TWI715302B - Bending damage detection apparatus and method for flexible display panel - Google Patents

Abstract

A bending damage detection apparatus and method for a flexible display panel are provided. The bending damage detection apparatus includes a comparing circuit and a processing circuit. The comparing circuit detects a target electrical characteristic of a target electrical component in a bending region of the flexible display panel, and detects a reference electrical characteristic of a reference electrical component in the flexible display panel and outside the bending region. The comparing circuit compares the target electrical characteristic with the reference electrical characteristic during the detection period to obtain a comparison result. The processing circuit is coupled to the comparing circuit to receive the comparison result.

Description

Device and method for detecting bending damage of flexible display panel

The present invention relates to a display device, and more particularly to a bending damage detection device and method for a flexible display panel.

More and more display devices use flexible display panels. For example, the display panels of some mobile phones can be bent or folded. Generally speaking, the flexible display panel has a bending area at the bending axis of the mobile phone. In any case, frequently bending the flexible display panel for a period of time will cause damage to the bending area of the flexible display panel.

The invention provides a bending damage detection device and method to detect bending damage of a flexible display panel.

The bending damage detection device of the present invention includes a bending sensor, a first comparison circuit and a processing circuit. The first comparison circuit is configured to detect the target electrical characteristics of the target electrical element in the bending area of the flexible display panel, and to detect the first reference electrical feature in the flexible display panel and outside the bending area The first reference electrical characteristic of the sexual element. The first comparison circuit compares the target electrical characteristic with the first reference electrical characteristic during the first detection period to obtain the first comparison result, wherein the first detection period includes the bending area of the flexible display panel being bent The initial stage or the initial stage when the bending area of the flexible display panel is flattened. The processing circuit is coupled to the first comparison circuit for receiving the first comparison result, and judging the bending damage condition of the flexible display panel according to the first comparison result. The bending sensor is configured in the bending area of the flexible display panel to detect whether the flexible display panel in the bending area is bent or not to obtain a sensing result. The processing circuit is coupled to the bending sensor to receive the sensing result. When the sensing result indicates "the flexible display panel in the bending area is bent", the processing circuit triggers the first comparison circuit to compare the target electrical characteristic with the first reference electrical characteristic to obtain the first comparison result.

The bending damage detection method of the flexible display panel of the present invention includes: detecting the target electrical characteristic of the target electrical component in the bending area of the flexible display panel by a first comparison circuit; and detecting by the first comparison circuit Measure the first reference electrical characteristics of the first reference electrical component in the flexible display panel and outside the bending area; the bending sensor detects whether the flexible display panel in the bending area is bent , To obtain a sensing result; when the sensing result indicates that the flexible display panel in the bending area is bent, the processing circuit triggers the first comparison circuit to compare the target electrical characteristic with the first reference electrical characteristic; The first comparison circuit compares the target electrical characteristic with the first reference electrical characteristic during the first detection period to obtain the first comparison result, wherein the bending area including the flexible display panel is bent during the first detection period Or the initial stage when the bending area of the flexible display panel is flattened; and the processing circuit determines the bending damage condition of the flexible display panel according to the first comparison result.

Based on the above, the bending area of the flexible display panel has the target electrical element, and the non-bending area of the flexible display panel has the first reference electrical element. The first comparison circuit can compare the electrical characteristics of the target electrical component and the first reference electrical component during the first detection period to obtain the first comparison result. In some embodiments, the processing circuit can determine the bending damage condition of the flexible display panel according to the first comparison result.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

The term "coupling (or connection)" used in the full description of the case (including the scope of the patent application) can refer to any direct or indirect connection means. For example, if the text describes that the first device is coupled (or connected) to the second device, it should be interpreted as that the first device can be directly connected to the second device, or the first device can be connected through other devices or some This kind of connection means is indirectly connected to the second device. The terms "first" and "second" mentioned in the full text of the description of this case (including the scope of the patent application) are used to name the element (element), or to distinguish different embodiments or ranges, and are not used to limit the number of elements The upper or lower limit is not used to limit the order of components. In addition, wherever possible, elements/components/steps with the same reference numbers in the drawings and embodiments represent the same or similar parts. Elements/components/steps using the same reference numerals or using the same terms in different embodiments may refer to related descriptions.

FIG. 1 is a schematic diagram of a circuit block of a bending damage detection device 100 according to an embodiment of the present invention. The flexible display panel 10 shown in FIG. 1 has a bending area 11. The target electrical element EEt is arranged in the bending area 11 of the flexible display panel 10. The reference electrical element EE1 is arranged in the flexible display panel 10 and outside the bending area 11. By comparing the electrical characteristics of the target electrical component EEt and the reference electrical component EE1, the bending damage detection device 100 can detect/determine the bending damage condition of the flexible display panel 10.

In the embodiment shown in FIG. 1, the bending damage detection device 100 includes a comparison circuit 110 and a processing circuit 120. The comparison circuit 110 can detect the electrical characteristics of the target electrical element EEt (herein referred to as the target electrical characteristics tar11). The comparison circuit 110 can also detect the electrical characteristics of the reference electrical element EE1 (herein referred to as reference electrical characteristics ref11). The comparison circuit 110 can compare the target electrical feature tar11 with the reference electrical feature ref11 during the detection period to obtain a comparison result. The detection period can be set according to design requirements. For example, in some embodiments, the detection period may be the initial stage (or the final stage) of bending the bending area 11 of the flexible display panel 10. In other embodiments, the detection period may be the initial stage (or the final stage) when the bending area 11 of the flexible display panel 10 is flattened. In other embodiments, when the bending area 11 of the flexible display panel 10 is flattened, and when the bending area 11 of the flexible display panel 10 is bent, the bending damage detection device 100 will enter the detection During the test.

