Display panel, crack detection method thereof, and display device

Abstract

The present invention discloses a display panel, a crack detection circuit and a display device thereof, wherein the display panel comprises: a display area, comprising a plurality of organic light emitting diodes connected in parallel; a non-display area located around the display area, wherein the non-display area comprises a virtual line surrounding the display area; and a crack detection circuit having two test ends; wherein the virtual line is a non-closed line, and has two terminals respectively connected to the two test ends of the crack detection circuit, so as to form a crack detection loop between the two test ends of the crack detection circuit. The display panel, the crack detection method and the display device provided by the embodiments of the present invention can reduce the area of ​​the display panel and accurately determine whether the display panel has cracks.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a display panel and a crack detection method thereof, and a display device. Background Art

[0002] For OLED (Organic Light-Emitting Diode) display panels, cracks are easily generated in the edge area. The current display panel crack detection (PCD) must wrap an extra crack detection line (Matal line) around the non-display area of ​​the display panel, which increases the area of ​​the display panel.

[0003] Figure 1 A schematic diagram of the structure of a display panel according to the prior art is shown. Figure 1 As shown, the display panel includes a display area 10 and a non-display area 20. The non-display area 20 is provided with a dummy line 21 surrounding the display area 10 and a crack detection line 22. The crack detection line 22 is provided with two terminals, and the two terminals are respectively connected to two test terminals of a crack detection circuit 40 to form a crack detection loop. The crack detection circuit 40 is located on the display control circuit 30. One test terminal of the crack detection circuit 40 outputs a detection signal det_A to the crack detection line 22. The crack detection line 22 outputs a detection signal det_B to the other test terminal of the crack detection circuit 40 according to the detection signal det_A. The crack detection circuit 40 determines whether the display panel has a crack according to the detection signal det_B.

[0004] Figure 2 FIG. 4 shows a schematic diagram of a crack detection circuit according to the prior art. Figure 2 As shown, the crack detection circuit 40 includes a voltage detection circuit 41. When the display panel is subjected to crack detection, the voltage detection circuit 41 outputs a detection signal det_A to the crack detection line 22. The crack detection line 22 outputs a detection signal det_B to the voltage detection circuit 41 according to the detection signal det_A. Finally, the voltage detection circuit 41 outputs a crack signal PCD_alarm according to the detection signal det_B. However, when the detection signal det_B is non-ideal (for example, high impedance attenuation), the voltage detection circuit 41 may misjudge the signal, thereby causing the output crack signal PCD_alarm to be inaccurate.

[0005] Therefore, a new display panel is needed to solve the above problems. Summary of the invention

[0006] In view of the above problems, an object of the present invention is to provide a display panel and a crack detection method thereof and a display device, so as to reduce the area of ​​the display panel and accurately determine whether the display panel has cracks.

[0007] According to one aspect of the present invention, there is provided a display panel, comprising: a display area, comprising a plurality of organic light emitting diodes connected in parallel; a non-display area located around the display area, the non-display area comprising a virtual line surrounding the display area; and a crack detection circuit having two test terminals; wherein the virtual line is a non-closed line, having two terminals respectively connected to the two test terminals of the crack detection circuit, so as to form a crack detection loop between the two test terminals of the crack detection circuit.

[0008] Optionally, the crack detection circuit includes a voltage detection module, configured to apply a test voltage to one of the two test terminals, detect a feedback voltage of the other of the two test terminals, and output a first detection signal based on a comparison result of the test voltage and the feedback voltage; a current detection module, configured to respectively detect a first current value and a second current value between the two test terminals and a common voltage, and output a second detection signal based on the first current value and the second current value and a comparison result thereof; and a logic circuit, configured to output a crack signal based on a digital signal represented by the first detection signal and the second detection signal.

[0009] Optionally, when the voltage detection module detects that the difference between the voltage values ​​of the test voltage and the feedback voltage is within a predetermined range, the voltage detection module outputs a first detection signal representing a digital signal of 0; when the voltage detection module detects that the difference between the voltage values ​​of the test voltage and the feedback voltage is outside the predetermined range, the voltage detection module outputs a first detection signal representing a digital signal of 1.

[0010] Optionally, the current detection module outputs a second detection signal representing a digital signal of 0 when it detects that the first current value and the second current value are not less than a preset value and the difference between the first current value and the second current value is within a predetermined range, and outputs a second detection signal representing a digital signal of 1 when it detects that the first current value and the second current value are less than a preset value and the difference between the first current value and the second current value is outside the predetermined range.

