Crack detector and display device having the same

Abstract

A crack detector and a display device having the same are provided. The crack detector may include a plurality of crack detection switches for connecting or disconnecting data lines of a display panel to each other. A signal supply unit may supply a detection control signal for controlling the opening / closing of the crack detection switch, and supply the crack detection signal to a first data line. A crack determination unit may be configured to determine a crack of the display panel by comparing an output signal supplied from a second data line connected to the first data line through one of the crack detection switches with a preset reference value.

Description

[0001] This application claims the priority of Korean Patent Application No. 10-2018-0119235 filed on October 5, 2018 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. Technical Field

[0002] The present disclosure relates generally to display devices, and more particularly, to a display panel crack detector, a display device including the display panel crack detector, and a method for driving the display device. Background Art

[0003] Pixels included in the display device emit light having a predetermined brightness based on the magnitude of a data voltage supplied by a data driver. The data voltage is supplied to the pixels through a plurality of data lines.

[0004] Meanwhile, as the resolution of display devices has recently increased, the integration of pixels within a display panel of the display device has increased. Therefore, various wires and patterns are gathered in a narrow space, so any cracks in the display panel may adversely affect performance and cause defects. Therefore, it is desirable to detect whether there are any cracks. Summary of the invention

[0005] The embodiment provides a crack detector for detecting a crack of a display panel using a current or a voltage supplied to a data line.

[0006] Embodiments also provide a display device including the crack detector and a method for driving the display device.

[0007] According to one aspect of the present disclosure, a crack detector may include a plurality of crack detection switches for connecting and disconnecting data lines of a display panel to each other. A signal supply unit may be configured to supply a detection control signal for controlling the opening / closing of the crack detection switches, and to supply a crack detection signal to a first data line among the data lines. A crack determination unit may be configured to detect a crack of the display panel by comparing an output signal supplied from a second data line among the data lines connected to the first data line through one of the crack detection switches with a preset reference value.

[0008] Each crack detection switch can be electrically connected to two different data lines.

[0009] Each crack detection switch may be connected to remote ends of two data lines adjacent to each other.

[0010] The crack detection switches may be turned on substantially simultaneously.

[0011] The crack detection signal may correspond to a preset test voltage. The reference value may correspond to a range obtained by applying a preset voltage drop offset to the test voltage.

[0012] When the output signal exceeds a threshold value corresponding to a reference value, the crack determination part may output crack data.

[0013] The crack detection signal may correspond to a preset test current. The reference value may correspond to a preset wire resistance range.

[0014] The crack determination section may output crack data when the resistance value calculated from the output signal is outside the line resistance range.

[0015] According to another aspect of the present disclosure, a display device is provided, the display device comprising: a display panel including a plurality of pixels connected to a plurality of scan lines and a plurality of data lines; a scan driver configured to supply a scan signal to each scan line; a data driver configured to supply a data signal to each data line; and a crack detector configured to detect a crack of the display panel based on a crack detection signal supplied to the data line. The crack detector may include: a plurality of crack detection switches for connecting / disconnecting the data lines to each other; a signal supply section configured to supply a detection control signal for controlling the closing / opening of the crack detection switch; and a crack determination section configured to determine a crack of the display panel by comparing an output signal supplied from the data line with a preset reference value.

[0016] Each crack detection switch may be connected to distal ends of two data lines adjacent to each other at one side of the display panel.

[0017] The number of crack detection switches may be half the number of data lines.

[0018] The crack detection switch may be turned on in a crack detection period included in the vertical blanking period.

[0019] During an interval within the range of 1H to 2H period, the crack detection switches may be turned on substantially simultaneously.

[0020] The data line may include an input data line connected to the signal supply part to receive a crack detection signal for crack detection; and an output data line connected to the crack determination part to provide an output signal to the crack determination part.

[0021] The crack detection switch may connect the input data line to the output data line, respectively.

[0022] The input data line and the output data line may be connected to the data driver in a display period, and may be connected to the crack detector in a vertical blanking period.

[0023] The data driver may output a crack detection signal for crack detection during a partial period of the vertical blanking period.

[0024] The data lines may include: an input data line connected to a data driver, the input data line receiving a data voltage in a display period, the input data line receiving a crack detection signal in a vertical blanking period; and an output data line connected to the data driver in the display period to receive the data voltage, and connected to a crack determination unit in the vertical blanking period to provide an output signal to the crack determination unit.

[0025] According to another aspect of the present disclosure, a method for driving a display device is provided, the method comprising: during a crack detection period included in a vertical blanking period, closing a crack detection switch to electrically connect an input data line and an output data line; when the input data line and the output data line are electrically connected, supplying a crack detection signal to the input data line and receiving an output signal supplied from the output data line; if the level of the output signal is within a preset range, displaying an image of a next frame; if the level of the output signal is outside the preset range, outputting crack data indicating the presence of a crack affecting the input data line and the output data line.

