A source line abnormality detection circuit and method based on charge sharing

Abstract

The application discloses a source line abnormality detection circuit and method based on charge sharing. The circuit comprises a source drive array, a display panel, a comparator and a reference module. The application adds a reference capacitor with a capacitance not greater than the parasitic capacitance of the source line, and converts the size of the parasitic capacitance of the source line which is difficult to directly measure into a detection voltage which can be compared with a reference voltage by using the voltage division principle after charge sharing, so that the faults such as disconnection or short circuit with adjacent lines of the source line can be accurately judged. The application realizes online and non-invasive abnormality monitoring of the source line, and can effectively improve the reliability and maintainability of the display chip and the display panel.

Description

Technical Field

[0001] This invention relates to the field of display detection technology, and specifically to a source line anomaly detection circuit and anomaly detection method based on charge sharing. Background Technology

[0002] Source lines are a key component of a display driving system. Source drivers transmit the analog voltage signal corresponding to each pixel to the pixel unit on the display panel via source lines, determining the brightness and color of the corresponding pixel unit, thereby enabling image display.

[0003] However, source wires can malfunction for various reasons, such as physical breaks or poor connections. When this happens, the analog voltage signal cannot be transmitted normally, causing the corresponding pixel unit to not receive the correct signal. This manifests as obvious visual defects on the display panel, such as black lines or color shifts, severely interfering with the integrity of the displayed content. Therefore, source wire malfunctions have a significant impact on the normal use of the display panel and the user experience, necessitating detection measures. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a source line anomaly detection circuit and anomaly detection method based on charge sharing.

[0005] The first aspect of the present invention provides a source line anomaly detection circuit based on charge sharing, including a source driving array, a display panel, a comparator, and a reference module; the source driving array is connected to the display panel via a source line and to the comparator via an auxiliary line; the reference module is disposed on the auxiliary line and located between the source driving array and the comparator;

[0006] The source drive array is used to receive pixel signal input and gating signal input, and determines whether to output the pixel signal to the display panel or comparator based on the gating signal input, and determines whether the source line is abnormal through the comparator.

[0007] Furthermore, the source driver array includes multiple source drivers; each source driver includes a decoder, a source amplifier, and a gating switch; the decoder is used to receive pixel signal input and grayscale voltage input, and its output is connected to the positive input of the source amplifier; the negative input of the source amplifier is connected to its output; the stationary end of the gating switch is connected to the source line, the first moving end is the output of the source amplifier, the second moving end is connected to the auxiliary line, and finally extends to the feedback input of the comparator.

[0008] Furthermore, the gating switch of each source driver in the source driver array is controlled according to the corresponding gating signal input.

[0009] Furthermore, the reference module includes a reference capacitor and a reference switch; the stationary terminal of the reference switch is connected to one end of the reference capacitor, the first moving terminal is connected to the auxiliary line, and the second moving terminal is connected to the signal ground; the other end of the reference capacitor is connected to the signal ground.

[0010] Furthermore, the capacitance of the reference capacitor is not greater than the parasitic capacitance of the source line.

[0011] Furthermore, the feedback input terminal of the comparator is connected to the auxiliary line, the reference input terminal is connected to the reference voltage input, and the output terminal outputs a common voltage; the source line is checked for abnormality by the change of the common voltage under different wiring conditions.

[0012] Another aspect of the present invention discloses a source line anomaly detection method based on charge sharing, applied to the above-mentioned anomaly detection circuit, comprising the following steps:

[0013] Select the target source line;

[0014] Charge the target source line to the first voltage;

[0015] Set the comparator's reference voltage input to half of the first voltage;

[0016] The target source line is short-circuited with the reference capacitor, so that the reference capacitor is charged to the second voltage;

[0017] The comparator compares the relationship between the second voltage and the first voltage to determine whether the target source line is abnormal.

[0018] Furthermore, the control target source line is short-circuited with the reference capacitor, specifically including the following steps:

[0019] Connect the selector switch in the source driver corresponding to the target source line to the auxiliary line;

[0020] The reference switch in the reference module is connected to the auxiliary line.

