KR100881229B1 - Circuit for compensation brightness interference of Passive Matrix-Organic Light Emitting Diode panel - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a luminance interference compensation circuit of a passive matrix organic light emitting diode (PM-OLED) panel, wherein the precharge voltage or current of the driver IC is varied according to the resistance of the scan line. Disclosed is a technique for minimizing a difference in luminance occurring on a scan line. The present invention is a driver IC for varying the precharge voltage or current to output a data line in response to the scan resistance of a plurality of scan lines, and sequentially supplying a plurality of scan lines by supplying scan pulses to the plurality of scan lines. A scan driver for driving and an OLED element at an intersection area between the plurality of scan lines and the data line, and driving the OLED element according to a precharge voltage or current applied through the data line to correspond to the scan resistance of the scan line. A passive matrix organic EL panel that compensates for luminance interference.

PM, OLED, Driver IC, Precharge, Precharge, Luminance, Scanline, Interference, Compensation, Variable

Description

Circuit for compensation brightness interference of Passive Matrix-Organic Light Emitting Diode panel}

1 is a circuit diagram of a conventional PM-OLED panel.

2 and 3 are diagrams for explaining a voltage application relationship in a conventional PM-OLED panel.

4 and 5 are diagrams for explaining the scan line voltage of the conventional PM-OLED panel.

6 is a circuit diagram showing an output equivalent circuit of a data driver of a conventional PM-OLED panel.

7 is a view for explaining the luminance difference between the scan line in the conventional PM-OLED panel.

8 is a view for explaining a problem of the conventional PM-OLED panel.

9 is a circuit diagram of a luminance interference compensation circuit of a PM-OLED panel according to the present invention;

FIG. 10 is a detailed circuit diagram illustrating an alternate type precharge driver of FIG. 9. FIG.

FIG. 11 is a detailed configuration diagram of the OLED of FIG. 9. FIG.

FIG. 12 is a diagram for explaining a precharge voltage of FIG. 9. FIG.

13 is a view showing the output waveform of the luminance-compensated OLED panel in the luminance interference compensation circuit of the PM-OLED panel according to the present invention.

14 is another embodiment of the luminance interference compensation circuit of the PM-OLED panel according to the present invention.

FIG. 15 is a detailed circuit diagram of an alternating precharge driver of FIG. 14. FIG.

FIG. 16 is a diagram for describing a precharge voltage of FIG. 14. FIG.

FIG. 17 is a view showing output waveforms of an OLED panel having luminance compensated in a luminance interference compensation circuit of a PM-OLED panel according to the present invention; FIG.

18 is a view illustrating an output image in which luminance interference is compensated for in a luminance interference compensation circuit of a PM-OLED panel according to the present invention;

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a luminance interference compensation circuit of a passive matrix organic light emitting diode (PM-OLED) panel, wherein the precharge voltage of the driver IC is varied according to the resistance of the scan line to scan line of the PM-OLED screen. It is a technology to minimize the difference in luminance occurring in the image.

Recently, various flat panel displays have been developed to reduce weight and volume, which are disadvantages of cathode ray tubes. Such flat panel displays include a liquid crystal display (LCD), a field effect display, a plasma display panel, an organic electroluminescence display, and the like.

In general, the liquid crystal display (LCD) is widely used as a video display device of a TV, a computer, or a mobile phone. The above-mentioned liquid crystal display requires a back light, which is not only heavy, but also thick and slow in response time. There is this.

An EL display device is attracting attention as a next-generation video display device replacing such a liquid crystal display. The EL display device is a self-light emitting device that emits a fluorescent material by recombination of electrons and holes, and includes an organic light emitting diode (OLED) display which is an inorganic EL and an organic EL according to a material and a structure.

OLED displays include extremely thin organic thin films of 0.1 μm or less. When the current flows through the organic thin film, electrons and holes recombine and emit light near the interface between the electron transport layer and the hole transport layer, and the light emission has an extremely fast response time of several hundred ns or less.

