1. Field of the Disclosure
The present disclosure relates to a liquid crystal display field, and in particular to a scan compensation method and a scan compensation circuit of a gate driver.
2. The Related Arts
In recent years, the liquid crystal display, LCD, gradually replaces the conventional cathode ray tube, CRT, display because of its small size, light weight, low power consumption and high display quality. The application of liquid crystal display is gradually expanding, which has evolved from the displays of audio and video products, notebook computer monitor and so on to desktop computers, monitors of engineering workstations, EWS, and so on.
The drive of liquid crystal display is to establish a driving electric field through adjusting phase, peak value, frequency and so on of the potential phase applied on the liquid crystal device electrode, in order to achieve the display effect of the liquid crystal device. The driving methods of liquid crystal display are many, the common driving method is dynamic driving method. When the pixels displayed on the liquid crystal display device are many (for example a dot matrix liquid crystal display device), in order to save the huge hardware driver circuit, processing the production and arrangement of the liquid crystal display device electrode, achieving the array structure, namely, connecting and leading the back electrode of a group of display pixels in horizontal, which calls column electrode. On the liquid crystal display device, each display pixel is confirmed by the location of column and row. The driving method correspondingly adopts the grating scan method similar to CRT. The dynamic driving method of liquid crystal display is cyclically applied the selection pulse to the row electrode (namely scanning the row), at the same time, all column electrodes of display data provide the corresponding selection or non-selection driving pulse, thereby achieving the display function of all display pixels of one row. The row scan is progressively and sequentially carried on, the cycle is very short, making the liquid crystal display stably display.
However, in the sequential scan mode, in several special circumstances of heavy load, the power of source driver will greatly increase, at the same time, the heat increases, it brings the risk to the normal operation of liquid crystal display. In order to optimize the operation state of liquid crystal display in such special circumstance of heavy load, a new non-sequential scan technology of gate driver has been provided. For example, in the normal screen, the scanning method of the gate driver is sequential scan mode, when detecting the heavy load, the scanning formula of the gate driver will be switched to non-sequential scan mode. According to the difference of display screen, able to switch between the sequential scan mode and non-sequential scan mode in unit of frame. Although using non-sequential scan can greatly reduce the power consumption and temperature of the source driver under several special circumstances (for example heavy load), there is still some disadvantages, one is because the potential holding time of liquid crystal capacitance, LC, between different rows is different and may occur stripe sense of the display screen. Therefore, in order to improve the display quality, the further optimized design of the gate driver is required.
In order to overcome the deficiencies of the prior art, the exemplary embodiments of the present disclosure provides a scan compensation method of the gate driver, which can reduce that the potential holding time affect the display through the row that the potential holding time of liquid crystal capacitor is changed since the scan sequence is changed.
According to one aspect of the exemplary embodiment of the present disclosure, providing a scan compensation used for a gate driver, wherein the scan compensation method comprises: when the gate driver switching from first scanning mode to second scanning mode or from second scanning mode to first scanning mode, performing a first operation to a clock signal and a first compensation signal of the gate driver, and performing a second operation to the obtained signals and a second compensation signal, wherein the first scanning mode is a sequential scan mode, the second scanning mode is non-sequential scan mode.
Preferably, the first operation is OR operation, the second operation is AND operation.
Preferably, the first compensation signal is use to reduce the degree of corresponding potential retention time increasing which is caused by mode switching of the gate driver, the second compensation signal is used to reduce the degree of corresponding potential retention time which is caused by mode switching of the gate driver decreasing.
Preferably, when the gate driver switches from the first scanning mode to the second scanning mode or from the second scanning mode to the first scanning mode, when m-th row of multiple rows of a liquid crystal display is scanned in n-th order, if m is less than n, aligning the falling edge of the first compensation signal and the rising edge of n-th cycle waveform of a clock signal of the driver in order to perform the first operation, if m is greater than n, aligning the falling edge of the second compensation signal and the rising edge of n-th cycle waveform of a clock signal of the driver in order to perform the second operation, if m is equal to n, in n-th cycle of the clock signal of the driver does not perform the first operation or the second operation, wherein n and m are positive integers.
