CN103544922A

CN103544922A - Liquid crystal display and keyboard scan compatible circuit and electronic product using same

Info

Publication number: CN103544922A
Application number: CN201210235068.9A
Authority: CN
Inventors: 罗世明; 许耀峰; 陈映州
Original assignee: LINGTONG TECHNOLOGY Co Ltd
Current assignee: LINGTONG TECHNOLOGY Co Ltd; Generalplus Technology Inc
Priority date: 2012-07-09
Filing date: 2012-07-09
Publication date: 2014-01-29
Anticipated expiration: 2032-07-09
Also published as: CN103544922B

Abstract

The invention discloses a liquid crystal display and keyboard scan compatible circuit and an electronic product using same. In order to increase flexibility of liquid crystal drive circuit application, the circuit is characterized in that when liquid crystal drive is not performed, the COM/SEG pin position of a chip is used as GPIO to perform key scanning, a Bulk of an input-output PMOS (p-channel metal oxide semiconductor) transistor of the COM/SEG pin position of the liquid crystal drive circuit is connected to VLCD to prevent communication of the circuit under a non-control situation. The circuit has the advantages that in order to solve the problems that when the COM/SEG pin position is used for key scanning, severe substrate effect causes the input-output PMOS transistor to have no low voltage high drive current capacity, an extra auxiliary transistor is parallelly connected beside the input-output PMOS transistor of the original COM/SEG pin position, low voltage drive capacity of key scanning is enhanced, low-voltage impedance can be lowered, external application circuit elements can be saved, and element cost can be lowered.

Description

Liquid crystal display and keyboard scan compatble circuit and the electronic product that uses it

Technical field

The present invention relates to a kind of driving circuit, further, the invention relates to a kind of liquid crystal display and keyboard scan compatble circuit.

Background technology

Since K.F.Braun invention Brown tube (cathode-ray tube (CRT)) in 1897, to nineteen twenty-nine, there is U.S. RCA Corp. Russia scientist descendants Zuo Lijin (Vladimir Kosma Zworykin) of the title of " father of TV " to invent the design of " scanning beam " automatically, and after color TV listing in 1954, until today, there is the time in a century nearly, the display technique application that the mankind are main, always be and take cathode-ray tube (CRT) (Cathode Ray Tube, CRT) technology as main.Yet, from nineteen ninety for the initial stage, since flat-panel screens starts commercialization, a new generation shows that scientific and technological development day is newly new again, with regard to volume production scale and product application popularization, and liquid crystal display (Liquid Crystal Display, LCD), far and away, be sure to occupy the main flow of plane display technique.

Fig. 1 is the structural drawing of existing twisted-nematic formula (Twisted Nematic, TN)/super twisted nematic formula (STN) display panels.Please refer to Fig. 1, this liquid crystal panel comprises a plurality of signal wire COM_0～COM_N and a plurality of section signal wire SEG_0～SEG_M of connecing altogether.Each connects the pixel that signal wire COM_0～COM_N and each section signal wire SEG_0～SEG_M staggered place are panel altogether.Fig. 2 is the equivalent circuit diagram of existing twisted-nematic formula (Twisted Nematic, TN)/super twisted nematic formula (STN) display panels.Please refer to Fig. 2, more different from the display panels of the thin film transistor (TFT) kenel that everybody knows at present, each meets altogether signal wire COM_0～COM_N and each section signal wire SEG_0～SEG_M staggered place is all equivalent to a capacitor C 201.In other words, each pixel does not comprise active member.

Fig. 3 is the system circuit diagram of existing twisted-nematic formula (Twisted Nematic, TN)/super twisted nematic formula (STN) display panels.Please refer to Fig. 3, this passive matrix type liquid crystal display comprises a passive matrix type display panels 301 and one drive circuit 302.Because the type of drive of this liquid crystal display systems has been existing, therefore it will not go into details.Yet this kind of twisted-nematic formula TN/ super twisted nematic formula stn liquid crystal display panel is to be mainly applied in small size, such as mobile phone, portability electronics recreation facility etc.

Yet, such practice, obviously too inefficent for system.Therefore, applicant drives and improves liquid crystal display, to increase the dirigibility of chip application.

Summary of the invention

An object of the present invention is to provide a kind of liquid crystal display and keyboard scan compatble circuit, increases the dirigibility of chip application.

Another object of the present invention is to provide a kind of liquid crystal display and keyboard scan compatble circuit, make scanning and keyboard scan multiplexing, except saving applications circuit component, reduce outside element cost the Jiong border that also can solve one-way only operation.

Another object of the present invention is to provide a kind of liquid crystal display and keyboard scan compatble circuit, in order to solve liquid crystal display scanning and keyboard scan, drive the different circuit that cause of level incompatible.

In view of this, the invention provides a kind of liquid crystal display and keyboard scan compatble circuit, in order to drive a passive display panels in the liquid crystal drive time, and in a standby time, drive at least one button, this liquid crystal display and keyboard scan compatble circuit comprise a driving microprocessing unit, most connect altogether/section weld pads, most pull-up control circuits, most pull-down control circuits, most pull up transistor, most pull-down transistors, at least one auxiliary transistor and at least one input/output port weld pad.Above-mentioned driving microprocessing unit comprises a power end, connects voltage end, an inner control logic circuit and an input/output control circuit altogether, wherein, above-mentioned input/output control circuit couples the first end of above-mentioned at least one button, wherein, power end receives a micro-processing power supply, wherein, connect altogether voltage end reception and connect altogether voltage.A plurality of the connect altogether/section lines that couple passive display panels that above-mentioned connect altogether/section weld pad is corresponding.At least one of them specific connect altogether/section weld pad of above-mentioned connect altogether/section weld pad couples the second end of above-mentioned at least one button.Above-mentioned at least one input/output port weld pad is coupled between the first end of above-mentioned input/output control circuit and above-mentioned button.Each pull-up control circuit comprises an input end and an output terminal, and the input end of each pull-up control circuit is corresponding is coupled to above-mentioned inner control logic circuit.Each those pull-down control circuit comprises an input end and an output terminal, and the input end of each those pull-down control circuit is corresponding is coupled to above-mentioned inner control logic circuit.

Each those pull up transistor and comprise respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, I the grid pulling up transistor couples the output terminal of I pull-up control circuit, I the first source-drain electrode pulling up transistor receives this micro-processing power supply, the matrix utmost point that I pulls up transistor couples a lcd power source end of passive display panels, and I the second source-drain electrode pulling up transistor is coupled to and couples I section/connect altogether weld pad.Each those pull-down transistor comprises respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the grid of J pull-down transistor is coupled to the output terminal of J pull-down control circuit, the first source-drain electrode of J pull-down transistor is coupled to J the second source-drain electrode pulling up transistor, the second source-drain electrode of J pull-down transistor receives and connects altogether voltage, and the matrix utmost point of J pull-down transistor receives and connects altogether voltage.Above-mentioned at least one auxiliary transistor comprises a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the first source-drain electrode of above-mentioned at least one auxiliary transistor receives this micro-processing power supply, the matrix utmost point of above-mentioned at least one auxiliary transistor is coupled to this and connects altogether voltage end, the second source-drain electrode of above-mentioned at least one auxiliary transistor is coupled to this particular section/connect altogether weld pad, the grid of above-mentioned at least one auxiliary transistor couples a reversed-phase output of a specific pull-up control circuit wherein of those pull-up control circuits, wherein, the single spin-echo of the output signal of the output signal of the above-mentioned reversed-phase output of above-mentioned specific pull-up control circuit and the output terminal of above-mentioned specific pull-up control circuit, wherein, I and J are natural number, and 0 < I <=those sections/connect altogether number of weld pad, and 0 < J <=those sections/connect altogether number of weld pad.

The present invention provides a kind of electronic product in addition, and this electronic product comprises a passive display panels, at least one button and a liquid crystal display and keyboard scan compatble circuit.This liquid crystal display and keyboard scan compatble circuit comprise a driving microprocessing unit, most connect altogether weld pad, most section weld pads, most pull-up control circuits, most pull-down control circuits, most pull up transistor, most pull-down transistors, at least one auxiliary transistor and at least one input/output port weld pad.Above-mentioned driving microprocessing unit comprises a power end, connects voltage end, inner control logic circuit and an input/output control circuit altogether, wherein, above-mentioned input/output control circuit couples the first end of above-mentioned at least one button, wherein, power end receives a micro-processing power supply, wherein, connect altogether voltage end reception and connect altogether voltage.A plurality of the connect altogether/section lines that couple passive display panels that above-mentioned connect altogether/section weld pad is corresponding.Above-mentioned connect altogether/section weld pad be at least wherein the second end that specific connect an altogether/section weld pad couples above-mentioned at least one button.Above-mentioned at least one input/output port weld pad is coupled between the first end of above-mentioned input/output control circuit and above-mentioned button.Each pull-up control circuit comprises an input end and an output terminal, and the input end of each pull-up control circuit is corresponding is coupled to above-mentioned inner control logic circuit.Each those pull-down control circuit comprises an input end and an output terminal, and the input end of each those pull-down control circuit is corresponding is coupled to above-mentioned inner control logic circuit.

Each those pull up transistor and comprise respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, I the grid pulling up transistor couples the output terminal of I pull-up control circuit, I the first source-drain electrode pulling up transistor receives this micro-processing power supply, I the matrix utmost point pulling up transistor couples a lcd power source end of passive display panels, and I the second source-drain electrode pulling up transistor is coupled to and couples I connect altogether/section weld pad.Each those pull-down transistor comprises respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the grid of J pull-down transistor is coupled to the output terminal of J pull-down control circuit, the first source-drain electrode of J pull-down transistor is coupled to J the second source-drain electrode pulling up transistor, the second source-drain electrode of J pull-down transistor receives and connects altogether voltage, and the matrix utmost point of J pull-down transistor receives and connects altogether voltage.Above-mentioned at least one auxiliary transistor comprises a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the first source-drain electrode of above-mentioned at least one auxiliary transistor receives this micro-processing power supply, the matrix utmost point of above-mentioned at least one auxiliary transistor is coupled to this and connects altogether voltage end, the second source-drain electrode of above-mentioned at least one auxiliary transistor is coupled to this specific connect altogether/section weld pad, the grid of above-mentioned at least one auxiliary transistor couples a reversed-phase output of a specific pull-up control circuit wherein of those pull-up control circuits, wherein, the single spin-echo of the output signal of the output signal of the above-mentioned reversed-phase output of above-mentioned specific pull-up control circuit and the output terminal of above-mentioned specific pull-up control circuit, wherein, I and J are natural number, and the number of 0 < I <=those connect altogether/section weld pads, and the number of 0 < J <=those connect altogether/section weld pads.

According to the liquid crystal display described in preferred embodiment of the present invention and keyboard scan compatble circuit and the electronic product that uses it, above-mentioned liquid crystal display and keyboard scan compatble circuit are in order to capable button of driving N row * M, and above-mentioned liquid crystal display and keyboard scan compatble circuit comprise M input/output port weld pad, and K input/output port weld pad couples the first end of those buttons that K is capable.Moreover above-mentioned liquid crystal display and keyboard scan compatble circuit also comprise N specific connect altogether/section weld pad, a N specific pull-up control circuit and N auxiliary transistor.P specific connect altogether/section weld pad couples the second end of those buttons of P row.Each those pull-up control circuit comprises an input end, an output terminal and a reversed-phase output, wherein, the single spin-echo of the output signal of above-mentioned reversed-phase output of above-mentioned specific pull-up control circuit and the output signal of the output terminal of above-mentioned specific pull-up control circuit, the input end of each those pull-up control circuit and those specific pull-up control circuits is corresponding is coupled to this inner control logic circuit.An above-mentioned N auxiliary transistor comprises a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the first source-drain electrode of above-mentioned P auxiliary transistor receives this micro-processing power supply, the matrix utmost point of above-mentioned P auxiliary transistor is coupled to this and connects altogether voltage end, the second source-drain electrode of above-mentioned P auxiliary transistor is coupled to P specific connect altogether/section weld pad, the grid of above-mentioned P auxiliary transistor couples the reversed-phase output of P specific pull-up control circuit, wherein, N, M and P are natural number, and 0 < P <=N.

In a preferred embodiment, when the number of connect altogether/section weld pad is R, above-mentioned liquid crystal display and keyboard scan compatble circuit comprise R pull-up control circuit and R auxiliary transistor.Each those pull-up control circuit comprises an input end, an output terminal and a reversed-phase output, wherein, the single spin-echo of the output signal of the output signal of the above-mentioned reversed-phase output of above-mentioned pull-up control circuit and the output terminal of above-mentioned specific pull-up control circuit, the input end of each those pull-up control circuit is corresponding is coupled to this inner control logic circuit.An above-mentioned R auxiliary transistor comprises a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the first source-drain electrode of above-mentioned S auxiliary transistor receives this micro-processing power supply, the matrix utmost point of above-mentioned S auxiliary transistor is coupled to this and connects altogether voltage end, the second source-drain electrode of above-mentioned S auxiliary transistor is coupled to S connect altogether/section weld pad, and the grid of above-mentioned S auxiliary transistor couples the reversed-phase output of S pull-up control circuit.

The present invention also provides a kind of liquid crystal display and keyboard scan compatble circuit, in order to drive a passive display panels in the liquid crystal drive time, and in a standby time, drive at least one button, this liquid crystal display and keyboard scan compatble circuit comprise a driving microprocessing unit, most connect altogether/section weld pads, most pull-up control circuits, most pull-down control circuits, most pull up transistor, most pull-down transistors, at least one auxiliary switch and at least one input/output port weld pad.Above-mentioned driving microprocessing unit comprises a power end, connects voltage end, an inner control logic circuit and an input/output control circuit altogether, wherein, above-mentioned input/output control circuit couples the first end of above-mentioned at least one button, wherein, power end receives a micro-processing power supply, wherein, connect altogether voltage end reception and connect altogether voltage.A plurality of the connect altogether/section lines that couple passive display panels that above-mentioned connect altogether/section weld pad is corresponding.Specific connect an altogether/section weld pad at least wherein of above-mentioned connect altogether/section weld pad couples the second end of above-mentioned at least one button.Above-mentioned at least one input/output port weld pad is coupled between the first end of above-mentioned input/output control circuit and above-mentioned button.Each pull-up control circuit comprises an input end and an output terminal, and the input end of each pull-up control circuit is corresponding is coupled to above-mentioned inner control logic circuit.Each those pull-down control circuit comprises an input end and an output terminal, and the input end of each those pull-down control circuit is corresponding is coupled to above-mentioned inner control logic circuit.

