Classifications

• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR 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
  • G06F3/033—Pointing devices displaced or positioned by the user, e.g. mice, trackballs, pens or joysticks; Accessories therefor
  • G06F3/0354—Pointing devices displaced or positioned by the user, e.g. mice, trackballs, pens or joysticks; Accessories therefor with detection of 2D relative movements between the device, or an operating part thereof, and a plane or surface, e.g. 2D mice, trackballs, pens or pucks
  • G06F3/03545—Pens or stylus

Definitions

• the present invention relates to a device of the type specified in the preamble of claim 1 , a method of the type specified in the preamble of claim 10 as well as a system of the type specified in the preamble of claim 1.
• Modern digital input devices can be controlled via a touch-sensitive, electrically capacitively acting input interface, referred to as electrically capacitively acting touchpad or simply as touchpad hereinafter.
• Particularly widely used devices are capacitively acting systems, in which e.g. a grid of conductors or a grid of electrodes applied to the lower surface of the cover of the input interface has an AC voltage applied thereto.
• the finger or the pointing device and the conductors or the electrodes define the two plates of a capacitor and the cover of the touchpad defines the dielectric thereof.
• the conductors or electrodes are part of an RC element, i.e. part of a circuit comprising a resistor and a capacitor, the change of capacitance caused by the approaching finger or pointing device can be measured and the touch point can be determined in this way.
• US 7 612 767 B1 describes such a conventional pointing device for a touchpad, the tip of said pointing device being capable of receiving the electric charges from the AC voltage-generated, projected-capacitive sensor field of the input interface and of causing an increase of the capacitance or of the effective capacitance of the pointing device by generating a countervoltage, so that the pointing device is able to influence, via the electrical capacitive coupling to the input interface, an electric charge accumulation on the input interface in a manner that can be interpreted by the input interface of the digital input device as touch of a finger.
• the above pointing devices and digital input devices exhibit disadvantages e.g. insofar as they are not able to differentiate whether the input interface is touched by an electronic pointing device or whether it is touched by a user's hand or finger.
• known pointing devices have a comparatively large contact surface of their tip and this may also be disadvantageous not least to the compactness and ergonomics of the pointing device.
• conventional electronic pointing devices cannot be used universally for all existing digital input devices having an electrically capacitively acting touchpad, but they can only be used for the subset of electrically capacitively acting touchpads whose evaluation electronics is capable of recognizing the electronic pointing device used.
• An electronic pointing device for carrying out inputs at a digital input device with an electrically capacitively acting touchpad, wherein the electronic pointing device is electrically capacitively coupled to an electrical measurement signal of the touchpad, may comprise at least one electronic circuit component configured for modulating the electrical capacitance in the tip of the electronic pointing device.
• the term electronic circuit component may here comprise an electronic circuit or a plurality of electronic circuits comprising at least one electronic component.
• the term electrical measurement signal is here intended to stand in particular for an electrical measurement signal that may comprise a series of electrical measurement pulses, in particular e.g. a series of alternating current pulses.
• modulation of the electrical capacitance in the tip of the electronic pointing device may in particular be understood as a sequence or as the modulation of a sequence of changes of the capacitance state or of the effective capacitance of the tip of the electronic pointing device.
• modulation of the electrical capacitance in the tip of the electronic pointing device may additionally comprise changes of the capacitance state, in the case of which the sign of the capacitance and/or the magnitude of the capacitance value and/or the duration of the capacitance state are changed.
• modulation of the electrical capacitance in the tip of the electronic pointing device may comprise periodic or non-periodic changes of the capacitance state at specific time intervals or specific time distances.
• the electronic circuit component of the electronic pointing device may be configured to carry out a modulation of the electrical capacitance of the tip of the electronic pointing device such that a changeover between e.g. at least two capacitance states of the tip can be effected, wherein at least one capacitance state may assume a capacitance value that may lie below a predetermined capacitance value, e.g. below a capacitance detection threshold value of the touchpad of a digital input device.
