JPH0420863Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a sheet conveying device that temporarily stacks and refeeds a plurality of sheets of single-sided processed paper each time.

Prior Art When performing double-sided copying or multiple copying with a copying machine, the sheet paper on which single-sided copying has been completed is reversed,
Alternatively, it is necessary to refeed the paper without reversing it. In that case, two originals to be copied on both sides,
Alternatively, in a copying machine where two originals to be copied multiple times are continuously circulated and conveyed onto a contact glass, the paper on which one-sided copying has been completed can be re-fed without being temporarily stored, but if the original is double-sided In the case of originals, or in a copying machine that places originals one by one on a contact glass, in order to flip or replace the original, the paper on which one-sided copying has been completed is carried into the intermediate tray, temporarily stored, and then re-feeded. It will be removed for storage.

loading paper into an intermediate tray for this purpose,
Conventionally, as a sheet conveying device for carrying out, as shown in FIG. The sheet on which one-sided copying has been completed is carried into the intermediate tray 9 from the rear end side of the intermediate tray 9, and after being temporarily stored, the sheet is delivered to the intermediate tray 9 by the paper feeding device 16 provided at the front end side of the intermediate tray 9 in response to a refeed signal. A device in which paper is re-fed to the transfer section of the photosensitive drum 1 is known. Such a sheet conveying device has the disadvantage that the conveying path is long and it takes time, especially when making one copy from one document, that is, so-called one-to-one copying.

In order to improve this, as shown in FIG. 4, sheets are fed into the intermediate tray 9 from above one end side of the intermediate tray 9 by a pair of carry-in rollers 15.
While the sheets are placed on the intermediate tray 9 due to their own weight, when refeeding the sheets, the bottom plate of the intermediate tray 9 is pushed up to the position shown by the broken line 9' in the figure, and the top surface of the stack of sheets placed on it is fed. A sheet conveying device is also known in which the sheet is brought into pressure contact with the roller 16 and is re-fed to the photoreceptor drum one by one in response to a re-feeding signal. It is necessary to separately provide a conveying means 15 for transporting the sheets and a conveying means 16 for conveying the sheets from the intermediate tray 9, which not only requires a large amount of space and increases costs, but also makes it difficult to align the sheets during stacking. There was a drawback that it was not good.

Purpose In view of the above-mentioned drawbacks of conventional sheet conveying devices having an intermediate tray, it is an object of the present invention to provide a conveying device that is simple in construction and does not take up much space.

Configuration In order to achieve the above-mentioned purpose, the sheet conveying device according to the present invention has an end on the paper input side to the intermediate tray and an end on the paper output side for refeeding the paper on the same side, and Separate rollers are placed across a paper path for carrying in paper and carrying out paper from the tray, and are constantly urged to rotate in the carry-in direction via a torque limiter, and when refeeding paper, are rotationally driven in the carry-out direction by a clutch means. At the time of conveyance, a feed roller is provided which rotates following the separation roller, and the intermediate tray can be switched between a position in which paper can be received and a position in which paper can be sent out, and a feed roller is provided in the paper path near the pair of rollers. Means for detecting the trailing edge of the paper carried into the intermediate tray is provided, and the clutch means is energized and the intermediate tray is controlled so as to be switched to a position in which the paper can be fed out in response to a trailing edge detection signal of the detection means. It is characterized in that it is made to look like this.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of an example of an electrophotographic copying machine having a double-sided copying function to which the present invention is applied. The paper on which the toner image has been transferred is supplied from a paper feed cassette 2, which is removably installed on the right side of the copying machine main body 100, via a paper feed roller 3 and a registration roller 4, to a transfer section around the photoreceptor drum 1. The image is fixed by the fixing device 6, and in the case of one-sided copying, by holding the switching claw 8 at the position shown by the solid line,
The paper is discharged onto the paper discharge tray 13 by the paper discharge roller pair 7 . During double-sided copying, by holding the switching claw 8 in the position shown by the broken line in the figure, the single-sided copied paper passes through the opening provided on the bottom of the copying machine body 100 and is placed under the copying machine body 100. The sheets are fed into a conveyance path in an attached optional automatic conveyance device 200, carried into the intermediate tray 9 provided at the right end of the automatic conveyance device 200 from the left end, and stacked on the tray. By pressing the re-feed button after turning over or replacing the original, the sheets stacked on the intermediate tray 9 are unloaded one by one from the same side as the one from which they were loaded into the intermediate tray 9 in accordance with the paper feed signal. and sent into the copying machine main body 100,
The paper is re-fed to the transfer section of the photosensitive drum 1 via the conveyance roller 5 and the registration roller 4, and is transferred to the back side.
The image is fixed by the fixing device 6 and discharged onto the discharge tray 13 by the pair of discharge rollers 7 .

