Method for detecting damages of touch display panel

This application claims the priority benefit of U.S. provisional application Ser. No. 63/650,924, filed on May 23, 2024. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

The invention relates to a detecting method, and in particular, to a method for detecting damages of a touch display panel.

TDDI (Touch with Display Driver) is a touch technology solution that integrates a panel driver IC and a touch panel IC into a single chip. In the case of a touch abnormality (e.g. sensor damage) or display abnormality (e.g., source line or gate line damage), since there is no detection mechanism in the IC, it is typically detected by manual touch or human eye observation. In order to enhance the safety coefficient, the automotive industry is striving to improve the panel touch and display monitoring function by IC, thus enabling the system to automatically report irregularities to achieve the goal of warning and strengthening driving safety.

The invention is directed to a detecting method, capable of detecting device abnormality of the touch display panel.

An embodiment of the invention provides a method for detecting damages of a touch display panel. The touch display panel includes a plurality of sensing pads and a plurality of signal lines. The method includes: selecting at least one first device of the sensing pads and the signal lines as a device under test (DUT); apply a first voltage to the DUT and receiving a feedback signal from the DUT, wherein the feedback signal comprises voltage information or capacitance information of the DUT; and determining whether the DUT is damaged according to the feedback signal.

To make the aforementioned more comprehensible, several embodiments accompanied with drawings are described in detail as follows.

The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.

FIG. 1 is a block diagram illustrating a touch display apparatus according to an embodiment of the invention.

FIG. 2 is a schematic diagram illustrating a detecting scheme according to an embodiment of the invention.

FIG. 3 is a schematic diagram illustrating a detecting scheme according to another embodiment of the invention.

FIG. 4 is a schematic diagram illustrating a detecting scheme according to another embodiment of the invention.

FIG. 5 A is a schematic diagram illustrating a case that sensing pads are detected according to an embodiment of the invention.

FIG. 5 B illustrates different waveforms of the LFD signal according to embodiments of the invention.

FIG. 6 is a schematic diagram illustrating another case that sensing pads are detected according to an embodiment of the invention.

FIG. 7 is a schematic diagram illustrating a case that source lines are detected according to an embodiment of the invention.

FIG. 8 is a schematic diagram illustrating another case that source lines are detected according to an embodiment of the invention.

FIG. 9 and FIG. 10 respectively illustrate different cases that gate lines are detected according to embodiments of the invention.

FIG. 11 is a schematic diagram illustrating another case that source lines are detected according to an embodiment of the invention.

FIG. 12 is a flowchart illustrating steps in a method for detecting damages of a touch display panel according to an embodiment of the invention.

FIG. 13 is a schematic diagram illustrating a case that the DUT is open itself according to an embodiment of the invention.

FIG. 14 is a schematic diagram illustrating a case that the DUT is shorted to the adjacent source line according to an embodiment of the invention.

FIG. 15 illustrates a plurality of the source lines are detected at the same time according to an embodiment of the invention.

FIG. 16 is a schematic diagram illustrating source lines are sequentially detected according to an embodiment of the invention.

FIG. 17 is a schematic diagram illustrating gate lines are sequentially detected according to an embodiment of the invention.

FIG. 18 is a schematic diagram illustrating sensing pads are sequentially detected according to an embodiment of the invention.

The term “coupled (or connected)” used in this specification (including claims) may refer to any direct or indirect connection means. For example, “a first device is coupled (connected) to a second device” should be interpreted as “the first device is directly connected to the second device” or “the first device is indirectly connected to the second device through other devices or connection means”. The terms “first” and “second” mentioned in the full text of the specification of the disclosure (including claims) are used to name elements or to distinguish different embodiments or scopes, neither to be used to limit upper or lower limit of the number of elements nor limit the sequence of the elements. In addition, wherever possible, elements/components/steps with the same reference numbers are used in the drawings and embodiments to represent the same or similar parts. Elements/components/steps using the same numbers or using the same terms in different embodiments may serve as cross-reference for each other.

