KR20130065328A

KR20130065328A - Electrophoresis display apparatus and method for driving the same

Info

Publication number: KR20130065328A
Application number: KR1020110132142A
Authority: KR
Inventors: 김동준; 임유석
Original assignee: 엘지디스플레이 주식회사
Priority date: 2011-12-09
Filing date: 2011-12-09
Publication date: 2013-06-19

Abstract

PURPOSE: An electrophoretic display device and driving a method thereof reduce power consumption occurred by updating an image. CONSTITUTION: A control unit (400) divides a display panel (100) into multiple domains (110,120) to produce and output multiple update control signals for updating an image data. A gate drive IC (Integrated Circuit) (200) supplies a scan pulse from a fixed start point to a fixed end point based on the update control signal. A data drive IC (300) supplies data voltage to the display panel according to a scan pulse supply time.

Description

Electrophoretic display device and its driving method {ELECTROPHORESIS DISPLAY APPARATUS AND METHOD FOR DRIVING THE SAME}

The present invention relates to an electrophoretic display device, and more particularly, to an electrophoretic display device and a driving method thereof capable of reducing power consumption and improving image update speed and display quality.

The electrophoretic display device refers to a device for displaying an image using an electrophoresis phenomenon in which colored charged particles move by an electric field applied from the outside. Here, the electrophoretic phenomenon refers to a phenomenon in which the charged particles move in the solvent by the Coulomb force when an electric field is applied while the charged particles are dispersed in the solvent.

The electrophoretic display apparatus using the electrophoretic phenomenon has a feature of bistable, and even if the applied voltage is removed, the displayed image can be displayed for a long time. That is, the electrophoretic display device is a display device suitable for the field of e-books that do not require a rapid exchange of the screen because it can maintain a constant screen for a long time even without applying a voltage continuously.

In addition, unlike the liquid crystal display device, the electrophoretic display device does not have a dependency on a viewing angle, and displays an image by reflecting external light, thereby providing a comfortable image to the eye as much as paper.

The electrophoretic display device according to the prior art includes a display panel and a driving circuit unit for driving the display panel. The driving circuit unit includes a data drive IC (data D-IC), a gate drive IC (Gate D-IC), and a control unit (T-con).

The data drive IC generates a data voltage according to the image data and supplies the data voltage to the data lines formed in the display panel. Here, the data voltage is generated as a positive voltage or a negative voltage according to the gray level of the image data.

The gate drive IC generates a scan pulse that swings between the gate high voltage VGH and the gate low voltage VGL using the gate clock input from the controller, and sequentially supplies the scan pulse to the gate lines formed on the display panel. do.

1 is a view showing a method of driving an electrophoretic display device according to the prior art.

Referring to FIG. 1, an electrophoretic display device displays an image through driving of three stages of a power-on period, an update period, and an idle period, and the next screen on the previous screen. Convert to the screen.

The power-on period is a period during which the electrophoretic display device is turned on to display an image, and the update period is a period during which image data is updated on the display panel to switch from the current screen to the next screen. It is a system stabilization period for stabilizing supplied image data to maintain an image for a predetermined time.

The electrophoretic display device uses a wave form to switch from the current screen to the next screen. The electrophoretic display device is not fast to change the screen due to the bi-stable characteristics. Therefore, the electrophoretic display device uses a waveform, which is a sequence of image data for screen switching, to supply the data voltage, thereby switching from the previous screen to the next screen. do.

At this time, a new data is written to the pixels through a data update process for a time of about 1 second, and the memory function maintains the current data until the next data update.

Therefore, the electrophoretic display device can reduce power consumption because it maintains the current data without supplying a separate driving power from the outside due to an intrinsic memory function of the electrophoretic pixel.

In this manner, after the image data is updated, the image is stabilized by maintaining the idle period for a predetermined time, and the display of the image can be maintained for a long time even if power is not supplied to the display panel after the idle period is over.

2 is a view showing a data update method of the electrophoretic display device according to the prior art.