[0026] A crack sensing image may be output in response to the crack data. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Example embodiments will now be described more fully below with reference to the accompanying drawings; however, example embodiments may be implemented in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the example embodiments to those skilled in the art.

[0028] Figure 1 is a diagram showing a display device according to an embodiment of the present disclosure.

[0029] Figure 2 is a diagram showing a crack detector according to an embodiment of the present disclosure.

[0030] Figure 3 It shows Figure 2 A block diagram of an example of a crack detector.

[0031] Figure 4 It shows that the Figure 1 FIG. 1 is a diagram of an example of pixels and data lines in a display device.

[0032] Figure 5 It shows that the Figure 1 A diagram showing an example of a connection relationship of data lines in a display device.

[0033] Figure 6 It shows Figure 1 A diagram of an example of the operation of a display device.

[0034] Figure 7 is a flowchart illustrating a method for driving a display device according to an embodiment of the present disclosure.

[0035] Figure 8 is a flow chart illustrating a method for driving a display device in which a crack is tested using a test current. DETAILED DESCRIPTION

[0036] Hereinafter, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. In the accompanying drawings, the dimensions may be exaggerated for clarity of illustration. It will be understood that when an element is referred to as being "between" two elements, the element may be the only element between the two elements, or one or more intermediate elements may also be present. The same reference numerals always represent the same elements.

[0037] Figure 1 is a diagram showing a display device 1000 according to an embodiment of the present disclosure. The display device 1000 may include a display panel 100, a scan driver 200, a data driver 300, a timing controller 400, and a crack detector 605. The crack detector 605 may include a crack detection circuit 600, a switch group 610, and an output signal switch 410.

[0038] The display device 1000 can be implemented using an organic light-emitting display device, a liquid crystal display device, etc. The display device 1000 can be a flat display device, a flexible display device, a curved display device, a foldable display device, or a bendable display device. In addition, the display device 1000 can be applied to a transparent display device, a head-mounted display device, a wearable display device, etc.

[0039] The display panel 100 may include a plurality of scan lines SL1 to SLn, a plurality of data lines DL1 to DLm, and a plurality of pixels P (n and m are integers greater than 1) connected to portions where the scan lines SL1 to SLn and the data lines DL1 to DLm intersect each other. The switch group 610 may be integrated with the display panel 100 as shown, or may be located elsewhere in the display device 1000.

[0040] The scan driver 200 , the data driver 300 , and the timing controller 400 , although illustrated as being separated from the display panel 100 , may be disposed in a peripheral region at the periphery of the display panel 100 .

[0041] The scan driver 200 may apply scan signals to the scan lines SL1 to SLn based on the scan control signal SCS provided by the timing controller 400. In an embodiment, the scan driver 200 may be integrated in the peripheral area of ​​the display panel 100 or may be mounted in the peripheral area of ​​the display panel 100 in the form of a driving chip.

[0042] The data driver 300 may apply respective data voltages to the data lines DL1 to DLm based on the data control signal DCS and the image data RGB provided by the timing controller 400. The data driver 300 may be integrated in a driving chip attached (mounted) in the peripheral area of ​​the display panel 100, or may be directly disposed in the peripheral area of ​​the display panel 100.

[0043] In an embodiment, the data driver 300 may supply a data voltage corresponding to the image data RGB to each of the data lines DL1 to DLm in a display period, and supply a predetermined test voltage corresponding to a crack detection signal to some (but not all) of the data lines DL1 to DLm in a vertical blanking period. Hereinafter, any data line DLi receiving a test voltage may be referred to as an input data line DILi, and any data line outputting an output signal obtained from the test voltage may be referred to as an output data line DOLi (where "i" is any integer between 1 and m).

[0044] The crack detector 605 can detect whether a crack has occurred in the display panel 100 based on a crack detection signal supplied to some of the data lines DL1 to DLm. The crack detector 605 can detect whether a crack has occurred and the position at which the crack has occurred. In an embodiment, as discussed later, the position at which the crack has occurred can be determined by control of the output signal switch 410, which can be connected to the corresponding output data line DOL.

[0045] The crack detector 605 may perform a crack detection operation based on a detector control signal CCS provided by the timing controller 400. In an embodiment, the crack detector 605 may perform a crack detection operation at a short time interval during a vertical blanking period between display periods. For example, a crack detection operation may be performed during one interval in the vertical blanking period, and the one interval may be in the range of about 1H to about 2H, where H is a horizontal period currently used by the display device 1000 to display one line of one frame.

[0046] The switch group 610 may include a plurality of crack detection switches CSW respectively connected between the data lines DL1 to DLm. For example, the first crack detection switch CSW1 may electrically connect / disconnect the adjacent data lines DL1 (input data line DIL1) and DL2 (output data line DOL1) to each other when controlled to be closed / open. (Hereinafter, any one of the marks "CSW" or "CSWi" may represent any crack detection switch in the switch group 610, where "i" is any integer.)