• the electronic circuit component of the electronic pointing device may additionally be configured to carry out a modulation of the electrical capacitance of the tip of the electronic pointing device such that a changeover between at least two capacitance states of the tip can be effected, wherein at least one capacitance state may assume a capacitance value that is equal to or higher than a predetermined capacitance value, e.g. a capacitance detection threshold value of the touchpad of a digital input device.
• a predetermined capacitance value e.g. a capacitance detection threshold value of the touchpad of a digital input device.
• the electronic circuit component of the electronic pointing device may additionally also be configured to changeover selectively and/or automatically between the above mentioned modulations.
• the electronic circuit component may be configured to carry out a modulation of the electrical capacitance of the tip of the electronic pointing device such that a changeover between at least two capacitance states of the tip can be effected, wherein at least one capacitance state may assume a capacitance value that lies below a predetermined capacitance value, e.g. below a capacitance detection threshold value of the touchpad of a digital input device, and wherein at least one capacitance state may assume a capacitance value that is equal to or higher than a predetermined capacitance value, e.g. a capacitance detection threshold value of the touchpad of a digital input device.
• the electronic pointing device according to the present invention offers numerous advantages in comparison with known electronic pointing devices.
• contacting of the touchpad by the electronic pointing device can advantageously be differentiated from contacting of the touchpad by the user's hand or fingers, in particular e.g. through the modulation of the electrical capacitance in the tip of the electronic pointing device according to the present invention, since the user's hand or fingers do not exhibit an electrical capacitance modulation according to the present invention.
• the modulation of the electrical capacitance in the tip of the electronic pointing device by the electronic circuit component comprises, as mentioned hereinbefore, e.g. capacitance states with capacitance values that lie below a capacitance detection threshold value of the touchpad of a digital input device, i.e. capacitance states with capacitance values at which the touchpad would neither detect nor register a touch, it can be achieved that the touchpad will alternately, i.e. according to the modulation realized, recognize and non- recognize a touch.
• the electronic pointing device according to the present invention can cause a modulation of the electrical capacitance registered by the touchpad, or the digital input device, that is different from the modulation caused by the user's hand or fingers.
• the modulation of the electrical capacitance in the tip of the electronic pointing device can be used for adapting the electronic pointing device to the sensitivity of the touchpad of the digital input device, i.e. to the touchpad sensitivity with which electrically capacitive signals can be registered.
• the modulation of the electrical capacitance in the tip of the electronic pointing device by the electronic circuit component comprises e.g. capacitance states with capacitance values which are equal to or higher than a predetermined capacitance value, e.g. a capacitance detection threshold value of the touchpad of a digital input device, it can advantageously be guaranteed that the touchpad of the digital input device will reliably recognize when it is being touched by the electronic pointing device.
• the electronic pointing device can be operated universally with each electrically capacitively acting touchpad of a digital input device, independently of the electrically capacitive sensitivity of the touchpad.
• the electronic circuit component of the electronic pointing device may also be configured to carry out a modulation of a sequence of capacitance state changes such that capacitance states are changed individually or in groups.
• the electronic circuit component may e.g. be configured as follows and allow the mode of operation described hereinafter.
• a small capacitive charge displacement current can flow between the touchpad and the tip.
• This displacement current taken up by the tip may e.g. flow first across a capacitor to a local ground potential of a voltage-to-current converter.
• the voltage-to-current converter may additionally also comprise an impedance converter and it may be provided with a plurality of outputs, e.g. a current output and optionally a voltage output.
• the current at the current output of the voltage-to-current converter may here be an image of the voltage drop across said capacitor. Since the touch capacitance or contact capacitance can form a capacitive voltage divider in combination with the capacitor, the voltage at the input of the voltage-to-current converter and, consequently, the current at its current output can be in phase with the electrical measurement signal of the touchpad and the measurement voltage of the touchpad, respectively.
