Patents by Inventor Robert Earl McCaleb

Robert Earl McCaleb has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4032777
    Abstract: A photometric monitoring device for detection and surveillance of objects entering and leaving a light field is provided wherein a monitored light source is compared with a reference light source in such a manner that abrupt or rapid changes in monitored light are detected and gradual changes are ignored. A first photo cell for monitoring a light source is coupled to the input of an operational amplifier having a feedback loop which includes a reference light source coupled to a second photocell. An RC network delays the reaction of the operational amplifier in balancing the voltage across both of said first and second photocells when abrupt changes occur, allowing a signal to be developed. Additional circuitry includes a comparator responsive to such developed signals which exceed predetermined limits, producing an output signal for use by a utilization device, such as a camera, recording device, alarm system, or the like.
    Type: Grant
    Filed: March 29, 1976
    Date of Patent: June 28, 1977
    Inventor: Robert Earl McCaleb