JPWO2016152504A1 - Rotary input device - Google Patents

Abstract

An object of the present invention is to provide a rotary input device that can accurately detect a change in capacitance and determine a rotation direction even when a signal component indicating a change in capacitance is close to a change in an offset component. The detection signal generation unit 110 generates a detection signal corresponding to the sum of charges accumulated in the first variable capacitance element VC1 and the second variable capacitance element VC2 by supplying a pulse voltage. Further, when the operation unit 10 is rotated by three steps, the detection signal at the stop position of the first variable capacitor VC1 and the stop of the second variable capacitor VC2 at the stop position of the third step without the variable capacitor. A detection signal having a value intermediate to the detection signal at the position is generated. The signal processing unit 120 determines the rotation direction of the operation unit 10 based on the change in the detection signal corresponding to the change in the capacitance of the variable capacitance element VC.

Description

  The present invention relates to a rotary input device such as a rotary encoder, and more particularly to a rotary input device that detects rotation using a change in capacitance.

  2. Description of the Related Art Conventionally, an apparatus that detects the rotation of an operating body using a change in capacitance is known. For example, in Patent Document 1 below, a plurality of fixed electrodes arranged on a fixed plate, a rotating plate arranged to be rotatable so as to face the fixed plate, and arranged on the rotating plate so as to face the fixed electrode A rotary electrostatic encoder having a rotary electrode formed thereon is described. By detecting the capacitance between the fixed electrode and the rotating electrode that changes according to the rotation of the rotating plate, the rotating direction and the rotating angle are detected.

Japanese Patent No. 5263822

  In the case of detecting the rotation by using the change in capacitance between the opposing electrodes, it is necessary to sufficiently narrow the gap between the electrodes in order to increase the detection sensitivity of the capacitance. However, for example, when a knob for rotating operation is provided on the front surface of the touch panel, it is desirable to provide a fixed electrode on the back surface of the touch panel in order to ensure strength, durability, water resistance, and the like. In this case, the rotating electrode and the fixed electrode are disposed on the front side and the back side of the touch sensor, and it is difficult to narrow the distance between them. As the electrode spacing increases, the detection sensitivity of the capacitance decreases, and the fluctuation of the offset component due to temperature changes and the signal component due to the change in capacitance approach each other, so the level of the signal component (high level) / Low level, etc.) cannot be determined by comparison with a fixed threshold value.

  The present invention has been made in view of such circumstances, and an object thereof is to accurately detect a change in capacitance and detect the direction of rotation even when a signal component indicating a change in capacitance is close to a change in an offset component. It is to provide a rotary input device that can determine the above.

A rotary input device according to a first aspect of the present invention includes a base part, an operation part rotatably supported by the base part, and provided in the operation part, from a rotation shaft of the operation part. A center corresponding to a plurality of movable electrodes arranged at equal intervals on the circumference of the first virtual circle having the same distance, and an arc sandwiched between the positions of the two movable electrodes adjacent on the circumference of the first virtual circle A moderation mechanism that suppresses rotation of the operation unit at a stop position set for each unit rotation angle that is an angle divided into N (N is an integer of 3 or more), and is provided in the base unit A plurality of variable capacitance elements arranged on a circumference of a second virtual circle that moves in parallel with the first virtual circle with respect to the rotation axis, and whose capacitance changes according to a positional relationship with the movable electrode. And a pulse voltage for supplying a pulse voltage to each of the plurality of variable capacitance elements. A supply unit; a detection signal generation unit configured to generate a detection signal corresponding to charges accumulated in the plurality of variable capacitance elements by supplying the pulse voltage; and determining a rotation direction of the operation unit based on the detection signal A signal processing unit.
The variable capacitance element has a capacitance at one stop position other than the N stop positions when the operation unit is rotated N steps from the stop position in a certain direction by the unit rotation angle. There is a large difference in capacitance with respect to the electrostatic capacity.
The plurality of variable capacitance elements has at least one first capacitance that causes an increase in the capacitance difference at the stop position of the first step when the operation unit is rotated by three unit rotation angles from the predetermined stop position in a predetermined direction. 1 variable capacitance element and at least 1 2nd variable capacitance element which produces the increase in the said capacitance difference in the stop position of a 2nd step.
The pulse voltage supply unit reverses the charge accumulated in the first variable capacitance element at the stop position of the first step and the charge accumulated in the second variable capacitance element at the stop position of the second step. The pulse voltage is supplied so as to have the same polarity or the same polarity and different magnitudes.
The detection signal generation unit generates the detection signal according to a sum of charges accumulated in the first variable capacitance element and the second variable capacitance element by supplying the pulse voltage, and performs the three-step rotation. At the stop position of the third step in this case, the detection signal having an intermediate value between the detection signal at the stop position of the first step and the detection signal at the stop position of the second step is generated.
The signal processing unit determines a rotation direction of the operation unit based on a change in the detection signal corresponding to a change in capacitance of the variable capacitance element.

  According to said structure, when the said stop position of the said operation part rotates to the said predetermined direction, and the case where it rotates to the direction opposite to the said predetermined direction, said 1st variable capacitance element and said 2nd Since the change in the sum of charges accumulated in the variable capacitance element is different, the change in the detection signal is different. Therefore, the rotation direction of the operation unit can be determined based on a change in the detection signal without comparing the detection signal with a fixed threshold value.

Preferably, the plurality of variable capacitance elements increase the capacitance difference at a stop position of a third step when the operation unit is rotated by three unit rotation angles from the predetermined stop position in the predetermined direction by the unit rotation angle. The resulting at least one third variable capacitance element may be included.
The pulse voltage supply unit reverses the charge accumulated in the first variable capacitance element at the stop position of the first step and the charge accumulated in the second variable capacitance element at the stop position of the second step. In the first operation mode in which the pulse voltage is supplied so as to have the same polarity or different sizes, and in the stop position of the second step, the second variable capacitance element is accumulated. The pulse voltage is supplied so that the electric charge and the electric charge accumulated in the third variable capacitance element at the stop position of the third step have opposite polarities or have the same polarity and different magnitudes. The second operation mode may be repeated alternately.
In the first operation mode, the detection signal generation unit generates a first detection signal corresponding to a sum of charges accumulated in the first variable capacitance element and the second variable capacitance element by supplying the pulse voltage. At the stop position of the third step, the first value having an intermediate value between the first detection signal at the stop position of the first step and the first detection signal at the stop position of the second step. A detection signal is generated, and in the second operation mode, a second detection signal corresponding to a sum of charges accumulated in the second variable capacitance element and the third variable capacitance element is generated by supplying the pulse voltage. The stop position of the first step has an intermediate value between the second detection signal at the stop position of the second step and the second detection signal at the stop position of the third step. It may generate a second detection signal.
The signal processing unit may determine a rotation direction of the operation unit based on changes in the first detection signal and the second detection signal corresponding to a change in capacitance of the variable capacitance element.

  According to the above configuration, the change in the first detection signal and the second detection signal corresponding to the change in the capacitance of the variable capacitance element is referred to as compared with the case where only one detection signal is referred to. Thus, the rotation direction and stop position of the operation unit are more accurately determined.

Preferably, the plurality of variable capacitance elements increase the capacitance difference at a stop position of a third step when the operation unit is rotated by three unit rotation angles from the predetermined stop position in the predetermined direction by the unit rotation angle. The resulting at least one third variable capacitance element may be included.
The pulse voltage supply unit includes a first charge accumulated in the first variable capacitance element at the stop position of the first step and a second charge accumulated in the second variable capacitance element at the stop position of the second step. In the first operation mode in which the pulse voltage is supplied so that the electric charges have opposite polarities or have the same polarity and different magnitudes, the second variable capacitance element is applied to the second variable capacitance element at the stop position of the second step A second operation mode in which the pulse voltage is supplied so that the first charge is accumulated and the second charge is accumulated in the third variable capacitance element at the stop position of the third step; and the first step The first charge is accumulated in the first variable capacitance element at a stop position, and the second charge is accumulated in the third variable capacitance element at the stop position in the third step. The third mode of operation to supply the scan voltage may be repeated sequentially.
The detection signal generator is
In the first operation mode, a first detection signal corresponding to a sum of charges accumulated in the first variable capacitance element and the second variable capacitance element is generated by supplying the pulse voltage, and the third step At the stop position, the first detection signal having an intermediate value between the first detection signal at the stop position of the first step and the first detection signal at the stop position of the second step is generated.
In the second operation mode, a second detection signal corresponding to a sum of charges accumulated in the second variable capacitance element and the third variable capacitance element by generating the pulse voltage is generated, and the first step At the stop position, the second detection signal having an intermediate value between the second detection signal at the stop position of the second step and the second detection signal at the stop position of the third step is generated.
In the third operation mode, a third detection signal corresponding to a sum of charges accumulated in the first variable capacitance element and the third variable capacitance element is generated by supplying the pulse voltage, and the second step At the stop position, the third detection signal having an intermediate value between the third detection signal at the stop position of the first step and the third detection signal at the stop position of the third step may be generated. .
The signal processing unit determines a rotation direction of the operation unit based on changes in the first detection signal, the second detection signal, and the third detection signal corresponding to a change in capacitance of the variable capacitance element. You can do it.

