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US 5,309,203 AGranted
Belt-type image forming apparatus having vibration resistance
AssigneeFuji Xerox Co., Ltd.
InventorNorio Hokari
Life of this patent
Estimating the term…
Abstract
In an image forming apparatus such as a copying machine, a belt member is put across a driving roll and a tension roll, and springs provided on the tension roll give a tension to the belt member in order to part the tension roll from the driving roll. A spring constant of the springs is defined so as to absorb vibration of the belt member due to the eccentric rotation of the roll.
Claims11
A belt device in an image forming apparatus comprising:
- an endless belt member;
- driving roll means, provided at one end of running direction of said belt which forms an action surface of said belt device, for driving said endless belt;
- driving means for driving said driving roll means;
- tension giving means, provided at another end of running direction of said belt, for giving a tension to said endless belt;
- and
- supporting means for supporting said driving roll means and said tension giving means, wherein a spring constant of the action surface of the endless belt member is k.sub.1 and a spring constant of said tension giving means is k, which are defined as:
- k.sub.1 =EA/L
- k<(XEA.times.10.sup.-3)/(2YL)
- where X (.mu.m) is allowable displacement quantity of said belt member corresponding to an image forming unit, E is Young's modulus of said belt member, A is sectional area (cm2), of said belt member, Y is displacement quantity (mm) of said tension roll means and L (mm) is original length of said belt.
6 more elements
An image forming apparatus comprising:
- a frame member;
- a plurality of roll members provided on said frame member;
- an endless belt put across said roll members;
- a plurality of image forming units arranged opposite said endless belt;
- and
- tension giving means, provided on said frame, for giving a tension to said endless belt,
- wherein toner images formed by said plurality of image forming units are transferred to a paper sequentially on said endless belt while matching positions of said toner images on the paper, and wherein a spring constant of the action surface of the endless belt is k.sub.1 and a spring constant of said tension giving means is k, which are defined as:
- k.sub.1 =EA/L
- k<(XEA.times.10.sup.-3)/(2YL)
- where X (.mu.m) is allowable displacement quantity of said belt member corresponding to the image forming unit, E is Young's modulus of said belt member, A is sectional area (cm.sup.2), of said belt member Y is displacement quantity (mm) of said tension roll means and L (mm) is original length of said belt.
7 more elements
Dependencies are inferred from the claim text.