TWI726537B - Bending damage detection apparatus for flexible display panel - Google Patents

Abstract

A bending damage detection apparatus for a flexible display panel is provided. The bending damage detection apparatus includes a pixel unit and a processing circuit. The pixel unit disposed in the flexible display panel includes a light emitting element, a light guiding layer, and a light sensing element. The light emitting element is located at a first end of the light guiding layer, and the light sensing element is located at a second end of the light guiding layer. The light sensing element senses light of the light emitting element through the light guiding layer during a detection period to obtain a light sensing result. The encapsulation material of the flexible display panel is disposed on the light guiding layer and between the light emitting element and the light sensing element. The processing circuit is coupled to the light sensing element to receive the light sensing result.

Description

Bending damage detecting device for flexible display panel

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

More and more display devices use flexible display panels. For example, the display panel of some mobile phones can be bent or curled. In any case, frequent bending of the flexible display panel will cause damage to the flexible display panel after a period of time.

The invention provides a bending damage detection device to detect the bending damage condition of a flexible display panel.

In one embodiment, the bending damage detection device includes a first pixel unit and a processing circuit. The first pixel unit is configured in the flexible display panel. The first pixel unit includes a first light emitting element, a first optical waveguide layer and a first light sensing element. The first light emitting element is located at the first end of the first optical waveguide layer, and the first light sensing element is located at the second end of the first optical waveguide layer. The first light-sensing element senses the light of the first light-emitting element through the first optical waveguide layer during the detection period to obtain a first light-sensing result. The packaging material of the flexible display panel is arranged on the first optical waveguide layer and between the first light-emitting element and the first light-sensing element. The processing circuit is coupled to the first light sensing element to receive the first light sensing result.

In one embodiment, the bending damage detection device includes a pixel unit and a processing circuit. The pixel unit is configured in the flexible display panel. The pixel unit includes a light emitting element, an optical waveguide layer and a light sensing element. The light emitting element is located at the first end of the optical waveguide layer, and the light sensing element is located at the second end of the optical waveguide layer. The light-sensing element senses the light of the light-emitting element through the optical waveguide layer during the detection period to obtain a light-sensing result. The packaging material of the flexible display panel is arranged between the light emitting element and the first light sensing element. The packaging material includes at least a lower layer and at least one upper layer. Part or all of the optical waveguide layer is arranged between the at least lower layer and the at least one upper layer. The processing circuit is coupled to the light sensing element to receive the light sensing result.

In one embodiment, the bending damage detection device includes a plurality of pixel units and a processing circuit. These pixel units are arranged in the flexible display panel. Each of these pixel units includes a light-emitting element, an optical waveguide layer, and a light-sensing element. The light emitting element is located at the first end of the optical waveguide layer, and the light sensing element is located at the second end of the optical waveguide layer. The light-sensing element senses the light of the light-emitting element through the optical waveguide layer during the detection period to obtain a light-sensing result. The packaging material of the flexible display panel is arranged between the light emitting element and the first light sensing element. The packaging material includes at least a lower layer and at least one upper layer. Part or all of the optical waveguide layer is arranged between the at least lower layer and the at least one upper layer. Wherein, the at least lower layers of these pixel units have different heights. The processing circuit is coupled to the light sensing elements of the pixel units to receive the light sensing results of the pixel units.

Based on the above, the flexible display panel has at least one pixel unit for detecting bending damage. The light sensing element of the pixel unit can sense the light of the light emitting element through the optical waveguide layer during the detection period to obtain a light sensing result. The bending stress can be applied to the optical waveguide layer of the pixel unit through the packaging material of the flexible display panel. After frequently bending the flexible display panel for a period of time, the bending stress may damage the packaging material and the optical waveguide layer. After the optical waveguide layer is damaged, it is difficult (or impossible) for the light of the light emitting element to reach the light sensing element. Therefore, the processing circuit can determine the bending damage condition of the optical waveguide layer according to the light sensing result of the light sensing element, and then infer the bending damage condition of the packaging material of the flexible display panel.

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 text of the specification of this case (including the scope of the patent application) can refer to any direct or indirect connection means. For example, if it is described in the text 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 of 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 that use the same reference numerals or use 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 bending damage detection device 100 shown in FIG. 1 has at least one pixel unit 110. The pixel unit 110 is configured in the flexible display panel 10 to detect the bending damage of the packaging material of the flexible display panel 10. According to design requirements, in some embodiments, the pixel unit 110 may be configured in the display area of the flexible display panel 10. The display area is also called an active area. In other embodiments, the pixel unit 110 may be arranged outside the display area of the flexible display panel 10.