  According to said structure, the rotation direction and stop position of the said operation part are determined more correctly by referring the change of three detection signals.

Preferably, the signal processing unit is a detection signal obtained by subtracting the second detection signal from the first detection signal, a detection signal obtained by adding the second detection signal and the third detection signal, In addition, the rotation direction of the operation unit may be determined based on a change in the detection signal obtained by adding the first detection signal and the third detection signal.
According to said structure, since the change of the signal used for determination of a rotation direction becomes large, more accurate determination is attained.

A rotary input device according to a second aspect of the present invention includes a base part, an operation part rotatably supported by the base part, and provided in the operation part, from the rotation shaft of the operation part. A center corresponding to a plurality of movable electrodes arranged at equal intervals on the circumference of the first virtual circle having the same distance, and an arc sandwiched between the positions of the two movable electrodes adjacent on the circumference of the first virtual circle A moderation mechanism that suppresses rotation of the operation unit at a stop position set for each unit rotation angle that is an angle divided into N (N is an integer of 3 or more), and is provided in the base unit A plurality of variable capacitance elements arranged on a circumference of a second virtual circle that moves in parallel with the first virtual circle with respect to the rotation axis, and whose capacitance changes according to a positional relationship with the movable electrode. And a pulse voltage for supplying a pulse voltage to each of the plurality of variable capacitance elements. A supply unit; a detection signal generation unit configured to generate a detection signal corresponding to charges accumulated in the plurality of variable capacitance elements by supplying the pulse voltage; and determining a rotation direction of the operation unit based on the detection signal A signal processing unit.
The variable capacitance element has a capacitance at one stop position among N stop positions when the operation unit is rotated N steps from the one stop position in a certain direction by the unit rotation angle. Large capacitance difference with respect to the capacitance at the stop position. The pulse voltage supply unit includes three detection signals generated by the detection signal generation unit at three stop positions when the operation unit is rotated by three unit rotation angles from a predetermined stop position in a predetermined direction. A pulse voltage is supplied to each of the plurality of variable capacitance elements so that the signals have different levels. The signal processing unit determines a rotation direction of the operation unit based on a change in the detection signal corresponding to a change in capacitance of the variable capacitance element.

Preferably, the rotary input device according to the first aspect and the second aspect may include a plurality of fixed electrodes provided on the base portion and disposed on a circumference of the second virtual circle. In this case, a pair of the fixed electrodes adjacent on the circumference of the second virtual circle may constitute one variable capacitance element.
Each fixed electrode forming the pair of fixed electrodes is provided at a position where it can overlap with the common movable electrode when viewed from a direction parallel to the rotation axis when the operation unit is at the stop position. It's okay.

  According to said structure, since the electrostatic capacitance between the said fixed electrode and the said movable electrode becomes large, the detection sensitivity of an electrostatic capacitance improves.

  Preferably, the signal processing unit determines a change pattern of the detection signal based on a difference between a reference value and the detection signal, and determines a rotation direction of the operation unit based on the determined change pattern. When the change in the detection signal does not continuously occur for a certain time, the previous reference value is updated to a new reference value based on the average value of the detection signal after the last change in the detection signal has occurred. You can do it.

  According to the above configuration, when the change in the detection signal is small, that is, when the operation unit is not rotating, the reference value is updated, so the old reference value is updated to the latest appropriate reference value. The

  Preferably, the signal processing unit rotates the operation unit from the predetermined stop position to the predetermined direction by the unit rotation angle by three steps based on a series of determination results of the rotation direction. When the current stop position is equal to the stop position when the reference value is updated, the detection signal generated at the current stop position is determined. Based on this, the reference value may be updated.

  According to said structure, even if the said operation part is rotating, an old reference value is updated to the newest appropriate reference value.

  Preferably, the signal processing unit includes the detection signal generated at the current stop position and the reference value even when the current stop position is equal to the stop position when the reference value is updated. If the difference is larger than a predetermined threshold value, updating of the reference value using the detection signal may be stopped.

  According to the present invention, even when the signal component indicating the change in capacitance is close to the fluctuation of the offset component, the rotation direction can be determined by accurately detecting the change in capacitance.

It is a figure which shows an example of a structure of the rotary input device which concerns on embodiment of this invention. It is sectional drawing of a rotary input device. It is the figure which looked at the operation part of the rotary input device from the back side. It is a figure which shows an example of the electrode pattern provided in the back surface of the base part. It is a figure which shows the positional relationship of a movable electrode and a fixed electrode. It is a figure which shows an example of the structure in connection with the detection of rotation in the rotary input device which concerns on this embodiment. It is a figure which shows an example of a structure of a touch sensor. It is a figure for demonstrating the drive method of the variable capacitance element (pair of fixed electrode) in the rotary input device which concerns on 1st Embodiment. It is a figure which shows the supply pattern of a pulse voltage, and the change of the detection signal by the change of a stop position. It is a figure showing change of a signal level by change of a stop position about a new detection signal generated by performing addition and subtraction on three detection signals. It is the figure which digitized and showed the state of the stop position which the combination of three detection signals after addition and subtraction shown in Drawing 10 represents. It is a figure showing the transition of the state ST of each stop position shown in FIG. It is a flowchart for demonstrating the update of a reference value. It is a figure for demonstrating the drive method of the variable capacitance element (pair of fixed electrodes) in the rotary input device which concerns on 2nd Embodiment. It is a figure which shows the supply pattern of the pulse voltage in two operation modes shown in FIG. 14, and the change of the detection signal by the change of a stop position. FIG. 15 is a diagram showing the state of a stop position represented by a combination of two detection signals corresponding to the two pulse voltage patterns shown in FIG. 14 in numerical form. It is the figure showing the transition of the state ST of each stop position shown in FIG. It is a figure for demonstrating the drive method of the variable capacitance element (pair of fixed electrode) in the rotary input device which concerns on 3rd Embodiment. It is a figure which shows the supply pattern of the pulse voltage in the drive method shown in FIG. 18, and the change of the detection signal by the change of a stop position. It is the figure which illustrated the relative change of the level of the detection signal by the change of a stop position.

<First Embodiment>
FIG. 1 is a diagram illustrating an example of a configuration of a rotary input device according to an embodiment of the present invention. The rotary input device according to the present embodiment is a device that detects a user's rotation operation using a change in capacitance between electrodes, and also has a function as a capacitive touch sensor. The rotary input device shown in FIG. 1 includes a base 5 having an operation area 1 of a touch sensor and an operation unit 10 that is rotatably supported by the base 5. The base 5 is a plate-like member such as glass, for example, and electrode patterns for rotation detection and touch sensor are formed on the surface opposite to the surface on which the operation unit 10 is attached. The front side plane corresponding to the area where the electrode pattern for the touch sensor is formed is used as the operation area 1 of the touch sensor.

  2 is a cross-sectional view taken along line A-A ′ in FIG. 1. A columnar support member 7 is fixed to the flat portion 51 on the front side of the base portion 5. The operation unit 10 is rotatably supported by the base unit 5 by the support member 7. The support member 7 has a flange portion 71 protruding perpendicularly to the rotation axis AX. Between the flange portion 71 and the flat portion 51 of the base portion 5, the ring-shaped edge portion 11 of the operation portion 10 is fitted. A plurality of bearings 18 are provided between the support member 7 and the operation unit 10.

  The support member 7 is made of a conductive material and is connected to the ground potential. Accordingly, the ring-shaped edge portion 11 of the operation unit 10 is covered with the flange portion 71 having the ground potential as viewed from the front side of the operation unit 10. A movable electrode (EM1 to EM8) to be described later is provided on the edge 11 of the operation unit 10.

