KR20220083211A - Display Device and Driving Method of the same - Google Patents

Abstract

The present invention provides a display panel for displaying an image; a data driver connected to the signal lines of the display panel; and a timing controller for controlling the data driver, wherein the data driver is electrically connected to a device causing a temperature rise during operation for a predetermined time and at least one of the signal lines to provide a display device having a heating path have.

Description

Display Device and Driving Method of the Same

The present invention relates to a display device and a driving method thereof.

With the development of information technology, the market for display devices, which is a connection medium between users and information, is growing. Accordingly, the use of display devices such as a light emitting display device (LED), a quantum dot display device (QDD), and a liquid crystal display device (LCD) is increasing.

The display devices described above include a display panel including sub-pixels, a driving unit outputting a driving signal for driving the display panel, and a power supply unit generating power to be supplied to the display panel or the driving unit, and the like.

In the above display devices, when a driving signal, for example, a scan signal and a data signal, is supplied to the sub-pixels formed on the display panel, the selected sub-pixel transmits light or directly emits light to display an image.

The present invention performs an operation capable of discharging the moisture that has penetrated into the interior of the display panel or the moisture remaining inside, thereby eliminating defects (dark spots, line dims, etc.) or driving defects or potential failure factors caused by short circuits in moisture permeability. To improve lifespan and reliability.

The present invention provides a display panel for displaying an image; a data driver connected to the signal lines of the display panel; and a timing controller for controlling the data driver, wherein the data driver is electrically connected to a device causing a temperature rise during operation for a predetermined time and at least one of the signal lines to provide a display device having a heating path have.

The heating path may be formed to evaporate moisture permeated into the display area of the display panel.

At least one of the signal lines may include data lines transmitting a data voltage to the sub-pixel of the display panel or reference lines transmitting a voltage sensed from the sub-pixel.

The device for causing the temperature increase may include a device that applies a voltage to at least one of the signal lines, senses the applied voltage, and converts the sensed analog voltage into a digital format.

The device for causing the temperature rise includes a voltage circuit unit for applying a voltage to at least one of the signal lines, a sampling circuit unit for sensing a voltage applied to at least one of the signal lines, and a voltage output from the sampling circuit unit. It may include an analog-to-digital converter that converts the analog voltage into a digital format.

The data driver may repeat a voltage application operation citing the voltage circuit unit, a sensing operation using the sampling circuit unit, and a conversion operation using the analog-to-digital converter unit to cause a temperature increase of the data driver unit.

The display panel further includes a humidity sensor unit for sensing humidity inside or outside the display panel, wherein the humidity sensor unit senses humidity and transmits the sensed humidity information to the timing control unit, and the timing control unit is based on the humidity information. It is possible to control whether or not a heating operation is used to increase the temperature of the data driver.

The heating operation of the data driver may be performed through a line in which a voltage drop due to moisture permeation exists among the data lines or reference lines.

The heating operation of the data driver may be performed through a plurality of lines selected from among the data lines and reference lines.

In another aspect, the present invention may provide a method of driving a display device including a display panel for displaying an image, a data driver connected to signal lines of the display panel, and a timing controller for controlling the data driver. A method of driving a display device includes: turning off all transistors included in sub-pixels of the display panel; and forming a heating path between the device and the line by electrically connecting at least one of the signal lines and a device causing a temperature increase when the data driver is operated for a predetermined time inside the data driver.

The step of forming a heating path between the device and the line includes applying a voltage to at least one of the signal lines, sensing a voltage applied to at least one of the signal lines, and the sensed analog form. It may include converting the voltage into digital form.

The steps of forming the heating path, applying the voltage, sensing the voltage, and converting the analog voltage into a digital format may be repeated to cause the temperature of the data driver to rise.

The present invention performs an operation capable of discharging the moisture that has penetrated into the interior of the display panel or the moisture remaining inside, thereby eliminating defects (dark spots, line dims, etc.) or driving defects or potential failure factors caused by short circuits in moisture permeability. It has the effect of improving the lifespan and reliability. In addition, the present invention has an effect of preventing problems in which a short circuit between different signal lines or a voltage or current drop may occur due to moisture permeated.

FIG. 1 is a block diagram schematically illustrating a light emitting display device according to a first embodiment of the present invention, and FIG. 2 is a configuration diagram schematically illustrating a sub-pixel shown in FIG. 1 .
3 is a diagram illustrating an arrangement example of a gate-in-panel type scan driver, and FIGS. 4 and 5 are exemplary configuration views of a device related to a gate-in-panel type scan driver.
6 is a plan view and a cross-sectional view of a display panel, and FIG. 7 is a diagram illustrating a portion in the display panel where a moisture permeation path may occur.
8 is a diagram illustrating a part of a light emitting display device according to the first embodiment of the present invention, and FIG. 9 is a diagram for explaining effects that may appear when the device shown in FIG. 8 is driven.
10 is a diagram illustrating a sub-pixel and a data driver, FIG. 11 is a diagram illustrating a display panel and a data driver, and FIG. 12 is a diagram illustrating one pixel in FIG. 11 .
13 is a diagram illustrating a part of a light emitting display device according to a second embodiment of the present invention, and FIGS. 14 to 16 are diagrams for briefly explaining a part related to driving of the device of FIG. 13 .
17 is a detailed view of a part of the device of FIG. 13 according to a second embodiment of the present invention, and FIGS. 18 to 22 are diagrams for explaining a method of driving the device shown in FIG. 17 .
23 is a diagram for explaining a modification of the second embodiment of the present invention, and FIG. 24 is a flowchart for explaining a driving method according to the modification of the second embodiment of the present invention.
25 is a diagram illustrating a part of a light emitting display device according to a third embodiment of the present invention, and FIGS. 26 to 30 are diagrams for explaining a method of driving the device shown in FIG. 25 .

The display device according to the present invention may be implemented as a television, an image player, a personal computer (PC), a home theater, an electric vehicle, a smart phone, and the like, but is not limited thereto. The display device according to the present invention may be implemented as a light emitting display device (LED), a quantum dot display device (QDD), a liquid crystal display device (LCD), or the like. However, hereinafter, for convenience of explanation, a light emitting display device that directly emits light based on an inorganic light emitting diode or an organic light emitting diode will be exemplified.

FIG. 1 is a block diagram schematically illustrating a light emitting display device according to a first embodiment of the present invention, and FIG. 2 is a configuration diagram schematically illustrating a sub-pixel shown in FIG. 1 .

1 and 2 , the light emitting display device according to the first embodiment of the present invention includes an image supply unit 110 , a timing controller 120 , a scan driver 130 , a data driver 140 , and a display panel. 150 and the power supply unit 180 may be included.

The image supply unit 110 (set or host system) may output various driving signals together with an image data signal supplied from the outside or an image data signal stored in an internal memory. The image supply unit 110 may supply a data signal and various driving signals to the timing control unit 120 .

The timing controller 120 includes a gate timing control signal GDC for controlling the operation timing of the scan driver 130 , a data timing control signal DDC for controlling the operation timing of the data driver 140 , and various synchronization signals ( Vsync, which is a vertical sync signal, and Hsync, which is a horizontal sync signal) can be output. The timing controller 120 may supply the data signal DATA supplied from the image supplier 110 together with the data timing control signal DDC to the data driver 140 . The timing controller 120 may be formed in the form of an integrated circuit (IC) and mounted on a printed circuit board, but is not limited thereto.

The scan driver 130 may output a scan signal (or a scan voltage) in response to the gate timing control signal GDC supplied from the timing controller 120 . The scan driver 130 may supply a scan signal to the sub-pixels included in the display panel 150 through the scan lines GL1 to GLm. The scan driver 130 may be formed in the form of an IC or may be formed directly on the display panel 150 in a gate-in-panel method, but is not limited thereto.

The data driver 140 samples and latches the data signal DATA in response to the data timing control signal DDC supplied from the timing controller 120 , and converts the digital data signal to analog data based on the gamma reference voltage. It can be converted to voltage and output. The data driver 140 may supply a data voltage to the sub-pixels included in the display panel 150 through the data lines DL1 to DLn. The data driver 140 may be formed in the form of an IC and may be mounted on the display panel 150 or mounted on a printed circuit board, but is not limited thereto.

The power supply unit 180 generates high potential first power and low potential second power based on an external input voltage supplied from the outside, and through the first power line EVDD and the second power line EVSS can be printed out. The power supply unit 180 is used to drive the first power and the second power as well as a voltage required for driving the scan driver 130 (eg, a gate voltage including a gate high voltage and a gate low voltage) or a data driver 140 . A necessary voltage (a drain voltage including a drain voltage and a half-drain voltage) may be generated and output.

The display panel 150 may display an image in response to a driving signal including a scan signal and a data voltage, and a first power and a second power. The sub-pixels of the display panel 150 directly emit light. The display panel 150 may be manufactured based on a substrate having rigidity or flexibility, such as glass, silicon, polyimide, or the like. In addition, the sub-pixels that emit light may include pixels including red, green, and blue or pixels including red, green, blue, and white.

For example, one sub-pixel SP may be connected to the first data line DL1 , the first scan line GL1 , the first power line EVDD, and the second power line EVSS, and a switching transistor, driving It may include a pixel circuit including a transistor, a capacitor, an organic light emitting diode, and the like. Since the sub-pixel SP used in the light emitting display device directly emits light, the circuit configuration is complicated. Also, there are various compensating circuits for compensating for deterioration of the organic light emitting diode that emits light as well as the driving transistor that supplies the driving current to the organic light emitting diode. Accordingly, reference is made to the simple illustration of the sub-pixel SP in the form of a block.

