JP2011197942A - Detection device and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detection device that withdraws electrode to be scanned without varying detection sensitivity of each detection electrode, and to provide a display device.SOLUTION: In sensor processing using "sparse scan", only calibration data for the detection electrodes selected for "sparse scan" is used, to decide a most suitable combination of the detection electrodes and calibration elements. The "sparse scan" is performed in sensor processing, "sparse scan" is also performed for calibration processing.

Description

  The present invention detects a position where an object such as a finger, hand, arm, or pen (hereinafter referred to as a “finger”) touches the detection surface, or when the finger is located away from the detection surface. The present invention relates to a detection device capable of detecting a spatial position or detecting movement of an object on a detection surface. The present invention also relates to a display device including such a detection device.

  Conventionally, a technique for inputting information by touching with a finger or the like is known. Among them, there is a display device capable of inputting information similar to a case where a normal button is pressed with a finger or the like by touching various buttons displayed on the display with a finger or the like as a technology that is particularly attracting attention ( (See Patent Documents 1 and 2). Since this technology enables the common use of the display and buttons, it brings great benefits such as space saving and a reduction in the number of parts.

  There are various types of touch sensors that detect contact with a finger or the like, and examples of commonly used touch sensors include a capacitance type sensor (see Patent Document 2). In this type, a change in the surface electric field of the panel by touching the touch panel with a finger or the like is captured by a change in the frequency of the current flowing in the detection electrode, and the contact with the finger or the like is detected.

  The above detection method is a method of reading a change in the surface electric field of the touch panel by a change in the frequency of the current flowing through the detection electrode. Therefore, it is necessary that a finger or the like is in contact with or sufficiently close to the surface of the touch panel. When the finger or the like is far from the surface (for example, 1 cm or more away from the surface), Information is not entered on the touch panel. However, as described in Patent Document 3, for example, even when a finger or the like is far from the surface by changing the interval between adjacent detection electrodes according to the spatial position of the object. It becomes possible to input information to the touch panel. In Patent Document 3, the interval between adjacent detection electrodes is changed by thinning out the detection electrodes to be scanned.

  In the above detection method, for example, when only two buttons are displayed on the display, it is conceivable to thin out the detection electrodes to be scanned in order to reduce power consumption. In the above detection method, for example, when it is necessary to continuously detect the movement of the object on the detection surface, it is conceivable to thin out the detection electrodes to be scanned in order to shorten the detection cycle.

JP 2005-275644 A JP 2006-23904 A JP 2008-117371 A

  By the way, in the detection method described above, the capacitance of the detection electrodes is not completely the same for all the detection electrodes, but varies for each detection electrode. Therefore, in order to prevent the detection sensitivity from varying for each detection electrode corresponding to the variation in the capacitance of the detection electrode, calibration of the detection sensitivity is usually performed. However, as described above, when the detection electrode to be scanned is thinned out, if the calibration value set on the assumption that the scanning detection electrode is not thinned out is used, the detection sensitivity may vary from detection electrode to detection electrode. was there.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a detection device capable of eliminating variation in detection sensitivity for each detection electrode when thinning the detection electrode to be scanned, and the detection device. Another object is to provide a display device.

  The detection device of the present invention selects a sensor unit in which a plurality of detection electrodes are arranged on a detection surface, a calibration unit in which a plurality of calibration elements are arranged, and one or more electrodes among the plurality of detection electrodes. And a selection unit that selects one or a plurality of elements among the plurality of calibration elements. The calibration apparatus also includes an oscillation unit whose oscillation frequency is determined by the capacitance generated in one or more detection electrodes and one or more calibration elements selected by the selection unit, and a signal from the oscillation unit according to the frequency. A frequency / voltage converter for converting to voltage. The calibration apparatus further includes a control unit that the selection unit sequentially selects only some of the plurality of detection electrodes and generates a selection signal for sequentially selecting the plurality of calibration elements and applies the selection signal to the selection unit. Yes. The control unit further uses the signal from the frequency / voltage conversion unit to generate a characteristic value in the combination of the detection electrode and the calibration element selected by the selection unit.

  A display device of the present invention includes a display panel that displays an image on a display surface based on a video signal, and the calibration device described above. In this display device, a plurality of detection electrodes in the sensor unit are arranged on the display surface of the display panel.

  In the detection device and the display device of the present invention, only a part of the plurality of detection electrodes is sequentially selected by the selection unit, and the plurality of calibration elements are sequentially selected. Using the signal from the frequency / voltage conversion unit obtained when such a thinning scan is performed, a characteristic value in the combination of the detection electrode and the calibration element selected by the selection unit is generated. Thereby, it is possible to generate a calibration value based on the premise that the detection electrodes to be scanned are thinned out.

  According to the detection device and the display device of the present invention, the calibration value is generated on the assumption that the detection electrode to be scanned is thinned out. Therefore, the object on the detection surface (display surface) is thinned out from the detection electrode to be scanned. It is possible to eliminate variation in detection sensitivity for each detection electrode.

It is a figure which shows the example of 1 structure of the detection apparatus which has a function of contact detection. It is a figure which shows one structural example of the detection apparatus which has a function of contact detection and proximity detection. It is a figure which shows the example of 1 structure of the display apparatus which concerns on the 1st Embodiment of this invention. It is a figure which shows the example of 1 structure of the detection apparatus contained in the display apparatus of FIG. It is a figure which shows an example of an internal structure of the detection apparatus of FIG. It is a figure which shows the other example of an internal structure of the detection apparatus of FIG. It is a figure which shows an example of the calibration table used in the case of sequential scanning. It is a figure which shows an example of the calibration table used in the case of a thinning scan. It is a flowchart showing an example of procedures, such as a calibration process in the detection apparatus of FIG. 10 is a flowchart illustrating an example of a procedure of a calibration process in FIG. 9. 10 is a flowchart illustrating an example of a procedure of determination processing in FIG. 9. It is a figure which shows the example of 1 structure of the display apparatus which concerns on the 2nd Embodiment of this invention. It is a figure which shows the example of 1 structure of the detection apparatus contained in the display apparatus of FIG. It is a figure which shows an example of an internal structure of the detection apparatus of FIG. It is a figure which shows the modification of the detection apparatus of FIG. It is a figure which shows the other modification of the detection apparatus of FIG.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the invention will be described in detail with reference to the drawings. The description will be given in the following order.

1. Basic principle of contact detection and proximity detection (Figs. 1 and 2)
2. First embodiment (display device capable of detecting contact) (FIGS. 3 to 11)
3. Second embodiment (display device capable of contact detection / proximity detection) (FIGS. 12 to 16)

<Basic principle of contact detection and proximity detection>
First, the basic principle of contact detection and proximity detection used in the display devices of the following embodiments will be described. FIG. 1 illustrates a configuration example of a detection device 100 capable of performing contact detection. FIG. 2 illustrates a configuration example of a detection device 200 that can perform not only contact detection but also proximity detection.

  The detection device 100 is a capacitance-type detection device, and includes, for example, a two-dimensional electrode 110 as shown in FIG. The two-dimensional electrode 110 is formed on a detection surface (not shown), and includes, for example, a plurality of detection electrodes 110H and a plurality of detection electrodes 110V. The plurality of detection electrodes 110H extend in the horizontal direction and are arranged in parallel at predetermined intervals in the vertical direction within one plane. The plurality of detection electrodes 110V extend in the vertical direction and are arranged in parallel at predetermined intervals in the horizontal direction in a plane parallel to the surface on which the plurality of detection electrodes 110H are arranged.

  In addition to the two-dimensional electrode 110, the detection apparatus 100 includes a switching element 120 for switching the two-dimensional electrode 110, a signal source 130 that supplies an AC signal to the two-dimensional electrode 110, and a frequency / voltage conversion circuit (F / V). Conversion circuit) 140. The switch element 120 is, for example, a multiplexer. A plurality of terminals provided on one end side of the multiplexer are connected to one end of each detection electrode 110H and each detection electrode 110V, and one terminal provided on the other end side of the multiplexer is connected to the signal source 130 and It is connected to the F / V conversion circuit 140.

