Digital broadcast method, data receiving device, and data transmitting device

A data receiving device comprising:

• a channel storage that stores an identifier of a first channel selected by a viewer;
• a receiving unit that receives audio data and video data that form a predetermined content corresponding to the first channel for digital broadcasting, and related data indicating a content related to the predetermined content;
• a data storage that stores the received related data;
• a channel changing unit that changes a viewing channel by receiving a changing instruction of the viewing channel from the viewer;
• and
• a related-data output unit
• that deletes the related data stored in the data storage and that replaces the identifier of the first channel stored in the channel storage by an identifier of the currently selected channel when the viewing channel is not changed before a predetermined time has passed since the viewing channel is once changed by the channel changing unit;
• that determines, when the viewing channel is further changed before the predetermined time has passed since the viewing channel is once changed by the channel changing unit, whether the lastly selected channel is identical to the first channel by comparing an identifier of the lastly selected channel and the identifier stored in the channel storage;
• and
• that outputs, when the lastly selected channel is identical to the first channel, the related data stored in the data storage with audio data and video data corresponding to the lastly selected channel to an output unit.

A data receiving method comprising:

• storing an identifier of a first channel selected by a viewer in a channel storage;
• receiving audio data and video data that form a predetermined content corresponding to the first channel for digital broadcasting, and related data indicating a content related to the predetermined content;
• storing, by the data receiving device, the received related data in a data storage;
• changing a viewing channel by receiving a changing instruction of the viewing channel from the viewer;
• deleting the related data stored in the data storage and replacing the identifier of the first channel stored in the channel storage by an identifier of the currently selected channel when the viewing channel is not changed before a predetermined time has passed since the viewing channel is changed at the changing;
• determining when the viewing channel is further changed before the predetermined time has passed since the viewing channel is changed at the changing, whether the lastly selected channel is identical to the first channel by comparing an identifier of the lastly selected channel and the identifier stored in the channel storage;
• and
• outputting, when the lastly selected channel is identical to the first channel, the related data stored in the data storage with audio data and video data corresponding to the lastly selected channel to an output unit.