According to another aspect of the exemplary embodiment of the present disclosure, providing a scan compensation circuit used for gate driver, wherein the scan compensation circuit comprises: a first compensation circuit, which is disposed to perform a first operation to a clock signal and a first compensation signal of the gate driver when the gate driver switching from first scanning mode to second scanning mode or from second scanning mode to first scanning mode; a second compensation circuit, which is disposed to perform a second operation to output signal of the first operation and a second compensation signal when the gate driver switching from first scanning mode to second scanning mode or from second scanning mode to first scanning mode, wherein the first scanning mode is a sequential scan mode, the second scanning mode is non-sequential scan mode.
Preferably, the first operation is OR operation, the second operation is AND operation.
Preferably, the first compensation signal is use to reduce the degree of corresponding potential retention time increasing which is caused by mode switching of the gate driver, the second compensation signal is used to reduce the degree of corresponding potential retention time which is caused by mode switching of the gate driver decreasing.
Preferably, wherein when the gate driver switches from the first scanning mode to the second scanning mode or from the second scanning mode to the first scanning mode, when m-th row of multiple rows of a liquid crystal display is scanned in n-th order, if m is less than n, aligning the falling edge of the first compensation signal and the rising edge of n-th cycle waveform of a clock signal of the driver in order to perform the first operation, if m is greater than n, aligning the falling edge of the second compensation signal and the rising edge of n-th cycle waveform of a clock signal of the driver in order to perform the second operation, if m is equal to n, in n-th cycle of the clock signal of the driver does not perform the first operation or the second operation, wherein n and m are positive integers.
According to the scan compensation method and scan compensation circuit of the gate driver provided by the exemplary embodiments of the present disclosure, which can reduce that the potential holding time affect the display through the row that the potential holding time of liquid crystal capacitor is changed since the scan sequence is changed.
The other aspect of the exemplary embodiment will be described as below, and the part of which will be obviously, or can be known by the practice of the present disclosure.
Through combining the following drawings to describe the embodiments, the above and/or other purpose and advantages of the present disclosure will be more clearly, wherein:
Exemplary embodiments will now be described in detail, the exemplary embodiments are illustrated in the drawings, wherein the same reference numbers refer to the same elements. In this regard, the exemplary embodiments may have different forms and should not be construed as limited to the description set forth herein. Therefore, the following will describe the exemplary embodiment through only referring the drawings in order to explain various aspects of the inventive concept. As used herein, the term “and/or” includes one or more listed items related to any and all combinations. When such as “ . . . in at least one” the statement is after a column of element, the statement modifies the entire column element, instead of modifying a single element of the column.
The terminology used herein is only for describing particular embodiments, and is not intended to limit the exemplary embodiments of the present invention. As used herein, unless the context clearly indicates otherwise, the singular forms are intended to include the plural forms. In addition, it should be understood that, when used in this specification, the term “comprising” and/or “including”, which indicates the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or attach one or more other features, integers, steps, operations, elements, components, or combinations thereof.
It should be understood that, although the terms used herein may be a first, second, third, etc., to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element discussed below, component, region, layer or section may be termed a second element, component, region in the present invention without departing from the teachings of the premise, layer or section.
Unless otherwise defined, all terms used herein (including technical and scientific terms), and the inventive concept having ordinary skill in the art as commonly understood meaning of the same meaning. It is also understood, unless expressly so defined otherwise, the terms (terms, such as in the general dictionary definition) should be interpreted as having their environmental related field and/or the present specification consistent with their meaning of meaning and will not be idealized or overly formal sense to explain them.
It should also be noted that in some alternative implementations, the shown operation may not be in the order shown in the figure occurs. For example, two drawings shown in succession may in fact be executed substantially concurrently, or may sometimes be executed sequentially contrary, depending on the function may be involved.
Reference will now be described more fully with reference to an exemplary embodiment. In the drawings, for clarity, and the thickness of layers and regions are exaggerated. Similar numerals in the figures refer to like elements throughout, and therefore the description thereof will be omitted.
