JP2013196618A - Touch sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touch sensor capable of shortening touch position calculation time in a tracing operation.SOLUTION: A touch sensor 30 comprises: eight electrodes 4A to 4H to which a tracing operation is performed; four electrodes 4I to 4L to which the tracing operation is not performed; a C/V converter that generates voltage according to a variation in capacitance for each electrode; and a calculation circuit 70 that calculates a touch position on the basis of the voltage generated by the C/V converter. The calculation circuit 70 is provided with: a normal mode of taking in all of the voltage to each electrode that is generated by the C/V converter; and a short mode of taking in the voltage to the electrodes to which the tracing operation is performed. The calculation circuit 70 switches from the normal mode to the short mode when the voltage taken in is determined to correspond to the electrodes to which the tracing operation is performed.

Description

  The present invention relates to a touch sensor that detects, for example, the proximity of a human finger using a change in capacitance.

  Conventionally, a touch sensor disclosed in Patent Document 1 is known. The touch sensor of Patent Document 1 includes five electrodes and five converters that convert the amount of change in capacitance into voltage. Four of the five electrodes are arranged in an annular shape, and one is arranged in the center of the four electrodes arranged in an annular shape. Five converters are provided for each of the five electrodes. When a finger approaches one of the five electrodes, the capacitance of that electrode changes. Each of the five converters generates a voltage corresponding to the amount of change in capacitance of the electrode corresponding to itself. Depending on the magnitude of the five voltages generated by the five transducers, it is possible to determine which of the five electrodes is touched by the finger.

JP 2000-18905 A

  By the way, in recent years, there is a demand for using a touch sensor to scroll various display screens, for example, a map screen of a navigation system, in a direction intended by the user. In Patent Document 1, it is possible to detect which of the five electrodes is touched. For this reason, it is possible to detect four directions with four electrodes arranged in an annular shape. Therefore, according to the touch sensor of Patent Document 1, the display screen can be scrolled in four directions. Note that the center electrode is not for detecting the direction, but is used, for example, to determine the setting of the destination selected through the four electrodes on the map screen.

  Now, when changing the scroll direction of the map screen by using such a touch sensor, many users do not touch the electrode in the direction that they want to scroll by once releasing their finger from the electrode that has been touched so far. It is known that a so-called tracing operation is performed in which a finger is slid from an electrode touched until now to an electrode in a direction to be scrolled. On the other hand, the controller that controls the scrolling of the map screen sequentially takes in the voltages generated by the five converters, determines which electrode is touched, and maps the map in the direction corresponding to the touched electrode. Scroll the screen. Therefore, the control unit captures all voltages generated by the five converters, regardless of whether the user performs a tracing operation or not. For example, even the voltage at the center electrode that is not touched is captured. For this reason, the determination of which electrode is touched in the control unit is delayed, and consequently, the start of scrolling the map screen in the direction corresponding to the touched electrode is delayed.

  The present invention has been made in view of such a situation, and an object thereof is to provide a touch sensor having a short calculation time of a touch position in a tracing operation.

  In order to solve the above-mentioned problem, the invention of claim 1 generates at least two electrodes to be traced, at least one electrode not to be traced, and a voltage corresponding to the amount of change in capacitance for each of the electrodes. And a calculation circuit that calculates a touch position based on the voltage generated by the C / V converter, the calculation circuit corresponding to each electrode generated by the C / V converter. A normal mode for capturing all voltages, and a shortening mode for capturing voltages for the electrodes to be traced. When it is determined that the captured voltage is for electrodes to be traced, the shortening from the normal mode is performed. The gist is to switch to the mode.

  In the conventional touch sensor, the touch position is calculated after taking in voltages for all the electrodes. For this reason, for example, even when the touch sensor is dragged, it takes time to calculate the touch position since the touch position is calculated after taking in the voltage for the electrode that is not dragged. . In this regard, according to this configuration, when the voltage for the electrode that is traced in the normal mode is captured, the voltage for the electrode that is not traced is not captured by switching to the shortening mode. As a result, the time required for calculating the touch position when the tracing operation is performed can be shortened.

  According to a second aspect of the present invention, in the touch sensor according to the first aspect, in the case where a plurality of the electrodes that are not subjected to the stroking operation are provided, the arithmetic circuit outputs all voltages for the electrodes that are not traversed in the shortening mode. The gist is not to capture.

