| 摘要 |
<p>PURPOSE:To prevent a sudden drop in temperature so as to prevent quick growth of a curl by constructing a section, which constitutes a curl straightening means, of a material hardly taking heat from a sheet material. CONSTITUTION:A curl straightening device 55 arranged in a conveying vertical path for both sides image formation consists of a metal roller 56 fixed in the predetermined position and a sponge roller 57 touching the roller 56. The outer circumferential face of the metal roller 56A is coated by a heat insulating layer 56A made of polyolefin or the like. When a sheet material S conveyed in the arrow direction on the conveying vertical path passes through a nip 58 of the rollers 56, 57, a curl, which is formed in the sheet material S and curled in the direction for not being wound on a transfer drum 5a, is straightened to the predetermined condition by means of the circular arc face of the roller 56 corresponding to the dent part of a sponge 57B on the roller 57. In this process, heat is hardly taken away from the passing sheet material S, as the outer circumferential face of the metal roller 56 is coated by the heat insulating layer 56A, so that no curl grows up rapidly.</p> |
