Optical and magnetic encoder for serially transmitting absolute position signals with an auxiliary power supply

A rotation type absolute encoder in which a magnetic type one-pulse encoder for detecting the number of rotations and the direction of rotation and an optical type absolute encoder for detecting an absolute angle within one rotation are combined on the same shaft, the absolute angle of rotations of said shaft is detected on the basis of detection signals of said encoders, and when a current which is supplied to said encoders is cut, a current is supplied from an external auxiliary power source to said one-pulse encoder and to an electronic circuit to measure the detection amount of the one-pulse encoder comprising:

• a disk with slit tracks where each of said slit tracks of said optical type absolute encoder is divided into a group corresponding to an area to which a LED can emit light, and wherein a reference track having a transparent portion is provided in said group, and the detection signals are converted into a square wave output by using the output signal of said reference track as an index.

A rotation type absolute encoder in which a magnetic type one-pulse encoder, for detecting the number of rotations and the direction of rotation and an optical type absolute encoder for detecting an absolute angle within one rotation are combined on the same shaft, the absolute angle of rotations of said shaft is detected on the basis of detection signals of said encoders, and when a current which is supplied to said encoders is cut, a current is supplied from an external auxiliary power source to said one-pulse encoder and to an electronic circuit to measure the detection amount of the one-pulse encoder comprising:

• a differential input current-to-voltage converter for detecting signals from a track of the maximum resolution and for outputting sinusoidal signals to the waveform shaping circuits.

A rotation type absolute encoder in which a magnetic type one-pulse encoder for detecting the number of rotations and the direction of rotation and an optical type absolute encoder for detecting an absolute angle within one rotation are combined one the same shaft, the absolute angle of rotations of the shaft is detected on the basis of detection signals of said encoders, and when a current which is supplied to said encoders is cut, a current is supplied from an external auxiliary power source to said one-pulse encoder and to an electronic circuit to measure the detection amount of the one-pulse encoder comprising:

• a control circuit for synthesizing and outputting one reference pulse per rotation from the detection signal of said magnetic type one-pulse encoder and from the detection signal of said optical type absolute encoder.

A rotation type absolute encoder in which a magnetic type one-pulse encoder, for detecting the number of rotations in the direction of rotation and an optical type absolute encoder for detecting an absolute angle within one rotation are combined on the same shaft, the absolute angle of rotations of said shaft is detected on the basis of detection signals of said encoders, and when a current which is supplied to said encoder is cut, a current is supplied form an external auxiliary power source to said one-pulse encoder and to an electronic circuit to measure the detection amount of the one pulse encoder comprising:

• an optical type absolute encoder with a rotary disk devoid of a minimum salt (MSB) corresponding to a one-pulse detection;
• and
• a magnetic encoder for detecting a one-pulse, in place of a pulse detected from the devoid minimum slit.