This application claims the benefit of priority of Korean Patent Application No. 10-2012-0073534, filed on Jul. 5, 2012, which is hereby incorporated by reference as if fully set forth herein.
The present disclosure relates to a liquid crystal display (LCD) device for reducing power consumption simultaneously while improving an image quality.
A liquid crystal display (LCD) device adjusts light transmittance of a liquid crystal having dielectric anisotropy using an electric field, so that it can display images thereon.
Generally, the liquid crystal display (LCD) device includes a liquid crystal panel in which a plurality of pixels is arranged in the form of a matrix, a drive circuit for driving the liquid crystal panel, and a backlight unit for irradiating light to the liquid crystal panel.
As LCD product groups have increased in number and have rapidly come into widespread use, many developers and companies are conducting intensive research into improved LCDs having excellent characteristics, such as a large screen, thin thickness, high image quality, low power consumption, etc.
Accordingly, embodiments of the present invention are directed to a liquid crystal display (LCD) device and a method for driving the same that obviate one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a liquid crystal display (LCD) device for reducing power consumption simultaneously while improving an image quality, and a method for driving the same.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by any combination of the structures described in the written description and claims hereof as well as the appended drawings.
In one aspect, a liquid crystal display (LCD) device includes: a liquid crystal panel in which a plurality of sub-pixels is defined by intersection of a plurality of gate lines and a plurality of data lines, and sub-pixels adjacent to each other in a column direction are connected by sharing the plurality of gate lines; a gate driver for sequentially driving even-numbered gate lines during a first subframe interval, and sequentially driving odd-numbered gate lines during a second subframe interval; a data driver for providing a data voltage for odd-column sub-pixels to the plurality of data lines during the first subframe interval, and providing the data voltage for even-column sub-pixels to the plurality of data lines during the second subframe interval; and a timing controller which arranges RGB data received from an external part in response to driving of the liquid crystal panel, provides the arranged RGB data to the data driver, generates a gate control signal and a data control signal, and thus controls the gate driver and the data driver, wherein the data driver provides the data voltage having different polarities to a neighbor data line during one frame interval in such a manner that the plurality of sub-pixels is driven by a horizontal 2-dot inversion scheme.
The gate driver may sequentially provide scan pulses to the even-numbered gate lines during a first subframe interval, and then sequentially provide the scan pulses to the odd-numbered gate lines during a second subframe interval.
The data driver may provide a data voltage for the odd-column sub-pixels to the plurality of data lines during the first subframe interval, and then provide a data voltage for the even-column sub-pixels to the plurality of data lines during the second subframe interval.
The odd-column sub-pixels may be connected by sharing the even-numbered gate lines, and the even-column sub-pixels may be connected by sharing the odd-numbered gate lines.
A connection structure may configure sub-pixels of a (4k−3)-th column (where k is a natural number) through sequential repetition of sub-pixels connected to even-numbered data lines and sub-pixels connected to odd-numbered data lines, sub-pixels of a (4k−1)-th column from among the odd-column sub-pixels may be achieved by sequential repetition of sub-pixels connected to odd-numbered data lines and sub-pixels connected to even-numbered data lines, sub-pixels of a (4k−2)-th column from among the even-column sub-pixels may be achieved by sequential repetition of sub-pixels connected to odd-numbered data lines and sub-pixels connected to even-numbered data lines, and sub-pixels of a 4k-th column from among the even-column sub-pixels may be achieved by sequential repetition of sub-pixels connected to even-numbered data lines and sub-pixels connected to odd-numbered data lines.
In another aspect, a method for driving a liquid crystal display (LCD) device in which a plurality of sub-pixels is defined by intersection of a plurality of gate lines and a plurality of data lines, and sub-pixels adjacent to each other in a column direction are connected by sharing the plurality of gate lines includes: sequentially driving even-numbered gate lines during a first subframe interval; sequentially driving odd-numbered gate lines during a second subframe interval; providing a data voltage for odd-column sub-pixels to the plurality of data lines during the first subframe interval; and providing the data voltage for even-column sub-pixels to the plurality of data lines during the second subframe interval, wherein the providing the data voltage to the plurality of data lines provides the data voltage having different polarities to a neighbor data line during one frame interval in such a manner that the plurality of sub-pixels is driven by a horizontal 2-dot inversion scheme.
The driving the gate lines may include: sequentially providing scan pulses to the even-numbered gate lines during a first subframe interval; and sequentially providing the scan pulses to the odd-numbered gate lines during a second subframe interval.
The providing the data voltage may include: providing a data voltage for the odd-column sub-pixels to the plurality of data lines during the first subframe interval; and providing a data voltage for the even-column sub-pixels to the plurality of data lines during the second subframe interval.
The odd-column sub-pixels may be connected by sharing the even-numbered gate lines; and the even-column sub-pixels may be connected by sharing the odd-numbered gate lines.
