Detection device using a capacitance sensor

Abstract

To provide a detection apparatus using a capacitive sensor that can reduce an influence between a plurality of capacitive sensors when performing separate detection operations using the plurality of capacitive sensors and prevent a decrease in detection sensitivity.SOLUTION: An input apparatus 100 includes a touch panel 110 that detects a contact position or an approach position of an indication body, a slider sensor 112, detection signal generation units 120, 122, signal measurement units 130, 132, an XY position detection unit 140, an X position detection unit 150, and a detection determination unit 142 and a detection operation limitation unit 160 that, when detecting the contact position or the approach position of the indication body by either one of the touch panel 110 or the slider sensor 112, limit a detection operation by the other.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a detection device using a capacitive sensor that detects a contact position or an approach position of a finger or the like using a plurality of capacitive sensors. Background Art

[0002] Conventionally, there have been known products configured to detect a contact position or an approach position of a user's finger or the like using a plurality of capacitive sensors respectively corresponding to a plurality of detection target regions.

[0003] FIG. 8 is a diagram showing a head unit mounted on a vehicle. The head unit 200 shown in FIG. 8 includes a capacitive touch panel 210 provided corresponding to the front surface so as to overlap a display screen provided on the front surface, and a capacitive slider sensor 220 provided at a lower portion of the touch panel 210. The touch panel 210 is used to detect a contact position or an approach position when a user points to a specific position on the display screen with a finger or the like or brings the finger or the like close to the display screen. Further, the slider sensor 220 is used to detect a contact position with respect to various buttons or the like drawn on an operation surface provided at a lower portion of the display screen.

[0004] When such two types of capacitive sensors (the touch panel 210 and the slider sensor 220) are operated simultaneously, a scan signal used for a detection operation of one sensor may affect the detection operation of the other sensor, which causes a problem that detection accuracy of one sensor deteriorates.

[0005] On the other hand, there has been conventionally known a detection device including an actuation unit having a plurality of partial regions, wherein each input information detection circuit is controlled such that a sensor signal detected by the input information detection circuit corresponding to each of the plurality of partial regions is not affected by a drive signal output from another input information detection circuit (see, for example, Patent Document 1). Prior Art Documents Patent Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2012-248077 [Overview of the project] [Problems that the invention aims to solve]

[0007] Incidentally, it is conceivable to combine the configuration shown in Figure 8 with the detection device method disclosed in Patent Document 1. Specifically, by associating the touch panel 210 and slider sensor 220 shown in Figure 8 with multiple partial regions of the detection device disclosed in Patent Document 1, it is possible to avoid the scan signal used for the detection operation of one sensor affecting the detection operation of the other sensor.

[0008] However, with this combination, the detection operation of the touch panel 210 and the detection operation of the slider sensor 220 are performed in a time-division manner, which creates a new problem: the overall detection sensitivity of the combined touch panel 210 and slider sensor 220 decreases.

[0009] This invention was created in view of the above points, and its purpose is to provide a detection device using a capacitance sensor that can reduce the influence between multiple capacitance sensors when performing separate detection operations and prevent a decrease in detection sensitivity. [Means for solving the problem]

[0010] To solve the above-mentioned problems, the detection device using a capacitance sensor of the present invention comprises a first capacitance sensor for detecting the contact position or approach position of an indicator, a second capacitance sensor for detecting the contact position or approach position of an indicator, and a detection operation limiting means for limiting the detection operation of either the first or second capacitance sensor when either the first or second capacitance sensor detects the contact position or approach position of an indicator.

[0011] When an indicator approaches either the first or second capacitance sensor and the detection operation of that indicator is initiated, the detection operation of the other sensor is restricted. This reduces the influence of the other capacitance sensor on the first capacitance sensor, making it possible to increase the detection sensitivity of the first capacitance sensor.

