JPH03205260A - Image forming device paper ejection device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a paper ejection device in an image forming apparatus such as a copying machine or a printer.

[Conventional technology] Conventionally, image forming devices such as printers and copiers have been used to continuously print multiple sheets of the same original, or to print multiple sets of originals each consisting of multiple sheets. In cases where a plurality of sets of prints, each consisting of a plurality of sheets, are continuously discharged, it would be very convenient for the user if they could be automatically sorted according to a preset number of discharged sheets.

Therefore, conventionally, the stacking positions have been shifted for each job. There are two types of job offset: one using means inside the apparatus, and the other by moving a paper discharge tray outside the apparatus.

[Problems to be Solved by the Invention] However, in the method of performing job offset inside the conventional example described above, transfer materials of all sizes that can be passed through can be sorted. In order to offset the transfer material of the maximum width that can be passed through the job, it is necessary to make it larger than the size required to pass the maximum width of the transfer material that can be passed through the image forming device. There were drawbacks.

Furthermore, conversely, if the image forming apparatus is of the size described above, it is possible to pass a transfer material of an even larger size unless job offset is performed.

In addition, in the method of performing job offset outside the image forming device, the mechanism for performing job offset is attached externally, which not only increases the size of the machine and requires a large amount of space, but also poses a risk of danger due to the movement of the device. Moreover, it had the disadvantage of being expensive.

[Means for Solving the Problems] According to the present invention, by making it possible to perform job offset for only small-sized sheet materials other than sheet materials with the maximum width that can be passed through, the paper width size that requires job offset can be adjusted. It is possible to pass a sheet material with a paper width one size larger than that of the image forming apparatus, without changing the size of the main body of the image forming apparatus.

[Example] Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

FIG. 1 is a longitudinal cross-sectional view of an image forming apparatus according to the present invention, and FIG. 2 is a diagram showing a sorting mechanism of paper ejection rollers.

The paper 1 fed from the paper cassette 2 by the paper feed roller 3 is sent to a laser scanner 4, a reflection mirror 5, and a photosensitive drum 6.
1. An image is recorded by a process cartridge 6 that includes process means such as a charger 62, a developing device 63, and a cleaner 64, and is transported along a transport path in the direction of the arrow in the figure, and then transferred to a fixing device 9.
The image is fixed.

The paper 1 with the image fixed on it further advances along the conveyance path,
The sheet is further conveyed toward a paper ejection roller 12 by a half-moon-shaped roller 10 which has a drive source (not shown) and is normally rotating, and is then ejected onto a paper ejection tray 13 by the paper ejection roller 12 to complete the printing operation.

The paper discharge roller 12 is connected to a drive source (not shown) via gears 128, 129, and 130. The paper discharge slot roller 12 and the lower roller 121 are each supported by bearings provided on a frame 122 that is movable in the axial direction on a base 127 by rollers 123. A link 125 is attached to the end of the frame, and the end engages with the solenoid 124.

When the solenoid 124 is not in operation, the frame 122 is supported by a spring 126 stretched between the pair of frames and the base 127.
As a result, the end of the frame is in its normal position (portion A) where it abuts against the wall of the base 127. Furthermore, when the solenoid 124 is actuated, the frame moves a certain amount in the direction of the arrow in the figure.

Next, the operation when sorting sheets will be explained.

However, the sheets to be sorted here are sheets of a size other than the maximum allowable size. Normally, the paper ejection roller 12 is located at the position shown in FIG. 2, and the paper is ejected to the position shown by the solid line in FIG. When a signal for sorting work is received, a sensor (not shown) detects that the trailing edge of the paper has passed through the conveyance roller 91 in the fixing device 9, and then the solenoid 124 is activated and the link 1
The pair of paper ejection rollers 12, 12 together with the frame 122 via 25
1 to the position shown by the chain line in FIG.

Here, the length of L in FIG. 3 is smaller than the maximum width of paper that can be passed through. At this time, since the paper is held between the pair of paper discharge rollers 12 and 121, the paper moves together with the paper discharge rollers 12 and 121 and is discharged to the position shown by the chain line in FIG. 3, thereby completing the sorting operation.

If the paper is held between the pair of half-moon rollers 10 and 11 while the paper is being moved while being held between the pair of paper discharge rollers 12 and 121, the paper will not be able to be conveyed normally and problems such as paper jams will occur. The half-moon-shaped roller pair is placed in a released state by its driving control.

Next, after a sensor (not shown) detects that the trailing edge of the paper has passed the paper ejection roller pair 12, 121, a solenoid is activated until the leading edge of the next paper reaches the paper ejection roller pair 12, 121. 124 is de-energized, and the spring 126 causes the roller pair 12, 121 to return to its original position. The above operation is repeated until a preset number of sheets are discharged, and the sorting work is performed.

When sorting paper, if the paper ejection roller moves in the axial direction with a large amount of paper protruding from the paper ejection roller, the leading edge of the paper will come into contact with the already sorted paper on the paper ejection tray due to its own weight, causing the paper to be unsorted. Since the paper is disturbed, the paper ejection roller starts moving in the axial direction with the paper slightly protruding from the paper ejection roller.