Sub-pixels of a (4k−3)-th column (where k is a natural number) from among the odd-column sub-pixels may be achieved by sequential repetition of sub-pixels connected to even-numbered data lines and sub-pixels connected to odd-numbered data lines, sub-pixels of a (4k−1)-th column from among the odd-column sub-pixels may be achieved by sequential repetition of sub-pixels connected to odd-numbered data lines and sub-pixels connected to even-numbered data lines, sub-pixels of a (4k−2)-th column from among the even-column sub-pixels may be achieved by sequential repetition of sub-pixels connected to odd-numbered data lines and sub-pixels connected to even-numbered data lines, and sub-pixels of a 4k-th column from among the even-column sub-pixels may be achieved by sequential repetition of sub-pixels connected to even-numbered data lines and sub-pixels connected to odd-numbered data lines.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:
Reference will now be made in detail to the exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
The LCD device shown in
This embodiment of the present invention may reduce power consumption of the gate driver 4 and the data driver 6. The reduction in power consumption may occur in two ways.
First, the LCD device may use an interlace driving scheme that includes dividing a frame into multiple subframes. The gate driver 4 may send a sequential scan pulse to a particular group of gate lines during a first subframe and to another group of gate lines during a second subframe. Thus, gate driver 4 may deactivate, power down, or otherwise limit power consumption for gate driving logic corresponding to gate lines that are inactive during a particular subframe, e.g., for which a scan pulse is not sent during the particular subframe. In this way, the LCD device may conserve power consumption.
Second, The LCD device may display pixels according to a dot inversion scheme even when the data driver 6 applies polarities to data lines according to a column inversion scheme. In this way, the LCD device may implement a dot inversion display without the data driver 6 having to alternate polarities sent through a particular data line (e.g., for each particular data voltage sent to a particular sub-pixel (P) connected to the data line). In other words, adjacent sub-pixels in a column of sub-pixels (P) may have different polarities even though the data driver 6 applies a single polarity to a particular data line, e.g., during a first frame or subframe.
In one example of a column inversion scheme, the data driver 6 may applies a first polarity pattern to a particular data line during a first frame and applies a second polarity pattern (e.g., opposite polarity) to the particular data line during a second frame.
Column inversion of the data driver 6 can be converted into horizontal 2-dot inversion, resulting in reduction of flicker and crosstalk. In addition, an unnecessary margin can be minimized in a thin film transistor (TFT) region of sub-pixels using a gate sharing structure, resulting in an increase in aperture ratio. For example and as described herein, adjacent pixels in a column of sub-pixels (P) may connect to the same gate line, allowing a reduction in the TFT region of the adjacent pixels.
Meanwhile, a connection structure of sub-pixels (P) of the data lines (D1 to Dn) may be implemented in units of four columns. As shown in
To illustrate, for sub-pixels (P) of the odd numbered (4k−3)-th column (where k is a natural number), odd-numbered sub-pixels (P) of the (4k−3)-th column are connected to an even-numbered data line (e.g., D2, D6 . . . ) and even-numbered sub-pixels (P) in the (4k−3)-th column are connected to an odd-numbered data line (e.g., D1, D5 . . . ). For example, for the first column of sub-pixels (P) shown in
In the case of sub-pixels (P) of the odd numbered (4k−1)-th column, sub-pixels (P) in the (4k−1)-th column sequentially alternate between connecting to an odd-numbered data line (e.g., D3, D7 . . . ) and to even-numbered data line (e.g., D4, D8 . . . ).
In the case of sub-pixels (P) of the even numbered (4k−2)-th column, sub-pixels (P) in the (4k−2)-th column sequentially alternate between connecting to an odd-numbered data line (e.g., D3, D7 . . . ) and to an even-numbered data line (e.g., D4, D8 . . . ).
In the case of sub-pixels (P) of the even numbered 4k-th column, sub-pixels (P) of the 4k-th column sequentially alternate between connecting to an even-numbered data line (D4, D8, . . . ) and to odd-numbered data lines (D5, D9 (not pictured) . . . ).
As shown in
The gate driver 4 sequentially generates scan pulses upon receiving a gate control signal (GCS) from the timing controller 8, for example, in response to a gate start pulse (GSP), a gate shift clock (GSC), a gate output enable (GOE) signal, or the like.
The gate driver 4 may divide a frame interval into multiple subframe intervals. As one example, the gate driver 4 divides a frame interval into a first subframe interval and a second subframe interval, and drives gate voltages (e.g. provides scan pulses) according to the first and second subframe intervals. That is, the gate driver 4 sequentially provides scan pulses to even-numbered gate lines (G2, G4, G6 . . . ) during the first subframe interval (See, e.g.,
The data driver 6 converts image data (e.g., RGB data) received from the timing controller 8 into a data voltage upon receiving a data control signal (DCS) from the timing controller 8. For example, the data driver 6 converts image data in response to a source start pulse (SSP), a source shift clock (SSC), a source output enable (SOE) signal, or the like. Upon receiving a polarity control signal from the timing controller 8, the data driver 6 may select a positive (+) or negative (−) gamma voltage having a predetermined level according to a gray scale value of RGB data, and generates a corresponding data voltage.