Referring to FIG. 2, in the related art, a global update mode or a regional update mode is used as a method of switching from a previous screen to a next screen.

The electrophoretic display device has an advantage of low power driving because it has bistable characteristics, but has a disadvantage in that the overall driving speed is slow because the response speed is slow and the gray scale is expressed using pulse width modulation (PWM). In addition, there is a problem in that the power consumption due to the update due to updating the entire screen, the screen flickers when the update due to the waveform (waveform) occurs.

The global update method has a disadvantage in that the driving speed is slow because the entire region is scanned and the image data is updated even when a pop-up window or a regional update for scrolling on the screen is performed.

The regional update method does not update the entire screen, but updates the image data only in the area that needs updating. After the scan pulses are supplied to all the gate lines of the display panel 10, image data is updated in the update area. On the other hand, a data voltage of 0V is supplied to the non-update region.

Therefore, the screen flicker may be partially improved, but the frame time of the actual update is the same as the global update method by sequentially scanning all the gate lines. Since the scan pulse is also supplied to the gate lines of the region that does not need to be updated, gray scale fluctuation occurs due to a kickback phenomenon in the corresponding region, and thus, display quality is deteriorated.

Disclosure of Invention The present invention has been made in view of the above-described problems, and it is an object of the present invention to provide an electrophoretic display device and a driving method thereof capable of reducing power consumption by updating an image.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an electrophoretic display device and a driving method thereof capable of improving an image update rate.

SUMMARY OF THE INVENTION The present invention has been made in an effort to solve the above problems, and provides an electrophoretic display device and a driving method thereof capable of improving display quality by reducing image gradation due to kickback phenomenon in an area where an image is not updated. It is a task.

Other features and advantages of the invention will be set forth in the description which follows, or may be obvious to those skilled in the art from the description and the claims.

Electrophoretic display device according to an embodiment of the present invention comprises a display panel for displaying an image using electrophoresis; A controller configured to generate and output a plurality of update control signals for updating the image data by dividing the display panel into a plurality of areas; A gate drive IC supplying a scan pulse from a start point set to the display panel to an end point based on an update control signal supplied from the controller; And a data drive IC configured to supply a data voltage to the display panel according to a timing at which a scan pulse is supplied to the display panel, wherein the display panel is divided into a plurality of update regions to update image data.

In a method of driving an electrophoretic display device according to an embodiment of the present invention, in a method of driving an electrophoretic display device including a display panel for displaying an image using electrophoresis, the display panel is divided into a plurality of regions, and thus an image is obtained. Generating a plurality of update control signals for updating data; Supplying a scan pulse from a start point set in the display panel to an end point based on the update control signal; And supplying a data voltage to the display panel at a time when a scan pulse is supplied to the display panel, wherein the display panel is divided into a plurality of update regions to update image data.

An electrophoretic display device and a driving method thereof according to an embodiment of the present invention can reduce power consumption by updating an image.

An electrophoretic display device and a driving method thereof according to an embodiment of the present invention can improve an image update speed.

An electrophoretic display device and a driving method thereof according to an embodiment of the present invention can improve display quality by reducing image gradation caused by a kickback phenomenon in a region where an image is not updated.

Other features and effects of the present invention may be newly understood through the embodiments of the present invention in addition to the features and effects of the present invention mentioned above.

1 is a view showing a method of driving an electrophoretic display device according to the prior art.
2 is a view showing a data update method of the electrophoretic display device according to the prior art.
3 and 4 illustrate an electrophoretic display device according to an embodiment of the present invention.
5 and 6 are views showing a method of driving an electrophoretic display device according to a first embodiment of the present invention.
7 is a view showing a method of driving an electrophoretic display device according to a second embodiment of the present invention.

Hereinafter, an electrophoretic display device and a driving method thereof according to an embodiment of the present invention will be described with reference to the accompanying drawings. Like reference numerals throughout the specification denote substantially identical components. In the following description, detailed descriptions of configurations and functions that are not related to the core configuration of the present invention and known in the art may be omitted.

