Fixing device and image forming apparatus

An image forming apparatus comprising:

• an image forming station configured to form a toner image on a sheet with toner containing parting material;
• first and second rotatable members forming a nip therebetween configured to fix a toner image formed on the sheet, said second rotatable member being disposed below said first rotatable member;
• a casing accommodating said first rotatable member and said second rotatable member and having a sheet introduction opening and a sheet discharge opening;
• a suppression portion provided adjacent a surface of said first rotatable member in a space from said sheet introduction opening to said sheet discharge opening in said casing and configured to suppress scattering of particles of predetermined particle sizes resulting from parting material, said suppression portion being disposed so that a gap G (mm) from said first rotatable member and a peripheral speed V (mm/s) of said first rotatable member satisfy 0.5≦G≦0.0059×V+0.72;
• and
• a substantially closed chamber provided above said casing and having an entrance for permitting entering of said particles guided to a outside of said casing by said suppression portion to stagnate the particles.

A fixing device comprising:

• first and second rotatable members forming a nip therebetween configured to fix a toner image formed on the sheet by said image forming station using toner containing parting material, said second rotatable member being disposed below said first rotatable member;
• a casing accommodating said first rotatable member and said second rotatable member and having a sheet introduction opening and a sheet discharge opening;
• a suppression portion provided at a position, away by not less than 0.5 mm and not more than 3.5 mm from a surface of the first rotatable member in a space from said sheet introduction opening to said sheet discharge opening in said casing and configured to suppress scattering of particles of predetermined particle sizes resulting from parting material adjacent said sheet introduction opening;
• a first closing portion substantially closing a gap between said casing and one longitudinal end of said first rotatable member;
• and
• a second closing portion substantially closing a gap between said casing and the other longitudinal end of said first rotatable member.

A fixing device comprising:

• first and second rotatable members forming a nip therebetween configured to fix a toner image formed on the sheet by said image forming station using toner containing parting material, said second rotatable member being disposed below said first rotatable member;
• a casing accommodating said first rotatable member and said second rotatable member and having a sheet introduction opening and a sheet discharge opening;
• a suppression portion provided adjacent a surface of said first rotatable member in a space from said sheet introduction opening to said sheet discharge opening in said casing and configured to suppress scattering of particles of predetermined particle sizes resulting from parting material, said suppression portion being disposed so that a gap G (mm) from said first rotatable member and a peripheral speed V (mm/s) of said first rotatable member satisfy 0.5≦G≦0.0059×V+0.72;
• a first closing portion substantially closing a gap between said casing and one longitudinal end of said first rotatable member;
• and
• a second closing portion substantially closing a gap between said casing and the other longitudinal end of said first rotatable member.