Contact-and-separation system, image forming apparatus, and contact-and-separation method

A contact-and-separation system comprising:

• a first roller contacting a belt;
• a second roller opposed to the first roller;
• a contact-and-separation device to contact or separate the belt to or from the second roller via a sheet conveyed, the contact-and-separation device including:
• an eccentric cam mounted on an end of a rotation shaft of the first roller;
• a memory;
• a motor to rotate the eccentric cam;
• and
• a circuitry to control the motor to rotate the eccentric cam to contact or separate the belt to or from the second roller via the sheet conveyed, and to decelerate a rotation speed of the motor on contact or separation of the belt to or from the second roller between the first roller and the second roller,
• wherein the circuitry is configured to store, on the memory, data on a timing at which the circuitry determines that the contact-and-separation device has separated the belt from the second roller, and
• wherein the circuitry is configured to drive the contact-and-separation device so that the rotation speed of the motor in a period of time before and after the timing at which the contact-and-separation device has separated the belt from the second roller is relatively lower than each of a rotation speed of the motor in reducing a contact pressure of the belt and the second roller from a contact state in which the belt is in contact with the first roller and the second roller and a rotation speed of the motor in relatively increasing a distance between the first roller and the second roller after the belt separates from the second roller.

A contact-and-separation system comprising:

• a first roller contacting a belt;
• a second roller opposed to the first roller;
• a contact-and-separation device to contact or separate the belt to or from the second roller via a sheet conveyed, the contact-and-separation device including:
• an eccentric cam mounted on an end of a rotation shaft of the first roller;
• a memory;
• a motor to rotate the eccentric cam;
• and
• a circuitry to control the motor to rotate the eccentric cam to contact or separate the belt to or from the second roller via the sheet conveyed, and to decelerate a rotation speed of the motor on contact or separation of the belt to or from the second roller between the first roller and the second roller,
• wherein the circuitry is configured to store, on the memory, data on a timing at which the circuitry determines that the contact-and-separation device has contacted the belt to the second roller, and
• wherein the circuitry is configured to drive the contact-and-separation device so that a pulse interval in a pulse section within a number of pulses before and after the timing at which the contact-and-separation device has contacted the belt to the second roller is relatively greater than each of a pulse interval in approaching the belt to the second roller from a separation state in which the belt is separated from the second roller and a pulse interval in pressing the first roller and the second roller to a contact pressure after the belt has contacted the second roller.