Test method for short circuit detection performed by liquid crystal display device, and display device including the liquid crystal display device

Abstract

This invention discloses a test method for detecting short circuits performed by a liquid crystal display device, and a display device including the liquid crystal display device. The liquid crystal display device performs the following operations: at a first time point, for a first test mode including at least a portion of multiple modes, a first test is performed to detect whether a data line of the display panel is short-circuited, each of the multiple modes including the resistance value of a feedback resistor included in a short-circuit detection circuit and a reference voltage value of a comparator; in the first test, based on the fact that no short circuit is detected in the first mode of the first test mode, at a second time point different from the first time point, for the first test mode, a second test is performed to detect whether a short circuit is short-circuited in the data line; in the second test, based on the fact that a short circuit is detected in the first mode, a progressive defect is identified, and at least one of the resistance value and the reference voltage value included in each of the multiple modes is different.

Claims

1. A display device for performing a test, wherein the display device includes a liquid crystal display device, the liquid crystal display device performing the following operations: at a first time point, for a first test mode including at least a portion of multiple modes, performing a first test for detecting whether a data line of a display panel is short-circuited, each of the multiple modes including a resistance value of a feedback resistor included in a short-circuit detection circuit and a reference voltage value of a comparator; in the first test, based on the fact that no short circuit was detected in the first mode of the first test mode, at a second time point different from the first time point, for the first test mode, performing a second test for detecting whether the data line is short-circuited; in the second test, based on the fact that a short circuit was detected in the first mode, identifying the presence of a progressive defect, wherein at least one of the resistance values ​​and the reference voltage values ​​included in each of the multiple modes is different from each other.

2. The display device of claim 1, wherein the liquid crystal display device performs the following operations: in the first test, based on the fact that a short circuit is not detected in the first mode of the at least some modes but a short circuit is detected in the second mode, the level of the short circuit current flowing through the feedback resistor is identified, and whether a picture quality defect of the display panel is detected is identified, and based on the fact that the picture quality defect is not detected, the second test is performed.

3. The display device of claim 2, wherein the first mode includes a first resistance value as the resistance value and a first reference voltage value as the reference voltage value, the second mode includes a second resistance value as the resistance value and the first reference voltage value, and the first resistance value is greater than the second resistance value.

4. The display device of claim 1, wherein the resistance value of the feedback resistor is the resistance value of the feedback resistor connected between the input node and the output node of the current-to-voltage converter of the short-circuit detection circuit, and the reference voltage value of the comparator is a reference voltage value applied to at least one of the input terminals of the comparator connected to the output node of the current-to-voltage converter.

5. The display device of claim 1, wherein the first test mode includes only a portion of the plurality of modes, the liquid crystal display device performs the following operations: based on the fact that no short circuit was detected in the first mode in the first test but a short circuit was detected in the second mode, a first threshold of the short circuit current flowing through the feedback resistor is identified; whether a picture quality defect of the display panel is detected is identified; based on the fact that the picture quality defect was not detected, a third mode capable of detecting a threshold greater than the first threshold is identified; using the third test mode including the third mode and the first test mode, a third test for detecting whether the data line is short-circuited is performed at a third time point different from the first time point.

6. The display device of claim 5, wherein the liquid crystal display device performs the following operations: in the third test, based on the detection of a short circuit in the first test mode, the existence of the progressive defect is identified; in the third test, based on the absence of a short circuit in the first test mode and the third mode, for the third test mode or any of the plurality of modes, at a fourth time point different from the third time point, a fourth test for detecting whether the data line is short-circuited is performed.

7. A test method for detecting short circuits, performed by a liquid crystal display device, comprising the following steps: at a first time point, for a first test mode including at least a portion of multiple modes, performing a first test for detecting whether a data line of a display panel is short-circuited, each of the multiple modes including a resistance value of a feedback resistor included in a short-circuit detection circuit and a reference voltage value of a comparator; in the first test, based on the fact that no short circuit was detected in the first mode of the first test mode, at a second time point different from the first time point, for the first test mode, performing a second test for detecting whether the data line is short-circuited; and in the second test, based on the fact that a short circuit was detected in the first mode, identifying the presence of a progressive defect, wherein at least one of the resistance values ​​and the reference voltage values ​​included in each of the multiple modes is different from each other.

8. The method of claim 7, wherein the step of performing the first test comprises the following steps: identifying the level of the short-circuit current flowing through the feedback resistor based on the fact that no short circuit was detected in the first mode of the at least some modes but a short circuit was detected in the second mode; and identifying whether a picture quality defect of the display panel was detected, and performing the second test based on the fact that no picture quality defect was detected.

9. The method of claim 8, wherein the first mode includes a first resistance value as the resistance value and a first reference voltage value as the reference voltage value, the second mode includes a second resistance value as the resistance value and the first reference voltage value, and the first resistance value is greater than the second resistance value.

10. The method of claim 7, wherein the resistance value of the feedback resistor is the resistance value of the feedback resistor connected between the input node and the output node of the current-to-voltage converter of the short-circuit detection circuit, and the reference voltage value of the comparator is a reference voltage value applied to at least one of the input terminals of the comparator connected to the output node of the current-to-voltage converter.

11. The method of claim 7, wherein the first test mode includes only a subset of the plurality of modes, the method further comprising the steps of: identifying a first threshold of the short-circuit current flowing through the feedback resistor based on the fact that no short circuit was detected in the first mode in the first test but a short circuit was detected in the second mode; identifying whether a picture quality defect of the display panel was detected; identifying a third mode capable of detecting a threshold greater than the first threshold based on the fact that the picture quality defect was not detected; and performing a third test for detecting whether the data line is short-circuited at a third time point different from the first time point using the third test mode including the third mode and the first test mode.

12. The method of claim 11, wherein the step of performing the third test includes the following steps: based on the detection of a short circuit in the first test mode, identifying the existence of the progressive defect, the method further includes the following steps: based on the absence of a short circuit in the first test mode and the third mode, for the third test mode or any of the plurality of modes, at a fourth time point different from the third time point, performing a fourth test to detect whether the data line is short-circuited.

13. A short-circuit detection circuit connected to the data lines of a display panel, wherein the short-circuit detection circuit comprises: A current-to-voltage converter connected to a node, a first node, and a second node to which a pre-charge voltage is applied, operates based on data voltages applied to the odd-numbered and even-numbered data lines of the display panel, respectively; a feedback resistor disposed between the first node and the second node to which the data voltage is applied; and a comparator for outputting a comparison between the output voltage of the first node and a reference voltage value, wherein the short-circuit detection circuit is capable of selecting the resistance value of the feedback resistor and the reference voltage value according to a test mode.

14. A display device comprising: The display panel includes multiple odd-numbered data lines and multiple even-numbered data lines, which are alternately arranged; a first short-circuit detection circuit is connected to the multiple odd-numbered data lines. The first and second short-circuit detection circuits are connected to the plurality of even-numbered data lines. The first and second short-circuit detection circuits include: a current-to-voltage converter connected to a node, a first node, and a second node to which a pre-charge voltage is applied, operating based on data voltages applied to the odd-numbered and even-numbered data lines of the display panel; a feedback resistor disposed between the first node and the second node to which the data voltage is applied; and a comparator for outputting a comparison between the output voltage of the first node and a reference voltage value. The first and second short-circuit detection circuits can select the resistance value of the feedback resistor and the reference voltage value according to the test mode.

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