[0047] The crack detection circuit 600 may include: a signal supply unit (eg, Figure 3 620), supplying a detection control signal CS for controlling the on / off of the crack detection switch CSW; and a crack determination unit (e.g., Figure 3 640 in the figure), a crack of the display panel 100 is detected and / or determined by comparing the output signal supplied from the data lines DL1 to DLm with a preset reference value. (Here, the "on" state of the switch is a closed state, and the "off" state is an open state.)

[0048] It should be noted that although Figure 1 The crack detector 605 is shown in a configuration separated from the configurations of the data driver 300 and the timing controller 400 in an alternating arrangement, but at least a portion of elements of the crack detector 605 may be included in the data driver 300 and / or the timing controller 400 .

[0049] Each of the data lines DL1 to DLm may have a proximal end on a first side of the display panel 100 and a distal end on an opposite second side of the display panel 100. In an embodiment, each of the crack detection switches CSW may be connected to the distal ends of two data lines adjacent to each other at the second side of the display panel 100. For example, the crack detection switch CSW may be disposed at an opposite side of the data driver 300 with respect to the display panel 100.

[0050] In an embodiment, the number of crack detection switches CSW may be half the number of data lines. In this case, there may be "j" crack detection switches CSW1 to CSWj, where j=m / 2. Therefore, cracks of the display panel 100 may be detected through all data lines DL1 to DLm, and the locations of the cracks may also be detected.

[0051] Data lines (eg, DL1 and DL2 ) connected to the crack detection switch CSW may be classified into an input data line DIL1 and an output data line DOL1 . The input data line DIL1 may receive a crack detection signal for crack detection, and the output data line DOL1 may provide an output signal to the crack detection circuit 600 .

[0052] The crack detection circuit 600 can determine whether a crack has occurred in the corresponding data lines DIL1 and DOL1 by analyzing the output signals. For example, the presence of a crack can be determined based on the level of the output signal. The location of the crack can be determined by knowing which output data line DOLi is outputting the output signal at any given time. In an example, a single output signal switch in the output signal switch 410 can be selectively closed to route the output signal from the corresponding output data line.

[0053] In a conventional display device, crack detection is performed by sensing a power supply voltage ELVDD or ELVSS or a current from a power supply line connected to a display panel. A light-emitting period and a non-light-emitting period are distinguished, and crack detection driving is performed during the non-light-emitting period by changing the power supply voltage ELVDD and / or the power supply voltage ELVSS. However, although this driving method can be applied to a pixel structure that requires an emission control signal, it is not suitable for application to an external sensing pixel structure. In addition, in such a display device, it is difficult to check the location of the crack by sensing the power supply voltage or current from the power supply line. In addition, crack detection is performed based on the load value of the entire display panel, which results in low detection accuracy.

[0054] However, in the display device 1000 according to an embodiment of the present disclosure, a data line pair is used to generate a conductive loop, and crack detection in each conductive loop is performed, so that the precise crack position can be checked. In addition, the crack detection operation can be performed at a very short time interval within the vertical blanking period in the external sensing pixel structure.

[0055] Figure 2 is a diagram illustrating elements of a crack detector 605 according to an embodiment of the present disclosure. Figure 3 It shows Figure 2 A block diagram of an example of a crack detector.

[0056] Reference Figures 1 to 3 The crack detector 605 may include a switch group 610, a signal supply unit 620, and a crack determination unit 640. (The crack detector 605 may also include a signal supply unit 620 and a signal supply unit 640.) Figure 4 and Figure 5 The switch discussed here (also referred to as the output signal switch) 410. )

[0057] The switch group 610 may include a plurality of crack detection switches CSW1 to CSWj (j and m are natural numbers of 2 or more) for connecting between the data lines DL1 to DLm.

[0058] Each of the crack detection switches CSW1 to CSWj may be controlled to electrically connect and disconnect two different data lines. For example, each of the crack detection switches CSW1 to CSWj may be connected to a distal end of an adjacent data line among the data lines DL1 to DLm, and the number of the crack detection switches CSW1 to CSWj may be half the number of the data lines DL1 to DLm.

[0059] In an embodiment, each of the crack detection switches CSW1 to CSWj may be constructed using a metal oxide semiconductor (MOS) transistor. Figure 2 As shown in , the crack detection switches CSW1 to CSWj can be implemented using N-type MOS (NMOS) transistors. However, this is merely illustrative, and the crack detection switches CSW1 to CSWj are not limited thereto. For example, P-type MOS (PMOS) transistors may be used instead.

[0060] The crack detection switches CSW1 to CSWj may be controlled by a detection control signal CS. For example, the gate electrodes of the crack detection switches CSW1 to CSWj may be connected to a single detection control line CSL to be simultaneously turned on or off. In an alternative switching scheme, the crack detection switches CSW1 to CSWj may be turned on sequentially, or only some of the crack detection switches CSW1 to CSWj may be turned on at a specific time.

