JPH0243183A - Image former - Google Patents

Abstract

PURPOSE:To make jam handling easily performable without making the height of an image former higher as a whole by constituting the underside of a stacker, where paper is temporarily stacked in pile, so as to have the paper passed through. CONSTITUTION:A paper conveyor 3 consists of a stacker 61, forming a temporary stacking part 60 where paper P is temporarily stacked in pile, a carry-in passage 62 leading the paper P to this stacker 61 and a carry-out passage 63 feeding a first branch conveyor passage 32a of a paper conveyor passage 32 with the paper P in the stacker 61. The carry-in passage 62 is formed so as to be passed through between the stacker 61 and a device body 1, not to be formed in the top side of the stacker 61 in the past, whereby such a height space as capable of jam handling is secured without making a height size H between the stacker 61 and the paper conveyor passage 32 higher than that in the past. In addition, this stacker 61 is made possible to be opened in a state of pushing this side upward with the rear end side as a turning fulcrum. Consequently, when the paper P is jammed at the underside of the stacker 61, the carry-in passage 62 is opened by opening the stacker 61 upward, thus the jam handling is carried out.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Field of Application) The present invention is directed to a paper transport path that passes through an image transfer section formed between an image bearing member and a transfer device and then reaches a fixing device. The present invention relates to an image forming apparatus having a built-in paper conveyance device (ADD) that can temporarily accumulate paper that has passed through the fixing device in a stacker and guide it to an image transfer section again.

(Prior Art) In recent years, various functions have become more versatile, and various image forming apparatuses capable of double-sided copying have been put into practical use.

Normally, in this type of image forming apparatus, a sheet of paper that has passed through the fixing device is placed below a paper conveyance path from a pair of registration rollers, through an image transfer section formed between an image bearing member and a transfer device, and then to a fixing device. The structure includes a built-in paper conveying device that can temporarily accumulate paper in a stacker and guide it to the image transfer section again.

Conventionally, the paper transport device is configured to transport the paper sent out from the fixing device into the stacker via a transport path formed between the paper transport path and the stacker.

(Problem to be Solved by the Invention) However, in the conventional configuration in which a paper entry path is formed between the paper transport path and the stacker, there is a problem that the space above the stacker is small and it is difficult to clear jams. Ta.

Furthermore, if the space above the stacker is increased, the height of the entire image forming apparatus increases, which poses a problem in reducing the size of the apparatus.

The present invention has been made based on the above-mentioned circumstances, and an object of the present invention is to provide an image forming apparatus having a built-in paper transport device that can temporarily accumulate paper that has passed through a fixing device in a stacker and guide it to an image transfer section again. An object of the present invention is to provide an image forming apparatus in which a large space is provided on the upper surface side of a stacker, and jam removal can be easily performed without increasing the height of the entire image forming apparatus.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, the present invention provides a method for transporting paper to a fixing device via an image transfer section formed between an image bearing member and a transfer device. An image forming apparatus having a built-in paper conveying device that can temporarily accumulate the paper that has passed through the fixing device in a stacker below the path and guide it again to the image transfer section, the lower surface side of the stacker that temporarily accumulates the paper. It is configured so that paper can pass through it.

Further, the stacker is made movable.

(Function) That is, the present invention temporarily accumulates the paper that has passed through the fixing device in a stacker below the paper conveyance path that reaches the fixing device via the image transfer section formed between the image carrier and the transfer device. In an image forming apparatus that includes a built-in paper transport device that can guide the paper to the image transfer section again, the paper is configured so that the paper passes through the bottom side of the stacker where the paper is temporarily accumulated, so that a large space can be taken on the top side of the stacker. Jam removal can be easily performed without increasing the height of the entire image forming apparatus.

In addition, the guide body can be directly attached to the bottom plate of the stacker and the apparatus main body, and the bottom plate of the stacker and the apparatus main body can also be used as a guide means, making it possible to reduce costs by reducing the number of parts.

