A rocker mechanism for a rocker recliner chair having a seat, a back, a pair of armrests, and a recliner mechanism. Input of the clock signal is prohibited just after the change in level of first and second control signals for switching between the second and third transistors. The optical subassembly comprises a printed circuit board, an optical semiconductor device, and an optical element. The result is an image that has a digital engraving effect that simulates a classic old world engraving.