Meanwhile, in the above description, the timing control unit 120 , the scan driving unit 130 , the data driving unit 140 , etc. have been described as individual components. However, depending on the implementation method of the light emitting display device, one or more of the timing controller 120 , the scan driver 130 , and the data driver 140 may be integrated into one IC.

3 is a diagram illustrating an arrangement example of a gate-in-panel type scan driver, and FIGS. 4 and 5 are exemplary configuration views of a device related to a gate-in-panel type scan driver.

3 , the gate-in-panel type scan drivers 130a and 130b are disposed in the non-display area NA of the display panel 150 . The scan drivers 130a and 130b may be disposed in the left and right non-display areas NA of the display panel 150 as shown in FIG. 3A . Also, the scan drivers 130a and 130b may be disposed in the upper and lower non-display areas NA of the display panel 150 as shown in FIG. 3B .

Although the scan drivers 130a and 130b are illustrated and described as being disposed in the non-display area NA positioned on the left or right or upper and lower sides of the display area AA as an example, only one of the scan drivers 130a and 130b may be disposed on the left, right, upper or lower side. .

4 , the gate-in-panel scan driver 130 may include a shift register 131 and a level shifter 135 . The level shifter 135 may generate clock signals Clks and a start signal Vst based on signals and voltages output from the timing controller 120 and the power supply unit 180 . The clock signals Clks may be generated in the form of K (K is an integer greater than or equal to 2) phases having different phases, such as two-phase, four-phase, eight-phase, and the like.

The shift register 131 operates based on the signals Clks and Vst output from the level shifter 135 and scan signals Scan[1] to Scan [m]) can be printed. The shift register 131 may be formed in the form of a thin film on the display panel by a gate-in-panel method. Accordingly, the portion formed on the display panel in the scan driver 130 may be the shift register 131 . And in FIG. 3 , 130a and 130b may correspond to 131 .

4 and 5 , unlike the shift register 131 , the level shifter 135 may be formed independently in the form of an IC or may be included in the power supply unit 180 . However, this is only an example and is not limited thereto.

6 is a plan view and a cross-sectional view of a display panel, and FIG. 7 is a diagram illustrating a portion in the display panel where a moisture permeation path may occur.

6 and 7 , the display panel 150 includes a first substrate 150a, a display area AA, a second substrate 150b (or a sealing layer), a sealing member 155, and the like. can do. Sub-pixels emitting light to display an image are included in the display area AA on the first substrate 150a. The sub-pixels may be arranged in an array form. Sub-pixels are vulnerable to moisture or oxygen. Accordingly, the display area AA may be sealed by the sealing member 155 disposed between the first substrate 150a and the second substrate 150b.

Although the display panel 150 is sealed by the sealing member 155 , moisture flows into the inside of the display area AA along a signal line or a power line that helps an electrical connection between the pad area PADA and the display area AA. can be permeable. In addition, moisture may be transmitted into the display area AA through cracks or damaged portions of the sealing member 150 . In addition, moisture introduced during the manufacturing process may remain in the display area AA.

Moisture or the like existing in the display area AA of the display panel 150 may cause potential defects. For this reason, a method of forming various structures (a moisture permeation delay structure) in the non-display area NA together with the sealing member 155 may be used.

However, if moisture permeation is made after the display panel 150 is shipped, or moisture that has already permeated to the inside fails to be discharged, display defects (dark spots, line dims, etc.) or driving defects may occur. The reason is that a short circuit between different signal lines or a voltage or current drop may occur due to moisture permeated.

Therefore, the present invention proposes the following method in order to solve the above problems.

8 is a diagram illustrating a part of a light emitting display device according to the first embodiment of the present invention, and FIG. 9 is a diagram for explaining effects that may appear when the device shown in FIG. 8 is driven.

As shown in FIG. 8 , the light emitting display device may include a display panel 150 (PNL), a data driver 140 (DIC), a timing controller 120 (ASIC), and a humidity sensor 190 (HSEN). .

The humidity sensor unit 190 is a device such as the inside of the display area AA of the display panel 150 , the surface of the lower or upper substrate constituting the display panel 150 , the data driving unit 140 or the timing control unit 120 , etc. It may be located on one of the external boards on which the is mounted.

The humidity sensor unit 190 may sense humidity and transmit the sensed humidity information HI to the timing control unit 120 . The timing controller 120 may generate a humidity removal driving signal HD based on the humidity information HI and provide it to the data driver 140 .

As shown in FIGS. 8 and 9 , the data driving unit 140 may perform a heating operation to heat the device based on the humidity removal driving signal HD. Heating driving may be defined as an operation for increasing the temperature of the data driving unit 140 . Heating driving of the data driver 140 is possible as long as it is a device that can cause a temperature rise during operation for a certain period of time among the devices included therein.

