Exit-entry sensing apparatus
First Claim
1. Sensing apparatus for monitoring the passage of objects through a portal including in combinationa source of radiant energy mounted at one side of the portal;
- first and second radiant energy detectors mounted at the opposite side of the portal for receiving first and second beams of radiant energy, respectively, directed across the portal from said source of radiant energy;
said radiant energy detectors being spaced apart in the direction of movement of objects through the portal so that an object passing through the portal in one direction interrupts the first beam of radiant energy and then the second beam of radiant energy and an object passing through the portal in the opposite direction interrupts the second beam of radiant energy and then the first beam of radiant energy;
said first radiant energy detector being operable to produce a first signal condition when receiving radiant energy from said source and to produce a second signal condition when not receiving radiant energy from said source;
said second radiant energy detector being operable to produce a first signal condition when receiving radiant energy from said source and to produce a second signal condition when not receiving radiant energy from said source;
first receiver means coupled to said first radiant energy detector for producing a first output condition in response to the first signal condition from the first radiant energy detector and a second output condition in response to the second signal condition from the first radiant energy detector;
second receiver means coupled to said second radiant energy detector for producing a first output condition in response to the first signal condition from the second radiant energy detector and a second output condition in response to the second signal condition from the second radiant energy detector;
logic means coupled to the first and second receiver means and having first and second operating states, said logic means being switched to said first operating state in response to the output condition from said first receiver means changing from the first to the second output condition while the second receiver means is producing its first output condition and being switched to said second operating state in response to the output condition from said second receiver means changing from the first to the second output condition while the first receiver means is producing its first output condition;
whereby passage of an object through the portal in the one direction causes the logic means to operate in said second operating state and passage of an object through the portal in the opposite direction causes the logic means to operate in said first operating state.
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Accused Products
Abstract
Sensing apparatus for monitoring the passage of objects, including people, through a doorway. A source of radiant energy is positioned at one side of the doorway and two spaced-apart detectors are positioned at the opposite side to receive beams of radiant energy from the source. A receiver is connected to each detector and produces a signal indicating whether the beam of radiation from the source is impinging on its associated detector or is being blocked by a passing object. Logic circuitry responds to the signals from the receivers and produces a first or second output condition depending upon which beam from the source is the last one to be interrupted by a passing object. Output circuitry coupled to the logic circuitry produces a pulse at one output terminal on a transition from the first to the second output condition indicating passage of an object through the doorway in one direction and produces a pulse at another output terminal on a transition from the second to the first output condition indicating passage of an object through the doorway in the opposite direction.
22 Citations
9 Claims
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1. Sensing apparatus for monitoring the passage of objects through a portal including in combination
a source of radiant energy mounted at one side of the portal; -
first and second radiant energy detectors mounted at the opposite side of the portal for receiving first and second beams of radiant energy, respectively, directed across the portal from said source of radiant energy; said radiant energy detectors being spaced apart in the direction of movement of objects through the portal so that an object passing through the portal in one direction interrupts the first beam of radiant energy and then the second beam of radiant energy and an object passing through the portal in the opposite direction interrupts the second beam of radiant energy and then the first beam of radiant energy; said first radiant energy detector being operable to produce a first signal condition when receiving radiant energy from said source and to produce a second signal condition when not receiving radiant energy from said source; said second radiant energy detector being operable to produce a first signal condition when receiving radiant energy from said source and to produce a second signal condition when not receiving radiant energy from said source; first receiver means coupled to said first radiant energy detector for producing a first output condition in response to the first signal condition from the first radiant energy detector and a second output condition in response to the second signal condition from the first radiant energy detector; second receiver means coupled to said second radiant energy detector for producing a first output condition in response to the first signal condition from the second radiant energy detector and a second output condition in response to the second signal condition from the second radiant energy detector; logic means coupled to the first and second receiver means and having first and second operating states, said logic means being switched to said first operating state in response to the output condition from said first receiver means changing from the first to the second output condition while the second receiver means is producing its first output condition and being switched to said second operating state in response to the output condition from said second receiver means changing from the first to the second output condition while the first receiver means is producing its first output condition; whereby passage of an object through the portal in the one direction causes the logic means to operate in said second operating state and passage of an object through the portal in the opposite direction causes the logic means to operate in said first operating state. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification