Abstract: The invention corresponds to wide signal period with simple structure by providing a relative position detection means for optically detecting a relative position of displacement of an object to be measured in a measuring direction. The invention includes a target mounted on the object to be measured and irradiated with light from a light source; a light receiver for detection of a relative position for receiving light by changing polarization state of reflected light at the target with respect to the light; and a relative position information output unit for outputting relative position information based on displacement of the target in the measuring direction. The target may include a reflector mounted on the object to be measured and a plurality of birefringent members provided on the reflector and having a thickness changing from a tip to a base end along the measuring direction.

Abstract: Example position detection means and displacement detection devices are described. A relative position detection means optically detects a relative position of displacement of an object to be measured in a measuring direction, including a target mounted on the object to be measured and irradiated with light from a light source; a light receiver for detection of relative position for receiving light by changing polarization state of reflected light at the target with respect to the light; and a relative position information output unit for outputting relative position information based on displacement of the target in the measuring direction based on change of polarization state of the reflected light. The target includes a reflector mounted on the object to be measured and a birefringent member on the reflector and having a thickness changing from a tip to a base end along the measuring direction.

Abstract: The invention corresponds to wide signal period with simple structure by providing a relative position detection means for optically detecting a relative position of displacement of an object to be measured in a measuring direction. The invention includes a target mounted on the object to be measured and irradiated with light from a light source; a light receiver for detection of a relative position for receiving light by changing polarization state of reflected light at the target with respect to the light; and a relative position information output unit for outputting relative position information based on displacement of the target in the measuring direction. The target may include a reflector mounted on the object to be measured and a plurality of birefringent members provided on the reflector and having a thickness changing from a tip to a base end along the measuring direction.

Abstract: Example position detection means and displacement detection devices are described. A relative position detection means optically detects a relative position of displacement of an object to be measured in a measuring direction, including a target mounted on the object to be measured and irradiated with light from a light source; a light receiver for detection of relative position for receiving light by changing polarization state of reflected light at the target with respect to the light; and a relative position information output unit for outputting relative position information based on displacement of the target in the measuring direction based on change of polarization state of the reflected light. The target includes a reflector mounted on the object to be measured and a birefringent member on the reflector and having a thickness changing from a tip to a base end along the measuring direction.