JPH03211138A - Endless belt conveyor device in automatic sheet conveyor device - Google Patents

Abstract

PURPOSE:To prevent lowering of the image quality of copies by providing protrusions, for preventing the endless belt of an endless belt conveyor device from deviation from a pair of rollers for driving the endless belt, outside the image forming region of the image forming device. CONSTITUTION:Sheets P from a stack base 9 are separated sheet by sheet by a separating device 11 to be fed and conveyed by endless belt conveyor devices 3, 5, 6 into the specified position of an image forming device 2. The image forming device 2 reads the sheets P and copies the read images. At this time, protrusions 7 provided outside the image forming region W of the image forming device 2 prevents the endless belt 3 of the endless belt conveyor devices 3, 5, 6 from deviating from a pair of rollers for driving the endless belt 3.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to an endless belt conveying device in an automatic sheet conveying device, and more particularly to an endless belt conveying device that prevents the endless belt from shifting.

(0) Conventional technology Conventionally, an automatic sheet conveying device separates the sheets stacked on a sheet stacking table one by one using a separating device, and uses an endless belt conveying device to form an image on an image forming device. The sheet is conveyed to the image forming area, and after copying is performed, the sheet is conveyed outside the image forming area.

As shown in FIGS. 7 and 8, in the endless belt conveying device, two drive rollers b, b are fitted and fixed on a shaft a with a gap C in the center. The driven rollers d have the same structure and are arranged opposite to each other, and an endless belt e is stretched around these drive rollers b, b and driven rollers d, d, and this endless belt e is shown in FIG. As shown in the figure, a rib f made of a hard resin is attached by heat welding to the inner surface of the endless belt e at the approximate center in the width direction, and an overhang g is formed on the back side of the belt e to which the rib f is attached. ing.

Also, this rib f, driving rollers b, b and driven roller d
, d, the heald e rotates, and the belt e is prevented from shifting from the rollers b, b, d, and d.

(c) Problems to be Solved by the Invention However, when the belt e is moving over the platen of the image forming apparatus, ink, toner, etc. from the conveyed sheet and dust on the platen are deposited on the projecting portion g of the belt e. It is known that dirt easily adheres to the heald e and is dirtier than other parts of the heald e, and this dirt deteriorates the quality of copied images. In other words, when a highly transparent sheet such as a second original is conveyed and an image read from this sheet is formed in an image forming apparatus, dirt or dirt may appear at approximately the center of the formed image. It has been pointed out that when a sheet, which is a reduced original, is conveyed by the belt e and an image is formed from a read image, almost the margins of the formed image become smudged.

(d) Means for solving the problem The present invention has been made in view of the above circumstances, and includes:
For example, referring to FIGS. 2 and 3, a sheet loading table (9) and sheets (P) loaded on the loading table (9) are separated and fed one by one to the sheet 1. Separation device (1
1), and an endless belt conveying device (3) that conveys the separated and fed sheet (P) to a predetermined position of the image forming apparatus (2).
An automatic sheet conveying device (1) having an endless belt (3) of the endless belt conveying device (3,5.6) or a pair of rollers (3) for driving the endless belt (3).
5, 6) is characterized in that a protrusion (7) is provided outside the image forming area (w) of the image forming apparatus (2).

(E) Function Based on the above configuration, the sheet (P) is placed on the sheet loading table (9).
) is separated one by one by the separating device (11) and fed into an endless belt conveyor bag! (3,s.

6) to a predetermined position of the image forming apparatus (2),
The image forming apparatus (2) reads the sheet (P) and copies the read image. At this time, the endless belt (3) of the endless belt conveying device (3, 5, 6) or the protrusion (7) provided outside the image forming area (w) of the image forming device (2) To prevent bells 1 to (3) from shifting from the pair of rollers (5, 6) that drive them.

The reference numerals in parentheses are for illustrative purposes only and do not limit the structure in any way.

(f) Example Embodiments of the present invention will be described below with reference to the drawings.

The automatic sheet conveying device 1 shown in FIG. 3 is a typical one, and is a circulating sheet automatic document conveying device (referred to as an RDF device) installed in an image forming apparatus 2 such as a copying machine. Reference numeral 3 denotes an endless belt that conveys the sheet P to a predetermined position on the platen 4, and on which the image forming apparatus 2 forms an image using the conveyed sheet P as a document. This belt 3 is stretched around a driving roller 5 and a driven roller 6.

