TW201102994A - Liquid crystal display and driving circuit thereof - Google Patents

Abstract

A liquid crystal display and a driving circuit thereof are provided. When an internal resistance of a reset circuit of the liquid crystal display is increasing while turning off the liquid crystal, the driving circuit maintains a voltage inputted to a logic circuit of the liquid crystal display at a low voltage level. Accordingly, thin film transistors of the liquid crystal are turned on for a longer period of time while turning off the liquid crystal, such that the duration for neutralizing the charges of the pixel electrodes of the liquid crystal is extended and that the residual image of the liquid crystal is eliminated completely and rapidly.

Description

201102994 jLjumwy-0026-TW 31408twf.doc/n VI. Description of the Invention: [Technical Field] The present invention relates to a liquid crystal display and a driving circuit thereof, and more particularly to a liquid crystal display that can be quickly turned off after being turned off. A liquid crystal display and its driving circuit that completely eliminate image sticking. [Prior Art]

Flat-panel displays, such as liquid crystal displays (IV) Display 'LCD', etc., are widely used in personal digital assistants due to their high quality, small size, light weight, low driving voltage, and low noise. Digital Assistant, PDA), mobile phone $, video recorder, notebook computer, singularly smashed by the package " photography TV and other consumer power-on display and cast H 1 , and gradually replaced the cathode ray tube (Cathode Ray Tube 'CRT) has become the mainstream of displays. Changhe liquid (four) shows ^ frame towel, after the shutdown, the liquid is not seen on the panel, sometimes even after a few seconds, this phenomenon does not meet the user's visual expectations, and will reduce the display of the liquid crystal display panel for a long time. f. Using the phase of Transistor, TFT) liquid helium / Japanese body (m Fi imaeew. ^ day and day ', ..., state as an example, causing shutdown afterimage (residual electrode white cause - for thin film transistor liquid crystal display The 昼素 stayed in the power of the singer after shutting down, the charge could not be released quickly and the residual electricity valley was 'and it had to wait for a while - after a while, 'in the liquid crystal display, usually will include a reset circuit, 201102994 brain-fine wvJ26 -TW 3l408twf.dOC/n is used to detect the level of electricity in the liquid crystal display, determine the liquid crystal display voltage, and according to the power supply, a reset signal XAO ink...=No is to close the command, and then control the electricity In the case that the above resetting is performed after the liquid crystal display is normally turned off, the above-mentioned resetting is the horse potential; and when the reset signal XAO is the low potential number XA, the potential is low.