[0011] Optionally, the logic circuit outputs a first crack signal when the digital signals represented by the first detection signal and the second detection signal are both 1; outputs a second crack signal when the digital signals represented by the first detection signal and the second detection signal are both 0; and outputs a third crack signal when one of the digital signals represented by the first detection signal and the second detection signal is 1 and the other is 0.

[0012] Optionally, the first crack signal indicates that the display panel is abnormal, and the second crack signal indicates that the display panel is normal.

[0013] Optionally, the logic circuit is configured as an AND gate.

[0014] Optionally, the dummy line is connected in series to anodes of a plurality of the organic light emitting diodes connected in parallel.

[0015] According to another aspect of the present invention, a crack detection method for a display panel is provided, which is applied to the display panel as described above, and the crack detection method comprises:

[0016] Applying a test voltage to a test end of a crack detection circuit, detecting a feedback voltage of another test end of the crack detection circuit, and outputting a first detection signal according to a comparison result between the test voltage and the feedback voltage;

[0017] Respectively detecting a first current value and a second current value between two test terminals of the crack detection circuit and a common voltage, and outputting a second detection signal according to the first current value and the second current value and a comparison result thereof;

[0018] A crack signal is output according to the digital signal represented by the first detection signal and the second detection signal.

[0019] According to another aspect of the present invention, a display device is provided, comprising the display panel as described above.

[0020] The present invention provides a display panel, a crack detection method and a display device thereof. The dummy line is used as a test line in the test stage of the display panel and as a crack detection line in the crack detection stage of the display panel. The dummy line is a non-closed line. The dummy line has two terminals respectively connected to two test ends of a crack detection circuit to form a crack detection loop between the two test ends of the crack detection circuit, which not only realizes the reuse of the dummy line, but also reduces the area of ​​the display panel.

[0021] In a preferred embodiment, the crack detection circuit applies a test voltage to a test end of the virtual line through a voltage detection module, detects a feedback voltage of another test end of the virtual line, and outputs a first detection signal based on a comparison result of the voltage values ​​of the test voltage and the feedback voltage. The current detection module detects a first current value and a second current value between two test ends of the crack detection circuit and a common voltage, and outputs a second detection signal based on the first current value and the second current value and a comparison result thereof. The logic circuit outputs a crack signal based on a digital signal represented by the first detection signal and the second detection signal. Through the dual detection of the voltage detection module and the current detection module, the crack detection of the display panel is more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0023] Figure 1 A schematic diagram showing the structure of a display panel according to the prior art is shown;

[0024] Figure 2 A schematic diagram of the structure of a crack detection circuit according to the prior art is shown;

[0025] Figure 3 A schematic diagram showing the structure of a display panel according to an embodiment of the present invention is shown;

[0026] Figure 4 A schematic diagram showing the connection between a virtual line and n organic light emitting diodes according to an embodiment of the present invention is shown;

[0027] Figure 5 A schematic structural diagram of a crack detection circuit according to an embodiment of the present invention is shown;

[0028] Figure 6 A connection diagram of a voltage detection circuit according to an embodiment of the present invention is shown;

[0029] Figure 7 A connection diagram of a current detection circuit according to an embodiment of the present invention is shown;

[0030] Figure 8 A flow chart of a crack detection method according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0031] Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, the same elements or modules are represented by the same or similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale.

[0032] It should be understood that in the following description, a "circuit" may include a single or multiple combined hardware circuits, programmable circuits, state machine circuits, and / or elements capable of storing instructions executed by programmable circuits. When an element or circuit is said to be "connected to" another element or an element or circuit is said to be "connected between" two nodes, it may be directly coupled or connected to another element or there may be an intermediate element, and the connection between the elements may be physical, logical, or a combination thereof. Conversely, when an element is said to be "directly coupled to" or "directly connected to" another element, it means that there is no intermediate element between the two.

[0033] In addition, it should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements defined by the statement "comprise one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements.

[0034] Figure 3 FIG. 4 shows a schematic diagram of the structure of a display panel according to an embodiment of the present invention. Figure 3 As shown, the display panel 100 includes a display area 110, a non-display area 120 and a crack detection circuit 130. The crack detection circuit 130 has two test terminals det_C and det_D, which are arranged on a display control circuit (not shown in the figure) and are located outside the display area 110 and the non-display area 120.

