TW571276B - Driving circuit of liquid crystal display using a stepwise charging/discharging manner - Google Patents

Abstract

A liquid crystal display (LCD) driving circuit is disclosed in the present invention, in which a stepwise charging/discharging manner is used to drive plural data lines of LCD. The invented circuit includes a clock controller, plural reference voltages, and plural analog voltage drivers. The clock controller is used to generate stepwise charging/discharging. The reference voltage is used to provide the stepwise charging/discharging reference voltage. Input terminal of the analog voltage driver is coupled with the clock controller, the reference voltage, the output of the conventional data line driving circuit, and the required polarity and brightness data. Output terminal of the analog voltage driver is coupled with one corresponding data line. When the analog voltage driver performs the driving step, the driving voltage of prior pixel is used as the start voltage and the analog driving voltage of the pixel to be driven as the ultimate voltage. Plural reference voltages distributed between the start voltage and the ultimate voltage are sequentially started according to the clock signal inputted to the clock controller. At last, the ultimate voltage is started.

Description

571276 V. Description of the invention (1) Detailed description: Technical field: The present invention relates to a step-type charging and discharging liquid crystal display driving circuit, and more particularly to a liquid crystal display driving circuit and driving method that greatly reduce power consumption. Background of the Invention: According to the current booming era of the information industry and the communication industry, liquid crystal displays are widely used in various products, such as notebook computers, palmtop computers, mobile phones, personal digital assistants, and so on. The daytime display of a liquid crystal display usually consists of tens to thousands of interlaced horizontal scanning lines and straight data lines. The interlaced points of each horizontal scanning line and straight data line form a pixel, whose brightness is determined by the voltage applied to the pixel. Please refer to FIG. 1 first, which shows a schematic diagram of a day array of an active matrix liquid crystal display. The figure shows the fifth scanning line 5 and the sixth scanning line 6 in the horizontal direction, the second data line 2 and the third data line 3 in the vertical direction, and the four celestial elements connected to it. Each of these elements includes a control switch 7 and a capacitor 8 for storing electric charge. The repeating array of daylight elements forms the daylight surface of the liquid crystal display. The traditional method of controlling the image of the liquid crystal display is to connect the control switches on the same row with a scan line, driven by a scan drive circuit, and turn on one scan line at a time from top to bottom to allow the material Write the capacitor that stores the electricity. On scan drive

Page 5 571276 V. Description of the invention (2) A scan line is opened on the line. The material line uses data to drive gray levels. Scan each cycle like this, followed by the image above. So, new many times. As each color is combined, a control voltage is applied. For a line with 4 8 0 lines X 6 4 0 to apply the control voltage to the end to drive all, apply a line scan in this circuit and then perform a typical day on the display. Therefore, after scanning the lines that control the voltage for each straight line, the scanning lines on the horizontal data are scanned, and the scanning cycle is completed to update each day line of the display every second. All colors will be changed. The red, green, blue, and other three-light daylight elements must be applied to the VGA LCD by three straight data lines. For the VGA LCD, it must have 19 2 0 vertical data. The vertical drive circuit must have 1 9 20 transmission lines 0 The principle of the LCD display image is to change the optical transmission characteristics of the liquid crystal material by adjusting the size of the control voltage. However, if a stable DC voltage is applied to the liquid crystal material, the physical properties of the liquid crystal will continue to degrade and dissociate. Therefore, the data driving circuit must provide an AC voltage to drive each day element. The above AC voltage is based on a preset bias voltage as a reference voltage, and the switching of the reference voltage is greater or less than the reference voltage to represent the polarity reversal. Depending on the quality of the day plane and the complexity of the driving circuit, the above polarity inversion with respect to the reference voltage can be divided into day plane inversion, column inversion, and J inversion. inversion) and dot inversion.

Page 6 571276 V. Description of the invention (3) Regarding which form is used, for each pixel, each time when the data is rewritten, it must be written with the opposite polarity. The diurnal reversal means that the writing polarity is the same in one diurnal plane, and it is converted to the opposite polarity in the next diurnal plane. The row reversal represents the opposite polarity of any two adjacent straight rows in the same diurnal plane. The polarity of any two adjacent rows in the same day plane is opposite; the point inversion indicates that the polarity of any two adjacent day elements in the same day plane are opposite. Among them, the best quality of daylight with dot inversion is the mainstream of future driving methods, but the complexity of the driving circuit is also the lowest, and the power consumption is also the largest. Under the same operating voltage, the power consumption of the circuit is proportional to the capacitance and frequency. The capacitance value of the data line experienced by the driving circuit is usually much larger than the capacitance value of any daytime storage capacitor, so the power consumption caused by the data line will be considerable. Especially in the case of column inversion and dot inversion, for the same data line, the polarity must be changed for each horizontal scanning period. More power. Therefore, the development of a low-power liquid crystal display driving method and its driving circuit has become a very important subject in the liquid crystal display industry. SUMMARY OF THE INVENTION: The main object of the present invention is to provide a low-power driving method for a liquid crystal display. A secondary object of the present invention is to provide a low-power liquid crystal display device.