Each those pull up transistor and comprise respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, I the grid pulling up transistor couples the output terminal of I pull-up control circuit, I the first source-drain electrode pulling up transistor receives this micro-processing power supply, I the matrix utmost point pulling up transistor couples a lcd power source end of passive display panels, and I the second source-drain electrode pulling up transistor is coupled to and couples I connect altogether/section weld pad.Each those pull-down transistor comprises respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the grid of J pull-down transistor is coupled to the output terminal of J pull-down control circuit, the first source-drain electrode of J pull-down transistor is coupled to J the second source-drain electrode pulling up transistor, the second source-drain electrode of J pull-down transistor receives and connects altogether voltage, and the matrix utmost point of J pull-down transistor receives and connects altogether voltage.Above-mentioned at least one auxiliary switch comprises a first end, one second end, one the 3rd end and a control end, wherein, the first end of above-mentioned at least one auxiliary switch receives this micro-processing power supply, the second end of above-mentioned at least one auxiliary switch is coupled to those specific matrix utmost points pulling up transistor pulling up transistor, wherein this specific this second source-drain electrode pulling up transistor couples this specific connect altogether/section weld pad, the control end of above-mentioned at least one auxiliary switch is coupled to the output terminal of a specific pull-up control circuit wherein of those pull-up control circuits, the 3rd end of above-mentioned at least one auxiliary switch couples this lcd power source end of this passive display panels, wherein, when in the liquid crystal drive time, pull-up control circuit is controlled specific pulling up transistor during conducting, the 3rd end of above-mentioned at least one auxiliary switch and the second end conducting of above-mentioned at least one auxiliary switch, when in standby time, this pull-up control circuit is controlled specific pulling up transistor during conducting, the second end conducting of the first end of above-mentioned at least one auxiliary switch and above-mentioned at least one auxiliary switch, wherein, I and J are natural number, and the number of 0 < I <=those connect altogether/section weld pads, and the number of 0 < J <=those connect altogether/section weld pads.

The present invention provides a kind of electronic product in addition, and this electronic product comprises a passive display panels, at least one button and a liquid crystal display and keyboard scan compatble circuit.This liquid crystal display and keyboard scan compatble circuit comprise a driving microprocessing unit, most connect altogether/section weld pads, most pull-up control circuits, most pull-down control circuits, most pull up transistor, most pull-down transistors, at least one auxiliary transistor and at least one input/output port weld pad.Above-mentioned driving microprocessing unit comprises a power end, connects voltage end, an inner control logic circuit and an input/output control circuit altogether, wherein, above-mentioned input/output control circuit couples the first end of above-mentioned at least one button, wherein, power end receives a micro-processing power supply, wherein, connect altogether voltage end reception and connect altogether voltage.A plurality of the connect altogether/section lines that couple passive display panels that above-mentioned connect altogether/section weld pad is corresponding.Specific connect an altogether/section weld pad at least wherein of above-mentioned connect altogether/section weld pad couples the second end of above-mentioned at least one button.Above-mentioned at least one input/output port weld pad is coupled between the first end of above-mentioned input/output control circuit and above-mentioned button.Each pull-up control circuit comprises an input end and an output terminal, and the input end of each pull-up control circuit is corresponding is coupled to above-mentioned inner control logic circuit.Each those pull-down control circuit comprises an input end and an output terminal, and the input end of each those pull-down control circuit is corresponding is coupled to above-mentioned inner control logic circuit.

The present invention provides a kind of liquid crystal display and keyboard scan compatble circuit in addition, in order to drive a passive display panels in the liquid crystal drive time, and in a standby time, drives at least one button.This liquid crystal display and keyboard scan compatble circuit comprise a driving microprocessing unit, most connect altogether/section weld pads, at least one input/output port weld pad, at least one pull-up control circuit, at least one pull-down control circuit, at least onely pull up transistor, at least one pull-down transistor and at least one auxiliary transistor.Drive microprocessing unit to comprise a power end, connect voltage end, an inner control logic circuit and an input/output control circuit altogether, wherein, above-mentioned input/output control circuit couples the first end of above-mentioned at least one button, wherein, this power end receives a micro-processing power supply, wherein, this connects altogether voltage end reception and connects altogether voltage.A plurality of the connect altogether/section lines that couple this passive display panels that above-mentioned connect altogether/section weld pad is corresponding, wherein, specific connect an altogether/section weld pad at least wherein of above-mentioned connect altogether/section weld pad couples the second end of above-mentioned at least one button.Above-mentioned at least one input/output port weld pad is coupled between the first end of above-mentioned at least one input/output control circuit and above-mentioned button.Above-mentioned at least one pull-up control circuit comprises an input end and an output terminal, and the input end of above-mentioned at least one pull-up control circuit is corresponding is coupled to above-mentioned input/output control circuit.Above-mentioned at least one pull-down control circuit comprises an input end and an output terminal, and the input end of above-mentioned at least one pull-down control circuit is corresponding is coupled to above-mentioned input/output control circuit.

Above-mentioned at least one pulling up transistor comprises respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, above-mentioned at least one grid pulling up transistor couples the output terminal of above-mentioned at least one pull-up control circuit, above-mentioned at least one the first source-drain electrode pulling up transistor receives this micro-processing power supply, above-mentioned at least one matrix utmost point pulling up transistor couples a lcd power source end of this passive display panels, and above-mentioned at least one the second source-drain electrode pulling up transistor is coupled to this and couples above-mentioned at least one input/output port weld pad.Above-mentioned at least one pull-down transistor comprises respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the grid of above-mentioned at least one pull-down transistor is coupled to the output terminal of above-mentioned at least one pull-down control circuit, the first source-drain electrode of above-mentioned at least one pull-down transistor is coupled to above-mentioned at least one the second source-drain electrode pulling up transistor, the second source-drain electrode of above-mentioned at least one pull-down transistor receives this and connects altogether voltage, and the matrix utmost point of above-mentioned at least one pull-down transistor receives this and connects altogether voltage.Above-mentioned at least one auxiliary transistor comprises a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the first source-drain electrode of above-mentioned at least one auxiliary transistor receives this micro-processing power supply, the matrix utmost point of above-mentioned at least one auxiliary transistor is coupled to this and connects altogether voltage end, the second source-drain electrode of above-mentioned at least one auxiliary transistor is coupled to above-mentioned at least one input/output port weld pad, the grid of above-mentioned at least one auxiliary transistor couples a reversed-phase output of above-mentioned at least one pull-up control circuit, wherein, the single spin-echo of the output signal of the output signal of the above-mentioned reversed-phase output of above-mentioned at least one pull-up control circuit and the output terminal of above-mentioned specific pull-up control circuit.

The present invention provides a kind of electronic product in addition, and this electronic product comprises a passive display panels, at least one button and a liquid crystal display and keyboard scan compatble circuit.This liquid crystal display and keyboard scan compatble circuit comprise a driving microprocessing unit, most connect altogether/section weld pads, at least one input/output port weld pad, at least one pull-up control circuit, at least one pull-down control circuit, at least onely pull up transistor, at least one pull-down transistor and at least one auxiliary transistor.Drive microprocessing unit to comprise a power end, connect voltage end, an inner control logic circuit and an input/output control circuit altogether, wherein, above-mentioned input/output control circuit couples the first end of above-mentioned at least one button, wherein, this power end receives a micro-processing power supply, wherein, this connects altogether voltage end reception and connects altogether voltage.A plurality of the connect altogether/section lines that couple this passive display panels that above-mentioned connect altogether/section weld pad is corresponding, wherein, specific connect an altogether/section weld pad at least wherein of above-mentioned connect altogether/section weld pad couples the second end of above-mentioned at least one button.Above-mentioned at least one input/output port weld pad is coupled between the first end of above-mentioned at least one input/output control circuit and above-mentioned button.Above-mentioned at least one pull-up control circuit comprises an input end and an output terminal, and the input end of above-mentioned at least one pull-up control circuit is corresponding is coupled to above-mentioned input/output control circuit.Above-mentioned at least one pull-down control circuit comprises an input end and an output terminal, and the input end of above-mentioned at least one pull-down control circuit is corresponding is coupled to above-mentioned input/output control circuit.

The present invention provides a kind of liquid crystal display and keyboard scan compatble circuit in addition, in order to drive a passive display panels in the liquid crystal drive time, and in a standby time, drives at least one button.This liquid crystal display and keyboard scan compatble circuit comprise a driving microprocessing unit, most connect altogether/section weld pads, at least one input/output port weld pad, at least one pull-up control circuit, at least one pull-down control circuit, at least onely pull up transistor, at least one pull-down transistor and at least one auxiliary switch.Drive microprocessing unit to comprise a power end, connect voltage end, an inner control logic circuit and an input/output control circuit altogether, wherein, above-mentioned input/output control circuit couples the first end of above-mentioned at least one button, wherein, this power end receives a micro-processing power supply, wherein, this connects altogether voltage end reception and connects altogether voltage.A plurality of the connect altogether/section lines that couple this passive display panels that above-mentioned connect altogether/section weld pad is corresponding, wherein, specific connect an altogether/section weld pad at least wherein of above-mentioned connect altogether/section weld pad couples the second end of above-mentioned at least one button.Above-mentioned at least one input/output port weld pad is coupled between the first end of above-mentioned input/output control circuit and above-mentioned button.Above-mentioned at least one pull-up control circuit comprises an input end and an output terminal, and the input end of above-mentioned at least one pull-up control circuit is corresponding is coupled to above-mentioned input/output control circuit.Above-mentioned at least one pull-down control circuit comprises an input end and an output terminal, and the input end of above-mentioned at least one pull-down control circuit is corresponding is coupled to above-mentioned input/output control circuit.

Above-mentioned at least one pulling up transistor comprises respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, above-mentioned at least one grid pulling up transistor couples the output terminal of above-mentioned at least one pull-up control circuit, above-mentioned at least one the first source-drain electrode pulling up transistor receives this micro-processing power supply, and above-mentioned at least one the second source-drain electrode pulling up transistor is coupled to this and couples above-mentioned at least one input/output port weld pad.Above-mentioned at least one pull-down transistor comprises respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the grid of above-mentioned at least one pull-down transistor is coupled to the output terminal of above-mentioned at least one pull-down control circuit, the first source-drain electrode of above-mentioned at least one pull-down transistor is coupled to above-mentioned at least one the second source-drain electrode pulling up transistor, the second source-drain electrode of above-mentioned at least one pull-down transistor receives this and connects altogether voltage, and the matrix utmost point of above-mentioned at least one pull-down transistor receives this and connects altogether voltage.Above-mentioned at least one auxiliary switch comprises a first end, one second end, one the 3rd end and a control end, wherein, the first end of above-mentioned at least one auxiliary switch receives this micro-processing power supply, the second end of above-mentioned at least one auxiliary switch is coupled to above-mentioned at least one matrix utmost point pulling up transistor, the control end of above-mentioned at least one auxiliary switch is coupled to the output terminal of above-mentioned at least one pull-up control circuit, the 3rd end of above-mentioned at least one auxiliary switch couples this lcd power source end of this passive display panels, wherein, when in this standby time, this pull-up control circuit is controlled this specific pulling up transistor during conducting, the second end conducting of the first end of this at least one auxiliary switch and this at least one auxiliary switch.

The present invention provides a kind of electronic product in addition, and this electronic product comprises a passive display panels, at least one button and a liquid crystal display and keyboard scan compatble circuit.This liquid crystal display and keyboard scan compatble circuit comprise a driving microprocessing unit, most connect altogether/section weld pads, at least one input/output port weld pad, at least one pull-up control circuit, at least one pull-down control circuit, at least onely pull up transistor, at least one pull-down transistor and at least one auxiliary switch.Drive microprocessing unit to comprise a power end, connect voltage end, an inner control logic circuit and an input/output control circuit altogether, wherein, above-mentioned input/output control circuit couples the first end of above-mentioned at least one button, wherein, this power end receives a micro-processing power supply, wherein, this connects altogether voltage end reception and connects altogether voltage.A plurality of the connect altogether/section lines that couple this passive display panels that above-mentioned connect altogether/section weld pad is corresponding, wherein, specific connect an altogether/section weld pad at least wherein of above-mentioned connect altogether/section weld pad couples the second end of above-mentioned at least one button.Above-mentioned at least one input/output port weld pad is coupled between the first end of above-mentioned input/output control circuit and above-mentioned button.Above-mentioned at least one pull-up control circuit comprises an input end and an output terminal, and the input end of above-mentioned at least one pull-up control circuit is corresponding is coupled to above-mentioned input/output control circuit.Above-mentioned at least one pull-down control circuit comprises an input end and an output terminal, and the input end of above-mentioned at least one pull-down control circuit is corresponding is coupled to above-mentioned input/output control circuit.

Spirit of the present invention is using section weld pad or connecing altogether weld pad as key scan function, to increase the dirigibility of chip application.And in order to solve liquid crystal display scanning and keyboard scan, drive the different circuit that cause of level incompatible, inner at its input and output pin, additionally increase by an auxiliary transistor, lower and drive the transistorized substrate impedance that effect causes of high-low pressure excessive.Therefore, guarantee that this chip can be used for driving display panels simultaneously and carry out keyboard scan.Therefore, the saving applications circuit component quantity that the present invention can be certain, the outer member cost of reduction product.

Accompanying drawing explanation

Accompanying drawing described herein is used to provide a further understanding of the present invention, forms the application's a part, does not form limitation of the invention.In the accompanying drawings:

Fig. 1 is the structural drawing of existing twisted-nematic formula (Twisted Nematic, TN)/super twisted nematic formula (STN) display panels.

Fig. 2 is the equivalent circuit diagram of existing twisted-nematic formula (Twisted Nematic, TN)/super twisted nematic formula (STN) display panels.

Fig. 3 is the circuit block diagram of existing passive matrix type liquid crystal display.

Fig. 4 illustrates the circuit block diagram into the electronic product of first embodiment of the invention.

Fig. 5 A illustrates the circuit diagram into the electronic product of first embodiment of the invention.

Fig. 5 B illustrates the operation waveform diagram into the electronic product of Fig. 5 A of first embodiment of the invention.

Fig. 6 A illustrates the circuit diagram into the electronic product of first embodiment of the invention.

