JP5746582B2 - INPUT DETECTING DEVICE, ITS CONTROL METHOD, PROGRAM, AND RECORDING MEDIUM - Google Patents

Description

  The present invention relates to a capacitance type input detection device, a control method therefor, a program, and a recording medium, and more particularly to a technique for detecting a moving direction of an operation member in a capacitance type sensor.

  2. Description of the Related Art In recent years, a touch panel display that can be operated by a user directly touching a display area with a finger is used in an electronic device having a display device such as a mobile phone, a car navigation system, and a digital camera. Various methods such as a capacitance method, a resistive film method, and an optical method have been proposed as methods for detecting user input in such a touch panel. A suitable detection method is selected in accordance with the use of the electronic device. Among them, the capacitance method is widely used because it has advantages in terms of detection accuracy and multipoint detection.

  In a touch panel display using a capacitance method, for example, as shown in FIG. 3A, a capacitive component of a person's ground (earth) is detected, that is, a conductor having a ground potential (GND) is used as a sensor. A method of detecting a change in capacitance caused by proximity is used. Such a capacitive sensing technique is applied not only to a touch panel display.

  Consider a case where a sensor electrode 301 as a sensor pattern and a conductor 302 having a ground potential are provided as shown in FIG. At this time, when the conductor 303 is brought close to the sensor electrode 301 and the conductor 302, the sensor electrode 301 and the conductor 303, and the conductor 302 and the conductor 303 are electrostatically coupled to each other. A closed circuit as shown in FIG. 3C is formed. That is, when the conductor 303 is brought close to the sensor electrode 301 and the conductor 302, the capacitance detected by the capacitance sensor IC 304 increases more than before the electrostatic coupling is performed. When this principle is used, for example, when a plurality of sensor electrodes 301 are arranged in the movable range of the conductor 303 and each capacitance can be detected independently, the sensor electrode 301 having an increased capacitance. The presence of the conductor 303 can be detected.

  In Patent Document 1, in an input device that detects rotational input, a rotation angle is detected by detecting a change in capacitance caused by a conductor that moves with the rotation of electrodes arranged in a rotational direction. Alternatively, a method for detecting the rotation direction is disclosed.

JP 2001-296966 A

  In Patent Document 1 described above, when the conductor that moves as the operation member rotates overlaps the sensor electrode, the capacitance is increased due to electrostatic coupling between the conductor and the sensor electrode. The sensor electrode where the conductor is located is detected.

  By the way, since the capacitance fluctuates depending on conditions such as the environmental temperature, in order to detect the change in capacitance due to the movement of the conductor, for example, calibration is performed at the start of the sensor, and each sensor electrode at the time of calibration is detected. Is used as a reference value. Specifically, depending on whether the amount of change in capacitance from the reference value exceeds a threshold value of capacitance that can discriminate between a state in which a conductor is present on the sensor electrode and a state in which a conductor is not present, It is determined whether or not the capacitance changes due to the movement of the body.

  Since the electrostatic coupling between the sensor electrode and the conductor increases depending on the overlapping area of the sensor electrode and the conductor, the conductor is basically configured to have substantially the same width as one sensor electrode, When the calibration is performed, it is assumed that one conductor is in a state of being substantially overlaid on one sensor electrode. In other words, by performing calibration when each of the plurality of sensor electrodes is in a state where the conductors overlap almost the whole surface or not at all, the movement of the conductor can be detected using the above threshold value. .

  However, since the conductor moves in analog with the physical operation member, depending on the state of the operation member, the conductor does not overlap the entire sensor surface, that is, two adjacent sensor electrodes. There are times when it stops overlaid. At this time, each of the two sensor electrodes that are overlapped across the conductor is electrostatically coupled to a conductor having a smaller area than the state of being overlapped over the entire surface, and the capacitance is increased. Become. Therefore, if calibration is performed in this state and the capacitance detected by each of the two sensor electrodes is set as a reference value, the two sensor electrodes are in a state in which the conductors are substantially overlapped on the entire surface or In a state where the conductors do not overlap at all, there is a possibility that the amount of change in the capacitance does not exceed the threshold value and the movement of the conductor cannot be detected.

  The present invention has been made in view of the above-described problems, and in a capacitance-type input detection device, it is possible to avoid a state in which the movement of a conductor to be detected cannot be detected due to a calibration failure. An object of the present invention is to provide an input detection device, a control method therefor, a program, and a recording medium.

In order to achieve the above-described object, the input detection device of the present invention includes:
A first conductor whose position is changed in the movable direction in accordance with the movement of the operation member;
3 or more detection electrodes, each of which is capable of independently detecting a capacitance and sequentially arranged in the moving direction of the first conductor, and at least excluding one or more of the three or more detection electrodes Three or more detection electrodes spaced apart from the first conductor so that any one of the detection electrodes is electrostatically coupled to the first conductor;
Detection means for detecting capacitance for each of the three or more detection electrodes;
Setting means for setting a first threshold value lower than the reference value and a second threshold value higher than the reference value for the reference value of each of the three or more detection electrodes;
The moving direction of the first conductor depends on whether the capacitance detected by the detection means has changed across the first threshold and whether there has been a change across the second threshold. Determining means for determining
When the detection means detects a state where the capacitance is lower than the first threshold value in the plurality of detection electrodes, or a state where the capacitance is higher than the second threshold value in the plurality of detection electrodes. And a correction means for correcting the reference value.

  With such a configuration, according to the present invention, it is possible to avoid a state in which the movement of the conductor to be detected cannot be detected due to a calibration failure in the capacitance type input detection device.

