JPH0373769A - Both-surface image forming device - Google Patents

Abstract

PURPOSE:To simplify the jam dissolving by installing a switch back transport means and a stocked paper transport means in lump into a lower part side partitioning case and forming a space for putting the transport means into a nontransport attitude between the first and second frames which constitute both the above-described means. CONSTITUTION:When a paper which is taken out into an intermediate tray 22 is jammed until the paper reaches the tray 22, the second frame 37 is shifted downward, switching an attitude holding means 40 in the holding released state. Then, the first frame 27 of a switch back transporting means 18 turns downward around a pivotal installation shaft 28, accompanied with the lowering of the frame 37, and also a paper receiving member 23 turns similarly downward, and a wide triangular space is formed between the first frame 27 and the upper part of a paper receiving member 32. At the same time, a triangular space for widening the lower part side of a passage reversal part 18c is formed on the lower part side of the first frame 27, or a rectangular-shaped space is formed by lifting up the free edge side of the first frame 27. Therefore, the jam generated in the transport system of the transport means 18 and 19 can be easily disposed of.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a double-sided image forming apparatus, such as a double-sided copying machine, which is capable of forming images on both the front and back sides of paper.

[Conventional technology]

For example, in a copying machine configured to allow double-sided copying, the device case is divided into two halves, one above and the other, along the paper path from the paper feed section, such as the manual feed section or paper cassette, to the paper output tray. a switchback transport means which is connected to the lower divided case so as to be openable and closable, and which switches back the paper after image formation; a stock paper feed transport means which stocks the paper after the switchback in the intermediate tray;
There is also a paper refeeding unit that refeeds the stocked paper to the image forming unit.

According to the above configuration, the paper after single-sided copying is taken out to the intermediate tray in the face amplifier position (the copying side is facing upward), and the paper is re-fed to the transfer unit, thereby copying the back side of the paper. is performed, and the paper after double-sided copying is taken out to the paper output tray.

In such a double-sided copying machine, the paper passage path from the paper feed section to the ejection section has a simple configuration and jams are extremely unlikely to occur, but the switchback conveyance means and stock leading to the paper refeed section are The conveyance path of the paper feed conveyance means has a complicated configuration, and it is no exaggeration to say that most jams occur on the conveyance paths of both conveyance means.

Conventionally, as shown in FIG. 4, the paper after single-sided copying is switched back to an upper divided case 53a that is divided into two along the paper path from the paper feed section 51 to the paper output tray 52. In addition, a conveyance means 56 is provided to feed the paper after the switchback to the paper refeeding section 55 of the lower divided case 53b as a stock, thereby preventing a jam from occurring in the switchback conveyance means 54. When this occurs, the upper divided case 53a is opened to pull out the paper jammed in the narrow conveyance path, and when a jam occurs in the stock paper feed conveyance means 56, the upper and lower conveyance elements 56a and 56b are opened. Jam processing is carried out.

[Problem to be solved by the invention]

However, because the locations where jams are likely to occur are different,
Regardless of whether the jam is disposed in the switchback conveyance means 54 or the stock feed conveyance means 56, both conveyance means 54.
Since it is necessary to check the jam for 56,
Both transport means 54 and 56 at different locations must be opened one by one, and in particular, small-sized paper is
When a jam occurs over a period of 4.56, it may be difficult to clear the jam even if the re-conveying means 54,56 are opened, so there is room for improvement.

An object of the present invention is to provide a double-sided image forming apparatus that eliminates the above-mentioned disadvantages through extremely rational improvements.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a double-sided image forming apparatus as described at the beginning, which includes a conveyance element on the lower side of the switchback conveyance means and a conveyance element on the upper side of the stock paper feed conveyance means. A second frame is pivotally attached to the lower divided case near the path reversal part of the switchback so as to be able to swing vertically, and a second frame is provided with a conveying element on the lower side of the stock paper feeding conveying means. , provided in the lower divided case so as to be vertically movable via a four-speed link mechanism, and configured to be able to freely switch the upper and lower conveying elements of each conveying means between a conveying position and a non-conveying position; Furthermore, the present invention is characterized in that a posture holding means for holding the conveying element in the conveying posture is provided in such a manner that the holding can be released.