Fig. 6 B illustrates the operation waveform diagram into the electronic product of Fig. 6 A of first embodiment of the invention.

Fig. 7 illustrates section pin position SEG or is total to the inside imput output circuit figure of pin position COM.

Fig. 8 illustrates the schematic circuit diagram into the liquid crystal display of second embodiment of the invention and keyboard scan compatble circuit 403.

Fig. 9 illustrates the peripheral circuit into the section signal input and output of the liquid crystal display of second embodiment of the invention and keyboard scan compatble circuit 403.

Figure 10 illustrates the peripheral circuit into the section signal input and output of the liquid crystal display of third embodiment of the invention and keyboard scan compatble circuit 403.

Figure 11 illustrates the peripheral circuit into the section signal input and output of the liquid crystal display of fourth embodiment of the invention and keyboard scan compatble circuit 403.

Figure 12 illustrates the peripheral circuit into the section signal input and output of the liquid crystal display of fifth embodiment of the invention and keyboard scan compatble circuit 403.

Figure 13 illustrates the analog result into the liquid crystal display of second embodiment of the invention, the 3rd embodiment and the improvement of keyboard scan compatble circuit 403.

Figure 14 illustrates the analog result into the liquid crystal display of second embodiment of the invention, the 3rd embodiment and the improvement of keyboard scan compatble circuit 403.

Drawing reference numeral:

COM_0～COM_N: connect altogether signal wire

SEG_0～SEG_M: section signal wire

C201: equivalent capacity

301: passive matrix type display panels

302: driving circuit

401: passive display panels

402:3 * 3 button

403: liquid crystal display and keyboard scan compatble circuit

PX, PY and PZ: input/output port

SEG-a～SEG-c, SEG: section pin position

COM: be total to pin position

501,601: diode

SEG_X: one of them output waveform of section pin position SEG-a～SEG-c

One of them output waveform of IOport: input/output port PX, PY and PZ

G50: the low-voltage that drives microprocessing unit

P50: the high voltage that drives microprocessing unit

T_DRIV: liquid crystal drive time

TKEY: standby time

701: inner control logic circuit

PMOSFET1: the first P-type mos field effect transistor

PMOSFET2: the second P-type mos field effect transistor

NMOSFET1: the first N-type mos field effect transistor

NMOSFET2: the second N-type mos field effect transistor

702: the first pull-up control circuits

703: the first pull-down control circuits

704: the second pull-up control circuits

705: the second pull-down control circuits

706: section/connect altogether driving circuit

ESD1, ESD2: electrostatic discharge protective circuit

PAD1, PAD2: weld pad

VLCD: lcd power source voltage

801: drive microprocessing unit

COM: most connect weld pad altogether

SEG: most section weld pads

PT: a plurality of input/output port

I/O: a plurality of imput output circuits

901,1001,1101,1201: inner control logic circuit

902,1002,1102,1202: the first pull-up control circuits

903,1003,1103,1203: the second pull-up control circuits

904,1004,1104,1204: the first pull-down control circuits

905,1005,1105,1205: the second pull-down control circuits

1012,1212: the three pull-up control circuits

1013,1213: the three pull-down control circuits

PMOS1 the first P-type mos field effect transistor

PMOS2: the second P-type mos field effect transistor

PMOS3: the 3rd P-type mos field effect transistor

NMOS1: the first N-type mos field effect transistor

NMOS2: the second N-type mos field effect transistor

NMOS3: the 3rd N-type mos field effect transistor

906,1010: the first auxiliary metallic oxide semiconductor field effect transistors

907,1011: the second auxiliary metallic oxide semiconductor field effect transistors

1016: the three auxiliary metallic oxide semiconductor field effect transistors

908,1006,1106,1206: the first electrostatic discharge protective circuits

909,1007,1107,1207: the second electrostatic discharge protective circuits

912,1014,1112,1214: the three electrostatic discharge protective circuits

910,1008,1108,1208: the first weld pads

911,1009,1109,1209: the second weld pads

913,1015,1113,1215: the three weld pads

914,1017,1114: the first sections/connect altogether driving circuit

915,1018,1115: the second sections/connect altogether driving circuit

916,1019,1116,1217: input/output control circuit

PL: above draw control signal

INVPL: draw control signal on anti-phase

1110,1210: the first auxiliary switches

1111,1211: the second auxiliary switches

1216: the three auxiliary switches

The conducting resistance of Ron:P type metal-semiconductor field effect transistor

Result when 1401:P type metal-semiconductor field effect transistor is original size

The result that 1402:P type metal-semiconductor field effect transistor is original size 10 times time

1403: be the result that P type metal-semiconductor field effect transistor is original size 100 times time

1404: the improved results that is the second embodiment, the 3rd embodiment

Embodiment

For above and other object of the present invention, feature and advantage can be become apparent, preferred embodiment cited below particularly, and coordinate appended graphicly, be described in detail below.

the first embodiment

Because the main application of passive liquid crystal panel is at undersized product, for example mobile phone, portability electronics recreation facility etc., in order to reduce the use of peripheral element, and lower the complexity of external circuit design, the present invention proposes a kind of design concept of electronic product.Fig. 4 illustrates the circuit block diagram into the electronic product of first embodiment of the invention.Please refer to Fig. 4, this electronic product comprises 401,3 * 3 buttons 402 of a passive display panels and a liquid crystal display and keyboard scan compatble circuit 403.The basic function of liquid crystal display and keyboard scan compatble circuit 403 is exactly for driving the driving circuit of passive display panels 401, and in this embodiment, liquid crystal display and keyboard scan compatble circuit 403 have additionally increased the function of keyboard scan.Owing to having increased the function of keyboard scan, therefore, this liquid crystal display and keyboard scan compatble circuit 403 chips additionally how three input/output port PX, PY and PZ.

When the driving time of liquid crystal scanning, liquid crystal display and keyboard scan compatble circuit 403 utilize the common pin position COM of its chip and section pin position SEG(to comprise SEG-a～SEG-c) drive passive display panels 401.As for driving the mode of passive display panels 401, be prior art, therefore do not repeat them here.Standby time after the driving of liquid crystal scanning completes, liquid crystal display and keyboard scan compatble circuit 403 carry out keyboard scan function by input/output port PX, PY and PZ and section pin position SEG-a～SEG-c of coupling button 402, now, the function of section pin position SEG-a～SEG-c is used as universal input and output (General Purpose Input/Output, GPIO).

From the above mentioned, the present embodiment can be saved applications circuit component, increase the dirigibility of chip application, and the design time that reduces outer member cost and reduce system design engineer.

Although above-described embodiment is with nine buttons as an example, yet, affiliated technical field has to be known when the knowledgeable it should be known that and make product only have single button conventionally, and deviser can for example do single keyboard scan with an input/output port (PX) and a section pin position (SEG-a).When if product only has two buttons, deviser can for example do two button scannings with an input/output port (PX) and two section pin positions (SEG-a, SEG-b), or deviser can for example do two button scannings with two input/output port (PX and PY) and a section pin position (SEG-a).In other words, Basic Design of the present invention can't change.Use that deviser of the present invention should the rest may be inferred according to embodiment.Therefore it will not go into details.

Above-described embodiment is only a kind of schematic diagram of design, and comparatively actual circuit please refer to Fig. 5 A and Fig. 6 A, and Fig. 5 A illustrates the circuit diagram into the electronic product of first embodiment of the invention.Fig. 6 A illustrates the circuit diagram into the electronic product of first embodiment of the invention.Please refer to Fig. 5 A, the difference of Fig. 5 A and Fig. 4 be Fig. 5 A additionally how 3 diodes 501, the anode of these 3 diodes 501 is coupled in respectively on 3 * 3 buttons 402 and (please refer to graphic), and the negative electrode of these 3 diodes 501 is coupled in respectively section pin position SEG-a, SEG-b and SEG-c.

For the operation of the above-mentioned circuit of simple declaration, be below divided into four kinds of situations:

Situation 1, section pin position SEG or altogether pin position COM drag down voltage (PULL LOW), input/output port PX, PY and for PZ high voltage drive (DRIVING HIGH) to carry out key scan driving:

Fig. 5 B illustrates the operation waveform diagram into the electronic product of Fig. 5 A of first embodiment of the invention.Please refer to Fig. 5 B, wherein, waveform SEG_X has represented one of them output waveform of section pin position SEG-a～SEG-c, and waveform IOport has represented one of them output waveform of input/output port PX, PY and PZ.At liquid crystal drive time T _ DRIV, waveform SEG_X section pin position SEG-a～SEG-c carries out the driving to passive display panels.At TKEY standby time, namely the key scan time, section pin position SEG-a～SEG-c is used as receiving end and uses, and now, waveform SEG_X is pulled in low-voltage G50.Input/output port PX, PY and PZ are taken as scanning end and use, now, input/output port PX, PY and PZ sequentially this oscillogram of output HIGH voltage P50(only in order to signal).When if the staggered button of input/output port PX and section pin position SEG-a is depressed, and input/output port PX is just at output HIGH voltage P50, and the high voltage of input/output port PX can be transferred to section pin position SEG-a.The internal circuit of section pin position SEG-a just can be judged " the staggered button of input/output port PX and section pin position SEG-a is depressed ".

Situation 2, section pin position SEG or altogether pin position COM draw high voltage (PULL HIGH), input/output port PX, PY and for PZ low voltage drive (DRIVING LOW) to carry out key scan driving:

Please with reference to figure 6A, the difference of Fig. 6 A and Fig. 4 be equally Fig. 6 A additionally how 3 diodes 601, the anode of these 3 diodes 601 is coupled in respectively section pin position SEG-a, SEG-b and SEG-c, and the negative electrode of these 3 diodes is coupled in respectively on 3 * 3 buttons 402 and (please refer to graphic).Fig. 6 B illustrates the operation waveform diagram into the electronic product of Fig. 6 A of first embodiment of the invention.Please refer to Fig. 6 B, same reason, waveform SEG_X has represented one of them output waveform of section pin position SEG-a～SEG-c, waveform IOport has represented one of them output waveform of input/output port PX, PY and PZ.At liquid crystal drive time T _ DRIV, waveform SEG_X section pin position SEG-a～SEG-c carries out the driving to passive display panels.At TKEY standby time, namely the key scan time, section pin position SEG-a～SEG-c is used as receiving end and uses, and now, section pin position SEG-a～SEG-c is drawn high voltage.Input/output port PX, PY and PZ are used as scanning end (drive end).Therefore, input/output port PX, PY and PZ can be driven low-voltage by sequentially output.When if the staggered button of input/output port PY and section pin position SEG-b is depressed, and input/output port PY is just at output LOW voltage G50, and the high voltage of section pin position SEG-b can be dragged down, and receives the low-voltage of input/output port PY.The internal circuit of section pin position SEG-b just can be judged " the staggered button of input/output port PX and section pin position SEG-a is depressed ".

Situation 3, input/output port PX, PY and PZ draw high voltage (PULL HIGH), section pin position SEG or altogether pin position for COM low voltage drive (DRIVING LOW) to carry out key scan driving:

Fig. 5 B illustrates the operation waveform diagram into the electronic product of Fig. 5 A of first embodiment of the invention.Please refer to Fig. 5 B, wherein, waveform SEG_X has represented one of them output waveform of section pin position SEG-a～SEG-c, and waveform IOport has represented one of them output waveform of input/output port PX, PY and PZ.At liquid crystal drive time T _ DRIV, waveform SEG_X section pin position SEG-a～SEG-c carries out the driving to passive display panels.At TKEY standby time, namely the key scan time, input/output port PX, PY and PZ are used as receiving end and use, and now, waveform IOport is pulled in high voltage P 50.Section pin position SEG-a～SEG-c is taken as scanning end and uses, now, section pin position SEG-a～SEG-c sequentially this oscillogram of output LOW voltage G50(only in order to signal).When if the staggered button of input/output port PX and section pin position SEG-a is depressed, and section pin position SEG-a is just at output HIGH voltage P50, and the high voltage of section pin position SEG-a can be transferred to input/output port PX.The internal circuit of input/output port PX just can be judged " the staggered button of input/output port PX and section pin position SEG-a is depressed ".

Situation 4, input/output port PX, PY and PZ drag down voltage (PULL LOW), section pin position SEG or altogether pin position for COM high voltage drive (DRIVING HIGH) to carry out key scan driving:

Fig. 6 B illustrates the operation waveform diagram into the electronic product of Fig. 6 A of first embodiment of the invention.Please refer to Fig. 6 B, same reason, waveform SEG_X has represented one of them output waveform of section pin position SEG-a～SEG-c, waveform IOport has represented one of them output waveform of input/output port PX, PY and PZ.At liquid crystal drive time T _ DRIV, waveform SEG_X section pin position SEG-a～SEG-c carries out the driving to passive display panels.At TKEY standby time, namely the key scan time, section pin position SEG-a～SEG-c is used as scanning end and uses, and now, section pin position SEG-a～SEG-c is sequentially drawn high voltage, and therefore, waveform SEG_X is pulled in high voltage P 50.Input/output port PX, PY and PZ are used as receiving end and are dragged down voltage, when if the staggered button of input/output port PY and section pin position SEG-b is depressed, and section pin position SEG-b is just at output HIGH voltage P50, and the high voltage of section pin position SEG-b can be transferred to input/output port PY.The internal circuit of input/output port PY just can be judged " the staggered button of input/output port PX and section pin position SEG-a is depressed ".

With general idea, these four kinds of situations are all rational in design.But in foregoing circuit operation, the operation of the circuit of situation 1 and situation 4 cannot operate.

Please refer to Fig. 7, Fig. 7 illustrates section pin position SEG or is total to the inside imput output circuit figure of pin position COM and input/output port (GPIO).As shown in Figure 7, this circuit comprises an inner control logic circuit 701, the first P-type mos field effect transistor PMOSFET1, the first N-type mos field effect transistor NMOSFET1, the first pull-up control circuit 702, the first pull-down control circuit 703, the first electrostatic discharge protective circuit ESD1, the first weld pad PAD1, the second P-type mos field effect transistor PMOSFET2, the second N-type mos field effect transistor NMOSFET2, the second pull-up control circuit 704, the second pull-down control circuit 705, the second electrostatic discharge protective circuit ESD2, the second weld pad PAD2, and section/connect altogether driving circuit 706.It couples relation and illustrates as schemed.

