TWI814283B - Liquid crystal display device and driving method of liquid crystal display panel - Google Patents

Abstract

A liquid crystal display device includes a liquid crystal display panel, a first driving circuit and a second driving circuit. The liquid crystal display panel includes multiple common conductive wires and multiple segment conductive wires. The common conductive wires and the segment conductive wires are interlaced with each other to define multiple pixels. The first driving circuit outputs a common signal to one of the common conductive wires in a scan period. The second driving circuit outputs a segment signal to one of the segment conductive wires in the scan period. At least one of the common signal and the segment signal is an oscillating signal. The oscillating signal has a highest level and a lowest level alternately switched and the oscillating signal further has a middle level closely between the two adjacent highest level and lowest level. Furthermore, a driving method of liquid crystal display panel is also disclosed herein.

Description

Liquid crystal display device and driving method of liquid crystal display panel

This case relates to a display device technology, particularly a liquid crystal display device and a driving method of a liquid crystal display panel.

Liquid crystal display devices are widely used in various electronic products. For common liquid crystal display devices, the liquid crystal display device usually includes a driving circuit. When the driving circuit transmits signals to the liquid crystal display panel, signal disturbance may be generated due to the transmission of continuous signals, causing the liquid crystal display panel to suffer from crosstalk interference (crosstalk). influence, thereby causing the displayed image to appear in grayscale. Therefore, how to develop related technologies that can overcome the above problems is an important issue in this field.

One embodiment of the present case is a liquid crystal display device including a liquid crystal display panel, a first driving circuit and a second driving circuit. The liquid crystal display panel includes a plurality of common conductors and a plurality of segment conductors. The common conductors and segment conductors are interlaced to define multiple pixels. The first driving circuit is electrically coupled to the liquid crystal display panel and outputs a common signal to one of the plurality of common conductors during the scanning period to select a corresponding pixel among the plurality of pixels. The second driving circuit is electrically coupled to the liquid crystal display panel, and outputs a segment signal to one of the plurality of segment wires during the scanning period to drive the corresponding pixel. At least one of the common signal and the segment signal is an oscillation signal, the oscillation signal has a highest level and a lowest level that alternately switch, and the oscillation signal further has an intermediate level immediately adjacent to the lowest level and the highest level. between.

Another embodiment of the present invention is a liquid crystal display device including a liquid crystal display panel, a first driving circuit and a second driving circuit. The liquid crystal display panel includes a plurality of common conductors and a plurality of segment conductors. The common conductors and segment conductors are interlaced to define multiple pixels. The first driving circuit is electrically coupled to the liquid crystal display panel and outputs a common signal to one of the plurality of common conductors during the scanning period to select a corresponding pixel among the plurality of pixels. The second driving circuit is electrically coupled to the liquid crystal display panel, and outputs a segment signal to one of the plurality of segment wires during the scanning period to drive the corresponding pixel. At least one of the common signal and the segment signal is an oscillation signal, and the oscillation signal includes at least a first partial oscillation signal and at least a second partial oscillation signal. At least a first partial oscillation signal has a highest level and a middle level that alternately switch. At least a second partial oscillation signal has an intermediate level and a lowest level that alternately switch. The oscillation signal further has an intermediate level immediately between the adjacent at least one first partial oscillation signal and the at least one second partial oscillation signal.

Another embodiment of the present invention is a method for driving a liquid crystal display panel, including: applying a common signal to one of a plurality of common conductors in the liquid crystal display panel, and applying a segment signal to a plurality of segment conductors in the liquid crystal display panel. One of them. In the liquid crystal display panel, a plurality of common conductors and a plurality of segment conductors are interlaced to define multiple pixels. At least one of the common signal and the segment signal is an oscillation signal. The oscillation signal has a highest level and a lowest level that alternately switch. The oscillation signal further has an intermediate level immediately after the lowest level, and the oscillation signal has the highest level. Immediately after the middle level.