FIG. 3 is a view of the operation unit 10 as viewed from the back side, and shows the back surface of the operation unit 10 facing the flat surface part 51 of the base unit 5.
On the back surface of the operation unit 10, eight movable electrodes (EM1 to EM8) arranged at equal intervals on the circumference of the first virtual circle IM1 having the same distance from the rotation axis AX of the operation unit 10 are provided. The movable electrodes EM1 to EM8 (hereinafter, any one movable electrode is referred to as “EM”) are included in the range of the sector region of the unit rotation angle θ when viewed from the center P of the first virtual circle IM1. Specifically, the movable electrode EM forms a unit rotation angle θ from two arcs Ar1 and Ar2 on the circumference of two circles CY1 and CY2 having the same center P and different diameters from the first virtual circle IM1 and the center P. And has a planar shape surrounded by two line segments Se1 and Se2 on the two straight lines L1 and L2 extending in the radial direction. Fixed electrodes EF1 to EF4 to be described later have the same shape as the movable electrodes EM1 to EM8. The unit rotation angle θ is a rotation angle from one stop position to the next stop position by the moderation mechanism 15 described below.

  The rotary input device according to the present embodiment includes a moderation mechanism 15 that suppresses the rotation of the operation unit 10 at a predetermined stop position set for each unit rotation angle θ. For example, as shown in FIG. 2, the moderation mechanism 15 includes a magnet 15 a provided on the outer periphery of the support member 7 and a magnet 15 b provided on the inner periphery of the operation unit 10. The magnets 15a and 15b have the same number of gear-shaped irregularities, respectively, and suppress the rotation of the operation unit 10 so as to maintain the state in which both convex portions face each other.

  The unit rotation angle θ is obtained by equally dividing the central angle φ corresponding to the arc sandwiched between the positions of two adjacent movable electrodes on the circumference of the first virtual circle IM1 (N is an integer of 3 or more). Set to an angle. That is, an angle obtained by dividing the rotation angle of one round (360 °) by N times the number of movable electrodes EM is the unit rotation angle θ. In the example of FIG. 3, since the number of movable electrodes is 8 and N is 3, the unit rotation angle θ is 15 °.

  Since the eight movable electrodes EM provided in the operation unit 10 have the same shape and are arranged at equal intervals on the circumference of the first virtual circle IM1, the arrangement of the movable electrodes EM viewed from the base unit 5 side. Returns to the same state each time the stop position by the moderation mechanism 15 is rotated in a fixed direction by N steps (3 steps in the example of FIG. 3).

FIG. 4 is a diagram illustrating an example of an electrode pattern provided on the back surface of the base unit 5.
Drive electrodes ED1 to ED23 and sense electrodes ES1 to ES32 are formed on the back surface of the base portion 5 as touch sensor electrodes, and fixed electrodes EF1 to EF4 are formed as rotation detection electrodes. These electrodes have, for example, a two-layer structure in which sense electrodes ES1 to ES32 and fixed electrodes EF1 to EF4 are formed on the first layer, and drive electrodes ED1 to ED23 are formed on the second layer above the first layer. The film formation layer 52 is formed. The drive electrodes ED1 to ED23 and the sense electrodes ES1 to ES32 are transparent conductive films such as ITO and transmit light from a liquid crystal panel (not shown).

  The drive electrodes ED1 to ED23 and the sense electrodes ES1 to ES32 are arranged in a lattice shape as shown in FIG. 4, and a capacitor CS is formed at each intersection of the drive electrode and the sense electrode. When an object such as a finger comes close to the operation region 1 of the base unit 5, the capacitance of the capacitor CS formed near the position where the finger is close changes. The drive electrodes ED1 to ED23 transmit a pulse voltage generated by a pulse voltage supply unit 100 described later to these capacitors CS. The sense electrodes ES <b> 1 to ES <b> 32 transmit the charge QS accumulated in the capacitor CS at each intersection by supplying a pulse voltage to the detection signal generation unit 110 described later.

  The fixed electrodes EF1 to EF4 are arranged on the circumference of the second virtual circle IM2 obtained by moving the first virtual circle IM2 parallel to the base part 5 with respect to the rotation axis AX, and are arranged side by side in the example of FIG. Has been. These four fixed electrodes EF1 to EF4 (hereinafter, any one fixed electrode is referred to as “EF”) have three variable capacitance elements VC1 to VC1 whose capacitances change according to the positional relationship with the movable electrode EM. VC3 is formed (hereinafter, an arbitrary variable capacitance element is referred to as “VC”). The first variable capacitance element VC1 is formed of a pair of adjacent fixed electrodes EF1 and EF2 on the circumference of the second virtual circle IM2. The second variable capacitance element VC2 is formed by a pair of fixed electrodes EF2 and EF3 adjacent on the circumference of the second virtual circle IM2. The third variable capacitor VC3 is formed of a pair of adjacent fixed electrodes EF3 and EF4 on the circumference of the second virtual circle IM2. Therefore, the fixed electrode EF2 is shared by the first variable capacitance element VC1 and the second variable capacitance element VC2, and the fixed electrode EF3 is shared by the second variable capacitance element VC2 and the third variable capacitance element VC3. The fixed electrodes EF2 and EF3 shared by the two variable capacitance elements are connected to a detection signal generation unit 110 described later.

  FIG. 5 is a diagram illustrating a positional relationship between the movable electrode EM and the fixed electrode EF. Each fixed electrode in the pair of fixed electrodes EF forming the variable capacitance element VC (the pair of EF1 and EF2, the pair of EF2 and EF3, and the pair of EF3 and EF4 in the example of FIGS. 4 and 5) When the moderation mechanism 15 is in the stop position, it is provided at a position where it can overlap with one common movable electrode EM when viewed from the direction parallel to the rotation axis AX. When the electrostatic capacity of the variable capacitance element VC is compared at the three stop positions when the operation unit 10 is rotated by three unit rotation angles θ from the stop position in a certain direction, the fixed electrode EF forming the variable capacitance element VC is compared. The capacitance at one stop position where the pair overlaps the movable electrode EM has a large capacitance difference from the capacitance at the other two stop positions where no overlap occurs. Therefore, it is possible to determine whether or not the movable electrode EM exists at a position where it overlaps with the pair of the fixed electrodes EF forming the variable capacitance element VC by examining the change in the capacitance of the variable capacitance element VC. It becomes possible.

  In the example of FIG. 5, each fixed electrode in the pair of fixed electrodes EF forming the variable capacitance element VC is parallel to the rotation axis AX when the operation unit 10 is at the stop position of the moderation mechanism 15 described above. In view of this, the common movable electrode EM is provided at a position where it can overlap with the same area. That is, the fixed electrode EF has the same shape as that of the movable electrode EM, and the unit of the fixed electrode EF is exactly the same as the position of the movable electrode EM when the operation unit 10 is at the stop position when viewed from the direction parallel to the rotation axis AX. It is formed at a position rotated on the circumference of the second virtual circle IM2 by half of the rotation angle θ (θ / 2). Since the pair of fixed electrodes EF overlaps with a common movable electrode EM, the amount of change in capacitance is larger than when the overlapping areas of the two are different.

  A ground electrode EG is formed on the film forming layer 52 on the back surface of the base portion 5 so as to cover the fixed electrode EF (FIG. 2). That is, the fixed electrode EF and the movable electrode EM are sandwiched between the edge 11 of the operation unit 10 having the ground potential and the ground electrode EG. Thereby, it is possible to reduce the influence of noise from an object such as a fingertip approaching from the front side of the base unit 5 or a liquid crystal panel positioned on the back side of the base unit 5.

FIG. 6 is a diagram illustrating an example of a configuration relating to rotation detection in the rotary input device according to the present embodiment.
The rotary input device includes a pulse voltage supply unit 100, a detection signal generation unit 110, a signal processing unit 120, and a storage unit 130 as a configuration related to rotation detection.

  The pulse voltage supply unit 100 is a circuit that supplies pulse voltages to the three variable capacitance elements (VC1 to VC3) of the base unit 5, and the pulse voltage supply patterns (pattern A, pattern B, pattern C) are different. The three operation modes (first operation mode, second operation mode, and third operation mode) are repeatedly executed while being switched in a time-sharing manner in order.

  In the following description, the stop position (stop position where the pair of fixed electrodes EF1 and EF2 overlaps the movable electrode EM) where the capacitance difference of the capacitance of the first variable capacitance element VC1 increases is “SP1”, the second The stop position (stop position where the pair of fixed electrodes EF2, EF3 and the movable electrode EM overlap) where the capacitance difference of the capacitance of the variable capacitor VC2 increases is “SP2”, and the electrostatic capacity of the third variable capacitor VC3. A stop position (a stop position where the pair of fixed electrodes EF3 and EF4 and the movable electrode EM overlap each other) where the capacitance difference between the capacitors increases is denoted as “SP3”. In this case, when the operation unit 10 is rotated from the stop position SP3 to the right in FIG. 5 by 3 unit steps by the unit rotation angle θ, the stop position of the first step becomes “SP1”, and the stop position of the second step becomes “SP2”. The stop position of the third step is “SP3”.

