Display device and associated detection method

A display device and a detection method applied to the display device are provided. The display device includes a display panel, a source control circuit, and a leakage estimation circuit. The display panel includes pixels being arranged in M columns, wherein at least one panel-partition is defined on the display panel. The source control circuit includes M source drivers which respectively provide data voltages to the M columns of pixels. The leakage estimation circuit includes an evaluation circuit, a defect detection circuit, and a mode-switch. The evaluation circuit controls the defect detection circuit to perform a leakage estimation procedure so that a leakage current corresponding to the panel-partition is estimated when the at least one mode-switch is turned on.

TECHNICAL FIELD

The disclosure relates in general to a display device and associated detection method, and more particularly to a display device and associated detection method capable of determining whether a short circuit occurs at a display panel.

BACKGROUND

FIG. 1(prior art) is a schematic diagram showing an intact display panel. When a display panel11is intact, images can be displayed properly. When the display panel11is cracked, the display panel11can no longer display images properly, and the display panel11might be burnt out.

FIG. 2(prior art) is a schematic diagram showing a break BRK on a cracked display panel. In daily use, the display panel13might be cracked by an external force so that a break BRK might appear on the surface of the display panel13. The external force, for example, might be caused by a pellet of an airsoft gun accidentally shot by a child. In other words, the display panel13is cracked because of the shot. On the display panel13, a short circuit might exist at the position of break BRK. However, the break BRK can be extremely tiny so that a user might not be aware that such a tiny break BRK may put the display panel13at the risk of being burnt out. Therefore, a detection mechanism for identifying whether the display panel13has a short circuit is required.

SUMMARY

The disclosure is directed to a display device and associated detection method capable of determining whether a display panel has a break. When a detection result shows that the estimated leakage is abnormal, the display panel is determined to have a short circuit. Consequentially, the display panel is determined as being cracked.

According to one embodiment, a display device is provided. The display device includes a display panel, a source control circuit, and a leakage estimation circuit. The display panel includes a plurality of pixels being arranged in M columns, wherein at least one panel-partition is defined on the display panel. The source control circuit is electrically connected to the display panel. The source control circuit includes M source drivers, which respectively provide data voltages to the M columns of pixels. The leakage estimation circuit includes an evaluation circuit, a defect detection circuit, and at least one mode-switch. The defect detection circuit is electrically connected to the evaluation circuit. At least one mode-switch is electrically connected to the defect detection circuit and the source control circuit. The evaluation circuit controls the defect detection circuit to perform a leakage estimation procedure so that a leakage current corresponding to the at least one panel-partition is estimated when the at least one mode-switch is turned on.

According to another embodiment, a detection method applied to a display panel is provided. The detection method includes the following steps. Firstly, at least one mode-switch is turned one. Then, a leakage estimation procedure is performed to estimate a leakage current corresponding to at least one panel-partition. Later, the leakage estimation circuit is controlled to perform a leakage estimation procedure so that the leakage current is estimated.

DETAILED DESCRIPTION

To prevent the display device from being burnt out, a leakage estimation circuit is provided. The leakage estimation circuit performs a leakage estimation procedure to estimate leakage current corresponding to the display panel. When the leakage estimated results indicate that the leakage current corresponding to the display panel is abnormal, the leakage estimation circuit generates a warning message accordingly.

FIG. 3is a schematic diagram illustrating a display device equipped with a leakage estimation circuit. The display device20includes a display panel23, a gate control circuit21, a timing controller25, a source control circuit27, and a leakage estimation circuit24. The gate control circuit21and the leakage estimation circuit24are both electrically connected to the timing controller25and the display panel23. The leakage estimation circuit24is electrically connected to the source drivers sd1, sd2, . . . sdM, and the timing controller25.

The source control circuit27and the gate control circuit21receive timing control signals from the timing controller25. The gate control circuit21is electrically connected to N gate lines GL[1]˜GL[N]. The source control circuit27includes M source drivers sd1, sd2, . . . sdM, which are respectively electrically connected to M source lines S[1]˜S[M]. In the display panel23, pixels P(1,1)˜P(M, N) are arranged in M columns and N rows. M and N are positive integers. The pixels located at the same column are electrically connected to the same source line S[1]˜S[M], and the pixels located at the same row are electrically connected to the same gate line GL[1]˜GL[N].

According to the embodiment of the present disclosure, operation of the leakage estimation circuit24is related to the source control circuit27and the timing controller25. In practical application, the leakage estimation circuit24and the source control circuit27can be integrated together or separate.

The timing controller25sends a mode control signal Smd to trigger the leakage estimation procedure being performed by the leakage estimation circuit24. Then, the leakage estimation circuit24determines if there is abnormal leakage current. Existence of the abnormal leakage current implies that the display panel has a short circuit, and the display panel23is under the risk of burning out. In a cast that the short circuit exists, the leakage estimation circuit24can transmit a warning signal Swm to notify the timing controller25. Later, the timing controller24may control the display panel23to display a warning message, or the timing controller24may directly shut down the display panel23. Consequentially, the display panel23can be well protected from being burnt out because of the short circuit.

FIG. 4is a schematic diagram illustrating internal components of the leakage estimation circuit. For the sake of illustration, the display panel33is assumed to have 10 columns of pixels, though the pixels are not drawn. The source control circuit37provides data voltages to the display panel33through source lines S[1]˜S[10].

The leakage estimation circuit34includes a mode-switch sw, a defect detection circuit36, a pre-stored circuit385, a storage circuit381, and a leakage current evaluation circuit343. The pre-stored circuit385is implemented with non-volatile memory devices, and storage circuit381is implemented with volatile/non-volatile memory devices.

In the pre-stored circuit385, a reference leakage current refLkg is saved. The evaluation circuit343may acquire the reference leakage current refLkg during the leakage estimation procedure. The storage circuit381further includes an original detection portion381aand a new detection portion381b. The original detection portion381ais used for storing an original comparison table origTbl, and the new detection portion is used for storing a new comparison table newTbl. Details about generation and usages of the original comparison table origTbl and the new comparison table newTbl will be illustrated below.

The mode-switch sw is electrically connected to the source control circuit37and the defect detection circuit36. The defect detection circuit36further includes a current source src, a comparator cmp. The current source src is electrically connected to the evaluation circuit343, a supply voltage Vdd and a comparison terminal Ncmp. The current source src provides a source current Isrc and the source current Isrc is adjustable by a current setting signal Sset. The current setting signal Sset represents different testing current values tstC used to set the source current Isrc. The comparator cmp is an operational amplifier having an inverting terminal (−), a non-inverting terminal (+), and an output terminal. The inverting terminal (−) receives a reference voltage Vref (for example, 0-18V), the non-inverting terminal (+) is electrically connected to the comparison terminal Ncmp, and the output terminal of the comparator cmp is electrically connected to the evaluation circuit343. The output terminal of the comparator cmp generates a detected signal Sdet. The detected signal Sdet is transmitted to the evaluation circuit343.