Page 7 571276 V. Description of the invention (4) Drive circuit. This clock is a one-time pulse controller for charging and discharging. Its number. The pressure. The device and the required polar material line. The driving voltage and pole voltage, after the start, the exposed mode driver, the mid-clock reference electric analog, the electric reference electric, and the brightness analog are the initial clock-wise voltage and the final exposure of a liquid crystal display. A plurality of reference voltages for driving the liquid crystal display, and a controller for generating a step voltage system for providing the input voltage of the step voltage driver and the traditional data line driving data; the output terminal is coupled The bipolar voltage between the voltage when the voltage driver is driving and the terminal voltage of the clock signal input by the day controller to be driven. The dynamic circuit, data line, and multiple types of charge-discharge charging / discharging circuits correspond to the input and output of the circuit. The previous drive numbers are sequentially referenced in a step-by-step manner. The reference pulse of the pulse signal controls and the voltage of one day of the element is the final distribution in the voltage. The best one is that the maximum number of steps of the step-type charge and discharge is four steps, so The reference voltages are arranged in descending order of a first reference voltage, a second reference voltage, and a third reference voltage. The first reference voltage is 75% of the voltage source voltage, the second reference voltage is the reference voltage of the alternating current, and the third reference voltage is 25% of the voltage source voltage. Preferably, the maximum number of steps of the step-type charge and discharge is four steps, so the reference voltages are arranged in order from the largest to the first reference voltage.

mm

Page 8 571276 V. Description of the invention (5) Voltage, second reference voltage, and third reference voltage. The first reference voltage is a positive polarity voltage corresponding to 50% of the light transmittance, the second reference voltage is a reference voltage of the alternating current, and the third reference voltage is 50% of the light transmittance. Corresponding negative polarity voltage. Preferably, the step-type charge and discharge can be divided into eight stages, and two bits are used to distinguish the brightness gray scale of the pixel. _ The better, you can divide the step-type charge and discharge into sixteen stages, and use three bits to distinguish the brightness gray scale of the day element. Drawing number description 3 _ Brother two data line 6-sixth scan line 8-capacitor 2 5 ~~ switch control logic 42-load 2-second data line 5-fifth scan line 7-control switch 2 0-clock control 30-Analog voltage driver The present invention discloses a low-power driving method and driving circuit for a liquid crystal display. The driving voltage polarity when driving a liquid crystal and the digital value corresponding to the driving voltage are used to determine the turn-on sequence of the stepped charge-discharge switch. To achieve power saving features.

Page 9 571276 V. Description of the invention (6) As stated in the background description, the liquid crystal display must be driven by alternating current. The bed ’s 1 ith guide, and the MW line drive circuit must continuously charge the capacitance on the data line.

Ant Ley, La Ze Hy U '疋 under the driving mode of column inversion and dot inversion. Aiming at such a driver, the present invention uses the polarity of the driving voltage and the wheel-in value of the digital analog switch ($ D AC) to control the on-off in the analog voltage driver to achieve the purpose of saving power, and to maintain the analogy. Voltage output to drive the display.

The bit analog driving voltage Vdac is a voltage converted by a digital analog converter in a conventional data line driving circuit to agitate the data line. As described in the background = the method of “conventional technique is to directly connect the analog voltage Vdac to the power line”, such a connection will consume a lot of power. The focus of the present invention is to achieve step-by-step charging and discharging methods to achieve the purpose of power saving. The principle used in the present invention is as follows.

Xin said that charging and discharging any capacitor will consume 1/2 of the energy (CV2) ^ where C represents the capacitance value and v represents the maximum voltage in the charge transfer process. Therefore, if the charging and discharging process is divided into n steps, and the voltage change of charging and discharging at each step is v / n, each charge and discharge will consume (1/2) ((^ 2) / 112 energy, so After 11 charging or discharging steps, the energy consumed is (1/2) (CV2) / n, which will be significantly lower than the energy consumed by the conventional technology. | For example, if the process of charging and discharging is divided into Four steps, the energy consumed will be only a quarter of the conventional skills.

571276 V. Description of the invention (7) Next, please refer to FIG. 2 for a circuit block diagram of the step-type charge-discharge driving circuit of the present invention. The driving circuit is composed of a clock controller 20, a plurality of reference voltages, and a plurality of analog voltage drivers 30. The first analog voltage driver 3 01 and the second analog voltage driver are shown in FIG. 3 0 2 and the m-th analog voltage driver 30 m. The function of the clock controller 20 is to generate a clock signal of step charging and discharging. Its input end is connected to the system clock CLK and RST, and its output end sends the clock signals 11, t 2, t 3, ..., t η for step charging and discharging to the first analog voltage driver. 3 〇 1, the second analog voltage driver 3 0 2, and the m-th analog voltage driver 30 m, and all analog voltage drivers. The value of η represents the number of steps of the step-type charge and discharge. If the number of steps of the step-type charge and discharge is set to the fourth order, the clock controller 2 0 will output four such as 11, t 2, t 3, 14, and so on. Please refer to Figure 3 for its waveform. The number of the reference voltages is determined by subtracting one from the maximum step number of step charging and discharging, and the voltage is distributed between the voltage source voltage and the ground line.