[0012] Furthermore, each of the first and second capacitance sensors described above inputs a predetermined detection signal to the electrode corresponding to the detection target area, detection The system detects contact or approach of an indicator to the target area, and the detection operation limiting means restricts the input of the detection signal, thereby limiting the detection operation. To restrict. In the detection operation of either the first or second capacitance sensor, the detection signal input in the detection operation of the other sensor becomes noise in accordance with the timing of its input. Therefore, by limiting the input of the detection signal that causes this noise, the influence of the other capacitance sensor on the first capacitance sensor can be reliably reduced.

[0013] Furthermore, it is desirable that the detection operation limiting means described above limit the detection operation by stopping or reducing the input frequency of the detection signal. This makes it possible to reliably reduce the power of the detection signal and suppress the generation of noise.

[0014] Furthermore, it is desirable that the detection operation limiting means described above restricts the detection operation of the other capacitance sensor when either the first or second capacitance sensor detects the contact position or proximity position of the indicator, and the detected position is within a predetermined range close to the other capacitance sensor, but does not restrict the detection operation of the other capacitance sensor when it is farther than the predetermined range. When the first capacitance sensor and the second capacitance sensor are close to each other (when the detection position is within the predetermined range), the influence of the other capacitance sensor on the first capacitance sensor becomes large, so it is possible to maintain high detection sensitivity without restricting the detection operation in ranges farther than this predetermined range.

[0015] Furthermore, since the detection signal described above is a signal that is repeatedly input at a predetermined interval, it is desirable for the detection operation limiting means to limit the detection operation by lengthening the period during which the detection signal is repeatedly input. Alternatively, since the detection signal described above is a signal that is repeatedly input at a predetermined interval, it is desirable for the detection operation limiting means to limit the detection operation by reducing the number of repetitions during which the detection signal is input. By reliably reducing the power of the detection signal in this way, it becomes possible to reliably suppress the generation of noise.

[0016] Furthermore, the other of the first and second capacitance sensors described above detects the position of the indicator by performing multiple detection operations with different detection methods, and it is desirable that the detection operation limiting means limit the detection operations by stopping some of the multiple detection operations. When one capacitance sensor supports multiple detection methods, it is possible to reduce the impact on the other capacitance sensor by limiting the detection operations of some detection methods, while allowing the detection operations of the remaining detection methods to be performed without restriction. [Brief explanation of the drawing]

[0017] [Figure 1] This figure shows the configuration of an input device according to one embodiment. [Figure 2] This is a flowchart showing the operation procedure of the input device of this embodiment. [Figure 3] This is an explanatory diagram showing the limited range of the detection operation in Modification Example 1. [Figure 4] This is a flowchart showing the operation procedure of the input device in modified example 1. [Figure 5] This diagram shows the detection signal input to the slider sensor in the modified example 2. [Figure 6] This figure shows a partial configuration of the touch panel in modified example 3. [Figure 7] This figure shows an example of a detection signal input to a touch panel having the electrodes shown in Figure 6. [Figure 8] This is a diagram showing the head unit installed in the vehicle. MODE FOR CARRYING OUT THE INVENTION

[0018] Hereinafter, an input device according to an embodiment to which the "detection device using a capacitance sensor" of the present invention is applied will be described with reference to the drawings.

[0019] FIG. 1 is a diagram showing the configuration of the input device according to one embodiment. As shown in FIG. 1, the input device 100 of the present embodiment includes a touch panel 110, a slider sensor 112, detection signal generators 120 and 122, signal measurement units 130 and 132, an XY position detector 140, a detection determination unit 142, an X position detector 150, and a detection operation restriction unit 160.

[0020] The touch panel 110 is disposed overlapping the display surface of a display unit 200 configured by an LCD (liquid crystal display device) or the like, and has a plurality of aligned transparent electrodes used for detecting the XY position (horizontal and vertical positions) of a pointer by a capacitance method. As the pointer, for example, a user's fingertip is assumed.

[0021] The slider sensor 112 is disposed on the surface of the housing of the input device 100 and below the touch panel 110, and detects the position (horizontal position) of a pointer that has contacted any of a plurality of detection electrodes by a capacitance method. For example, various buttons to be operated are printed on the surface of the slider sensor 112, and these buttons are pointed by a user's finger or the like. Note that when the slider sensor 112 is formed of a transparent member such as a transparent electrode, these buttons may be drawn on the surface of the housing of the input device 100.

