A method of analyzing vibration in a longitudinal direction of a transmission belt that is trained around at least a drive pulley and a driven pulley in a power transmission system. In one embodiment, the processor includes an instruction decoder unit that can decode a macro instruction into at least one micro-operation with a set of data fields. The linkage structure is driven by the fluid driven actuator and is coupled to at least one of the pair of opposable jaw members. A decoding time at which data of the decoding buffers is accessed and decoded is computed using reference information. A photodiode detects the intensities of the respective first and second light beams or the sum of the intensities. The case includes: a rear case ; and a front case removably attached to the rear case, which has an opening portion for exposing a touch detection region and a visible region of the touch panel and the display unit stacked together.