Patent Application
20240221553
The present application claims priority to Korean Patent Application No. 10-2022-0187619, filed on Dec. 28, 2022 in the Republic of Korea, the entire contents of which is hereby expressly incorporated by reference into the present application.
The present invention relates to a display device and a driving method thereof.
Recently, display devices utilizing self-illuminating organic light-emitting diodes (OLEDs) have gained attention due to their advantages such as fast response time, high luminous efficiency, brightness, and wide viewing angles.
These display devices include sub-pixels composed of organic light-emitting diodes (OLEDs) and driving transistors, which are arranged in a matrix format on the display panel and control the brightness of sub-pixels selected through scan signals based on the gradation of the data.
These display devices have various signal lines and signal transmission structures to facilitate their operation.
When defects such as open or short circuits in the signal lines, as well as issues with the connection and bonding of the signal transmission structures, occur, these display devices can experience a panel burnt phenomenon, which can cause abnormal operation and damage to the display panel.
Therefore, there is a strong need to proactively detect any defects that lead to the panel burnt phenomenon before the occurrence of the panel burnt phenomenon.
In addition, there is a need to accurately identify and efficiently manage the detected defects that can cause the panel burnt phenomenon. Through such management, immediate and appropriate measures can be taken in response to the occurrence of defects.
Embodiments of the present invention provide display devices and driving methods thereof that are capable of preventing a panel burnt phenomenon by efficiently managing any detected defects after the defect has been detected.
Embodiments of the present invention provide display devices and driving methods thereof that are capable of efficiently managing defects by determining the cause (e.g., type) of defects, generating defect signals based on the cause of the defect, and storing the defect signals in a defect management unit.
Embodiments of the present invention provide display devices and driving methods thereof that are capable of allowing for users to easily identify the occurrence timing and the cause of defects.
A display device according to an embodiment of the present invention can include a display panel on which a plurality of sub-pixels are arranged, a data driver configured to apply data voltage to the plurality of sub-pixels, a gate driver configured to apply a gate signal to the plurality of sub-pixels, a power controller configured to detect a defect of the display panel and generate and output a defect signal with a waveform different depending on the type of the detected defect, and a timing controller configured to store information on the defect signal in a memory.
The power controller can generate the defect signal to have different pulse counts depending on the type of defect.
The information on the defect signal can include at least one of the pulse counts, the occurrence timing of the defect signal, and the type of the defect.
The timing controller can identify the type of defect based on the pulse count.
The power controller can detect the defect based on at least one of a sensing value for the display panel, a current value measured in correspondence to a voltage value of the gate signal, shutdown information generated by the power controller, and an internal burnt detection signal input to the power controller.
The power controller can include a detect detection unit configured to detect the defect and output a burnt detection signal different depending on the type of the detected defect and a defect signal generation unit configured to output the defect signal corresponding to the burnt detection signal.
The timing controller can include the memory comprising a non-volatile storage medium and a defect management unit configured to storing the information on the defect signal in the memory.
The power controller can output the defect signal to the timing controller and an external host system.
A driving method of a display device according to an embodiment of the present invention drives the display device including a display panel on which a plurality of sub-pixels are arranged, a data driver applying data voltage to the plurality of sub-pixels, a gate driver applying a gate signal to the plurality of sub-pixels, a power controller applying a driving voltage to the display panel, and a timing controller controlling operations of the data driver and the gate driver.
The method can include detecting, by the power controller, a defect of the display panel, outputting, by the power controller, a defect signal having a waveform different depending on the type of the detected defect, and storing, by the timing controller, information on the defect signal in the memory.
The defect signal can be generated to have different pulse counts depending on the type of the defect.
The information on the defect signal can include at least one of the pulse count, occurrence timing of the defect signal, and type of the defect.
The method can further include identifying, by the timing controller, the type of the defect based on the pulse count.
The detecting of the defect can include detecting the defect based on at least one of a sensing value for the display panel, a current value measured in correspondence to a voltage value of the gate signal, shutdown information generated by the power controller, and an internal burnt detection signal input to the power controller.
The method can further include outputting, by the power controller, the defect signal to an external host system.
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention.
Hereinafter, embodiments of the present invention will be described with reference to accompanying drawings. In the specification, when a component (or area, layer, part, etc.) is mentioned as being “on top of,” “connected to,” or “coupled to” another component, it means that it can be directly connected/coupled to the other component, or one or more third components can be placed between them.
The same reference numerals refer to the same components. In addition, in the drawings, the thickness, proportions, and dimensions of the components are exaggerated for effective description of the technical content. The expression “and/of” is taken to include one or more combinations that can be defined by associated components.
