Belt unit and image forming apparatus
AssigneeOki Data Corporation
InventorMakoto Kitamura
Life of this patent
Estimating the term…
Abstract
A belt unit (10) includes a drive roller (5), an idle roller (6) and an endless belt (4) stretched around the drive roller (5) and the idle roller (6). The drive roller (5) is supported by a belt frame (8) via bearings (2). The idle roller (6) is supported by the idle roller frame (16) via bearing members (10L, 10R). The idle roller frame (16) is rotatable relative to the belt frame (8) about a rotation axis aligned with the center position of the belt frame (8), with the result that the influence of the deformation of the belt frame (8) is not exerted on the idle roller frame (16).
Claims11
A belt unit attachable to and detachable from a main body, said belt unit comprising:
- a first roller rotated by a driving force of a driving source;
- a second roller having an axis substantially in parallel to an axis of said first roller;
- an endless belt stretched around said first and second rollers;
- a first supporting member that supports said first roller;
- a second supporting member that supports said second roller;
- a positioning member provided on said first supporting member for positioning said belt unit with respect to said main body;
- a rotational supporting mechanism that supports said second supporting member with respect to said first supporting member in such a manner that said second supporting member is rotatable relative to said first supporting member;
- and
- a parallelism maintaining mechanism comprising:
- a first shaft holding portion that holds shaft portions or bearing portions of said first roller;
- and
- a second shaft holding portion that holds shaft portions or bearing portions of said second roller, said second shaft holding portion being fixed to said first shaft holding portion.
An image forming apparatus including a belt unit attachable to and detachable from a main body, said belt unit comprising:
- a first roller rotated by a driving force of a driving source;
- a second roller having an axis substantially in parallel to an axis of said first roller;
- an endless belt stretched around said first and second rollers;
- a first supporting member that supports said first roller;
- a second supporting member that supports said second roller;
- a positioning member provided on said first supporting member for positioning said belt unit with respect to said main body;
- a rotational supporting mechanism that supports said second supporting member with respect to said first supporting member in such a manner that said second supporting member is rotatable relative to said first supporting member;
- and
- a parallelism maintaining mechanism comprising:
- a first shaft holding portion that holds shaft portions or bearing portions of said first roller;
- and
- a second shaft holding portion that holds shaft portions or bearing portions of said second roller, said second shaft holding portion being fixed to said first shaft holding portion.
Dependencies are inferred from the claim text.