CN101876872A - Image display system and control method for touch-control panel - Google Patents

1

10

100 capacitance type touch-

200

202

2022

208 charge-

2082

Noise suppresses

2084

2086

Switch

1, SW1 ', SW2, SW2 '

With reference to figure 1, it is

1 according to an embodiment of the invention, comprise have

100

10 of (for example liquid crystal indicator or OLED display device), particularly capacitance type touch-

200 is installed on the

100,

100 also comprises a power supply supply (figure do not show) for

200 runnings, and the image that the user can watch

100 to be provided by capacitance type touch-

200.

In present embodiment, the

10 with

100 can be embodied as mobile phone, digital camera, PDA(Personal Digital Assistant), notebook computer, desktop computer, TV, automobile-used display, aviation display, GPS (GPS) or portable digital video and audio CD disc (DVD) player.

Fig. 2 a shows the circuit of capacitance type touch-

200 according to an embodiment of the invention.In present embodiment, capacitance type touch-

200 comprises a plurality of

202 and treatment circuit 208.Wherein, each

202 also comprises a plurality of

2022, and each

2022 comprises a capacitor sensor Cs respectively, and the electrode of capacitor sensor Cs can be embodied as transparency electrode, its material can be indium tin oxide (Indium Tin Oxide is called for short ITO), and width is between 0.1mm～0.5mm, and transparency electrode also can be arbitrary shape except elongate in shape.For example pointed or pointer when touching when

2022, the capacitance among the capacitor sensor Cs changes.This part is known by those skilled in the art, repeats no more.

But it is noted that, have capacitor parasitics Cp between the common electrode PV of the electrode of

2022 and

100 or the electrode of

2022, and capacitor parasitics Cp produces when

200 is made and is arranged at

100, wherein, the capacitance of capacitor parasitics Cp is approximately fixed.Fig. 2 b is the synoptic diagram that concerns of the capacitance variation that area caused that touched by object under test according to

2022, and wherein, X-axis is represented capacitance, and Y-axis is represented the area that

2022 is touched.The increase of the area that is touched along with

2022, the capacitance of its capacitor sensor Cs also increase thereupon, and storable electric weight also changes thereupon.

208 also comprise charge-

2082,

2084, with comparator circuit 2086.According to the different function mode of (figure does not show) of sweep circuit in the

200, charge-

2082 can carry out charge and discharge to

2022, or in regular turn or simultaneously a plurality of

2022 is carried out charge and discharge.What deserves to be mentioned is that aforesaid capacitor parasitics Cp also can impact

2022, but shown in Fig. 2 b, the capacitance of capacitor parasitics Cp approximately is a definite value, can whether does not have touched and change along with

2022.

Charge-

2082 will provide a fixing charging voltage V, in order to

2022 is charged, and provide electric current I that a plurality of

2022 in

2022 or the

202 are discharged in regular turn or simultaneously, and when

208 and

2022 conductings, can measure the equivalent voltage of a plurality of

2022 in

2022 or the

202 in node A, and when

2022 is touched by object under test, the variation of the capacitance of capacitor sensor Cs will influence the equivalent voltage VA of node A.

2084 and comprises sampling capacitor device Cc, when

2022 discharges with charge-

2082 conductings, the electric weight that the

2022 that is used for sampling capacitor device Cc is flowed out, and the capacitance or the capacitance variation of Measurement of

2022 whereby; Or in other embodiments, when a plurality of capacitor modules in the

202 2022 and charge-

2082 in regular turn or conducting simultaneously and when discharging, sampling capacitor device Cc is used for the electric weight that one or

2022 of the bill of store is flowed out, and measures the capacitance or the capacitance variation of single or a plurality of

2022 whereby.

As previously mentioned,

2022 can contain capacitor parasitics Cp inevitably, and capacitor parasitics Cp is formed with respect to the common electrode PV of

100, and when common electrode PV has noise, the electric weight that will make

2022 and sampling capacitor device Cc store all is subjected to the influence of noise, and the capacitance of Measurement of

2022 exactly.Therefore, in the present embodiment, the end of sampling capacitor device Cc is connected with one or

2022, and the other end of sampling capacitor device Cc then is connected with the common electrode PV of display device 100.As shown in the figure, sampling capacitor device Cc two ends all can be subjected to the influence of common electrode PV simultaneously and mutually offset, therefore when equivalent voltage VA was subjected to influencing of common electrode PV noise, sampling capacitor device Cc still can correctly measure the electric weight that

2022 is flowed out.

Fig. 2 c shows according to an embodiment of the invention, and noise suppresses circuit 2084.

2084 comprise a sampling capacitor device Cc, first group of

1 and SW1 ', with second group of switch SW 2 and SW2 '.First group of

1 and SW1 ' synchronous operation, wherein,

1 is arranged between sampling capacitor device Cc and the

2022, and switch SW 1 ' be arranged on sampling capacitor device Cc and jointly between the electrode PV.Second group of switch SW 2 and SW2 ' synchronous operation, wherein, switch SW 2 is arranged between sampling capacitor device Cc and the ground connection, and switch SW 2 ' be arranged between sampling capacitor device Cc and the comparator circuit 2086.In addition, first group of

1 and SW1 ' and second group of switch SW 2 and the anti-phase running of SW2 '.