Depending on the comparison between the reference voltage Vref and the voltage at the comparison terminal (that is, the comparison voltage Vcmp, the state of the detected signal Sdet is determined. The reference voltage Vref is adjustable, depending on the precision requirement of the leakage estimation.

When the comparison voltage Vcmp is greater than the reference voltage Vref, the detected signal Sdet outputs a logic high level (state “1”) to the evaluation circuit343. When the comparison voltage Vcmp is less than or equivalent to the reference voltage Vref, the detected signal Sdet outputs a logic low level (state “0”) to the evaluation circuit343. In a case that the short circuit on the display panel33exists, the comparison voltage Vcmp is changed, and the detected signal Sdet might be affected as well. Therefore, the state of the detected signal Sdet can be referred by the evaluation circuit343to determine whether the display panel33is intact or cracked.

The evaluation circuit343is electrically connected to the defect detection circuit36, the pre-stored circuit385, the storage circuit381, and the timing controller. The evaluation circuit343receives the mode control signal Smd from the timing controller and transmits a warning signal Swm to the timing controller if necessary.

InFIG. 4, all the source lines S[1]˜S[10] are electrically connected to their corresponding source drivers sd1˜sd10. On the other hand, the source lines S[1]˜S[10] are alternatively electrically connected to the mode-switch sw. Depending on whether the source line S[1]˜S[10] is electrically connected to the mode-switch sw or not, the source lines S[1]˜S[10] can be classified into two groups. For example, a group includes the odd-numbered source lines S[1], S[3], S[5], S[7], S[9], and another group includes the even-numbered source lines S[2], S[4], S[6], S[8], S[10]. In practical application, the even-numbered source lines S[2], S[4], S[6], S[8], S[10] might be the ones being electrically connected to the mode-switch sw, not the odd-numbered source lines S[1], S[3], S[5], S[7], S[9].

The display panel33, according to the embodiment of the present disclosure, may operate in two modes, a normal display mode, and a leakage estimation mode. Depending on the operation mode of the display panel33, switching statuses of the mode-switch sw, the channel-switches sw1a, sw3a, sw5a, sw7a, sw9a, and the detection-switches sw1b, sw3b, sw5b, sw7b, sw9bare different.

When the mode control signal Smd is set to a first logic state (for example, “0”), the display panel operates in the normal display mode. Meanwhile, the mode-switch sw is turned off, the channel-switches sw1a, sw3a, sw5a, sw7a, sw9aare turned on, and the detection-switches sw1b, sw3b, sw5b, sw7bare turned off. Alternatively speaking, the defect detection circuit36is disconnected to the source control circuit37, and the source drivers sd1˜sd10respectively provide data voltages to source lines S[1]˜S[10].

On the other hand, when the mode control signal Smd is set to a second logic state (for example, “1”), the display panel operates in the leakage estimation mode. Meanwhile, the mode-switch sw is turned on, the channel-switches sw1a, sw3a, sw5a, sw7a, sw9aare turned off, and the detection-switches sw1b, sw3b, sw5b, sw7bare turned on. Thus, the defect detection circuit36is capable of detecting the status of the source control circuit37through the mode-switch sw.

In practical application, the timing controller sets the display panel33to enter the leakage estimation mode when the screen is not displaying images. For example, soon after the display panel is just power on, or when the display panel is in a blank duration. The blank duration can be, for example, the horizontal synchronization duration (hereinafter, Hsync), or the vertical synchronization duration (hereinafter, Vsync).

FIGS. 5 and 6are schematic diagrams illustrating how the leakage currents of the intact display panel and the cracked display panel are estimated, respectively. In both figures, a leakage current i_Lkg, i_Lkg′ flows from the comparison terminal Ncmp to the display panel33through the mode-switch sw and the detection-switches sw1b, sw3b, sw5b, sw7b, sw9b. When the display panel33remains intact, as shown inFIG. 5, the source lines S[3], S[4] are separate and independent. InFIG. 6, the break BRK causes a short circuit between the source lines S[3], S[4] so that the source lines S[3], S[4] are mutually influenced. The short circuit between the source lines S[3], S[4] can be considered as a shortage resistor Rst.

InFIG. 5, the leakage current i_Lkg flows to the source control circuit37and the display panel. The leakage current i_Lkg is divided into five branch currents Lkg1, Lkg2, Lkg3, Lkg4, Lkg5. When the display panel33is intact, the branch current Lkg1flows to the source line S[1] through conduction of the detection-switch sw1b, the branch current Lkg2flows to the source line S[2] through conduction of the detection-switch sw2b, the branch current Lkg3flows to the source line S[3] through conduction of the detection-switch sw3b, the branch current Lkg4flows to the source line S[4] through conduction of the detection-switch sw4b, and the branch current Lkg5flows to the source line S[5] through conduction of the detection-switch sw5b.

Similarly, inFIG. 6, the leakage current i_Lkg′ is divided into five branch currents Lkg1′, Lkg2′, Lkg3′, Lkg4′, Lkg5′. Although flowing paths of the branks currents Lkg1′, Lkg3′, Lkg4′, Lkg5′ are similar to their counterparts inFIG. 5, the flowing path of the branch current i_Lkg2′ is different. The branch current i_Lkg2′ is conducted from the source line S[3] to the source line S[4] because of the shortage resistor Rst. As the flowing path of the brank current i_Lkg2′ has been changed, the current value of the brank current i_Lkg2′, the current value of the leakage current i_Lkg′, the comparison voltages Vcmp, and the comparison voltage Vcmp inFIG. 6are all affected. Therefore, the detected signal Sdet can be utilized to indicate if there is a short circuit in the display panel.

FIG. 7is a schematic diagram illustrating generation of the detected signal Sdet and operation of the defect detection circuit. The panel equivalent resistor Req_dp is shown to represent the overall resistance value of the display panel, and the resistance of the panel equivalent resistor Req_dp is varied if the short circuit occurs. The panel equivalent resistor Req_dp is electrically connected to the comparison terminal Ncmp and a ground terminal Gnd.

When there is no break BRK on the display panel33(as shownFIG. 5), all the source lines remain separate, and the resistance of the panel equivalent resistor Req_dp is equivalent to a default resistance value. On the other hand, when the break BRK exists (as shown inFIG. 6), the resistance of the panel equivalent resistor Req_dp is no longer equivalent to the default resistance value because of the shortage resistor Rst. Whenever there is short circuit, at least one of the branch currents is changed, so as the panel equivalent resistor Req_dp.

The current source src can be considered as a source equivalent resistor Rec_src being electrically connected to the supply voltage Vdd and the comparison terminal Ncm. The source current Isrc, as mentioned above, is set by the current setting signal Sset. In the present disclosure, the source current Isrc can be set to different testing current values tstC. The comparison voltage Vcmp is related to the source equivalent resistor Req_src, the panel equivalent resistor Req_dp, the supply voltage Vdd, the source current Isrc, and the leakage current i_Lkg.

In the present application, when the display panel is intact, the reference voltage Vref and comparison voltage Vcmp are designed to be equivalent. Whereas, when the leakage current i_Lkg changes, the comparison voltage Vcmp is affected, so as the state of the detected signal Sdet. Therefore, the state of the detected signal Sdet can be utilized to recognize whether the leakage current i_Lkg is changed or not.