[0021] Furthermore, before the step of connecting the gating switch in the source driver corresponding to the target source line to the auxiliary line, the following steps are also included:

[0022] The reference switch in the reference module is connected to the signal ground, causing the reference capacitor to discharge to the voltage level of the signal ground.

[0023] Furthermore, the step of comparing the relationship between the second voltage and the first voltage using the comparator to determine whether the target source line is abnormal specifically includes the following steps:

[0024] When the second voltage is greater than half of the first voltage, the target source line is considered to be working normally.

[0025] When the second voltage is not greater than half of the first voltage, the target source line is judged to be in an abnormal state.

[0026] This invention also discloses a computer program product or computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device can read the computer instructions from the computer-readable storage medium and execute the computer instructions, causing the computer device to perform the aforementioned method.

[0027] The embodiments of the present invention have the following beneficial effects: The present invention provides a source line anomaly detection circuit and method based on charge sharing. By adding a reference capacitor with a capacitance no greater than the parasitic capacitance of the source line, and utilizing the voltage division principle after charge sharing, the parasitic capacitance of the source line, which is difficult to measure directly, is converted into a detection voltage that can be compared with a reference voltage. This allows for accurate detection of faults such as open circuits or short circuits with adjacent lines in the source line. The present invention achieves online, non-invasive anomaly monitoring of the source line, effectively improving the reliability and maintainability of display chips and display panels.

[0028] Additional aspects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description or may be learned by practice of the invention. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the source line anomaly detection circuit based on charge sharing according to the present invention;

[0031] Figure 2 This is a schematic flowchart of the source line anomaly detection method based on charge sharing according to the present invention.

[0032] Figure 3 This is a schematic diagram of the voltage change of the source line under normal conditions;

[0033] Figure 4 This is a schematic diagram of voltage changes under abnormal source line conditions. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0035] like Figure 1 As shown, the first embodiment of the present invention provides a source line anomaly detection circuit based on charge sharing, including a source driving array, a display panel, a comparator, and a reference module; the source driving array is connected to the display panel through a source line and to the comparator through an auxiliary line; the reference module is disposed on the auxiliary line and located between the source driving array and the comparator;

[0036] The source drive array is used to receive pixel signal input and gating signal input. Based on the gating signal input, it determines whether to output the pixel signal to the display panel or comparator, and uses the comparator to determine whether the source line is abnormal.

[0037] In this embodiment of the invention, the source driver array is used to select the corresponding grayscale voltage through a decoder based on the input pixel data, and then amplify it by a source amplifier to output an analog voltage signal to the source line. Specifically, the source driver array includes multiple source drivers; each source driver includes a decoder, a source amplifier, and a gating switch; the decoder is used to receive pixel signal input and grayscale voltage input, and its output terminal is connected to the positive input terminal of the source amplifier; the negative input terminal of the source amplifier is connected to the output terminal; each source driver controls the voltage level of one source line, charging the source line to a first voltage level.

[0038] In this embodiment of the invention, a gating switch is provided between the output terminal of each source driver and the source line. The stationary terminal of the gating switch is connected to the source line, the first moving terminal is the output terminal of the source amplifier, and the second moving terminal is connected to an auxiliary line, ultimately extending to the feedback input terminal of the comparator. The gating switch of each source driver in the source driver array is controlled according to the corresponding gating signal input. When the gating switch connects the source amplifier and the source line, the source line normally receives the analog voltage signal from the source driver. Since the source line has parasitic capacitance, the normal operation of the source line can be determined by measuring the level of parasitic capacitance.

[0039] In this embodiment of the invention, the second moving terminal of each source driver selector switch is connected to the same auxiliary line. During source line anomaly detection, only the target source line and the auxiliary line are connected, while other source lines are normally connected to the source driver. This cycle repeats to achieve anomaly detection for all source lines. Since the display panel has a blanking period for pixel display in different areas, the source lines do not need to update their analog voltage within the blanking period time window. Therefore, this invention can, for example, utilize the blanking period time window to perform time-division detection on the corresponding source lines, and can even achieve source line anomaly detection without affecting the operation of the display panel.

