KR20080094240A - Organic light emitting display, display for multi function keypad having the same and driving method thereof - Google Patents

Abstract

An organic light emitting display device, a display device for a multi-functional keypad having the OLED, and a driving method thereof are provided to suppress an image sticking phenomenon by preventing a stationary image from being displayed for a long time. An organic light emitting display device includes a data driver(110), a timer(120), a mode determining unit(130), a light emitting time controller(140), and an OLED(Organic Light Emitting Device) display panel(160). The data driver supplies a data signal. The timer measures a light emitting time and outputs an electrical time signal. The mode determining unit is electrically connected to the data driver and the timer. The light emitting time controller is electrically connected to the mode determining unit and controls a light emitting time of a pixel circuit. The OLED display panel includes at least one pixel circuit which is electrically connected to the light emitting time controller.

Description

Organic light emitting display device, display device for multifunction keypad using same and driving method thereof {Organic Light Emitting Display, Display for Multi Function Keypad Having the Same And Driving Method}

1 is an exploded perspective view showing the configuration of a multi-function keypad display device using the organic light emitting display device according to the present invention.

2 is a block diagram illustrating a configuration of an organic light emitting display device according to an exemplary embodiment of the present invention.

3 is a block diagram illustrating a configuration of a mode determination unit of an organic light emitting display device according to an exemplary embodiment of the present invention.

4 is a circuit diagram illustrating a connection relationship between a mode determiner, an emission time controller, and a pixel circuit of an organic light emitting display device according to an exemplary embodiment of the present invention.

FIG. 5 is a circuit diagram illustrating a connection relationship between a mode determiner, an emission time controller, and a pixel circuit of an organic light emitting display device according to another exemplary embodiment.

6 is a driving timing diagram illustrating an operation of an organic light emitting display device according to an exemplary embodiment of the present invention.

<Short description of drawing symbols>

100,200; Organic electroluminescent display device according to an embodiment of the present invention

110; A data driver 120; timer

130; A mode determination unit 131; Data storage

132; A comparison judgment unit 133; Control signal output

140; A light emission time controller 150; Scan driver

160; The organic electroluminescent display panel 161; Pixel circuit

SW; Switching capacitor C; Pixel capacitors

TR; Drive transistor OLED; Organic electroluminescent display

SW-C; Control transistor

Vrst; Initialization transistor

The present invention relates to an organic light emitting display device, a display device for a multifunction keypad using the same, and a driving method thereof. More particularly, the organic light emitting display device and a multifunction keypad using the same can be used to prevent color sticking. It relates to a display device.

In general, an organic light emitting display device is a display device for electrically exciting a fluorescent or phosphorescent organic compound to emit light, and is capable of displaying an image by driving N × M organic light emitting diodes (OLEDs). The organic light emitting display device is classified into an active organic light emitting display device and a passive organic light emitting display device.

Organic Light Emitting Display (OLED) The organic light emitting cells have a structure of an anode (ITO), an organic thin film, and a metal (metal). The organic thin film has a multilayer structure including an emission layer, an electron transport layer (ETL), and a hole transport layer (HTL), and has a separate electron injecting layer (EIL) and holes. It may include a hole injecting layer (HIL).

The organic light emitting display device is a self emitting display method in which holes injected from an anode and electrons injected from a cathode combine to emit light by combining in the emission layer.

However, in the organic light emitting display device, an afterimage may occur when data is applied to a fixed screen for a long time. That is, when data that does not change for a long time is applied to the organic light emitting display device, there is a problem of image sticking in which afterimages of previous data remain at the moment when the data changes.

Furthermore, when the organic electroluminescent display is used for a keypad in a device such as a mobile phone, the image sticking becomes more problematic because text such as numbers or letters is often displayed on the keypad.

SUMMARY OF THE INVENTION The present invention has been made to overcome the above-mentioned conventional problems, and an object of the present invention is to enable color conversion when fixed data is applied to a display for a predetermined time or more, thereby preventing organic sticking. SUMMARY A display device and a display device for a multi-function keypad using the same are provided.

In order to achieve the above object, the organic light emitting display device according to the present invention includes a data driver for supplying a data signal, a timer measuring an emission time and outputting an electrical time signal, a data driver, and a mode determination unit electrically connected to the timer. The organic light emitting display panel may include an emission time controller electrically connected to a mode determining unit to control an emission time of a pixel circuit, and at least one pixel circuit electrically connected to the emission time controller.

Here, the mode determiner may determine whether the image mode or the text mode is analyzed by analyzing the data signal displayed on the pixel circuit.

The mode determination unit may include a data storage unit electrically connected to a data driver to store the data signal, a comparison determination unit electrically connected to a data storage unit, and a control signal output unit electrically connected to the comparison determination unit. can do.

The comparison determiner may receive a time signal from a timer and compare the data signal stored in the data storage to determine whether the image mode or the text mode is used.

The control signal output unit may receive a signal from the comparison determination unit to control a signal supplied to the emission time controller.