  When a plurality of electrodes that are not subjected to the tracing operation are provided, it is also conceivable to take in voltages for some of the electrodes. Even in this case, the calculation time of the touch position at the time of the tracing operation is shorter than when all the voltages are taken in. However, there is a case where it is desired to shorten the calculation time. According to this configuration, when the arithmetic circuit is set to the shortening mode, the calculation circuit captures only the voltage for the electrode to be traced. It is possible to further reduce the time required for the calculation.

  According to a third aspect of the present invention, in the touch sensor according to the first aspect, in the case where a plurality of the electrodes that are not subjected to the stroking operation are provided, the arithmetic circuit, The gist is to capture a part.

  According to this configuration, for example, even when an electrode that is not dragged with a finger different from the finger that is dragged is touched, the touch of the electrode can be detected. In addition, the calculation time of the touch position can be shortened as compared with the case where the voltages for all the electrodes are captured.

  According to a fourth aspect of the present invention, in the touch sensor according to any one of the first to third aspects, the arithmetic circuit has a voltage for the electrode to be dragged set in advance in the shortening mode. The gist is to switch to the normal mode when the value is lower than the reference value.

  According to this configuration, since the mode is switched to the normal mode immediately after the end of the tracing operation, even when an electrode that is not subjected to the tracing operation is touched immediately after the end of the tracing operation, it is possible to reduce the time required to detect the touch of the electrode. it can.

  The gist of a fifth aspect of the present invention is the touch sensor according to any one of the first to fourth aspects, wherein the arithmetic circuit periodically switches to the normal mode during the shortening mode.

  According to this configuration, for example, even when an electrode that is not dragged with a finger that is different from the finger that is dragged is touched, the detection frequency of the touch of the electrode is increased.

  In the present invention, it is possible to provide a touch sensor having a short calculation time of a touch position in a tracing operation.

The block diagram which shows schematic structure of a navigation system. (A) is a front view which shows arrangement | positioning of an electrode, (b) is a front view of the knob by which an electrode is affixed on the back surface. The figure which shows the area as scroll data memorize | stored in memory of a microcomputer. (A) is a time chart which shows the reading timing of the reading part in normal mode, (b) is a time chart which shows the reading timing of the reading part in shortening mode. The time chart which shows another example of the read timing in the reading part of other embodiment.

Hereinafter, an embodiment in which a touch sensor according to the present invention is embodied as a navigation system will be described with reference to FIGS.
<Overall system configuration>
As shown in FIG. 1, the navigation system 1 includes a display 10 that displays various types of information, and a microcomputer 20 that controls the display of the display 10. The microcomputer 20 is provided with a nonvolatile memory 21. The memory 21 stores map information. The microcomputer 20 reads the map information stored in the memory 21 and displays it on the display 10. Various control target devices including audio (not shown) and a touch sensor 30 are connected to the microcomputer 20. Input to the control information to the microcomputer 20 is performed through the touch sensor 30. The microcomputer 20 controls various devices to be controlled based on control information from the touch sensor 30.
<Touch sensor>
The touch sensor 30 includes twelve electrodes 4A to 4L, twelve oscillation circuits 5A to 5L connected to the twelve electrodes 4A to 4L, and twelve oscillation circuits 5A to 5L. Twelve conversion circuits 6A to 6L to be connected and an arithmetic circuit 70 to which each of the 12 conversion circuits 6A to 6L is connected are provided. The arithmetic circuit 70 is connected to the microcomputer 20. The oscillation circuits 5A to 5L and the twelve conversion circuits 6A to 6L function as C / V converters.