[0022] The detection signal generation unit 120 generates detection signals necessary for position detection operation using the touch panel 110. These detection signals are scan signals input to each transparent electrode of the touch panel 110 during position detection, and signals corresponding to the detection method are input to the transparent electrodes necessary for detection. For example, to detect the contact position of an indicator using the Mutual cap method, scan signals input to multiple transparent electrodes extending in the horizontal direction are used. Also, to detect the approaching position of an indicator during hover operation using the Self cap method, scan signals input to multiple transparent electrodes extending in the horizontal direction and multiple transparent electrodes extending in the vertical direction are used.

[0023] The detection signal generation unit 122 generates a detection signal necessary for position detection operation using the slider sensor 112. This detection signal is a scan signal that is input to each detection electrode of the slider sensor 112 during position detection.

[0024] The scan signal described above is used to detect changes in the capacitance of each electrode included in the touch panel 110 and slider sensor 112. By inputting a scan signal having a pulsed or sinusoidal waveform to these electrodes, it becomes possible to detect changes in the capacitance of these electrodes in response to the presence or absence of an indicator object. Furthermore, although the content of the scan signal will vary depending on the detection method, the present invention focuses on the impact on the detection operation by using a scan signal accompanied by voltage fluctuations, so any detection method can be adopted.

[0025] The signal measurement unit 130 measures the current output from the transparent electrode or the voltage appearing on the transparent electrode or the like when a detection signal is input to the touch panel 110 from the detection signal generation unit 120.

[0026] The signal measurement unit 132 measures the current output from the electrode or the other object to be detected, or the voltage appearing on the transparent electrode or the other object, when a detection signal is input to the slider sensor 112 from the detection signal generation unit 122.

[0027] The XY position detection unit 140 detects the position where the change in capacitance value is greatest, based on the change in the current value (or voltage value) of the signal measured by the signal measurement unit 130, as the X and Y positions of the indicator on the touch panel 110.

[0028] The detection and determination unit 142 determines whether or not a position has been detected by the XY position detection unit 140 (whether or not the indicator is in contact with or approaching the target).

[0029] The X-position detection unit 150 detects the position where the change in capacitance value is greatest, based on the change in the current value (or voltage value) of the signal measured by the signal measurement unit 132, as the X-position of the indicator on the slider sensor 112.

[0030] When the detection determination unit 142 determines that a position has been detected (when the indicator object touches or approaches the touch panel 110), the detection operation limiting unit 160 sends an instruction to the detection signal generation unit 122 to interrupt the generation of the detection signal and the input to the slider sensor 112, thereby limiting (stopping) the detection operation of the slider sensor 112.

[0031] The touch panel 110, slider sensor 112, detection signal generation units 120, 122, signal measurement units 130, 132, and XY position detection unit 140 described above correspond to the first and second capacitive sensors, respectively, while the detection determination unit 142 and detection operation limiting unit 160 correspond to the detection operation limiting means.

[0032] In this embodiment, the input device 100 interrupts the position detection operation by the slider sensor 112 while the touch panel 110 is performing a position detection operation, and does not input the detection signal (scan signal) necessary for this position detection operation to the slider sensor 112. The operation of this device will now be explained.

[0033] Figure 2 is a flowchart showing the operation procedure of the input device 100 in this embodiment. Note that this flowchart focuses on the procedure for temporarily suspending the position detection operation using the slider sensor 112 when a position detection operation is performed using the touch panel 110, and various processing contents corresponding to the position detected by the touch panel 110 and the slider sensor 112 are omitted.