The input terminal of the first analog voltage driver 3 Ο 1 is coupled to the clock controller 20, the reference voltage V 1,..., Vn-1 used in step charging and discharging, and the traditional data line driving circuit. Output analog driving voltage Vdac: l, voltage polarity P, and brightness data, MSB table with its digital data

Page 11 571276 V. Description of the invention (8) No, and its output end is consumed to the first data line 'to drive the first data line. In addition, the connection situations of the second analog voltage driver 3 0 2 to the m-th analog voltage driver 3 0 m and the like are all the same as those of the first analog voltage driver 3 0 1, and are not repeated here. Please refer to FIG. 4 for a circuit diagram of an analog voltage driver according to the present invention. The input terminal of the analog voltage driver 30 receives an analog driving voltage Vdac 1 output from a conventional data line driving circuit and a reference voltage VI,..., Vn-1 from the switch control logic 25; its output terminal is connected to the driving Data line, that is, load 42. The analog voltage driver 30 includes a first switching element and other η-1 switching elements. The switching element may be a metal-oxide-semiconductor field-effect transistor, and the control circuit converts all the The switching elements of the analog voltage driver 30 are sequentially turned on and off, and step-type charging and step-type discharging can be obtained, as shown in FIG. 3. Next, the driving method of the present invention is disclosed. Since the liquid crystal operates in an AC mode, the voltage of the reference electrode is set to 50% of the voltage source voltage Vdd. In the case of positive polarity, the output voltage of the digital analog converter DAC falls between the reference voltage and the voltage source voltage Vdd; in the case of negative polarity, the output voltage of the digital analog converter DAC falls between the reference voltage and the ground line between. Taking a normally dark (η 〇 r m a 1 1 y b 1 a c k) liquid crystal panel as an example, the liquid crystal layer does not transmit light when no voltage is applied, and the larger the applied voltage is, the higher the light transmittance is. That is, when the output voltage is between the voltage source voltage Vdd and ground

Page 12 571276 V. Description of the invention (9) Brightness is high when near the line

The brightness is low near the reference voltage. The first embodiment of the present invention shows the case of η = 4, that is, the analog voltage driver 30 divides the voltage range of charge and discharge into four stages. The reference voltage (labeled as Vdd 50%) is located between the voltage source voltages vdd and Between ground, two additional reference voltages are added, which are 75% of the voltage source voltage Vdd (labeled Vdd 75%) and 25% (labeled vdd 25%), as shown in Figure 5. Since the operation of the liquid crystal is carried out in an AC manner, the voltage converted by the digital analog converter will be symmetrical to the reference voltage, and the gray scale of the daylight in adjacent positions is usually close to ', so it can be based on polarity and brightness (can be input by its digital The most important bits are represented by MSB) to determine the order of turning on the four switching elements of vdd 25%, Vdd 50%, Vdd 7 5%, and Vdac, which can be divided into the following four cases: 1. Positive polarity (P = 1), brighter (MSB = 1): turn on Vdd 25%, Vdd 50 ° / 〇, Vdd 75%, and Vdac〇 Negative polarity (P = 0), brighter (MSB = 1) ): Turn on Vdd 75%, Vdd 50 0 / 〇, Vdd 25%, and Vdac in sequence. 3. Positive polarity (P = 1), darker (MSB = 0): turn on vdd 50% sequentially, and Vdac. 4. Negative polarity (P = 0), darker (MSB = 0): turn on vdd sequentially. 50%, and Vdaco In the first case above, a brighter daylight should be driven with positive polarity, so the voltage output by the digital analog converter should fall between Vdd and vdd

Page 13 571276 V. Description of the invention (ίο) 75%. This embodiment assumes that the gray scale of the previous pixel is close to this pixel, but the polarity must be opposite, so the voltage of the previous pixel falls between ground and Vdd 25%. Therefore, when driving this pixel after driving the previous day, the data line should be connected to Vdd 25%, Vdd 50%, and Vdd 75% in sequence, and finally to V d a c. As mentioned earlier, step-by-step charging can greatly reduce the power required to achieve power saving. In the second case above, a brighter pixel is driven with negative polarity, so the voltage output by the digital analog converter should fall between ground and Vd75 25%. This embodiment assumes that the gray scale of the previous celestial element is close to that of the book element, but the polarity must be opposite, so the voltage of the previous celestial element falls between Vdd and V d d 7 5. Therefore, when driving the book pixel after driving the previous pixel, let the data line connect to Vdd 75 ° / in order. , Vdd 50%, and Vdd 2 5%, and then received V d a c. As mentioned earlier, performing stepwise discharge in this way can greatly reduce the power required to achieve power saving. In the second case above, a dark book should be driven with positive polarity, so the voltage output by the digital analog converter should fall between Vdd 50% and Vdd 75%. This embodiment assumes that the gray scale of the previous celestial element is close to this one, but the polarity must be opposite, so the voltage of the previous celestial element falls between Vdd 50% and Vdd 25%. Therefore, when driving the current day after driving the previous day, the data line should be connected to Vdd 50% first, and then to Vdac. As mentioned earlier, the step-by-step charging in this way can greatly reduce the power required to achieve power saving.