  As shown in FIG. 2 (a), eight electrodes 4A to 4H out of the twelve electrodes have a radius d and a center angle that coincide with each other (center O) from a sector shape having a radius 2d and a center angle of 40 °. It is the shape which removed the fan side of 40 degrees. The eight electrodes 4A to 4H are arranged in an annular shape with a gap of 5 ° between adjacent electrodes. Specifically, the electrode 4A is at the 12 o'clock position, the electrode 4C is at the 3 o'clock position, the electrode 4E is at the 6 o'clock position, the electrode 4G is at the 9 o'clock position, the electrode 4B is between the electrode 4A and the electrode 4C, and the electrode 4D Is between the electrode 4C and the electrode 4E, the electrode 4F is between the electrode 4E and the electrode 4G, and the electrode 4H is between the electrode 4G and the electrode 4A. When these are applied to a two-dimensional orthogonal coordinate system having the center O as the origin, the electrode 4A is 70 ° to 110 °, the electrode 4B is 25 ° to 65 °, the electrode 4C is 340 ° (−20 °) to 20 °, The electrode 4D occupies a range from 295 ° to 335 °, the electrode 4E from 250 ° to 290 °, the electrode 4F from 205 ° to 245 °, the electrode 4G from 160 ° to 200 °, and the electrode 4H from 115 ° to 155 °. As shown in FIG. 2 (b), these eight electrodes 4A to 4H are arranged so that the outer arcs thereof coincide with the outer periphery of the circular switch knob 80 having a radius 2d. It is affixed to the back of the. The surface of the switch knob 80 can be touched by a user's finger. The switch knob 80 is made of a non-conductive resin material, and its thickness is thin enough to be ignored with respect to the distance d (1/2 of the radius 2d). For this reason, even when any position on the surface of the switch knob 80 is touched, the distance between the finger and each of the electrodes 4A to 4H is within 3d. On the surface of the switch knob 80, a circular pattern having a radius d and twelve isosceles triangles that gradually become sharper toward the outside from 1 o'clock to 12 o'clock on the outside of the circle. The design of and. Here, the twelve isosceles triangle symbols are provided at a position away from the center of the switch knob 80 by a distance of 3d / 2.

  As shown in FIG. 2A, of the 12 electrodes, the two electrodes 4I and 4J are squares having a side length d. The electrode 4I is disposed on the right side of the electrodes 4B and 4C, and the electrode 4J is disposed on the right side of the electrodes 4C and 4D. The electrodes 4I and 4J are aligned vertically. As shown in FIG. 2B, these two electrodes 4I and 4J are affixed to the back surfaces of switch knobs 8I and 8J that are square with sides having a length d. The surface of the switch knobs 8I and 8J can be touched by the user's finger. The switch knobs 8I and 8J are made of a nonconductive resin material. A “+” mark is designed on the surface of the switch knob 8I, and a “−” mark is designed on the surface of the switch knob 8J.

  As shown in FIG. 2 (a), of the 12 electrodes, the two electrodes 4K and 4L are rectangles having a vertical side length d and a horizontal side length 1.5d. . The electrode 4K is disposed below the electrodes 4D and 4E, and the electrode 4L is disposed below the electrodes 4E and 4F. The electrodes 4K and 4L are aligned horizontally. As shown in FIG. 2B, these two electrodes 4K and 4L are formed on the back surface of the switch knobs 8K and 8L having a rectangular shape with a vertical side of d and a horizontal side of 1.5d. It is affixed. The surface of the switch knobs 8K and 8L can be touched by the user's finger. The switch knobs 8K and 8L are made of a nonconductive resin material. Note that the letter “MENU” is on the surface of the switch knob 8K, and the U-shape is tilted so that the left side that means “return to the previous screen” is the opening on the surface of the switch knob 8L. Each mark is designed.

  When a conductor comes close to the electrodes 4A to 4L, for example, when a human finger comes into contact with the switch knobs 80 and 8I to 8L, the electrodes 4A to 4L generate polarization in which charges are biased due to electrostatic induction. Thereby, the electrostatic capacitance in electrode 4A-4L changes. The oscillation circuits 5A to 5L always generate an oscillation signal. The oscillation circuits 5A to 5L generate oscillation signals whose amplitudes are changed when the capacitances of the electrodes 4A to 4L change. The oscillation circuits 5A to 5L in this example oscillate with an amplitude having a magnitude inversely proportional to the magnitude of the change in capacitance. The oscillation signals oscillated from the oscillation circuits 5A to 5L are input to the conversion circuits 6A to 6L. The conversion circuits 6A to 6L convert the voltage into a voltage V (scalar) inversely proportional to the amplitude of the input electric signal. That is, the voltage V is proportional to the proximity of the distance between the finger and the electrodes 4A to 4L. Therefore, the distance between the finger and the electrodes 4A to 4L is x, the distance between the finger and the electrodes 4A to 4L when the oscillation circuits 5A to 5L start to oscillate is xl, and the distance between the oscillation circuits 5A to 5L oscillates at the maximum frequency. When the voltage is Vmax, the magnitude of the voltage V is expressed by the following (Equation 1).

