JP2014003374A - Detection device and detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detection device that shortens the period of detecting an operation input.SOLUTION: The detection device includes a detection section 30 for detecting, from a panel (10) in which an electromagnetic change occurs in the position where an object of detection is in contact with or in proximity to a detection surface, a signal Vs depending on the electromagnetic change. The detection section 30 has delay elements 35 connected in series, and outputs data depending on delayed data (out1 to out64) from the respective delay elements 35 based on the signal Vs input thereinto, as data determinative of whether or not there is contact with or proximity to the detection surface.

Description

  The present invention relates to a detection apparatus and a detection method for detecting an operation input by an electromagnetic change.

  Detection devices such as a touch panel, a touch screen, and a touch pad that detect a planar contact position with a fingertip, a dedicated pen, or the like are used as pointing devices for operating a computer. For example, in Patent Document 1, a CR time constant circuit is formed by the stray capacitance of the detection electrode and the resistance of the detection electrode, and the charge or discharge of the stray capacitance of the detection electrode is controlled with a certain period of rest period. A capacitive touch panel is disclosed that stray capacitance, which increases slightly due to an input operation approaching the detection electrode, can be detected by increasing the elapsed time until the potential of the detection electrode reaches the threshold potential. ing.

JP 2011-186509 A

  However, in the technique of Patent Document 1, since the charge / discharge time is enlarged and measured by intermittent control using a PWM signal, the resolution of PWM signal generation and time measurement depends on the clock frequency, and the period for detecting an operation input is long. There was a problem of becoming.

  Therefore, the present invention has been made in view of the above-described problems and the like, and an example of the problem is to provide a detection device or the like with a reduced detection cycle for detecting an operation input.

  In order to solve the above problems, the invention according to claim 1 is a detection that detects a signal corresponding to an electromagnetic change from a panel that generates an electromagnetic change at a position where a detection target is in contact with or close to the detection surface. From each delay element that receives the signal as data for determining whether or not the detection unit has a delay element connected in series and is in contact with or close to the detection surface. Data corresponding to the delayed data is output.

  The invention according to claim 2 is the detection device according to claim 1, further comprising a voltage applying unit that applies a voltage to the panel, wherein the detecting unit is configured to apply the voltage of the voltage applying unit. A signal is detected.

According to a third aspect of the present invention, in the detection device according to the second aspect, the signal is a signal of a transient response due to application of a voltage of the voltage application unit, and the detection unit includes the transient response. Is detected.

  According to a fourth aspect of the present invention, in the detection device according to the third aspect, the detection unit detects the transient response when a voltage value of the transient response exceeds a predetermined threshold value. Features.

  According to a fifth aspect of the present invention, in the detection device according to any one of the first to fourth aspects, the detection unit stores reference data for comparison with the delay data from the delay elements. And a detection unit that outputs differential data between the delay data from each delay element and the reference data.

  According to a sixth aspect of the present invention, in the detection device according to the fifth aspect, the register stores past delay data from the delay elements as the reference data.

  According to a seventh aspect of the present invention, in the detection device according to any one of the first to sixth aspects, the delay element includes an inverter element.

  According to an eighth aspect of the present invention, in the detection apparatus according to any one of the first to seventh aspects, the panel is a capacitive panel.

  The invention according to claim 9 is the detection device according to any one of claims 2 to 8, wherein the voltage application unit includes a plurality of electrodes arranged in parallel along the detection surface of the panel. A voltage is sequentially applied to each electrode of the first electrode in a predetermined cycle, and the detection unit detects the signal from the second electrode in which a plurality of electrodes are arranged in parallel in a direction intersecting the first electrode. It is characterized by doing.

  In the detection device according to any one of claims 1 to 9, it is determined whether or not the detection device is in contact with or close to the detection surface based on an output from the detection unit. It is characterized by further comprising a determination unit for

  According to an eleventh aspect of the present invention, there is provided a detection method of a detection apparatus for detecting contact on a panel that causes an electromagnetic change at a position where a detection target is in contact with or close to a detection surface, and includes delay elements connected in series. A detection unit that outputs data corresponding to the delay data from each delay element detects a signal for detecting the electromagnetic change from the panel, and an output from the detection unit is input. And a determination step of determining whether or not the detection unit is in contact with or close to the detection surface based on an output from the detection unit that receives the signal.

  According to the present invention, since the signal can be detected with the resolution of the delay time interval of each delay element, the period for detecting the operation input can be shortened.