In addition, the emission time controller may control a supply time of data supplied to the pixel circuit.

The emission time controller may control the supply time of the data such that each RGB pixel emits light sequentially.

In addition, the light emission time controller may be a demux.

In addition, the keypad assembly using the organic light emitting display device according to the present invention in order to achieve the above object has a plurality of openings on the organic light emitting display device, the organic electroluminescent display device through the opening on the circuit board and the circuit board formed. The organic light emitting display includes a pad sheet in which a transparent window is formed at a position corresponding to the opening so that the organic light emitting display is visible from the outside. A timer for outputting a time signal, a mode determiner electrically connected to the data driver and a timer, an emission time controller electrically connected to the mode determiner to control an emission time of the pixel circuit, and at least one pixel electrically connected to the emission time controller Organic electroluminescent display panel with circuit Can contain boards.

In addition, the mode determination unit may determine whether the image mode or the text mode by analyzing the data signal displayed on the pixel circuit.

The mode determination unit may include a data storage unit electrically connected to a data driver to store the data signal, a comparison determination unit electrically connected to a data storage unit, and a control signal output unit electrically connected to the comparison determination unit. can do.

The comparison determiner may receive a time signal from a timer and compare the data signal stored in the data storage to determine whether the image mode or the text mode is used.

The control signal output unit may receive a signal from the comparison determination unit to control a signal supplied to the emission time controller.

In addition, the emission time controller may control a supply time of data supplied to the pixel circuit.

The emission time controller may control a data supply time so that each RGB pixel emits light sequentially.

In addition, the light emission time controller may be a demux.

In addition, in order to achieve the above object, a method of driving an organic light emitting display device according to the present invention includes a data driving step in which a data driver supplies a data signal, and a light emission time in which a timer measures an emission time to output an electrical time signal. A mode determining step of determining whether the mode determiner electrically connected to the measurement step, the data driver and the timer is the image mode or the text mode, and the emission time controller electrically connected to the mode determiner controls the application time of the data signal. And a light emitting step of emitting light by the pixel circuit of the organic light emitting display panel electrically connected to the light emitting time controller.

The mode determining step may include a step of determining whether the mode determining unit is an image mode or a text mode by analyzing the data signal displayed on the pixel circuit.

The mode determining unit may further include a data storage unit electrically connected to a data driver to store the data signal, a comparison determination unit electrically connected to a data storage unit, and a control connected to the comparison determination unit. It may include a signal output unit.

In addition, the mode determining step may include a step of comparing the time signal received from the timer by the comparison determination unit and comparing the data signal stored in the data storage unit to determine whether the image mode or text mode.

The mode determining step may include controlling a signal supplied to the emission time controller by receiving a control signal output unit from the comparison determination unit.

The light emission time controlling step may be a step in which the light emission time control unit controls a supply time of data supplied to the pixel circuit.

In addition, the light emitting time controlling may include controlling the light emitting time control unit to sequentially emit light of each RGB pixel by controlling the data supply time.

In the light emitting time controlling step, the light emitting time controller may be a demux.

In addition, in order to achieve the above object, a method of driving a keypad assembly using an organic light emitting display device according to the present invention includes a signal input step in which an external input signal is applied through a pad sheet having a transparent window, and a plurality of openings. And a keypad signal output step in which a circuit board electrically connected to the pad sheet receives the input signal and outputs a keypad signal, and a keypad image display step in which an organic electroluminescent display electrically connected to the circuit board displays an image on a keypad. The keypad image display step may include a data driving step of supplying a data signal to a data driver, a light emitting time measuring step of outputting an electrical time signal by a timer measuring a light emitting time, and whether the mode determining unit is an image mode or a text mode. Mode determination step of determining, light emission time control unit A light emission time control step of controlling the application time of the data signal, may include a light emitting method comprising: a pixel circuit of an organic light emitting display panel to emit light.

The mode determining step may include determining whether the mode determining unit is in an image mode or a text mode by comparing data signals displayed on the pixel circuit.

The mode determining unit may further include a data storage unit electrically connected to the data driver to store a data signal, a comparison determination unit electrically connected to the data storage unit, and a control signal electrically connected to the comparison determination unit. It may include an output unit.

In addition, the comparison determination unit in the mode determination step may receive a time signal from a timer, and compare the data signal stored in the data storage unit to determine whether the image mode or the text mode.

In addition, the control signal output unit in the mode determination step may receive a signal from the comparison determination unit to control a signal supplied to the emission time controller.

In addition, the light emission time controlling may include controlling the supply time of data supplied to the pixel circuit by the light emission time controller.

In addition, the light emitting time control may include a step in which the light emitting time control unit controls the supply time of data so that each RGB pixel sequentially emits light.

In addition, the emission time control step may be the emission time control unit Demux (DEMUX).

As described above, the organic light emitting display device according to the present invention, the keypad assembly using the same, and a driving method thereof prevent image sticking by sequentially driving an RGB pixel in the text mode.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily practice the present invention.

