Distance measuring apparatus

A distance measuring apparatus, comprising:

• a light emitting unit for emitting light;
• a light receiving unit comprising one or more cells configured to receive incoming light and output a signal corresponding to an amount of the received light;
• a motor;
• a first rotary unit for changing a path of outgoing light which is emitted from the light emitting unit while being rotated by the motor;
• and
• a second rotary unit for changing a path of the incoming light so that the incoming light enters the light receiving unit while being rotated by the motor synchronously with the first rotary unit,
• wherein the first rotary unit comprises a first mirror for changing the path of the outgoing light by 90 degrees and a first cylinder, the first cylinder having a first end which is open toward the light emitting unit and a second end which is equipped with the first mirror, and the second rotary unit comprises a second mirror for changing the path of the incoming light by 90 degrees and a second cylinder, the second cylinder having a first end which is open toward the light receiving unit and a second end which is equipped with the second mirror,
• wherein the first and second mirrors are oriented toward a same direction while the first and second rotary units synchronously rotate, and
• wherein gears which are respectively formed on outer circumferences of the first and second cylinders are respectively engaged with a gear formed on a rotation shaft of the motor.