TW201619791A - Test apparatus for touch panel and test method thereof - Google Patents

Abstract

A test apparatus for a touch panel and a test method thereof are provided. Detect voltages of signal transmission lines on the touch panel to obtain a sensing result when switching coupling relationship between the signal transmission lines and a test voltage, and determine whether short circuit occurs among the signal transmission lines or occurs between the signal transmission lines and a ground according the sensing result.

Description

Touch panel test device and test method thereof

The present invention relates to a test device, and more particularly to a touch panel test device and a test method thereof.

With the rapid development of technology, electronic devices such as notebook computers, mobile phones, and portable multimedia players are gradually replacing the traditional keyboards with a touch panel as a new generation input interface. Among them, the capacitive touch panel is widely used because of its multi-touch characteristics.

Generally, a capacitive touch panel is designed to form a plurality of touch scan lines and touch sense lines on a surface of a substrate. When the user approaches or touches the surface of the capacitive touch panel with a finger or a conductive object, the capacitance value on the touch sensing line changes correspondingly. The capacitive touch panel can sense and calculate the touch position through the change of the capacitance value. However, in the production of the touch panel, both the touch scan line and the touch sense line may have a short circuit problem, so it is necessary to test after the touch panel is completed, in order to screen out the problematic panel. The correctness of the sensing of the capacitive touch panel mainly depends on the electrical characteristics of the touch scanning lines and the touch sensing lines. Therefore, if the touch scan line and the touch sensing line are short-circuited, the correctness of the touch sensing will be greatly affected. Traditionally, this short-circuit problem needs to be tested by expensive instruments, and the cost of detecting the touch panel is increased.

The invention provides a test method for a touch panel test device and a touch panel test device, which can detect a short circuit of a touch scan line or a touch sense line of the touch panel, thereby effectively reducing the detection cost.

The touch panel testing device of the present invention comprises a switching unit, a control unit and a plurality of sensing units. The switch unit is coupled to a plurality of signal transmission lines on the contact panel. The control unit is coupled to the switch unit, and the control switch unit changes a coupling relationship between each signal transmission line and the test voltage. The plurality of sensing units are coupled to the control unit, and when the control unit controls the switching unit to switch the coupling relationship between the signal transmission lines and the test voltage, the voltage on the signal transmission line is sensed, and the control unit determines according to the sensing result of the sensing unit. Whether there is a short circuit between the signal transmission lines or between the signal transmission lines and the ground.

In an embodiment of the invention, the switch unit includes a plurality of switches and a multiplex unit. A plurality of switches are respectively coupled to the plurality of signal transmission lines and the test voltage. The multiplex unit, the coupling switch and the control unit, are controlled by the control unit switching switch to change the coupling relationship between the signal transmission line and the test voltage.

In an embodiment of the present invention, the control unit controls the multiplex unit to switch the switch so that the signal transmission lines are alternately coupled to the test voltage, and determine whether at least two signal transmission lines are determined according to the sensing result of the sensing unit. Voltage equal to measurement The test voltage, if the voltage of at least two signal transmission lines is equal to the test voltage, it is determined that the at least two signal transmission lines are short-circuited.

In an embodiment of the invention, when any signal transmission line is coupled to the test voltage, the remaining signal transmission lines are coupled to the corresponding sensing unit.

In an embodiment of the invention, the touch panel testing device further includes a DC voltage source and a capacitor. The DC voltage source is coupled between the multiplex unit and the ground. The first end of the capacitor is coupled to the DC voltage source and the multiplex unit, and the second end of the capacitor is coupled to the ground, and the test voltage is supplied to the signal transmission line at the first end.

In an embodiment of the present invention, the control unit controls the multiplex unit switching switch to couple each signal transmission line to the input end of the corresponding sensing unit, and determine the signal transmission line according to the sensing result of the sensing unit. Whether the voltage is equal to the voltage of the ground, and if the voltage of at least one signal transmission line is equal to the voltage of the ground, it is determined that the at least one signal transmission line is short-circuited with the ground.

In an embodiment of the invention, wherein the sensing unit comprises an analog digital converter, the control unit comprises a microcontroller.