FIG. 2 is a schematic block diagram illustrating the circuit of the pixel unit 110 shown in FIG. 1 according to an embodiment of the present invention. FIG. 3 is a schematic top view illustrating the layout of the pixel unit 110 shown in FIG. 1 according to an embodiment of the present invention. 4 is a schematic cross-sectional view illustrating the layout of the pixel unit 110 shown in FIG. 1 according to an embodiment of the present invention. Please refer to Figure 1 to Figure 4. The pixel unit 110 includes a light emitting element 111, an optical waveguide layer 114 and a light sensing element 112.

The first end of the light emitting element 111 is coupled to the switch SW1. The second end of the light emitting element 111 is coupled to a reference voltage Vref (for example, a ground voltage or other fixed voltage). According to design requirements, the light-emitting element 111 can be any light-emitting element. For example, the light emitting element 111 may be a light emitting diode (LED), an organic light emitting diode (OLED), or other light emitting elements. The light-emitting element 111 is located at the first end of the optical waveguide layer 114.

The light of the light emitting element 111 can enter the optical waveguide layer 114. According to design requirements, the material of the optical waveguide layer 114 can be any light-guiding material. For example, the optical waveguide layer 114 may be a semiconductor layer of the flexible display panel 10. In some embodiments, the semiconductor layer may be a Low Temperature Poly-Silicon (LTPS) layer of the flexible display panel 10.

According to design requirements, the light sensing element 112 can be any light sensor. For example, the light sensing element 112 may be a photoresistor, a photodiode, a photoelectric crystal, or other light sensors. The light sensing element 112 is located at the second end of the optical waveguide layer 114. According to design requirements, the capacitor 113 can be selectively configured in the pixel unit 110. The first end of the capacitor 113 and the first end of the light sensing element 112 are coupled to the switch SW2. The second end of the capacitor 113 and the second end of the light sensing element 112 are coupled to the node ND. According to design requirements, the node ND can be floating or coupled to a reference voltage (such as a ground voltage or other fixed voltages).

During the detection period, the light sensing element 112 can sense the light of the light emitting element 111 through the optical waveguide layer 114 to obtain a light sensing result. According to design requirements, the "detection period" can be any period. For example, in some embodiments, the “detection period” may be a normal operation period of the flexible display panel 10. In some other embodiments, the "detection period" may be the initialization period of the flexible display panel 10 after booting. In still other embodiments, the “detection period” may be the initial stage (or the final stage) when the flexible display panel 10 is bent. In still other embodiments, the “detection period” may be the initial stage (or the final stage) when the flexible display panel 10 is flattened. In other embodiments, when the flexible display panel 10 is flattened, and when the flexible display panel 10 is bent, the bending damage detection device 100 will enter the detection period.

During the detection period, the control signal of the gate line G can turn on the switch SW1 and the switch SW2. When the switch SW1 is turned on, the voltage (or current) of the source line S may be transmitted to the light emitting element 111 so that the light emitting element 111 emits light to the optical waveguide layer 114. When the switch SW2 is turned on, the light sensing element 112 can transmit the light sensing result to the sensing line L. During the non-detection period, the control signal of the gate line G can turn off the switch SW1 and the switch SW2.

The packaging material 11 of the flexible display panel 10 is disposed on the optical waveguide layer 114. In the embodiment shown in FIG. 4, the packaging material 11 of the flexible display panel 10 is arranged between the light-emitting element 111 and the light-sensing element 112. In the embodiment shown in FIG. 3, the packaging material 11 of the flexible display panel 10 is further covered on the light sensing element 112. In the embodiment shown in FIG. 2, the packaging material 11 of the flexible display panel 10 further covers the light-emitting element 111 and the light-sensing element 112.

During the detection period, the light sensing element 112 can sense the light of the light emitting element 111 through the optical waveguide layer 114 to obtain a light sensing result. The processing circuit 120 is coupled to the light sensing element 112 of the pixel unit 110 to receive the light sensing result. The processing circuit 120 can determine the bending damage condition of the flexible display panel 10 according to the light sensing result of the light sensing element 112.