The magnitude of the capacitance change in the electrodes 4A to 4L varies depending on the thickness of the electrode, the distance between the electrode and the conductor, and the relative dielectric constant of the dielectric. In this example, it is assumed that the switch knobs 80 and 8I to 8L are touch-operated by a human finger, and the electrodes 4A to 4L are used when the distance x between the human finger and the electrodes 4A to 4L is closer than the distance 3d. Furthermore, it has a relative dielectric constant and a thickness with which the capacitance changes. Therefore, since distance xl = distance 3d, (Equation 1) described above can be rewritten as (Equation 2) below.

Note that k in (Expression 2) is a variable representing the proximity between the finger and the electrodes 4A to 4L. The variable k indicates that the finger is closer to the electrodes 4A to 4L as it is closer to 1, and that the finger is closer to the electrodes 4A to 4L as it is closer to 0.

  The arithmetic circuit 70 includes a reading unit 78 that sequentially reads the voltage V generated by the conversion circuits 6A to 6L in this order. As shown in FIG. 1, the arithmetic circuit 70 calculates the touch position on the switch knob 80 or which of the switch knobs 8I to 8L is touched based on the voltage V captured by the reading unit 78. Then, the arithmetic circuit 70 outputs an electrical signal indicating the calculated touch position to the microcomputer 20.

<Calculation circuit>
As shown in FIG. 1, the memory 71 of the arithmetic circuit 70 has a first reference voltage V for determining whether or not the switch knob 80 is touched compared to the voltage V input from the conversion circuits 6A to 6H. Various calculation formulas 72 for calculating the touch position T from ₀ and the voltage V are stored. Here, the first reference voltage V ₀ is set to 0 V (volt). That is, the arithmetic circuit 70 determines that the finger has been touched by the switch knob 80 when a voltage V greater than 0 is input from all of the conversion circuits 6A to 6H. The calculation formula 72 includes a distance calculation formula 73 for calculating the distance Xt from the center O of the touch position T based on the voltage V generated by the conversion circuits 6A to 6L, and the voltage V generated by the conversion circuits 6A to 6L. And a center angle calculation formula 74 for calculating a center angle θ which is an angle formed by a line segment extending from the center O in the direction of 3 o'clock and the line segment OT is stored. The touch position T can be identified from the distance Xt and the central angle θ calculated from the distance calculation formula 73 and the central angle calculation formula 74. These distance calculation formula 73 and center angle calculation formula 74 are shown in the following (formula 3) and (formula 4). In this example, the derivation of the distance calculation formula 73 and the central angle calculation formula 74 is omitted.

Further, the memory 71 stores a second reference voltage V ₁ for determining whether or not any of the switch knobs 8 I to 8 L is touched compared to the voltage V input from the conversion circuits 6 I to 6 L. ing. Here, the second reference voltage V ₁ is a 1V (volt). That is, when a voltage V having a magnitude of 1 V (volt) is input from any of the conversion circuits 6I to 6L, the arithmetic circuit 70 has electrodes 4I to 4L corresponding to the conversion circuits 6I to 6L to which the voltage is input. It is determined that (switch knobs 8I to 8L) are touched with a finger.

The arithmetic circuit 70 includes a determination unit 76 and a calculation unit 77. The determination unit 76 determines whether the voltage V input from each of the conversion circuits 6A to 6H is greater than the first reference voltage V ₀ (here, 0 V (volt)) stored in the memory 21, that is, (Equation 2) It is determined whether or not the variable k is greater than zero. In addition, the determination unit 76 determines whether or not the voltage V input from each of the conversion circuits 6I to 6L is the second reference voltage V ₁ (here, 1 V (volt)) stored in the memory 21, that is, It is determined whether or not the variable k in (Expression 2) is 1.