[Effect]

According to the characteristic configuration described above, by switching the posture holding means to the holding release state and setting the upper and lower conveying elements of both conveying means to the non-transferring posture, a triangular shape that widens the lower side near the path reversal portion is formed. A space is formed between the first and second frames, and a triangular space is formed in the upper part of the first frame to widen the upper part of the free end of the first frame.

Alternatively, by lifting the free end side of the first frame, a wide rectangular space is formed between the first and second frames.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a double-sided copying machine as an example of a double-sided image forming apparatus.
A photoreceptor 4 is placed horizontally on a device case 3 equipped with an original placing table 1 and an original presser 2, and a charging device 5, a charging device 5,
Two developing devices 6 containing developers of different colors, a transfer device 7, a paper separation device 8, and a cleaning device 9 are arranged, and an exposure device 10 with a movable optical system is arranged in the upper space of the device case 3. and the upper and lower cassette paper feed sections 1
), a paper feed conveyance device 12 conveys the paper a housed in
A paper ejection conveyance device 14 for transporting the fixed paper a, and a paper ejection roller pair 16 for ejecting the fixed paper a to a paper ejection tray 15 are provided.

Then, from the upper cassette paper feed section 1) to the paper output tray 1
The device case 3 is divided into upper and lower parts with the paper passing path leading to the paper passing path as a boundary, and the upper divided case 3a is divided into upper and lower parts.
is connected to the lower divided case 3b so as to be openable and closable around the axis P, while a paper refeeding section 17 is provided at the lower part of the lower divided case 3b, and the paper a after single-sided copying is switched back. Switchback conveyance means 1 day and
A stock paper feeding conveyance means 19 for stock feeding the switched back paper a to the paper refeeding section 17 is provided on the upper side of the paper refeeding section 17 with respect to the lower divided case 3b, A conveying device 20 is provided which merges and feeds the paper a stocked in the paper re-feeding section 17 to the paper feeding and conveying device 13, and the first path switching mechanism 21 changes the conveying path to change the sheet after single-sided copying. The configuration is such that it is possible to select between a mode in which the sheet a is taken out to the tray 15 and a mode in which the sheet a after single-sided copying is taken out to the paper refeeding section 17 and then re-fed to the transfer device.

As shown in FIG. 2, the paper refeeding section 17 includes an intermediate tray (
The leading edge position of the paper a is controlled on the downstream side in the paper refeeding direction of the inclined tray part 22a and the horizontal tray part 22b which is connected to the inclined tray part 22a and is also used by the bottom plate of the lower divided case 3b. Position regulating tool 2 that forces the tip alignment
3 is provided so that the restriction can be released at a predetermined timing, and a width alignment mechanism 24 is provided for aligning the widths of the sheets a whose leading edge positions are regulated. A prevention means 25 (consisting of an upper paper feed roller 25a and a lower double-feed prevention roller 25b) is provided, and the paper a stocked on the intermediate tray 22 is directed toward the double-feed prevention means 25. A re-feeding roller 26 is provided to re-feed the paper.

Next, the specific structure of the switchback conveyance means 18 will be explained. This switchback conveyance means 18 is as follows:
A first frame 27 having a half length of the intermediate tray 22 is pivotally mounted around a shaft 28 on the lower side of the paper ejection roller pair 16 so as to be vertically swingable. A roller 29 is attached to each of the moving base side, the free end side, and the longitudinal middle, and a plurality of endless belts 30 are wound around the roller 29 in the middle direction, and upwardly from between the strips of the endless belt 30. The rib member C is erected on the first frame 27 in a protruding state.

A roller 31 that is switched to a state of contacting the endless belt 30 at a predetermined timing is disposed above the roller 29 on the swinging base side, while a paper receiver made of a rod-shaped member supports the member 32 as described above. The paper receiver is provided near the frame 25 so as to be able to swing up and down, and the free end side of the member 32 is connected to the free end side of the first frame 27. The paper receiver is mounted on and supported by the member 33.

By switching the first path switching mechanism 21 to the state shown by the imaginary line in FIG. 2 and the second path switching mechanism 34 to the state shown by the solid line, the paper feed direction is always returned (in the reverse direction in the figure). A sheet of paper a is introduced between the roller 31 and the conveyance start end of the endless belt 30, which is rotating in a clockwise direction), and the sheet of paper a is scooped up by the lip member C. When the paper a is introduced into the back path and is of long size, its leading end side or paper receiver is supported by the member 32.

