JP2014149770A - Driving method of sensor module and driving method of electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving method of a sensor module capable of preventing erroneous determination of no input by input means, and a driving method of an electronic apparatus.SOLUTION: The driving method includes: driving a sensor circuit to thereby detect input information indicating the intensity of electrostatic capacity coupling generated according to input operation by input means; driving a first determination section to determine the detected input information, and outputting first information indicating that input is made or second information indicating that no input is made; driving a second determination section to determine a period where the output of the first determination section serves as the first information and a compensation period tc after the timing of switching from the first information to the second information, as a period where input is made by the input means. The driving method further includes driving the sensor circuit and the second determination section under the condition satisfying 2*tc>1/|fs-fn|.

Description

  Embodiments described herein relate generally to a sensor module driving method and an electronic device driving method.

  In general, electronic devices such as a PDA (Personal Digital Assistant) and a tablet PC (Personal Computer) are configured so that data can be directly input from a display screen using a pen or the like. The electronic device employs, for example, an in-cell touch panel system provided with a capacitive touch sensor. The electronic device includes a sensor circuit that detects a change in capacitance in a display area for displaying an image. For this reason, the electronic device can extract the position information of the part touched by the input means by taking out the change in the capacitance of the sensor circuit.

JP 2006-40289 A

  In the in-cell touch panel method, a human body (finger), a conductor, or the like is brought close to (in contact with) the detection electrode of the sensor circuit, the change in the capacitance of the detection electrode is read, and the presence or absence of input (contact) is determined. However, since the electronic device uses a storage battery as a power source, the sensor circuit often does not operate with respect to the ground (ground). In addition, since the electronic device is not electrically connected to an operator who touches the electronic device, the output signal (output voltage) output from the sensor circuit is the frequency of the surrounding electrical environmental noise (AC of the power supply (AC power supply)). It fluctuates under the influence of the voltage frequency etc., and there is a risk of misjudging that there is no input (contact).

  The present invention has been made in view of the above points, and an object thereof is to provide a method for driving a sensor module and a method for driving an electronic device that can suppress erroneous determination that there is no input by an input unit.

The driving method of the sensor module according to one embodiment is as follows:
In a driving method of a sensor module including a sensor circuit, a first determination unit, and a second determination unit,
Drive the sensor circuit, detect input information indicating the strength of capacitive coupling that occurs according to the input operation by the input means,
Driving the first determination unit, determining the detected input information, outputting first information indicating that there is an input or second information indicating that there is no input;
A period in which the input means inputs the period during which the second determination unit is driven and the output of the first determination unit becomes the first information and the compensation period after the timing at which the first information is switched to the second information. It is determined that
When the compensation period is tc, the driving frequency of the sensor circuit is fs, and the frequency of electrical environmental noise is fn,
The sensor circuit and the second determination unit are driven under the condition of 2tc> 1 / | fs-fn |.

In addition, a method for driving an electronic device according to an embodiment includes:
A method for driving an electronic device, comprising: a display panel that displays an image in a display area; a sensor module having a sensor circuit located in an input area overlapping the display area; a first determination unit; and a second determination unit. In
Driving the display panel;
Drive the sensor circuit, detect input information indicating the strength of capacitive coupling that occurs according to the input operation by the input means,
Driving the first determination unit, determining the detected input information, outputting first information indicating that there is an input or second information indicating that there is no input;
A period in which the input means inputs the period during which the second determination unit is driven and the output of the first determination unit becomes the first information and the compensation period after the timing at which the first information is switched to the second information. It is determined that
When the compensation period is tc, the driving frequency of the sensor circuit is fs, and the frequency of electrical environmental noise is fn,
The sensor circuit and the second determination unit are driven under the condition of 2tc> 1 / | fs-fn |.