Note that when two originals are fed alternately onto the contact glass in single-sided multiple copying, the paper fed from the switching claw 8 to the conveyance path in the automatic conveyance device 200 is carried into the intermediate tray 9. The paper is sent directly from the branch path to the pair of transport rollers of the copying machine main body 100.

Now, based on the present invention, the same sheet conveying means is used in common for carrying the paper into the intermediate tray 9 and carrying out the paper from the intermediate tray 9. Hereinafter, this conveying device will be explained in detail with reference to FIG. 2.

The paper is carried into the intermediate tray 9 in the direction of the arrow A through the paper conveyance path in the automatic conveyance device 200, and is carried out from the intermediate tray 9 and transferred to the copying machine main body 1 in the direction of the arrow B.
Feed roller 20 and separate roller 2 across the paper conveyance path toward conveyance roller pair 5 in 00
1 are provided so as to be in pressure contact with each other. The feed roller 20 is driven from the drive system of the copying machine body via an electromagnetic clutch 24 in the direction shown by arrow E in the figure.
That is, it is rotationally driven in the direction in which the paper in the intermediate tray is carried out, and is freely rotatable in any direction when the electromagnetic clutch 24 is off. Further, the separate roller 21 is supported at the tip of an arm 29 which is urged to rotate counterclockwise around a shaft 31 by a spring 30 so as to press against the feed roller 20 and rotate. Via
When the feed roller 20 is being driven in the clockwise direction shown by arrow C, that is, the direction in which paper is carried into the intermediate tray 9, and the feed roller 20 is rotating in the direction of arrow E, when a certain load is applied to the separation roller in the counterclockwise direction, the torque limiter is activated. Arrow D contrary to the torque of 25
It is designed to rotate in the direction.

The intermediate tray 9 is provided with a bottom plate 27 whose lower surface near the front end is pressed by a pressure arm 23 inside the tray body 26 and which can be raised and lowered by rotating around the rear end. A pick-up roller 22 is provided which rotates in the same direction in synchronization through the rollers and the like. Bottom plate 27
is pushed up by the pressure arm 23, the top surface of the bottom plate or the top surface of the paper placed thereon comes into pressure contact with the pick-up roller 22, and when the pressure arm 23 descends and the bottom plate 27 falls downward, the bottom plate The upper surface or the upper surface of the paper placed thereon is separated from the pick-up roller 22.

A sensor 28 for detecting the trailing edge of the paper carried into the intermediate tray in the direction of arrow A is provided in the paper conveyance path near the opposite side of the intermediate tray 9 between the roller pair of the feed roller 20 and the separate roller 21. . Further, a gate pawl 32 is indicated by a solid line in the figure at the branching point between the paper path that enters the roller pair 20, 21 in the direction of arrow A and the path that is carried out from the roller pair 20, 21 and heads in the direction of arrow B. It is provided so as to be movable between the position shown by the broken line and the position shown by the broken line.

When a command is given to carry paper into the intermediate tray 9 for double-sided copying, etc., the bottom plate 27 is lowered and separated from the pick-up roller 22, the electromagnetic clutch 24 is turned off, and the gate claw 32 is moved to the position shown by the solid line. When a command is issued to carry out paper from the intermediate tray 9 for switching or copying the back side,
Control is performed such that the bottom plate 27 is raised and the upper surface of the paper stacked thereon is brought into pressure contact with the pick-up roller 22, the electromagnetic clutch 24 is turned on, and the gate claw 32 is switched to the position shown by the broken line.