[0061] The input data lines DIL1 to DILj and the output data lines DOL1 to DOLj may be connected to opposite ends of the crack detection switches CSW1 to CSWj, respectively. (It should be noted here that one "end" of a MOS transistor may be a source electrode, and the other end of the transistor may be a drain electrode.)

[0062] When the crack detection switches CSW1 to CSWj are turned on, m / 2 detection loop paths may be formed. Therefore, crack detection of all data lines DL1 to DLm may be performed. For example, a predetermined test voltage or test current may be input through the input data lines DIL1 to DILj to be output to the crack determination unit 640 through the output data lines DOL1 to DOLj. (Note that when a test voltage generates a current on a data line to which the test voltage is applied and the test current is generated by the voltage, the method of measuring the output signal from the output data line DOLi may differ depending on whether the test voltage or test current is applied to the input data line DILi.)

[0063] The signal supply part 620 may supply a detection control signal CS for controlling on / off of the crack detection switches CSW1 to CSWj to the switch group 610. The signal supply part 620 may supply a crack detection signal CDS to the data lines DL1 to DLm, specifically, to the input data line DIL. Figure 3It is shown that the crack detection signal CDS can be applied to any input data line DILi and can be routed to the output data line DOLi through the switch CSWi. Here, the output data line DOLi can output the output signal OSi derived from the crack detection signal CDS to the crack determination part 640.

[0064] In an embodiment, the detection control signal CS may have a gate-on voltage in the vertical blanking period. For example, the detection control signal CS may have a gate-on voltage during a time interval group within a range of 1H to 2H periods in the vertical blanking period.

[0065] The crack detection signal CDS may correspond to a preset test voltage or a preset test current. When the crack detection switches CSW1 to CSWj are turned on, the crack detection signal CDS may be supplied to the input data line DIL.

[0066] The crack determination unit 640 may receive an output signal OS supplied from the data lines DL1 to DLm (specifically, the output data line DOL). The crack determination unit 640 may detect a crack of the display panel 100 by comparing the output signal OS with a preset reference value RV. For example, the crack determination unit 640 may receive a voltage or waveform of the output signal OS received when a period of about 2H has passed after the detection control signal CS is supplied. The crack determination unit 640 may include a hardware component such as a comparator circuit.

[0067] In an embodiment, the crack determination section 640 may include a plurality of comparators corresponding to the output data lines DOL Each comparator compares the output signal OS on the corresponding output data line DOL with the reference value RV.

[0068] In an embodiment, the crack determination unit 640 may include a single comparator (or a comparator having a number less than the number of output data lines DOL) to compare the output signal OS with the reference value RV. The comparator may receive an output signal from each of the output data lines at different timings. In this case, the crack determination unit 640 may also include a timing buffer or a switch (output signal switch) connected to each of the output data lines DOL to control the input timing of the output signal supplied to the comparator. Alternatively, the crack determination unit 640 may also include a memory for storing data of the output signal and sequentially outputting the output signal to the comparator. The crack detection signal CDS may be changed by the line resistance of the data line and the crack detection switch and other circuit factors. Therefore, a voltage drop and a current leakage may occur due to factors other than the presence of a crack. Therefore, even when there is no crack, a difference in signal level within a predetermined range based on an expected change may occur between the crack detection signal CDS and the output signal OS. Therefore, the reference value RV may be set to a value just beyond the offset range obtained by reflecting these factors.

[0069] Figure 3 An example is shown in which each of the output data lines DOL1 to DOLj is directly connected to the crack determination section 640. In one embodiment, the crack determination section 640 includes j separate comparator circuits arranged in parallel, wherein each comparator circuit compares the output signal OS on the corresponding output data line DOL with the reference value RV. In this way, the location of any detected crack can be identified. For example, if the output signal OS1 on the output data line DOL1 has a signal level indicating a crack, the signal level being measured by the respective comparator circuits within the crack determination section 640 connected to the output data line DOL1, it can be assumed that a crack has occurred at a location along the output data line DOL1 or the input data line DIL1.

[0070] In an alternative configuration, the crack determination section 640 has only a single comparator circuit which compares one output signal OS at a time with the reference value RV. In this case, a switch 410 (see FIG. 4 ) may be included between each output data line DOL and the comparator circuit. Figure 4 and Figure 5 That is, there may be j switches 410 connected between j corresponding output data lines DOL1 to DOLj and the comparator circuit, and at any given time only one of the j switches 410 is closed to provide the output signal OS from the corresponding output data line DOL to the comparator circuit.

