JP2011003071A - Proximity detection device and proximity detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To present a proximity detection device and a proximity detection method, allowing low-voltage drive and drive with low power consumption.SOLUTION: The proximity detection device includes: a transmission electrode 3 and a reception electrode 4 installed in a detection area 2 on a support board 1; a multi-line drive means 5 for simultaneously applying periodic AC voltage to two or more electrodes of the transmission electrode 3; a current measurement means 6 for measuring current or a charge amount from the reception electrode 4 in synchronization with drive to the transmission electrode 3; an arithmetic means 10 for obtaining a proximity position or proximity of an object to the detection area 2; and a control means 9a for managing a sequence and status of the whole. The control means 9a includes: a timing signal generation means 40; and a current measurement switch control means 43 for controlling supply of power.

Description

  The present invention relates to a proximity detection device that detects the approach and position of an object such as a human finger by a change in electrostatic capacitance at each intersection of a plurality of electrodes arranged corresponding to two-dimensional coordinates.

  It is known that a conventional proximity detection device changes the capacitance between electrodes when an object such as a human finger approaches between two electrodes arranged in the vicinity. An electrostatic touch sensor that applies this principle to detection of capacitance at each intersection of a plurality of electrodes arranged corresponding to the two-dimensional coordinates of a detection region, and a proximity detection device capable of simultaneous detection of a plurality of points (For example, refer to Patent Document 1).

  An example of a conventional proximity detection device will be described with reference to FIG.

  In the example of FIG. 2, the transmission electrode 3 corresponding to the vertical coordinate and the reception electrode 4 corresponding to the horizontal coordinate are arranged orthogonal to each other in the detection region 2 of the support substrate 1. A periodic AC voltage is applied to the plurality of electrodes simultaneously from the multiline driving means 5 to the transmission electrode 3. This AC voltage is transmitted to the reception electrode 4 by electrostatic coupling at the intersection of the transmission electrode 3 and the reception electrode 4. The current measuring means 6 detects a value corresponding to the electrostatic coupling at each corresponding intersection from the current flowing through the virtually grounded receiving electrode 4 and outputs the detected value to the computing means 10. Here, in order to identify the detection position of each intersection, the calculation means 10 converts the measurement value obtained by the current measurement means 6 into a value corresponding to the electrostatic coupling at each intersection by performing a linear calculation with the linear calculation means 7. A conventional proximity detector is constituted by the proximity calculation means 8 that determines the proximity of the object to the detection region and the calculation means 10 that obtains the proximity position based on the calculated value or its transition.

US Patent Application Publication No. 2009/009483

  In the conventional proximity detection apparatus described above, a plurality of electrodes are simultaneously driven by multiline driving. However, conventional proximity detectors consume a lot of power, especially when used in portable devices, etc., because of the large amount of power consumed, the battery will not last long, and a large battery is required to supply sufficient power as a portable device. There was a problem that had to be prepared.

  Therefore, the present invention provides the following apparatus and method in order to solve these problems.

  Current measurement switch control means for controlling the current measurement switch so as to supply power to the current measurement means only when receiving a signal from the reception electrode in the control means and not to supply power to the current measurement means when no signal is received from the transmission electrode. Is provided. Similarly, in the current measurement method, in the current measurement process, the current measurement switch is turned on at the timing of measuring the detected current from the receiving electrode, and the current measurement switch is turned off after the measurement of the detected current is completed. By having a current measurement switch-off step, the unnecessary power consumption is suppressed and the above-described problems are solved.

  The proximity detection apparatus according to the present invention has the following configuration.

  A plurality of transmission electrodes corresponding to one dimension in the detection region on the support substrate are provided via an insulating layer for electrically insulating the reception electrodes corresponding to the other dimension. Multi-line driving means for applying a periodic alternating voltage simultaneously to at least two electrodes of the transmission electrode. Current measuring means for measuring the current or charge amount from the receiving electrode in synchronization with the driving to the transmitting electrode. Calculation means for converting the current value or the charge amount measured by the current measurement means into a value corresponding to the electrostatic capacitance at each intersection of the transmission electrode and the reception electrode, and obtaining the proximity or proximity position of the object to the detection region. Control means for managing the overall status and sequence.

  The control means includes timing signal generation means and current measurement switch control means for controlling supply of power to the current measurement means. The calculating means linearly calculates the current value or the amount of charge measured by the current measuring means and converts it into a value corresponding to the capacitance at each intersection of the transmitting electrode and the receiving electrode, and from the output of the linear calculating means It is comprised by the proximity calculation means which calculates | requires the approach determination of an object to a detection area, or an approach position. The current measurement switch control means is turned on only when measuring the current or charge amount from the receiving electrode to supply power to the current measuring means, and is turned off when not measuring the current or charge amount from the receiving electrode. The switch is controlled so as not to supply power.

  The following delay time adjusting means and power save mode switching means are not indispensable and have arbitrary configurations.

  The multi-line driving means includes a delay time adjusting means for correcting a delay time that occurs in accordance with each measurement position.

  The control means includes an interval generating means for providing an arbitrary interval during the measurement of the current corresponding to the transmission electrode a plurality of times when the multi-line driving means drives the transmission electrode a plurality of times, and a normal mode for performing proximity detection. In addition, power save mode switching means for switching between modes in which the multiline driving means is driven at least less than the number of transmission electrodes is provided.

  Further, the proximity detection method according to the present invention has the following configuration.

  A multi-line driving process in which a periodic AC voltage is simultaneously applied to a plurality of transmission electrodes corresponding to one dimension in a detection region for detecting the approach of an object, and a current or charge from a reception electrode corresponding to the other dimension A drive measurement process comprising a current measurement process for measuring the amount in synchronization with the drive to the transmission electrode. A calculation step of converting the current value or the charge amount obtained in the drive measurement step into a value corresponding to the capacitance at each intersection of the transmission electrode and the reception electrode to determine the proximity of the object to the detection region or the proximity position.

  The calculation process includes a linear calculation process for linearly calculating the current value or charge amount obtained in the drive measurement process and converting the value into a value corresponding to the capacitance at each intersection of the transmission electrode and the reception electrode, and from the output of the linear calculation process. It consists of a proximity calculation step for determining the proximity of an object to the detection region or obtaining a proximity position.

  The current measurement step includes a current measurement switch-on step for turning on the power supply of the apparatus related to the current measurement step only when measuring the current or charge amount from the reception electrode, and a detection current for measuring the current or charge amount from the reception electrode. After the measurement process and the detected current measurement process, the process is composed of three processes: a current measurement switch-off process for turning off the power supply of the apparatus related to the current measurement process.

  The following configurations or features of the proximity detection method are not essential and are arbitrary configurations.