The data driver 140 electrically connects a device that generates heat among devices included therein and the signal lines (part or all) of the display panel 150 , and the display panel 150 and the data driver ( 140) may form a heating path between them. As such, when a heating path is formed between the display panel 150 and the data driver 140 , heat generated from the data driver 140 may be conducted along the heating path to the signal lines and their surroundings. In addition, moisture contained in the display area AA of the display panel 150 may be discharged (evaporated) to the outside of the display panel 150 due to heat conducted through the signal lines. That is, the data driver 140 may perform an operation for inducing moisture evaporation of the display panel 150 based on the humidity removal driving signal HD.

Accordingly, moisture permeated through signal lines that help electrical connection between the display panel 150 and the data driver 140 , etc., moisture permeated through cracks or damaged portions of the sealing member 150 , and the manufacturing process Moisture (residual content), etc. introduced into the phase can be easily discharged. In addition, even after the display panel 150 is shipped, the moisture permeated through the above-described moisture increase induction operation may be discharged. As a result, display defects (dark spots, line dims, etc.) or driving defects caused by moisture permeated can be resolved.

10 is a diagram illustrating a sub-pixel and a data driver, FIG. 11 is a diagram illustrating a display panel and a data driver, and FIG. 12 is a diagram illustrating one pixel in FIG. 11 .

10 , one sub-pixel SP may include a switching transistor SW, a driving transistor DT, a sensing transistor ST, a capacitor CST, and an organic light emitting diode (OLED). .

The driving transistor DT may have a gate electrode connected to a first electrode of the capacitor CST, a first electrode connected to a first power line EVDD, and a second electrode connected to an anode electrode of the organic light emitting diode OLED. have. The capacitor CST may have a first electrode connected to the gate electrode of the driving transistor DT and a second electrode connected to the anode electrode of the organic light emitting diode OLED. The organic light emitting diode OLED may have an anode electrode connected to the second electrode of the driving transistor DT and a cathode electrode connected to the second power line EVSS.

The switching transistor SW has a gate electrode connected to the first A scan line GL1a included in the first scan line GL1 , a first electrode connected to the first data line DL1 , and a gate of the driving transistor DT. A second electrode may be connected to the electrode. The sensing transistor ST has a gate electrode connected to the 1B scan line GL1b included in the first scan line GL1, a first electrode connected to the first reference line REF1, and the A second electrode may be connected to the anode electrode.

The sensing transistor ST is a kind of compensation circuit added to compensate for deterioration (such as a threshold voltage) of the driving transistor DT or the organic light emitting diode OLED. The sensing transistor ST may enable sensing of a physical threshold voltage based on a source follower operation of the driving transistor DT. The sensing transistor ST may operate to acquire a sensing voltage through a sensing node defined between the driving transistor DT and the organic light emitting diode OLED.

Meanwhile, although the first scan line GL1 is divided into the first A scan line GL1a and the first B scan line GL1b as an example, they may be integrated into one. That is, the switching transistor SW and the sensing transistor ST are commonly connected to the first scan line GL1 and may be turned on or off at the same time.

The data driver 140 may include a driving circuit unit 141 for driving the sub-pixel SP and a sensing circuit unit 145 for sensing the sub-pixel SP. The driving circuit unit 141 may be connected to the first data line DL1 through the first data channel DCH1 , and may be connected to the first reference line VREF1 through the first sensing channel SCH1 . The driving circuit unit 141 may output a data voltage for driving the sub-pixel SP through the first data channel DCH1 . The sensing circuit unit 145 may acquire a sensing voltage sensed from the sub-pixel SP through the first sensing channel SCH1 .

11 and 12 , the data drivers 140a and 140b may be mounted on the flexible film COF. The flexible film COF may be electrically connected to the pad area PADA of the display panel 150 by an anisotropic conductive film or the like.

The sensing circuit units 145a and 145b included in the data drivers 140a and 140b may be electrically connected to the first to Mth reference lines VREF1 to VREFm. The first to Mth reference lines VREF1 to VREFm may be electrically connected to the pixel P included in the display area AA. The first to Mth reference lines VREF1 to VREFm may be disposed in the non-display area NA and the display area AA to electrically connect the sensing circuit units 145a and 145b and the pixel P.

One pixel P may include a red sub-pixel SPR, a white sub-pixel SPW, a green sub-pixel SPG, and a blue sub-pixel SPB. The red sub-pixel SPR, the white sub-pixel SPW, the green sub-pixel SPG, and the blue sub-pixel SPB are respectively the first data line DL1, the second data line DL2, and the third data line DL3) and the fourth data line DL4 may be separately connected. However, the red sub-pixel SPR, the white sub-pixel SPW, the green sub-pixel SPG, and the blue sub-pixel SPB may be commonly connected to share the first reference line VREF1.