FIG. 2 is a schematic flowchart of a bending damage detection method according to an embodiment of the invention. Please refer to Figure 1 and Figure 2. During the detection period, the comparison circuit 110 can detect the target electrical characteristic tar11 of the target electrical element EEt in the bending area 11 of the flexible display panel 10, and detect the target electrical characteristics tar11 in the flexible display panel 10 and The reference electrical characteristic ref11 of the reference electrical component EE1 outside the bending area 11 (step S210). During the detection period, the comparison circuit 110 may compare the target electrical characteristic tar11 with the reference electrical characteristic ref11 to obtain a comparison result (step S220). The processing circuit 120 is coupled to the comparison circuit 110 to receive the comparison result. The processing circuit 120 can determine the bending damage condition of the flexible display panel 10 according to the comparison result (step S230).

For example, the target electrical element EEt may be a thin film transistor (TFT), and the reference electrical element EE1 may be another thin film transistor. The target electrical characteristic tar11 may be the on-resistance of the target electrical element EEt, and the reference electrical characteristic ref11 may be the on-resistance of the reference electrical element EE1. When the target electrical component EEt is good, the difference (comparison result) between the on-resistance of the target electrical component EEt and the on-resistance of the reference electrical component EE1 is within the design specification. After the flexible display panel 10 is frequently bent for a period of time, the pixel circuit (not shown) in the bending area 11 of the flexible display panel 10 may be damaged, and the target electrical element EEt may also be damaged.

3 is a schematic diagram illustrating the curves of the target electrical characteristic tar11 and the reference electrical characteristic ref11 shown in FIG. 1 according to an embodiment of the present invention. The horizontal axis shown in FIG. 3 represents time, and the vertical axis represents the level of electrical characteristics. In the embodiment shown in FIG. 3, the target electrical characteristic tar11 may be the output voltage of the target electrical element EEt that is turned on, and the reference electrical characteristic ref11 may be the output of the reference electrical element EE1 that is turned on. Voltage. In the initial stage (that is, when the target electrical component EEt is good), the on-resistance of the target electrical component EEt (target electrical characteristic tar11) and the on-resistance of the reference electrical component EE1 (reference electrical characteristic ref11) The difference (comparison result) is within the design specification. As the number of bending times of the bending zone 11 increases, the bending damage condition of the target electrical element EEt will get worse. Once the difference between the on-resistance of the target electrical element EEt and the on-resistance of the reference electrical element EE1 exceeds the design specification, the processing circuit 120 can determine that the bending damage condition of the flexible display panel 10 is “damaged”.

Therefore, the processing circuit 120 can provide an early warning mechanism. Before the flexible display panel 10 is damaged, the processing circuit 120 can provide a warning message to the user. In another application example, the processing circuit 120 can provide information for reference by panel designers for pre-checking and maintenance, or as a basis for improving design.

4 is a circuit block diagram of a bending damage detection device 400 according to another embodiment of the present invention. The flexible display panel 20 shown in FIG. 4 has a bending area 21. The target electrical element EEt is arranged in the bending area 21 of the flexible display panel 20. The reference electrical element EE1 and the reference electrical element EE2 are arranged in the flexible display panel 20 and outside the bending area 21. The flexible display panel 20, the bending area 21, the reference electrical element EE1 and the target electrical element EEt shown in FIG. 4 can refer to the flexible display panel 10, the bending area 11, the reference electrical element EE1 and the target shown in FIG. Relevant instructions for electrical components EEt. By comparing the electrical characteristics of the target electrical element EEt, the reference electrical element EE1 and the reference electrical element EE2, the bending damage detection device 400 can detect/determine the bending damage condition of the flexible display panel 20.

In the embodiment shown in FIG. 4, the bending damage detection device 400 includes a comparison circuit 410 and a processing circuit 420. The comparison circuit 410 and the processing circuit 420 shown in FIG. 4 can refer to the related description of the comparison circuit 110 and the processing circuit 120 shown in FIG. 1. The comparison circuit 410 can detect the electrical characteristics of the target electrical element EEt (herein referred to as the target electrical feature tar41), and detect the electrical characteristics of the reference electrical element EE1 (herein referred to as the reference electrical feature ref41), And to detect the electrical characteristics of the reference electrical element EE2 (herein referred to as reference electrical characteristics ref42).

For example, the comparison circuit 410 may compare the target electrical feature tar41 with the reference electrical feature ref41 during the first detection period to obtain the first comparison result, and compare the target electrical feature tar41 with the reference electrical feature during the second detection period. Feature ref42 obtains the second comparison result. The first detection period and the second detection period can be set according to design requirements. For example, in some embodiments, the first detection period may be the initial (or final) period when the bending area 21 of the flexible display panel 20 is bent, and the second detection period may be The initial stage (or the final stage) when the bending area 21 of the flexible display panel 20 is flattened. In other embodiments, the first detection period may be the initial stage when the bending area 21 of the flexible display panel 20 is flattened, and the second detection period may be the bending of the flexible display panel 20 The initial stage of zone 21 being bent.

In the embodiment shown in FIG. 4, the bending damage detection device 400 further includes a bending sensor BS. The bending sensor BS is disposed in the bending area 21 of the flexible display panel 20. The bending sensor BS can detect whether the flexible display panel 20 in the bending area 21 is bent to obtain a sensing result. The processing circuit 420 is coupled to the bending sensor BS to receive the sensing result. This embodiment does not limit the implementation of the bending sensor BS. For example, in some embodiments, the bending sensor BS may have a piezoelectric material. When the flexible display panel 20 in the bending area 21 is bent, the piezoelectric material of the bending sensor BS is compressed (or stretched). The deformation of the piezoelectric material can be reflected in the output voltage (sensing result).