(First operation mode / Pattern A)
In the first operation mode, the pulse voltage supply unit 100 includes the first charge Q1 accumulated in the first variable capacitance element VC1 when the operation unit 10 is at the stop position SP1, and the first voltage Q1 accumulated when the operation unit 10 is at the stop position SP2. The pulse voltage is supplied to the first variable capacitance element VC1 and the second variable capacitance element VC2 so that the second charge Q2 stored in the two variable capacitance element VC2 has a reverse polarity. In the example of FIG. 5, the pulse voltage supply unit 100 supplies a pulse voltage of a positive voltage “+ V” to the fixed electrode EF1 of the first variable capacitor VC1 and a negative voltage “+” to the fixed electrode EF3 of the second variable capacitor VC2. -V "pulse voltage is supplied, and a ground potential is applied to the common fixed electrode EF2 of the first variable capacitance element VC1 and the second variable capacitance element VC2.
The pulse voltage supply unit 100 supplies the pulse voltage to the first variable capacitance element VC1 and the second variable capacitance element VC2 so that the first charge Q1 and the second charge Q2 have the same polarity and different sizes. May be. Also in this case, in the detection signal generation unit 110 described later, the detection signal Ds at each stop position can have a different level.

  In the example of FIG. 5, the pulse voltage supply unit 100 applies a positive voltage “+ V” to the fixed electrode EF4 of the third variable capacitance element VC3 that does not supply the pulse voltage.

(Second operation mode / Pattern B)
In the second operation mode, the pulse voltage supply unit 100 stores the first charge Q1 in the second variable capacitance element VC2 when the operation unit 10 is at the stop position SP2, and the third when the operation unit 10 is at the stop position SP3. A pulse voltage is supplied to the second variable capacitor VC2 and the third variable capacitor VC3 so that the second charge Q2 is accumulated in the variable capacitor VC3. In the example of FIG. 5, the pulse voltage supply unit 100 supplies a pulse voltage of a positive voltage “+ V” to the fixed electrode EF2 of the second variable capacitance element VC2, and a negative voltage “to the fixed electrode EF4 of the third variable capacitance element VC3. -V "pulse voltage is supplied, and a ground potential is applied to the common fixed electrode EF3 of the second variable capacitor VC2 and the third variable capacitor VC3.

  In the example of FIG. 5, the pulse voltage supply unit 100 applies a positive voltage “+ V” to the fixed electrode EF1 of the first variable capacitance element VC1 that does not supply the pulse voltage.

(Third operation mode / pattern C)
In the third operation mode, the pulse voltage supply unit 100 stores the first charge Q1 in the first variable capacitance element VC1 when the operation unit 10 is at the stop position SP1, and the third when the operation unit 10 is at the stop position SP3. The pulse voltage is supplied to the first variable capacitor VC1 and the third variable capacitor VC3 so that the second charge Q2 is accumulated in the variable capacitor VC3. In the example of FIG. 5, the pulse voltage supply unit 100 supplies a pulse voltage of a positive voltage “+ V” to the fixed electrode EF1 of the first variable capacitor VC1, and a negative voltage “+” to the fixed electrode EF4 of the third variable capacitor VC3. −V ”pulse voltage is supplied, and a ground potential is applied to the fixed electrode EF2 of the first variable capacitor VC1 and the fixed electrode EF3 of the third variable capacitor VC3, respectively.

  The pulse voltage supply unit 100 is synchronized with the timing when one of the drive electrodes ED1 to ED23 is selected and driven by the touch sensor drive unit 210 in the touch sensor 2 described later, and the pulse voltage in each operation mode described above. Supply.

The detection signal generation unit 110 is a circuit that generates a detection signal Ds corresponding to charges accumulated in the three variable capacitance elements (VC1 to VC3) by supplying a pulse voltage. The detection signal generation unit 110 includes, for example, a charge amplifier that inputs charge and converts it into a voltage, and an AD converter that samples the voltage and converts it into a digital signal.
The detection signal generation unit 110 operates as follows according to the operation mode of the pulse voltage supply unit 100.

(First operation mode / Pattern A)
In the first operation mode, the detection signal generation unit 110 detects the detection signal Ds (first detection signal Ds1) corresponding to the sum of charges accumulated in the first variable capacitance element VC1 and the second variable capacitance element VC2 by supplying the pulse voltage. ) Is generated. That is, the detection signal generation unit 110 inputs a charge corresponding to the sum of charges accumulated in the fixed electrode EF2 shared by the first variable capacitance element VC1 and the second variable capacitance element VC2, and inputs the input charge. The first detection signal Ds1 corresponding to is generated.

  When the operation unit 10 is at the stop position SP3, the amount of change in capacitance in the first variable capacitance element VC1 and the second variable capacitance element VC2 (capacitance change due to the movable electrode EM overlapping the pair of fixed electrodes EF) is small. For this reason, charges corresponding to the amount of change in capacitance are not input to the detection signal generation unit 110. In this case, the detection signal generation unit 110 distinguishes between the case where the operation unit 10 is at the stop position SP1 or the stop position SP2 and the case where the operation unit 10 is at the stop position SP3, so that the first detection signal Ds1 at the stop position SP1. And a first detection signal Ds1 having a different value (for example, an intermediate value) from the first detection signal Ds1 at the stop position SP2. For example, when the detection signal generator 110 sets the first detection signal Ds1 at the stop position SP3 to zero, one of the first detection signals Ds1 at the stop position SP1 and the stop position SP2 is positive and the other is negative. First detection signal Ds1 is generated.

(Second operation mode / Pattern B)
In the second operation mode, the detection signal generation unit 110 detects the detection signal Ds (second detection signal Ds2) corresponding to the sum of charges accumulated in the second variable capacitance element VC2 and the third variable capacitance element VC3 by supplying the pulse voltage. ) Is generated. That is, the detection signal generation unit 110 inputs a charge corresponding to the sum of the charges accumulated in the fixed electrode EF3 shared by the second variable capacitance element VC2 and the third variable capacitance element VC3. A second detection signal Ds2 corresponding to the above is generated.

  When the operation unit 10 is at the stop position SP1, the amount of change in capacitance in the second variable capacitance element VC2 and the third variable capacitance element VC3 is small, so that the charge corresponding to the amount of change in capacitance is detected signal generation unit. 110 is not input. In this case, the detection signal generation unit 110 makes a distinction between when the operation unit 10 is at the stop position SP2 or the stop position SP3 and when it is at the stop position SP1, so that the second detection signal Ds2 at the stop position SP2 is obtained. And a second detection signal Ds2 having a different value (for example, an intermediate value) from the second detection signal Ds2 at the stop position SP3. For example, when the detection signal generation unit 110 sets the second detection signal Ds2 at the stop position SP1 to zero, one of the second detection signals Ds2 at the stop position SP2 and the stop position SP3 becomes positive and the other becomes negative. The second detection signal Ds2 is generated.

(Third operation mode / pattern C)
In the third operation mode, the detection signal generation unit 110 detects the detection signal Ds (third detection signal Ds3) corresponding to the sum of charges accumulated in the first variable capacitance element VC1 and the third variable capacitance element VC3 by supplying the pulse voltage. ) Is generated. That is, the detection signal generation unit 110 inputs and inputs charges corresponding to the sum of charges accumulated in the fixed electrode EF2 of the first variable capacitance element VC1 and the fixed electrode EF3 of the third variable capacitance element VC3. A third detection signal Ds3 corresponding to the charge is generated.

  When the operation unit 10 is at the stop position SP2, the amount of change in capacitance in the first variable capacitance element VC1 and the third variable capacitance element VC3 is small, so that the charge corresponding to the amount of change in capacitance is detected signal generation unit. 110 is not input. In this case, the detection signal generation unit 110 distinguishes between the case where the operation unit 10 is at the stop position SP1 or the stop position SP3 and the case where the operation unit 10 is at the stop position SP2, so that the third detection signal Ds3 at the stop position SP1 is obtained. And a third detection signal Ds3 having a different value (for example, an intermediate value) from the third detection signal Ds3 at the stop position SP3. For example, when the detection signal generation unit 110 sets the third detection signal Ds3 at the stop position SP2 to zero, one of the third detection signals Ds3 at the stop position SP1 and the stop position SP3 becomes positive and the other becomes negative. The third detection signal Ds3 is generated.

