Information reproduction apparatus and information reproduction method

An information reproduction apparatus comprising:

• an analog-to-digital (AD) converter which reproduces information recorded on a magnetic recording medium, and converts an analog signal amplified by a predetermined gain into a digital signal;
• a peak detector which detects a peak point of a reproduced signal according to a threshold, which is a determination level made to conform to an output of the AD converter from the digital signal;
• and
• an information generation unit which generates a rectangular wave signal of the reproduced signal subjected to waveform shaping performed in accordance with interval information on peak points detected by the peak detector, wherein
• the peak detector includes:
• a first intermediate value acquisition unit which applies, to a first peak value to be determined, a second peak value immediately before the first peak value, a third peak value, which is a second preceding peak value with respect to the first peak value, and a next peak value, and obtains a first intermediate value between the third peak value and the second peak value;
• a second intermediate value acquisition unit which obtains a second intermediate value between the second peak value and the first peak value;
• a first correction value acquisition unit which obtains a first correction value obtained by multiplying a difference between the third peak value and the second peak value by a predetermined ratio based on the difference;
• a first threshold acquisition unit which obtains a first threshold by adding the first correction value to the first intermediate value;
• a second correction value acquisition unit which obtains a second correction value obtained by multiplying a difference between the second peak value and the first peak value by a predetermined ratio based on the difference;
• a second threshold acquisition unit which obtains a second threshold by adding the second correction value to the second intermediate value;
• and
• a peak value decision unit which ignores the first threshold when a difference between the first intermediate value and the second intermediate value is greater than or equal to a first difference value, and decides the first peak value after confirming that a digital value corresponding to the next peak value has exceeded the second threshold.