FIG. 1 is a schematic perspective view illustrating an electronic apparatus according to an embodiment. 2 is a schematic configuration diagram showing the electronic device shown in FIG. 1, and is a plan view showing an array substrate, a rechargeable battery, an IC, a power circuit, and the like. FIG. 3 is a diagram illustrating an equivalent circuit such as a pixel and a sensor circuit of the electronic device. FIG. 4 is an equivalent circuit diagram for explaining a configuration example of the sensor circuit. FIG. 5 is a plan view showing the array substrate, and shows a schematic configuration of the sensor module. FIG. 6 is a timing chart showing the input operation of the input means and the output signal of the sensor circuit when the voltage value of the output signal of the sensor circuit is assumed to be an ideal value. FIG. 7 is a timing chart showing the actual voltage value of the output signal of the sensor circuit and the output signal of the filter circuit. FIG. 8 is a plan view showing the array substrate, and shows a state where the array substrate is affected by environmental noise and the GND of the array substrate is not set to 0V. FIG. 9 is a plan view showing the array substrate, and shows a state where the electrical relationship between the array substrate and the input means is equivalent to the case of FIG. FIG. 10 illustrates the difference between the driving frequency of the sensor circuit and the frequency of the environmental noise, the output signal of the sensor circuit, and the output signal of the filter circuit, when considering that the sensor circuit is affected by environmental noise. It is a timing chart which shows. FIG. 11 shows the difference between the sensor circuit drive frequency and the environmental noise frequency, the sensor circuit output signal, and the filter circuit output signal when the sensor circuit drive frequency is adjusted in consideration of the environmental noise frequency. It is a timing chart which shows.

  Hereinafter, a method for driving a sensor module and a method for driving an electronic apparatus including the sensor module according to an embodiment will be described in detail with reference to the drawings. In this embodiment, the electronic device is a liquid crystal display device. First, the configuration of the electronic device will be described.

  As shown in FIGS. 1 to 3, the electronic device includes a liquid crystal display panel P as a display panel for displaying an image, a sensor module M provided in the liquid crystal display panel P, a backlight unit B, and a power source. A rechargeable battery 40. In this embodiment, the liquid crystal display panel P and the sensor module M constitute an active in-cell touch panel.

  The liquid crystal display panel P includes an array substrate AS, a counter substrate OS, and a liquid crystal layer LC. The extended portion of the array substrate AS and the substrate 50 are connected by an FPC (flexible printed circuit) 52. The liquid crystal display panel P has a display area (active area) R1. Note that an input area R2, which will be described later, overlaps the display area R1.

  Outside the display region R1, an X driver XD and Y drivers YD1, YD2 and the like are formed on the array substrate AS side (on a glass substrate 1 described later). The IC 51 (sensor LSI) formed (mounted) on the substrate 50 is electrically connected to the X driver XD and the Y drivers YD1 and YD2 via the FPC 52. The IC 51, the X driver XD, the Y drivers YD1, YD2, and the like function as a drive unit that drives the liquid crystal display panel P and a sensor circuit SN described later.

  The IC 51 supplies data to the X driver XD and Y drivers YD1 and YD2. Data for image display is supplied to the X driver XD and the Y driver YD1. Sensing data is given to the X driver XD and the Y driver YD2.

  A power circuit 53 is provided on the substrate 50. The power supply circuit 53 supplies power to the IC 51 or supplies power to the array substrate AS (sensor module M) via the FPC 52 or a wiring (not shown). Thereby, an AC voltage is applied to the array substrate AS (sensor module M). In this embodiment, the frequency of the AC voltage is 61 Hz.

  The array substrate AS and the counter substrate OS are arranged to face each other while holding a predetermined gap by a plurality of columnar spacers (not shown). The array substrate AS and the counter substrate OS are bonded to each other by a sealing material 31 disposed at the peripheral edge of both substrates.

  In this embodiment, the liquid crystal display panel P has, for example, a display surface on the array substrate AS side. The display surface also functions as an input surface. For this reason, the liquid crystal display panel P has a structure called a front array structure, and the array substrate AS is arranged on the user side with respect to the counter substrate OS.

  The backlight unit B is disposed on the opposite side of the array substrate AS with respect to the counter substrate OS. The backlight unit B emits light toward the counter substrate OS. The liquid crystal display panel P controls whether or not the incident backlight is transmitted. The liquid crystal display panel P displays an image in the display region R1 by transmitting light to the outer surface side of the array substrate AS.

  As shown in FIGS. 2 and 3, the array substrate AS has a plurality of pixels PX provided in a matrix along the row direction X and the column direction Y orthogonal to each other. The plurality of pixels PX overlap the display region R1. The pixels PX are arranged in the row direction X and the column direction Y.