  Based on the detection signal Ds generated by the detection signal generation unit 110, the signal processing unit 120 determines whether or not the operation unit 10 is rotated and the rotation direction. In other words, the signal processing unit 120 includes the first detection signal Ds1, the second detection signal Ds2, and the second detection signal Ds2 corresponding to the change in capacitance of the variable capacitance element VC (capacitance change caused when the movable electrode EM overlaps the pair of fixed electrodes EF). Based on the change of the third detection signal Ds3, the rotation direction of the operation unit 10 is determined. Specifically, the signal processing unit 120 adds a detection signal (Ds1-Ds2) generated by subtracting the second detection signal Ds2 from the first detection signal Ds1, and adds the second detection signal Ds2 and the third detection signal Ds3. The rotation direction of the operation unit 10 is determined based on the detection signal (Ds2 + Ds3) generated in this way and the change in the detection signal (Ds1 + Ds3) generated by adding the first detection signal Ds1 and the third detection signal Ds3. . The combination of these three signals represents the state of the stop position of the operation unit 10 as will be described later. The signal processing unit 120 identifies the change from one stop position to the adjacent stop position by tracking the state of the stop position specified from the combination of the three signals, and determines the rotation direction of the operation unit 10. .

  Further, the signal processing unit 120 evaluates a change in detection signal corresponding to a change in capacitance of the variable capacitance element VC (capacitance change caused when the movable electrode EM overlaps the pair of fixed electrodes EF). The change pattern of the detection signal is determined based on the difference between the detection signal and the detection signal, and the rotation direction of the operation unit 10 is determined based on the determined change pattern. For example, the signal processing unit 120 calculates a difference between the first detection signal Ds1 and the reference value R1, a difference between the second detection signal Ds2 and the reference value R2, and a difference between the third detection signal Ds3 and the reference value R3, respectively. These differences are regarded as the first detection signal Ds1, the second detection signal Ds2, and the third detection signal Ds3, and the detection signal (Ds1-Ds2), the detection signal (Ds2 + Ds3), and the detection signal (Ds1 + Ds3) described above are used. calculate. Then, the signal processing unit 120 compares each of the calculated detection signals with two predetermined threshold values to determine which of the three levels each detection signal corresponds to. The combination of the ternary levels determined for each detection signal represents the state of the stop position of the operation unit 10 as will be described later. Therefore, the signal processing unit 120 can determine the rotation direction of the operation unit 10 based on the determined level (detection signal change pattern).

The signal processing unit 120 updates the above-described reference value R used for determining the change pattern of the detection signal under a predetermined condition. That is, if the change in the detection signal does not continuously occur for a certain time, the signal processing unit 120 sets the previous reference value as a new reference based on the average value of the detection signal after the last change in the detection signal occurs. Update to value. Specifically, when the signal processing unit 120 determines that a change has occurred in the detection signal from the determination result of the change pattern, each time the reference value R is acquired from the storage unit 130, the one reference value R Is used to calculate an average value after occurrence of a change for the detection signal to be subjected to the change pattern determination, and the calculated average value is stored in the storage unit 130 in association with the one reference value R. Then, when the change in the detection signal does not continuously occur for a certain time, the signal processing unit 120 newly sets the previous reference value R based on the average value stored in the storage unit 130 in association with the reference value R. To a new reference value R.
As a result, the reference value R is updated based on the average value of the stable detection signal when no change in the detection signal occurs for a certain period of time. Therefore, the reference value R varies greatly due to drift caused by a temperature change or the like. Even in this case, an appropriate reference value R can be obtained following this variation.

  Further, the signal processing unit 120 changes the reference value R for each drive state of the touch sensor 2 in order to compensate for variations in the reference value R due to the influence of the drive pulse voltage of the drive electrodes ED <b> 1 to ED <b> 23 in the touch sensor 2. That is, the signal processing unit 120 acquires the reference value R prepared for each driving state of the touch sensor 2 from the storage unit 130 and uses the reference value R to determine the change pattern of the detection signal.

  For example, the storage unit 130 includes drive electrodes (ED1 to ED3) that are selected and driven by the touch sensor 2, sense electrodes (ES1 to ES32) that are selected for detecting capacitance, and the pulse voltage supply unit 100. The reference value R of the detection signal is stored in association with the operation modes (first operation mode to third operation mode). When the signal processing unit 120 receives detection signals (Ds1 to Ds3) generated in a specific operation mode executed at a timing synchronized with the timing at which the specific drive electrode and the sense electrode are selected in the touch sensor 2, A reference value R corresponding to the selected combination of the specific drive electrode and the sense electrode and corresponding to the executed specific operation mode is acquired from the storage unit 130, and the acquired reference value R is used. A change pattern of the detection signal is determined.

  Note that the processing of the signal processing unit 120 may be executed using, for example, a computer that executes processing based on a program stored in the storage unit 130, or at least part of the processing is performed by a dedicated logic circuit (ASIC). Etc.). Or you may perform at least one part process using the same computer as the control part 230 of the touch sensor 2 mentioned later.

  The storage unit 130 stores a computer program for executing the processing of the signal processing unit 120, constant data used for the processing (reference value R, etc.), variable data temporarily used in the process, and the like. For example, it is configured using a volatile memory such as a DRAM or SRAM, a nonvolatile memory such as a flash memory, a hard disk, or the like.

FIG. 7 is a diagram illustrating an example of the configuration of the touch sensor 2.
The touch sensor 2 shown in FIG. 7 includes a sensor unit 200 including drive electrodes ED1 to ED23 and sense electrodes ES1 to ES32, a touch sensor drive unit 210, a touch sensor detection unit 220, a control unit 230, and a storage unit 250. Have.

  The touch sensor drive unit 210 sequentially selects drive electrodes from the drive electrodes ED1 to ED23, and supplies a pulse voltage to the selected drive electrodes.

  The touch sensor detection unit 220 sequentially selects a part of the sense electrodes from the sense electrodes ES1 to ES32 in parallel with the selection of the drive electrodes that the touch sensor drive unit 210 performs to supply the pulse voltage, and performs the selection. The touch detection signal corresponding to the charge QS of the capacitor CS transmitted through the sense electrode is generated. As shown in FIG. 4, the sense electrodes ES1 to ES32 are divided into two 16 sense electrode groups ES_A and ES_B, and the touch sensor detection unit 220 alternately selects the two sense electrode groups ES_A and ES_B. , 16 touch detection signals corresponding to the 16 sense electrodes are generated in parallel.

  The control unit 230 is a circuit that controls the overall operation of the touch sensor 2, for example, a computer that performs processing according to an instruction code of a program stored in the storage unit 250, or a logic circuit (ASIC that implements a specific function). Etc.). The control unit 230 controls the drive electrode selection in the touch sensor drive unit 210, the sense electrode selection in the touch sensor detection unit 220, the generation timing of the touch detection signal, and the like. Further, the control unit 230 performs a process of calculating the contact position of the object in the operation region 1 based on the touch detection signal input from the touch sensor detection unit 220.

  The storage unit 250 stores constant data and variable data used for processing in the control unit 230. When the control unit 230 includes a computer, the storage unit 230 may store a program executed on the computer. The storage unit 250 is configured using, for example, a volatile memory such as DRAM or SRAM, a nonvolatile memory such as flash memory, a hard disk, or the like.

  Next, the operation of the rotary input device according to this embodiment having the above-described configuration will be described.

First, the operation of determining the rotation direction of the operation unit 10 will be described.
FIG. 8 is a diagram for explaining a driving method of the variable capacitance element VC (a pair of fixed electrodes) in the rotary input device according to the present embodiment.