When driving a portable display device using an OLED, a uniform brightness display is required. In particular, in order for an OLED display to be used in high quality, the data driving circuit of the OLED, which is a current control element, needs to convert image data to be displayed into a current and supply it to the OLED panel.

The organic EL display device is driven by a passive matrix method and an active matrix method using a thin film transistor (TFT). Passive matrix OLED has faster response time than TFT LCD, so it can realize perfect video and self-illumination by current driving, which eliminates the need for back light to shoot from the back, reducing power consumption. There is an advantage to this.

Here, in order to drive the passive matrix organic EL panel, the scan line of the panel should be sequentially turned on for each frame section. The luminance of each pixel has a characteristic almost proportional to the amount of current flowing through the OLED pixel.

1 is a circuit diagram of a conventional PM-OLED panel.

The conventional PM-OLED panel includes a driver IC (Drive Integrated Circuit) 10, a scan driver 20 and a passive matrix organic EL panel 30, the OLED is arranged in a structure as shown in FIG. have.

When each pixel is turned on during the active period of the scanline SCAN, the current flowing to the scanline SCAN becomes the sum of the data currents connected to the entire scanline SCAN, so that a large current flows.

The driver IC 10 for driving the passive matrix organic EL panel 30 includes a pulse width modulation (PWM) and a pulse amplitude modulation (PAM) according to its control method. . However, each driving method has a problem of voltage drop of scan line SCAN due to parasitic resistance component of scan line SCAN.

2 and 3 are diagrams for describing a voltage application relationship in a conventional PM-OLED panel.

The OLED panel has a voltage drop due to the resistance component applied to the scan line SCAN when the screen is driven due to the resistance component of the metal material used as the electrode, and due to the parasitic resistance when the current is supplied to the OLED device, The potential difference is generated.

In this case, since the sum of the currents of the pixel data flows in the scan line SCAN, a relatively large current passes through the parasitic resistance. In this case, a voltage is applied across the parasitic resistance in the scan line SCAN to increase the potential difference between the OLED elements on the same scan, which is the cathode electrode of the OLED, as shown in FIGS. 2 and 3. Accordingly, in order to maintain the potential difference of the OLED, the potential of data, which is the anode electrode of the OLED, is also raised.

In this case, in order to increase the potential of the data, it is necessary to charge the parasitic capacitor connected to the data. During this period, the set current is not sufficiently supplied to the OLED, and part of the supply current is consumed to charge the parasitic capacitor. The luminance of the OLED will decrease during the additional charge time with this parasitic capacitor.

4 and 5 illustrate a scan line voltage of a conventional PM-OLED panel.

The OLED panel initially used a structure that connects all the scanline SCAN to one side as shown in FIG.

Since the current OLED panel typically connects the scan line SCAN in the left and right regions of the panel, when the scan line SCAN is turned on as shown in FIG. 5, the voltage of the scan line SCAN is different for each adjacent scan line SCAN. Will have In particular, the voltage difference is large at the left and right ends of the panel, which causes a large difference in luminance between the scan line scans at the left and right ends of the panel. This difference in brightness represents a more significant problem as the panel grows from the existing 96 × 64 resolution to 160 × 128 resolution.

6 is a circuit diagram illustrating an output equivalent circuit of a data driver in a conventional PM-OLED panel.

In the conventional PM-OLED panel, the same size precharge transistor MPRC is applied to each data driver 40. Here, the precharge transistor MPRC is formed of a PMOS transistor selectively driven according to the precharge signal PRC applied from the precharge PWM control unit. The reset switch NM resets the data line by pulling down the data line to the ground voltage when the reset signal RESET applied from the precharge PWM controller is activated. Accordingly, it is not possible to compensate for the difference in luminance appearing in the scan line SCAN according to the voltage difference of the scan line SCAN disposed in the left and right regions of the panel.

FIG. 7 is a diagram illustrating a luminance difference between scan lines in a conventional PM-OLED panel.

In the conventional PM-OLED panel, when a video signal as shown in the left figure A of FIG. 7 is input, a luminance difference between scan lines is severely detected at left and right portions of the screen as shown in the right figure B of FIG. 7. Such luminance change or luminance interference of the screen is referred to as crosstalk, and a generation mechanism will be described with reference to FIG. 8.