[0035] The non-display area 120 is located around the display area 110. A dummy line 121 surrounding the display area 110 is provided on the non-display area 120. The dummy line 121 is used as a test line in the test phase of the display panel 100, and is used as a crack detection line in the crack detection phase of the display panel 100. The dummy line 121 is a non-closed line. The dummy line 121 has two terminals respectively connected to the two test terminals det_C and det_D of the crack detection circuit 130 to form a crack detection loop between the two test terminals det_C and det_D of the crack detection circuit 130. The dummy line 121 connects the anodes (A1-An) of n (n is a positive integer) organic light emitting diodes OLED in parallel in series, and the cathodes (K1-Kn) of the n organic light emitting diodes OLED are connected to the common voltage VCOM. Figure 4 A schematic diagram showing the connection between the dummy line 121 and n organic light emitting diodes OLED is shown.

[0036] In the display panel 100 provided by the embodiment of the present invention, the dummy line 121 is used as a test line in the test phase of the display panel 100, and is used as a crack detection line in the crack detection phase of the display panel 100. The dummy line 121 is a non-closed line. The dummy line 121 has two terminals respectively connected to the two test terminals det_C and det_D of the crack detection circuit 130 to form a crack detection loop between the two test terminals det_C and det_D of the crack detection circuit 130. This not only realizes the reuse of the dummy line 121, but also reduces the area of ​​the display panel 100.

[0037] Figure 5 FIG. 4 shows a schematic diagram of a crack detection circuit according to an embodiment of the present invention. Figure 5 As shown, the crack detection circuit 130 includes a voltage detection module 131 , a current detection module 132 and a logic circuit 133 .

[0038] The voltage detection module 131 is configured to apply a test voltage to a test terminal det_C of the crack detection circuit 130 , detect a feedback voltage of another test terminal det_D of the crack detection circuit 130 , and output a first detection signal V_a to the logic circuit 133 according to a comparison result between the test voltage and the feedback voltage.

[0039] The current detection module 132 is configured to respectively detect a first current value I_C_a and a second current value I_D_b between the two test terminals det_C and det_D of the crack detection circuit 130 and the common voltage VCOM, and output a second detection signal I_a to the logic circuit 133 according to the first current value I_C_a and the second current value I_D_b and a comparison result thereof.

[0040] The logic circuit 133 is used to receive the first detection signal V_a and the second detection signal I_a, and output the crack signal PCD_alarm according to the digital signal represented by the first detection signal V_a and the second detection signal I_a.

[0041] The logic circuit 133 is set as an AND gate, for example, to output a first crack signal PCD_alarm1 when the digital signals represented by the first detection signal V_a and the second detection signal I_a are both 1, to output a second crack signal PCD_alarm2 when the digital signals represented by the first detection signal V_a and the second detection signal I_a are both 0, and to output a third crack signal PCD_alarm3 when one of the digital signals represented by the first detection signal V_a and the second detection signal I_a is 0 and the other is 1. The first crack signal PCD_alarm1 is used to indicate that the display panel 100 is abnormal, that is, cracks have occurred, the second crack signal PCD_alarm2 is used to indicate that the display panel 100 is normal, that is, no cracks have occurred, and the third crack signal PCD_alarm3 is used to warn that a slight crack has occurred in the display panel, but it does not affect the use of the display panel.

[0042] Further, the test voltage is a turn-on voltage of the organic light emitting diode OLED.

[0043] The crack detection circuit 130 provided in the embodiment of the present invention applies a test voltage to a test terminal det_C of the crack detection circuit 130 through a voltage detection module 131, detects a feedback voltage of another test terminal det_D of the crack detection circuit 130, and outputs a first detection signal V_a according to a comparison result of the voltage values ​​of the test voltage and the feedback voltage. The current detection module 132 respectively detects a first current value I_C_a and a second current value I_D_b between the two test terminals det_C and det_D of the crack detection circuit 130 and a common voltage VCOM, and outputs a second detection signal I_a according to the first current value I_C_a and the second current value I_D_b and a comparison result thereof. The logic circuit 133 outputs a crack signal PCD_alarm according to a digital signal represented by the first detection signal V_a and the second detection signal I_a. Through the dual detection of the voltage detection module 131 and the current detection module 132, the crack detection of the display panel 100 is more accurate.

[0044] In another embodiment provided by the present invention, the crack detection circuit 130 only includes a voltage detection module 131 or a current detection module 132. When the crack detection circuit 130 only includes the current detection module 132, the current detection module 132 outputs a test voltage to a test terminal det_C of the crack detection circuit 130.

[0045] Figure 6 FIG. 4 shows a connection diagram of a voltage detection circuit according to an embodiment of the present invention. Figure 6 As shown, the voltage detection circuit includes n organic light emitting diodes OLED connected in parallel, the cathodes of the n organic light emitting diodes OLED are connected to a common voltage VCOM, and the anodes are connected in series with the voltage detection module 131 through a dummy line 121 .