Hereinafter, a display device for a multifunction keypad using the organic light emitting display device of the present invention will be described.

1 is a perspective view illustrating a configuration of a display device for a multi-function keypad using an organic light emitting display device according to the present invention.

As shown in FIG. 1, a multi-function keypad display device using the organic light emitting display device of the present invention is formed on a case 10, a main circuit board 20 formed on the case, and an upper portion of the main circuit board. The organic light emitting display panel 30, a circuit board 40 formed on the organic light emitting display panel, a pad 50 formed on the circuit board, and a cover mounted on the pad. can do.

The case 10 may include a bottom surface 11 and a plurality of sidewalls 12 formed at a predetermined height at an edge side of the bottom surface 11. The case 10 may be formed of any one selected from a plastic resin, a metal, and an equivalent thereof, but is not limited thereto.

The main circuit board 20 includes a substrate body 21 having a substantially rectangular plate shape, a plurality of active elements 22 mounted on the substrate body 21, a plurality of passive elements 23, and a first one. Flexible printed circuit 24, connector 25, and the like. The main circuit board 20 supplies or receives an electrical signal to the organic light emitting display panel 30, the circuit board 40, or a main display panel of an electronic device to be described below. Here, the first flexible printed circuit 24 may be electrically connected to the circuit board 40, and the connector 25 may be connected to the organic electroluminescent display panel 30 to be described later. The circuit 33 can be electrically connected.

The organic electroluminescent display panel 30 may be formed by arranging the plurality of display regions 32 in a substantially matrix form with the non-display region 31 as a boundary. Of course, a second flexible printed circuit 33 electrically connected to the connector 25 of the main circuit board 20 may be electrically connected to one side of the organic light emitting display panel 30. In addition, the organic electroluminescent display panel 30 may be surrounded by a bottom surface and a side surface of the bezel 34 made of resin or metal so as not to be damaged by an external impact.

The display area 32 freely changes and outputs letters, numbers, special symbols, still images, or moving images according to a user's selection, thereby making the user interface shallower, thereby facilitating key operation. Of course, since no image is output to the non-display area 31 formed outside the display area 32, power consumption is minimized. That is, pixels may be formed in the display area 32 of the organic light emitting display panel 30 to output light of a predetermined color (red, green, or blue), and light is output in the non-display area 31. The pixel may not be formed so as not to.

The display area 32 may be driven in an image mode and a text mode according to a user's selection. In the text mode, text is often displayed on the display area 32 for a long time. However, in this case, when the user attempts to change the display image of the display area 32 by manipulation of the keypad, there may be a problem of image sticking, in which the existing text remains in the afterimage on the display area 32.

The organic electroluminescent display device according to the present invention is to solve the image sticking problem in the text mode, which will be described in detail in the following embodiments of the present invention.

The circuit board 40 may include a substrate body 41 having an opening 42 formed in an area corresponding to the display area 32 of the organic light emitting display panel 30, and as one side of the opening 42. The key 43 may be formed in an area corresponding to the non-display area 31. In addition, a plurality of keys 44 may be formed in the circuit board 40 in an area that does not correspond to the display area 32 of the organic light emitting display panel 30. That is, a plurality of keys 44 may be formed in an area that does not correspond to the opening 42. The circuit board 40 may be electrically connected to the main circuit board 20 by the first flexible printed circuit 24. Therefore, the operation signals of the keys 43 and 44 provided on the circuit board 40 can be properly transmitted to the main circuit board 20 through the first flexible printed circuit 40.

The pad 50 may include a pad body 51 having a transparent window 52 formed in an area corresponding to the opening 42 (that is, an area corresponding to the display area 32), and the transparent window 52. As one side of the key 43 may be made of a pressing unit 53 formed in a region corresponding to the. Here, the pad 50 may further include a plurality of pressing parts 54 in regions where the display area 32 of the organic light emitting display panel 30 does not correspond to the opening 42 of the circuit board 40. Can be. That is, a plurality of pressing parts 54 may be formed in an area corresponding to the key 44 of the circuit board 40. In addition, the transparent window 52 may be closed by any one selected from transparent resin, transparent glass, and equivalents thereof. The pad 50 of this structure operates the keys 43 and 44 when the user presses the pressing parts 53 and 54, and an operation signal of the keys 43 and 44 is the first flexible printed circuit 24. It may be delivered to the main circuit board 20 through.

The cover 60 may include a cover body 61 having a window 62 formed in an area corresponding to the opening 42 and the pressing portion 53 of the pad 50. Therefore, the display area 32 of the organic light emitting display panel 30 is visible through the window 62 of the cover 60, and the user is exposed through the window 62 of the cover 60. By operating the press part 53 which has been provided, it becomes possible to input a predetermined command.

As described above, when the organic electroluminescent display is used for the multifunction keypad, a fixed data value is often displayed for a long time in the text mode of the keypad, and image sticking is often problematic. Accordingly, the keypad assembly according to the present invention uses an organic light emitting display device for preventing such image sticking, and a detailed description of the organic light emitting display device will be given below.