As shown in FIGS. 1 and 2, ribs 7 made of hard resin are attached to the inner sides of both sides of the belt 3 by heat welding. Note that 8 is a shaft fitted into the center of the drive roller 5. The rollers 5 and 6 are fitted between the ribs 7 and 7 on both sides, and the belt 3 is guided by both sides of the rollers 5 and 6 to prevent it from shifting.

The image forming area W of the image forming apparatus 2 is located at the rib 7.7.
The lower outer side of the belt 3 faces the platen 4 with a small gap therebetween.

Further, 9 is a sheet loading table, 10 is a half-moon-shaped pickup roller, 11 is a separating device, 12 is a registration roller, 13 is a backup roller, 14 is a reversing roller, 15
is a paper ejection roller, 16.17 is a flapper, I, n,
m, IV, and V are the first, second, third, fourth, and fifth conveyance paths, respectively.

Next, the operation of this embodiment will be explained.

Among the sheets P stacked on the sheet stacking table 9, the lowest sheet P is fed by a pickup roller 10, separated and conveyed one by one by a separating device 11, and then transferred to a flapper 16.
At the dashed line position, the sheet P is skew-corrected by the registration roller 12, and then conveyed to the first conveyance path (■) by the registration roller 12, then conveyed to the end of the platen 4, and then conveyed to the end of the platen 4. 3, it is conveyed to a predetermined position on the platen 4 and stopped.

Then, the image on this sheet P is scanned by the image forming apparatus 2 to form an image.

After the image formation, the heald 3 moves in the opposite direction to eject the sheet P, and the sheet P is stacked on the sheet stacking table 9 by the reversing roller 14 at the solid line position of the flapper 17 via the fourth conveyance path (2) by the paper ejecting roller 15. The sheet P is discharged onto the sheet P.

1, when the belt 3 is driven by the drive roller 5 and moves in the forward and reverse directions to convey the sheet P over the platen 4, the ribs 7.7 of the belt 3 are driven by the roller pair 5,
The sheet P is guided by the side surface of the platen 6, moves without shifting, and accurately conveys the sheet P onto the platen 4.

In addition, since the gaps between the bells 1 to 3 and the platen 4 are small, the back side of the ribs 7.7 forms an overhanging part, so it may rub against the platen 4 and cause dirt to adhere to it, or ink or Even if it gets dirty due to adhesion of toner etc., this dirty part is outside the maximum image forming area W shown in FIG.
When the image forming apparatus 2 scans the sheet P, the stain is not scanned and the image formed by the image forming apparatus 2 is not contaminated.

Next, another embodiment will be described with reference to FIGS. 4 and 5.

In this embodiment, the driving roller 5 and the driven roller 6 of the previous embodiment are replaced with 18 and 19, respectively, and these rollers 18,
19 has one groove 18a outside the maximum image area W,
Since the rib 21 of the belt 20 fits into this groove 18a, the rib 21 is outside the maximum image forming area W as in the previous embodiment, and the effect is the same as in the previous embodiment.

(G) As described in detail, according to the present invention, a protrusion is provided outside the image forming area to prevent the endless belt that conveys the sheet to a predetermined position of the image forming apparatus from shifting. Even if an overhang is formed on the surface of the endless belt that conveys the sheet due to the ridges and becomes dirty, this dirt is not scanned by the image forming apparatus, so that it is possible to prevent the image quality of the copy from deteriorating.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an endless belt conveying device showing an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1, FIG. 3 is a cross-sectional side view of the automatic sheet conveying device, and FIG. A perspective view showing another embodiment, FIG. 5 is a cross-sectional view taken along line B-B in FIG. 4, FIG. 6 is a cross-sectional view showing the protrusions for preventing shifting of a conventional endless belt, and FIG. 7 is a conventional endless belt. FIG. 8 is a sectional view taken along line C-C of the conveying device. 1... Sheet automatic conveyance device 2... Image forming bag W 3... Endless belt 3,5.6... Endless belt conveyance device 5, 6... Roller pair 7...
Rib 9... Sheet loading platform 1... Separation device P... Sheet W... Image forming area

Claims (1)

[Claims] 1. A sheet stacking table, a separating device that separates and feeds the sheets loaded on the sheet stacking table one by one, and separates and feeds the separated sheets to an image forming apparatus. an endless belt conveying device that conveys the sheet to a predetermined device; and an endless belt conveying device that conveys the endless belt to a predetermined device. An endless belt conveyance device in an automatic sheet conveyance device, characterized in that it is provided outside an image forming area.