• the current at the current output of the voltage-to-current converter can then be converted via a resistor into a voltage relative to a system ground.
• This voltage can be amplified via an amplifier and fed into the local ground potential of the voltage-to-current converter.
• the effective amplification and the polarity of the amplification can be adjusted in a suitable manner, e.g. via a control signal of a digital control unit, e.g. a microcontroller.
• the optional voltage output of the voltage-to-current converter or impedance converter it is possible to supply e.g. the input voltage applied to the voltage-to-current converter / impedance converter, or an image of the voltage at the tip of the electronic pointing device, to the / an amplifier.
• the electrical capacitance in the tip of the electronic pointing device can be increased or reduced, e.g. with respect to a reference capacitance or limit capacitance.
• the above mentioned voltage which is opposite in phase to the voltage at said capacitor of the tip may also be referred to as countervoltage, and the above mentioned voltage which is in phase with the voltage at said capacitor of the tip may also be referred to as cooperative voltage.
• the electronic circuit component can be regarded as a current-controlled negative impedance converter.
• a countervoltage generated by the electronic circuit component, or an inverse voltage generated with respect to the touchpad may here have an effect as if a negative capacitance were connected in series with the capacitance between the tip and the touchpad, a circumstance that can be registered by the touchpad as an increased capacitance.
• the electronic circuit component may be configured to limit the magnitude of a countervoltage, generated for modulating the electrical capacitance of the tip of the electronic pointing device, to a maximum value, so as to avoid undesirable electrical oscillations of the electrically capacitive coupling between the pointing device and the touchpad.
• the regulation of the countervoltage for stabilizing the function and the operation of the electronic circuit component and of the electronic pointing device, respectively, may here take place dynamically.
• the digital control unit e.g. a microcontroller
• the digital control unit may continuously measure, monitor and regulate the amplitude of the countervoltage, so that, if necessary, the countervoltage can be reduced so as to avoid said undesirable electrical oscillations; it can, however, be guaranteed that a sufficiently high countervoltage can be generated, which is capable of creating in the tip of the electronic pointing device an electrical capacitance that can be detected and recognized by the touchpad.
• the electronic circuit component may additionally be configured to carry out the modulation of the electrical capacitance in the tip of the electronic pointing device in time synchronism with a measuring frequency of the digital input device at which contact position determination sensors of the touchpad, e.g. electrodes, are queried.
• Such a synchronization of the modulation of the electrical capacitance in the tip with the measurement cycles of the touchpad for contact position determination can advantageously allow defining unequivocal capacitance modulations, which can be recognized by the evaluation electronics of the touchpad in a particularly simple and clear manner.
• modulation patterns are imaginable, according to which the tip of the electronic pointing device assumes a first capacitance state e.g. over three measurement cycles of the touchpad, followed by two measurement cycles of the touchpad, in which the tip of the electronic pointing device assumes a second capacitance state.
• the recognition of a measurement cycle of the touchpad of the electronic pointing device may here take place e.g. through an amplitude measurement of the voltage taken up through the contact with the touchpad.
• the modulation of the electrical capacitance in the tip of the electronic pointing device according to the present invention allows the tip of the electronic pointing device to be implemented more compact in comparison with conventional electronic pointing devices, and e.g. the area of the tip which can be brought into contact with the touchpad may have mean diameters of less than 3 mm.
• the contact area at the tip of the electronic pointing device may have mean diameters of 2 - 3 mm, e.g. for accomplishing an advantageous ergonomic design and/or a higher accuracy of inputs at the touchpad.
• the modulation of the electrical capacitance in the tip of the electronic pointing device according to the present invention in comparison with conventional electronic pointing devices allows e.g. the use of thinner tips or of tips with smaller diameters, and thus also improves advantageously the accuracy with which inputs can be carried out by means of the electronic pointing device on a touchpad of a digital input device, since a higher resolution of contact positions on the touchpad can be supported.