  When the voltage V is input from the conversion circuits 6 </ b> A to 6 </ b> H, the calculation unit 77 calculates the touch position T to the switch knob 80 using the calculation formula 72 stored in the memory 71 from the voltage V. When the voltage V is input from any of the conversion circuits 6I to 6L, the calculation unit 77 determines the positions of the electrodes 4I to 4L (switch knobs 8I to 8L) corresponding to the conversion circuits 6I to 6L as the touch position T. And

As shown in FIG. 4A, the reading unit 78 includes a normal mode in which all the voltages V generated by the conversion circuits 6A to 6L are sequentially read in this order, and a conversion circuit as shown in FIG. 4B. A shortening mode in which only the voltage V generated by 6A to 6H is sequentially read in this order. The determination unit 76 switches between the normal mode and the operation mode. That is, the determination unit 76 also functions as a switching unit between the normal mode and the operation mode in the reading unit 78. For example, when the reader 78 is in the normal mode, when the voltage V inputted from any of the conversion circuit 6A~6H is determined to be larger than the first reference voltage V _0, determination unit 76, The reading unit 78 is switched to the shortening mode. When the reading unit 78 is in the shortening mode, when the voltage V input from all of the conversion circuits 6A to 6H is determined to be equal to or lower than the first reference voltage V ₀ , the determining unit 76 sets the reading unit 78 to Switch to normal mode.

<Microcomputer>
The memory 21 of the microcomputer 20 stores scroll data 22 for scrolling the map displayed on the display 10 in the direction of the touch position T. The scroll data 22 divides a circular area inside the outer periphery of the electrodes 4A to 4H (projection area in which the electrodes 4A to 4H are considered as circular) into 13 areas E0 to E12, and is displayed on each area E0 to E12 and the display 10 Is associated with the scroll direction of the map. As shown in FIG. 3, the area E0 is a circular region whose distance from the center O is within a distance d. Areas E1 to E12 are regions obtained by dividing an annular region whose distance from the center O is larger than the distance d and within the distance 2d into 30 ° intervals. Here, area E1 is 45 ° to 75 °, area E2 is 15 ° to 45 °, area E3 is 345 ° (−15 °) to 15 °, area E4 is 315 ° to 345 °, and area E5 is 285 ° to 285 °. 315 °, area E6 is 255 ° to 285 °, area E7 is 225 ° to 255 °, area E8 is 195 ° to 225 °, area E9 is 165 ° to 195 °, area E10 is 135 ° to 165 °, area E11 Occupies a range of 105 ° to 135 ° and area E12 occupies a range of 75 ° to 105 °. The scroll directions associated with the areas E0 to E12 are the direction of 1 o'clock (60 °) in the area E1, the direction of 2 o'clock (30 °) in the area E2, the direction of 3 o'clock (0 °) in the area E3, Area E4 at 4 o'clock (330 °), Area E5 at 5 o'clock (300 °), Area E6 at 6 o'clock (270 °), Area E7 at 7 o'clock (240 °), Area E8 At 8 o'clock (210 °), area E9 at 9 o'clock (180 °), area E10 at 10 o'clock (150 °), area E11 at 11 o'clock (120 °), area E12 at 12 The direction of the hour (90 °). Note that the scroll direction is not set in the area E0.

  As shown in FIG. 1, the memory 21 stores volume data 25 for changing the volume of audio (not shown). In the volume data 25, the area E13 that is the projection area of the electrode 4I and the volume increase shown in FIG. 3 are associated with the area E14 that is the projection area of the electrode 4J and the volume reduction.

  As shown in FIG. 1, the memory 21 stores screen data 26 for changing an image displayed on the display 10. In the screen data 26, an area E15 that is a projection region of the electrode 4K shown in FIG. 3 and a MENU screen for inputting control information to various control devices (not shown) are associated with each other. Further, the screen data 26 is obtained by associating the area E16, which is the projection area of the electrode 4L, with the display screen immediately before the current display screen.

  As shown in FIG. 1, the microcomputer 20 includes a specifying unit 23 and a control unit 24. The specifying unit 23 specifies which area of the 17 areas E0 to E16 the touch position T input from the arithmetic circuit 70 corresponds to. When the calculated touch position is on the boundary between adjacent areas, the specifying unit 23 specifies that the area corresponds to the clockwise direction. That is, when the calculated touch position T is 45 ° on the boundary between the area E1 and the area E2, it is specified as the area E2 on the clockwise direction side.