[0046] When the display panel 100 performs crack detection, the voltage detection module 131 applies a test voltage to a test terminal det_C of the crack detection circuit 130, detects a feedback voltage of another test terminal det_D of the crack detection circuit 130, and detects the voltage value of the test voltage and the feedback voltage. When it is detected that the difference between the voltage values ​​of the two test terminals det_C and det_D of the crack detection circuit 130 is within a predetermined range, the voltage detection module 131 outputs a first detection signal V_a representing a digital signal of 0, indicating that the display panel 100 is normal. When it is detected that the difference between the voltage values ​​of the two test terminals det_C and det_D of the crack detection circuit 130 is outside the predetermined range, the voltage detection module 131 outputs a first detection signal V_a representing a digital signal of 1, indicating that the display panel 100 is abnormal.

[0047] Further, when the difference between the voltage values ​​of the two test terminals det_C and det_D of the crack detection circuit 130 is within a predetermined range, the voltage values ​​of the two test terminals det_C and det_D are similar, and when the difference between the voltage values ​​of the two test terminals det_C and det_D of the crack detection circuit 130 is outside the predetermined range, the difference between the voltage values ​​of the two test terminals det_C and det_D is relatively different. The predetermined range of the difference between the voltage values ​​of the two test terminals det_C and det_D can be set according to actual conditions.

[0048] Figure 7 FIG. 4 shows a connection diagram of a current detection circuit according to an embodiment of the present invention. Figure 7 As shown, the current detection circuit includes n organic light emitting diodes OLED connected in parallel, the cathodes of the n organic light emitting diodes OLED are connected to the common voltage VCOM, and a current detection module 132 is connected in parallel between the two test terminals det_C and det_D of the dummy line 121 and the common voltage VCOM.

[0049] The current detection module 132 respectively detects the first current value I_C_a and the second current value I_D_b between the two test terminals det_C and det_D of the crack detection circuit 130 and the common voltage VCOM. When it is detected that the first current value I_C_a and the second current value I_D_b are both greater than the preset value, and the difference between the first current value I_C_a and the second current value I_D_b is within a predetermined range, the current detection module 132 outputs the second detection signal I_a representing a digital signal of 0, indicating that the display panel 100 is normal; when it is detected that the first current value I_C_a and the second current value I_D_b are both less than the preset value, and the difference between the first current value I_C_a and the second current value I_D_b is outside the predetermined range, the current detection module 132 outputs the second detection signal I_a representing a digital signal of 1, indicating that the display panel 100 is abnormal.

[0050] Further, the preset value is the sum of currents of n organic light emitting diodes OLED under the test voltage.

[0051] Further, when the difference between the first current value I_C_a and the second current value I_D_b is within a predetermined range, the first current value I_C_a and the second current value I_D_b are similar, and when the difference between the first current value I_C_a and the second current value I_D_b is outside the predetermined range, the first current value I_C_a and the second current value I_D_b are different. The predetermined range of the difference between the first current value I_C_a and the second current value I_D_b can be set according to actual conditions.

[0052] The present invention further provides a method for detecting cracks in a display panel 100 , which is applied to the display panel as described above. Figure 8 A flow chart of a crack detection method according to an embodiment of the present invention is shown. Figure 8 The crack detection method shown comprises the following steps:

[0053] S1: applying a test voltage to a test terminal det_C of the crack detection circuit 130, detecting a feedback voltage of another test terminal det_D of the crack detection circuit 130, and outputting a first detection signal V_a according to a comparison result between the test voltage and the feedback voltage;

[0054] In step S1, when the difference between the voltage values ​​of the two test terminals det_C and det_D of the crack detection circuit 130 is within a predetermined range, the voltage detection module 131 outputs a first detection signal V_a representing a digital signal of 0, indicating that the display panel 100 is normal; when the difference between the voltage values ​​of the two test terminals det_C and det_D of the crack detection circuit 130 is outside the predetermined range, the voltage detection module 131 outputs a first detection signal V_a representing a digital signal of 1, indicating that the display panel 100 is abnormal.

