Absolute type encoder apparatus and method for operating the same

Abstract

A high-precision absolute type encoder apparatus includes a controller electrically connected to an incremental type encoder and generating a control signal to the incremental type encoder, a comparator electrically connected to outputs of the incremental type encoder and generating first pulse signals, a latch unit electrically connected to outputs of the comparator and generating second pulse signals by latching the generating first pulse signals. When power failure occurs, the controller generates the control signal as successive pulses with predetermined period to drive the latch unit and the incremental type encoder. Therefore, the controller knows angular information of the incremental type encoder by counting the second pulse signals. The absolute angular information can be obtained by combining the angular information and an initial position after power failure.