FIG. 5 is a schematic flowchart of a bending damage detection method according to another embodiment of the present invention. Please refer to Figure 4 and Figure 5. In the first detection period, the comparison circuit 410 can detect the target electrical feature tar41 of the target electrical element EEt in the bending area 21 of the flexible display panel 20, and detect the target electrical feature tar41 in the flexible display panel 20 The reference electrical characteristic ref41 of the reference electrical element EE1 in the middle and outside the bending area 21 (step S510). In the first detection period, the comparison circuit 410 may compare the target electrical characteristic tar41 with the reference electrical characteristic ref41 to obtain a first comparison result (step S520). For example, when the sensing result of the bending sensor BS indicates that the flexible display panel 20 in the bending area 21 is bent, the processing circuit 420 may trigger the comparison circuit 410 to compare the target electrical characteristic tar41 with the reference The electrical characteristic ref41 is used to obtain the first comparison result.

In the second detection period, the comparison circuit 410 can detect the target electrical feature tar41 of the target electrical element EEt in the bending area 21 of the flexible display panel 20, and detect the target electrical feature tar41 in the flexible display panel 20 The reference electrical characteristic ref42 of the reference electrical element EE2 in the middle and outside the bending area 21 (step S530). In the second detection period, the comparison circuit 410 may compare the target electrical characteristic tar41 with the reference electrical characteristic ref42 to obtain a second comparison result (step S540). For example, when the sensing result of the bending sensor BS indicates that the flexible display panel 20 in the bending area 21 is flattened, the processing circuit 420 may trigger the comparison circuit 410 to compare the target electrical characteristic tar41 with the reference electrical characteristic. Sex feature ref42 to obtain the second comparison result.

It should be noted that although the embodiment shown in FIG. 5 first performs step S510 and step S520, and then performs step S530 and step S540, the implementation of the present invention should not be limited to this. For example, in other embodiments, step S530 and step S540 may be executed first, and then step S510 and step S520 are executed. The processing circuit 420 is coupled to the comparison circuit 110 to receive the first comparison result and the second comparison result. The processing circuit 120 can determine the bending damage condition of the flexible display panel 20 according to the first comparison result and the second comparison result (step S550).

For example, the reference electrical element EE1 may be a first transistor (for example, a thin film transistor), the reference electrical element EE2 may be a second transistor (for example, a thin film transistor), and the target electrical element EEt may be a third transistor. Transistors (such as thin film transistors). The target electrical characteristic tar41 may be the on-resistance of the target electrical element EEt, the reference electrical characteristic ref41 may be the on-resistance of the reference electrical element EE1, and the reference electrical characteristic ref42 may be the on-resistance of the reference electrical element EE1. The electrical specifications of the third transistor (the target electrical element EEt) are the same as the electrical specifications of the transistor of the pixel circuit (not shown) of the flexible display panel 20. The channel width-to-length ratio (W/L) of the second transistor (reference electrical element EE2) is smaller than that of the third transistor, and the channel width and length of the first transistor (reference electrical element EE1) The ratio is smaller than the channel width to length ratio of the second transistor.

When the target electrical element EEt is good, the difference between the on-resistance of the target electrical element EEt and the on-resistance of the reference electrical element EE1 (the first comparison result) is within the design specification, and the target electrical element EEt The difference between the on-resistance and the on-resistance of the reference electrical element EE2 (the second comparison result) is also within the design specification. After the flexible display panel 20 is frequently bent for a period of time, the pixel circuit (not shown) in the bending area 21 of the flexible display panel 20 may be damaged, and the target electrical element EEt may also be damaged.

In the embodiment shown in FIG. 4, the comparison circuit 410 includes a comparator 411 and a comparator 412. The first input terminal of the comparator 411 is coupled to the target electrical element EEt to receive the target electrical characteristic tar41. The second input terminal of the comparator 411 is coupled to the reference electrical element EE1 to receive the reference electrical feature ref41. In the embodiment shown in FIG. 4, the target electrical characteristic tar41 may be the output voltage of the turned-on target electrical element EEt, and the reference electrical characteristic ref41 may be the output voltage of the turned-on reference electrical element EE1. The output terminal of the comparator 411 is coupled to the processing circuit 420 to provide the first comparison result. The first input terminal of the comparator 412 is coupled to the target electrical element EEt to receive the target electrical characteristic tar41. The second input terminal of the comparator 412 is coupled to the reference electrical element EE2 to receive the reference electrical feature ref42. In the embodiment shown in FIG. 4, the target electrical characteristic tar41 may be the output voltage of the turned-on target electrical element EEt, and the reference electrical characteristic ref42 may be the output voltage of the turned-on reference electrical element EE2. The output terminal of the comparator 412 is coupled to the processing circuit 420 to provide the second comparison result.

6 is a schematic diagram illustrating the curves of the target electrical characteristic tar41, the reference electrical characteristic ref41 and the reference electrical characteristic ref42 shown in FIG. 4 according to an embodiment of the present invention. The horizontal axis shown in FIG. 6 represents time, and the vertical axis represents the level of electrical characteristics (for example, the voltage level). As the number of bending times of the bending zone 11 increases, the bending damage condition of the target electrical element EEt will get worse.

FIG. 7 is a circuit block diagram illustrating the target electrical component EEt, the reference electrical component EE1 and the reference electrical component EE2 shown in FIG. 4 according to an embodiment of the present invention. The flexible display panel 20, the bending area 21, the reference electrical element EE1, the reference electrical element EE2, the target electrical element EEt, the bending sensor BS, the comparison circuit 410, and the processing circuit 420 shown in FIG. The related description of 1 will not be repeated here.

