KR20090054320A - Organic light emitting display and driving method for the same - Google Patents

Abstract

The present invention provides a display device including a plurality of sub pixels; A scan driver which alternately supplies a scan signal in a first direction and a second direction to the display unit; And a data driver for dividing the display unit into a plurality of subfields and supplying a gradually increasing data signal having a weight of 2 ⁿ (n ≦ 0). When the scan signal is supplied in the first direction, the data unit generates a data signal that increases as the unit of bits increases in the second direction of the display unit. When the scan signal is supplied in the second direction, the unit of bits is directed to the first direction of the display unit. Provided is an organic light emitting display device that generates an increasing data signal.

Organic light emitting display device, subfield, bit

Description

Organic Light Emitting Display and Driving Method for the same

The present invention relates to an organic light emitting display device and a driving method thereof.

The organic light emitting display device used in the organic light emitting display device was a self-light emitting device having a light emitting layer formed between two electrodes.

In addition, the organic light emitting device has a top emission type and a bottom emission type according to the direction in which light is emitted, and a passive matrix type and an active matrix type according to the driving method. Active Matrix).

Among the organic light emitting display devices, an organic light emitting display device using an active matrix type includes a transistor, a capacitor, and an organic light emitting diode positioned inside a subpixel when a scan signal and a data signal are supplied to a plurality of subpixels arranged in a matrix form on a display unit. The diode is driven to display an image.

Such an organic light emitting display device is a self-luminous display device, which does not require a backlight, which enables not only light weight and thinness, but also simplifies the process, enables low temperature production, and has a fast response speed of 1 ms or less. , Low power consumption, wide viewing angle, and high contrast.

However, the conventional organic light emitting display device has a problem in that the display quality is degraded due to the contour noise, and thus an improvement thereof is required.

An object of the present invention for solving the above problems of the background art is to provide an organic light emitting display device and a driving method thereof that can minimize the influence of pseudo contours.

According to the above-mentioned problem solving means, the present invention provides a display unit including a plurality of sub-pixels; A scan driver which alternately supplies a scan signal in a first direction and a second direction to the display unit; And a data driver for dividing the display unit into a plurality of subfields and supplying a gradually increasing data signal having a weight of 2 ⁿ (n ≦ 0). When the scan signal is supplied in the first direction, the data unit generates a data signal that increases as the unit of bits increases in the second direction of the display unit. When the scan signal is supplied in the second direction, the unit of bits is directed to the first direction of the display unit. Provided is an organic light emitting display device that generates an increasing data signal.

In another aspect, the present invention provides a display device including a plurality of sub pixels; A scan driver which alternately supplies a scan signal in a first direction and a second direction to the display unit; And a data driver for dividing the display unit into a plurality of subfields and supplying a gradually increasing data signal having a weight of 2 ⁿ (n ≦ 0). When the scan signal is supplied in the first direction, the data unit generates a data signal that increases as the unit of bits increases toward the first direction of the display unit. Provided is an organic light emitting display device that generates an increasing data signal.

The plurality of subfields may be arranged in order from least significant bit to most significant bit.

The plurality of subfields may include an address, a light emission, and an erase period.

The scan signal includes an address signal and an erase signal, and each of the plurality of subpixels includes: a switching transistor switched by the address signal, a capacitor for storing a data signal supplied through the switching transistor as a data voltage, and a capacitor stored in the capacitor. The driving transistor may include a driving transistor driving in response to a data voltage, an organic light emitting diode emitting light as the driving transistor is driven, and an erasing transistor for stopping light emission of the organic light emitting diode by an erase signal.

Each of the plurality of subpixels includes a switching transistor having a gate connected to an address scan line supplied with an address signal and one end connected to a data line supplied with a data signal, and a gate connected to the other end of the switching transistor and connected to a first power line. A gate is connected to the connected driving transistor, a capacitor connected between the first power line and the gate of the driving transistor, and an erase scan line to which an erase signal is supplied, and one end is connected to the first power line, and the other end is connected to the gate of the driving transistor. The organic light emitting diode may include an erase transistor connected to each other, and an organic light emitting diode connected to a second electrode of the driving transistor and a second electrode connected to a second power line.

In another aspect, the present invention provides a scan signal supplying step of supplying a scan signal by alternating in a first direction and a second direction to a display unit including a plurality of sub pixels; And a data signal supplying step of supplying a data signal which is divided into a plurality of subfield units on the display unit and has a weight of 2 ⁿ (n ≦ 0), wherein a unit of bits constituting the plurality of subfields is gradually increased. The signal increases as the unit of bits increases in the second direction of the display unit when the scan signal is supplied in the first direction, and increases as the unit of bits increases in the first direction of the display unit when the scan signal is supplied in the second direction. A driving method of an organic light emitting display device is provided.

