US Patent 7568033 Image storage system and image accumulation apparatus

An image accumulation server has a storage area management section for managing a storage area of an image storage section and a customer information management section for managing customer information. The storage area is set to reserve a predetermined capacity as the initial state for one customer and after the expiration of a predetermined time period, the service providing contents for each customer including the storage area and usage charge in the next predetermined time period are again set in response to the customer information. If an unused area exists, in the next predetermined time period, the storage area is decreased and the usage charge is reduced or is made free of, or the storage area is decreased as much as the capacity corresponding to the usage charge, so that a part of the unused storage area is canceled as an equivalent for the usage charge.