In order to maintain the equivalence between the comparison voltage Vcmp and the reference voltage Vref, the current value of the source current Isrc should be adjusted to be equivalent to the leakage current i_Lkg. In other words, the comparison voltage Vcmp can be equivalent to the reference voltage Vref again even if the leakage current i_Lkg is affected by the break on the display panel as long as the source current Isrc is equivalent to the leakage current i_Lkg. In other words, by setting the leakage current i_Lkg with different testing current values (tst1, tst2, and so forth), the current value of the leakage current i_Lkg can be estimated.

It is possible to increase the testing current values gradually so that the leakage current i_Lkg to be detected can be identified. For the sake of illustration, four different testing current values are respectively used to set the source current Isrc, and the testing current values are assumed to be in ascending order. That is, tst1<tst2<tst3<tst4. In response to the four different testing current values tst1,tst2, tst3, tst4, the states of the detected signal Sdet might have five possible combinations, as shown inFIGS. 8A˜8E.FIGS. 8A˜8E are schematic diagrams illustrating how the leakage current i_Lkg is estimated based on the states of the detected signal Sdet.

InFIG. 8A, the detected signal Sdet switches to state “1” when the source current Isrc is set to any of the testing current values tst1, tst2, tst3, tst4, and this implies that the leakage current i_Lkg is less than or equivalent to the testing current value tst1. That is, i_Lkg≤tst1. Alternatively speaking, the comparison voltage Vcmp becomes greater than the reference voltage Vref if the source current Isrc is greater than or equivalent to the testing current value tst1. Therefore, the leakage current i_Lkg is estimated as being equivalent to the testing current value tst1.

InFIG. 8B, the detected signal Sdet switches to state “0” when the source current Isrc is set to the testing current value tst1, and this implies that the leakage current i_Lkg is greater than the testing current value tst1. Moreover, the detected signal Sdet switches to state “1” when the source current Isrc is set to any of the testing current values tst2, tst3, tst4, and this implies that the leakage current i_Lkg is less than or equivalent to the testing current value tst2. That is, tst1<i_Lkg≤tst2. Alternatively speaking, the comparison voltage Vcmp becomes greater than the reference voltage Vref if the source current Isrc is set to a testing current value greater than or equivalent to the testing current value tst2. Therefore, the leakage current i_Lkg is estimated as being equivalent to the testing current value tst2.

InFIG. 8C, the detected signal Sdet switches to state “0” when the source current Isrc is set to any of the testing current values tst1, tst2. This implies that the leakage current i_Lkg is greater than the testing current value tst2. Moreover, the detected signal Sdet switches to state “1” when the source current Isrc is set to any of the testing current values tst3, tst4, and this implies that the leakage current i_Lkg is less than or equivalent to the testing current value tst3. That is, tst2<i_Lkg≤tst3. Alternatively speaking, the comparison voltage Vcmp becomes greater than the reference voltage Vref if the source current Isrc is set to a testing current value greater than or equivalent to the testing current value tst3. Therefore, the leakage current i_Lkg is estimated as being equivalent to the testing current value tst3.

InFIG. 8D, the detected signal Sdet switches to state “0” when the source current Isrc is set to any of the testing current values tst1, tst2, tst3. This implies that the leakage current i_Lkg is greater than the testing current value tst3. Moreover, the detected signal Sdet switches to state “1” when the source current Isrc is set to the testing current value tst4, and this implies that the leakage current i_Lkg is less than or equivalent to the testing current value tst4. That is, tst3<i_Lkg≤tst4. Alternatively speaking, the comparison voltage Vcmp becomes greater than the reference voltage Vref if the source current Isrc is set to a testing current value greater than or equivalent to the testing current value tst4. Therefore, the leakage current i_Lkg is estimated as being equivalent to the testing current value tst4.

InFIG. 8E, the detected signal Sdet switches to state “0” when the source current Isrc is set to any of the testing current values tst1, tst2, tst3, tst4. Alternatively speaking, the comparison voltage Vcmp is always less than the reference voltage Vref, even if the greatest testing current value tst4has been set. Thus, it can be concluded that the leakage current i_Lkg to be estimated is greater than all of the testing current values tst1, tst2, tst3, ts4. That is, tst4<i_Lkg.

In the present disclosure, the leakage estimation procedure can be triggered in two occasions, soon after the display panel is just power-on and when the display panel continuously displays images. The estimated leakage currents are further compared and analyzed to determine when the display panel is cracked.

FIG. 9is a schematic diagram illustrating that the original leakage current origLkg is estimated based on the original comparison table origTbl. In the leakage estimation procedure performed soon after the display panel is just power-on, the source current Isrc is respectively set to the testing current values tst1, tst2, tst3, tst4, and the original-detected signals Sdet_orig(tst1), Sdet_orig(tst2), Sdet_orig(tst3), Sdet_orig(tst4), are generated accordingly. The states of the original-detected signals Sdet_orig(tst1), Sdet_orig(tst2), Sdet_orig(tst3), Sdet_orig(tst4) listed in the original comparison table origTbl are then used for estimating the original leakage current origLkg, according to the previous descriptions inFIGS. 8A˜8E.

FIG. 10is a schematic diagram illustrating that the new leakage current newLkg is estimated based on the new comparison table newTbl. In the leakage estimation procedure performed during the leakage estimation procedure performed when the display panel continuously displays images, the source current Isrc is respectively set to the testing current values tst1, tst2, tst3, tst4, and the detected signals Sdet_new(tst1), Sdet_new(tst2), Sdet_new(tst3), Sdet_new(tst4), are generated. The states of the new-detected signals Sdet_new(tst1), Sdet_new(tst2), Sdet_new(tst3), Sdet_new(tst4) listed in the new comparison table newTbl are then used for estimating the new leakage current newLkg, according to the previous descriptions inFIGS. 8A˜8E.

In practical application, the leakage estimation procedure can be repetitively performed, and the new comparison table newTbl can be updated while the display panel remains power-on and is continuously displaying images. Moreover, as illustrated above, the vertical synchronization duration Vsync and the horizontal synchronization duration Hsync are utilized to perform the leakage estimation procedure. As the vertical synchronization duration Vsync and the horizontal synchronization duration Hsync are relatively short, the new comparison table newTbl can be constructed in separate blank durations.

In the specification, the original comparison table origTbl represents the existing features of the display panel. Relatively, the new comparison table newTbl represents immediate features of the display panel. These immediate features do not exist when the display panel is just power-on but start to appear only after the display panel starts to display images. As the original comparison table origTbl and the new comparison newTbl can represent attributes of the display panel, they are referred by the evaluation circuit to identify whether and when the display panel is cracked by the external force.

