CN2788224Y

CN2788224Y - Circuit wiring structure of display screen drive module and liquid crystal display screen

Info

Publication number: CN2788224Y
Application number: CN 200420060509
Authority: CN
Inventors: 马红旭
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2004-07-27
Filing date: 2004-07-27
Publication date: 2006-06-14
Anticipated expiration: 2014-07-27

Abstract

The utility model discloses a circuit wiring structure of a display screen drive module and a liquid crystal display screen. The utility model comprises a base plate and a display screen drive module positioned on the base plate, wherein the display screen drive module comprises an RAM, other logic circuits and a voltage regulating circuit which provides driving voltage for a display screen, and two power input ends of the display screen drive module are respectively connected with an external circuit through two groups of running cables on the base plate. At least one power input end of the voltage regulating circuit is used for leading a running cable connected with the external circuit and running cables used for being connected with the external circuit at corresponding power input ends of the RAM and other logic circuits to be separated and be independently arranged on the base plate. The utility model leads the access frequency of the RAM not to influence a voltage times dividing circuit part, the driving voltage is stabilized, and the displaying quality is improved.

Description

A kind of wiring structure and LCDs of display screen driver module

[technical field]

The utility model relates to a kind of display screen, relates in particular to the wiring structure of display screen driver module and utilizes the LCDs of this wire structures.

[background technology]

LCD (LCD) needs a more stable driving voltage Vop, promptly can only allow Vop to float within the specific limits, and the domain of walker of general driving voltage is decided to be Vop ± 0.2V.But be subjected to the influence of peripheral circuit, certain fluctuation can appear in Vop, causes DRIVER IC (drive integrated circult) that the driving force of LCD is reduced, thereby display effect is reduced, color distortion for example, and contrast changes, even can not normally show.In the market the STN-LCD (Supertwist liquid crystal display) that uses of mobile phone from black and white STN-LCD to colored STN-LCD transition, the information capacity of colored STN-LCD is generally all bigger, this just requires the dot matrix quantity of display bigger, thereby the scan electrode number of display is also just many, and the fashion trend on the mobile phone market is a 128-240 scan electrode at present.Along with increasing of scan electrode, because its information capacity is big, the LCD static current of lcd increases accordingly, be easy to cause the driving voltage Vop of DRIVER IC output to change in a big way, thereby it is bad to cause LCD to show.In order to address this problem, usually the way of producer is the consistance of the threshold voltage vt h of control LCD, this helps improving the display quality of LCD to a certain extent, but experiment is found when MCU is higher to the access frequency of LCD module, the output voltage of DRIVER IC is that the drift of driving voltage Vop is bigger, domain of walker is Vop ± 0.5V, and just great changes will take place to show contrast like this, shows very light or shows dense.Cause LCD to show bad true cause so the drift of driving voltage is only, the threshold voltage vt h that improves LCD can not fundamentally control the consistance of the driving voltage of LCD module effectively.

[summary of the invention]

Fundamental purpose of the present utility model is exactly in order to solve the problem of lcd drive voltage drift in the prior art, a kind of LCDs of wire structures and a kind of this wire structures of application of display screen driver module to be provided, having reduced the range of drift of driving voltage.

For achieving the above object, the utility model proposes a kind of wiring structure of display screen driver module, comprise substrate and the display screen driver module that is positioned on the substrate, described display screen driver module includes RAM and other logical circuit and the voltage-regulating circuit of driving voltage is provided for display screen, two power inputs of described display screen driver module are used for linking to each other with external circuits by two groups of cablings on the substrate respectively, and the cabling that at least one power input of described voltage-regulating circuit is used for linking to each other with external circuits separates and separate cabling on substrate with the cabling that the corresponding power input of described RAM and other logical circuit is used for linking to each other with external circuits.