[0040] In this embodiment of the invention, the reference module includes a reference capacitor and a reference switch; the stationary terminal of the reference switch is connected to one end of the reference capacitor, the first moving terminal is connected to an auxiliary line, and the second moving terminal is connected to signal ground; the other end of the reference capacitor is connected to signal ground. The feedback input terminal of the comparator is connected to the auxiliary line, the reference input terminal is connected to a reference voltage input, and the output terminal outputs a common voltage; the change in the common voltage under different wiring conditions determines whether the source line is abnormal. Preferably, in this embodiment of the invention, the capacitance value of the reference capacitor is set to be no greater than the parasitic capacitance value of the source line. This setting ensures that under normal circumstances, after short-circuiting the source line, the voltage level of the reference capacitor will be greater than half of the parasitic capacitance voltage level, allowing the determination of whether the source line is abnormal based on the voltage level.

[0041] like Figure 2 As shown, the second embodiment of the present invention discloses a source line anomaly detection method based on charge sharing, applied to the above-mentioned anomaly detection circuit, including the following steps:

[0042] S1. Select the target source pole line;

[0043] S2. Charge the target source line to the first voltage;

[0044] S3. Set the comparator's reference voltage input to half of the first voltage;

[0045] S4. Short-circuit the target source line with the reference capacitor, so that the reference capacitor is charged to the second voltage;

[0046] S5. By comparing the relationship between the second voltage and the first voltage using a comparator, it can be determined whether the target source line is abnormal.

[0047] In this embodiment of the invention, the target source line is first determined by inputting a gating signal, and the gating switch corresponding to the target source line is activated, while other gating switches remain inactive. Preferably, anomaly detection of the target source line can be performed during non-effective display periods such as the horizontal blanking period, while other source lines maintain normal connection with their respective source amplifiers to ensure the continuity of display function.

[0048] After determining the target source line, the target source line is first charged to the first voltage VSOUT level during the normal display process, and half of the first voltage VSOUT is used as the reference voltage input to the reference input terminal of the comparator.

[0049] After charging the target source line to a first voltage level, the target source line is short-circuited with the reference capacitor, causing the reference capacitor to be charged to a second voltage. Specifically, short-circuiting the target source line with the reference capacitor includes the following steps:

[0050] S2-1. Connect the gating switch in the source driver corresponding to the target source line to the auxiliary line;

[0051] S2-2. The reference switch in the control reference module is connected to the auxiliary line.

[0052] In this embodiment of the invention, before connecting the gating switch in the source driver corresponding to the target source line to the auxiliary line, the reference switch in the reference module is first connected to signal ground, causing the reference capacitor to discharge to the voltage level of signal ground. Then, the gating switch is changed from connecting point A to connecting point B. At this time, the source amplifier is disconnected, and the source line is connected to the VOUT detection node. Simultaneously, the reference switch is also changed from connecting point B to connecting point A, causing the other end of the reference capacitor to also connect to the VOUT detection node. This results in charge sharing between the parasitic capacitance of the source line and the reference capacitor, charging the reference capacitor to the second voltage VOUT level.

[0053] VOUT = VSOUT × Cp / (Cp + Cref);

[0054] In the formula, Cp represents the parasitic capacitance of the target source line, and Cref represents the reference capacitance.

[0055] Since the capacitance of the reference capacitor is not greater than the parasitic capacitance of the target source line, under normal source line conditions, the second voltage VOUT after short circuit should be greater than half of VSOUT. However, if the second voltage VOUT is not greater than half of VSOUT, the target source line may have a broken wire or a short circuit with an adjacent line, requiring repair.

[0056] Figure 3 , Figure 4 The voltage changes during target source line anomaly detection are presented under normal and abnormal conditions, respectively. Since this embodiment of the invention sets half of VSOUT as the reference voltage input, the level of the comparator output can be used to determine whether the target source line is abnormal. A high level output from the comparator indicates that the target source line is normal, while a low level output indicates that the target source line is abnormal.