In the embodiment shown in FIG. 7, the bending damage detection device further includes a driving circuit 430. The driving circuit 430 can drive the flexible display panel 20 to display images in the display area. The display area is also called an active area. The driving circuit 430 can provide a reference voltage to the first end (for example, the drain) of the first transistor (reference electrical element EE1), the second transistor (reference electrical element EE2), and the third transistor (target electrical element EEt). pole). The control terminals (eg, gates) of the first transistor, the second transistor and the third transistor are controlled by the driving circuit 430. Based on the control of the processing circuit 420, the driving circuit 430 conducts the first transistor and the third transistor during the first detection period (for example, the initial stage when the bending region 21 of the flexible display panel 20 is bent), and Turn off the second transistor. In addition, based on the control of the processing circuit 420, the driving circuit 430 conducts the second transistor and the third transistor during the second detection period (for example, the initial stage when the bending area 21 of the flexible display panel 20 is flattened) , And turn off the first transistor.

The second terminal (for example, the source) of the first transistor (refer to the electrical element EE1) is coupled to the second input terminal of the comparator 411 of the comparison circuit 410. The second terminal (for example, the source) of the second transistor (refer to the electrical element EE2) is coupled to the second input terminal of the comparator 412 of the comparison circuit 410. The second terminal (for example, the source) of the third transistor (the target electrical element EEt) is coupled to the first input terminal of the comparator 411 and the first input terminal of the comparator 412. The electrical specifications of the third transistor (the target electrical element EEt) are the same as the electrical specifications of the transistor of the pixel circuit (not shown) of the flexible display panel 20. The channel width-to-length ratio (W/L) of the second transistor (reference electrical element EE2) is smaller than that of the third transistor, and the channel width and length of the first transistor (reference electrical element EE1) The ratio is smaller than the channel width to length ratio of the second transistor. The source voltage of the first transistor (reference electrical element EE1) can refer to the curve of the reference electrical characteristic ref41 shown in FIG. 6. The source voltage of the second transistor (reference electrical element EE2) can refer to the curve of the reference electrical characteristic ref42 shown in FIG. 6. The source voltage of the third transistor (the target electrical element EEt) can refer to the curve of the target electrical characteristic tar41 shown in FIG. 6.

The output terminal of the comparator 411 is coupled to the processing circuit 420 to provide the first comparison result. The output terminal of the comparator 413 is coupled to the processing circuit 420 to provide a second comparison result. When the output of the comparator 411 (the first comparison result) indicates that the source voltage of the third transistor is greater than the first transistor (refer to the electrical element EE1) at the initial stage when the bending area 21 of the flexible display panel 20 is bent When the source voltage of the comparator 412 (the second comparison result) indicates “in the flexible display panel, the target electrical characteristic tar41 is greater than the reference electrical characteristic ref41 during the first detection period). At the initial stage when the bending region 21 of 20 is flattened, the source voltage of the third transistor is greater than the source voltage of the second transistor (reference electrical element EE2)" (that is, the target voltage during the second detection period) If the characteristic tar41 is greater than the reference electrical characteristic ref42), the processing circuit 420 can determine that the bending damage condition of the transistor of the pixel circuit (not shown) of the flexible display panel 20 is “good”. Conversely, the processing circuit 420 can determine that the bending damage condition of the transistor of the pixel circuit (not shown) of the flexible display panel 20 is “not good”.

FIG. 8 is a circuit block diagram illustrating the target electrical component EEt, the reference electrical component EE1 and the reference electrical component EE2 shown in FIG. 4 according to another embodiment of the present invention. The flexible display panel 20, the bending area 21, the reference electrical element EE1, the reference electrical element EE2, the target electrical element EEt, the bending sensor BS, the comparison circuit 410, and the processing circuit 420 shown in FIG. For the related description of 1, the flexible comparison circuit 410, the processing circuit 420, and the driving circuit 430 shown in FIG. 8 can refer to the related description of FIG. 7, so they will not be repeated.

In the embodiment shown in FIG. 8, the reference electrical element EE1 may be a first capacitor, the reference electrical element EE2 may be a second capacitor, and the target electrical element EEt may be a third capacitor. The first terminals of the first capacitor, the second capacitor and the third capacitor are coupled to the driving circuit 430 to receive the reference voltage. The second ends of the first capacitor, the second capacitor, and the third capacitor are coupled to the comparison circuit 410. The packaging material of the flexible display panel 20 can be used as the dielectric of the first capacitor, the second capacitor and the third capacitor.

FIG. 9 is a schematic diagram illustrating the layout of the target electrical element EEt, the reference electrical element EE1 and the reference electrical element EE2 shown in FIG. 8 according to an embodiment of the present invention. The first capacitor (reference electrical element EE1), the second capacitor (reference electrical element EE2), and the third capacitor (target electrical element EEt) may be arranged beside the display area of the flexible display panel 20. The display area is also called an active area.

10 is a schematic cross-sectional view illustrating the layout of the third capacitor (target electrical element EEt) shown in FIG. 9 according to an embodiment of the present invention. Please refer to Figure 9 and Figure 10. The two electrodes 1001 and 1002 of the third capacitor (the target electrical element EEt) may be arranged on the substrate of the flexible display panel 20. The electrode 1001 is electrically connected to the driving circuit 430, and the electrode 1002 is electrically connected to the conversion circuit 413 of the comparison circuit 410. In the packaging process, the packaging material can not only encapsulate the circuit in the display area, the packaging material of the flexible display panel 20 can also be arranged on the two electrodes (also on the two electrodes) of the third capacitor (the target electrical element EEt). Between two electrodes), as shown in Figure 10. Therefore, the packaging material of the flexible display panel 20 can be used as the dielectric of the third capacitor (the target electrical element EEt). Other capacitors (reference electrical component EE1 and reference electrical component EE2) can be deduced by referring to the relevant description of the third capacitor (target electrical component EEt), so they will not be repeated.