FIG. 11is a flow diagram illustrating how the display panel is determined to have a short circuit or not. Firstly, as soon as the display panel is power-on (step S301), the mode-switch sw is turned on, and the evaluation circuit is triggered to perform the leakage estimation procedure (step S303). In the leakage estimation procedure, the defect detection circuit generates the original-detected signals Sdet_orig(tst1)˜Sdet_orig(tst4) to construct the original comparison table origTbl. Then, the original comparison table origTbl is referred by the evaluation circuit to estimate the original leakage current orgLkg. After the original leakage current orgLkg is estimated, the mode-switch sw is turned off (step S307), and the display panel starts to continuously display images (step S309). In practical application, it is possible that the original comparison table origTbl is constructed at this stage but referred to estimate the original leakage current origLkg later.

The timing controller determines if any of the blank durations (such as Vsync, Hsync) starts (step S311). If not, step S309is performed repeatedly. If the blank duration starts, the timing controller further determines if the leakage estimation procedure should be performed (step S313). If the determination result of step S313is negative, the mode-switch sw is turned off, and the leakage estimation circuit is disabled (step S321). Then, step S309is executed again.

If the determination result of step S313is positive, the timing controller sends the mode control signal Smd to the leakage estimation circuit34so that the mode-switch sw is turned on and the evaluation circuit starts to perform the leakage estimation procedure. In the leakage estimation procedure, the defect detection circuit generates the new-detected signals Sdet_new(tst1)˜Sdet_new(tst4) to construct the new comparison table newTbl. Then, the new comparison table newTbl is referred by the evaluation circuit to estimate the new leakage current newLkg (step S315). Later, the evaluation circuit determines whether the display panel is cracked based on comparisons between the reference leakage current refLkg, the original leakage current origLkg, and the new leakage current newLkg (step S317). Details and variations about step S317are illustrated inFIG. 12.

The reference leakage current refLkg represents a baseline current value of the leakage current corresponding to the display panel, and its origin should not be limited. The reference leakage current refLkg can be provided by the manufacturer of the display device. Alternatively, the reference leakage current refLkg can be the leakage current being estimated previously when the display panel was power-on before, and the reference leakage refLkg is pre-stored at the pre-stored circuit385. Or, the reference leakage refLkg can also be obtained by choosing the minimum among the original leakage currents origLkg corresponding to the panel-partitions.

Based on the comparison results between the reference leakage current refLkg, the original leakage current origLkg, and the new leakage current newLkg, the evaluation circuit may determine whether the display panel is cracked or not (step S319). If the display panel is not cracked, step S321is executed. If the display panel is cracked, the evaluation circuit transmits the warning signal Swm to the timing controller. Later, the timing controller may turn off the display panel to prevent the display panel from being burnt-out.

FIG. 12is a flow diagram illustrating whether and when the display panel is cracked. The evaluation circuit firstly compares the new leakage current newLkg and the reference leakage current refLkg (step S317a). If the new leakage current newLkg and the reference leakage current refLkg are equivalent, the evaluation circuit determines that the display panel is not cracked (step S317b). If the new leakage current newLkg and the reference leakage current refLkg are different, the evaluation circuit determines that the new leakage current newLkg is abnormal. Then, the equivalence or inequivalence between the new leakage current newLkg and the original leakage current origLkg is determined to find out when the display panel is cracked (step S317c).

If the determination result of step S317cis positive, the evaluation circuit recognizes that original leakage current origLkg is also abnormal. Thus, the evaluation circuit further determines that the abnormal phenomenon should have already existed as soon as the display panel is power-on. In other words, the evaluation circuit confirms that the display panel is cracked while the display panel was power-off/not in operation (step S317d).

If the determination result of step S317cis negative, the evaluation circuit recognizes that the abnormal phenomenon does not exist when the display panel is just power-on but starts to exist after the display panel starts to display images. Therefore, the evaluation circuit confirms that the display panel is cracked while the display panel is power-on/in operation (step S317e).

In practical application, the display panel can be divided into J panel-partitions, and the defect detection circuit might estimate the leakage currents corresponding to these panel-partitions separately. J is a positive integer. In consequence, the position of the break BRK can be identified. An example showing that the display panel is divided into four panel-partitions (that is, J=4) is illustrated below.

FIG. 13is a schematic diagram illustrating that the leakage estimation procedure is performed to four panel-partitions defined on the display panel. The display panel233includes 1000 channels which are classified into four panel-partitions PT1, PT2, PT3, PT4. The boundary line L1separates channels in the panel-partition PT1and the panel-partition PT2, the boundary line L2separates channels in the panel-partition PT2and the panel-partition PT3, and the boundary line L3separates channels in the panel-partition PT3and the panel-partition PT4. That is, each of the boundary lines L1, L2, L3can be considered as a boundary of two adjacent panel-partitions. The boundary lines L1, L2, L3are drawn to assist illustration, and they might not be physically labeled on the display panel.

InFIG. 13, the source lines S[1]˜S[1000] receive data voltages from the source drivers, respectively. The even-numbered source drivers and source lines are not shown to simplify the complexity. The source drivers in the source control circuit271are divided into four source-control partitions srcPT1, srcPT2, srcPT3, srcPT4. The layout of the panel-partitions and their relative connections are summarized in Table 1.

All the 1000 source drivers are electrically connected to the timing controller, and each of the source-control partition srcPT1, srcPT2, srcPT3, srcPT4includes 250 source drivers (M/J=1000/4=250). In addition to the timing controller, the odd-numbered source drivers located at the source-control partition srcPT1(source drivers corresponding to channels ch1, ch3, . . . ch249) are electrically connected to the mode-switch sw1. Alternatively speaking, half out of the 250 source drivers in source-control partition srcPT1are electrically connected to the mode-switch sw1. The source drivers located at the source-control partitions srcPT2, srcPT3, srcPT4have similar connections, so they are not illustrated.

When the display panel operates in the normal display mode, the mode-switches sw1, sw2, sw3, sw4are all turned off. When the display panel operates in the leakage estimation mode, one of the mode-switches sw1, sw2, sw3, sw4is turned on each time, depending on which of the panel-partitions PT1, PT2, PT3, PT4is selected for leakage estimation. When the panel-partition PT1is selected for leakage estimation, the mode-switch sw1is turned on, and the mode-switches sw2, sw3, sw4are turned off. Meanwhile, the detection-switches sw1bcorresponding to the odd-numbered channels (ch1, ch3, . . . ch249) in the source-control partition srcPT1are turned on. The similar control mechanism can be applied to the panel-partitions PT2, PT3, PT4. In a case that more panel-partitions are defined on the display panel, sizes of the original comparison table origTbl and the new comparison table newTbl expand accordingly.

In practical application, the defect detection circuit261might include multiple sets of the mode-switches, the current sources, and the comparators so that the leakage estimation procedure can be performed in a parallel manner. For example, each of the panel-partitions PT1, PT2, PT3, PT4is corresponding to a specific mode-switch, a specific current source, and a specific comparator.

For the sake of illustration, for the original comparison table origTbl and the new comparison table newTbl involving different panel-partitions and different testing current values, the parameter “pt” is used to represent the panel-partition, and the parameter “tstC” is used to represent the testing current value being set to the source current Isrc. Moreover, the coordinate (pt, tstC) is used to indicate the attributes related to the detected signal Sdet. Once all the panel-partitions have been selected for the leakage estimation procedures when the screen continuously displays images, an original comparison table origTbl showing different original-detected signals Sdet_orig(pt, tstC) similar toFIG. 14and a new comparison table newTbl showing different new-detected signals Sdet_new(pt, tstC) similar toFIG. 15are generated.

