CN101719045B

CN101719045B - Automatic correction method of touch panel

Info

Publication number: CN101719045B
Application number: CN2010101023604A
Authority: CN
Inventors: 刘杰; 杜小雷
Original assignee: Suzhou Pixcir Microelectronics Co Ltd
Current assignee: Suzhou Pixcir Microelectronics Co Ltd
Priority date: 2010-01-28
Filing date: 2010-01-28
Publication date: 2012-05-30
Anticipated expiration: 2030-01-28
Also published as: CN101719045A

Abstract

The invention relates to an automatic correction method of a touch panel, which is used for detecting the change of a noise value when around time is stable by utilizing the change of noise data on a time shaft and enabling a differential induction value to form a high peak and a low peak through an effective touch signal so as to achieve the purpose of automatic correction. The method for automatically correcting the touch panel overcomes the defects of a method for manually correcting the touch panel, not only has simple method and can automatically regulate the touch panel, but also can correct an external noise value in real time and continually change along with the change of an external environment, thereby being difficult to interfere by the external environment and having very strong anti-interference capacity.

Description

The automatic bearing calibration of contact panel

Technical field

The present invention relates to a kind of bearing calibration, refer in particular to a kind of automatic bearing calibration of touch panel.

Background technology

Along with high-speed development of science and technology, snafu variation has taken place in electronic product, along with the appearance of recent touch electronic product; The increasing people of receiving of touch-control product pursue; Not only it can save the space, be convenient for carrying, but and the user through finger or pointer etc. direct control just; Use comfortable, very convenient.For example, the common personal digital assistant (PDA) of existing market, touch-control class mobile phone, portable notebook computer or the like have all strengthened the input to touch technology, use so touch-control device must have more widely in every field in the future.

At present, capacitance type touch-control panel since wear-resistant, life-span long and on light loss and system behavio(u)r, have more advantage, so capacitance type touch-control panel has received pursuing of market recently; Various capacitance touching control screen products emerge one after another, thereby the principle of work of capacitance type touch-control panel generally is to come the capacitance variations of induction panel to judge the position and the action of finger through a touch-control chip, so just need know that panel is having no the original capacitance under the input state to do reference; Promptly do not having finger or other object touching state original capacitance value down as a reference, so just need a method of proofreading and correct panel, the method for present common correction panel all is a manual calibration; Promptly under the initial environment when having no the input media touching; Write into this influence value in the touch-control chip, but under initial environment, even without any input media; Also can receive numerous influences like external environments such as temperature, humidity; Be commonly referred to noise, so just there is instability in initial environment, in case initial environment changes like this; The operation of contact panel will be influenced, and normal condition can not be recovered.

Therefore need solve above problem for users provide a kind of easier method.

Summary of the invention

The actual technical matters to be solved of the present invention is the method how a kind of automatically calibrating contact panel is provided.

In order to realize above-mentioned purpose of the present invention, the invention provides a kind of automatic bearing calibration of contact panel, it may further comprise the steps: the effective touching signal that takes place on the detecting Trackpad; Utilize the variation of noise data on time shaft, judge effectively whether the touching signal makes the difference influence value form the oscillogram that has peak and ebb simultaneously; If form above-mentioned oscillogram, the NF that continues again relatively to form when constantly stablizing before and after peak and the ebb is big or small; If both are close, then store this noise figure constantly, as the numerical value of after this effectively touching the target signal filter noise.

Method from the NMO correction contact panel of the present invention; Overcome the method that conventional manual is proofreaied and correct panel; Not only method simple, can regulate touch panel automatically, and can proofread and correct the outside noise value in real time, can constantly change with the variation of external environment; So be not vulnerable to the interference of external environment, have very strong antijamming capability.

Description of drawings

Fig. 1 is the variation diagram that contact panel has no induction amount when importing;

Fig. 2 is the variation diagram of contact panel induction amount during according to existing differential capacitance;

Fig. 3 is based on the automatic timing induction of the present invention amount to scheme over time;

Fig. 4 is a kind of induction amount variation diagram of touching according to the present invention behind the Trackpad;

Fig. 5 is another induction amount variation diagram of touching according to the present invention behind the Trackpad.

Embodiment

Below in conjunction with accompanying drawing and embodiment the present invention is further described.

At present common inductance capacitance adopts the method for difference measurement, and so-called difference measurement is meant: after contact panel powered on, sweep trace began scanning; When having no the input media contact surface plate, the variation of whole touch panel capacitance is tending towards a steady state value, and is as shown in Figure 1; When any input equipment such as this panel of finger touches, this capacitance will change, after scanning for the first time; When scanning for the second time, two capacitances of same position have just formed a difference again, and so just having formed is just having, having negative capacitance; Promptly finally form minimum and maximum capacitance, thereby can judge the position of finger, as shown in Figure 2.

The mode of above-mentioned difference measurement capacitance, the method for just getting relative capacitance is through facts have proved; Have more intense antijamming capability, but when calibrating panel automatically, whether the relative electric capacity of this kind really is difficult to judge there are input media such as finger touches panel or noise arranged; Because when finger also touching receive the influence of inductance capacitance when promptly not being suspended in the top of panel, also can form a differential capacitance this moment; When finger really touches this panel; Can form a differential capacitance again, might be input in the chip in the panel by the influence value when pointing that practical touch is not to panel this moment, like this when finger is really touched this panel; Operation is just unstable, occurs variety of issue easily.