Has not yet dropped to a low potential, the job a0 t If its first operating voltage VDD line will be _, 岐彳f of each of the tons of sweeps, and speed up the elimination of the afterimage: the charge on the electrodes 1 is a conventional liquid crystal display t diagram, and the liquid crystal display 100 has a block diagram. Please refer to the 1st and LCD panel 30. It is worth noting that the electric 1G and the gate driver 20 are different from the present invention in that the liquid crystal display has other components, for example, the guillotine liquid daily display device 100. These components are the technical experts of the present invention. The sequence control circuit is used to emphasize the edge of the present invention. The reset signal of the gate ^ is from the ramp 40. Both ends of the resistor R are respectively connected to the first output terminal 12 of the logic reset circuit 10. Logic i VDD and the output 12 of reset circuit 10. Logic circuit: t terminal is also consumed to (intercept), output buffer circuit 40 has i-shift register XAO is low, so that 1 input 重置 § reset signal is high potential. When the scanning line 201102994 jnuvi-^v/uy-0026-TW 31408twf.doc/n of the night day panel 30 is high, the thin film transistor of each pixel electrode of the liquid crystal panel 30 is turned on, and The liquid crystal panel 3G = the charge of the pole is neutralized with each other. For example, the constant current reset circuit 10 has a - switching element 14 for causing the output terminal of the reset circuit 1 ; when the first operation T to - the preset value; 2 consumption to the -_ voltage VSS. The second operating voltage is generally grounded and will be lower than the first operating voltage VDD. When the LCD monitor is turned off, the Brother-Lin voltage VDD will drop to the vicinity of the operating voltage vss. However, when the liquid crystal display (10) is closed and the second operation is performed, the internal resistance I: Na of the switching element 重置 of the reset circuit 1 is also increased because the first operation voltage is small. And when the internal equivalent resistance is changed. The voltage of the reset ^#ϋΧΑ〇 will be boosted. When the reset voltage is raised to a certain potential, the logic circuit 4 will be turned on and the first pole will be connected. The membrane transistor will be turned off, and the residual image of the liquid day and day panel 30 will not be completely completed. Eliminate the ground. SUMMARY OF THE INVENTION A drive circuit for a liquid crystal display is provided to prevent the internal resistance of the reset circuit from becoming large after the liquid crystal causes it, thereby causing the problem that the afterimage is not completely eliminated. , r曰' month seven, a kind of liquid crystal display, which has a driving circuit for extending the liquid crystal panel after the liquid 4^_, the voltage is at 201102994 mvi-zuu^-uu26-TW 31408twf.doc/n = potential The N-interval' enables the residual image of the liquid crystal display to be completely and quickly eliminated. The present invention proposes a liquid crystal display circuit including a reset circuit and a pull-up failure. ,Drive circuit. The above-mentioned driving circuit has a wheel-out terminal and a suitable pull-down circuit. The voltage of the re-signal is low after the LCD is turned on and the reset is turned off. When the power is pulled up, the potential is applied to the liquid crystal display, and the second end of the pull-up circuit is connected to the input terminal of the first operating device coupled to the output of the $w+ reset circuit. The second end of the buffer circuit is connected to the second operation circuit. The present invention proposes a liquid crystal display two liquid crystal panel and a driving circuit. =, the device includes the pull-up circuit, _ to record the Wei. ^ Reset the circuit, where the voltage of the reset signal is dry on the liquid crystal: 3 =, and the LCD _ is low = the terminal is connected to the reset voltage, and the output of the second r of the pull-up circuit is pulled to The wheel end of the buffer, and the first end of the pull-down circuit is lightly applied. The younger brother is coupled to the second operating circuit. The output of the first buffer of the I-channel, including the logic buffer, is connected to the liquid crystal display. The output of the circuit is coupled to a liquid crystal display. 201102994 ^-0026-TW 31408twf.d〇c /n crystal panel. The logic circuit is used to eliminate liquid crystal residual image when the first output of the logic circuit is outputted by the first of the pull-down circuit. The ❿ line potential, in the embodiment, wherein the first operating voltage is higher than the first resistance. In the embodiment of the present invention, the pull-down circuit has a pull-down in an embodiment of the present invention. Oxygen half-field effect transistor __ and =^ electric = ρ-type gold-oxygen half-field effect transistor gate connection _ 上: ^ Ρ 金 type gold effect transistor source lightly connected first operation type: type The field crystal has no extreme pull-up resistance—# and the milk half-field effect is connected to the output of the reset circuit and the input end of the buffer. The second end of the resistor is light. In one embodiment of the invention, the resistance of the upper resistor is as large as the first operation. Inverter. The upper 11 绫 包括 包括 包括 包括 包括 包括 包括 包括 包括 包括 包括 包括 包括 ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; The opening time, and then the use of afterimage can quickly and completely eliminate the long, and make the above features and advantages of the liquid crystal display more obvious, the following 7 201102994 nv,-zWy-vu26-TW 31408twf. Doc/n The embodiment is described in detail with reference to the accompanying drawings. [Embodiment] FIG. 2 is a functional block diagram of a liquid crystal display according to an embodiment of the present invention. = Referring to FIG. 2, the liquid (four) indicator in the present embodiment has a liquid crystal panel = and a driving circuit 110. The driving circuit 11 is configured to control the opening and closing of the thin film transistors (not shown) on the scanning lines (not shown) of the liquid crystal panel. The drive circuit 11G has a reset circuit 1G 'pull-up circuit 12', a buffer 130, a pull-down circuit 14A, and a logic circuit 15A. % of the value shows that the 二 二 ΐ 勘 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶 液晶The LL η circuit 1 〇 has an output terminal 12 and is adapted to output the above-mentioned reset pull-up power == two-off: the latter is low. The second end 124 of the 12 120 is drained to the wheel end 12 of the reset circuit 10. The input end 132 of the buffer 130 is coupled to the first end 124 of the circuit m to the reset/= U 和 和 和 铱 ^ ^ 。 。 。 。 。 。 。 。 149. The first end of the pull-down circuit 140 is the wheel-out terminal 134' of the Erlishan buffer 130 and the first-command voltage of the pull-down circuit 140 is the first operating voltage. 4 positive electricity £ H operating voltage vss is generally grounded. 201102994— 314〇8twf.doc/n Circuit 15〇 has shift register and output buffer! I and so on. The wheel end 152 of the logic circuit 15G is secret to the i% 134 of the buffer 130 and the first end 142 of the pull down circuit 14A. The logic circuit 2 output 154 is switched to the liquid crystal panel 3 of the liquid crystal display 2 . Logic When the voltage XA〇2 is at a low potential, the sweeps of the outputs :, , .1 G are at the south potential. When the sweep line voltage % is high, the liquid will be pumped to the potential of the shirt, and the LCD panel will be called.