  In this detection apparatus 100, the plurality of detection electrodes 110H are sequentially selected one by one by the switch element 120, and the plurality of detection electrodes 110V are sequentially selected one by one. As a result, signals from the signal source 130 are sequentially applied to the plurality of detection electrodes 110H one by one, and are sequentially applied to the plurality of detection electrodes 110V one by one. At this time, when a finger or the like (not shown) contacts the detection surface, for example, the surface electric field of the detection surface changes, and the change changes the frequency of the current flowing through the two-dimensional electrode 110, and the change in the frequency is F. Converted to a change in voltage by the V conversion circuit 140. By evaluating this voltage change, a contact position of a finger or the like on the detection surface can be detected.

  In this detection apparatus 100, it is possible to thin out the detection electrodes to be scanned for the purpose of reducing power consumption and shortening the detection cycle. For example, the switch element 120 sequentially selects only one predetermined electrode from the plurality of detection electrodes 110H one by one and simultaneously selects only one predetermined electrode from the plurality of detection electrodes 110V one by one. Can be done.

  Like the detection device 100, the detection device 200 is a capacitance-type detection device. For example, as illustrated in FIG. 2, the two-dimensional electrode 110, the switch element 120, the signal source 130, and the F / V conversion circuit 140 are provided. It has. The detection device 200 further includes a switch element 150 between the two-dimensional electrode 110 and the switch element 120, and an amplifier 160 that supplies a signal from the signal source 130 to the wiring between the switch element 120 and the switch element 150. And a resistor 170. The switch element 150 is a switch in which the number of input terminals and the number of output terminals are equal to each other, and is a switch that performs electrical disconnection between one input terminal and one output terminal independently for each terminal. is there.

  In the detection device 200, the switch element 150 selects only a predetermined electrode from the plurality of detection electrodes 110H and selects only a predetermined electrode from the plurality of detection electrodes 110V. Note that an electrode selected by the switch element 150 among the plurality of detection electrodes 110H is referred to as a selection electrode 110H ′ (not shown), and an electrode selected by the switch element 150 among the plurality of detection electrodes 110V is the selection electrode 110V ′. (Not shown).

  Further, the switch element 120 sequentially selects the plurality of selection electrodes 110H ′ one by one and sequentially selects the plurality of selection electrodes 110V ′ one by one. That is, the signal from the signal source 130 is always applied to the plurality of selection electrodes 110 </ b> H ′ and the plurality of selection electrodes 110 </ b> V ′ via the amplifier 160 and the resistor 170. In this state, the electrodes are sequentially selected one by one by the switch element 120. At this time, a surface electric field corresponding to the arrangement of the plurality of selection electrodes 110H ′ and the plurality of selection electrodes 110V ′ is formed on the surface of the detection surface (not shown). In this detection device 200, for example, when a finger or the like (not shown) comes close to the detection surface and the output voltage (detection sensitivity) of the F / V conversion circuit 140 changes, the switching element changes according to the change in the voltage value. The number (detection electrode pitch) of the plurality of detection electrodes 110H and the plurality of detection electrodes 110V selected by 150 changes. That is, the detection sensitivity is controlled by changing the number of electrodes to be thinned out (detection electrode pitch) according to the spatial position of a finger or the like. Thereby, not only the contact position of the finger or the like on the detection surface but also the spatial position of the finger or the like away from the detection surface and the movement of the finger or the like on the detection surface can be detected.

<First Embodiment>
FIG. 3 illustrates an example of a cross-sectional configuration of the display device 1 according to the first embodiment of the present invention. The display device 1 is a display device with a touch sensor. For example, the display device 1 includes a liquid crystal display element as a display element, and a capacitive touch sensor is provided on the surface of the liquid crystal display element separately from the liquid crystal display element. It is prepared by the body.

  For example, as shown in FIG. 3, the display device 1 includes a liquid crystal display panel 10, a touch panel 20, a backlight 30, a peripheral circuit 40, and a detection circuit 50. The touch panel 20 is disposed on the viewer side (front side) of the liquid crystal display panel 10, and the backlight 30 is disposed behind the liquid crystal display panel 10.

[Liquid Crystal Display Panel 10]
The liquid crystal display panel 10 displays images by transmitting and modulating light from a light source (backlight 30) by changing the arrangement of liquid crystal molecules. The liquid crystal display panel 10 is, for example, a transmissive display panel in which a plurality of pixels (not shown) arranged in a matrix are driven by a peripheral circuit 40 in accordance with the video signal 40A and the synchronization signal 40B. The liquid crystal display panel 10 has, for example, a plurality of scanning lines WSL1 arranged in rows and a plurality of signal lines DTL arranged in columns. A plurality of pixels are arranged in a matrix corresponding to the intersection between each scanning line WSL1 and each signal line DTL.

[Touch panel 20]
The touch panel 20 is for inputting information by touching the image display surface 20A (the surface of the touch panel 20) of the display device 1 with a finger or the like. The touch panel 20 is provided separately from the liquid crystal display panel 10, for example, and is bonded to the surface of the liquid crystal display panel 10 via an adhesive (not shown), for example. The touch panel 20 corresponds to a specific example of the capacitive touch sensor described above, and detects contact / non-contact using an XY (matrix) matrix.

[Backlight 30]
The backlight 30 illuminates the liquid crystal display panel 10 from behind. For example, the light guide plate, a light source arranged on the side surface of the light guide plate, and an optical element arranged on the upper surface (light emission surface) of the light guide plate And. The light guide plate guides light from the light source to the upper surface of the light guide plate, and has a function of scattering and uniformizing light incident from the side surface. The light source is a linear light source, and includes, for example, a HCFL (Hot Cathode Fluorescent Lamp), a CCFL (Cold Cathode Fluorescent Lamp), or a plurality of LEDs (Light Emitting Diodes) arranged in a row. The optical element is configured by laminating, for example, a diffusion plate, a diffusion sheet, a lens film, a polarization separation sheet, and the like.

[Detection device 2]
FIG. 4 shows an extracted part (detection device 2) of the display device 1 that is involved in contact / non-contact detection. The detection device 2 is a detection device capable of performing contact detection, similar to the detection device 100 illustrated in FIG. 1, and includes, for example, the touch panel 20 and the detection circuit 50 as illustrated in FIG. 4. ing. The touch panel 20 includes, for example, a sensor unit 21. On the other hand, the detection circuit 50 includes, for example, a selection unit 51, an oscillation unit 52, a conversion unit 53, a control unit 54, an output unit 55, an input unit 56, a calibration unit 57, and a memory unit 59.

  The sensor unit 21 detects contact / non-contact with the image display surface 20A such as a finger. The sensor unit 21 is formed on the image display surface 20A that is a detection surface, and includes, for example, a plurality of detection electrodes 21H and a plurality of detection electrodes 21V as shown in FIG. The plurality of detection electrodes 21H extend in the horizontal direction and are arranged in parallel at predetermined intervals in the vertical direction within one plane. The plurality of detection electrodes 21V extend in the vertical direction and are arranged in parallel at predetermined intervals in the horizontal direction in a plane parallel to the surface on which the plurality of detection electrodes 21H are arranged.

  The calibration unit 57 is used when calibrating the impedance variation of each detection electrode 21H and the impedance variation of each detection electrode 21V. For example, as illustrated in FIGS. 5 and 6, the calibration unit 57 includes a plurality of calibration elements 57 </ b> H (four calibration elements 57 </ b> H- 1 to 57 </ b> H- 4) that calibrate variations in impedance of the detection electrodes 21 </ b> H. Have. Furthermore, the calibration unit 57 further includes, for example, a plurality of calibration elements 57V (not shown) that calibrate variations in impedance of the detection electrodes 21V.

