| 摘要 |
PROBLEM TO BE SOLVED: To attain the improvement of security by preventing an instruction, which is not intended by a user, from being executed by an optical disk drive because of a malicious program invading a computer system. SOLUTION: After an instruction 1 from a host computer 1 is received by an optical disk drive 2 (S1), the operation of the switch for eject of a disk or tray provided with the drive 2 is detected (S2) and it is counted how many times eject operation is performed (S3). Continuously, the next instruction 2 from the host computer 1, namely, a value showing how many times the switch for elect is operated is received (S4), this value is compared with the count value of eject operation and when the respective values are coincident, the instruction 1 transmitted from the host computer 1 is executed (S6) but in the other case, the execution of that instruction 1 is canceled (S7). |