  The pixel PX displays one of a plurality of colors, and in this embodiment, displays any one of red, green, and blue. In this embodiment, the red pixel PX, the green pixel PX, and the blue pixel PX are repeatedly arranged in the row direction X. The red pixel PX is overlaid on a red colored layer described later, the green pixel PX is overlaid on a green colored layer described below, and the blue pixel PX is overlaid on a blue colored layer described below.

  The array substrate AS has a plurality (n) of signal lines s, a plurality (m) of scanning lines g, and a plurality (m) of auxiliary capacitance lines c. The signal lines s extend in the column direction Y and are arranged at intervals in the row direction X. The signal line s is connected to the X driver XD. During the horizontal scanning period and the vertical scanning period, video signals are supplied to the plurality of signal lines s via the X driver XD.

  The scanning lines g extend in the row direction X and are arranged at intervals in the column direction Y. The auxiliary capacitance line c is arranged with an interval from the scanning line g. As with the scanning line g, the storage capacitor line c extends in the row direction X and is arranged at intervals in the column direction Y. The scanning line g and the auxiliary capacitance line c are connected to at least one of the Y drivers YD1 and YD2. In this embodiment, the scanning line g and the auxiliary capacitance line c are connected to the Y driver YD1.

  The plurality of pixels PX are provided in the vicinity of intersections of the plurality of signal lines s, the plurality of scanning lines g, and the plurality of auxiliary capacitance lines c. The pixel PX is connected to the signal line s, the scanning line g, and the auxiliary capacitance line c. The pixel PX includes a switching element GSW, a pixel electrode PE, and an auxiliary capacitor Cs.

  The switching element GSW is formed of a TFT (thin film transistor), and here is formed of an NMOS type TFT. The pixel electrode PE is electrically connected to the switching element GSW. The auxiliary capacitor Cs is electrically connected to the pixel electrode PE. The auxiliary capacitance Cs includes an auxiliary capacitance line c and an auxiliary capacitance electrode (not shown), and forms a capacitance.

  In this embodiment, the liquid crystal display panel P adopts an FFS (Fringe Field Switching) mode using a lateral electric field. A plurality of slits are formed in the pixel electrode PE. Therefore, a passivation film and a planarizing film are sequentially formed on the interlayer insulating film on which the signal line s and the like are formed, and the common electrode CE, the insulating film, the pixel electrode PE, and the alignment film are formed on the planarizing film. It is formed in order.

The counter substrate OS has another glass substrate as a transparent insulating substrate. On the other glass substrate, a color filter and an alignment film are sequentially formed. The color filter has a black matrix layer and a plurality of colored layers of red, green, and blue.
Optical elements including polarizing plates are arranged on the outer surfaces of the glass substrate 1 (array substrate AS) and another glass substrate (counter substrate OS).

  As shown in FIGS. 2 to 4, the sensor module M includes a plurality of sensor circuits SN, a plurality of capacitive coupling lines cup1, cup2, a plurality of precharge lines pre, and a plurality of precharge control lines preg. A plurality of readout lines out and a plurality of readout control lines outg are provided.

  One sensor circuit SN is arranged in a region (pixel group) where a plurality of adjacent pixels PX are provided. In this embodiment, one sensor circuit SN is arranged for every 24 pixels PX (2 rows × 12 columns).

  The precharge control line preg is arranged with an interval between the scanning line g and the auxiliary capacitance line c. The precharge control lines preg extend in the row direction X and are arranged at intervals in the column direction Y. The precharge control line preg is connected to at least one of the Y driver YD1 and the Y driver YD2. In this embodiment, the precharge control line preg is connected to the Y driver YD2. The precharge control line preg is supplied with a precharge control signal PG from the Y driver YD2.

  The read control line outg is arranged at intervals with respect to the scanning line g, the auxiliary capacitance line c, and the precharge control line preg. The read control lines outg extend in the row direction X and are arranged at intervals in the column direction Y. The read control line outg is connected to at least one of the Y driver YD1 and the Y driver YD2. In this embodiment, the read control line outg is connected to the Y driver YD2. A read control signal RG is given to the read control line outg from the Y driver YD2.