That is, a total of four sub-pixels SPR, SPW, SPG, and SPB included in one pixel P are connected to the sensing circuit unit 145a of the data driver 140a or 140b through one reference line (eg, VREF1). Alternatively, it may have a structure connected to 145b). With this structure, each of the four sub-pixels SPR, SPW, SPG, and SPB included in one pixel P may compensate for deterioration (threshold voltage, etc.).

Hereinafter, in the second embodiment of the present invention, as described above, a light emitting display device including a data driver capable of sensing and applying a signal or voltage through another signal line such as a reference line (or sensing line) in addition to the data line. The present invention will be described with an example.

13 is a diagram illustrating a part of a light emitting display device according to a second embodiment of the present invention, and FIGS. 14 to 16 are diagrams for briefly explaining a part related to driving of the device of FIG. 13 .

As shown in FIG. 13 , the light emitting display device may include a data driver 140 , a timing controller 120 (ASIC), a humidity sensor unit 190 (HSEN), and a voltage generation circuit unit 170 (VAR). The data driver 140 includes a driving circuit unit 141 connected to the first data line DL1 of the sub-pixel SP and a sensing circuit unit 145 connected to the first reference line VREF1 as described with reference to FIG. 10 . can do.

As described with reference to FIG. 8 , the humidity sensor unit 190 includes the inside of the display area AA of the display panel, the surface of the lower or upper substrate constituting the display panel, the data driver 140 or the timing controller 120 , etc. It may be located on one of the external boards on which the device is mounted.

The humidity sensor unit 190 may sense humidity and transmit the sensed humidity information HI to the timing control unit 120 . The timing controller 120 may generate a humidity removal driving signal HD based on the humidity information HI and provide it to the data driver 140 .

The data driver 140 may perform a heating operation to heat the device based on the humidity removal driving signal HD. Heating driving may be defined as an operation for increasing the temperature of the data driving unit 140 . Heating driving of the data driver 140 is possible as long as it is a device that can cause a temperature rise during operation for a certain period of time among the devices included therein.

When generating the humidity removal driving signal HD based on the humidity information HI, the timing controller 120 may generate a voltage control signal VC and supply the voltage control signal VC to the voltage generating circuit unit 170 . The voltage generating circuit unit 170 may vary and supply current or voltage required for driving the data driver 140 to generate heat in response to the voltage control signal VC.

As shown in FIG. 14 , the data driving unit 140 may generate heat based on the driving circuit unit 141 . At this time, the sensing circuit unit 145 may take a non-driven state. As shown in FIG. 15 , the data driving unit 140 may generate heat based on the sensing circuit unit 145 . In this case, the driving circuit unit 141 may take a non-driven state. As shown in FIG. 16 , the data driving unit 140 may generate heat based on the driving circuit unit 141 and the sensing circuit unit 145 .

The data driver 140 may generate heat by using at least one of the devices included therein as described above. In addition, a heating path may be formed between the display panel and the data driver 140 by electrically connecting the device that drives the heat to at least one of the signal lines (eg, a first data line or a first reference line) of the display panel. have.

Hereinafter, the description will be embodied as an example of heating driving based on the sensing circuit unit 145 .

17 is a detailed view of a part of the device of FIG. 13 according to a second embodiment of the present invention, and FIGS. 18 to 22 are diagrams for explaining a method of driving the device shown in FIG. 17 .

17 , the sensing circuit unit 145 may include a first voltage circuit unit SPRE, a second voltage circuit unit RPRE, a sampling circuit unit SAM, an analog-to-digital converter ADC, and the like.

The first voltage circuit unit SPRE and the second voltage circuit unit RPRE receive a first reference from the first reference voltage source VPRES and the second reference voltage source VPRER to initialize the node or circuit included in the sub-pixel SP. It may serve to output the voltage and the second reference voltage, respectively. The first reference voltage may be defined as a voltage used in a sensing mode (compensation mode) for deterioration compensation, and the second reference voltage may be defined as a voltage used in a driving mode (normal mode) for displaying an image. In addition, the first reference voltage may be set to a lower voltage than the second reference voltage.

The sampling circuit unit SAM may perform a sampling operation for acquiring a sensing voltage through the first reference line VREF1 . The analog-to-digital converter ADC may convert the sensing voltage in the analog form acquired by the sampling circuit unit SAM into the sensing voltage in the digital form and output the converted voltage.

The sensing circuit unit 145 acquires the first sensing voltage Vsen1 for compensating for deterioration of the driving transistor DT or the organic light emitting diode OLED included in the sub-pixel SP through the first reference line REF1 . and can be printed.

The first sensing voltage Vsen1 output from the sensing circuit unit 145 may be transmitted to the timing control unit 120 . In addition, the timing controller 120 determines whether the driving transistor DT or the organic light emitting diode OLED included in the sub-pixel SP is deteriorated based on the first sensing voltage Vsen1, and performs a compensation operation to compensate the deterioration. can be done

In the second embodiment of the present invention, heat is driven in the sensing circuit unit 145 through an iterative process of applying the second reference voltage of the second reference voltage source VPRER to the first reference line VREF1 and repeating the sensing operation. can make this happen. To this end, the voltage generating circuit unit 170 may vary and supply the second reference voltage of the second reference voltage source VPRER included in the sensing circuit unit 145 in response to the voltage control signal VC.

