CN100343792C - Method for operating touch-screen system - Google Patents
Method for operating touch-screen system Download PDFInfo
- Publication number
- CN100343792C CN100343792C CNB200510085929XA CN200510085929A CN100343792C CN 100343792 C CN100343792 C CN 100343792C CN B200510085929X A CNB200510085929X A CN B200510085929XA CN 200510085929 A CN200510085929 A CN 200510085929A CN 100343792 C CN100343792 C CN 100343792C
- Authority
- CN
- China
- Prior art keywords
- frequency
- touch
- controller
- screen
- touch screen
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Position Input By Displaying (AREA)
- Electronic Switches (AREA)
Abstract
The present invention provides a method and a device which adapt an acoustic touch screen to a specific touch screen and are required by working frequency. An adaptive controller can utilize a lookup table to obtain expected output frequency or can adopt multistep processing, wherein the frequency requirement of the touch screen is determined; then, the frequency characteristic of a pulse series or the center frequency of a receiver circuit is adjusted, or both the frequency characteristic of the pulse series and the center frequency of the receiver circuit are adjusted. In an embodiment, the adaptive controllers compensates the mismatch error of global frequency; in the embodiment, a digital multiplier is adopted to modify the output of a crystal reference oscillator. The output of the reference oscillator is adopted to control the frequency of signals from a receiving transducer and/or to generate the expected frequency of an audio pulse series which is sent to the transmitting transducer. In another embodiment which is designed for simultaneously compensating global frequency variation and local frequency variation, the adaptive controller adopts a digital signal processor which defines specific center frequency best according to signal delay variation according to a correction value contained in a memory so that the variation caused by local variation in a sound wave reflection array is considered. In next embodiment, a non-crystal local oscillator is adopted to provide reference signals in the adaptive controller. Because the oscillator is used, the controller can be minimized to the sufficient extent that the controller can be directly installed on a base plate of a touch screen. A feedback loop is adopted to compensate the drift of the oscillator. A frequency discriminator circuit determines the deviation degree with the expected frequency. The output of the frequency discriminator is utilized to adjust the frequency of the local oscillator so that the.
Description
Technical field
The present invention relates generally to touch-screen, more particularly, relate to the frequency of adjusting touch screen controller, so that make the method and apparatus of the concrete operating characteristic coupling of controller and specific touch screen.
Background technology
Touch-screen cooperates various type of displays, comprise cathode-ray tube (CRT) (being CRT) and LCDs (being the LCD screen), as the device that information is input to data handling system.On touch-screen is placed in display screen or when being integrated in the display screen, can select shown icon or element by target icon on the touch screen or the pairing position of element for the user.In various application, comprise for example point of sales system, information bulletin booth, auto-teller (being ATM), data entry system etc., touch-screen has become part commonly used.
In a kind of touch-screen of particular type, acoustic touch screen, produce sound wave or ultrasound wave, and utilize surface acoustic wave phenomenon such as R wave, Love wave or other ripples directly they to be propagated by touch screen surface.In general, each of touch-screen spool comprises single transmitting transducer and single receiving transducer and a pair of reflective array.Transmitting transducer and receiving transducer are connected to controller, and this controller produces the drive signal that is applied to transmitting transducer, and amplify, adjust and signal that response obtains from receiving transducer.The sound wave that each transmitting transducer produces is positioned near the reflective array reflection the touch-screen edge.Reflective array is usually along the array total length reflective sound wave that meets at right angles, thereby is formed on the surface acoustic wave mode that propagate the effective coverage of touch-screen.The surface acoustic wave of propagating have be the uniform linear wave of amplitude substantially before.The acoustic reflection that relative reflective array is propagated the surface is to receiving transducer.By monitoring, can determine the position of any wave attenuation point on the touch screen surface along each the time of arrival and the amplitude of conduct acoustic waves of touch-screen.Decay may cause because of finger or stylus or other medium contact screens.
The manufacturer of touch-screen system makes usually or buys the controller with predetermined oscillation frequency, and described predetermined oscillation frequency is in the clear and definite frequency range of boundary, and crystal oscillator provides reference frequency.Like this in manufacture process, as required, determine and adjust the characteristic frequency of each touch-screen, fully mate between the oscillation frequency of touch-screen and controller so that guarantee.
Let us comes more carefully to define the characteristic frequency of touch-screen.Here the attribute that has narrow-band pass filter as the acoustic touch screen that will pay close attention to type.The centre frequency of arrowband is decided by the spacing harmony wave propagation velocity of reverberator.As a result, after sound wave passed to the pairing time delay of receiving transducer with the shortest possible path, the burst that is applied to transmitting transducer will occur with the form of the long elongation wave train.Because duration of train of impulses is short, the frequency spectrum of input pulse string is quite wide usually, and the frequency spectrum of the output wave train can be very desirable, and is very narrow and in characteristic frequency outstanding peak value is arranged.Described characteristic frequency is called the characteristic frequency of touch-screen.Preferably the characteristic frequency of the frequency of operation of touch system and touch-screen is mated.
In principle, desirable touch-screen has single characteristic frequency.In principle, the variation in the manufacturing may cause the characteristic frequency of a plurality of characteristic frequencies or certain limit.Present practice is included in carries out enough investments on the touch-screen manufacturing process, the feasible determined frequency matching of reference oscillator that only has single touch-screen characteristic frequency and this characteristic frequency and controller effectively.In order to reach control to touch-screen manufacturing process expectation, need the accurate coordination of array design, carefully monitor the supply chain of input material and to the rapid Electronic Testing of reflective array.In addition, when change of finding not to be contemplated to or variation, also need corrective action fast.For example, array may need to redesign and make new mask to print.Keeping has increased processing cost to the desired coordination of the control of touch-screen characteristic frequency, supervision and test degree, and makes production only limit to finished by the good workman's who trains factory.This is main restriction to existing acoustic touch screen technology.
In general, frequency mismatch can classify as of overall importance or locality in nature.In frequency mismatch was situation of overall importance, the mismatch source can influence whole touch screen.For example, if the reference oscillator shift of controller is if perhaps glass substrate has the velocity of sound do not expected (for example, because the glass substrate of being made by different glass supplier), frequency matching between touch-screen and the controller all can be impaired, and with touch-screen on the location independent paid close attention to.Comparatively speaking, be in the situation of locality in frequency mismatch, only there is the specific region of touch-screen may present mismatch with controller.
