JPH0432457A - Paper reversing/discharging device - Google Patents

Abstract

PURPOSE:To simplify structure, make a device compact and reverse/discharge sheets easily in a paper reversing/discharging device for a copying machine or the like by providing a discharge opening with a reversing drum with a sheet tip holding grip member fitted thereto, and also providing grip member switch mechanism in the specified position in the rotating direction of the drum. CONSTITUTION:At a paper discharge opening 11, a reversing drum 20 controlled in its rotation by the on-off operation of an electromagnetic clutch 19 is disposed correspondingly to a discharge roller 14. In the required surface position of this reversing drum 20, there is provided a discharge roller 21 brought into contact with the discharge roller 4 at the time of face-up mode so as to lead a sheet 6 around to convey it in the discharge direction. Also on the upstream side in the rotating direction of the discharge roller 21, there is provided a sheet tip holding metal plate made grip member 22 energized in the normally closed direction by a spring 23. Magnets 24, 25 are further provided respectively in the illustrated positions. The grip member 22 is thereby switched in the position relation with the magnets 24, 25 to grip/release the sheet end alternate ly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a reversing sheet ejecting device that enables reversing sheet ejection in laser printers, copying machines, facsimile machines, and the like.

[Conventional technology] Reverse paper ejection technology for laser printers, etc.
Conventionally, methods of changing the paper passing path and paper ejection tray, a method of switching back, etc. are known.

[Problem to be Solved by the Invention] However, in order to switch between ejecting paper with the printed surface facing up (face-up) or facing down (face-down), in the former case, the paper feeding path must be changed. It is necessary to make a major change and discharge the paper onto another tray, and in the latter case, it is necessary to transport the paper that has been conveyed twice in the opposite direction again and discharge the paper. For this reason, it is necessary to set a long conveyance path or incorporate a complicated mechanism, which causes problems such as larger machines, higher costs, and slower printing speeds. .

In view of this, the present invention has been developed so that by incorporating it into a paper ejection port, paper can be easily reversed and ejected without setting a new paper path, and the mechanism is simple, compact, and can be manufactured at low cost. This paper aims to provide a paper ejecting device.

[Means for Solving the Problems] In order to solve the above problems, the present invention disposes a reversing drum configured to be stopped at a predetermined position at a predetermined timing at a paper discharge port, and a reversing drum configured to stop at a predetermined position at a predetermined timing. , a grip member for holding the leading edge of the paper conveyed for paper ejection is attached, and a mechanism for opening and closing the grip member is provided at a predetermined position in the rotational direction of the reversing drum. .

Further, the reversing drum may be configured to incorporate a blowing device 31 for blowing air toward the inside of the sheet whose leading end is held by the grip member.

Furthermore, it is preferable that the reversing drum is provided with a paper ejection roller that corresponds to the paper ejection roller provided at the paper ejection port.

[Function] When the grip member holds the paper conveyed for ejection and the reversing drum is rotated to a predetermined position, the paper can be reversed so as to draw an arc. Further, by blowing air toward the inside of the paper using a blower, the above-mentioned reversing operation can be performed more reliably. Furthermore, if the position of the reversing drum is selected and the paper ejection roller is made to correspond to the paper ejection roller, the paper can be ejected without being reversed by the paper ejection roller and the paper ejection roller.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

Figure 1 shows the case where it is adopted in a lower conveyance type laser printer. OP charged by charger 1
A latent image is formed on the C belt 2 by the optical writing unit 3,
A developing unit 4 applies toner to the latent image to form a toner image, a paper 6 fed from a paper feed cassette 5 is superimposed on the toner image, and a transfer charger 7 transfers the toner image. After the paper 6 is fixed by the fixing unit 8, it is conveyed upward by the conveyance roller 9, and is guided by the paper discharge guide 12 from the paper discharge port 11 formed at the top of the printer main body 10 onto the paper discharge tray 13. In a laser printer that is designed to eject paper with the print side facing upward (face-up mode), the reversing paper ejection device 18 of the present invention is incorporated into the paper ejection port 11. Note that 14 is a paper ejection roller provided at the paper ejection port 11;
5 is a cooling fan, 16 is a cleaning device for the OPC belt 2, and 17 is a paper feed roller.

As shown in detail in FIGS. 2 to 5, the reversing sheet discharge device 18 of the present invention has a sheet discharge port 11 in FIG. 1 whose rotation is controlled by 0N10FF operation of an electromagnetic clutch 19. The reversing drum 20 is arranged in correspondence with the paper discharge roller 14.