Inner control logic circuit 701 is used for controlling the first pull-up control circuit 702, the first pull-down control circuit 703, the second pull-up control circuit 704 and the second pull-down control circuit 705.The first pull-up control circuit 702 is mainly to control the first PMOSFET1 conducting of P-type mos field effect transistor and cut-off.The first pull-down control circuit 703 is mainly to control the first NMOSFET1 conducting of N-type mos field effect transistor and cut-off.The second pull-up control circuit 704 is mainly to control the second PMOSFET2 conducting of P-type mos field effect transistor and cut-off.The second pull-down control circuit 705 is mainly to control the second NMOSFET2 conducting of N-type mos field effect transistor and cut-off.Electrostatic discharge protective circuit ESD1 and ESD2 do electrostatic protection.Section/connect altogether 706 of driving circuits is in order to the section of liquid crystal panel/wiring drives altogether.

By upper figure, can be seen, electrostatic discharge protective circuit ESD1 and ESD2 provide three groups of voltages by inner control logic circuit here, are respectively lcd power source voltage VLCD, voltage P50 and voltage G50.For simple declaration the problems referred to above, the voltage P50 in Fig. 7 operates in 2.1～5.5 volts, and lcd power source voltage VLCD operates in 3.7～7 volts.In general voltage G50 is ground connection.

In general liquid crystal display drive circuit, pin position COM and section pin position SEG are switched on (IO PMOS p-n junction turn-on) in order to prevent the PN junction of the first P-type mos field effect transistor PMOSFET1 of input and output altogether, so the matrix utmost point (Bulk) of the first P-type mos field effect transistor PMOSFET1 can be connected on VLCD voltage.When common pin position COM or section pin position SEG are taken as universal input and output (GPIO) or pure output (Pure Output) for Key Scan, because the matrix utmost point (Bulk) of the first P-type mos field effect transistor PMOSFET1 is connected on lcd power source voltage VLCD, therefore, in the time of can causing drain power voltage VDD low pressure because of Body Effect when drain power voltage VDD is less than lcd power source voltage VLCD without the ability of high current drives (Driving high), and when low voltage operated, the impedance of the first P-type mos field effect transistor PMOSFET1 is very large.Same, extra input/output port (GPIO) in liquid crystal display drive circuit is identical with the structure of above-mentioned pin position COM altogether and section pin position SEG, and the matrix utmost point (Bulk) of its second P-type mos field effect transistor PMOSFET2 is also connected on lcd power source voltage VLCD.Therefore, above-mentioned situation 1 and above-mentioned situation 4 are actually and cannot operate.

In order to increase the compatibility of circuit, following examples improve the input and output of above-mentioned liquid crystal display and keyboard scan compatble circuit 403 (meeting altogether COM, section SEG, IO).

the second embodiment

Fig. 8 illustrates the schematic circuit diagram into the liquid crystal display of second embodiment of the invention and keyboard scan compatble circuit 403.Please refer to Fig. 8, the section signal input and output peripheral circuit of this liquid crystal display and keyboard scan compatble circuit 403 refers specifically to the pin position that can be used to simultaneously do keyboard scan and liquid crystal drive.This liquid crystal display and keyboard scan compatble circuit 403 comprise a driving microprocessing unit 801, most individual weld pad COM, most section weld pad SEG, a plurality of input/output port PT and a plurality of imput output circuit I/O of connecing altogether.

Although the weld pad COM that connects altogether of above-described embodiment only illustrates 8, and section weld pad SEG also only illustrates 8, but, affiliated technical field has knows that the knowledgeable should know conventionally, above-mentioned pin position number is to make decision according to the number vertical, level of passive display panels 401, also multiway position more, this embodiment is only the schematic diagram that illustrated for convenience of description.The present invention is not as limit.In addition, although above-mentioned input/output port PT only illustrates 4,, affiliated technical field has knows that the knowledgeable should understand conventionally, and input/output port PT can design according to the number of the button of needed control, and the present invention is not also as limit.

In order to describe more accurately the circuit of its periphery, and under allowing, technical field has and conventionally knows that the knowledgeable can understand spirit of the present invention more, below with Fig. 9, explains.Fig. 9 illustrates the peripheral circuit into the section signal input and output of the liquid crystal display of second embodiment of the invention and keyboard scan compatble circuit 403.Please refer to Fig. 9, this circuit comprises an inner control logic circuit 901, the first pull-up control circuit 902, the second pull-up control circuit 903, the first pull-down control circuit 904, the second pull-down control circuit 905, the first P-type mos field effect transistor PMOS1, the second P-type mos field effect transistor PMOS2, the first N-type mos field effect transistor NMOS1, the second N-type mos field effect transistor NMOS2, one first auxiliary metallic oxide semiconductor field effect transistor 906, one second auxiliary metallic oxide semiconductor field effect transistor 907, one first electrostatic discharge protective circuit 908, one second electrostatic discharge protective circuit 909, one first weld pad 910, one second weld pad 911, one the 3rd electrostatic discharge protective circuit 912, one the 3rd weld pad 913, the first section/connect altogether driving circuit 914, the second section/connect altogether driving circuit 915 and input/output control circuit 916.It couples relation and illustrates as schemed.

Above-mentioned inner control logic circuit 901 is a part that drives microprocessing unit 801, in order to control the second pull-up control circuit 903, the first pull-down control circuit 904, the first section/connect altogether driving circuit 914, the second section/connect altogether driving circuit 915.Above-mentioned input/output control circuit 916 is also for driving a part for microprocessing unit 801, in order to control universal input and output (GPIO), the first pull-up control circuit 902 and the first pull-down control circuit 904.

In addition, input/output control circuit 916 is also to belong to a kind of inner control logic circuit, in order to represent its functional difference, at the present embodiment and following embodiment, the inner control logic circuit of controlling the function (or input/output port) of universal input and output (GPIO) being depicted as to input/output control circuit 916 in addition, and controlling section pin position SEG(or pin position COM altogether) the inner control logic circuit that is used as the function of key scan is depicted as inner control logic circuit 901.

In this embodiment, suppose that above-mentioned the first weld pad 910, the first electrostatic discharge protective circuit 908, the first N-type mos field effect transistor NMOS1, the first P-type mos field effect transistor PMOS1, the first pull-up control circuit 902, the first pull-down control circuit 904, the first auxiliary metallic oxide semiconductor field effect transistor 906 and input/output control circuit 916 are to belong to input/output port, namely the circuit group of GPIO; Above-mentioned the second weld pad 911, the second electrostatic discharge protective circuit 909, the second N-type mos field effect transistor NMOS2, the second P-type mos field effect transistor PMOS2, the second pull-up control circuit 903, the second pull-down control circuit 905 and the second auxiliary metallic oxide semiconductor field effect transistor 907 are to belong to share section pin position SEG(or pin position COM altogether) be used as the circuit group of key scan; In addition, above-mentioned the 3rd electrostatic discharge protective circuit 912 and 913 of the 3rd weld pads are to belong to there is no the section of key scan function pin position SEG(or pin position COM altogether) circuit group.In addition, the first section/connect altogether driving circuit 914, the second section/connect altogether driving circuit 915 are to belong to for driving the circuit of display panels.

When carrying out passive display panels driving, this circuit is by the first section/connect altogether driving circuit 914 and the second section/connect altogether driving circuit 915 to drive section corresponding on display panels/wiring altogether, the action of this circuit is identical with prior art, and therefore it will not go into details.Yet, when utilizing above-mentioned section pin position SEG(or pin position COM altogether) circuit group of key scan, the second weld pad 911 namely, the second electrostatic discharge protective circuit 909, the second N-type mos field effect transistor NMOS2, the second P-type mos field effect transistor PMOS2, the second pull-up control circuit 903, the second pull-down control circuit 905, the second auxiliary metallic oxide semiconductor field effect transistor 907, while carrying out key scan (namely situation 4), please also refer to Fig. 6 A and Fig. 9, now, section signal pin SEG is used to do scanning end, namely be used for output HIGH voltage P50, although receiving lcd power source voltage VLCD, the matrix utmost point of the second P-type mos field effect transistor PMOS2 cause low-voltage P50 driving force not enough, but, because this enforcement power has additionally increased an auxiliary N-type mos field effect transistor 907, the grid of this auxiliary N-type mos field effect transistor 907 is coupled in the reversed-phase output of the second pull-up control circuit 903, and the grid of the second P-type mos field effect transistor PMOS2 is coupled in the output terminal of the second pull-up control circuit 903.While drawing control signal PL to drive the second P-type mos field effect transistor PMOS2 conducting in the second pull-up control circuit 903 outputs one, its reversed-phase output has also been exported on anti-phase and has been drawn control signal INVPL, impel auxiliary N-type mos field effect transistor 907 and the second P-type mos field effect transistor PMOS2 conducting simultaneously, therefore, can make up the second P-type mos field effect transistor PMOS2 driving force deficiency.

Same reason, when utilizing the circuit group of above-mentioned input/output port (GPIO), the first weld pad 910 namely, the first electrostatic discharge protective circuit 908, the first N-type mos field effect transistor NMOS1, the first P-type mos field effect transistor PMOS1, the first pull-up control circuit 902, the first pull-down control circuit 904, the first auxiliary metallic oxide semiconductor field effect transistor 906, while carrying out key scan (namely situation 1), please also refer to Fig. 5 A and Fig. 9, now, section signal pin SEG is used to do receiving end, and input/output port is used to do drive end, namely be used for output HIGH voltage P50, although receiving voltage VLCD, the matrix utmost point of the first P-type mos field effect transistor PMOS1 cause low-voltage P50 driving force not enough, but, because the present embodiment has additionally increased an auxiliary N-type mos field effect transistor 906, the grid of this auxiliary N-type mos field effect transistor 906 is coupled in the reversed-phase output of the first pull-up control circuit 902, and the grid of the first P-type mos field effect transistor PMOS1 is coupled in the output terminal of the first pull-up control circuit 902.While drawing control signal PL to drive the first P-type mos field effect transistor PMOS1 conducting in the first pull-up control circuit 902 outputs one, its reversed-phase output has also been exported on anti-phase and has been drawn control signal INVPL, impel auxiliary N-type mos field effect transistor 906 and the first P-type mos field effect transistor PMOS1 conducting simultaneously, therefore, can make up the first P-type mos field effect transistor PMOS1 driving force deficiency.Also solved the awkward situation of situation 1 akinesia simultaneously.

In this embodiment, using section pin position SEG(pin position COM altogether) be divided into can be used as button scanning pin position and cannot be as the pin position of button scanning.In this embodiment, although only illustrate a section pin position SEG(who can be used as button scanning, be total to pin position COM),, affiliated technical field has knows that the knowledgeable it should be known that, according to different application, pin number order can increase thereupon conventionally.Suppose to have M * N button, need section pin position SEG(that M input/output port and N can be used as button scanning pin position COM altogether), or N input/output port and M section pin position SEG(that can be used as button scanning are total to pin position COM).Therefore the present invention is not as limit.

In addition, in above-described embodiment, be that to take the matrix utmost point of P-type mos field effect transistor of peripheral circuit of input/output port (GPIO) be that to receive lcd power source voltage VLCD be example.With general circuit design, extra input/output port (GPIO) is all and section pin position SEG(pin position COM altogether conventionally) framework identical, namely the matrix utmost point of P-type mos field effect transistor is coupled on voltage VLCD.Therefore, above-described embodiment, also adopts auxiliary transistor of the present invention as improvement for input/output port (GPIO), to avoid high voltage drive bad.Yet, it must be appreciated, when input/output port (GPIO) is when being designed to be used as pure general object input and output (GPIO) and using, the matrix utmost point of the P-type mos field effect transistor of input/output terminal (GPIO) is to be designed to be coupled in voltage P50.

In addition, if input/output terminal (GPIO) is to be purely used as to draw high (PULL HIGH) action, but not as high while driving (DRIVING HIGH) or scanning (KEY SCAN) function, now, the second auxiliary metallic oxide semiconductor field effect transistor 906 is can be unwanted.Reason is, drawing high (PULL HIGH) action does not need large driven current density, because when drawing high (PULL HIGH) action, its peripheral circuit is all at high impedance status, therefore only needs slightly energy just can complete to draw high (PULL HIGH) to move.Otherwise, when high driving (DRIVING HIGH) or scanning (KEY SCAN) function, need large electric current, high-energy to drive, if do not design the auxiliary transistor of the second embodiment of the present invention, will cause high voltage drive bad.

According to above-mentioned situation, if being only used for, input/output port (GPIO) draws high (PULL HIGH) action, only only have section pin position SEG(pin position COM altogether) need to use auxiliary transistor of the present invention to improve the bad situation of high drive.Therefore, the present invention do not get rid of only have part or only have altogether pin position COM of a section pin position SEG() dispose auxiliary transistor.In other words, as long as there is section pin position SEG(pin position COM altogether) dispose auxiliary transistor, belong to exactly the circuit that utilizes spirit of the present invention to implement.Identical reason, when section pin position SEG(is total to pin position COM) be only used for and draw high (PULL HIGH) action, only only have input/output port (GPIO) need to use auxiliary transistor of the present invention to improve the bad situation of high drive.Therefore,, as long as there is an input/output port (GPIO) to dispose auxiliary transistor, belong to exactly the circuit that utilizes spirit of the present invention to implement.

the 3rd embodiment

Figure 10 illustrates the peripheral circuit into the section signal input and output of the liquid crystal display of third embodiment of the invention and keyboard scan compatble circuit 403.Please refer to Figure 10, this circuit comprises an inner control logic circuit 1001, the first pull-up control circuit 1002, the second pull-up control circuit 1003, the first pull-down control circuit 1004, the second pull-down control circuit 1005, the first P-type mos field effect transistor PMOS1, the second P-type mos field effect transistor PMOS2, the first N-type mos field effect transistor NMOS1, the second N-type mos field effect transistor NMOS2, one first electrostatic discharge protective circuit 1006, the second electrostatic discharge protective circuit 1007, one first weld pad 1008, one second weld pad 1009, one first auxiliary metallic oxide semiconductor field effect transistor 1010, one second auxiliary metallic oxide semiconductor field effect transistor 1011, the 3rd pull-up control circuit 1012, the 3rd pull-down control circuit 1013, the 3rd P-type mos field effect transistor PMOS3, the 3rd N-type mos field effect transistor NMOS3, one the 3rd electrostatic discharge protective circuit 1014, one the 3rd weld pad 1015, one the 3rd auxiliary metallic oxide semiconductor field effect transistor 1016, the first section/connect altogether driving circuit 1017, the second section/connect altogether driving circuit 1018 and input/output control circuit 1019.It couples relation and illustrates as schemed.

