CN109426384B

CN109426384B - Touch panel and touch panel detection method

Info

Publication number: CN109426384B
Application number: CN201710771011.3A
Authority: CN
Inventors: 林家宇; 陈志强
Original assignee: Acer Inc
Current assignee: Acer Inc
Priority date: 2017-08-31
Filing date: 2017-08-31
Publication date: 2021-06-04
Anticipated expiration: 2037-08-31
Also published as: CN109426384A

Abstract

A touch panel includes a touch sensing circuit, an electrostatic discharge protection circuit and a processor. The touch sensing circuit is composed of a plurality of sensing pads and used for sensing a touch action of at least one touch object to output a sensing signal. The electrostatic discharge protection circuit is connected with the touch sensing circuit, surrounds the periphery of the touch sensing circuit and generates a circuit load. The processor is coupled to the touch sensing circuit and the ESD protection circuit, and is configured to receive the sensing signal and the circuit load, execute a corresponding action according to the sensing signal, and determine whether to generate an alarm signal according to a change of the circuit load.

Description

Touch panel and touch panel detection method

Technical Field

The present invention relates to a touch panel and a method for detecting the touch panel, and more particularly, to a touch panel and a method for detecting the touch panel, which can determine the health status of the touch panel according to the load variation of an esd protection circuit.

Background

In recent years, touch products have been developed vigorously, and electronic devices with touch functions are commonly used in daily life. However, although different inspection processes are arranged according to different assembly sequences in the manufacturing process of the touch panel, failure may not be detected due to some reasons, and thus defective products may flow into the market. Therefore, how to determine whether the touch panel generates an abnormal condition after the touch panel leaves the factory is a problem to be solved at present.

Disclosure of Invention

In order to solve the above problems, an embodiment of the invention provides a touch panel including a touch sensing circuit, an esd protection circuit, and a processor. The touch sensing circuit is composed of a plurality of sensing pads and used for sensing a touch action of at least one touch object to output a sensing signal. The electrostatic discharge protection circuit is connected with the touch sensing circuit, surrounds the periphery of the touch sensing circuit and generates a circuit load. The processor is coupled to the touch sensing circuit and the ESD protection circuit, and is configured to receive the sensing signal and the circuit load, execute a corresponding action according to the sensing signal, and determine whether to generate an alarm signal according to a change of the circuit load.

Another embodiment of the present invention provides a method for detecting a touch panel, including the steps of: sensing a touch action of at least one touch object through a touch sensing circuit to output a sensing signal, wherein the touch sensing circuit is composed of a plurality of sensing pads; executing a corresponding action according to the sensing signal through a processor; receiving, by a processor, a circuit load corresponding to an electrostatic discharge protection circuit, wherein the electrostatic discharge protection circuit is connected to the touch sensing circuit and surrounds the touch sensing circuit; and determining whether to generate an alarm signal according to the change of the circuit load through the processor.

Drawings

Fig. 1 is a block diagram of a touch panel according to an embodiment of the invention.

Fig. 2 is a schematic diagram illustrating a load variation of a circuit according to an embodiment of the invention.

Fig. 3 is a schematic diagram illustrating a touch panel according to an embodiment of the invention.

Fig. 4 is a schematic diagram illustrating a touch panel according to another embodiment of the invention.

FIG. 5 is a flowchart illustrating a touch panel detection method according to some embodiments of the invention.

Description of reference numerals:

100-a touch panel;

110 touch sensing circuit;

120. 450 to an electrostatic discharge protection circuit;

130 to a processor;

310 to a first sensing series;

311 to a first sensing pad;

320-a second sensing series;

321 to a second sensing pad;

350-electrostatic discharge protective ring;

451 to dummy patterns;

d1-first direction;

d2-second direction;

I₁-inner loop current;

I₂-outer loop current;

S501-S508-step flow.