Precharge line pre, readout line out, and capacitive coupling lines cup1, cup2
Is shared with the signal line s. The precharge line pre, the capacitive coupling line cup1 and the readout line out are arranged at a ratio of one for each of the plurality of sensor circuits SN arranged in the same column direction Y (every 12 columns). The capacitive coupling line cup2 is arranged at a ratio of nine for each of the plurality of sensor circuits SN (for every 12 columns) arranged in the same column direction Y.

  The capacitive coupling line cup2 forms a coupling capacitance with a detection electrode DE described later. In this embodiment, the capacitive coupling line cup1 forms a coupling capacitance with the detection electrode DE.

The sensor circuit SN includes a detection electrode DE, a precharge control switch PSW, an amplification switch AMP as an amplifier, and a readout switch OSW.
As will be described later, the detection electrode DE extends in the row direction X, and the detection capacitance Cf changes according to the input operation by the input means 30.

  The precharge control switch PSW is formed of a TFT, and here is formed of a PMOS type TFT. The precharge control switch PSW is connected between the precharge line pre and the detection electrode DE, and switches whether the precharge voltage PR input through the precharge line pre is applied to the detection electrode DE.

  Further, when the voltage of the capacitive coupling pulse signal CPL given to the capacitive coupling line cup1 changes, the potential of the detection electrode DE changes via the coupling capacitor Cp. At this time, the potential of the detection electrode DE fluctuates in accordance with the strength of capacitive coupling generated according to the input operation by the input means 30.

  The amplification switch AMP is formed of a TFT, and here is formed of a PMOS type TFT. The gate electrode of the amplification switch AMP is connected to the detection electrode DE. The source electrode of the amplification switch AMP is connected to the capacitive coupling line cup1. The amplification switch AMP is in a conductive state (on) when a low (L) level voltage is applied from the detection electrode DE, and is in a non-conductive state (when the high (H) level voltage is applied from the detection electrode DE ( Off).

  The amplification switch AMP adjusts the reference voltage Vst (capacitance coupling pulse signal CPL) given via the capacitance coupling line cup1 to a voltage value corresponding to the potential of the detection electrode DE, and outputs it to the read switch OSW.

  The read switch OSW is formed of a TFT, and here is formed of a PMOS type TFT. The read switch OSW is connected between the amplification switch AMP and the read line out. The read switch OSW switches to a conductive state or a non-conductive state in which the reference voltage Vst whose voltage value is adjusted is output to the read line out.

  The potential of the readout line out varies based on the presence / absence and strength of the detection capacitor Cf. That is, by acquiring the fluctuation of the potential of the readout line out (the voltage of the output signal of the sensor circuit SN), it is possible to detect the input information indicating the strength of the capacitive coupling generated according to the input operation by the input unit 30. it can.

  As described above, the sensor circuit SN is driven by receiving various signals from the X driver XD and the Y driver YD2. Note that detection of input information using the sensor circuit SN (position information of the input surface of the electronic device touched by the input means 30) is performed during a horizontal blanking period or a vertical blanking period during which no video signal is written. Performed moderately.

Next, the configuration of the sensor module M will be further described.
As shown in FIG. 5, the sensor module M includes a reference voltage generator 11, a comparator 12, a mapping circuit 13, a coordinate detection circuit 14, a filter circuit 15, and feedback provided on the glass substrate 1 outside the input region R <b> 2. A circuit 16 is further included. The reference voltage generator 11, the comparator 12, the mapping circuit 13, the coordinate detection circuit 14, the filter circuit 15, and the feedback circuit 16 are driven based on a signal supplied from the IC 51, a voltage supplied from the power supply circuit 53, and the like.
The reference voltage generator 11 generates a reference voltage and supplies the reference voltage to the comparator 12.

  The comparator 12 functions as a first determination unit. The comparator 12 determines input information detected by the sensor circuit SN. When making the determination, the comparator 12 compares the voltage of the output signal of the sensor circuit SN with the reference voltage generated by the reference voltage generator 11. Accordingly, the comparator 12 outputs the first information (signal) indicating that there is an input from the input means 30 or the second information (signal) indicating that there is no input to the mapping circuit 13. For example, the comparator 12 outputs the first information when determining that the voltage value of the output signal of the sensor circuit SN is equal to or higher than the value of the reference voltage. On the other hand, the comparator 12 outputs the second information when determining that the voltage value of the output signal of the sensor circuit SN is less than the value of the reference voltage.