• a method according to the present invention used for carrying out inputs at a digital input device with an electrically capacitively acting input surface, i.e. with a touchpad, by means of an electronic pointing device, may comprise e.g. the following steps: receiving an electrical measurement signal of the touchpad at the electronic pointing device, modulating the electrical capacitance in the tip of the electronic pointing device.
• a system according to the present invention used for carrying out and recording inputs at a digital input device with an electrically capacitively acting touchpad, may comprise the following components: a digital input device with an electrically capacitively acting touchpad, an electronic pointing device for carrying out inputs at said digital input device, wherein the electronic pointing device is electrically capacitively coupled to an electrical measurement signal of the touchpad, wherein the electronic pointing device is configured for receiving an electrical measurement signal of the touchpad, and wherein the electronic pointing device comprises at least one electronic circuit component, which may be configured for modulating the electrical capacitance in the tip of the electronic pointing device.
• Fig. 1 an exemplary system for digital inputs
• FIG. 2 an exemplary electronic circuit component Fig. 1 shows an exemplary system 100 for carrying out and recording inputs 107 by means of an exemplary electronic pointing device 101 at a digital input device 102 with an electrically ca- pacitively acting, touch-sensitive input interface / electrically capacitively acting touchpad 108.
• the electronic pointing device 101 may additionally comprise an electrically conductive rod whose tip 104 can be projected from the end part 105 that may also be configured as an electrically conductive component.
• the electronic pointing device 101 may be electrically capacitively coupled to an electrical measurement signal of the touchpad 108 and may receive, e.g. via the tip 104, an electrical measurement signal of the touchpad 108 of the digital input device 102.
• the tip 104 of the electronic pointing device 101 may here be part of an electronic circuit component according to the present invention or may be electrically connected to an electronic circuit component according to the present invention (not shown).
• the parts of the electronic circuit component may be arranged as close as possible to the pointing device tip and may be electrically shielded.
• a digital control unit, microcontrollers and/or a local voltage supply may, however, be arranged more remote from the pointing device tip.
• the digital input device 102 may optionally be configured for transmitting a control signal to the electronic pointing device 101.
• Said control signal may comprise information on the signal strength of an electrical measurement signal triggered by the electronic pointing device on the touchpad 108, so as to determine a position on the touchpad 108.
• the digital input device 102 may comprise e.g. at least one speaker 109 that is capable of transmitting control signals to the electronic pointing device 101 by sound, e.g. by ultrasound.
• the electronic pointing device 101 may include at least one microphone 103.
• the microphone 103 used for receiving the control signals may e.g. be accommodated below a gripping section 106 in an end part 105 of the electronic pointing device 101.
• the electronic pointing device 101 may modulate the electrical capacitance of the tip 104 of the electronic pointing device 101 depending on the received control signal, so as to determine the position of a contact point on the touchpad 108,
• Fig 2 shows exemplarily a possible embodiment of an electronic circuit component 200, or of an electronic circuit, which is intended to be used in an electronic pointing device, e.g. the pointing device 101 , and which may be configured and operated as described hereinafter.
• the touchpad of a digital input device may, as mentioned above, generate an electrical measurement signal, e.g. a sequence of alternating current pulses.
• a small capacitive displacement current can flow via an electrically capacitive coupling between the touchpad and the tip.
• This displacement current can flow via an optional (first) capacitor 202, which can serve as protection against direct current voltage components when the tip comes into contact with the touchpad, and, optionally, via an additional capacitor 203 to a local ground potential of an input component, e.g. to a local ground potential 211 of a voltage-to-current converter 204.
• an optional (first) capacitor 202 which can serve as protection against direct current voltage components when the tip comes into contact with the touchpad
• an additional capacitor 203 to a local ground potential of an input component, e.g. to a local ground potential 211 of a voltage-to-current converter 204.
• the voltage-to-current converter 204 may be provided with an independent local voltage supply and a local voltage source, respectively.