Hereinafter, the configuration of the organic light emitting display device 100 according to an exemplary embodiment will be described.

2 and 3 are block diagrams illustrating the configuration of the organic light emitting display device 100 according to an exemplary embodiment of the present invention.

As shown in FIG. 2, the organic light emitting display device 100 according to an exemplary embodiment of the present invention has a mode connected to a data driver 110, a timer 120, and the data driver 110 and the timer 120. A light emission time controller 140 connected to the determination unit 130, the data driver 110, and the mode determiner 130, a scan driver 150, and a light emission time controller 140 and the scan driver 150. The organic light emitting display panel 160 may be included.

The data driver 110 applies a data voltage value to the organic light emitting display panel 160. The emission level of the organic light emitting display panel 160 is determined by a data voltage applied thereto. Accordingly, the data driver 110 controls the emission level of the organic light emitting display panel 160 to display image information by controlling data values.

The timer 120 measures the time that the organic light emitting display panel 160 emits light. The operation of the timer 120 will be described below.

First, the timer 120 receives a clock pulse applied to the data driver 110 and the scan driver 150.

The clock pulse is an electrical signal that is repeated at regular intervals and becomes a reference signal for distinguishing frames in the organic light emitting display device. In general, the clock pulses are simultaneously applied to the data driver and the scan driver in order to achieve synchronization in the organic light emitting display.

In the organic light emitting display device 100 according to an exemplary embodiment of the present invention, a clock pulse is applied to the timer 120, and the timer 120 may maintain synchronization by the clock pulse. In addition, the timer 120 may measure the time that the organic light emitting display panel 160 emits light by the data driver 110 and the scan driver 150 by counting the pulse number of the clock pulse. The timer 120 applies the measured time signal to the mode determiner 130.

The mode determiner 130 is electrically connected to the data driver 110 and the timer 120. In addition, referring to FIG. 3, the mode determination unit 130 may include a data storage unit 131, a comparison determination unit 132 electrically connected to the data storage unit 131, and the comparison determination unit 132. The control signal output unit 133 may be electrically connected.

The data storage unit 131 is electrically connected to the data driver 110. The data storage unit 131 receives and stores a data value from the data driver 110. In addition, by applying the stored data value to the comparison determination unit 132 which will be described later, the comparison determination unit 132 may compare the current and previous data values.

The comparison determination unit 132 is electrically connected to the data storage unit 131. In addition, referring to FIG. 3, the comparison determining unit 132 is also electrically connected to the timer 120. Accordingly, the comparison determination unit 132 receives the stored data value of the data storage unit 131 and the time signal of the timer 120.

The comparison determination unit 132 analyzes the data signal to determine whether an image displayed on the organic light emitting display panel is an image mode or a text mode. That is, the comparison determination unit 132 analyzes the stream of the data signal to determine whether the data signal supplied to the organic light emitting display panel 160 is an image signal or a text (character) signal. .

When the data signal is in the image mode through the above process, the data signal is applied to the organic light emitting display panel 160 without any additional process.

However, when the data signal is in the text mode, the following process is performed to solve the above-described problem of image sticking.

In the text mode, the comparison determination unit 132 determines the change of the data value during the reference time. That is, the comparison determination unit 132 determines whether the data value of the data driver 110 is changed based on the time signal applied through the timer 120.

The reference time is determined by using factors such as a current value flowing through the organic light emitting display device, a material used for the light emitting layer of the organic light emitting display device, a type of a device using the organic light emitting display device, and the like. The determination is made based on the time signal.

If the data value does not change beyond the reference time, image sticking may occur in text mode. When the data value does not change in the text mode, the comparison determination unit 132 applies an output signal to the control signal output unit 133 to control the emission time controller 140.

The control signal output unit 133 is electrically connected to the comparison determination unit 132 and the emission time control unit 140. The control signal output unit 133 applies the control signal when the comparison plate end 132 determines the picture mode or when the control mode outputs the data value within the reference time. ) Does not work. That is, since the image sticking problem does not occur in the above case, the emission time controller 140 does not operate, and the data voltage value is directly applied from the data driver 110 to the organic light emitting display panel 160.

However, when the comparison determining unit 132 determines that the text value is in the text mode and the data value does not change during the reference time, the control signal output unit 133 emits a control signal for causing the emission time control unit 140 to operate. It is applied to the time controller 140. The shape of the control signal and the operation of the light emission time driver will be described in detail later with reference to FIGS. 4 and 5.

The light emission time controller 140 is electrically connected to the data driver 110 and the mode determiner 130. The emission time controller 140 receives a control signal from the control signal output unit 133 to control an application time of a data signal applied to the organic light emitting display panel 160.

The emission time controller 140 may be configured using a demultiplexer (DEMUX), but may be configured to control an application time of a data signal applied to the organic light emitting display panel 160 without being limited thereto. The light emission time controller 140 may be used.

When the comparison determining unit 132 determines that the data value changes in the image mode or the text mode during the reference time, the emission time controller 140 does not operate and the data signal is the organic light emitting display panel 160. As it is, it is described above.