8 is a view for explaining the problem of the conventional PM-OLED panel.

FIG. 8 illustrates data output waveforms of the driver IC 10 corresponding to each of A, B, and C areas of the screen on the same scan line SCAN of FIG. 7. As shown in FIG. 8, if the precharge voltage is set based on the B region, the scan line resistance is greater in the A region than in the B region, thereby increasing the scan voltage VSCAN_ON.

This requires increasing the data voltage Vseg to output the same current to the OLED. In order to increase the data voltage Vseg, an additional current needs to be charged in the parasitic capacitor, so that the luminance of the charge time in the A region is lower than that in the B region.

On the contrary, in the case of the C region, since the resistance of the scan line SCAN is relatively smaller than that of the B region, the data voltage Vseg should be lowered than that of the B region. As a result, the current in the parasitic capacitor is discharged to the OLED, and the sum of the currents applied to the OLED is higher than that in the B region, thereby increasing the luminance.

Accordingly, there is a problem in that such a difference in voltage is large in the left and right end areas A and C of the panel, which causes a significant difference in luminance between scan lines SCAN in the left and right ends of the panel.

SUMMARY OF THE INVENTION The present invention was created to solve the above problems, and it is possible to minimize the difference in luminance occurring on the scan line of the PM-OLED screen by varying the precharge voltage of the driver IC according to the resistance of the scan line. Its purpose is.

The luminance interference compensation circuit of the PM-OLED panel of the present invention for achieving the above object comprises a driver IC for varying the precharge voltage corresponding to the scan resistance of the plurality of scan lines to output to the data line; A scan driver for sequentially supplying scan pulses to the plurality of scan lines to sequentially drive the plurality of scan lines; And a passive matrix including an OLED element at an intersection area between the plurality of scan lines and the data line, and driving the OLED element according to a precharge voltage applied through the data line to compensate for luminance interference corresponding to the scan resistance of the scan line. Organic EL panel; characterized by including.

In addition, the present invention includes a driver IC for varying the precharge current corresponding to the scan resistance of the plurality of scan lines to output to the data line; A scan driver for sequentially supplying scan pulses to the plurality of scan lines to sequentially drive the plurality of scan lines; And an OLED element in an intersection region between the plurality of scan lines and the data line, and driving the OLED element according to a precharge current applied through the data line to compensate for luminance interference corresponding to the scan resistance of the scan line. Matrix organic EL panel; characterized by including.

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of the present invention.

9 is a circuit diagram of a luminance interference compensation circuit of a PM-OLED panel according to the present invention.

The present invention includes a driver integrated circuit (IC) 100, a scan driver 200 and a passive matrix organic EL panel 300, wherein the OLEDs are arranged in a matrix structure as shown in FIG.

Here, the driver IC 100 includes a pulse width modulation (PWM) control unit 110, a precharge control unit 120, an alternating type precharge driver 130, a bias transistor P0 to P (m-1), Switches SW0 to SW (m-1) and reset switches RSW0 to RSW (m-1).

Here, the bias transistors P0 to P (m-1), which are P-type transistors, are connected between the power supply voltage terminal and the switches SW0 to SW (m-1), respectively, and the bias voltage BIAS is applied through the common gate terminal. These bias transistors P0 to P (m-1) have their output currents determined according to the bias voltage BIAS.

The switches SW0 to SW (m-1) are connected between the bias transistors P0 to P (m-1) and the reset switches RSW0 to RSW (m-1) and are applied from the PWM control unit 110 to the pulse width control signal PWM0. Selective switching operation is performed by -PWM (m-1). In addition, the reset switches RSW0 to RSW (m-1) are connected between the switches SW0 to SW (m-1) and the ground voltage terminal in accordance with the reset signals RESET0 to RESET (m-1) applied from the PWM control unit 110. Perform an optional switching operation.

Although not shown, the driver IC 100 includes a shift register circuit, a current mirror circuit, a current sink circuit, and the like for sequentially sampling data. The driver IC 100 samples the digital image data and supplies data corresponding to the gray level value of the data to the data line DATA via the precharge control unit 120 and the alternate type precharge driver 130.