When the sensing circuit unit 145 is driven by heat, the second reference voltage of the second reference voltage source VPRER may be applied to the first reference line VREF1 and used as a voltage to form a current or voltage required for sensing. However, the second reference voltage is changed by the voltage generating circuit unit 170 and may have a higher or lower level than the voltage used in the driving mode (normal mode). And the reason for using the variable voltage will be dealt with again below.

18 and 19 , when the sensing circuit unit 145 is driven by heat, the data voltage Data is not applied. Also, the scan signals G1a and G1b for driving the switching transistor SW and the sensing transistor ST are not applied. That is, a state in which the signal or voltage of the logic low L is not applied to the first data line DL1 , the first A scan line GL1a , and the first B scan line GL1a may be maintained. That is, the switching transistor SW and the sensing transistor ST may be turned off.

In the first step S1, the above state is maintained and the first voltage control signal Spre is converted from a logic low (L) to a logic high (H) to the first reference voltage of the first reference voltage source VPRES. The first reference line VREF1 may be initialized. When the first reference line VREF1 is initialized to the first reference voltage, a residual voltage that may exist in the previous step may be removed.

In the second step S2, the first reference line VREF1 is charged with the variable voltage of the second reference voltage source VPRES by converting the second voltage control signal Rpre from a logic low (L) to a logic high (H). can do.

The third step S3 is a step of electrically floating the first reference line VREF1 charged with the variable voltage. When a short circuit occurs between the first reference line VREF1 and another signal line due to moisture or the like, a voltage or current drop due to leakage may occur.

For this reason, if the floating step is provided, it is possible to find a reference line in which a short circuit between different signal lines or a voltage or current drop occurs due to leakage due to moisture transmitted through a subsequent sensing process. That is, the third step ( S3 ) may be defined as a section for finding a reference line in which a short between different signal lines or a voltage or current drop occurs together with the subsequent fourth step ( S4 ).

In the fourth step (S4), the variable voltage charged in the first reference line VREF1 can be sensed through the sampling circuit unit SAM by converting the sampling signal Sam from a logic low (L) to a logic high (H). have. In the fourth step ( S4 ), the analog-to-digital converter ADC may convert the analog variable voltage sensed by the sampling circuit unit SAM into a digital variable voltage and transmit it to the timing controller 120 .

The timing controller 120 may detect whether a voltage or a current drop occurs in which reference line based on the variable voltage acquired through the sensing operation of the sensing circuit unit 145 . The timing controller 120 may determine that the reference line in which the voltage or current drop occurs is a problem due to moisture permeated, and may form a heating path with respect to the reference line.

The timing controller 120 may repeat sampling and conversion operations through the sampling circuit unit SAM and the analog-to-digital converter ADC of the sensing circuit unit 145 to form a heating path. To this end, the timing control unit 120 may provide the humidity removal driving signal HD to the data driving unit 140 .

In the fifth step (S5), the second voltage control signal Rpre is converted from a logic low (L) to a logic high (H) so that the operation as described above is performed to obtain a variable voltage of the second reference voltage source VPRES. The process of charging the first reference line VREF1 may be repeated for a predetermined period. Then, the process of sensing the variable voltage charged in the first reference line VREF1 through the sampling circuit unit SAM by switching the sampling signal Sam from a logic low (L) to a logic high (H) is repeated for a certain period of time. can In addition, the process of converting the analog variable voltage sensed through the analog-to-digital converter (ADC) into the digital variable voltage may be repeated for a predetermined period.

By repeating the sensing operation of the sampling circuit unit SAM and the conversion operation of the analog-to-digital converter ADC, the sensing circuit unit 145 of the data driver 140 may generate a condition for performing a heating operation. In addition, a heating path may be formed between the first reference line VREF1 and the sensing circuit unit 145 by the heating operation of the sensing circuit unit 145 . The moisture-permeable short circuit formed between the first reference line VREF1 and another signal line (or power supply line) by the heating path formed between the first reference line VREF1 and the sensing circuit unit 145 may be resolved.

On the other hand, in the above description, it is taken as an example to form a heating path limited to the reference line in which a voltage or current drop (Drop) occurs due to moisture permeated. However, according to the present invention, a heating path may be formed for all reference lines (or a plurality of selected data lines) irrespective of voltage or current drop, and an operation for inducing evaporation of moisture may be performed throughout the display panel (or in units of blocks). .

In addition, the fifth step ( S5 ) may be continuously repeated until a leakage defect such as a voltage or current drop is resolved. In addition, after the fifth step ( S5 ) is performed for a certain period of time so that the leakage defect is completely resolved, the process performed from the first step ( S1 ) to the fifth step ( S5 ) may be performed again.