FIG. 14is a schematic diagram illustrating that the states of the detected signals summarized in the original comparison table are utilized to estimate the original leakage currents origLkg respectively corresponding to different panel-partitions are estimated. The original comparison table origTbl inFIG. 14includes four sets of original-detected signals Sdet_orig(pt, tstC) and each of which is shown with a bold rectangle.

Basically, the original leakage current corresponding to the panel-partition PT1origLkg(PT1) is jointly determined by the original-detected signals Sdet_orig(PT1, tst1), Sdet_orig(PT1, tst2), Sdet_orig(PT1, tst3), Sdet_orig(PT1, tst4). The original-detected signals Sdet_orig(PT1, tst1), Sdet_orig(PT1, tst2), Sdet_orig(PT1, tst3), Sdet_orig(PT1, tst4) are respectively obtained by applying different testing current values tst1, tst2, tst3, tst4to estimate the original leakage current corresponding to the panel-partition PT1origLkg(PT1) when the display panel is just power on. Similarly, the original leakage currents origLkg(PT2), origLkg(PT3), origLkg(PT4) can be respectively estimated. Moreover, based on comparisons between the original leakage currents origLkg(PT1), origLkg(PT2), origLkg(PT3), orgLkg(PT4), the reference leakage current refLkg can be determined.

FIG. 15is a schematic diagram illustrating that the states of the detected signals summarized in the new comparison table are utilized to estimate the new leakage currents newLkg respectively corresponding to different panel-partitions are estimated. The new leakage current corresponding to the panel-partition PT1newLkg(PT1) is determined according to the new-detected signals Sdet_new(PT1, tst1)˜Sdet_new(PT1, tst4). The new-detected signals Sdet_new(PT1, tst1), Sdet_new(PT1, tst2), Sdet_new(PT1, tst3), Sdet_new(PT1, tst4) are respectively obtained by applying different testing current values tst1, tst2, tst3, tst4to estimate the new leakage current corresponding to the panel-partition PT1newLkg(PT1) when the display panel remains in operation. Similarly, the new leakage currents newLkg(PT2), newLkg(PT3), newLkg(PT4) can be estimated, respectively.

Furthermore, in the specification, a majority leakage current majLkg can be defined. The majority leakage current majLkg is the mode of the new leakage currents newLkg(PT1), newLkg(PT2), newLkg(PT3), newLkg(PT4). The majority leakage current majLkg is greater than or equivalent to the reference leakage current refLkg.

FIG. 16is a flow diagram illustrating whether and when the panel-partition is cracked. In short, the steps inFIG. 16are mainly modified from steps inFIG. 12. For example, steps S317a′˜S317e′ are similar to steps S317a˜S317e. InFIG. 16, steps S317f′˜S317i′ are shown in bold frames to represent that some modifications are needed when the display panel is divided into multiple panel-partitions.

FIG. 17is a schematic diagram illustrating a scenario in which the evaluation circuit determines that the display panel is cracked by the external force while the display panel is in operation. Estimations of the original leakage currents origLkg(PT1)˜origLkg(PT4) and the new leakage currents newLkg(PT1)˜PT(4) inFIG. 17are analog to the previous descriptions inFIGS. 8A˜8E.

According to the original comparison table origTbl, the estimated original leakage current origLkg(PT1) is 2 mA, and the estimated original leakage currents origLkg(PT2), origLkg(PT3), origLkg(PT4) are 3 mA. InFIG. 17, the reference leakage current refLkg is assumed to be the minimum of the original leakage currents origLkg(PT1), origLkg(PT2), origLkg(PT3), origLkg(PT4), that is, 2 mA. On the other hand, according to the new comparison table newTbl, the estimated new leakage current newLkg(PT1) is 2 mA, the estimated new leakage currents newLkg(PT2), newLkg(PT3) are 3 mA, and the estimated new leakage current newLkg(PT3) is 4 mA. By definition, the majority leakage current majLkg is 3 mA.

After the original leakage currents origLkg(PT1)˜origLkg(PT4), and the new leakage currents newLkg(PT1)˜newLkg(PT4) are estimated, they are respectively compared in pairs. Please refer toFIGS. 16 and 17together. As the steps inFIG. 16are repetitively performed to different panel-partitions, the discussion below starts with step S317a′ for each panel-partition.

For the panel-partition PT1, the reference leakage refLkg (2 mA) and the new leakage current newLkg(PT1) (2 mA) are equivalent to each other. Thus, the determination result of step S317a′ is positive, and the evaluation circuit determines that the panel-partition PT1is not cracked (step S317b′).

For the panel-partition PT2, the reference leakage refLkg (2 mA) and the new leakage current newLkg(PT2) (3 mA) are not equivalent (determination result of step S317a′ is negative). Thus, step S317c′ is executed. As the new leakage current newLkg(PT2) (3 mA) and the original leakage current orgLkg(PT2) (3 mA) are equivalent, step S317h′ is executed. In step S317h′, the new leakage current newLkg(PT2) is further compared with the majority leakage current majLkg (3 mA). As the new leakage current newLkg(PT2) is equivalent to the majority leakage current majLkg (3 mA), the determination result of step S317h′ is positive, and the evaluation circuit determines that the panel-partition PT2is not cracked (step S317b′).

For the panel-partition PT3, the reference leakage refLkg (2 mA) and the new leakage current newLkg(PT3) (3 mA) are not equivalent (determination result of step S317a′ is negative). Then, the new leakage current newLkg(PT4) is further compared with the majority leakage current majLkg (3 mA). Thus, step S317c′ is executed. As the new leakage current newLkg(PT4) (4 mA) and the original leakage current origLkg(PT4) (3 mA) are not equivalent, the evaluation circuit determines that the panel-partition PT3is cracked by the external force while the display panel is in operation (step S317e′).

For the panel-partition PT4, the reference leakage refLkg (2 mA) and the new leakage current newLkg(PT4) (3 mA) are not equivalent (determination result of step S317a′ is negative). Thus, step S317c′ is executed. As the new leakage current newLkg(PT4) (3 mA) and the original leakage current orgLkg(PT4) (3 mA) are equivalent, step S317h′ is executed. In step S317h′, the new leakage current newLkg(PT4) is further compared with the majority leakage current majLkg (3 mA). As the new leakage current newLkg(PT4) is equivalent to the majority leakage current majLkg (3 mA), the determination result of step S317h′ is positive, and the evaluation circuit determines that the panel-partition PT4is not cracked (step S317b′).

FIG. 18is a schematic diagram illustrating a scenario in which the evaluation circuit determines that the display panel is cracked while the display panel is not in operation. Estimations of the original leakage currents origLkg(PT1)˜origLkg(PT4) and the new leakage current currents newLkg(PT1)˜newLkg(PT4) inFIG. 17are analog to the previous descriptions inFIGS. 8A˜8E.