1 is a block diagram showing a functional configuration of a digital camera according to an embodiment of the present invention. The figure which showed the external appearance of the digital camera containing the operation member based on embodiment of this invention Diagram for explaining capacitive sensing method The figure which showed the structure of the rotation operation part 201 which concerns on Embodiment 1 of this invention. Another figure showing composition of rotation operation part 201 concerning Embodiment 1 of the present invention. The state transition diagram which showed the relationship between the conductor 420 and the board | substrate 430 which change with rotation operation of the operation member based on Embodiment 1 of this invention. The figure which showed the mode of the change from the starting time of each electrostatic capacitance in each detection electrode 432 which changes with rotation operation of the operation member based on Embodiment 1 of this invention. The figure which showed the relationship between the conductor 420 and the board | substrate 430 which fail in the calibration which concerns on Embodiment 1 of this invention. The figure which showed the mode of the change from the time of starting of the electrostatic capacitance in each detection electrode 432 which changes with rotation operation of the operation member at the time of the calibration which concerns on Embodiment 1 of this invention failing The figure which showed the mode of the change of the electrostatic capacitance in each detection electrode 432 in the case of re-calibrating in the middle which changes with rotation operation of the operation member which concerns on Embodiment 1 of this invention. The figure which showed the mode of the change from the time of starting of the electrostatic capacitance in each detection electrode 432 which changes with rotation operation of the operation member in case the environmental temperature which concerns on Embodiment 2 of this invention changes. The figure which showed the mode of the change of the electrostatic capacitance in each detection electrode 432 in the case of recalibrating in the middle which changes with rotation operation of the operation member in case the environmental temperature which concerns on Embodiment 2 of this invention changes. The figure which showed the structure of the rotation operation part 201 which concerns on the modification of this invention. The figure which showed the structure of the slider 202 which performs the movement detection of an electrostatic capacitance system

[Embodiment 1]
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. In addition, one embodiment described below describes an example in which the present invention is applied to a sensor unit capable of detecting movement of an operation member provided in a digital camera as an example of an input detection device by a capacitance method. To do. However, the present invention can be applied to any device that can detect the movement of an object by a capacitance method.

<Functional configuration of digital camera 100>
FIG. 1 is a block diagram showing a functional configuration of a digital camera 100 according to an embodiment of the present invention.

  The CPU 101 controls the operation of each block included in the digital camera 100. Specifically, the CPU 101 controls the operation of each block of the digital camera 100 by reading, for example, a program for detecting a moving direction (to be described later) from the ROM 102 and developing the program in the RAM 103 for execution.

  The ROM 102 is, for example, a rewritable nonvolatile memory, and stores setting parameters and the like necessary for the operation of each block in addition to a moving direction detection processing program described later. In the present embodiment, the ROM 102 uses two predetermined threshold values (first threshold value and second threshold value) that are used in the movement direction detection process to determine each increase and decrease in capacitance due to movement. As the information, the widths from the reference values of the two types of threshold values are stored.

  The RAM 103 is, for example, a volatile memory, and is used not only as a development area for a program for moving direction detection processing but also as a storage area for temporarily storing intermediate data output in the operation of each block.

  The display unit 104 is a display device provided in the digital camera 100 such as a small LCD, for example, and displays an image signal output from an imaging unit (not shown) or image data recorded on a recording medium (not shown). Since the present invention detects the moving direction of the operation member in the sensor unit 110 described later, detailed description of the processing related to imaging and the processing related to image display is omitted.

  The operation input unit 105 is an operation member provided in the digital camera 100, such as a rotation operation unit 201, a slider 202, and a power switch 203 as illustrated in FIG. In the present embodiment, among the illustrated operation members, for example, rotation (movement) generated by a user operating a rotation operation unit 201 that is a rotary encoder is detected by a capacitive sensor unit 110. To do.

  The sensor unit 110 includes a capacitance sensor IC 111 that can detect the capacitance of each of the sensor electrodes 112 that are three or more detection electrodes arranged in the rotation operation unit 201. The capacitance sensor IC 111 can arbitrarily detect a change in capacitance with respect to the ground, applies a voltage to the sensor electrode 112, and periodically monitors the capacitance of each sensor electrode 112.

  In the present embodiment, the capacitance sensor IC 111 calibrates the sensor electrode 112 when the digital camera 100 is activated, detects each capacitance of the sensor electrode 112, and uses a sensor (not shown) as a reference value for each sensor electrode. Store in RAM. In addition, the capacitance sensor IC 111 receives notification of threshold information stored in the ROM 102 from the CPU 101, and based on the notification, the lower threshold (first threshold) and the upper threshold (with respect to the reference value of each sensor electrode) (Second threshold) is set. Then, the capacitance sensor IC 111 notifies the CPU 101 of an interrupt when any capacitance of the sensor electrode 112 crosses either the lower threshold value or the upper threshold value. As described above, the sensor unit 110 according to the present embodiment can detect the presence or absence of the movement of the operation member by monitoring the change in capacitance from the reference value for each detection electrode, and notify the CPU 101 of it. Upon receiving the notification, the CPU 101 requests the sensor unit 110 to output information on the capacitance state of each detection electrode, and uses the information to determine the moving direction of the operation member as will be described later. .

  In the present embodiment, the information on the first threshold value and the second threshold value will be described below on the assumption that the CPU 101 reads the information from the ROM 102 and transmits it to the capacitance sensor IC 111 after the digital camera 100 is activated. However, the threshold information may be stored in advance in a nonvolatile memory (not shown) built in the sensor unit 110, for example.