23 is a diagram for explaining a modification of the second embodiment of the present invention, and FIG. 24 is a flowchart for explaining a driving method according to the modification of the second embodiment of the present invention.

10 and 23 , the device for supplying the second reference voltage of the second reference voltage source VPRER variably provides the programmable gamma voltage PGMA to the data driver 140 in a programmable manner. It may be replaced by the unit 170 . The programmable gamma unit 170 is a device that provides a gamma voltage necessary for forming a data voltage in the driving circuit unit 141 of the data driving unit 140 .

23 and 24 , according to a modified example of the second embodiment of the present invention, the moisture evaporation induction operation of the display panel may be performed when a power cutoff signal to cut off the power is generated. same.

After the device is driven (S110), it may be determined whether a power cutoff signal is generated (S115). When the power cut-off signal is not generated (N), the driving mode for displaying an image (Normal Mode) (S120) may be maintained (S120). Accordingly, the operation of displaying the image on the display panel may be continued (S125).

Contrary to this, when a power cut-off signal is generated (Y), the timing controller 120 may sense the humidity information HI by driving the humidity sensor unit 190 (S130). The timing controller 120 may determine whether the humidity is within a normal range based on the humidity information HI ( S140 ).

When the humidity falls within the normal range (the preset range is satisfied) (Y), a compensation mode (OFFRS Mode) for compensating for deterioration of the display panel may be selected (S150). In addition, the timing controller 120 and the data driver 140 may perform an operation for compensating for deterioration of the display panel (S155).

On the other hand, if the humidity does not fall within the normal range (dissatisfied with the preset range) (N), the timing controller 120 and the data driver 140 are abnormal instead of the compensation mode (OFFRS Mode) for compensating for deterioration of the display panel. An operation of detecting a line may be performed (S160). In this case, the abnormal line refers to a reference line in which a voltage or current drop occurs due to leakage due to permeable moisture or the like. In addition, the step of detecting the abnormal line ( S160 ) may be performed based on the first step ( S1 ) to the fourth step ( S4 ) of FIG. 18 .

On the other hand, in FIG. 24, after the step of sensing the current humidity (S130) and the step of determining whether the humidity is within the normal range (S14), if the humidity does not fall within the normal range, the step of detecting the abnormal line (S160) proceeds has been described as an example. However, the step of sensing the current humidity (S130) and the step of determining whether the humidity is in the normal range (S140) may be omitted. In this case, after determining whether the power cut-off signal is generated (S115), if the power cut-off signal is generated (Y), the step of detecting an abnormal line (S160) may proceed. Conversely, if the power cut-off signal does not occur (N), a compensation mode (OFFRS Mode) for compensating for deterioration of the display panel may proceed.

The timing controller 120 may generate a voltage control signal VC together with the humidity removal driving signal HD and supply it to the data driving unit 140 and the programmable gamma unit 170 . The timing control unit 120 , the data driving unit 140 , the programmable gamma unit 170 , etc. may perform an operation for inducing water evaporation to form a heating path in the abnormal line. Since the moisture evaporation induction operation is the same as that described with reference to FIGS. 18 to 22 , refer to this.

Meanwhile, the voltage variable operation in which the programmable gamma unit 170 varies the second reference voltage of the second reference voltage source VPRER is a correction operation for correcting the deviation of the analog-to-digital converter ADC included in each sensing circuit unit 145 . can also be used for

The present invention can be applied to a light emitting display device having only a data line and not a reference line, which will be described as follows. However, hereinafter, different parts will be mainly described compared to the above-described embodiments.

25 is a diagram illustrating a part of a light emitting display device according to a third embodiment of the present invention, and FIGS. 26 to 30 are diagrams for explaining a method of driving the device shown in FIG. 25 .

25 , the sub-pixel SP may include a switching transistor SW, a driving transistor DT, a capacitor CST, and an organic light emitting diode (OLED). That is, the sub-pixel SP is a general sub-pixel having no transistor for compensation therein.

The data driver 140 may include a driving circuit unit 141 for driving the sub-pixel SP, a sensing circuit unit 145 for sensing the sub-pixel SP, a selection unit SEL, and the like. The selection unit SEL may be turned on only during the driving period of the sensing circuit unit 145 .

The driving circuit unit 141 includes a latch unit 145 that latches and outputs a data signal supplied from the outside, and a digital-analog converter (DAC) that converts the data signal output from the latch unit 145 into a data voltage and outputs it. may include The driving circuit unit 141 may output a data voltage through the first data line DL1 . The sensing circuit unit 145 may include a voltage circuit unit RPRE, a sampling circuit unit SAM, an analog-to-digital converter (ADC), and the like. The voltage circuit unit RPRE may form a variable voltage based on the voltage output from the programmable gamma unit 170 .

