Classifications

• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
  • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
  • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
  • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
  • G06F3/044—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means
  • G06F3/0446—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
  • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
  • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
  • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
  • G06F3/045—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
  • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
  • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
  • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
  • G06F3/047—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means using sets of wires, e.g. crossed wires
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F2203/00—Indexing scheme relating to G06F3/00 - G06F3/048
  • G06F2203/041—Indexing scheme relating to G06F3/041 - G06F3/045
  • G06F2203/04106—Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F2203/00—Indexing scheme relating to G06F3/00 - G06F3/048
  • G06F2203/041—Indexing scheme relating to G06F3/041 - G06F3/045
  • G06F2203/04111—Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate

Definitions

• the present invention relates to a capacitive / resistive alternating electronic analysis circuit for a passive matrix multicontact tactile sensor.
• the present invention relates to the field of passive matrix multicontact tactile sensors.
• This type of sensor is provided with means for simultaneous acquisition of the position, the pressure, the size, the shape and the displacement of several fingers on its surface, in order to control an equipment, preferably via an interface graphic.
• Said sensors can be used, in a non-limiting manner, as interfaces for personal computers, portable or not, cell phones, ATMs (banks, points of sale, ticketing), game consoles, multimedia players portable devices (digital walkmans), control of audiovisual equipment or appliances, control of industrial equipment, GPS navigators.
• Such a sensor is constituted by a tactile interaction surface having two non-parallel networks.
• Each network consists of a set of generally parallel tracks. These networks define between them nodes located at the projection of the intersection of one network on the other. At these nodes are provided physical measuring means delivering information depending on the presence on the corresponding contact area.
• each node corresponds to a measurement of voltage or capacitance at the terminals of the two network elements associated with the considered node.
• Each network is scanned sequentially and rapidly to recreate an image of the sensor several times per second.
• Said device further comprises an electronic analysis circuit for acquiring and analyzing the sensor data with a sampling frequency of 100 Hertz.
• the sensor can be divided into several zones in order to perform a parallel treatment on said zones. It comprises a matrix of conductive tracks, said matrix comprising supply means on one of the two axes, and means for detecting electrical characteristics on the other axis, at intersections between the two axes.
• the actual measured electrical characteristic can be resistance or capacitance. We will speak respectively of resistive or capacitive sensor.
• the choice of an electrical characteristic among the resistance and the capacitance gives rise to drawbacks making the retained solution unsuitable for various applications.
• the measure of the capacitance restricts contact with the fingers - or other object specific to capacitive sensors - while offering a better sensitivity to contact, the presence of a finger that can be measured before it is physically touched the sensor.
• the resistance measurement has a lower sensitivity, but is intended for any type of contact object, finger, stylus, or any object coming into contact with the surface of the sensor.
• the object of the present invention is to overcome this drawback by proposing an electronic analysis circuit for a multicontact transparent passive matrix touch sensor, this electronic analysis circuit being suitable for carrying out measurements of capacitance and resistance.
• a multipoint touch sensor comprising such an electronic analysis circuit can provide optimal and complete information in all circumstances.
• the present invention proposes an electronic analysis circuit for a passive matrix multicontact tactile sensor comprising means for supplying power to one of the two axes of the array, and means for detecting the electrical characteristics according to FIG. another axis of the matrix at the intersections between the two axes, characterized in that the measured electrical characteristic is alternately capacitance and resistance.
• a multi-point tactile sensor comprising such an electronic analysis circuit incorporates the advantages of capacitive measurement, ie a high sensitivity making it possible to detect the approach of the finger without necessarily having physical contact with the sensor, which provides an anticipated contact, so more subtle.
• This sensor also incorporates the advantages of resistive measurement, the reliability of the signal measured with any contact tool.
• the alternation of the measured electrical characteristic is conditioned by the detection of at least one artifact; the measured electrical characteristic is the resistance in the case of detection of at least one artifact.
• a multi-point touch sensor comprising such an electronic analysis circuit has the advantage of avoiding any artefact appearance problem that can occur regularly.
• the measurement performed is the resistive measurement, which offers a greater reliability of the measured information compared to the resistive measurement. This sensor is thus able to adapt according to the context to provide the best tactile information possible.
• the alternation of the measured electrical characteristic is conditioned by the receipt of a control signal.
• a multi-point touch sensor comprising such an electronic analysis circuit makes it possible to benefit from an adaptation, for example, to the type of contact tool of the user. Indeed, in the case of a measurement with a contact tool other than a finger (for example a stylus), the resistive measurement will be preferred. In the case of a measurement with a finger, the capacitive measurement will provide the optimal information.
• the user uses for example a stylus
• he can activate a control signal delivering information towards the multipoint touch sensor so that the latter operates in a resistive measurement mode.