  The multi-line driving process includes a multi-line waveform generating process for generating a waveform for applying a periodic AC voltage to a plurality of transmitting electrodes corresponding to one dimension in a detection region for detecting the approach of an object, and a receiving electrode. The delay time adjustment process which produces a delay is provided so that the dispersion | variation in the delay time which generate | occur | produces may be eliminated.

  In the drive measurement process, when the multi-line drive process drives the transmission electrode a plurality of times, a random interval is provided during the measurement of the current corresponding to the reception electrode a plurality of times. Furthermore, the drive measurement step switches between a mode in which the transmission electrodes are driven less than the number of transmission electrodes and a mode in which the transmission electrodes are driven at a number greater than or equal to the number of transmission electrodes.

  According to the present invention, in addition to driving with constant voltage driving at a high speed and a high dynamic range, it is possible to drive with low power consumption by setting the current measuring means control switch to OFF when current measurement is not required.

1 is a block diagram showing a preferred embodiment of a proximity detection apparatus according to the present invention. Block diagram of a conventional proximity detector The block diagram which shows the Example of the multi-line drive means based on this invention Timing chart of drive measurement process according to the present invention Process flow diagram of proximity detection method according to the present invention Another process flow diagram of the proximity detection method according to the present invention The figure regarding the current measurement means and switch concerning this invention

  In describing the present invention, description will be made based on the following examples.

  In FIG. 1, the proximity detection device according to the present invention does not conduct a plurality of transmission electrodes 3 corresponding to one dimension of two-dimensional coordinates in the detection region 2 on the support substrate 1 and reception electrodes 4 corresponding to the other dimension. Corresponding to the electrostatic coupling of the intersection of the transmission electrode 3 and the reception electrode 4 with the multi-line driving means 5 that is provided via the insulating layer and applies a periodic AC voltage to the plurality of electrodes of the transmission electrode 3 simultaneously. Current measuring means 6 that measures the magnitude of the current or charge amount from the receiving electrode 4 that changes in synchronization with the driving of the transmitting electrode 3, and the transmitting electrode 3 and the receiving electrode 4 from the current value measured by the current measuring means 6. Linear computing means 7 for converting the values to the electrostatic couplings at the respective intersections, and values corresponding to the electrostatic couplings at the respective intersecting points from the linear computing means 7 or the transition thereof, Find approach position A contact operation means 8, was constructed by the control unit 9a that manages the overall status and sequence. The control means 9a includes a timing signal generation means 40, a current measurement switch control means 43, an interval generation means 41, and a power save mode switching means 42 as specific configurations to be noted. The linear calculation means 7 and the proximity calculation means 8 are collectively referred to as calculation means 10.

The features of the proximity detector of the present invention will be described based on the difference from the conventional example.
(1) Addition of current measurement switch control means 43. In the present invention, in order to reduce power consumption, the power is supplied to the current measuring means 6 only when the current or charge amount of the receiving electrode 4 is measured, and when the current or charge amount of the receiving electrode 4 is not measured. The switch is controlled so that the power is not supplied to the current measuring means 6 by turning it off. As a result, a significant reduction in power consumption can be expected.
(2) Addition of an interval generating means 41 for adding a random interval to the control means 9a. In the present invention, noise is reduced by randomizing the influence of noise, the required drive voltage is reduced, and as a result, power consumption can be reduced. Specifically, a random interval is inserted as necessary at the timing of output from the transmission electrode 3. Thereby, the influence of the liquid crystal noise or the like generated at a constant cycle can be randomized, and the influence of the noise can be reduced. Therefore, it is not necessary to drive at a high voltage in order to avoid the influence of noise, which can contribute to reduction of power consumption.
(3) Addition of power save mode switching means 42 to the control means 9a. In order to accurately determine the proximity position of the finger, it is necessary to drive each transmission electrode 3 as many times as the number of transmission electrodes 3 as one cycle of measurement. However, when there is no need to know an exact proximity position such as a state where a detection target such as a human finger is not in proximity on the detection region 2, each transmission electrode is performed with a number of times less than the number of transmission electrodes 3 as one cycle measurement. Driving 3 can reduce power consumption. Therefore, the proximity calculation means 8 determines whether or not a detection target such as a finger is close (proximity determination), and when the detection target such as a finger is not close by the power save mode switching means 42, transmission is performed in one cycle. The mode is switched to a mode (power save mode) in which each transmission electrode 3 is driven less than the number of electrodes 3 and when the detection target such as a finger is in proximity, each transmission is performed by the number of transmission electrodes 3 in one cycle measurement. The mode is switched to driving the electrode 3. In the power save mode described above, power consumption can be expected to be reduced if the number of times of driving is less than the number of each transmission electrode 3, but it is most preferable to drive only once. In this case, the detection position of the detection region 2 cannot be specified, but information on the presence or absence of detection in all the detection regions 2 can be obtained. When a detection target such as a finger is detected in the power save mode, power consumption can be suppressed by switching from the power save mode to a mode in which each transmission electrode 3 is driven by the number of transmission electrodes 3 in one cycle of measurement.
(4) Addition of delay time adjusting means 7 to the multiline driving means 5.

Similarly, the features of the proximity detection process of the present invention will be described based on the difference from the conventional example. The details are the same as the features of the proximity detection device, and thus will be omitted.
(1) In the current measurement step 21, a current measurement switch-on step 27 and a current measurement switch-off step 29 are added.
(2) A feature of adding a random interval in the drive measurement step 20.
(3) The drive measurement step 20 is characterized in that the mode for driving the transmission electrode 4 with a smaller number of times than the number of the transmission electrodes 3 and the mode for driving the transmission electrode 4 with a number of times greater than or equal to the number of the transmission electrodes 3 are switched.
(4) Addition of a delay time adjustment step 25 for correcting a delay caused in accordance with the distance from each transmission electrode 3 to the current measuring means 6 in the multiline driving step 26.

  Hereafter, each means and each process which comprise the proximity detection apparatus and its method by this invention are demonstrated in detail.

  In the detection region 2 of the support substrate 1, for example, a transmission electrode 3 corresponding to the vertical coordinate and a reception electrode 4 corresponding to the horizontal coordinate are arranged orthogonal to each other. However, the arrangement of the transmission electrode 3 and the reception electrode 4 is not limited to this, and any arrangement may be used as long as it corresponds to a two-dimensional coordinate such as an oblique coordinate or a circle coordinate composed of an angle and a distance from the origin. . These electrodes are conductive, and at the intersection of the transmission electrode 3 and the reception electrode 4, both electrodes are galvanically insulated and electrically electrostatically coupled by an insulating layer.

  Here, for convenience of explanation, it is assumed that the transmission electrode 3 exists at each position where the corresponding coordinate value is represented by a natural number from 1 to N, and the corresponding transmission electrode 3 is distinguished by the subscript n. Similarly, the receiving electrode 4 is present at each position where the corresponding coordinate value is represented by a natural number from 1 to M, and the corresponding receiving electrode 4 is distinguished by the subscript m.