However, when the comparison determining unit 132 determines that the text value is in the text mode and the data value does not change during the reference time, the control signal output unit 133 applies an application signal of the data signal applied to the organic light emitting display panel 160. To control.

That is, in the above case, in order to prevent image sticking, the emission time of each RGB pixel is controlled. In the control method, the RGB pixel includes red (R), green (G), It can be made to drive in order of blue (B). That is, image sticking is prevented by driving all of the RGB pixels instead of continuously emitting light. However, the driving order of each RGB pixel in the organic light emitting display device 100 according to an exemplary embodiment of the present invention is not limited as described above, and the order may be changed in some cases. Do. In addition, a detailed description of the sequential driving will be made in the description of FIGS. 4 and 5 to be described below.

The scan driver 150 applies a scan signal to the organic light emitting display panel 160. The organic light emitting display panel 160 is divided into an active organic light emitting display panel and a passive organic light emitting display panel according to the presence or absence of a transistor. In the active organic light emitting display panel, the scan driver 150 is connected to a control electrode of the transistor to control on / off of the switching transistor. In addition, in the passive organic light emitting display panel, the scan driver 150 is connected to a cathode of an organic light emitting display device (OLED).

The organic light emitting display panel 160 is electrically connected to the emission time controller 140 and the scan driver 150. Referring to FIG. 2, the organic light emitting display panel 160 is electrically connected to a plurality of data lines D [1] to D [m] electrically connected to the emission time controller 140 and the scan driver. A plurality of scan lines S [1] to S [n], data lines D [1] to D [m] and scan lines S [1] to S [n] are connected to each other. A plurality of pixel circuits 161 may be included.

The pixel circuit 161 is an area that emits light in the organic light emitting display device, and the pixel circuit 161 may be classified into an active type and a passive type according to the presence or absence of a transistor. The structure of the pixel circuit 161 will be described later with reference to FIGS. 4 and 5.

Hereinafter, the relationship between the mode determiner 130, the emission time controller 140, and the pixel circuit 161 in the organic light emitting display device 100 according to an exemplary embodiment will be described.

4 is a circuit diagram illustrating a connection relationship between a mode determiner 130, an emission time controller 140, and a pixel circuit 161 in the organic light emitting display device 100 according to an exemplary embodiment.

As shown in FIG. 4, the organic light emitting display device 100 according to an embodiment of the present invention has a light emission time including a mode determination unit 130 and at least one transistor connected to the mode determination unit 130. The pixel circuit 161 may include a controller 140 and at least one transistor connected to the emission time controller 140.

4, the mode determiner 130 may be connected to the emission time controller 140 through a plurality of control lines CR, CG, and CB. The control lines CR, CG, and CB distinguish each control line connected to each RGB pixel. Referring to FIG. 3, the control lines CR, CG, and CB are connected to the control signal output unit 133 among the mode determination unit 130. 4, an initialization signal line Rst is connected to the mode determination unit 130. The initialization signal line Rst is for initializing the pixel circuit 161 before new data is applied to the pixel circuit 161. Although shown in the drawing, the initialization signal line Rst may be omitted in some cases.

The emission time controller 140 displays an example using a demux (DEMUX, Demultiplxer), and as shown in FIG. 3, the control transistors SW-CR, SW-CG, CW-CB, and the initialization transistor Vrst-R. , Vrst-G, Vrst-B). Hereinafter, a configuration and an operation of the light emission time controller 140 will be described using a red pixel as a representative example.

In the red pixel, the control transistor SW-CR has a control electrode (gate electrode) connected to the mode determining unit 130 through a control line CR. In addition, a first electrode (source or drain electrode) of the control transistor SW-CR is connected to the data driver 110, and a second electrode (drain or source electrode) is connected to the pixel circuit 161. It is.

When the mode determiner 130 determines that the data signal is a picture mode or a text mode in which the data value changes during the reference time, the control transistor SW-CR is turned on. That is, a low voltage signal is applied from the mode determining unit 130 through the control line CR to turn on the control transistor SW-CR. Therefore, the data voltage value Vdata of the data driver 110 is applied to the pixel circuit 161 as it is, so that the pixel circuit 161 emits light.

On the other hand, when the mode determination unit 130 determines that the data signal is a text mode in which the data value does not change during the reference time, the control line CR is applied to the control electrode of the control transistor SW-CR. Signal changes. That is, the control signal through the control lines CR, CG, and CB is applied in a pulse train of a constant cycle.

Accordingly, the turn on / off of the control transistors SW-CR, SW-CG, and SW-CB is periodically changed according to the period of the control signal. As a result, a process in which a data value of the data driver 110 is applied to the organic light emitting display panel 160 and a process of blocking the data value is periodically performed according to the period of the control signal.

Accordingly, the RGB pixels periodically repeat the turn-on / turn-off process even though the data value of the data driver 110 remains constant. Therefore, even in the text mode, the pixels repeat the turn-on / turn-off states, thereby solving the conventional image sticking problem.