Of overall importance or locality frequency mismatch all may be caused by homology not.Though some mismatch sources can overcome by sufficient quality control, the cost of this type of control usually can be very high.For example, the variation of touch-screen glass substrate aspect may change acoustic velocity, thereby causes the global frequencies mismatch, fully controls glass supply chain and manufacturing process and guarantees that it may be infeasible economically that the acoustic velocity of all substrates all is in the close limit.Control glass supply chain and manufacturing process more are being a problem under the following situation: the acoustic reflection array is directly printed onto on the panel of cathode-ray tube (CRT) (being CRT).Be difficult to control to the particular glass feature of avoiding the desired degree of global frequencies mismatch and comprise chemical composition and thermal history (for example, annealing time and temperature etc.).
Another frequency mismatch source is owing to be printed on the variation of the non-expectation in the reflective array on the touch screen base plate and cause.These variations may be for example in the screen printing operation due to the array mask distortion.If array will be directly printed onto on the crt panel, then the mask to print distortion especially is a problem.Other array printing technology such as impression also can run into the registration error of introducing in the printing process, and this may cause further frequency mismatch.Another frequency mismatch source may come from the incorrect correction to the spherical geometry effect of on-plane surface substrate surface.
The method and apparatus that needs a kind of frequency of operation that is used to make the controller oscillation frequency to adapt to the specific touch screen to require in the prior art.The invention provides this method and apparatus.
Summary of the invention
The invention provides the method and apparatus that a kind of frequency of operation that is used to make the frequency adaptation specific touch panel substrate of controller requires, wherein touch screen base plate comprises reflective array.More particularly, adjust controller, make it that burst signal is outputed to the transmitting transducer of touch-screen or regulate signal, thereby adapt to the particular job frequency characteristic of touch screen base plate from the receiving transducer of touch-screen.
In a kind of application of the present invention, at first determine one or more characteristic frequencies of specific touch screen.Adjustment will cooperate the characteristic frequency of the controller frequency of this substrate use with one or more measurements of coupling substrate then, thereby make these two assemblies be paired into the coupling group.In another kind is used, before making the frequency of operation coupling of touch screen base plate and controller, with these two assembly pairings.After the pairing, system carries out initialization during the frequency characteristic of determining touch screen base plate.Adjust the frequency characteristic of controller then so that mate with the frequency characteristic of substrate.If necessary, system can be regularly the frequency characteristic of test base again, and thinking the output of readjusting controller in case of necessity.
Be mainly among the embodiment who the global frequencies mismatch error is compensated and design of the present invention, adaptive controller of the present invention adopts analog signal processing and crystal reference oscillator.Adopt digital multiplier to revise the output of reference oscillator, generate baseband signal so that produce the expected frequency of the audio pulse string that sends to transmitting transducer and/or change the used frequency of receiving circuit.Burst length is determined by the train of impulses circuit.The frequency of operation of expectation comprises circuit decision by frequency mixer, and this circuit compares the output signal of the suitable adjusting of the output of digital multiplier and receiving transducer.The output that frequency mixer comprises circuit is used to definite frequency of operation of expecting.
For simultaneously the overall situation and local frequency change being compensated among another embodiment that designs, adaptive controller of the present invention adopts digital signal processing and crystal reference oscillator of the present invention.In this embodiment, digital signal processor receives digitizing and filtered output from a pair of frequency mixer.The input of delivering to frequency mixer is a pair of reference signal, and one of them is by 90 degree phase shifts, and the receiving transducer RF signal of suitable filtering and amplification.This embodiment is the example that adopts the controller of phase sensitive, and wherein content, for example phase place and the amplitude with the complete mathematics of the signal that receives carries out digitizing.Because the information of fully digitalization can be handled for digital signal processor algorithm, so the signal that software tunable frequency wave filter can be applied to receive.The frequency filter that utilization has particular centre frequency based on the digital signal processor of corrected value contained in the storer, described particular centre frequency preferably changed according to sent the time delay that pulse strings from last time.Thus, system can be adapted to by the variation that localized variation caused in the acoustic reflection array.
In another embodiment of the present invention, adopt noncrystal local oscillator that reference signal in the adaptive controller is provided.Utilize this oscillator can make the degree that controller minimizes to be enough to be directly installed on the touch screen base plate.Feedback control loop is used for the drift of compensated oscillator.In this embodiment, carry out mixing from the output of RF signal after the adjusting of touch-screen receiving transducer and local oscillator.The IF of frequency mixer output is by kam-frequency circuit, and this circuit generates a voltage, and the symbol of described voltage depends on that frequency is higher than or is lower than expectation value, and its amplitude depends on the departure degree with expected frequency.The output of frequency discriminator is used to adjust the frequency of local oscillator, makes it follow the tracks of the frequency of touch-screen.For the burst frequencies that obtains expecting, mixing is carried out in the stable output of local oscillator and the output of IF oscillator.
In another embodiment of the present invention, train of impulses is enough broadbands, and making is enough to only adjust by voltage-controlled variable frequency bandpass filter the centre frequency of the circuit of handling receiving circuit.
With reference to this instructions with lower part and accompanying drawing, can further understand the features and advantages of the present invention.
Description of drawings
Fig. 1 is the graphic extension according to the acoustic touch screen of prior art;
Fig. 2 be about the touch-screen of prior art an axle, by the oscillogram of signal amplitude-time that surface acoustic wave transducer received;
Fig. 3 is the synoptic diagram of waveform shown in Fig. 2, wherein this waveform be touched the screen on the disturbance of touch institute;
Fig. 4 be with the direction of Fig. 2 and waveform quadrature shown in Figure 3 on through the synoptic diagram of the disturbance waveform of touch screen surface;
Fig. 5 is the process flow diagram that explanation utilizes a kind of method of the present invention;
Fig. 6 is the process flow diagram that explanation utilizes another kind of method of the present invention;
Fig. 7 illustrative is used to proofread and correct the adaptive controller of global change according to the present invention;
Fig. 8 is the process flow diagram that the technology of the frequency that is used for tuning digital multiplier shown in Figure 7 is described;
Fig. 9 illustrative quadrature and detecting device;
Figure 10 is the process flow diagram of the explanation method relevant with another embodiment of the present invention shown in Figure 11;
Figure 11 illustrative is used to proofread and correct the adaptive controller of the overall situation and localized variation according to the present invention;
The digit pulse string manipulation device that Figure 12 illustrative cooperates Figure 11 and adaptive controller shown in Figure 15 to use;
Figure 13 illustrative can be directly installed on the controller on the touch screen base plate;
Figure 14 is the process flow diagram of the explanation method relevant with another embodiment of the present invention shown in Figure 15;
The adaptive controller that Figure 15 illustrative is all effectively proofreaied and correct according to the present invention, to the overall situation and localized variation;
Figure 16 illustrative is according to the present invention, only adjust the adaptive controller of receiver centre frequency; And
Figure 17 is the graphic extension that utilizes the acoustic touch screen of the additional transducer group that is used for the touch-screen characterization.