  The multiline driving means 5 applies a periodic AC voltage corresponding to the transmission voltage matrix T (t, n) to the plurality of transmission electrodes 3. The subscript t of the transmission voltage matrix T corresponds to the t-th driving with the row number of the matrix, and the subscript n corresponds to the nth transmission electrode 3 with the column number. That is, the AC voltage applied to the third transmission electrode 3 in the second drive corresponds to T (2, 3).

  A plurality of AC voltage waveforms applied simultaneously are AC voltage waveforms obtained by multiplying a certain AC voltage waveform by a corresponding element T (t, n) of the transmission voltage matrix as a coefficient. Therefore, when the element of the transmission voltage matrix is negative, it means that an AC voltage waveform having a reverse phase is applied. At this time, even if the DC component is superimposed, there is no influence.

  Here, the transmission voltage matrix T (t, n) is a regular matrix that is a square matrix having an inverse matrix. Therefore, the subscript t is a natural number from 1 to the number N of transmission electrodes. In the case of conventional line sequential driving, the transmission voltage matrix T (t, n) matches the unit matrix I (t, n).

  The periodic AC voltage is, for example, a rectangular wave, a sine wave, a triangular wave, or the like. However, each electrode has its own resistance value and capacitance, so that the high frequency is attenuated, and the intersection is attenuated at low frequency because of the series capacitance. Considering these, it is desirable that the frequency of the voltage applied to the transmission electrode 3 is a frequency with small attenuation.

In order to further simplify the configuration, for example, each element of the transmission voltage matrix T (t, n) is set to one, 0, or −1, for example, the absolute value of each element except 0 is the same value. If the periodic AC voltage is a rectangular wave, the multiline driving means 5 can be configured with a simple logic circuit as shown in FIG. 3, for example.
Here, the configuration of FIG. 3 will be described. A timing signal corresponding to the row number t of the transmission voltage matrix is output from the timing signal generation means 40 in the control means 9a of FIG. 1 to the transmission voltage matrix reference means 12 of FIG. 3, and a rectangular wave is generated in synchronization. The timing signal is output to the rectangular wave generating means 11. The rectangular wave generating means 11 generates a plurality of cycles of rectangular waves based on the timing signal described above, and is connected to N selection means 13 having two types of wirings that pass through the inverter 16 and wirings that do not pass through the inverter 16. . The selection means 13 selects a wiring that does not pass through the inverter 16 when the value of the input from the transmission voltage matrix reference means 12 is 1, and passes through the inverter 16 when the value of the corresponding element of the transmission voltage matrix is -1. The wiring to be selected is selected, and when the value of the corresponding element of the transmission voltage matrix is 0, the wiring of 0V is selected. The signal selected by the selection unit 16 is output as a drive waveform via the delay time adjustment unit 14 as necessary. The delay time adjusting means 14 is connected to a resistor in series for each of the plurality of transmission electrodes 3, and is connected to the other terminal of a capacitor that is connected to a constant voltage power source via the resistor. A buffer may be provided at the output of the delay time adjusting means 14 as necessary in order to lower the impedance.

  When a certain element of the transmission voltage matrix T (t, n) to the transmission voltage matrix reference means 12 is 0, for example, the selection means 13 sets 0V to the transmission electrode in order to set the AC voltage waveform corresponding to that element to 0V. Connect to 3. When the element of the transmission voltage matrix T (t, n) is 1, the short wave generating means 11 selects the wiring that does not go through the inverter 16 by the selecting means 13. When the element of the transmission voltage matrix T (t, n) is −1, the short wave generating means 11 selects the wiring passing through the inverter 16 by the selecting means 13. In this way, the operation may be performed by the elements of the transmission voltage matrix T (t, n).

  The receiving electrode 4 in FIG. 1 itself has a resistance value and a capacitance, so that a delay time is generated in the transmission of alternating current. In FIG. 3, the delay time adjusting means 14 behind the selecting means 13 is for fine adjustment of this, and is provided as necessary. This is for correcting a delay caused according to the distance from each transmission electrode 3 to the current measuring means 6. That is, the delay time of the near transmitting electrode 3 is set to be long in order to match the transmitting electrode 3 far from the current measuring means 6. Thereby, it is expected that the variation in delay time generated up to the reception electrode 4 is eliminated and transmitted to the current measuring means 6 at the same time.

  The periodic AC voltage applied to the nth transmission electrode 3 is transmitted to the mth reception electrode 4 through electrostatic coupling at the intersection of the nth transmission electrode 3 and the mth reception electrode 4. Is done. Although it is limited to the mth receiving electrode 4 here, it actually affects the plurality of receiving electrodes 4 that intersect with the nth transmitting electrode 3. If there is an influence such as contamination on the detection surface, the impedance of the approaching object itself is high, so the electric field between the transmission electrode 3 and the reception electrode 4 is increased by the electric field through the approaching object, and the transmission electrode 3 and the reception are received. The electrostatic coupling between the electrodes 4 increases, and the reception current flowing through the reception electrode 4 also increases. Conversely, when an object having a relatively low impedance such as a finger of a person to be detected approaches, the action of absorbing the AC electric field from the transmission electrode 3 is stronger, so that the gap between the transmission electrode 3 and the reception electrode 4 is greater. The electrostatic coupling decreases and the reception current flowing through the reception electrode 4 decreases. Accordingly, it is possible to easily distinguish between detection targets such as dirt and human fingers.

  Here, in order to prevent the reception electrode 4 from being affected even when an object approaches other than the vicinity of the intersection to be detected, fluctuations in voltage are suppressed by grounding or virtual grounding. For this reason, the transmission to the receiving electrode 4 is a current rather than a voltage. That is, an alternating electric field is generated by electrostatic coupling at the intersection of the selected transmission electrode 3 and a certain reception electrode 4, so that a reception current flows through the reception electrode 4. Therefore, since the AC electric field changes at the intersection where the object approaches, the reception current flowing through the reception electrode 4 changes.

  The current measuring means 6 measures the received current flowing through the mth receiving electrode 4 every time the AC voltage waveform corresponding to the transmission voltage matrix T (t, n) is applied to the transmitting electrode 3 by the multiline driving means 5. Then, for example, it is converted into a digital value by a delta sigma type AD converter or the like, and the value of the corresponding reception current matrix R (t, m) is updated and output to the linear operation means 7. Here, the subscript t is a row number of the matrix, which indicates a current generated by the t-th driving in the multiline driving means 5, and the subscript m is a column number corresponding to the number of the receiving electrode 4.

