Apparatus for sensing rotating body

An apparatus for sensing a rotating body, the apparatus comprising:

• a first unit to be detected connected to the rotating body and comprising a plurality of patterns having a first phase;
• a second unit to be detected connected to the rotating body and comprising a plurality of patterns having a second phase different from the first phase;
• a first sensing coil facing the first unit to be detected;
• a second sensing coil facing the second unit to be detected;
• an oscillator comprising:
• a first capacitor connected to the first sensing coil to form a first oscillation circuit;
• and
• a second capacitor connected to the second sensing coil to form a second oscillation circuit;
• and
• a rotation information calculator configured to:
• count a frequency of a first oscillation signal output from the first oscillation circuit to generate a first count value,
• count a frequency of a second oscillation signal output from the second oscillation circuit to generate a second count value, and
• calculate a rotation direction of the rotating body based on a change in the first count value and a change in the second count value.

An apparatus for sensing a rotating body, the apparatus comprising:

• a plurality of units to be detected provided on the rotating body;
• at least two oscillation circuits coupled to the units to be detected and configured to respectively output at least two oscillation signals having respective frequencies that change as the rotating body rotates;
• and
• a processor configured to:
• count the frequencies of at the least two oscillation signals to generate a first count value and a second count value, and
• calculate a rotation direction of the rotating body based on a change in the first count value and a change in the second count value.

An apparatus for sensing a rotating body, the apparatus comprising:

• a first unit to be detected connected to the rotating body and comprising a plurality of patterns having a first phase;
• a second unit to be detected connected to the rotating body and comprising a plurality of patterns having a second phase different from the first phase;
• two oscillation circuits coupled to the units to be detected and configured to respectively output two oscillation signals having respective frequencies that change as the rotating body rotates;
• and
• a processor configured to:
• count the frequencies of the two oscillation signals to generate a first count value and a second count value, and
• calculate a rotation direction of the rotating body based on a change in the first count value and a change in the second count value.