Abstract: A surface-pressure distribution sensor includes a plurality of unit detection elements placed in a sensor area of a substrate and a switch formed on the substrate. The sensor is configure to operate under an operation mode in which the unit detection elements are sequentially selected or a standby mode in which the unit detection elements are not selected. The sensor is also configured to alternate between the two modes. The switch is configured change the standby mode to the operation mode when the switch is operated on.

Abstract: A method for detecting displacements of a micro-electromechanical sensor including a fixed body and a mobile mass, and forming a first sensing capacitor and a second sensing capacitor having a common capacitance at rest. The first and second sensing capacitors being connected to a first input terminal and, respectively, to a first output terminal and to a second output terminal of the sensing circuit. The method includes the steps of closing a first negative-feedback loop, which is formed by the first and second sensing capacitors and by a differential amplifier, feeding an input of the differential amplifier with a staircase sensing voltage through driving capacitors so as to produce variations of an electrical driving quantity which are inversely proportional to the common sensing capacitance, and driving the sensor with the electrical driving quantity.

Abstract: An oscillatory or pulsed first signal is operatively coupled to a first electrode placed between a conductive heating element and a seating region of a seat containing the heating element. A second signal substantially equal to the first signal is operatively coupled to a second electrode placed between the heating element and the first electrode. An occupant in the seat is sensed from a response to the first signal, responsive to which a safety restraint system may be controlled. In other embodiments, the second signal is operatively coupled to an electrode placed proximate to a side of the heating element away from the seating region of the seat, the second electrode comprises a sheath at least partially around at least a portion of the heading element, or the operative coupling of the first or second signals comprises AC coupling, for example, through an associated first or second capacitor.

Abstract: A method for determining the position of a rotor with respect to a stator. The method includes generating offset N and Q signals when the rotor moves with respect to the stator and sampling the N and Q signals at a predetermined time interval. A section of a polar plot in which the N and Q signal sample lies is determined and compared to the section of a polar plot in which a previous N and Q signal sample lies. A long range rotor position is calculated by maintaining a count of the change of sections from previous N and Q signal samples. A sub-section rotor position for the N and Q signal sample is calculated and combined with the long range rotor position to create a linear position signal.

Abstract: A MEMS sensor packaged with an integrated circuit includes switches and control circuitry. In a test mode, the control circuitry causes the switches to turn off and on such that the first and second capacitance of the MEMS sensor can be monitored individually. During a normal mode of operation, the switches are maintained such that the MEMS sensor packaged with the integrated circuit operates to produce a filtered and trimmed output reflecting the sensed phenomena.

Abstract: A touch sensor with a sensor surface insulated with respect to ground potential, the sensor surface being connected via a measuring resistor to an a.c. voltage generator, and the voltage across the measuring resistor being used as a difference measuring signal. At least one touch sensor can advantageously be integrated in a sanitary fitting and used to control solenoid valves on water feeds of the fitting. An operating element of the fitting is used as a sensor surface and is connected via a connecting cable to control electronics of the sensor. A method of detecting a touch on an electrically conductive surface, a capacitive touch sensor being used which detects the complex conductance of a human body. The touch detection is carried out by measuring and evaluating a current flow in the direction from the sensor to the person who touches the sensor surface and/or in the direction from the person into the sensor.

Abstract: A compact and light semiconductor sensor for detecting pressure and acceleration. A pressure sensor is formed on a first surface of an intermediate plate. An acceleration sensor is formed on a second surface of the intermediate plate. A first plate having a diaphragm is bonded to the intermediate plate to define a hermetic chamber of the pressure sensor. A second plate is bonded to the second surface of the intermediate plate. A spring support supports the mass in a manner relatively movable with respect to the second plate.

Abstract: This invention describes (i) an occupant classification, (ii) a baby seat detection, and (iii) an integrated occupant sensory system. The main goal of the invention is to provide the vehicle's restraint device(s) with enough information about the vehicle's occupant as to take the most appropriate actions necessary for the safety of the occupant. This invention (or some sub-modules of it) does not have to be restricted to the use in automotive restraint systems as it may be used in several other applications as well.