In addition, the turn-on / turn-off pattern of the pixels may be generated according to the shape of the control signal. In addition, if the RGB pixels are sequentially driven with periodicity, the human eye cannot recognize that the light emitting pixels of the display image change in the text mode, and thus there is no problem in expressing the required color of the image. Only the problem of image sticking can be solved. The pattern of turn-on / turn-off of each of the RGB pixels corresponding to the control signals CR, CG, and CB applied to the RGB pixels will be described later with reference to FIG. 6.

The initialization transistor Vrst-R is turned on when the mode determining unit 130 applies an initialization signal through the initialization signal line Rst. That is, when the mode determining unit 130 maintains a high voltage value and applies a low voltage signal, the initialization transistor Vrst-R is turned on. In this case, the initialization voltage Vrst, which is the high voltage value, is applied to the pixel circuit 161 so that the pixel circuit 161 is initialized. However, the initialization transistor Vrst-R for initialization may be omitted in some cases.

Referring to FIG. 4, the pixel circuit 161 may include a switching transistor SW, a driving transistor TR connected to a second electrode of the switching transistor, and a control electrode of the driving transistor TR and a first electrode. The capacitor C may include an organic light emitting display OLED connected to the second electrode of the driving transistor. That is, it is an active matrix type having a transistor. Hereinafter, a red pixel will be described as a representative example.

Referring to FIG. 4, in the red pixel, the switching transistor SW-R is electrically connected to the scan driver 150 through a scan line S [n]. In more detail, in the switching transistor SW-R, a control electrode is connected to the scan line S [n], and a first electrode is connected to the data line D [m]. Therefore, when a low voltage signal is applied from the scan driver 150, the switching transistor SW-R is turned on and the data value of the data driver 110 is applied to the driving transistor TR-R. do.

A control electrode of the driving transistor TR-R is electrically connected to the second electrode of the switching transistor SW-R. Therefore, when the switching transistor SW-R is turned on, a data value is applied to the control electrode of the driving transistor TR-R. In this case, a current generated by the voltage value difference between the control electrode and the first electrode of the driving transistor TR-R flows through the organic light emitting display device OLED, and the organic electroluminescence is generated by the current. The display element OLED emits light.

The capacitor C is electrically connected between the control electrode and the first electrode of the driving transistor TR-R. Therefore, even if a data signal is not continuously applied to the control electrode of the driving transistor TR-R, the capacitor C maintains a constant voltage difference between the control electrode of the driving transistor TR-R and the first electrode. Make it. As a result, a constant current flows through the organic light emitting display device OLED, so that brightness of light is maintained constant.

The organic light emitting display device 100 according to an embodiment of the present invention allows the RGB pixels to sequentially emit light in the text mode as described above, so that the color of the image required for the human eye is not affected. The advantage is that only the problem of image sticking can be solved.

Hereinafter, the configuration of the organic light emitting display device 200 according to another exemplary embodiment will be described.

5 is a circuit diagram illustrating a connection relationship between a mode determiner, an emission time controller, and a pixel circuit of an organic light emitting display device 200 according to another exemplary embodiment.

Referring to FIG. 5, the organic light emitting display device 200 according to another exemplary embodiment of the present invention may include a mode determining unit 130 and an emission time control unit including at least one transistor connected to the mode determining unit 130. In addition to 140, a pixel circuit 261 including at least one transistor connected to the emission time controller 140 may be included.

The organic electroluminescent display 200 according to another exemplary embodiment of the present invention except for the pixel circuit 261, the rest of the organic electroluminescent display 100 according to an embodiment of the present invention described above Is the same as Parts having the same configuration and operation have been given the same reference numerals, and will be described below based on the differences.

The pixel circuit 261 may include an organic light emitting display OLED formed in a region divided by a plurality of scan lines S [n] and a plurality of data lines D [m].

An anode of the organic light emitting diode OLED is electrically connected to the data driver 110 through the data line D [m], and a cathode of the organic light emitting diode OLED is connected to the scan line S [n]. It is electrically connected to the scan driver 150. That is, the data voltage value by the data driver 110 and the voltage value by the scan driver 110 are applied to both ends of the organic light emitting display device OLED, so that the organic light emitting display device OLED is It is a passive matrix that emits light.

As described above, when the mode determining unit 130 determines the image mode or the text mode in which the data value changes during the reference time, the mode determining unit 130 is connected to the control electrodes of the control transistors SW-CR, SW-CG, and SW-CB. A low voltage control signal is applied. Accordingly, the pixel circuits 261 emit light corresponding to data values for each RGB pixel.

On the contrary, when the mode determining unit 130 determines that the text mode does not change during the reference time, the control signals through the control lines CR, CG, and CB change periodically and sequentially. Therefore, in this case, the pixel circuits 261 are sequentially driven to prevent image sticking, as in the above-described embodiment.