• the voltage-to-current converter 204 may additionally also comprise an impedance converter as well as a plurality of outputs, e.g. a current output and optionally a voltage output.
• the current at an output, e.g. at the current output, of the voltage-to-current converter 204 may be regarded as an image of the voltage drop across the capacitor 203. Since the capacitance, which exists when the tip and the touchpad touch one another and which is e.g. referred to as touch capacitance, can form a capacitive voltage divider in combination with the capacitor 203, the voltage at the input of the voltage-to-current converter 204 and, consequently, the current at its current output can be in phase with the electrical measurement signal of the touchpad and in phase with a measurement voltage of the touchpad, respectively.
• the current at the current output of the voltage-to-current converter 204 can be converted via the resistor 205 into a voltage relative to the system ground 210.
• This voltage can be amplified via the amplifier 207 and fed into the local ground potential 21 1 of the voltage-to-current converter 204. in so doing, the effective amplification and the polarity of the amplification can be adjusted and regulated in a suitable manner, e.g. via a control signal 213 from a digital control unit, e.g. the microcontroller 208.
• the amplification of the amplifier 207 can be adjusted by the microcontroller 208 via the control signal 213 such that the voltage at the local ground 211 is opposite in phase to the voltage across the capacitor 203.
• the local ground 21 1 can here be independent of the system ground 210.
• the voltage-to- current converter 204 may therefore have a voltage supply 209 of its own.
• the effect which the rise in the displacement current has on the touchpad corresponds to that of an increased capacitance.
• the countervoltage may here preferably be adjusted to a sufficiently high value for the touchpad to recognize a sufficiently high capacitance so that touching of the touchpad through the tip of the pointing device can be recognized.
• the degree of cooperative coupling may here depend on the touch capacitance between the touchpad and the tip 201.
• the cooperative coupling may here increase to such an extent that the electrically capacitively coupled system starts oscillating.
• the microcontroller 208 is able to measure and monitor the countervoltage, e.g. through an amplitude measurement 206 carried out e.g. between the diode 215 and the capacitor 216.
• the microcontroller 208 is capable of adjusting the amplification via a control signal 213 such that, on the one hand, a sufficiently high countervoltage can be generated, whereas, on the other hand, undesired electrical oscillation can be avoided.
• the level of the displacement current may depend on the effective capacitance, i.e. on the touch area of the tip 201. A higher capacitance may lead to an increase in the displacement current.
• the circuit may start oscillating in the case of an excessively high amplification.
• the countervoltage should, however, be as high as possible so that a good function can be guaranteed.
• the amplification should preferably be adjusted and corrected in a suitable manner during operation.
• microcontroller 208 It is able to measure the countervoltage and to adjust it to e.g. the maximum admissible value at which oscillations will not yet occur.
• microcontroller 208 is able to measure the maximum and the minimum countervoltage.
• a countervoltage will, e.g. in the case of a correct adjustment, be created only if the touchpad is just carrying a voltage. In the possible measurement voltage pauses of the touchpad, no countervoltage will be created.
• the microcontroller 208 can evaluate this and adjust the amplification such that the maximum countervoltage reaches a value at which significant distortions will not yet occur. In addition, the microcontroller 208 can ensure that no voltage and thus no oscillations will occur in the pauses.
• the microcontroller Via a control signal 212 for controlling and regulating the modulation of the electrical capacitance or of the electrically effective capacitance in the tip of the electronic pointing device, and optionally e.g. by the use of a switch 214, the microcontroller is able to modulate and e.g. block the creation of the countervoltage.
• Blocking may e.g. lead to a decrease in capacitance below the detection threshold of the touch- pad.
• a touch will alternately be recognized and not be recognized by the touchpad. This allows to differentiate in an advantageous manner between the pointing device tip and the user's hand.