Furthermore, since the stacker is made movable, the stacker can be moved upward to open its lower surface, and jams in the carry-in path formed on the lower surface of the stacker can be easily cleared.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 2 shows the external appearance of the image forming apparatus with the platen cover opened, and FIG. 3A shows the internal structure of the entire apparatus. 1 in the figure is charging, exposure, development, and transfer.

This is an apparatus main body that incorporates image forming process constituent means 2 such as cleaning and fixing, and a paper transport device (ADD) 3. On the top surface of this apparatus main body 1, a document tray is set on a platen glass 4 serving as a document placement table. A platen cover 5 is provided to hold down the original document. Further, on the front edge of the upper surface of the main body 1, as shown in FIG. 2, an operation panel 9 is arranged, on which a numeric keypad 6, a guide display section 7, a copy key 8, etc. are arranged.

On the right side of the apparatus main body 1, there are a paper feed cassette 15 containing paper P such as plain paper to be supplied to the image forming process configuration means 2, a large capacity paper feeder (LCF) 16, and a manual paper feed tray 17. It is installed. Furthermore, a tray 18 is installed on the left side of the apparatus main body 1 to collect fixed sheets P.

The image forming process configuration means 2 has the following configuration. That is, a drum-shaped photoreceptor 20 serving as an image carrier is arranged approximately in the center of the apparatus main body 1, and a charging device 21 . The exposure section 22a of the exposure device 22, the developing device 23. Transfer device 24. Peeling device 25. Cleaning devices 26 and the like are sequentially arranged.

Further, inside the main body 1 of the apparatus, paper P1 is automatically fed from the paper feed cassette 15 or the large capacity paper feed device 16.
Alternatively, the paper P manually fed via the manual paper feed tray 17 is passed through the image transfer section 30 between the photoreceptor 20 and the transfer device 24, and then passed through the pair of paper ejection rollers 31 provided on the left side of the apparatus main body 1. A paper conveyance path 32 is formed that leads to.

A pair of registration rollers 33 is arranged on the upstream side of the image transfer section 30 of the paper transport path 32, and a fixing device 34 is arranged on the downstream side.
is located. Further, a suction conveyance means 35 is arranged between the image transfer section 30 and the fixing device 34, and a conveyance roller pair 36° and a sorting means are disposed between the fixing device 34 and the paper ejection roller pair 31. A gate 37 is provided.

Further, in the vicinity of the installed portion of the paper feed cassette 15, there is a take-out roller 40 that is attached to a swingable arm and takes out the sheets P one by one, and a take-out roller 40 that receives the sheets P taken out through the take-out roller 40. Separation and conveyance means 41 consisting of a conveyance roller and a separation roller that feeds the paper into the first branch conveyance path 32a forming the upstream side of the paper conveyance path 32 is provided. Also, in the vicinity of the large-capacity paper feeder 16, there is a take-out roller 42 that is attached to a swingable arm and takes out sheets of paper P one by one; Separation and conveyance means 43 consisting of a conveyance roller and a separation roller that feeds into the second branch conveyance path 32b forming the upstream side of the conveyance path 32 is provided. Further, in the vicinity of the manual paper feed tray 17, a third branch conveyance path 3 is provided which merges the manually fed paper P with the second branch conveyance path 32b.
A pair of manual feed rollers 44 for feeding the paper into the 2C is provided.

Further, as shown in FIG. 3, the exposure device 22 has an exposure lamp 46 whose back is surrounded by a reflector 45 and a first mirror 47 mounted on a carriage (not shown), and is mounted along the lower surface of the document table 3. In the figure, the first optical means 48 moves from the left side to the right side at a speed V, and the second optical means 48 moves from the left side to the right side at a speed V. A third mirror 49.degree. 50 is mounted on a carriage (not shown) and includes a second optical means 51 which moves in synchronization with the first optical means 48 at a speed of V/2 in the same direction. Irradiates light onto the set document tray and captures the reflected light through lens 5.
a moving optical system that guides the light transmitted through the lens 52 to a photoreceptor 20 serving as an image carrier, which is an exposed portion;
．． Fifth. and a fixed optical system consisting of a sixth mirror 53, 54, and 55.

Further, the developing device 23 includes an upper developing unit 23a for color development and a lower unit 23b for black development, and can selectively develop black or other colors such as red.