[0071] In an embodiment, when the crack detection signal CDS corresponds to a test voltage, the reference value RV may correspond to a range obtained by applying a preset voltage drop offset to the test voltage. In other words, the reference value RV may be set to a level that just exceeds the range of the output signal expected when no crack exists in the corresponding data line pair. (Here, the corresponding data line pair is an output data line DOL and an input data line DIL connected to that output data line through a crack detection switch CSW.) When the output signal OS has a voltage level that is not within the range of the reference value RV (e.g., below the reference value RV), the crack determination unit 640 may determine that a crack has occurred in the corresponding data lines DIL and DOL. When the output signal OS has a level below the reference value RV (or, not within the range of the reference value RV), the crack determination unit 640 may output crack data CRD indicating the presence of a crack. The crack data CRD may include crack occurrence information and crack location information.

[0072] In an embodiment, a warning signal or a warning image may be output in response to the crack data CRD from the display device 1000. Alternatively, power of the display device 1000 may be automatically cut off in response to the crack data CRD.

[0073] In an embodiment, the crack data CRD may be stored in a predetermined memory. For example, when the crack data CRD accumulates to exceed a preset threshold, a fault occurrence image may be output, or the power of the display device 1000 may be cut off.

[0074] When the output signal OS is within the expected range of the condition that there is no crack, for example, the output signal OS has a voltage within the range of the reference value RV, the crack determination part 640 may determine that the state of the display panel 100 is normal. Therefore, the image of the next frame may be displayed normally.

[0075] In an embodiment, when the crack detection signal CDS corresponds to a test current, the reference value RV may correspond to a current level at the boundary of a preset line resistance range or just beyond the preset line resistance range. Here, the reference value RV may be referred to as a threshold current level. The line resistance range may be a normal resistance range obtained by considering one or more factors such as current leakage. If a crack exists in a corresponding data line pair from which an output signal is provided, an open circuit may exist in the input data line or the output data line, and the resulting current may be lower than or close to zero. Therefore, the resulting current may exceed the threshold current level due to being below the reference value RV, and may correspond to a resistance outside the normal resistance range.

[0076] When the output signal OS exceeds the threshold current level, the crack determination section 640 may output crack data CRD. The crack data CRD may include crack occurrence information and crack position information.

[0077] As described above, in the display device 1000 according to an embodiment of the present disclosure and the crack detector 605 included therein, whether a crack has occurred in the display panel 100 and the crack position can be relatively accurately detected using all the data lines DL1 to DLm with a relatively simple configuration. In addition, crack detection can be performed on the entire area of ​​the display panel 100 at a short time interval within the vertical blanking period. Therefore, crack detection accuracy can be improved, and product reliability can be significantly improved.

[0078] Figure 4 is shown in Figure 1 FIG. 1 is a diagram of an example of pixels and data lines in a display device.

[0079] Figure 4 The pixel P is a pixel connected to the j-th scan line SLj and the k-th data line DLk (j and k are natural numbers).

[0080] Reference Figure 1 and Figure 4 , the pixel P may include an organic light emitting diode OLED, a first transistor (driving transistor) T1 , a second transistor T2 , a third transistor T3 , and a storage capacitor Cst.

[0081] The anode electrode of the organic light emitting diode OLED may be connected to the second electrode of the first transistor T1, and the cathode electrode of the organic light emitting diode OLED may be connected to the second driving power supply providing the power supply voltage ELVSS. The organic light emitting diode OLED generates light having a predetermined brightness corresponding to the amount of current supplied from the first transistor T1.

[0082] A first electrode of the first transistor T1 may be connected to a first driving power supply providing a power supply voltage ELVDD, and a second electrode of the first transistor T1 may be connected to an anode electrode of the organic light emitting diode OLED. A gate electrode of the first transistor T1 may be connected to a tenth node N10. The voltage of the first transistor T1 corresponding to the tenth node N10 controls the amount of current flowing through the organic light emitting diode OLED.

[0083] A first electrode of the second transistor T2 may be connected to the data line DLk, and a second electrode of the second transistor T2 may be connected to the tenth node N10. A gate electrode of the second transistor T2 may be connected to the scan line SLj. When a scan signal Sj is supplied to the scan line SLj, the second transistor T2 may be turned on to transfer a data voltage from the data line DLk to the tenth node N10.

[0084] The third transistor T3 may be connected between the readout line RLk and the second electrode of the first transistor T1 (i.e., the eleventh node N11). The third transistor T3 may transmit a sensing current to the readout line RLk in response to a sensing control signal SEj transmitted through the sensing control line SSLj. The sensing current may be used to calculate a mobility of the first transistor T1 and a change in a threshold voltage of the first transistor T1. Mobility and threshold voltage information may be calculated based on a relationship between the sensing current and a voltage for sensing. In an embodiment, the sensing current may be converted into a voltage form for use in a compensation operation of a data voltage.

[0085] The storage capacitor Cst may be connected between the tenth node N10 and the anode electrode of the organic light emitting diode OLED.