The mapping circuit 13 rearranges information (first information or second information) of each sensor circuit SN and outputs a signal indicating the rearranged information to the coordinate detection circuit 14.
The coordinate detection circuit 14 converts the input signal into a coordinate (XY coordinate) signal. Thereby, the sensor module M primarily determines the coordinates of the input position.

  The filter circuit 15 functions as a second determination unit. Based on the signal input from the coordinate detection circuit 14, the filter circuit 15 interpolates the missing coordinates (determines that there is input from the input means 30) and eliminates erroneously detected coordinates (no input from the input means 30). Judgment).

  The filter circuit 15 includes a period in which the input from the input means 30 is input, a period during which the output of the coordinate detection circuit 14 (comparator 12) is the first information, and a compensation period after the timing at which the first information is switched to the second information. It is determined that The compensation period can be set to a specific value. When the output of the coordinate detection circuit 14 (comparator 12) is switched from the second information to the first information within the compensation period, the compensation period by the filter circuit 15 (compensation that the input by the input unit 30 is considered to be present) ends. . The filter circuit 15 outputs a signal reflecting the compensation. Thereby, the sensor module M finally determines the coordinates of the input position.

  The feedback circuit 16 controls the operations of the filter circuit 15, the X driver XD, and the Y driver YD 2 according to the output signal (coordinates of the input position) of the filter circuit 15.

  Here, the compensation period is tc, the drive frequency of the sensor circuit SN is fs, and the frequency of electrical environmental noise that affects the liquid crystal display panel P, the sensor circuit SN, etc. is fn. Then, the sensor circuit SN and the filter circuit 15 are driven under the condition of 2tc> 1 / | fs-fn |.

  When setting the above conditions, the feedback circuit 16 specifies the frequency fn. At that time, the frequency fn is specified based on the output of the sensor circuit SN that is driven by changing the drive frequency fs at least once while maintaining the state where there is an input by the input means 30.

  In this embodiment, the frequency fn is assumed to be the frequency of an alternating voltage applied from the power supply circuit 53 to the liquid crystal display panel P side. When the frequency fn can be specified in advance, the operation for specifying the frequency fn can be omitted.

Next, the feedback circuit 16 performs the adjustment described in any one of (1) to (3) below.
(1) The operation of the drive unit (IC 51, X driver XD, Y driver YD2, etc.) is controlled based on the specified frequency fn information, and the drive frequency fs is adjusted.
(2) Based on the information on the specified frequency fn, the operation of the drive unit (IC51, X driver XD, Y driver YD2, etc.) and the filter circuit 15 is controlled, and the drive frequency fs and the compensation period tc are adjusted.
(3) The operation of the filter circuit 15 is controlled based on the information on the specified frequency fn, and the compensation period tc is adjusted.

Next, the process of deriving the condition of 2tc> 1 / | fs-fn | will be described.
First, the case where the voltage value of the output signal of the sensor circuit SN is an ideal value will be described.
As shown in FIG. 6, the ideal voltage value of the output signal of the sensor circuit SN becomes “H” level “1” that is equal to or higher than the reference voltage when there is input (contact) by the input means 30, and the input ( When there is no contact), the L level is “0”, which is less than the reference voltage.

  For example, the value of the reference voltage generated by the reference voltage generator 11 is set slightly higher than the voltage value (background) of the output signal of the sensor circuit SN at the time of non-contact. For this reason, the reference voltage is set so that the voltage value of the output signal of the sensor circuit SN exceeds the reference voltage only when there is an input (contact).

  For this reason, the comparator 12 outputs the first information during the contact period in which there is an input from the input means 30, and outputs the second information in the non-contact period without the input. From the above, when the voltage value of the output signal of the sensor circuit SN becomes an ideal value, the sensor module M can be configured without the filter circuit 15.

Next, the actual voltage value of the output signal of the sensor circuit SN and the necessity of the filter circuit 15 will be described.
As shown in FIG. 7, the actual output signal of the sensor circuit SN may be lost during the contact period held in a state where there is an input from the input means 30. In this case, the comparator 12 determines (erroneously determines) that the voltage value of the output signal of the sensor circuit SN is less than the reference voltage.