The reversing drum 20 is provided with a paper ejecting roller 21 at a required position on its surface for applying conveying force to the paper 6 for ejecting the paper by bringing it into contact with the paper ejecting roller 14 and rotating it in the face-up mode. At the same time, the leading edge of the paper 6 conveyed to the paper discharge port 11 side by the conveyance roller 9 is held at a position upstream of the paper discharge roller 21 in the rotational direction (direction of arrow X in FIG. 1). A grip member 22 made of a sheet metal is arranged so as to be openable and closable, and a closing force is normally applied by a spring 23, and the reversing drum 20 is rotated while the leading end of the paper 6 is held by the grip member 22. By doing so, the leading edge side of the paper 6 is transferred to the reversing drum 20.
so that it can be wrapped around. Further, the grip member 22, which is closed by a spring 23, is placed at a position on the upstream side of the paper discharge roller 14 in the rotational direction of the reversing drum 20 and at a position immediately after passing the paper discharge tray 13, by applying a suction force against the elasticity of the spring 23. Magnet 24 for opening
and 25, respectively, so that when the grip member 22 reaches the position of these magnets 24 and 25 as the reversing drum 20 rotates, the grip member 22 can be automatically opened.

Furthermore, a blower duct 26 as a blower device connected to the cooling fan 15 in the printer main body 10 is arranged concentrically at the axial center of the reversing drum 20 so that it can rotate together with the reversing drum 20. At the same time, an elongated reversing air outlet 27 extending in the axial direction is provided in one place on the peripheral wall of the air duct 26 to protrude 2 , and the protruding reversing air outlet 27 is connected to the above-mentioned grip on the reversing drum 20 . The air duct 2 is fitted into an opening 27a formed elongated in the axial direction in the body wall on the upstream side of the member 22 in the rotational direction.
The wind from the reversing air outlet 27 of No. 6 is blown outward from the opening 27a of the reversing drum 20, so that air blowing pressure is applied inward to the paper 6 wound around the reversing drum 20, and further, In order to blow air to the paper 6 in the rotational direction of the reversing drum 20, from the position past the paper ejection roller 14 to the position just before it passes the paper ejection tray 13, the air duct 26 is A ventilation escape port 28 that opens toward the rear is provided at the rear end and at a position shifted from the axis position in the same direction as the ventilation port 27,
and a rear side plate 2 that rotatably supports the reversing drum 20.
9, a paper discharge tray 13 along the rotation direction of the reversing drum 20.
An arc-shaped opening 30 that reaches from the position past the paper discharge roller 14 to the position of the paper ejection roller 14 is provided in correspondence with the air outlet 28, and the air outlet 28 is opened according to the rotational position of the reversing drum 20. 30 so that the air blown by the air duct 26 can escape to the rear of the rear side plate 29.

In the normal face-up mode in which the paper 6 is discharged with the print side facing upward, the rotational position of the reversing drum 20 is regulated to a position where the paper discharge roller 21 contacts the paper discharge roller 14, as shown in FIG. I'll keep it. At this time, the grip member 22 is in a closed state away from the conveyance path of the paper 6, and the ventilation duct 26 is in a state in which the ventilation outlet 28 is in communication with the opening 3G of the rear side plate 29. Therefore, the paper 6 transported by the transport roller 9 toward the paper ejection port 11 is transported by the paper ejection roller 14 and the paper ejection roller 21, which rotate together, without interfering with the grip member 22 or being affected by the air blow. As a result, the paper is ejected onto the paper ejection tray 13 with the print side facing upward.

On the other hand, when switching to the face-down mode in which the paper 6 is ejected with the print side facing downward, the grip member 22 moves from the position of the reversing drum 20 (as shown in FIG. 6) to the paper ejection roller 14.
It is rotated by a predetermined angle until it reaches the position immediately before the position shown in FIG. 6, and then stops.

At this time, since the grip member 22 is opposed to the magnet 24 disposed on the outer side thereof, the grip member 22 is attracted to the magnet 24 and becomes open toward the transport path of the paper 6. In this state, when the paper 6 is transported by the transport roller 9, the grip member 22
Since the leading end of the paper 6 can be stopped by
At this time, at the same time, the rotation of the reversing drum 2G is started at a speed substantially equal to the transport speed of the paper 6. When the grip member 22 passes the position of the magnet 24 due to the rotation of the reversing drum 20, the attraction by the magnet 24 is released and it is automatically closed by the force of the spring 23.
As shown in FIG. 6, the leading end of the paper 6 is held by the grip member 22. Therefore, the paper 6 is not ejected onto the paper ejection tray 13 as it is, but the leading edge side is wound around the reversing drum 20 as it rotates.