Abstract: A sensor for sensing the angular position of a rotatable body including a stationary transmitter plate with at least one transmitter electrode, a stationary receiver plate with at least a first and a second receiver electrode, and a rotor formed of a dielectric material and positioned between the facing electrodes of the plates. The rotor is smaller than the plates and rotates with the rotatable body to change the capacitance between the transmitter electrode(s) and opposed receiver electrodes. The induced voltages on the receiver electrodes indicate the angular position of the rotatable body. Preferably, the sensor uses a square waveform signal and two transmitter electrodes receive signals 180 degrees out of phase. Then, four receiver electrodes forming two receiver pairs are connected so that the current flowing between each pair is measured and converted to a voltage. A lookup table compares the values of the voltage pairs to known values from calibration, giving the angular position.

Abstract: A robot arm for industrial robots comprises one or several jointed arms (1, 1c) that are mutually connected to each other by means of rotary joints (1a, 1b), and a jointed arm (1) connected to a base (3), in which an angle transducer is arranged in the rotary joints (1a, 1b) in order to measure exactly the angular relationship between the jointed arms (1, 1c) or between the jointed arm (1) and the base (3), in order to make possible adjustment of the robot arm into the desired angular position.

Abstract: One aspect of the present invention provides instruments for measuring mechanical properties of a combinatorial library of materials. The instruments include at least one capacitor to which a member of a library of material samples is removably secured for testing; at least one voltage source for delivering one or more forces to each library member; and at least one sensing device for monitoring the response each library member to the one or more forces. Another aspect of the present invention provides methods of screening a combinatorial library of materials where the method monitors the responses of a plurality of samples on a substrate to a force induced by a capacitor.

Abstract: A system for detecting motion and proximity by determining capacitance between a sensor and an object. The sensor includes sensing surfaces made of a thin film of electrically conductive material mounted on a non-conductive surface. In another embodiment, the sensor is a human body. The sensor senses the capacitance between a sensor's surface and an object in its vicinity and provides the capacitance to a control system that directs machine movement. Because the sensor does not require direct contact or line-of-sight with the object, a machine can be controlled before harm occurs to the object.

Abstract: A capacitive dynamic quantity sensor includes a semiconductor substrate, a weight, a movable electrode, and two fixed electrodes. The weight is movably supported by the semiconductor substrate. The movable electrode is integrated with the weight. The fixed electrodes are stationarily supported by the semiconductor substrate. The fixed electrodes face the movable electrode to provide a narrow gap and a wide gap and form a detection part having a capacitance. The weight and the movable electrode are displaced relative to the fixed electrodes in response to a dynamic quantity to be detected such that one of the gaps increases while the other decreases. The dynamic quantity is detected on the basis of the variation in the capacitance. One of wide gap electrode surfaces, which define the wide gap, is smaller than narrow gap electrode surfaces, which define the narrow gap, to improve sensor sensitivity.

Abstract: A sensor unit having capacitance element electrodes and a displacement electrode being opposite thereto is disposed on a substrate. A detective button is supported onto the substrate in such a manner that the detective button is positioned above the sensor unit to define a specified space between the supporting member for supporting the detective button and the displacement electrode.

Abstract: A capacitance element electrode is formed on a first surface of FPC, and a displacement electrode is formed on a second surface of the FPC. The FPC is folded at its connecting portion in such a manner that the first surface and the second surface are opposite to each other, whereby a capacitance element is formed between the capacitance element electrode and the displacement electrode.

Abstract: A control signal generator transmits a first signal to a movable electrode and a fixed electrode to detect a change in a capacitance formed between the movable electrode and the fixed electrode during a normal physical quantity detection timing interval. Also, the control signal generator transmits a second signal to the movable electrode and the fixed electrode instead of the first signal to move the movable electrode for diagnosing a malfunction of each of a plurality of physical quantity detection portions during a self diagnosis timing interval. The control signal generator transmits the second signal to the movable electrode and the fixed electrode of each physical quantity detection portion during a different timing intervals.

Abstract: In a capacitance type sensor of the present invention, a capacitance element is constituted between a displacement electrode and a capacitance element electrode. A return-switch movable electrode is arranged above and spaced from the displacement electrode, to be placed in contact with the displaying electrode due to a displacement of a direction button. When the direction button is operated, the return-switch movable electrode is first displaced into contact with the displacement electrode. Then, the both make a displacement while keeping a contact state. When the displacement electrode is displaced to change the spacing to the capacitance element electrode, changed is the capacitance value of the capacitance element. Based on this change, a force is recognized. Herein, in the course of a transit from a state the displacement electrode and the return-switch electrode are not in contact to a state of their contact, the output signal varies necessarily beyond a threshold voltage.