In an embodiment of the invention, the signal transmission line includes a touch scan line and a touch sense line.

The present invention provides a test method for a touch panel test device. The touch panel test device includes a plurality of switches coupled to a plurality of signal transmission lines on the touch panel. The test method of the touch panel test device includes the following steps. The coupling relationship between each signal transmission line and the test voltage is switched by the plurality of switches. The voltage on the signal transmission line is sensed to obtain a sensing result. Judging between signal transmission lines based on sensing results Or whether there is a short circuit between the signal transmission line and the ground.

In an embodiment of the invention, the switch is switched in turn, and each signal transmission line is coupled to the test voltage in turn, and the step of determining whether the signal transmission lines are short-circuited according to the sensing result further comprises the following steps. It is determined according to the sensing result whether the voltage of at least two signal transmission lines is equal to the test voltage. If the voltage on at least two signal transmission lines is equal to the test voltage, it is determined that the at least two signal transmission lines are short-circuited.

In an embodiment of the invention, each of the signal transmission lines is switched to be coupled to an input end of the corresponding sensing unit, and the step of determining whether the signal transmission line is shorted between the ground and the ground according to the sensing result further comprises the following steps. According to the sensing result, it is judged whether the voltage on the signal transmission line is equal to the voltage of the ground. If at least one signal transmission line has a voltage equal to the ground voltage, it is determined that the at least one signal transmission line is shorted to ground.

Based on the above, the embodiment of the present invention senses the voltage on the signal transmission line while switching the coupling relationship between each signal transmission line and the test voltage, and determines whether there is a signal transmission line or between the signal transmission line and the ground according to the sensing result. Short circuit. In this way, detecting the short circuit of the touch scan line or the touch sensing line can simplify the test circuit and effectively reduce the detection cost.

The above described features and advantages of the invention will be apparent from the following description.

102‧‧‧Switch unit

104_1~104_4, 302_1~302_3‧‧‧ Sensing unit

106‧‧‧Control unit

202‧‧‧Multiple units

L1~L4, L1'~L3'‧‧‧ signal transmission line

V1‧‧‧ test voltage

SW1~SW4‧‧‧ switch

Vs‧‧‧ DC voltage source

C1‧‧‧ capacitor

S502~S506, S602~S610, S702~S710‧‧‧ Test method steps of touch panel test device

FIG. 1 is a schematic diagram of a touch panel testing device according to an embodiment of the invention.

2 is a schematic diagram of a touch panel testing device according to another embodiment of the present invention.

3 is a schematic diagram of a touch panel testing device according to another embodiment of the present invention.

4 is a schematic diagram of a touch panel testing device according to another embodiment of the present invention.

FIG. 5 is a schematic flow chart of a test method of a touch panel testing device according to an embodiment of the invention.

FIG. 6 is a schematic flow chart of a test method of a touch panel testing device according to another embodiment of the present invention.

FIG. 7 is a schematic flow chart of a test method of a touch panel testing device according to another embodiment of the present invention.

FIG. 1 is a schematic diagram of a touch panel testing device according to an embodiment of the invention. Please refer to FIG. 1 . The touch panel test device includes a switch unit 102, a sensing unit 104_1~104_4, and a control unit 106. The control unit 106 is coupled to the switch unit 102 and the sensing unit 104_1~104_4. The switch unit 102 is coupled to the sensing unit 104_1~104_4. Signal transmission lines L1~L4 on the control panel. In this embodiment, the signal transmission lines L1 to L4 are touch sensing lines. However, the signal transmission lines L1 to L4 may also be touch scanning lines. In addition, for ease of description, the present embodiment uses four signal transmission lines L1 L L4 and four sensing units 104_1 104 104_4 as an example to perform a touch surface. The description of the board testing device, however, the number of sensing units and signal transmission lines is not limited to this embodiment.