According to the original comparison table origTbl, the estimated original leakage current origLkg origLkg(PT1) is greater than 4 mA (but the actual value is still unknown unless greater testing current values tstC>4 are tested). The estimated original leakage currents origLkg(PT2), origLkg(PT3), origLkg(PT4) are 3 mA, 4 mA, 4 mA, respectively. InFIG. 18, the reference leakage current refLkg is 3 mA. According to the new comparison table newTbl, the estimated new leakage current newLkg(PT1) is greater than 4 mA (but the actual value is still unknown unless greater testing current values tstC>4 are tested), the estimated new leakage current newLkg(PT2) is 3 mA, and the estimated new leakage currents newLkg(PT3), newLkg(PT4) are 4 mA. By definition, the majority leakage current majLkg is 4 mA.

After the original leakage currents origLkg(PT1)˜origLkg(PT4), and the new leakage currents newLkg(PT1)˜newLkg(PT4) are estimated, they are respectively compared in pairs. Please refer toFIGS. 16 and 18together. As the steps inFIG. 16are repetitively performed to different panel-partitions, the following discussion starts from step S317a′ for each panel-partition.

For the panel-partition PT1, the reference leakage refLkg (3 mA) and the new leakage current newLkg(PT1) (>4 mA) are not equivalent. Thus, the determination result of step S317a′ is negative, and the evaluation circuit further compares the new leakage current newLkg(PT1) (>4 mA) with the original leakage current origLkg(PT1) (>4 mA) (step S317c′). The determination result of step S317c′ is positive, and the new leakage current newLkg(PT1) (>4 mA) is further compared with the majority leakage current majLkg (4 mA) (step S317h′). As the determination result of step S317h′ is negative, the evaluation circuit determines that the panel-partition PT4is cracked by the external force while the display panel is not in operation (step S317d′).

For the panel-partition PT2, the reference leakage refLkg (3 mA) and the new leakage current newLkg(PT2) (3 mA) are equivalent. Thus, the evaluation circuit determines that the panel-partition PT1is not cracked (step S317b′).

For the panel-partition PT3, the reference leakage refLkg (3 mA) and the new leakage current newLkg(PT3) (4 mA) are not equivalent. The new leakage current newLkg(PT3) (4 mA) is compared with the original leakage current origLkg(PT3) (4 mA) (step S317c′). As the determination result of step S317c′ is positive, the new leakage current newLkg(PT3) (4 mA) is further compared with the majority leakage current (4 mA) (step S317h′). The determination result of step S317h′ is positive, and the evaluation circuit determines that the panel-partition PT3is not cracked (step S317b′).

For the panel-partition PT4, the reference leakage refLkg (3 mA) and the new leakage current newLkg(PT4) (4 mA) are not equivalent. Thus, step S317c′ is executed to compare the new leakage current newLkg(PT4) (4 mA) with the original leakage current origLkg(PT4) (4 mA). As the determination result of step S317c′ is positive, the new leakage current newLkg(PT4) (4 mA) is further compared with the majority leakage current (4 mA) (step S317h′). As the determination result of step S317h′ is positive, the evaluation circuit determines that the panel-partition PT4is not cracked (step S317b′).

FIG. 19is a schematic diagram illustrating that the leakage estimation circuit might not recognize the leakage currents if the breaks are located at boundaries of the panel-partitions. Similar toFIG. 13, four panel-partitions PT1, PT2, PT3, PT4are defined on the display panel233. In addition, three breaks BRK1, BRK2, BRK3are shown. The break BRK1is located at the boundary line L1between the panel-partition PT1and the panel-partition PT2, the break BRK2is located at the boundary line L2between the panel-partition PT2and the panel-partition PT3, and the break BRK3is located at the boundary line L3between the panel-partition PT3and the panel-partition PT4.

FIG. 20is a schematic diagram illustrating the original comparison table origTbl and the new comparison table newTbl corresponding toFIG. 19. Based on the original comparison table origTbl, the original leakage currents origLkg(PT1), origLkg(PT2), origLkg(PT3), origLkg(PT4) are all greater than 4 mA, so the reference leakage current refLkg is not available. Based on the new comparison table newTbl, the new leakage currents newLkg(PT1), newLkg(PT2), newLkg(PT3), newLkg(PT4) are all greater than 4 mA, and the majority leakage current majLkg is not available. Therefore, the original comparison table origTbl and the new comparison table newTbl cannot provide useful information to the evaluation circuit.

FIGS. 20 and 21collectively show that the evaluation circuit is incapable of estimating the leakage current in some cases when the partition configuration having panel-partitions PT1, PT2, PT3, PT4with equal sizes and without coordinate shift is adopted. To reduce the chance of failure, a different partition configuration adapting coordinate shift is shown inFIG. 21.

FIG. 21is a schematic diagram illustrating that ranges of the four panel-partitions are shifted when an alternative partition configuration is adapted. Four panel-partitions PT1, PT2′, PT3′, PT4′ are defined on the display panel. The panel-partition PT4′ further includes two sub-partitions PT4a′, PT4b′. The positions of the breaks BRK1, BRK2, BRK3inFIG. 21are identical to the ones inFIG. 19, but the physical area of the panel-partitions being defined inFIGS. 19 and 21are different.

As the left boundary of the panel-partition PT1′ is not corresponding to the left edge of the display panel, such a partition configuration is defined as the partition configuration with the coordinate shift. Because of the coordinate shift, the break BRK1is now located at the panel-partition PT1′, the break BRK2is now located at the panel-partition PT2′, and the break BRK3is now located at the panel-partition PT3′. In consequence, the original comparison table orgTbl and the new comparison table newTbl inFIG. 22are different from those inFIG. 20.

Please refer toFIGS. 16 and 22together. Based on the original comparison table origTbl, the original leakage currents origLkg(PT1), origLkg(PT2) are both greater than 4 mA, and the reference leakage current refLkg is 2 mA. Moreover, the original leakage current origLkg(PT3) is 4 mA, and the original leakage current origLkg origLkg(PT4) is 2 mA. Based on the new comparison table newTbl, the new leakage currents newLkg(PT1), newLkg(PT2) are both greater than 4 mA. Moreover, the new leakage current newLkg(PT3) is 4 mA, and the new leakage current newLkg origLkg(PT4) is 2 mA. Therefore, the original comparison table origTbl and the new comparison table newTbl cannot be referred for recognizing states of the display panel.

For the panel-partition PT1, the reference leakage refLkg (2 mA) and the new leakage current newLkg(PT1) (>4 mA) are not equivalent. Thus, the determination result of step S317a′ is negative, and the evaluation circuit further compares the new leakage current newLkg(PT1) (>4 mA) with the original leakage current origLkg(PT1) (>4 mA) (step S317c′). The determination result of step S317c′ is positive so that the new leakage current newLkg(PT1) (>4 mA) is further compared with the majority leakage current majLkg(4 mA) (step S317h′). As the majority leakage current majLkg is not available, the determination result of step S317h′ is considered as negative. Therefore, the evaluation circuit determines that the panel-partition PT1is cracked by the external force, while the display panel is not in operation (step S317d′).