  In this embodiment, the CPU 101 is described as determining the rotation direction of the rotation operation unit 201 that is an operation member from the information on the capacitance change for each detection electrode output from the sensor unit 110. This determination is not limited to this. For example, the capacitance sensor IC 111 may determine and output the movement direction along with the detection of movement, or the CPU 101 may monitor and move the capacitance of each detection electrode as in the capacitance sensor IC 111. The configuration may be such that the direction is determined.

(Configuration of the rotation operation unit 201)
Here, the configuration of the rotation operation unit 201 will be described in detail below with reference to the drawings.

  As shown in the cross-sectional view of FIG. 4A, the rotation operation unit 201 has a SET button 440 in the center, a movable unit 400 having the SET button 440 central axis as a rotation axis, a guide ring 410, a conductor 420, And a substrate 430.

  The movable part 400 is a rotatable member that can be moved by a rotation operation by the user with the circumferential direction as the movable direction as shown in FIG. A conductor 420 described later is configured to rotate together with the movable portion 400.

  The guide ring 410 is a fixed member provided so as to perform the rotational movement of the movable part 400 in a predetermined movement unit as shown in FIG. On the same plane as the guide ring 410, there are a spring 411 provided in the radial direction of the rotation axis of the SET button 440 and a ball 412 provided at one end of the spring 411, and the other end of the spring 411 is a movable part. 400 is fixed. A concave portion 413 and a convex portion 414 are provided periodically and continuously on the inner circle side of the guide ring 410, and the ball 412 is urged in the radial direction by a spring 411 so as to be fitted into the concave portion 413. The spring 411 is supported by a guide 415 so that the spring 411 is not bent by the rotational movement of the movable portion 400 and the urging direction does not change.

  In this way, when the movable part 400 rotates so that the ball 412 moves from the concave part 413 over the convex part 414 to the adjacent concave part 413, the ball 412 is in any concave part by the elastic force of the spring 411. Resistive force is generated in the movable portion 400 so as to be fitted into 413. That is, the rotational movement of the movable part 400 is basically performed with the angle defined by the interval between the concave parts 413 as a unit of movement. In one rotation of the moving unit, the ball 412 that has been in the concave portion 413 in the steady state reaches the different concave portion 413 in the steady state again via the convex portion 414 in the transient state. Note that an impact generated when the spring 411 is fitted into the recess 413 by this resistance force is perceived by the user via the movable portion 400, and thus a suitable operation feeling (click feeling) can be given to the user.

  The conductor 420 (first conductor) is electrostatically coupled when it overlaps with each detection electrode of the sensor electrode 112 as shown in FIG. 4D, and causes a change in capacitance to the detection electrode. It is a member that moves as the movable part 400 moves. The conductor 420 includes a GND facing portion 421 provided around the SET button 440 and a plurality of blade-shaped detection electrode facing portions 422 extending radially from the GND facing portion 421, each of which has a GND pattern on the substrate 430 described later. 431 and the detection electrode 432 are electrostatically coupled.

  The substrate 430 is a circuit board on which a plurality of detection electrodes 432 that are sensor electrodes 112 and a GND pattern 431 that is a conductor having a ground potential are arranged as shown in FIG. The conductor 420 and the substrate 430 are arranged so that the GND facing portion 421 and the GND pattern 431 and the detection electrode facing portion 422 and the detection electrode 432 face each other with a predetermined interval.

  A voltage is applied to each of the detection electrodes 432 from the capacitance sensor IC111, and the capacitance is regularly detected by the capacitance sensor IC111 as described above. The size of one detection electrode 432 in the circumferential direction is defined by a rotational resolution that is a unit of rotational movement of the movable unit 400. That is, the sensor unit 110 needs to detect that a change in electrostatic capacitance has occurred in the detection electrode 432 when the movable unit 400 is rotated by the movement unit. It is defined by the rotation angle for the moving unit. Similarly, the size in the circumferential direction of one detection electrode facing portion 422 of the conductor 420 that opposes the detection electrode 432 is also defined by the rotation angle corresponding to 400 movement units.

  Furthermore, in a state where the ball 412 is fitted in one recess 413, the area where one detection electrode facing portion 422 and one detection electrode 432 overlap is maximized. That is, when attention is paid to one detection electrode 432, when the ball 412 is fitted in the recess 413 during the movement of the movable portion 400, the detection electrode 432 does not face the one detection electrode facing portion 422 at all. , It shall be one of the states where almost the entire surface is opposed.

  Note that the capacitance is proportional to the area where the opposing conductors (the GND facing portion 421, the GND pattern 431, the detection electrode facing portion 422, and the detection electrode 432) overlap with each other, so that the amount of change in the capacitance is small depending on the rotational resolution. Therefore, there is a possibility that the movement of the operation member cannot be detected. Therefore, the plurality of detection electrodes 432 are classified into a group composed of a predetermined number of detection electrodes as shown in FIG. 4E, and the detection electrode facing portions 422 are the same as shown in FIG. 4D. Are configured to overlap simultaneously with a predetermined number of detection electrodes classified into the group. In the example of FIG. 4E, the plurality of detection electrodes 432 are classified into four groups a, b, c, and d, and the detection electrodes 432 of each group are a, b, c, d in the circumferential direction. Are periodically circulated in this order. In the figure, the rotation angle corresponding to the movement unit of the movable unit 400 is 18 degrees, and 20 detection electrodes 432 are arranged in the circumferential direction, so that five detection electrodes 432 are classified into one group. . That is, the conductor 420 is provided with the five detection electrode facing portions 422 so as to simultaneously overlap the detection electrodes 432 classified into the same group.