Detailed Description

Other areas of applicability of the touch panel and the touch panel detection method of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the following detailed description and specific examples, while indicating exemplary embodiments of the touch panel and touch panel detection method, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

Fig. 1 is a block diagram of a touch panel 100 according to an embodiment of the invention. The touch panel 100 may include a touch sensing circuit 110, an esd protection circuit 120, and a processor 130. The touch sensing circuit 110 includes a plurality of first sensing series and a plurality of second sensing series. The first sensing series is composed of a plurality of first sensing pads, extends along a first direction, and is electrically insulated from each other. The second sensing series is composed of a plurality of second sensing pads, extends along a second direction, and is electrically insulated from each other. Wherein the first direction is perpendicular to the second direction. When the touch sensing circuit 110 senses a touch action of at least one touch object, the touch sensing circuit 110 generates a corresponding sensing signal. The esd protection circuit 120 is connected to the touch sensing circuit 110 and surrounds the touch sensing circuit 110 to provide a current path for esd, so as to prevent current from flowing into the touch sensing circuit 110. In addition, the ESD protection circuit 120 is further used to generate a circuit load. The circuit load may be an RC load or only a resistance value. After the esd protection circuit 120 generates the circuit load, the analog signal of the circuit load is converted into a digital signal through an analog-to-digital conversion for the processor 130 to interpret. Certain parameters may also be selectively amplified during digital-to-analog conversion to enhance the characteristics of the parameters. The processor 130, which may be a microprocessor or a control circuit including a microprocessor, receives the sensing signal from the touch sensing circuit 110, and defines a position corresponding to the touch action according to the sensing signal to execute the corresponding action. In addition, the processor 130 further receives a digital signal corresponding to the circuit load from the esd protection circuit 120 to determine whether the change of the circuit load exceeds the allowable range. When the processor 130 determines that the circuit load of the esd protection circuit 120 exceeds the allowable range, it outputs an alarm message to inform the user to perform the repair detection.

Generally, in a normal situation, after the touch panel is manufactured, if the touch panel is not interfered by an external force, the circuit load of the touch panel is approximately stable within a certain interval, and only a little disturbance is generated due to the change of the environment, but the circuit load is not greatly changed due to the time. FIG. 2 is a schematic diagram illustrating normal and abnormal circuit load variations according to an embodiment of the invention. In this embodiment, the normal range of RC loading values is between 1000-1100, and 1200 and 900 are buffer values. For example, as shown in the figure, under normal conditions, the RC load variation curve of a good touch panel should be as shown in curve 1, i.e. the variation of the RC load value is between 1000 and 1100. However, when the RC load variation curve of the touch panel is as shown in curve 2, that is, the RC load value rises upwards to exceed 1200 or the slope thereof changes to exceed a predetermined value, it indicates that the touch panel may be defective or abnormal. To avoid the above situation, when the processor 130 determines that the value of the circuit load output by the esd protection circuit 120 is not between 1000 and 1100, but is still less than 1200 or 900, a first warning message is output to alert a user that an abnormal condition may occur on the touch panel. When the value of the circuit load determined by the processor 130 is over 1200 or lower than 900, which indicates that the touch panel may be a defective product or a failure occurs, a second warning signal is output to remind the user to repair the touch panel. The normal range of the value of the circuit load can be determined according to the value of the touch panel when the touch panel leaves the factory. Or, in order to avoid the situation that the environment of the factory is different from the environment of the user and further causes misjudgment, the normal range of the value of the circuit load can also be determined according to the initial value generated when the user starts up for the first time.

Fig. 3 is a schematic diagram illustrating a touch panel according to an embodiment of the invention. As shown in the figure, the touch sensing circuit is provided with a plurality of first sensing circuitsA string 310 and a plurality of second sensing strings 320. The first sensing series 310 is disposed along the first direction D1 and is composed of a plurality of first sensing pads 311. The second sensing series 320 is disposed along the second direction D2 and is composed of a plurality of second sensing pads 321. All the first sensing strings and the second sensing strings are connected to the processor 130. In this embodiment, the ESD protection circuit is formed by a single line of an ESD protection ring 350. As shown, the esd protection ring 350 firstly wraps around along the touch sensing circuit 110, and then wraps around along the same path in the opposite direction. Thus, the inner ring wire current I of the ESD protection ring₁Direction of and outer conductor current I₂The direction of the electrostatic discharge protection ring is opposite to the direction of the touch sensing circuit 110, so that the electrostatic discharge protection ring cannot generate a magnetic field, i.e., the operation of the touch sensing circuit 110 is not disturbed.

Fig. 4 is a schematic diagram illustrating a touch panel according to another embodiment of the invention. The touch sensing circuit in fig. 4 has the same structure as the touch sensing circuit in fig. 3, and will not be described herein for simplicity. The esd protection circuit 450 is composed of a plurality of dummy patterns (dummy patterns) 451 which are made of the same material as the

sensing pads

311, 321 but have no touch function, and driven under the same condition, so that the aging condition of the esd protection circuit 450 is the same as that of the

sensing pads

311, 321.