  When the area E specified by the specifying unit 23 is any of the areas E1 to E12, the control unit 24 scrolls the map displayed on the display 10 in the scroll direction associated with the areas E1 to E12. The map information is read from the memory 21 as shown. Thereby, the map displayed on the display 10 is scrolled. The control unit 24 increases the audio volume when the area E specified by the specifying unit 23 is the area E13, and decreases the audio volume when the area E is the area E14. Further, the control unit 24 displays the MENU screen on the display 10 when the area E specified by the specifying unit 23 is the area E15, and displays the MENU screen on the display 10 more than the current display screen when the area E is the area E16. Display the previous display screen.

<Touch sensor processing>
The reading unit 78 is normally in a normal mode. Therefore, as shown in FIG. 4A, the reading unit 78 sequentially reads all the voltages V generated by the conversion circuits 6A to 6L in this order. By this, one of the electrodes 4I～4L is touched, when the voltage V generated by the conversion circuit 6I~6L becomes greater than the second reference voltage _{V 1,} the arithmetic circuit 70, electrode 4I～4L ( A touch position signal indicating that the switch knobs 8I to 8L) are touched is sent to the microcomputer 20. Thereby, the microcomputer 20 can increase / decrease the volume of the audio, or can change the screen displayed on the display to the current previous screen or the MENU screen.

When any one of the electrodes 4A to 4H is touched and the voltage V generated by any of the conversion circuits 6A to 6H becomes larger than the first reference voltage V ₀ , the arithmetic circuit 70 calculates the distance calculation formula 73 and The touch position T is calculated using the center angle calculation formula 74. Then, a touch position signal indicating the touch position T is sent to the microcomputer 20. Thereby, the microcomputer 20 can scroll the map displayed on the display 10 in the direction of the touch position T. Further, determining unit 76, the voltage V generated by any of the conversion circuit 6A~6H is greater than the first reference voltage V _0, switches the reading unit 78 to the low latency mode. Therefore, thereafter, the reading unit 78 sequentially reads only the voltage V generated by the conversion circuits 6A to 6H in this order, as shown in FIG. As shown in FIG. 4A and FIG. 4B, the reading unit 78 in the shortened mode takes less voltage by four conversion circuits than in the normal mode. Therefore, the reading unit 78 can read the voltage V generated by the conversion circuits 6A to 6H used for the tracing operation for the time required to read the voltages for the four conversion circuits. As a result, the time taken for the arithmetic circuit 70 to calculate the touch position T using the distance calculation formula 73 and the center angle calculation formula 74 is shortened, and the touch position signal indicating the touch position T is transmitted to the microcomputer. The time to send to 20 is also shortened. Thereby, the microcomputer 20 can scroll the map smoothly in the direction intended by the user.

  In this example, 13 areas E0 to E12 are stored in the memory 21 of the microcomputer 20 for the eight electrodes 4A to 4H used in the tracing operation. That is, the detection resolution of the touch position T in the microcomputer 20 is 13 which is larger than 8 which is the number of electrodes. Thus, the detection resolution of the touch position T in the microcomputer 20 does not depend on the number of electrodes. In other words, the detection resolution can be increased by setting the area divisions more finely.

As described above in detail, according to the present embodiment, the following effects can be obtained.
(1) A reading unit 78 is provided in the arithmetic circuit 70. The reading unit 78 has a normal mode in which all the voltages V generated by the conversion circuits 6A to 6L are sequentially read in this order, and a shortening mode in which only the voltage V generated by the conversion circuits 6A to 6H is sequentially read in this order. Have. In addition, a determination unit 76 is provided in the arithmetic circuit 70. Determining unit 76, the converting circuit voltage V inputted from 6A~6H the first reference voltage _{V 0} or not greater than, and the voltage V is a second reference input from the converter circuit 6I~6L It is determined whether or not the voltage is V ₁ . Further, determining unit 76, when the voltage V inputted from any of the conversion circuit 6A~6H is determined to be larger than the first reference voltage V _0, switches the reading unit 78 from the normal mode to the reduction mode. Thereby, when the electrodes 4A to 4H are traced, the arithmetic circuit 70 reads only the voltage corresponding to the electrodes 4A to 4H and calculates the touch position. Therefore, the arithmetic circuit 70 can calculate the touch position earlier by the time for reading the voltages corresponding to the electrodes 4I to 4L.