Note that the charging device 21. Exposure device 22. Developing device 23
．． Transfer device 24. Peeling device 25. Cleaning device 26. Since the fixing device 34 and the like have well-known configurations, detailed explanations thereof will be omitted.

Note that a cooling fan 56 is disposed above the paper ejection roller pair 31 in the apparatus main body 1.

Further, the image forming apparatus configured in this manner is divided into an upper unit IA and a lower unit IB with the paper conveyance path 32 as the border, and the upper unit IA and the lower unit IB are separated as necessary.
It can be opened clockwise in the figure with A as the pivot point (not shown) as the center of rotation. The upper surface side of the paper conveyance path 32 from the pair of registration rollers 33 to the pair of paper ejection rollers 31 can be opened.

Further, below the paper conveyance path 32, the fixing device 3
The paper transport device (ADD) 3 is provided which can guide the paper P1 that has passed through the image transfer unit 30, that is, the paper P that has undergone single-sided copying, to the image transfer section 30 again for double-sided copying or single-sided multiple copying. This paper conveyance device (ADD) 3 has a configuration as shown in FIG. That is, as shown in FIG. 3, there is a stacker 61 forming a temporary stacking section 6o for temporarily stacking paper P, a carry-in path 62 that guides paper P to this stacker 61, and a transport path for transporting paper P in stacker 61. It is configured to include an unloading path 63 that feeds into the first branch conveying path 32a of the path 32.

Further, the carry-in path 62 is not formed on the upper surface side of the stacker 61 as in the conventional case, but is configured to pass between the stacker 61 and the apparatus main body 1, and is configured to pass between the stacker 61 and the paper transport path 3.
The structure is such that it is possible to secure a height space in which the jam can be cleared without increasing the height H (see FIG. 3) between the paper and the paper 2 (see FIG. 3) as in the conventional case.

Further, the carry-in path 62 includes guide plates 64, 65 arranged diagonally below the gate 37, guide bodies 66 attached to the lower surface of the stacker 61 as shown in FIG. Guide body 67 attached to base 1a of main body 1...
and the mutually opposing surfaces of guide plates 68, 69 and 70, 71 disposed near the separating and conveying means 41 disposed corresponding to the paper feed cassette 15. Further, as shown in FIGS. 1 and 4, a pair of conveyance rollers 72 are provided at the midway point of the carry-in path 62.
73, 74, and 75 are provided.

Further, the rear end of the stacker 61 is pivoted by a known pivot mechanism, so that the stacker 61 can be opened to push up the front side using the rear end as a rotational fulcrum, as shown by the two-dot chain line in FIG. The structure is such that the carry-in path 62 can be opened as necessary.

Further, the carry-out path 63 is formed on mutually opposing surfaces of the guide plates 77 and 78, and is provided with a pair of conveying rollers 79.

Further, as shown in detail in FIG. 5, the first branch conveyance path 32a1 carry-in path 62. A gate 80 as a sorting means is provided at the confluence of the discharge path 63. By positioning the gate 80 to the left as shown in FIG. 6, the paper P taken out from the paper feed cassette 15 can be guided to the registration roller pair 33 side. Furthermore, by positioning the gate 80 to the right as shown in FIG.
can be guided to the stacker 61.

Further, by positioning the gate 80 to the left as shown in FIG. 8, the paper P taken out from the stacker 61 via the paper feed roller 81 can be double-sided copied to the registration roller pair 33 side by the registration roller pair 33. It is now possible to lead to the side. Further, by positioning the gate 80 to the left as shown in FIG. 9, the paper P on which one-sided copying has been completed can be led to the registration roller pair 33 side for single-sided multiple copying.

Further, the stacker 61 is provided with a movable stopper 82 (see FIG. 4) that can automatically move to a predetermined position depending on the paper size, so that the sheets can be stacked in the stacker 61 in an orderly manner. .