  Therefore, the sensor module M has a filter circuit 15. The filter circuit 15 can make a final determination that compensates the primary determination by the comparator 12 within a specific compensation period tc. For this reason, in a state where the input by the input means 30 is actually present, the filter circuit 15 outputs an output signal that continuously becomes H level “1”, not an output signal that intermittently becomes H level “1”. be able to.

  However, in the above case, the compensation period tc is preferably set to a period during which the sensor module M does not malfunction. For example, if the compensation period tc is too short, compensation of the output signal of the comparator 12 becomes insufficient, and the filter circuit 15 may erroneously determine that there is no input by the input means 30 (separation, non-contact). . Further, if the compensation period tc is too long, the filter circuit 15 continues to maintain an erroneous determination that there is an input by the input means 30 even after shifting to the non-contact state.

  Next, a description will be given of the fact that even if the compensation period tc is simply set, if the sensor circuit SN is affected by electrical environmental noise, it may be erroneously determined that there is no input (contact) by the input means 30. .

  As shown in FIG. 8, in an environment where electrical and periodic noise (environmental noise fn) is generated, there is a possibility that a malfunction may occur in the input information detection operation by the sensor circuit SN. This is because the GND of the array substrate AS (sensor circuit SN) does not become 0 V when the electronic device is used without being grounded and is in an electrically floating state. This is because an AC voltage having a frequency of 61 Hz applied from the power supply circuit 53 to the array substrate AS becomes environmental noise. As a result, the GND of the array substrate AS (sensor circuit SN) fluctuates with a frequency of 61 Hz and an amplitude of several hundred volts.

  On the other hand, the GND of the input means 30 is assumed to be 0V. In addition, although the GND of the input means 30 may fluctuate, it is slight compared with the potential fluctuation of the GND of the array substrate AS. Therefore, here, the GND of the input means 30 is regarded as 0V.

  As shown in FIG. 9, when FIG. 8 is shown equivalently, the GND of the array substrate AS (sensor circuit SN) is 0 V, and the GND of the input means 30 changes in potential at a frequency of 61 Hz and an amplitude of several hundred V. It will be. That is, it can be considered that input is performed by the input means 30 in which noise is generated.

  As shown in FIG. 10, when the sensor circuit SN is affected by environmental noise, a difference between the environmental noise frequency fn and the driving frequency fs of the sensor circuit SN is generated as a “beat” in the output signal of the sensor circuit SN. . The “fu” frequency fu can be expressed by the following equation.

fu = | fn−fs |
In this embodiment, when the frequency fn is 61 Hz and the driving frequency fs is 60 Hz, the frequency fu is 1 Hz. In this embodiment, the driving frequency of the liquid crystal display panel P is 60 Hz, which is the same as the driving frequency fs. For this reason, due to the alias effect, a long-period “beat (1 Hz beat)” is generated in the output signal of the sensor circuit SN. When the frequency fu is only a few Hz, the above-mentioned “beat” is long.

  As a result, the voltage value of the output signal of the sensor circuit SN becomes less than the reference voltage for 0.5 seconds, which is half of the period (1 second), and the comparator 12 outputs the second information. That is, for 0.5 seconds, regardless of the input operation by the input unit 30, it is primarily determined that there is no input by the input unit 30.

Even if the compensation period tc is set to 0.1 second, the filter circuit 15 finally determines that there is no input by the input unit 30 regardless of the input operation by the input unit 30 for 0.4 seconds.
As can be seen from the above description, when the sensor circuit SN is affected by environmental noise, there is a risk of erroneous determination that there is no input (contact) by the input means 30.

  Therefore, in the present embodiment, the sensor circuit SN and the filter circuit 15 are driven under the condition of 2tc> 1 / | fs-fn |. For example, in the example illustrated in FIG. 10, the feedback circuit 16 may perform the adjustment (3). The feedback circuit 16 controls the operation of the filter circuit 15 based on the information on the frequency fn, and the filter circuit 15 adjusts the compensation period tc to 0.5 seconds. Thereby, the erroneous determination that there is no input (contact) by the input means 30 can be suppressed.