In addition, the scan driver 200 is connected to a column line which is a cathode end of the passive matrix organic EL panel 300 to sequentially select the corresponding scan line SCAN. That is, the scan driver 200 generates a scan pulse in response to the scan control signal, and supplies the scan pulse synchronized with the data current to the scan line SCANs to sequentially drive the scan line SCANs.

In the passive matrix organic EL panel 300, a plurality of display elements are arranged in a matrix matrix form while forming pixels. The OLED, which is a display element, is arranged on the scan line SCAN to emit light in proportion to the amount of current supplied from the alternating precharge driver 130.

That is, in the passive matrix organic EL panel 300, a plurality of scan line SCANs are formed in a first direction, and a plurality of data lines DATA spaced at regular intervals in a second direction crossing the first direction are formed to form one pixel. Define the area.

Here, the OLED is disposed in an area where the scan line SCAN in the first direction and the data line DATA in the second direction cross, the scan line SCAN is connected to the cathode of the OLED, and the data line DATA is connected to the anode of the OLED. Accordingly, the OLED is driven by the scan pulse when the signals of the scan line SCAN are enabled, and generates light corresponding to the magnitude of the amount of current applied from the alternating precharge driver 130 through the data line DATA. Done.

FIG. 10 is a detailed circuit diagram illustrating an alternating precharge driver 130 of FIG. 9.

The alternating precharge driver 130 includes a precharge alternating block 131 including the precharge transistors PT1 and PT2 and a 3-bit precharge fine to finely adjust the equivalent resistance of the precharge transistors PT1 and PT2. And a precharge fine-tuning block 132.

Here, the precharge transistors PT1 and PT2 are connected in parallel between the precharge voltage terminal VPRC and the precharge voltage output terminal and constitute PMOS transistors to which even / odd precharge signals PRC_E and PRC_O are applied through respective gate terminals. The drain-source turn-on resistance RDS_ON of the precharge transistor PT2 is preferably larger than the precharge transistor PT1.

In addition, the precharge fine adjustment unit 132 is connected in parallel between the precharge voltage terminal VPRC and the precharge voltage output terminal, and the fine adjustment transistors PC3 to which the fine adjustment signals PTUN (0) to PTUN (2) are applied through respective gate terminals. PC5 is included. Here, it is preferable that a fine adjustment transistor consists of a PMOS transistor.

Further, it is preferable that the drain-source turn-on resistance RDS_ON of the fine tuning transistor PC5 is larger than the fine tuning transistor PC4, and the drain-source turn-on resistance RDS_ON of the fine tuning transistor PC4 is larger than the fine tuning transistor PC3.

The alternating precharge driver 130 discharges the data line DATA before charging the data line DATA before being supplied to the data line DATA under the control of the precharge control unit 120, and then charges it with a precharge current. The data line DATA is selectively discharged or charged before the grayscale data is supplied to the data line DATA.

To this end, the alternate type precharge driver 130 alternately switches the precharge transistors PT1 and PT2 according to the even or odd scan line SCAN information of the scan driver 200.

The data driver 400 includes a current source of each PWM0 to PWM (m-1) branch, a precharge changeover switch of PRC0 to PRC (m-1), and a reset switch of RESET0 to RESET (m-1). It is. The data driver 400 having such a configuration includes a current output circuit, the current output circuit generates a bias current corresponding to the magnitude of the output current output to each channel, and the bias current is sinked in the bias circuit of the selected channel. Sink). In addition, the reset switch NM resets the data line DATA by driving down to the ground voltage when the reset signal RESET applied from the PWM controller 110 is activated.

FIG. 11 is a detailed configuration diagram illustrating the OLED of FIG. 9.

As shown in Fig. 11, the OLED of the passive organic EL panel includes a parasitic capacitor OLED and parasitic resistors RDATA and RSCAN.

FIG. 12 is a diagram for describing the precharge voltage of FIG. 9.

The present invention uses a technique of increasing or decreasing a precharge voltage according to an output position of data to compensate for luminance deviation on the same scan line SCAN.

