Control method for sheet member conveying apparatus and control method for recording apparatus

A control method for a recording apparatus which has a conveying roller for conveying a sheet member, a conveying motor for generating a driving force to drive said conveying roller, driving transmission means for transmitting the driving force of said conveying motor to said conveying roller, and detecting means for detecting a position and a speed of said conveying roller, and which executes recording on the sheet member by a recording head, said method comprising:

• a period profile detecting step of detecting a periodic speed change or torque change of said conveying roller as a period profile;
• an origin judging step of judging a specific phase angle in said period profile as an origin;
• a correlating step of correlating an offset phase angle having a specific offset from said origin with an optimal suspension phase angle on said period profile, said optimal suspension phase angle being a phase angle to suspend said conveying roller;
• and
• a phase managing step of controlling the suspension phase angle so that the suspension phase angle on said period profile at which said conveying roller is suspended becomes said optimal suspension phase angle.