The terms “first,” “second,” etc., are used to describe various components, but the components should not be limited by these terms. The terms are used solely for the purpose of distinguishing one component from another component, and may not define any order or sequence. For example, a first component can be referred to as a second component and, similarly, the second component can be referred to as the first component, without departing from the scope of the present invention. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise.
The terms such as “below,” “lower,” “above,” “upper,” etc., are used to describe the relationship of components depicted in the drawings. The terms are relative concepts and are described based on the direction indicated on the drawing.
It will be further understood that the terms “comprises,” “has,” “includes,” and the like are intended to specify the presence of stated features, numbers, steps, operations, components, parts, or a combination thereof but are not intended to preclude the presence or possibility of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.
Further, all components of each display device according to all embodiments of the present invention are operatively coupled and configured.
With reference to
The timing controller 140 supplies various control signals to the data driver 120 and gate driver 130 to control the data driver 120 and gate driver 130.
The timing controller 140 determines the timing for initiating scanning in each frame, converts the input video data received from external sources into the data signal format used by the data driver 120, outputs the converted video data, and controls the data driving at appropriate times synchronized with the scanning process.
The data driver 120 drives the plurality of data lines DL1 to DLm by supplying data voltages to the plurality of data lines DL1 to DLm. The data driver 120 is also referred to as the “source driver.”
The gate driver 130 sequentially supplies scanning signals to the plurality of gate lines GL1 to GLn, thereby sequentially driving the gate lines. The gate driver 130 is also known as the “scan driver.”
Under the control of the timing controller 140, the gate driver 130 supplies scanning signals of on or off voltages to the plurality of gate lines GL1 to GLn in a sequential manner.
When a specific gate line is turned on by the gate driver 130, the data driver 120 converts the received video data, which is in digital form, into analog data voltages and supplies the analog data voltages to the plurality of data lines DL1 to DLm.
Although the data driver 120 is located only on one side (e.g., top or bottom) of the display panel 110 in
Although the gate driver 130 is located on one side (e.g., left or right) of the display panel 110 in
The timing controller 140 receives various timing signals including vertical sync signals, horizontal sync signals, input data enable signals, and clock signals, along with the input video data from an external source (e.g., host system).
To control the data driver 120 and gate driver 130, the timing controller 140 generates various control signals based on the timing signals such as vertical sync signals, horizontal sync signals, input data enable (DE) signals, and clock signals, and outputs the generated signals to the data driver 120 and gate driver 130.
For example, the timing controller 140 outputs various gate control signals GCS including a gate start pulse signal, a gate shift clock signal, and a gate output enable signal to control the gate driver 130.
The timing controller 140 also outputs various data control signals DCS including a source start pulse signal, a source sampling clock signal, and a source output enable signal to control the data driver 120.
With reference to
Each source driver integrated circuit SDIC can be connected to the bonding pads of the display panel 110 using tape-automated-bonding (TAB) or chip-on-glass (COG) techniques or directly placed on the display panel 110 or, in some cases, integrated within the display panel 110, depending on the specific configuration. Further, each source driver integrated circuit SDIC can be implemented using a chip-on-film (COF) method, which is mounted on a source-side film FS connected to the display panel 110, as shown in
Each source driver integrated circuit SDIC can include components such as a shift register, a latch circuit, a digital-to-analog converter (DAC), and an output buffer.
Each source driver integrated circuit SDIC may, in some cases, include an analog-to-digital converter ADC.
The gate driver 130 can include at least one gate driver integrated circuit GDIC to drive the plurality of gate lines GL1 to GLn. Each gate driver integrated circuit GDIC can be connected to the bonding pad of the display panel 110 using tape-automated bonding (TAB) or chip-on-glass (COG) techniques or directly placed on the display panel 110 by being implemented as a gate-in-panel (GIP) type or, in some cases, integrated within the display panel 110. Furthermore, each gate driver integrated circuit GDIC can be implemented using a chip-on-film (COF) method, where it is mounted on a gate-side film FG connected to the display panel 110, as shown in
In an embodiment of the present invention, the display device 100 can include at least one source printed circuit board S-PCB for the circuit connection of at least one source driver integrated circuit SDIC, and a control printed circuit board C-PCB for mounting control components and various electrical devices. The at least one source printed circuit board S-PCB can accommodate at least one source driver integrated circuit SDIC or can be connected to the source-side film(s) FS where at least one source driver integrated circuit SDIC is mounted.
The control printed circuit board C-PCB can include the timing controller 140 for controlling the operation of the data driver 120 and gate driver 130, and a power controller for supplying various voltages or currents to the display panel 110, data driver 120, and gate driver 130 or controlling the supply of various voltages or currents. The at least one source printed circuit board S-PCB and the control printed circuit board C-PCB can be electrically connected to each other through at least one flexible flat cable FFC1.
