A contrast ratio improving device includes a controller and a photo detector. A flash memory controller having memory that stores an address translation table for translating between a logical page address and a physical page address in the flash memory chip controls regular mode and low power consumption mode of operating at lower power consumption than in regular mode by halting operation, or decreasing power supply voltage or lowering operating frequency. The hydrogen is circulated within the enclosure from a gas inlet to a gas outlet. The cover provides structural stability to the deck panel. The sink assembly may further include a storage container for storing the plumbing apparatus when not in use or when the sink top is in the stowed position.