Electrophotography – Diagnostics – Document handling
Reexamination Certificate
1999-12-20
2001-09-11
Brase, Sandra (Department: 2852)
Electrophotography
Diagnostics
Document handling
C399S021000, C399S381000
Reexamination Certificate
active
06289183
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a sheet conveying apparatus for conveying sheets, and an image forming apparatus such as a copier, a facsimile apparatus, a laser printer or a compound apparatus of these having the sheet conveying apparatus.
2. Related Background Art
A sheet conveying apparatus for conveying sheets has heretofore been provided, for example, in an image forming apparatus.
This sheet conveying apparatus is provided with a plurality of pairs of rollers, disposed along a sheet conveying path for guiding sheets, for conveying the sheets, and a plurality of drive motors for rotating the pairs of rollers and other rotary members, and is adapted to convey a sheet fed from a sheet cassette to image forming means for forming an image on one surface of the sheet, and thereafter discharge the sheet out of the main body of an image forming apparatus, or convey the sheet having an image formed on one surface thereof again to the image forming means to thereby form an image also on the other surface of the sheet, and thereafter discharge the sheet out of the main body of the image forming apparatus.
Now, the sheet conveying apparatus makes initial multiple rotations during the opening and closing of the front face opening and closing cover of the main body of the image forming apparatus. These multiple rotations are effected, supposing that after the clearance of jam, there is a sheet left in the image forming apparatus, to drive each pair of rollers for a predetermined time to thereby convey the sheet from a position at which it has not been detected by a sheet detecting sensor disposed in a sheet conveying path to an area in which the sheet detecting sensor can detect the sheet, and operate the sheet detecting sensor to inform a user.
These initial multiple rotations are generally effected to confirm the absence of remaining sheets in the image forming apparatus also when the power source switch of the image forming apparatus in its normal state is closed.
In the sheet conveying apparatus according to the conventional art, however, the conveying rollers have been started at a time during the initial multiple rotations and therefore, shock sounds and starting sounds during the meshing engagement between gears have been created at a time, and the starting sounds have become great and have given unpleasant feeling to the user. So, a countermeasure for the sounds has been taken by reinforcing the mounting portions for the drive motors or using a damping material and a soundproof material for each part of the image forming apparatus or the main body of the image forming apparatus and therefore, the size of the main body of the image forming apparatus has sometimes become large.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a sheet conveying apparatus in which a starting sound is reduced without causing a great increase in cost, and an image forming apparatus which is provided with this sheet conveying apparatus and is made compact.
The sheet conveying apparatus of the present invention is provided with a plurality of pairs of rotary members, disposed along a sheet conveying path for guiding a sheet, for conveying the sheet, a plurality of rotary driving means for rotating the pairs of rotary members, and control means for staggering the starting time of each of the rotary driving means and starting the rotary driving means.
The sheet conveying apparatus conveys the sheet along the sheet conveying path by the rotation of the pairs of rotary members. The pairs of rotary members are rotated by the rotary driving means. Each of the rotary driving means is started by the control means with the starting time thereof staggered.
Accordingly, in the sheet conveying apparatus of the present invention, the starting noise by the rotary driving means is low during the starting thereof.
In the sheet conveying apparatus of the present invention, the control means may start in the order from the rotary driving means corresponding to the pair of rotary members on the upstream side in the sheet conveying direction.
The sheet conveying apparatus is designed such that in the normal state thereof or after the clearance of sheet jam, the rotary driving means are started in the order from the upstream side in the sheet conveying direction and therefore, even if it happens that the upstream end and downstream end of a sheet are interposed between the pair of rotary members on the upstream side and the pair of rotary members on the downstream side, it will never happen that the pair of rotary members on the downstream side pulls and tears the sheet. Also, it will never happen that the rotary driving means on the upstream side is pulled by the rotary driving means on the downstream side through the sheet and steps out.
In the sheet conveying apparatus of the present invention, from the rotary driving means corresponding to the pair of rotary member on the upstream side, the rotary driving means may be divided into a plurality of groups, and the control means may start in the order from the group on the upstream side.
In the sheet conveying apparatus of the present invention, the control means may accelerate and rotate the pairs of rotary members to such a degree as not to impart damage to the sheet, during the time after the start of the conveyance of the sheet and until the sheet assumes a predetermined conveyance speed.
The sheet conveying apparatus starts the conveyance of the sheets without imparting damage to the sheets.
In the sheet conveying apparatus of the present invention, a plurality of sheet detecting means for detecting the sheet may be disposed along the sheet conveying path, and the control means may stop the rotary driving means when a jammed sheet is detected by the sheet detecting means.
In the sheet conveying apparatus, when sheet jam occurs, the jammed sheet may be detected by the sheet detecting means and the control means may stop the rotary driving means.
In the sheet conveying apparatus of the present invention, the pairs of rotary members may be pairs of rollers, and the rotary driving means may be motors.
The rotary driving means may be clutches for transmitting the rotational forces of motors to said pairs of rotary members.
The image forming apparatus of the present invention is provided with any one of the aforementioned sheet conveying apparatuses, and image forming means disposed in the course of the sheet conveying path of the sheet conveying apparatus for forming images on sheets conveyed along the sheet conveying path.
REFERENCES:
patent: 4234305 (1980-11-01), Miyake et al.
patent: 4548394 (1985-10-01), Koyama et al.
patent: 4954848 (1990-09-01), Arima
patent: 5010363 (1991-04-01), Higashio et al.
patent: 5136342 (1992-08-01), Ida et al.
patent: 5415387 (1995-05-01), Suzuki
patent: 5775686 (1998-07-01), Miyake
patent: 0 768 186 (1997-04-01), None
patent: 10-333379 (1998-12-01), None
Brase Sandra
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
LandOfFree
Sheet conveying apparatus and image forming apparatus having... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sheet conveying apparatus and image forming apparatus having..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sheet conveying apparatus and image forming apparatus having... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2499678