[0055] S2: respectively detecting a first current value I_C_a and a second current value I_D_b between the two test terminals det_C and det_D of the crack detection circuit 130 and the common voltage VCOM, and outputting a second detection signal I_a according to the first current value I_C_a and the second current value I_D_b and a comparison result thereof;

[0056] In step S2, when it is detected that the first current value I_C_a and the second current value I_D_b are both greater than the preset value, and the difference between the first current value I_C_a and the second current value I_D_b is within the predetermined range, the current detection module 132 outputs the second detection signal I_a representing the digital signal of 0, indicating that the display panel 100 is normal; when it is measured that the first current value I_C_a and the second current value I_D_b are both less than the preset value, and the difference between the first current value I_C_a and the second current value I_D_b is outside the predetermined range, the current detection module 132 outputs the second detection signal I_a representing the digital signal of 1, indicating that the display panel 100 is abnormal.

[0057] S3: Output a crack signal PCD_alarm according to the digital signal represented by the first detection signal V_a and the second detection signal I_a.

[0058] In step S3, the first crack signal PCD_alarm1 is output when the digital signals represented by the first detection signal V_a and the second detection signal I_a are both 1, the second crack signal PCD_alarm2 is output when the digital signals represented by the first detection signal V_a and the second detection signal I_a are both 0, and the third crack signal PCD_alarm3 is output when one of the digital signals represented by the first detection signal V_a and the second detection signal I_a is 0 and the other is 1.

[0059] The present invention further provides a display device, comprising the display panel 100 described above.

[0060] According to the embodiments of the present invention, as described above, these embodiments do not describe all the details in detail, nor do they limit the invention to specific embodiments. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and the modified use based on the present invention. The scope of protection of the present invention shall be based on the scope defined by the claims of the present invention and their equivalents.

Claims

1. A display panel, comprising: A display area including a plurality of organic light emitting diodes connected in parallel; a non-display area located around the display area, the non-display area including a virtual line surrounding the display area; as well as A crack detection circuit having two test terminals; The dummy line is a non-closed line having two terminals respectively connected to two test ends of the crack detection circuit to form a crack detection loop between the two test ends of the crack detection circuit. The dummy line is used as a test line in the test phase of the display panel and as a crack detection line in the crack detection phase of the display panel. Wherein, the crack detection circuit comprises: a voltage detection module configured to apply a test voltage to one of the two test terminals, detect a feedback voltage of the other of the two test terminals, and output a first detection signal according to a comparison result between the test voltage and the feedback voltage; a current detection module configured to respectively detect a first current value and a second current value between the two test terminals and a common voltage, and output a second detection signal according to the first current value and the second current value and a comparison result thereof; and The logic circuit is configured to output a crack signal according to the digital signal represented by the first detection signal and the second detection signal.

2. The display panel according to claim 1, wherein: When the voltage detection module detects that the difference between the voltage values ​​of the test voltage and the feedback voltage is within a predetermined range, the voltage detection module outputs a first detection signal representing a digital signal of 0; when the voltage detection module detects that the difference between the voltage values ​​of the test voltage and the feedback voltage is outside the predetermined range, the voltage detection module outputs a first detection signal representing a digital signal of 1.

3. The display panel according to claim 1, wherein: The current detection module outputs a second detection signal representing a digital signal of 0 when it detects that the first current value and the second current value are not less than a preset value and the difference between the first current value and the second current value is within a predetermined range, and outputs a second detection signal representing a digital signal of 1 when it detects that the first current value and the second current value are less than a preset value and the difference between the first current value and the second current value is outside the predetermined range.

4. The display panel according to claim 1, wherein: The logic circuit outputs a first crack signal when the digital signals represented by the first detection signal and the second detection signal are both 1, outputs a second crack signal when the digital signals represented by the first detection signal and the second detection signal are both 0, and outputs a third crack signal when one of the digital signals represented by the first detection signal and the second detection signal is 1 and the other is 0.

5. The display panel according to claim 4, wherein: The first crack signal indicates that the display panel is abnormal, the second crack signal indicates that the display panel is normal, and the third crack signal indicates that a slight crack occurs on the display panel.

6. The display panel according to claim 4, wherein: The logic circuit is configured as an AND gate.

7. The display panel according to claim 1, wherein: The dummy line is connected in series to anodes of a plurality of the organic light emitting diodes connected in parallel.

8. A crack detection method for a display panel, applied to the display panel according to any one of claims 1 to 7, the crack detection method comprising: Applying a test voltage to a test end of a crack detection circuit, detecting a feedback voltage of another test end of the crack detection circuit, and outputting a first detection signal according to a comparison result between the test voltage and the feedback voltage; Respectively detecting a first current value and a second current value between two test terminals of the crack detection circuit and a common voltage, and outputting a second detection signal according to the first current value and the second current value and a comparison result thereof; A crack signal is output according to the digital signal represented by the first detection signal and the second detection signal.

9. A display device, comprising the display panel according to any one of claims 1 to 7.

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