For the panel-partition PT2, the reference leakage refLkg (2 mA) and the new leakage current newLkg(PT2) (>4 mA) are not equivalent. Thus, the determination result of step S317a′ is negative, and the evaluation circuit further compares the new leakage current newLkg(PT2) (>4 mA) with the original leakage current origLkg(PT2) (>4 mA) (step S317c′). The determination result of step S317c′ is positive so that the new leakage current newLkg(PT2) (>4 mA) is further compared with the majority leakage current majLkg(4 mA) (step S317h′). As the majority leakage current majLkg is not available, the determination result of step S317h′ is considered as negative. Therefore, the evaluation circuit determines that the panel-partition PT2is cracked by the external force, while the display panel is not in operation (step S317d′).

For the panel-partition PT3, the reference leakage refLkg (3 mA) and the new leakage current newLkg(PT3) (4 mA) are not equivalent. Thus, the determination result of step S317a′ is negative, and the evaluation circuit further compares the new leakage current newLkg(PT3) (4 mA) with the original leakage current orgLkg(PT3) (4 mA) (step S317c′). The determination result of step S317c′ is positive so that the new leakage current newLkg(PT1) (4 mA) is further compared with the majority leakage current majLkg(NA) (step S317h′). As the majority leakage current majLkg is not available, the determination result of step S317h′ is considered as negative. Therefore, the evaluation circuit determines that the panel-partition PT1is cracked by the external force, while the display panel is not in operation (step S317d′).

For the panel-partition PT4, the reference leakage refLkg (2 mA) and the new leakage current newLkg(PT4) (4 mA) are equivalent. Thus, the determination result of step S317a′ is positive, and the evaluation circuit determines that the panel-partition PT4is not cracked (step S317b′).

Please refer toFIGS. 19, 20, 21, and 22together.FIG. 19shows that the evaluation circuit is not able to estimate the leakage current in some extreme cases. However, by changing the partition configuration, the evaluation circuit is still able to recognize the abnormal leakage current. In both the partition configurations shown inFIGS. 19 and 21, the display panels are in divided into 4 panel-partitions. Whereas, the source lines in the panel-partitions inFIG. 19are different from those inFIG. 21. According to the embodiment of the present disclosure, the display panel may be designed to support different partition configurations simultaneously. The partition configurations are then alternatively adapted for estimation during the leakage estimation procedure. Consequentially, the chance of not being able to correctly detect the leakage current can be decreased significantly. InFIG. 21, the display panel supporting two types of partition configurations is shown. For the sake of illustration, each partition configuration is assumed to include only two panel-partitions. The implementation of the partition configurations having a different number of panel-partitions is similar.

FIG. 22is a schematic diagram illustrating the original comparison table origTbl and the new comparison table newTbl corresponding toFIG. 21.

The original comparison table origTbl shows that the original leakage current origLkg(PT1) is greater than 4 mA, the original leakage current origLkg(PT2) is greater than 4 mA, the original leakage current origLkg(PT3) is determined to be 4 mA, and the original leakage current origLkg(PT4) is determined to be 2 mA. Moreover, the reference leakage current refLkg is determined to be 2 mA.

The new comparison table newTbl shows that the new leakage current newLkg(PT1) is greater than 4 mA, the new leakage current newLkg(PT2) is greater than 4 mA, the new leakage current newLkg(PT3) is determined to be 4 mA, and the new leakage current newLkg(PT4) is determined to be 2 mA. Based on the original comparison table origTbl and the new comparison table newTbl, the majority leakage current majLkg is greater than 4 mA.

FIG. 23is a schematic diagram illustrating that some modifications are applied to the source control circuit when the leakage estimation circuit simultaneously supports the leakage estimation function of two partition configurations. For illustration purpose, the display panel63is assumed to include 16 channels, and the source control circuit67includes 16 source drivers67a, which are respectively electrically connected to the source lines S[1]˜S[16].

The boundary lines L1″, L2″, L3″ collectively divide the display panel63into four screen portions SA1-2a, SA1-1, SA2-1, SA2-2b. The screen portion SA1-2ais corresponding to source lines S[1]˜S[4], the screen portion SA1-1is corresponding to source lines S[5]˜S[8], the screen portion SA2-1is corresponding to source lines S[9]˜S[12], and the screen portion SA2-2bis corresponding to source lines S[13]˜S[16].

The display panel63can be defined by two partition configurations PC1, PC2. Each of the partition configurations PC1, PC2is corresponding to dividing the display panel63into two panel-partitions. Each panel-partition in the partition configuration PC1is partially overlapped with each panel-partition in the partition configuration PC2. For the sake of illustrations, the sizes of the panel-partitions are assumed to be equal. However, the sizes of the panel-partitions and the overlapped areas of the panel-partitions in different partition configurations might not be the same.

According to the partition configuration PC1, two panel-partitions PT1, PT2are defined. When the partition configuration PC1is adapted, one of the mode-switches sw1, sw2is turned on. When the mode-switch sw1is turned on, the leakage estimation procedure is performed to the panel-partition PT1. When the mode-switch sw2is turned on, the leakage estimation procedure is performed to the panel-partition PT2.

The panel-partition PT1includes screen portion SA1-2a, SA1-1, and the panel-partition PT2includes screen portions SA-1, SA2-2b. Alternatively speaking, the panel-partition PT1includes source drivers used for providing data voltages to the pixels located at the first column to the eighth column through the source lines S[1]˜S[8], and the panel partition PT2includes source drivers used for providing data voltages to the pixels located at the ninth column to the sixteenth column through the source lines S[9]˜S[16].

According to the partition configuration PC2, another two panel-partitions PT1′, PT2′ are defined. When the partition configuration PC2is adapted, one of the mode-switches sw1′, sw2′ is turned on. When the mode-switch sw1′ is turned on, the leakage estimation procedure is performed to the panel-partition PT1′. When the mode-switch sw2′ is turned on, the leakage estimation procedure is performed to the panel-partition PT2′.

The panel-partition PT1′ includes screen portions SA1-1, SA2-1, and the panel-partition PT2′ includes screen portions SA1-2a, SA2-2b. Alternatively speaking, the panel-partition PT1′ includes source drivers used for providing data voltages to the pixels located at the fifth to the twelfth columns through the source lines S[5]˜S[12], and the panel partition PT2′ includes source drivers used for providing data voltages to pixels located at the first column to the fourth column and the pixels located at the thirteenth column to the sixteenth column through the source lines S[1]˜S[4], S[13]˜S[16].

The screen portion SA1-2ais considered as a part of the panel partition PT1when the partition configuration PC1is adapted, or as a part of the panel partition PT2′ when the partition configuration PC2is adapted. Therefore, two groups of detection-switches671a,672bare provided on the screen portion SA1-2a. The detection-switches671aare used when the partition configuration PC1is adapted because they can selectively connect the source drivers67abelonging to the screen portion SA1-2ato the mode-switch sw1. On the other hand, the detection-switches672bare used when the partition configuration PC2is adapted because they can selectively connect the source drivers67abelonging to the screen portion SA1-2ato the mode-switch sw2′.