The alternating precharge driver 130 of the present invention has a three-bit precharge fine adjustment unit 132 having a precharge alternating portion 131 and a relatively high drain-source turn-on resistance RDS_ON compared to the precharge alternating portion 131. It consists of Further, the first and second precharge signals PRC_E and PRC_O are selectively contacted according to the precharge enable signal PRC_ENB switched for each scan line SCAN. Accordingly, the precharge transistors PT1 and PT2 selectively switch to operate to increase or decrease the size of the precharge transistors PT1 and PT2 according to the data position.

Here, when the difference between the precharge voltages of the two precharge transistors PT1 and PT2 of the precharge alternating part 131 is large, the precharge fine adjustment unit 132 may adjust the three-bit fine adjustment signals PTUN (0) to PTUN ( By selectively turning on the fine adjustment transistors PC3 to PC5 according to 2), the precharge voltage is finely adjusted in eight steps to compensate for the optimized precharge voltage difference.

FIG. 13 is a view showing an output waveform of an OLED panel whose luminance is compensated in the luminance interference compensation circuit of the PM-OLED panel according to the present invention.

When applying the mechanism of the present invention, the output from the OLED panel shows a driving waveform whose luminance is compensated as shown in FIG.

As shown in FIG. 5, the OLED panel adopts a structure for connecting scan line SCANs to the left and right sides of the panel. In this structure, the resistance change on the scanline SCAN will repeat the increase-decrease-increase-decrease with the even and odd lines of the scanline SCAN.

Accordingly, the precharge alternator 131 of the present invention has a large precharge transistor PT2 and a large precharge transistor PT1 having a large drain-source turn-on resistance RDS_ON to compensate for the repetitive characteristics of the increase or decrease of the scan resistance on the panel structure. Are alternately connected to every even or odd scan line SCAN to convert the precharge voltage according to the even or odd scan line SCAN.

In addition, the precharge transistors PT1 and PT2 of the precharge alternating unit 131 are configured to increase the MPE and decrease the MPO as they move from the left and right beginning of the panel to the opposite end according to the position of the entire data.

14 is another embodiment of a luminance interference compensation circuit of the PM-OLED panel according to the present invention.

The present invention includes a driver IC 500, a scan driver 600 and a passive matrix organic EL panel 700, wherein the OLEDs are arranged in a matrix structure as shown in FIG.

Here, the driver IC 500 includes a timing controller 510, a precharge controller 520, an alternating precharge driver 530, current sources PAM0 to PAM (m-1), and switches SW0 to SW (m. -1) and reset switches RSW0 to RSW (m-1).

Here, the current sources PAM0 to PAM (m-1) are connected between the power supply voltage terminal and the switches SW0 to SW (m-1), respectively, and input control signals using pulse amplitude modulation (PAM) through image data. Receive. The output current of such current sources PAM0 to PAM (m-1) is determined in accordance with the output of the video data.

The switches SW0 to SW (m-1) are connected between the current sources PAM0 to PAM (m-1) and the reset switches RSW0 to RSW (m-1), and are applied from the timing controller 510 to the pulse magnitude control signal DISP0 to. Selective switching operation is performed by DISP (m-1). In addition, the reset switches RSW0 to RSW (m-1) are connected between the switches SW0 to SW (m-1) and the ground voltage terminal in accordance with the reset signals RESET0 to RESET (m-1) applied from the timing controller 510. Perform an optional switching operation.

Although not shown, the driver IC 500 includes a shift register circuit, a current mirror circuit, a current sink circuit, and the like for sequentially sampling data. The driver IC 500 samples the digital image data and supplies data corresponding to the gray level value of the data to the data line DATA via the precharge control unit 520 and the alternating type precharge driver 530.

In addition, the scan driver 600 is connected to a column line which is a cathode end of the passive matrix organic EL panel 700 to sequentially select the corresponding scan line SCAN. That is, the scan driver 600 generates a scan pulse in response to the scan control signal, and supplies the scan pulse synchronized with the data current to the scan line SCANs to sequentially drive the scan line SCANs.