The thin film transistors to which the pixel electrodes are coupled are turned on, and the charges of the respective pixel electrodes of the liquid layer panel 3G are neutralized with each other, whereby the afterimage of the panel 30 is turned off after the liquid crystal display is turned off. eliminate. The reset signal XA0 that is turned on by the output terminal 12 of the 、 其 会 会 会 = = = = = pull: circuit then the second end 124 and the input circuit m of the buffer 13 包括 include the P-type MOS half-effect transistor Pi #P1 and pull-up resistor Rh. P-type gold oxide half field effect transistor

Gate _ is connected to the second operating voltage vss, p-type MOS half-field effect transistor ^ source _ brother - (four) voltage VDD, and p-type half-field effect transistor and one end of the pole pull-up resistor rh. As for the other end of the pull-up resistor RH, the output terminal 12 of the reset circuit H) and the input terminal 132 of the buffer m are switched. In addition, in the embodiment, the pull-down circuit M has a pull-down resistance

Rl 0 Since the second operating voltage VSS is applied to the gate of the P-type MOS field-effect transistor P1, the p-type MOS field-effect transistor P1 is turned on. In addition, when the liquid crystal display 200 is turned on, the switching element 201102994 i-hvl-^uu^-u〇26-TW 31408twf.doc/n 14 of the reset circuit 1 is turned off, so the voltage of the signal Xa〇 is reset at this time. Will remain at a high potential. In contrast, the switching element 14 of the reset circuit 10 is turned on for a short period of time after the liquid crystal display 200 is turned off, and the resistance value of the internal equivalent resistance RS is small when the liquid crystal display 200 is just turned off. It can be ignored, so the voltage of the reset signal XAO at this time is almost equal to the second operating voltage VSS and is at a low potential. However, when the liquid crystal display 2 is turned off, as time elapses, the first operating voltage VDD gradually decreases to approach the first operating voltage VSS, and when the first operating voltage becomes smaller, the switching element is affected. The degree of conduction of 14 causes the resistance value of the internal equivalent resistance ^ to become larger as the first operating voltage VDD decreases. When the resistance value of the internal equivalent resistance ~ becomes larger, the voltage of the reset signal χΑ〇 also rises. In this embodiment, the ink cartridge 2 that is turned on by the buffer 130 is turned on, and the voltage of the signal X ship is different from the first operating voltage VDD or the second station voltage VSS. In detail, when the reset signal XA (close to the first-operating power VDD, the voltage will be dirty and wait for the voltage, and when the voltage of the reset signal XAO is closer to |:, the battery will be xa〇2 Equal to the second operation · The resistance value of the resistance ~ becomes larger, but even if the internal voltage is equalized by the pull-up, the voltage is divided, and the 3 electric 2 and the internal equivalent resistance are reset. The Chinese doctor also == Then... Rl is connected to the The three operating power M vss, so ^f (10) pull down the power section 饴, the private time 1 as private recognition, so although the LCD monitor 2 〇〇 探 缓 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 130 -----------0026-TW 3 ]408twf.doc/n Press vss, so that the logic thunder is maintained for a long period of time at a high potential. ====================================================== The driving circuit 11G is in the circuit of FIG. 1, and the thin film transistor is used on the liquid crystal display panel for all the time, and then used to neutralize; the time of the electric current of the I electrode can be extended. The residual image of the liquid crystal age 1 can be quickly arrested and completely eliminated. In the other embodiment, the liquid crystal display 200

The voltage is equal to the second operating power. When the heavy voltage is equal to the second operating voltage, the voltage ΧΑ〇2 of the 苐-terminal 142 of the pull-down circuit ho will also be equal to the VSS ' and the scan line voltage % will be longer _ at the high potential two-phase - In the invention - in the embodiment, the buffer BG includes two serially connected inverse = (uncentered) 'for performing two inversion processing on the reset signal ' and then outputting the above voltage χΑ〇2. In the embodiment of FIG. 2, the pull-up circuit 120 of the drive circuit 110, the 爰 益 iso iso, the pull-down circuit Μ 0, and the logic circuit ls 〇 are disposed within the inter-pole driver 160. However, the invention is not limited thereto. In the present invention, the components of the implementation of the circuit 11G may be provided in whole or in part outside the gate 16G, or may be entirely within the driver 160. In summary, the driving circuit of the liquid crystal display device in the above embodiment of the present invention can maintain the scan line voltage outputted by the logic circuit at a high voltage for a long time when the internal equivalent resistance becomes large. And make the LCD panel 11 31408twf.doc/n 201102994