The display device 100 can also include a main printed circuit board M-PCB for accommodating a main controller M-CON and other components in addition to the at least one source printed circuit board S-PCB and the control printed circuit board C-PCB. The main printed circuit board M-PCB can be connected to the control printed circuit board C-PCB through at least one flexible flat cable FFC2. The at least one of the source printed circuit board S-PCB, the control printed circuit board C-PCB and the main printed circuit board M-PCB can be integrated into a single printed circuit board.
Each sub-pixel SP arranged on the display panel 110 can be composed of circuit components such as transistors. For example, each sub-pixel SP can include an organic light-emitting diode OLED and a driving transistor to operate the organic light-emitting diode OLED. The types, configurations and quantities of circuit components constituting each sub-pixel SP can vary depending on the desired functions and design approach.
With reference to
The organic light-emitting diode OLED can include a first electrode (e.g., anode electrode), an organic layer, and a second electrode (e.g., cathode electrode), but can have other configurations.
The driving transistor DRT drives the organic light-emitting diode OLED by supplying driving current to the organic light-emitting diode OLED. The second node N1 of the driving transistor DRT can be electrically connected to the first electrode of the organic light-emitting diode OLED and can be the source node or the drain node. The second node N2 is electrically connected to the source node or the drain node of the switching transistor SWT and can be the gate node. The third node N3 can be electrically connected to a driving voltage line DVL for supplying a high-potential driving voltage EVDD and can be the drain node or the source node.
The first transistor SWT is electrically connected between the corresponding data line DL and the second node N2 of the driving transistor DRT and is controlled by a scan signal SCAN received through the corresponding gate line and applied at the gate node thereof. The first transistor SWT is turned on by the scan signal SCAN and can transmit the data voltage Vdata supplied through the data line DL to the second node N2 of the driving transistor DRT.
The storage capacitor Cst can be electrically connected between a first node N1 and the second node N2 of the driving transistor DRT. The storage capacitor Cstg can be an external capacitor intentionally designed outside the driving transistor DRT rather than an internal capacitor such as parasitic capacitors (e.g., Cgs and Cgd) existing between the first node N1 and the second node N2 of the driving transistor DRT.
Meanwhile, in the display device 100 according to an embodiment of the present invention, as the driving time of each sub-pixel SP increases, there may be a degradation of circuit components such as the organic light-emitting diodes OLED and driving transistor DRT. As a result, the intrinsic characteristic values of the circuit components can change. These characteristic values can include the threshold voltage and mobility of the driving transistor DRT and the threshold voltage of the organic light-emitting diode OLED. Such changes in the characteristic values of the circuit components can lead to variations in the luminance of the corresponding sub-pixels, which can cause a decrease in the uniformity of brightness in the display panel 110 and a deterioration of image quality.
To address this issue, the display device 100 according to an embodiment of the present invention can provide sensing functionality to sense the characteristic values or changes in the characteristic values of the circuit components and compensation functionality to compensate for the characteristic value deviations between circuit components based on the sensing results. This configuration will now be discussed referring to
With reference to
The sensing transistor SENT can be electrically connected between the first node N1 of the driving transistor DRT and a reference voltage line RVL supplying a reference voltage Vref and can be controlled by a sensing signal SENSE as a type of scan signal applied to the gate node thereof. The sensing transistor SENT turns on in response to the sensing signal SENSE and applies the reference voltage Vref supplied through the readout line (reference voltage line) RVL to the first node N1 of the driving transistor DRT. The sensing transistor SENT can also serve as one of the voltage sensing paths for the first node N1 of the driving transistor DRT.
In an embodiment of the present invention, the scan signal SCAN and the sensing signal SENSE can be separate gate signals. In this case, the scan signal SCAN and the sensing signal SENSE can be applied to the gate nodes of the switching transistor SWT and the sensing transistor SENT, respectively, through different gate lines. In another embodiment of the present invention, the scan signal SCAN and the sensing signal SENSE can be the same gate signal. In this case, the scan signal SCAN and the sensing signal SENSE can be commonly applied to the gate nodes of both the switching transistor SWT and the sensing transistor SENT through the same gate line.
The driving transistor DRT, the switching transistor SWT, and the sensing transistor SENT can each be implemented as an n-type or p-type transistor.
With reference to
The sensing unit 310 can be configured to include at least one analog-to-digital converter (ADC). The at least one analog-to-digital converter (ADC) can be included within the source driver integrated circuit SDIC or positioned outside the source driver integrated circuit SDIC, depending on the case or configuration. The sensing data output from the sensing unit 310 can have a low voltage differential signaling (LVDS) data format as an example.