  Here, the value of the capacitance at each intersection is usually a minute value of about 1 pF, and the reception current flowing through the reception electrode 4 and its change are also weak. Therefore, in order to detect the reception current flowing through the reception electrode 4, currents having a plurality of periods applied from the transmission electrode 3 are accumulated and detected. However, since the reception current flowing through the reception electrode 4 is alternating current, if it is simply accumulated, the accumulated value becomes zero. In order to avoid this, it is possible to use the same method as in the case of the conventional line sequential driving. In other words, accumulation is performed in synchronization with the phase of the alternating current. For example, the cumulative capacitor is switched by synchronizing with a periodic AC voltage applied to the transmission electrode 3 or the demodulated waveform is convoluted by convolution with the periodic AC voltage applied to the transmission electrode 3. There are ways to do it. However, depending on the value of the transmission voltage matrix, the received current value may be a negative value. Even in this case, it is necessary to take care not to saturate the receiving circuit. As a specific method, for example, the reference voltage or the power supply voltage in the linear calculation means 7 is set or adjusted to a value that does not saturate.

  If the current measuring means 6 subtracts a value close to the measured value when the object to be detected is not approaching as an offset, the change in the measured value due to the approach of the object can be measured more accurately. At this time, the measured value when the object to be detected is not approaching is greatly affected by the transmission voltage matrix T (t, n). Therefore, a different value corresponding to the subscript t is subtracted as an offset. Furthermore, when there is an influence such as contamination on the detection surface, it is preferable to subtract a different value for each m-th receiving electrode 4 as an offset.

  The values of the received current matrix R (t, m) measured when multiline driving is performed are as follows: the transmission voltage matrix T (t, n) and the intersection coupling matrix P (n, m) And is represented by the product of the matrix. Here, the intersection coupling matrix P (n, m) corresponds to the strength of electrostatic coupling at each intersection of the electrodes corresponding to the two-dimensional coordinates, and the transmission voltage matrix performs line sequential driving of the unit matrix. It assumes the value of the received current matrix that would be obtained if it was performed. Here, the subscript n corresponds to the nth transmission electrode 3 in the row number of the matrix, and the subscript m corresponds to the mth reception electrode 4 in the column number.

(Equation 1) R (t, m) = T (t, n) P (n, m)
This is because the addition theorem holds because the current due to electrostatic coupling is linear. For example, when an AC voltage of 1V is applied to the n1th transmission electrode 3, the reception current flowing into the mth reception electrode 4 is R (n1, m), and an AC voltage of 1V is applied to the n2th transmission electrode 3 In this case, the reception current flowing into the mth reception electrode 4 is R (n2, m). When an AC voltage of 2V is applied to the n1st transmission electrode 3 and 3V to the n2nd transmission electrode 3 simultaneously, R (n1, m) is doubled and R (n2, m) is tripled. The added current flows through the mth receiving electrode 4.

  Therefore, the linear calculation means 7 multiplies the reception current matrix R (t, m) from the current measurement means 6 by the inverse matrix of the transmission voltage matrix T (t, n) from the left as shown in Equation 2. Thereby, it is converted into an intersection coupling matrix P (n, m) that will flow when line sequential driving is performed. Since the transmission voltage matrix is a regular matrix, there is always an inverse matrix. Formula 2 is obtained by multiplying both sides of Formula 1 by the inverse matrix of the transmission voltage matrix T (t, n) from the left and exchanging the right side and the left side.

(Equation 2) P (n, m) = {inverse matrix of T (t, n)} R (t, m)
However, the inverse matrix of the transmission voltage matrix T (t, n) here does not need to be calculated every time, and a normally calculated one may be used.

  Further, the calculation of the linear calculation means 7 does not necessarily need to perform matrix multiplication, and it is not necessary to calculate the term in which the element value of the inverse matrix of the transmission voltage matrix T (t, n) is 0. If the value is 1 or −1 multiplied by the same coefficient, simple addition / subtraction may be performed. That is, the calculation of Formula 2 may be performed after multiplying all elements of the inverse matrix of the transmission voltage matrix T (t, n) by the same coefficient. This is because if all the decimal elements are made integers, the calculation is simplified. In particular, when the absolute values of all elements except 0 are the same decimal number, all elements can be set to 1 or 0 or −1 by coefficient multiplication, so that only simple addition and subtraction can be performed. Even if the coefficient is multiplied, the proximity calculation means 8 performs a proximity calculation using a relative value instead of an absolute value, and therefore has a characteristic that there is almost no influence on the result of the calculation. Is beneficial.

  The proximity calculation means 8 is an intersection coupling matrix P that will flow when line-sequential driving is performed as a current value depending on the electrostatic coupling of each intersection of the electrodes corresponding to the two-dimensional coordinates obtained by the linear calculation means 7. The approach and position of the object to be detected are calculated from (n, m) or its transition.

  The control means 9a manages the status and sequence of the overall operation. The status here refers to a state such as during current measurement, for example, and the sequence refers to an on / off procedure for current measurement. The control means 9a comprises a timing signal generating means 40, an interval generating means 41, a power save mode switching means 42, and the like. However, the interval generation means 41 and the power save mode switching means 42 are added as necessary. Further, as a feature of the present invention, there is provided a current measurement switch control means 43 that switches on / off of current measurement corresponding to the current measurement means in a sequence. Since this has a characteristic operation different from the conventional sequence, it is called the current measurement switch control means 43 including the meaning of distinction.

  An example of a specific operation by the proximity detection method according to the present invention will be described with reference to FIG. This is an example of the case where the calculation is performed in the calculation process after driving and measurement for N rows of the transmission voltage matrix are collectively performed in the drive measurement process 20.

  After starting the flow of FIG. 5, in the drive measurement step 20, the drive is measured to measure the current and the received current matrix is updated. The drive measurement process 20 includes two processes, a multiline drive process 26 and a current measurement process 21 for measuring the received current. The multiline driving process 26 and the current measurement process 21 are performed almost simultaneously. In the measurement step 21, the current is supplied from the reception electrode 4 after the current measurement switch-on step 27 for turning on the power of the apparatus related to the current measurement step 21 only when measuring the current or charge amount from the reception electrode 4. A detection current measuring step 28 for measuring the charge amount is performed. After the measurement of the current or charge amount from the receiving electrode 4 is completed, a current measurement switch-off step 29 for turning off the power supply of the device according to the current measurement step 21 is performed.

  In the multiline driving step 26, a multiline waveform generating step 24 for generating a waveform for simultaneously applying a periodic AC voltage to a plurality of transmitting electrodes 3 corresponding to one dimension in the detection region 2 for detecting the approach of an object. And a delay time adjustment step 25 for correcting a delay caused by the distance from each transmission electrode 3 to the current measuring means 6 as necessary. In the drive measurement process 20, the reception current matrix is updated N times from t = 1 to N, thereby performing a drive corresponding to all elements of the transmission voltage matrix. Thereafter, the calculation process 30 is performed to perform the calculation. The calculation process 30 includes a linear calculation process 22 and a proximity calculation process 23. In the linear calculation step 22, the reception current matrix updated in the drive measurement step 20 is linearly calculated to update the intersection coupling matrix. Then, the approach or position of the object to be detected is detected from the value of the intersection coupling matrix updated in the linear calculation step 22 by the proximity calculation step 23 or its transition. The proximity detection method is realized by repeating this series of steps at a constant period.

