Document Type and Number:
Japanese Patent JPH0450963
Kind Code:
B2
Abstract:
An encoder having improved output abnormality detection. First and second input signals differing in phase from one another are compared by respective first and second comparators with a first reference level at an amplitude center of each of the first and second signals, and the outputs of the first and second comparators are applied to respective inputs of an EXCLUSIVE-OR gate. Third and fourth comparators compare a composite signal of the first and second signals with respective third and fourth reference levels located on opposite sides of the first reference level, and the output of the third and fourth comparators are applied to respective inputs of a first AND gate. A second AND gate, at the output of which the circuit output is provided, receives as inputs the output of the first AND gate and the output of the EXCLUSIVE-OR gate.
Inventors:
HARA MASATO
Application Number:
JP9072285A
Publication Date:
August 17, 1992
Filing Date:
April 25, 1985
Export Citation:
Assignee:
ASAHI OPTICAL CO LTD
International Classes:
G01D5/245; G01D5/244; H03M1/00
Next Patent: JPH0450964