FIG. 1 is a block diagram illustrating a touch display apparatus according to an embodiment of the invention. Referring to FIG. 1 , the touch display apparatus 100 includes a touch display panel 110 and a driver circuit 120 . The driver circuit 120 is configured to drive the touch display panel 110 to perform a display operation and a touch sensing operation. In an embodiment, the driver circuit 120 may be a touch with display driver integrated circuit (TDDI IC), but the invention is not limited thereto.

In the present embodiment, the driver circuit 120 is further configured to perform a method for detecting damages of the touch display panel 110 . The damages of the touch display panel 110 indicates that sensing pads, source lines, or gate lines are open themselves, or sensing pads, source lines, or gate lines are shorted to adjacent sensing pads, source lines, or gate lines.

To be specific, FIG. 2 is a schematic diagram illustrating a detecting scheme according to an embodiment of the invention. Referring to FIG. 1 and FIG. 2 , the touch display panel 110 includes a plurality of sensing pads 112 for sensing a touch event. The driver circuit 120 includes a plurality of switch circuits 122 for signal selection. For clarity, only one sensing pad 112 and one switch circuit 122 are shown in FIG. 2 , but the number of the sensing pads 112 and the switch circuits 122 is not intended to limit the invention. In an embodiment, the switch circuit 122 may include at least one multiplexer for transmitting and receiving signals, but the invention is not limited thereto.

During a detection period, the sensing pad 112 may serve as a device under test (DUT), and the switch circuit 122 is switched to select a first voltage V 1 to be applied to the sensing pad 112 and receive a feedback signal FB from the sensing pad 112 in different times. During another detection period, the sensing pad 112 may serve as a reference device for detecting other sensing pads, and the switch circuit 122 is switched to select a second voltage V 2 to be applied to the sensing pad 112 or make the sensing pad 112 be in a floating state or in a high impedance state HiZ. In an embodiment, the second voltage V 2 may a ground voltage, but the invention is not limited thereto.

FIG. 3 is a schematic diagram illustrating a detecting scheme according to another embodiment of the invention. Referring to FIG. 3 , the touch display panel 110 further includes a plurality of source lines 114 for the display operation and a plurality of first switch circuits 122 _ 1 , and a plurality of second switch circuits 122 _ 2 are added for damage detection. For clarity, only one first switch circuit 122 _ 1 and one second switch circuit 122 _ 2 are shown in FIG. 3 , but the numbers of the first switch circuits 122 _ 1 and the second switch circuits 122 _ 2 are not intended to limit the invention.

In the present embodiment, the first voltage V 1 may be a load free driving (LFD) signal LFD, and the second voltage V 2 may be a ground voltage GND. In another embodiment, the first voltage V 1 may be a direct-current (DC) voltage, but the invention is not limited thereto. During a display period and a touch sensing period, the first voltage V 1 , the second voltage V 2 , and a data signal Sn are applied to respective devices of the touch display panel 110 for the display operation and the touch sensing operation.

During the detection period, the first voltage V 1 and the second voltage V 2 are applied to respective devices of the touch display panel 110 for the damage detection. For example, the sensing pad 112 may serve as a DUT, and at least one of the source lines 114 may serve as a reference device. The first voltage V 1 is applied to the sensing pad 112 , and the second voltage V 2 is applied to the source line 114 . The feedback signal FB can be received from the sensing pad 112 to determine whether the sensing pad 112 is damaged.

In another embodiment, the at least one of the source lines 114 may serve as a DUT, and sensing pad 112 may serve as a reference device. The first voltage V 1 is applied to the source line 114 , and the second voltage V 2 is applied to the sensing pad 112 . The feedback signal FB can be received from the source line 114 to determine whether the source line 114 is damaged.

FIG. 4 is a schematic diagram illustrating a detecting scheme according to another embodiment of the invention. Referring to FIG. 4 , the touch display panel 110 further includes a plurality of gate lines 116 for the display operation and a plurality of first switch circuits 122 _ 3 , and a plurality of second switch circuits 122 _ 4 are added for damage detection. For clarity, only one first switch circuit 122 _ 3 and one second switch circuit 122 _ 4 are shown in FIG. 4 , but the numbers of the first switch circuits 122 _ 3 and the second switch circuits 122 _ 4 are not intended to limit the invention.