  In the present embodiment, as shown in the figure, the capacitance sensor IC 111 has a plurality of detection electrodes 432 that are sensor electrodes 112 classified into four groups of a, b, c, and d. It is assumed that it is detected. That is, the detection electrodes 432 classified into each group are connected as shown in FIG. 5, and the capacitance sensor IC 111 detects the total capacitance of the detection electrodes 432 for each group.

  In order to detect whether the moving direction of the movable part 400 is the positive direction or the negative direction, it is necessary to detect a change in capacitance with each of at least three detection electrodes. For this reason, when the detection electrodes 432 are classified into groups as in the present embodiment, they are classified into three or more groups. It will be readily understood that the detection electrodes 432 need not necessarily be classified into groups, such as when the rotational resolution of the movable unit 400 is small. Hereinafter, when one detection electrode is referred to, it means one group of detection electrodes.

  In addition, the predetermined distance formed between the conductor 420 and the substrate 430 is a distance at which the opposing devices can be electrostatically coupled. In this embodiment, after the digital camera 100 is activated, one of the plurality of detection electrodes 432 is always electrostatically coupled to the detection electrode facing portion 422 of the conductor 420. In addition, the GND facing portion 421 and the GND pattern 431 are always opposed to each other, and are configured such that the facing area does not change, that is, the capacitance does not change.

<Rotation operation detection principle of the rotation operation unit 201>
The principle of detecting the direction of the rotation operation of the rotation operation unit 201 performed by the user in the digital camera 100 of the present embodiment having such a configuration will be described below in detail with reference to the drawings.

  FIG. 6 is a diagram illustrating transition of the relationship between the conductor 420 and the substrate 430 when the movable unit 400 of the rotation operation unit 201 is rotated clockwise by the user. Here, the conductor 420 is arranged in the state of FIG. 6A when the digital camera 100 is activated, and FIG. 6A → (b) → (c) → (d) → (a) by rotation operation. The change in capacitance of each detection electrode (group) when transitioning to... Will be described. The capacitance sensor IC 111 calibrates each detection electrode of the sensor electrode 112 at the time of activation, and stores the capacitance of each detection electrode in the sensor RAM as a reference value.

  FIG. 7 is a diagram showing the amount of change from the capacitance (reference value) detected when the digital camera 100 is activated for each of the detection electrodes (groups) 432a, b, c, and d. Each of the periods 710, 711, 712, 713, and 714 is a period in which the conductor 420 and the substrate 430 are in the states of FIGS. 6 (a), (b), (c), (d), and (a). It corresponds.

  A period 710 is a state in which the movable unit 400 is not rotated from the state in which the electrostatic capacitance is detected for each detection electrode when the digital camera 100 is activated. At this time, if there is no change in environmental conditions such as temperature, the capacitance detected for each detection electrode is substantially equal to the reference value.

  When the relationship between the conductor 420 and the substrate 430 transitions from the state of FIG. 6A to the state of FIG. 6B, the capacitance changes to the value of the period 711. Specifically, the detection electrode facing portion 422 that overlaps the detection electrode 432a overlaps the detection electrode 432b that did not overlap in the period 710, and does not overlap the detection electrode 432a at all, as shown in FIG. The capacitances of the detection electrodes 432a and b change. The capacitance detected by the detection electrode 432a decreases to less than the reference value because the capacitance that has been increased by the electrostatic coupling with the detection electrode facing portion 422 at the time of activation decreases because the electrostatic coupling is released. . Further, the capacitance detected for the detection electrode 432b was not electrostatically coupled at the time of startup, but increased due to the electrostatic coupling opposed to the detection electrode facing portion 422 due to the rotational movement of the movable portion 400, thereby increasing the reference value. It is super.

  Similarly, when the relationship between the conductor 420 and the substrate 430 transitions from the state of FIG. 6B to the state of FIG. 6C, the capacitances of the detection electrode 432b and the detection electrode 432c change from the value of the period 711 to the period. It changes to a value of 712. Further, when the relationship between the conductor 420 and the substrate 430 is changed from the state of FIG. 6C to the state of FIG. 6D, the capacitances of the detection electrode 432c and the detection electrode 432d are changed from the value of the period 712 to the period 713. Changes to the value of. When the relationship between the conductor 420 and the substrate 430 is changed from the state of FIG. 6D to the state of FIG. 6A, the capacitances of the detection electrode 432d and the detection electrode 432a are changed from the value of the period 713 to the period 714. And return to the same capacitance as in the period 710.

  That is, for each detection electrode, the rotation operation performed on the movable portion 400 can be detected from the amount of change from the capacitance detected when the digital camera 100 is activated. Specifically, as the movable part 400 rotates, the electrostatic capacity of at least one of the detection electrodes 432 decreases, and at the same time, the electrostatic capacity of at least one of the detection electrodes 432 increases.

  In this embodiment, in order to distinguish between a change in capacitance that occurs due to the movement of the conductor 420 and a change in capacitance due to measurement variations at the time of detection, the amount of change in capacitance from the time of startup. Is set to an upper threshold 715 (second threshold) and a lower threshold 716 (first threshold). The capacitance sensor IC 111 detects the amount of change in capacitance from the time of activation when both the detection electrode straddling the first threshold and the detection electrode straddling the second threshold are detected. Notify interrupt.