[0057] In summary, this invention, by adding a reference capacitor smaller than the parasitic capacitance of the line and utilizing the voltage division principle after charge sharing, converts the difficult-to-measure parasitic capacitance into a detection voltage that can be compared with a reference voltage. This allows for accurate detection of faults such as open circuits or short circuits with adjacent lines in the source line. This invention achieves online, non-invasive health monitoring of the source lines from the outside of the DDIC chip all the way to the pixel electrodes, greatly improving the reliability and maintainability of the display system. Furthermore, this detection function is completed during the idle period of the existing driving timing, adding almost no extra cost or power consumption.

[0058] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0059] Furthermore, the terms "first," "second," etc., used in the embodiments of this invention are for descriptive purposes only and should not be construed as indicating or implying relative importance, or implicitly specifying the number of technical features indicated in this embodiment. Therefore, features defined with terms such as "first" and "second" in the embodiments of this invention can explicitly or implicitly indicate that the embodiment includes at least one of those features. In the description of this invention, the word "multiple" means at least two or more, such as two, three, four, etc., unless otherwise explicitly specified in the embodiments.

[0060] In embodiments of the present invention, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, components, features, and elements with the same names in different embodiments of the present invention may have the same meaning or different meanings, the specific meaning of which must be determined by its interpretation in that specific embodiment or further in conjunction with the context of that specific embodiment.

[0061] Although embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention. Other embodiments of the present invention will readily conceive of by considering the specification and practicing the invention. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

Claims

1. A source line anomaly detection circuit based on charge sharing, characterized in that, It includes a source driver array, a display panel, a comparator, and a reference module; the source driver array is connected to the display panel via a source line and to the comparator via an auxiliary line; the reference module is disposed on the auxiliary line and located between the source driver array and the comparator; The source drive array is used to receive pixel signal input and gating signal input, and determines whether to output the pixel signal to the display panel or comparator according to the gating signal input, and determines whether the source line is abnormal through the comparator. The reference module includes a reference capacitor and a reference switch; the stationary terminal of the reference switch is connected to one end of the reference capacitor, the first moving terminal is connected to the auxiliary line, and the second moving terminal is connected to the signal ground. The other end of the reference capacitor is connected to signal ground; The capacitance of the reference capacitor is less than the parasitic capacitance of the source line. The reference voltage input of the comparator is half of the first voltage, which is the voltage after the target source line is charged. The target source line is the source line determined by the gating signal; The comparator's feedback input is connected to the auxiliary line, its reference input is connected to the reference voltage input, and its output is a common voltage. The source line is checked for abnormality by the change of the common voltage under different wiring conditions.

2. The source line anomaly detection circuit based on charge sharing according to claim 1, characterized in that, The source driver array includes multiple source drivers; each source driver includes a decoder, a source amplifier, and a gating switch; the decoder is used to receive pixel signal input and grayscale voltage input, and the output of the decoder is connected to the positive input of the source amplifier; the negative input of the source amplifier is connected to the output of the source amplifier; the stationary terminal of the gating switch is connected to the source line, the first moving terminal is the output of the source amplifier, the second moving terminal is connected to the auxiliary line, and finally extends to the feedback input of the comparator.

3. The source line anomaly detection circuit based on charge sharing according to claim 2, characterized in that, The gating switch of each source driver in the source driver array is controlled according to the corresponding gating signal input.

4. A source line anomaly detection method based on charge sharing, applied to the anomaly detection circuit as described in any one of claims 1-3, characterized in that, Includes the following steps: Select the target source line; Charge the target source line to the first voltage; Set the comparator's reference voltage input to half of the first voltage; The target source line is short-circuited with the reference capacitor, so that the reference capacitor is charged to the second voltage; The comparator compares the relationship between the second voltage and the first voltage to determine whether the target source line is abnormal.

5. The source line anomaly detection method based on charge sharing according to claim 4, characterized in that, The control of short-circuiting the source line of the target electrode with the reference capacitor specifically includes the following steps: Connect the gating switch in the source driver corresponding to the target source line to the auxiliary line; The reference switch in the reference module is connected to the auxiliary line.

6. The source line anomaly detection method based on charge sharing according to claim 5, characterized in that, Before the step of connecting the gating switch in the source driver corresponding to the target source line to the auxiliary line, the following steps are also included: The reference switch in the reference module is connected to the signal ground, causing the reference capacitor to discharge to the voltage level of the signal ground.

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