  However, this is only an example, and the next drive measurement step 20 may be performed simultaneously during the linear calculation step 22 and the proximity calculation step 23 by, for example, parallel processing.

  Thus, in the drive measurement step 20, the current of the reception electrode 4 is measured in the current measurement step 21 while being driven to the transmission electrode 3 by the multiline drive step 26, and converted into a digital value. At this time, the driving corresponding to all the elements of the transmission voltage matrix is performed one by one by repeating N times until the number t of normal driving reaches 1 to N.

  FIG. 4 shows a schematic diagram of the timing of the driving to the transmitting electrode 3 and the current measurement from the receiving electrode 4 in more detail.

  In FIG. 4, the drive waveform shows the voltage waveform of each transmission electrode 3, and the current measurement shows the timing of measuring the alternating current corresponding to the drive waveform. The random interval is insertion of a random waiting time for randomizing the influence of noise. For example, an arbitrary interval may be inserted as needed while measuring the current corresponding to the transmission electrode 3 a plurality of times. The horizontal axis is a time axis common to these. FIG. 4 shows six waveforms for convenience from the driving waveform 1 to the driving waveform 6, but this is a schematic one, and there are N driving waveforms. For example, when the current measurement is t = 4 in the driving waveform 1 and the driving waveform 2, the driving waveform 1 applies a three-cycle short wave starting from the rising edge, whereas the driving waveform 2 reverses the polarity. A three-cycle short wave starting from the falling edge is applied. In addition, in the state of the current measurement t = 5 in the drive waveform 4 and the current measurement t = 6 in the drive waveform 6, a three-cycle short wave starting from the falling edge with the polarity reversed is applied. Then, a short wave of 3 cycles starting from the rising edge is applied. These polarities correspond to the values of the elements of the transmission voltage matrix.

  The timing in FIG. 4 is an example when a matrix T shown in Equation 11 described later is used as a transmission voltage matrix, and a drive waveform is sequentially applied to each transmission electrode 3 with a polarity based on the value of the transmission voltage matrix. In this schematic diagram, for the sake of convenience, the application of the rectangular wave in one drive is three cycles, but it is needless to say that this is not the case. Note that the drive to the transmission electrode 3 and the AC current measurement from the reception electrode 4 are synchronized in the same manner as in the case of the conventional line-sequential drive 35, and the signs of the current measurement values by the inverted drive are reversed. . The value of the received current matrix is updated with the current measured by driving in this way. All elements of the reception current matrix are also updated by performing a single drive corresponding to all elements of the transmission voltage matrix.

  In the linear calculation step 22, the value of the intersection coupling matrix is updated by performing a linear calculation on the reception current matrix updated in the current measurement step 21.

  In the proximity calculation step 23, the proximity calculation means 8 detects the approach or position of the object to be detected from the value of the intersection coupling matrix updated in the linear calculation step 22 or its transition.

  However, when the object to be detected is not yet approaching and it is not necessary to calculate an accurate position, the driving to the transmission electrode 3 and the current from the reception electrode 4 are not necessarily performed for all rows of the transmission voltage matrix. There is no need to make measurements. At least, it is sufficient to drive only the rows of the transmission voltage matrix for driving all the transmission electrodes 3. In other words, it is sufficient to drive each column at least once. For example, in the case of using the transmission voltage matrix T shown in Equation 11 described above, if only the row corresponding to t = 1 to 3 is driven, all the transmission electrodes 3 are driven, and the transmission voltage matrix shown in Equation 9 is used. When T is used, it is sufficient to drive only one of the rows. That is, the number of driving times is smaller than the number of transmission electrodes 3. In this case, the linear calculation step 22 may be omitted because only changes can be extracted. This is because, even if an object approaches any intersection, there is usually some change in the value of the received current matrix, so that the proximity computing means 8 can detect that the object has approached. By doing so, it is possible to reduce power consumption while waiting for an object to approach. This is so-called power saving. For example, when all the transmission electrodes 3 described later are driven simultaneously, as shown in FIG. 6, only the drive to the transmission electrode 3 and the current measurement from the reception electrode 4 are performed for one row of the transmission voltage matrix. It is also possible. Further, in the case of the transmission voltage matrix T shown in Expression 11, all the transmission electrodes 3 are driven by driving for the first three rows.

  The procedure shown in FIG. 6 will be described. 6 includes almost the same steps as those in FIG. The difference is the number of drive measurements in the drive measurement step 20. In this proximity detection method, for example, every time driving and measurement of one row of the transmission voltage matrix is performed, linear calculation and proximity calculation are performed based on the updated received current matrix, and this is repeated at regular intervals. Is shown. Compared with the process of FIG. 5, the power consumption can be reduced by reducing the number of times of driving. This drive mode is called a power save mode.

  The multi-line drive of the present invention will be described while comparing with the case of line-sequential drive that drives line by line. As described above based on Equation 1 and Equation 2, using the transposed matrix of the transmission voltage matrix T (t, n), the intersection coupling matrix P (n, m), and the reception current matrix R (t, m), Needless to say, the same applies even if the order of matrix multiplication is changed. In this case, Equation 3 corresponds to Equation 1, and Equation 4 corresponds to Equation 2. This calculation process is performed in the linear calculation step 22 by the linear calculation means 7.

(Equation 3) R ^T (m, t) = P ^T (m, n) T ^T (n, t)
(Equation 4) P ^T (m, n) = R ^T (m, t) {Inverse matrix of T ^T (n, t)}
In addition, although the example at the time of measuring the alternating current corresponding to the electrostatic capacitance of the alternating voltage waveform of the transmission electrode 3 and the intersection of the transmission electrode 3 and the reception electrode 4 with the current measurement means 6 was shown above, the current measurement means 6, when a step-like voltage change is applied to the transmission electrode 3, a value corresponding to the amount of charge flowing in proportion to the capacitance at the intersection of the transmission electrode 3 and the reception electrode 4 may be measured. In this case, the voltage change including the polarity of the nth transmission electrode 3 corresponding to the transmission voltage matrix T (t, n) corresponds to V (t, n) and the intersection coupling matrix P (n, m). Then, the capacitance at the intersection of the nth transmitting electrode 3 and the mth receiving electrode 4 is measured by the current measuring means 6 corresponding to C (n, m) and the received current matrix R (t, m). When the amount of charge flowing through the second receiving electrode 4 is Q (t, m) and the number of voltage changes of the transmitting electrode 3 for measuring the amount of charge is 1, Equations 5 and 6 hold. Equation 6 is used by the linear calculation means 7 and the linear calculation step 22 to convert the intersection corresponding to the intersection coupling matrix into a capacitance.

