Digitizing planimeter
First Claim
1. A planimeter comprising:
- A) a housing;
B) a pair of distance sensors secured to the housing, each of which is associated with a different sensor region and includes;
i) a radiation transmitter operable to send radiation into the sensor region associated with the distance sensor that includes that distance sensor; and
ii) a radiation receiver that is disposed in the housing and generates in response to echo radiation reflected from the sensor region associated with that distance sensor a sensor output dependent on that echo radiation; and
C) computation circuitry contained in the housing and so arranged as to;
i) determine a respective two-dimensional position of the housing, for each of a sequence of locations of the housing, from the difference between times of radiation transmission and reception that occur while the housing is disposed at that location;
ii) store the sequence of two-dimensional positions thereby determined;
iii) compute at least one length from the difference between a pair of such two-dimensional positions in that sequence; and
iv) generate an output representative of a quantity that depends on at least one such length.
2 Assignments
0 Petitions
Accused Products
Abstract
A planimeter includes a movable housing in which are mounted orthogonally aimed x- and y-position sensors. Each position sensor comprises a piezoelectric ultrasound transmitter and receiver for sending ultrasound to a reflector disposed on a drawing and sensing resultant echoes. Circuitry in the housing computes from the sensor outputs the housing'"'"'s position for each of a sequence of locations on a drawing at which a user positions the housing, and from those it computes scaled distances between those positions as well as quantities that can be derived from those distances. The transmitter'"'"'s and receiver'"'"'s respective positions with respect to positioning crosshairs are such as to suppress the results of orientation errors. The planimeter'"'"'s handle is angled at 45° to the directions in which the sensors are aimed so that it lends itself to both right- and left-handed operation.
73 Citations
21 Claims
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1. A planimeter comprising:
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A) a housing; B) a pair of distance sensors secured to the housing, each of which is associated with a different sensor region and includes; i) a radiation transmitter operable to send radiation into the sensor region associated with the distance sensor that includes that distance sensor; and ii) a radiation receiver that is disposed in the housing and generates in response to echo radiation reflected from the sensor region associated with that distance sensor a sensor output dependent on that echo radiation; and C) computation circuitry contained in the housing and so arranged as to; i) determine a respective two-dimensional position of the housing, for each of a sequence of locations of the housing, from the difference between times of radiation transmission and reception that occur while the housing is disposed at that location; ii) store the sequence of two-dimensional positions thereby determined; iii) compute at least one length from the difference between a pair of such two-dimensional positions in that sequence; and iv) generate an output representative of a quantity that depends on at least one such length. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A planimeter comprising:
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A) a housing that forms a handle portion; B) a pair of distance sensors secured to the housing and so aimed that the direction of the handle portion'"'"'s axis is farther from both of the directions in which the distance sensors are aimed than from the direction of the bisector of the angle between them, each of the distance sensors being associated with a different sensor region and including; i) a radiation transmitter operable to send radiation into the sensor region associated with the distance sensor that includes that distance sensor; and ii) a radiation receiver that is disposed in the housing and generates in response to echo radiation reflected from the sensor region associated with that distance sensor a sensor output dependent on that echo radiation; and C) computation circuitry so arranged as to; i) determine the housing'"'"'s two-dimensional positions from the differences between times of radiation transmission and reception; ii) compute a quantity from the positions thus determined; and iii) generate an output representative of that quantity. - View Dependent Claims (17)
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18. A planimeter comprising:
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A) a housing that forms a positioning indicium adapted for alignment with a drawing feature; B) a pair of distance sensors secured to the housing and so arranged that i) each of the distance sensors is associated with a different sensor region; ii) each distance sensor includes; a) a radiation transmitter operable to send radiation into the sensor region associated with the distance sensor that includes that distance sensor; and b) a radiation receiver that is disposed in the housing and generates in response to echo radiation reflected from the sensor region associated with that distance sensor a sensor output dependent on that echo radiation; and iii) each radiation sensor'"'"'s radiation transmitter and receiver are so spaced from the positioning indicium that pivoting of the housing through small angles about the pivoting indicium from an orientation in which the sensor is aimed perpendicularly at an elongated reflector; a) results in an increase in the distance from the reflector to that radiation sensor'"'"'s radiation transmitter if a decrease in the distance from the reflector to the radiation sensor'"'"'s radiation receiver results from that pivoting; and b) results in a decrease in the distance from the reflector to that radiation sensor'"'"'s radiation transmitter if an increase in the distance from the reflector to the radiation sensor'"'"'s radiation receiver results from that pivoting; and C) computation circuitry so arranged as to; i) determine the positioning indicium'"'"'s two-dimensional positions from the differences between times of radiation transmission and reception; ii) compute a quantity from the positions thus determined; and iii) generate an output representative of that quantity. - View Dependent Claims (19, 20, 21)
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Specification