  The calibration elements 57H (57H-1 to 57H-4) are, for example, capacitive elements as shown in FIG. 5, and the element capacities are slightly different for the calibration elements 57H-1 to 57H-4. . The calibration element 57H (57H-1 to 57H-4) may be a wiring as shown in FIG. 6, for example. In this case, for example, the length of the wiring is different for each of the calibration elements 57H-1 to 57H-4, and the wiring capacity of each of the calibration elements 57H-1 to 57H-4 is slightly different depending on the length. ing. The calibration element 57V is, for example, a capacitive element like the calibration element 57H, and the element capacity is slightly different for each calibration element 57V. The calibration element 57V may be a wiring, for example, similarly to the calibration element 57H. In this case, for example, the length of the wiring is different for each calibration element 57V, and the wiring capacity for each calibration element 57V is slightly different according to the length.

  The selection unit 51 electrically disconnects each detection electrode in the sensor unit 21 and each calibration element in the calibration unit 57. Specifically, the selection unit 51 selects one or a plurality of electrodes from the plurality of detection electrodes 21H and 21V, and selects one or a plurality of elements from the plurality of calibration elements 57H and 57V. ing. The selection unit 51 includes a switching element 51A for switching a plurality of detection electrodes 21H (four detection electrodes 21H-1 to 21H-4 in FIGS. 5 and 6). The selection unit 51 also includes a switching element 51B for switching between a plurality of calibration elements 57H (four calibration elements 57H-1 to 57H-4 in FIGS. 5 and 6). The selection unit 51 further includes a switching element 51C (not shown) for switching the plurality of detection electrodes 21V and a switching element 51D (not shown) for switching the plurality of calibration elements 57V. .

  Each of the switching elements 51A to 51D is, for example, a multiplexer. In the switching element 51A, a plurality of terminals provided on one end side of the multiplexer are connected to one end of each detection electrode 21H via the scanning line WSL2, and one terminal provided on the other end side of the multiplexer. Is connected to the adder 51E. In the switching element 51B, a plurality of terminals provided on one end side of the multiplexer are connected to one end of each calibration element 57H, and one terminal provided on the other end side of the multiplexer is an adder. 51E. In addition, although not shown, in the switching element 51C, a plurality of terminals provided on one end side of the multiplexer are connected to one end of each detection electrode 21V via the scanning line WSL3, and are connected to the other end side of the multiplexer. One provided terminal is connected to the adder 51E. Although not shown, in the switching element 51D, a plurality of terminals provided on one end side of the multiplexer are connected to one end of each calibration element 57V, and one terminal provided on the other end side of the multiplexer is provided. The terminal is connected to the adding unit 51E.

  The switching elements 51 </ b> A to 51 </ b> D switch internal switches according to a selection signal and an EN signal (described later) input from the control unit 54. When the EN signal is enabled, the switching elements 51 </ b> A and 51 </ b> C electrically connect the terminal selected by the selection signal among the plurality of terminals on the sensor unit 21 side and the terminal on the side opposite to the sensor unit 21. It is supposed to be. When the EN signal is enabled, the switching elements 51 </ b> B and 51 </ b> D electrically connect the terminal selected by the selection signal among the plurality of terminals on the calibration unit 57 side and the terminal on the opposite side of the calibration unit 57. It is supposed to be. When the EN signal is disabled, the switching elements 51A and 51C are configured to electrically open all terminals on the sensor unit 21 side and terminals on the side opposite to the sensor unit 21. When the EN signal is disabled, the switching elements 51B and 51D are configured to electrically open all terminals on the calibration unit 57 side and terminals on the opposite side of the calibration unit 57.

  The adding unit 51E includes a voltage at a terminal opposite to the sensor unit 21 of the switching element 51A, a voltage at a terminal opposite to the calibration unit 57 of the switching element 51B, and the sensor unit 21 of the switching element 51C. Is the sum of the voltage at the terminal on the opposite side, the voltage at the terminal on the switching element 51D opposite to the calibration section 57, and the voltage at the output end of the oscillating section 52. For example, the adding unit 51E is opposite to the terminal of the switching element 51A opposite to the sensor unit 21, the terminal of the switching element 51B opposite to the calibration unit 57, and the switching element 51C opposite to the sensor unit 21. The terminal on the side, the terminal on the side opposite to the calibration unit 57 of the switching element 51D, and the output end of the oscillation unit 52 are configured by wirings that connect each other.

  The oscillation unit 52 has an oscillation frequency determined by the capacitance generated in the one or more detection electrodes 21H and 21V and the one or more calibration elements 57H and 57V selected by the selection unit 51. The oscillating unit 52 includes, for example, a signal source that generates an AC signal. The oscillation unit 52 applies an AC signal to each detection electrode 21H via the addition unit 51E and the switching element 51A, and applies an AC signal to each detection electrode 21V via the addition unit 51E and the switching element 51C. ing.

  For example, the conversion unit 53 includes an F / V conversion circuit and an A / D converter (not shown). The F / V conversion circuit converts a signal from the oscillation unit 52 into a voltage according to the frequency. The F / V conversion circuit, for example, converts the signal at the output end of the oscillating unit 52 into a voltage value corresponding to the magnitude of the frequency of the signal, and outputs an analog signal of the voltage value. The A / D converter converts an input analog signal into a digital signal. For example, the A / D converter converts an analog signal output from an F / V conversion circuit into a digital signal. The output unit 55 outputs, for example, the contact coordinates derived by the control unit 54 as the detection signal 50A. The input unit 56 receives, for example, inputs such as a synchronization signal 50B used when driving the detection circuit 50 and a position signal 50C indicating the coordinates of functional parts such as buttons displayed on the image display surface 20A. .

  The control unit 54 controls the switching elements 51 </ b> A to 51 </ b> D included in the selection unit 51. The control unit 54 generates a selection signal for the selection unit 51 to sequentially select only some of the plurality of detection electrodes 21H and 21V and to sequentially select the plurality of calibration elements 57H and 57V. The switching elements 51A to 51D) are applied. Specifically, the control unit 54 switches the internal switches of the switching elements 51A to 51D by inputting an EN signal and a selection signal to the switching elements 51A to 51D.

  For example, the control unit 54 inputs disable to the switching element 51A as an EN signal at a predetermined time. Thereby, in the switching element 51 </ b> A, all terminals on the sensor unit 21 side and terminals on the side opposite to the sensor unit 21 are electrically opened. Similarly, the control unit 54 is configured to input disable as an EN signal to the switching element 51B at a predetermined time, for example. Thereby, in the switching element 51B, all terminals on the calibration unit 27 side and terminals on the opposite side to the calibration unit 27 are electrically opened. For example, the control unit 54 inputs disable as an EN signal to the switching element 51C at a predetermined time. Thereby, in the switching element 51 </ b> C, all terminals on the sensor unit 21 side and terminals on the opposite side to the sensor unit 21 are electrically opened. For example, the control unit 54 inputs disable as an EN signal to the switching element 51D at a predetermined time. Thereby, in the switching element 51D, all terminals on the calibration unit 27 side and terminals on the opposite side to the calibration unit 27 are electrically opened.

  Further, for example, the control unit 54 inputs a selection signal to the switching element 51A and inputs enable as an EN signal at a predetermined time. Thereby, in the switching element 51 </ b> A, the terminal selected by the selection signal among the plurality of terminals on the sensor unit 21 side and the terminal on the opposite side to the sensor unit 21 are electrically connected. Similarly, for example, the control unit 54 inputs a selection signal to the switching element 51B and inputs enable as an EN signal at a predetermined time. Thereby, in the switching element 51B, the terminal selected by the selection signal among the plurality of terminals on the calibration unit 27 side and the terminal on the opposite side to the calibration unit 27 are electrically connected. For example, at a predetermined time, the control unit 54 inputs a selection signal to the switching element 51C and inputs enable as an EN signal. Thereby, in the switching element 51 </ b> C, the terminal selected by the selection signal among the plurality of terminals on the sensor unit 21 side and the terminal on the opposite side to the sensor unit 21 are electrically connected. For example, at a predetermined time, the control unit 54 inputs a selection signal to the switching element 51D and inputs enable as an EN signal. Thereby, in the switching element 51D, the terminal selected by the selection signal among the plurality of terminals on the calibration unit 27 side and the terminal on the opposite side to the calibration unit 27 are electrically connected.

  When the control unit 54 inputs the selection signal and the EN signal to the switching elements 51A and 51C connected to the sensor unit 21, the control unit 54 applies the detection electrodes 21H and 21V connected to the terminals selected by the selection signal. Corresponding selection signals and EN signals are generated. Specifically, the control unit 54 uses the calibration table describing the combinations of the detection electrodes 21H and 21V in the sensor unit 21 and the calibration elements 57H and 57V in the calibration unit 57 to select the selection signal and An EN signal is generated.

  Here, the calibration table is, for example, a list of voltage values as shown in FIG. 7A or a list of correction values as shown in FIG. 7B, for example. The calibration table is stored in the memory 59.

  The voltage value shown in FIG. 7A is output from the F / V conversion circuit by switching the internal switches of the switching elements 51A and 51B when there is no finger or the like on the image display surface 20A and its vicinity. This is a value obtained by measuring the measured voltage value. In FIG. 7A, a circle is attached to a combination (a combination of the detection electrode 21H and the calibration element 57H) in which the measured voltage values are equal to each other in all the detection electrodes 21H-1 to 21H-4. Yes. The voltage values output from the F / V conversion circuit are equal to each other in all the detection electrodes 21H-1 to 21H-4. In each combination, equivalent capacitors are attached to the output end of the oscillation unit 52. Means that Therefore, when the combination of each detection electrode 21H in the sensor unit 21 and each calibration element 57H in the calibration unit 57 is a combination with a circle in FIG. Regardless of where the display surface 20A is touched, the amount of change in the voltage value output from the F / V conversion circuit is substantially equal.

  Therefore, in the present embodiment, the control unit 54, for example, each detection electrode 21H in the sensor unit 21 so that the voltage values output from the F / V conversion circuit are equal to each other in all the detection electrodes 21H, Each calibration element 57H in the calibration unit 57 is combined. Specifically, the control unit 54, for example, combines the detection electrodes 21H in the sensor unit 21 with the calibration elements 57H in the calibration unit 57, for example, the combinations indicated by circles in FIG. Thus, the EN signal and the selection signal input to the switching element 51B are determined. Similarly, the control unit 54, for example, detects each detection electrode 21V in the sensor unit 21 and the calibration unit 57 so that the voltage values output from the F / V conversion circuit are equal to each other in all the detection electrodes 21V. Each calibration element 57V is combined.

  The correction values shown in FIG. 7B are output from the F / V conversion circuit as a result of switching the internal switches of the switching elements 51A and 51B when there is no finger or the like on the image display surface 20A and its vicinity. This is a numerical value obtained by performing desired arithmetic processing on the voltage value. In FIG. 7B, circles are attached to combinations (combinations of the detection electrode 21H and the calibration element 57H) in which correction values are equal to each other. The correction values are equal to each other in all the detection electrodes 21H-1 to 21H-4. In each combination, the reference condition of the image display surface 20A in consideration of the correction processing is set at any location on the image display surface 20A. It means that they are also available. Therefore, when the combination of each detection electrode 21H in the sensor unit 21 and each calibration element 57H in the calibration unit 57 is a combination with a circle in FIG. Regardless of which location on the display surface 20A is touched, the amount of change in the correction value after the correction processing becomes substantially equal.

  Therefore, in the present embodiment, the control unit 54, for example, each detection electrode 21H in the sensor unit 21 and each calibration element in the calibration unit 57 so that the correction values are equal to each other in all the detection electrodes 21H. It is designed to be combined with 57H. Specifically, the control unit 54, for example, a combination of each detection electrode 21H in the sensor unit 21 and each calibration element 57H in the calibration unit 57 is a combination indicated by a circle in FIG. 7B, for example. Thus, the EN signal and the selection signal input to the switching element 51B are determined. Similarly, for example, the control unit 54 combines each detection electrode 21V in the sensor unit 21 and each calibration element 57V in the calibration unit 57 so that the correction values are equal to each other in all the detection electrodes 21V. It has become.

  By the way, the control unit 54 normally inputs a signal for sequentially scanning all the detection electrodes 21H and 21V in the sensor unit 21 one by one as a selection signal to the switching elements 51A and 51C in the selection unit 51. It is like that. However, in the present embodiment, the control unit 54 uses, as a selection signal, a signal for scanning only a predetermined electrode among all the detection electrodes 21H and 21V in the sensor unit 21 under a predetermined condition. The switching elements 51A and 51C are input. Here, as the “predetermined condition”, for example, when only two buttons are displayed on the image display surface 20A, or the movement of an object such as a finger on the detection surface needs to be continuously detected. The case where there is. In this way, by performing “decimation scan” in which only predetermined electrodes among all the detection electrodes 21H and 21V in the sensor unit 21 are scanned, the power consumption can be reduced or the detection cycle can be shortened. it can.

  Specifically, the control unit 54 outputs, to the switching element 51A as a selection signal, a signal for sequentially scanning only a predetermined electrode among all the detection electrodes 21H in the sensor unit 21 under a predetermined condition. It is supposed to be. In addition, the control unit 54 selects, as a selection signal, a switching element 51C (not shown) that scans only one predetermined electrode sequentially at a time among all the detection electrodes 21V in the sensor unit 21 under a predetermined condition. ) Is output.

  At this time, for example, in the calibration table of FIG. 7A or FIG. 7B, the control unit 54 does not use data on the detection electrode that is the target of thinning. For example, it is assumed that the detection electrodes to be thinned out are the detection electrodes 21H-2 and 21H-3. At this time, the control unit 54 does not use the data in the columns 21H-2 and 21H-3 in the calibration table of FIG. 7A or FIG. 7B, for example. That is, the control unit 54 determines the selection signal and the EN signal to be input to the switching elements 51A and 51C using, for example, a tooth missing calibration table as shown in FIG. 8A or 8B. become. As a result, the control unit 54 is different from the combination selected when the detection electrodes in the sensor unit 21 are sequentially scanned one by one (the portions indicated by circles in FIGS. 7A and 7B). There are cases in which (a part indicated by a circle in FIGS. 8A and 8B) is selected.

  Next, an example of the operation in the detection device 2 of the present embodiment will be described.

[Overall operation]
FIG. 9 illustrates an example of the procedure of the entire operation in the detection device 2. First, for example, when the display device 1 is turned on or the detection device 2 is activated, the control unit 54 starts the operation of the detection device 2 (step S101). First, the control unit 54 investigates the combinations of the detection electrodes 21H and 21V in the sensor unit 21 and the calibration elements 57H and 57V in the calibration unit 57, and determines an appropriate combination (step S102). Next, the control unit 54 detects contact / non-contact with the image display surface 20A such as a finger using the combination determined in the previous step S102 (step S103). Thereafter, the control unit 54 determines whether to continue to execute step S103 or return to step S102. In FIG. 9, the description of the step of completing the operation of the detection device 2 is omitted.

[Proofreading]
FIG. 10 shows an example of the procedure of the calibration process (step S102) in the detection apparatus 2. The control unit 54 starts calibration processing with the start of the operation of the detection device 2 (step S201). First, the controller 54 measures calibration data (step S202). Specifically, the control unit 54 measures calibration data in all combinations of the detection electrodes 21H in the sensor unit 21 and the calibration elements 57H in the calibration unit 57. Further, the control unit 54 measures calibration data in all combinations of the detection electrodes 21V in the sensor unit 21 and the calibration elements 57V in the calibration unit 57. Specifically, the control unit 54 uses the signal from the conversion unit 53 to generate a characteristic value in the combination of the detection electrodes 21H and 21V and the calibration elements 57H and 57V selected by the selection unit 51. Next, the control unit 54 stores the data (characteristic values) obtained as a result thereof in the memory unit 59 as calibration data (step S203).

  For example, the control unit 54 inputs a selection signal for selecting a terminal connected to one detection electrode 21H in the sensor unit 21 and inputs enable as an EN signal to the switching element 51A. Further, for example, the control unit 54 inputs a selection signal for selecting a terminal connected to one calibration element 57H in the calibration unit 57 to the switching element 51B and inputs enable as an EN signal. Thereby, the detection electrode 21H selected by the control unit 54 and the calibration element 57H selected by the control unit 54 are electrically connected to each other. In this state, the control unit 54 acquires the voltage value output from the conversion unit 53 (F / V conversion circuit) and stores it in the memory unit 59. The control unit 54 sequentially performs this series of processes on all the detection electrodes 21H in the sensor unit 21 and all the calibration elements 57H in the calibration unit 57.

  For example, the control unit 54 inputs a selection signal for selecting a terminal connected to one detection electrode 21 </ b> V in the sensor unit 21 to the switching element 51 </ b> C and inputs enable as an EN signal. Further, for example, the control unit 54 inputs a selection signal for selecting a terminal connected to one calibration element 57V in the calibration unit 57 and inputs enable as an EN signal to the switching element 51D. As a result, the detection electrode 21V selected by the control unit 54 and the calibration element 57V selected by the control unit 54 are electrically connected to each other. In this state, the control unit 54 acquires the voltage value output from the conversion unit 53 (F / V conversion circuit) and stores it in the memory unit 59. The control unit 54 sequentially performs this series of processes on all the detection electrodes 21V in the sensor unit 21 and all the calibration elements 57V in the calibration unit 57.

  For example, the control unit 54 inputs a selection signal for selecting a terminal connected to one detection electrode 21H in the sensor unit 21 to the switching element 51A and inputs enable as an EN signal. Further, for example, the control unit 54 inputs disable as an EN signal to the switching element 51B. Thereby, the detection electrode 21H selected by the control unit 54 is disconnected from any calibration element 57H in the calibration unit 57. In this state, the control unit 54 acquires the voltage value output from the conversion unit 53 (F / V conversion circuit) and stores it in the memory unit 59. The control unit 54 sequentially performs this series of processes on all the detection electrodes 21H in the sensor unit 21.

  For example, the control unit 54 inputs a selection signal for selecting a terminal connected to one detection electrode 21 </ b> V in the sensor unit 21 to the switching element 51 </ b> C and inputs enable as an EN signal. Further, for example, the control unit 54 inputs disable as an EN signal to the switching element 51D. As a result, the detection electrode 21V selected by the control unit 54 is disconnected from any calibration element 57V in the calibration unit 57. In this state, the control unit 54 acquires the voltage value output from the conversion unit 53 (F / V conversion circuit) and stores it in the memory unit 59. The control unit 54 sequentially performs this series of processes for all the detection electrodes 21 </ b> V in the sensor unit 21.

  The control unit 54 may further store a correction value for the voltage value acquired through the above-described series of processes in the memory unit 59.

  Next, the control part 54 determines a combination (step S204). Specifically, the control unit 54 first determines the most preferable combination of each detection electrode 21H in the sensor unit 21 and each calibration element 57H in the calibration unit 57 using the calibration data. For example, in the combination of the detection electrode 21H and the calibration element 57H selected by the selection unit 51, the control unit selects a combination in which the obtained data (characteristic values) are the same. Further, the control unit 54 determines the most preferable combination of each detection electrode 21V in the sensor unit 21 and each calibration element 57V in the calibration unit 57 using the calibration data. For example, in the combination of the detection electrode 21V and the calibration element 57V selected by the selection unit 51, the control unit selects the combination in which the obtained data (characteristic values) are the same. For example, the control unit 54 determines the combination so that the variation is reduced as a whole. For example, the control unit 54 determines the combination so that the difference between the maximum error value and the minimum error value is small.

  The control unit 54 performs calibration processing (step S102) when performing “decimation scanning” in which only predetermined electrodes are scanned among all the detection electrodes 21H and 21V in the sensor unit 21 in the sensor processing (step S103). For example, the following process is executed. In the following description, an electrode selected for performing the “thinning scan” among the plurality of detection electrodes 21H is referred to as a selection electrode 21H ′, and the electrode selected for performing the “thinning scanning” among the plurality of detection electrodes 21V. The electrode is referred to as a selection electrode 21V ′.

  The control unit 54 uses the calibration data to make the most preferable combination of each selection electrode 21H ′ in the sensor unit 21 and each calibration element 57H in the calibration unit 57 so as to be the most preferable combination in the “decimation scan”. To decide. For example, in the combination of the selection electrode 21H ′ and the calibration element 57H selected by the selection unit 51, the control unit selects the combination in which the obtained data (characteristic values) are the same. Further, the control unit 54 uses the calibration data to make the most preferable combination of each selection electrode 21V ′ in the sensor unit 21 and each calibration element 57V in the calibration unit 57 so as to be the most preferable combination in the “decimation scan”. A preferred combination is determined. For example, in the combination of the selection electrode 21V ′ and the calibration element 57V selected by the selection unit 51, the control unit selects a combination in which the obtained data (characteristic values) are the same.

  At this time, the control unit 54 determines the most preferable combination of the selection electrodes 21H 'and 21V' and the calibration elements 57H and 57V using only the calibration data for the selection electrodes 21H 'and 21V'. That is, in the “thinning-out scan”, the control unit 54 provides calibration data for electrodes other than the selection electrode 21H ′ among the plurality of selection electrodes 21H and electrodes other than the selection electrode 21V ′ among the plurality of selection electrodes 21V. Do not use. Therefore, the most preferable combination may differ between when “decimation scan” is performed and when “decimation scan” is not performed. In that case, the control unit 54 uses calibration data of an optimal combination according to the scanning method.

  Thereafter, the control unit 54 ends the series of calibration processing (step S205).

[Calibration judgment]
FIG. 11 shows an example of the procedure of calibration judgment (step S104) in the detection apparatus 2. The control unit 54 starts calibration determination upon completion of step S103 (step S301). First, the control unit 54 determines whether or not the sensor unit 21 has detected something from the data obtained in the previous step S103 (step S302). If the control unit 54 determines that the sensor unit 21 has detected something, it executes step S103. On the contrary, when it is judged that the sensor part 21 has not detected anything, the control part 54 judges whether it is immediately after the detection state is complete | finished (step S303).

  If the control unit 54 determines that the detection state has just ended, it executes step S103. Conversely, when the control unit 54 determines that the predetermined period has elapsed since the detection state has ended, the voltage value output from the conversion unit 53 (F / V conversion circuit) or the voltage value thereof It is determined whether the corrected value is less than the allowable value (step S304). When the control unit 54 determines that the voltage value or the value obtained by correcting the voltage value is less than the allowable value, the control unit 54 executes Step S103. Conversely, when the control unit 54 determines that the voltage value or the value obtained by correcting the voltage value is greater than or equal to the allowable value, the control unit 54 determines whether continuous measurement should be performed in system operation (step S305). When the control unit 54 determines that continuous measurement should be performed, the control unit 54 executes Step S103. Conversely, if the control unit 54 determines that continuous measurement should not be performed, it executes step S102.

[effect]
In the present embodiment, when the sensor process is performed by the “thinning scan”, only the calibration data for the selection electrodes 21H ′ and 21V ′ selected to perform the “thinning scan” is used to select the selection electrode 21H ′. , 21V ′ and the calibration elements 57H, 57V are most preferably combined. Thereby, when the detection electrodes 21H and 21V to be scanned are thinned out and an object on the image display surface 20A is detected, it is possible to prevent the detection sensitivity from varying for each detection electrode.

[Modification]
In the above-described embodiment, the controller 54 scans all the detection electrodes 21H and 21V in the calibration process (step S102) even when the “decimation scan” is performed in the sensor process (step S103). Scan ". However, when performing the “decimation scan” in the sensor process (step S103), the control unit 54 may perform the “decimation scan” also in the calibration process (step S102). At this time, the detection electrodes 21H and 21V selected in the calibration process (step S102) need to be equal to the detection electrodes 21H and 21V selected in the sensor process (step S103). As described above, in the calibration process (step S102), when the “thinning scan” is performed, the time required for the calibration process (step S102) is shortened compared to the case where the “sequential scan” is performed. be able to.

<Second Embodiment>
FIG. 12 shows an example of a cross-sectional configuration of the display device 3 according to the second embodiment of the present invention. The display device 3 is a display device with a proximity sensor. For example, the display device 3 includes a liquid crystal display element as a display element. Further, a capacitive proximity sensor is separated from the liquid crystal display element on the surface of the liquid crystal display element. It is prepared by the body.

  The display device 3 includes, for example, a liquid crystal display panel 10, a proximity panel 60, a backlight 30, a peripheral circuit 40, and a detection circuit 70 as shown in FIG. The proximity panel 60 is disposed on the viewer side (front side) of the liquid crystal display panel 10, and the backlight 30 is disposed behind the liquid crystal display panel 10.

[Proximity panel 60]
The proximity panel 60 touches the image display surface 60A (the surface of the proximity panel 60) of the display device 3 with a finger, moves the finger or the like close to the image display surface 60A, or moves the finger or the like on the image display surface 60A. This is for inputting information. For example, the proximity panel 60 is provided separately from the liquid crystal display panel 10 and is bonded to the surface of the liquid crystal display panel 10 via an adhesive (not shown) or the like. The proximity panel 60 corresponds to a specific example of the capacitive touch sensor described above, and detects contact / non-contact with an XY (matrix) matrix, detects a spatial position, and moves. It is something to detect.

[Detecting device 4]
FIG. 13 shows an extracted part (detection device 4) of the display device 3 that is involved in detection of contact / non-contact, spatial position, and movement. The detection device 4 is a detection device capable of performing contact detection and proximity detection similarly to the detection device 200 illustrated in FIG. 2. For example, as illustrated in FIG. 13, the detection device 4 includes a proximity panel 60 and a detection circuit 70. It is configured to include. The proximity panel 60 has, for example, the sensor unit 21. On the other hand, the detection circuit 70 includes, for example, a selection unit 58, an oscillation unit 52, a conversion unit 53, a control unit 54, an output unit 55, an input unit 56, a calibration unit 57, and a memory unit 59 as shown in FIG. It consists of

  In the present embodiment, the sensor unit 21 detects contact / non-contact with the image display surface 60A such as a finger, detects a spatial position, and detects movement. The sensor unit 21 includes a plurality of detection electrodes 21H and a plurality of detection electrodes 21V, like the sensor unit 21 of the above embodiment.

  For example, as illustrated in FIG. 14, the selection unit 58 includes a switching element 58A, a resistor 58B, an amplifier 58C, and a switching element 58D (not shown) in the selection unit 51 of the above embodiment. It has become. The switching element 58A is inserted between the detection electrode 21H and the switching element 51A, and the switching element 58D is inserted between the detection electrode 21V and the switching element 51C (not shown). In the selection unit 58, the output end of the oscillation unit 52 is connected to each terminal on the sensor unit 21 side of the switching elements 51A and 51C via the resistor 58B and the amplifier 58C. That is, the selection unit 58 includes not only the terminals of the switch elements 51A and 51C on the side opposite to the sensor unit 21 but also the terminals of the switch elements 51A and 51C on the sensor unit 21 side. Is also applied to.

  The switch elements 58A and 58D are, for example, switches having a plurality of pairs of input terminals and output terminals, and are switches that perform electrical connection between one input terminal and one output terminal independently for each terminal. It is. The resistor 58B is, for example, a resistor having a plurality of pairs of input terminals and output terminals, and is a resistor in which a resistance element is provided between one input terminal and one output terminal. The amplifier 58C amplifies the output of the oscillation unit 52.

  The control unit 54 controls each switching element included in the selection unit 58. Specifically, the control unit 54 switches the internal switch of each switching element included in the selection unit 58 by inputting an EN signal and a selection signal to each switching element included in the selection unit 58. It is like that.

  For example, the control unit 54 is configured to input disable to the switching element 58A as an EN signal at a predetermined time. Thereby, in the switching element 58A, all the terminals on the sensor unit 21 side and all the terminals on the opposite side to the sensor unit 21 are electrically opened, and the output of the oscillation unit 52 is applied to any detection electrode 21H. No longer applied. Similarly, the control unit 54 inputs a disable signal as an EN signal to the switching element 51D at a predetermined time, for example. Thereby, in the switching element 51D, all the terminals on the sensor unit 21 side and all the terminals on the side opposite to the sensor unit 21 are electrically opened, and the output of the oscillation unit 52 is applied to any detection electrode 21V. No longer applied.

  For example, the control unit 54 inputs a selection signal to the switching element 58A and inputs enable as an EN signal at a predetermined time. Thereby, in switching element 58A, one or a plurality of pairs of input terminals and output terminals (hereinafter referred to as “selection terminals”) selected by the selection signal among a plurality of pairs of input terminals and output terminals are electrically connected. . As a result, the output of the oscillation unit 52 is applied to the electrode connected to the selection terminal among the plurality of detection electrodes 21H via the amplification unit 58C and the resistor 58B. At this time, in the switching element 58A, all pairs of input terminals and output terminals may be electrically connected.

  Similarly, for example, the control unit 54 inputs a selection signal to the switching element 58D and inputs enable as an EN signal at a predetermined time. Thereby, in switching element 58D, one or a plurality of pairs of input terminals and output terminals (hereinafter referred to as “selection terminals”) selected by the selection signal among a plurality of pairs of input terminals and output terminals are electrically connected. . As a result, the output of the oscillation unit 52 is applied to the electrode connected to the selection terminal among the plurality of detection electrodes 21V via the amplification unit 58C and the resistor 58B. At this time, in the switching element 58D, all pairs of input terminals and output terminals may be electrically connected.

  The control of the control unit 54 with respect to the switching elements 51A to 51D is the same as in the above embodiment. However, the control of the control unit 54 for the switching elements 51A and 51C may be linked with the control for the switching elements 58A and 58D.

  For example, in the switching element 51A, the control unit 54 selects only the terminal connected to the terminal of the switch that is turned on (connected) among the plurality of internal switches in the switching element 58A by the selection signal. ing. Accordingly, the control unit 54, for example, of the plurality of detection electrodes 21H, is connected to one or a plurality of terminals selected by the selection signal input to the switching element 58A (hereinafter referred to as “selection electrode 21H ′ (not shown). Z))) can be scanned at a higher speed.

  Similarly, for example, in the switching element 51C, the control unit 54 selects only the terminal connected to the terminal of the switch that is turned on (connected) among the plurality of internal switches in the switching element 58D using the selection signal. It is like that. Accordingly, the control unit 54, for example, among the plurality of detection electrodes 21V, is connected to one or a plurality of terminals selected by the selection signal input to the switching element 58D (hereinafter referred to as “selection electrode 21V ′ (not shown). Z))) can be scanned at a higher speed.

  Further, the control unit 54 scans all the selection electrodes 21H ′ in the same time as when all the detection electrodes 21H are scanned, for example, and outputs the output of the oscillation unit 52 to each selection electrode 21H ′ for a long time. It is also possible to apply. Similarly, the control unit 54 scans all the selection electrodes 21V ′ in the same time as when scanning all the detection electrodes 21V, for example, and outputs the output of the oscillation unit 52 to each selection electrode 21V ′ for a long time. It is also possible to apply. In such a case, it may be possible to realize highly accurate contact detection and space detection.