Common circuit all can have two power input terminals, and one is the supply voltage input end; Another is a ground terminal.The power input of voltage-regulating circuit described in the utility model comprises supply voltage input end and earth terminal, the cabling that can be supply voltage input end and external circuits separates with RAM and the corresponding cabling of other logical circuit, the cabling that also can be earth terminal and external circuits separates with RAM and the corresponding cabling of other logical circuit, can also be that the cabling of two power inputs and external circuits separates with RAM and the corresponding cabling of other logical circuit.

First cabling 21 that is used for linking to each other with external circuits as the earth terminal VSS2 in the power input of voltage-regulating circuit separates with the 3rd cabling 11 that the earth terminal VSS1 of described RAM and other logical circuit is used for linking to each other with external circuits and on substrate during separate cabling, the width L1 of described first cabling 21 is greater than the width of the 3rd cabling 11.

The 4th cabling 12 that second cabling 22 that is used for linking to each other with external circuits as the supply voltage input end VDD2 in the power input of described voltage-regulating circuit and the supply voltage input end VDD1 of described RAM and other logical circuit are used for linking to each other with external circuits separates and on substrate during separate cabling, the width of described second cabling 22 is greater than the width of the 4th cabling 12.

Described voltage-regulating circuit is the multiplication of voltage bleeder circuit.

Know that by Fig. 1 driving voltage Vop is by the dividing potential drop acquisition again after power input VDD2 is boosted of multiplication of voltage bleeder circuit.And all hot ends of DRIVER IC and earthing potential all will be by the acquisitions that is connected with external circuits FPC (flexible circuit board) of the ITO on the substrate (indium tin oxide, a kind of transparent conductive materials) cabling, and the ITO cabling has certain ITO and walks line resistance 1.Existing DRIVER IC interface (interface) design is that the RAM of DRIVER IC and the earth terminal VSS1 of other logical circuit are linked to each other with external FPC by same ITO cabling with the earth terminal VSS2 of multiplication of voltage bleeder circuit and other mimic channel (not shown), as shown in Figure 2.The edge of label 3 expression glass substrates among Fig. 2, label 4 is FPC crimping district, label 5 is the edge of DRIVER IC.Because of the ITO cabling is the bigger conductor of a kind of resistivity, along with increasing of scan electrode, MCU increases the frequency of carrying out exchanges data between the RAM of DRIVER IC, the frequency variation scope also increases, the static current of lcd of LCD and DRIVER IC is along with to the increase of RAM access frequency and corresponding increase, pressure drop above the ITO cabling of connection earth terminal VSS also can increase, thereby causes the outputting drive voltage Vop after the DRIVER IC multiplication of voltage dividing potential drop to reduce.Figure 3 shows that experiment driving voltage Vop drop-out value of gained and ITO walk the corresponding relation between line resistance and the RAM access frequency, horizontal ordinate is that ITO walks line resistance, ordinate is a driving voltage Vop drop-out value, as can be seen, line resistance is big more if ITO walks, the RAM access frequency is high more then cause driving voltage Vop drop-out value bigger.And walk under the constant situation of line resistance at ITO, the RAM access frequency becomes main influence to the influence of driving voltage Vop.So the present invention separates the earth terminal of the earth terminal of multiplication of voltage bleeder circuit and the ITO cabling between the FPC and RAM and other logical circuit and ITO cabling between the FPC, makes the RAM access frequency no longer influence multiplication of voltage bleeder circuit part.But two the ITO cabling is separately on substrate during independent cabling, owing to be subjected to the influence of cabling space, every ITO trace width can be when being combined into a cabling originally narrow, because ITO walks line resistance and trace width is inversely proportional to, so ITO walks line resistance will be bigger than original change, so change in order to reduce this, when design, make the earth terminal of multiplication of voltage bleeder circuit and the ITO trace width between the FPC greater than the earth terminal of RAM and other logical circuit and the ITO trace width between the FPC.And, further reduce ITO and walk line resistance by selecting suitable ITO square resistance.If but only walk line resistance by selecting suitable ITO square resistance to reduce ITO, thus reduce the drift of driving voltage Vop, though produce effect, can't avoid of the influence of RAM access frequency to the drift of driving voltage Vop.