[0086] The data line DLk may be an input data line or an output data line. In an embodiment, the data line DLk may be connected to the data driver 300 in the display period. Therefore, a data voltage corresponding to a gray scale may be supplied to the data line DLk. In addition, the data line DLk may be connected to the data driver 300 in a sensing period (e.g., a threshold voltage sensing period, a mobility sensing period, or an organic light emitting diode sensing period) other than the display period.

[0087] In an embodiment, switches may be connected to both ends of at least one data line DLk, respectively. For example, one switch CSW may be a switch for connecting between adjacent data lines, and another switch 410 may be a switch for connecting the data line DLk to the data driver 300 and / or the crack detection circuit 600.

[0088] In an embodiment, the data line DLk may be connected to the crack detection circuit 600 during a portion of the blanking period. For example, the data line DLk and the crack detection circuit 600 may be electrically connected to each other during a crack detection period included in the blanking period. During this time, the connection between the data line DLk and the data driver 300 may be cut off.

[0089] When the data line DLk is an input data line, the crack detection signal CDS may be supplied to the data line DLk. For example, the data line DLk may be connected to the signal supply part 620 of the crack detector 605.

[0090] When the data line DLk is an output data line, the data line DLk may transmit an output signal to the crack detection circuit 600. For example, the data line DLk may be connected to the crack determination part 640 of the crack detection circuit 600.

[0091] As described above, all data lines may be connected to the data driver 300 in the display period and the sensing period, and connected to the crack detection circuit 600 in the crack detection period.

[0092] As described above, in an embodiment, the crack determination unit 640 may have only a single comparator circuit for comparing one output signal OS with the reference value RV at a time. In this case, one switch 410 may be included between each output data line DOL and the crack determination unit 640 (see Figure 4 and Figure 5 ). That is, there may be j switches 410 connected between j corresponding output data lines DOL1 to DOLj and the crack determination section 640, and only one of the j switches 410 is closed at any given time to provide the output signal OS from the corresponding output data line DOL to the crack determination section 640. In one embodiment, the output signals from different corresponding output data lines DOL are received by the crack determination section 640 during a single frame. In another embodiment, the output signal OS is provided to the crack determination section 640 during different frames. In this case, for example, by selective on / off switching of the switch 410, since the first switch 410 connected to the output data line DOLi is in an on state, one output signal OSi from the output data line DOLi is received by the crack determination section 640 during the test period of the first frame. At the same time during the first frame, since the second switch 410 connected to another output data line DOLk is in an off state, no output signal is received from the output data line DOLk. In another frame, the opposite switching condition may occur to measure the output signal from the output data line DOLk instead of the output data line DOLi.

[0093] In an embodiment, the crack determination unit 640 may have a plurality of comparator circuits, each of which compares one output signal OS with a reference value RV at a time. In this case, j switches 410 are closed at any given time to provide the output signal from the corresponding output data line to the comparator circuit. In an embodiment, the output signals from different corresponding output data lines DOL are received by the crack determination unit 640 during a frame period (e.g., a portion of a blanking period).

[0094] Figure 5 It shows that the Figure 1 A diagram showing an example of a connection relationship of data lines in a display device 1000.

[0095] Reference Figure 1 , Figure 3 , Figure 4 and Figure 5 , the input data line DILk and the output data line DOLk may be connected to each other through the crack detection switch CSWk and form a conductive loop.

[0096] In an embodiment, the input data line DILk may be connected to the data driver 300. The data driver 300 may output a data voltage corresponding to a gray scale in a display period. The data driver 300 may output a crack detection signal in a crack detection period included in a partial period of a vertical blanking period. That is, the input data line DILk may receive a data voltage in a display period, and may receive a crack detection signal in a crack detection period.

[0097] In an embodiment, the data driver 300 may output a preset sensing voltage corresponding to a sensing purpose during a sensing period.

[0098] In an embodiment, the output data line DOLk may be selectively connected to the data driver 300 and the crack detection circuit 600. The output data line DOLk may be connected to the data driver 300 in a display period to receive a data voltage. The output data line DOLk may be connected to the crack detection circuit 600 in a crack detection period of a vertical blanking period to provide an output signal to the crack detection circuit 600.

[0099] That is, the crack detection switch CSW may be connected to one end of the output data line DOLk, and a switch for connecting the output data line DOLk to the data driver 300 and / or the crack detector 605 may be connected to the other end of the output data line DOLk.

[0100] As described above, the input data line DILk and the output data line DOLk may have different connection relationships. Therefore, the number of switches and lines for connecting the data driver 300 and the crack detector 605 to the data lines may be reduced. In addition, the data driver 300 may selectively output a data voltage, a sensing voltage, and a crack detection signal.

[0101] Figure 6 It shows Figure 1 A diagram of an example of the operation of a display device.

[0102] Reference Figure 1 , Figure 4 , Figure 5 and Figure 6 , the display device 1000 can sequentially write data voltages along the pixel lines and sequentially emit light along the pixel lines.