  In the example of FIG. 7, in the period 711, the capacitance of the detection electrode 432a is equal to or lower than the lower threshold set with respect to the reference value, and the capacitance of the detection electrode 432b is set with respect to the reference value. The value is equal to or higher than the upper threshold value. Similarly, in the period 712, the capacitance of the detection electrode 432a is equal to or lower than the lower threshold value, and the capacitance of the detection electrode 432c is equal to or higher than the upper threshold value. In the period 713, the capacitance of the detection electrode 432a is a value equal to or lower than the lower threshold value, and the capacitance of the detection electrode 432d is equal to or higher than the upper threshold value.

  Note that the first threshold value and the second threshold value may be values that can detect the rotation of the moving unit 400 of the movable unit 400, and are the same values when the absolute value of the difference from the reference value is taken. Or a different value.

  When the CPU 101 receives an interrupt notification from detecting the rotation of the movable unit 400 from the capacitance sensor IC 111, the CPU 101 performs reading from the sensor unit 110. At this time, the reading from the sensor unit 110 may be the value of the amount of change in capacitance, or the detection electrode whose capacitance is equal to or higher than the upper threshold and the capacitance is equal to or lower than the lower threshold. It may be information on which (a group) the detection electrode is. The determination of the rotation direction caused by the rotation operation of the movable unit 400 of the rotation operation unit 201 only needs to include information on whether or not a change in capacitance due to movement has occurred. For this reason, in this embodiment, a method for determining the rotation direction using information on which detection electrode has a capacitance equal to or higher than the upper threshold value and which detection electrode has a capacitance equal to or lower than the lower threshold value. explain.

  When the relationship between the conductor 420 and the substrate 430 is changed as shown in FIG. 6A → (b) → (c) → (d) → (a), the capacitance sensor IC 111 has a capacitance in each state. A detection electrode straddling the upper threshold and a detection electrode straddling the lower threshold are detected, and an interrupt is notified to the CPU 101. The CPU 101 receives the interrupt notification, acquires information on the detection electrode from the sensor unit 110 in each period, and stores the information in the RAM 103.

  At this time, by calculating the difference in the amount of change in capacitance or the difference in capacitance between the states that are determined to have moved, it is possible to calculate the upper Information on the detection electrode 432 whose capacitance has decreased across the threshold or the lower threshold and information on the detection electrode 432 whose capacitance has increased across the upper threshold or the lower threshold can be acquired. In other words, the detection electrode 432 whose capacitance has fallen across any threshold is the detection electrode that the detection electrode facing portion 422 is opposed to before the rotation, and the capacitance across any threshold. The detection electrode 432 having increased is a detection electrode opposed to the detection electrode facing portion 422 in the rotated state. For this reason, the moving direction of the conductor 420 moved by the rotation operation is changed from the detection electrode 432 whose capacitance has decreased across any threshold to the detection electrode 432 whose capacitance has increased across any threshold. It can be determined that the direction is heading.

<Capacitance change when calibration fails>
In the rotation operation detection principle described above, by providing two threshold values for the reference value of each detection electrode at the time of calibration, the rotation of the movement unit of the conductor 420 by the rotation operation of the movable unit 400 and the conductor 420 are performed. The direction of rotation is determined. However, in this determination, as shown in FIG. 6A, only one of the four types of detection electrodes 432a to 432d is electrostatically coupled to the detection electrode facing portion 422, and the other detection electrodes 432 are The calibration can be performed accurately when the detection electrode facing portion 422 is not opposed to the detection electrode facing portion 422 and is not electrostatically coupled. The threshold value set for the capacitance (reference value) from the calibration is the entire surface from the state in which the detection electrode 432 does not oppose the detection electrode facing portion 422 from the entire surface or from the state in which it does not oppose at all. It is set to discriminate that it is in a state of opposing. For this reason, the reference value of the capacitance for each detection electrode needs to be acquired in a state where it is opposed to the entire surface of the detection electrode facing portion 422 or in a state where it is not opposed at all.

  The rotation operation unit 201 of the present embodiment is configured such that when the movable unit 400 is rotated as described above, the ball 412 transiently passes through the projection 414 and fits into the recess 413. . However, for example, as shown in FIG. 8, when calibration is performed in a state in which the movable portion 400 is held by the user without the ball 412 being fitted into the recess 413 or in a state where the ball is stopped by the bias of the spring 411, And the direction of rotation cannot be determined.

  In FIG. 9, the conductor 420 is arranged in the state of FIG. 8 when the digital camera 100 is started. FIG. 8 → FIG. 6 (a) → (b) → (c) → (d) → (a )... Are diagrams showing the amount of change from the reference value detected for each of the detection electrodes (groups) 432a, b, c, and d. In each period 910, 911, 912, 913, 914, and 915, the conductor 420 and the substrate 430 are shown in FIGS. 8, 6 (a), 6 (b), (c), (d), and (a). Corresponds to a period that is a state.

  When the conductor 420 is in the state of FIG. 8, the detection electrode facing portion 422 is electrostatically coupled across the detection electrodes 432a and d. That is, the detection electrodes 432a and d are smaller than the capacitance when the respective detection electrodes 432 are opposed to the detection electrode facing portion 422 over the entire surface, but are larger than the capacitance when they are not opposed at all. Capacitance will be detected. When calibration is performed at this time and the capacitance of each detection electrode 432 is set as a reference value, the state of change in capacitance of each detection electrode when transitioning to each state is as shown in FIG. Is different.