In the passive matrix organic EL panel 700, a plurality of display elements are arranged in a matrix matrix form while forming pixels. The OLED, which is a display element, is arranged on the scan line SCAN to emit light in proportion to the amount of current supplied from the alternating precharge driver 530.

That is, in the passive matrix organic EL panel 700, a plurality of scan line SCANs are formed in a first direction, and a plurality of data lines DATA spaced at regular intervals in a second direction crossing the first direction are formed to form one pixel. Define the area.

Here, the OLED is disposed in an area where the scan line SCAN in the first direction and the data line DATA in the second direction cross, the scan line SCAN is connected to the cathode of the OLED, and the data line DATA is connected to the anode of the OLED. Accordingly, the OLED is driven by the scan pulse when the signals of the scan line SCAN are enabled and generate light corresponding to the magnitude of the amount of current applied from the alternating precharge driver 530 through the data line DATA. Done.

FIG. 15 is a detailed circuit diagram of an alternating precharge driver 530 of FIG. 14.

The alternating precharge driver 530 includes a precharge alternating block 531 and a 4-bit precharge fine-tuning block 532.

The precharge alternating part 531 includes precharge transistors PT3 and PT4 and bias switches P1 to P4. Here, the bias switches P1 and P2 are controlled by the high level bias voltage BiasH, and the bias switches P3 and P4 are controlled by the low level bias voltage BiasL.

The precharge fine-tuning block 532 includes four-bit fine tuning transistors PC6 to PC9 and bias switches P5 to P12 that finely adjust the output currents of the precharge transistors PT3 and PT4. Here, the bias switches P5 to P8 are controlled by the high level bias voltage BiasH, and the bias switches P9 to P12 are controlled by the low level bias voltage BiasL.

Here, the precharge transistors PT3 and PT4 are formed as PMOS transistors connected in parallel between the voltage terminal VDDH and the precharge voltage output terminal and applied with even / odd precharge signals PRC_E and PRC_O through respective gate terminals.

Then, the precharge fine adjustment unit 532 is connected in parallel between the voltage terminal VDDH and the precharge voltage output terminal, and the fine adjustment transistors PC6 to PC9 to which the fine adjustment signals PTUN (0) to PTUN (3) are applied through respective gate terminals. It includes. Here, it is preferable that a fine adjustment transistor consists of a PMOS transistor.

The alternating precharge driver 530 discharges the data line DATA and charges it with a precharge current before it is supplied to the data line DATA under the control of the precharge control unit 520 and is higher than the reference gray scale. The data line DATA is selectively discharged or charged before the grayscale data is supplied to the data line DATA.

To this end, the alternate type precharge driver 530 alternately switches the precharge transistors PT3 and PT4 according to the even or odd scan line SCAN information of the scan driver 600.

The data driver 540 includes a current source of each PAM0 to PAM (m-1), a precharge switching switch of PRC0 to PRC (m-1), and a reset switch of RESET0 to RESET (m-1). It is. The data driver 540 having such a configuration includes a current output circuit, the current output circuit generates a bias current corresponding to the magnitude of the output current output to each channel, and the bias current is sinked in the bias circuit of the selected channel. Sink). The reset switch NM resets the data line DATA by driving down to the ground voltage when the reset signal RESET applied from the timing controller 510 is activated.

FIG. 16 is a diagram for describing the precharge voltage of FIG. 15.

The present invention uses a technique of increasing or decreasing a precharge current according to an output position of data to compensate for luminance deviation on the same scan line SCAN.

The alternating precharge driver 530 of the present invention has a precharge alternating portion 531 and a 4-bit precharge fine adjusting portion 532 having a relatively low W / L (Width Length) compared to the precharge alternating portion 531. It consists of Further, the first and second precharge signals PRC_E and PRC_O are selectively contacted according to the precharge enable signal PRC_ENB switched for each scan line SCAN. Accordingly, the precharge transistors PT3 and PT4 are selectively switched to increase or decrease the size of the precharge transistors PT3 and PT4 according to data positions.