Abstract: The invention provides a superior electrostatic capacitance detection device. An electrostatic capacitance detection device includes an M number of individual power-supply lines and an N number of individual output lines arranged in a matrix of M rows and N columns, and an electrostatic capacitance detecting element formed at the intersection thereof. The electrostatic capacitance detecting element includes a signal detection element and a signal amplifying element. The signal detection element includes a capacitance detecting electrode and a capacitance detecting dielectric layer. The signal amplifying element includes an MIS thin-film semiconductor device for signal amplification, including a gate electrode, a gate insulator, and a semiconductor layer.

Abstract: An AC/DC voltage reference system has at least one micromechanically fabricated electrode pair having first and second electrodes facing each other so that the electrodes are disposed at a distance from each other, whereby at least one of the electrodes is movable against a spring force. An AC signal is applied over the electrodes to establish an electrostatic force at a frequency substantially higher than the effective mechanical resonant frequency of the movable electrode. The system further includes an apparatus for detecting the AC voltage applied between the electrodes, thus forming an AC voltage reference.

Abstract: A capacitance-based position sensor configured to sense relative position of a pair of objects. The sensor includes capacitor circuitry having a capacitor that varies in capacitance with relative position of the pair of objects. A source is coupled to the capacitor circuitry, and is configured to apply a time-varying input to the capacitor circuitry. The capacitor circuitry is configured to yield a time-varying, capacitance-dependent output in response to application of the time-varying input from the source. The sensor further includes an integrator configured to integrate, for a predetermined time period, a received signal that is based upon the time-varying, capacitance-dependent output from the capacitor circuitry. The integration yields an integrator output which is proportional to the value of the capacitance. This output is usable to determine relative position of the objects.

Abstract: The method and a device to measure the repeatable and non-repeatable runouts of a rotating component of a spindle motor with the aid of at least one probe measuring changes in the distance between the probe and the rotating component depending on the angle of rotation. The probe records a first test signal in a first test cycle from which a signal defining the RRO is determined and stored. In a second test cycle, a command signal proportional to the amplitude and phase of the RRO signal is generated and fed to an electromechanical actuator supporting the probe. Depending on the command signal derived from the first test signal, the actuator changes the distance between the probe and the outer perimeter of the rotating component, thus compensating the runout defined by the RRO signal, while the probe records a second test signal defining the NRRO.

Abstract: An apparatus (100) for sensing presence and weight of a vehicle occupant includes a first conductor (120) that is electrically coupled to an oscillating circuit and disposed adjacent a first surface (112) of a compliant pad (110) within the seat of the vehicle. A first conductor (120) generates an oscillating signal at a first intensity. A second conductor (130) is disposed adjacent a second opposing surface (114) of the compliant pad (110) and is capable or receiving the oscillating signal at a second intensity. A detection circuit electrically coupled to the second conductor (130) and capable of receiving the oscillating signal at the second intensity determines the presence and weight of a vehicle occupant based upon the second intensity of the oscillating signal.

Abstract: A pocket-sized object finder has a compact housing containing a battery, circuitry and a capacitor plate for detecting an object hidden behind a wall. The battery powered circuitry includes multiple signal indicators that illuminate in a serial manner when the object is being detected. The signal indicators are successively tapered and are mounted at a front side of a tapered end of the housing. The capacitor plate is disposed in the housing along its rear wall and is responsive to variations in capacitance that occur as the object finder is brought near and over the object. The compact housing defines a cavity with a width that is no more than two inches and one third its length. A removable access door, with a pocket clip, at an end opposite the signal indicators allows access to the battery within the housing cavity.

Abstract: A capacitive measuring sensor which detects changes in an angle of electrode surfaces arranged at an acute angle to one another. The sensor outputs capacitive changes as a sensor signal. The sensor is preferably elongated and has at its end regions two fastening elements for connection to a body to be measured, two capacitor electrodes and two fastening elements. Changes in the angle of the capacitor electrodes is effected by displacement between the fastening points on the object to be measured.

Abstract: This invention relatives to a method for detecting quantity variation of high purity liquid chemicals by way of detecting capacitance variation to determine the liquid level of liquid chemicals. Meanwhile, the ratio of the area of the smallest electrode of the capacitor to the distance between the electrodes is adjusted to magnify the capacitance so that a very small variation can be observed clearly. This invention also discloses a device to carry out this method.