It is a block diagram which shows the example of a schematic structure of the detection apparatus which concerns on embodiment of this invention. It is a block diagram which shows the example of a schematic structure of the detection part of FIG. It is a block diagram which shows the example of a schematic structure of the time digitizer of FIG. FIG. 4 is a block diagram illustrating a schematic configuration example of a delay element in FIG. 3. It is a schematic diagram which shows an example of the output of the time digitizer of FIG. It is a flowchart which shows the operation example of the detection apparatus of FIG. It is a schematic diagram which shows an example of the output of the time digitizer of FIG. It is a schematic diagram which shows an example of the output of the time digitizer of FIG. It is a schematic diagram which shows an example of difference data. It is a schematic diagram which shows an example of a comparison with this embodiment and a prior art.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, embodiment described below is embodiment at the time of applying this invention with respect to a detection apparatus.

[1. Overview of detection device configuration and functions]

  First, the configuration and outline function of a detection apparatus according to an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a block diagram illustrating a schematic configuration example of a detection apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram illustrating a schematic configuration example of the detection unit. FIG. 3 is a block diagram illustrating a schematic configuration example of the time digitizer. FIG. 4 is a block diagram illustrating a schematic configuration example of the delay element. FIG. 5 is a schematic diagram showing an example of the output of the time digitizer.

  As shown in FIG. 1, the detection device 1 includes a panel unit 10 that generates an electromagnetic change at a position where a detection target such as a human finger is in contact with or close to the detection surface, and a voltage application unit that applies a voltage to the panel unit 10. 20, a detection unit 30 that detects a response signal (an example of a signal corresponding to an electromagnetic change) due to an applied voltage of the voltage application unit 20, and a control unit 40 that controls the voltage application unit 20 and the detection unit 30. Prepare.

  The panel unit 10 is, for example, a touch panel, and includes a touch sensor that detects an electromagnetic change at a position where a detection target is in contact with or close to the detection surface, and a display panel that displays an image. The touch sensor of the panel unit 10 is disposed on the upper layer of the display panel, and the surface of the touch sensor forms a detection surface of the panel unit 10.

  The touch sensor of the panel unit 10 is, for example, a capacitive type, and a first electrode in which electrodes extending in the x direction are arranged in parallel in the y direction along the detection surface of the panel unit 10 as shown in FIG. An electrode 11 and an electrode extending in the y direction are arranged between the second electrode 12 arranged in parallel in the x direction along the detection surface of the panel unit 10, for example, between the first electrode 11 and the second electrode 12. Sheet-like dielectric. The 1st electrode 11 is connected to the voltage application part 20, and has a function of a drive electrode. The second electrode 12 is connected to the detection unit 30 and has a function of a detection electrode. The electrodes of the first electrode 11 and the second electrode 12 are, for example, transparent electrodes such as indium tin oxide.

  The respective electrodes of the first electrode 11 are arranged in parallel in order from the first row in the y direction. Each electrode of the second electrode 12 is arranged in parallel in order from the first column in the x direction (an example of a direction intersecting with the electrode of the first electrode). And in the touch sensor of the panel part 10, the electrostatic capacitance between the electrode of the 1st electrode 11 and the electrode of the 2nd electrode 12 in the position where the finger | toe etc. approached or contacted changes (an example of an electromagnetic change). From the row number of the electrode of the first electrode 11 and the column number of the electrode of the second electrode 12 where the capacitance has changed, the position where the finger or the like approaches or contacts can be specified. The electrodes of the first electrode 11 and the second electrode 12 that intersect with each other form a detection electrode at the intersecting position.

  As shown in FIG. 1, the voltage application unit 20 is connected to each electrode of the first electrode 11 of the panel unit 10. The voltage application unit 20 applies a voltage to each electrode of the first electrode 11 in order from the first row of electrodes in a predetermined cycle. For example, a step voltage is applied to the electrode in a row of the first electrode 11 as the charge / discharge applied voltage Vin, the voltage application is terminated, and the step voltage is applied to the electrode in the next row. When the voltage is applied up to the last row of electrodes, the step returns to the first row of electrodes and a step voltage is applied. As described above, the voltage application unit 20 applies a voltage in the detection cycle with respect to the panel unit 10 from the first row electrode to the last row electrode in order.

  As a transient response of application of the step voltage by the voltage application unit 20, the panel unit 10 outputs a signal (hereinafter referred to as a panel signal) (detection voltage Vs) from each panel of the second electrode 12 from the panel. The panel signal is an example of a signal corresponding to an electromagnetic change.

  As shown in FIG. 2, the detection unit 30 includes a time digitizer 31 ((Time to Digital Converter: TDC)) that receives an output from the panel unit 10, and a register 32 that stores the output of the time digitizer 31. The detection unit 30 detects a change in stray capacitance caused by a finger or the like approaching or contacting the touch sensor of the panel unit 10.