Embodiment
Fig. 1 is the graphic extension of utilization according to the touch-screen 100 of the surface acoustic wave of prior art.This touch-screen is suitable for cooperating cathode-ray tube (CRT) (being CRT) display, LCD (being LCD) or other type of display to use.Common acoustic touch screen adopts R wave, and terminology used here comprises accurate R wave.Relate to the R wave touch-screen explanation as an example United States Patent (USP) 4642423,4645870,4700176,4746914,4791416 and the Re 33151 that comprises Adler disclosed; People's such as Adler United States Patent (USP) 4825212,4859996 and 4880665; People's such as Brenner United States Patent (USP) 4644100; People's such as Davis-Cannon United States Patent (USP) 5739479; And the United States Patent (USP) 5708461 and 5854450 of Kent.It also is known adopting the acoustic touch screen of the combination (comprising the combination that contains R wave) of the sound wave (as Lamb wave or shear wave) of other types or dissimilar sound waves, and explanation discloses the United States Patent (USP) 5591945 and 5854450 that comprises Kent as an example; The United States Patent (USP) 5072427,5162618,5177327,5243148,5329070 and 5573077 of Knowles; And people's such as Knowles United States Patent (USP) 5260521.Mentioned these files of this paragraph are all incorporated herein by reference to be used for various purposes.Here will go through surface acoustic wave touch screen, so that can more fully understand the present invention.
Touch-screen 100 comprise be suitable for the propagation surface sound wave, for example to the substrate 101 of R wave, Love wave and other ripple of touch-sensitive on the surface.In order to determine the touch coordinate along x-axle 103, the system that is adopted comprises: the reflective array 109 and 111 that transmitting transducer 105, receiving transducer 107 and a pair of difference are associated.Adopt similar system to determine along the coordinate of y-axle 113, it comprises transmitting transducer 115, receiving transducer 117 and associated reflective array 119 and 121. Transmitting transducer 105 and 115 is connected to controller 123, and controller is normally under the control of processor 125. Receiving transducer 107 and 117 is also connected to controller 123, and described controller 123 comprises signal processing system 127.Though can simultaneously signal be applied to transducer 105 and 115, preferably successively signal is added to these transducers, reduce by two interference and cross-talks between the coordinate sense channel thus.Detection method has also reduced circuit complexity successively, because can be used alternatingly many essential circuit in these two sense channels, repeats thereby exempt unnecessary circuit.In order further to reduce circuit complexity, prior art sends the train of impulses of same frequency to transmitting transducer 105 and 115 usually.
One of sense channel is described in more detail below.The explanation that this passage is done is equally applicable to second sense channel.In order to determine that along the touch coordinate of the x-axle 103 of substrate 101 transmitting transducer 105 is 129 transmission train of impulses sound waves (for example, the train of impulses of about 5 microseconds) along the path.Because the relevant relative broad of bandwidth of train of impulses sound wave therewith is not so frequency is that very boundary is clearly demarcated.Reflective array 109 comprise a plurality of along the path 129 reflecting elements 131 that are provided with, 129 one-tenth in each element 131 and path be miter angle roughly.Element 131 is designed to extract a plurality of acoustic component 133 from the sound wave of propagating along path 129, and transmits component 133 along substrate surface 101, and direction is preferably parallel with y-axle 113.The design of array 109 is such, makes each component of each reverberator 131 reflections coherently add together, thereby forms the wavefront of the substantially linear with uniform amplitude.Acoustic component 133 reconfigures by a plurality of reflecting elements 135 in the array 111, element 135 will be along the path 137 acoustic component be directed to receiving transducer 107.Each array element 135 is by 137 settings and orientation become miter angle approximately with this path along the path.Owing to the speed of sound relevant with substrate 101 causes the time delay of the sound wave that transducer 105 is transmitted, so receiving transducer 107 receives relatively the signal (duration of for example about 150 microseconds) than long duration, but not burst.
Receiving transducer 107 will 137 shape informations that receive be converted to electric signal along the path.For example analyze, analyze this electric signal by carrying out the time of arrival that receives sound wave.Fig. 2 is the figure of the typical time series analysis of this sound wave of explanation.As shown in the figure, amplitude, be that the envelope of the RF signal of the ripple that received was drawn corresponding to the time.At time t
1, signal is offered transducer 105 by source 123.Time t
2It is the start time of the ripple of transducer 107 receptions.t
1And t
2Between time delay come from first element 139 that ripple that transducer 105 sends arrives array 109, by propagating and by the time delay between first element, 141 reflections of array 111 on plate 101 surfaces.At time t
3, the end of sound wave arrives transducer 107.Because the spacing and the design of array element suppose that sound wave is undisturbed, time t
2And t
3Between the amplitude of curve constant relatively.
Fig. 3 is the curve of second waveform that received of transducer 107.As shown in the figure, the amplitude of waveform is at time t
1Exist and descend 301.Descend 301 is because on the substrate 101 due to the acoustic attenuation at 143 places, position.By analyzing t
1And t
2Between time delay, signal processor 127 combines with processor 125 to calculate and touches 143 x coordinate.Equally, processor 125 and 127 together with source 123, transducer 115 and 117 and reflective array 119 and 121 can calculate and touch 143 y coordinate.Fig. 4 is the curve of the waveform that received of transducer 117, has wherein represented to descend 401 because of touching 143 decay that cause.
Fig. 5-the 6th illustrates the process flow diagram of the basic skills relevant with adaptive controller of the present invention.Method shown in Figure 5 is suitable in the touch-screen system process for making most, though also can adopt the method at customer location.In step 501, one or more characteristic frequencies of specific touch screen are to utilize in the various well-known measuring technologies any to determine.
For example, if one side of manufacturer then can be placed in the test fixture at the test touch screen, can on substrate surface, send sound wave.In case know one or more characteristic frequencies of touch-screen, then can adjust the frequency that is designed for this touch-screen of controller so that with tested touch-screen frequency matching (step 503).Usually adjust the frequency of controller, till obtaining desired frequency.Perhaps, controller can comprise a look-up table, the output frequency that has wherein write down the controller setting and drawn.Preferably this look-up table is exclusively used in given controller, and promptly each controller all has a look-up table of having considered variation in each controller.In case determine the frequency of operation of touch-screen, just use the look-up table of the controller that matches with this given touch-screen to carry out suitable controller setting.No matter adopt which kind of method to adjust controller,, just can assemble touch-screen system (step 505) in case it is adjusted to and the substrate coupling.