  Note that, for example, the control unit 54 may select a terminal connected to each terminal of the switching element 51A with a selection signal regardless of the states of a plurality of internal switches in the switching element 58A.

  When the control unit 54 inputs the selection signal and the EN signal to the switching elements 51A and 51C connected to the sensor unit 21, the control unit 54 applies the detection electrodes 21H and 21V connected to the terminals selected by the selection signal. Corresponding selection signals and EN signals are generated. Specifically, the control unit 54 uses the calibration table describing the combinations of the detection electrodes 21H and 21V in the sensor unit 21 and the calibration elements 57H and 57V in the calibration unit 57 to select the selection signal and An EN signal is generated.

  Here, the control unit 54 uses, for example, a list of voltage values as shown in FIG. 7A as the calibration table when all the internal switches in the switching element 58A are turned on (connected). It is supposed to be. At this time, the control unit 54 uses the calibration table to calibrate each detection electrode 21H in the sensor unit 21 so that the voltage values output from the F / V conversion circuit are equal to each other in all the detection electrodes 21H. Each calibration element 57H in the unit 57 is combined. Further, when all the internal switches in the switching element 58D are turned on (connected), the control unit 54 uses, for example, a list of voltage values similar to that in FIG. 7A as the calibration table. It has become. At this time, the control unit 54 uses the calibration table to calibrate each detection electrode 21V in the sensor unit 21 so that the voltage values output from the F / V conversion circuit are equal to each other in all the detection electrodes 21V. Each calibration element 57V in the unit 57 is combined.

  In addition, when all the internal switches in the switching element 58A are turned on (connected), the control unit 54 uses, for example, a list of correction values as shown in FIG. 7B as a calibration table. It is like that. At this time, the control unit 54 uses each calibration electrode in the sensor unit 21 and each calibration element 57H in the calibration unit 57 using the calibration table so that the correction values are equal to each other in all the detection electrodes 21H. And come to be combined. Further, when all the internal switches in the switching element 58D are turned on (connected), the control unit 54 uses, for example, a correction value list similar to that in FIG. 7B as the calibration table. It has become. At this time, the control unit 54 uses each calibration electrode in the sensor unit 21 and each calibration element 57V in the calibration unit 57 using the calibration table so that the correction values are equal to each other in all the detection electrodes 21V. And come to be combined.

  Further, when only a part of the internal switches in the switching element 58A are turned on (connected), the control unit 54 uses, for example, a list of voltage values as shown in FIG. 8A as a calibration table. It is designed to be used. At this time, the control unit 54 uses the calibration table so that the voltage values output from the F / V conversion circuit are equal to each other in all the selection electrodes 21H ′. The calibration elements 57 in the calibration unit 57 are combined with each other. Further, when only a part of the internal switches in the switching element 58D are turned on (connected), the control unit 54 uses, for example, a list of voltage values as shown in FIG. 8A as a calibration table. It is designed to be used. At this time, the control unit 54 uses the calibration table so that the voltage values output from the F / V conversion circuit are equal to each other in all the selection electrodes 21V ′. The calibration elements 57 in the calibration unit 57 are combined with each calibration element 57V.

  Further, when only a part of the internal switches in the switching element 58A are turned on (connected), the control unit 54 uses, for example, a correction value list as shown in FIG. 8B as a calibration table. It is designed to be used. At this time, the control unit 54 uses each calibration electrode in the sensor unit 21 and each calibration electrode in the calibration unit 57 using the calibration table so that the correction values are equal to each other in all the selection electrodes 21H ′. The element 57H is combined. Further, when only a part of the internal switches in the switching element 58D are turned on (connected), the control unit 54 uses, for example, a correction value list similar to that in FIG. 8B as the calibration table. It is like that. At this time, the control unit 54 uses each calibration electrode in the sensor unit 21 and each calibration electrode in the calibration unit 57 using the calibration table so that the correction values are equal to each other in all the selection electrodes 21V ′. The element 57V is combined.

  As described above, when only a part of the internal switches in the switching elements 58A and 58D are turned on (connected), the control unit 54 uses data on the detection electrode that is the object of thinning in the calibration table. There is no longer to do. Therefore, the control unit 54 determines a selection signal and an EN signal to be input to the switching elements 51A and 51C using, for example, a calibration table for missing teeth as shown in FIG. 8A or FIG. 8B. become. As a result, the control unit 54 is different from the combination selected when the detection electrodes in the sensor unit 21 are sequentially scanned one by one (the portions indicated by circles in FIGS. 7A and 7B). There are cases in which (a part indicated by a circle in FIGS. 8A and 8B) is selected.

  Next, an example of operation | movement of the detection apparatus 4 of this Embodiment is demonstrated. The procedure of the entire operation in the detection device 4 is the same as that in the first embodiment. The procedure of the calibration process (step S102) in the detection device 4 is the same as that in the first embodiment when all the internal switches in the switching elements 58A and 58D are turned on (connected). . The procedure for the calibration determination (step S104) in the detection device 4 is also the same as in the first embodiment.

  On the other hand, in the procedure of the calibration process (step S102) in the detection device 4, the procedure for turning on (connecting) only some of the internal switches in the switching elements 58A and 58D is the first embodiment described above. And different. Therefore, in the following description, parts different from those of the first embodiment will be mainly described, and description of parts common to the first embodiment will be omitted.

[Proofreading]
The control unit 54 starts the calibration process as the operation of the detection device 4 starts. First, the control unit 54 measures calibration data. Specifically, the control unit 54 measures calibration data in all combinations of the selection electrodes 21H ′ in the sensor unit 21 and the calibration elements 57H in the calibration unit 57. Further, the control unit 54 measures calibration data in all combinations of the selection electrodes 21V ′ in the sensor unit 21 and the calibration elements 57V in the calibration unit 57. At this time, the detection electrodes 21H and 21V selected in the calibration process (step S102) need to be equal to the detection electrodes 21H and 21V selected in the sensor process (step S103). Next, the control unit 54 stores the data obtained as a result thereof in the memory unit 59 as calibration data.

  For example, the control unit 54 inputs a selection signal for selecting a terminal connected to one selection electrode 21 </ b> H ′ in the sensor unit 21 and inputs enable as an EN signal to the switching element 51 </ b> A. Further, for example, the control unit 54 inputs a selection signal for selecting a terminal connected to one calibration element 57H in the calibration unit 57 to the switching element 51B and inputs enable as an EN signal. Thereby, the selection electrode 21H ′ selected by the control unit 54 and the calibration element 57H selected by the control unit 54 are electrically connected to each other. In this state, the control unit 54 acquires the voltage value output from the conversion unit 53 (F / V conversion circuit) and stores it in the memory unit 59. The control unit 54 sequentially performs this series of processes on all the selection electrodes 21 </ b> H ′ in the sensor unit 21 and all the calibration elements 57 </ b> H in the calibration unit 57.

  Further, for example, the control unit 54 inputs a selection signal for selecting a terminal connected to one selection electrode 21V ′ in the sensor unit 21 and inputs enable as an EN signal to the switching element 51C. Further, for example, the control unit 54 inputs a selection signal for selecting a terminal connected to one calibration element 57V in the calibration unit 57 and inputs enable as an EN signal to the switching element 51D. Accordingly, the selection electrode 21V ′ selected by the control unit 54 and the calibration element 57V selected by the control unit 54 are electrically connected to each other. In this state, the control unit 54 acquires the voltage value output from the conversion unit 53 (F / V conversion circuit) and stores it in the memory unit 59. The control unit 54 sequentially performs this series of processes on all the selection electrodes 21V ′ in the sensor unit 21 and all the calibration elements 57V in the calibration unit 57.