  FIG. 2 shows an equivalent circuit of the detection resistor Rs and the detection electrode capacitance Cs (floating capacitance) in the electrode having the first electrode 11 and the electrode having the second electrode 12 of the panel unit 10. The stray capacitance Cs of the detection electrode has a value of about 10 pF, for example, and changes by about 1 to 3 pF depending on the approach of the detection target. The detection resistor Rs is, for example, 28 kΩ.

  As shown in FIG. 1, each detection unit 30 is connected to each electrode of the second electrode 12 of the panel unit 10. Each detection unit 30 detects a panel signal from each column of electrodes (each electrode of the second electrode 12) in the panel unit 10. And each detection part 30 is connected with the electrode of the 1st electrode 11 which exists in the position of the row currently applied among the electrodes (each electrode of the 1st electrode 11) of each line in panel part 10, and detection part 30 is connected. The panel signal at the position where the electrode of the second electrode 12 at the position of the row intersects is detected.

  As shown in FIG. 3, the time digitizer 31 includes a delay line in which delay elements 35 are connected in series. For example, 64 stages of delay elements 35 are connected.

  The setting of the number of delay elements 35 in the time digitizer 31 depends on the delay time of the delay element 35, the time constant of the transient response of the panel unit 10 due to the voltage application of the voltage application unit 20, or the relaxation time. For example, when it is desired to detect the transient response in time, the delay time of the delay element 35 is shortened and the number of stages of the delay element 35 is increased. Further, when it is desired to detect the transient response for a long time, the number of stages of the delay elements 35 is increased.

  Each delay element 35 includes two inverter elements 36 connected in series as shown in FIG. The time lag (unit delay time) τb of each delay element 35 is, for example, 2 n seconds. The inverter element 36 is a NOT logic element, and when the input voltage exceeds the threshold voltage Vsh (logic threshold voltage), the Hi voltage (logic level “1”) is output from the Low voltage (logic level “0”). To do. When the circuit element of the inverter element 36 is a CMOS (Complementary Metal Oxide Semiconductor), the threshold voltage Vsh is about 0.7 Vdd with respect to the power supply voltage Vdd. The threshold voltage Vsh of the time digitizer input becomes the threshold voltage Vsh of the inverter element 36. Note that a comparator may be provided in the preceding stage of the time digitizer 31 to set the threshold voltage of the time digitizer input. The number of inverter elements 36 is not limited to an even number, and may be an odd number. In this case, the output is inverted (a logic level “0” is output).

  The delay time of the delay element 35 is set according to the accuracy of time resolution, the time length for measuring the transient response of the panel unit 10 due to the voltage application of the voltage application unit 20, the number of stages of the delay element 35 in the time digitizer 31, and the like. The The circuit element of the inverter element may be TTL (Transistor-Transistor-Logic). The delay element 35 may be composed of a flip-flop circuit.

  The delay element 35 (first-stage delay element 35) connected to the electrode of the second electrode 12 of the panel unit 10 receives an input of a panel signal from the electrode of the second electrode 12. As shown in FIG. 5, the first-stage delay element 35 outputs the delay data of the time digitizer output out1 to the register 32 and the second-stage delay element 35. When the voltage of the panel signal of the analog signal, which is a transient response between the detection resistor Rs and the detection capacitor Cs, exceeds the threshold voltage Vsh, the first-stage delay element 35 outputs a Hi voltage delayed by τb.

  The second-stage delay element 35 outputs the delay data of the time digitizer output out2 (data having Hi voltage delayed by 2 × τb time) to the register 32 and the third-stage delay element 35.

  The third-stage delay element 35 outputs the delay data of the time digitizer output out3 (data having a Hi voltage delayed by 3 × τb time) to the register 32 and the fourth-stage delay element 35.

  The delay element 35 at the final stage outputs the delay data of the time digitizer output out64 (data having a voltage of Hi delayed by 64 × τb time) to the register 32.

  Each delay element 35 outputs delay data having a time lag τb corresponding to the stage in the serial connection. The time digitizer 31 outputs 64-bit delay data from each delay element 35 to the register 32. The time digitizer 31 instantly measures the rising timing of the binarized signal as a digital value with high resolution (in the order of several tens of ps). Thus, the resolution is determined by the delay time of the unit delay cell configured using the transmission delay of the logic circuit.

  The register 32 includes a storage element that stores 64-bit delay data from the time digitizer 31, a reference data storage element that stores 64-bit reference data for comparison with the delay data from each delay element, and delay data And a difference element that outputs difference data between the reference data and the reference data. Here, the register 32 functions as an example of a register that stores reference data for comparison with delay data from each delay element.