The control unit 106 can control the switching unit 102 to change the coupling relationship between the signal transmission lines L1 LL4 and the test voltage V1, and the sensing units 104_1 ～ 104_4 can switch between the signal transmission lines L1 LL4 and the test voltage V1 at the switching unit 102. At the same time as the coupling relationship, the voltages on the signal transmission lines L1 to L4 are sensed. In this way, the control unit 106 can determine whether there is a short circuit between the signal transmission lines L1 LL4 or between the signal transmission lines L1 LL4 and the ground according to the sensing results of the sensing units 104_1 104104_4. Since the touch panel test device can be implemented by using a simple circuit, which can be implemented, for example, by integrating a circuit board or a wafer (for example, integrating the panel test device into the touch wafer), the detection cost can be effectively reduced, and the panel test device can be reduced. volume of.

2 is a schematic diagram of a touch panel testing device according to another embodiment of the present invention. Please refer to FIG. 2 . In detail, the above-mentioned switch unit 102 may include, for example, switches SW1 SW SW4 and a multiplexing unit 202. The sensing units 104_1 104 104_4 may be implemented by analog converters in this embodiment, and the control unit 106 may be implemented by a microcontroller. Implementation. The switches SW1 - SW4 are respectively coupled to the signal transmission lines L1 - L4 and coupled to the multiplex unit 202 . The multiplex unit 202 is further coupled to the control unit 106 . In addition, in the embodiment, the touch panel test device may further include a DC voltage source Vs and a capacitor C1. The DC voltage source Vs is coupled between the multiplex unit 202 and the ground, and the first end of the capacitor C1 is coupled to the DC voltage. The source Vs is connected to the multiplex unit 202, and the second end of the capacitor C1 is coupled to the ground. The DC voltage source Vs and the capacitor C1 can supply the test voltage V1 to the signal transmission lines L1 to L4 through the multiplex unit 202 and the switches SW1 to SW4.

The control unit 106 can control the multiplexing unit 202 to switch the switches SW1 SW SW4 to change the coupling relationship between the signal transmission lines L1 L L4 and the test voltage V1. In this embodiment, the control unit 106 controls the multiplex unit 202 to alternately switch the switches SW1 SW SW4 so that the signal transmission lines L1 LL4 are alternately coupled to the test voltage V1. While the multiplexing unit 202 alternates the switches SW1 SW SW4 , the sensing units 104_1 104 104_4 can sense the voltages on the signal transmission lines L1 L L4 and convert the sensed voltage signals into digital signals for transmission to the control unit 106 . (In the present embodiment, the sensing units 104_1~104_4 are analog-like digital converters, and the control unit 106 is a microcontroller), so that the control unit 106 determines whether the capacitance value of the capacitor C1 can be read from the signal transmission lines L1 to L4. . If there is no short circuit between the signal transmission lines L1 to L4, the control unit 106 can only read the capacitance value of the capacitor C1 from the signal transmission line corresponding to the switch in the on state, and cannot read from the remaining signal transmission lines. Take the capacitance value of capacitor C1 (that is, the sensed capacitance value is 0).

If the control unit 106 determines, according to the sensing result of the sensing units 104_1 104104_4, that the voltage of the at least two signal transmission lines is equal to the test voltage V1, that is, the capacitance value of the capacitor C1 is read from the at least two signal transmission lines, which represents A short circuit occurs between at least two signal transmission lines. For example, in the embodiment of FIG. 2, the switch SW1 is in an on state. At this time, if the sensing units 104_1 and 104_2 sense that the voltages of the signal transmission lines L1 and L2 are equal to the test voltage V1, that is, the control unit 106 from the signal transmission lines L1 and L2. The capacitance value of the capacitor C1 is read, that is, a short circuit occurs between the signal transmission lines L1 and L2. On the other hand, if the capacitance value of the capacitor C1 can be read only from the signal transmission line L1, it represents between the signal transmission line L1 and the other signal transmission lines L2 to L4. No short circuit occurs.

3 is a schematic diagram of a touch panel testing device according to another embodiment of the present invention. Referring to FIG. 3, in the embodiment, the signal transmission lines L1' L3' are scanning sensing lines, but not limited thereto, the signal transmission lines L1' L L3' may also be touch sensing lines. In addition, for ease of description, the present embodiment uses the three signal transmission lines L1 ′ to L3 ′ and the three sensing units 302_1 ～ 302 _ 3 as an example to describe the touch panel testing device, but the number of sensing units and signal transmission lines is not This embodiment is limited. The difference between the switch SW1 ′ and SW3 ′ included in the switch unit 102 is controlled by the multiplex unit 202 and is switched to the test voltage or the sensing unit 302_1~302_3. Input. In some embodiments, the test voltage may be other voltages, and is not limited to the grounded voltage of the embodiment.