The compensation unit 330 can be included internally or externally to the timing controller 140 depending on the case or configuration.
In an embodiment of the present invention, the display device 100 (e.g., the SDIC) can include a first switch SW1 that controls the supply of the reference voltage Vref to the reference voltage line RVL for controlling the sensing operation, and a second switch SW2 that switches the connection between the reference voltage line RVL and the sensing unit 310.
When the first switch SW1 is turned on, the reference voltage Vref is supplied to the reference voltage line RVL. The reference voltage Vref supplied to the reference voltage line RVL can be applied to the first node N1 of the driving transistor DRT through the turned-on sensing transistor SENT.
Furthermore, when the voltage at the first node N1 of the driving transistor DRT reaches a voltage state reflecting the sub-pixel characteristics, the voltage on the reference voltage line RVL can also be in a voltage state reflecting the sub-pixel characteristics. In this case, the voltage reflecting the sub-pixel characteristics can be charged to the line capacitor formed on the reference voltage line RVL. In other words, when the sensing transistor SENT is turned on, the voltage at the first node N1 of the driving transistor DRT can be the same as the voltage charged to the line capacitor formed on the reference voltage line RVL.
When the voltage at the first node N1 of the driving transistor DRT reaches a voltage state reflecting the sub-pixel characteristics, the second switch SW2 can be turned on, allowing the sensing unit 310 to be connected to the reference voltage line RVL. Accordingly, the sensing unit 310 can sense the voltage of the reference voltage line RVL in the voltage state reflecting the sub-pixel characteristics. In the regard, the reference voltage line RVL is also referred to as a “sensing line.” That is, the sensing unit 310 senses the voltage at the first node N1 of the driving transistor DRT.
This reference voltage line RVL, for example, can be per sub-pixel column or per two or more sub-pixel columns. For instance, in the case where one pixel is composed of four sub-pixels (e.g., red sub-pixel, white sub-pixel, green sub-pixel, blue sub-pixel), the reference voltage line RVL can be arranged with one line per pixel column containing four sub-pixel columns (e.g., red sub-pixel column, white sub-pixel column, green sub-pixel column, blue sub-pixel column).
In the case of sensing the threshold voltage of the driving transistor DRT, the voltage sensed by the sensing unit 310 can be a voltage value (Vdata-Vth or Vdata-ΔVth) including the threshold voltage (Vth) or threshold voltage variation (ΔVth) of the driving transistor DRT. Meanwhile, in the case of sensing the mobility of the driving transistor DRT, the voltage sensed by the sensing unit 310 can be a voltage value representing the mobility of the driving transistor DRT.
Hereinafter, descriptions are briefly made of the threshold voltage sensing operation and mobility sensing operation for the driving transistor DRT (e.g., of
In this regard,
Referring to
The voltage at the first node N1 of the driving transistor DRT increases until it saturates, gradually reducing the magnitude of the voltage increase. The saturated voltage at the first node N1 of the driving transistor DRT can correspond to the difference between the data voltage Vdata and the threshold voltage Vth or the difference between the data voltage Vdata and the threshold voltage variation ΔVth.
Once the voltage at the first node N1 of the driving transistor DRT saturates, the saturated voltage is sensed by the sensing unit 310.
The sensed voltage Vsen by the sensing unit 310 can be the voltage obtained by subtracting the threshold voltage Vth from the data voltage Vdata (Vdata-Vth) or the voltage obtained by subtracting the threshold voltage variation ΔVth from the data voltage Vdata (Vdata-ΔVth).
Referring to
Subsequently, the first switch SW1 is turned off, causing the first node N1 of the driving transistor DRT to float. In this case, the switching transistor SWT can be turned off, allowing the second node N2 of the driving transistor DRT to also float. As a result, the voltage at the first node N1 of the driving transistor DRT begins to rise. The rate of voltage rises during a specific period of time at the first node N1 of the driving transistor DRT, which is indicated by the voltage rise magnitude ΔV, depends on current-carrying capacity, i.e., mobility, of the driving transistor DRT. For example, a driving transistor DRT with higher current-carrying capacity (mobility) will exhibit a steeper voltage rise at the first node N1, resulting in a larger voltage rise magnitude ΔV during the specified time period.
After the voltage at the first node N1 of the driving transistor DRT has risen for the predetermined time duration, the sensing unit 310 senses the elevated voltage at the first node N1 (i.e., the voltage on the reference voltage line RVL increased along with the voltage rise at the first node N1 of the driving transistor DRT).