In method shown in Figure 6, before attempting making the frequency matching of controller and touch-screen, with both pairings (step 601).Then, finish the installation (step 603) and the beginning system initialization (step 605) of touch-screen system.In the system initialization process, test touch shields to determine its one or more characteristic frequencies (step 607).This testing procedure preferably adopts common touch-screen transmitter/receiving transducer with the work of single burst test pattern (promptly 105/107 and/or 115/117).Perhaps, also can adopt special-purpose transducer right.In case determine one or more characteristic frequencies of substrate, just adjust the frequency (step 609) of controller, thereby for normal operations, system's ready (step 611).
As the variant of said method shown in Figure 6, design system to and in the touch operation process, regularly adjust controller, so that guarantee optimum frequency matching.But, different with previous described system, carry out the routine test program, wherein test touch screen and readjust controller (step 613) again.Readjusting of controller can be set to enter when powering on program or through execution after the scheduled time slot in each system.Usually when touch screen base plate or controller tend to the fluctuation of temperature correlation, need regular controller adjustment.For example, if adopt polymeric substrates, the acoustic velocity of substrate changes with variation of ambient temperature probably.Equally,, may make frequency reference be subjected to the drift influence, therefore need controller adjustment initiatively if controller does not adopt crystal oscillator.
Because the fault (for example destroying purposely) of touch screen base plate or controller failure caused under the situation that the customer location touch-screen system lost efficacy all can be found the obvious advantage of above-mentioned adaptive controller.Reason owing to the frequency self-adaption quality of controller, new touch-screen or new controller can be installed at an easy rate at the scene, this solution is better than the whole touch screen system is sent back to manufacturer's place under repair, and perhaps touch-screen/the controller that will mate sends to customer location and carries out the scene and change.For example, if the touch-screen of existing touch-screen system needs to change, old controller can be carried out a new initialization test, wherein determines one or more characteristic frequencies of new touch-screen, and the frequency of resetting controller is to make it and described one or more characteristic frequency coupling.Perhaps, can utilize above-mentioned look-up table to use the identification code of new touch-screen that the frequency of controller is set.Equally,, can make new controller and existing touch-screen coupling, perhaps can utilize the identification code of look-up table method and old touch-screen that it is set by initialization test if customer location needs new controller.In a kind of method in back, both can locate in manufacturer, also can controller be set at the user place.
Embodiments of the invention have a lot, the function that they provide the frequency adaptation touch-screen that makes controller to require separately.These embodiment are different on the frequency mismatch type that adaptive controller is proofreaied and correct.Embodiment illustrated in fig. 7 being designed for is subjected to " overall situation " frequency mismatch error, promptly influences the system of the error effect of the frequency compatibility between controller and the touch-screen equably.For example the acoustic velocity of glass sheet is different with its definite composition usually.Like this, because composition is different between each batch glass or each glass manufacturer, and suppose that other factors that influence frequency obtain enough control, then the error introduced of composition difference can be because the difference between each batch product and influence the characteristic frequency of whole touch screen equably on the acoustic velocity.In particular instance, during the touch-screen manufacturing process, need carry out the glass tempering step usually.Time and temperature characterisitic with the glass tempering step are decided, and the characteristic frequency between each touch-screen may be different.
Become when non-in the touch-screen of global frequencies mismatch error (for example, the glass ingredient difference) influence being subjected to, adaptive controller of the present invention preferably adopts single adaptive frequency algorithm.In this scheme, do not need repeatedly or continuous frequency adaptation, because the time to time change not of the mismatch between controller and the touch-screen.On the contrary, being intended that of this embodiment makes touch-screen of selecting at random during final system assembling or system maintenance and the controller of selecting at random (being the touch-screen/controller group of non-matching) successfully to match.Thus, the preliminary examination that is preferably in the touch-screen/controller of pairing powers on and carries out this adaptive frequency algorithm during the program.
The embodiment of adaptive controller shown in Figure 7 adopts analog signal processing.But, obviously also can adopt digital signal processing in this embodiment.Have in the controller 700 with crystal oscillator 701 near the hunting of frequency of expected frequency.The output of this reference oscillator 701 is fed to digital multiplier 703 (being also referred to as digital frequency divider) and the microprocessor 705 in the controller 700.Digital multiplier 703 is revised the output (for example, crystal oscillator frequency being multiply by rational number A/B) of crystal oscillator with mathematical way, so that the order that sends to it according to microprocessor 705 generates expected frequency.Thus, digital multiplier 703 constitutes the king oscillator 704 of the simulation system relevant with touch-screen with crystal oscillator 701 combinations.
The output of digital multiplier 703 is used to generate audio pulse string, and this audio pulse string road 707 along the line outputs to the transmitting transducer (for example transducer 105 and 115 of Fig. 1) of touch-screen.Audio pulse string is in the frequency of multiplier 703 outputs, and has the train of impulses circuit 709 determined burst lengths that are connected with microprocessor 705.Before audio pulse string is sent to transmitting transducer, regulate and amplification through train of impulses amplifier 711 usually.
In order to determine the frequency of operation of expectation, the output of receiving transducer (for example 107 of Fig. 1 and 117) road 713 along the line sends to frequency mixer and comprises circuit 715.Transducer output is preferably at first by bandpass filter 717 and RF amplifier 719.Bandpass filter 717, normally the fixed broadband wave filter mainly as noise suppression circuit, is regulated the RF input.RF amplifier 719 is amplified to signal the level of expectation.Frequency mixer comprise circuit 715 will be from the adjusting of receiving transducer and the frequency component of the signal after amplifying compare with the output signal of digital multiplier 703, thereby relatively slowly variation and be the baseband signal of direct current substantially of output.Frequency mixer comprises the output of circuit 715 and carries out digitizing by analog to digital converter 723, and is fed to microprocessor 705.As selection scheme, low-pass filter 721 provided extra adjusting to it before the output that frequency mixer comprises circuit is digitized, but frequency mixer comprises circuit limited narrow-band filtering is provided usually.
As previously described, project 703 A/B digital multiplier preferably.But, should be appreciated that generally say, project 703 only is the frequency modification circuit, therefore can comprise any numeral, simulation or the DA combination electronic circuit of response from the control signal modification crystal oscillator frequency of microprocessor 705.
