Abstract: A Micro Electro-Mechanical System (MEMS) acceleration sensing device, formed of a sensing element having first and second substantially planar and parallel spaced apart opposing surfaces and being suspended for pendulous motion about a hinge axis oriented along a minor axis of the sensing element; and one or more substrates each having a face spaced from one of the opposing surfaces of the sensing element, each of the substrates having pluralities of electrodes arranged substantially crosswise to the hinge axis of the sensing element symmetrically to a longitudinal axis of the sensing device and forming respective first and second capacitors with the moveable sensing element. Each of the one or more substrates optionally including a clearance relief for extending the rotational range of motion of the sensing element.

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 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: Capacitance element electrodes (E1 to E5) and a grounded reference electrode (E0) are formed on a substrate (20). At a position opposite to these electrodes (E0 to E5), a displacement electrode (40) is disposed that is Z-axially deformable as a detective member (30) is externally operated to move Z-axially. The displacement electrode (40) cooperates with the reference electrode (E0) and capacitance element electrodes (E1 to E5) to form capacitance elements (C0 to C5), respectively. Each of the capacitance elements (C1 to C5) is connected in series with the capacitance element (C0) with respect to a signal externally input. Changes in the capacitance values of the capacitance elements (C1 to C5) as the detective member (30) is moved are detected to sense the displacement of the detective member (30).

Abstract: A capacitive sensor assembly for a robot to prevent damage to the robot when it moves in an undesired manner is disclosed. The robot may be used in conjunction with semiconductor fabrication applications. The capacitive sensor assembly can include a hit contact, one or more fixed contacts, one or more damping springs, and a capacitive sensor. The hit contact comes into contact with a barrier as a result of undesired movement by the robot. The damping springs are compressed against the fixed contacts when the hit contact comes into contact with the barrier. The capacitive sensor has a capacitance that changes as the hit contact comes into contact with the barrier. The capacitance of the capacitive sensor is used to detect the robot coming into contact with the barrier, so that damage to the robot can be prevented.

Abstract: A capacitive sensor assembly is disclosed. In an exemplary embodiment, the assembly includes a capacitive strip having an elongated body for flexible mounting to a panel along a bottom surface of the elongated body. A first elongated planar conductor is contained within an upper section of the elongated body, while a longitudinal cavity is formed through a central portion of the elongated body. The longitudinal cavity is disposed between the planar conductor and the bottom surface. A capacitance detector module is inserted within the longitudinal cavity, the capacitance detector module including a capacitance detector circuit therein that is coupled to the first elongated planar conductor.

Abstract: The present invention relates to a method and a device for evaluating the deformations or forces to which a structure comprising an elastomeric body (2) is subjected, said device comprising a dipole (6), the dielectric (3) of which is formed by said elastomeric body and an electronic analysing circuit sensitive to a variation of a capacitive characteristic of the dipole caused by said deformations of said body.

Abstract: A position sensor is provided comprising a coil (1) and an electric conductor (2) or magnetic (3) both arranged so that the size of their overlapping area (p) is varied as the position of an object to be examined changes, a resistor (6), a capacitor (4), a comparator (5) of an inverse output type, and a timing circuit (50a) arranged for uniformly restraining the period (T) of a continuous oscillating motion, herein a displacement of the object to be examined is detected as a change in the time duration (t) which extends from the leading end of the period (T) to a time when the output of the comparator (5) is turned to a high level as timed with substantially the trailing end of the period (T). The resistance of the resistor (6) is determined so that a change in the time duration (t) remains minimum when the resistance of the resistor (6) is varied and when the temperature is at a predetermined degree.

Abstract: A phase angle determining circuit for determining a phase angle from a first input signal and a second input signal includes an input circuit configured to receive the first input signal and the second input signal and to provide a third signal, and an output circuit configured to receive the third signal and to provide an output signal representative of the phase angle. The first and second signal may be provided by a transducer. The transducer may be a steering wheel transducer and the phase angle determining system may be utilized in a vehicle system to control a vehicle system based on the phase angle of the steering wheel.

