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US 5,708,910 AGranted
Device for detecting insufficient sheet conveyance
AssigneeMita Industrial Co., Ltd.
InventorsMasahiko Fukano, Kunihiko Ishii
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AssigneeMita Industrial Co., Ltd.
InventorsMasahiko Fukano, Kunihiko Ishii
Estimating the term…
A jam detecting device according to the present invention quickly outputs a jam detection signal when a part of a sheet is insufficiently conveyed during conveyance. A discharge detecting switch 55 is provided in the vicinity of discharge rollers 36. In addition, a plurality of (for example, three) pulse output units 230, 231 and 232 are provided in relation to the discharge detecting switch 55. Each of the pulse output units 230, 231 and 232 is so constructed as to output a pulse as the sheet is moved. In a jam judging circuit 235, when a signal of the discharge detecting switch 55 is on, a jam signal is outputted on the basis of the fact that no pulses are applied for not less than a predetermined time period from at least one of the pulse output units 230, 231 and 232. When a Jam occurs, therefore, the jam can be quickly detected. Consequently, the jam can be detected before a large sheet is crumpled or is tangled with a delivery roller in an image forming apparatus, whereby measures against the jam is easily taken.
A device for detecting insufficient conveyance of a sheet for an image forming apparatus of such a type as to convey a sheet the length of which is larger than the length of a conveying path by not less than a predetermined value along said conveying path, transfer an image on the sheet being conveyed, and fix the transferred image to the sheet, said device comprising:
A jam detecting device for an image forming apparatus of such a type as to convey a sheet along a conveying path, transfer an image onto the sheet being conveyed, and fix the transferred image to the sheet, said device comprising:
Dependencies are inferred from the claim text.