Same, this embodiment be also hypothesis above-mentioned the first weld pad 1008, the first electrostatic discharge protective circuit 1006, the first N-type mos field effect transistor NMOS1, the first P-type mos field effect transistor PMOS1, the first pull-up control circuit 1002, the first pull-down control circuit 1004, the first auxiliary metallic oxide semiconductor field effect transistor 1010 and, input/output control circuit 1019 is to belong to input/output port, the circuit group of GPIO namely; Above-mentioned the second weld pad 1009, the second electrostatic discharge protective circuit 1007, the second N-type mos field effect transistor NMOS2, the second P-type mos field effect transistor PMOS2, the second pull-up control circuit 1003, the second pull-down control circuit 1005 and the second auxiliary metallic oxide semiconductor field effect transistor 1011 are to belong to have altogether pin position COM of shared section pin position SEG() be used as the circuit group of key scan; In addition, above-mentioned the 3rd pull-up control circuit 1012, the 3rd pull-down control circuit 1013, the 3rd P-type mos field effect transistor PMOS3, the 3rd N-type mos field effect transistor NMOS3, one the 3rd electrostatic discharge protective circuit 1014, one the 3rd weld pad 1015 and one the 3rd auxiliary metallic oxide semiconductor field effect transistor 1016 are to belong to share section pin position SEG(pin position COM altogether) be used as the circuit group of key scan.In addition, the first section/connect altogether driving circuit 1017 and the second section/connect altogether driving circuit 1018 are to belong to for driving the circuit of display panels.

Different from above-described embodiment, at this embodiment, each pin position can be used to do the function of key scan.Although this embodiment can increase a little chip area,, because the area of auxiliary metallic oxide semiconductor field effect transistor does not need very greatly, and can facilitate circuit system Application Engineer design circuit and layout external circuit.Therefore it is many that the area that the benefit of bringing increases more than chip will come.

Same reason, in above-described embodiment, is that to take the matrix utmost point of P-type mos field effect transistor of peripheral circuit of input/output port (GPIO) be that to receive lcd power source voltage VLCD be example.With general circuit design, extra input/output port (GPIO) is all and section pin position SEG(pin position COM altogether conventionally) framework identical, namely the matrix utmost point of P-type mos field effect transistor is coupled on voltage VLCD.Therefore, above-described embodiment, also adopts auxiliary transistor of the present invention as improvement for input/output port (GPIO), to avoid high voltage drive bad.Yet side circuit design is upper, also likely designing extra can be for doing other functions by input/output port (GPIO), but not key scan.For example, input/output port (GPIO) is to be designed to be used as pure general object input and output (GPIO) use, the matrix of the P-type mos field effect transistor of the input/output port of other non-key scan functions of work now, extremely can be coupled in voltage P50.

In addition, if input/output port (GPIO) is to be purely used as to draw high (PULL HIGH) action, but not as high while driving (DRIVING HIGH) or scanning (KEY SCAN) function, now, the second auxiliary metallic oxide semiconductor field effect transistor 906 is can be unwanted.Reason is, drawing high (PULL HIGH) action does not need large driven current density, because when drawing high (PULL HIGH) action, its peripheral circuit is all at high impedance status, therefore only needs slightly energy just can complete to draw high (PULL HIGH) to move.Otherwise, when high driving (DRIVING HIGH) or scanning (KEY SCAN) function, need large electric current, high-energy to drive, if do not design the auxiliary transistor of the second embodiment of the present invention, will cause high voltage drive bad.

According to above-mentioned situation, if being only used for, input/output port (GPIO) draws high (PULL HIGH) action, only have above-mentioned section pin position SEG(pin position COM altogether) need to use auxiliary transistor of the present invention to improve the bad situation of high drive.Therefore, the present invention do not get rid of only have part or only have altogether pin position COM of a section pin position SEG() dispose auxiliary transistor.Reason is, suppose to only have a button, if key scan is, while carrying out key scan with two section pin position SEG (altogether pin position COM) or a section pin position SEG (pin position COM altogether), only to need at least one section pin position SEG(pin position COM altogether) dispose auxiliary transistor and just can reach effect of the present invention.Therefore, the present invention does not limit must altogether pin position COM of section pin position SEG() and the input/output port (GPIO) coordinating all to have auxiliary transistor.With above-mentioned example, only need at least one section pin position SEG(pin position COM altogether) dispose auxiliary transistor, belong to exactly spirit of the present invention.

In addition, in application of the present invention, can also only have part or all of section pin position SEG(pin position COM altogether) dispose auxiliary transistor, and input/output port (GPIO) does not all have auxiliary transistor.Reason is, in application, draws high the driving force that (PULL HIGH) action only need to be less, can not need auxiliary transistor to increase driving force.If input/output port (GPIO) is only used in, draw high (PULL HIGH) action, only need altogether pin position COM of section pin position SEG() dispose auxiliary transistor.Moreover, if key scan function is only used altogether pin position COM of section pin position SEG() while carrying out, input/output port (GPIO) is not used completely, now, also only need part or all of section pin position SEG(pin position COM altogether) dispose auxiliary transistor and just can make key scan, therefore, the present invention does not limit input/output port (GPIO) must auxiliary transistor.

If section pin position SEG(is total to pin position COM conversely speaking) be only used in and draw high (PULL HIGH) action, now also only have part or all of input/output port (GPIO) need to dispose auxiliary transistor.Because reason is identical, affiliated technical field has knows the knowledgeable conventionally, by narrating above, should understand, therefore do not repeat them here.

the 4th embodiment

Figure 11 illustrates the peripheral circuit into the section signal input and output of the liquid crystal display of fourth embodiment of the invention and keyboard scan compatble circuit 403.Please refer to Figure 11, this circuit comprises an inner control logic circuit 1101, the first pull-up control circuit 1102, the second pull-up control circuit 1103, the first pull-down control circuit 1104, the second pull-down control circuit 1105, the first P-type mos field effect transistor PMOS1, the second P-type mos field effect transistor PMOS2, the first N-type mos field effect transistor NMOS1, the second N-type mos field effect transistor NMOS2, one first electrostatic discharge protective circuit 1106, the second electrostatic discharge protective circuit 1107, one first weld pad 1108, one second weld pad 1109, one first auxiliary switch 1110, one second auxiliary switch 1111, one the 3rd electrostatic discharge protective circuit 1112, one the 3rd weld pad 1113, the first section/connect altogether driving circuit 1114, the second section/connect altogether driving circuit 1115 and input/output control circuit 1116.It couples relation and illustrates as schemed.

In this embodiment, suppose above-mentioned the first weld pad 1108, the first electrostatic discharge protective circuit 1106, the first N-type mos field effect transistor NMOS1, the first P-type mos field effect transistor PMOS1, the first pull-up control circuit 1102, the first pull-down control circuit 1104, the first auxiliary switch 1110 and, input/output control circuit 1116 is to belong to input/output port, the circuit group of GPIO namely; Above-mentioned the second weld pad 1109, the second electrostatic discharge protective circuit 1107, the second N-type mos field effect transistor NMOS2, the second P-type mos field effect transistor PMOS2, the second pull-up control circuit 1103, the second pull-down control circuit 1105 and the second auxiliary switch 1111 are to belong to have altogether pin position COM of shared section pin position SEG() be used as the circuit group of key scan; In addition, the 3rd electrostatic discharge protective circuit 1112 and the 3rd weld pad 1113 are to belong to there is no altogether pin position COM of the section of key scan function pin position SEG() circuit group.In addition, the first section/connect altogether driving circuit 1114 and the second section/connect altogether driving circuit 1115 are to belong to for driving the circuit of display panels.

Wherein, above-mentioned the first auxiliary switch 1110 comprises a first end, one second end, one the 3rd end and a control end.The first end of above-mentioned the first auxiliary switch 1110 receives micro-processing power supply P50.The second end of above-mentioned the first auxiliary switch 1110 is coupled to the matrix utmost point of the first P-type mos field effect transistor PMOS1.The control end of above-mentioned the first auxiliary switch 1110 is coupled to the output terminal of the first pull-up control circuit 1102, and the 3rd end of above-mentioned the first auxiliary switch 1110 couples this lcd power source VLCD of passive display panels.Above-mentioned the second auxiliary switch 1111 comprises a first end, one second end, one the 3rd end and a control end.The first end of above-mentioned the second auxiliary switch 1111 receives micro-processing power supply P50.The second end of above-mentioned the second auxiliary switch 1111 is coupled to the matrix utmost point of the second P-type mos field effect transistor PMOS2.The control end of above-mentioned the second auxiliary switch 1111 is coupled to the output terminal of the second pull-up control circuit 1103, and the 3rd end of above-mentioned the second auxiliary switch 1111 couples this lcd power source VLCD of passive display panels.

When carrying out passive display panels driving, now, the 3rd end of the first auxiliary switch 1110 and the second end conducting of the first auxiliary switch 1110, and the 3rd end of the second auxiliary switch 1111 and the second end conducting of the second auxiliary switch 1111 pour into prevent high pressure.Now, this circuit is by the first section/connect altogether driving circuit 914 and the second section/connect altogether driving circuit 915 to drive section corresponding on display panels/wiring altogether, and because the action of circuit is identical with prior art, so it will not go into details.

Yet, when utilizing the circuit group of above-mentioned key scan, the second weld pad 1109 namely, the second electrostatic discharge protective circuit 1107, the second N-type mos field effect transistor NMOS2, the second P-type mos field effect transistor PMOS2, the second pull-up control circuit 1103, the second pull-down control circuit 1105, while carrying out key scan (namely situation 4), please also refer to Fig. 6 A and Figure 11, now, section signal pin SEG(is pin position COM altogether) be to be used to do scanning end, namely be used for output HIGH voltage P50, although receiving VLCD, the matrix utmost point of the second P-type mos field effect transistor PMOS2 cause high voltage P 50 driving forces not enough, but, because the present embodiment has additionally increased by second auxiliary switch 1111, now, the control of drawing control signal PL on exporting by the second pull-up control circuit 1103, the second end conducting of the first end of the second auxiliary switch 1111 and the second auxiliary switch 1111, make the matrix utmost point receiver voltage P50 of the second P-type mos field effect transistor PMOS2, therefore, can increase the driving force of drawing high of the second P-type mos field effect transistor PMOS2.

Same reason, when utilizing above-mentioned input/output port, the circuit group of GPIO namely, the first weld pad 1108 namely, the first electrostatic discharge protective circuit 1106, the first N-type mos field effect transistor NMOS1, the first P-type mos field effect transistor PMOS1, the first pull-up control circuit 1102, the first pull-down control circuit 1104 and the first auxiliary switch 1110, while carrying out key scan (namely situation 1), please also refer to Fig. 5 A and Figure 11, now, input/output port (GPIO) is to be used to do scanning end, namely be used for output HIGH voltage P50, although receiving VLCD, the matrix utmost point of the first P-type mos field effect transistor PMOS1 cause high voltage P 50 driving forces not enough, but, because the present embodiment has additionally increased by first auxiliary switch 1110, now, the control of drawing control signal PL on exporting by the first pull-up control circuit 1103, the second end conducting of the first end of the first auxiliary switch 1110 and the first auxiliary switch 1110, make the matrix utmost point receiver voltage P50 of the first P-type mos field effect transistor PMOS1, therefore, can increase the driving force of drawing high of the first P-type mos field effect transistor PMOS1.

Same reason, this embodiment and the second embodiment are similar, are the several appointment pin positions passive liquid crystal display drive circuit, as key scan function.In this embodiment, be also that section pin position SEG is divided into and can be used as the pin position of button scanning and the pin position that cannot scan as button.In this embodiment, although only illustrate a section pin position SEG who can be used as button scanning,, affiliated technical field has knows that the knowledgeable it should be known that, according to different application, pin number order can increase thereupon conventionally.Suppose to have M * N button, need M input/output port and N section pin position SEG that can be used as button scanning, or N input/output port and M section pin position SEG that can be used as button scanning.Therefore the present invention is not as limit.

In addition, although above-described embodiment is to have altogether pin position COM of a section signal pin SEG() and an input/output port (GPIO) there is auxiliary switch, but, affiliated technical field has knows that the knowledgeable should know conventionally, with general circuit design, extra input/output port (GPIO) is all and section pin position SEG(pin position COM altogether conventionally) framework identical, namely the matrix utmost point of P-type mos field effect transistor is coupled on voltage VLCD.Therefore, above-described embodiment, also adopts auxiliary transistor of the present invention as improvement for input/output port (GPIO), to avoid high voltage drive bad.

Yet, it must be appreciated, when input/output port (GPIO) is when being designed to be used as pure general object input and output (GPIO) and using, the matrix utmost point of the P-type mos field effect transistor of input/output port (GPIO) is to be designed to be coupled in voltage P50.

In addition, if input/output port (GPIO) is to be purely used as to draw high (PULL HIGH) action, but not as high while driving (DRIVING HIGH) or scanning (KEY SCAN) function, now, the first auxiliary switch 1110 is can be unwanted.Reason is, drawing high (PULL HIGH) action does not need large driven current density, because when drawing high (PULL HIGH) action, its peripheral circuit is all at high impedance status, therefore only needs slightly energy just can complete to draw high (PULL HIGH) to move.Otherwise, when high driving (DRIVING HIGH) or scanning (KEY SCAN) function, need large electric current, high-energy to drive, if do not design the auxiliary transistor of the second embodiment of the present invention, will cause high voltage drive bad.

According to above-mentioned situation, if being only used for, input/output terminal (GPIO) draws high (PULL HIGH) action, only only have section pin position SEG(pin position COM altogether) need to use auxiliary switch of the present invention to improve the bad situation of high drive.Therefore, the present invention do not get rid of only have part or only have altogether pin position COM of a section pin position SEG() dispose auxiliary switch.In other words, as long as there is section pin position SEG(pin position COM altogether) dispose auxiliary switch, belong to exactly the circuit that utilizes spirit of the present invention to implement.Identical reason, when section pin position SEG(is total to pin position COM) be only used for and draw high (PULL HIGH) action, only only have input/output port (GPIO) need to use auxiliary transistor of the present invention to improve the bad situation of high drive.Therefore,, as long as there is an input/output port (GPIO) to dispose auxiliary switch, belong to exactly the circuit that utilizes spirit of the present invention to implement.