During the detection period, the first voltage V 1 and the second voltage V 2 are applied to respective devices of the touch display panel 110 for the damage detection. The feedback signal FB can be received from the sensing pad 112 or at least one of the gate lines 116 to determine whether the sensing pad 112 or the at least one of the gate lines 116 is damaged.

FIG. 5 A is a schematic diagram illustrating a case that sensing pads are detected according to an embodiment of the invention. Referring to FIG. 5 A , the driver circuit 520 is configured to detect whether a sensing pad is open itself.

The driver circuit 520 includes a switch circuit 522 , an analog-front-end (AFE) circuit 524 , and a processor circuit 526 . Input signals are respectively set for sensing pads 512 , source lines 514 and gate lines 516 . For example, the LFD signal LFD is applied to the sensing pad 512 , and the source lines 514 are grounded. The gate lines 516 are set to the high impedance state HiZ. In an embodiment, the processor circuit 526 may include an analog-to-digital converter (ADC).

The AFE circuit 524 receives the feedback signal FB from the sensing pad 512 via the switch circuit 522 , and outputs the feedback signal FB to the processor circuit 526 for data processing. The feedback signal FB includes voltage information or capacitance information of the sensing pad 512 . The driver circuit 520 can determines whether the sensing pad 512 is damaged according to the feedback signal FB.

Regarding hardware structures of the driver circuit 520 , the processor circuit 526 may be a processor having computational capability. In addition, enough teaching, suggestion, and implementation illustration for hardware structures of the switch circuit 522 , the AFE circuit 524 , and the processor circuit 526 can be obtained with reference to common knowledge in the related art, which is not repeated hereinafter.

In FIG. 5 A , the LFD signal LFD is a positive sine wave, but the invention is not limited thereto. FIG. 5 B illustrates different waveforms of the LFD signal according to embodiments of the invention. Referring to FIG. 5 B , (a) of FIG. 5 B shows the LFD signal LFD is a positive sine wave. (b) and (c) of FIG. 5 B respectively show the LFD signal LFD is a positive square wave and a positive triangle wave. In addition, the LFD signal LFD may be a negative voltage. For example, (d), (e) and (f) of FIG. 5 B respectively show the LFD signal LFD is a negative sine wave, a negative square wave and a negative triangle wave. The waveforms illustrated in FIG. 5 B are not intended to limit the invention.

FIG. 6 is a schematic diagram illustrating another case that sensing pads are detected according to an embodiment of the invention. Referring to FIG. 6 , the driver circuit 520 is configured to detect whether a sensing pad is shorted to adjacent sensing pads, source lines or gate lines. In the present embodiment, the DC signal DC is applied to the sensing pad 512 , and the source lines 514 and the gate lines 516 are grounded.

FIG. 7 is a schematic diagram illustrating a case that source lines are detected according to an embodiment of the invention. Referring to FIG. 7 , the driver circuit 520 is configured to detect whether a source line is open itself. In the present embodiment, the LFD signal LFD is applied to the source line 514 to be detected, and the sensing pad 512 , the adjacent source line, and the gate lines 516 are grounded.

FIG. 8 is a schematic diagram illustrating another case that source lines are detected according to an embodiment of the invention. Referring to FIG. 8 , the driver circuit 520 is configured to detect whether a source line is shorted to adjacent sensing pads, source lines or gate lines. In the present embodiment, the DC signal DC is applied to the source line 514 to be detected, and the sensing pad 512 , the adjacent source line and the gate lines 516 are also grounded.

FIG. 9 and FIG. 10 respectively illustrate different cases that gate lines are detected according to embodiments of the invention. Referring to FIG. 9 and FIG. 10 , in FIG. 9 , the driver circuit 520 is configured to detect whether a gate line is open itself, and in FIG. 10 , the driver circuit 520 is configured to detect whether a gate line is shorted to adjacent sensing pads, source lines or gate lines. The LFD signal LFD is applied to the gate line 516 to be detected for open detection, and the DC signal DC is applied to the gate line 516 for short detection. The sensing pad 512 , the source lines 514 , and the adjacent gate lines are grounded in the two cases.