Here, when the difference between the precharge currents of the two precharge transistors PT3 and PT4 of the precharge alternating unit 531 is large, the precharge fine adjustment unit 532 uses the four bit fine adjustment signals PTUN (0) to PTUN ( By selectively turning on the fine adjustment transistors PC6 to PC9 according to 3), the precharge current is finely adjusted in 16 steps to compensate for the optimized precharge voltage difference. Here, the plurality of fine tuning transistors PC6 to PC9 preferably have different W / L (Width Length).

FIG. 17 is a view illustrating output waveforms of luminance compensated OLED panels in a luminance interference compensation circuit of a PM-OLED panel according to the present invention.

When applying the mechanism of the present invention, the output from the OLED panel shows a driving waveform whose luminance is compensated as shown in FIG.

As shown in FIG. 5, the OLED panel adopts a structure for connecting scan line SCANs to the left and right sides of the panel. In this structure, the resistance change on the scanline SCAN will repeat the increase-decrease-increase-decrease with the even and odd lines of the scanline SCAN.

Accordingly, the precharge alternating part 531 of the present invention evenly or oddly uses the precharge transistor PT4 having a large W / L and the small precharge transistor PT3 to compensate for the repetitive characteristics of the increase or decrease of the scan resistance on the panel structure. It alternately connects each scan line SCAN and converts the precharge voltage according to the even or odd scan line SCAN.

18 is a diagram illustrating an output image in which luminance interference is compensated for in a luminance interference compensation circuit of a PM-OLED panel according to the present invention. In the present invention, as shown in FIG. 18, it is possible to reproduce an image having uniform luminance in all of A, B, and C regions, and the luminance difference between scan lines SCAN is significantly reduced.

In addition, a preferred embodiment of the present invention is for the purpose of illustration, those skilled in the art will be able to various modifications, changes, substitutions and additions through the spirit and scope of the appended claims, such modifications and changes are the following claims It should be seen as belonging to a range.

As described above, in the present invention, the luminance change due to the resistance component present in the scan line electrode inside the passive matrix organic EL display panel is minimized to maintain almost the same luminance on the same scan line. In other words, by adjusting the pre-charge voltage or current in several steps so that it can be changed according to the resistance of the scan line, there is almost no difference in luminance on the scan line, thereby maintaining the almost same luminance even when the resolution of the panel increases. It significantly reduces the luminance interference problem, which is one of the biggest problems, and provides the effect of expanding the application range of OLED in the market.

Claims (26)

