A method captures images of objects using an image capturing apparatus. In an exemplary embodiment, the method includes receiving a desired voltage command to be applied to the motor and determining whether the magnitude of the desired voltage command falls between a first value and a second value. A second signal extraction unit extracts differential reference signals from an output from the Fourier transform unit. A detent mechanism may be included which assists in maintaining the hinge assembly in a pre-selected position. The usability of the time segment is determined using the usability indicator.