form a pair of transmitting-receiving conductive wire pairs. Here, a first group of conductive wires Ti is arranged at intervals, and a second group of conductive wires Ri is next to it. The next one is the first group of conductive wires Ti+1, and then Ri+1. In this way, the signal transmitting device T sends a periodic square wave signal on the conductive wire Tj. If the touch is between the conductive wires Tj and Rj at this time, as shown in FIG. Figure 1 When the touch point P1 in the touch screen is touched, the signal receiving device R connected to the conductive line Rj will receive the signal. At this time, the horizontal coordinate of the touch point on the touch screen can be determined by the serial number j of the conductive line Tj or the conductive line Rj, and the vertical coordinate of the touch point P1 is determined by the transmission distance of the transmitted signal on the conductive line Tj. In this embodiment, Figure 1 As shown, transparent silver wire (or ITO, etc.) is used as the conductive wire. The resistivity of the conductive wire, that is, the resistance per unit length is inversely proportional to the cross-sectional area of ​​the conductive wire, that is, inversely proportional to the product of the thickness and width of the conductive wire. In practice, the thickness of the conductive wire is basically the same. In this way, when the width of the conductive wire becomes narrower, its resistance per unit length will increase, such as Figure 1As shown, when the touch point P1 is at different positions of the conductive line Tj, the resistance of the conductive line Tj will be different. We know that the signal flowing through the conductive line Tj will be delayed due to the resistance of the conductive line Tj itself, and the phase of the delay is related to the resistance. After long-term experiments, the phase of the delay is proportional to the resistance. Therefore, in order to overcome the influence of phase delay, the touch screen manufacturer adopts the method of using materials with lower resistivity, which will further increase the cost. In this embodiment, it is not necessary to reduce the phase delay. On the contrary, it is necessary to detect the phase delay and use the detected phase delay to determine the ordinate of the touch point P1. When the touch point is at different places on the conductive line Tj, the delay of the signal received at the conductive line Rj is different. In this way, the touch positioning device of the display screen can determine the ordinate of the touch point P1 according to the detected phase delay.

[0016] In this embodiment, in order to accurately locate the ordinate of the touch point P1, the measurement is carried out according to practice. First, the touch point is set at the uppermost end of the touch screen, and the delay phase amount θ1 of the signal received at the conductive line Rj is measured at this time. Then, the touch point is set at the lowermost end of the touch screen, and the delay phase amount θ2 of the signal received at the conductive line Rj is measured at this time. The difference between the two phase delays △θ=θ2-θ1 is calculated; combined with the height H of the touch screen, the delay amount per unit height is calculated. Thus, when the touch point is at any point, the delay phase θ of the signal received at the conductive line Rj corresponds to the height In this way, the ordinate of the touch point P1 can be calculated.

[0017] In the above embodiment 1, the transmitting device T transmits at the upper end of the first group of conductive wires T1, T2, T3 ... Tn, and the signal receiving device R receives at the end of the second group of conductive wires R1, R2, R3 ... Rn. Therefore, conductive wires of the same width cannot be used, and only the first group of conductive wires T1, T2, T3 ... Tn with gradually narrowing widths can be used. In this way, the position of the touch point P1 in the first group of conductive wires T1, T2, T3 ... Tn is proportional to the distance passing through it, because if the width of the first group of conductive wires T1, T2, T3 ... Tn and the second group of conductive wires R1, R2, R3 ... Rn remains unchanged, the resistance change will not be obvious.

[0018] In summary, in this embodiment, only one conductive line layer is used, which saves costs. In this embodiment, the delay characteristic of the signal passing through the conductive lines with different impedances can be used to determine the distance the signal is transmitted on the conductive line, thereby determining its ordinate.

[0019] Embodiment 2, as Figure 3As shown, the transmitting device T and the signal receiving device R are respectively arranged at the same end of the first group of conductive wires T1, T2, T3...Tn and the second group of conductive wires R1, R2, R3...Rn, so that the higher the touch point P2, the smaller the delay, and the two groups of conductive wires do not need to change width.

Claims

1. A single-layer capacitive touch screen, comprising a conductive circuit layer and a touch positioning device, characterized in that: On the conductive circuit layer, a first group of conductive wires (T1, T2, T3 ... Tn) and a second group of conductive wires (R1, R2, R3 ... Rn) are extended along a first direction, and the first group of conductive wires (T1, T2, T3 ... Tn) and the second group of conductive wires (R1, R2, R3 ... Rn) are arranged at intervals; the single-layer capacitive touch screen also includes a signal transmitting device (T) and a signal receiving device (R), the signal transmitting device (T) respectively sends a setting electrical signal from the starting end of the first group of conductive wires (T1, T2, T3 ... Tn), and the signal receiving device (R) The signal receiving device (R) receives electrical signals from the second group of conductive wires (R1, R2, R3 ... Rn) respectively; the signal receiving device (R) is also provided with a detection device for detecting the phase delay between the received signal and the set electrical signal; the touch positioning device determines the position of the touch point in the first direction according to the sequence number of the second group of conductive wires (R1, R2, R3 ... Rn) of the signal received by the signal receiving device (R), and determines the position of the touch point in the direction perpendicular to the first direction according to the phase delay of the signal received by the signal receiving device (R); Locating the vertical coordinate of the touch point (P1) includes the following steps: First, the touch point is set at the top of the touch screen, and the delay phase θ1 of the signal received at the conductive line (Rj) is measured at this time; Then, the touch point is set at the bottom of the touch screen, and the delayed phase amount θ2 of the signal received at the conductive line (Rj) is measured at this time; Calculate the difference between the two phase delays △θ = θ2-θ1; Combined with the height H of the touch screen, calculate the delay per unit height Thus, when the touch point is at any point, the delay phase θ of the signal received at the conductive line (Rj) corresponds to the height In this way, the vertical coordinate of the touch point (P1) can be calculated.

2. The single-layer capacitive touch screen according to claim 1, characterized in that: The conductive wires in the first group of conductive wires (T1, T2, T3...Tn) are arranged in parallel.

3. The single-layer capacitive touch screen according to claim 2, characterized in that: The resistance per unit length of each conductive wire in the first group of conductive wires (T1, T2, T3...Tn) and the second group of conductive wires (R1, R2, R3...Rn) is linearly related to its length.

4. The single-layer capacitive touch screen according to claim 1, characterized in that: The signal transmitting device (T) and the signal receiving device (R) are respectively arranged at the same end of the conductive wires of the first group of conductive wires (T1, T2, T3...Tn) and the second group of conductive wires (R1, R2, R3...Rn).

5. The single-layer capacitive touch screen according to claim 1, characterized in that: The set electrical signal emitted by the signal emitting device (T) is a periodic square wave signal.

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