When the flexible display panel 10 is bent, the bending stress is applied to the packaging material of the flexible display panel 10. Therefore, the bending stress can be applied to the optical waveguide layer 114 of the pixel unit 110 through the packaging material 11 of the flexible display panel 10. After the flexible display panel 10 is frequently bent for a period of time, the bending stress may damage the packaging material 11 and the optical waveguide layer 114. After the optical waveguide layer 114 is damaged, it is difficult (or impossible) for the light of the light emitting element 111 to reach the light sensing element 112. Therefore, the processing circuit 120 can determine the bending damage condition of the optical waveguide layer 114 according to the light sensing result of the photo sensing element 112, and then infer the bending damage condition of the packaging material of the flexible display panel 10.

FIG. 5 is a schematic top view illustrating the layout of the pixel unit 110 shown in FIG. 1 according to an embodiment of the present invention. FIG. 6 is a schematic diagram illustrating the signal timing of the pixel units 110_1 to 110_6 shown in FIG. 5 according to an embodiment of the present invention. In the embodiment shown in FIG. 5, a plurality of pixel units 110 may be arranged outside the display area of the flexible display panel 10 in order to detect the bending damage of the packaging material of the flexible display panel 10. The pixel units 110 may be ring-shaped and surround the periphery of the display area of the flexible display panel 10. The left side of FIG. 5 shows a partial enlarged schematic diagram of the ring-shaped pixel unit 110. In the partially enlarged schematic diagram, these pixel units 110 include pixel units 110_1, 110_2, 110_3, 110_4, 110_5, and 110_6. For each of the pixel units 110_1 to 110_6, reference may be made to the related description of the pixel unit 110 shown in FIG. 3, so the details are omitted.

The gate line G1 (refer to the gate line G shown in FIG. 3) is coupled to the pixel units 110_1, 110_2, and 110_3. The gate line G2 (refer to the gate line G shown in FIG. 3) is coupled to the pixel units 110_4, 110_5, and 110_6. The source line S1 (refer to the source line S shown in FIG. 3) is coupled to the pixel units 110_1 and 110_4. The source line S2 (refer to the source line S shown in FIG. 3) is coupled to the pixel units 110_2 and 110_5. The source line S3 (refer to the source line S shown in FIG. 3) is coupled to the pixel units 110_3 and 110_6. The sensing line L1 (refer to the sensing line L shown in FIG. 3) is coupled to the pixel unit 110_1. The sensing line L2 (refer to the sensing line L shown in FIG. 3) is coupled to the pixel unit 110_4. The sensing line L3 (refer to the sensing line L shown in FIG. 3) is coupled to the pixel unit 110_2. The sensing line L4 (refer to the sensing line L shown in FIG. 3) is coupled to the pixel unit 110_5. The sensing line L5 (refer to the sensing line L shown in FIG. 3) is coupled to the pixel unit 110_3. The sensing line L6 (refer to the sensing line L shown in FIG. 3) is coupled to the pixel unit 110_6.

For the flat plate to be bent and deformed due to the bending moment, the upper part of the flat plate (the bent outer side) is subjected to tension, and the lower part of the plate (the bent inner side) is subjected to compression. There is a plane between the upper and lower sides of the slab, the longitudinal length of which is constant (no stretch or compression). This plane is called the neutral plane of the slab. The line intersecting this neutral plane with any section plane is called the neutral axis of the section. In order to minimize the possibility of the electrical components (such as pixel circuits) of the flexible display panel 10 suffering bending damage, the electrical components of the flexible display panel 10 can be arranged in the flexible display panel 10 as much as possible. Sex axis (neutral plane). In the embodiment shown in FIG. 4, the optical waveguide layer 114 can be arranged as close as possible to the neutral axis (neutral plane) of the flexible display panel 10.

The distance between the optical waveguide layer 114 and the neutral axis (neutral plane) may be referred to as the neutral axis distance. The farther the neutral axis is, the more susceptible the optical waveguide layer 114 is to bending damage. Based on such characteristics, in the plurality of pixel units 110, the neutral axis distances of different pixel units 110 may be different from each other. Taking the pixel units 110_1 to 110_6 shown in FIG. 5 as an example, the neutral axis distances of the pixel units 110_1 to 110_3 may be different from each other. For example, the cross-section of the layout of the pixel unit 110_1 can be referred to as shown in FIG. 4, the cross-section of the layout of the pixel unit 110_2 can be referred to as shown in FIG. 7, and the cross-section of the layout of the pixel unit 110_3 can be referred to as shown in FIG.

