1. Technical Field
The present disclosure relates to a liquid crystal display and a driving method of the same, in particular, to a liquid crystal display with the low power consumption and a driving method of the same.
2. Description of Related Art
As liquid crystal displays advance, the liquid crystal display with the low power consumption becomes inevitably necessary, especially for adapting to the miniaturized electronic device, such as the electronic tag, smart phone, tablet computer, etc. The power consumption of the liquid crystal display directly affects the endurance of the whole electronic device.
Generally speaking, the liquid crystal display has a frame rate, and the frequency of the frame rate is around 50-70 Hz, i.e., 50-70 frames per second. When a user wants to get the liquid crystal display having lower power consumption, decreasing the frame rate is effective, for example, the frame rate decrease from 60 Hz to 1 Hz. However, although the lower frame rate can reduce the power consumption, but thin-film-transistor (TFT) of the liquid crystal display will cause the issue of negative gate bias stress.
To address the above issues, the inventor strives via associated experience and research to present the instant disclosure, which can effectively improve the limitation described above.
Accordingly, an objective of the instant disclosure is to provide a liquid crystal display and a driving method of the same, and which drives scanning lines and data lines by a timing controller. The thin-film-transistors (TFTs) share a front transistor to write data to be displayed to the liquid crystal capacitor of each pixel element. When writing the data to the liquid crystal capacitor, the thin-film-transistor (TFT) and the front transistor of the corresponding liquid crystal capacitor are turned on simultaneously. After finishing writing data to the liquid crystal capacitor, the thin-film-transistor (TFT) and the front transistor of the corresponding liquid crystal capacitor are turned on alternately. Therefore, the liquid crystal display and the driving method of the same can reduce the time of the gate of the thin-film-transistor (TFT) being in the negative gate bias stress to achieve de-stress.
An exemplary embodiment of the instant disclosure provides a liquid crystal display. The liquid crystal display includes a plurality of scanning lines, a plurality of data lines, a gate driving circuit, a source driving circuit, and a timing controller. The scanning lines are sequentially arranged in parallel and divided into a plurality of scanning groups. Each scanning group has two scanning lines. The data lines are vertically intersected with the scanning lines. A crossing of each data line and each scanning line configures a pixel element. The gate driving circuit is electrically connected to the scanning lines. The source driving circuit is electrically connected to the data lines. The timing controller is electrically connected to the scanning lines and the data lines. The timing controller is configured for generating a common voltage periodically. The common voltage has a low-voltage time and a high-voltage time in each period. A data writing period and a de-stress period are defined in the low-voltage time and the high-voltage time. In the data writing period, the timing controller controls the source driving circuit for providing a data signal to each data line and controls the gate driving circuit for sequentially generating a high-voltage signal to each scanning line. The high-voltage signals of two adjacent scanning lines overlap. When the high-voltage signals of two adjacent scanning lines overlap, the timing controller sequentially transmits the data signal to each pixel element. In the de-stress period, the timing controller controls the gate driving circuit for generating a pulse signal to each scanning line continuously, and the pulse signals generated by each scanning line do not overlap.
An exemplary embodiment of the instant disclosure provides a driving method of a liquid crystal display. The liquid crystal display includes a plurality of scanning lines and a plurality of data lines. The scanning lines are sequentially arranged in parallel and divided into a plurality of scanning groups. Each scanning group has two scanning lines. The data lines are vertically intersected with the scanning lines. A crossing of each data line and each scanning line configures a pixel element. The driving method of the liquid crystal display includes the following steps: periodically generating a common voltage, wherein the common voltage has a low-voltage time and a high-voltage time in each period, and a data writing period and a de-stress period are defined in the low-voltage time and the high-voltage time; in the data writing period, providing a data signal to each data line and sequentially generating a high-voltage signal to each scanning line, wherein the high-voltage signals of two adjacent scanning lines overlap, and when the high-voltage signals of two adjacent scanning lines overlap, sequentially transmitting the data signal to each pixel element; and in the de-stress period, generating a pulse signal to each scanning line continuously, wherein the pulse signals generated by each scanning line do not overlap.
To sum up, the exemplary embodiments of the instant disclosure provide a liquid crystal display and a driving method of the same, which can reduce the time of the gate of the thin-film-transistor (TFT) being in the negative gate bias stress, so that the liquid crystal display can achieve the more accurate initial voltage under the lower frame rate operation and can avoid the leakage of data signal stored in the liquid crystal capacitor.