Decide with application, only adjusting train of impulses centre frequency or receiving center frequency may be just enough.only adjust the train of impulses centre frequency with regard to those enough situations in, circuit 715 need not the input from digital multiplier 703.Therefore, can be replaced by the more detector element of standard, as those common in existing controller elements.only adjust the receiving center frequency with regard to those enough situations in, the connection between digital multiplier 703 and the train of impulses circuit 709 no longer is essential.
Fig. 8 be the explanation frequency that is used for tuning digital multiplier 703 with the process flow diagram of the technology of the frequency matching of the touch-screen that will be connected.As mentioned above, this embodiment preferably only mates (step 801) with the frequency of controller with touch-screen when powering on.Perhaps, system can be designed to termly or only implementation controller frequency adjustment in the cycle that powers on for the first time.
In the step 801 that powers on, microprocessor 705 makes the output of digital multiplier 703 scan (step 803) in scheduled frequency range.Controller is preferably carried out the coarse tuning operation earlier, carries out the fine tuning operation then, but can be with these two operative combination in the single scanning program.Therefore, in step 803, adopt the predetermined frequency range of relatively large frequency jump scanning.With the output summation (step 805) of the A-D converter 723 of each frequency jump, and select maximum signal amplitude (step 806), it has indicated immediate coupling between the output of king oscillator and the touch-screen.Repeat this scanning/optimizing process (step 807-809) then, scan the output frequency of king oscillator near the frequency that adopts less frequency jump formerly to select.Then with determine in the step 809 near in the frequency input store of touch-screen natural frequency (step 811), guarantee that thus the output of king oscillator maintains desired frequency.
Though represented two synchronizing frequency scanning methods among Fig. 8, those skilled in the art should be known in the output frequency that also has many other technologies to can be used for determining expectation.For example, the present invention can also utilize shake or successive approximation method.
The rudimentary algorithm of Fig. 8 does not need to use the summation of A-D converter.In general, any measurable amount to frequency mismatch degree sensitivity is collected in step 805 and 808 expressions, and step 806 and 809 expressions are selected corresponding to little measurable amount to acceptable frequency mismatch.For example, for the given time interval, microprocessor 705 can be added up the RF periodicity in the output of signal that receives and digital multiplier 703.Difference between the RF periodicity provides measuring of frequency mismatch.For a person skilled in the art, also have other well-known circuit and technology to realize same purpose.
Fig. 9 illustrative comprises the quadrature and the detecting device of the illustrative example of circuit 715 as frequency mixer.In frequency mixer 903, RF input signal after the adjusting 901 with from the output carrying out of the oscillator in the digital multiplier 703 mixing.Two incoming frequencies of frequency mixer 903 output with frequency and difference frequency.Utilize the about 10MHz of low-pass filter 905 filterings the place and frequency.All the other frequencies approach zero, i.e. base band.Though can adopt above-mentioned single mixer that baseband signal is provided, output is decided with the relative phase of oscillator output and RF input signal.In order to realize the relative phase irrelevance, promptly to avoid beat pattern occurring in 723 digitized waveforms of A-D converter, quadrature and detecting device have two channels shown in Figure 9.As shown in the figure, adopt second frequency mixer 907, wherein carry out phase shift by 90 degree from the frequency input of oscillator.The output of second frequency mixer 907 is by after another low-pass filter 905, with the output addition from the first passage of quadrature and circuit 909.The output of circuit 909 is baseband signals 911, and it avoids beat pattern and the cut position is irrelevant really with the signal that receives.The quadrature of Fig. 9 and detecting device provide narrow band filter effectively, and its centre frequency can be adjusted and be controlled by the frequency of digital multiplier 703 outputs.
In the another embodiment of the present invention shown in Figure 10-12, controller can be programmed as follows: make it both can to adapt to global change, promptly influence the frequency change of the characteristic frequency of whole touch screen equably, also can adapt to localized variation, i.e. frequency change in the regional area of touch-screen.Only for illustrative purposes, present embodiment adopts digital signal processing.But should be appreciated that present embodiment also can adopt analog signal processing to realize.
Figure 10 is the process flow diagram of the explanation method relevant with the embodiment of the invention.After touch screen base plate manufacturing (comprising any required array deposit and glass tempering operation) is finished, measure the characteristic frequency of this touch-screen, comprise the influence (step 1001) of any partial array distortion.These measurements are preferably in and utilize the testing apparatus of production scene to finish in the manufacturing works.According to these measurements, calculate a series of frequency correction value (step 1003), have functional relation their time delay common and x and y coordinate.Then peculiar this group corrected value of each touch-screen is packed into (step 1005) in the storer of adaptive controller 1100, this controller is specific touch screen pairing (step 1007) therewith.Should be appreciated that step 1005 and 1007 can put upside down on order, touch screen base plate frequency change measuring process 1001 and correction value step 1003 can be combined.
Method shown in Figure 10 is changed slightly, and each touch screen base plate is provided with an identification code.Then with identification code and each identification code the table filing of specific dependent correction value, preferably come together to finish by manufacturer, dealer or the two.Thus, if for example because breakage needs more changer controller, and the user only need provide identification code, so that the new controller of the essential corrected value that obtains packing in advance.
In the Figure 11 and the embodiment of the invention shown in Figure 12, adaptive controller 1100 adopts oscillators 1101 as a reference.Preferably adopt stable crystal oscillator as frequency source.The output of oscillator 1101 is sent to divider/shifter 1103, and it is the expected frequency of about 5.53MHz with frequency from about 22MHz frequency division, and a part is exported phase shift 90 degree.Then will be not in frequency mixer 1109 and 1111 oscillator frequency 1107 and the suitable filtering of the oscillator frequency 1105 of phase shift and phase shift and the receiving transducer RF signal that amplifies carry out mixing.With the same in controller 700, from the RF signal of the receiving transducer of touch-screen by bandpass filter 1113, normally the fixed broadband wave filter carries out filtering, thereby remove various noise components, amplify by amplifier 1115 then, so that obtain the signal level of expectation.
X and y signal amplitude are represented in frequency mixer 1109 and 1111 output in complex plane.
Thus, utilize a pair of frequency mixer and a pair of reference signal (one of them 90 degree of phase shift), can determine phase place and the complex amplitude relevant with phase place.Frequency mixer 1109 and 1111 output by a pair of low- pass filter 1117 and 1119, are carried out digitizing by A-D converter 1121 and 1123 respectively respectively then.Then these signals are sent to digital signal processor (being DSP) 1125.
