JP2013239237A - Capacitive coupling sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitive coupling sensor for position detection in which the problems of form factor, route and manufacture of Hall effect switch, mechanical displacement switch, optical beam interruption switch, do not occur, and which is not affected by mixture of a foreign matter.SOLUTION: A capacitive coupling sensor 200 is constituted of a transmitter 204 and a receiver 206 configured to be coupled capacitively when the coupling conditions are satisfied, and an integration circuit 202 which determines whether or not a reception signal 210 received by the receiver 206 matches a transmission signal 208 transmitted by the transmitter 204.

Description

  The position detection switch has many uses. For example, a laptop computer or notebook computer is generally provided with a lid switch that initiates a sleep state when the lid of the computer, which typically includes the computer display, is closed. FIG. 1 shows an embodiment of a general two-fold mechanical configuration of a notebook computer. As illustrated, the notebook computer 100 includes a display surface 102 and a keyboard / control electronics surface 104. The surface 102 and the surface 104 are connected by a hinge (hinge), and can be closed so that the display surface 102 covers the keyboard surface 104 when the notebook computer 100 is not used. The open / closed state of the notebook computer 100 is usually indicated by the state of the switch coupled to the surface 102 and the surface 104. The state of the switch changes based on the relative position of surface 102 and surface 104.

  A Hall effect switch is generally used as an existing lid switch. In the case of the Hall effect switch, it is necessary to attach a magnet to one surface of the surface 102 and the surface 104 and attach a sensor to the opposite surface. Since magnets have a three-dimensional volume, especially when mounted on surface 102, it affects the maximum possible effective area of the display and can result in an undesirable form factor. On the other hand, when the magnet is attached to the surface 104 and the sensor is attached to the surface 102, the path formation becomes more complicated, and the signal output from the sensor on the surface 102 is transmitted to the surface 104 via the folded hinge. It will take a route to reach the electronic device attached to the. Furthermore, Hall effect switch magnets can generate undesirable magnetic fields. The magnetic field may adversely affect certain functions related to the notebook computer 100, such as functions that require a compass. Magnets are relatively expensive parts and require special processing and handling during manufacturing. Other commonly used switches include a mechanical displacement switch and a light beam cutoff switch. In the case of such a switch, the same form factor, route, and manufacturing problem as those of the Hall effect switch occur, and the influence due to contamination by foreign matter is also conceivable.

  Various embodiments of the present invention are described in detail below with reference to the accompanying drawings.

The figure which shows embodiment of the general two-fold mechanical structure of a notebook personal computer.

The high-level block diagram which shows embodiment of the integrated circuit type sensor using capacitive coupling.

The figure which shows embodiment of the process which produces | generates the output signal which shows a certain state.

The figure which shows embodiment of the sensor structure which has arrange | positioned two components of a transmitter part and a receiver part on a different plane.

The figure which shows embodiment which applied the sensor structure shown to FIG. 3A.

The figure which shows embodiment of the sensor structure which uses a coupler.

The figure which shows embodiment which applied the sensor structure shown to FIG. 4A.

The figure which shows another embodiment to which the sensor structure shown to FIG. 4A is applied.

The figure which shows embodiment of the differential structure which has arrange | positioned several transmitters and several receivers on a separate surface.

The figure which shows embodiment of the differential structure which has arrange | positioned several transmitters and several receivers on the same surface, and connected via several passive couplers. The figure which shows another embodiment of the differential structure which has arrange | positioned several transmitters and several receivers on the same surface, and connected via several passive couplers.

1 is a circuit diagram of an embodiment of a sensor that includes major components of an integrated circuit in accordance with the sensor design of the present invention. FIG. 5 is a circuit diagram of another embodiment of a sensor including the major components of an integrated circuit according to the sensor design of the present invention.

The circuit diagram which shows the main components containing embodiment of a pattern comparator.

  The present invention is stored on a process, apparatus, system, composition of matter, computer program product embodied on a computer readable storage medium, and / or a processor, eg, a memory coupled to the processor, and It may be implemented in various forms, such as a processor configured to execute instructions provided by a memory. In the present specification, these embodiments and other arbitrary forms capable of realizing the present invention are referred to as techniques. In general, the order of the steps in the processes disclosed herein can be changed within the scope of the present invention. Unless stated otherwise, a component such as a processor or memory that is configured to perform a task is implemented as a generic component that is temporarily configured to perform the task at a given time. Or may be realized as a specific part manufactured to perform the task. The term “processor” as used herein refers to one or more devices, circuits, and / or processing cores that are configured to process data, such as computer program instructions.

  Embodiments of the invention are described in detail below with reference to the accompanying drawings, which illustrate the principles of the invention. Although the present invention will be described in connection with some embodiments, the present invention is not limited to these embodiments. The scope of the present invention is limited only by the scope of the claims, and includes various modifications and changes and equivalents thereof. Hereinafter, specific details will be described in order to help understanding of the present invention. However, these details are merely examples, and even if some or all of these specific details are omitted, the present invention is claimed according to the claims. The invention can be implemented. In order to provide a clear description without unnecessarily obscuring the present invention, the technical content known in the technical fields related to the present invention will not be described in detail.

  Various configurations of integrated circuit type sensors using capacitive coupling are disclosed. In some embodiments, such a sensor may be used as a switch. Using the techniques disclosed herein, multiple states (eg, true / false state, open / closed state, on / off state, touch or proximity state, etc.) are identified and based on the detected state Producing an output signal can facilitate an appropriate response. The sensor design disclosed herein can be applied to a wide range of technical fields. In some embodiments, the sensor may be used as a position detection switch. Applications of such switches include, but are not limited to, lid computers such as laptops shown in FIG. 1, cell phones, PDAs and other electronic devices, printer latches and / or Examples include a switch for detecting a tray state and an intrusion detection switch for a system such as a hard disk drive of a data storage system. In some embodiments, the sensor may be used as a touch or proximity detection sensor. Applications of such sensors include, but are not limited to, touch sensors that serve as alternatives to mechanical buttons or switches, touch sensors for touch screens or trackpads, tablet computers, mobile phones, PDAs And a proximity or presence detection sensor that wakes up a system such as an electronic device from a sleep state. The capacitively coupled sensor design described herein has many advantages, such as low cost, low power consumption, and low form factor. Specific examples of the sensor configuration and application will be described below, but the method disclosed in this specification can be similarly used for any other appropriate configuration and application.

  FIG. 2A shows a high level block diagram of an embodiment of an integrated circuit sensor utilizing capacitive coupling. As illustrated, the sensor 200 includes an integrated circuit 202, a transmitter 204, and a receiver 206. Integrated circuit 202 generates a signal 208 that is transmitted from the antenna of transmitter 204. On the other hand, the signal 210 received by the antenna of the receiver 206 is input to the integrated circuit 202. The integrated circuit 202 compares the transmission signal 208 and the reception signal 210 to determine the state. For example, the integrated circuit 202 detects a first state when the received signal 210 matches the transmitted signal 208, and detects a second state when the received signal 210 does not match the transmitted signal 208. In this case, for example, there is sufficient capacitive coupling between the transmitter 204 and the receiver 206 to allow the signal transmitted by the transmitter 204 to be transmitted to the receiver 206 at an appropriate power or strength and / or within error limits. Integrated circuit 202 detects the first condition. On the other hand, if the signal transmitted by the transmitter 204 cannot be received by the receiver 206, or if the receiver 206 cannot receive the signal at an appropriate output or strength and / or within an error limit, the integrated circuit 202 Detect the state of. Based on the coupling change between transmitter 204 and receiver 206, two or more states can be identified. The integrated circuit 202 actively scans the received signal 210 against the transmission pattern 208 and generates an output signal (not shown in FIG. 2A) based on the detected state. In some embodiments, the output signal may include a binary true / false signal or a 1/0 signal. A system management circuit or other circuit may use the output signal to facilitate an appropriate response or event. In various embodiments, the components of sensor 200 may be arranged in any suitable mechanical configuration. In some embodiments, the components of the sensor 200 may be distributed and arranged in a plurality of planes that are movable relative to one another in one or more directions. Such relative movement changes the capacitive coupling between transmitter 204 and receiver 206. In another embodiment, the active components of sensor 200 (ie, integrated circuit 202, transmitter 204, and receiver 206) may be located on substantially the same plane. If a passive component (not shown in FIG. 2A) that moves relative to the active component has some capacitive coupling between the transmitter 204 and the receiver 206, the degree of capacitive coupling is determined by the passive component. Change based on the position. These and other embodiments are described in further detail.

