Method of transferring toner powder image by pressure and apparatus therefor

An apparatus for transferring a toner powder image to a transfer paper by pressure, which comprises;

• a rotatable member onto which a toner image is to be formed;
• means for rotating said rotatable member;
• means for forming the toner image contracted or enlarged on said rotatable member in the rotating direction thereof;
• means for transferring the toner image including a pressure roller having a circumferential surface with an elastic modulus of at least about 10 kg/mm.sup.2 and extending parallel to the rotating axis of said rotatable member and in contact with said rotatable member under a pressure of at least about 20 kg/cm.sup.2 ;
• and
• means for rotating said pressure roller at a speed faster than the rotating speed of said rotatable member when the contracted toner image is formed and at a speed slower than the rotating speed of said rotatable member when the enlarged image is formed thereby producing sliding between said rotatable member and said transfer paper as the latter is transported between said rotatable member and said pressure roller, the amount of said sliding being about 0.67% to 27% of the length of the transfer paper.

An apparatus for transferring a toner powder image to a transfer paper by pressure, which comprises:

• a rotatable member onto which a toner image is to be formed;
• means for rotating said rotatable member;
• means for forming the toner image obliquely on said rotatable member in the rotating direction thereof;
• means for transferring the toner image including a pressure roller in contact with the surface of said rotataber under a pressure of at least about 20 kg/cm.sup.2 and so disposed to intersect its rotating axis with the rotating axis of said rotatable member at an angle of about 0.5.degree. to 2.degree. for producing lateral sliding parallel to the rotating axis of said rotatable member between said rotatable member and said transfer paper as the latter is transported between said rotatable member and said pressure roller both of which are rotating.

An apparatus for transferring a toner powder image to a transfer paper by pressure, which comprises;

• a rotatable member onto which a toner image is to be formed;
• means for rotating said rotatable member;
• means for applying a lubricant to the surface of said rotatable member;
• means for forming the toner image contracted or enlarged on said rotatable member in the rotating direction thereof;
• means for transferring the toner image including a pressure foller having a circumferential surface with an elastic modulus of at least about 10 kg/mm.sup.2 and extending parallel to the rotating axis of said rotatable member and in contact with said rotatable member under a pressure of at least about 20 kg/cm.sup.2 ;
• and
• means for rotating said pressure roller at a speed faster than the rotating speed of said rotatable member when the contracted toner image is formed and at a speed slower than the rotating speed of said rotatable member when the enlarged image is formed thereby producing sliding between said rotatable member and said transfer paper as the latter is transported between said rotatable member and said pressure roller, the amount of said sliding being about 0.67% to 27% of the length of the transfer paper.