Abstract: A transmission electrode 10 and a detection electrode 12 are placed in an electrode section of a sensor and are capacity-coupled with a reception electrode placed on an opposed scale. Capacity change between the transmission electrode 10 and the reception electrode caused by displacement is detected with the detection electrode 12. A plurality of signals different in phase are supplied to the transmission electrode 10. The signal lines are wired like a zigzag using an upper layer and a lower layer and the distances between the signal lines and the detection electrode 12 are made substantially equal for making uniform the crosstalk amounts relative to the detection electrode 12.

Abstract: A pointing device some or all of whose elements are made from capacitive sensors. Such elements may include a rotary motion detector which includes a rotating member and a plurality of fixed capacitive detecting members; a rolling ball with patterned conductive surface and a plurality of fixed capacitive detecting members; capacitive touch sensors or capacitive switches to serve as mouse buttons; and a scrolling wheel, knob, or touch surface built from capacitive sensors. The pointing device further includes a capacitance measuring circuit and processor to measure variations of capacitance on the various capacitive elements and to determine the movement of and other activations of the mouse.

Abstract: A capacitance type load sensor is provided with outer and inner tubes made of plastic and formed into a hollow circular cylinder shape and outer and inner electrodes respectively attached to the inner and outer peripheral faces of the outer and inner tubes. A coil spring is disposed within the interior space of the inner tube, and load-applied hooks of the coil spring are individually coupled to respective end walls of the outer and inner tubes. When a tensile load is applied to the hooks of the coil spring and hence the coil spring is elongated, a relative motion occurs between the outer and inner tubes so that the facing area between the outer and inner electrodes and accordingly the capacitance between these electrodes decrease. The load sensor measures the applied load based on an amount of change in the capacitance between before and after the application of the load.

Abstract: The capacitive angular displacement transducer includes a first stator (2) comprising a plurality of electrically conductive; circular ring-shaped electrodes (51) which are electrically isolated from each other and have a predetermined sector angle, with a second stator (4) arranged parallel to the first stator comprising a receiving electrode (6), and with a rotor (3) mounted on a rotatable shaft (7) comprising at least one rotor blade (8a, 8b) in the form of circle sectors and located perpendicular to the shaft and the rotor blade being located parallel to and between the first and the second stators. The sum of the central angles of all transmitting electrodes is less than 2&pgr; (360°), preferably ranging from &pgr;/12 (30°) to 5&pgr;/6 (300°), and the central angle of each rotor blade is essentially equal to the sum of the central angles of n adjacent or neighboring transmitting electrodes.

Abstract: A joystick that detects position and movement using a capacitive sensor. The joystick has a stick mounted to allow movement within a housing, a conductive element at a first end of the stick, and a capacitive sensor. The capacitive sensor may be a capacitive touchpad. It determines position by measuring the change in capacitance on a set of conductive traces. The capacitive sensor may be shaped as a plane or may be hemispherically-shaped. The conductive element may also be triangular or other distinctive shape to allow detection of movement. An advantage of such a joystick is that absolute positioning may be determined, along with relative positioning.

Abstract: The edge portion of an electro-conductive material inserted between a pair of the transmitting electrodes of triangular plate disposed flatly in opposite directions each other and the receiving electrode. The exciting signal source applies respectively the alternating voltage signal S1 with frequency f1 on one of the transmitting electrodes and the alternating voltage signal S2 with frequency f2 on the other transmitting electrode. The insertion extent of the strip edge of the electro-conductive material is evaluated with the ratio between the current I1 with frequency f1 and the current I2 with frequency f2 generated on the receiving electrode.

Abstract: This invention includes a first electrode (10a, 10b, 10c, 30) and a second electrode (20a, 20b, 20c, 20d) which are arranged to face each other so as not to come into contact with each other and a gap between which changes in accordance with a change in an amount to be detected, and a signal processor 4 for calculating the amount to be detected on the basis of an electrostatic capacitance formed between the first and second electrodes. The first electrode has a portion (12a, 14a) and a portion (12b, 14b), areas of which that face the second electrode increases and decreases, respectively, upon a positioning error that occurs in a direction (x, y) parallel to the first electrode. These portions have the same area.

