In a method for reproducing information recorded on an information recording medium by detecting changes in the phase of light, there is a problem in that the decoding capability decreases due to dimming of the light at the recording cell edge and intersymbol interference arising during reproduction. Therefore, provided is an information recording medium having recording cells in which phase information is recorded and having an edge dimming information region in which is recorded information pertaining to the rate of reduction of the optical intensity at the edges of the recording cells. Furthermore, provided is an information reproduction device that estimates a target from an input signal by calculating the time-average value (85) of a target that makes the PRML decoding result (80) of the phase information a state variable vector.
INFORMATION RECORDING MEDIUM AND INFORMATION REPRODUCTION DEVICE