In order to further understand the techniques, means and effects of the present disclosure, the following detailed descriptions and appended drawings are hereby referred to, such that, and through which, the purposes, features and aspects of the instant disclosure can be thoroughly and concretely appreciated; however, the appended drawings are merely provided for reference and illustration, without any intention to be used for limiting the present disclosure.
The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
Reference will now be made in detail to the exemplary embodiments of the instant disclosure, examples of which are illustrated in the accompanying drawings. However, they may be embodied in different forms and should not be construed as being limited to the embodiments set forth herein. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
Firstly, please refer to
The scanning lines G1-Gk are sequentially arranged in parallel. The data lines S1-Sk are vertically intersected with the scanning lines G1-Gk. More specifically, the scanning lines G1-Gk extending along with a row direction are parallel to each other. The data lines S1-Sk extending along with a column direction are parallel to each other and vertically intersected with the scanning lines G1-Gk. The scanning lines G1-Gk are divided into a plurality of scanning groups. Each scanning group has two scanning lines. For example, the scanning lines G1 and G2 are the same scanning group, the scanning lines Gn and Gn+1 are another scanning group GPA, the scanning lines Gn+2 and Gn+3 are another scanning group GPB, and etc.
The source driving circuit 120 is electrically connected to the data lines S1-Sk to transmit the data to be displayed through the data lines S1-Sk. The gate driving circuit 130 is electrically connected to the scanning lines G1-Gk, and sequentially drives the scanning lines G1-Gk to store the data signal (i.e., the frame data) in the corresponding pixel element PXL. The pixel element PXL is configured at a crossing of each data line S1-Sk and each scanning group to display the data signal on the display panel of the LCD 100. Persons of ordinary skill in this technology field should realize implementation and operation of displaying the data signal stored in the pixel element PXL on the display panel of the LCD 100, and further descriptions are hereby omitted.
The timing controller 110 is electrically connected to the gate driving circuit 130 and the source driving circuit 120 and periodically generates a common voltage COM. As shown in
As shown in
Please refer to
As shown in the upper figure of
In the de-stress period, the timing controller 110 controls gate driving circuit 130 to continuously generate a pulse signal to each scanning line G1-Gk, and the pulse signals generated by each scanning line G1-Gk do not overlap. In the instant disclosure, the timing controller 110 can control the gate driving circuit 130 periodically or randomly, to generate the pulse signal to each scanning line G1-Gk. The instant disclosure is not limited thereto.
As shown in the upper figure of
Please return to
The front transistor MF has a first end, a second end, and a front control end. The first transistor MP1 has a third end, a fourth end, and a first control end. The first end of the front transistor MF electrically connects to the corresponding data line Sn. The front control end of the front transistor MF electrically connects the scanning line Gn+1 of the corresponding scanning group GPA (i.e., the latter scanning line of the scanning group GPA). The second end of the front transistor MF electrically connects to the third end of the first transistor MP1. The first control end of the first transistor MP1 electrically connects to the scanning line Gn of the scanning group GPA (i.e., the former scanning line of the scanning group GPA). The fourth end of the first transistor MP1 electrically connects to an end of the first liquid crystal capacitor C1. Another end of the first liquid crystal capacitor C1 receives the common voltage COM.
The second transistor MP2 has a fifth end, a sixth end, and a second control end. The fifth end of the second transistor MP2 electrically connects between the second end of the front transistor MF and the third end of the first transistor MP1. The second control end of the second transistor MP2 electrically connects the scanning line Gn+2 of the scanning group GPB (i.e., the former scanning line of the next scanning group GPB). the sixth of the second transistor MP2 electrically connects an end of the second liquid crystal capacitor C2. Another end of the second liquid crystal capacitor C2 receives the common voltage COM.
In conjunction with
In the de-stress period DS, when the scanning lines Gn and Gn+1 of the scanning group GPA and the scanning line Gn+2 of the scanning group GPB (i.e., the scanning lines electrically connected to the corresponding pixel element PXL of the scanning group GPA) respectively receive the pulse signal (i.e., the scanning line Gn receives the pulse signal SAn, the scanning line Gn+1 receives the pulse signal SAn+1, and the scanning line Gn+2 receives the pulse signal SAn+2), the front transistor MF, the first transistor MP1, and the second transistor MP2 are alternately turned on according to the received pulse signal. Because the front transistor MF, the first transistor MP1, and the second transistor MP2 of each pixel element PXL are not simultaneously turned on and continuously turned on or off in the de-stress period DS, the data signal DATA stored in the first liquid crystal capacitor C1 and the second liquid crystal capacitor C2 does not lose, and the gate of the front transistor MF, the gate of the first transistor MP1, and the gate of the second transistor MP2 do not stay at the negative gate bias stress for a long time (i.e., the stress during the gate-source voltage VGS being less than the threshold voltage VT).