Then, when the roller 31 is switched to a state where it comes into contact with the endless belt 30 at a predetermined timing,
The paper a introduced into the switchback path is returned to the roller 31 by the endless belt 3 rotating in the paper feeding direction.
By being sandwiched between sheet A and conveyed in a switchback manner, sheet a after the one-sided copying is fed to the stock sheet feeding and conveying means 19 with the front and back reversed.

That is, the switchback conveying means 18 for switching back the sheet a after the single-sided copying is constructed by using the roller 31 and the upper conveying portion of the endless belt 3o as upper and lower conveying elements 18a and 18b, respectively.

On the other hand, the stock paper feeding and conveying means 19 is constructed as follows.

That is, a pair of brackets 35 are erected in the paper feeding direction on the lower side of the first frame 27 with respect to the lower divided case 3b, and a second The frame 37 is pivotally connected, and the second frame 37, the pair of links 36, and the lower divided case 3b constitute a four-speed link mechanism 38 that vertically moves the second frame 37 in parallel. When the pivot axis P of the pair of links 36 relative to the second frame 37 slightly exceeds the dead point Pt as the second frame 37 is lifted, the roller 39 that comes into contact with the endless belt 30 is A posture holding means 4o is provided on the second frame 37 in correspondence with the roller 29 and maintains the lifted posture of the second frame 37, and a path switching claw 41 is provided between the rollers 39 and 39, respectively. It is.

The posture holding means 40 is composed of a convex portion d and a concave portion e formed in the free end side portion of the first frame 27 and the corresponding second frame 37 portion, and the pivot axis P, When Pg slightly exceeds the dead point), the convex portion d and the concave portion e fit into each other to maintain the lifted posture of the second frame 37, and in turn, the endless belt 3
The roller 39 is kept in contact with the roller 39, and the roller 39 and the lower conveying portion of the endless belt 30 in this maintained state are moved to the upper and lower conveying elements 19a, 1, respectively.
9b, the stock paper feed conveyance means 19 is constructed such that the starting end of its conveyance path faces the path reversal section 18c of the switchback conveyance means 18.

Then, the paper a after the switchback from the switchback transport means 18 is taken out to the stock paper feed transport means 19, and if the paper a is short in size, it is taken out from the end of the transport path, or if the paper size is long In this case, the paper a is taken out to the intermediate tray 22 from a predetermined path switching claw 41 protruding into the transport path, and the paper a is re-fed to the transfer device 7, thereby performing double-sided copying.

Alternatively, if the second path switching mechanism 34 is switched to the state shown by the imaginary line in FIG. At the same time as being taken out, the sheet a is re-fed to the transfer device 7, thereby performing composite copying.

According to the above configuration, if the paper a taken out to the intermediate tray 22 jams before reaching the intermediate tray 22, the posture holding means 40 is switched to the holding release state as shown in FIG. while the second frame 3
7 is moved downward.

Then, as the second frame 37 descends, the first frame 27 of the switchback conveying means 18 rotates downward around the pivot shaft 28, and the paper receiver member 32 similarly rotates downward. The first frame 27 and the paper tray move to form a wide triangular space at the upper part of the member 32, and the lower side of the path reversing part 18c is widened at the lower side of the first frame 27. A triangular space or a square space is formed by lifting the free end side of the first frame 27.

Therefore, it is possible to easily clear a jam that occurs in the transport system of the switchback transport means 18 or a jam that occurs in the transport system of the stock paper feed transport means 19. In particular, the first frame 27 A space is formed on the lower side of the path reversing section 18c to widen the lower side of the path reversing section 18c, so that jams occurring across the conveyance system from the switchback conveyance means 18 to the stock paper feed conveyance means 19 can be cleared, and the switchback conveyance can be easily handled. It is possible to easily clear a jam generated from the conveyance system that bypasses the means 18 to the conveyance system of the stock paper feed conveyance means 19 through the above-mentioned wide space.

That is, the paper a to be stocked in the intermediate tray 22 is stored at multiple locations (in the above example, at 4 locations) until it reaches the intermediate tray 22.
The paper refeeding unit 17 handles jams that occur in the conveyance system of
This can be easily done at one location near the.