The switch SW3 shown in FIG. 7 can be analogized with reference to the related description of the switch SW1 shown in FIG. 4. The light-emitting element 711 shown in FIG. 7 can be analogized with reference to the related description of the light-emitting element 111 shown in FIG. 4. The light sensing element 712 shown in FIG. 7 can be analogized with reference to the related description of the light sensing element 112 shown in FIG. 4. The optical waveguide layer 714 shown in FIG. 7 can be deduced by analogy with reference to the related description of the optical waveguide layer 114 shown in FIG. 4. In the embodiment shown in FIG. 7, the packaging material 11 includes at least a lower layer and at least one upper layer, and part or all of the optical waveguide layer 714 is disposed between the at least lower layer and the at least one upper layer, as shown in FIG. Shown. The layout shown in Figure 4 has a small neutral axis distance (the distance between the optical waveguide layer 114 and the neutral axis), while the layout shown in Figure 7 has a large neutral axis distance (the height of the at least the lower layer ).

The switch SW4 shown in FIG. 8 can be analogized with reference to the related description of the switch SW1 shown in FIG. 4. The light-emitting element 811 shown in FIG. 8 can be analogized with reference to the related description of the light-emitting element 111 shown in FIG. 4. The light sensing element 812 shown in FIG. 8 can be analogized with reference to the related description of the light sensing element 112 shown in FIG. 4. The optical waveguide layer 814 shown in FIG. 7 can be analogized with reference to the related description of the optical waveguide layer 114 shown in FIG. 4. In the embodiment shown in FIG. 8, the packaging material 11 includes at least a lower layer and at least one upper layer, and part or all of the optical waveguide layer 814 is disposed between the at least lower layer and the at least one upper layer, as shown in FIG. Shown. The layout shown in FIG. 7 has a small neutral axis distance (the height of the at least the lower layer), and the layout shown in FIG. 8 has a larger neutral axis distance (the height of the at least the lower layer).

These pixel units 110_1 to 110_3 have different neutral axis distances. The greater the distance of the neutral axis, the greater the bending stress (tensile or compressive force) that the optical waveguide layer is subjected to, and the more easily the optical waveguide layer is damaged. Therefore, these pixel units 110_1 to 110_3 can provide an early warning mechanism for the bending damage of the packaging material 11 of the flexible display panel 10. The processing circuit 120 can determine the bending damage condition of the flexible display panel 10 according to the light sensing results of the pixel units 110_1 to 110_3 (the number of damaged pixel units in the pixel units 110_1 to 110_3). The processing circuit 120 can determine the bending damage condition of the flexible display panel 10 according to the number of damaged pixel units among the pixel units 110_1 to 110_3.

For example, when the optical waveguide layers of the pixel units 110_1 to 110_3 are all good, the processing circuit 120 can determine that the bending damage condition of the packaging material 11 of the flexible display panel 10 is “good”. When the optical waveguide layers of the pixel units 110_1 to 110_2 are good but the optical waveguide layer of the pixel unit 110_3 is damaged, the processing circuit 120 can determine that the bending damage condition of the packaging material 11 of the flexible display panel 10 is "will be damaged". When the optical waveguide layer of the pixel unit 110_1 is good but the optical waveguide layers of these pixel units 110_2 to 110_3 are all damaged, the processing circuit 120 can determine that the bending damage condition of the packaging material 11 of the flexible display panel 10 is "probably damaged". When the optical waveguide layers of the pixel units 110_1 to 110_3 are all damaged, the processing circuit 120 can determine that the bending damage condition of the packaging material 11 of the flexible display panel 10 is "damaged".

FIG. 9 is a partial enlarged schematic diagram illustrating the ring-shaped pixel unit 110 of the flexible display panel 10 shown in FIG. 5 according to another embodiment of the present invention. The embodiment shown in FIG. 9 includes pixel units 110_91, 110_92, 110_93, 110_94, 110_95, and 110_96. The pixel units 110_91, 110_92, 110_93, 110_94, 110_95, and 110_96 shown in FIG. 9 can refer to the related descriptions of the pixel units 110_1, 110_2, 110_3, 110_4, 110_5, and 110_6 shown in FIG. For the pole line G2, the source line S1, the source line S2, the source line S3, the sensing line L1, the sensing line L2, the sensing line L3, the sensing line L4, the sensing line L5, and the sensing line L6, please refer to the related description of FIG. 5, So I won't repeat it.