The project 1125 of Figure 11 is meant digital signal processor (being DSP) on ordinary meaning.Its expression mathematics or digital processing to carrying out from the digitized signal of A-D converter 1121 and 1123.DSP 1125 may be implemented in a variety of ways.For example, DSP 1125 can be the code of being carried out by microprocessor 1131.Perhaps, DSP 1125 is the custom-designed digital circuit of acoustic touch screen controller.Moreover digital signal processing can be carried out in the silicon of encapsulation, and this type of chip is called " dsp chip " usually by the Electronics Engineer, but is to be understood that it is not limited in this.
For the transmitting transducer train of impulses is provided, the output of crystal oscillator 1101 is fed to digit pulse serializer circuit 1129.Train of impulses circuit 1129 is according to this signal of instruction process that receives from microprocessor 1131, and microprocessor 1131 receives the instruction of relevant required centre frequency from permanent storage 1127.If necessary, before road 1135 along the line sends to transmitting transducer with the output of digit pulse serializer circuit 1129, amplify by train of impulses amplifier 1133.
Figure 12 is the synoptic diagram of an example of digit pulse serializer circuit 1129.In train of impulses circuit 1129, the bit register 1201 (for example 64 * eight bit register) that is connected to microprocessor 1131 is arranged.Microprocessor 1131 is with required bit pattern (that is, the output of microprocessor 1131 response permanent storagies 1127 and the digital pattern that generates) load register 1201, and the centre frequency of train of impulses is determined in this bit pattern.For each train of impulses, the bit pattern in the load register 1201 is latched in the shift register 1203, and in order to produce train of impulses, shift register is wanted clock synchronization (clocked out).Should be appreciated that, can adopt the train of impulses centre frequency of the x coordinate and the y coordinate of the different incompatible definite touch-screens of hyte, include the variation between these two axles in consideration thus.Be noted that bit pattern can be calculated from the frequency correction data that storer 1127 obtains by microprocessor 1131 response, also can directly be stored in the storer 1127.
In another example of this embodiment that can adopt adaptive controller, touch-screen adopts grating transducer.In grating transducer, piezoelectric element is applied to the back side of substrate, and grating is applied to the substrate front.Grating is used for the pressure wave that the coherent diffraction piezoelectric element is produced, and generates the sound wave of propagating along the face on surface thus.This grating transducer proof is the most effective during corresponding to thickness of glass resonance in frequency of operation.Because the thickness of glass resonance frequency of substrate depends on substrate thickness, so preferably measure thickness of glass earlier, calculating optimum frequency of operation, and utilization then is at the suitable reflective array and the grating of this frequency optimum traffic design.Utilize adaptive controller of the present invention, for example 1100 then, with the frequency of controller and the frequency characteristic coupling of touch-screen.But be different from some application of present embodiment, this example requires this adaptive controller paired pulses string frequency to make the change of 10-20% from reference oscillator frequencies.Any reception bandpass filter, need be tunable or enough broadbands as wave filter 1113, so that contain the whole mobility scale of touch-screen frequency characteristic.
Another embodiment of Figure 13 illustrative adaptive controller, it can directly be installed on the touch screen base plate, and therefore size and cost benefit are provided.In this embodiment, crystal oscillator is replaced by local oscillator 1301, and required size is provided thus.For example, local oscillator 1301 can be made of the circuit component on the silicon fully.Suppose that local oscillator 1301 has drift with respect to crystal oscillator, then need feedback control loop that necessary frequency stability is provided.Because feedback control loop arranged, controller 1300 on one's own initiative, promptly adjust to expected frequency with oscillator frequency repeatedly.
According to previous embodiment, from the RF signal of touch-screen receiving transducer at first by bandpass filter 1303 and amplifier 1305 to regulate.RF signal after the adjusting carries out mixing in frequency mixer 1307 Yu from the output of local oscillator 1301.Oscillator 1301 is variable oscillators, and its medium frequency is by for example input voltage control.Utilize suitable buffer circuit between capacitor 1308 and the oscillator 1301, oscillator 1301 can provide the electricity input of other types, such as electric current.In this embodiment, local oscillator or reference oscillator are operated in than on the high frequency of touch-screen frequency.For example, for the nominal touch-screen frequency of 5.5MHz, oscillator 1301 can be operated on the frequency of about 6MHz.The output of frequency mixer 1307 then is on the IF frequency of about 500kHz.
In system's power up, local oscillator 1301 may depart from the sizable difference of expected frequency, thereby stops feedback control loop stabilized oscillator effectively.For this reason, controller 1300 preferably includes the slope processing capacity of the frequency of little by little adjusting local oscillator 1301, till feedback control loop can be taken over.In a kind of working method, during powering on, switch 1313 disconnects and second switch 1315 closures.D-A converter (being DAC) 1317 is adjusted the frequency of oscillator 1301 under the control of microprocessor 1314, increase the output that (or reducing) this frequency is utilized detecting device 1319 observation frequency mixer 1307 simultaneously.Detecting device 1319 is connected with microprocessor 1314 by A-D converter 1321.When thereby the output of detecting device 1319 surpassed predetermined threshold indication local oscillator 1301 near expected frequency, microprocessor 1314 cut-off switch 1315 and Closing Switch 1313 made feedback control loop can finely tune the frequency of local oscillator.Perhaps, in power up, can switch 1313 and switch 1315 is all closed.In this mode, in case oscillator frequency is in the bandwidth of bandpass filter 1303, microprocessor 1314 is finely tuned frequency with regard to cut-off switch 1315 forward thereby feedback control loop can be put since then.
Different with previous described embodiment, the frequency of local oscillator 1301 is not adjusted to the burst frequencies of expectation.But the frequency of the frequency-tracking touch-screen of local oscillator 1301 is so that keep two fixed differences (being 500kHz in this example) between the frequency.Therefore, for the burst frequencies that obtains to expect, in second frequency mixer 1323, mixing is carried out in the stable output of local oscillator 1301 and the output of IF oscillator 1325.IF oscillator 1325 works in the frequency (be in this example be about 500kHz) identical with IF bandpass filter 1309.The output of frequency mixer 1323 is in the burst frequencies (being to be about 5.5MHz in this example) of expectation.The bandpass filter (not shown) can be inserted between frequency mixer 1323 and the train of impulses circuit 1327, so that only from frequency mixer 1323 pass through to expect and or difference frequencies.The same with previous embodiment, the length of the audio pulse string on this frequency is by train of impulses circuit 1327 controls that are connected to microprocessor 1314.Audio pulse string was amplified to desired amplitude by train of impulses amplifier 1329 usually before road 1331 along the line outputs to one of touch-screen transmitting transducer.
Circuit among Figure 13 is a kind of practical circuit, and it is the frequency from RF frequency shift frequency to lower not necessarily base band with received signal, for example 500kHz.For the designer of adaptive frequency controller, there is a kind of current techique to use.This lower frequency may be selected in any position between RF frequency and the base band.Its optimal value depends on concrete property, noise source of particular electrical circuit etc.