  The storage element and the reference data storage element are semiconductor circuits that store and hold data. The value stored in the storage element changes according to the change in the output value of the time digitizer 31. In response to a hold signal from the control unit 40, the storage element of the register 32 holds and reads the value.

  The reference data storage element stores a plurality of reference data corresponding to the number of electrodes of the first electrode, that is, the number of rows of electrodes of the panel unit 10. That is, the reference data corresponding to the electrode of each row of the panel unit 10 that intersects the electrode of the column of the panel unit 10 to which the detection unit 30 is connected is stored. The reference data storage element stores, for example, delay data from the time digitizer 31 one cycle before the inspection cycle as reference data.

  The difference element is composed of, for example, a NOT logical operation and a product logical product circuit. The difference element calculates difference data between the reference data corresponding to the electrode of the row to which the voltage is applied and the delay data, triggered by the hold signal from the control unit 40. The register 32 outputs the difference data to the control unit 40.

  The control unit 40 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and functions as a computer. The control unit 40 has a program for determining whether or not the detection surface of the panel unit 10 is touched or approached based on the difference data, and calculating a coordinate position based on the difference data. Furthermore, the control unit 40 controls the charging / discharging timing and the charging / discharging order of the panel unit 10 by the voltage application unit 20, and controls the detection timing by a hold signal to the detection unit 30. In addition, the control unit 40 outputs a clock signal for determining a detection cycle for scanning the electrodes of the panel unit 10 and synchronizing the voltage application unit 20 and the detection unit 30. Note that the program processing in the control unit 40 may be performed by hardware.

  The control unit 40 outputs the calculated coordinate information to a main control unit (not shown). A main control unit configured by a CPU, a ROM, a RAM, and the like and functioning as a computer changes the display on the display panel of the panel unit 10 based on the coordinate information or performs a process instructed by a finger or the like. .

  The control unit 40 functions as an example of a determination unit that determines whether or not the detection surface is touched or approached based on an output from the detection unit that receives a signal.

[2. Operation of the detection system]
Next, the operation of the detection apparatus according to one embodiment of the present invention will be described with reference to FIGS.

  FIG. 6 is a flowchart illustrating an operation example of the detection apparatus. 7 and 8 are schematic diagrams showing an example of the output of the time digitizer. FIG. 9 is a schematic diagram illustrating an example of difference data.

  As shown in FIG. 6, the detection apparatus 1 applies a voltage to the electrodes in the first row (step S1). Specifically, the voltage application unit 20 applies a step voltage to the first row of electrodes in the first electrode 11 of the panel unit 10 under the control of the control unit 40. For example, as illustrated in FIG. 7, the voltage application unit 20 applies a step voltage as the charge / discharge application voltage Vin. The rising time of the charge / discharge applied voltage Vin is t0. Further, it is assumed that no voltage is applied to the electrodes in other rows.

  Next, the detection apparatus 1 outputs a panel signal (step S2). Specifically, the electrodes in each column of the second electrodes 12 of the panel unit 10 output step response panel signals corresponding to an equivalent circuit of the detection resistor Rs and the detection electrode capacitance Cs to each detection unit 30. For example, as shown in FIG. 7, the panel unit 10 outputs a panel signal Vs having a step response having a time constant τcr corresponding to the detection resistor Rs and the detection electrode capacitance Cs.

  Next, the detection apparatus 1 outputs delay data based on the panel signal (step S3). Specifically, the time digitizer 31 of the detection unit 30 outputs data of logic level “0” from each delay element 35 before the voltage of the panel signal Vs exceeds the threshold voltage Vsh. That is, out <1:64> = 0 ([000... 000]) in which all 64 bits are 0 is output as the delay data by the panel signal. In the case of non-contact, for the sake of convenience, the threshold voltage Vsh of the time digitizer input with respect to the power supply voltage Vdd is, for example, from the corresponding time constant τcr (for example, 280 nsec) between the detection resistor Rs and the detection electrode capacitance Cs. 0.632Vdd.

  The first stage of the time digitizer 31 after the unit delay time τb from the time when the voltage of the panel signal Vs exceeds the threshold voltage Vsh (for example, after t0, after the time constant τcr (280 nsec) at the time of non-contact). The delay element 35 of the eye outputs data of logic level “1”. That is, out <1: 1> = 1, out <2:64> = 0 ([100..., 000]) is output as delay data by the panel signal.