FIG. 11 is a schematic diagram illustrating another case that source lines are detected according to an embodiment of the invention. FIG. 12 is a flowchart illustrating steps in a method for detecting damages of a touch display panel according to an embodiment of the invention. Referring to FIG. 11 and FIG. 12 , a touch display panel 1110 includes a plurality of sensing pads 1112 and a plurality of signal lines, wherein the signal lines are source lines S 0 , S 1 , S 2 , S 3 and gate lines G 0 , G 1 , G 2 of the touch display panel 1110 .

In step S 100 , during the detection period, the driver circuit 1120 selects at least one first device of the sensing pads 1112 and the signal lines S 0 , S 1 , S 2 , S 3 and G 0 , G 1 , G 2 as a DUT, and selects at least one second device of the sensing pads 1112 and the signal lines S 0 , S 1 , S 2 , S 3 and G 0 , G 1 , G 2 as a reference device. In FIG. 11 , the source line S 0 is selected as the DUT, and the sensing pad 1112 , the source lines S 1 , S 2 , S 3 , and the gate lines G 0 , G 1 , G 2 are selected as reference devices. The reference devices 1112 , S 1 , S 2 , S 3 and G 0 , G 1 , G 2 are adjacent to the DUT S 0 .

In step S 110 , the driver circuit 1120 applies a first voltage V 1 to the DUT S 0 , and applies a second voltage V 2 to the reference devices 1112 , S 1 , S 2 , S 3 and G 0 , G 1 , G 2 . In an embodiment, the first voltage V 1 may be a LFD signal or a DC voltage, and the second voltage V 2 may be a ground voltage. In an embodiment, the driver circuit 1120 may make the reference devices 1112 , S 1 , S 2 , S 3 and G 0 , G 1 , G 2 be in a floating state or in a high impedance state.

In step S 120 , the driver circuit 1120 receives a feedback signal FB from the DUT S 0 , wherein the feedback signal FB includes voltage information or capacitance information of the DUT S 0 . For example, the capacitance information includes capacitance values Cs 1 , Cs 2 , . . . , CsN between the DUT S 0 and the reference devices 1112 , S 1 , S 2 , S 3 and G 0 , G 1 , G 2 , as illustrated in FIG. 11 . The DUT S 0 and the reference devices 1112 , S 1 , S 2 , S 3 and G 0 , G 1 , G 2 have a first capacitance value Cs=Cs 1 +Cs 2 + . . . +Cs 7 + . . . +CsN in a normal state, wherein N is a positive integer.

On the other hand, the DUT S 0 is connected to the AFE circuit 1124 with operational amplifier virtual short circuit feature, and thus the DUT S 0 can be maintained at the first voltage V 1 . In addition, the input signal of the reference devices 1112 , S 1 , S 2 , S 3 and G 0 , G 1 , G 2 is the second voltage V 2 . Therefore, the voltage information includes a first voltage difference value ΔV between the DUT S 0 and the reference devices 1112 , S 1 , S 2 , S 3 and G 0 , G 1 , G 2 in the normal state, wherein ΔV=V 1 −V 2 .

In the present embodiment, the driver circuit 1120 switches a switch circuit 1122 to apply the first voltage V 1 to the DUT S 0 , apply the second voltage V 2 to the reference devices 1112 , S 1 , S 2 , S 3 and G 0 , G 1 , G 2 , or receive the feedback signal FB from the DUT S 0 . For a detailed description of the switching operation of the switch circuit 1122 , please refer to the embodiments provided in FIG. 2 to FIG. 4 .

In step S 130 , the driver circuit 1120 determines whether the DUT S 0 is damaged according to the feedback signal FB, wherein the damage of the DUT S 0 indicates that the DUT S 0 is open itself or shorted to the adjacent sensing pads 1112 or the adjacent signal lines S 1 , S 2 , S 3 and G 0 , G 1 , G 2 . The driver circuit 1120 can analyze the capacitance information and the voltage information of the DUT S 0 to obtain a detection result via a processor circuit 1126 and/or other back-end circuits.