Figure 14-15 explanation is for the comparatively ideal another embodiment of the present invention of the touch-screen that has the variation on the substrate acoustic velocity in the use.For example, as mentioned previously, the acoustic velocity characteristic of polymeric substrates may with temperature correlation.Therefore, in use, may present global change (for example the variation of whole room temperature is caused) or localized variation (for example the temperature difference of screen different piece causes) based on the touch-screen of polymeric substrates.Embodiment shown in Figure 14 and 15 is designed to adapt to this variation.
Figure 14 is the process flow diagram of the method for the embodiment that links to each other of the initiatively adaptive touch-screen of explanation its middle controller 1500 and needs.In this embodiment, first step is to determine whether touch-screen senses touch (step 1401).If do not sense touch, controller 1500 is carried out test procedure to determine the frequency characteristic of touch-screen.First step in this program preferably determines how long to have passed through after the test procedure since last time (step 1403).Do not preset the period (step 1405) if surpass, then systemic circulation turns back to starting point.Preset the period if surpass, the substrate frequency characteristic (step 1407) of substrate x and y coordinate is then measured by system, and determines one group of corrected value (step 1409).These corrected values are loaded into the storer (step 1411) of controller 1500, and systemic circulation turns back to starting point (step 1413).Then, in case sense touch (step 1415), system then determines touch coordinate (step 1417) and these coordinates is sent to operating system (step 1419).
Initiatively adaptive controller 1500 as shown in figure 15.This controller is identical with controller 1100 basically, and difference is some little changes.For example, permanent storage 1127 is replaced with scratchpad memory 1501.With the same in the controller 1100, the characteristic frequency that touch-screen is proofreaied and correct in storer 1501 storages changes required frequency correction value.Need scratchpad memory in the present embodiment, because the aforesaid corrected value of controller 1500 regular updates.In addition, because the necessary regular update of storer, it is that microprocessor 1131 is arrived in bi-directional chaining.Therefore, during the characteristic test program, microprocessor 1131 utilizes the output of DSP 1125 to determine the desired frequency corrected value they to be stored in storer 1501.
The same with embodiment shown in Figure 11, the train of impulses of digit pulse string manipulation device 1129 output expectation burst frequencies.In addition, also the power spectrum of output pulse string is repaired according to the corrected value that is stored in the scratchpad memory 1501.Can adopt various technology to adjust the burst power spectrum, comprise the phase place of each RF pulse (is for example carried out the time modulation, impulse phase adjustment based on sin (x)/x curve), the paired pulses string carries out Modulation and Amplitude Modulation (for example trapezoidal envelope or the stack of the digit pulse string of different length), and perhaps utilizing with the RF cycle is the non-integer burst length of unit.
In the embodiment shown in Figure 16, only adjust the centre frequency that is used to handle received signal, the frequency of promptly uncomfortable whole pulse string.Present embodiment is applicable to the situation that need not to adjust burst frequencies, and is very short as train of impulses, and for example the duration is less than 10 RF cycles, and therefore enough broadbands are to contain the variation of expecting in the touch-screen characteristic frequency.
As shown in figure 16, microprocessor 1601 is accepted nominal RF frequency of operation, and trigger pulse serializer circuit 1603, thus stimulated emission transducer (not shown).The same with previous embodiment, train of impulses amplifier 1605 can be used for the output of regulating impulse serializer circuit 1603.The narrowest bandpass filter is an alterable band-pass filter 1607 in the acceptor circuit chain.The Control of Voltage that the centre frequency of alterable band-pass filter 1607 is provided by D-A converter 1609, the D-A converter is controlled by microprocessor 1601 again.At alterable band-pass filter, as the related circuit of wave filter 1607 design is that those skilled in the art is well-known, therefore is not further described.Can be transmitted bandpass filter 1611 by relative broad from the signal of receiving transducer (not shown), and be amplified by amplifier 1613 before being transmitted by alterable band-pass filter 1607, described wave filter 1607 defines centre frequencies.Convert signal to base band from RF by detecting device 1615 then, and utilize A-D converter 1617 its digitizing.Microprocessor 1601 is determined the optimum setting of D-A converter 1609, for example utilizes handling procedure shown in Figure 8.Then the setting of optimum D-A converter is stored in the storer 1619, microprocessor 1601 uses the value of being stored in general touch operation process.For x signal and y signal, can store the value of D-A converter respectively.
Among disclosed in the above each embodiment, preferably used transducer such as transducer 105,107,115 and 117 also is used for controller and touch-screen adaptive in the touch sensible process.Thus, for example transducer 105 received signals that sound wave produced that receive with transducer 107 that send can be used as the frequency reference of adaptive controller of the present invention, perhaps to provide touch information with the same or analogous mode of conventional touch-screen.But, should be appreciated that these are used for determining the touch-screen characteristic frequency not needing identical with the transducer that is used for senses touch and information gathering so that adjust the transducer of controller.For example, as shown in figure 17, transducer is used for delay line back-coupled generator (not shown) determining the characteristic frequency of touch-screen to 1701 and 1703, and these transducers are as to the transducer 105,107,115 that uses in the touch sensible process and 117 condiment.Perhaps, the independent transducer with independent reflective array can be set at the touch screen base plate back side.Preferably the circuit 707 and 713 of the input and output of Fu Jia transducer and controller 700 is multiplexing, and is perhaps multiplexing with the corresponding line of controller 1100,1300 or 1500.This method provides the freedom of optimizing the character of frequency reference signal, and irrelevant with the needs of touch sensible sound travel.
Though top description and a plurality of embodiment of the present invention has been described should be appreciated that, it is contemplated that other embodiment that utilize adaptive approach of the present invention.In addition, the various aspects that be also to be understood that the foregoing description are not deviating under the prerequisite of the present invention and can change.For example, can adopt noncrystal reference oscillator used among the embodiment shown in Figure 13 and feedback control loop to come crystal oscillator used among the embodiment shown in the alternate figures 11-12.Therefore, under the prerequisite that does not deviate from the present invention's spirit and essential characteristic, the present invention can other particular forms implement.Therefore, the disclosure of this paper and description only are used for explanation, but not as limiting, scope of the present invention is stated by following claims.
Claims (6)
1. the method for an operating touch-screen system, described method comprises the steps:
For described touch-screen system provides electric power, described touch-screen system comprises touch screen base plate and adaptable touch screen controller;
On described touch screen base plate, send sound wave;
Receive described sound wave;
Analyze the measured value of described sound wave with the characteristic frequency of definite described touch screen base plate; And
Adjust the frequency of described adaptable touch screen controller, so that described characteristic frequency coupling basic and described touch screen base plate.