[0103] In an embodiment, the display device 1000 may include Figure 4 The pixels P. The scan signals S1 to Sn may be sequentially written to the pixel lines during the display period DISPLAY, and the pixel lines may sequentially emit light having a certain gray scale corresponding to the written data voltages.

[0104] A portion of the vertical blanking period VBLANK may be defined as a crack detection period. The detection control signal CS may have a gate-on voltage during the crack detection period. Thus, the crack detection switch CSW may be turned on. In an embodiment, the crack detection period may be preset to have a duration in the range of about a 1H period to about a 2H period. For example, if the display device 1000 is driven at 120 Hz, the crack detection period may be very short, about 8 μs or less.

[0105] In an embodiment, when the data line has Figure 5 When the connection structure is configured as shown in FIG. 1 , the data driver 300 may output a voltage corresponding to the crack detection signal CDS in the crack detection period. The crack detection signal CDS may be simultaneously supplied to all the input data lines DIL.

[0106] In an embodiment, when the data line has Figure 4 When the connection structure is formed, the signal supply part 620 included in the crack detection circuit 600 can output the crack detection signal CDS in the crack detection period.

[0107] Meanwhile, in an embodiment, mobility sensing may be performed on some of the pixel lines in a partial period of the vertical blanking period VBLANK.Since the crack detection period may correspond to a very short time interval, the crack detection period and the mobility sensing period do not overlap each other.

[0108] Figure 7 is a flowchart showing a method for driving a display device according to an embodiment of the present disclosure. The method may include turning on a crack detection switch (S100) for electrically connecting an input data line and an output data line during a vertical blanking period, and supplying a crack detection signal to the input data line (S200). The crack detection signal may be received by a crack determination unit (including at least one comparator) as an output signal supplied from an output data line (S220). Then, the method may determine whether the level of the output signal exceeds a threshold value (S300) (for example, the threshold value is set at the edge of a range expected for normal operation of the corresponding data line pair in the absence of a crack or just beyond the range). When the output signal level does not exceed the threshold value, an image of the next frame may be displayed (S400). When the output signal level exceeds the threshold value, crack data may be output (S500).

[0109] Continue to refer to Figure 7 , a crack detection switch for electrically connecting the input data line and the output data line may be turned on during the vertical blanking period (S100). The period during which the crack detection switch is turned on may correspond to the crack detection period. For example, the crack detection period may have a duration in the range of about 1H period to about 2H period.

[0110] In an embodiment, half of all data lines included in the display device 1000 may be input data lines, and the other half may be output data lines. Therefore, the number of crack detection switches may be half of the number of data lines.

[0111] In an embodiment, when the crack detection switch is turned on, a crack detection signal may be supplied to the input data line, and an output signal from the output data line may be output (S200, S220). In an embodiment, the crack detection signal may correspond to a preset test current.

[0112] Thereafter, a comparison of the output signal with a threshold value (preset reference value) may be performed (S300). The reference value may be an offset value obtained by considering a general voltage drop or voltage rise factor such as line resistance.

[0113] When the output signal derived from the crack detection signal does not exceed the threshold value, it can be determined that no crack occurs in the display panel. Therefore, the display device can operate normally. For example, when the output signal voltage is not less than the voltage corresponding to the reference value, the image of the next frame can be displayed normally (S400).

[0114] When the output signal level is below the reference value, it may be determined that a crack has occurred in the display panel. Therefore, crack data may be output (S500). The crack data may include crack occurrence information and crack location information.

[0115] In an embodiment, a warning signal or a warning image may be output in response to the crack data from the display device 1000. Alternatively, power to the display device may be turned off in response to the crack data.

[0116] In an embodiment, crack data may be stored in a predetermined memory. Due to a sudden voltage fluctuation caused by an external factor such as static electricity, crack data may appear unintentionally. In order to minimize erroneous determination, when crack data accumulates to exceed a preset threshold, it can be determined that a crack has finally appeared at the corresponding position.

[0117] When it is determined that a crack has occurred, a failure occurrence image (crack sensing image) may be output, or power to the display device may be turned off.

[0118] Figure 8 1 is a flow chart showing a method for driving the display device 1000 according to an embodiment of the present disclosure, in which a test current is used to test cracks. Figure 8 As shown in , a crack detection current may be supplied to an input data line, and an output signal (output current) may be output from an output data line (S210). In an embodiment, the crack detection current may correspond to a preset test current.

[0119] The detection resistance can be calculated from the output current corresponding to the crack detection current. Figure 8 As shown in , the detection resistor and the preset reference resistor can be compared (S310).

[0120] When the detection resistance is equal to or less than the reference resistance, it can be determined that no cracks occur in the display panel. Therefore, the display device can operate normally. For example, when the detection resistance is equal to or less than the reference resistance, the image of the next frame can be displayed normally (S410).

[0121] When the detection resistance exceeds the reference resistance, it may be determined that a crack has occurred in the display panel. Therefore, crack data may be output (S500).