  FIG. 2B illustrates an embodiment of a process for generating an output signal indicating a state. In some embodiments, the integrated circuit 202 of the sensor 200 shown in FIG. 2A may perform this process 220. When the process 220 begins, a signal is generated and transmitted to the transmitter at step 222. In some embodiments, the generated signal may include a unique patterned signal. For example, the generated signal may include a unique bitstream that includes a fixed number of bits or a configurable number of bits. In one embodiment, the generated signal may include an 8-bit serial stream. The pattern of the generated signal may be automatically selected or may be user settable. In some embodiments, the generated signal may include a low power and / or low frequency (eg, 41 kHz) signal that does not substantially interfere with other applications such as WiFi, Bluetooth, and wireless. In step 224, a signal is received from the receiver. In step 226, the transmission signal and the reception signal are compared to determine whether the two signals match. Any suitable matching algorithm, matching criteria, and / or matching threshold may be used to determine whether the transmitted signal and the received signal match at step 226. In some embodiments, step 226 may comprise determining whether the output or strength (eg, voltage) of the received signal meets a threshold value. In some embodiments, the step of determining whether the received signal and the transmitted signal match at step 226 may comprise determining an error between the transmitted signal and the received signal. In such a case, for example, when it is detected that there is no error between the transmission signal and the reception signal, or when it is detected that the error is equal to or less than the error limit value, it is determined that the matching condition is satisfied. It may be a thing. In some embodiments, the step of determining whether the received signal and the transmitted signal match at step 226 includes averaging two signals at least for a predetermined number of samples. May be provided with a step of determining whether or not. For example, in one embodiment, a match condition is met when 8000 samples included in the transmitted signal pattern are detected in the received signal continuously or nearly continuously (eg, on average). It may be determined. If it is determined in step 226 that the transmission signal and the reception signal match, an output signal indicating the first state of the sensor is generated in step 228. On the other hand, if it is determined in step 226 that the transmission signal and the reception signal do not match, an output signal indicating the second state of the sensor is generated in step 230. The output signal generated in step 228 or step 230 may be used, for example, to initiate an event or action that requires an accompanying system to have a sensor.

  FIG. 3A shows an embodiment of a sensor configuration in which two parts of a transmitter unit and a receiver unit are arranged on different planes. Although not shown in FIG. 3A, the sensor integrated circuit may be connected to both the transmitter 302 and the receiver 304 as shown in FIG. 2A and placed on the same plane as either the transmitter 302 or the receiver 304. However, they may be arranged on different planes. In the example shown, if there is any coupling between the transmitter 302 and the receiver 304, this coupling changes in response to movement in one or more directions between these components. For example, in another embodiment, the transmitter 302 and the receiver 304 may move relative to each other in one or more of the x, y, and z directions. Whether the receiver 304 can properly receive a signal transmitted by the transmitter 302 via capacitive coupling depends on the relative positional relationship between the transmitter 302 and the receiver 304 at any point in time. As the capacitance between transmitter 302 and receiver 304 increases, for example, as the distance between transmitter 302 and receiver 304 decreases, and / or the alignment between transmitter 302 and receiver 304 increases. As the surface area of the transmitter 302 and receiver 304 increases (eg, as the alignment of the surface area of the transmitter 302 and receiver 304 increases), the strength of the signal received by the receiver 304 increases. In some embodiments, the transmitter 302 and receiver 304 have the same and / or similar shape and / or geometric shape, for example, to facilitate capacitive coupling between the two components. But you can. As described above, the integrated circuit compares the transmission signal and the reception signal to generate an appropriate output signal.

  FIG. 3B shows an embodiment to which the sensor configuration shown in FIG. 3A is applied. In the example shown in FIG. 3B, the sensor is used as a lid switch of a notebook computer. In the illustrated example, the transmitter 302 is disposed on the display surface of the notebook computer, while the receiver 304 and the integrated circuit 306 are disposed on the keyboard surface. The integrated circuit 306 is connected to both the transmitter 302 and the receiver 304, and is connected to the transmitter 302 via the keyboard surface, hinge (hinge), and display surface of the notebook computer. In this example, if there is any capacitive coupling between the transmitter 302 and the receiver 304, the degree of capacitive coupling depends on the angle between the display surface of the notebook computer and the keyboard surface. When the folded surface of the notebook computer is completely or almost completely closed, the transmitter side of the capacitor plate and the receiver side of the capacitor plate are close enough to complete the circuit. Since the receiver 304 can properly receive the transmission signal, the integrated circuit 306 detects the coincidence state. On the other hand, when the folded surface of the notebook computer is opened, even if there is capacitive coupling between the transmitter 302 and the receiver 304, it is very weak and the circuit cannot be completed. Since the transmission signal cannot be properly received, the integrated circuit 306 detects a mismatch condition. In this example, when the notebook personal computer enters the standby mode or the sleep mode, it becomes a coincidence state.