Abstract: Measuring the electrical resistance of a resistive body, in particular a reservoir containing a printing product such as ink. According to the invention, the resistive body is used to define a capacitance arrangement formed from a capacitive branch which includes a capacitor electrically connected to the resistive body and this is incorporated in a resonant circuit that includes a variable capacitor. The resonant circuit is supplied with a fixed frequency, and as the capacitance of the variable capacitor is varied the peak of the signal is sought. The amplitude of the peak is representative of the resistance of the resistive body.

Abstract: A non-contacting capacitive position transducer comprises a stator substrate carrying two electrically conducting inverted wedge regions 14,16 whose width varies inversely in a sensing direction. A moveable pick-off 20 is capacitively coupled to both wedges. The wedges 14,16 are driven with respective distinguishable time varying periodic waveforms, e.g. a sine wave and a cosine wave, and the pick-off voltage at 20 processed to determine the position of the pick-off in the sensing direction. Various configurations of transducer are described, including those of linear, cylindrical and disc form. The pick-off voltage is preferably transferred from the pick-off 20 back to the stator by capacitively coupling the pick-off to a suitably screened pick-off track 36 on the stator.

Abstract: The capacitive angular displacement transducer includes a first stator (2) comprising a plurality of electrically conductive, circular ring-shaped electrodes (51) which are electrically isolated from each other and have a predetermined sector angle, with a second stator (4) arranged parallel to the first stator comprising a receiving electrode (6), and with a rotor (3) mounted on a rotatable shaft (7) comprising at least one rotor blade (8a, 8b) in the form of circle sectors and located perpendicular to the shaft and the rotor blade being located parallel to and between the first and the second stators. The sum of the central angles of all transmitting electrodes is less than 2&pgr; (360°), preferably ranging from &pgr;/12 (30°) to 5&pgr;/6 (300°), and the central angle of each rotor blade is essentially equal to the sum of the central angles of n adjacent or neighboring transmitting electrodes.

Abstract: A capacitance measurement system amenable to implementation on an integrated circuit includes a switching network, a voltage driving element, a sensor network, and a feedback network. The sensor network includes a fixed capacitor connected in series to a variable sensing capacitor. The feedback network receives the voltage generated at the junction node between the two capacitors, and the other side of the sensor capacitor is connected to system ground. The voltage driving element, responsive to a signal from the switching network, shifts the local voltage which supplies power to the feedback network. The feedback network generates a feedback signal representative of the difference in the charge stored on the series capacitors from a predetermined value.

Abstract: A low-cost, high-resolution capacitive position sensor is provided using a variable capacitor. A vane moves parallel to a stator, where a dielectric is interposed between vane and stator, such that the vane overlaps at least a portion of the stator, creating a capacitance that varies as the vane moves relative to the fixed stator. The capacitor circuit outputs a signal having a phase shift relative to an input driver signal based on the relative positions of the vane and stator. The phase-shifted signal is used to derive the absolute position of the vane with respect to the stator. Two or more stator can be provided to provide two phase-shifted signals and a difference signal free of common mode effects. Enhanced embodiments include interdigitated stator portions for greater sensing resolution, and/or a two or three-pole filter to double or triple the dynamic range of the sensor.

Abstract: Determination of the quantity of consumable product present in a reservoir, for example the quantity of ink present in the reservoir of an inkjet printing device. According to the invention, the movable reservoir can be engaged in the dielectric space of a capacitor consisting of two plates, a signal generator applies a signal to the capacitor and the reservoir is moved, a comparator changes state when a threshold is reached and the distance travelled by the reservoir makes it possible to determine the quantity of product situated therein.

Abstract: The present invention is directed to a weight sensing apparatus (10) for a vehicle seat (22). The weight sensing apparatus (10) includes a differential capacitor (150) including a first capacitor (152) and a second capacitor (176). The first capacitor (152) includes first and second opposed plate assemblies (154 and 156). The second capacitor (179) includes a third plate assembly (180) and the second plate assembly (156). Each plate assembly (154, 156, and 180) includes a plurality of electrically conductive elongated members that extend in an axial direction. The second plate assembly (156) is interposed between the first and third plate assemblies (154 and 180) and is movable in an axial direction relative to the first and third plate assemblies (154 and 180) in response to a load being applied to a vehicle seat. A source of alternating current supplies electrical energy to the differential capacitor (150) and an output circuit is electrically connected with the differential capacitor (150).

