04725723 is referenced by 13 patents and cites 4 patents.

An optical rotary encoder comprises reflecting portions and nonreflecting portions provided alternately on a peripheral surface of a measured body freely rotatable, a light emitting diode for projecting light onto the measured body, a number of light receiving elements each delivering an output pulse signal upon reception of the light reflected from the reflecting portions of the measured body, and a counter for counting the number of pulses of the output signal obtained from the light receiving element for providing an output corresponding to a rotating angle of the measured body. A monitoring light receiving element is further provided near the light emitting diode, and the light output of the light emitting diode is controlled based on the output signal obtained from the monitoring light receiving element.

Title
Optical rotary encoder with light monitoring and control
Application Number
6/702824
Publication Number
4725723
Application Date
February 19, 1985
Publication Date
February 16, 1988
Inventor
Yoji Shimojima
Furukawa
JP
Agent
Guy W Shoup
Assignee
Alps Electric
JP
IPC
G01J 1/32
View Original Source