571276 V. Description of the invention (11) In the fourth case above, a darker daylight should be driven with negative polarity, so the voltage output by the digital analog converter should fall between Vdd 50% and Vdd 25% . This embodiment assumes that the gray scale of the previous celestial element is close to this one, but the polarity must be opposite, so the voltage of the previous celestial element falls between Vdd 50% and Vdd 75%. Therefore, when driving this pixel after driving the previous pixel, the data line can be connected to V d d 50% first, and then to V d a c. As mentioned earlier, the step-by-step charging in this way can greatly reduce the power required to achieve power saving. Also, there is no need to consume the road. However, the same. , The most reset after giving control,

Vdd 7 5 ° / 〇

Vdd 2 5% III. IV. In the first embodiment, it is assumed that the gray scale of the previous day element and this pixel are in actual operation. The phenomenon is taken into consideration in order to further reduce the energy. In the second embodiment, the four switching sequences of the analog voltage driver V dd 25%, V dd 50%, V dd 75% and V dac can be modified according to the daytime factor. The voltage polarity (P), brightness (represented by its digital key bit MSB), and MSB of the previous day prime (represented by Mp) can be divided into the following eight cases: P = l, MSB = Mp = l: Turn on Vdd 25%, Vdd 50%, 'and V dac 〇P = 0, MSB = Mp = 1: Turn on Vdd 75%, Vdd 50%,' and V dac 〇P = 1, MSB = Mp = 0 : Turn on Vdd 50% and Vdac in sequence. P = 0, MSB = Mp = 0: turn on Vdd 50%, and then Vdac.

Page 15 571276 5. Description of the invention (12) PM, MSBH, Mp = 〇: turn on Vdd 50%, Vdd 75%, and Vdac 〇 P = 0, MSB 21, Mp = 〇: Turn on Vdd 50%, vdd 25%, and Vdac sequentially. 7. PM, MSB 20, Mp = l: turn on Vdd 25%, Vdd 50%, and Vdaco 8.P = 0, MSB = 0, Mp = l: turn on Vdd 75%, vdd 50%, And Vdac. In the first case described above, a brighter daylight ’is driven with a positive polarity so the voltage output by the digital analog converter should fall between V d d and v d d 75%. In this case, the MSB of the previous pixel is the same as this pixel but with the opposite polarity, so the voltage of the previous pixel falls between ground and vdd 25 0 / 〇. Therefore, when driving the celestial element after driving the previous celestial element, the data line should be connected to Vdd 25% and Vdd 50 ° / in order. After receiving 75% and Vdd, Vdac was finally received. As mentioned earlier, step charging in this way can greatly reduce the power required to achieve power saving. In the above case "In a case," a brighter pixel should be driven with negative polarity, so the voltage output by the digital analog converter should fall to ground and Vdd φ 2 5 ° /. between. In this case, the MSB of the previous celestine is the same as this one, but the polarity is opposite, so the voltage of the previous celestine falls between V d d and V d d 75%. Therefore, when driving the previous celestial element after driving the previous celestial element, the data line should be connected to Vdd 7 5 ° / 〇, Vdd 50%, and Vdd 2 5% in order.

Page 16 571276 V. Description of the invention (13) Connected to Vdac. As mentioned earlier, performing stepwise discharge in this way can greatly reduce the power required to achieve power saving. In the above second case >, 'to drive a darker day with positive polarity, so the voltage output by the digital analog converter should fall between v d d 50% and Vdd 75%. In this case, the MSB of the previous celestine is the same as that of the celestine but the polarity is opposite, so the voltage of the previous celestine falls between Vdd 50% and Vdd 25%. Therefore, when driving the previous day element after driving the previous day element, the data line should be connected to Vdd 50% first, and then to Vdac. As mentioned earlier, the step-by-step charging in this way can greatly reduce the power required to achieve power saving. In the fourth case mentioned above, 'to drive a darker day with negative polarity, so the voltage output by the digital analog converter should fall between Vdd 50% and Vdd 25%. In this case, the MSB of the previous pixel is the same but the polarity is opposite, so the voltage of the previous pixel falls between vdd 50% and Vdd 75%. Therefore, when driving the previous day after driving the previous day, the data line should be connected to Vdd 50% first, and then to Vdac. As mentioned earlier, the step-by-step charging in this way can greatly reduce the power required to achieve power saving.

In the fifth case mentioned above, a brighter daylight 'is driven with positive polarity, so the voltage output by the digital analog converter should fall between 75% of vdd and Vdd. In this case, the previous daylight is the darker daylight, with its MSB

Page 17 571276 Explanation of the invention (14) Once the primes are different and their polarities are reversed, the voltage of the previous day is between Vdd 50% and Vdd 25%. Therefore, when driving the f pixel after driving the previous pixel, let the data line be connected to Vdd 50% and Vdd 75% in order, and then to Vdac. As mentioned earlier, step-by-step charging can greatly reduce the power required to achieve power saving.

In the sixth case above, a brighter pixel is driven with a negative polarity. ’Therefore the voltage output by the digital analog converter should fall between ground and Vdd 2 5 / Q. In this case, the previous pixel is a darker daylight, with μ s B f, the daylight is different and of opposite polarity, so the voltage of the previous pixel falls between Md 50% and Vdd 75%. Therefore, after driving the previous day, the driver must drive the drive, and the data line should be connected to V d d 50% and v d d 25% in order before receiving V da c. As mentioned earlier, step-by-step discharge is carried out in this way, and Dajin Tian reduces the power required to achieve power saving. In the seventh case above, a darker picture should be driven with positive polarity. 1 The voltage output by this digital analog converter should fall between Vdd 50% and vertical. In this case, the previous celestial element is a brighter pixel, 2 ^ celestial elements are different and have opposite polarities, so the voltage of the previous celestial element

',, Line and V d d 25%. Therefore, before driving—after checking the element, the current line must be connected to the vdd 25% 5, 0%, and then lower: L. As mentioned earlier, the step-by-step charging can consume a lot of power in order to save power.

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571276 V. Description of the invention (15) In the eighth case above, a dark daylight is driven with negative polarity, so the voltage output by the digital analog converter should fall between Vdd 50% and Vdd 25% between. In this case, the previous pixel is a brighter pixel, and its MSB is different from this one and the polarity is opposite, so the voltage of the previous pixel falls between V d d and V d d 75%. Therefore, when driving the previous day element after driving the previous day element, the data line should be connected to Vdd 75%, Vdd 50%, and then to Vdac. As mentioned earlier, step charging in this way can greatly reduce the power required to achieve power saving. In the second embodiment described above, the case where the gray scale of the previous pixel may be different from the present pixel is considered. In the step-type charging and discharging method of the present invention, when MS_ of two adjacent celestial elements is different, no extra charging and discharging occurs, and energy loss can be greatly reduced. Especially when the gray levels of two adjacent pixels are changed from lighter to brighter ^ the vehicle driver is dark ', this embodiment sequentially turns on the reference voltage of its voltage passing range, so it does not consume extra energy. ~ In the two implementation examples described above, the reference voltage of step charging and discharging is set to f Vdd, Vdd 7 5%, Vdd 50 0%, and Vdd 2 5%, which is based on the assumption that the liquid crystal has a linear photoelectric curve. . In the non-linear characteristic of the present invention, the two voltages and the reference electrical reference voltage are usually an embodiment. It is also taken into account. The light transmission rate I is used for step charging and discharging. The photoelectric curve of the liquid crystal is 50% of the positive and negative electrical reference voltage. Gamma required in these circuits

Page 19 571276 V. Description of the invention (16) Calibration reference voltage can be shared. In another embodiment of the present invention, instead of providing a reference voltage, a large capacitor may be connected instead. The other end of the capacitor is grounded, and its capacitance value needs to be much larger than its load, that is, the total load of the data line. In this way, regardless of the initial value of each connected capacitor, it will eventually approach the position where the average operating voltage range is divided equally to provide the required reference voltage. · Of course, the present invention is by no means limited to dividing the step-type charge and discharge into four stages. In another embodiment of the present invention, the step charging and discharging can be divided into two phases. In this case, the reference voltage of the alternating current is used as a reference voltage, wherein a region between the voltage source voltage and the reference voltage is driven with positive polarity, and a region between the reference voltage and ground is indicated by Negative polarity drives it. The implemented technology is exactly the same as the previous embodiment, and will not be described again. In another embodiment of the present invention, the step-type charge / discharge area can be divided into eight stages. In this case, the polarity and two bits can be used to distinguish the gray scale of the brightness of the day element. There are seven reference voltages, which are arranged in order from the first reference voltage, the second reference voltage, and the third reference voltage. , A fourth reference voltage, a fifth reference voltage, a sixth reference voltage, and a seventh reference voltage. Wherein the fourth reference voltage is a reference voltage of the alternating current; a region between the electric-voltage source voltage and the first reference voltage is a first bright spot region, which is driven with a positive polarity; the first reference voltage and Second reference voltage

Page 20 571276 (17) The domain is the third and third domains; a nil. Bearing I--0¾ ^ 0 reference area, the seventh parameter polarity drive. The two highlights refer to the first area of the reference voltage, and the voltage between the five references refers to the negative area of the reference voltage to move it. Area, the voltage between the three references to the positive area voltage and sexual drive as the third and ground its implementation 5. The zone reference voltage between the description of the positive drive area is the first and the fifth drive; the fourth dark spot seven The reference electric; the domain, with the same negative, no longer using the positive region as the voltage and the third driving the sixth dark reference; the technology and driving of the area between the bright spots; One dark spot has four reference voltages; the sixth spot between voltages is the sixth reference point, and the negative region is the fourth. The second region is implemented as described above. The four reference voltages between voltages are negative voltage regions and The example of the second driving party is completely similar. In another embodiment of the present invention, step charging and discharging can be divided into sixteen stages. In this case, the polarity and three bits can be used to distinguish the brightness gray scale of the day element. However, the number of steps of step charging and discharging cannot be increased indefinitely, otherwise not only will it increase the time required for charging and discharging, but it will also increase the complexity of the control circuit and increase the power consumption. The above description uses the preferred embodiments to explain the present invention in detail, but does not limit the scope of the present invention, and those skilled in the art will also understand that appropriate changes and adjustments will still be made without losing the essence of the present invention Without departing from the spirit and scope of the invention.

Page 21 571276 Brief description of the drawings Brief description of the drawings: Figure 1 is a schematic diagram of a daylight array of an active matrix liquid crystal display. FIG. 2 is a circuit block diagram of a step-type charging and discharging driving circuit according to the present invention. FIG. 3 is a waveform diagram of a signal according to the present invention. FIG. 4 is a schematic circuit diagram of an analog voltage driver according to the present invention. FIG. 5 is a schematic diagram of a reference voltage according to an embodiment of the present invention.

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Claims (1)

571276 Case No. 891 Amendment in November 11351 6. Scope of patent application Patent scope of application: Clock signal of charging and discharging of multiple pieces of data of the liquid crystal display under AC driving condition; the number is determined by the step charging voltage distribution When the electrical source of the voltage source is coupled to the analog drive of the clock control line drive circuit output, the output terminal is coupled to a plurality of pixels connected to it. The analog pixel driving voltage of the previous pixel driving is that the clock signals of the pixels sequentially start the plurality of reference voltages distributed. 1. A driving circuit of a liquid crystal display is driven by step charging and discharging. Line, which includes:-a clock controller for generating a stepped plurality of reference voltages, the maximum number of steps of the reference voltage discharge minus one, between its voltage and the ground line; and a plurality of analog voltages Drivers, each of which is an analog voltage driver input, the reference voltage, the traditional data dynamic voltage, and the corresponding polarity and brightness information A data line, in which the driving voltage of the pixel to be driven has opposite polarities; the analog voltage driver performs the driving voltage as the starting voltage, and the final voltage to be driven according to the input of the clock controller. Finally, the start voltage is restarted between the start voltage and the end voltage. 2. The driving circuit of liquid crystal display as described in item 1 of the patent application of Snake Shield, wherein the maximum number of steps of the step-type charge and discharge is four steps, so the reference voltage has three, of which: Page 571 276 Case No. 89111351_ Year, Month, and Day Amendment 6. The three reference voltages mentioned in the scope of the patent application are arranged in order from the first reference voltage, the second reference voltage, and the-** reference voltage J. The second reference voltage is The area between the reference voltage of the alternating current 1 and the voltage source voltage and the first reference voltage is a first point area driven with a positive polarity, and the area between the first and second reference voltages is a first dark area. The dot region y is driven by a positive polarity; the region between the second reference voltage and the second reference voltage is a second dark spot region, and the region between the second reference voltage and the second reference voltage is driven by a negative polarity, and the region between the second reference voltage and ground is The second point area 1 is driven by a negative polarity of 0. 3. The liquid crystal display as described in the scope of patent application:焉 区 动 电路 j Where the first reference voltage is 75% of the voltage source voltage and the second reference voltage is 25% of the voltage source voltage. As stated: f Patent Scope: The driving circuit j of the liquid crystal display, wherein the first reference voltage is a positive polarity voltage corresponding to 50% of the light transmittance and the second reference voltage is 5% of the light transmittance. The corresponding negative polarity voltage is 0. 5. The driving circuit of the liquid crystal display according to item 2 of the claim: 5. The first reference voltage is the analog voltage driver connected to a capacitor. Corresponding positive polarity voltage after the second charge and discharge 1 Section '——Reference Electricity page 24 571276 _ Case No. 891 11351 _ month and month revision _ 6. The scope of the patent application is to connect the analog voltage driver to a capacitor and After several charge and discharge Corresponding to zero voltage and the third reference voltage is to connect the analog voltage to a capacitive drive and a negative voltage by charging and discharging corresponding to several. 6. The driving circuit of the liquid crystal display as described in item 2 of the scope of patent application, The voltage of the day pixel to be driven is located in the first bright spot area and the voltage of the previous pixel is located in the second spot-free area. When the pixel is to be driven, the analog voltage driver sequentially starts the third reference voltage, the first Two reference voltages, a first reference voltage, and an analog driving voltage. 7. The driving circuit of the liquid crystal display as described in the second item of the scope of patent application, wherein the voltage of the day pixel to be driven is located in the second bright spot area and the voltage of the previous pixel is located in the first bright spot area. The analog-to-voltage driver sequentially activates the first reference voltage, the second reference voltage, the third reference voltage, and the analog drive voltage in sequence. 8. The driving circuit of the liquid crystal display as described in item 2 of the scope of patent application, The voltage of the pixel to be driven is located in the first dark spot area and the voltage of the previous pixel is located in the second dark spot area. When the day pixel is to be driven, the analog voltage driver sequentially starts the second reference voltage and Analog driving voltage. 9. The driving circuit of the liquid crystal display as described in the second item of the patent application range, wherein the voltage of the day pixel to be driven is located in the second dark spot area and the previous pixel Page 25 571276 Case No. 89111351 Month Year Amendment 6. The voltage in the patent application range is located in the first dark spot area. When the pixel is to be driven, the analog voltage driver starts the second reference voltage and the analog drive voltage in sequence. 10. The driving circuit for liquid crystal display as described in item 2 of the scope of the patent application, wherein the voltage of the pixel to be driven is located in the first bright spot area and the voltage of the previous pixel is located in the second dark spot area. To drive the pixel, the analog voltage driver sequentially activates the second reference voltage, the first reference voltage, and the analog driving voltage. 1 1. The driving circuit for a liquid crystal display according to item 2 of the scope of patent application, wherein the voltage of the pixel to be driven is located in the second bright spot area and the voltage of the previous pixel is located in the first dark spot area. In this pixel, the analog voltage driver sequentially activates the second reference voltage, the third reference voltage, and the analog drive voltage. 1 2. The driving circuit of the liquid crystal display device described in item 2 of the patent application scope, wherein the voltage of the pixel to be driven is located in the first dark spot area and the voltage of the previous pixel is located in the second bright spot area. To drive the pixel, the analog voltage driver sequentially activates the third reference voltage, the second reference voltage, and the analog driving voltage. 1 3. As described in the patent application, the driver circuit of the liquid crystal display is described in the second paragraph, wherein the voltage of the day pixel to be driven is located in the second dark spot area and the voltage of the previous pixel is located in the first bright spot area. When driving the pixel, said P.26 571276 _Case No. 89111351_Year Month Date__ VI. Scope of patent application Analog voltage driver starts the first reference voltage, the second reference voltage, and the analog drive voltage in sequence. 14. The driving circuit for a liquid crystal display according to item 1 of the scope of patent application, wherein the maximum number of steps of the step-type charging and discharging is two steps, and the reference voltage of the alternating current is used as a reference voltage, The area between the voltage source voltage and the Cangkao voltage is driven with positive polarity, and the area between the reference voltage and ground is driven with negative polarity. 1 5. The driving circuit for a liquid crystal display according to item 1 of the scope of patent application, wherein the maximum number of steps of the step-type charge and discharge is eight steps, so there are seven reference voltages, of which: The seven reference voltages are arranged in descending order of a first reference voltage, a second reference voltage, a third reference voltage, a fourth reference voltage, a fifth reference voltage, a sixth reference voltage, and a seventh reference voltage. Four reference voltages are the reference voltage of the alternating current; the area between the voltage source voltage and the first reference voltage is the first bright spot area, which is driven with positive polarity; between the first reference voltage and the second reference voltage The area between is the second bright spot area and is driven with a positive polarity; the area between the second reference voltage and the third reference voltage is a first dark spot area and is driven with a positive polarity; the third reference voltage and the The area between the four reference voltages is the second dark spot area, which is driven with positive polarity; Page 27 571276 _Case No. 89111351 _ year and month amend_ VI. The area between the fourth reference voltage and the fifth reference voltage mentioned in the scope of the patent application is the third dark spot area, which is driven with negative polarity; The area between the fifth reference voltage and the sixth reference voltage is the fourth dark spot area, which is driven with negative polarity; the area between the sixth reference voltage and the seventh reference voltage is the third bright spot area, which is driven with negative polarity The area between the seventh reference voltage and ground is the fourth bright spot area, and it is driven with negative polarity. 16. —A kind of driving method for liquid crystal display action 'Under the condition of driving by parent galvano, the data line of the liquid crystal display is driven by step charging and discharging, which includes: a. Provide a clock control Device for generating clock signals of step charging and discharging; b. Providing a plurality of reference voltages, the number of which is determined by the maximum number of steps of step charging and discharging, and the voltage is distributed in voltage Between the source voltage and the ground line; and _ c. Providing a plurality of analog voltage drivers whose input terminals are coupled to the clock controller, the reference voltage, and the analog output of the traditional data line driver circuit The driving voltage and the required polarity and brightness data; the output is coupled to a corresponding data line. The data line is connected to a plurality of celestial elements, wherein the driving voltage polarity of the pixel to be driven is opposite to that of the previous celestial element; and d. Driving by the analog voltage driver, using the previous element of Page 28 571276 _Case No. 89111351_ year month and month revision_ VI. Patent application range The driving voltage is the starting voltage, the analog driving voltage of the day driving element to be driven is the ultimate voltage, and it is based on the time input by the clock controller. The pulse signal sequentially starts the plurality of reference voltages distributed between the start voltage and the final voltage, and finally starts the final voltage. 1 7. According to the method for driving a liquid crystal display according to item 16 of the scope of patent application, the maximum number of steps of the step-type charge and discharge is divided into four steps, so there are three reference voltages, of which: The three reference voltages are arranged in descending order as a first reference voltage, a second reference voltage, and a third reference voltage; the second reference voltage is a reference voltage of the alternating current; the voltage source voltage and the first reference voltage A region between a reference voltage is a first bright spot region, which is driven with a positive polarity; a region between the first reference voltage and a second reference voltage is a first dark spot region, which is driven with a positive polarity; the first The area between the second reference voltage and the third reference voltage is a second dark spot area, which is driven by a negative polarity; the area between the third reference voltage and the ground is a second bright spot area, which is driven by a negative polarity. 1 8. The method for driving a liquid crystal display according to item 17 of the scope of the patent application, wherein the second reference voltage is 75% of the voltage source voltage, and the fourth reference voltage is the voltage source voltage 25 percent. Page 29 571276 _Case No. 89111351_Year Month Date _ ^ _ VI. Application for patent scope 1 9. The method for driving a liquid crystal display according to item 17 of the scope of patent application, wherein the second reference voltage is transparent A positive polarity voltage corresponding to a rate of 50%, and the fourth reference voltage is a negative polarity voltage corresponding to a rate of 50%. 