Preferably, first group of

1 and SW1 ' should be according to opening or close from the first clock signal CLK1 of

100, and second group of switch SW 2 and SW2 ' should be according to opening or close from the second clock signal CLK2 of display device 100.Among this embodiment, first group of

1 can be embodied as identical n type or the electric crystal of p type with second group of switch SW 2 with SW2 ' with SW1 ', and the first clock signal CLK1 and the second clock signal CLK2 can be anti-phase clock signal, if and first group of

1 is embodied as opposite n type or the electric crystal of p type with second group of switch SW 2 with SW2 ' with SW1 ', then the first clock signal CLK1 and the second clock signal CLK2 are the clock signal of homophase.

Below further specify the running that noise suppresses circuit 2084.In the embodiment of Fig. 2 c, first group of

1 all is embodied as n type electric crystal with second group of switch SW 2 with SW2 ' with SW1 ', and the first clock signal CLK1 and the second clock signal CLK2 are anti-phase clock signal.At first, in the phase one, shown in Fig. 2 c left side, first group of

1 is unlatching with SW1 ', second group of switch SW 2 and SW2 ' are for closing, this moment, sampling capacitor device Cc was electrically connected

2022 and common electrode PV, the electric weight that 2022 discharges of receiving condenser module are flowed out, and because of sampling capacitor device Cc one end is connected with common electrode PV, therefore as discussed previously, even can being subjected to the noise that common electrode PV had because of the

2022 of discharge, the equivalent voltage VA of node A influences, this noise can appear at the two ends of sampling capacitor device Cc simultaneously and mutually offset, and can not influence the electric weight that sampling capacitor device Cc is received, so the formed voltage Vs of sampling capacitor device Cc can correctly react the capacitance of

2022.

And in next stage, shown in Fig. 2 c right side, when first group of

1 and SW1 ' when closing, second group of switch SW 2 is unlatching with SW2 ', this moment, sampling capacitor device Cc was electrically connected

2086 and ground connection, and the stored voltage Vs of sampling capacitor device Cc will be received from Node B by

2086 in previous stage, and further relatively this a voltage Vs and a reference voltage Vref, and produces output signal Vc.About this part, will be illustrated in conjunction with Fig. 2 d subsequently.

Shown in Fig. 2 d,

2086 can comprise operational amplifier OP_AMP and integrating condenser Cf, in order to comparative voltage Vs and reference voltage Vref, and, produce output signal Vc and give follow-up treatment circuit (not shown) according to the comparative result of voltage Vs and reference voltage

2086 also comprises low-pass filter LPF, the noise of following reference voltage Vref to be produced in transmission course in order to filtering.Preferably, as voltage Vs during less than reference voltage Vref, then

2086 produces output signal Vc, changes with the capacitance of

2022, represents

2022 to be subjected to user's contact wittingly.What deserves to be mentioned is that as discussed previously, according to different scan modes, sampling capacitor device Cc can be used to the electric weight that one or

2022 of the bill of store is flowed out, relatively sampling capacitor device Cc estimate the voltage Vs that will form may be also difference to some extent.For " storing the electric weight that

2022 is flowed out " or the different demands of " storing the electric weight that a plurality of

2022 are flowed out in the

202 ", can be according to the number of

2022, adopt different sampling capacitor device Cc,

2086, or adopt different reference voltage Vref.

Fig. 2 e is the time sequential routine figure according to the contact panel in the embodiment of the invention, and in conjunction with Fig. 2 a and Fig. 2 c explanation the present invention, and hypothesis does not have the noise of common voltage PV to produce.With

2022, at first, charge-

2082 provides charging voltage V to

2022 chargings, and then charge-

2082 discharges to

2022 again, and has equivalent voltage VA at node A.Discharge and recharge the stage at this, the first clock signal CLK1 opens first group of

1 and SW1 ', and the second clock signal CLK2 closes second group of switch SW 2 and SW2 ', makes sampling capacitor device Cc charge with equivalent voltage VA, and has sampling voltage Vs.And after

2022 discharges and sampling capacitor device Cc charging end, the first clock signal CLK1 closes first group of

1 and SW1 ', and the second clock signal CLK2 opens second group of switch SW 2 and SW2 ', make

2086 receive sampling voltage Vs and comparison sampling voltage Vs and reference voltage Vref, and produce output signal Vc according to the comparative result of sampling voltage Vs and reference voltage Vref.As discussed previously, when object under test did not touch

200,

2022 only had stray capacitance Cp; When object under test touched

200,

2022 had stray capacitance Cp and sense capacitance Cs in parallel, so total capacitance value can increase (as shown in Fig. 2 b).In one embodiment, charge-

2082 provides fixing electric current, and its discharge time is also fixing, therefore the electric weight that flows out from

2022 is fixing relatively, therefore when the capacitance of

2022 increased, sampling voltage Vs can reduce, as shown in Fig. 2 e.When sampling voltage Vs is lower than default reference voltage Vref,

2086 outputs one low-voltage is as output signal Vc.Otherwise, if

2022 is not subjected to user's contact, its capacitance does not change, and correspondingly the sampling voltage Vs of sampling capacitor device does not increase yet, and be higher than default reference voltage Vref, so

2086 outputs one high voltage is as output signal Vc.And follow-up treatment circuit (not shown) can be judged the contact the

200 whether user has a mind to according to the voltage of output signal Vc again, and whether decision produces an input instruction.