26 to 30 , the selection unit SEL may be turned on in response to the logic high selection signal Sel. The selection signal Sel may maintain a logic high (H) during the first step S1 to the fourth step S4 .

The voltage circuit unit RPRE may output a variable voltage during the first step S1 and the fourth step S4 in response to the logic high voltage control signal Rpre. The sampling circuit unit SAM may perform a sampling operation for sensing the variable voltage during the third step S3 and the fourth step S4 in response to the logic high sampling signal Sam. The analog-to-digital converter ADC may perform an operation of converting the variable voltage into a digital form during the fourth step ( S4 ).

During the fourth step ( S4 ), the sensing operation of the sampling circuit unit SAM and the conversion operation of the analog-to-digital converter ADC may be repeated. The sensing circuit unit 141 may form a condition for performing a heating operation by repeating the sensing operation of the sampling circuit unit SAM and the conversion operation of the analog-to-digital converter ADC. In addition, a heating path may be formed between the first data line DL1 and the sensing circuit unit 141 by the heating operation of the sensing circuit unit 141 . The moisture-permeable short circuit formed between the first data line DL1 and another signal line (or power line) by the heating path formed between the first data line DL1 and the sensing circuit unit 141 may be resolved.

Meanwhile, according to the above description, it is possible to detect a data line in which a voltage or current drop occurs due to moisture permeated by moisture, and to form a heating path only for the detected data line. However, according to the present invention, a heating path may be formed for all data lines (or a plurality of selected data lines) irrespective of voltage or current drop, and an operation for inducing moisture evaporation may be performed throughout the display panel (or in units of blocks). .

As described above, the present invention performs an operation capable of discharging the moisture that has penetrated into the interior of the display panel or the moisture remaining inside, thereby eliminating defects (dark spots, line dims, etc.) or driving defects or potential failure factors caused by short circuits in moisture permeability. It has the effect of improving the lifespan and reliability of the In addition, the present invention has an effect of preventing problems in which a short circuit between different signal lines or a voltage or current drop may occur due to moisture permeated.

150: display panel 140: data driver
120: timing controller 190: humidity sensor unit
145: sensing circuit unit VREF1: first reference line
170: voltage generation circuit unit or programmable gamma unit

Claims (12)

a display panel for displaying an image;
a data driver connected to the signal lines of the display panel; and
a timing control unit for controlling the data driving unit;
The data driver is electrically connected to at least one of a device for causing a temperature rise during operation for a predetermined time and at least one of the signal lines to have a heating path. According to claim 1,
The heat path is
A display device formed to evaporate moisture permeated into the display area of the display panel. According to claim 1,
at least one of the signal lines
and data lines transmitting a data voltage to the sub-pixels of the display panel or reference lines transmitting a voltage sensed from the sub-pixels. According to claim 1,
The device causing the temperature rise is
and a device for applying a voltage to at least one of the signal lines, sensing the applied voltage, and converting the sensed analog voltage into a digital form. According to claim 1,
The device causing the temperature rise is
a voltage circuit unit for applying a voltage to at least one of the signal lines;
a sampling circuit unit for sensing a voltage applied to at least one of the signal lines;
and an analog-to-digital converter converting the analog voltage output from the sampling circuit part into a digital form. 6. The method of claim 5,
The data driver
A display device that repeats a voltage application operation citing the voltage circuit unit, a sensing operation using the sampling circuit unit, and a conversion operation using the analog-to-digital converter unit to cause a temperature increase of the data driver. 4. The method of claim 3,
Further comprising a humidity sensor unit for sensing the humidity inside or outside the display panel,
The humidity sensor unit senses the humidity and transmits the sensed humidity information to the timing control unit, and the timing control unit controls whether or not a heating operation to increase the temperature of the data driver is used based on the humidity information. 8. The method of claim 7,
The heating operation of the data driver is
A display device performed through a line in which a voltage drop due to moisture permeation exists among the data lines or reference lines. 8. The method of claim 7,
The heating operation of the data driver is
A display device performed through a plurality of lines selected from among the data lines and reference lines. A method of driving a display device comprising: a display panel for displaying an image; a data driver connected to signal lines of the display panel; and a timing controller for controlling the data driver, the method comprising:
turning off all transistors included in the sub-pixels of the display panel; and
and forming a heating path between the device and the line by electrically connecting at least one of the signal lines and a device causing a temperature increase when the data driver is operated for a predetermined time inside the data driver. 11. The method of claim 10,
The step of forming a heating path between the device and the line is
applying a voltage to at least one of the signal lines;
sensing a voltage applied to at least one of the signal lines;
and converting the sensed analog voltage into digital form. 12. The method of claim 11,
In order to cause the temperature of the data driver to rise
The steps of forming the heating path, applying the voltage, sensing the voltage, and converting the analog voltage into a digital form are repeated.

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