The pulse voltage supply unit 100 supplies a pulse voltage to four fixed electrodes (FE1 to FE4) arranged adjacent to each other by using three patterns (pattern A, pattern B, and pattern C).
In the first operation mode (pattern A), the pulse voltage supply unit 100 supplies a pulse voltage of a positive voltage “+ V” to the fixed electrode FE1, applies a ground potential to the fixed electrode FE2, and applies a negative voltage to the fixed electrodes FE3 and FE4. A pulse voltage of “−V” is supplied. In the first operation mode, the detection signal generation unit 110 generates the first detection signal Ds1 corresponding to the sum of the charges of the first variable capacitance element VC1 and the second variable capacitance element VC2 transmitted from the fixed electrode FE2.
In the second operation mode (pattern B), the pulse voltage supply unit 100 supplies a pulse voltage of a positive voltage “+ V” to the fixed electrodes FE1 and FE2, applies a ground potential to the fixed electrode FE3, and supplies the fixed electrodes FE3 and FE4 with a ground potential. A pulse voltage of negative voltage “−V” is supplied. The detection signal generation unit 110 generates a second detection signal Ds2 corresponding to the sum of charges of the second variable capacitance element VC2 and the third variable capacitance element VC3 transmitted from the fixed electrode FE3.
In the third operation mode (pattern C), the pulse voltage supply unit 100 supplies a pulse voltage of a positive voltage “+ V” to the fixed electrode FE1, applies a ground potential to the fixed electrodes FE2 and FE3, and applies a negative voltage to the fixed electrode FE4. A pulse voltage of “−V” is supplied. The detection signal generation unit 110 generates a second detection signal Ds2 corresponding to the sum of charges of the first variable capacitance element VC1 and the third variable capacitance element VC3 transmitted from the fixed electrodes FE2 and FE3.

  FIG. 9 is a diagram illustrating a pulse voltage supply pattern and a change in the detection signal due to a change in the stop position. In FIG. 9, the numbers surrounded by circles indicate the numbers of the three stop positions SP1, SP2 and SP3 shown in FIG. Further, alphabets A to C indicate pulse voltage supply patterns, respectively.

  FIG. 9A shows the polarities of the pulse voltages applied to the three variable capacitance elements (VC1, VC2, VC3) corresponding to the three stop positions (SP1, SP2, SP3). “P” indicates a pulse voltage with a positive voltage “+ V”, “N” indicates a pulse voltage with a negative voltage “−V”, and “0” indicates that no pulse voltage is applied.

  According to FIG. 9A, when the operation unit 10 rotates from the stop position SP1 to the stop position SP2, the first detection signal Ds1 generated in the pattern A (first operation mode) includes the first variable capacitance element VC1. A change in level corresponding to a change from a charge due to the pulse voltage of the positive voltage “+ V” to a charge due to the pulse voltage of the negative voltage “−V” of the second variable capacitance element VC2 occurs. If the change from “P” to “N” is represented by a numerical value “2”, the numerical value indicating the change from “N” to “P” can be represented by “−2”. Further, the change from “P” to “0” and the change from “0” to “N” correspond to half of the change from “P” to “N”, and therefore can be represented by the numerical value “1”. . The change from “N” to “0” and the change from “0” to “P” correspond to half of the change from “N” to “P”, and therefore can be represented by a numerical value “−1”.

  9B to 9D show the changes in the detection signals (Ds1 to Ds3) when rotating from the reference stop position to another stop position, respectively, as described above in “2”, “1”, “−1”, “ -2 ". However, the reference stop position is represented by a numerical value “0”. This numerical value represents the magnitude of the relative change of the detection signals (Ds1 to Ds3) in five levels. In order to discriminate this level for the actual detection signals (Ds1 to Ds3), it is independent. It is necessary to use these four threshold values. Assuming that the change in capacitance is small, it is desirable that the number of levels to be determined is as small as possible.

  Therefore, in the rotary input device according to the present embodiment, in order to reduce the number of levels and increase the amplitude of change in the detection signal, the three detection signals (Ds1 to Ds3) generated by the three patterns are used. Add and subtract. That is, the signal processing unit 120 generates a detection signal (Ds1-Ds2) generated by subtracting the second detection signal Ds2 from the first detection signal Ds1, and adds the second detection signal Ds2 and the third detection signal Ds3. The detected signal (Ds2 + Ds3) and the detection signal (Ds1 + Ds3) generated by adding the first detection signal Ds1 and the third detection signal Ds3 are calculated.

  FIG. 10 is a diagram illustrating a change in signal level due to a change in the stop position of a new detection signal generated by performing addition / subtraction on the three detection signals (Ds1 to Ds3). When adding and subtracting “Ds1−Ds2 (A−B)”, “Ds2 + Ds3 (B + C)”, and “Ds1 + Ds3 (A + C)” with respect to the numerical values in FIGS. 9B to 9D, as shown in FIG. Are aggregated into three levels of “3”, [0], and “−3”. Further, the maximum amplitude of the signal to be determined increases from 2 to 3 by addition / subtraction with respect to the three detection signals (Ds1 to Ds3). Therefore, the level of the minute detection signal can be accurately determined.

  FIG. 11 is a diagram showing the state of the stop position represented by the combination of the three detection signals (“A−B”, “B + C”, “A + C”) after addition and subtraction shown in FIG. “ST” in FIG. 11 is obtained by quantifying three detection signals (“A−B”, “B + C”, and “A + C”) in a radix-3. When the numerical values of the three detection signals shown in FIG. 10 are represented by the symbols [AB], [B + C], and [A + C], the state ST is represented by the following equation.

[Equation 1]
ST = [A−B] + [B + C] × 3 + [A + C] × 9 (1)

  In FIG. 11, the state ST that can occur during the rotation from the reference stop position to the adjacent stop position is also expressed in numerical form. As can be seen from FIG. 11, the transition of the state ST is “α”, “β”, or “γ” depending on which of the “SP1”, “SP2”, and “SP3” is the reference stop position. Divided into patterns. When the reference stop position is “SP1”, the state transition is “α”, when the reference stop position is “SP2”, the state transition is “β”, and the reference stop position is “SP3”. In this case, the state transition is “γ”.

FIG. 12 is a diagram illustrating transition of the state ST at each stop position illustrated in FIG. 11.
In the state transition pattern shown in FIG. 12, the numerical values of the state ST at each stop position are all different. In addition, the numerical value of the state ST that may occur during the rotation from one stop position to another stop position does not overlap with the numerical value of the state ST at each stop position. Therefore, even when the reference stop position is unknown, when the first stop position changes, the three detection signals (“A−B”, “B + C”, By obtaining the state ST of the expression (1) from “A + C”), the signal processing unit 120 can immediately determine the state transition pattern and the current stop position. Therefore, the signal processing unit 120 can accurately determine the rotation direction by comparing the previous stop position with the current stop position.

Next, reference value updating will be described with reference to the flowchart of FIG.
When the signal processing unit 120 receives three patterns of detection signals (Ds1 to Ds3) from the detection signal generation unit 110, the signal processing unit 120 acquires reference values (R1 to R3) corresponding to the respective detection signals from the storage unit 130, and detects the detection signals. The difference between (Ds1 to Ds3) and the reference value (R1 to R3) is calculated. The signal processing unit 120 regards this calculation result as a normal detection signal (Ds1 to Ds3), performs subsequent addition / subtraction processing (FIG. 10) and state ST calculation (equation (1)) to determine the rotation direction. I do. Therefore, if the reference value fluctuates due to the influence of drift such as temperature, the rotational direction cannot be correctly determined. Therefore, the signal processing unit 120 performs a process of updating the reference value based on the average value of the detection signals (Ds1 to Ds3) input from the detection signal generation unit 110.

  The signal processing unit 120 determines a change pattern of the detection signal based on the difference between the detection signal and the reference value, and always repeatedly performs a process of determining the rotation direction of the operation unit 10 based on the determined change pattern. When the detection signal changes due to the rotation of the operation unit 10 (ST100), the signal processing unit 120 starts calculating the average value of the detection signals generated by the detection signal generation unit 110 (ST110). Each time the signal processing unit 120 acquires one reference value from the storage unit 130, the signal processing unit 120 calculates an average value after occurrence of a change for the detection signal to be used to determine the change pattern using the one reference value, The calculated average value is stored in the storage unit 130 in association with the one reference value. For example, when the reference value R1 corresponding to the first detection signal Ds1 generated in the first operation mode (pattern A) is read from the storage unit 130, the first detection signal Ds1 input after a change due to rotation occurs. Is calculated, and the calculated average value is stored in the storage unit 130 in association with the reference value R1. In addition, when the calculation of the average value of the detection signals is started, the signal processing unit 120 starts counting with a timer in order to measure the elapsed time from the start time (ST120).

  Further, the signal processing unit 120 is set to a position where the current stop position is a reference (the stop position where the state ST is zero in FIG. 11 and the same as the stop position where the reference value was updated in step ST160 described later). If it becomes (ST130), the current reference value is updated based on the latest detection signal obtained in the detection signal generation unit 110 (ST140). For example, the signal processing unit 120 stores the result obtained by adding a predetermined weight to the latest detection signal and the current reference value in the storage unit 130 as a new reference value. As a result, the reference value can be updated even during the rotation of the operation unit 10.