Though more than explanation is illustrated with

2022, also can be applicable to a plurality of

2022 in the capacitor group 202.If a plurality of

2022 together discharge in this

202, the running of then follow-up first group of

1 and SW1 ', second group of switch SW 2 and SW2 ' and

2086 all as hereinbefore, only noting to need to adopt different sampling capacitor device Cc and different reference voltage Vref.If a plurality of

2022 discharge in regular turn in this

202, then follow-up first group of

1 carried out with corresponding each

2022 of the running of SW2 ' and

2086 in regular turn with SW1 ', second group of switch SW 2, repeats no more.

1. an image display system comprises a display device, and described display device comprises a capacitance type touch-control panel and a power supply supply, and wherein, described display device has community electrode, and described contact panel comprises:

One capacitor sensor module connects described common electrode, and the capacitance of described capacitor sensor module is variable; And

One sampling capacitor device, described sampling capacitor device optionally is electrically connected described capacitor sensor module and described common electrode.

2. image display system according to claim 1, wherein, described contact panel also comprises a comparator circuit, optionally connect described sampling capacitor device, wherein, when described sampling capacitor device is not electrically connected described capacitor sensor module and described common electrode, the voltage of the more described sampling capacitor device of described comparator circuit and a reference voltage, and produce an output signal.

3. image display system according to claim 1, wherein, described contact panel also comprises:

First group of switch is arranged between described sampling capacitor device and the described capacitor sensor module and between described sampling capacitor device and the described common electrode; And

Second group of switch is arranged between described sampling capacitor device and the described comparator circuit and between described sampling capacitor device and the ground connection, and with described first group of switch inverse running.

4. image display system according to claim 3, wherein, described first group of switch opens or cuts out according to first clock signal, and described second group of switch opens or cuts out according to second clock signal.

5. image display system according to claim 1, wherein, described contact panel also comprises a charge-discharge circuit, and described capacitor sensor module is discharged and recharged;

Wherein, when described capacitor sensor module was discharged, described sampling capacitor device was electrically connected described capacitor sensor module and described common electrode.

6. image display system according to claim 1, also comprise an electronic installation, described electronic installation comprises described display device, and described electronic installation is a mobile phone, a digital camera, a personal digital assistant, a notebook computer, a desktop computer, a TV, a GPS, an automobile-used display, an aviation display, a digital frame or a Portable DVD projector.

7. an image display system comprises a display device, and described display device comprises a capacitance type touch-control panel and a power supply supply, and wherein, described display device has community electrode, and described contact panel comprises:

One capacitor group, described capacitor group comprises:

The first capacitor sensor module connects described common electrode, and the capacitance of the described first capacitor sensor module is variable; And

The second capacitor sensor module connects described common electrode, and the capacitance of the described second capacitor sensor module is variable; And

The sampling capacitor device, described sampling capacitor device optionally is electrically connected described capacitor group and described common electrode.

8. image display system according to claim 7, wherein, when described sampling capacitor device was electrically connected described capacitor group, described sampling capacitor device was electrically connected described first capacitor sensor module and the described second capacitor sensor module in regular turn.

9. image display system according to claim 7, wherein, when described sampling capacitor device was electrically connected described capacitor group, described sampling capacitor device was electrically connected described first capacitor sensor module and the described second capacitor sensor module simultaneously.

10. control method for touch-control panel, be applied to be incorporated into the capacitance type touch-control panel in the display device, described display device has community electrode, described contact panel comprises a capacitor sensor module and a sampling capacitor device, described capacitor sensor module connects described common electrode, and the capacitance of described capacitor sensor module is variable, and described method comprises:

(a) described capacitor sensor is charged;

(b) described capacitor sensor is discharged; And

(c) when described capacitor sensor module is discharged, described sampling capacitor device is electrically connected with described capacitor sensor module and described common electrode.

11. method according to claim 10 also comprises:

(d) after described capacitor sensor module discharge finishes, with described sampling capacitor device and described capacitor sensor module and the insulation of described common electrode; And

(e) voltage of more described sampling capacitor device and a reference voltage, and produce an output signal.

12. method according to claim 11, described contact panel also comprises one first group of switch and one second group of switch, described first group of switch is arranged between described sampling capacitor device and the described capacitor sensor module and between described sampling capacitor device and the described common electrode, and described second group of switch is arranged between described sampling capacitor device and the described comparator circuit and between described sampling capacitor device and the ground connection;

Wherein, step (c) also comprises: open described first group of switch with one first clock signal, and close described second group of switch with one second clock signal, described first clock signal and described second clock signal are anti-phase; And

Wherein, step (d) also comprises: close described first group of switch with described first clock signal, and open described second group of switch with described second clock signal.