In another aspect, the present invention provides a scan signal supplying step of supplying a scan signal alternately in a first direction and a second direction to a display unit including a plurality of sub pixels; And a data signal supplying step of supplying a data signal which is divided into a plurality of subfield units on the display unit and has a weight of 2 ⁿ (n ≦ 0), wherein a unit of bits constituting the plurality of subfields is gradually increased. The signal increases as the unit of bits increases in the first direction of the display unit when the scan signal is supplied in the first direction, and increases as the unit of bits increases in the second direction of the display unit when the scan signal is supplied in the second direction. A driving method of an organic light emitting display device is provided.

The scan signal supplying step may include an address signal for selecting a plurality of subpixels and an erase signal for stopping light emission of the plurality of subpixels.

Each of the plurality of subpixels includes: a switching transistor for switching by an address signal, a capacitor for storing a data signal supplied through the switching transistor as a data voltage, a driving transistor for driving in response to a data voltage stored in the capacitor; The organic light emitting diode may emit light as the driving transistor is driven, and the erasing transistor may stop light emission of the organic light emitting diode by an erase signal.

The present invention has an effect of providing an organic light emitting display device and a driving method thereof that can minimize the influence of pseudo contours.

Hereinafter, with reference to the accompanying drawings, the specific content for the practice of the present invention will be described.

First Embodiment

1 is a schematic diagram of an organic light emitting display device according to a first embodiment of the present invention.

As shown in FIG. 1, the organic light emitting display device according to the first exemplary embodiment of the present invention may include a display unit 120 including a plurality of sub pixels P11.. P61. In addition, the display driver 120 may include scan drivers 130a and 130b that alternately supply the scan signals S1..S6 in the first direction and the second direction. In addition, the display unit 120 is supplied with a data signal D1..Dn, which is divided into a plurality of subfield units and has a weight of 2 ⁿ (n ≦ 0), in which a unit of bits constituting the plurality of subfields has a weight of 2 ⁿ (n ≦ 0). The data driver 140 may be included. Here, n may increase in the form of 0, 1, 2, 3, 4, 5 ...

However, when the scan signals S1, S3, and S5 are supplied in the first direction, the data driver 140 may receive a data signal D1..Dn that increases in units of bits toward the second direction of the display unit 120. Can be generated. When the scan signals S2, S4, and S6 are supplied in the second direction, the data signal D1..Dn may increase in the unit of the bit toward the first direction of the display unit 120.

Meanwhile, the scan drivers 130a and 130b may be provided in the first direction of the display unit 120 in the second direction of the first scan driver 130a and the display unit 120 to supply the first scan signals S1, S3, and S5. The second scan driver 130b may be configured to supply the second scan signals S2, S4, and S6. In addition, each of the first scan signals S1, S3, S5, and the second scan signals S2, S4, S6 may include an address signal for selecting one or more of the plurality of subpixels P11 .. P61 and a plurality of subpixels. It may include an erase signal for stopping one or more of the light emission.

Hereinafter, a circuit configuration of one subpixel P11 of the plurality of subpixels P11.. P61 included in the display unit 120 will be described.

2 is a diagram illustrating a circuit configuration of the subpixel illustrated in FIG. 1.

As illustrated in FIG. 2, the subpixel may include a switching transistor T1 having a gate connected to an address scan line G1 to which an address signal is supplied and one end connected to a data line D1 to which a data signal is supplied. have. In addition, a gate may be connected to the other end of the switching transistor T1 and may include a driving transistor T2 having one end connected to the first power line VDD. In addition, the capacitor C may be connected between the first power line VDD and the gate of the driving transistor T2. In addition, a gate may be connected to the erase scan line E1 to which the erase signal is supplied, and one end thereof may be connected to the first power source line VDD and the other end thereof may be connected to the gate of the driving transistor T2. have. In addition, the organic light emitting diode D may include an organic light emitting diode D connected to the other end of the driving transistor T2 and connected to the second power line VSS.

When the switching transistor T1, which receives the address signal through the address scan line G1, is turned on, the sub pixel may receive a data signal through the data line D1. In this case, the supplied data signal may be stored as a data voltage in the capacitor. In addition, when the driving transistor T2 is driven by the data voltage stored in the capacitor, the organic light emitting diode D may receive power from the first power line VDD and emit light. Thereafter, when the erase signal is supplied through the erase scan line E1, the organic light emitting diode D may stop emitting light.

