Patent ID: 8280298

Claim:
A sheet humidifying device comprising: a pair of humidifying rollers which form a nip portion by pressure contacting against each other, and which are adapted to provide water to a sheet passing through the nip portion; a water-supply roller that pressure contacts at least one of the pair of humidifying rollers and supplies water to the at least one of the pair of humidifying rollers; a water vessel that stores water to be supplied to the water-supply roller; a pressure-contact releasing section that releases pressure-contact between the pair of humidifying rollers and releases pressure-contact between the at least one of the pair of humidifying rollers and the water-supply roller; a controller which controls the pressure-contact releasing section so that after a drive motor starts to rotate at least one of the pair of humidifying rollers, a state of the pair of humidifying rollers and the water-supply roller is changed from a released state to a state of pressure contact, thereby bringing the pair of humidifying rollers as well as the at least one of the pair of humidifying rollers and the water-supply roller into pressure contact with each other; an additional water-supply roller, wherein the two water-supply rollers are respectively provided to be in pressure contact with the pair of humidifying rollers, and wherein the pair of humidifying rollers and the two water-supply rollers are arranged on a bilateral symmetry basis in a horizontal direction with the nip portion serving as a center; and a pair of outer control rollers, wherein pressure of the pair of outer control rollers brings the pair of humidifying rollers as well as the pair of humidifying rollers and the two water-supply rollers into the state of pressure contact; wherein the pressure-contact releasing section comprises a pair of cam plates, a pair of driven plates, and a pair of drive motors; wherein the pair of drive motors respectively rotate the pair of cam plates to bring the pair of humidifying rollers and the two water-supply rollers in the state of pressure contact or in the released state; and wherein in the released state, the pair of cam plates are in contact with each other, and the pair of driven plates are respectively in contact with the pair of cam plates.