Patent attributes
The gain controlling portion sets a gain of an RF amplifier to a maximum range when an activation process starts for an optical disk. The binary process condition setting portion sets an upper threshold level and a lower threshold level corresponding to 80% of upper and lower levels of the maximum range as the binary process condition for the binary process portion. A vacant part without a signal between the upper threshold level and the lower threshold level corresponds to a part of a CAPA signal. The binary signal ratio calculating portion measures a time period of a binary signal from a binary process portion that performs a binary process on the vacant part, and it calculates a binary signal ratio indicating a ratio of the time period of the binary signal to a time period corresponding to one rotation of the optical disk. The disk discriminating portion determines that the loaded optical disk is a DVD-RAM if the binary signal ratio is a value within the range of 4±1 %.