  FIG. 4A shows an embodiment of a sensor configuration using a passive coupler. In this example, the active components of the sensor (transmitter 402, integrated circuit 404 and receiver 406) are co-planar and are fixed so as not to move relative to each other. However, in this embodiment, the sensor further includes a coupler 408 as a passive component. In some embodiments, the coupler 408 may comprise a conductor such as a metal piece or a metal plate. There is no physical connection or contact between the active components 402-406 and the coupler 408, and the coupler 408 is located in a different plane than the active components 402-406. Movement between the coupler surface and the active component surface changes the coupling state between transmitter 402 and receiver 406. In various embodiments, the coupler surface and the active component surface may move relative to each other in one or more of the x, y, and z directions. In some embodiments, the shape and / or geometry of coupler 408 is selected to facilitate coupling between transmitter 402 and receiver 406 (eg, match transmitter 402 and receiver 406). You may do it. Coupler 408 facilitates capacitive coupling between transmitter 402 and receiver 406 by being proximate to and / or in line with transmitter 402 and receiver 406. Depending on whether coupler 408 can effectively connect between transmitter 402 and receiver 406 and close the circuit between the two via capacitive coupling, receiver 406 transmits by transmitter 402 via capacitive coupling. Whether or not the received signal can be properly received. As the capacitance between coupler 408 and transmitter 402 and receiver 406 increases, for example, as the distance between coupler 408 and the active component surface decreases, and / or between coupler 408 and transmitter 402 and receiver 406 As the degree of alignment increases, the strength of the signal received by the receiver 406 increases. As described above, the integrated circuit 404 compares the transmission signal and the reception signal to generate an appropriate output signal.

  FIG. 4B shows an embodiment to which the sensor configuration shown in FIG. 4A is applied. In the example shown in FIG. 4B, the sensor is used as a lid switch of a notebook computer. In the illustrated example, the active components 402 to 406 are disposed on the keyboard surface of the notebook computer, while the coupler 408 is disposed on the display surface. Integrated circuit 404 is connected to both transmitter 402 and receiver 406. The coupler 408 is not physically connected to and / or is not in physical contact with any of the active components 402-406, and thus constitutes a floating part of the sensor. In this example, if there is any capacitive coupling between transmitter 402 and receiver 406, the degree of capacitive coupling depends on the angle between the laptop display surface and the keyboard surface, i.e., transmitter 402 and It depends on the proximity and / or alignment of the coupler 408 to the receiver 406. When the folded surface of the laptop is completely or nearly completely closed, the coupler 408 can be sufficiently close and aligned with the transmitter 402 and receiver 406 to complete the circuit, i.e., the receiver. Integrated circuit 404 detects a match condition because 406 can properly receive the transmitted signal. On the other hand, when the folded plane of the notebook computer is opened, the coupler 408 is too far to capacitively couple with the transmitter 402 and the receiver 406 to complete the circuit, that is, the receiver 406 transmits the transmission signal. The integrated circuit 404 detects a mismatch condition because it cannot be properly received. In this example, when the notebook personal computer enters the standby mode or the sleep mode, it becomes a coincidence state. FIG. 4C shows another embodiment to which the sensor configuration shown in FIG. 4A is applied, in which an opening / closing state of a sliding keyboard of a smartphone is detected.

  The sensor embodiment shown in FIGS. 3A and 4A comprises a single-ended configuration. In some embodiments, a differential configuration may be desirable. By adopting a differential configuration, for example, the range can be expanded and / or security can be improved. A differential configuration can reduce the sensor sensitivity to noise and / or disturbances in the external environment that can lead to false results. FIG. 5A shows an embodiment of a differential configuration in which a plurality of transmitters and a plurality of receivers are arranged on different planes. The differential configuration shown in FIG. 5A is similar to the single-ended configuration shown in FIG. 3A. 5B and 5C show an embodiment of a differential configuration in which a plurality of transmitters and a plurality of receivers are arranged on the same plane and connected via a plurality of passive couplers. The differential configuration shown in FIGS. 5B and 5C is similar to the single-ended configuration shown in FIG. 4A. In the cross-shaped or key-shaped embodiment shown in FIGS. 5B and 5C, one or both of the plurality of couplers includes a plurality of portions electrically connected by wiring. In some embodiments, the Tx # and Rx # signals shown in FIGS. 5A-5C are inverted signals of the Tx and Rx signals, respectively. In the differential configurations of FIGS. 5A-5C, if the configuration used is not correct, the corresponding transmitter and receiver pair (ie, Tx and Rx and Tx # and Rx #) will not be properly connected, so noise and other external Design that is less affected by factors is possible. The single-ended configuration and the differential configuration have been described above. However, in another embodiment, the sensor may include a coupler including an arbitrary number of transmitters, receivers, and / or an arbitrary number of connection coupler units. .