Based on the threshold voltage and/or mobility sensing operation as described above, the sensing unit 310 converts the sensed voltage Vsen into a digital value and generates and outputs sensing data including the converted digital value (sensing value). The sensing data outputted from the sensing unit 310 can be stored in the memory 320 or provided to the compensation unit 330.
The compensation unit 330 can determine the characteristic values (e.g., threshold voltage and mobility) of the driving transistor DRT within the corresponding sub-pixel or changes in the characteristic values based on the sensing data stored in the memory 320 or provided by the sensing unit 310 and perform a characteristic value compensation process.
Here, the changes in the characteristic values of the driving transistor DRT can refer to the change in the current sensing data compared to the previous sensing data, or the change in the current sensing data compared to the reference compensation data.
By comparing the characteristic values or changes in the characteristic values between driving transistors DRT, the compensation unit 330 can determine the deviations in characteristic values among the driving transistors DRT. When the changes in characteristic values of the driving transistor DRT refer to the change in the current sensing data compared to the reference sensing data, it is possible to determine the deviations in characteristic values (i.e., sub-pixel luminance deviations) among the driving transistors DRT based on the changes in the characteristic values of the driving transistors DRT.
The characteristic value compensation process can include a threshold voltage compensation process for compensating the threshold voltage of the driving transistor DRT and a mobility compensation process for compensating the mobility of the driving transistor DRT.
The threshold voltage compensation process involves calculating compensation values for the threshold voltage or threshold voltage deviation (threshold voltage variation) and storing the calculated compensation values in the memory 320 or modifying the corresponding video data Data using the computed compensation values.
The mobility compensation process involves calculating compensation values for the mobility or threshold mobility deviation (mobility variation) and storing the calculated compensation values in the memory 320 or modifying the corresponding video data Data using the computed compensation values.
The compensation unit 330 can modify the video data Data through the threshold voltage compensation or mobility compensation and supply the modified data to the corresponding source driver integrated circuit SDIC within the data driver 120. Consequently, the source driver integrated circuit SDIC converts the data modified by the compensation unit 330 into a data voltage via a digital-to-analog converter (DAC) 340 and supplies the data voltage to the corresponding sub-pixel, allowing for actual compensation of sub-pixel characteristic values (e.g., threshold voltage compensation and/or mobility compensation). The sub-pixel characteristic value compensation helps reduce or prevent luminance deviations among the sub-pixels, leading to an improvement in the uniformity of luminance across the display panel 110 and the overall image quality.
With reference to
Meanwhile, the display device 100 according to an embodiment of the present invention can perform sensing of the characteristic values of circuit components within each sub-pixel upon detection of a power-on signal but before the display driving begins. This sensing process that occurs after the power-on signal is generated before the display driving can be called “on-sensing.”
Furthermore, the display device 100 according to an embodiment of the present invention can perform sensing of the characteristic values of circuit components within each sub-pixel during the display driving (e.g., when the display panel is driven to display images). This sensing process that occurs during the display driving is referred to as “real-time sensing” or “RT sensing.” The real-time sensing takes place at each blank time between active times, which is determined by the vertical sync signal.
Meanwhile, when one or more of the signal lines (DL, RVL, GL, and DVL) arranged on the display panel 110 are open or when two or more signal lines are shorted, the sensing values can be obtained abnormally. Accordingly, when the difference between the sensing values obtained through the sensing process described above and the reference sensing values (sensing value obtained when the signal lines are in a normal state) exceeds a predetermined range, it is possible to determine that there is a defect on the signal lines.
According to this embodiment of the present invention, the display device 100 includes interfaces such as an enhanced parallel interface (EPI) and low-voltage differential signaling LVDS interface between the timing controller 140 and the six source driver integrated circuits SDIC1 to SDIC6 to facilitate the transmission of signals such as video data, sensing data, and various control signals.
With reference to
The first source driver integrated circuit SDIC1 can transmit one of a high-level interface signal indicative of its normality and a low-level interface signal indicative of its abnormality to the next SDIC2.
When receiving a low-level interface signal from the first source driver integrated circuit SDIC1, the second source driver integrated circuit SDIC2 can forward the low-level interface signal to the third source driver integrated circuit SDIC3, regardless of its own state. On the other hand, when receiving a high-level interface signal from the first source driver integrated circuit SDIC1, the second source driver integrated circuit SDIC2 can transmit one of a high-level interface signal indicative of its own normality and a low-level interface signal indicative of its own abnormality to the third source driver integrated circuit SDIC3. For instance, when the high-level interface signal (normal state) is received from the first source driver integrated circuit SDIC1, the second source driver integrated circuit SDIC2 does not forward the received high-level interface signal, but generates its own high-level interface signal or low-level interface signal indicating the normal/abnormal state of the second source driver integrated circuit SDIC2 and transmits that signal to the third source driver integrated circuit SDIC3. This process is continued in the subsequent source driver integrated circuits SDIC3, SDIC4, SDIC5, etc.