[0034] When the power to the input device 100 is turned on, a position detection operation using the touch panel 110 (step 100) and a position detection operation using the slider sensor 112 (step 102) are started. In parallel with these two types of detection operations, the detection determination unit 142 determines whether or not position detection has been performed by the touch panel 110 (step 104). Note that the position detection by the touch panel 110 may target only a portion of the image area displayed on the display unit 200 on which the touch panel 110 is superimposed and for which position detection is necessary, or it may target the entire range of the touch panel 110 limited to such image area. If position detection is not performed (when the user's finger, etc., is not in contact with or close to the touch panel 110), a negative determination is made, and this determination is repeated.

[0035] Furthermore, if position detection is performed, a positive judgment is made in the determination in step 104. Next, the detection operation limiting unit 160 sends a stop command to the detection signal generation unit 122, stopping the input of a detection signal from the detection signal generation unit 122 to the slider sensor 112. As a result, the detection operation by the slider sensor 112 is stopped (step 106).

[0036] Next, the detection and determination unit 142 determines whether or not the position detection by the touch panel 110 has finished (step 108). The time for this determination is set to a reasonably long predetermined time (for example, several seconds), taking into consideration that the user's operation to be detected by the touch panel 110 may be performed on a single target area, or on multiple target areas sequentially (for example, when entering each character on a keyboard or navigating through a hierarchical menu screen). A negative determination is made until the predetermined time has elapsed, and the process returns to step 104 to repeat the position detection determination.

[0037] Furthermore, if a predetermined time has elapsed since the last operation (position detection), an affirmative judgment is made in the determination in step 108. Next, the detection operation limiting unit 160 sends a restart instruction to the detection signal generation unit 122, causing the detection signal generation unit 122 to resume inputting a detection signal to the slider sensor 112. This restarts the detection operation by the slider sensor 112 (step 110). After that, the process returns to step 104 and the position detection determination is repeated.

[0038] Thus, in the input device 100 of this embodiment, when an object (the user's finger) approaches the touch panel 110 and the detection operation of this object begins, the detection operation of the slider sensor 112 is restricted (stopped). This reduces the influence of the slider sensor 112 on the touch panel 110, and makes it possible to improve the sensitivity of position detection using the touch panel 110.

[0039] The slider sensor 112 detects contact of an indicator object with a target area by inputting a predetermined detection signal (scan signal) to an electrode corresponding to the area to be detected. The detection operation limiting unit 160 limits the detection operation by restricting the input of this detection signal. The detection signal input to the slider sensor 112 in this way becomes noise in the detection operation of the touch panel 110 in accordance with the timing of its input. Therefore, by limiting the input of the detection signal that causes this noise, the impact on the detection operation using the touch panel 110 can be reliably reduced.

[0040] In particular, the detection operation limiting unit 160 limits the detection operation by stopping or reducing the input frequency of the detection signal, thereby reliably reducing the power of the detection signal and suppressing the generation of noise.

[0041] It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the gist of the present invention.

[0042] (Variation 1) In the embodiment described above, the detection operation of the slider sensor 112 was restricted when contact of an indicator object was detected across the entire range of the touch panel 110. However, since the influence of the detection signal input to the slider sensor 112 on the detection operation of the touch panel 110 is greater the closer it is to the slider sensor 112 and smaller the further away it is, the detection operation of the slider sensor 112 may be restricted only when an indicator object makes contact in an area where the influence is greatest.

[0043] Figure 3 is an explanatory diagram showing the restricted range of the detection operation in Modification 1. As shown in Figure 3, the detection area of ​​the touch panel 110 can be divided into a specific area 110a close to the slider sensor 112 and another area 110b adjacent to the specific area 110a but farther from the slider sensor 112. The detection operation by the touch panel 110 is restricted only when a user's finger or other object touches (or approaches) the specific area 110a.

[0044] Figure 4 is a flowchart showing the operation procedure of the input device 100 in the modified example 1. The operation procedure shown in Figure 4 differs from the operation procedure shown in Figure 2 in that step 104 is replaced with step 104A and step 108 is replaced with step 108A.

[0045] In step 104A, the detection and determination unit 142 determines whether or not position detection has been performed in a specific area 110a of the touch panel 110. If position detection has been performed in the specific area 110a, an affirmative judgment is made in the determination in step 104A, and the operation proceeds to step 106.