Meanwhile, the first scan signals S1, S3, and S5 and the second scan signals S2, S4, and S6 described above may be described in detail as follows.

3A is a diagram illustrating a driving waveform for explaining the first scan signal, FIG. 3B is a diagram illustrating a driving waveform for explaining the second scan signal, and FIG. 4 is a diagram illustrating bit weights of the data signal. Reference is made together to FIG. 1 to help understand the description.

First, referring to FIGS. 1 and 3A, the first scan signals S1, S3, and S5 may include address signals G1, G3, and G5 and erase signals E1, E3, and E5, as described above. Can be. Here, the first scan signals S1, S3, and S5 may be supplied in a first direction (eg, leftward direction) of the illustrated display unit 120.

Next, referring to FIGS. 1 and 3B, the second scan signals S2, S4, and S6 may include address signals G2, G4, and G6 and erase signals E2, E4, and E6, as described above. Can be. Here, the second scan signals S2, S4, and S6 may be supplied in a second direction (eg, a right direction) of the illustrated display unit 120.

When the scan signal is supplied in this manner, when the first scan signals S1, S3, and S5 are supplied in the first direction, the data driver 140 increases in units of bits toward the second direction of the display unit 120. A data signal D1..Dn can be generated. In addition, when the scan signals S1..S6 are supplied in the second direction, the data signal D1..Dn may increase in the unit of the bit toward the first direction of the display unit 120.

Therefore, as shown in FIG. 4, the plurality of subpixels positioned in the odd scan lines corresponding to the first, third, and fifth have 1, 2, 4, and 8 weights of bits constituting the subfield from the left. Increasing data signal can be supplied. That is, the plurality of subpixels receiving the first scan signals S1, S3, and S5 may receive the data signals arranged in the order in which the bits constituting the subfield are arranged with the least significant bit on the left and the most significant bit on the right. Can be.

On the contrary, the plurality of subpixels positioned in the even scan lines corresponding to the second, fourth, and sixth have data in which weights of bits constituting the subfield are increased from the right side to 1, 2, 4, 8, and so on. Signals can be supplied. That is, the plurality of sub-pixels receiving the second scan signals S2, S4, and S6 receive data signals arranged in the order that the bits constituting the subfield are positioned with the most significant bit on the right and the least significant bit on the left. Can be supplied.

Meanwhile, the weight of the bits constituting the subfield may be described in more detail as follows.

5 is a diagram illustrating a configuration of a subfield. For better understanding of the description, the subfields supplied to the plurality of subpixels positioned in the odd scan line are shown. However, one subfield may include a total of four subfields as an example. However, this is for the purpose of describing the exemplary embodiments and the configuration of the subfields is not limited thereto.

As shown in FIG. 5, a total of four subfields include a first subfield A1, E1, D1, a second subfield A2, E2, D2, a third subfield A4, E4, D4, and The fourth subfields A8, E8, and D8 may be included.

Referring to the first subfields A1, E1, and D1 as an example, one subfield includes, as described above, an address section A1 for receiving an address signal, an emission section E1 for emitting an organic light emitting diode, and an organic light emitting diode. An erasing period D1 receives an erasing signal to stop light emission of the diode.

 Here, it can be seen that the fourth subfields A8, E8, and D8 emit longer than the first subfields A1, E1, and D1. That is, it can be seen that the longer the weight of the bit, the longer the light emission time. Therefore, the organic light emitting display device according to the first exemplary embodiment of the present invention is a digital driving method for expressing gray scales by controlling the emission time of the organic light emitting diode included in the subpixel.

As described above, when the data signal is supplied to the organic light emitting display device adopting the digital driving method, the influence of the pseudo contour (in other words, the contour noise) is minimized by alternating the weights of the bits constituting the subfield. It can be effective.

Second Embodiment

6 is a schematic diagram of an organic light emitting display device according to a second embodiment of the present invention.

As shown in FIG. 6, the organic light emitting display device according to the second embodiment of the present invention may include a display unit 120 including a plurality of sub pixels P11.. P61. In addition, the display driver 120 may include scan drivers 130a and 130b that alternately supply the scan signals S1..S6 in the first direction and the second direction. In addition, the display unit 120 is supplied with a data signal D1..Dn, which is divided into a plurality of subfield units and has a weight of 2 ⁿ (n ≦ 0), in which a unit of bits constituting the plurality of subfields has a weight of 2 ⁿ (n ≦ 0). The data driver 140 may be included. Here, n may increase in the form of 0, 1, 2, 3, 4, 5 ...