  By the way, as described above, when the compensation period tc is adjusted to 0.5 seconds, the filter circuit 15 continues for 0.5 seconds after the timing when the actual input by the input means 30 switches from “present” to “not present”. It is finally determined that there is an input by the input means 30.

  For this reason, when the condition of 2tc> 1 / | fs−fn | is met, it may not be desirable to adjust the compensation period tc. In this case, the feedback circuit 16 may perform the adjustment (1). The feedback circuit 16 controls the operation of the drive unit (IC51, X driver XD, Y driver YD2, etc.) based on the information on the frequency fn, and adjusts the drive frequency fs. As a result, it is possible to adapt to the above conditions without making an adjustment to increase the compensation period tc.

Next, an example in which the feedback circuit 16 performs the adjustment (1) will be described.
As shown in FIG. 11, the frequency fn is 61 Hz, but the feedback circuit 16 adjusts the drive frequency fs to 70 Hz. Then, the frequency fu becomes 9 Hz. By sufficiently separating the driving frequency fs from the frequency fn, it is possible to increase the frequency of “beat” due to the alias effect. Thereby, the period during which the voltage value of the output signal of the sensor circuit SN is primarily determined to be less than the reference voltage can be shortened.

  The half period of the 1/9 Hz period (about 0.11 second) is 1/18 Hz (about 0.06 second). After the timing when the actual input by the input unit 30 switches from “present” to “not present”, the filter circuit 15 can finally determine that there is an input by the input unit 30 for 0.06 seconds. For this reason, the time can be significantly shortened from 0.5 seconds to 0.06 seconds.

  Further, the compensation period tc may be set to 0.1 seconds, for example, and can be adapted to the condition of tc> 1/18 Hz. From the above, by adjusting the drive frequency fs, it is possible to meet the condition of 2tc> 1 / | fs−fn | without adjusting the compensation period tc to be 0.5 seconds or the like.

  According to the driving method of the sensor module M and the driving method of the electronic apparatus including the sensor module according to the embodiment configured as described above, first, the sensor circuit SN is driven, and the input unit 30 responds to the input operation. The input information indicating the strength of the capacitive coupling that occurs is detected. Next, the comparator 12 is driven, input information detected by the sensor circuit SN is determined, and first information indicating that there is an input or second information indicating that there is no input is output.

  Thereafter, the filter circuit 15 is driven, and the input means 30 inputs the period when the output of the coordinate detection circuit 14 (comparator 12) becomes the first information and the compensation period tc after the timing when the first information is switched to the second information. It is determined that it is a period. In this embodiment, the sensor circuit SN and the filter circuit 15 are driven under the condition of 2tc> 1 / | fs-fn |.

  For this reason, even if the liquid crystal display panel P, the sensor circuit SN, and the like are affected by environmental noise, an erroneous determination that there is no input by the input unit 30 can be suppressed. And the determination precision of the presence or absence of the input by the input means 30 can be improved.

By adjusting the drive frequency fs of the sensor circuit SN and increasing | fs-fn |, the adjustment for increasing the compensation period tc (for example, adjustment for changing from 0.1 second to 0.5 second) is not performed. Good. For this reason, after the timing when the actual input by the input means 30 switches from “present” to “absent”, it is possible to suppress the lengthening of the period during which the filter circuit 15 finally determines that there is an input.
From the above, it is possible to obtain a driving method of the sensor module M and a driving method of the electronic device that can suppress erroneous determination that there is no input by the input unit 30.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  For example, the environmental noise is not limited to AC voltage. For this reason, the above-described embodiment can obtain the above-described effects even when various environmental noises affect the electronic device.

  The compensation period tc is preferably 0.1 seconds or less. Thereby, the determination accuracy of the presence or absence of input by the input means 30 can be further improved.

  The sensor circuit SN may be driven independently of driving the liquid crystal display panel P. The driving frequency fs of the sensor circuit SN (frequency of the signal used for driving) may be different from the driving frequency of the liquid crystal display panel P. As a result, the drive frequency fs can be adjusted without affecting the drive of the liquid crystal display panel P.