(Equation 5) Q (t, m) = l · V (t, n) C (n, m)
(Equation 6) C (n, m) = {inverse matrix of V (t, n)} Q (t, m) / l
These Formula 5 and Formula 6 correspond to Formula 1 and Formula 2. It goes without saying that Formulas 5 and 6 are the same even if the order of matrix multiplication is changed using a transposed matrix, as shown in Formulas 7 and 8.

(Expression 7) Q ^T (m, t) = l · C ^T (m, n) V ^T (n, t)
(Equation 8) C ^T (m, n) = Q ^T (m, t) {Inverse matrix of V ^T (n, t)} / l
The relationship between the value of each element of the transmission voltage matrix T (t, n), which is a feature of the present invention, and the effect will be described. As described above, the transmission voltage matrix needs to be a regular matrix having an inverse matrix. Also, the element value of the transmission voltage matrix T (t, n) is preferably a value obtained by multiplying 1, 0, or −1 by the same coefficient in order to simplify the drive circuit. Furthermore, in order to simplify the linear operation, it is desirable that the elements of the inverse matrix are also values obtained by multiplying the integer by the same coefficient, particularly by multiplying the same coefficient by 1 or 0 or −1. Further, when the transmission voltage matrix is an orthogonal matrix, the power supply voltage can be efficiently reduced. The orthogonal matrix here is a matrix whose product with the transposed matrix is a unit matrix.

  As a matrix satisfying these conditions, for example, a Hadamard matrix is known. This Hadamard matrix is a square matrix whose elements are either 1 or -1 and whose rows are orthogonal to each other.

  As an example of the first transmission voltage matrix, a case where all the transmission electrodes 3 are simultaneously driven by this Hadamard matrix will be described. For convenience of explanation, the case of using an 8-by-8 Hadamard matrix shown in Equation 9 will be described here, but this is not restrictive. In the following examples, the features will be described with a relatively small matrix for convenience, but it goes without saying that the same is not true.

この場合には、１ラインずつ駆動する線順次駆動の場合と比較すると、各電極とも駆動する回数が８倍になっており、同じ電圧で駆動した場合には、駆動には８倍の消費電力が必要になる。しかし、線順次駆動を行った場合に流れるであろう交点結合行列Ｐ（ｎ，ｍ）を求める場合に掛け算する送信電圧行列の逆行列は各要素の大きさが８分の１になっている。この８分の１倍の演算により、ノイズの大きさも８分の１倍になる。このため、８回の駆動の合成ノイズの強さは、ノイズがランダムの場合には二乗和の平方根により求められるため、線順次駆動の場合のノイズの強さを１とすると、数式１０に示すように約０．３５倍になる。あるいは、８回の測定値の平均によってノイズが約０．３５倍になると考えても良い。このように直交行列を用いた場合には、同時に駆動する送信電極３の数の平方根の逆数に比例してノイズを減衰させることができる。

In this case, the number of times each electrode is driven is 8 times that in the case of line-sequential driving that drives one line at a time. Is required. However, the inverse matrix of the transmission voltage matrix to be multiplied when obtaining the intersection coupling matrix P (n, m) that will flow when line sequential driving is performed has the size of each element being 1/8. . By this one-eighth operation, the noise magnitude is also one-eighth. For this reason, the intensity of the combined noise of the eight times of driving is obtained by the square root of the sum of squares when the noise is random. Therefore, assuming that the noise intensity in the case of line sequential driving is 1, Equation 10 shows It becomes about 0.35 times. Alternatively, it may be considered that the noise is increased by about 0.35 times by the average of eight measurement values. When an orthogonal matrix is used in this way, noise can be attenuated in proportion to the inverse of the square root of the number of transmission electrodes 3 that are driven simultaneously.

また、１ラインずつ駆動する線順次駆動の場合と同様のＳ／Ｎ比とする場合には、信号の強さは駆動する電圧に比例するため、電源電圧を約０．３５倍に小さくすることができる。ここで、駆動のために必要な消費電力が電源電圧の二乗に比例すると考えられるので、駆動回数が８倍になってもほぼ同じ消費電力に抑えることが出来る。また、昇圧回路の規模や昇圧電力効率や駆動回路の耐圧などを考慮すると、駆動電圧を大幅に低くできるメリットは大きい。
あるいは、同時に複数の送信電極３を駆動することにより、例えば同じ電源電圧で駆動する場合には駆動するマルチライン駆動手段５より出力される交流電圧のサイクル数を少なくすることができることにより、ＳＮ比を低下させずに検出速度を速くすることができる。また、同じ検出速度で交流電圧のサイクル数を少なくすれば、ＳＮ比を低下させずに受信にともなう消費電力を大幅に削減させることが出来る。何故ならば、図７に示すように、受信電流を測定する時だけ電流測定手段に電源を供給するようにすれば、測定する交流電圧のサイクル数が減ったことに対応して、電流測定手段で消費する消費電流を少なくすることができる。例えば、数９に示す送信電圧行列の場合には、線形演算手段７あるいは線形演算工程２２で、８回の受信値を基に線形演算するため、充放電サイクル数を８分の１倍にしてもほぼ同様のＳＮ比を確保することが出来る。したがって、電流測定手段での消費電流、ひいては消費電力を約８分の１に低下させることが出来る。

Also, when the S / N ratio is the same as in the case of line-sequential driving for driving one line at a time, since the signal strength is proportional to the driving voltage, the power supply voltage should be reduced by about 0.35 times. Can do. Here, since it is considered that the power consumption required for driving is proportional to the square of the power supply voltage, even when the number of times of driving becomes eight times, it can be suppressed to substantially the same power consumption. Considering the scale of the booster circuit, the boosted power efficiency, the withstand voltage of the drive circuit, etc., there is a great merit that the drive voltage can be significantly lowered.
Alternatively, by simultaneously driving a plurality of transmission electrodes 3, for example, when driving with the same power supply voltage, it is possible to reduce the cycle number of the AC voltage output from the driving multiline driving means 5, thereby reducing the SN ratio. It is possible to increase the detection speed without lowering. Further, if the number of AC voltage cycles is reduced at the same detection speed, the power consumption associated with reception can be greatly reduced without reducing the SN ratio. This is because, as shown in FIG. 7, if power is supplied to the current measuring means only when the received current is measured, the current measuring means corresponds to the decrease in the number of cycles of the alternating voltage to be measured. Current consumption can be reduced. For example, in the case of the transmission voltage matrix shown in Equation 9, the linear calculation means 7 or the linear calculation step 22 performs a linear calculation based on eight received values, so the number of charge / discharge cycles is increased by a factor of eight. Can also ensure a substantially similar signal-to-noise ratio. Therefore, the current consumption in the current measuring means, and hence the power consumption, can be reduced to about 1/8.

