Patent ID: 6877854

Claim:
An image forming apparatus for forming an image by using an ink jet recording head for discharging ink on a sheet material conveyed along a first sheet material conveying path in a first direction, comprising: conveying means disposed downstream of the ink jet recording head in the first sheet material conveying path with respect to the first direction for conveying the sheet material along the first sheet material conveying path in the first direction; a second sheet material conveying path branched from the first sheet material conveying path at a branch portion located downstream of said conveying means in the first sheet material conveying path with respect to the first direction; a first sheet material conveying rotary member disposed downstream of the branch portion in the first sheet material conveying path with respect to the first direction, wherein said first sheet material conveying rotary member is provided at its periphery with a plurality of protruded portions for discontinuous contact with a surface of the sheet material on which an image is formed by the ink jet recording head; a second sheet material conveying rotary member disposed downstream of the branch portion in the first sheet material conveying path with respect to the first direction, wherein said second sheet material conveying rotary member is provided with a conveying peripheral surface for continuous contact with the surface of the sheet material on which the image is formed by the ink jet recording head; a displacement mechanism for displacing said first and second sheet material conveying rotary members between a first condition so that said first sheet material conveying rotary member is in a position where it is in contact with a surface of the sheet material and said second sheet material conveying rotary member is in a position where it is not in contact with the sheet material and a second condition so that said second sheet material conveying rotary member is in a position where it is in contact with a surface of the sheet material and said first sheet material conveying rotary member is in a position where it is not in contact with the sheet material, wherein said displacement mechanism displaces said first and second sheet material conveying rotary members to the first condition when the sheet material is conveyed in the first direction through the first sheet material conveying path, and said displacement mechanism displaces said first and second sheet material conveying rotary members to the second condition when the sheet material is conveyed in a second direction opposed to the first direction; and a guide member disposed at the branch portion for guiding the sheet material to said second sheet material conveying path from the first sheet material conveying path by contacting a leading end of the sheet material in a sheet material advancing direction when the second condition is selected and the sheet material is conveyed in the second direction.