Abstract: A windowed shutter on a micro-electro-mechanical system improves output current of a non-contacting electrostatic voltmeter. The output current is increased by increasing the area modulated by the micro-electro-mechanical shutter system and by increasing the speed of that modulation. The increase in the area modulated by the windowed shutter is in direct proportion to the number of windows used. Moreover, the speed of the modulation is increased by increasing the resonant frequency of the system. Less shutter mass increases the frequency thus increasing shutter movement over time.

Abstract: For determining the respective geometrical position, the displacement or angle of a body by capacitive sensing, a supply voltage applied to a voltage-distribution element is switched, and/or phase-shifted voltages are applied, in such a way that at least two different distribution patterns of the supply voltage, that follow each other in time, are obtained across the voltage divider.

Abstract: A capacitive rotary position sensor is provided. The rotary positions sensor includes a housing, a stator, and a rotor. The stator is formed of a disc shaped piece of insulating material including a plurality of conductive plates formed in a circular pattern on the surface of the disc. Similarly, the rotor is formed as a second disc of insulating material having a single conductive plate formed on the surface thereof. A signal generator provides a polyphase signal for driving each of the conductive plates formed on the rotor with an individual component of the polyphase signal. The stator and rotor are placed in parallel to the stator disc, and the plurality of conductive plates on the stator face the single conductive plate formed on the rotor. A thin dielectric coating applied to the rotor plate prevents the rotor conductive plate from shorting the adjacent stator conductive plates.

Abstract: Double-emitting and multiple-receiving capacitive measuring device: it comprises a scale equipped with an array of electrodes and a transducer, which moves parallel to and opposite the scale and is equipped with two emitting electrodes and an array of receiving electrodes distributed into N groups. The capacitive coupling between the different electrodes allows the position of the transducer to be determined. A generator emits two emission signals (E0, E1) in phase opposition on the two emitting electrodes of the transducer. The frequency of generated emission signals (E0, E1) depends upon the speed of displacement of the transducer. Processing means determine a dimension with the aid of N signals (R0, R7) received on the receiving electrodes. The more significant bits of the result are provided by a primary counting system using a first algorithm. The less significant bits are provided by a secondary precision system using a second algorithm.

Abstract: In a measuring arrangement for determining the lift of a valve including a cylindrical valve stem member arranged in overlapping telescopic relationship with a stationary cylindrical member so as to be movable relative thereto, one of the cylindrical members has on its surface adjacent the other cylindrical member first and third capacitor structures which are axially spaced, and insulated from, each other and the other is provided on its surface adjacent the one cylindrical member with a second capacitor structure extending axially over the first and third capacitor structures when the valve is in a closed position, all the capacitor structures being electrically connected to a control unit for determining from the capacitance difference between the first and third capacitor structures the position of the valve member.

Abstract: A small position detection and positioning device detects relative displacement between two members with high precision. A moving medium-type memory device using such positioning device is also provided. The position detection device includes a linear array of first electrodes at equal pitches on one of the two members that have relative displacement in at least one dimension, and a linear array of at least one second electrode on the other member. The first electrodes are positioned opposite the second electrodes and separated from them by a minute gap. The first electrodes are divided into a first electrode set composed of alternate ones of the first electrodes, and a second electrode set composed of alternate ones of the first electrodes not in the first electrode set. A signal source which applies a first alternating signal to the first electrode set and a second alternating signal that differs in phase by 180.degree.

Abstract: A position detection device that comprises a first substrate, a second substrate, an alternating current (AC) bridge comprised of four variable capacitors, and a detection circuit. The first and second substrates have a flat first electrode surface and a flat second electrode surface, respectively. The second substrate is mounted opposite the first substrate with the first electrode surface opposite the second electrode surface and separated from the second electrode surface by a minute gap. The second substrate and the first substrate are movable relative to one another in the plane of the electrode surfaces. Each of the variable capacitors is composed of a first capacitor electrode located on the first electrode surface and a second capacitor electrode located opposite the first capacitor electrode on the second electrode surface.