Similar to the embodiment of FIG. 2, in the embodiment of FIG. 3, the control unit 106 controls the multiplex unit 202 to alternately switch the switches SW1'~SW3' so that the signal transmission lines L1'~L3' are alternately coupled to the ground. When a signal transmission line is coupled to the ground, the remaining signal transmission lines are coupled to the corresponding sensing unit. If there is no short circuit between the signal transmission lines L1'~L3', only the sensing unit corresponding to the grounded signal transmission line can sense the grounding voltage, and the remaining sensing units sense the signal. The transmission line is in a floating state. If the control unit 106 determines that the voltage of at least two signal transmission lines is equal to the ground voltage according to the sensing result of the sensing units 302_1 302 302_3, it represents that a short circuit occurs between the at least two signal transmission lines. For example, in the embodiment of FIG. 3, the switch SW1' is coupled to the ground. At this time, if the sensing unit 302_1, 302_2 senses that the voltage on the signal transmission lines L1', L2' is equal to The ground voltage, that is, the short circuit between the signal transmission lines L1' and L2' occurs. On the other hand, if only the voltage on the signal transmission line L1' is sensed to be equal to the grounded voltage, it is assumed that there is no short circuit between the signal transmission line L1' and the other signal transmission lines L2', L3'.

4 is a schematic diagram of a touch panel testing device according to another embodiment of the present invention. Referring to FIG. 4, when it is required to detect whether there is a short circuit between each signal transmission line L1'~L3' and the ground, the control unit 106 can control the multiplexing unit 202 to switch the signal transmission lines L1' to L3' to the corresponding ones. The input terminals of the sensing units 302_1~302_3. The control unit 106 can determine whether the voltage on the signal transmission line L1'~L3' is equal to the ground voltage according to the sensing result of the sensing unit 302_1~302_3. If any voltage of the signal transmission line is equal to the ground voltage, it represents the signal transmission line and A short circuit occurs between grounds.

FIG. 5 is a schematic flow chart of a test method of a touch panel testing device according to an embodiment of the invention. It can be seen from the above embodiments that the testing method of the touch panel testing device can include the following steps. First, a plurality of switches coupled to the plurality of signal transmission lines on the touch panel are switched to change a coupling relationship between the signal transmission lines and the test voltage (step S502). Next, the voltage on the signal transmission line is sensed to obtain a sensing result (step S504). Finally, based on the sensing result, it is judged whether there is a short circuit between the signal transmission lines or between the signal transmission line and the ground (step S506).

In detail, when detecting whether the signal transmission lines are short-circuited, the flow may be as shown in FIG. 6. First, the plurality of switches are switched in a rotating manner so that the signal transmission lines are alternately coupled to the test voltage (step S602). ), then re-sensing the signal The voltage on the transmission line is obtained to obtain a sensing result (step S604). And determining, according to the sensing result, whether the voltages on the at least two signal transmission lines are equal to the test voltage (step S606). If the voltages on the at least two signal transmission lines are equal to the test voltage, determining that the at least two signal transmission lines are short-circuited (step S608). ), on the other hand, it represents a case where there is no short circuit between the signal transmission lines (step S610).

In addition, when detecting whether there is a short circuit between the signal transmission line and the ground, the flow may be as shown in FIG. 7. First, each signal transmission line is switched and coupled to the input end of the corresponding sensing unit (step S702). Next, the voltage on the signal transmission line is sensed to obtain a sensing result (step S704). Then, it is judged based on the sensing result whether the voltage on the signal transmission line is equal to the voltage of the ground (step S706). If the voltage on the at least one signal transmission line is equal to the voltage of the ground, it is determined that the at least one signal transmission line is short-circuited with the ground (step S708), and conversely, there is no short circuit between the signal transmission line and the ground (step S710).