• he uses a finger instead, no signal will be delivered and the multi-touch sensor will operate in a resistive measurement mode.
• the measured electrical characteristic is the resistance at each scanning phase of the sensor.
• an additional measure of capacity is operated on this zone as a whole in order to determine the nature of this contact.
• the measured capacity will be different from the reference capacity of the sensor. If on the contrary, it is a stylus, the measured capacity will be unchanged.
• the measured electrical characteristic is the resistance to each scanning phase of the sensor.
• the measured electrical characteristic is the capacity at each scanning phase of the sensor.
• an additional measure of resistance is operated on this graphic object as a whole in order to determine the force exerted by this contact on this graphic object. This allows for example to validate or invalidate whether a contact is intentional or not. Indeed, it is possible thanks to this technique to differentiate a touch of a support.
• the present invention also relates to a multicontact passive matrix touch sensor comprising means for supplying power to one of the two axes of the matrix, and means for detecting electrical characteristics along the other axis of the matrix, at intersections between the two axes, said touch sensor also comprising an electronic analysis circuit according to any one of the embodiments above.
• a sensor thus has three modes of operation each having different advantages: a periodic mode, a mode conditioned by the detection of artifact and a mode conditioned by the reception of a control signal.
• the mode conditioned by the reception of a control signal may have priority over the conditioned mode by the artefact detection, which itself may have priority over the periodic mode.
• FIG. 1 a view of a passive matrix multicontact tactile display
• FIG. 2 a diagram of a data acquisition method on the entire tactile sensor, implemented by an electronic circuit according to the present invention.
• FIG. 3 is a diagram of a data analysis method implemented by an electronic circuit according to the present invention;
• FIG. 4 is a diagram of an acquisition and analysis method implemented in FIG. implemented by an electronic circuit according to a first embodiment of the present invention, this method comprising periodic capacitive / resistive alternation,
• FIG. 5 a diagram of an acquisition and analysis method implemented by a circuit. in accordance with a second exemplary embodiment of the present invention, this method comprising a capacitive / resistive alternation conditioned by the possible detection of an artifact, FIG.
• FIG. 6 a diagram of a method of acquisition and analysis implemented by an electronic circuit according to a third embodiment of the present invention, this method comprising a capacitive / resistive alternation conditioned by the reception of a control signal;
• FIG. 7 a diagram of an acquisition and analysis method implemented by an electronic circuit according to a fourth embodiment of the present invention, this method comprising a capacitive / resistive alternation conditioned by the reception of a control signal,
• FIG. 8 a timing diagram relating to the detection of a contact according to the method according to the fourth embodiment
• FIGS. 9A to 9D diagrams of a touch screen during contacts during the process according to the fourth exemplary embodiment
• FIG. 10 a diagram of an acquisition and analysis method implemented by a circuit. electronic circuit according to a fifth embodiment of the present invention, this method comprising a capacitive / resistive alternation conditioned by the reception of a control signal,
• FIG. 11 a timing diagram relating to the detection of a contact according to the method according to the fifth exemplary embodiment.
• FIGS. 12A to 12D diagrams of a touch screen during contacts during the process according to the fifth embodiment of FIG.
• An electronic analysis circuit in accordance with the invention aims to integrate into a passive matrix multicontact tactile sensor.
• FIG. 1 represents a view of a tactile electronic device comprising:
• main processor 4 a main processor 4
• graphic processor 5 a graphic processor 5.
• the first fundamental element of said touch device is the touch sensor 1, necessary for the acquisition - the multicontact manipulation - using a capture interface 3.
• This capture interface 3 contains the electronic circuits for acquisition and control. analysis.
• Said touch sensor 1 is of the matrix type. Said sensor can be optionally divided into several parts in order to accelerate the capture, each part being scanned simultaneously.
• Data from the capture interface 3 is transmitted after filtering to the main processor 4.
• the main processor 4 also transmits to the graphical interface the data to be displayed on the display screen 2.
• This graphic interface can also be driven by a graphics processor 5.
• the touch sensor is controlled in the following way: one feeds successively, during a first phase of scanning, the tracks of one of the networks and the response is detected on each of the tracks of the second network.
• Contact zones corresponding to the nodes whose state is modified with respect to the idle state are determined as a function of these responses.
• One or more sets of adjacent nodes are determined whose state is changed. A set of such adjacent nodes defines a contact area. From this set of nodes is computed a position information qualified in the sense of the present cursor patent. In the case of several sets of nodes separated by non-active zones, several independent cursors will be determined during the same scanning phase.
• This information is refreshed periodically during new scan phases.
• Cursors are created, tracked or destroyed based on information obtained during successive scans.
• the cursor is for example calculated by a barycentre function of the contact zone.