In the embodiment shown in FIG. 9, the capacitance value of the third capacitor (target electrical element EEt) is greater than the capacitance value of the first capacitor (reference electrical element EE1), and the capacitance value of the first capacitor is greater than that of the second capacitor (reference The capacitance value of the electrical component EE2). When the target electrical element EEt is good, the difference between the capacitance value of the target electrical element EEt and the capacitance value of the reference electrical element EE1 (the first comparison result) is within the design specification, and the target electrical element EEt The difference between the capacitance value and the capacitance value of the reference electrical component EE2 (the second comparison result) is also within the design specification. After the flexible display panel 20 is frequently bent for a period of time, the packaging material in the bending area 21 of the flexible display panel 20 may be damaged, thereby changing the capacitance value of the target electrical element EEt.

In the embodiment shown in FIG. 8, the comparison circuit 410 includes a conversion circuit 413, a comparator 411 and a comparator 412. The conversion circuit 413 is coupled to the second end of the first capacitor (reference electrical element EE1), the second end of the second capacitor (reference electrical element EE2) and the second end of the third capacitor (target electrical element EEt) . The conversion circuit 413 can convert the capacitance value of the first capacitor into a corresponding voltage (herein referred to as a first voltage), and output the first voltage to the comparator 411. The conversion circuit 413 can convert the capacitance value of the second capacitor into a corresponding voltage (referred to herein as a second voltage), and output the second voltage to the comparator 412. The conversion circuit 413 may convert the capacitance value of the third capacitor into a corresponding voltage (referred to as a third voltage herein), and output the third voltage to the comparators 411 and 412.

The first input terminal of the comparator 411 is coupled to the conversion circuit 413 to receive the first voltage. The second input terminal of the comparator 411 is coupled to the conversion circuit 413 to receive the third voltage. The output terminal of the comparator 411 is coupled to the processing circuit 420 to provide the first comparison result. The first input terminal of the comparator 412 is coupled to the conversion circuit 413 to receive the second voltage. The second input terminal of the comparator 412 is coupled to the conversion circuit 413 to receive the third voltage. The output terminal of the comparator 412 is coupled to the processing circuit 420 to provide a second comparison result.

Please refer to Figure 6 and Figure 8. When the output of the comparator 411 (the first comparison result) indicates "the third voltage is greater than the first voltage at the initial stage when the bending area 21 of the flexible display panel 20 is bent" (that is, during the first detection period) The target electrical characteristic tar41 is greater than the reference electrical characteristic ref41), and when the output of the comparator 412 (the second comparison result) indicates "In the initial stage when the bending area 21 of the flexible display panel 20 is flattened, the third voltage is greater than the second When the voltage is "" (that is, the target electrical characteristic tar41 is greater than the reference electrical characteristic ref42 during the second detection period), the processing circuit 420 can determine that the bending damage condition of the packaging material of the flexible display panel 20 is "good". Conversely, the processing circuit 420 can determine that the bending damage condition of the packaging material of the flexible display panel 20 is "not good".

FIG. 11 is a circuit block diagram of a bending damage detection device 1100 according to another embodiment of the present invention. The flexible display panel 30 shown in FIG. 11 has a bending area 31. The bending damage detection device 1100 shown in FIG. 11 includes a processing circuit 420, a driving circuit 430, a detection circuit 1110, and a detection circuit 1120. The processing circuit 420 and the driving circuit 430 shown in FIG. 11 can refer to the related descriptions of the processing circuit 420 and the driving circuit 430 shown in FIG. 7 and FIG.

The detection circuit 1110 shown in FIG. 11 includes the reference electrical component EE1 (first transistor), the reference electrical component EE2 (second transistor), the target electrical component EEt (third transistor), and the comparison Circuit 410 (comparators 411 and 412). Therefore, the detection circuit 1110 shown in FIG. 11 can refer to the related description of FIG. 7, so it will not be repeated. The detection circuit 1110 can output the “first comparison result” and the “second comparison result” to the processing circuit 420. When the "first comparison result" indicates that "the source voltage of the third transistor (the target electrical element EEt shown in FIG. 7) at the initial stage of bending the bending area 31 of the flexible display panel 30 is greater than that of the first transistor ( The source voltage of the reference electrical element EE1 shown in FIG. 7" (that is, the target electrical characteristic tar41 is greater than the reference electrical characteristic ref41 during the first detection period), and when the "second comparison result" indicates " At the initial stage where the bending area 31 of the flexible display panel 30 is flattened, the source voltage of the third transistor (the target electrical element EEt shown in FIG. 7) is greater than that of the second transistor (the reference electrical element EE2 shown in FIG. )" (that is, during the second detection period, the target electrical characteristic tar41 is greater than the reference electrical characteristic ref42), the processing circuit 420 can determine the pixel circuit (not shown) of the flexible display panel 30 The bending damage condition of the transistor is "good". Conversely, the processing circuit 420 can determine that the bending damage condition of the transistor of the pixel circuit (not shown) of the flexible display panel 30 is “not good”.