FIG. 10 is a partially enlarged schematic diagram illustrating the ring-shaped pixel unit 110 of the flexible display panel 10 shown in FIG. 5 according to another embodiment of the present invention. FIG. 11 is a schematic diagram illustrating the signal timing of the pixel units 110_1 to 110_6 shown in FIG. 10 according to an embodiment of the present invention. For the pixel units 110_1, 110_2, 110_3, 110_4, 110_5, and 110_6 shown in FIG. 10, reference may be made to the related description of FIG. 5. The gate line G1, gate line G2, source line S1, source line S2, and source line shown in FIG. The polar line S3 can refer to the related description of FIG. 5, so it will not be repeated. In the embodiment shown in FIG. 10, the sensing line L11 (refer to the sensing line L shown in FIG. 3) is coupled to the pixel units 110_1 and 110_4. The sensing line L22 (refer to the sensing line L shown in FIG. 3) is coupled to the pixel units 110_2 and 110_5. The sensing line L33 (refer to the sensing line L shown in FIG. 3) is coupled to the pixel units 110_3 and 110_6.

FIG. 12 is a circuit block diagram illustrating a bending damage detection device according to another embodiment of the present invention. The bending damage detection device shown in FIG. 12 has a plurality of pixel units 110 arranged in a ring shape. The pixel unit 110 shown in FIG. 12 can be deduced by analogy with reference to the related descriptions in FIGS. 5 to 11, so it will not be repeated. The bending damage detection device shown in FIG. 12 also has a processing circuit 1220, a bending sensor 1230, and a driving circuit 1240. The processing circuit 1220 shown in FIG. 12 can be deduced by referring to the related description of the processing circuit 120 shown in FIG. 1, so it will not be repeated.

Referring to FIG. 12, the driving circuit 1240 can drive the flexible display panel 10 to display images in the display area. The display area is also called an active area. Based on the control of the processing circuit 1220, the driving circuit 1240 can provide scan signals to the gate lines of the pixel unit 110 (refer to the gate lines G shown in Figures 2 and 3, or refer to the gate lines shown in Figures 5, 9, and 10 Polar lines G1～G2). The driving circuit 1240 can also provide a driving voltage (current) to the source line of the pixel unit 110 (refer to the source line S shown in FIGS. 2 and 3, and also refer to the source line shown in FIGS. 5, 9, and 10. S1～S3). Based on the scanning timing of the pixel unit 110 by the driving circuit 1240, the processing circuit 1220 can read the sensing line of the pixel unit 110 (refer to the sensing line L shown in FIG. 2 and FIG. 3, or refer to the sensing line L shown in FIGS. The sensing lines L1 to L6) obtain the light sensing result of the light sensing element.

Please refer to FIG. 12, the bending sensor 1230 is configured in the flexible display panel 10. The bending sensor 1230 can detect whether the flexible display panel 10 is bent to obtain a sensing result. The processing circuit 1220 is coupled to the bending sensor 1230 to receive the sensing result. According to design requirements, the bending sensor 1230 may include a light sensor, a micro switch, or other sensors.

FIG. 13 is a schematic side view illustrating that the flexible display panel 10 shown in FIG. 12 is flattened (but not completely flattened) according to an embodiment of the present invention. When the flexible display panel 10 is opened (flattened) from the rolled (bent) state, the bending sensor 1230 senses the ambient light and outputs the sensing result to the processing circuit 1220. When the sensing result of the bending sensor 1230 indicates that the flexible display panel 10 is opened (flattened), the processing circuit 1220 can perform a light sensing on the pixel unit 110 (that is, detecting light through a light sensing element). Waveguide layer to obtain light sensing results).

FIG. 14 is a schematic side view illustrating that the flexible display panel 10 shown in FIG. 12 is rolled (bent) according to an embodiment of the present invention. When the flexible display panel 10 is rolled (bent) from the open (flat) state, the bending sensor 1230 cannot sense the ambient light and outputs the sensing result to the processing circuit 1220. When the sensing result of the bending sensor 1230 indicates that the flexible display panel 10 is curled (bent), the processing circuit 1220 can perform another light sensing on the pixel unit 110 (that is, detecting by a light sensing element). Optical waveguide layer to obtain light sensing results).

