A technique for manufacturing a microcrystalline semiconductor layer with high mass productivity is provided. The apparatus includes a battery power-level detection unit and a controlling unit. With such a structure, parallel lighting can be achieved by parallel driving. The high-gear body is axially non-movably arranged between the low-gear body and the expanded part. In an embodiment, the object storage controller is operably coupled to a processor and a memory or stored on a computer readable medium.