In summary, the embodiment of the present invention senses the voltage on the signal transmission line while switching the coupling relationship between each signal transmission line and the test voltage, and determines the signal transmission line or the signal transmission line and the ground according to the sensing result. Is there a short circuit between them? In this way, detecting the short circuit of the touch scan line or the touch sensing line can simplify the test circuit and effectively reduce the detection cost.

102‧‧‧Switch unit

104_1~104_4‧‧‧Sensor unit

106‧‧‧Control unit

L1~L4‧‧‧ signal transmission line

V1‧‧‧ test voltage

Claims (11)

A touch panel testing device includes: a switch unit coupled to a plurality of signal transmission lines on a touch panel; a control unit coupled to the switch unit to control the switch unit to change between each of the signal transmission lines and a test voltage And a plurality of sensing units coupled to the control unit, and sensing the signal transmission lines while the control unit controls the switching unit to switch the coupling relationship between the signal transmission lines and the test voltage The voltage of the sensing unit determines whether there is a short circuit between the signal transmission lines or between the signal transmission lines and a ground according to the sensing results of the sensing units. The touch panel test device of claim 1, wherein the switch unit comprises: a plurality of switches respectively coupled to the signal transmission lines and the test voltage; and a multiplexing unit coupled to the switches and The control unit is controlled by the control unit to switch the switches to change a coupling relationship between the signal transmission lines and the test voltage. The touch panel test device of claim 2, wherein the control unit controls the multiplex unit to alternately switch the switches so that the signal transmission lines are alternately coupled to the test voltage, and according to the senses The sensing result of the measuring unit determines whether the voltage of at least two signal transmission lines is equal to the test voltage, and if the voltage of the at least two signal transmission lines is equal to the test voltage, determining that the at least two signal transmission lines are short-circuited. The touch panel test device of claim 3, wherein when any of the signal transmission lines are coupled to the test voltage, the remaining signal transmission lines are coupled to the corresponding sensing units. The touch panel test device of claim 3, further comprising: a DC voltage source coupled between the multiplex unit and the ground; and a capacitor having a first end coupled to the DC voltage The source and the multiplex unit, the second end of the capacitor is coupled to the ground, and the test voltage is supplied to the signal transmission lines at the first end. The touch panel test device of claim 2, wherein the control unit controls the multiplex unit to switch the switches so that the signal transmission lines are coupled to the input ends of the corresponding sensing units. And determining, according to the sensing result of the sensing units, whether the voltage on the signal transmission lines is equal to the voltage of the grounding. If the voltage of the at least one signal transmission line is equal to the voltage of the grounding, determining between the at least one signal transmission line and the grounding Short circuit. The touch panel testing device of claim 1, wherein the sensing units comprise an analog-to-digital converter, and the control unit comprises a microcontroller. The touch panel test device of claim 1, wherein the signal transmission lines comprise a touch scan line and a touch sense line. A test method for a touch panel test device, the touch panel test device includes a plurality of switches coupled to a plurality of signal transmission lines on the touch panel, and the test method of the touch panel test device includes the following steps: The switch switches the coupling between each of the signal transmission lines and a test voltage Sensing the voltages on the signal transmission lines to obtain a sensing result; and determining whether a short circuit between the signal transmission lines or between the signal transmission lines and a ground is determined according to the sensing result. The method for testing a touch panel test device according to claim 9, wherein the switches are switched in turn, and each of the signal transmission lines is coupled to the test voltage in turn, and the sensing result is determined according to the sensing result. The step of short-circuiting between the signal transmission lines further includes: determining, according to the sensing result, whether the voltage of at least two signal transmission lines is equal to the test voltage: and if the voltage of the at least two signal transmission lines is equal to the test voltage, determining the Short circuit between at least two signal transmission lines. The method for testing a touch panel test device according to claim 9, wherein each of the signal transmission lines is switched and coupled to an input end of the corresponding sensing unit, and the signal transmission lines are determined according to the sensing result. The step of short-circuiting between the grounds further includes: determining, according to the sensing result, whether the voltage on the signal transmission lines is equal to the voltage of the ground; and determining the at least one signal if the voltage on the at least one signal transmission line is equal to the voltage of the grounding A short circuit between the transmission line and the ground.