Abstract: Capacitance sensor electrodes are arranged in a form of matrix on a semiconductor substrate and coated with a cover film. These capacitance sensor electrodes are connected to a drive circuit. ESD electrodes are arranged in the vicinities of corner portions of the capacitance sensor electrodes. Each ESD electrode is composed of a film containing, for example, aluminum excellent in conductivity and a TiN film formed thereon. The ESD electrodes are grounded through the semiconductor substrate. On each ESD electrode, a plurality of fine ESD holes reaching the ESD electrode from a surface of the cover film are formed.

Abstract: A capacitive sensor includes a fixed board provided with a fixed electrode unit consisting of one or more electrodes, a movable member provided with a movable electrode unit consisting of one or more electrodes which faces the fixed electrode unit with a gap therebetween, the movable member being rotatable with respect to the fixed board, a weight provided on the movable member, and a retaining element which is disposed between the fixed plate and the weight and retains the movable member in a rotatable manner. At least one of the movable electrode unit and the fixed electrode unit includes a plurality of electrodes.

Abstract: A capacitive sensor includes a retaining member, an intermediate member retained by the retaining member such that the intermediate member can rotate around a first axis, a movable member retained by the intermediate member such that the movable member can rotate around a second axis which is perpendicular to the first axis, a weight provided on the movable member, a movable electrode unit consisting of one or more electrodes which is provided on the movable member, and a board on which a fixed electrode unit consisting of one or more electrodes is provided such that the fixed electrode unit faces the movable electrode unit. At least one of the movable electrode unit and the fixed electrode unit includes a plurality of electrodes, and capacitances between the one or more electrodes of the movable electrode unit and the one or more electrodes of the fixed electrode unit are detected.

Abstract: An apparatus (100) for sensing presence and weight of a vehicle occupant includes a first conductor (120) that is electrically coupled to an oscillating circuit and disposed adjacent a first surface (112) of a compliant pad (110) within the seat of the vehicle. A first conductor (120) generates an oscillating signal at a first intensity. A second conductor (130) is disposed adjacent a second opposing surface (114) of the compliant pad (110) and is capable or receiving the oscillating signal at a second intensity. A detection circuit electrically coupled to the second conductor (130) and capable of receiving the oscillating signal at the second intensity determines the presence and weight of a vehicle occupant based upon the second intensity of the oscillating signal.

Abstract: Rotating devices including actuators and position sensors that employ combdrives are described. One design of a combdrive fabricated from a single layer is provided such that, in a nominal state, the two sets of comb fingers are substantially interdigitated according to a predetermined engagement. A rotating element may be attached to a rotatable flexure disposed along an axis and coupled to the comb fingers along with a biasing element attached to the rotating element to cause the comb fingers along with the rotating element to undergo a controlled angular displacement from the initial engagement and in response to feedback from sensing the position of the movable or rotating element. A voltage may be applied between comb fingers to cause the rotating element to undergo further rotation about the axis in a predetermined manner.

Abstract: The invention relates to a tactile sensor in which a fiber (1) is linked with an instrument transformer (4) which is configured as a capacitor in such a manner that if the free end of the fiber is touched by an object, the touch is converted to electric signals. The force acting between the object and the sensor is kept at a minimum by using soft, elastic fibers. The inventive tactile sensor is especially useful for applications in robotics since due to the appropriate arrangement of the sensor on the contact surface of the robot gripper the sensor function is independent of any forces that might occur during the manipulation of objection. Another advantage of the tactile sensor is that it allows the dynamic registration of touches, thereby making it possible to determine the relative speed between the sensor and the object and to detect gliding or slipping movements on the basis of detected vibrations.

Abstract: A current value of each second harmonic content is measured while changing a frequency of an AC drive voltage applied to comb capacitors within a specified range. A frequency-current value characteristic is obtained for the second harmonic content, and the obtained characteristic is substituted with the vibration frequency-velocity characteristic of a microactuator.

Abstract: A circuit (40) and method are provided to create a drive voltage that is linearly proportional to a position of a movable member (12) of an electrostatic actuator device (10) that is positioned by a voltage (18) applied thereto. The circuit (40) has a sensor (42) to sense a position of the movable member (12) from a reference position (d0) to provide an analog position indicating signal. An analog-to-digital converter (ADC) (46) receives the analog position indicating signal and converts it to a digital position indicating signal. A digital signal processor (DSP) (48), programmed to convert the digital position indicating signal into a digital signal that is linearly proportional to the position of the movable member, receives the digital position indicating signal.

