POSITION DETECTOR USING MAGNETIC RESISTANCE ELEMENT AND LENS BARREL USING THE SAME

PROBLEM TO BE SOLVED: To provide a small position detector that is not broken when mechanical shocks are imposed during an assembling time and at the time of falling and can maintain performance with a simple configuration, and a lens barrel using the same.SOLUTION: A lens barrel 100 includes: a fixed member 1; a position detector composed of a pressure member 19, a wiring member 17, and a magnetic resistance element, and attached to the fixed member; a protective member 7 that is provided while being overlapped on the position detector and is larger than the pressure member; a rotary member 3 that rotates relative to the fixed member; and a magnetic recording medium 9 that is attached onto the rotary member and whose N pole and S pole are magnetized at a predetermined pitch. The position of the rotary member relative to the fixed member is detected by the measurement of the travel amount of the magnetic recording medium by the magnetic resistance element. The sensitive face of the magnetic resistance element is provided so as to oppose the magnetic recording medium. The protective member is disposed so as to cover the contour of the pressure member.