(2) determining unit 76, when the voltage V supplied from all transform circuits 6A~6H is determined that the first reference voltage V ₀ or less, switches the reading unit 78 from the reduction mode to the normal mode. As a result, the mode is switched from the shortening mode to the normal mode immediately after the end of the tracing operation, so even when an electrode that is not subjected to the tracing operation is touched immediately after the end of the tracing operation, the time required for detecting the touch of the electrode can be reduced. it can.

  (3) The electrodes 4A to 4H were attached to the back surface of the switch knob 80, and the electrodes 4I to 4J were attached to the back surface of the switch knobs 8I to 8J. Thereby, electrode 4A-4J and a finger | toe do not contact directly. In other words, conductive dust or the like that changes the capacitance of the electrodes 4A to 4J does not adhere to the electrodes 4A to 4J. For this reason, the detection reliability of the touch sensor due to the proximity of the electrodes 4A to 4J and the conductive dust or the like being maintained, and hence the operability deterioration of the navigation system 1 is avoided.

In addition, you may change the said embodiment as follows.
In the above embodiment, the reading unit 78 does not capture all the voltages of the conversion circuits 6I to 6L for the electrodes 4I to 4L in the shortening mode, but sequentially reads a part of the conversion circuits 6I to 6L. It may be. For example, as shown in FIG. 5, the voltage from the conversion circuits 6A to 8H is first taken in, then the voltage from the conversion circuit 6I is taken in, and then the voltage from the conversion circuits 6A to 8H is taken in and then from the conversion circuit 6J. The voltage is taken in, and then the voltage from the conversion circuits 6A to 8H is taken in, and then the voltage from the conversion circuit 6K is read. If comprised in this way, even when the electrodes 4I-4L are touched with the finger different from the finger operated by the tracing, the touch of the electrodes 4I-4L can be detected.

  In the above embodiment, the reading unit 78 may periodically switch from the shortening mode to the normal mode. For example, when the voltages from the conversion circuits 6A to 8H are captured three times in the shortening mode, the mode is switched to the normal mode. If comprised in this way, even when the electrodes 4I-4L are touched with the finger different from the finger operated by the tracing, the touch of the electrodes 4I-4L can be detected.

In the above embodiment, the number of electrodes is not limited to twelve, and it is sufficient if two or more electrodes are touched and dragged and one or more electrodes are touched only.
In the above embodiment, the switch knob 80 may be omitted. Further, the switch knobs 8I to 8J may be omitted. Even when configured in this way, the same effects as the effects (1) and (2) in the above embodiment can be obtained.

  In the above embodiment, the design of the surface of the switch knob 80 and the switch knobs 8I to 8J may be omitted. Even when configured in this manner, the same effects as those of the above-described embodiment can be obtained.

  In the above embodiment, the distance calculation formula 73 stored in the memory 21 may be omitted. In this case, the arithmetic circuit 70 can calculate only the center angle θ of the touch position T using the center angle calculation formula 74. The memory 21 of the microcomputer 20 stores a plurality of areas partitioned only by angles instead of the areas E0 to E12 of the above embodiment. A scroll direction is associated with each of the plurality of areas. If comprised in this way, the microcomputer 20 will determine which area the center angle | corner (theta) calculated in the arithmetic circuit 70 corresponds to among the some areas memorize | stored in the memory 21, and will be in that area The map can be scrolled in the associated scroll direction. Note that if the arithmetic circuit 70 outputs the voltage V input from the conversion circuits 6A to 6L to the microcomputer 20, the microcomputer 20 may change the touch position T according to the magnitude of each input voltage V. It can be determined whether or not corresponds to the area E0.

In the above embodiment, the center angle θ of the touch position T is calculated by a combination of inverse sin (sin ⁻¹ ) and inverse cos (cos ⁻¹ ), but it can also be calculated by other methods. For example, the center angle θ of the touch position T is calculated by combining inverse tan (tan ⁻¹ ) with sin or cos. Even if it does in this way, the effect similar to the said embodiment can be acquired.

  In the above embodiment, the electrodes 4A to 4L change the electrostatic capacity when the distance from the finger is closer than the distance 3d. The distance at which the capacity changes may be arbitrarily changed. For example, the shorter the distance at which the capacitance changes, the shorter it is necessary for the finger to be closer to the electrode, so that the map is prevented from scrolling when the finger approaches the electrode unintentionally. .

