Dual-layer-compatible optical head: integration with a liquid-crystal panel

We have developed a dual-layer-compatible optical head integrated with a liquid-crystal panel. We conclude that our optical head possesses sufficient ability for recording and reading a dual-layer disc whose layer separation is 20 μm or more. We have also confirmed the efficiency of a new method to drive a liquid-crystal panel, which is to mix the controlling signals of a liquid-crystal panel into the driving signals of a two-axis actuator. By using this integrated optical head instead of a beam expander, a compact optical pickup for dual-layer discs can be realized.