3 and 4 illustrate an electrophoretic display device according to an exemplary embodiment of the present invention.

First, referring to FIG. 3, an electrophoretic display apparatus according to an exemplary embodiment of the present invention may include a display panel 100; Gate drive IC 200; Data drive IC 300; The controller 400 and a power supply circuit (not shown) are included.

The display panel 100 is formed such that m gate lines and n data lines cross each other. By the intersection of the data lines and the gate lines, m × n pixels (Cells) are formed in a matrix form.

Each pixel is formed with a thin film transistor (hereinafter, referred to as a TFT) as a switching element to switch the supply of image data (data voltage) to each pixel. The gate electrode of the TFT is connected with the gate line, the source electrode is connected with the data line, and the drain electrode is connected with the pixel electrode.

In addition, the display panel 100 includes a pixel electrode for supplying a data voltage to a pixel and a common electrode for supplying a common voltage Vcom, and an electrophoretic layer is formed between the pixel electrode and the common electrode. Here, the pixel electrode may be formed on the lower substrate on which the TFT array is formed, and the common electrode may be formed on the upper substrate.

The electrophoretic layer may be formed into a film type including a microcapsule, a micro cup type or an internalization type in which the electrophoretic particles and the solvent are internalized on the lower substrate.

The controller 400 generates a gate control signal for controlling the gate drive IC 200 using the timing signal TS input from the outside, and supplies the gate signal to the gate drive IC 200. In addition, a data control signal for controlling the data drive IC 300 is generated and supplied to the data drive IC 300.

Here, the timing signal TS includes a vertical synchronization signal V-sync, a horizontal synchronization signal H-sync, and a clock signal CLK.

The gate control signal includes an update control signal for dividing the display panel 100 into a plurality of areas to update image data.

The update control signal may be a start pulse vertical (SPV) signal indicating a point at which a scan pulse starts to be supplied to the display panel 100. When the display panel 100 is driven by being divided into a plurality of regions, a plurality of start pulse vertical (SPV) signals are also generated and supplied to the gate drive IC 200.

In addition, the controller 400 arranges the image data input from the outside or the image data stored in the memory provided therein in units of frames and supplies the image data to the data drive IC 300.

The gate drive IC 200 supplies a scan pulse from the start point set to the display panel 100 to the end point based on the update control signal (start pulse vertical signal) supplied from the controller 400.

In detail, the gate drive IC 200 generates a gate clock, that is, a scan pulse, based on the gate control signal supplied from the controller 400, and sequentially supplies the scan pulses to gate lines formed in the display panel 100. do.

Here, the gate drive IC 200 divides and drives the display panel 100 into K regions (K is an integer of 2 or more). To this end, the gate drive IC 200 divides m gate lines formed in the display panel 100 into K units to supply scan pulses.

In FIG. 3, the display panel 100 is divided into two regions, in which the image data is an update region, in which the first update region 110 and the second update region 120 are updated. region 2).

Meanwhile, as illustrated in FIG. 4, the image data may be updated by dividing the display panel 100 into four areas. The four regions may include a first update region 110 (update region 1) and a second update region 120 (update region 2) positioned above the center, and a third update region positioned below the center. 130, update region 3), and fourth update region 140 (update region 4).

5 and 6 are diagrams illustrating a method of driving an electrophoretic display device according to a first embodiment of the present invention. 5 and 6 will be described a method of driving an electrophoretic display device according to a first embodiment of the present invention.

The gate driver IC 200 moves the display panel 100 to the first update region 110 and the second update region 120 based on the start pulse vertical (SPV) signal included in the gate control signal supplied from the controller 400. The scan pulse can be supplied by dividing by). In this case, the scan pulse is generated by the gate high voltage VGH of the positive polarity (+) and the gate low voltage VGL of the negative polarity (−) and supplied to the gate line.