In the above embodiment, the first reference voltage V ₀ as the reference value for determining whether or not the electrodes 4A to 4L are touched is set to 0, but it may not be 0. When it is not 0, that is, when it is larger than 0, even if the distance from the finger is closer than 3d, the microcomputer 20 does not determine that the finger and the electrodes 4A to 4H are close to each other. That is, in order to scroll the map, it is necessary to bring the finger closer to the electrodes 4A to 4H. Therefore, when comprised in this way, it is suppressed that a map scrolls, when a finger | toe unintentionally approaches 4A-4H.

In the above embodiment, although the second reference voltages _{V 1} and 1V (V) may be smaller than 0V (volts) greater than 1V (volt). If comprised in this way, even if a finger and the electrodes 4I-4L do not contact, since the microcomputer 20 judges the proximity | contact (touch) with a finger and the electrodes 4I-4L, a user's convenience improves.

  In the above embodiment, the electrodes 4A to 4H are arranged in a circular shape, but may be arranged in an elliptical shape. When arranged in this way, the voltage which is a variable of the distance calculation formula 73 and the center angle calculation formula 74 is weighted according to the distance of each electrode from the center O. If comprised in this way, even if electrode 4A-4H is arrange | positioned at ellipse, the effect similar to the said embodiment can be acquired.

  In the above embodiment, the electrodes 4I to 4L are provided on the right and lower sides of the electrodes 4A to 4H. However, the positions at which these electrodes are provided are not limited to this. It may be provided.

  In the above embodiment, the shapes of the electrodes 4A to 4L are not limited. For example, it may be a circle or a polygon such as a rectangle. Even in this case, the same effect as that of the above embodiment can be obtained.

  -In above-mentioned embodiment, although electrode 4A-4H was used in order to scroll a map, you may apply besides this. For example, the volume of the in-vehicle audio is increased when a clockwise rotation operation is detected through the tracing operation of the electrodes 4A to 4H, or the volume of the in-vehicle audio is decreased when a counterclockwise rotation operation is detected. May be. Even in such a configuration, the microcomputer 20 can be controlled variously through the touch operation of the touch sensor 30. Moreover, you may apply to things other than a vehicle.

  In the above embodiment, the function of the arithmetic circuit 70 may be provided in the microcomputer 20. Even when configured in this manner, the same effects as those of the above-described embodiment can be obtained.

DESCRIPTION OF SYMBOLS 1 ... Navigation system, 4A-4L ... Electrode, 5A-5L ... Oscillator circuit, 6A-6L ... Conversion circuit, 8I-8L, 80 switch knob, 10 ... Display, 20 ... Microcomputer, 21, 71 ... Memory, 22 ... Scroll data, 23 ... specific part, 24 ... control part, 25 ... volume data, 26 ... screen data, 30 ... touch sensor, 70 ... arithmetic circuit, 72 ... calculation formula, 73 ... distance calculation formula, 74 ... center angle calculation formula , 76 ... determination unit, 77 ... calculation unit, 78 ... reading unit.

Claims (5)

At least two electrodes to be traced, at least one electrode not to be traced, a C / V converter that generates a voltage corresponding to the amount of change in capacitance for each electrode, and the C / V converter. An arithmetic circuit that calculates a touch position based on the generated voltage,
The arithmetic circuit has a normal mode for capturing all voltages for each electrode generated by the C / V converter and a shortened mode for capturing a voltage for the electrode to be traced, and the captured voltage is traced. A touch sensor that switches from the normal mode to the shortened mode when it is determined that the current mode is for an electrode. The touch sensor according to claim 1,
When a plurality of electrodes that are not subjected to the tracing operation are provided,
The arithmetic circuit is a touch sensor that does not capture all voltages for the electrodes that are not dragged in the shortening mode. The touch sensor according to claim 1,
When a plurality of electrodes that are not subjected to the tracing operation are provided,
In the shortening mode, the arithmetic circuit is a touch sensor that captures a part of the voltage of the electrode that is not dragged. In the touch sensor as described in any one of Claims 1-3,
In the shortening mode, the arithmetic circuit is a touch sensor that switches to the normal mode when a voltage with respect to the electrode to be traced is lower than a preset reference value. In the touch sensor as described in any one of Claims 1-4,
The arithmetic circuit is a touch sensor that periodically switches to a normal mode during the shortening mode.