Abstract: The invention concerns dew point hygrometers based on condensation of dew on ends of optical fibers, or on surfaces of an optical prism. The invention also concerns a dew sensor for determining the natural dew condensation by optical means and a dew sensor capable of detecting dew by detecting a change in capacitance.

Abstract: An electromagnetic field presence sensor independently evaluates the presence or absence of an object in a variety of frequency ranges. Conflicting indications of the presence of the object in these different ranges, such as may be caused by electromagnetic interference, is resolved through a voting system. In this way, band limited noise may be resisted while improving the sensitivity of the sensor and without reducing its response speed.

Abstract: Measurement of the permittivity of thin films is facilitated through the use of a short cylindrical metal cavity containing parallel plates between which a specimen to be measured is placed. The use of such parallel plates contained within such a cavity is particularly advantageous when swept frequency measurement methods utilizing frequency ranges from 0 to 20 GHz are employed. A test fixture which is preferred for use in providing such a cavity is disclosed as are methods of using the test fixture.

Abstract: A capacitance position sensor comprises a pair of opposed tabular electrodes, an LC oscillator circuit having a toroidal core winding and whose oscillating frequency varies with change in capacitance between the pair of electrodes, and an arithmetic processing unit for calculating an absolute value of a distance between the electrodes from the oscillating frequency of the oscillator circuit. A position controller comprises a stationary member formed with one electrode of the pair of electrodes of the position sensor, a movable member on which the other electrode of the pair of electrodes is formed, and moving means for moving the movable member relative to the stationary member.

Abstract: A method of measuring changes in signal level output of an integrated circuit sensor by providing a direct current (DC) or low frequency (AC) bias to the sensor and placing a floating gate semiconductor device on-chip and coupling the floating gate of the semiconductor device with the sensor. As a result, changes in signal level output of the sensor modulate charge at the gate. The semiconductor device in turn converts the modulated charge at the gate into output signals proportional to the changes in the signal level output. The measurement method provides a resolution in the sub-atto range.

Abstract: A non-contact measuring method and apparatus for producing a signal representative of a distance between facing surfaces of first and second parts, which are closely spaced apart such as the rotor and stator of an electric rotating machine. The method resides in positioning a sensor on the surface of the first part. The sensor includes first and second parallel, superimposed conductive plates electrically insulated from one another. The second plate is located in between the first plate and the surface of the first part. The first plate is fed with a high frequency signal through a resistance. A high impedance, low input capacity, unitary gain voltage amplifier is fed with the high frequency signal through the resistance. The second plate is fed with an output signal of the amplifier. The output signal of the amplifier is directly proportional to the distance between the two surfaces.

Abstract: A wireless liquid sensing system includes a beverage container and a table top for holding the container. Embedded in the walls and bottom of the container are two electrically conductive plates coupled to a transponder wire coil. A reader radiates an RF signal at a predetermined frequency through a reader antenna. A microprocessor, also coupled to the transponder coil and the two plates, is powered by a rectifier circuit that gains power from then radiated RF signal. The microprocessor amplitude modulates the RF signal in accordance with the amount of liquid in the container. The reader can then detect this modulation with a peak detector to sense the amount of the substance in the container when the transponder antenna is inductively coupled to the reader antenna at the predetermined frequency.

Abstract: A wood drying installation for a wood drying kiln including a pair of electrodes adapted to be inserted into a wood stack contained in the kiln, a resistance connected in a series circuit with the electrodes, an AC voltage source connected to apply an AC voltage across the series circuit, a phase detecting circuit connected to the series circuit operable to generate a signal representing the phase angle between AC voltages applied to different parts of the series circuit, and a processor to receive the signal. The system is operable to determine a moisture value corresponding to a capacitive component of the reactive impedance between the electrodes in accordance with a predetermined arithmetic algorithm relating the value to the phase angle.

Abstract: The present invention provides a process for determining the spacing between a heater and a showerhead. First, at least one variable capacitor is placed between the heater and the showerhead, such that the spacing between the heater and the showerhead is in a predetermined relationship to the capacitance of the variable capacitor. Then, the capacitance of the variable capacitor is measured, and the spacing between the heater and the showerhead is converted from the capacitance. The determination process of the present invention can be conducted at high temperature above 350° C., and the spacing can be determined without opening the deposition chamber. This makes the entire process very convenient and the cost can be saved.

Abstract: The apparatus senses the positions of X- and Y- axes of the stage by applying an excitation signal having a phase difference to a stator of each axis of the XY-stage and then time-division detecting changes in capacitance from a moving plate.

