Abstract: A first sensor and a second sensor provided on both ends of a moving portion connected to a fixed portion via an elastic body detect displacements of the moving portion that is in an oscillating movement. An angle calculating unit calculates a displacement angle of the moving portion based on the displacements detected by the first sensor and the second sensor and a distance between the first sensor and the second sensor.

Abstract: An authenticity identifying film (10) has a reflective film (11) having a circularly polarized light selectivity to reflect at least only either of right-handed circularly polarized light and left-handed circularly polarized light of incident light to produce reflected light. The reflective film (11) is provided with a hologram forming part (11a). The hologram forming part (11a) reflects circularly polarized light of the same circular polarization as that of the reflected light in a direction different from that of the reflected light to form a holographic image. The reflected light reflected by the reflective film (11) and the holographic image formed by the hologram forming part (11a) are detected by detectors disposed at different positions, respectively.