  In addition, in order to increase the possibility of randomizing the periodic noise received every time driving, as shown in FIG. 4, a random interval is inserted between each driving, and the phase of the AC voltage for each driving is changed. The relationship may not be constant.

  However, since the Hadamard matrix for driving all the transmission electrodes 3 simultaneously is a power of 2, the number of the transmission electrodes 3 is limited to a power of 2. Next, in the example of the second transmission voltage matrix shown in Formula 11, the number of transmission electrodes 3 is not limited to a power of 2, and a larger transmission voltage matrix is configured by putting a small Hadamard matrix in a diagonal element. Is. For example, Expression 11 shows an example in which three 6-row 6-column transmission voltage matrices are formed by putting three 2-by-2 Hadamard matrices in diagonal elements. However, in order to shorten the driving cycle and increase the synchronism of detection between the electrodes, as shown in Expression 11, a transmission voltage matrix in which rows are rearranged may be used. Moreover, there is no particular problem even if the rows are rearranged.

この例では、数式９の場合の例と同様に、従来の線順次と同様のＳ／Ｎ比としつつ、電源電圧を２の平方根の逆数倍、すなわち約０．７１倍に小さくすることができる。この場合の消費電力は、１ラインずつ駆動する線順次駆動の場合とほぼ同じである。あるいは、同様に検出速度を早くしても良い。

In this example, the power supply voltage can be reduced to the inverse of the square root of 2, that is, approximately 0.71 times, while the S / N ratio is the same as that in the conventional line sequential, as in the case of Expression 9. it can. The power consumption in this case is almost the same as in the case of line sequential driving in which one line is driven. Alternatively, the detection speed may be increased similarly.

  The example in which only the Hadamard matrix is used as the Hadamard matrix itself or the partial matrix has been shown above. Further, each element of the 2-by-2 Hadamard matrix is multiplied by −1 to replace the left and right columns. Formula 12 shows an example in which addition is made so as to start from the fourth row, first column, the sixth row, third column, and the second row, fifth column.

この例では、送信電極３の数が２のべき乗である必要はなく、同時に４つの送信電極３を駆動しているため、数式１１の場合の例より電源電圧や検出速度を改善したものである。

In this example, the number of the transmission electrodes 3 does not need to be a power of 2, and the four transmission electrodes 3 are driven at the same time. Therefore, the power supply voltage and the detection speed are improved compared to the example of Expression 11. .

  As another method of obtaining a transmission voltage matrix that is not a power of 2, a larger Hadamard matrix submatrix may be used. For example, the transmission matrix shown in Formula 13 is obtained as a partial matrix excluding the first row and the eighth column of the Hadamard matrix of 8 rows and 8 columns as the transmission voltage matrix of 7 rows and 7 columns. However, in this case, since it is not an orthogonal matrix, even if the seven transmission electrodes 3 are driven simultaneously, only the same effect as when the average of four measurements is performed can be obtained. Nevertheless, compared to line sequential driving, for example, when driven at the same voltage, the effect of shortening the detection speed four times is significant. The four measurements here correspond to the fact that there are four non-zero elements in each row of the inverse matrix of T shown in Equation 13 in order to obtain the value of each element of the intersection coupling matrix in the linear operation step 22. To do. That is, although the transmission electrode 3 is driven seven times, the capacitance of each intersection coupling is determined by predetermined four measurements.

なお、数式９に示したアダマール行列を用いると、１行目を駆動している時には全ての送信電極３の極性が同じになるために、指が接近していない場合でも、受信電極４を流れる合成された電流が大きくなり、電流測定手段６において飽和を生じやすくなる。このように送信電圧行列の行に印加される電流の合計値の絶対値が大きいと電流測定手段６において飽和しやすくなる。数式９に示すアダマール行列の場合には、１行目の合計値が８で、他の行の合計値は０である。飽和を回避するために、電流測定手段６のゲインを下げてしまうと、検出の分解能を低下させたり、電流測定手段６が受けるノイズの影響が相対的に大きくなったりしてしまう。
そこで、電流測定手段６のゲインを下げずに飽和を回避するために、送信電圧行列Ｔの列毎に係数倍することにより、指が接近していない場合の受信電流を小さくして、電流測定手段６での飽和を生じないようにすることが出来る。さらに、行の合計値の極性を揃えるために、行毎に係数倍しても良い。例えば、数式９に示すアダマール行列の２列目と３列目と５行目をマイナス１倍した数式１４に示す送信電圧行列Ｔを用いることにより、行の合計値の絶対値の最大のものが４になるため、指が接近していない場合の受信電極４の電流の最大値は数式９に示すアダマール行列の約半分に抑えることができる。この場合の逆行列は、送信電圧行列の転置行列を８で割ったものである。

If the Hadamard matrix shown in Equation 9 is used, the polarity of all the transmission electrodes 3 becomes the same when the first row is driven, so that even when the finger is not approaching, the flow flows through the reception electrode 4. The synthesized current increases and saturation is likely to occur in the current measuring means 6. Thus, if the absolute value of the total value of the currents applied to the rows of the transmission voltage matrix is large, the current measuring means 6 is likely to be saturated. In the case of the Hadamard matrix shown in Equation 9, the total value of the first row is 8, and the total value of the other rows is 0. If the gain of the current measuring means 6 is lowered in order to avoid saturation, the detection resolution is lowered, and the influence of noise on the current measuring means 6 is relatively increased.
Therefore, in order to avoid saturation without lowering the gain of the current measuring means 6, the received current when the finger is not approaching is reduced by multiplying the coefficient for each column of the transmission voltage matrix T, thereby measuring the current. Saturation in the means 6 can be prevented from occurring. Furthermore, in order to make the polarity of the total value of the rows uniform, a coefficient may be multiplied for each row. For example, by using the transmission voltage matrix T shown in Formula 14 in which the second column, the third column, and the fifth row of the Hadamard matrix shown in Formula 9 are multiplied by −1, the maximum absolute value of the total value of the rows can be obtained. Therefore, the maximum value of the current of the receiving electrode 4 when the finger is not approaching can be suppressed to about half of the Hadamard matrix shown in Equation 9. The inverse matrix in this case is the transposed matrix of the transmission voltage matrix divided by 8.