In the following embodiments, separately provide a kind of whole pin position to affiliated technical field, to have and conventionally to know the knowledgeable's reference as the implementing circuit of key scan function.

the 5th embodiment

Figure 12 illustrates the peripheral circuit into the section signal input and output of the liquid crystal display of fifth embodiment of the invention and keyboard scan compatble circuit 403.Please refer to Figure 12, this circuit comprises an inner control logic circuit 1201, the first pull-up control circuit 1202, the second pull-up control circuit 1203, the first pull-down control circuit 1204, the second pull-down control circuit 1205, the first P-type mos field effect transistor PMOS1, the second P-type mos field effect transistor PMOS2, the first N-type mos field effect transistor NMOS1, the second N-type mos field effect transistor NMOS2, one first electrostatic discharge protective circuit 1206, the second electrostatic discharge protective circuit 1207, one first weld pad 1208, one second weld pad 1209, one first auxiliary switch 1210, the second auxiliary switch 1211, the 3rd pull-up control circuit 1212, the 3rd pull-down control circuit 1213, the 3rd P-type mos field effect transistor PMOS3, the 3rd N-type mos field effect transistor NMOS3, one the 3rd electrostatic discharge protective circuit 1214, one the 3rd weld pad 1215, one the 3rd auxiliary switch 1216 and input/output control circuit 1217.It couples relation and illustrates as schemed.Due to the relation in drawing space, corresponding to the second electrostatic discharge protective circuit 1207 and the 3rd electrostatic discharge protective circuit 1214, be used for carrying out the section of liquid crystal drive/connect altogether driving circuit to be omitted and not illustrate in this way.

Wherein, above-mentioned the first auxiliary switch 1210 comprises a first end, one second end, one the 3rd end and a control end.The first end of above-mentioned the first auxiliary switch 1210 receives micro-processing power supply P50.The second end of above-mentioned the first auxiliary switch 1210 is coupled to the matrix utmost point of the first P-type mos field effect transistor PMOS1.The control end of above-mentioned the first auxiliary switch 1210 is coupled to the output terminal of the first pull-up control circuit 1202, and the 3rd end of above-mentioned the first auxiliary switch 1210 couples the lcd power source VLCD of passive display panels.Above-mentioned the second auxiliary switch 1211 comprises a first end, one second end, one the 3rd end and a control end.The first end of above-mentioned the second auxiliary switch 1211 receives micro-processing power supply P50.The second end of above-mentioned the second auxiliary switch 1211 is coupled to the matrix utmost point of the second P-type mos field effect transistor PMOS2.The control end of above-mentioned the second auxiliary switch 1211 is coupled to the output terminal of the second pull-up control circuit 1203, and the 3rd end of above-mentioned the second auxiliary switch 1211 couples the lcd power source VLCD of passive display panels.Above-mentioned the 3rd auxiliary switch 1216 comprises a first end, one second end, one the 3rd end and a control end.The first end of above-mentioned the 3rd auxiliary switch 1216 receives micro-processing power supply P50.The second end of above-mentioned the 3rd auxiliary switch 1216 is coupled to the matrix utmost point of the 3rd P-type mos field effect transistor PMOS3.The control end of above-mentioned the 3rd auxiliary switch 1216 is coupled to the output terminal of the 3rd pull-up control circuit 1212, and the 3rd end of above-mentioned the 3rd auxiliary switch 1216 couples the lcd power source VLCD of passive display panels.

When carrying out passive display panels driving, now, the 3rd end of the first auxiliary switch 1210 and the second end conducting of the first auxiliary switch 1210, and the 3rd end of the second auxiliary switch 1211 and the second end conducting of the second auxiliary switch 1211, and the 3rd end of the 3rd auxiliary switch 1216 and the second end conducting of the 3rd auxiliary switch 1216, the action of this circuit is identical with prior art, and therefore it will not go into details.Yet, when carrying out key scan, the first end conducting of the second end of the first auxiliary switch 1210 and the first auxiliary switch 1210, and the first end conducting of the second end of the second auxiliary switch 1211 and the second auxiliary switch 1211, and the first end conducting of the second end of the 3rd auxiliary switch 1216 and the 3rd auxiliary switch 1216, therefore, can increase by the first P-type mos field effect transistor PMOS1, high voltage P 50 driving forces of the second P-type mos field effect transistor PMOS2 and the 3rd P-type mos field effect transistor PMOS3.

Different from above-mentioned the 4th embodiment, at this 5th embodiment, each pin position can be used to do the function of key scan.Although this 5th embodiment can increase a little chip area,, because the area of auxiliary switch does not need very greatly, and can facilitate circuit system Application Engineer design circuit and layout external circuit.Therefore it is many that the area that the benefit of bringing increases more than chip will come.

analog result

Figure 13 illustrates the analog result into the liquid crystal display of second embodiment of the invention, the 3rd embodiment and the improvement of keyboard scan compatble circuit 403.Please refer to Figure 13, wherein, ordinate Ron represents the conducting resistance of P type metal-semiconductor field effect transistor, the voltage swing of horizontal ordinate representative voltage P50.By above-mentioned analog result, can be found out, along with VLCD changes (only indicating 8V～5V), while not adding auxiliary transistor, the conducting resistance of P type metal-semiconductor field effect transistor is changed to 100K ohm by 10G ohm, by it, be that VLCD voltage equals 8V, and when P50 voltage equals 2V, P type metal-semiconductor field effect transistor does not have conducting at all.But, having added after auxiliary transistor, VLCD voltage equals 8V, and P50 voltage is while equaling 2V, and the conducting resistance of P type metal-semiconductor field effect transistor is between 2K ohm to 500 ohm.Contrast can be said quite obvious.

Figure 14 illustrates the analog result into the liquid crystal display of second embodiment of the invention, the 3rd embodiment and the improvement of keyboard scan compatble circuit 403.Please refer to Figure 14, result when the 1401st, P type metal-semiconductor field effect transistor is original size, the result that the 1402nd, P type metal-semiconductor field effect transistor is original size 10 times time, the result that the 1403rd, P type metal-semiconductor field effect transistor is original size 100 times time, 1404 is improved results of the second embodiment, the 3rd embodiment.By above-mentioned Figure 14, can find out, even by hundred times of P type metal-semiconductor field effect transistor area changes, at P50 voltage hour, affect also little.But when P50 voltage is large, hundred times of P type metal-semiconductor field effect transistor area changes can cause the rapid decline of equivalent resistance Ron.This has been not phenomenon.Reason is, excessive when high drive electric current, can cause the problem of electromagnetic interference (EMI) (Electromagnetic Interference, EMI).And by above-mentioned two results, can be found out that can the further drive current of high-low pressure of the improvement of the embodiment of the present invention is stablized and reduced electromagnetic interference (EMI) and occurs.

In sum, spirit of the present invention is using section weld pad or connecing altogether weld pad as key scan function, to increase the dirigibility of chip application.And in order to solve liquid crystal display scanning and keyboard scan, drive the different circuit that cause of level incompatible, inner at its input and output pin, additionally increase by an auxiliary transistor, lower and drive the transistorized substrate impedance that effect causes of high-low pressure excessive.Therefore, guarantee that this chip can be used for driving display panels simultaneously and carry out keyboard scan.Therefore, the saving applications circuit component quantity that the present invention can be certain, the outer member cost of reduction product.

The specific embodiment proposing in the detailed description of preferred embodiment is only in order to convenient explanation technology contents of the present invention, but not the present invention is narrowly limited to above-described embodiment, in the situation that does not exceed spirit of the present invention and claim scope, the many variations of doing is implemented, and all belongs to scope of the present invention.Therefore protection scope of the present invention is when being as the criterion depending on the claim scope person of defining.

Claims

1. liquid crystal display and a keyboard scan compatble circuit, is characterized in that, in order to drive a passive display panels in the liquid crystal drive time, and in a standby time, drives at least one button, and this liquid crystal display and keyboard scan compatble circuit comprise:

One drives microprocessing unit, comprise a power end, connect voltage end, an inner control logic circuit and an input/output control circuit altogether, wherein, described at least one input/output control circuit couples the first end of described at least one button, this power end receives a micro-processing power supply, wherein, the described voltage end that connects altogether receives and to connect altogether voltage;

At least one input/output port weld pad, wherein, described at least one input/output port weld pad is coupled between the first end of described at least one input/output control circuit and described button;

Most connect an altogether/section weld pad, wherein, a plurality of the connect altogether/section lines that couple described passive display panels that described connect altogether/section weld pad is corresponding, wherein, specific connect an altogether/section weld pad at least wherein of described connect altogether/section weld pad couples the second end of described at least one button;

Most pull-up control circuits, wherein, described in each, pull-up control circuit comprises an input end and an output terminal, described in each, the input end of pull-up control circuit is corresponding is coupled to described inner control logic circuit;

Most pull-down control circuits, wherein, described in each, pull-down control circuit comprises an input end and an output terminal, described in each, the input end of pull-down control circuit is corresponding is coupled to described inner control logic circuit;

Most pull up transistor, wherein, described in each, pull up transistor and comprise respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, I the grid pulling up transistor couples the output terminal of I pull-up control circuit, I the first source-drain electrode pulling up transistor receives described micro-processing power supply, I the matrix utmost point pulling up transistor couples a lcd power source end of described passive display panels, described in I the second source-drain electrode pulling up transistor is coupled to, couples I connect altogether/section weld pad;

A most pull-down transistor, wherein, described in each, pull-down transistor comprises respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the grid of J pull-down transistor is coupled to the output terminal of J pull-down control circuit, the first source-drain electrode of J pull-down transistor is coupled to J the second source-drain electrode pulling up transistor, and the second source-drain electrode of J pull-down transistor receives the described voltage that connects altogether, and the matrix utmost point of J pull-down transistor receives the described voltage that connects altogether; And

At least one auxiliary transistor, wherein, described at least one auxiliary transistor comprises a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the first source-drain electrode of described at least one auxiliary transistor receives described micro-processing power supply, the matrix utmost point of described at least one auxiliary transistor is coupled to the described voltage end that connects altogether, the second source-drain electrode of described at least one auxiliary transistor is coupled to described specific connect altogether/section weld pad, the grid of described at least one auxiliary transistor couples a reversed-phase output of a specific pull-up control circuit wherein of described pull-up control circuit, wherein, the single spin-echo of the output signal of the output signal of the described reversed-phase output of described specific pull-up control circuit and the output terminal of described specific pull-up control circuit,

Wherein, I and J are natural number, and the number of 0 < I <=described connect altogether/section weld pad, and the number of 0 < J <=described connect altogether/section weld pad.

2. liquid crystal display as claimed in claim 1 and keyboard scan compatble circuit, is characterized in that, described liquid crystal display and keyboard scan compatble circuit be in order to capable the button of driving N row * M, and described liquid crystal display and keyboard scan compatble circuit comprise:

M input/output port weld pad, wherein, K input/output port weld pad couples the first end of the described button that K is capable;

N specific connect altogether/section weld pad, wherein, P particular section weld pad couples the second end of the described button of P row;

N specific pull-up control circuit, wherein, described in each, specific pull-up control circuit comprises an input end, an output terminal and a reversed-phase output, wherein, the single spin-echo of the output signal of the output signal of the described reversed-phase output of described specific pull-up control circuit and the output terminal of described specific pull-up control circuit, described in each, the input end of pull-up control circuit and described specific pull-up control circuit is corresponding is coupled to described inner control logic circuit; And

N auxiliary transistor, wherein, a described N auxiliary transistor comprises a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the first source-drain electrode of described P auxiliary transistor receives described micro-processing power supply, the matrix utmost point of described P auxiliary transistor is coupled to the described voltage end that connects altogether, the second source-drain electrode of described P auxiliary transistor is coupled to P specific connect altogether/section weld pad, the grid of described P auxiliary transistor couples the described reversed-phase output of P specific pull-up control circuit

Wherein, N, M and P are natural number, and 0 < P <=N.

3. liquid crystal display as claimed in claim 2 and keyboard scan compatble circuit, is characterized in that, more comprises:

N one-way breakover element, wherein, described in each, one-way breakover element comprises respectively a first end and one second end, wherein, the first end of Q one-way breakover element couples Q specific connect altogether/section weld pad, and the second end of Q one-way breakover element couples the second end of the described button that Q is listed as, wherein, the conducting direction of described one-way breakover element is the second end from the first end of described one-way breakover element to described one-way breakover element

Wherein, Q is natural number, and 0 < Q <=N.

4. liquid crystal display as claimed in claim 2 and keyboard scan compatble circuit, is characterized in that, more comprises:

N one-way breakover element, wherein, described in each, one-way breakover element comprises respectively a first end and one second end, wherein, the first end of Q one-way breakover element couples Q specific connect altogether/section weld pad, and the second end of Q one-way breakover element couples the second end of the described button that Q is listed as, wherein, the conducting direction of described one-way breakover element is the first end from the second end of described one-way breakover element to described one-way breakover element

Wherein, Q is natural number, and 0 < Q <=N.

5. liquid crystal display as claimed in claim 2 and keyboard scan compatble circuit, is characterized in that, the number of described connect altogether/section weld pad is R, and described liquid crystal display and keyboard scan compatble circuit comprise:

R pull-up control circuit, wherein, described in each, pull-up control circuit comprises an input end, an output terminal and a reversed-phase output, wherein, the single spin-echo of the output signal of the output signal of the described reversed-phase output of described pull-up control circuit and the output terminal of described specific pull-up control circuit, described in each, the input end of pull-up control circuit is corresponding is coupled to described inner control logic circuit; And

R auxiliary transistor, wherein, a described R auxiliary transistor comprises a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the first source-drain electrode of described S auxiliary transistor receives described micro-processing power supply, the matrix utmost point of described S auxiliary transistor is coupled to the described voltage end that connects altogether, the second source-drain electrode of described S auxiliary transistor is coupled to S connect altogether/section weld pad, the grid of described S auxiliary transistor couples the described reversed-phase output of S pull-up control circuit

Wherein, R and S are natural number, and 0 < S <=R.