  On the other hand, in order for the user to perform an operation input on the detection surface of the panel unit 10, the user's finger contacts or approaches the detection surface in the vicinity of the electrode of the first electrode 11 to which a voltage is applied. As shown in FIG. 5, when the detection electrode capacitance Cs changes, the unit delay from the time when the voltage of the panel signal Vs exceeds the threshold voltage Vsh (for example, after the time constant τcr (308 nsec) at the time of contact from t0). After time τb, the delay element 35 in the first stage of the time digitizer 31 outputs data of logic level “1”. Depending on the configuration of the panel unit 10, a detection target such as a finger may be in contact with or close to the detection surface of the panel unit 10, and the time constant τcr may be shortened.

  After 2 × unit delay time τb from the time when the threshold voltage Vsh is exceeded, the first-stage and second-stage delay elements 35 of the time digitizer 31 output data of logic level “1”. That is, out <1: 2> = 1, out <3:64> = 0 ([110..., 000]) is output as delay data by the panel signal. Thus, the value of the delay data changes for each unit delay time τb.

  Thus, the detection unit 30 functions as an example of a detection unit that detects a signal generated by applying a voltage from the voltage application unit. The detection unit 30 functions as an example of a detection unit that detects a signal of a transient response due to application of a voltage from the voltage application unit. The detection unit functions as an example of a detection unit that detects a transient response when the voltage value of the transient response exceeds a predetermined threshold.

  As described above, the detection device 1 includes delay elements connected in series, and a detection unit that outputs data corresponding to the delay data from each delay element detects a signal for detecting the electromagnetic change from the panel. Functions as an example of a detecting means for detecting.

  Next, the detection apparatus 1 reads delay data after a predetermined time (step S4). The control unit 40 transmits a hold signal to the detection unit 30 after a predetermined time th, and the register 32 of the detection unit 30 reads the 64-bit delay data from the time digitizer 31. For example, after a predetermined time th (= 400 n seconds) from the rising time t0, the register 32 reads the 64-bit delay data of the time digitizer 31.

  When the detection target such as a finger is not in contact with or close to the vicinity of the intersection of the electrode of the row to which the voltage is applied and the electrode of the column to which the detection unit 30 is connected on the detection surface of the panel unit 10, As shown in FIG. 7, the register 32 outputs out <1:60> = 1, out <61:64> = 0 ([11111111111... 111110000]) is read.

  On the other hand, the detection target such as a finger is in contact with or close to the vicinity of the intersection of the electrode of the row to which the voltage is applied and the electrode of the column to which the detection unit 30 is connected on the detection surface of the panel unit 10. In this case, as shown in FIG. 8, the register 32 stores out <1:46> = 1, out <47: 64 = 0> ([11111... 11000000000000000000]) as delay data by the panel signal. Read 64-bit delay data.

  Next, the detection apparatus 1 calculates and outputs difference data (step S5). Specifically, the register 32 of the detection unit 30 reads the reference data from the reference data storage element of the register 32 corresponding to the electrode of the row to which the voltage is applied. That is, the register 32 reads out the delay data one detection cycle before as the reference data in the detection cycle in which the panel unit 10 is scanned from the first row electrode to the last row electrode.

  Then, the register 32 calculates 64-bit difference data that is the difference between the 64-bit reference data and the delay data, and outputs the difference data to the control unit 40. For example, the register 32 calculates NOT of the delay data, and calculates a logical product of the NOT delay data and the reference data. Then, the control unit 40 acquires difference data from each detection unit 30.

  The difference data is an example of data corresponding to the delay data. The detection unit 30 may output delay data to the control unit 40, and the control unit 40 may calculate difference data. In this case, the control unit 40 stores reference data instead of the register 32.

  As shown in FIG. 9, for example, a detection target such as a finger is in the vicinity of an intersection of a row electrode to which a voltage is applied and a column electrode to which the detection unit 30 is connected on the detection surface of the panel unit 10. If it is not in contact with or in close proximity, out <1:64> = 0 ([000... 000]) is calculated as difference data.

  On the other hand, as shown in FIG. 9, for example, a detection target such as a finger intersects an electrode in a row to which a voltage is applied and an electrode in a column to which the detection unit 30 is connected on the detection surface of the panel unit 10. If you are in contact with or close to the vicinity, out <1:46> = 0, out <47:60> = 1, out <61:64> = 0 ([000 ... 001111111110000 ]).

  Next, after calculating the difference data, the register 32 stores the read delay data in the reference data storage element of the register 32 corresponding to the electrode of the row to which the voltage is applied. The read delay data becomes the delay data one detection cycle before the next detection cycle. As described above, the register 32 functions as an example of a register that stores past delay data from each delay element as reference data.