  When the relationship between the conductor 420 and the substrate 430 transitions from the state of FIG. 8 to the state of FIG. 6A, the capacitance changes to the value of the period 911. Specifically, the detection electrode facing portion 422 that overlaps the detection electrodes 432a and d overlaps the detection electrode 432a and does not overlap the detection electrode 432d at all, so that the detection electrodes 432a and d of FIG. The capacitance changes. The capacitance detected with respect to the detection electrode 432a increases because the capacitance that has been increased by electrostatic coupling with a part of the surface of the detection electrode facing portion 422 at the time of startup is further electrostatically coupled over the entire surface. Exceeds the reference value. Further, the electrostatic capacitance detected for the detection electrode 432d is reduced because the electrostatic capacitance that has been increased by electrostatic coupling with a part of the surface of the detection electrode facing portion 422 at the time of activation is released. And become less than the reference value. However, none of them is a change from the state in which the detection electrode 432 does not oppose the detection electrode facing portion 422 to the state in which the detection electrode 432 opposes the entire surface, or the state in which the detection electrode 432 opposes the entire surface to the state in which it does not oppose at all. The change width of the electrostatic capacitance in the detection electrodes 432a and d becomes small.

  In the example of FIG. 9, the capacitance detected for the detection electrode 432a in the period 911 does not exceed the upper threshold value, and only the capacitance detected for the detection electrode 432d is lower than the lower threshold value. That is, the capacitance sensor IC 111 can detect the transition to the state of FIG. 6A by the change in the capacitance of the detection electrode 432d, but the rotation direction of the movable portion 400 at that time, that is, the conductive state. The rotation direction of the body 420 cannot be known.

  In the example of FIG. 9, the capacitance detected in the period 911 for the detection electrode 432d is below the lower threshold value. However, the capacitance detected for the detection electrode 432d does not become lower than the lower threshold depending on the area where the detection electrode 432 faces the detection electrode facing portion 422 and the lower threshold during calibration. That is, the capacitance sensor IC 111 may not be able to detect even that the conductor 420 has transitioned to a steady state.

  On the other hand, in order to detect the rotation direction of the conductor 420 by the rotation operation, at least the detection amount 432 in which the change amount of the capacitance crosses the upper threshold and the change amount of the capacitance crosses the lower threshold value. When both of the detection electrodes 432 are detected, it is determined that the transition from the steady state to the steady state has been made.

  In the example of FIG. 9, when a transition is made from the steady state to the state of FIG. 6B through the state of FIG. 8 during the period 912, that is, the state of FIG. 6A, the steady state is changed to the steady state. It is determined that the transition has been made. When the state of FIG. 8 and the state of FIG. 6B are directly compared, the detection electrode facing portion 422 that overlaps the detection electrodes 432a and d overlaps the detection electrode 432b that did not overlap in the period 910, and the detection electrode Since the electrodes 432a and d do not overlap at all, the capacitances of the detection electrodes 432a, b, and d change as shown in FIG. At this time, the capacitance detected for the detection electrodes 432a and d is increased by electrostatic coupling with a part of the surface of the detection electrode facing portion 422 at the time of activation, and the electrostatic coupling is released. As a result, it falls to below the reference value. The electrostatic capacitance detected for the detection electrode 432b was not electrostatically coupled at the time of startup, but increased because the electrostatic coupling was performed against the detection electrode facing portion 422 by the rotational movement of the movable portion 400, and the reference electrode It's over time.

  However, in this case, a plurality (a and d) of detection electrodes 432 whose capacitance change amount is equal to or lower than the lower threshold value appear. However, such a phenomenon does not occur when calibration is correctly performed in a steady state.

  In the present embodiment, the capacitance sensor IC 111 fails in the calibration when the capacitance is equal to or higher than the upper threshold value or lower threshold value set for each of the two or more (plural) detection electrodes. It is assumed that the process is performed, and calibration is performed again.

  Similarly to the example of FIG. 9, when the relationship between the conductor 420 and the substrate 430 changes from FIG. 8 → FIG. 6A → (b) → (c) → (d) → (a). , The number of detection electrodes whose capacitance is equal to or lower than the lower threshold value is 2 or more. At this time, when the capacitance sensor IC 111 performs calibration again, the capacitance detected in the period 912 becomes a new reference value in the period 920 after calibration as shown in FIG. Also, an upper threshold value and a lower threshold value are set for the new reference value. By doing so, in the period 921 in which the state transitions from the state shown in FIG. 6B to the state shown in FIG. 6C, the amount of change in capacitance straddles the upper threshold as in the case where the calibration is correctly performed. One detection electrode and one detection electrode straddling the lower threshold are detected one by one. That is, the rotation of the conductor 420 and the rotation direction can be determined.

<Capacitance change in transient state>
As described above, the movable portion 400 is configured to reach a steady state in which the ball 412 is fitted into the concave portion 413 of the guide ring 410 by the spring 411 and the ball 412. Let us consider a case where the movable unit 400 moves from a steady state different from a steady state by a user operation, that is, moves from the concave portion 413 into which the ball 412 is inserted to a different concave portion 413 adjacent to the convex portion 414. At this time, depending on the values of the upper threshold value and the lower threshold value described above, the capacitance acquired by the capacitance sensor IC 111 for each of the detection electrodes 432 in the transient state where the ball 412 is on the convex portion 414 is equal to or higher than the upper threshold value or May be below the lower threshold.