Another embodiment of the present case is a method for driving a liquid crystal display panel, including: applying a common signal to one of a plurality of common conductors in the liquid crystal display panel, and applying a segment signal to a plurality of segment conductors in the liquid crystal display panel. One of them. In the liquid crystal display panel, a plurality of common conductors and a plurality of segment conductors are interlaced to define multiple pixels. At least one of the common signal and the segment signal is an oscillation signal. The oscillation signal includes a plurality of first partial oscillation signals and a plurality of second partial oscillation signals. The plurality of first partial oscillation signals and the plurality of second partial oscillation signals are alternately switched. . The plurality of first partial oscillation signals have a highest level and an intermediate level that are alternately switched. The plurality of second partial oscillation signals have a middle level and a lowest level that are alternately switched. The oscillation signal has an intermediate level immediately between any two adjacent one of the first partial oscillation signals and one of the plurality of second partial oscillation signals.

In this document, when an element is referred to as "connected" or "coupled," it may mean "electrically connected" or "electrically coupled." "Connection" or "coupling" can also be used to indicate the coordinated operation or interaction between two or more components. In addition, although terms such as "first", "second", ... are used to describe different elements herein, the terms are only used to distinguish elements or operations described by the same technical terms. Unless the context clearly indicates otherwise, the term does not specifically refer to or imply a sequence or sequence, nor is it used to qualify the case.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms including "at least one" unless the content clearly dictates otherwise. "Or" means "and/or". As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. It will also be understood that when used in this specification, the terms "comprises" and/or "includes" designate the presence of stated features, regions, integers, steps, operations, elements and/or components but do not exclude one or more The presence or addition of other features, regions, steps, operations, elements, parts and/or combinations thereof.

Figure 1 is a schematic diagram of a liquid crystal display device 100 according to some embodiments of the present invention. The liquid crystal display device 100 includes a liquid crystal display panel 130, a first driving circuit 140 and a second driving circuit 150. The liquid crystal display panel 130 includes a plurality of common conductors 141 and a plurality of segment conductors 151 . The common conductors 141 and the segment conductors 151 are interlaced with each other to define a plurality of pixels 131 . The first driving circuit 140 and the second driving circuit 150 are electrically coupled to the liquid crystal display panel 130 . The liquid crystal display device 100 further includes a processor 110 and a controller 120 . The controller 120 is coupled to the processor 110, the first driving circuit 140 and the second driving circuit 150. Figure 1 is only an example and is not intended to limit this case.

In some embodiments, the liquid crystal display panel 130 is a cholesteric liquid crystal display panel. This type of cholesteric liquid crystal display panel is composed of two substrates sealed with liquid crystal, and a plurality of common conductors and a plurality of segment conductors (such as the above-mentioned common conductors 141 and segment conductors 151) are respectively formed on the two substrates. A common conductor and a plurality of segment conductors cross each other. The pixels (such as the above-mentioned pixel 131) in the above-mentioned cholesteric liquid crystal display panel are driven by electrodes formed by the intersection of common conductors and segment conductors. In some embodiments, the first driving circuit 140 may be a common signal generator or a common signal output circuit. In some embodiments, the second driving circuit 150 may be a segment signal generator or a segment signal output circuit.

As shown in FIG. 1 , in some embodiments, the processor 110 transmits the image signal 111 and the coordinate signal 112 (coordinates covered by the image to be displayed) of the entire screen to the controller 120 . In some embodiments, the processor 110 transmits the image signal 111 to the controller 120 through a signal interface (eg, Low-Voltage Differential Signaling (LVDS)). In some embodiments, the processor 110 transmits the coordinate signal 112 to the controller 120 through a serial interface (eg, Serial Peripheral Interface Bus, SPI).

Then, the controller 120 generates a control signal 121 according to the image signal 111 and the coordinate signal 112 to control the first driving circuit 140 and the second driving circuit 150 . In some embodiments, the control signal 121 generated by the controller 120 may include a digital-to-analog signal (eg, STB signal), a data signal (eg, MLxP signal), and a ground signal (eg, SDOZ signal). In some embodiments, the first driving circuit 140 and the second driving circuit 150 are used to output an analog signal corresponding to the received digital signal according to the above-mentioned digital-to-analog signal.