• the general principle is to create as many sliders as there are zones detected on the touch sensor and to follow their evolution over time. When the user removes his fingers from the sensor, the associated sliders are destroyed. In this way, it is possible to capture the position and the evolution of several fingers on the touch sensor simultaneously.
• the actual measured electrical characteristic can be resistance or capacitance.
• the electrical characteristics - voltage, capacitance or inductance - are measured at the terminals of each node of the matrix.
• the main processor 4 executes the program for associating the sensor data with graphical objects that are displayed on the viewing screen 2 in order to be manipulated.
• FIG. 2 shows a diagram of the process
• the sensor comprises M rows and N columns.
• This method has the function of determining the state of each node of the matrix sensor 1, namely whether said node is activated or not.
• Said method corresponds to the measurement of all the nodes of a "voltage" matrix.
• Said matrix is a matrix [N, M] containing at each point (I, J) the value of the voltage measured at the intersection point of line I and column J, with l ⁇ I ⁇ N and l ⁇ J ⁇ M. This matrix makes it possible to give the state of each of the points of the matrix sensor 1 at a given instant.
• the acquisition method 11 begins with an initialization step 12 of the data obtained during a previous acquisition.
• the axis of the columns constitutes the axis of supply and the axis of the lines constitutes the axis of detection.
• the line axis constitutes the feed axis and the axis of the columns constitutes the detection axis.
• the method 11 first scans the first column. It is powered for example in 5 volts.
• the electronic circuit measures an electrical characteristic at the point of intersection between said column and each of the lines from 1 to N.
• the process goes to the next column and starts again the measurements of electrical characteristics at the intersection of the new column considered and of each of the lines from 1 to N.
• FIG. 3 represents a diagram of the analysis method 21 of the data implemented by the electronic circuit.
• Said method 21 consists of a series of algorithms carrying out the following steps:
• the software is able to apply to the virtual graphic objects of the tactile electronic device the various specific processes in order to refresh said tactile electronic device in real time. Areas encompassing the contact areas, detected during the data acquisition step 11, are also defined.
• FIG. 4 represents a diagram of a method 31 of acquisition and analysis implemented by an electronic circuit according to a first embodiment of the present invention.
• Said method 31 is a capacitive / resistive measurement alternating method, said alternation being periodic.
• the circuit electronics performs step 32 corresponding to the succession of acquisition steps 11 and analysis 21 with the capacitance as the measured electrical characteristic.
• step 33 a new step is performed, this step 33 corresponding to the succession of acquisition steps 11 and analysis 21 with this time the resistance as the measured electrical characteristic.
• the method 31 performs a loop comprising the succession of steps 32 and 33. It thus alternates the measurements of electrical characteristics selected from the capacitance and the resistance.
• the method realizes K times the first step 32, then L times the second step 33, K and L being integers of which at least one is strictly greater than 1.
• the refresh rate is of the order of 100 Hz.
• FIG. 5 represents a diagram of a method 41 of acquisition and analysis implemented by an electronic circuit according to a second embodiment of the present invention.
• Said method 41 is a capacitive / resistive measurement alternating method, said alternation being conditioned by the possible detection of an artifact.
• the method 41 performs steps 32 and 33.
• transition from one to the other of steps 32 and 33 is conditioned by the possible detection of an artefact resulting from each of the analysis steps 21 performed in steps 32 and 33.
• step 21 implemented during step 32 or 33, the electronic circuit determines whether an artefact-type parasitic phenomenon is present on the least part of the matrix sensor 1 whose status data of each of the nodes have been acquired and analyzed. If no artifact is detected at the output of step 32 or 33, then the process loops back to the same step. If an artifact has been detected, then the process alternates step.
• step 32 For example, if an artifact is not detected at the output of step 32, the method loops back to said step 32, but if an artifact is actually detected, the method alternates at step 33.
• FIG. 6 represents a diagram of a method 51 of acquisition and analysis implemented by an electronic circuit according to a third embodiment of the present invention.
• Said method 51 is a capacitive / resistive measurement alternating method, said alternation being conditioned by a control signal.
• the method performs steps 32 and 33.
• step 21 implemented during step 32 or 33, the electronic circuit determines whether it has received a control signal between said step and the previous one. If no control signal has been received, then the process loops back to the same step. If a control signal has been received, then the method alternates the step.
• step 32 For example, if a control signal has been received at the output of step 32, the method loops over said step 32, but if a control signal has actually been received, the method alternates on step 33.
• Such a control signal may for example be operated by the user of the multipoint tactile electronic device. Indeed, this user can only use the capacitive measurement if his contact tool is a finger. If not, he is forced to use a resistive measure. Thus, when the user uses for example a stylus, he can activate a control signal delivering information towards the multi-touch sensor 1 so that the latter operates in a resistive measurement mode.