Same existing DRIVER IC interface (interface) design links to each other the RAM of DRIVER IC and the supply voltage input end VDD1 of other logical circuit by same ITO cabling with the supply voltage input end VDD2 of multiplication of voltage bleeder circuit with external FPC, pressure drop above the ITO cabling that connects power input VDD is increased, thereby the actual power voltage that the multiplication of voltage bleeder circuit is experienced descends, and then causes the outputting drive voltage Vop after the DRIVER IC multiplication of voltage dividing potential drop to reduce.So also can being used for the supply voltage input end of described multiplication of voltage bleeder circuit the 4th cabling 12 that the supply voltage input end of second cabling 22 that links to each other with external FPC and described RAM and other logical circuit is used for linking to each other with external FPC, separates and separate cabling on substrate the utility model.The width of described second cabling 22 is greater than the width of the 4th cabling 12.The power input of multiplication of voltage bleeder circuit and the ITO cabling between the FPC also no longer are subjected to the influence of RAM access frequency like this, have further improved the drift of driving voltage Vop.

For achieving the above object, the utility model proposes a kind of LCDs, comprise substrate and the display screen driver module that is positioned on the substrate, described display screen driver module includes RAM and other logical circuit and the voltage-regulating circuit of driving voltage is provided for display screen, two power inputs of described display screen driver module are used for linking to each other with external circuits by two groups of cablings on the substrate respectively, and the cabling that at least one power input of described voltage-regulating circuit is used for linking to each other with external circuits separates and separate cabling on substrate with the cabling that the corresponding power input of described RAM and other logical circuit is used for linking to each other with external circuits.

The beneficial effects of the utility model are: 1) because the earth terminal of multiplication of voltage bleeder circuit and earth terminal to the ITO branch of FPC of RAM and other logical circuit are opened cabling, make the ITO cabling pressure drop of multiplication of voltage bleeder circuit ground wire no longer be subjected to the influence of RAM access frequency, thereby reduced the drift of driving voltage Vop.2) the supply voltage input end of multiplication of voltage bleeder circuit to the ITO cabling of FPC and other ITO cablings are all separated independently on substrate, connect up, the actual voltage that obtains of multiplication of voltage bleeder circuit can not reduced because of the rising of RAM access frequency, thereby driving voltage Vop also can not reduced because of the rising of RAM access frequency.3) two power inputs of multiplication of voltage bleeder circuit are separated to the ITO cabling of the FPC corresponding ITO cabling with RAM and other logical circuit, make the multiplication of voltage bleeder circuit not be subjected to the influence of RAM access frequency fully, thereby the drift of driving voltage Vop is further improved, thereby the display quality of LCD is provided.4) eliminated of the influence of RAM access frequency, for further providing precondition from reducing to walk the drift that line resistance improves driving voltage Vop to driving voltage Vop.

Feature of the present utility model and advantage will be elaborated in conjunction with the accompanying drawings by embodiment.

[description of drawings]

Fig. 1 represents that ITO walks the influence synoptic diagram of line resistance to driving voltage Vop in the prior art;

Fig. 2 represents ITO wire bond composition of the prior art;

Fig. 3 represents that Vop and ITO walk the graph of a relation of line resistance and RAM access frequency;

Fig. 4 represents the ITO wire bond composition of a kind of embodiment of the present utility model;

Fig. 5 represents the ITO wire bond composition of another embodiment of the present utility model.