According to the above-described interface transmission method, when all six source driver integrated circuits SDIC1 to SDIC6 are in a normal state, the outermost sixth source driver integrated circuit SDIC6 on the other side can output a high-level interface signal to the timing controller 140. If the high-level interface signal from the sixth source driver integrated circuit SDIC6 is received, the timing controller 140 recognizes it to mean that all six source driver integrated circuits SDIC1 to SDIC6 are in normal states and are capable of performing data driving properly.
According to the above-described interface transmission method, when any of the six source driver integrated circuits SDIC1 to SDIC6 is in an abnormal state, the outermost sixth source driver integrated circuit SDIC6 on the other side can output a low-level interface signal to the timing controller 140. When such a signal is received, the timing controller 140 recognizes it to mean that at least one of the six source driver integrated circuits SDIC1 to SDIC6 is in an abnormal state and is unable to perform data driving properly. As a variation, when one of the five source driver integrated circuits SDIC1 to SDIC5 is in an abnormal state and generates a low-level interface signal, then the next one among the six source driver integrated circuits SDIC1 to SDIC6 can stop its own normal/abnormal checking and can merely pass the received low-level interface signal to the next source driver integrated circuit and so on, so that at the end, the sixth source driver integrated circuit SDIC6 basically forwards the received low-level interface signal to the timing controller 140.
Furthermore, the timing controller 140 can receive a low-level interface signal from the sixth source driver integrated circuit SDIC6, not only when at least one of the six source driver integrated circuits SDIC1 to SDIC6 is in an abnormal state but also when the connectivity of the flexible flat cable FFC1 between the source printed circuit board S-PCB and the control printed circuit board C-PCB is faulty or has an issue.
In the present specification, the interface signal (e.g., high-level or low-level interface signal discussed above) can be, for example, a lock signal.
With reference to
Each of the five gate integrated circuits, GDIC1 to GDIC5 generates and outputs gate signals SCAN and SENSE based on the received gate voltages VGH and VGL. However, when there is an abnormality in the gate voltages VGH and VGL, each of the five gate integrated circuits GDIC1 to GDIC5 may not be able to perform normal gate driving.
Therefore, in an embodiment of the present invention, the display device 100 can determine the presence of abnormalities in the gate voltages VGH and VGL that are entering the display panel 110. For example, the display device 100 according to an embodiment of the present invention can utilize circuits such as comparators to sense the current corresponding to the gate voltages VGH and VGL when they actually enter the display panel 110 and compare the sensed current with a reference current corresponding to the normal current, in order to determine whether or not the current corresponding to the gate voltages VGH and VGL that are actually entering the display panel 110 is abnormal (e.g., overcurrent).
When it is detected that the current corresponding to the gate voltages VGH and VGL is determined to be abnormal, it can mean a presence of a defect in at least one of the gate voltage lines on the display panel 110, the gate-side film FG, the source-side film FS, the source printed circuit board S-PCB, the flexible flat cable FFC1, or the control printed circuit board C-PCB.
With reference to
In the presence of such defects, the display panel 110 can experience a panel burnt phenomenon and may not function properly. Moreover, the display device 100 can malfunction and, in very extreme cases, can even lead to fire incidents.
Therefore, it is needed to proactively detect and manage the defects that lead to the panel burnt phenomenon, so that the panel burnt phenomenon does not occur. Moreover, efficient management of potential defects that could result in a panel burnt phenomenon is also needed. This facilitates prompt and suitable response measures in the event of such a defect occurrence.
The display device 100 according to an embodiment of the present invention can incorporate a method for managing defects efficiently by generating, upon detection of a defect, a burnt detection and protection signal BDP corresponding to the type (e.g., cause) of the defect.
Hereinafter, a method and system for preventing a panel burnt phenomenon according to one or more embodiments of the present invention is described in detail.
Particularly,
With reference to
The defect detection unit 1110 detects defects in the display device 100. For example, the defect detection unit 1110 can detect defects in the signal lines inside or outside the display panel 110 or defects related to the malfunction of the display panel 110. Furthermore, the defect detection unit 1110 generates and outputs burnt detection and protection signals BDPs corresponding to the type of detected defects. In an embodiment of the present invention, the defect detection unit 1110 can output the BDP signal to an external host system (e.g., an external device communicating with the display device or the power controller 900), e.g., wirelessly.