The screen portion SA1-1is considered as a part of the panel partition PT1when the partition configuration PC1is adapted, or as part of the panel partition PT1′ when the partition configuration PC2is adapted. Therefore, two groups of detection-switches671a,672aare provided in the screen portion SA1-1. The detection-switches671aare used when the partition configuration PC1is adapted because they can selectively connect the source drivers67abelonging to the screen portion SA1-1to the mode-switch sw1. The detection-switches672aare used when the partition configuration PC2is adapted because they can selectively connect the source drivers67abelonging to the screen portion SA1-1to the mode-switch sw1′.

The screen portion SA2-1is considered as a part of the panel partition PT2when the partition configuration PC1is adapted, or as part of the panel partition PT1′ when the partition configuration PC2is adapted. Therefore, two groups of detection-switches671b,672aare provided in the screen portion SA2-1. The detection-switches671bare used when the partition configuration PC1is adapted because they can selectively connect the source drivers67abelonging to the screen portion SA2-1to the mode-switch sw1. The detection-switches672aare used when the partition configuration PC2is adapted because they can selectively connect the source drivers67abelonging to the screen portion SA2-1to the mode-switch sw1′.

The screen portion SA2-2bis considered as a part of the panel partition PT2when the partition configuration PC1is adapted, or as part of the panel partition PT2′ when the partition configuration PC2is adapted. Therefore, two groups of detection-switches671b,672bare provided on the screen portion SA2-2b. The detection-switches671bare used when the partition configuration PC1is adapted because they can selectively connect the source drivers67abelonging to the screen portion SA2-2bto the mode-switch sw2. The detection-switches672bare used when the partition configuration PC2is adapted because they can selectively connect the source drivers67abelonging to the screen portion SA2-2bto the mode-switch sw2′.

Once the two partition configurations PC1, PC2are provided simultaneously and the panel-partitions defined in both partition configuration PC1, PC2are alternatively detected by the evaluation circuit, the chance of not being able to find the leakage current is extremely low. Details about the layout of the partition configurations PC1, PC2show inFIG. 24are summarized in Table 2.

In the above illustrations, the evaluation circuit recognizes the minimum of testing current values tstC that causes the detected signal Sdet to switch to state “1” as the leakage current i_Lkg. However, the estimated leakage current i_Lkg based on such an approach might be inaccurate in some occasions. The cause of the inaccurate estimation can be, for example, instantaneous signal fluctuation of the detected signal Sdet.

For example, in a case that the actual leakage current i_Lkg is 4 mA, the detected signal Sdet should remain at state “0” while the source current Isrc is set to the testing current values tst1=1 mA, tst2=2 mA, or tst3=3 mA. However, during the leakage estimation procedure, the detected signal Sdet is somehow affected by instantaneous signal fluctuation and transits to state “1” when the testing current value tst1=1 mA.

If the above-mentioned approach is adapted, the leakage current i_Lkg will be recognized as 1 mA, which is incorrect. Actually, the detected signal Sdet might transit to state “0” when the testing current values tst2=2 mA or tst3=3 mA is applied. Therefore, the recognition rule of the leakage current i_Lkg to be detected can be further modified to avoid misjudgment of the leakage current i_Lkg.FIGS. 25A and 25Bare examples showing an alternative way to estimate the leakage current i_Lkg.

The dotted circles c1, c2, c3, c4inFIG. 25Aand the dotted circles c1′, c2′, c3′, c4′ inFIG. 25Bindicate the alternative way to recognize the leakage current i_Lkg. InFIGS. 25A and 25B, the evaluation circuit considers the leakage current i_Lkg to be detected to be equivalent to the second continuous and minimum testing current values which cause the detected signal Sdet to change to state “1”. Alternatively speaking, the evaluation circuit recognizes the leakage current i_Lkg only when the detected signal Sdet has two continuous states “1”. Adoption of such a relatively strict requirement can prevent the evaluation circuit from estimating the leakage current i_Lkg incorrectly.

In the above example, the current setting signal Sset is set by 2 bits, and four different testing current values tstC (1 mA˜4 mA, with a gap of 1 mA) are used. In practical application, the source current Isrc can be set by the current setting signal Sset having more bits. InFIGS. 25A and 25B, an example of the current setting signal Sset having a length of 6-bits is utilized for identifying the leakage current i_Lkg. By adapting the 6-bit current setting signal Sset, 64 different testing current values tstC (1 mA˜32 mA, with a gap of every 0.5 mA) are used.

FIG. 24Ais a schematic diagram illustrating an exemplary original comparison table origTbl representing32that testing current values are utilized in response to the current setting signal Sset having a length of 6-bits four panel-partitions generated. InFIG. 25A, the dotted circle c1shows that the detected signal Sdet switches to state “1” when the source current Isrc is set to any of the testing current values 2.5 mA˜32 mA, and the detected signal Sdet switches to state “0” when the source current Isrc is set to any of the other testing current values 0.5 mA˜2 mA. Although the state of the detected signal Sdet changes from “0” to “1” when the testing current value tstC changes from 2 mA to 2.5 mA, the evaluation circuit does not directly recognize the original leakage current orgLkg(PT1) as 2 mA. Instead, the evaluation circuit identifies the original leakage current orgLkg(PT1) as 3 mA, which is the second testing current value that causes the detected signal Sdet to change to state “1”. Similarly, the dotted circles c2, c3, c4respectively indicate the original leakage currents orgLkg(PT2)=3.5 mA, orgLkg(PT3)=3.5 mA, orgLkg(PT4)=4 mA. Moreover, the reference leakage current refLkg is 3 mA.

FIG. 24Bis a schematic diagram illustrating an exemplary new comparison table newTble representing that 32 testing current values are utilized in response to the current setting signal Sset having a length of 6-bits. The dotted circles c1′, c2′, c3′, c4′ inFIG. 25Bindicate the new leakage currents newLkg(PT1)=3 mA, newLkg(PT2)=6.5 mA, newLkg(PT3)=3.5 mA, newLkg(PT4)=31 mA. As new leakage currents newLkg(PT1), newLkg(PT2), newLkg(PT3), newLkg(PT4) are different the majority leakage current majLkg is not available. Similar to the above illustrations, the detection results shown inFIGS. 24A and 24Bcan be compared based onFIG. 16. Details are omitted to avoid redundancy.

According to the embodiments of the present disclosure, a display device and associated detection method capable of determining whether short circuit occurs at the display panel are provided. If the short circuit exists and the display panel is under the risk of burnt out, the display device can be automatically turned off by the timing controller. Then, the user may send the display panel for repair, so the self-detection and protection mechanism can provide safety. In a case that the short circuit related to the gate line(s), the comparison voltage Vcmp may drop dramatically. In a case that the shortage is related to the source line(s), dropping of the comparison voltage Vcmp is relatively non-obvious. Thus, it is possible to diagnose the cause/occasion of the short circuit.