Abstract: A pump control system which can distinguish between water and oil so that a pump can be controlled to pump water and deactivated before oil is pumped. Sensing is accomplished by a pair of capacitive sensors, one located above the other in a vessel in which water accumulates. A dual mode frequency oscillator is associated with each sensor. Each sensor reacts to the dielectric constant of the liquid at the sensor by changing its capacitance, to thus detect the presence of a conductive substance, such as a liquid, to cause the sensor's oscillator to switch its mode of oscillation. The dual mode oscillator of each sensor selectively generates a control signal having two different duty cycles. As the dielectric constant of the liquid medium is sensed, a logic circuit interposed between the sensors allows the output of each sensor to be turned off when only the lower sensor is in water. The circuit turns on the pump only when both sensors are in water and the pump remains on until both sensors are out of water.

Abstract: A circuit board has an arcuate array of conductor segments each subject to a digital waveform differing in phase for the various segments, and a concentric pickup conductor. A rotary encoder disk has a conductive pattern which sums and couples the waveforms from selected segments, depending on rotary position, to the pickup conductor. A synchronous phase detector generates a phase signal from the summed waveforms and the zero crossing of the phase signal is detected. A counter develops count signals used to generate the digital waveforms. The count signals are input to a latch which is clocked at the zero crossing point to latch the count value which is a digital measure of the encoder angle.

Abstract: A method and apparatus for synthesizing spatial waveforms in electronic position encoders allows the position of a composite spatial waveform applied to an electronic position transducer to be incremented by amounts less than the pitch of the electrodes of the electronic position transducer. The position of the composite spatial waveform is adjusted by applying several individual spatial waveforms to the electronic position transducer during a position measurement. The position of one or more individual spatial waveforms is altered by increments of the electrode pitch. As a result, a position of the composite spatial waveform resulting from the individual spatial waveforms is the average position of the individual spatial waveforms. In one embodiment, the composite spatial waveform is applied to the transmitter electrodes of an electronic position transducer. The position of the composite spatial waveform is adjusted so that the voltage from the electronic position transducer is minimized.

Abstract: A sensor for providing an indication of the movement of one component of a system with respect to another includes a plurality of discrete electrodes and a common electrode affixed to the non-moving component along the axis of movement of the moving component and a pointer affixed to the moving component also along the axis of movement. As the moving component moves, it positions the pointer at consecutive ones of the plurality of discrete electrodes forming a capacitor structure with each in succession. When interrogated, the capacitor provides a signal indicative of the position of the moving component. The sensor is useful for indicating linear movement, angular displacement and pressure, strain and temperature when adapted to structures which indicate such parameters as a function of displacement. Alternative structures include "Bar Codes" with a laser as a pointer and magnetic stripes with a magnetic read head as the pointer.

Abstract: The fast sampling method for taking a position measurement with an electronic measurement system incorporating a capacitive position transducer of this invention allows such capacitive position transducers to be used in contaminant filled environments, such as on a shop floor or in the outdoors. By sampling the output signals within 25 ns-35 ns from when the input signals were applied to the capacitive position transducer, the adverse effects of resistive contamination can be avoided.

Abstract: The invention concerns rainwater sensors for windshields. In one embodiment, a first, inner, conductive film is applied to the inner surface of the windshield, and a second film, of same size and shape as the first, is applied to the outer surface. However, a narrow strip is removed from the second film, forming a gap which divides the second film into parts 1 and 2. The resulting structure forms two capacitors, namely: (1) inner film plus part 1, and (2) inner film plus part 2. The impedance of one capacitor is monitored. When rain occurs, it falls into the gap between parts 1 and 2, and acts as a resistor, bridging part 1 to part 2. This bridging adds a new impedance in parallel with the first capacitor, thereby changing the effective impedance. This change indicates the presence of rain.