2. the method for claim 1 is characterized in that, described set-up procedure is carried out automatically.
3. the method for claim 1, it is characterized in that, repeat the described step of sending, receive, analyzing and adjust, so that obtain the optimum matching between the described characteristic frequency of the described frequency of described adaptable touch screen controller and described touch screen base plate.
4. the method for claim 1 is characterized in that, described analysis and set-up procedure are being carried out when described touch-screen system provides electric power at every turn.
5. the method for claim 1 is characterized in that, described analysis and set-up procedure are regularly carried out.
6. the method for claim 1 is characterized in that, described analysis and set-up procedure are carried out during described touch-screen system initially powers on.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB200510085929XA CN100343792C (en) | 2000-11-21 | 2000-11-21 | Method for operating touch-screen system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB200510085929XA CN100343792C (en) | 2000-11-21 | 2000-11-21 | Method for operating touch-screen system |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB008200254A Division CN1236378C (en) | 2000-11-21 | 2000-11-21 | Adaptive frequency touchscreen controller |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1722073A CN1722073A (en) | 2006-01-18 |
| CN100343792C true CN100343792C (en) | 2007-10-17 |
Family
ID=35912408
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB200510085929XA Expired - Fee Related CN100343792C (en) | 2000-11-21 | 2000-11-21 | Method for operating touch-screen system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100343792C (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100555194C (en) * | 2006-02-17 | 2009-10-28 | 鸿富锦精密工业（深圳）有限公司 | Touch type inductor and its implementation |
| JP5424494B2 (en) * | 2010-08-20 | 2014-02-26 | 株式会社ジャパンディスプレイ | Detection device, display device, and electronic device |
| FR2995702B1 (en) * | 2012-09-14 | 2014-10-03 | Commissariat Energie Atomique | SYSTEM AND METHOD FOR DETECTING AND LOCATING AT LEAST ONE TOUCH ON A TOUCH SURFACE OF AN OBJECT. |
| US10578499B2 (en) * | 2013-02-17 | 2020-03-03 | Microsoft Technology Licensing, Llc | Piezo-actuated virtual buttons for touch surfaces |
| US9448631B2 (en) | 2013-12-31 | 2016-09-20 | Microsoft Technology Licensing, Llc | Input device haptics and pressure sensing |
| US10061385B2 (en) | 2016-01-22 | 2018-08-28 | Microsoft Technology Licensing, Llc | Haptic feedback for a touch input device |
| US10423277B2 (en) * | 2016-12-30 | 2019-09-24 | Texas Instruments Incorporated | Interference reduction circuit for touch system |
| CN110497425A (en) * | 2018-05-17 | 2019-11-26 | 张家港市光武智能科技有限公司 | A kind of robot skin based on Lamb wave and R wave |
| CN112946771B (en) * | 2021-01-30 | 2023-01-10 | 杭州微伽量子科技有限公司 | High-speed stable broadband frequency counting method, system and storage medium |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1120205A (en) * | 1993-10-22 | 1996-04-10 | 国际商业机器公司 | Touch-screen input device using the monitor as a light source operating at an intermediate frequency |
| CN1208190A (en) * | 1997-08-07 | 1999-02-17 | 富士通株式会社 | Optical scanning-type touch panel |
| US5940065A (en) * | 1996-03-15 | 1999-08-17 | Elo Touchsystems, Inc. | Algorithmic compensation system and method therefor for a touch sensor panel |
| WO2000058906A1 (en) * | 1999-03-26 | 2000-10-05 | Elo Touchsystems, Inc. | Acoustic touchscreen constructed directly on a cathode ray tube |
-
2000
- 2000-11-21 CN CNB200510085929XA patent/CN100343792C/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1120205A (en) * | 1993-10-22 | 1996-04-10 | 国际商业机器公司 | Touch-screen input device using the monitor as a light source operating at an intermediate frequency |
| US5940065A (en) * | 1996-03-15 | 1999-08-17 | Elo Touchsystems, Inc. | Algorithmic compensation system and method therefor for a touch sensor panel |
| CN1208190A (en) * | 1997-08-07 | 1999-02-17 | 富士通株式会社 | Optical scanning-type touch panel |
| WO2000058906A1 (en) * | 1999-03-26 | 2000-10-05 | Elo Touchsystems, Inc. | Acoustic touchscreen constructed directly on a cathode ray tube |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1722073A (en) | 2006-01-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6630929B1 (en) | Adaptive frequency touchscreen controller | |
| US6473075B1 (en) | Adaptive frequency touchscreen controller employing digital signal processing | |
| US6396484B1 (en) | Adaptive frequency touchscreen controller using intermediate-frequency signal processing | |
| CN100343792C (en) | Method for operating touch-screen system | |
| CN1914585A (en) | Touch sensing with touch down and lift off sensitivity | |
| TW200530929A (en) | Touch sensitive device employing bending wave vibration sensing and excitation transducers | |
| JPH012124A (en) | coordinate input device | |
| CN1236378C (en) | Adaptive frequency touchscreen controller | |
| US20030014138A1 (en) | Coordinate data entry device | |
| US20110141033A2 (en) | Mulit-point touch screen and touch detection method | |
| CN110285777A (en) | Ultrasonic sensor and electronic equipment | |
| EP0207527A2 (en) | Coordinate input method and apparatus using elastic wave | |
| US10949030B2 (en) | Shear-poled curved piezoelectric material | |
| EP0656605B1 (en) | Distance measuring device, and coordinate input apparatus utilizing the same | |
| EP0656604B1 (en) | Distance measuring device, and corresponding coordinate input apparatus | |
| CN104820526A (en) | Display apparatus, touch panel, and method for detecting touch incidents | |
| DE102009011871A1 (en) | Angular velocity detection device | |
| JP3270544B2 (en) | Coordinate input device | |
| JP5283134B2 (en) | Control device adaptable to touch screen frequency | |
| US6041284A (en) | Apparatus and method for determining coordinates of a designated point | |
| EP0368351A2 (en) | Coordinate input apparatus | |
| KR20140045209A (en) | Operating frequency optimizing apparatus and method of ultrasonic sensor | |
| JP2000321105A (en) | Flow rate measuring apparatus | |
| Schiopu et al. | Layer thickness measurement using ultrasonic waves | |
| KR200305086Y1 (en) | User interface method in the hand writing input system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20071017 Termination date: 20091221 |