  The electrical connection position of the filter circuit 15 is not limited to the above-described example, and can be modified. If the filter circuit 15 is connected to the subsequent stage of the comparator 12, the above-described effects can be obtained.

The common electrode for generating an electric field applied to the liquid crystal layer together with the pixel electrode PE may be provided on the array substrate AS side, or may be provided on the counter substrate OS side. The liquid crystal display panel P can adopt a display mode other than the FFS mode. The liquid crystal display panel P may have a structure called a rear array structure. In this case, the counter substrate OS is arranged on the user side with respect to the array substrate AS.
The driving method of the sensor module M and the driving method of the electronic device described above can be applied to various driving methods of the sensor module M and driving method of the electronic device.

  P ... Liquid crystal display panel, PX ... Pixel, XD ... X driver, YD1, YD2 ... Y driver, M ... Sensor module, SN ... Sensor circuit, DE ... Detection electrode, Cf ... Detection capacitance, 11 ... Reference voltage generator, 12 Comparator, 13 ... Mapping circuit, 14 ... Coordinate detection circuit, 15 ... Filter circuit, 16 ... Feedback circuit, 30 ... Input means, 40 ... Rechargeable battery, 51 ... IC, 53 ... Power supply circuit, tc ... Compensation period, fn ... Frequency, fs ... drive frequency, R1 ... display area, R2 ... input area.

Claims (7)

In a driving method of a sensor module including a sensor circuit, a first determination unit, and a second determination unit,
Drive the sensor circuit, detect input information indicating the strength of capacitive coupling that occurs according to the input operation by the input means,
Driving the first determination unit, determining the detected input information, outputting first information indicating that there is an input or second information indicating that there is no input;
A period in which the input means inputs the period during which the second determination unit is driven and the output of the first determination unit becomes the first information and the compensation period after the timing at which the first information is switched to the second information. It is determined that
When the compensation period is tc, the driving frequency of the sensor circuit is fs, and the frequency of electrical environmental noise is fn,
A sensor module driving method for driving the sensor circuit and the second determination unit under a condition of 2tc> 1 / | fs-fn |. In the driving method of the sensor module further comprising a driving unit for driving the sensor circuit,
Based on the output of the sensor circuit that is driven by changing the drive frequency one or more times while holding the input by the input means, the frequency of the environmental noise is identified,
The sensor module driving method according to claim 1, wherein the driving frequency is adjusted by controlling an operation of the driving unit based on information on the frequency of the specified environmental noise. In the driving method of the sensor module further comprising a driving unit for driving the sensor circuit,
Based on the output of the sensor circuit that is driven by changing the drive frequency one or more times while holding the input by the input means, the frequency of the environmental noise is identified,
2. The sensor module driving method according to claim 1, wherein the driving frequency and the compensation period are adjusted by controlling operations of the driving unit and the second determination unit based on information on the frequency of the specified environmental noise. Based on the output of the sensor circuit that is driven by changing the drive frequency one or more times while holding the input by the input means, the frequency of the environmental noise is identified,
2. The sensor module driving method according to claim 1, wherein the compensation period is adjusted by controlling an operation of the second determination unit based on information on the frequency of the specified environmental noise. The sensor module uses an alternating voltage to drive at least the sensor circuit;
The sensor module driving method according to claim 1, wherein the frequency of the environmental noise is a frequency of the AC voltage.   The sensor module driving method according to claim 1, wherein the compensation period is 0.1 second or less. A method for driving an electronic device, comprising: a display panel that displays an image in a display area; a sensor module having a sensor circuit located in an input area overlapping the display area; a first determination unit; and a second determination unit. In
Driving the display panel;
Drive the sensor circuit, detect input information indicating the strength of capacitive coupling that occurs according to the input operation by the input means,
Driving the first determination unit, determining the detected input information, outputting first information indicating that there is an input or second information indicating that there is no input;
A period in which the input means inputs the period during which the second determination unit is driven and the output of the first determination unit becomes the first information and the compensation period after the timing at which the first information is switched to the second information. It is determined that
When the compensation period is tc, the driving frequency of the sensor circuit is fs, and the frequency of electrical environmental noise is fn,
An electronic device driving method for driving the sensor circuit and the second determination unit under a condition of 2tc> 1 / | fs-fn |.

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