From the above; If want contact panel to write down differential capacitance value accurately, just need carry out from NMO correction contact panel, utilize the form of differential capacitance to carry out really having technological difficulties at present from NMO correction; Promptly in the different moment; The noise data value is in constantly changing under the different environment, wants these noises of filtering accurately, must proofread and correct these noise figures in real time.And can know by above-mentioned analysis, effectively touch signal can make the differential capacitance value form height peak oscillogram, utilize the variation of noise data on time shaft again, just can detect the variation of front and back noise figure, thereby reach purpose from NMO correction, below we specifically discuss.

Please refer to shown in Figure 3; At first we set up an original noise data and the coordinate system of time, though the influence value of original noise on different sweep traces vary, as far as any sweep trace; Over time; Its original NF is tending towards a steady state value, does not have obvious conversion, as among Fig. 3 from initial point zero beginning until t1 in the time period raw value be t1_data; As any touch object like finger after continue moving certain distance on the said Trackpad; Promptly point the instantaneous Trackpad that streaks; Influence value on the sweep trace that finger touches is crossed will change; This moment, the useful signal that detects will make influence value produce maximum, minimum influence value, as among Fig. 3 t2 constantly this touching signal intensity reach the maximal value t2_data of forward, t3 moment signal intensity reaches the maximal value t3_data of negative sense; Along with change of time, the influence value of this moment tends towards stability again at t4 constantly, promptly shows effective touching blackout then.At this moment; The size of comparing data t1_data and data t4_data if the difference between them is very little, promptly is no more than 5 percent under certain proportion; So just store this original noise figure constantly, as the raw value of after this effective touching target signal filter noise.And, then abandon storing the NF of this moment if the ratio of data t1_data and data t4_data surpasses 5 percent, so far just realized the purpose of real-time monitoring induced noise making effective touching signal more accurate when filtering noise.

, in the method for NMO correction contact panel, can sum up and draw by above-mentioned: at first need detect the effective touching signal that takes place on the Trackpad; Utilize the variation of noise data on time shaft then, judge effectively whether the touching signal makes the difference influence value form the oscillogram that has peak and ebb simultaneously; If form above-mentioned oscillogram, the NF that continues again relatively to form when constantly stablizing before and after peak and the ebb is big or small; At last, judge both numerical values recited,, then store this noise figure constantly, as the numerical value of after this effectively touching the target signal filter noise if both are close.

In above-mentioned difference measurement data; Constantly impact some differential comparators if effectively touch signal, promptly the user points the said Trackpad of touching of discontinuity, rather than instantaneous streaking; Raw data may form following two kinds of one of any situation so: perhaps have only crest; Perhaps have only trough, promptly perhaps have only maximum data, perhaps have only minimum data.Below we just specifically discuss the noise under the filtering both of these case how.

Please refer to Fig. 4 and shown in Figure 5, if behind the said Trackpad of touching of finger discontinuity, promptly be not the instantaneous said Trackpad that streaks, then the situation that crest perhaps has only trough only can appear in inductive waveform, promptly has only maximum data or minimum data.For both of these case, we abandon detecting, promptly not as the raw value of filtering noise.

In real system is used; In the process of NMO correction contact panel, the more than one group of difference raw data of possibility, but n group; And each group difference raw data all need be proofreaied and correct; Suppose that the correction of one group of difference raw data needs t second, the n group just needs n to multiply by the t time of second so, and being formulated is n*t second.If differential data is all proofreaied and correct then certainly will be made the total system overload each time, cause other incidents to be postponed to handle.Because the output result once of system will be postponed n*t second, certainly will influence the speed of total system operation like this, so system can not accepted.At this moment we can disassemble the original data set that need proofread and correct, and in system once effectively circulated, iff was proofreaied and correct one group of difference raw data, and the once effective round-robin that is brought by correction so just is t second time delay, has lacked n doubly than above-mentioned; If in system once effectively circulates, proofread and correct two groups of difference raw data, it is 2t second that the once effective round-robin that is brought by correction so postpones; Lacked you n/2 times than above-mentioned; By that analogy, up to finding system's acceptable equilibrium point, reach the dual needs of delay and efficient.

Claims

1. the automatic bearing calibration of a contact panel, it may further comprise the steps:

The effective touching signal that takes place on the detecting Trackpad;

Utilize the variation of noise data on time shaft, judge effectively whether the touching signal makes the difference influence value form the oscillogram that has peak and ebb simultaneously;

If form above-mentioned oscillogram, the NF that continues again relatively to form when constantly stablizing before and after peak and the ebb is big or small;

If both are close, promptly under certain proportion, be no more than 5 percent, then store this noise figure constantly, as the numerical value of after this effectively touching the target signal filter noise.

2. the method for claim 1 is characterized in that: if judging effective touching signal can not form the oscillogram that has peak and ebb simultaneously, then not as the raw value of filtering noise.

3. method as claimed in claim 2 is characterized in that: if judging effective touching signal only has the oscillogram on peak, then abandon the raw value as filtering noise.

4. method as claimed in claim 2 is characterized in that: if judge the oscillogram that effective touching signal only has ebb, then abandon the raw value as filtering noise.

5. the method for claim 1 is characterized in that: if it is bigger to compare between the NF size when constantly stablize before and after peak and the ebb difference, promptly under certain proportion above 5 percent, then abandon storing the noise figure in this moment.