As described above, image sticking may be prevented, and the transistors of the emission time controller 140 and the pixel circuit 161 are illustrated as p-type metal oxide semiconductor field effect transistors (PMOS), but the present invention It is not limited to the p-type Metal Oxide Semiconductor Field Effect Transistor (PMOS), and it is also possible to use an n-type Metal Oxide Semiconductor Field Effect Transistor (NMOS), a Bubble Junctioin Transisror (BJT), and an equivalent thereof.

Hereinafter, the pattern of the control signal and the light emission pattern of each RGB pixel in the organic light emitting display device 100 according to an exemplary embodiment of the present invention will be described with reference to the driving timing diagram.

6 is a driving timing diagram illustrating an operation of the organic light emitting display device 100 according to an exemplary embodiment of the present invention.

Referring to FIG. 6, the driving timing diagram illustrates a control signal at each control line CR, CG, and CB and a turn on / off operation at each RGB pixel.

When the mode determiner 130 determines that the data signal is a text mode that does not change for a reference time, control signals of the control lines CR, CG, and CB change periodically.

6 illustrates an example of a pattern in which the control signal changes, and a control signal having a low voltage value is transmitted to the red pixel control transistor SW- of the emission time controller through the red pixel control line CR. When applied to the control electrode of CR, the red pixel circuit is first turned on.

Subsequently, a control signal having a low voltage value is transmitted through the green pixel control line CG at a predetermined time interval (1/5 of one frame period in the drawing) to control the green pixel control transistor SW-CG of the emission time controller. Is applied to the control electrode. Thus, the green pixel circuit is turned on. That is, at this time, both the red pixel circuit and the green pixel circuit are turned on.

Subsequently, a control signal of low voltage value is supplied to the blue pixel control transistor SW of the emission time controller at a predetermined time interval (1/5 of one frame period in the drawing) through the blue pixel control line CB. -CB) is applied to the control electrode. Thus, the blue pixel circuit is turned on. That is, at this time, all of the red pixel circuit, the green pixel circuit, and the blue pixel circuit are turned on.

In a state where all of the red, green, and blue pixel circuits are turned on, a control signal having a high voltage value is applied to the red pixel control transistor SW of the emission time controller through the red pixel control line CR. -CR) is applied to the control electrode. Thus, the red pixel circuit is turned off. That is, at this time, only the green pixel circuit and the blue pixel circuit are turned on.

In this manner, after that, only the red pixel circuit and the blue pixel circuit are turned on, and after a predetermined time, only the red pixel circuit and the green pixel circuit are turned on, and the process is repeated.

As described above, by sequentially driving the RGB pixel circuit, the problem of conventional image sticking can be solved. In the driving timing diagram of FIG. 6, the case where the time interval to be turned on is 1/5 of one frame has been described as an example. However, in some cases, the time interval may be different. That is, as long as it is a pattern capable of sequentially driving the RGB pixel circuits, various modifications can be made without being concerned with the order and time interval.

As described above, the organic light emitting display device according to the present invention, a display device for a multi-function keypad using the same, and a method of driving the same according to the present invention are known in the order of knowing the organic light emitting display device when a certain data is applied to a fixed screen for a long time. It is possible to prevent the image sticking phenomenon in which a conventional afterimage occurs due to the fixed image not being maintained for a long time by driving each color.

What has been described above is just one embodiment for implementing the organic light emitting display device and the display device for the multi-function keypad using the same, the present invention is not limited to the above-described embodiment, the following claims As claimed in the present invention, those skilled in the art to which the present invention pertains will have the technical spirit of the present invention to the extent that various modifications can be made without departing from the gist of the present invention.

Claims (32)