The detection circuit 1120 shown in FIG. 11 includes a reference electrical component EE1 (first capacitor), a reference electrical component EE2 (second capacitor), a target electrical component EEt (third capacitor), and a comparison circuit 410 ( Comparator 411, comparator 412 and conversion circuit 413). Therefore, the detection circuit 1120 shown in FIG. 11 can refer to the related description of FIG. 8, so it will not be repeated. The detection circuit 1120 can output the “third comparison result” and “fourth comparison result” to the processing circuit 420. When the "third comparison result" indicates that "in the initial stage when the bending area 31 of the flexible display panel 30 is bent, the capacitance value of the third capacitor (the target electrical element EEt shown in FIG. 8) is greater than that of the first capacitor (as shown in FIG. Shows the capacitance value of the reference electrical element EE1)” (that is, the target electrical characteristic tar41 is greater than the reference electrical characteristic ref41 during the first detection period), and when the “fourth comparison result” means “in the flexible display At the initial stage when the bending area 31 of the panel 30 is flattened, the capacitance value of the third capacitor (the target electrical element EEt shown in Fig. 8) is greater than the capacitance value of the second capacitor (the reference electrical element EE2 shown in Fig. 8)" That is, during the second detection period, the target electrical characteristic tar41 is greater than the reference electrical characteristic ref42), and the processing circuit 420 can determine that the bending damage condition of the packaging material of the flexible display panel 30 is “good”. Conversely, the processing circuit 420 can determine that the bending damage condition of the packaging material of the flexible display panel 30 is "not good".

The processing circuit 420 can determine the bending damage condition of the flexible display panel 30 according to the comparison result of the detection circuit 1110 and the comparison result of the detection circuit 1120. For example, when "the bending damage condition of the transistor of the pixel circuit (not shown) of the flexible display panel 30 is good" and "the bending damage condition of the packaging material of the flexible display panel 30 is good", The processing circuit 420 can determine that the bending damage condition of the flexible display panel 30 is "normal". When "the bending damage condition of the transistor of the pixel circuit (not shown) of the flexible display panel 30 is good" but "the bending damage condition of the packaging material of the flexible display panel 30 is not good", the processing circuit 420 It can be judged that the bending damage condition of the flexible display panel 30 is "will be damaged". When the bending damage condition of the transistor of the pixel circuit (not shown) of the flexible display panel 30 is not good" but "the bending damage condition of the packaging material of the flexible display panel 30 is good", the processing circuit 420 may The bending damage condition of the flexible display panel 30 is judged to be "possibly damaged". When "the bending damage condition of the transistor of the pixel circuit (not shown) of the flexible display panel 30 is not good" and "the bending damage condition of the packaging material of the flexible display panel 30 is not good", the processing circuit 420 can determine that the bending damage condition of the flexible display panel 30 is "damaged".

It should be noted that the embodiment shown in FIG. 11 is equipped with a detection circuit 1110 and a detection circuit 1120 in the bending damage detection device 1100. In any case, the number of detection circuits 1110 and/or the number of detection circuits 1120 can be according to design requirements. That is, in other embodiments, the plurality of detection circuits 1110 and/or the plurality of detection circuits 1120 may be configured in the bending damage detection device 1100.

To sum up, if the flexible display panel is abnormal, the thin film transistor (TFT) or the packaging material in the flexible display panel is usually damaged. Therefore, the bending damage detection devices described in the foregoing embodiments can monitor whether the electrical characteristics of the thin film transistor and/or the packaging material change after the bending area has been bent multiple times. In conjunction with the count of the reference side of the bending sensor BS and the number of bending times, the bending damage detection device can know how many times the bending caused the package and/or the thin film transistor to be damaged. Therefore, the bending damage detection device can provide an early warning mechanism. Before the flexible display panel is damaged, the bending damage detection device can provide a warning message to the user. In other application examples, the bending damage detection device can provide information for reference by panel designers for pre-checking and repairing, or as a basis for improving design.

According to different design requirements, the implementation of the blocks of the comparison circuit, processing circuit, and/or drive circuit can be hardware, firmware, software, or the aforementioned three. A combination of more of them.

In terms of hardware, the blocks of the comparison circuit, the processing circuit, and/or the driving circuit can be implemented in a logic circuit on an integrated circuit. The above-mentioned comparison circuit, processing circuit, and/or related functions of the driving circuit may be implemented as hardware using hardware description languages (for example, Verilog HDL or VHDL) or other suitable programming languages. For example, the related functions of the comparison circuit, the processing circuit, and/or the driving circuit can be implemented in one or more controllers, microcontrollers, microprocessors, and application-specific integrated circuits (Application-specific integrated circuit). , ASIC), digital signal processor (DSP), Field Programmable Gate Array (FPGA) and/or various logic blocks, modules and circuits in other processing units.

In terms of software form and/or firmware form, the relevant functions of the above-mentioned comparison circuit, processing circuit, and/or driving circuit can be implemented as programming codes. For example, general programming languages (such as C, C++, or assembly language) or other suitable programming languages are used to implement the aforementioned comparison circuit, processing circuit, and/or driving circuit. The programming code may be recorded/stored in a recording medium, which includes, for example, a read-only memory (Read Only Memory, ROM), a storage device, and/or a random access memory (Random Access Memory, RAM). . A computer, a central processing unit (CPU), a controller, a microcontroller, or a microprocessor can read and execute the programming code from the recording medium, thereby achieving related functions. As the recording medium, a "non-transitory computer readable medium" can be used, for example, tape, disk, card, semiconductor memory, and Programming logic circuits, etc. Furthermore, the program can also be provided to the computer (or CPU) via any transmission medium (communication network, broadcast wave, etc.). The communication network is, for example, the Internet, wired communication, wireless communication, or other communication media.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention shall be determined by the scope of the attached patent application.