• the microcontroller 208 is able to detect, e.g. through the amplitude measurement 206, the measurement times of the touchpad, it is here additionally possible to carry out the modulation of the countervoltage, or the modulation of the electrical capacitance or of the electrically effective capacitance in the tip of the electronic pointing device, synchronously with the measurement cycles of the touchpad.
• This ai!ows e.g. unequivocal patterns, e.g. three measurement cycles active, two measurement cycles inactive, which can be recognized by the evaluation electronics of the digital input device in a particularly clear manner.
• the electronic circuit component 200 represents a current-controlled negative impedance converter, in which a positive current at the tip 201 leads to a negative voltage at the tip 201 and vice versa.
• This voltage variation may lead to an increase in the current flowing into the tip 201.
• the effective capacitance between the touchpad and the tip can increase in accordance with the voltage amplification of the circuit 200.
• it can be guaranteed that even very thin pointing device tips, having e.g. a mean diameter of less than 3 mm, can be recognized by the touchpad.
• the capacitance of the tip can be reduced, so that a modulation of the capacitance is possible also in this case.
• the optional voltage output of the voltage-to-current converter 204 or impedance converter it is possible to supply e.g. the input voltage applied to the voltage-to-current converter / impedance converter, or an image of the voltage at the tip of the electronic pointing device, directly, e.g. via a connection 217, to the amplifier 207.
• the voltage fed by the amplifier 207 may thus be in phase with the voltage across the capacitor 203 or in phase with the voltage at the voltage output of the voltage-to- current converter 204 or e.g. in phase with the input voltage.
• a current that flows into the tip 201 can then lead to a voltage rise at the local ground 21 1. This can lead to a reduction of the capacitance of the pointing device tip. With a sufficiently high gain, the capacitance of the tip may then fall below the detection threshold of the touchpad.
• a system amplification of slightly less than 1 may already allow a sufficient reduction of the capacitance of the pointing device tip.
• a high, non-inverting amplification may be chosen e.g. via the control 213 of the amplification 213.
• the electronic circuit component is able to switch between the described operating possibilities, i.e. it can selectively and automatically change between a modulation with increased capacitance in comparison with a predetermined capacitance value (use case 1) and a modulation with reduced capacitance in comparison with a predetermined capacitance value (use case 2),
• Comparatively insensitive touchpads according to use case 1 are able to reliably recognize e.g. the capacitance increased through the countervoltage. Although the capacitance reduced by a cooperative voltage would not be necessary, it would certainly be recognized as "not touched”.
• Comparatively sensitive touchpads according to use case 2 would e.g. already recognize a normal touch without any countervoltage, but the capacitance increased by the countervoltage does not disturb.
• the case "not touched” could, however, be recognized through the capacitance reduced by means of the cooperative voltage.
• the reference numerals identify the following: system for carrying out and recording inputs at a digital input device with an electrically capacitively acting, touch-sensitive input interface / electrically capacitively acting touch- pad
• (first) capacitor used e.g. as a protection capacitor against direct current voltage components when the tip of the electronic pointing device enters into contact with the touch- pad
• voltage-to-current converter may optionally also comprise an additional impedance converter
• microcontroller e.g. microcontroller
• the digital control unit e.g. microcontroller
• the amplifier or e.g. connection of the digital control unit to a switch, for controlling and regulating the modulation of the electrical capacitance or of the electrically effective capacitance in the tip of the electronic pointing device / control signal for controlling and regulating the modulation of the electrical capacitance or of the electrically effective capacitance in the tip of the electronic pointing device
• the switch e.g. controlled by the digital control unit, e.g. microcontroller, for controlling and regulating the modulation of the electrical capacitance or of the electrically effective capacitance in the tip of the electronic pointing device

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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)

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Citations (6)

• 2015
  • 2015-10-23 DE DE202015105664.8U patent/DE202015105664U1/de active Active
• 2016
  • 2016-10-21 WO PCT/EP2016/075354 patent/WO2017068111A1/en active Application Filing

Patent Citations (6)

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