A data driver supplying a data signal; A timer measuring the light emission time and outputting an electrical time signal; A mode determiner electrically connected to the data driver and a timer; An emission time control unit electrically connected to the mode determination unit to control an emission time of a pixel circuit; And an organic electroluminescent display panel having at least one pixel circuit electrically connected to the emission time controller. The organic light emitting display device as claimed in claim 1, wherein the mode determiner analyzes a data signal displayed on the pixel circuit to determine whether the image mode is a text mode or a text mode. The method of claim 1, wherein the mode determination unit A data storage unit electrically connected to the data driver to store the data signal; A comparison determination unit electrically connected to the data storage unit; And And a control signal output unit electrically connected to the comparison determination unit. The organic light emitting display device as claimed in claim 3, wherein the comparison determination unit receives a time signal from the timer and compares the data signal stored in the data storage unit to determine whether the image mode or the text mode is used. . The organic light emitting display as claimed in claim 3, wherein the control signal output unit controls a signal supplied to the emission time controller by receiving a signal from the comparison determination unit. The organic light emitting display device as claimed in claim 1, wherein the emission time controller controls a supply time of data supplied to the pixel circuit. The organic light emitting display as claimed in claim 1, wherein the emission time controller controls the data supply time so that each RGB pixel emits light sequentially. The organic light emitting display as claimed in claim 1, wherein the emission time controller is a demux. Organic electroluminescent display; A circuit board having a plurality of openings on the organic light emitting display device; And And a pad sheet on the circuit board through which the transparent window is formed at a position corresponding to the opening such that the organic electroluminescent display is visible from the outside. The organic light emitting display device includes a data driver for supplying a data signal, a timer measuring an emission time, and outputting an electrical time signal, a mode determiner electrically connected to the data driver and the timer, and electrically connected to the mode determiner. And an organic electroluminescent display panel having at least one pixel circuit electrically connected to the emission time controller to control an emission time of a pixel circuit. The keypad assembly of claim 9, wherein the mode determiner analyzes a data signal displayed on the pixel circuit to determine whether the image mode is a text mode or a text mode. The method of claim 9, wherein the mode determination unit A data storage unit electrically connected to the data driver to store the data signal; A comparison determination unit electrically connected to the data storage unit; And And a control signal output unit electrically connected to the comparison determining unit. The keypad assembly of claim 11, wherein the comparison determining unit receives a time signal from the timer and compares the data signal stored in the data storage unit to determine whether the image mode or the text mode is used. The keypad assembly of claim 11, wherein the control signal output unit controls a signal supplied to the emission time controller by receiving a signal from the comparison determination unit. The keypad assembly of claim 9, wherein the emission time controller controls a supply time of data supplied to the pixel circuit. The keypad assembly of claim 9, wherein the emission time controller controls the supply time of the data such that each RGB pixel emits light sequentially. The keypad assembly of claim 9, wherein the light emission time controller is a demux. A data driving step of supplying a data signal to the data driver; A light emission time measuring step of outputting an electrical time signal by a timer measuring light emission time; A mode determination step of determining whether a mode determination unit electrically connected to the data driver and a timer is an image mode or a text mode; An emission time control step of controlling an application time of the data signal by an emission time control unit electrically connected to the mode determination unit; And And emitting light from a pixel circuit of the organic light emitting display panel electrically connected to the light emitting time controller. 18. The organic light emitting display device as claimed in claim 17, wherein the mode determining step includes determining whether the mode determining unit is an image mode or a text mode by analyzing a data signal displayed on the pixel circuit. Method of driving. The method of claim 17, wherein the mode determination unit of the mode determination step A data storage unit electrically connected to the data driver to store the data signal; A comparison determination unit electrically connected to the data storage unit; And And a control signal output unit electrically connected to the comparison determination unit. 20. The method of claim 19, wherein the determining of the mode comprises: receiving the time signal from the timer by the comparison determination unit, and comparing the data signal stored in the data storage unit to determine whether the image mode or the text mode is used. A method of driving an organic light emitting display device, characterized in that. The method of claim 19, wherein the determining of the mode comprises: controlling the signal supplied to the emission time controller by the control signal output unit receiving a signal from the comparison determination unit; Way. The method of claim 17, wherein the controlling of the emission time comprises controlling the supply time of data supplied to the pixel circuit. 18. The organic light emitting display of claim 17, wherein the controlling of the light emitting time comprises causing the light emitting time controller to control the supply time of the data so as to sequentially light each RGB pixel. Method of driving the device. 18. The method of claim 17, wherein the emission time control step is a demux (DEMUX). A signal input step of applying an external input signal through the pad sheet on which the transparent window is formed; A keypad signal output step of outputting a keypad signal by receiving the input signal from a circuit board having a plurality of openings and electrically connected to the pad sheet; And A keypad image display step of displaying an image on a keypad by an organic electroluminescent display electrically connected to the circuit board, The keypad image display step includes a data driving step of supplying a data signal by a data driver, a light emitting time measuring step of outputting an electric time signal by measuring a light emitting time by a timer, and determining whether the mode determining unit is an image mode or a text mode. And a light emitting time controlling step of controlling a mode of applying the data signal, and a light emitting step of emitting light from a pixel circuit of an organic light emitting display panel. 26. The method of claim 25, wherein the mode determining step includes the step of comparing the data signal displayed on the pixel circuit to determine whether the image mode or the text mode is used. . The method of claim 25, wherein the mode determination unit of the mode determination step A data storage unit electrically connected to the data driver to store the data signal; A comparison determination unit electrically connected to the data storage unit; And And a control signal output unit electrically connected to the comparison determination unit. The keypad of claim 27, wherein the comparison determining unit of the mode determining step receives a time signal from the timer and compares the data signal stored in the data storage unit to determine whether the image mode is the text mode or the text mode. Method of driving the assembly. 28. The method of claim 27, wherein the control signal output unit of the mode determination step receives a signal from the comparison determination unit to control a signal supplied to the light emission time controller. 26. The method of claim 25, wherein the step of controlling the light emission time comprises controlling the time of supply of data supplied to the pixel circuit by the light emission time controller. 26. The method of claim 25, wherein the step of controlling the light emission time comprises the step of controlling the supply time of the data by the light emission time control unit to cause each of the RGB pixels to emit light sequentially. Way. 27. The method of claim 25, wherein the light emitting time control step is the light emitting time control unit is a demux (DEMUX).

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