Refer to
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Although using non-sequential scan can greatly reduce the power consumption and temperature of the source driver under several special circumstances, there are still some disadvantages. For example, in the sequence scan mode, for each row, because the turning on time of each frame of the row is the same, when switching frame, after charge completing, the potential holding time (as shown in
Refer to
Similarly, when the gate driver is switched from the second scanning mode to the first scanning mode, the potential holding time of each row is also changed. For example, in the exemplary embodiment, in order to recover the progressive sequence scan, the turning on time of L2 needs to be in advance, the turning on time of L3 needs to be increase. Meanwhile, for L2 that the turning on time is in advance, aligning the rising edge of the clock signal CKV of the corresponded gate driver and the falling edge of the second compensation signal S2, thereby adjusting the waveform of corresponded cycle of the operated signal CKV_C through executing the second operation (namely AND operation). Therefore, L2 is delayed to be turned on due to the affection of second compensation signal S2, thereby making the decrease degree of potential holding time of L2 caused by switching to the first scanning mode corresponding decrease. On the other aspects, for the L3 that the turning on time is delay, aligning the rising edge of the clock signal CKV of the corresponded gate driver and the falling edge of the first compensation signal S1, thereby adjusting the waveform of corresponded cycle of the operated signal CKV_C through executing the first operation (namely OR operation). Therefore, L3 is turned on in advance due to the affection of first compensation signal S1, thereby making the increase degree of potential holding time of L3 caused by switching to the first scanning mode corresponding decrease.
According to the above exemplary embodiments, through adjusting the degree of potential holding time of L2 and L3 caused by switching the scanning mode, which can significantly reduce the negative impacts such as the stripe sense of display screen and so on.
Refer to
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As shown in
As described above, according to the scan compensation method and scan compensation circuit of the gate driver provided by the exemplary embodiments of the present disclosure, which can reduce that the potential holding time affect the display through the row that the potential holding time of liquid crystal capacitor is changed since the scan sequence is changed, improving the stability of liquid crystal display.
According to the exemplary embodiments, the components, elements or at least one of units represented by the block as shown in
The methods and steps can be performed to execute one or more programmable processors function by one or more computer programs through operating on input data and generating output. The methods and steps can also be special purpose logic circuitry (e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit)) is performed, and the device may also be implemented as special purpose logic circuitry.
In various embodiments, the computer readable medium may include instructions, when the instruction is executed, the apparatus execute at least one portion of the methods and steps. In some embodiments, the computer readable medium may be included in the magnetic media, optical media, other media or a combination thereof (for example, CD-ROM, hard disk drive, read only memory, flash drives, etc.). In such embodiments, the computer readable medium may be manufactured goods that are tangible and not temporarily achieved.
Those skilled in the art would recognize that while this paper has been illustrated and described in detail a number of exemplary embodiments of the present invention, however, without departing from the spirit and scope of the invention, may be made under this disclosure content directly to determine or derive many other variations or modifications consistent with the principles of the present invention. Therefore, it should be realized that the above embodiments are not to limit, but only exemplary. Therefore, the scope of the inventive concept defined by the appended claims and the broadest permissible interpretation of equivalents to determine, but should not be limited or restricted more specific embodiments. Therefore, it should be realized that the appended claims are intended to cover all modifications fall within the true spirit of the inventive concept and scope of the improvements and other exemplary embodiments.
Number | Date | Country | Kind |
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2016 1 0397934 | Jun 2016 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2016/095501 | 8/16/2016 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2017/211008 | 12/14/2017 | WO | A |
Number | Name | Date | Kind |
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8026868 | Bae | Sep 2011 | B2 |
9824653 | Park | Nov 2017 | B2 |
20020190934 | Yoshida | Dec 2002 | A1 |
20080036497 | Chung | Feb 2008 | A1 |
20120169678 | Shin | Jul 2012 | A1 |
Number | Date | Country |
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1648987 | Aug 2005 | CN |
102402033 | Apr 2012 | CN |
102903341 | Jan 2013 | CN |
204857151 | Dec 2015 | CN |
2008026800 | Feb 2008 | JP |
Number | Date | Country | |
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20180190226 A1 | Jul 2018 | US |