  As described above, an example of a detection unit that outputs data corresponding to delay data from each delay element that receives a signal as data for determining whether or not the detection unit 30 has touched or approached the detection surface. Function as.

  Next, the detection apparatus 1 determines whether or not it is a predetermined number or more (step S6). Specifically, the control unit 40 counts the number of bits that are “1” in the difference data for each difference data acquired from each detection unit 30, and determines whether or not the number is equal to or greater than a predetermined number. . When the count number is equal to or greater than the predetermined number, it is assumed that the detection target such as a finger is in contact with or close to the detection surface of the panel unit 10, and when the count number does not reach the predetermined number, the detection target such as a finger is Suppose that they are not in contact with or close to the detection surface. Note that the number of bits of “1” in the difference data indicates how many of the delay elements 35 are shifted between the delay data and the reference data.

  As described above, the detection device 1 determines whether or not the determination unit to which the output from the detection unit is input is in contact with or close to the detection surface based on the output from the detection unit that receives the signal. It functions as an example of means.

  If the number is greater than or equal to the predetermined number (step S6; YES), the detection apparatus 1 calculates the contact position (step S7). Specifically, the control unit 40 outputs the row number of the electrode of the first electrode 11 to which the voltage application unit 20 is applying a voltage, and the detection unit 30 that outputs the difference data whose count number is equal to or greater than a predetermined number. The contact position in the panel unit 10 is calculated from the column number of the connected second electrode 12. When there are a plurality of detection units 30 that output differential data whose count number is equal to or greater than a predetermined number, the control unit 40 calculates a plurality of contact positions.

  And the control part 40 outputs the information of a contact position to a main control part.

  After calculating the contact position in step S7, or when the contact position is not greater than or equal to the predetermined number (step S6; NO), the detection device 1 determines whether or not the power is ON (step S8). Specifically, the control unit 40 determines whether the power of the touch panel including the detection device 1 is ON.

  When the power is ON (step S8; YES), the detection apparatus 1 determines whether or not the electrode is in the last row (step S9). Specifically, the control unit 40 determines whether or not the voltage application by the voltage application unit 20 is an electrode in the last row among the electrodes of the first electrode 11.

  When the power is OFF (step S8; NO), the detection device 1 ends the process.

  When it is the electrode of the last line (step S9; YES), the detection apparatus 1 returns to step S1, and performs a process. Moreover, the detection apparatus 1 transmits the coordinate information of the position which contacted or approached the detection surface of the panel part 10 to a main control part.

  When it is not the electrode of the last row (step S9; NO), the detection apparatus 1 applies to the electrode of the next row (step S10). Specifically, at the clock frequency of the clock signal of the control unit 40, according to the control of the control unit 40, the voltage application unit 20 starts charging the detection electrode capacitor Cs with a step voltage for one clock, and discharges for four clocks. After that, a step voltage is applied to the next row of electrodes in the first electrode 11 of the panel unit 10. For example, when the clock frequency is 2.5 MHz, if the detection cycle per electrode is 5 clocks, the detection cycle is 2 μs. The detection cycle for scanning the entire panel unit 10 is the number of rows of each electrode of the first electrode 11 × 2 μsec.

  Next, the detection apparatus 1 performs the process of step S2.

  Based on the coordinate information from the detection device 1, the main control unit changes the display on the display panel of the panel unit 10 or performs processing instructed by a finger or the like.

  As described above, according to the present embodiment, the detection unit 30 that detects the panel signal Vs corresponding to the electromagnetic change of the panel unit 10 from the panel unit 10 that generates an electromagnetic change at a position where the detection target is in contact with or close to the detection surface. The detection unit 30 includes delay elements 35 connected in series, and receives each panel signal Vs as data for determining whether or not the detection unit 30 is in contact with or close to the detection surface of the panel unit 10. Data corresponding to the delay data (out1 to out64) from the delay element 35 is output. Therefore, since the panel signal Vs can be detected with the resolution of the delay time interval of each delay element 35, the cycle for detecting the operation input can be shortened.

  For example, as shown in FIG. 10, the panel signal Vs can be detected with the resolution of the delay time interval of the delay elements 35 connected in series during one clock of the clock signal. Therefore, in a transient response in which the time constant at the time of non-contact is small and the response waveform rises quickly, even if the time constant changes due to contact or the like, the detection device 1 can detect the change in the time constant.

  In FIG. 10, the panel signal Vc schematically shows a transient response according to the technique of Patent Document 1. In the technique of Patent Document 1, it is necessary to increase the detection resistance Rs so that the time constant increases as shown in FIG. Moreover, in the technique of Patent Document 1, since the number of clocks is counted and detected, the detection of the panel signal is delayed.