  6A and 6B show circuit diagrams of two different sensor embodiments including the major components of an integrated circuit according to the sensor design of the present invention. The embodiment shown in FIG. 6A corresponds to a single-ended / single plane / passive coupler configuration like the configuration shown in FIG. 4A. On the other hand, the embodiment shown in FIG. 6B is a differential mode type and corresponds to the separation surface configuration as in the configuration shown in FIG. The integrated circuit 600 includes an oscillator 602 that provides a clock frequency or a reference frequency. The pattern generator 604 of the integrated circuit 600 generates a patterned signal that is unlikely to be reproduced by random noise. For example, the pattern generator 604 may generate a noise removal code word having an n-bit length. Here, n is a fixed value or a settable value. The signal output from the pattern generator 604 is amplified by the buffer 606. The signal amplified by the buffer 606 is output from the integrated circuit 600 to drive the transmitter 608 and transmit the signal. A signal received by the receiver 610 is input into the integrated circuit 600 and amplified by the amplifier 612. The amplified received signal is compared with the transmission signal by the pattern comparator 614. The output 616 of the integrated circuit 600 indicates whether the received signal matches the transmitted signal based on the determination result by the comparator 614. In the embodiment shown in FIG. 6A, the position of the floating coupler 618 determines the degree of capacitive coupling when there is capacitive coupling between the transmitter 608 and the receiver 610. In the embodiment shown in FIG. 6B, due to the relative positions of the corresponding transmitters 608 and receivers 610, there is capacitive coupling between the transmitter 608 and receiver 610 pair, shown as a capacitor plate in FIG. 6B. In addition, the degree of capacitive coupling is determined. FIG. 6C shows a circuit diagram of the main components including an embodiment of the pattern comparator 614. As shown in the figure, the counter 620 counts up to n (in the case of an n-bit pattern), sends a reset pulse, and while repeating this, each bit of the received signal and transmitted signal is compared. Although some of the major components of an integrated circuit according to the sensor design of the present invention have been described with reference to FIGS. 6A-6C, the integrated circuit can be configured in any suitable manner, such as a digital / analog converter, It may comprise one or more of any other suitable components or circuits, such as an analog / digital converter.

  In various embodiments, the sensor design may optionally include any one or more suitable components. For example, in some embodiments, a tuning capacitor (eg, with a value in the range of 1-10 pF) may be connected between the receiver output and ground to adjust the sensitivity. A shunt capacitor effectively reduces the sensing range. In some cases, a capacitor may be disposed outside the integrated circuit of the sensor. In some embodiments, the sensitivity may be adjusted by adding a boost circuit and / or a charge pump to the integrated circuit to increase the strength of the transmitted signal. When the voltage of the transmission signal is increased, the sensitivity range of the sensor is expanded in some cases. In some embodiments, a circuit that facilitates sleep / wake duty cycle for the integrated circuit is added to the integrated circuit so that the integrated circuit does not remain on all the time, reducing the active power consumption of the sensor can do. For example, the integrated circuit may be configured to operate for 10 milliseconds per second. In such a case, the sleep / wake duty cycle may be settable by the user. In some embodiments, an analog filter having a band around the transmission signal frequency may be provided between the receiver and the amplifier that amplifies the reception signal. By using such a filter, it becomes easy to prevent the noise picked up by the receiver from being processed by the integrated circuit. As a result, in many cases, the effective power consumption by the integrated circuit can be suppressed.