A driver IC for varying the precharge voltage corresponding to the scan resistance of the plurality of scan lines and outputting the precharge voltage to the data lines; A scan driver which sequentially supplies scan pulses to the plurality of scan lines to sequentially drive the plurality of scan lines; And An OLED device in an intersection area between the plurality of scan lines and the data line, and driving the OLED device according to the precharge voltage applied through the data line to correspond to luminance interference corresponding to the scan resistance of the scan line Passive matrix organic EL panel to compensate for the luminance interference compensation circuit of the PM-OLED panel comprising a. The method of claim 1, wherein the driver IC A pulse width modulation controller for outputting a pulse width modulation signal and a reset signal; A precharge controller for selectively outputting a precharge enable signal according to scan information applied from the scan driver; And And an alternating precharge driver for supplying the data line to the data line by varying the precharge voltage in response to the scan resistance in response to the precharge enable signal. The method of claim 2, wherein the driver IC A bias transistor for supplying an output current according to the bias voltage; A switch for selectively supplying an output current of the bias transistor according to the pulse width modulation signal; And And a reset switch for resetting the data line according to the reset signal. The method of claim 2, wherein the alternating precharge driver A precharge alternating unit supplying the variable precharge voltage for each even / odd scan line according to the precharge enable signal; And And a precharge fine adjustment unit for fine-adjusting an equivalent resistance of the precharge alternating unit. The method of claim 4, wherein the precharge alternator The brightness of the PM-OLED panel, characterized in that it comprises a first and second precharge transistor connected in parallel between the precharge voltage stage and the precharge voltage output stage and selectively driven by an even precharge signal and an odd precharge signal. Interference compensation circuit. 6. The luminance interference compensation circuit of claim 5, wherein the first and second precharge transistors are PMOS transistors. 6. The luminance interference compensation circuit of claim 5, wherein the second precharge transistor has a larger drain-source turn-on resistance value than the first precharge transistor. The luminance of the PM-OLED panel of claim 5, wherein the alternating precharge driver alternately switches the first and second precharge transistors according to even or odd scan line information of the scan driver. Interference compensation circuit. The method of claim 5, wherein the precharge alternating unit is configured to compensate for a repetitive characteristic of increasing or decreasing scan resistance on a panel structure, and the first precharge having a small turn-on resistance and the second precharge transistor having a large drain-source turn-on resistance. A luminance interference compensation circuit of a PM-OLED panel, characterized in that a transistor is connected alternately every odd or even scan line to convert a precharge voltage according to an even or odd scan line. 5. The luminance interference compensation circuit of claim 4, wherein the precharge fine adjustment unit finely adjusts the precharge voltage to 3 bits. The method of claim 4, wherein the precharge fine adjustment unit And a plurality of fine adjustment transistors connected in parallel between the precharge voltage stage and the precharge voltage output stage and to which a plurality of fine adjustment signals are applied through respective gate terminals. 12. The luminance interference compensation circuit of claim 11, wherein the plurality of fine tuning transistors are PMOS transistors. delete 5. The luminance interference compensation circuit of claim 4, wherein the precharge fine adjustment unit has a drain-source turn-on resistance relatively higher than that of the precharge alternating unit. A driver IC for varying the precharge current corresponding to the scan resistance of the plurality of scan lines and outputting the precharge current to the data lines; A scan driver which sequentially supplies scan pulses to the plurality of scan lines to sequentially drive the plurality of scan lines; And An OLED element in an intersection region between the plurality of scan lines and the data line, and driving the OLED element according to the precharge current applied through the data line to thereby interfere with luminance corresponding to the scan resistance of the scan line Passive matrix organic EL panel to compensate for the luminance interference compensation circuit of the PM-OLED panel comprising a. The method of claim 15, wherein the driver IC A timing controller configured to output a pulse size modulation signal and a reset signal; A precharge controller for selectively outputting a precharge enable signal according to scan information applied from the scan driver; And And an alternating precharge driver configured to vary a precharge current according to the scan resistance and supply the precharge current to the data line according to the precharge enable signal. The method of claim 16, wherein the driver IC A current source for supplying an output current; A switch for selectively supplying an output current of the current source according to the pulse size modulation signal; And And a reset switch for resetting the data line according to the reset signal. The method of claim 16, wherein the alternating precharge driver A precharge alternator for supplying the variable precharge current for each even / odd scan line according to the precharge enable signal; And And a pre-charge fine adjustment unit for fine-adjusting the current of the pre-charge alternating unit. 19. The method of claim 18, wherein the precharge alternator Compensation for luminance interference of a PM-OLED panel, comprising first and second precharge transistors connected in parallel between a voltage terminal and a precharge voltage output terminal and selectively driven by an even precharge signal and an odd precharge signal. Circuit. 20. The luminance interference compensation circuit of claim 19, wherein the first and second precharge transistors are PMOS transistors. 20. The luminance of the PM-OLED panel of claim 19, wherein the alternating precharge driver alternately switches the first and second precharge transistors according to even or odd scan line information of the scan driver. Interference compensation circuit. 19. The luminance interference compensation circuit of claim 18, wherein the precharge fine adjustment unit finely adjusts the precharge current to 4 bits. The method of claim 18, wherein the precharge fine adjustment unit And a plurality of fine adjustment transistors connected in parallel between the voltage terminal and the precharge voltage output terminal and to which a plurality of fine adjustment signals are applied through respective gate terminals. 24. The luminance interference compensation circuit of claim 23, wherein the plurality of fine tuning transistors are PMOS transistors. delete 19. The luminance interference compensation circuit of claim 18, wherein the precharge fine adjustment unit has a relatively lower W / L (Width Length) than the precharge alternating unit.

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