Specifically, the defect signal generation unit 1120 generates and transmits defect signals DS with different signal waveforms corresponding to the detected defects (e.g., types of defects). Here, the different signal waveforms can be, for example, waveforms with varying pulse counts (e.g., rising edge count, high/low-level interval count, etc.).
The defect management unit 1130 can store and manage information related to the defect signals DS. The information on the defect signal DS can include the occurrence time of each defect signal DS (e.g., indicative of when a defect is generated or detected) and the waveform of each defect signal DS (e.g., indicative of a specific type of defect). In an embodiment of the present invention, the defect management unit 1130 receives the defect signal DS, analyzes the waveform of the received defect signal DS to determine or recognize the type of defect, and stores the determined result in the memory 1140 for management. The memory 1140 can be a non-volatile storage medium that retains data even when the power of the display device is turned off, and it can be implemented as, e.g., a negative and direct (NAND) memory. However, the memory 1140 is not limited thereto and can be of a different type.
By using the above-described panel burn prevention system, users of the display device 100 or another apparatus/system capable of communicating with the display device 100 can identify the occurrence timing, cause, and location of defects based on the stored information or the determined result from the defect management unit 1130. This allows for appropriate measures to be taken in response to detected defects, according to the type of the defect detected.
In one embodiment, the defect management unit 1130 can perform power-off processing based on the recognized defect type. For example, the defect management unit 1130 can perform power-off processing for the drive voltage EVDD of an organic light-emitting diode OLED of the display panel 110. Through such power-off processing by the defect management unit 1130, it is possible to prevent the panel burnt phenomenon on the display panel 110 proactively.
In an embodiment of the present invention, the defect detection unit 1110 and defect signal generation unit 1120 can be included in the timing controller 140 on the control printed circuit board C-PCB, as an example. The defect management unit 1130 can be located on the main printed circuit board M-PCB) and, in some cases, can be integrated into the internal components of the main controller M-CON on the main printed circuit board M-PCB.
With reference to
The defect detection unit 1110 can determine whether or not the sensing value obtained from on-sensing, real-time (RT) sensing, or off-sensing of the display panel 110 has fallen within a normal sensing value range and identify the occurrence of a defect if the sensing value has fallen outside the normal sensing value range.
Furthermore, the defect detection unit 1110 can compare the voltage value (e.g., gate voltage) or current value (e.g., gate voltage current) in the display panel 110 with a reference voltage value or reference current value and identify, when a difference thereof is detected, the occurrence of a defect on the corresponding signal line supplying the voltage or current or the location where the corresponding signal line is arranged.
Additionally, the defect detection unit 1110 can determine the occurrence of an open or short circuit defect based on the INBDP signal received from the timing controller 140 and/or the gate driver integrated circuit GDIC in the display panel 110. In an embodiment of the present invention, if the INBDP signal has a level below a predetermined normal range, the defect determination unit 1210 can determine that an open defect (e.g., an open circuit defect) has occurred. Conversely, if the INBDP signal has a level exceeding the predetermined normal range, the defect determination unit 1210 can determine that a short defect (e.g., a short circuit defect) has occurred.
In an embodiment of the present invention, the INBDP signal can be input to the defect detection unit 1110 when a line defect LD is detected based on sensing value acquired through real-time (RT) sensing, when a lock signal (e.g., low-level lock signal or low-level interface signal) is detected through an internal interface such as the EPI interface as described with reference to
Furthermore, the defect detection unit 1110 can determine the occurrence of a shutdown defect (e.g., shutdown operation defect) when a power protection operation (e.g., shutdown), performed by the power controller 900 or the gamma voltage generator due to various causes or other defects, is not performed properly or is repeated a predetermined number of times which can indicate a presence of a defect.
As described above, the defect detection unit 1110 can efficiently detect various types of defects that can occur at various timings and locations in the display device 100 by using various methods to identify potential defects in the display device 100.
Accordingly, the defect detection unit 1110 can then output corresponding BDP signals based on the detected defect types.
With reference to
Furthermore, the defect detection unit 1110 can output one of first to fourth BDP signals VGH1 BDP, VGL1 BDP, VGL2 BDP, and VGLUD BDP, and an eighth BDP signal VGH2 BDP, when the detected defect is caused by the current corresponding to the gate voltages VGH and VGL used in the gate driver 130 exceeding the abnormal current (e.g., overcurrent protection OCP) level. For instance, when the overcurrent in the power management IC (PMIC) output (e.g., VGH, VGL) occurs, then the defect detection unit 1110 can output one of the BDP signals VGH1 BDP, VGL1 BDP, VGL2 BDP, VGLUD BDP, VGH2 BDP, etc.