When the rotation of the reversing drum 20 is stopped when the grip member 22 reaches the end of the paper discharge tray 13 as shown in FIG. , the middle part of the paper 6 protrudes above the paper discharge tray 13 as shown in FIG. The paper will be ejected with the printed side facing down. At this time, if the paper 6 is a thin paper with low stiffness, there is a risk that it will be bent in the middle and cannot be reversed, and if the paper 6 is a thick paper with a strong stiffness, the trailing edge will get caught on the paper ejection guide 12 and the paper will not be reversed. There is a possibility that it cannot be done. In this regard, in the present invention, the paper 6 can be reliably reversed by applying a sufficiently strong blowing pressure from the blowing duct 26. That is, the air outlet 27 of the air duct 26 opens in the body wall of the reversing drum 20 as the reversing drum 20 rotates.
When the sheet 6 passes the position of the paper discharge roller 14, the air outlet 28, which had been communicating with the opening 30 of the rear side plate 29, is blocked by the rear side plate 29, so that the paper 6 wound around the reversing drum 20 is Air blowing pressure can be applied inward from the air blowing port 27. Therefore, the paper 6 can be reliably reversed without being affected by the strength of the user's waist.

Thereafter, the reversing drum 20 is further rotated to the position shown in Fig. 6 when the next sheet is to be ejected in the 7-eight up mode, or to the position shown in Fig. 6 when it is in the face-down mode. In the process, when the grip member 22 passes the edge of the paper output tray 13, as shown in FIG.
The grip member 22 is opened by being attracted to the magnet 25 to release the leading edge of the paper 6 held therein, so that the leading edge of the paper 6 is exposed to the air blown from the air outlet 27 through the opening 27a of the reversing drum 20. The paper falls onto the paper ejection tray 13 with assistance from the paper output tray 13.

As described above, in the present invention, by winding the paper 6 whose leading end is held by the grip member 22 around the reversing drum 20, the paper 6 can be reversed in an arcuate manner. , the paper 6 can be reversed and ejected without setting a new paper passing path or providing another tray.

In addition, although the above embodiment shows the case where it is adopted in a laser printer, it is also possible to similarly adopt it in copying machines, facsimile machines, etc., and that the grip member may be opened and closed in other ways. It goes without saying that the blowing device may be of a type other than that shown and described, and that various changes may be made without departing from the gist of the invention.

[Effects of the Invention] As described above, according to the reversing paper discharge device of the present invention, the sheet whose leading end is held by the grip member can be reversed by rotating the reversing drum.
Unlike conventional methods, paper can be reversed and ejected using a simple mechanism without setting up a new paper path for reversing, making it possible to reduce size and cost.
In addition, by blowing air from the blower when reversing,
The paper can be reliably reversed regardless of the strength of the user's backs. Furthermore, by selecting the stop position of the reversing drum and matching the paper ejection roller to the paper ejection roller on the paper ejection port side, the paper can be easily reversed. By switching, the paper can be ejected without reversing the paper, and therefore the paper can be ejected onto the same paper ejection tray either face-up or face-down, providing excellent effects.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a laser printer showing an embodiment of the reversing sheet ejecting device of the present invention, FIG. 2 is a perspective view showing the external appearance of the reversing sheet ejecting device, and FIG. 3 is a perspective view showing an overview of the air duct. ,
(B) (C) )(E)(F)
(G) is a schematic diagram showing the operating state of the reversing paper discharge device. 6... Paper, 11... Paper ejection port, 14... Paper ejection roller, 18... Reversing paper ejecting device, 19... Electromagnetic clutch, 20... Reversing drum, 21... Ejecting Paper roll, 22・
...Grip member, 23...Spring, 24.25
...Magnet, 26...Blower duct (Blower device)
.

Claims (3)

[Claims] (1) A reversing drum configured to be stopped at a predetermined position at a predetermined timing is arranged at the paper ejection port, and the leading edge of the paper conveyed for ejection is held on the reversing drum. What is claimed is: 1. A reversing paper ejecting device, comprising: a grip member attached thereto; and a mechanism for opening and closing the grip member provided at a predetermined position in the rotational direction of the reversing drum. (2) The reversing sheet ejecting device according to claim (1), wherein the reversing drum incorporates an air blower for blowing air toward the inside of the sheet whose leading end is held by the grip member. (3) The reversing paper discharge device according to claim 1 or (2), wherein the reversing drum is provided with a paper discharge roller that corresponds to the paper discharge roller provided at the paper discharge port.