  For this reason, in the sensor unit 110 of the present embodiment, in order to determine whether the movable unit 400 is in a steady state or in a transient state, detection that the amount of change in capacitance is greater than or equal to the upper threshold value or less than the lower threshold value. The time during which it is determined that the electrode is present is measured, and when it is determined that the electrode is present for a predetermined time (for example, about several milliseconds to several hundred milliseconds), it is determined that the movable unit 400 is in a steady state. May be. That is, the mechanism having the guide ring 410 described above is in a transient state because the ball 412 does not stay on the convex portion 414 and moves to the concave portion 413 basically by the bias of the spring 411. Time is considered a short time. For this reason, if the time during which the determination that the detection electrode having the capacitance change amount is equal to or higher than the upper threshold or lower is present is less than the predetermined time, the detection is assumed to be in a transient state. It may not be determined whether or not the calibration has failed. It should be noted that whether or not the time during which a detection electrode whose capacitance change is equal to or greater than the upper threshold or less than the lower threshold continues for a predetermined time or longer continues is not limited to time measurement, but is detected by the capacitance sensor IC111. Depending on the sampling rate at which the capacitance value is acquired from the electrode 432, the determination may be made based on how many times the same capacitance state is detected.

  As described above, the capacitance-type input detection device according to this embodiment can avoid a state in which the movement of the conductor to be detected cannot be detected due to a calibration failure.

[Embodiment 2]
In the first embodiment described above, recalibration is performed when the number of detection electrodes whose capacitance is equal to or higher than the upper threshold and lower than or equal to the lower threshold is two or more (plural) due to the failure of calibration. Explained how to do. In this embodiment, a method for performing recalibration when the capacitance changes as the environmental temperature rises will be described.

  FIG. 11 shows the case where the environmental temperature continues to rise when the relationship between the conductor 420 and the substrate 430 transitions from FIG. 6 (a) → (b) → (c) → (d) → (a). It is the figure which showed the change of the electrostatic capacitance of the detection electrodes 432a-d in each state. Respective periods 1110, 1111, 1112, 1113, and 1114 are periods in which the conductor 420 and the substrate 430 are in the states shown in FIGS. 6A, 6B, 6C, 6D, and 6A. It corresponds.

  As shown in the figure, the capacitance is a reference value acquired by calibration at the start of the period 1110. However, the capacitance increases as time passes. By increasing the overall capacitance as described above, for example, during the period 1113, the number of detection electrodes whose capacitance change amount is equal to or lower than the lower threshold is 0, and the capacitance change This results in a state where the number of detection electrodes whose amount is equal to or greater than the upper threshold value is three.

  Even in such a case, as in the first embodiment described above, this corresponds to a case where the number of detection electrodes whose electrostatic capacity is equal to or higher than the upper threshold value or lower than the lower threshold value is equal to or higher than 2. Therefore, recalibration is performed. Do. As a result, as shown in a period 1120 in FIG. 12, the rotation can be detected again by resetting the reference value of the capacitance for each detection electrode again.

[Modification 1]
In the first embodiment described above, it has been described that one detection electrode facing portion 422 of the rotation operation unit 201 overlaps one detection electrode 432 as shown in FIG. The configuration of rotation detection by the capacitance method is not limited to this. For example, the conductor 420 may have a structure as shown in FIG. When the conductor 420 in FIG. 13A overlaps the substrate 430, detection is performed except for one (group) of the plurality of detection electrodes 432, which are the sensor electrodes 112, as shown in FIG. 13B. The detection electrode facing portion 422 is configured to face the electrode. Unlike the first embodiment, the rotation operation unit 201 having such a conductor 420 detects whether or not the movable unit 400 has moved by detecting the detection electrode 432 that is not electrostatically coupled to the detection electrode facing unit 422. to decide.

  That is, in the configurations of the first and second embodiments described above, the moving direction of the conductor 420 moved by the rotation operation is such that the capacitance decreases from the detection electrode 432 whose capacitance has decreased to the lower threshold value or less due to the movement to the upper threshold value or more. However, in the case of this modification, the determination of the moving direction is different.

  For example, in FIG. 13B, the detection electrode 432a is not in opposition to the detection electrode facing portion 422. After the calibration is performed in this state, when the conductor 420 is rotated clockwise by the rotation operation, the detection electrode 432a that did not face the detection electrode facing portion 422 before the movement is separated from the detection electrode facing portion 422. Since it will be in a state of opposition, the capacitance will increase above the upper threshold. Further, since the detection electrode 432b that has been opposed to the detection electrode facing portion 422 before the movement is not opposed to the detection electrode facing portion 422, the capacitance is reduced below the lower threshold value. That is, when the conductor 420 has a structure as shown in FIG. 13A, the detection electrode 432 whose capacitance has increased across the upper threshold value or the lower threshold value crosses the upper threshold value or the lower threshold value. Thus, it can be determined that the conductor 420 has moved in the direction toward the detection electrode 432 whose capacitance has decreased.

  In the first and second embodiments and the modifications described above, the rotary operation unit 201 including the rotary encoder that performs electrostatic capacitance type rotational movement detection is described as an example. However, the present invention is a translational movement such as the slider 202. It is also applicable to the detection of the movement of the operation member that receives.

<Configuration of Slider 202>
When the movement detection of the slider 202 is performed by the capacitance method, for example, the movement detection of the operation member of the capacitance method similar to the rotation operation unit 201 is possible by being configured as shown in FIG. .

  As shown in the cross-sectional view of FIG. 14A, the slider 202 is a movable portion 1500 and a guide frame 1510 as members corresponding to the movable portion 400, the guide ring 410, the conductor 420, and the substrate 430 of the rotation operation portion 201. A conductor 1520 and a substrate 1530. In the case of the slider 202, the movable unit 1500 is instructed by the rail 1501 so that the movable unit 1500 moves only in the movable direction (the horizontal direction in the figure).