Abstract: A movable electrode is positioned between two fixed electrodes. The movable electrode is rotated in correspondence to a rotation angle to be detected. The fixed electrodes and the movable electrode are split into first split electrode members and second split electrode members not conducting with each other respectively. The first fixed split electrode members are electrically connected with a first external terminal, and the second fixed split electrode members are electrically connected with a second external terminal. Thus, electrostatic capacitances which are derived from the external terminals are varied by rotation of the movable electrode. In this sensor, the varied electrostatic capacitances can be derived through conductive paths comprising no sliding contact portions, while a variable range of the electrostatic capacitances can be increased.

Abstract: A conductive strip detector comprises a capacitor defined by an elongate, electrically conductive element (5) and a laterally spaced, electrically conductive member (1). Monitoring circuitry (15,16) monitors changes in the capacitance of the capacitor when an electrically conductive strip substantially parallel with the element is passed by the capacitor and indicates when a change in capacitance is due to the presence of an electrically conductive strip.

Abstract: A circuit arrangement for an analytical function generator with a capacitive differential transducer for editing the signals measured by the differential transducer into a transmittable signal at the output of the circuit arrangement which comprises two coupled RC-oscillators, wherein a first of the two oscillators is arranged in the feedback of the second of the two oscillators and the capacitance of the two oscillators is formed by one of the two partial capacitances of the differential transducer, two bistable trigger circuits connecting the two oscillators with one another, wherein one of the two trigger circuits causes a level inversion, and a gate for the linkage of the partial signals appearing at the output of the two trigger circuits so that a logic twin pulse signal corresponding to the measured magnitude or variable is generated at the output of the gate.

Abstract: A capacitive bend sensor includes a first element having a comb-patterned portion of conducting material, and a second element having a comb-patterned portion of conducting material. A dielectric material is disposed between the comb-patterned portion of the first element and the comb-patterned portion of the second element. The first element is bonded to the second element such that the comb-patterned portion of the first element slides relative to the comb-patterned portion of the second element when the first and second elements are bent. Bend angle is measured according to the alignment of the comb-patterned portion of the first element and the comb-patterned portion of the second element. The sensor may be coupled to a human finger to measure bend angle of the finger, or may be coupled to a joint of a human body to measure bend angle of the joint.

Abstract: Measuring device for the measurement of a rotor angle including a capacitive angular displacement transducer generating an output that varies with an angular displacement of a shaft. A first stator has a plurality of transmitting electrodes to generate electric fields within the transducer due to excitation signals applied to the plurality of transmitting electrodes which are electrically conducting circle sectors of equal area which are electrically isolated from each other and which completely cover a rotational angle of 2.pi. on the first stator. A second stator is parallel and coaxial to the first stator and includes a conductive ring electrode receiving excitation from the first stator and producing an electric output signal. A rotor is located coaxially, parallel to the first stator and the second stator. The rotor has at least one rotor blade in the form of circle sectors, the central angle of each rotor blade being equal to at least the sum of the central angles of two sectors of the first stator.

Abstract: An electronic caliper configuration making such calipers more reliable in the presence of liquid and particulate contaminants. Included in the caliper configuration is an elongated cavity added to the main beam of the caliper. The cavity is sealed with a cover. The measuring scale element of the measuring transducer, and the associated shorter pickoff element are mounted in this cavity. The depth bar, ordinarily attached to the sliding jaw in conventional calipers, is inserted into the cavity through a hole or holes aligned parallel to the longitudinal axis of the caliper and internally joined to the moving transducer element. A conventional lip seal provides an effective seal around the diameter of the depth bar. An external portion of the depth bar is coupled to the sliding jaw of the caliper via axially rigid linkage or alternately an axially rigid flexure. In this way, the internally isolated transducer elements can be actuated by the external sliding caliper jaw.

Abstract: The capacitance sensor (1) comprises a linear or curvilinear array of electrodes (10) connected to means generating on these electrodes (10) a spatially periodic electric potential pattern shifting by increments along said array. Electrodes (10) are disconnected in turn to act as momentarily receiving electrodes (10R), also according to a spatially periodic pattern, shifting by the same increments. Both patterns shift alternately, i.e. the shifts of one pattern taking place between the shifts of the other. A linear or curvilinear scale (2), with a periodic pattern of electrodes (20) or dielectric or conducting relief, facing the sensor, will thus create a periodic fluctuation of the signal coupled on the momentarily receiving electrodes. The relative position between scale (2) and sensor (1) may then be accurately determined by evaluating the phase, after demodulation, of said signal.