  For example, the control unit 54 inputs a selection signal for selecting a terminal connected to one selection electrode 21 </ b> H ′ in the sensor unit 21 to the switching element 51 </ b> A and inputs enable as an EN signal. Further, for example, the control unit 54 inputs disable as an EN signal to the switching element 51B. Accordingly, the selection electrode 21H ′ selected by the control unit 54 is disconnected from any calibration element 57H in the calibration unit 57. In this state, the control unit 54 acquires the voltage value output from the conversion unit 53 (F / V conversion circuit) and stores it in the memory unit 59. The control unit 54 sequentially performs this series of processes for all the selection electrodes 21 </ b> H ′ in the sensor unit 21.

  Further, for example, the control unit 54 inputs a selection signal for selecting a terminal connected to one selection electrode 21V ′ in the sensor unit 21 and inputs enable as an EN signal to the switching element 51C. Further, for example, the control unit 54 inputs disable as an EN signal to the switching element 51D. As a result, the selection electrode 21V ′ selected by the control unit 54 is disconnected from any calibration element 57V in the calibration unit 57. In this state, the control unit 54 acquires the voltage value output from the conversion unit 53 (F / V conversion circuit) and stores it in the memory unit 59. The control unit 54 sequentially performs this series of processes on all the selection electrodes 21V ′ in the sensor unit 21.

  The control unit 54 may further store a correction value for the voltage value acquired through the above-described series of processes in the memory unit 59.

  Next, the control unit 54 determines a combination. Specifically, the control unit 54 first determines the most preferable combination of each selection electrode 21H ′ in the sensor unit 21 and each calibration element 57H in the calibration unit 57 using the calibration data. Further, the control unit 54 determines the most preferable combination of each selection electrode 21 </ b> V ′ in the sensor unit 21 and each calibration element 57 </ b> V in the calibration unit 57 using the calibration data. For example, the control unit 54 determines the combination so that the variation is reduced as a whole. For example, the control unit 54 determines the combination so that the difference between the maximum error value and the minimum error value is small.

  As described above, in the present embodiment, when performing the sensor processing by “thinning scan”, the control unit 54 performs “thinning scanning” also in the calibration processing. This is because the value of the calibration table obtained by the calibration process may be different when “decimation scan” is performed and when “sequential scan” is performed. In the present embodiment, the control unit 54 dares to perform “thinning-out scanning” even during calibration processing in order to prevent such errors from entering the calibration table.

[effect]
In the present embodiment, when the sensor process is performed by the “thinning scan”, only the calibration data for the selection electrodes 21H ′ and 21V ′ selected to perform the “thinning scan” is used to select the selection electrode 21H ′. , 21V ′ and the calibration elements 57H, 57V are most preferably combined. Furthermore, in the present embodiment, when performing “decimation scan” when performing sensor processing, “decimation scan” is also performed in calibration processing. Thereby, when the detection electrodes 21H and 21V to be scanned are thinned out and an object on the image display surface 20A is detected, it is possible to prevent the detection sensitivity from varying for each detection electrode.

[Modification]
In the above embodiment, the switching element 58A is inserted in the scanning line WSL2 that connects the detection electrode 21H and the switching element 51A to each other, but may be inserted in another place. For example, as shown in FIG. 15, the switching element 58A may be inserted into a wiring connecting the scanning line WSL2 and the resistor 58B to each other. Further, for example, as shown in FIG. 16, the switching element 58A may be inserted into a wiring connecting the resistor 58B and the amplifier 58C to each other.

  The present invention has been described above with reference to the embodiment and its modifications and application examples. However, the present invention is not limited to the embodiment and the like, and various modifications can be made.

  For example, in the above-described embodiment and the like, the case where a transmissive element is used as the liquid crystal display element has been described. However, other than the transmissive element, for example, a reflective element can be used. However, in that case, it is necessary to eliminate the light source (backlight 30) or to dispose it on the upper surface side of the liquid crystal display element.

  In the above-described embodiments and the like, the case where the present invention is applied to a display device using a liquid crystal display element as a display element has been described. However, the display device using other display elements, for example, organic EL elements, is used. Is also applicable.

  In addition, the series of processing described in the above-described embodiments and the like can be performed by hardware or software. When a series of processing is performed by software, a program constituting the software is installed in a general-purpose computer or the like. Such a program can be recorded in advance in a recording medium built in the computer.

  DESCRIPTION OF SYMBOLS 1,3 ... Display apparatus, 2, 4, 100, 200 ... Detection apparatus, 10 ... Liquid crystal display panel, 20 ... Touch panel, 20A, 60A ... Image display surface, 21 ... Sensor part, 21H, 21H-1, 21H-2 , 21H-3, 21H-4, 21V, 21V-1, 21V-2, 21V-3, 21V-4, 110H, 110V ... detection electrode, 30 ... backlight, 40 ... peripheral circuit, 40A ... video signal, 40B , 50B ... synchronization signal, 50, 70 ... detection circuit, 50A ... detection signal, 50C ... position signal, 51, 58 ... selection unit, 51A, 51B, 51C, 51D, 58A, 58D ... switching element, 51E ... addition unit, 52 ... Oscillator, 53 ... Converter, 54 ... Control, 55 ... Output, 56 ... Input, 57 ... Calibration, 57H, 57H-1, 57H-2, 57H-3, 57H-4, 57V Calibration element, 58B, 170 ... resistor, 58C, 180 ... amplifier, 59 ... memory unit, 60 ... proximity panel, 110 ... two-dimensional electrode, 120,150 ... switch element, 130 ... signal source, 140 ... FV Conversion circuit, DTL ... signal line, WSL, WSL1, WSL2, WSL3 ... scanning line.

Claims (4)

A sensor unit in which a plurality of detection electrodes are arranged on the detection surface;
A calibration section in which a plurality of calibration elements are arranged;
A selection unit that selects one or a plurality of electrodes among the plurality of detection electrodes, and selects one or a plurality of elements among the plurality of calibration elements;
An oscillation unit whose oscillation frequency is determined by the capacitance generated in the one or more detection electrodes and the one or more calibration elements selected by the selection unit;
A frequency / voltage conversion unit that converts a signal from the oscillation unit into a voltage according to a frequency; and
The selection unit sequentially selects only a part of the plurality of detection electrodes and generates a selection signal for sequentially selecting the plurality of calibration elements and applies the selection signal to the selection unit, and the frequency / voltage conversion unit And a control unit that generates a characteristic value in the combination of the detection electrode and the calibration element selected by the selection unit using a signal from the calibration device. The calibration apparatus according to claim 1, wherein the control unit selects a combination in which the characteristic values are most equal to each other in the combination of the detection electrode and the calibration element selected by the selection unit. The selection unit includes:
A first selection unit that selects a plurality of selection electrodes that constantly apply the output of the oscillation unit among the plurality of detection electrodes;
A second selection unit that connects one or more electrodes among the plurality of selection electrodes selected by the first selection unit and the oscillation unit;
The calibration apparatus according to claim 1, further comprising: a third selection unit that connects one or more of the plurality of calibration elements and the oscillation unit to each other. A display panel for displaying an image on a display surface based on a video signal;
A sensor unit in which a plurality of detection electrodes are arranged on the display surface;
A calibration section in which a plurality of calibration elements are arranged;
A selection unit that selects one or a plurality of electrodes among the plurality of detection electrodes, and selects one or a plurality of elements among the plurality of calibration elements;
An oscillation unit whose oscillation frequency is determined by the capacitance generated in the one or more detection electrodes and the one or more calibration elements selected by the selection unit;
A frequency / voltage conversion unit that converts a signal from the oscillation unit into a voltage according to a frequency; and
The selection unit sequentially selects only a part of the plurality of detection electrodes and generates a selection signal for sequentially selecting the plurality of calibration elements and applies the selection signal to the selection unit, and the frequency / voltage conversion unit And a control unit that generates a characteristic value in the combination of the detection electrode and the calibration element selected by the selection unit using a signal from the display unit.

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