The first update area 110 and the second update area 120 indicate a start point indicating a gate line at which a scan pulse starts to be supplied, and a gate line at which supply of the scan pulse is terminated. Has an end point.

The gate driver IC 200 sequentially supplies scan pulses from the start point to the end point of the first update area 110 and the second update area 120 based on the start pulse vertical (SPV) signal. As a result, the display panel 100 is divided into a first update area 110 and a second update area 120 to drive pixels.

On the other hand, the data drive IC 300 converts the digital image data input based on the data control signal supplied from the controller 400 into an analog data voltage and adjusts one horizontal line in accordance with the timing at which the scan pulse is supplied to the gate line. The data voltage of is supplied to the data lines.

The data voltage supplied to the data line is supplied to the pixel electrode of the pixel turned on by the scan pulse, and an electric field is formed in the pixel by the data voltage supplied to the pixel electrode and the common voltage Vcom supplied to the common electrode. Thus, electrophoresis of charged particles is achieved.

As illustrated in FIG. 6, when an image is updated from a previous screen to a next screen, the display panel 100 may be divided into two regions to update image data.

For example, when there is no image change in the first update area 110 among the plurality of update areas of the display panel 100 and there is an image change in the second update area 120, image data may be updated as follows. have.

The controller 400 generates a start pulse vertical (SPV) signal indicating the first gate line among the gate lines formed in the second update area 120 as a start point, and indicating the last gate line as an end point. Output to (200).

The gate driver IC 200 supplies a scan pulse only to the second update area 120 based on the start pulse vertical (SPV) signal input from the controller 400.

Here, the scan pulse may be supplied to the start point 122 of the gate line formed at the top of the display panel 100, and after setting a plurality of start points, the gate line corresponding to any one start point ends from the gate line. The supply of scan pulses may be made up to point 124.

When there is no image change in the first update area 110 and there is a change in the image in the second update area 120, the gate drive IC 200 supplies a scan pulse only to the second update area 120.

That is, the gate drive IC 200 does not supply a scan pulse to the gate lines formed in the first update region 110. Scan pulses are sequentially supplied from the start point 122 to the end point 124 to the gate lines formed in the second update area 120 requiring the image data to be updated.

When scan pulses are sequentially supplied to the gate lines of the second update area 120, the data drive IC 300 supplies the data voltages of one horizontal line to the data lines to update the image data. To lose. At this time, the image data is updated using the waveform.

The data drive IC 300 selects one of the three-phase voltages Vpos, Vneg, and Vss as data voltages and outputs them to the data lines in response to the image data input from the controller 400 in the process of updating the image data. Can be. In this case, the data voltage may be generated as a positive data voltage, a negative data voltage, or a ground voltage Vss.

As such, when the image data is updated by dividing the display panel 100 into a plurality of regions, the update time may be shortened to 1 / K (K is the number of divided update regions) compared to the conventional global update method. .

In addition, since the scan pulse is supplied only to the gate lines corresponding to the update region requiring updating of the image data without supplying the scan pulse to all the gate lines, power consumption according to the update can be reduced.

In particular, since the scan pulse is not supplied to the first update area for which image data is not required to be updated, the display quality can be improved by preventing the image gradation caused by the kickback phenomenon from occurring in the area where the update is not necessary.

7 is a view showing a method of driving an electrophoretic display device according to a second embodiment of the present invention. In the description of the method of driving the electrophoretic display device according to the second embodiment of the present invention, the same contents as those of the first embodiment will be omitted.

Referring to FIG. 7, a gate clock capable of scanning an entire frame is supplied to the gate driver IC 200 from the controller 400.

The gate driver IC 200 does not supply a scan pulse by blocking an output to gate lines formed in the first update area 110 that do not require updating of image data.

Specifically, the controller 400 generates a gate clock of one full frame and supplies the gate driver IC 200. The gate driver IC 200 generates a scan pulse of one full frame in accordance with the gate clock supplied from the controller 400. However, the output of the scan pulse is blocked in the first update area 100 that does not need to update the image data. Therefore, the pixels of the first update area 100 that do not need updating of the image data remain off.