10, 20, 30: Flexible display panel 11, 21, 31: bending area 100, 400, 1100: bending damage detection device 110, 410: comparison circuit 120, 420: processing circuit 411, 412: Comparator 413: conversion circuit 430: drive circuit 1001, 1002: electrode 1110, 1120: detection circuit BS: Bend sensor EE1, EE2: Reference electrical components EEt: target electrical component tar11, tar41: target electrical characteristics ref11, ref41, ref42: reference electrical characteristics S210～S230, S510～S550: steps

FIG. 1 is a schematic diagram of a circuit block of a bending damage detection device according to an embodiment of the present invention. FIG. 2 is a schematic flowchart of a bending damage detection method according to an embodiment of the invention. 3 is a schematic diagram illustrating the curves of the target electrical characteristic tar11 and the reference electrical characteristic ref11 shown in FIG. 1 according to an embodiment of the present invention. 4 is a circuit block diagram of a bending damage detection device according to another embodiment of the invention. FIG. 5 is a schematic flowchart of a bending damage detection method according to another embodiment of the present invention. 6 is a schematic diagram illustrating the curves of the target electrical characteristic tar41, the reference electrical characteristic ref41 and the reference electrical characteristic ref42 shown in FIG. 4 according to an embodiment of the present invention. FIG. 7 is a circuit block diagram illustrating the target electrical component EEt, the reference electrical component EE1 and the reference electrical component EE2 shown in FIG. 4 according to an embodiment of the present invention. FIG. 8 is a circuit block diagram illustrating the target electrical component EEt, the reference electrical component EE1 and the reference electrical component EE2 shown in FIG. 4 according to another embodiment of the present invention. FIG. 9 is a schematic diagram illustrating the layout of the target electrical element EEt, the reference electrical element EE1 and the reference electrical element EE2 shown in FIG. 8 according to an embodiment of the present invention. 10 is a schematic cross-sectional view illustrating the layout of the third capacitor (target electrical element EEt) shown in FIG. 9 according to an embodiment of the present invention. FIG. 11 is a circuit block diagram of a bending damage detection device 1100 according to another embodiment of the present invention.

S210~S230: steps

Claims (12)