[0122] Already referred to Figures 1 to 6 Describes Figure 7 and Figure 8 Therefore, their repeated description is omitted.

[0123] As described above, in the display device and the method for driving the display device according to the embodiment of the present disclosure, it is determined whether a crack has occurred in the display panel, and if it has occurred, the crack position can be accurately detected with a relatively simple structure using all data lines. Therefore, the crack detection accuracy can be improved, and the product reliability can be significantly improved.

[0124] The inventive concept can be applied to any suitable electronic device including a display device. For example, the present disclosure can be applied to HMD devices, TVs, digital TVs, 3D TVs, PCs, home appliances, notebook computers, tablet computers, mobile phones, smart phones, PDAs, PMPs, digital cameras, music players, portable game consoles, navigation systems, wearable displays, etc.

[0125] In a crack detector, a display device including the crack detector, and a method for driving the display device according to the inventive concept, it is determined whether a crack has occurred in a display panel, and if it has occurred, the crack position can be accurately detected with a relatively simple configuration using a voltage or current applied to all data lines. In addition, crack detection can be performed on the entire area of ​​the display panel at a short time interval of a vertical blanking period. Therefore, crack detection accuracy can be improved, and product reliability can be significantly improved.

[0126] Example embodiments have been disclosed herein, and although specific terms are employed, they are used and interpreted in a general and descriptive sense only and not for purposes of limitation. In some cases, it will be apparent to one of ordinary skill in the art as of the time of filing this application that, unless otherwise specifically noted, features, characteristics, and / or elements described in conjunction with a particular embodiment may be used alone or in combination with features, characteristics, and / or elements described in conjunction with other embodiments. Therefore, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the present disclosure as set forth in the claims.

Claims

1. A crack detector, comprising: a plurality of crack detection switches for connecting / disconnecting the data lines of the display panel to each other; a signal supply section configured to supply a detection control signal for controlling closing / opening of the plurality of crack detection switches, and configured to supply a crack detection signal to a first data line among the data lines; as well as a crack determination unit configured to determine a crack of the display panel by comparing an output signal supplied from a second data line connected to the first data line through a first crack detection switch of the plurality of crack detection switches with a preset reference value, wherein the data line is connected to the pixel and supplied with a data voltage, Each of the plurality of crack detection switches electrically connects or disconnects two data lines to each other, and The number j of the plurality of crack detection switches is half the number m of the data lines of the display panel.

2. The crack detector according to claim 1, wherein: Each of the data lines has a proximal end and a distal end, and each of the plurality of crack detection switches connects the distal ends of two data lines, wherein the two data lines are adjacent to each other.

3. The crack detector according to claim 1, wherein: The detection control signal causes each of the plurality of crack detection switches to be closed simultaneously, and thereby electrically connects an input data line and an output data line of a corresponding pair of the data lines.

4. The crack detector according to claim 1, wherein: The crack detection signal corresponds to a preset test voltage, Wherein the reference value is a voltage outside an expected range of the output signal for a crack-free condition, wherein an edge of the range is a preset voltage offset from the test voltage.

5. The crack detector according to claim 4, wherein: When the output signal is outside the range of the reference value, the crack determination section outputs crack data indicating the presence of a crack affecting the first data line and the second data line.

6. The crack detector according to claim 1, wherein: The crack detection signal corresponds to a preset test current, The reference value corresponds to a preset line resistance range.

7. The crack detector according to claim 6, wherein: The crack determination section outputs crack data indicating the presence of a crack affecting the first data line and the second data line when the resistance value calculated from the output signal is outside the line resistance range.

8. A display device, comprising: A display panel including a plurality of pixels connected to a plurality of scan lines and a plurality of data lines; a scan driver configured to supply a scan signal to each of the plurality of scan lines; a data driver configured to supply a data signal to each of the plurality of data lines; as well as a crack detector configured to detect a crack of the display panel based on a crack detection signal supplied to the plurality of data lines, Wherein, the crack detector comprises: a plurality of crack detection switches, used to connect / disconnect the plurality of data lines to each other; a signal supply section configured to supply a detection control signal for controlling closing / opening of the plurality of crack detection switches; and a crack determination unit configured to determine a crack of the display panel by comparing output signals supplied from the plurality of data lines with a preset reference value, Each of the plurality of crack detection switches electrically connects or disconnects two data lines to each other, and The number j of the plurality of crack detection switches is half the number m of the data lines of the display panel.

9. The display device according to claim 8, wherein: Each of the plurality of data lines has a proximal end and a distal end, and each of the plurality of crack detection switches is connected to the distal ends of two data lines adjacent to each other at one side of the display panel, wherein the plurality of crack detection switches are closed during a crack detection period included in a vertical blanking period, and The plurality of crack detection switches are closed simultaneously during a time interval in the range of 1H to 2H, wherein H is a horizontal period currently used by the display device to display one line of a frame.

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