More specifically, 24 or example, the defect detection unit 1110 can output the first BDP signal VGH1 BDP for the defect detected in association with the first high-potential gate voltage VGH1, the second BDP signal VGL1 BDP for the defect detected in association with the first low-potential gate voltage VGL1, the third BDP signal VGL2 BDP for the defect detected in association with the second low-potential gate voltage VGL2, the fourth BDP signal VGLUD BDP for the defect detected in association with the VGLUD voltage, and the eighth BDP signal VGH2 BDP for the defect detected in association with the second high-potential gate voltage VGH2.
When the defect is caused by a shutdown operation performed by the power controller 900 (e.g., PMIC shutdown) within the display device 100, the defect detection unit 1110 can output a fifth BDP signal (e.g., shutdown BDP).
When the defect is caused by an open circuit on signal lines, DL, GL, DVL, RVL, gate voltage wiring, etc., arranged in the display panel 110, the defect detection unit 1110 can output a sixth BDP signal INBDP (OPEN). For example, when a line defect (LD) is detected based on the sensing value obtained through real-time sensing (RT sensing), when a lock signal (e.g., low-level lock signal) is detected through an internal interface such as the EPI interface as described with reference to
When the defect is caused by a short circuit in signal lines, DL, GL, DVL, RVL, gate voltage wiring, etc., the defect detection unit 1110 can output a seventh BDP signal INBDP (SHORT). For example, when a wiring short circuit occurs due to a crack at the edge (or another part) of the display panel 110, the defect detection unit 1110 can determine the occurrence of a short circuit defect and output the seventh BDP signal, INBDP (SHORT).
When the defect is caused by a shutdown operation performed by the power controller 900 or a gamma voltage generator located within the display device 100, the defect detection unit 1110 can output a ninth BDP signal P-Gamma BDP.
In summary, by determining the type of defect based on the detected cause and generating the corresponding BDP signals BDP, the defect management unit 1130 can identify the cause of the occurred defect from the BDP signals.
With reference to
For example, the defect signal generation unit 1120 can output the defect signal DS corresponding to the first BDP signal VGH1 BDP with one pulse, the defect signal DS corresponding to the second BDP signal VGL1 BDP with two pulses, the defect signal DS corresponding to the third BDP signal VGL2 BDP with three pulses, and the defect signal DS corresponding to the fourth BDP signal VGLUD BDP with four pulses. The defect signal generation unit 1120 can output the defect signal DS corresponding to the fifth BDP signal Shutdown BDP with five pulses, the defect signal DS corresponding to the sixth BDP signal INBDP (OPEN) with six pulses, the defect signal DS corresponding to the seventh BDP signal INBDP (SHORT) with seven pulses, and the defect signal DS corresponding to the eighth BDP signal VGH2 BDP with eight pulses. The defect signal generation unit 1120 can also output the defect signal DS corresponding to the ninth BDP signal P-Gamma BDP with nine pulses. The defect signal generation unit 1120 can output the defect signal DS corresponding to a zero or no BDP (Comparator BDP) with no pulse.
In an embodiment of the present invention, the defect signal DS output from the defect signal generation unit 1120 can have an inverted phase compared to the aforementioned pulse signal. However, this embodiment of the present invention is not limited to this approach, and other variations such as different shaped pulse or waveform are possible.
With reference to
The above-described defect management method is capable of identifying the cause of the detected defects in the display device 100 and facilitating the determination of the time and location of the occurrence of the defects. This allows for appropriate measures to be taken in response to the defects, according to the type of defect.
The display devices and driving methods thereof according to embodiments of the present invention are capable of preventing a panel burnt phenomenon by efficiently managing the detected defects after the defect detection.
The display devices and driving methods thereof according to embodiments of the present invention are capable of efficiently managing defects by determining the type of defect, generating a defect signal indicative of the occurrence of the type of defect depending on the type of defect determined, and transmitting the defect signal to the defect management unit so that the defect management unit or the user/administrator can address such defect.
The display devices and driving methods thereof according to embodiments of the present invention are capable of allowing for users, administrators, external devices, etc. to easily identify the occurrence timing and the types of defects, so such defects can be addressed efficiently.
Although embodiments of this invention have been described above with reference to the accompanying drawings, it will be understood that the technical configuration of this invention described above can be implemented in other specific forms by those skilled in the art without changing the technical concept or essential features of the present invention. Therefore, it should be understood that the embodiments described above are exemplary and not limited in all respects. Furthermore, the scope of the present invention is defined by the claims set forth below, rather than the detailed description above. In addition, it should be understood that all modifications or variations derived from the meaning and scope of the claims and their equivalent concept are included within the scope of this invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0187619 | Dec 2022 | KR | national |