The first driving circuit 140 is used to output a common signal 142 to one of the plurality of common conductors 141 during the scanning period to select corresponding pixels among the plurality of pixels 131 . The second driving circuit 150 is used to output the segment signal 152 to one of the plurality of segment wires 151 during the scanning period to drive the corresponding pixels in the plurality of pixels 131 . In some embodiments, during the scan cycle, at least one of the output common signal 142 and the segment signal 152 is an oscillation signal. This oscillation signal has a highest level and a lowest level that alternately switch, and the oscillation signal is more There is an intermediate level immediately between the adjacent lowest level and the highest level, as shown in the following embodiment.

Figure 2 is a schematic waveform diagram of the oscillation signal 200 according to some embodiments of the present application. In the scanning period T, the oscillation signal 200 is a signal in which the highest level H1 and the lowest level L1 alternately switch, and there is an intermediate level G1 between the adjacent lowest level L1 and the highest level H1 in the oscillation signal 200 . In one embodiment, as shown in FIG. 2 , the oscillation signal 200 has an intermediate level G1 immediately between any two adjacent lowest levels L1 and highest levels H1 . In other words, during the scanning period T, part of the oscillation signal 200 sequentially switches from the highest level H1 to the intermediate level G1, the lowest level L1, the intermediate level G1, and then returns to the highest level H1, or partially The oscillation signal 200 may also switch sequentially from the lowest level L1 to the intermediate level G1, the highest level H1, the intermediate level G1, and then back to the lowest level L1. Since the oscillation signal 200 has an intermediate level G1 immediately between the adjacent lowest level L1 and the highest level H1, it can release charges when driving the electrodes on both sides of the liquid crystal and reduce the pixel to a constant voltage during the scan period T. The driving time ratio prevents the LCD panel from being affected by crosstalk interference due to signal disturbance.

Figure 3 is a schematic waveform diagram of the oscillation signal 300 according to some embodiments of the present case. In another embodiment, compared with the embodiment in Figure 2, during the scanning period T, part of the oscillation signal 300 is directly switched from the highest level H2 to the lowest level L2, and the highest level H2 to the lowest level L2 There is no intermediate level in the interval, and then the oscillation signal 300 then switches from the lowest level L2 to the intermediate level G2, and then switches from the intermediate level G2 to the highest level H2. In other words, as shown in FIG. 3 , in the scanning period T, the oscillation signal 300 has an intermediate level G2 immediately after each lowest level L2. Since the oscillation signal 300 has an intermediate level G2 immediately after each lowest level L2, it can release charges when driving the electrodes on both sides of the liquid crystal and reduce the proportion of time the pixel is driven at a constant voltage in the scan period T. Improved the crosstalk interference caused by signal disturbance on the LCD panel.

In some embodiments, during the scan cycle, compared with Figures 2 and 3 above, some of the oscillation signals switch directly from the lowest level to the highest level, and the interval from the lowest level to the highest level does not exist. any intermediate level (not shown), then the oscillating signal then switches from the highest level to the intermediate level, and then from the intermediate level to the lowest level. In other words, part of the oscillating signal has an intermediate level immediately following each highest level.

Figure 4 is a schematic diagram of the waveform of the oscillation signal 400 according to some embodiments of the present application. In different embodiments, referring to FIGS. 1 and 4 , at least one of the common signal 142 output by the first driving circuit 140 and the segment signal 152 output by the second driving circuit 150 is as shown in FIG. 4 Oscillation signal 400 is shown. Specifically, the oscillation signal 400 includes a first partial oscillation signal P1 and a second partial oscillation signal P2. The first partial oscillation signal P1 has an alternately switching highest level H3 and a middle level G3. The second partial oscillation signal P2 has an alternately switching highest level H3 and an intermediate level G3. The intermediate level G3 and the lowest level L3, and the oscillation signal 400 further has an intermediate level G3 immediately between the adjacent first partial oscillation signal P1 and the second partial oscillation signal P2.