Abstract: A broken tine detector for agricultural machines is provided for machines such as balers and forage harvesters. The tines form a first plate of a capacitor which rotates about the axis of a reel. The second plate of the capacitor may be provided by a back-plate which is located at the front of an agricultural machine adjacent to the ends of the tines and which is connected to machine ground. An alternate embodiment of the invention is devised by utilizing conductive strips on a tine guard. Each of the conductive strips may be utilized to form the second plate of the capacitor. The row of tines pass through individual slots in the tine guard so that a particular row in which the tine is broken may be detected. When a tine is broken the total capacitance between the tines and the back-plate will change and will be detected, and an indication will be supplied to an operator so that the operator may stop the machine and remove the tines.

Abstract: A device is provided to measure and record the movement of an object according to a change in magnetic flux which changes as the object moves. The device contains a micro machine which has a rotation detection member, a driving gear which is formed coaxially with the rotation detection member, and a first detection plate which is also formed coaxially with the rotation detection member. The rotation detection member rotates according to the change in magnetic flux, and the rotation of the rotation detection member causes the driving gear and the first detection plate to rotate. The driving gear engages a follower gear, so as to form a gear train, and a second detection plate is formed coaxially with the follower gear and rotates when the follower gear rotates.

Abstract: A proximity detection system includes a dual mode oscillator for generating a pair of ON and OFF control signals. A sensing circuit including a capacitance device detects the presence of a conductive object, such as a liquid, to cause the oscillator to switch its modes of oscillation.

Abstract: A bridge-type capacitance transducer comprising four active components is disclosed. The symmetry of this transducer is maintained in the presence of capacitance change induced by motion. Consequently, there is greater immunity to extraneous stray capacitances, thus greater sensitivity and range of linearity. Sensitivity is further increased by means of synchronous detection at the output.

Abstract: A capacitive measuring device or apparatus; in particular, a length-measuring apparatus, which incorporates a scale portion and a scanning unit which is movable relative to the former and which supports transmitting electrodes and at least one receiving electrode. Herein, a transmission circuit applies transmitting signals at a basic frequency to the transmitting electrodes, and with the receiving electrode being connected to a reception circuit, to the output side of which there is connected an evaluating circuit for the receiving signals. The transmitting signals are applied to the transmitting electrodes through a pulse width modulator and a synchronous modulator and the receiving signal is conducted through a demodulator.

Abstract: A measuring device for absolute measurement of positions is disclosed, which comprises a displacement sensor having a fixed element and a movable element which is relatively movable against the fixed element and being adapted to output a signal corresponding to the relative position of the movable element against the fixed element, demodulators for processing the output signal of the displacement sensor so as to obtain cyclic square signals for detecting at least two types of displacement of coarse scale and fine scale, each edge of the square signals having phase information, phase detectors for detecting phase information from each square signal obtained by the demodulators so as to obtain phase data of at least coarse scale and fine scale, a composing circuit for composing phase data of the coarse scale and fine scale obtained by the phase detectors so as to obtain an absolute displacement of the movable element against the fixed element, a display portion for displaying the absolute displacement obtained

Abstract: A capacitance-type measuring apparatus includes first and second support members which are movable with respect to one another along a measurement axis; a first electrode array and a second electrode disposed on the first support member; and a third electrode array disposed on the second support member and capacitively coupling the first electrode array and second electrode for transmission of a signal between the first electrode array and second electrode through the third electrode array. One of the first electrode array or the second electrode is formed to have end portions configured such that the degree of coupling between the first electrode array and second electrode through the third electrode array decreases linearly along the extent of each end portion relative to the measurement axis. This configuration permits improved measurement accuracies by reducing the effects of tilt between the first and second support members which changes the spacing between such members along the axis of measurement.