FIG. 13 is a schematic diagram illustrating a case that the DUT is open itself according to an embodiment of the invention. Referring to FIG. 11 and FIG. 13 , the DUT S 0 is in an abnormal state, e.g. open itself. In the open state, the DUT S 0 and the reference devices 1112 , S 1 , S 2 , S 3 and G 0 , G 1 , G 2 have a second capacitance value Cs′, wherein the first capacitance value Cs is larger than the second capacitance value Cs' since the first voltage V 1 is only applied to the disconnection part of the DUT S 0 .

For example, the first capacitance value Cs of the normal state and the second capacitance value Cs' of the abnormal state can be listed in the following Table 1:

FIG. 11 shows the DUT S 0 in the normal state, and FIG. 13 shows the DUT S 0 in the abnormal state (open state). The driver circuit 1120 can obtain the capacitance information with receiving the feedback signal FB, and determine whether the DUT S 0 is open itself according to the capacitance information and Table 1. The values listed in Table 1 are not intended to limit the invention.

In a similar manner, the driver circuit 1120 can determine whether a sensing pad or a gate line is open itself according to the capacitance information.

FIG. 14 is a schematic diagram illustrating a case that the DUT is shorted to the adjacent source line according to an embodiment of the invention. Referring to FIG. 11 and FIG. 14 , the DUT S 0 is in an abnormal state, e.g. shorted to the adjacent source line S 1 . In the short state, there is a second voltage difference value ΔV′ between the DUT S 0 and the source line S 1 , wherein the first voltage difference value ΔV is larger than the second voltage difference value ΔV′ since the DUT S 0 is shorted to the source line S 1 .

For example, when the DUT S 0 is shorted to the source line S 1 , the second voltage difference value ΔV′ may be 1 voltage (V). The first voltage difference value ΔV of the normal state and the second voltage difference value ΔV′ of the abnormal state can be listed in the following Table 2:

FIG. 11 shows the DUT S 0 in the normal state, and FIG. 14 shows the DUT S 0 in the abnormal state (short state). The driver circuit 1120 can obtain the voltage information with receiving the feedback signal FB, and determine whether the DUT S 0 is shorted to the source line S 1 according to the voltage information and Table 2. The values listed in Table 2 are not intended to limit the invention.

In a similar manner, the driver circuit 1120 can determine whether the DUT S 0 is shorted to the adjacent sensing pads or the adjacent gate lines according to the voltage information.

In FIG. 11 , only one source line S 0 is selected as the DUT, but the invention is not limited thereto. FIG. 15 illustrates a plurality of the source lines are detected at the same time according to an embodiment of the invention. Referring to FIG. 15 , taking the open test for example, the source lines S 0 , S 4 , S 8 are selected to be detected at the same time. In this case, the driver circuit 1120 ′ includes a plurality of switch circuits, a plurality of AFE circuits, and a plurality of processor circuits for testing multiple DUTs. In another embodiment, the plurality of processor circuits may be integrated as a single circuit.

FIG. 16 is a schematic diagram illustrating source lines are sequentially detected according to an embodiment of the invention. Referring to FIG. 16 , the source lines S 0 , S 1 , S 2 , S 3 are sequentially detected. FIG. 17 is a schematic diagram illustrating gate lines are sequentially detected according to an embodiment of the invention. Referring to FIG. 17 , the gate lines G 0 , G 1 , G 2 are sequentially detected. FIG. 18 is a schematic diagram illustrating sensing pads are sequentially detected according to an embodiment of the invention. Referring to FIG. 18 , the sensing pads 1112 _ 1 , 1112 _ 2 , 1112 _ 3 are sequentially detected.

In FIG. 16 to FIG. 18 , during the detection period, the first voltage V 1 is sequentially applied to the DUT, and the second voltage V 2 is applied to the reference devices.

In summary, in the embodiment of the invention, during the detection period, the driver circuit applies the first voltage to the DUTs, and applies the second voltage to the reference devices or make the reference devices be in the floating state or in the high impedance state, to obtain voltage information or capacitance information of the DUTs. The driver circuit can detect device abnormality of the touch display panel according to the voltage information or the capacitance information of the DUTs.

It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure covers modifications and variations provided that they fall within the scope of the following claims and their equivalents.