In some embodiments, as shown in FIG. 4 , during the scan period T, the oscillation signal 400 further includes a plurality of first partial oscillation signals P1 and a plurality of second partial oscillation signals P2. The plurality of first partial oscillation signals P1 and The plurality of second partial oscillation signals P2 are alternately switched, and the oscillation signal 400 has one of the plurality of first partial oscillation signals P1 and one of the plurality of second partial oscillation signals P2 immediately following any two adjacent ones. The intermediate level between G3. In other words, during the scan period T, the oscillation signal 400 may sequentially switch from the first partial oscillation signal P1 to the intermediate level G3, the second partial oscillation signal P2, the intermediate level G3, and then return to the first partial oscillation signal P1 , or the oscillation signal 400 may be switched sequentially from the second partial oscillation signal P2 to the intermediate level G3, the first partial oscillation signal P1, the intermediate level G3, and then back to the second partial oscillation signal P2. Since the oscillation signal 400 has an intermediate level G3 immediately between the adjacent first partial oscillation signal P1 and the second partial oscillation signal P2, it can release charges when driving the electrodes on both sides of the liquid crystal and shorten the scanning period. The time proportion of constant voltage driving in T improves the crosstalk interference caused by signal disturbance on the LCD panel.

Referring to Figures 2 to 4, in various embodiments, the voltages of intermediate levels (eg, intermediate levels G1, G2, and G3) of the oscillation signals (eg, the oscillation signals 200, 300, and 400) are greater than or equal to In the range of about −5 volts and less than or equal to about 5 volts. In some embodiments, the intermediate level may be about 0 volts, which is the level at ground, or a level close to 0 volts.

Continuing to refer to FIGS. 2 to 4 , in some embodiments, in the scan period T, the time when the oscillation signal is at the intermediate level accounts for about 10 to 15% of the scan period T. In some embodiments, in the scan period T, the time the oscillation signal is at the intermediate level does not exceed 40% of the scan period T.

Figure 5 is a flow chart of a driving method 500 for a liquid crystal display panel according to some embodiments of the present application. The liquid crystal display panel driving method 500 includes step 510 and step 520 . Next, the driving method 500 of the liquid crystal display panel 130 will be described with reference to FIGS. 1 and 5 .

As shown in FIG. 5 , in step 510 , a common signal 142 is applied to one of the plurality of common conductors 141 in the liquid crystal display panel 130 . In some embodiments, the above steps are through the first driving circuit 140 outputting the common signal 142 to one of the plurality of common conductors 141 during the scanning period.

In step 520, the segment signal 152 is applied to one of the plurality of segment conductors 151 in the liquid crystal display panel 130, and the common conductor 141 and the segment conductors 151 in the liquid crystal display panel 130 are staggered to define multiple Pixel 131. In some embodiments, the above step is to output the segment signal 152 to one of the plurality of segment conductors 151 during the scanning period through the second driving circuit 150 .

In some embodiments, in steps 510 to 520, at least one of the applied common signal 142 and the segment signal 152 is an oscillation signal. The oscillation signal has a highest level and a lowest level that are alternately switched. The oscillation signal is more There is an intermediate level immediately after the lowest level, and the highest level of the oscillating signal is immediately after the intermediate level. In some embodiments, the oscillation signal (eg, the oscillation signal 200 of FIG. 2 ) has an intermediate level immediately between any two adjacent lowest levels and highest levels.

In different embodiments, at least one of the common signal 142 applied through the first driving circuit 140 and the segment signal 152 applied through the second driving circuit 150 in steps 510 to 520 is an oscillation signal, as described above. Compared with the oscillation signal of the embodiment, this type of oscillation signal (for example, the oscillation signal 400 in Figure 4) includes a plurality of first partial oscillation signals and a plurality of second partial oscillation signals, and the first partial oscillation signals alternate with the second partial oscillation signals. switch. The above-mentioned first part of the oscillation signal has a highest level and a middle level that are alternately switched, and the above-mentioned second part of the oscillation signal has an alternately switching middle level and a lowest level. Specifically, the oscillation signal has an intermediate level immediately between any two adjacent ones of the first partial oscillation signals and one of the second partial oscillation signals. In some embodiments, the oscillation signal is sequentially switched from the first part of the oscillation signal to the intermediate level, the second part of the oscillation signal, the intermediate level, and then back to the first part of the oscillation signal.

To sum up, in this case, through the mentioned driving method of the liquid crystal display device and the liquid crystal display panel, the oscillation signal output to the liquid crystal display panel has an intermediate level for releasing charges, so as to reduce the pixels in the scanning period. The constant voltage driving time ratio improves the crosstalk interference caused by signal disturbance on the LCD panel, allowing the LCD panel to present a cleaner image.

Although this case has been disclosed as above using embodiments, they are not intended to limit this case. Anyone with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of this case. Therefore, the protection of this case The scope shall be determined by the appended patent application scope.

100:Liquid crystal display device

110: Processor

111:Image signal

112:Coordinate signal

120:Controller

121:Control signal

130:LCD display panel

131:pixel

140: First drive circuit

141: Common wire

142:Common signal

150: Second drive circuit

151: Section wire

152: Section signal

200,300,400: Oscillation signal

G1, G2, G3: intermediate level

H1, H2, H3: the highest level

L1, L2, L3: lowest level

T: scan cycle

P1: The first part of the oscillation signal

P2: The second part of the oscillation signal

500: Driving method of liquid crystal display panel

510,520: steps

Figure 1 is a schematic diagram of a liquid crystal display device according to some embodiments of the present invention. Figure 2 is a schematic waveform diagram of an oscillation signal according to some embodiments of the present invention. Figure 3 is a schematic waveform diagram of an oscillation signal according to some embodiments of this case. Figure 4 is a schematic diagram of the waveform of an oscillation signal according to some embodiments of this case. Figure 5 is a flow chart of a driving method of a liquid crystal display panel according to some embodiments of the present invention.

Domestic storage information (please note in order of storage institution, date and number) without Overseas storage information (please note in order of storage country, institution, date, and number) without

100:Liquid crystal display device

110: Processor

111:Image signal

112:Coordinate signal

120:Controller

121:Control signal

130:LCD display panel

131:pixel

140: First drive circuit

141: Common wire

142:Common signal

150: Second drive circuit

151: Section wire

152: Section signal

Claims (7)

A liquid crystal display device, including: a liquid crystal display panel, including a plurality of common conductors and a plurality of segment conductors, the common conductors and the segment conductors are interlaced to define a plurality of pixels; a first drive circuit, electrically electrically coupled to the liquid crystal display panel and used to output a common signal to one of the common conductors in a scanning period to select a corresponding pixel among the pixels; and a second drive circuit, electrically coupled Connected to the liquid crystal display panel, and used to output a segment signal to one of the segment wires in the scan cycle to drive the corresponding pixel; wherein at least one of the common signal and the segment signal is a Oscillation signal, the oscillation signal includes at least a first partial oscillation signal and at least a second partial oscillation signal, the at least a first partial oscillation signal has a highest level and a middle level that alternately switch, the at least a second partial oscillation signal The signal has the intermediate level and a lowest level that alternately switch, and the oscillation signal further has the intermediate level immediately between the adjacent at least one first partial oscillation signal and the at least one second partial oscillation signal. between. The liquid crystal display device of claim 1, wherein part of the oscillation signal is switched from the lowest level to the intermediate level, and then switched from the intermediate level to the highest level. The liquid crystal display device as claimed in claim 1, wherein the oscillator The swing signal has the intermediate level immediately between the lowest level and the highest level of any two adjacent ones. The liquid crystal display device of claim 1, wherein the voltage of the intermediate level is in a range of greater than or equal to about -5 volts and less than or equal to about 5 volts. The liquid crystal display device of claim 1, wherein the oscillation signal includes a plurality of first partial oscillation signals and a plurality of second partial oscillation signals, and the first partial oscillation signals and the second partial oscillation signals alternately switch. The liquid crystal display device of claim 5, wherein the oscillation signal has an intermediate point immediately between any two adjacent one of the first partial oscillation signals and one of the second partial oscillation signals. Level. A driving method for a liquid crystal display panel, including: applying a common signal to one of a plurality of common conductors in a liquid crystal display panel; and applying a segment signal to one of a plurality of segment conductors in the liquid crystal display panel. , wherein the common conductors and the segment conductors in the liquid crystal display panel are interlaced with each other to define a plurality of pixels; wherein at least one of the common signal and the segment signal is an oscillation signal, and the oscillation signal includes at least one a first portion of the oscillating signal and at least a second Partial oscillation signal, the at least one first partial oscillation signal has a highest level and a middle level that alternately switches, the at least one second partial oscillation signal has the middle level and a lowest level that alternately switches, and the oscillation The signal further has the intermediate level immediately between the adjacent at least one first partial oscillation signal and the at least one second partial oscillation signal.

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