However, when the scan signals S1, S3, and S5 are supplied in the first direction, the data driver 140 may receive a data signal D1..Dn that increases as the bit unit increases toward the first direction of the display unit 120. Can be generated. When the scan signals S2, S4, and S6 are supplied in the second direction, the data signal D1..Dn may increase in units of bits in the second direction of the display unit 120.

Meanwhile, the scan drivers 130a and 130b may be provided in the first direction of the display unit 120 in the second direction of the first scan driver 130a and the display unit 120 to supply the first scan signals S1, S3, and S5. The second scan driver 130b may be configured to supply the second scan signals S2, S4, and S6. In addition, each of the first scan signals S1, S3, S5, and the second scan signals S2, S4, S6 may include an address signal for selecting one or more of the plurality of subpixels P11 .. P61 and a plurality of subpixels. It may include an erase signal for stopping one or more of the light emission.

Hereinafter, since the circuit configuration of the sub-pixels located in the display unit 120 is the same as in the first embodiment described above, the description thereof will be omitted to avoid duplication of description, and the following description will be given for the parts different from the first embodiment. Add

7A is a diagram illustrating a driving waveform for explaining the first scan signal, FIG. 7B is a diagram illustrating a driving waveform for explaining the second scan signal, and FIG. 8 is a diagram showing bit weights of the data signal. Reference is made to FIG. 6 together to help understand the description.

First, referring to FIGS. 6 and 7A, the first scan signals S1, S3, and S5 may include the address signals G1, G3, and G5 and the erase signals E1, E3, and E5, as described above. Can be. Here, the first scan signals S1, S3, and S5 may be supplied in a first direction (eg, leftward direction) of the illustrated display unit 120.

Next, referring to FIGS. 6 and 7B, the second scan signals S2, S4, and S6 may include address signals G2, G4, and G6 and erase signals E2, E4, and E6, as described above. Can be. Here, the second scan signals S2, S4, and S6 may be supplied in a second direction (eg, a right direction) of the illustrated display unit 120.

When the scan signal is supplied in this manner, the data driver 140 increases the unit of bits toward the first direction of the display unit 120 when the first scan signals S1, S3, and S5 are supplied in the first direction. A data signal D1..Dn can be generated. In addition, when the scan signals S1..S6 are supplied in the second direction, the data signals D1..Dn may increase in the second direction of the display unit 120.

Accordingly, as illustrated in FIG. 8, the plurality of subpixels positioned in the odd scan lines corresponding to the first, third, and fifth have weights of bits constituting the subfield from 1, 2, 4, 8 from the right. Increasing data signal can be supplied. That is, the plurality of subpixels receiving the first scan signals S1, S3, and S5 may receive the data signals arranged in the order in which the bits constituting the subfield are located at the lowest bit on the right and the most significant bit on the left. Can be.

On the contrary, the plurality of subpixels positioned in the even scan lines corresponding to the second, fourth, and sixth have data in which the weights of the bits constituting the subfield are increased from the left side to 1, 2, 4, 8, etc. Signals can be supplied. That is, the plurality of subpixels receiving the second scan signals S2, S4, and S6 supply data signals arranged in the order in which the bits constituting the subfield are arranged with the most significant bit on the left and the least significant bit on the right. I can receive it.

Meanwhile, since the weights of the bits constituting the subfield are the same as those described with reference to FIG. 5 in the first embodiment, description thereof will be omitted.

As described above, when the data signal is supplied to the organic light emitting display device adopting the digital driving method, the influence of the pseudo contour (in other words, the contour noise) is minimized by alternating the weights of the bits constituting the subfield. It can be effective.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical configuration of the present invention described above may be modified in other specific forms by those skilled in the art to which the present invention pertains without changing its technical spirit or essential features. It will be appreciated that it may be practiced. Therefore, the embodiments described above are to be understood as illustrative and not restrictive in all aspects. In addition, the scope of the present invention is shown by the claims below, rather than the above detailed description. Also, it is to be construed that all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention.

1 is a schematic diagram of an organic light emitting display device according to a first embodiment of the present invention.

FIG. 2 is an exemplary circuit diagram of a subpixel illustrated in FIG. 1. FIG.

3A is an exemplary drive waveform for explaining a first scan signal.

3B is an exemplary drive waveform for explaining a second scan signal.