  The sensor may optionally include an automatic calibration circuit. In some embodiments, such circuitry may be used to automatically and dynamically compensate for inherent self-interaction between the transmitter and receiver. For example, in an embodiment where the transmitter and receiver are co-located (as in the configurations shown in FIGS. 4A, 5B, and 5C), even if the transmitter and receiver cannot be connected, the connection between the transmitter and receiver You may make it induce a certain amount of self-interaction by approaching. Based on non-ideal manufacturing tolerances (eg, antenna pad geometry, material type, etc.) and the environment in which the sensor is located (eg, nearby conductors may increase self-interaction) The degree of self-interaction of each sensor may change. If the transmitter and receiver cannot be connected, automatic calibration may be performed when the sensor is in a mismatched state. In some embodiments, the auto-calibration circuit may comprise a finite state machine that gradually increases the reference voltage of the received signal amplifier until the self-interaction voltage is completely or substantially cancelled. In other embodiments, any other suitable circuit that corrects for self-interaction may be used. In some embodiments, an option to enable or disable the sensor auto-calibration feature may be provided.

  The sensor design of the present invention can be similarly applied to touch sensors and / or presence detection sensors. In some embodiments, such a sensor may comprise the configuration shown in FIG. 2A, with the transmitter and receiver intentionally placed in close proximity to each other to induce self-interaction. In such cases, a match occurs when the self-interaction or electric field between the transmitter and receiver is not disturbed by the external object, while the self-interaction or electric field between the transmitter and receiver is disturbed by the external object. Inconsistent state. In the case of such a sensor, an optional automatic calibration circuit may be used as an option, and may be operated in a manner opposite to the above-described method. That is, a finite state machine may be used to gradually reduce the reference voltage to compensate for any self-interaction that exists in the case of a mismatch condition. When such a sensor is applied to a mobile phone, the touch screen of the smartphone can be deactivated during a call in which the presence of a person is detected very close to the touch screen. Such sensors may be used to awaken the system by detecting that a person is near the system (eg, a tablet computer or other electronic device).

  As mentioned above, although embodiment of this invention was described in detail for the purpose of assisting understanding of this invention, this invention is not limited to these details. The present invention can be implemented in variously modified and changed forms, and the above-described embodiments are merely examples, and do not limit the present invention.

Claims (20)

A sensor,
A transmitter and receiver configured to capacitively couple when a coupling condition is met;
A circuit configured to determine whether a received signal received by the receiver matches a transmitted signal transmitted by the transmitter. The sensor according to claim 1,
The circuit is further configured to generate an output signal;
The sensor, wherein the output signal indicates a first state when the received signal matches the transmitted signal, and indicates a second state when the received signal does not match the transmitted signal. The sensor according to claim 1,
A sensor, wherein the coupling condition is satisfied when the transmitter and the receiver are in proximity. The sensor according to claim 3,
A sensor, wherein the transmitter and the receiver are arranged on different surfaces. The sensor according to claim 1,
A sensor, wherein the coupling condition is satisfied when a passive coupler is proximate to the transmitter and the receiver. The sensor according to claim 5,
A sensor, wherein the transmitter and the receiver are arranged substantially in a single plane. The sensor according to claim 5,
The passive coupler comprises a conductor. The sensor according to claim 1,
The sensor is further configured to generate the transmission signal. The sensor according to claim 1,
Determining whether the received signal matches the transmitted signal includes determining the strength of the received signal. The sensor according to claim 1,
Determining whether the received signal matches the transmitted signal includes determining an error if there is an error between the received signal and the transmitted signal. The sensor according to claim 1,
Determining whether the received signal matches the transmitted signal includes determining whether the received signal matches the transmitted signal for a predetermined number of samples. The sensor according to claim 1,
The sensor wherein the transmission signal includes a patterned signal. The sensor according to claim 1,
Further, a sensor comprising a circuit for adjusting a sensitivity range of the sensor. The sensor according to claim 1,
Furthermore, the sensor provided with the circuit which suppresses the power consumption of the said sensor. The sensor according to claim 1,
A sensor further comprising an automatic calibration circuit that compensates for self-interaction between the transmitter and the receiver. The sensor according to claim 1,
A sensor with a differential configuration. The sensor according to claim 1,
A sensor comprising one or more of a switch, a position detection sensor, a proximity detection sensor, a presence detection sensor, and a touch sensor. The sensor according to claim 1,
The circuit comprises an integrated circuit. A method for determining a state,
Configuring the transmitter and receiver to capacitively couple when coupling conditions are met;
Determining whether a received signal received by the receiver matches a transmitted signal transmitted by the transmitter. A computer program product for determining a state,
A computer-readable storage medium;
Computer instructions,
The computer instructions are:
Configure transmitters and receivers to capacitively couple when coupling conditions are met,
A computer program product for determining whether a received signal received by the receiver matches a transmitted signal transmitted by the transmitter.

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