[embodiment]

Embodiment one: the wiring structure of driver module of the present utility model can be used for the design of display screen, as shown in Figure 4, be applied to the design of colored stn liquid crystal display screen for the utility model, dot matrix is 128*128, DUTY=1/128, BAIS=1/12, DRIVER IC are PCF8833, DRIVER IC is positioned at the non-display area of LCDs, and vertical with SEG line (signal electrode).First cabling 21 that the earth terminal VSS2 of described multiplication of voltage bleeder circuit is used for linking to each other with external FPC separates and separate cabling on substrate with the 3rd cabling 11 that the earth terminal VSS1 of described RAM and other logical circuit is used for linking to each other with external FPC, and the width state L1 of first cabling 21 is greater than the width of the 3rd cabling 11, because walking the width of line resistance and cabling is inversely proportional to, make two cablings separately, then the width of every cabling must be less than the width of former cabling, if make the width of first cabling 21 account for the major part of former trace width, can reduce it and walk the variation that line resistance causes owing to the variation of trace width, by selecting suitable square resistance for use, then can make cabling resistance constant or reduce.Simultaneously the supply voltage input end VDD1 of the supply voltage input end VDD2 of described multiplication of voltage bleeder circuit second cabling 22 that is used for linking to each other and described RAM and other logical circuit the 4th cabling 12 that is used for linking to each other with external FPC with external FPC separate and on substrate separate cabling, and the width L2 of second cabling 22 is greater than the width of the 4th cabling 12.First cabling 21, second cabling 22, the 3rd cabling 11 and the 4th cabling 12 extend to the glass edge 3 of glass substrate respectively by the source, limit 5 of DRIVER IC, carry out crimping at FPC crimping district 4 (dash area among the figure) with external FPC.

Embodiment two: as shown in Figure 5, different with embodiment one is because DRIVER IC PCF8833 separates the supply voltage input end VDD2 of multiplication of voltage bleeder circuit and the supply voltage input end VDD3 of other mimic channel, so the 5th cabling 23 that the supply voltage input end VDD3 of second cabling 22 that present embodiment also is used for the supply voltage input end VDD2 of multiplication of voltage bleeder circuit to link to each other with external FPC and other mimic channel is used for linking to each other with external FPC separates and separate cabling on substrate.Selecting the ITO square resistance is 5 Ω/, and what make the 3rd cabling 11, first cabling 21 walks line resistance less than 10 ohm.The 4th cabling 12, second cabling 22 and the 5th cabling 23 walk line resistance less than 20 ohm.

Embodiment three: different with embodiment two is, and to select the ITO square resistance be 10 Ω/ or bigger, and at this moment the 3rd cabling 11, first cabling 21 walks line resistance greater than 10 ohm.The 4th cabling 12, second cabling 22 and the 5th cabling 23 walk line resistance greater than 20 ohm.

Be illustrated in figure 2 as the existing wire structures of STN-LCD, the dot matrix of STN-LCD is 128*128, DUTY=1/128, and BAIS=1/12, DRIVER IC:PCF8833, ITO square resistance are 10 Ω/.VDD2 is the supply voltage input end of multiplication of voltage bleeder circuit, VDD3 is the supply voltage input end of other mimic channel, VDD1 is the supply voltage input end of RAM and other logical circuit, VSS2 is the earth terminal of multiplication of voltage bleeder circuit and other mimic channel, and VSS1 is the earth terminal of RAM and other logical circuit.

When interface designed, the ITO cabling that VSS1, VSS2 link to each other with external FPC was not separated, and it walks line resistance greater than 10 ohm, and the ITO cabling that VDD1, VDD2, VDD3 link to each other with external FPC is also not separated, and it walks line resistance greater than 20 ohm.

Know that by the experimental data shown in the table 1 drift of the driving voltage Vop of embodiment two and embodiment three is littler than the drift of the driving voltage of existing wire structures shown in Figure 2, and ITO to walk line resistance more little, the drift of driving voltage Vop is also more little.