A bending damage detection device for a flexible display panel, comprising: a first comparison circuit configured to detect a target electrical characteristic of a target electrical component in a bending area of a flexible display panel , And detecting a first reference electrical characteristic of a first reference electrical element in the flexible display panel and outside the bending area, wherein the first comparison circuit compares the The target electrical characteristic and the first reference electrical characteristic are compared to obtain a first comparison result, wherein the first detection period includes an initial stage when the bending area of the flexible display panel is bent or the flexible display An initial stage when the bending area of the panel is flattened; a processing circuit, coupled to the first comparison circuit, for receiving the first comparison result, and judging the bending of the flexible display panel according to the first comparison result A bending damage condition; and a bending sensor including a piezoelectric material, the bending sensor is arranged in the bending area of the flexible display panel to detect the bending area in the bending area Whether the flexible display panel is bent to obtain a sensing result, wherein the processing circuit is coupled to the bending sensor to receive the sensing result; when the sensing result indicates the bending area When the flexible display panel is bent, the processing circuit triggers the first comparison circuit to compare the target electrical characteristic with the first reference electrical characteristic to obtain the first comparison result; and the target electrical element and the second A reference electrical component is either a transistor or a capacitor, and the target electrical characteristic and the first reference electrical characteristic are both on-resistance, or both are output voltages, or both are capacitance values. The bending damage detection device as described in claim 1, wherein the first comparison circuit is further configured to detect a second reference electrical property in the flexible display panel and outside the bending area A second reference electrical characteristic of the device, the first comparison circuit compares the target electrical characteristic with the second reference electrical characteristic during a second detection period to obtain a second comparison result, and the processing circuit is based on the The first comparison result and the second comparison result determine the bending damage condition of the flexible display panel, wherein the first detection period is an initial stage when the bending area of the flexible display panel is bent, and the second The second detection period is an early stage when the bending area of the flexible display panel is flattened. The target electrical component, the first reference electrical component, and the second reference electrical component are all transistors, or all Is a capacitance, the target electrical characteristic, the first reference electrical characteristic, and the second reference electrical characteristic are all on-resistances, or all are output voltages, or all are capacitance values. The bending damage detection device according to the second item of the patent application, wherein the first reference electrical element is a first transistor, the second reference electrical element is a second transistor, and the target electrical The element is a third transistor, the electrical specification of the third transistor is the same as that of a transistor of a pixel circuit of the flexible display panel, and the channel width to length ratio of the second transistor is smaller than that of the first transistor. The channel width to length ratio of the tri-transistor, and the channel width to length ratio of the first transistor is smaller than the channel width to length ratio of the second transistor. The bending damage detection device as described in item 3 of the scope of patent application further includes: a driving circuit configured to drive the flexible display panel to display an image, which The driving circuit provides a reference voltage to a first terminal of the first transistor, a first terminal of the second transistor, and a first terminal of the third transistor, a first terminal of the first transistor Two terminals, a second terminal of the second transistor and a second terminal of the third transistor are coupled to the first comparison circuit, a control terminal of the first transistor, a control terminal of the second transistor The control terminal and a control terminal of the third transistor are controlled by the drive circuit, and the drive circuit conducts the first transistor and the third transistor during the first detection period based on the control of the processing circuit, and The driving circuit conducts the second transistor and the third transistor during the second detection period based on the control of the processing circuit. The bending damage detection device according to claim 4, wherein the first comparison circuit includes: a first comparator having a first input terminal coupled to the second terminal of the third transistor , Wherein a second input terminal of the first comparator is coupled to the second terminal of the first transistor, and an output terminal of the first comparator is coupled to the processing circuit to provide the first comparison result And a second comparator having a first input terminal coupled to the second terminal of the third transistor, wherein a second input terminal of the second comparator is coupled to the second transistor of the The second terminal and an output terminal of the second comparator are coupled to the processing circuit to provide the second comparison result; wherein when the first comparison result represents the voltage of the third transistor during the first detection period Is greater than the voltage of the first transistor, and the second comparison result indicates that during the second detection period, the voltage of the third transistor is greater than the voltage of the second transistor, the processing circuit determines that the flexible display panel is The bending of a transistor of a pixel circuit The damage condition is good. The bending damage detection device as described in item 5 of the scope of patent application further includes: a second comparison circuit configured to detect a first capacitor in the flexible display panel and outside the bending area , Detecting a second capacitor in the flexible display panel and outside the bending area, detecting a third capacitor in the bending area of the flexible display panel, wherein the second comparison circuit is During the first detection period, the first capacitor is compared with the third capacitor to obtain a third comparison result. The second comparison circuit compares the second capacitor with the third capacitor during the second detection period to obtain a first Four comparison results, a packaging material of the flexible display panel is used as the dielectric of the first capacitor, the second capacitor, and the third capacitor, a first end of the first capacitor, and a second capacitor of the second capacitor One end and a first end of the third capacitor are coupled to a reference voltage, and a second end of the first capacitor, a second end of the second capacitor, and a second end of the third capacitor are coupled Connect to the second comparison circuit. According to the bend damage detection device described in claim 6, wherein the second comparison circuit includes: a conversion circuit coupled to the second end of the first capacitor and the second end of the second capacitor The terminal and the second terminal of the third capacitor are configured to convert a first capacitance value of the first capacitor into a first voltage, and to convert a second capacitance value of the second capacitor Is converted to a second voltage, and a third capacitance value of the third capacitor is converted into a third voltage; a third comparator having a first input terminal and a second input terminal coupled to the conversion circuit To receive the first voltage and the third voltage, wherein an output terminal of the third comparator is coupled to the processing circuit to provide the third comparison result; and a fourth comparator having a first input terminal and A second input terminal is coupled to the conversion circuit to receive the second voltage and the third voltage, and an output terminal of the fourth comparator is coupled to the processing circuit to provide the fourth comparison result. The bend damage detection device described in item 7 of the scope of patent application, wherein when the third comparison result indicates that the third voltage is greater than the first voltage during the first detection period, and the fourth comparison result indicates that When the third voltage is greater than the second voltage during the second detection period, the processing circuit determines that the bending damage condition of the packaging material of the flexible display panel is good. As for the bending damage detection device described in the scope of patent application 2, wherein the first reference electrical element is a first capacitor, the second reference electrical element is a second capacitor, and the target electrical element is A third capacitor, a packaging material of the flexible display panel is used as the dielectric of the first capacitor, the second capacitor, and the third capacitor, a first end of the first capacitor, a first end of the second capacitor The first terminal and a first terminal of the third capacitor are coupled to a reference voltage, and a second terminal of the first capacitor, a second terminal of the second capacitor, and a second terminal of the third capacitor Is coupled to the first comparison circuit. According to the bend damage detection device described in item 9 of the scope of patent application, the first comparison circuit includes: A conversion circuit coupled to the second end of the first capacitor, the second end of the second capacitor, and the second end of the third capacitor, and is configured as a first capacitor of the first capacitor Converting the value into a first voltage, converting a second capacitance value of the second capacitor into a second voltage, and converting a third capacitance value of the third capacitor into a third voltage; a first comparator , Having a first input terminal and a second input terminal coupled to the conversion circuit to receive the first voltage and the third voltage, wherein an output terminal of the first comparator is coupled to the processing circuit to provide the A first comparison result; and a second comparator having a first input terminal and a second input terminal coupled to the conversion circuit to receive the second voltage and the third voltage, wherein one of the second comparator The output terminal is coupled to the processing circuit to provide the second comparison result; wherein when the first comparison result indicates that the third voltage is greater than the first voltage during the first detection period, and the second comparison result indicates that the When the third voltage is greater than the second voltage during the second detection period, the processing circuit determines that the bending damage condition of the packaging material of the flexible display panel is good. A method for detecting bending damage of a flexible display panel includes: detecting, by a first comparison circuit, a target electrical characteristic of a target electrical component in a bending area of a flexible display panel; The first comparison circuit detects a first reference electrical characteristic of a first reference electrical element in the flexible display panel and outside the bending area; a bending sensor detects the bending Whether the flexible display panel in the area is bent to obtain a sensing result, wherein the bending sensor includes a piezoelectric material; When the sensing result indicates that the flexible display panel in the bending area is bent, the processing circuit triggers the first comparison circuit to compare the target electrical characteristic with the first reference electrical characteristic; The first comparison circuit compares the target electrical characteristic with the first reference electrical characteristic during a first detection period to obtain a first comparison result, wherein the first detection period includes the flexible display panel An initial stage when the bending area is bent or an initial stage when the bending area of the flexible display panel is flattened; and a processing circuit determines the bending damage condition of the flexible display panel according to the first comparison result , Wherein the target electrical element and the first reference electrical element are both transistors or capacitors, and the target electrical feature and the first reference electrical feature are both on-resistances, or both are output voltages, Or both are capacitance values. The bending damage detection method as described in claim 11 further includes: detecting a second reference electrical element in the flexible display panel and outside the bending area by the first comparison circuit A second reference electrical feature of the first comparison circuit; compare the target electrical feature with the second reference electrical feature during a second detection period by the first comparison circuit to obtain a second comparison result, wherein the first detection The test period is an initial stage when the bending area of the flexible display panel is bent, and the second detection period is an initial stage when the bending area of the flexible display panel is flattened; and by the processing circuit Judging the bending damage condition of the flexible display panel according to the first comparison result and the second comparison result, Wherein, the target electrical component, the first reference electrical component, and the second reference electrical component are all transistors or capacitors, the target electrical feature, the first reference electrical feature, and the second The reference electrical characteristics are all on-resistance, or all are output voltage, or all are capacitance values.

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