In the above embodiment, an electrostatographic copying machine of a type that can perform superimposed copying in addition to double-sided copying was exemplified. However, the present invention can be applied to various other image forming apparatuses.

〔Effect of the invention〕

As described above, in the double-sided image forming apparatus of the present invention, the switchback conveyance means and the stock paper feed conveyance means are provided in the lower divided case at -4 positions, and the first frame constituting the switchback conveyance means is provided. It is characterized in that it is possible to form a space between the upper part of the frame and the second frame constituting the stock paper feeding and conveying means, each of which puts the conveying means in a non-conveying position. By using the above space, even if the jam occurs in either of the conveyance systems of the above two conveyance means, or the jam occurs at the path reversal section that spans the conveyance systems of both conveyance means, the processing work can be performed. can be done extremely easily in one place.

Alternatively, by adopting a configuration in which the second frame is pivotally mounted near the path reversing section, it is possible to easily clear a jam occurring in the stock paper feeding and conveying means. The space between the first and second frames in the vicinity is narrow, making it difficult to clear the jam at the path reversal section.

However, in the present invention, the second frame is provided to be vertically movable via a four-speed link mechanism, and a space is formed between the first and second frames to widen the lower side of the path reversal section. Therefore, jam removal at the path reversal section can be easily performed, and overall, by simple improved technology, an image forming apparatus with unprecedented ease of use is provided in which jam removal work can be easily performed at one location. We have now been able to do it.

4,

[Brief explanation of drawings]

FIG. 1 is a schematic vertical sectional side view of a double-sided copying machine as an example of a double-sided image forming apparatus, FIG. 2 is a detailed view showing switchback and stock paper feeding conveyance means, and FIG. 3 is a switchback conveyance means and stock paper feed. FIG. 4 is a detailed view of a state in which the conveying element of the conveying means is switched to a non-conveying position, and FIG. 4 is a schematic longitudinal sectional side view of a conventional double-sided copying machine. 3a... Upper divided case, 3b... Lower divided case, 1)... Paper feed section, 15... Paper output tray,
17... Paper refeeding section, 18... Switchback conveyance means, 18a, 18b... Conveyance element of switchback conveyance means, 18C... Path reversal section, 19... Stock paper feeding conveyance means, 19a, 19b... Conveyance element of stock paper feed conveyance means, 22... Intermediate tray, 27... First frame, 36... Link, 37... Second frame, 38... Four speed Link mechanism, 40... Posture holding means, Pl... Pivot axis, Pl... Punto point, a
...Paper, b...Paper passing path, d...Protrusion, e...
・Concavity. Applicant: Mita Kogyo Co., Ltd. Agent: Hideo Fujimoto, patent attorney

Claims (2)

[Claims] (1) The upper divided case, which is divided into two by the paper path from the paper feed section to the paper output tray, is connected to the lower divided case in an openable and closable manner, and the paper is switched back after image formation. A double-sided image forming apparatus comprising a switchback conveyance means, a stock paper feed conveyance means for stocking the paper after the switchback in an intermediate tray, and a paper refeeding section for refeeding the stocked paper to the image forming section. In this step, a first frame including a lower conveying element of the switchback conveying means and an upper conveying element of the stock paper feed conveying means is moved near the path reversal part of the switchback with respect to the lower divided case. A second frame, which is pivotally attached to the frame so as to be vertically swingable, and a second frame provided with a conveying element on the lower side of the stock paper feed conveying means is provided in the divided case on the lower side so as to be movable up and down via a quadruple link mechanism. , the upper and lower conveying elements of each conveying means are configured to be able to be switched freely between a conveying position and a non-conveying position, and further provided with posture holding means for holding the conveying elements in the conveying position so as to be able to be released from holding. A double-sided image forming apparatus characterized by: (2) The posture holding means includes a convex portion and a concave portion formed between a free end side portion of the first frame and a corresponding second frame portion, and the second frame and the lower side are separated. A quadruple link mechanism is constructed by pivotally connecting the case with a pair of links, and when the posture is maintained by fitting the convex portion and the concave portion of the posture maintaining means, the pivot axes of the pair of links relative to the second frame are formed. 2. The double-sided image forming apparatus according to claim 1, wherein the double-sided image forming apparatus is configured to slightly exceed a dead point.