Table 1

	Embodiment two	Embodiment three	Prior art
	Embodiment two	Embodiment three	Prior art	Test quantity (PCS)	10000	10000	10000
Vop scope (V)	16.0±0.1	16.0±0.3	16.0±0.5	Test quantity (PCS)	10000	10000	10000

Claims

1. the wiring structure of a display screen driver module, comprise substrate and the display screen driver module that is positioned on the substrate, described display screen driver module includes RAM and other logical circuit and the voltage-regulating circuit of driving voltage is provided for display screen, two power inputs of described display screen driver module are used for linking to each other with external circuits by two groups of cablings on the substrate respectively, it is characterized in that: the cabling that at least one power input of described voltage-regulating circuit is used for linking to each other with external circuits separates and separate cabling on substrate with the cabling that the corresponding power input of described RAM and other logical circuit is used for linking to each other with external circuits.

2. the wiring structure of display screen driver module as claimed in claim 1, it is characterized in that: first cabling (21) that the earth terminal in the power input of described voltage-regulating circuit (VSS2) is used for linking to each other with external circuits separate with the 3rd cabling (11) that the earth terminal (VSS1) of described RAM and other logical circuit is used for linking to each other with external circuits and on substrate separate cabling, the width of described first cabling (21) is greater than the width of the 3rd cabling (11).

3. the wiring structure of display screen driver module as claimed in claim 1 or 2, it is characterized in that: the 4th cabling (12) that second cabling (22) that the supply voltage input end (VDD2) in the power input of described voltage-regulating circuit is used for linking to each other with external circuits and the supply voltage input end (VDD1) of described RAM and other logical circuit are used for linking to each other with external circuits separate and on substrate separate cabling, the width of described second cabling (22) is greater than the width of the 4th cabling (12).

4. the wiring structure of display screen driver module as claimed in claim 3, it is characterized in that: described display screen driver module also comprises other mimic channel, and described second cabling (22) separates and separate cabling on substrate with the 5th cabling (23) that the supply voltage input end (VDD3) of other mimic channel is used for linking to each other with external circuits.

5. the wiring structure of display screen driver module as claimed in claim 1 is characterized in that: described voltage-regulating circuit is the multiplication of voltage bleeder circuit.

6. LCDs, comprise substrate and the display screen driver module that is positioned on the substrate, described display screen driver module includes RAM and other logical circuit and the voltage-regulating circuit of driving voltage is provided for display screen, two power inputs of described display screen driver module are used for linking to each other with external circuits by two groups of cablings on the substrate respectively, it is characterized in that: the cabling that at least one power input of described voltage-regulating circuit is used for linking to each other with external circuits separates and separate cabling on substrate with the cabling that the corresponding power input of described RAM and other logical circuit is used for linking to each other with external circuits.

7. LCDs as claimed in claim 6, it is characterized in that: first cabling (21) that the earth terminal in the power input of described voltage-regulating circuit (VSS2) is used for linking to each other with external circuits separate with the 3rd cabling (11) that the earth terminal (VSS1) of described RAM and other logical circuit is used for linking to each other with external circuits and on substrate separate cabling, the width of described first cabling (21) is greater than the width of the 3rd cabling (11).

8. as claim 6 or 7 described LCDs, it is characterized in that: the 4th cabling (12) that second cabling (22) that the supply voltage input end (VDD2) in the power input of described voltage-regulating circuit is used for linking to each other with external circuits and the supply voltage input end (VDD1) of described RAM and other logical circuit are used for linking to each other with external circuits separate and on substrate separate cabling, the width of described second cabling (22) is greater than the width of the 4th cabling (12).

9. LCDs as claimed in claim 8, it is characterized in that: described display screen driver module also comprises other mimic channel, and described second cabling (22) separates and separate cabling on substrate with the 5th cabling (23) that the supply voltage input end (VDD3) of other mimic channel is used for linking to each other with external circuits.

10. LCDs as claimed in claim 6 is characterized in that: described voltage-regulating circuit is the multiplication of voltage bleeder circuit.