PURPOSE: To make a device easy to carry on hand and to hold information for a long time by duplexing the information of a recording and reproducing part with a first backup circuit and a second backup circuit large in current capacity.
CONSTITUTION: Two systems of backup circuits are provided on the recording and reproducing part 2 to hold the information by a power source circuit. In other words, the first backup circuit is constituted by a power source Vb1 incorporated in the recording and reproducing part 2. Meanwhile, the second backup circuit with power source Vb0 is provided newly as an information holding device to hold the information when no recording and reproducing part 2 is used in a form of data holding case 16. In such a case, a large current is required in a reproduction operation, and small capacity is requested for a buil-in power source due to high transportability, therefore, information holding time by the first backup circuit of the recording and reproducing part 2 is limited in a short time, however, the global information holding time can be extended by the second backup circuit provided with the power source Vb0 large in current capacity that is the information holding device.
SASAKI KATSURO
KIMURA KATSUTAKA
NAGATA MINORU
HAMAMOTO NOBUO
OGAWA KATSUO