6. an electronic product, is characterized in that, comprising:

One passive display panels;

At least one button;

One liquid crystal display and keyboard scan compatble circuit, comprising:

One drives microprocessing unit, comprise a power end, connect voltage end, an inner control logic circuit and an input/output control circuit altogether, wherein, described input/output control circuit couples the first end of described at least one button, wherein, described power end receives a micro-processing power supply, and wherein, the described voltage end that connects altogether receives and to connect altogether voltage;

Most connect an altogether/section weld pad, wherein, a plurality of the connect altogether/section lines that couple described passive display panels that described connect altogether/section weld pad is corresponding,

Specific connect an altogether/section weld pad at least wherein of wherein, described connect altogether/section weld pad couples the second end of described at least one button;

Wherein, I and J are natural number, and the number of 0 < I <=those connect altogether/section weld pads, and the number of 0 < J <=those connect altogether/section weld pads.

7. electronic product as claimed in claim 6, is characterized in that, this liquid crystal display and keyboard scan compatble circuit be in order to capable the button of driving N row * M, and this liquid crystal display and keyboard scan compatble circuit comprise:

M input/output port weld pad, wherein, K input/output port weld pad couples the first end of those buttons that K is capable;

N specific connect altogether/section weld pad, wherein, P particular section weld pad couples the second end of those buttons of P row;

N specific pull-up control circuit, wherein, each those specific pull-up control circuit comprises an input end, an output terminal and a reversed-phase output, wherein, the single spin-echo of the output signal of described reversed-phase output of described specific pull-up control circuit and the output signal of the output terminal of described specific pull-up control circuit, the input end of each those pull-up control circuit and those specific pull-up control circuits is corresponding is coupled to this inner control logic circuit; And

N auxiliary transistor, wherein, a described N auxiliary transistor comprises a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the first source-drain electrode of described P auxiliary transistor receives this micro-processing power supply, the matrix utmost point of described P auxiliary transistor is coupled to this and connects altogether voltage end, the second source-drain electrode of described P auxiliary transistor is coupled to P specific connect altogether/section weld pad, the grid of described P auxiliary transistor couples this reversed-phase output of P specific pull-up control circuit

Wherein, N, M and P are natural number, and 0 < P <=N.

8. electronic product as claimed in claim 7, is characterized in that, more comprises:

N one-way breakover element, wherein, each those one-way breakover element comprises respectively a first end and one second end, wherein, the first end of Q one-way breakover element couples Q specific connect altogether/section weld pad, and the second end of Q one-way breakover element couples the second end of those buttons that Q is listed as, wherein, the conducting direction of those one-way breakover elements is the second end from the first end of those one-way breakover elements to those one-way breakover elements

Wherein, Q is natural number, and 0 < Q <=N.

9. electronic product as claimed in claim 7, is characterized in that, more comprises:

N one-way breakover element, wherein, each those one-way breakover element comprises respectively a first end and one second end, wherein, the first end of Q one-way breakover element couples Q specific connect altogether/section weld pad, and the second end of Q one-way breakover element couples the second end of those buttons that Q is listed as, wherein, the conducting direction of those one-way breakover elements is the first end from the second end of those one-way breakover elements to those one-way breakover elements

Wherein, Q is natural number, and 0 < Q <=N.

10. electronic product as claimed in claim 7, is characterized in that, the number of those connect altogether/section weld pads is R, and this liquid crystal display and keyboard scan compatble circuit comprise:

R pull-up control circuit, wherein, each those pull-up control circuit comprises an input end, an output terminal and a reversed-phase output, wherein, the single spin-echo of the output signal of described reversed-phase output of described pull-up control circuit and the output signal of the output terminal of described specific pull-up control circuit, the input end of each those pull-up control circuit is corresponding is coupled to this inner control logic circuit; And

R auxiliary transistor, wherein, a described R auxiliary transistor comprises a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the first source-drain electrode of described S auxiliary transistor receives this micro-processing power supply, the matrix utmost point of described S auxiliary transistor is coupled to this and connects altogether voltage end, the second source-drain electrode of described S auxiliary transistor is coupled to S connect altogether/section weld pad, the grid of described S auxiliary transistor couples this reversed-phase output of S pull-up control circuit

Wherein, R and S are natural number, and 0 < S <=R.

11. 1 kinds of liquid crystal displays and keyboard scan compatble circuit, is characterized in that, in order to drive a passive display panels in the liquid crystal drive time, and in a standby time, drive at least one button, this liquid crystal display and keyboard scan compatble circuit comprise:

One drives microprocessing unit, comprise a power end, connect voltage end, an inner control logic circuit and an input/output control circuit altogether, wherein, described input/output control circuit couples the first end of described at least one button, wherein, this power end receives a micro-processing power supply, and wherein, this connects altogether voltage end reception and connects altogether voltage;

Most connect an altogether/section weld pad, wherein, a plurality of the connect altogether/section lines that couple this passive display panels that those connect altogether/section weld pads are corresponding,

Wherein, at least one of them specific connect altogether/section weld pad of described connect altogether/section weld pad couples the second end of described at least one button;

Most pull-up control circuits, wherein, each those pull-up control circuit comprises an input end and an output terminal, the input end of each those pull-up control circuit is corresponding is coupled to this inner control logic circuit;

Most pull-down control circuits, wherein, each those pull-down control circuit comprises an input end and an output terminal, the input end of each those pull-down control circuit is corresponding is coupled to this inner control logic circuit;

Most pull up transistor, wherein, each those pull up transistor and comprise respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, I the grid pulling up transistor couples the output terminal of I pull-up control circuit, I the first source-drain electrode pulling up transistor receives this micro-processing power supply, I the matrix utmost point pulling up transistor couples a lcd power source end of this passive display panels, and I the second source-drain electrode pulling up transistor is coupled to this and couples I connect altogether/section weld pad;

A most pull-down transistor, wherein, each those pull-down transistor comprises respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the grid of J pull-down transistor is coupled to the output terminal of J pull-down control circuit, the first source-drain electrode of J pull-down transistor is coupled to J the second source-drain electrode pulling up transistor, and the second source-drain electrode of J pull-down transistor receives this and connects altogether voltage, and the matrix utmost point of J pull-down transistor receives this and connects altogether voltage; And

At least one auxiliary switch, wherein, described at least one auxiliary switch comprises a first end, one second end, one the 3rd end and a control end, wherein, the first end of described at least one auxiliary switch receives this micro-processing power supply, the second end of described at least one auxiliary switch is coupled to those specific matrix utmost points pulling up transistor pulling up transistor, wherein this specific this second source-drain electrode pulling up transistor couples this specific connect altogether/section weld pad, the control end of described at least one auxiliary switch is coupled to the output terminal of one of them specific pull-up control circuit of those pull-up control circuits, the 3rd end of described at least one auxiliary switch couples this lcd power source end of this passive display panels, wherein, when in this liquid crystal drive time, this pull-up control circuit is controlled this specific pulling up transistor during conducting, the 3rd end of this at least one auxiliary switch and the second end conducting of this at least one auxiliary switch, when in this standby time, this pull-up control circuit is controlled this specific pulling up transistor during conducting, the second end conducting of the first end of this at least one auxiliary switch and this at least one auxiliary switch,

12. liquid crystal displays as claimed in claim 11 and keyboard scan compatble circuit, is characterized in that, this liquid crystal display and keyboard scan compatble circuit be in order to capable the button of driving N row * M, and this liquid crystal display and keyboard scan compatble circuit comprise:

M input/output port weld pad, wherein K input/output port weld pad couples the first end of those buttons that K is capable;

N specific connect altogether/section weld pad, wherein, P specific connect altogether/section weld pad couples the second end of those buttons of P row;

N auxiliary switch, wherein, a described N auxiliary switch comprises a first end, one second end, one the 3rd end and a control end, wherein, the first end of described P auxiliary switch receives this micro-processing power supply, the second end of described P auxiliary transistor is coupled to P the matrix utmost point pulling up transistor, the 3rd end of described P auxiliary transistor couples this lcd power source end of this passive display panels, the control end of described P auxiliary switch is coupled to the output terminal of P pull-up control circuit

Wherein, N, M and P are natural number, and 0 < P <=N.

13. liquid crystal displays as claimed in claim 12 and keyboard scan compatble circuit, is characterized in that, more comprises:

Wherein, Q is natural number, and 0 < Q <=N.

14. liquid crystal displays as claimed in claim 12 and keyboard scan compatble circuit, is characterized in that, more comprises:

Wherein, Q is natural number, and 0 < Q <=N.

15. liquid crystal displays as claimed in claim 12 and keyboard scan compatble circuit, is characterized in that, the number of those connect altogether/section weld pads is R, and this liquid crystal display and keyboard scan compatble circuit comprise:

R pull-up control circuit, wherein, each those pull-up control circuit comprises an input end and an output terminal, wherein, the input end of each those pull-up control circuit is corresponding is coupled to this inner control logic circuit, and the output terminal of each those pull-up control circuit couples the corresponding grid pulling up transistor; And

R auxiliary switch, wherein, a described R auxiliary switch comprises a first end, one second end, one the 3rd end and a control end, wherein, the second end of described S auxiliary switch be coupled to that S pulls up transistor the matrix utmost point, the 3rd end of described S auxiliary switch couples this lcd power source end of this passive display panels, the control end of described S auxiliary switch is coupled to the output terminal of S pull-up control circuit, wherein, when in this liquid crystal drive time, when this pull-up control circuit is controlled this and is pulled up transistor conducting, the 3rd end of this at least one auxiliary switch and the second end conducting of this at least one auxiliary switch, when in this standby time, when this pull-up control circuit is controlled this and is pulled up transistor conducting, the second end conducting of the first end of those auxiliary switches and those auxiliary switches,

Wherein, R and S are natural number, and 0 < S <=R.

16. 1 kinds of electronic products, is characterized in that, comprising:

One passive display panels;

At least one button;

One liquid crystal display and keyboard scan compatble circuit, comprising:

One drives microprocessing unit, comprise a power end, connect voltage end, an inner control logic circuit and at least one input/output control circuit altogether, wherein, described input/output control circuit couples the first end of described at least one button, wherein, this power end receives a micro-processing power supply, and wherein, this connects altogether voltage end reception and connects altogether voltage;

17. electronic products as claimed in claim 16, is characterized in that, described liquid crystal display and keyboard scan compatble circuit be in order to capable the button of driving N row * M, and described liquid crystal display and keyboard scan compatble circuit comprise:

N specific connect altogether/section weld pad, wherein, P specific connect altogether/section weld pad couples the second end of the described button of P row;

N auxiliary switch, wherein, a described N auxiliary switch comprises a first end, one second end, one the 3rd end and a control end, wherein, the first end of described P auxiliary switch receives described micro-processing power supply, the second end of described P auxiliary transistor is coupled to P the matrix utmost point pulling up transistor, the 3rd end of described P auxiliary transistor couples the described lcd power source end of described passive display panels, the control end of described P auxiliary switch is coupled to the output terminal of P a little pull-up control circuits

Wherein, N, M and P are natural number, and 0 < P <=N.

18. electronic products as claimed in claim 17, is characterized in that, more comprise:

Wherein, Q is natural number, and 0 < Q <=N.

19. electronic products as claimed in claim 17, is characterized in that, more comprise:

Wherein, Q is natural number, and 0 < Q <=N.

20. electronic products as claimed in claim 17, is characterized in that, the number of described connect altogether/section weld pad is R, and described liquid crystal display and keyboard scan compatble circuit comprise:

R pull-up control circuit, wherein, described in each, pull-up control circuit comprises an input end and an output terminal, wherein, described in each, the input end of pull-up control circuit is corresponding is coupled to described inner control logic circuit, and described in each, the output terminal of pull-up control circuit couples the corresponding grid pulling up transistor; And

R auxiliary switch, wherein, a described R auxiliary switch comprises a first end, one second end, one the 3rd end and a control end, wherein, the second end of described S auxiliary switch be coupled to that S pulls up transistor the matrix utmost point, the 3rd end of described S auxiliary switch couples the described lcd power source end of described passive display panels, the control end of described S auxiliary switch is coupled to the output terminal of S pull-up control circuit, wherein, when in the described liquid crystal drive time, while pulling up transistor conducting described in described pull-up control circuit control, the 3rd end of described at least one auxiliary switch and the second end conducting of described at least one auxiliary switch, when in described standby time, while pulling up transistor conducting described in described pull-up control circuit control, the second end conducting of the first end of described auxiliary switch and described auxiliary switch,

Wherein, R and S are natural number, and 0 < S <=R.

21. 1 kinds of liquid crystal displays and keyboard scan compatble circuit, is characterized in that, in order to drive a passive display panels in the liquid crystal drive time, and in a standby time, drive at least one button, described liquid crystal display and keyboard scan compatble circuit comprise:

One drives microprocessing unit, comprise a power end, connect voltage end, inner control logic circuit and an input/output control circuit altogether, wherein, described input/output control circuit couples the first end of described at least one button, wherein, described power end receives a micro-processing power supply, and wherein, the described voltage end that connects altogether receives and to connect altogether voltage;

At least one input/output port weld pad, wherein, described at least one input/output port weld pad is coupled between the first end of described input/output control circuit and described button;

At least one pull-up control circuit, wherein, described at least one pull-up control circuit comprises an input end and an output terminal, the input end of described at least one pull-up control circuit is coupled to described input/output control circuit;

At least one pull-down control circuit, wherein, described at least one pull-down control circuit comprises an input end and an output terminal, the input end of described at least one pull-down control circuit is coupled to described input/output control circuit;

At least one pulling up transistor, wherein, described at least one pulling up transistor comprises respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, described at least one grid pulling up transistor couples the output terminal of described at least one pull-up control circuit, described at least one the first source-drain electrode pulling up transistor receives this micro-processing power supply, described at least one matrix utmost point pulling up transistor couples a lcd power source end of described passive display panels, described at least one the second source-drain electrode pulling up transistor is coupled to described at least one input/output port weld pad,

At least one pull-down transistor, wherein, described at least one pull-down transistor comprises respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the grid of described at least one pull-down transistor is coupled to the output terminal of described at least one pull-down control circuit, the first source-drain electrode of described at least one pull-down transistor is coupled to described at least one the second source-drain electrode pulling up transistor, the second source-drain electrode of described at least one pull-down transistor receives the described voltage that connects altogether, and the matrix utmost point of described at least one pull-down transistor receives the described voltage that connects altogether; And

At least one auxiliary transistor, wherein, described at least one auxiliary transistor comprises a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the first source-drain electrode of described at least one auxiliary transistor receives described micro-processing power supply, the matrix utmost point of described at least one auxiliary transistor is coupled to the described voltage end that connects altogether, the second source-drain electrode of described at least one auxiliary transistor is coupled to described at least one input/output port weld pad, the grid of described at least one auxiliary transistor couples a reversed-phase output of described at least one pull-up control circuit, wherein, the single spin-echo of the output signal of the output signal of the described reversed-phase output of described at least one pull-up control circuit and the output terminal of described specific pull-up control circuit.