Since this device is configured as described above,
When carrying paper into the intermediate tray 9, the electromagnetic clutch 24 is turned off, so the feed roller 20
The paper is driven by the separation roller 21 which is rotationally driven in the direction of arrow C by the torque limiter 25, and the paper that has advanced in the direction of arrow A along the upper edge of the gate pawl 32 located at the position shown by the solid line is separated by rotating in the direction of arrow C. The sheet is conveyed toward the intermediate tray 9 by the roller 21 and the feed roller 20 driven by the roller 21, and is dropped with the copied side facing down onto the bottom plate 27, which is spaced apart from the pick-up roller 22 and lowered. In the case of multiple copying, the sheets brought in one after another are completely stacked on the bottom plate 27 and are aligned by an alignment means (not shown).

Next, when the paper refeed key is pressed after the original is turned over or replaced for back-side copying, the bottom plate 27 rises and the top surface of the paper placed thereon comes into pressure contact with the pick-up roller 22. The clutch 24 is turned on and the feed roller 20 is driven for a certain period of time in the direction shown by arrow E, and the pick up roller 22 is also rotated in the same direction in synchronization with this. Therefore, the sheets on the bottom plate are fed out one by one by the pick-up roller 22, and double feeding is separated by the feed roller 20 and the separate roller 21.
The paper is carried out in the direction of arrow B along the gate claw 32 located at the position of the broken line, and is re-fed so that the uncopied surface contacts the photosensitive drum 1.

When originals to be copied on both sides are automatically circulated and alternately fed onto the contact glass, the paper on which one side has been copied is immediately ejected in the direction of arrow B after being carried into the intermediate tray 9 and transferred to the registration rollers 4. You can wait there. In that case, when the sensor 28 detects the rear end of the paper that enters from the direction of arrow A and is carried into the intermediate tray by the feed roller 20 and the separate roller 21, the electromagnetic clutch 24 is turned on and the feed roller is moved in the paper transport direction. and switch the gate pawl 32 to the position indicated by the broken line.
When the sensor 28 detects the rear end (original front end) of the paper, the electromagnetic clutch 24 and the bottom plate 27
Then, the gate claw 32 may be returned to the position when the paper was carried in.

Incidentally, the intermediate tray 9 may be of a cassette type or a tray type, as shown in the figures of the above embodiment. Alternatively, the pick-up roller may be retracted upward as a means for separating the pick-up roller and the bottom plate.

Effects As described above, according to the present invention, the side where the paper is carried into the intermediate tray and the side where it is carried out are made to be the same, and the same pair of rollers are shared, so the paper conveyance distance is shortened, and both sides can be Copying time is shortened, less space is required, and costs are reduced. Also, from one manuscript
This simplifies operations when making double copies and reversing paper feeding. Note that the intermediate tray can also be used as a second or third paper feeding section.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the overall schematic configuration of an embodiment of a copying machine to which the present invention is applied, FIG. 2 is a cross-sectional view showing a sheet conveying device near the intermediate tray, and FIGS. 3 and 4 are conventional FIG. 2 is a cross-sectional view showing an example of a sheet conveying device using an intermediate tray. 9...Intermediate tray, 20...Feed roller,
21... Separate roller, 22... Pick up roller, 23... Pressure arm, 24... Electromagnetic clutch, 25... Torque limiter, 26... Intermediate tray body, 27... Bottom plate, 28... Paper sensor, 32... ...Gate claw.

Claims (1)

[Scope of utility model registration request] In a sheet conveying device having an intermediate tray from which single-sided processed paper is carried in from one end and carried out from the same end for re-feeding, the paper is carried into the intermediate tray and the paper is unloaded from the tray. A separate roller that is always urged to rotate in the carry-in direction via a torque limiter across the paper path to be carried out, and a feed roller that is rotationally driven in the carry-out direction by a clutch means when refeeding paper, and rotates following the separation roller during carry-in. The intermediate tray is switchable between a position in which paper can be received and a position in which paper can be sent out, and a trailing edge of the paper carried into the intermediate tray is detected in the paper path near the pair of rollers. A sheet conveying means is provided, and the clutch means is energized and the intermediate tray is controlled so as to be switched to a position in which the sheet can be sent out in response to a paper trailing edge detection signal from the detection means. Device.