The data driver 6 transmits data voltages having different polarities to neighbor data lines (D1 to Dm) during one frame interval. In doing so, the data driver 6 may transmit a data voltage for sub-pixels (P) of odd-numbered columns to a plurality of data lines (D1 to Dm) during the first subframe interval. Subsequently, the data driver 6 may transmit a data voltage for sub-pixels (P) of even-numbered columns to a plurality of data lines (D1 to Dm) during the second subframe interval.
The timing controller 8 arranges RGB data received from an external part in response to driving of the liquid crystal panel 2, and provides the arranged RGB data to the data driver 6 for each of the first and second subframes. In addition, the timing controller 8 generates a gate control signal (GCS) and a data control signal (DCS) using at least one of external input synchronization signals (e.g., a dot clock (DCLK) signal, a data enable (DE) signal, a horizontal synchronization (Hsync) signal, and a vertical synchronization (Vsync) signal). The timing controller 8 provides the generated GCS and DCS signals to each of the gate and data drivers 4 and 6, thus allowing the timing controller 8 to control the gate and data drivers 4 and 6 using the GCS and DCS signals.
Referring to
Referring to
As described above, the embodiment of the present invention can reduce power consumption of the gate and data drivers 4 and 6 using the interlace drive scheme, and can drive the data driver 6 using the column inversion scheme, resulting in reduction of power consumption of the data driver 6. Column inversion of the data driver 6 is converted into horizontal 2-dot inversion through Z-inversion driving, resulting in reduction of flicker and crosstalk. In addition, an unnecessary margin can be minimized in a thin film transistor (TFT) region of sub-pixels using a gate sharing structure, resulting in an increase in aperture ratio.
In accordance with the above embodiment, after the gate driver 4 provides scan pulses to even-numbered gate lines (G2, G4, G6 . . . ), the gate driver 4 provides scan pulses to odd-numbered gate lines (G1, G3, G5 . . . ). However, the above-mentioned order of supplying such scan pulses to the even-numbered gate lines and the odd-numbered gate lines is disclosed only for illustrative purposes, and the supply order is not limited thereto and may also be changed according to any number of orderings. For instance, the gate driver 4 may provide scan pulses to the odd-numbered gate lines (G1, G3, G5 . . . ) during a first subframe interval and, subsequently, provide scan pulses to even-numbered gate lines (G2, G4, G6 . . . ) during a second subframe interval. In this case, the data driver 6 is synchronized with the scan pulses such that the data driver 6 provides a data voltage for even-numbered columns of sub-pixels (P) to a plurality of data lines (D1 to Dm) during the first subframe interval. Then, the data driver 6 provides a data voltage for odd-numbered columns of sub-pixels (P) to the data lines (D1 to Dm) during the second subframe interval.
In another embodiment as shown in
As is apparent from the above description, the liquid crystal display (LCD) device and a method for driving the same can reduce power consumption of gate and data drivers using an interlace drive scheme, and can drive the data driver using a column inversion scheme, resulting in reduction of power consumption of the data driver.
Column inversion of the data driver is converted into horizontal 2-dot inversion through Z-inversion driving, resulting in reduction of flicker and crosstalk.
In addition, an unnecessary margin can be minimized in a thin film transistor (TFT) region of sub-pixels using a gate sharing structure, resulting in an increase in aperture ratio.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
Number | Date | Country | Kind |
---|---|---|---|
10-2012-0073534 | Jul 2012 | KR | national |
Number | Name | Date | Kind |
---|---|---|---|
20020154085 | Kim | Oct 2002 | A1 |
20060061534 | Lee | Mar 2006 | A1 |
20070182685 | Park et al. | Aug 2007 | A1 |
20090322660 | Chung et al. | Dec 2009 | A1 |
20100097366 | Kitayama et al. | Apr 2010 | A1 |
20110012887 | Lee et al. | Jan 2011 | A1 |
20110299023 | Lee | Dec 2011 | A1 |
20120026206 | Moon et al. | Feb 2012 | A1 |
20120120035 | Yang | May 2012 | A1 |
Number | Date | Country |
---|---|---|
101308271 | Nov 2008 | CN |
101424850 | May 2009 | CN |
101669162 | Mar 2010 | CN |
2009098311 | May 2009 | JP |
1020050097032 | Oct 2005 | KR |
Entry |
---|
Office Action issued in corresponding Korean Patent Application No. 10-2012-0073534, mailed Sep. 27, 2013, 4 pages. |
Office Action issued in corresponding Korean Patent Application No. 10-2012-0073534, mailed Mar. 13, 2014, 4 pages. |
Office Action dated Jul. 21, 2015 for corresponding Chinese Patent Application No. 201310279320.0, 12 pages. |
Number | Date | Country | |
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20140009458 A1 | Jan 2014 | US |