As explained above, the paper sorting work is performed.

Further, the cassette loading port of the image forming apparatus main body is equipped with a microswitch SW, which is a sensor for detecting the type of paper loaded in the loaded paper cassette, and the paper cassette 2 is equipped with the microswitch SW. Frame 2f for pressing
is provided. Therefore, when the paper feed cassette is installed, the image forming apparatus main body can recognize the type of paper being conveyed, and it prohibits sorting work only when the paper has the maximum width that can be passed through the image forming apparatus, and other types of paper are prohibited. Control is performed to enable sorting of small size paper.

If we assume that job offset is possible for paper with the maximum size width that can be passed through the above-mentioned machine, then in the case where only small-sized paper is offset by the stroke amount that the paper ejection roller pair 12, 121 moves as shown in Fig. 2. At the same time, the width of the paper conveyance path after the fixing/discharging roller 9l and the paper discharging tray must also be increased, resulting in a larger machine.

[Example 2] FIG. 4 shows an explanatory diagram of Example 2. In the figure, a, b
, c are each a group of sheets stacked on the paper ejection tray in one job. In Example 1, FIG.
), but as shown in FIG. 4(2), it is also possible to sort into more than two groups, for example into three groups. However, P in the figure is smaller than the maximum width of paper that can be passed, and the paper is sorted within this range. For example, in Figure 4 (1), when paper group b is extracted, paper group a and paper group C overlap because they are in the same location, and cannot be distinguished. However, in case (2), even if group b is extracted, group a and group C are located at different positions, so they do not overlap and have the advantage of being able to be distinguished.

[Embodiment 3] In Embodiment 3, as shown in FIG. 5 (2), small-size width paper, excluding the maximum width paper that can be passed without offset, is placed on the paper output tray. The paper is discharged while being offset to align with the end position when stacked.

Embodiment 3 will be described below using a laser beam printer shown in FIG.

The laser beam printer shown in FIG. 6 can be equipped with two paper feed cassettes, 2a and 2b. Paper 1a is fed from the upper paper cassette 2a, and paper 1a is fed from the lower paper cassette 2b. It is designed to be able to form images on each of the sheets 2b, and the structure other than the above is the same as that shown in FIG. Now, in the laser beam printer shown in Fig. 6, image formation is performed on a center basis, which is advantageous in various respects, such as pressure on the paper conveyance roller in the image forming device or friction. The cassette 2a contains LTR (LETTE), which is the maximum width that can pass through the laser beam printer.
R. It is assumed that A4 size paper is loaded in the lower cassette 2b.

Now, when paper is fed from the cassettes 2a and 2b according to the purpose, and when the paper is ejected straight onto the paper ejection tray and stacked, it becomes as shown in Fig. 5 (1) (here, a, c and e are LTR size, b and d are A4 size). However, when loaded in this way, the width of LTR size is 216mm, and the width of A4 size is 21mm.
Since it is 0 mm, the amount of deviation is adjusted at the center, so it is only 3 mm on one side, making it almost impossible to distinguish between A4 and LTR. However, as shown in FIG. 5 (2), the A4 size paper 1b has a maximum width of LTR1.
If the sheets are discharged and stacked offset so that the edges are aligned, the difference will be 6 mm, which has the advantage of clearly distinguishing between A4 and LTR.

[Effects of the Invention] As explained above, by making it impossible to offset only the maximum width size paper among the paper that can be passed through, the paper size is smaller than the paper size that is normally ejected by job offset. Also, large size paper can be passed through an image forming apparatus of the same size.

Further, this is very effective for users who only rarely use the maximum size paper with the job offset function.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing an embodiment of the present invention, Fig. 2 is an explanatory diagram of the movement of the paper ejection roller in the axial direction, Fig. 3 is an explanatory diagram of the sorting operation, and Fig. 4 is an explanation showing another embodiment. FIG. 5 is an explanatory diagram showing another embodiment, FIG. 6 is a vertical sectional view showing another embodiment, and FIG. 7 is a block diagram. 12: Paper ejection roller 91: Fixing paper ejection roller

Claims (3)

[Claims] (1) In the paper ejection device of an image forming apparatus such as a copying machine or printer, in which ejected sheet materials are stacked in an offset manner, small-size width sheet materials other than the maximum width sheet material that can be passed through are A paper ejecting device for an image forming apparatus that is capable of ejecting sheets offset in a direction perpendicular to the conveying direction of the sheet material. (2) A paper discharge device for an image forming apparatus according to claim 1, wherein the job offset can be performed in multiple stages. (3) Printing is performed based on the center, and in the image forming apparatus, when the sheet material with the maximum width that can be passed is stacked on the paper output tray, another A paper ejecting device for an image forming apparatus according to claim 1, wherein offset is performed so as to align edges of small-sized transfer materials.