Patent ID: 7587975

Claim:
An embossed sheet forming apparatus having first and second embossing rollers juxtaposed in parallel with each other to allow the first and second embossing rollers to form a both-sided embossed sheet by pressing opposite sides of the same sheet, comprising: first-roller rotational origin position detecting means for detecting a rotational origin position of the first embossing roller; second-roller rotational origin position detecting means for detecting a rotational origin position of the second embossing roller; rotary phase difference computing means for computing a rotary phase difference equivalent to a difference between the rotational origin position of the first embossing roller detected by the first-roller rotational origin position detecting means and the rotational origin position of the second embossing roller detected by the second-roller rotational origin position detecting means; and rotary phase difference correction-amount computing means for computing a correction amount to correct a rotary speed ratio between the first and second embossing rollers such that when fluctuation occurs in a rotary phase difference computed by the rotary phase difference computing means, the fluctuation in the rotary phase difference is cancelled; wherein the rotary speed ratio between the first and second embossing rollers is corrected based on the correction amount computed by the rotary phase difference correction-amount computing means; and wherein the rotary phase difference correction-amount computing means computes a reference value based on an average value of the rotary phase difference at a time when the reference value is established, computes a fluctuation amount based on a difference between the reference value and the rotary phase difference at a time when the rotary phase difference is corrected, and computes the correction amount based on the fluctuation amount.