• the characteristic measured at each scanning phase is the resistance, point by point, over the entire sensor (step 32). We then obtain information on the existence of a possible contact. If a contact is detected in at least one point, the measured characteristic becomes the capacity for a single measurement, on a block of points included in the sensor (step 34). This block corresponds to the cursor created following the detection (step 13) of the contact in resistive mode.
• This capacitive measurement (step 14) on this slider - or contact zone - then provides, after analysis (step 21) and deduction (step 35), information on the nature of the contact, namely whether the contact means is a finger (detected by a capacitive measurement) or a stylus (not detected by a capacitive measurement).
• a first contact 81 with a finger and a second contact with a stylus are detected on the touch screen 80 during a resistive measurement.
• a capacitive measurement is then carried out on these two contact zones 81 and 82.
• This measurement allows the detection of a contact in the zone of the first contact 81 (finger ) and gets no detection on the area of the second contact 82 (stylus).
• FIG. 9D it is thus possible to discriminate the two types of contacts, that is to say a finger 1 for the first contact 81 and a stylus 1 for the second contact 82.
• This capacitive measurement is performed once on this cursor created (FIG. 8), the nature of the contact formed by this cursor can not a priori not change as long as it is maintained, and parallel scanning phases are carried out. in resistive mode.
• This variant of the electronic analysis circuit makes it possible to determine the nature of the contact in order to take it into account, for example to adapt the accuracy of the next resistive measurement - the resolution to be greater for a stylus - or to reject a contact if its nature is not one that the touch sensor or part of it is likely to tolerate.
• the measurements are made in resistive mode on the entire sensor, point by point, at each scanning phase. If a release of the cursor corresponding to this contact is detected, a capacitive measurement is made on the cursor area in one block. This measurement makes it possible to determine whether the finger is always close to the relaxed contact zone, which is a sign of an unexpected release of the finger during prolonged contact (for example when handling a graphic object corresponding to a drop-down window).
• This variant of the electronic analysis circuit thus makes it possible not to lose a cursor defined by a finger when this loss of the cursor is not intentional.
• a graphic object is secured.
• a capacitive measurement is performed on a graphic object to be secured, point by point, at each scanning phase (step 32).
• a contact is detected according to this capacitive mode, it is proceeded to a detection of the contact zone (step 13), then to a measurement in resistive mode (step 15) on the whole of the graphic object, which makes it possible to obtain after analysis (step 21) information on the force exerted by the detected contact. It is then proceeded to the following deduction (step 35): if this force does not exceed a threshold value, the contact is insufficient and is not considered as a contact giving rise to the creation of a cursor. Otherwise, the cursor is created.
• three contacts 83 (graphic object 91), 84 and 85 (graphic object 92) with a finger are detected on the touch screen 80 during a capacitive measurement.
• a resistive measurement is then carried out on the graphic object 91 or 92 associated with each contact zone.
• This measurement enables the detection of a contact in the zones of the three contacts 83, 84 and 85.
• FIG. 12D it is thus possible to validate the fact that the three contacts are intentional and not accidental contacts.
• another contact had been detected on the touch screen 80 during the capacitive measurement, corresponding for example to a touch, it would not have been detected during the resistive measurement and therefore would not have been valid.
• This resistive measurement is performed once on this cursor created (FIG. 11), the nature of the contact constituted by this cursor can not a priori not change as long as it is maintained, and parallel scanning phases are carried out. in capacitive mode.
• a multi-point tactile display incorporating an electronic analysis circuit according to any one of the previously described embodiments has the advantage of combining the advantages of a capacitive measurement - better sensitivity of the "touch" - and a resistive measurement. - adaptation to any type of contact tool - without being constrained by the respective disadvantages. Such a multi-touch display is therefore able to provide in all circumstances optimal and complete information.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Theoretical Computer Science (AREA)
• Human Computer Interaction (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Position Input By Displaying (AREA)
• User Interface Of Digital Computer (AREA)

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Citations (5)

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• 2007
  • 2007-12-19 FR FR0760015A patent/FR2925714B1/fr not_active Expired - Fee Related
• 2008
  • 2008-12-19 CA CA2709696A patent/CA2709696A1/fr not_active Abandoned
  • 2008-12-19 JP JP2010538845A patent/JP2011507121A/ja active Pending
  • 2008-12-19 EP EP08872788A patent/EP2235614B1/fr not_active Not-in-force
  • 2008-12-19 US US12/809,434 patent/US20100289508A1/en not_active Abandoned
  • 2008-12-19 CN CN2008801219926A patent/CN101903855B/zh not_active Expired - Fee Related
  • 2008-12-19 WO PCT/FR2008/001805 patent/WO2009106736A1/fr not_active Ceased
  • 2008-12-19 KR KR1020107015950A patent/KR20100098706A/ko not_active Withdrawn

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