FIG. 5 is a flowchart illustrating a touch panel detection method according to some embodiments of the invention. The touch panel detection method starts in step S501, and the user starts using the touch panel 100 for the first time. In step S502, the processor 130 determines a normal range corresponding to the circuit load according to a factory value or an initial value generated when the user powers on for the first time. In step S503, the touch sensing circuit 110 starts sensing a touch action corresponding to at least one touch object to output a sensing signal. In step S504, the processor 130 executes a corresponding action according to the sensing signal. In step S505, the esd protection circuit 120 outputs a circuit load. In step S506, the circuit load is converted into a digital signal by an analog-to-digital converter. In step S507, the processor 130 receives the digital signal corresponding to the circuit load and determines whether the value or variation of the circuit load is within a normal range. When the processor 130 determines that the value or the change of the circuit load is within the normal range, it returns to step S503, and the touch sensing circuit 110 continues to perform the operation of sensing the touch. Otherwise, when the processor 130 determines that the value or the variation of the circuit load is beyond the normal range, the process proceeds to step S508, and the processor 130 generates an alarm signal.

In summary, according to the touch panel and the touch panel detection method provided by the embodiment of the invention, the processor of the touch panel can determine whether the function of the touch panel is abnormal by determining the circuit load change of the esd protection circuit having the same material as the touch sensing circuit and having no touch function. In addition, in order to avoid the touch sensing circuit from being damaged by the charges passing through the gap due to the off design of the esd protection circuit, an esd protection ring having an inner ring and an outer ring is further configured to prevent the above situation. In order to further simulate the aging condition of the sensing pad, the esd protection circuit according to another embodiment of the invention is further formed by a plurality of dummy patterns, wherein the material of the dummy patterns is the same as the material of the sensing pad in the touch sensing circuit, so as to improve the accuracy of the determination.

The foregoing describes features of various embodiments so that others skilled in the art may readily understand the aspects of the present description. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure.

Claims

1. A touch panel, comprising:

a touch sensing circuit, which is composed of a plurality of sensing pads and is used for sensing a touch action of at least one touch object to output a sensing signal;

an electrostatic discharge protection circuit connected to the touch sensing circuit and surrounding the touch sensing circuit to generate a circuit load; and

a processor coupled to the touch sensing circuit and the ESD protection circuit for receiving the sensing signal and the circuit load, performing a corresponding action according to the sensing signal, and determining whether to generate an alarm signal according to a change of the circuit load;

the ESD protection circuit is formed by a circuit having a first segment and a second segment, wherein the first segment and the second segment surround the touch sensing circuit, but a current direction corresponding to the first segment is opposite to a current direction corresponding to the second segment, and the touch sensing circuit is formed of the same material as the ESD protection circuit.

2. The touch panel as recited in claim 1, wherein the circuit load is an RC load or a resistance value, and the warning signal is generated when the processor determines that the variation of the circuit load exceeds a predetermined range.

3. The touch panel as recited in claim 1, wherein the esd protection circuit comprises a plurality of sensing pads.

4. The touch panel as recited in claim 2, wherein the predetermined range is defined according to a factory initial value or a power-on initial value of the touch panel.

5. A touch panel detection method includes:

sensing a touch action of at least one touch object through a touch sensing circuit to output a sensing signal, wherein the touch sensing circuit is composed of a plurality of sensing pads;

executing a corresponding action according to the sensing signal through a processor;

receiving, by the processor, a circuit load corresponding to an esd protection circuit, wherein the esd protection circuit is connected to the touch sensing circuit and surrounds the touch sensing circuit; and

determining whether to generate a warning signal according to the change of the circuit load through the processor;

6. The method as claimed in claim 5, wherein the step of determining whether to generate the warning signal according to the change of the circuit load by the processor further comprises:

judging whether the change of the circuit load exceeds a set range through the processor;

when the processor judges that the change of the circuit load exceeds the set range, the warning signal is generated; and

the circuit load is an RC load or a resistance value.

7. The method as claimed in claim 5, wherein the ESD protection circuit comprises a plurality of sensing pads.

8. The method as claimed in claim 6, wherein the predetermined range is defined according to a factory initial value or a power-on initial value of the touch panel.