According to different design requirements, the blocks of the processing circuit and/or the driving circuit can be implemented in hardware, firmware, software, or more of the three. The combination form.

In summary, the flexible display panel 10 has at least one pixel unit 110 for detecting the bending damage of the packaging material of the flexible display panel 10. The light sensing element of the pixel unit 110 can sense the light of the light emitting element through the optical waveguide layer during the detection period to obtain a light sensing result. The bending stress can be applied to the optical waveguide layer of the pixel unit 110 through the packaging material 11 of the flexible display panel 10. After the flexible display panel 10 is frequently bent for a period of time, the bending stress may damage the packaging material 11 and the optical waveguide layer. After the optical waveguide layer is damaged, it is difficult (or impossible) for the light of the light emitting element to reach the light sensing element. Therefore, the processing circuit can determine the bending damage condition of the optical waveguide layer according to the light sensing result of the light sensing element, and then infer the bending damage condition of the packaging material of the flexible display panel 10.

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 relevant 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: Flexible display panel

11: Packaging materials

100: bending damage detection device

110, 110_1, 110_2, 110_3, 110_4, 110_5, 110_6, 110_91, 110_92, 110_93, 110_94, 110_95, 110_96: pixel unit

111, 711, 811: light-emitting element

112, 712, 812: light sensing element

113: Capacitance

114, 714, 814: optical waveguide layer

120, 1220: processing circuit

1230: Bend sensor

1240: drive circuit

G, G1, G2: gate line

L, L1, L2, L3, L4, L5, L6, L11, L22, L33: sensing line

ND: Node

S, S1, S2, S3: source line

SW1, SW2, SW3, SW4: switch

Vref: reference voltage

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 block diagram illustrating the circuit of the pixel unit shown in FIG. 1 according to an embodiment of the present invention. FIG. 3 is a schematic top view illustrating the layout of the pixel unit shown in FIG. 1 according to an embodiment of the present invention. 4 is a schematic cross-sectional view illustrating the layout of the pixel unit shown in FIG. 1 according to an embodiment of the present invention. FIG. 5 is a schematic top view illustrating the layout of the pixel unit shown in FIG. 1 according to an embodiment of the present invention. 6 is a schematic diagram illustrating the signal timing of the pixel unit shown in FIG. 5 according to an embodiment of the present invention. FIG. 7 is a cross-sectional schematic diagram illustrating the layout of the pixel unit shown in FIG. 5 according to another embodiment of the present invention. FIG. 8 is a cross-sectional schematic diagram illustrating the layout of the pixel unit shown in FIG. 5 according to another embodiment of the present invention. FIG. 9 is a partial enlarged schematic diagram illustrating the ring-shaped pixel unit of the flexible display panel shown in FIG. 5 according to another embodiment of the present invention. FIG. 10 is a partial enlarged schematic diagram illustrating the ring-shaped pixel unit of the flexible display panel shown in FIG. 5 according to another embodiment of the present invention. FIG. 11 is a schematic diagram illustrating the signal timing of the pixel unit shown in FIG. 10 according to an embodiment of the present invention. FIG. 12 is a circuit block diagram illustrating a bending damage detection device according to another embodiment of the present invention. FIG. 13 is a schematic side view illustrating that the flexible display panel shown in FIG. 12 is flattened (but not completely flattened) according to an embodiment of the present invention. FIG. 14 is a schematic side view illustrating that the flexible display panel shown in FIG. 12 is rolled (bent) according to an embodiment of the present invention.

11: Packaging materials

111: light-emitting element

112: light sensing element

114: optical waveguide layer

SW1: switch

Claims (9)