[0046] Furthermore, in step 108A, the detection determination unit 142 determines whether or not position detection in a specific area 110a of the touch panel 110 has been completed. A negative determination is made until a predetermined time has elapsed since the completion of the detection operation in the specific area 110a.

[0047] Thus, when the touch panel 110 and the slider sensor 112 are close to each other (when the detection position is included in a predetermined range (specific region 110a)), the influence of the slider sensor 112 on the detection operation of the touch panel 110 becomes greater. Therefore, for other regions 110b that are farther from this characteristic region 110a, it is possible to maintain high detection sensitivity without restricting the detection operation of the slider sensor 112.

[0048] (Modification 2) In the embodiment described above, as a specific example of limiting the detection operation of the slider sensor 112, the input of a detection signal (scan signal) to the slider sensor 112 was stopped. However, the signal strength (power) of the input detection signal may also be reduced.

[0049] Figure 5 shows the detection signal input to the slider sensor 112 in Modification Example 2. Figure 5(A) shows an example of a detection signal when the detection operation is not restricted, and the detection signal input to the slider sensor 112 when the detection operation of the slider sensor 112 is not restricted is shown. Specifically, the detection signal when there is no restriction outputs 16 pulses with a period of 15 kHz over a period of 1.06 ms, and then after a time interval of 5 ms, the same operation is repeated. The capacitance change of each part of the slider sensor 112 is monitored in response to the input of such pulses.

[0050] Figure 5(B) shows a detection signal that reduces the number of pulses output. Specifically, in this detection operation limit, eight pulses with a period of 15 kHz are output over a period of 0.533 ms, followed by a 5 ms interval, after which the same operation is repeated. By reducing the number of pulses (repetitions) that are intermittently input in this way, the power of the detection signal is reliably reduced, and the generation of noise in the touch panel 110 can be reliably suppressed.

[0051] Figure 5(C) shows a detection signal with a longer pulse period (interval between repeated outputs). Specifically, in this detection operation limitation, 16 pulses with a 15kHz period are output over a period of 1.06ms, followed by a 11.05ms interval, after which the same operation is repeated. By increasing the interval between these intermittently input pulses, the power of the detection signal can be reliably reduced, and noise generation in the touch panel 110 can be reliably suppressed.

[0052] (Variation 3) In the embodiment described above, the detection operation using the slider sensor 112 was restricted when the detection operation using the touch panel 110 was performed. However, conversely, the detection operation using the touch panel 110 may be restricted when the detection operation using the slider sensor 112 is performed. In this case, the restriction of the detection operation using the touch panel 110 could be done by stopping the entire detection operation as described above, reducing the number of pulses in the detection signal, or lengthening the interval between the pulse groups that are repeatedly output. However, in cases where Mutual cap type position detection and Self cap type position detection are performed in parallel using the touch panel 110 (when performing multiple detection operations with different detection methods), the entire detection operation may be restricted by stopping one of the detection operations.

[0053] Figure 6 shows a partial configuration of the touch panel 110 of Modification 3, and the electrodes used for position detection are shown. In the touch panel 110, multiple transparent electrodes 110x and multiple transparent electrodes 110y are orthogonal to each other in the same plane, and a ground layer 110g is provided opposite these transparent electrodes 110x and 110y.

[0054] Figure 7 shows an example of a detection signal input to a touch panel 110 having the electrodes shown in Figure 6. The detection signal shown in Figure 7 includes a first pulse group P1 consisting of multiple pulses used for self-cap detection operation and a second pulse group P2 consisting of multiple pulses used for mutual-cap detection operation, both within one cycle. This cycle is repeated if the detection operation is not restricted.

[0055] The first pulse group P1 described above is input to, for example, one end of each of the transparent electrodes 110x and 110y shown in Figure 6, and a self-capacitation detection operation is performed by detecting the voltage (or current) that appears at the other end of each. When an object approaches the touch panel 110, the capacitance between the transparent electrodes 110x and 110y near the object and the ground layer 100g changes, and the detected voltage etc. changes. By observing this change, the position of the non-contact object performing the hover operation can be detected.

