Pressure responsive sensor having controlled scanning speed
First Claim
1. A circuit for scanning an array of pressure responsive pressure points, each of which points is defined by the intersection of a selected drive electrode and a selected sense electrode, there being a pressure sensitive resistance between the electrodes intersecting at each of said points, the circuit comprising:
- a test signal generator adapted to generate T test signals during each scan of said array;
a sensor array having T sets of drive electrodes, each of which sets has at least one drive electrode, and at least one of which sets has a plurality of drive electrodes, there being pressure points in a predetermined pattern intersected by the drive electrodes of each set, a sense electrode for each pressure point of a set, a test signal being applied simultaneously to the drive electrodes of each set, and a different test signal being applied to each set, each test signal flowing through a drive electrode to which the test signal is applied, and through pressure points intersected by such drive electrode for which the resistance is in a lowered resistance state, to the sense electrode intersecting the point, and sensor output lines to which said sense electrodes are selectively connected; and
an output circuit to which said sensor output lines are selectively connected.
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Accused Products
Abstract
A circuit and various sensor arrays are provided which facilitate the scanning of an array of pressure responsive points at higher speed than is possible with currently available circuits and sensor arrays and also provides greater flexibility in selecting scanning speed and in making a tradeoff between scanning speed and resolution. These objectives are achieved by providing a sensor array having T sets of drive electrodes, with pressure points in a predetermined pattern intersected by drive electrodes of each set and a sense electrode for each pressure point of a set. A test signal is applied simultaneously to the drive electrodes of each set, with a different test signal being applied to each set, each test signal flowing through a drive electrode to which the test signal is applied, and through pressure points intersected by such drive electrode for which the resistance is in a lowered resistance state, to the sense electrode intersecting the point, and through sensor output lines to which the sense electrodes are selectively connected. The sense electrodes may be selectively connected to an output circuit which may for example provide a separate A/D converter for each sensor output line or may multiplex the sensor output lines to a single A/D converter. For one embodiment of the invention, T=1 so that a single test pulse may be applied simultaneously to all of the pressure points of the sensor array. Various techniques are also provided for enhancing resolution in areas of interest while sacrificing resolution in areas which are not of interest so as to permit higher speed scanning to be performed without significant sacrifice in resolution.
166 Citations
20 Claims
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1. A circuit for scanning an array of pressure responsive pressure points, each of which points is defined by the intersection of a selected drive electrode and a selected sense electrode, there being a pressure sensitive resistance between the electrodes intersecting at each of said points, the circuit comprising:
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a test signal generator adapted to generate T test signals during each scan of said array; a sensor array having T sets of drive electrodes, each of which sets has at least one drive electrode, and at least one of which sets has a plurality of drive electrodes, there being pressure points in a predetermined pattern intersected by the drive electrodes of each set, a sense electrode for each pressure point of a set, a test signal being applied simultaneously to the drive electrodes of each set, and a different test signal being applied to each set, each test signal flowing through a drive electrode to which the test signal is applied, and through pressure points intersected by such drive electrode for which the resistance is in a lowered resistance state, to the sense electrode intersecting the point, and sensor output lines to which said sense electrodes are selectively connected; and an output circuit to which said sensor output lines are selectively connected. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A sensor array for use in a circuit for scanning an array of pressure responsive sensor points by applying at least one test signal through the sensor array comprising:
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T sets of drive electrodes, each of which sets has at least one drive electrode, and at least one of which sets has a plurality of drive electrodes, there being pressure points in a predetermined pattern intersected by the drive electrodes of each set, a sense electrode for each pressure point of a set, a test signal applied to a set of drive electrodes flowing through a drive electrode, and through pressure points intersected by such drive electrode for which the resistance is in a lowered resistance state, to a sense electrode at the point; an input through which a test pulse may be applied to each of said T sets of interconnected drive electrodes; and sensor output lines to which said sense electrode are selectively connected. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification