Abstract: A capacitive position sensing system has a pickup electrode, a shield electrode partially enclosing the pickup electrode, and an essentially grounded relatively movable target near the pickup electrodes; a capacitance-to-digital converter, and switching means for connecting each electrode in turn to the converter input or to ground. A capacitive position sensing method in the system includes measuring a first capacitance C1 of at least one pickup electrode set with the shield electrode set grounded, measuring a second capacitance C2 of at least one shield electrode set with the pickup electrode set grounded, and measuring a third capacitance C3 of the pickup electrode set and the shield electrode set connected together; and calculating a first result indicating a position of a target using the first capacitance C1, the second capacitance C2 and the third capacitance C3.

Abstract: A capacitive position sensing system has a pickup electrode, a shield electrode partially enclosing the pickup electrode, and an essentially grounded relatively movable target near the pickup electrodes; a capacitance-to-digital converter, and switching means for connecting each electrode in turn to the converter input or to ground. A capacitive position sensing method in the system includes measuring a first capacitance C1 of at least one pickup electrode set with the shield electrode set grounded, measuring a second capacitance C2 of at least one shield electrode set with the pickup electrode set grounded, and measuring a third capacitance C3 of the pickup electrode set and the shield electrode set connected together; and calculating a first result indicating a position of a target using the first capacitance C1, the second capacitance C2 and the third capacitance C3.

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 capacitive position sensor has a scale (10), having hollow or raised topographical features, and a cursor (20) having an electrode array comprising at least two transmitting electrodes (21a, 21b) and at least one receiving electrode (21c) separated by shielding electrodes (21g). The coupling capacitances (Cac, Cbc) between transmitting and receiving cursor (20) electrodes are modified as a function of the position (x) of the scale topographic feature (11) relative to the cursor, the evaluation of the variation of the signals picked up by the receiving electrode permitting a precise measurement of the relative displacement between scale and cursor.

Abstract: A capacitive position sensor has a scale (10), having hollow or raised topographical features, and a cursor (20) having an electrode array comprising at least two transmitting electrodes (21a, 21b) and at least one receiving electrode (21c) separated by shielding electrodes (21g). The coupling capacitances (Cac, Cbc) between transmitting and receiving cursor (20) electrodes are modified as a function of the position (x) of the scale topographic feature (11) relative to the cursor, the evaluation of the variation of the signals picked up by the receiving electrode permitting a precise measurement of the relative displacement between scale and cursor.

Abstract: The capacitive detector of position between two supports (10 and 30) comprises a series of electrodes (11) on support (10) and a series of electrodes (13) on support (30). The electrodes (13) of support (30) and electronic circuitry (21) are formed on the lower face of an integrated circuit substrate (20) constituting the electronic part intended for the application of incremental potentials to the electrodes (13).

Abstract: A capacitive sensor for measuring a displacement comprises a slide carrying groups of emitting electrodes (1 to 32) disposed facing receiving electrodes (51 and 52) carried by a scale. A periodic configuration of signals is applied to the emitting electrodes by electronic circuits (60 to 65h) which permit a separate switching of each group of electrodes. There is thus obtained a more precise definition of the signals received by the receiving electrodes situated facing the scale and thus a greater precision of the measurement of displacements.

Abstract: The device consists of a slider (2) operating in a sliding manner with respect to a ruler (1). Slider (2) is fitted with emitting electrodes (10) and receiving electrodes (19,20) connected to an electronic assembly (50). Ruler (1) is provided with L and inverted L-shaped coupling electrodes (6,7) which interlock mutually to form electrode-pairs which position is limited by straight lines. The vertical parts of the L's (40) are arranged to face emitting electrodes (10), whereas the horizontal parts of the L's (41) are arranged to face the receiving electrodes (19,20), providing an optimal capacitative coupling. This arrangement of the coupling electrodes (6,7) makes it possible to obtain a precision type manufacture of the ruler and a side by side (juxtaposition) arrangement of several rulers to fit the measuring needs.

Abstract: The means for the capacitive measurement of displacements includes a scale in the form of a belt (10) movable longitudinally in relation to a measuring device which is provided with several groups of electrodes (22 to 25) connected by lines (27) to an electronic means. The belt (10) is made of metal and is provided with a plurality of regularly spaced rectangular openings (11). The belt (10) constitutes, with the transmitting electrodes (22 to 25) and a receiving electrode (29) situated relative to the transmitting electrodes, a differential condenser permitting the accomplishment of capacitive measurement of displacements.

Abstract: Several electrodes (20) are movable respective to several groups of electrodes (11 to 18). The latter receive, from modulating devices (28) modulation voltages which induce a voltage into the electrodes (20). The induced voltage is amplified in (21) and demodulated by a synchronous demodulating device (22) guided by an oscillator (23). The comparator (24) controls a binary counting device (25) the state of which constitutes a direct measurement of the relative position of the electrodes. The low-level outputs of counting device (25) govern a digital-analogical transformer (26) which delivers a modulation voltage to a function generator (27).

Abstract: An electrical length-measuring system comprises two capacitors and electronic means for obtaining an indication voltage proportional to the displacement. The measuring capacitor, whose capacitance is varied in a linear manner by the displacement to be measured, is connected to a reference a.c. voltage, whilst the reference capacitor with the same dielectric is connected to a measuring a.c. voltage of the same frequency and opposite phase, whose amplitude can be varied by electronic means in such a way that the a.c. voltage induced on an electrode common to both capacitors becomes zero, forcing the measuring a.c. voltage to be proportional to the displacement.Preferably the capacitance change of the measuring capacitor is brought about by an earthed screen inserted between both electrodes.