  On the other hand, in the present embodiment, the panel signal is detected by the time digitizer 31 in which delay elements having a short delay time are connected in series even in one clock of the clock signal, so that the detection speed is increased. That is, the detection time of electromagnetic change can be shortened.

  Further, the detection resistance Rs having a small resistance value can be set, the time constants of the first electrode 11 and the second electrode 12 of the panel unit 10 can be designed to be small, and a transient response with a fast rise can be detected. Furthermore, since the detection resistor Rs can reduce the resistance value, the discharge time of the detection electrode capacitance Cs can be shortened, the discharge time can be shortened, and the detection cycle can be shortened. Moreover, since a large detection resistor is not required, the burden on the voltage application unit 20 can be suppressed.

  Unlike the technique of Patent Document 1, the detection speed does not depend on the clock frequency of the clock signal. Accordingly, since the time measurement by the time digitizer 31 does not depend on the clock frequency, the time measurement can realize high resolution at high speed.

  Furthermore, since the detection cycle can be increased, the number of electrode rows of the first electrode 11 and the number of electrode columns of the second electrode 12 of the panel unit 10 can be increased. Can be increased in size.

  The thick line in FIG. 10 indicates a non-contact case, and the broken line in the drawing indicates a contact case. As shown in FIG. 10, it is possible to detect a smaller change in capacitance (such as a touch operation with a glove). Whether the time constant becomes shorter or longer due to contact or the like depends on the type of the panel unit 10.

  The delay element 35 of the time digitizer 31 can instantaneously measure the rising timing of the binarized signal as a digital value with high resolution (in the order of several tens of ps).

  Further, since the panel signal Vs of the analog signal is converted into the delay data of the digital signal, the determination by the control unit 40 becomes easy. In the control part 40 from the detection part 30, it becomes robust with respect to a noise and can determine accurate contact etc.

  In addition, when a voltage application unit 20 for applying a voltage to the panel is further provided and the detection unit 30 detects a panel signal Vs due to the application of 20 voltages (Vin) of the voltage application unit, an electromagnetic change is a response due to the application of the voltage. Can be detected as Not only the transient response, but the voltage application unit 20 may apply a periodic voltage and detect the frequency response. Furthermore, by sequentially applying a voltage to each electrode of the first electrode 11, the row number of the electrode can be specified, and the contact position in the y direction on the panel unit 10 can be known.

  Further, when the panel signal Vs is a signal of a transient response due to application of the voltage of the voltage application unit 20 and the detection unit 30 detects the transient response, it can be detected as a change in the time constant of the panel unit 10.

  Further, when the detection unit 30 detects a transient response when the voltage value of the transient response exceeds a predetermined threshold (threshold voltage Vsh), the change in the time constant can be accurately detected by the threshold.

  In addition, the detection unit 30 further includes a register 32 that stores reference data for comparison with the delay data from each delay element 35, and the detection unit 30 includes the delay data from each delay element 35 and the reference data. When outputting the difference data, counting the number of “1” in the difference data makes it easy to determine whether or not the detection surface is touched or approached. Moreover, erroneous determination can be reduced by providing a threshold value for the number of counts.

  Further, when the register 32 stores past delay data from each delay element 35 as reference data, an electromagnetic change can be accurately captured at a position in contact with or close to the detection surface. For example, in the detection cycle in which the panel unit 10 is scanned from the first row electrode to the last row electrode, the difference data from the delay data (reference data) one detection cycle before is calculated, thereby touching or approaching the detection surface. The electromagnetic change can be accurately captured at the position.

  When the delay element 35 is composed of an inverter element, the unit delay time of the delay element can be set at a high speed, for example, 2 ns. Thus, the resolution is determined by the delay time of the unit delay cell configured using the transmission delay of the logic circuit.

  Further, when the panel is a capacitance type panel, the contact or proximity can be detected by a change in the detection electrode capacitance Cs caused by a detection target such as a finger contacting or approaching the detection surface.

  In addition, the voltage application unit 20 sequentially applies a voltage to each electrode of the first electrode 11 in which a plurality of electrodes are arranged in parallel along the detection surface of the panel unit 10 in a predetermined cycle. When detecting the panel signal Vs from the second electrode 12 in which a plurality of electrodes are arranged in parallel in the direction intersecting with the one electrode 11, the panel unit 10 is simply provided with the detection unit 30 for each electrode of the second electrode 12. It is possible to know the contact position or the proximity position. Further, the position of the intersection of each electrode of the first electrode 11 and each electrode of the second electrode 12 can be detected on the detection surface of the panel unit 10.