  When the measured value of the timer started in step ST120 reaches a predetermined time (ST150), the signal processing unit 120 converts the previous reference value to a new reference value based on the average value started to be calculated in step ST110. Update to For example, the average value calculated in step ST110 is directly stored in the storage unit 130 as a new reference value (ST160). When the update of the reference value is completed, the signal processing unit 120 stops the timer started in step ST120, resets the time measurement value, and ends the average value calculation process (ST170). Each time the signal processing unit 120 performs capacitance detection and rotation direction determination processing, the signal processing unit 120 executes the processing of steps ST100 to ST170 described above.

<Second Embodiment>
Next, a second embodiment of the present invention will be described.
In the first embodiment described above, the level of the detection signal after addition / subtraction is increased to three by performing addition / subtraction operations on the three detection signals (Ds1 to Ds3) obtained by the three types of pulse voltage supply patterns. In addition to aggregation, the signal amplitude is increased. However, since it is necessary to perform an operation of supplying three patterns of pulse voltages in order to calculate the state ST, the processing time for obtaining the state ST becomes long. Therefore, in the rotary input device according to the present embodiment, the pulse voltage supply pattern is reduced from 3 to 2.

FIG. 14 is a diagram for explaining a driving method of a variable capacitance element (a pair of fixed electrodes) in the rotary input device according to the second embodiment.
As shown in FIG. 14, the two operation modes (first operation mode and second operation mode) of the variable capacitance element in the rotary input device according to the second embodiment are the first operation mode and the first operation mode shown in FIG. It is the same as 2 operation modes.

  FIG. 15 is a diagram showing pulse voltage supply patterns in the two operation modes shown in FIG. 14 and detection signal changes due to changes in the stop position. FIG. 16 is a diagram quantifying the state of the stop position represented by the combination of two detection signals corresponding to the two pulse voltage patterns (pattern A, pattern B) shown in FIG. When the numerical values of the patterns A and B are represented by symbols [A] and [B], the state ST is represented by the following equation.

[Equation 2]
ST = [A] + [B] × 5 (2)

  However, the numerical values “0”, “1”, and “2” in FIG. 15 are used as the values of [A] and [B], respectively, and the numerical values “−1” and “−2” are “3”. ”And“ 4 ”. Since the state ST at each stop position does not overlap as shown in the state transition of FIG. 17, one stop position can be determined from the state ST as in the first embodiment.

<Third Embodiment>
Next, a third embodiment of the present invention will be described.
In the rotary input device according to the first embodiment and the second embodiment described above, a plurality of detection signals Ds are generated by a plurality of pulse voltage supply patterns for the three variable capacitance elements (VC1 to VC3). The state of the stop position is determined from the combination of the change patterns generated in the plurality of detection signals Ds. On the other hand, in the rotary input device according to the present embodiment, the determination of the rotation direction of the operation unit 10 is determined based on one detection signal Ds obtained from a single pulse voltage supply pattern.

  In the rotary input device according to the present embodiment, the pulse voltage supply unit 100 has three stop positions (SP1 to SP3) when the operation unit 10 is rotated by three unit rotation angles from a predetermined stop position in a predetermined direction. , Pulse voltages are respectively supplied to the first variable capacitance element VC1 and the second variable capacitance element VC2 so that the three detection signals Ds generated by the detection signal generation unit 110 have different levels.

  FIG. 18 is a diagram for explaining a driving method of a variable capacitance element (a pair of fixed electrodes) in the rotary input device according to the third embodiment. The pulse voltage supply pattern (pattern A) shown in FIG. 18 is the same as the pulse voltage supply pattern in the first operation mode in FIGS. In the rotary input device according to the present embodiment, the pulse voltage supply unit 100 repeatedly executes the supply of the pulse voltage of the pattern A shown in FIG.

FIG. 19 is a diagram illustrating a pulse voltage supply pattern in the driving method illustrated in FIG. 18 and changes in the detection signal Ds due to a change in the stop position. FIG. 19A shows the polarities of the pulse voltages applied to the three variable capacitance elements (VC1, VC2, VC3) corresponding to the three stop positions (SP1, SP2, SP3). FIG. 19B shows the change of the detection signal when the operation unit 10 rotates from the stop position to another stop position for each reference stop position as “2”, “1”, “0”, “−1”. , “−2”.
FIG. 20 is a diagram illustrating a relative change in the level of the detection signal due to the change of the stop position, and shows a numerical value (FIG. 19B) of the level of the detection signal Ds. The numerical value on the vertical axis of the graph is a value when the reference stop position is “SP3”, but even when the reference stop position is “SP1” or “SP2”, the change in the numerical value represented by the graph is The pattern is similar.

  As can be seen from the graph of FIG. 20, the level change of the detection signal Ds when the rotation in the left direction occurs is “+1” or “−2”, and the detection signal Ds when the rotation in the right direction occurs. The level change is “−1” or “+2”. That is, the level change pattern of the detection signal Ds is different between the rotation to the left and the rotation to the right. This is because when the operation unit 10 is rotated in a certain direction from a predetermined stop position, the three variable capacitance elements (VC1 to VC3) so that the level of the detection signal Ds changes in a certain direction (upward or downward). ) Is supplied with a pulse voltage. In the example of FIG. 20, when the right rotation from the stop position SP2 to the stop position SP1, the level of the detection signal Ds decreases by “1”, and when the left rotation from the stop position SP1 to the stop position SP2 is performed. The level of the detection signal Ds increases by “1”.

The signal processing unit 120 determines the rotation direction of the operation unit 10 based on the change in the detection signal Ds corresponding to the change in the capacitance of the first variable capacitance element VC1 and the second variable capacitance element VC2.
Specifically, the signal processing unit 120 compares the detection signal Ds (subtraction of the reference value R from the initial detection signal Ds generated by the detection signal generation unit 110) with four predetermined threshold values. Then, it is determined whether the level of the detection signal Ds is “2”, “1”, “0”, “−1”, or “−2”. When the level of the detection signal Ds changes due to the rotation of the operation unit 10, the signal processing unit 120 determines that the rotation is in the right direction if the level change is “−1” or “+2”, and the level change occurs. If it is “+1” or “−2”, it is determined that the rotation is in the left direction.

According to the rotary input device according to the present embodiment, since the rotation direction of the operation unit 10 can be determined by a single pulse voltage supply pattern, the time required for determining the rotation direction can be shortened.
Note that, in the rotary input device according to the present embodiment, as in the rotary input devices according to the first and second embodiments described above, immediately after the stop position is unknown, it is immediately changed by one stop position. Although the stop position cannot be specified, the current stop position can be specified by referring to a plurality of stop position change histories.

  The present invention is not limited to the above embodiment, and various modifications obvious to those skilled in the art are possible.

  In the above-described embodiment, one variable capacitance element VC showing a large change in capacitance is provided at each of the three stop positions (SP1 to SP3), but the present invention is not limited to this example. In another embodiment of the present invention, a plurality of variable capacitance elements that exhibit a large change in capacitance at one stop position may be provided. By adding signals (charges) obtained from a plurality of variable capacitance elements, the level of the detection signal is increased, so that the detection sensitivity can be increased.

DESCRIPTION OF SYMBOLS 1 Operation area 2 Touch sensor 5 Base part 7 Support member 71 Flange part 10 Operation part 11 Edge part 15 Moderation mechanism 18 Bearing 100 Pulse voltage supply part 110 Detection signal generation part 120 Signal processing part 130 Storage part 200 Sensor part 210 Touch sensor Drive unit 220 Touch sensor detection unit 230 Control unit 250 Storage units EF1 to EF4 Fixed electrodes EM1 to EM8 Movable electrodes VC1 to VC3 Variable capacitance elements

Claims (9)