From the aforementioned description, in the data writing period DIN, the timing controller 110 sequentially stores the data signal DATA in the first liquid crystal capacitor C1 and the second liquid crystal capacitor C2 of each pixel element PXL through the scanning lines G1-Gk, to display the data signal DATA on the display panel of the LCD 100. In the de-stress period DS, the timing controller 110 controls the front transistor MF, the first transistor MP1, and the second transistor MP2 of each pixel element PXL to alternately and continuously turn on the above-mentioned transistors of each pixel element PXL through the scanning lines G1-Gk, so that the first liquid crystal capacitor C1 and the second liquid crystal capacitor C2 of each pixel element PXL can make sure the gate of the front transistor MF, the gate of the first transistor MP1, and the gate of the second transistor MP2 do not stay at the negative gate bias stress for a long time under the situation of keeping the data signal DATA. Accordingly, the LCD 100 can achieve the more accurate initial voltage under the lower frame rate operation and can avoid the leakage of data signal DATA stored in the first liquid crystal capacitor C1 and the second liquid crystal capacitor C2.
Next, please refer to
As shown in the upper figure of
Therefore, in the data writing period DIN, when the scanning lines Gn and Gn+1 of the scanning group GPA simultaneously receive the high-voltage signal (i.e., the scanning line Gn receives the second high-voltage pulse BBn and the scanning line Gn+1 receives the first high-voltage pulse BAn+1), the front transistor MF and the first transistor MP1 of the corresponding pixel element PXL of the scanning group GPA are simultaneously turned on, to store the data signal DATA in the first liquid crystal capacitor C1. When the scanning line Gn+1 of the scanning group GPA (i.e., the latter scanning line of the scanning group GPA) and the scanning line Gn+2 of the scanning group GPB (i.e., the former scanning line of the scanning group GPB) simultaneously receive the high-voltage signal (i.e., the scanning line Gn+1 receives the second high-voltage pulse BBn+1 and the scanning line Gn+2 receives the first high-voltage pulse BAn+2), the front transistor MF and the second transistor MP2 of the corresponding pixel element PXL of the scanning group GPA are simultaneously turned on, to store the data signal DATA in the second liquid crystal capacitor C2. From
Accordingly, the liquid crystal display can reduce the time of the gate of the thin-film-transistor (TFT) being in the negative gate bias stress to achieve de-stress.
From the aforementioned exemplary embodiments, the instant disclosure may generalize a driving method, which is adapted for the aforementioned liquid crystal display. Please refer to
In the data writing period DIN, the liquid crystal display 100 provides the data signal DATA to each data line S1-Sk, and sequentially generates high-voltage signal to each scanning line G1-Gk. The high-voltages of two adjacent scanning lines G1-Gk overlap. When the high-voltages signals of two adjacent scanning lines overlap, the liquid crystal display 100 sequentially transmits the data signal DATA to each pixel element PXL (step S220). With respect to the liquid crystal display 100 driving each data line S1-Sk, each scanning line G1-Gk, and each pixel element PXL in data writing period DIN are illustrated in the aforementioned exemplary embodiments, so their detailed description is omitted.
In the data writing period DS, the liquid crystal display 100 generates a pulse signal to each scanning line G1-Gk continuously, and the pulse signals generated by each scanning line G1-Gk do not overlap (step S230). Similarly, with respect to the liquid crystal display 100 driving each data line S1-Sk, each scanning line G1-Gk, and each pixel element PXL in de-stress period DS are illustrated in the aforementioned exemplary embodiments, so their detailed description is omitted.
In summary, the exemplary embodiments of the instant disclosure provide a liquid crystal display and a driving method of the same, which can reduce the time of the gate of the thin-film-transistor (TFT) being in the negative gate bias stress, so that the liquid crystal display can achieve the more accurate initial voltage under the lower frame rate operation and can avoid the leakage of data signal stored in the liquid crystal capacitor.
The above-mentioned descriptions represent merely the exemplary embodiment of the instant disclosure, without any intention to limit the scope of the instant disclosure thereto. Various equivalent changes, alterations or modifications based on the claims of instant disclosure are all consequently viewed as being embraced by the scope of the instant disclosure.
Number | Date | Country | Kind |
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103139254 | Nov 2014 | TW | national |