なお、ここでは２列目と３列目と５行目をマイナス１倍した場合の例を示したが、この限りではなく、行の合計値の範囲が小さくなるものであればどの行や列にマイナス１倍をしても良い。これらの係数は、例えば列の係数について１またはマイナス１の全組み合わせについて各行の合計値の絶対値を小さくなるものをプログラムで判定させて、各行の合計値がマイナスの行をマイナス１倍するようにしても、容易に得ることが出来る。あるいは、各行の合計値の絶対値の大きな行に着目してその値を小さくするように列の係数を変えるようにするとより高速に望ましい係数を容易に求めることができる。

Here, an example in which the second column, the third column, and the fifth row are minus 1 has been shown. However, this is not restrictive, and any row or column can be used as long as the total value range of the rows is small. It may be minus 1 times. For these coefficients, for example, a program that makes the absolute value of the total value of each row smaller for all combinations of 1 or minus 1 for the column coefficient is determined by the program, so that the row where the total value of each row is minus is multiplied by minus 1. However, it can be easily obtained. Alternatively, if a column coefficient is changed so as to reduce the value by paying attention to a row having a large absolute value of the total value of each row, a desired coefficient can be easily obtained at a higher speed.

  As an example, the method for determining the transmission voltage matrix has been described for the case where the number of transmission electrodes 3 is small for convenience. However, the transmission voltage matrix can be determined by the same method even when the number of transmission electrodes 3 is increased. Needless to say.

  Although the transmission voltage matrix T and its inverse matrix have been described above, the same applies to the matrix V indicating the voltage change and its inverse matrix.

  The transmission voltage matrix, reception current matrix, and intersection coupling matrix described above are expressed in an abstract manner for the sake of convenience. Specifically, the transmission voltage matrix, the reception current matrix, and the intersection coupling matrix are not realized by a plurality of storage elements or computing means 10. Needless to say.

  As described above, according to the present invention, it is possible to reduce the power supply voltage without decreasing the S / N ratio by simultaneously driving the plurality of transmission electrodes 3, or proximity detection with a high detection speed. An apparatus and its method can be realized. Alternatively, it is possible to realize a proximity detection apparatus and method that can detect well even when the wiring resistance is high by slowing the frequency of the AC voltage. Alternatively, when the power supply voltage, the detection speed, and the frequency of the AC voltage are the same, it is possible to realize a proximity detection apparatus and method that can reduce the influence of noise.

DESCRIPTION OF SYMBOLS 1 Support substrate 2 Detection area | region 3 Transmission electrode 4 Reception electrode 5 Multiline drive means 6 Current measurement means 7 Linear calculation means 8 Proximity calculation means 9a Control means 9b Conventional control means 10 Calculation means 11 Rectangular wave generation means 12 Transmission voltage matrix Reference means 13 Selection means 14 Delay time adjustment means 16 Inverter 20 Drive measurement process 21 Current measurement process 22 Linear calculation process 23 Proximity calculation process 24 Multiline waveform generation process 25 Delay time adjustment process 26 Multiline drive process 27 Current measurement switch-on process 28 Detection Current Measurement Step 29 Current Measurement Switch-Off Step 30 Calculation Step 35 Conventional Line Sequential Driving Unit 40 Timing Signal Generation Unit 41 Interval Generation Unit 42 Power Save Mode Switching Unit 43 Current Measurement Switch Control Unit

Claims (14)

A proximity detection device for determining the approach of an object or a proximity detection device for determining a proximity position,
A plurality of transmission electrodes disposed in a detection region on the support substrate; and a reception electrode electrically insulated from the transmission electrodes;
Multiline driving means for simultaneously applying a periodic alternating voltage to at least two of the transmitting electrodes;
Current measuring means for measuring a current or a charge amount from the receiving electrode in synchronization with driving to the transmitting electrode;
Arithmetic means for converting the current value or the amount of charge measured by the current measuring means into a value corresponding to the capacitance of each intersection of the transmitting electrode and the receiving electrode, and obtaining the proximity or proximity position of the object to the detection region; ,
Control means for managing the overall status and sequence,
The proximity detecting device includes a timing signal generating means and a current measurement switch control means for controlling supply of power. The computing means is
A linear calculation means for linearly calculating a current value or a charge amount measured by the current measurement means and converting the value into a value corresponding to a capacitance at each intersection of the transmission electrode and the reception electrode;
Proximity calculation means for obtaining an approach determination or an approach position of an object to the detection region from the output of the linear calculation means;
The proximity detection device according to claim 1, comprising:   The proximity detection device according to claim 1, wherein the AC voltage corresponds to a transmission voltage matrix, and the transmission voltage matrix is a regular matrix.   2. The proximity detection apparatus according to claim 1, wherein the current measurement switch control means supplies power to the current measurement means only when measuring a current or a charge amount from the reception electrode.   The control means includes interval generating means for providing a random interval while measuring the current corresponding to the transmission electrode a plurality of times when the multi-line driving means drives the transmission electrode a plurality of times. The proximity detection apparatus according to claim 1.   The control means includes power save mode switching means for switching between a normal mode in which proximity detection is performed and a simple mode in which the multi-line driving means is driven at least less than the number of transmission electrodes. Item 2. The proximity detection device according to Item 1.   The proximity detection apparatus according to claim 1, wherein the multi-line driving unit includes a delay time adjusting unit that corrects a variation in delay time generated in each of the reception electrodes. A proximity detection method for determining approach of an object or a proximity detection method for determining an approach position,
A multi-line driving process for simultaneously applying a periodic AC voltage to a plurality of transmission electrodes;
A current measuring step of measuring a current or a charge amount from a receiving electrode corresponding to another one dimension in synchronization with driving of the transmitting electrode;
An operation for converting the current value or the charge amount obtained in the current measuring step into a value corresponding to the capacitance at each intersection of the transmitting electrode and the receiving electrode, and determining the proximity of the object to the detection region or calculating the proximity position Process,
The current measurement step is a proximity detection method in which the power source of the apparatus according to the current measurement step is turned on only when measuring the current or charge amount from the receiving electrode. In the calculation step,
A linear calculation step of linearly calculating the current value or the amount of charge obtained in the current measurement step and converting it to a value corresponding to the capacitance of each intersection of the transmission electrode and the reception electrode;
Proximity calculation step for determining the proximity or proximity position of an object to the detection region from the output of the linear calculation step;
The proximity detection method according to claim 8, comprising:   9. The proximity detection method according to claim 8, wherein, in the multi-line driving step, the AC voltage corresponds to a transmission voltage matrix, and the transmission voltage matrix is a regular matrix.   The proximity detection method according to claim 10, wherein the transmission voltage matrix is determined based on a Hadamard matrix.   The proximity detection method according to claim 8, wherein in the multi-line driving step, when the transmission electrode is driven a plurality of times, an arbitrary interval is provided between measurement of a current corresponding to the transmission electrode a plurality of times.   9. The proximity detection according to claim 8, wherein, in the multiline driving step and the current measurement step, switching is performed between a normal mode in which proximity detection is performed and a simple mode in which the transmission electrodes are driven less than the number of transmission electrodes. Method.   The proximity detection method according to claim 8, wherein the multiline driving step includes a delay time adjustment step of correcting a variation in delay time generated in each of the reception electrodes.

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