[0056] Furthermore, the second pulse group P2 described above is input sequentially to each of the multiple transparent electrodes 110y shown in Figure 6, for example. Mutual cap detection is performed by detecting the voltage (or current) that appears in each of the multiple transparent electrodes 110x in accordance with this input timing. As the capacitance between the intersecting transparent electrodes 110x and 110y changes at the point where the indicator touches, the detected voltage, etc., changes. By observing this change, the position where the indicator touches on the touch panel 110 can be detected.

[0057] Generally, the time during which the second pulse group P2 is input is longer than the time during which the first pulse group P1 is input. Therefore, when it is determined that position detection has been performed by the slider sensor 112, the input of the second pulse group P2 is stopped, thereby limiting the detection operation using the touch panel 110. This reduces the influence of the detection signal input to the touch panel 110 on the slider sensor 112. Furthermore, even in this case, since the input of the first pulse group P1 is continued, it is possible to maintain the detection operation of the object being pointed to during hover operation.

[0058] Alternatively, the input of the second pulse group P2 may be continued and the input of the first pulse group P1 may be stopped to restrict the detection operation of the touch panel 110.

[0059] Furthermore, although the above-described embodiment described a case in which a touch panel 110 and a slider sensor 112 are combined, the type of capacitive sensor to be combined is not limited to this combination. As long as it is a capacitive sensor, the contact and approach position of the indicator is detected by inputting a detection signal (scan signal) and monitoring the change in capacitance, so the present invention can be applied to any combination. [Industrial applicability]

[0060] As described above, according to the present invention, when an indicator approaches either the first or second capacitance sensor and the detection operation of the indicator is initiated, the detection operation of the other is restricted. This reduces the influence of the other capacitance sensor on the first capacitance sensor, and makes it possible to increase the detection sensitivity of the first capacitance sensor. [Explanation of Symbols]

[0061] 100 Input Devices 110 Touch Panel 112 Slider Sensor 120, 122 Detection signal generation unit 130, 132 Signal measurement section 140 XY position detection unit 142 Detection and Determination Unit 150 X position detection unit 160 Detection operation limiting unit 200 Display

Claims

1. A first capacitive sensor for detecting the contact position or proximity position of an indicator, A second capacitance sensor detects the contact position or approach position of the indicator, A detection operation limiting means that, when either the first or second capacitance sensor detects the contact position or proximity position of the indicator, limits the detection operation of either the first or second capacitance sensor, The system comprises the first and second capacitance sensors, each of which detects contact or approach of the indicator to the detection target area by inputting a predetermined detection signal to an electrode corresponding to the detection target area. The detection device using a capacitive sensor is characterized in that the detection operation limiting means limits the input of the detection signal to limit the detection operation.

2. The detection device using a capacitance sensor according to claim 1, characterized in that the detection operation limiting means limits the detection operation by stopping or reducing the input frequency of the detection signal.

3. The detection device using a capacitance sensor according to claim 1, wherein the detection operation limiting means, when one of the first and second capacitance sensors detects a contact position or approach position of the indicator, restricts the detection operation of the other sensor when the detected position is within a predetermined range close to the other sensor, and does not restrict the detection operation of the other sensor when it is farther from the predetermined range.

4. The aforementioned detection signal is a signal that is repeatedly input at a predetermined period, The detection device using a capacitance sensor according to claim 1, characterized in that the detection operation limiting means limits the detection operation by increasing the period for repeatedly inputting the detection signal.

5. The detection signal is a signal in which multiple pulses are intermittently and repeatedly input at a predetermined period. The detection device using a capacitance sensor according to claim 1, characterized in that the detection operation limiting means limits the detection operation by reducing the number of pulses that are intermittently input.

6. The other of the first and second capacitance sensors detects the position of the indicator by performing multiple detection operations with different detection methods. The detection device using a capacitance sensor according to claim 1, characterized in that the detection operation limiting means limits the detection operation by stopping a part of the plurality of detection operations.

Images