A bending damage detection device for a flexible display panel, comprising: a first pixel unit configured in the flexible display panel, wherein the first pixel unit includes a first light-emitting element and a first optical waveguide layer And a first light-sensing element, the first light-emitting element is located at a first end of the first optical waveguide layer, the first light-sensing element is located at a second end of the first optical waveguide layer, the first The light-sensing element senses the light of the first light-emitting element through the first optical waveguide layer during a detection period to obtain a first light-sensing result, and the packaging material of the flexible display panel is disposed on the first light-emitting element. On the optical waveguide layer and between the first light-emitting element and the first light-sensing element; a second pixel unit is configured in the flexible display panel, wherein the second pixel unit includes a second light-emitting element , A second optical waveguide layer and a second optical sensing element, the second light emitting element is located at a first end of the second optical waveguide layer, and the second optical sensing element is located at a first end of the second optical waveguide layer At the second end, the second light-sensing element senses the light of the second light-emitting element through the second optical waveguide layer during the detection period to obtain a second light-sensing result, the package of the flexible display panel The material is arranged between the second light emitting element and the second light sensing element, the packaging material includes at least a lower layer and at least one upper layer, and part or all of the second optical waveguide layer is arranged on the at least lower layer. Layer and the at least one upper layer; and a processing circuit, coupled to the first light sensing element to receive the first light sensing result, and coupled to the second light sensing element to receive the second Light sensing result; wherein the detection period includes an initial stage when the flexible display panel is bent or the An initial stage when the flexible display panel is flattened, and the processing circuit determines the bending damage condition of the flexible display panel according to the first light sensing result and the second light sensing result. According to the bend damage detection device described in claim 1, wherein the first pixel unit is arranged outside a display area of the flexible display panel. According to the bend damage detection device described in claim 1, wherein the first optical waveguide layer is a low temperature polysilicon layer of the flexible display panel. The bending damage detection device as described in the first item of the scope of patent application further includes: a bending sensor, which is arranged in the flexible display panel to detect whether the flexible display panel is bent or not To obtain a sensing result, wherein the processing circuit is coupled to the bending sensor to receive the sensing result; and when the sensing result indicates that the flexible display panel is bent, the processing circuit passes the second A light sensing element detects the first optical waveguide layer to obtain the first light sensing result. A bending damage detection device for a flexible display panel includes: a pixel unit configured in the flexible display panel, wherein the pixel unit includes a light-emitting element, an optical waveguide layer, and a light sensing element. The light-emitting element is located at a first end of the optical waveguide layer, the light-sensing element is located at a second end of the optical waveguide layer, and the light-sensing element senses the light-emitting element through the optical waveguide layer during a detection period. Light to obtain a light sensing result, the packaging material of the flexible display panel is arranged between the light emitting element and the first light sensing element, and the packaging material includes at least one Layer and at least one upper layer, and part or all of the optical waveguide layer is disposed between the at least lower layer and the at least one upper layer; and a processing circuit coupled to the light sensing element to receive the light sensing The result; wherein the detection period includes an initial stage when the flexible display panel is bent or an initial stage when the flexible display panel is flattened, and the processing circuit determines the flexible display panel according to the light sensing result Bending damage condition. In the bending damage detection device described in item 5 of the scope of patent application, the pixel unit is arranged outside a display area of the flexible display panel. The bending damage detection device as described in item 5 of the scope of patent application further includes: a bending sensor arranged in the flexible display panel to detect 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; and when the sensing result indicates that the flexible display panel is bent, the processing circuit passes the light The sensing element detects the optical waveguide layer to obtain the optical sensing result. A bending damage detection device for a flexible display panel includes a plurality of pixel units arranged in the flexible display panel, wherein each of the pixel units includes a light-emitting element, an optical waveguide layer and a light-emitting element. The light-emitting element is located at a first end of the optical waveguide layer, the light-sensing element is located at a second end of the optical waveguide layer, and the light-sensing element senses through the optical waveguide layer during a detection period. Measuring the light of the light emitting element to obtain a light sensing result, the packaging material of the flexible display panel is arranged between the light emitting element and the first light sensing element, the packaging material It includes at least a lower layer and at least one upper layer, part or all of the optical waveguide layer is disposed between the at least lower layer and the at least one upper layer, and the at least lower layers of the pixel units have different heights; and a process A circuit is coupled to the light sensing element of the pixel units to receive the light sensing result of the pixel units; wherein the detection period includes an initial stage when the flexible display panel is bent or the flexible display panel At an early stage when the display panel is flattened, and the processing circuit judges the bending damage condition of the flexible display panel according to the light sensing result of the pixel units. For the bending damage detection device described in item 8 of the scope of patent application, the light sensing result of the pixel units indicates the number of damaged pixel units in the pixel units, and the processing circuit is based on the number of pixel units in the pixel units. The number of damaged pixel units is used to determine the bending damage condition of the flexible display panel.

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