Abstract: An enhanced fingerprint sensing circuit in which a voltage change is applied to the body during sensing. When the person's fingerprint is being sensed, the person's body is in contact with an electrical terminal. When the sensing occurs, the voltage on the electrical terminal changes, which changes the voltage on the person's body. The pattern of the fingerprint performs two functions in the sensing circuit. In addition to being a plate of a capacitor whose distance is being sensed, it is now a source of input charge as well. The electrical effect on the cell of a voltage change on a person's finger is different at a ridge than at a valley in the fingerprint sensing circuit. Thus, the input capacitance to the sensing circuit is variable, depending upon whether a ridge or a valley is present. The sensing circuit also detects a change in its own capacitance based on the presence of a ridge or a valley.

Abstract: First and second predetermined charging voltages are applied between the movable and fixed electrodes of a capacitive type of sensor to measure first and second capacitances between the movable and fixed electrodes, respectively. The first and second electrostatic capacitances are compared to obtain a characteristic of the sensor from a result of comparison. In measuring the first and second capacitances, first and second charging voltages are generated of which magnitudes are determined in accordance with the first and second capacitances, respectively. Equalization is made between the first output voltage when the first charging voltage is applied between the movable and fixed electrodes in a predetermined normal condition of the movable electrode and the second output voltage outputted when the second charging voltage is applied between the movable and fixed electrodes in the predetermined normal condition.

Abstract: A microelectromechanical system (MEMS) motion sensor is disclosed for detecting movement in three dimensions of a semiconductor wafer structure. The MEMS device has top, middle, and bottom layers, with a mover attached to the middle layer by a flexure that allows the mover to move in three dimensions relative to the layers. The mover has mover electrodes that create a capacitance with counter electrodes positioned on an adjacent layer. The capacitance changes as the mover moves. A capacitance detector receives signals from the electrodes and detects movement of the mover based on the change in capacitances. The MEMS device processes the detected capacitances to determine the nature of the movement of the mover. The mover and counter electrodes comprise x-y electrodes for detecting movement in an x-y plane parallel to the middle layer and z electrodes for detecting movement in a direction orthogonal to the x-y plane.

Abstract: The device for measuring the capacitance of electrical wires has a first and a second measuring tube both connected to a voltage source of high frequency. The first measuring tube has a conventional length while the second measuring tube is significantly shorter. With the first measuring tube the capacitance of the wire can be measured in a conventional manner. The second measuring tube allows the measurement of local changes of the capacitance.

Abstract: A capacitance element electrode (E1) and a reference electrode (E31) are formed on a substrate (20) so as to be opposite to a displacement electrode (40). A dome-shaped movable switch electrode (E21) is disposed so as to be in contact with the reference electrode (E31) and at a distance from a fixed switch electrode (E11) formed inside the reference electrode (E31), and to cover the fixed switch electrode (E11). When an operation is applied to a detective member (30) and a portion of the movable switch electrode (E21) in the vicinity of its top is displaced to be brought into contact with fixed switch electrode (E11), a switch is turned ON. On the other hand, from a change in capacitance value of a capacitance element (C1) formed between the displacement electrode (40) and the capacitance element electrode (E1), the intensity of the force to the detective member (30) can be recognized.

Abstract: This invention is directed to a method of making a capacitive distance sensor that includes one or more sensor cells each with first and second capacitor plates. The method includes determining an expected range of sizes of objects the sensor will be used to detect and determining a total perimeter value for each of a plurality of capacitor patterns. Each capacitor pattern includes a different arrangement of the first and second capacitor plates and the total perimeter value is the sum of the perimeter values for the first and second capacitor plates. The method selects one of the capacitor patterns based on the expected size of the object and on the total perimeter values determined for the capacitor patterns. The selecting step includes selecting whichever one of the capacitor patterns has the largest total perimeter value if the object is smaller than each of the one or more sensor cells.

Abstract: A semiconductor memory device is provided, which includes a chip enable buffer and an address buffer. The chip enable buffer generates first and second control signals having opposite phases of logic, the first and second control signals enable and disable operations of the semiconductor memory device, respectively. The address buffer includes an input terminal, and a blocking terminal connected to the input terminal, the input terminal receiving an external address signal under control of the first control signal, and the blocking terminal generating an address signal in response to the second control signal. The address buffer further includes a shift detecting circuit connected to the blocking terminal for generating first and second short pulses by detecting shift of the address signal, wherein the pluses are used as signals for reading data of the semiconductor memory device.