  As shown in FIG. 14B, in the guide frame 1510, the ball 1512 attached to the movable portion 1500 via the spring 1511 fits into the recess 1512, similarly to the guide ring 410 of the rotation operation portion 201. Thus, the guide frame 1510 enables the movable unit 1500 to move in units of detection electrodes 1532.

  Further, the substrate 1530 is provided with a plurality of detection electrodes 1532 having the same size sequentially arranged in the movable direction of the movable portion 1500 as shown in FIG. 14C, and a GND pattern 1531 extending in the movable direction. ing. The conductor 1520 that moves with the movement of the movable portion 1500 is opposed to the substrate 1530 with a predetermined interval, and the conductor 1520 is in a state where the ball 1512 is fitted in the recess of the guide frame 1510. The detection electrode 1532 and the GND pattern 1531 are electrostatically coupled. Although not shown, each of the detection electrodes 1532 is connected to the capacitance sensor IC 111, and the capacitance is detected by the capacitance sensor IC 111.

  As described above, the moving direction detection method of the present invention electrostatically uses at least three or more detection electrodes that electrostatically couple a conductor that moves as the operating member moves with each other. Any configuration that can detect a change in capacitance is applicable.

  The control of the CPU 101 may be performed by a single piece of hardware, or the entire apparatus may be controlled by a plurality of pieces of hardware sharing the processing. Further, in each of the embodiments described above, the processing described as being performed separately by the CPU 101 and the capacitance sensor IC 111 may be performed by one piece of hardware. Although the present invention has been described in detail based on the preferred embodiments thereof, the present invention is not limited to these specific embodiments, and various forms without departing from the gist of the present invention are also included in the present invention. included. Furthermore, each embodiment mentioned above shows only one embodiment of this invention, and it is also possible to combine each embodiment suitably.

  In the above-described embodiment, the case where the present invention is applied to a digital camera has been described as an example. However, this is not limited to this example, and any device can be applied. That is, the present invention can be applied to a personal computer, a PDA, a mobile phone terminal, a portable image viewer, a printer device including a display, a digital photo frame, a music player, a game machine, an electronic book reader, and the like.

(Other embodiments)
The present invention is also realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, etc.) of the system or apparatus reads the program code. It is a process to be executed. In this case, the program and the storage medium storing the program constitute the present invention.

Claims (9)

A first conductor whose position is changed in the movable direction in accordance with the movement of the operation member;
3 or more detection electrodes, each of which is capable of independently detecting a capacitance and sequentially arranged in the moving direction of the first conductor, and at least excluding one or more of the three or more detection electrodes Three or more detection electrodes spaced apart from the first conductor so that any one of the detection electrodes is electrostatically coupled to the first conductor;
Detection means for detecting capacitance for each of the three or more detection electrodes;
Setting means for setting a first threshold value lower than the reference value and a second threshold value higher than the reference value for the reference value of each of the three or more detection electrodes;
The moving direction of the first conductor depends on whether the capacitance detected by the detection means has changed across the first threshold and whether there has been a change across the second threshold. Determining means for determining
When the detection means detects a state where the capacitance is lower than the first threshold value in the plurality of detection electrodes, or a state where the capacitance is higher than the second threshold value in the plurality of detection electrodes. And an input detecting device characterized by comprising correction means for correcting the reference value.   The input detection device according to claim 1, further comprising a second conductor having a ground potential and electrostatically coupled to the first conductor.   The correction means is a state in which the detection means has a capacitance lower than the first threshold value in the plurality of detection electrodes, or a state in which the detection electrodes have a capacitance higher than the second threshold value in the plurality of detection electrodes. The input detection device according to claim 1, wherein the reference value is not corrected when the time at which is detected is less than a predetermined time.   The determination unit is configured such that the capacitance exceeds the first threshold or the second threshold from the one detection electrode whose capacitance has increased across the first threshold or the second threshold. 4. The input detection device according to claim 1, wherein it is determined that the first conductor has moved in the direction of one of the decreased detection electrodes. 5.   The determination unit is configured such that the electrostatic capacitance crosses the first threshold or the second threshold from one detection electrode whose electrostatic capacitance decreases across the first threshold or the second threshold. 4. The input detection device according to claim 1, wherein it is determined that the first conductor has moved in the direction of one of the increased detection electrodes. 5.   The input detection device according to claim 1, wherein the input detection device is a rotary encoder. A first conductor whose position is changed in the movable direction in accordance with the movement of the operation member;
3 or more detection electrodes, each of which is capable of independently detecting a capacitance and sequentially arranged in the moving direction of the first conductor, and at least excluding one or more of the three or more detection electrodes Three or more detection electrodes spaced apart from the first conductor so that any one of the detection electrodes is electrostatically coupled to the first conductor;
A control method for an input detection device having detection means for detecting capacitance for each of the three or more detection electrodes,
A setting step for setting a first threshold value lower than the reference value and a second threshold value higher than the reference value for the reference value of each of the three or more detection electrodes;
The moving direction of the first conductor depends on whether the capacitance detected by the detection means has changed across the first threshold and whether there has been a change across the second threshold. A determination step for determining
When the detection means detects a state where the capacitance is lower than the first threshold value in the plurality of detection electrodes, or a state where the capacitance is higher than the second threshold value in the plurality of detection electrodes. And a correction step for correcting the reference value.   The program which makes a computer function as each means of the input detection apparatus described in any one of Claims 1 thru | or 6.   A storage medium storing a program that causes a computer to function as each unit of the input detection device according to any one of claims 1 to 6.

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