2 0. The method for driving a liquid crystal display according to item 17 of the scope of patent application, wherein the first reference voltage is a positive polarity corresponding to connecting the analog voltage driver to a capacitor and charging and discharging several times. Voltage, the second reference voltage is the zero voltage corresponding to connecting the analog voltage driver to a capacitor and charging and discharging several times, and the third reference voltage is connecting the analog voltage driver to a capacitor and passing through The corresponding negative polarity voltage after several charge and discharge. 2 1. The method for driving a liquid crystal display according to item 17 of the scope of patent application, wherein the voltage of the day pixel to be driven is located in the first bright spot area and the voltage of the previous pixel is located in the second bright spot area. In this pixel, the analog voltage driver sequentially activates the third reference voltage, the second reference voltage, the first reference voltage, and the analog drive voltage. 2 2. The method for driving a liquid crystal display according to item 17 of the scope of patent application, wherein the voltage of the pixel to be driven is located in the second bright spot area and the voltage of the previous pixel is located in the first bright spot area. During the daytime, the analog voltage driver starts the first reference voltage, the second reference voltage, Page 30 571276 _Case No. 89111351_ Year Month Amendment_ VI. Scope of Patent Application Third reference voltage and analog driving voltage. 2 3. The method for driving a liquid crystal display as described in item 17 of the scope of patent application, wherein the voltage of the daylight element to be driven is located in the first dark spot area and the voltage of the previous daylight element is located in the second dark spot area. When the pixel is to be driven, the analog voltage driver sequentially activates the second reference voltage and the analog driving voltage. 2 4. The method for driving a liquid crystal display as described in item 17 of the scope of patent application, wherein the voltage of the pixel to be driven is located in the second dark spot area and the voltage of the previous pixel is located in the first dark spot area. When the pixel is to be driven, the analog voltage driver sequentially activates the second reference voltage and the analog driving voltage. 25. The method for driving a liquid crystal display as described in item 17 of the scope of patent application, wherein the voltage of the pixel to be driven is located in the first bright spot area and the voltage of the previous day pixel is located in the second dark spot area. When driving the pixel, the analog voltage driver sequentially activates the second reference voltage, the first reference voltage, and the analog driving voltage. 26. The method for driving a liquid crystal display according to item 17 of the scope of the patent application, wherein the voltage of the pixel to be driven is located in the second bright spot area and the voltage of the previous pixel is located in the first dark spot area. When the pixel is driven, the analog voltage driving device sequentially activates the second reference voltage, the second reference voltage, and the analog driving voltage. Page 31 571276 Case No. 89111351 Amendment VI. Patent Application Scope 2 7. The method for driving a liquid crystal display as described in Item 17 of the Patent Application Scope, wherein the voltage of the daylight element to be driven is located in the first dark spot region The voltage of the previous pixel is located in the second bright spot area. When the day pixel is to be driven, the analog voltage driver sequentially activates the third reference voltage, the second reference voltage, and the analog driving voltage. 28. The method for driving a liquid crystal display as described in item 17 of the scope of patent application, wherein the voltage of the day pixel to be driven is located in the second dark spot area and the voltage of the previous pixel is located in the first bright spot area. When driving the pixel, the analog voltage driver sequentially activates the first reference voltage, the second reference voltage, and the analog driving voltage. 2 9. The method for driving a liquid crystal display according to item 16 of the scope of patent application, wherein the maximum number of steps of the step-type charging and discharging is two steps, and the reference voltage of the alternating current is used as a reference voltage The area between the voltage source voltage and the reference voltage is driven with positive polarity, and the area between the reference voltage and ground is driven with negative polarity. 30. The method for driving a liquid crystal display according to item 16 of the scope of the patent application, wherein the maximum number of steps of the step-type charge and discharge is eight steps, so there are seven reference voltages, of which: The seven reference voltages are arranged in descending order of a first reference voltage, a second reference voltage, a third reference voltage, a fourth reference voltage, a fifth reference voltage, a sixth reference voltage, and a seventh reference voltage; Page 32 571276 Case No. 89111351 Amendment VI. The fourth reference voltage source voltage region described in the scope of the patent application, with the positive first reference region, the positive second reference region, and the positive reference. The third reference point area is positive, the fourth reference point area, negative the fifth reference point area, negative the sixth reference point area, and the seventh reference point is negative driving voltage. The reference voltage of the alternating current; the area between the first reference voltage and the first reference voltage are driven by the first bright spot; the area between the test voltage and the second reference voltage are driven by the second bright polarity; the test voltage and the third The area between the reference voltage is driven by the first dark polarity; the area between the reference voltage and the fourth reference voltage is driven by the second dark polarity; the area between the reference voltage and the fifth reference voltage is driven by the third dark polarity. The area between the test voltage and the sixth reference voltage is driven by the fourth dark polarity; the area between the test voltage and the seventh reference voltage is driven by the third polarity; the area between the test voltage and ground Yun brother four point 5 of the area. Page 33