  When a determination unit (control unit 40) for determining whether or not the detection surface is touched or approached based on an output from the detection unit 30 is provided, the detection unit 30 can be a simple circuit and is suitable for an increase in the size of the panel. ing.

  Note that the panel unit is not limited to a change in the detection capacitance Cs as an example of an electrical change, as in an electrostatic capacitance type panel, but as an example of an electromagnetic change, a detection target is in contact with or close to the detection surface. In the case of an electrical change in which the resistance value changes so as to change the detection resistance Rs, it may be a case of a magnetic change or an optical change.

  Moreover, the detection unit 30 and the control unit 40 may be connected via a bus. In this case, each detection unit 30 transmits delay data to the control unit 40 together with header information corresponding to the row number.

  In the present embodiment, the detection unit 30 is installed for each electrode of the second electrode 12, but one detection unit 30 may be provided for each block in which each electrode of the second electrode 12 is divided. One detection unit 30 may be provided for the electrode 12. In these cases, the detection unit 30 sequentially detects each connected electrode.

  Moreover, the detection apparatus 1 may capture a change in which the finger has changed from contact to non-contact. When the detection device 1 stores delay data one detection cycle before as reference data, “1” appears in the difference data when the finger changes from contact to non-contact.

  Further, delay data when not in contact with or in proximity may be measured in advance and set in a register as reference data. Further, when there is little variation between each electrode of the first electrode 11 and each electrode of the second electrode 12, the detection device 1 only needs to have one reference data when it is not in contact with or close to the first electrode 11. The unit 30 may not have a register, the control unit 40 may store reference data, and the control unit 40 may calculate difference data.

  Further, the present embodiment may be applied to a touch pad.

  Furthermore, the present invention is not limited to the above embodiments. Each of the embodiments described above is an exemplification, and any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and has the same operational effects can be used. It is included in the technical scope of the present invention.

1: Detection device 10: Panel (panel)
11: 1st electrode 12: 2nd electrode 20: Voltage application part 30: Detection part 31: Time digitizer 32: Register 35: Delay element 36: Inverter element 40: Control part (determination part)

Claims (11)

A detection unit that detects a signal corresponding to the electromagnetic change from a panel that generates an electromagnetic change at a position where the detection target is in contact with or close to the detection surface;
The detection unit includes delay elements connected in series, and as data for determining whether the detection unit is in contact with or close to the detection surface, the delay data from each delay element that receives the signal is input. A detection device that outputs data corresponding to the detected data. The detection device according to claim 1,
A voltage applying unit for applying a voltage to the panel;
The detection device, wherein the detection unit detects the signal due to application of a voltage of the voltage application unit. The detection device according to claim 2,
The signal is a signal of a transient response due to application of a voltage of the voltage application unit,
The detection device, wherein the detection unit detects the transient response. The detection device according to claim 3,
The detection device, wherein the detection unit detects the transient response when a voltage value of the transient response exceeds a predetermined threshold value. In the detection device according to any one of claims 1 to 4,
The detection unit further includes a register that stores reference data for comparison with delay data from each delay element;
The detection device, wherein the detection unit outputs difference data between the delay data from each delay element and the reference data. The detection device according to claim 5,
The detection apparatus, wherein the register stores past delay data from each delay element as the reference data. The detection device according to any one of claims 1 to 6,
The detection device, wherein the delay element is composed of an inverter element. The detection device according to any one of claims 1 to 7,
The detection device, wherein the panel is a capacitive panel. The detection device according to any one of claims 2 to 8,
The voltage application unit sequentially applies a voltage to each electrode of the first electrode in which a plurality of electrodes are arranged in parallel along the detection surface of the panel in a predetermined cycle,
The detection device, wherein the detection unit detects the signal from a second electrode in which a plurality of electrodes are arranged in parallel in a direction intersecting the first electrode. The detection device according to any one of claims 1 to 9,
The detection apparatus further comprising a determination unit that determines whether or not the detection surface is touched or approached based on an output from the detection unit. In a detection method of a detection device for detecting contact in a panel in which an electromagnetic change occurs at a position where a detection target contacts or is close to a detection surface,
A detection unit that includes delay elements connected in series and outputs data corresponding to the delay data from each of the delay elements, a detection step of detecting a signal for detecting the electromagnetic change from the panel;
A determination step in which a determination unit to which an output from the detection unit is input determines whether or not the detection unit is in contact with or close to the detection surface based on an output from the detection unit that receives the signal.
A detection method comprising:

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