Π All the thin film transistors on JVl-Z.VV>»-wJ can maintain a longer turn-on time after the liquid crystal display is turned off, and the time for neutralizing the charge of the pixel electrode can be extended, and the residual image of the liquid crystal display is made. Can be quickly caught and completely eliminated. Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a functional block diagram of a conventional liquid crystal display. 2 is a functional block diagram of a liquid crystal display according to an embodiment of the present invention. [Key element symbol description] io: reset circuit 12: output terminal 14: switching element _ 20: gate driver 30: liquid crystal panel 40: logic circuit U〇: drive circuit 120. Pull-up circuit 122: first end U4: second end 12 201102994

-U026-TW 3l408twf.doc/n 130 : Buffer 132 : Input 134 : Output 140 : Pull-down circuit 142 : First end 144 : Second end 150 : Logic circuit 152 : Input ® 154 : Output 200. LCD display XAO: reset signal XA02: voltage VDD: first operating voltage VSS: second operating voltage R: resistance Rh: pull-up resistor φ RL: pull-down resistor

Rs : Internal equivalent resistance P1 : P-type gold oxide half field effect transistor V G : Scanning line voltage

Claims (1)

201102994 &quot;...丄---026-TW 3l408twf.doc/n VII. Patent application scope: 1. The driving circuit of liquid crystal display, including: reset circuit, with one round of output, the reset weight, signal ' Where is the resettlement signal of the reset signal? . : Turn-out - is high, and after the liquid crystal display _ is low-hearted 7 ^ open day: a pull-up circuit, the light-up circuit of the circuit is connected to the voltage 'the pull-up circuit' - the second end is connected to ::The first out; a buffer, one input end of the buffer coupled to the output end and the second end of the pull-up circuit; and the second circuit f of the clamping circuit 4, the voltage-pull-down circuit of the output end, The first end of the pull-down circuit is coupled to at least one of them, and the second end of the pull-down circuit is coupled to 2. The driving circuit according to claim 1, further comprising: a logic circuit 'the round end of the logic circuit, the = input terminal of the buffer and the first end of the pull-down circuit, The turn-out end of the circuit is coupled to a liquid crystal panel of the liquid crystal display, and the logic circuit is configured to rotate the wheel of the logic circuit when the first end of the pull-down circuit is low A scan line voltage is high to eliminate the afterimage of the liquid crystal panel. 3. The driving circuit of claim </RTI> wherein the first operating voltage is higher than the second operating voltage. 4. The driving circuit of claim </RTI> wherein the snagging circuit has a pull-down resistor. 14-U026-TW 31408twf.doc/n 201102994 Power-up iT: The driving circuit described in the first paragraph of the patent scope, wherein the pull-in field effect transistor (pm〇sfet) has a gate coupled to its source Extremely consuming the first-operating voltage; and the first end and the pole, the first end of the p-type MOS field-effect transistor is coupled to the output end of the reset circuit and the buffer As described in the second application of the circuit ===, the dynamic circuit, in which the reset drops, becomes larger. The resistance value is changed according to the punch of the first operating voltage, wherein the liquid crystal display comprises: a liquid crystal panel; and the circuit is connected to the liquid crystal panel. The driving circuit comprises: -Heavy output terminal' The reset circuit is suitable for the voltage when the inverter is turned on, and the voltage of the No. 1 is reset to the liquid crystal display position; ', and after the liquid crystal display is turned off, the power is low - Operate electric: pull = circuit r, connect to the output of the - road; the younger brother - the end is lightly connected to the reset electric-buffer, the buffer is crying all the way out and the pull-up; Road reset power 15 201102994 -J26-TW 31408twf.d〇c/n terminal is coupled to the stand-up and transferred to the first pull-down circuit, one of the output terminals of the punch, and two operating voltages. One of the pull-down circuits - the pull-down circuit - the liquid crystal display of the second drive, wherein the liquid crystal display circuit, the output of the buffer and the pull-down circuit The output end of the human terminal is coupled to the liquid crystal panel, and the logic circuit is used to make the logic of the liquid crystal panel of the liquid crystal panel. The liquid crystal display of the eighth item, wherein the voltage is known to be south of the second operating voltage. The ramie of the 8th rhyme, which is composed of a pull-down resistor. The liquid crystal display of the third aspect of the invention, wherein the ° system pull-up circuit comprises: Oxygen field effect transistor (pmosfet), which has a closed-end surface 5 as a voltage, a source of which is lightly connected to the first operating electric dust; and -,, ",", "the first end coupling Connected to the p-type MOS field-effect transistor 5, the first end of which is coupled to the output end of the reset circuit and the input end of the buffer. 13. The liquid crystal display according to claim 8, wherein the resistance value of an internal equivalent resistance of the circuit becomes larger as the first electric gate decreases. 14. The liquid crystal display of claim 8, wherein the buffer comprises two inverters connected in series. 16