Meanwhile, the gate driver IC 200 supplies scan pulses to gate lines formed in the second update area 120 requiring the update of the image data, thereby turning on the pixels in the second update area.

When scan pulses are sequentially supplied to the gate lines of the second update area 120, the data drive IC 300 supplies the data voltages of one horizontal line to the data lines to update the image data. To lose.

In the driving method of the electrophoretic display apparatus according to the second exemplary embodiment of the present invention, since the scan is performed for the entire period of one frame, the update time of the image data is not shortened.

Since the scan pulse is not supplied to the first update area that does not need updating of image data, and the scan pulse is supplied only to the second update area that requires updating, an image gradation may be generated due to the kickback phenomenon in the area that does not need updating. Can improve the display quality.

It will be understood by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

100: display panel 200: gate drive IC
300: data drive IC 400: control unit
110: first update area 120: second update area
130: third update area 140: update area
122: start point 124: end point

Claims

A display panel displaying an image using electrophoresis;
A controller configured to generate and output a plurality of update control signals for updating the image data by dividing the display panel into a plurality of areas;
A gate drive IC supplying a scan pulse from a start point set to the display panel to an end point based on an update control signal supplied from the controller; And
A data drive IC configured to supply a data voltage to the display panel at a time when a scan pulse is supplied to the display panel;
And dividing the display panel into a plurality of update regions to update image data.

The method according to claim 1,
The control unit generates an update control signal equal to the number of the plurality of regions,
The update control signal may be a start pulse vertical signal including a start point indicating a gate line at which the supply of the scan pulse is started and an end point indicating a gate line at which the supply of the scan pulse is terminated. .

The method of claim 2,
In the case where there is no change of the image in the first update area of the plurality of update areas and there is an image change in the second update area,
The controller generates a start pulse vertical signal indicating a first gate line among the gate lines formed in the second update area as a start point, and indicates a last gate line as an end point, and outputs the start pulse vertical signal.
And the gate driver IC supplies a scan pulse only to the second update area based on an input start pulse vertical signal.

The method of claim 3,
The gate driver IC generates a scan pulse corresponding to gate lines formed in the second update region,
And a scan pulse is supplied from the start point of the second update area to the end point based on the input start pulse vertical signal.

The method of claim 3,
The gate driver IC generates a scan pulse of one frame,
And supplying a scan pulse to the first update area that does not need updating of the image, and supplying a scan pulse only to the second update area based on an input start pulse vertical signal.

6. The method according to any one of claims 3 to 5,
And the data drive IC updates the image data by supplying a data voltage according to a scan pulse supplied to the display panel.

In the driving method of an electrophoretic display device comprising a display panel for displaying an image using electrophoresis,
Generating a plurality of update control signals for updating image data by dividing the display panel into a plurality of areas;
Supplying a scan pulse from a start point set in the display panel to an end point based on the update control signal; And
Supplying a data voltage to the display panel at a time when a scan pulse is supplied to the display panel.
And dividing the display panel into a plurality of update regions to update image data.

The method of claim 7, wherein
The update control signal is a start pulse vertical signal including a start point indicating a gate line at which the supply of the scan pulse is started and an end point indicating a gate line at which the supply of the scan pulse is terminated.
And generating the start pulse vertical signal in the same number as the number of the plurality of regions.

The method of claim 8,
In the case where there is no change of the image in the first update area of the plurality of update areas and there is an image change in the second update area,
A first pulse line among the gate lines formed in the second update area is indicated as a start point, and a start pulse vertical signal indicating the last gate line as an end point is generated and output.
And a scan pulse is supplied only to the second update area based on the start pulse vertical signal to update image data.

10. The method of claim 9,
Generate a scan pulse corresponding to the gate lines formed in the second update region,
And a scan pulse is supplied from the start point of the second update area to the end point based on the input start pulse vertical signal to update the image data.