Typewriting machines – Sheet or web – Including friction-feed means
Reexamination Certificate
1998-08-28
2001-08-14
Yan, Ren (Department: 2854)
Typewriting machines
Sheet or web
Including friction-feed means
C400S639200, C400S636000
Reexamination Certificate
active
06273624
ABSTRACT:
TECHNICAL FIELD
The present invention relates to an image forming apparatus in which a printing member for printing figures, characters, etc. is reciprocated in a predetermined direction to form an image on a recording sheet.
BACKGROUND ART
There is known, as one of output devices of computers and workstations, an image forming apparatus employing an ink-jet system in which ink is ejected to form an image on a recording sheet. The image forming apparatus employing an ink-jet system comprises, for example, a print head having a plurality of ink ejection outlets each for ejecting ink, a carriage on which the print head is mounted, said carriage reciprocating in a predetermined direction, and a conveying device for intermittently conveying recording sheets in a direction (a recording sheet conveying direction) intersecting perpendicularly to the predetermined direction.
In the event that an image is recorded on a recording sheet, the recording sheet in the course of conveyance by the conveying device is temporarily stopped, and while the carriage is reciprocated in the predetermined direction, ink is ejected from the ink ejection outlets in accordance with a control of the print head to form (print) a band of image on a portion located at an image formation area of the recording sheet. Thereafter, the recording sheet is fed by a predetermined length to form an image on a new portion located at the image formation area, of the recording sheet. Such a performance is repeated.
The conveying device comprises, usually, a drive roller having a drive roller axle extending in a direction intersecting perpendicularly to the recording sheet conveying direction, and a plurality of driven rollers each detachably mounted on the drive roller for pressing the outer peripheral surface of the drive roller. The drive roller and the driven rollers support a recording sheet in cooperation with one another and convey the recording sheet to the image formation area in such a manner that the recording sheet is sticked on the outer peripheral surface of the drive roller.
In the course of conveyance of the recording sheet in this manner, it happens that a jam occurs for example, around the drive roller. In case of the occurrence of the jam, there is a need to remove the recording sheet by separating the driven rollers from the drive roller. It happens, however, that a movable distance of the driven rollers for separation from the drive roller is too short to access the place at which the jam has occurred. Further, even if it is accessible, it happens that the recording sheet is broken because of insufficient grasp for the recording sheet. Consequently, in some cases, it would take a long time to solve the jam.
After solving the jam, the drive roller is pressed by the driven rollers and the recording sheet is conveyed while supported by the drive roller and the driven rollers. In this case, it happens that the driven rollers are out of their regular positions. In such a case, it happens that rotating the drive roller in some turns causes the driven rollers to take to the drive roller so that the driven rollers are regulated in their positions. However, in this case, it happens that the recording sheet is not conveyed in a proper conveyance direction during a period of time until the driven rollers have been regulated in their positions. Thus, there is a possibility that the jam again occurs.
Further, when the jam occurs, it happens that the carriage stops upward the driven rollers. In such a situation, when the driven rollers are separated from the drive roller so as to remove the recording sheet, there is a possibility that the driven rollers collide with the carriage or the print head which is mounted on the carriage, and as a result they are damaged.
DISCLOSURE OF THE INVENTION
In view of the foregoing, it is an object of the present invention is to provide an image forming apparatus capable of readily removing, when a jam occurs, a recording sheet which undergoes the jam.
The present invention has been made to attain the above-mentioned object and is to provide a first image forming apparatus in which a recording sheet is conveyed in a predetermined recording sheet conveyance direction, and an image is formed on a portion of the conveying recording sheet, said portion being located at an image forming area for forming images, said image forming apparatus comprising:
(1) a drive roller, having a drive roller axle extending in a direction intersecting said predetermined recording sheet conveyance direction, for rotating on said drive roller axle to convey recording sheets to said image forming area;
(2) a first shaft rotatably fixed on a main frame of the apparatus, extending in parallel to said drive roller axle at a position apart from said drive roller;
(3) a driven roller for supporting and conveying a recording sheet between said drive roller and said driven roller by pressing an outer peripheral surface of said drive roller, said driven roller being separated from the outer peripheral surface by rotating on said first shaft in cooperation with a rotation of said first shaft;
(4) a discharge roller, having a discharge roller axle extending in a direction intersecting said predetermined recording sheet conveyance direction, for rotating on said discharge roller axle to discharge recording sheets, said discharge roller being arranged at downward stream end with respect to the recording sheet conveyance direction as compared with said image forming area;
(5) a second shaft rotatably fixed on the main frame of the apparatus, extending in parallel to said discharge roller axle at a position apart from said discharge roller;
(6) a driven discharge roller for supporting and discharging a recording sheet between said driven discharge roller and said discharge roller by pressing an outer peripheral surface of said discharge roller, said driven roller being separated from the outer peripheral surface by rotating on said second shaft in cooperation with a rotation of said second shaft; and
(7) a control lever rotatable in a predetermined direction for rotating both said first and second shafts in cooperation with a rotation of said control lever in the predetermined direction,
wherein said driven roller comprises:
a first driven roller for pressing the outer peripheral surface of said drive roller; and
a second driven roller for pressing a surface, of the outer peripheral surface of said drive roller, which surface is different from a surface, of the outer peripheral surface of said drive roller, pressed by said first driven roller, and
wherein said image forming apparatus further comprising:
a first lever of which the tip portion said first driven roller is rotatably fixed on, said first lever being rotatable on its rear portion in a first detachable direction in which said first driven roller is attachable and detachable to and from the outer peripheral surface of said drive roller; and
a second lever of which the center portion said second driven roller is rotatably fixed on, the tip portion of said second lever being located in the vicinity of said first lever, said second lever being rotatable on its rear portion in a second detachable direction in which said second driven roller is attachable and detachable to and from the outer peripheral surface of said drive roller,
wherein said second lever is rotated so as to separate said second driven roller from the outer peripheral surface of said drive roller through pressing the tip portion of said second lever by said first lever when said first lever rotates so that said first driven roller separates from the outer peripheral surface of said drive roller.
In the image forming apparatus as mentioned above, said driven roller comprises:
(8) a first driven roller for pressing the outer peripheral surface of said drive roller within a range between two straight lines which incline by 45° to a rotational direction of said drive roller and a reverse direction opposite to the rotational direction, respectively, with respect to a Y axis perpendicularly intersectin
Izuma Kensuke
Kawamura Iwao
Kiyohara Naoki
Murakami Kazuhiro
Namekata Kiyokazu
Copyer Co. Ltd.
Dellett and Walters
Yan Ren
LandOfFree
Image forming device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Image forming device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Image forming device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2546520