A base,
An operation unit rotatably supported by the base unit;
A plurality of movable electrodes provided at the operation unit and arranged at equal intervals on a circumference of a first virtual circle having the same distance from the rotation axis of the operation unit;
A unit rotation angle that is an angle obtained by dividing a central angle corresponding to an arc sandwiched between the positions of two adjacent movable electrodes on the circumference of the first virtual circle into N equal parts (N represents an integer of 3 or more). A moderation mechanism that suppresses rotation of the operation unit at a stop position set for each;
Provided on the base part, arranged on the circumference of a second virtual circle that moves in parallel with the first virtual circle with respect to the rotation axis, and the capacitance changes according to the positional relationship with the movable electrode A plurality of variable capacitance elements,
A pulse voltage supply unit for supplying a pulse voltage to each of the plurality of variable capacitance elements;
A detection signal generation unit that generates a detection signal according to charges accumulated in the plurality of variable capacitance elements by supplying the pulse voltage;
A signal processing unit that determines a rotation direction of the operation unit based on the detection signal,
The variable capacitance element has a capacitance at one stop position among N stop positions when the operation unit is rotated N steps from the one stop position in a certain direction by the unit rotation angle. Has a large capacitance difference with respect to the capacitance at the stop position,
The plurality of variable capacitance elements has at least one first capacitance that causes an increase in the capacitance difference at the stop position of the first step when the operation unit is rotated by three unit rotation angles from the predetermined stop position in a predetermined direction. 1 variable capacitance element, and at least one second variable capacitance element that causes an increase in the capacitance difference at the stop position of the second step,
The pulse voltage supply unit reverses the charge accumulated in the first variable capacitance element at the stop position of the first step and the charge accumulated in the second variable capacitance element at the stop position of the second step. Or supply the pulse voltage to have the same polarity and different magnitudes,
The detection signal generation unit generates the detection signal according to a sum of charges accumulated in the first variable capacitance element and the second variable capacitance element by supplying the pulse voltage, and performs the three-step rotation. In the stop position of the third step in the case, the detection signal having an intermediate value between the detection signal at the stop position of the first step and the detection signal at the stop position of the second step is generated,
The rotary input device, wherein the signal processing unit determines a rotation direction of the operation unit based on a change in the detection signal corresponding to a change in capacitance of the variable capacitance element. The plurality of variable capacitance elements cause at least one increase in the capacitance difference at a stop position of a third step when the operation unit is rotated by three unit rotation angles from the predetermined stop position in the predetermined direction by the unit rotation angle. Including a third variable capacitance element,
The pulse voltage supply unit
The charge accumulated in the first variable capacitance element at the stop position of the first step and the charge accumulated in the second variable capacitance element at the stop position of the second step have opposite polarities, or A first operation mode for supplying the pulse voltage to have the same polarity and different magnitudes; and
The charge accumulated in the second variable capacitance element at the stop position of the second step and the charge accumulated in the third variable capacitance element at the stop position of the third step have opposite polarities, or , Alternately repeating the second operation mode for supplying the pulse voltage so as to have the same polarity and different sizes,
The detection signal generator is
In the first operation mode, a first detection signal corresponding to a sum of charges accumulated in the first variable capacitance element and the second variable capacitance element is generated by supplying the pulse voltage, and the third step At the stop position, the first detection signal having an intermediate value between the first detection signal at the stop position of the first step and the first detection signal at the stop position of the second step is generated.
In the second operation mode, a second detection signal corresponding to a sum of charges accumulated in the second variable capacitance element and the third variable capacitance element by generating the pulse voltage is generated, and the first step At the stop position, the second detection signal having an intermediate value between the second detection signal at the stop position of the second step and the second detection signal at the stop position of the third step is generated.
The signal processing unit determines a rotation direction of the operation unit based on changes in the first detection signal and the second detection signal corresponding to a change in capacitance of the variable capacitance element. The rotary input device according to claim 1. The plurality of variable capacitance elements cause at least one increase in the capacitance difference at a stop position of a third step when the operation unit is rotated by three unit rotation angles from the predetermined stop position in the predetermined direction by the unit rotation angle. Including a third variable capacitance element,
The pulse voltage supply unit
The first charge accumulated in the first variable capacitance element at the stop position of the first step and the second charge accumulated in the second variable capacitance element at the stop position of the second step have opposite polarities. A first operation mode in which the pulse voltage is supplied so as to have the same polarity or different sizes;
The first charge is accumulated in the second variable capacitor at the stop position of the second step, and the second charge is accumulated in the third variable capacitor at the stop position of the third step. A second operation mode for supplying voltage; and
The first charge is accumulated in the first variable capacitor at the stop position of the first step, and the second charge is accumulated in the third variable capacitor at the stop position of the third step. The third operation mode for supplying voltage is repeated in order,
The detection signal generator is
In the first operation mode, a first detection signal corresponding to a sum of charges accumulated in the first variable capacitance element and the second variable capacitance element is generated by supplying the pulse voltage, and the third step At the stop position, the first detection signal having an intermediate value between the first detection signal at the stop position of the first step and the first detection signal at the stop position of the second step is generated.
In the second operation mode, a second detection signal corresponding to a sum of charges accumulated in the second variable capacitance element and the third variable capacitance element by generating the pulse voltage is generated, and the first step At the stop position, the second detection signal having an intermediate value between the second detection signal at the stop position of the second step and the second detection signal at the stop position of the third step is generated.
In the third operation mode, a third detection signal corresponding to a sum of charges accumulated in the first variable capacitance element and the third variable capacitance element is generated by supplying the pulse voltage, and the second step At the stop position, the third detection signal having an intermediate value between the third detection signal at the stop position of the first step and the third detection signal at the stop position of the third step is generated.
The signal processing unit determines a rotation direction of the operation unit based on changes in the first detection signal, the second detection signal, and the third detection signal corresponding to a change in capacitance of the variable capacitance element. The rotary input device according to claim 1, wherein: The signal processing unit includes a detection signal obtained by subtracting the second detection signal from the first detection signal, a detection signal obtained by adding the second detection signal and the third detection signal, and the The rotary input device according to claim 3, wherein the rotation direction of the operation unit is determined based on a change in a detection signal obtained by adding the first detection signal and the third detection signal. A base,
An operation unit rotatably supported by the base unit;
A plurality of movable electrodes provided at the operation unit and arranged at equal intervals on a circumference of a first virtual circle having the same distance from the rotation axis of the operation unit;
A unit rotation angle that is an angle obtained by dividing a central angle corresponding to an arc sandwiched between the positions of two adjacent movable electrodes on the circumference of the first virtual circle into N equal parts (N represents an integer of 3 or more). A moderation mechanism that suppresses rotation of the operation unit at a stop position set for each;
Provided on the base part, arranged on the circumference of a second virtual circle that moves in parallel with the first virtual circle with respect to the rotation axis, and the capacitance changes according to the positional relationship with the movable electrode A plurality of variable capacitance elements,
A pulse voltage supply unit for supplying a pulse voltage to each of the plurality of variable capacitance elements;
A detection signal generation unit that generates a detection signal according to charges accumulated in the plurality of variable capacitance elements by supplying the pulse voltage;
A signal processing unit that determines a rotation direction of the operation unit based on the detection signal,
The variable capacitance element has a capacitance at one stop position among N stop positions when the operation unit is rotated N steps from the one stop position in a certain direction by the unit rotation angle. Has a large capacitance difference with respect to the capacitance at the stop position,
The pulse voltage supply unit includes three detection signals generated by the detection signal generation unit at three stop positions when the operation unit is rotated by three unit rotation angles from a predetermined stop position in a predetermined direction. Supplying a pulse voltage to each of the plurality of variable capacitance elements so that the signals have different levels;
The signal processing unit determines a rotation direction of the operation unit based on a change in the detection signal corresponding to a change in capacitance of the variable capacitance element. A plurality of fixed electrodes provided on the base and disposed on the circumference of the second virtual circle;
A pair of the fixed electrodes adjacent on the circumference of the second virtual circle constitutes the variable capacitance element,
Each fixed electrode in the pair of fixed electrodes is provided at a position where it can overlap with the common movable electrode when viewed from a direction parallel to the rotation axis when the operation unit is at the stop position.
The rotary input device according to claim 1, wherein the rotary input device is a rotary input device. The signal processing unit
Determining a change pattern of the detection signal based on a difference between a reference value and the detection signal, determining a rotation direction of the operation unit based on the determined change pattern;
If the change in the detection signal does not continuously occur for a certain time, the previous reference value is updated to a new reference value based on the average value of the detection signal after the last change in the detection signal has occurred. The rotary input device according to claim 1, wherein the rotary input device is a rotary input device. The signal processing unit
Based on a series of determination results of the rotation direction, the current stop position is determined based on the three stop positions when the operation unit is rotated by three unit rotation angles from the predetermined stop position to the predetermined direction. Determine which is,
The reference value is updated based on the detection signal generated at the current stop position when the current stop position is equal to the stop position when the reference value is updated. The rotary input device described in 1. The signal processing unit has a difference between the detection signal generated at the current stop position and the reference value even when the current stop position is equal to the stop position when the reference value is updated. The rotary input device according to claim 8, wherein updating of the reference value using the detection signal is stopped if the threshold value is larger than the predetermined threshold value.

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