22. liquid crystal displays as claimed in claim 21 and keyboard scan compatble circuit, is characterized in that, described liquid crystal display and keyboard scan compatble circuit be in order to capable the button of driving N row * M, and described liquid crystal display and keyboard scan compatble circuit comprise:

M input/output port weld pad, K input/output port weld pad is coupled between the first end and described input/output control circuit of the described button that K is capable;

N the first specific pull-up control circuit, wherein, described in each, the first specific pull-up control circuit comprises an input end, an output terminal and a reversed-phase output, wherein, the single spin-echo of the output signal of the output terminal of the output signal of the described reversed-phase output of described the first specific pull-up control circuit and described the first specific pull-up control circuit, described in each, the input end of the first specific pull-up control circuit is corresponding is coupled to described inner control logic circuit;

N the first auxiliary transistor, wherein, described N the first auxiliary transistor comprises a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the first source-drain electrode of described P the first auxiliary transistor receives described micro-processing power supply, the matrix utmost point of described P the first auxiliary transistor is coupled to the described voltage end that connects altogether, the second source-drain electrode of described P the first auxiliary transistor is coupled to P specific connect altogether/section weld pad, and the grid of described P auxiliary transistor couples the described reversed-phase output of P specific pull-up control circuit;

M the second specific pull-up control circuit, wherein, described in each, the second specific pull-up control circuit comprises an input end, an output terminal and a reversed-phase output, wherein, the single spin-echo of the output signal of the output terminal of the output signal of the described reversed-phase output of described the second specific pull-up control circuit and described the second specific pull-up control circuit, described in each, the input end of the second pull-up control circuit and described the second specific pull-up control circuit is corresponding is coupled to described input/output control circuit; And

M the second auxiliary transistor, wherein, described M the second auxiliary transistor comprises a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the first source-drain electrode of described T the second auxiliary transistor receives described micro-processing power supply, the matrix utmost point of described T auxiliary transistor is coupled to the described voltage end that connects altogether, the second source-drain electrode of described T auxiliary transistor is coupled to P specific connect altogether/section weld pad, the grid of described T auxiliary transistor couples the described reversed-phase output of P specific pull-up control circuit

Wherein, N, M, T and P are natural number, and 0 < P <=N and 0 < T <=M.

23. liquid crystal displays as claimed in claim 22 and keyboard scan compatble circuit, is characterized in that, more comprises:

Wherein, Q is natural number, and 0 < Q <=N.

24. liquid crystal displays as claimed in claim 22 and keyboard scan compatble circuit, is characterized in that, more comprises:

Wherein, Q is natural number, and 0 < Q <=N.

25. liquid crystal displays as claimed in claim 22 and keyboard scan compatble circuit, is characterized in that, the number of described input/output port weld pad is R, and described liquid crystal display and keyboard scan compatble circuit comprise:

R pull-up control circuit, wherein, described in each, pull-up control circuit comprises an input end, an output terminal and a reversed-phase output, wherein, the single spin-echo of the output signal of the output signal of the described reversed-phase output of described pull-up control circuit and the output terminal of described specific pull-up control circuit, described in each, the input end of pull-up control circuit is corresponding is coupled to described input/output control circuit; And

R auxiliary transistor, wherein, a described R auxiliary transistor comprises a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, the first source-drain electrode of described S auxiliary transistor receives described micro-processing power supply, the matrix utmost point of described S auxiliary transistor is coupled to the described voltage end that connects altogether, the second source-drain electrode of described S auxiliary transistor is coupled to S input/output port weld pad, the grid of described S auxiliary transistor couples the described reversed-phase output of S pull-up control circuit

Wherein, R and S are natural number, and 0 < S <=R.

26. 1 kinds of electronic products, is characterized in that, comprising:

One passive display panels;

At least one button;

One liquid crystal display and keyboard scan compatble circuit, comprising:

At least one pulling up transistor, wherein, described at least one pulling up transistor comprises respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, described at least one grid pulling up transistor couples the output terminal of described at least one pull-up control circuit, described at least one the first source-drain electrode pulling up transistor receives described micro-processing power supply, described at least one matrix utmost point pulling up transistor couples a lcd power source end of described passive display panels, described at least one the second source-drain electrode pulling up transistor is coupled to described at least one input/output port weld pad,

27. electronic products as claimed in claim 26, is characterized in that, described liquid crystal display and keyboard scan compatble circuit be in order to capable the button of driving N row * M, and described liquid crystal display and keyboard scan compatble circuit comprise:

M input/output port weld pad, K input/output port weld pad is coupled between the first end and a described M input/output control circuit of those buttons that K is capable;

M the second specific pull-up control circuit, wherein, described in each, the second specific pull-up control circuit comprises an input end, an output terminal and a reversed-phase output, wherein, the single spin-echo of the output signal of the output terminal of the output signal of the described reversed-phase output of described the second specific pull-up control circuit and described the second specific pull-up control circuit, described in each, the input end of the second pull-up control circuit and described specific pull-up control circuit is corresponding is coupled to described input/output control circuit; And

Wherein, N, M, T and P are natural number, and 0 < P <=N and 0 < T <=M.

28. electronic products as claimed in claim 27, is characterized in that, more comprise:

Wherein, Q is natural number, and 0 < Q <=N.

29. electronic products as claimed in claim 27, is characterized in that, more comprise:

Wherein, Q is natural number, and 0 < Q <=N.

30. electronic products as claimed in claim 27, is characterized in that, the number of described input/output port weld pad is R, and described liquid crystal display and keyboard scan compatble circuit comprise:

Wherein, R and S are natural number, and 0 < S <=R.

31. 1 kinds of liquid crystal displays and keyboard scan compatble circuit, is characterized in that, in order to drive a passive display panels in the liquid crystal drive time, and in a standby time, drive at least one button, this liquid crystal display and keyboard scan compatble circuit comprise:

At least one pull-up control circuit, wherein, described at least one pull-up control circuit comprises an input end and an output terminal, the input end of described at least one pull-up control circuit is corresponding is coupled to described input/output control circuit;

At least one pull-down control circuit, wherein, described at least one pull-down control circuit comprises an input end and an output terminal, the input end of described at least one pull-down control circuit is corresponding is coupled to described input/output control circuit;

At least one pulling up transistor, wherein, described at least one pulling up transistor comprises respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, described at least one grid pulling up transistor couples the output terminal of described at least one pull-up control circuit, described at least one the first source-drain electrode pulling up transistor receives described micro-processing power supply, and described at least one the second source-drain electrode pulling up transistor is coupled to described at least one input/output port weld pad;

At least one auxiliary switch, wherein, described at least one auxiliary switch comprises a first end, one second end, one the 3rd end and a control end, wherein, the first end of described at least one auxiliary switch receives described micro-processing power supply, the second end of described at least one auxiliary switch is coupled to described at least one matrix utmost point pulling up transistor, the control end of described at least one auxiliary switch is coupled to the output terminal of described at least one pull-up control circuit, the 3rd end of described at least one auxiliary switch couples the described lcd power source end of described passive display panels, wherein, when in described standby time, described pull-up control circuit is controlled described specific pulling up transistor during conducting, the second end conducting of the first end of described at least one auxiliary switch and described at least one auxiliary switch.

32. liquid crystal displays as claimed in claim 31 and keyboard scan compatble circuit, is characterized in that, described liquid crystal display and keyboard scan compatble circuit be in order to capable the button of driving N row * M, and described liquid crystal display and keyboard scan compatble circuit comprise:

N the first specific pull-up control circuit, wherein, described in each, the first specific pull-up control circuit comprises an input end and an output terminal, described in each, the input end of the first specific pull-up control circuit is corresponding is coupled to described inner control logic circuit;

N the first specific pulling up transistor, wherein, described N the first specific pulling up transistor comprises respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, described P the first specific grid pulling up transistor couples the output terminal of described P the first specific pull-up control circuit, described P the first specific the first source-drain electrode pulling up transistor receives described micro-processing power supply, described in described P the first specific the second source-drain electrode pulling up transistor is coupled to, couples described P specific connect altogether/section weld pad;

N the first auxiliary switch, wherein, described N the first auxiliary switch comprises a first end, one second end, one the 3rd end and a control end, wherein, the first end of described P the first auxiliary switch receives described micro-processing power supply, the second end of described P the first auxiliary switch is coupled to P the first specific matrix utmost point pulling up transistor, the 3rd end of described P auxiliary switch couples the described lcd power source end of described passive display panels, and the control end of described P auxiliary switch is coupled to the output terminal of P the first specific pull-up control circuit;

M the second specific pull-up control circuit, wherein, described in each, the second specific pull-up control circuit comprises an input end and an output terminal, described in each, the input end of the second specific pull-up control circuit is corresponding is coupled to described input/output control circuit;

M the second specific pulling up transistor, wherein, described M the second specific pulling up transistor comprises respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, described T the second specific grid pulling up transistor couples the output terminal of described T the second specific pull-up control circuit, described T the second specific the first source-drain electrode pulling up transistor receives described micro-processing power supply, described in described T the first specific the second source-drain electrode pulling up transistor is coupled to, couples described T input/output port weld pad;

M the second auxiliary switch, wherein, described N the second auxiliary switch comprises a first end, one second end, one the 3rd end and a control end, wherein, the first end of described T the second auxiliary switch receives described micro-processing power supply, the second end of described T the second auxiliary switch is coupled to T the second specific matrix utmost point pulling up transistor, the 3rd end of described T the second auxiliary switch couples the described lcd power source end of described passive display panels, the control end of described T auxiliary switch is coupled to the output terminal of T the second specific pull-up control circuit

Wherein, N, M, T and P are natural number, and 0 < P <=N and 0 < T <=M.

33. liquid crystal displays as claimed in claim 32 and keyboard scan compatble circuit, is characterized in that, more comprises:

Wherein, Q is natural number, and 0 < Q <=N.

34. liquid crystal displays as claimed in claim 32 and keyboard scan compatble circuit, is characterized in that, more comprises:

Wherein, Q is natural number, and 0 < Q <=N.

35. liquid crystal displays as claimed in claim 32 and keyboard scan compatble circuit, is characterized in that, the number of described input/output port weld pad is R, and described liquid crystal display and keyboard scan compatble circuit comprise:

R pull-up control circuit, wherein, described in each, pull-up control circuit comprises an input end and an output terminal, wherein, described in each, the input end of pull-up control circuit is corresponding is coupled to described input/output control circuit, and described in each, the output terminal of pull-up control circuit couples the corresponding grid pulling up transistor;

R pulls up transistor, wherein, described in each, pull up transistor and comprise respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, described S the grid pulling up transistor couples the output terminal of described S pull-up control circuit, described S the first source-drain electrode pulling up transistor receives described micro-processing power supply, and described S the second source-drain electrode pulling up transistor is coupled to described S input/output port weld pad; And

R auxiliary switch, wherein, a described R auxiliary switch comprises a first end, one second end, one the 3rd end and a control end, wherein, the second end of described S auxiliary switch be coupled to that S pulls up transistor the matrix utmost point, the 3rd end of described S auxiliary switch couples the described lcd power source end of described passive display panels, the control end of described S auxiliary switch is coupled to the output terminal of S pull-up control circuit, wherein, when in the described liquid crystal drive time, while pulling up transistor conducting described in described pull-up control circuit control, the 3rd end of described auxiliary switch and the second end conducting of described auxiliary switch, when in described standby time, while pulling up transistor conducting described in described pull-up control circuit control, the second end conducting of the first end of described auxiliary switch and described auxiliary switch,

Wherein, R and S are natural number, and 0 < S <=R.

36. 1 kinds of electronic products, is characterized in that, comprising:

One passive display panels;

At least one button;

One liquid crystal display and keyboard scan compatble circuit, comprising:

At least one pulling up transistor, wherein, described at least one pulling up transistor comprises respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, described at least one grid pulling up transistor couples the output terminal of described at least one pull-up control circuit, described at least one the first source-drain electrode pulling up transistor receives described micro-processing power supply, described in described at least one the second source-drain electrode pulling up transistor is coupled to, couples described at least one input/output port weld pad;

37. electronic products as claimed in claim 36, is characterized in that, described liquid crystal display and keyboard scan compatble circuit be in order to capable the button of driving N row * M, and described liquid crystal display and keyboard scan compatble circuit comprise:

M the second specific pulling up transistor, wherein, described M the second specific pulling up transistor comprises respectively a grid, one first source-drain electrode, one second source-drain electrode and a matrix utmost point, wherein, described T the second specific grid pulling up transistor couples the output terminal of described T the second specific pull-up control circuit, described T the second specific the first source-drain electrode pulling up transistor receives described micro-processing power supply, and described T the first specific the second source-drain electrode pulling up transistor is coupled to this and couples described T input/output port weld pad;

Wherein, N, M, T and P are natural number, and 0 < P <=N and 0 < T <=M.

38. electronic products as claimed in claim 37, is characterized in that, more comprise:

Wherein, Q is natural number, and 0 < Q <=N.

39. electronic products as claimed in claim 37, is characterized in that, more comprise:

Wherein, Q is natural number, and 0 < Q <=N.

40. electronic products as claimed in claim 37, is characterized in that, the number of described input/output port weld pad is R, and described liquid crystal display and keyboard scan compatble circuit comprise:

R auxiliary switch, wherein, a described R auxiliary switch comprises a first end, one second end, one the 3rd end and a control end, wherein, the second end of described S auxiliary switch be coupled to that S pulls up transistor the matrix utmost point, the 3rd end of described S auxiliary switch couples the described lcd power source end of described passive display panels, the control end of described S auxiliary switch is coupled to the output terminal of S pull-up control circuit, wherein, when in the described liquid crystal drive time, when this pull-up control circuit is controlled this and is pulled up transistor conducting, the 3rd end of described auxiliary switch and the second end conducting of described auxiliary switch, when in described standby time, while pulling up transistor conducting described in described pull-up control circuit control, the second end conducting of the first end of described auxiliary switch and described auxiliary switch,

Wherein, R and S are natural number, and 0 < S <=R.