4 illustrates bit weights of a data signal.

5 is an exemplary configuration diagram of a subfield.

6 is a schematic view of an organic light emitting display device according to a second embodiment of the present invention.

7A is an exemplary drive waveform for explaining a first scan signal.

7B is an exemplary drive waveform for explaining a second scan signal.

8 illustrates bit weights of a data signal.

<Explanation of symbols on main parts of the drawings>

120: display unit 130a, 130b: scan driver

140: data driver

Claims (10)

A display unit including a plurality of sub pixels; A scan driver to alternately supply a scan signal in a first direction and a second direction to the display unit; And The display unit may include a data driver that is divided into a plurality of subfield units and supplies a data signal that gradually increases with a weight of 2 ⁿ (n ≦ 0). The data driver, A unit of the bit is generated when the scan signal is supplied in the first direction and increases in the second direction of the display unit, and the unit of the bit when the scan signal is supplied in the second direction The organic light emitting display device of claim 1, wherein the organic light emitting display device generates a data signal that increases in the first direction of the display unit. A display unit including a plurality of sub pixels; A scan driver to alternately supply a scan signal in a first direction and a second direction to the display unit; And The display unit may include a data driver that is divided into a plurality of subfield units and supplies a data signal that gradually increases with a weight of 2 ⁿ (n ≦ 0). The data driver, A unit of the bit is generated when the scan signal is supplied in the first direction and increases in the first direction of the display unit, and is a unit of the bit when the scan signal is supplied in the second direction The organic light emitting display device as claimed in claim 1, wherein the organic light emitting display device generates a data signal that increases in the second direction. The method according to claim 1 or 2, The plurality of subfields, An organic light emitting display device arranged in order from least significant bit to most significant bit. The method according to claim 1 or 2, The plurality of subfields, An organic light emitting display device comprising an address, light emission, and erasing period. The method according to claim 1 or 2, The scan signal includes an address signal and an erase signal. Each of the plurality of subpixels, A switching transistor for switching operation by the address signal, a capacitor for storing the data signal supplied through the switching transistor as a data voltage, a driving transistor for driving in response to the data voltage stored in the capacitor, An organic light emitting display device comprising: an organic light emitting diode that emits light as a driving transistor is driven; and an erasing transistor that stops light emission of the organic light emitting diode by the erase signal. The method of claim 5, Each of the plurality of subpixels, A gate connected to an address scan line to which the address signal is supplied, one end of which is connected to the data line to which the data signal is supplied, a gate to the other end of the switching transistor, and one end to a first power line A gate is connected to the driving transistor, the capacitor connected between the first power line and the gate of the driving transistor, and an erase scan line to which the erase signal is supplied, and one end thereof is connected to the first power line; And the organic light emitting diode having a second electrode connected to a second end of the driving transistor and a second electrode connected to a second power line. A scan signal supplying step of supplying a scan signal alternately in a first direction and a second direction to a display unit including a plurality of sub pixels; And And a data signal supplying step of supplying a data signal, which is divided into a plurality of subfield units, and gradually increases, wherein a bit unit constituting the plurality of subfields has a weight of 2 ⁿ (n ≦ 0). , The data signal, When the scan signal is supplied in the first direction, the unit of the bit increases toward the second direction of the display unit, and when the scan signal is supplied in the second direction, the unit of the bit is the unit of the display unit. A method of driving an organic light emitting display device that increases in a first direction. A scan signal supplying step of supplying a scan signal alternately in a first direction and a second direction to a display unit including a plurality of sub pixels; And And a data signal supplying step of supplying a data signal which is divided into a plurality of subfield units and has a weight of 2 ⁿ (n ≦ 0), wherein a unit of bits constituting the plurality of subfields is gradually increased. The data signal, When the scan signal is supplied in the first direction, the unit of the bit increases toward the first direction of the display unit, and when the scan signal is supplied in the second direction, the unit of the bit is the unit of the display unit. A method of driving an organic light emitting display device that increases in a second direction. The method according to claim 7 or 8, The scan signal supply step, And an address signal for selecting the plurality of sub-pixels and an erase signal for stopping light emission of the plurality of sub-pixels. The method of claim 9, Each of the plurality of subpixels, A switching transistor for switching by the address signal, a capacitor for storing the data signal supplied through the switching transistor as a data voltage, a driving transistor for driving in response to the data voltage stored in the capacitor, and the driving transistor And an erasing transistor which stops light emission of the organic light emitting diode according to the erase signal.

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