Next, a double-sided copying operation on paper P taken out from the large capacity paper feeder 16 will be explained with reference to FIGS. 2, 3, and 10. First, a document tray is set on the platen glass 4 shown in FIGS. 2 and 3, and then various image forming conditions such as paper size, number of copies, 2-sided copying, color specification etc. After entering
Press copy key 8. As a result, the drum-shaped photoreceptor 20 (
(see FIG. 3) rotates in the direction of the arrow (clockwise), and the photoreceptor 20 is uniformly charged by the charging device 21. On the other hand, an original set on the platen glass 4 is scanned by the exposure device 22, and the photoreceptor 20 is exposed to slit light. Then, an electrostatic latent image corresponding to the original is formed on the photoreceptor 20.

The electrostatic latent image on the photoreceptor 20 is transferred to the upper developing unit 23a of the developing device 23 based on the color designation from the operation panel 9.
Alternatively, it is developed and visualized by the lower developing unit 23b.

On the other hand, in synchronization with this developer image forming operation, FIG.
), the paper P is automatically fed from the large capacity paper feeder 16.
is taken out. At this time, the movable stopper 82 of the stacker 61 has been moved to a predetermined position in response to the paper size designation signal.

The paper P automatically taken out from the large capacity paper feeder 16 is
As shown in FIG. 10(b), the developer image is sent to the image transfer section 30 via the registration roller pair 33, and the developer image previously formed on the photoreceptor 20 is transferred onto the paper P by the action of the transfer device 24. Then, the paper P is peeled off from the photoreceptor 20 by the peeling device 25 and conveyed to the fixing device 34 side via the paper conveyance path 32. Next, as shown in FIG. 10(C), the developer image is sent to the fixing device 34, where the developer image is melted and fixed on the paper P, and then guided to the paper transport device 3 side by the gate 37.

After the developer image is transferred onto the paper P, the photoreceptor 20 faces the cleaning device 26 to clean the remaining developer (residual toner) and return to a normal state in which the next copying operation can be performed. .

On the other hand, the paper P led to the paper transport device 3 side is transported through the carry-in path 62 and placed in the stacker 6 as shown in FIG. 10(d).
The materials are transported to the temporary stacking section 60 of No. 1 and stacked as shown in FIG. 10(e). Then, as shown in FIG. 10(f), when a predetermined number of sheets P on which one-sided copying has been completed is accumulated in the temporary accumulation section 60, a message to replace the original is displayed on the guide display section 7. When the original paper is replaced and the copy key 8 is pressed, an image forming operation is performed on the photoreceptor 20, and the paper feed roller 81 is lowered to take out the paper P from the temporary stacking section 60, as shown in FIG. 10(f). Conveying roller pair 7
9 and a pair of registration rollers 33 to the image transfer section 30.

Then, in the same manner as described above, after the developer image is transferred to the paper P and the paper P is peeled off from the photoreceptor 20, it is sent to the fixing device 34 via the paper transport path 32, as shown in FIG. 10(g). After the developer image is fused and fixed on the paper P, it is guided by the gate 37 to the paper ejection roller pair 31 side and then transferred to the tray 18.
guided by.

FIG. 11 shows the operating state of the stacker 61 section of the paper conveying device 3. FIG. In b), the paper P with one-sided copy is placed in the stacker 61.
The state shown is that it is sent to the bottom side of the . Also, Figure 11 (
c) shows a state in which a sheet P on which one side has been copied is conveyed on the bottom side of the stacker 61, and FIG. Further, FIG. 11(e) shows a state in which sheets P with one-sided copies already accumulated are stacked on the upper surface side of the stacker 61.
FIG. 11(f) shows a state in which the stacked sheets P are taken out for re-supply.

In addition, when performing single-sided multiple copying, by switching the gate 80 to a predetermined position (the state shown in FIG. 9), the paper P can be directly fed to the image transfer section 30 without being led to the stacker 61, so that the same side of the paper P can be copied. The images will be superimposed.

Note that image formation is performed in the same manner when the paper P is fed from the paper feed cassette 15 or the paper P is fed from the manual paper feed tray 17. In addition, in the case of single-sided copying, the paper can be directly transferred to the tray without being guided to the paper conveying device 3.
It will be discharged on 8th.

In addition, if the paper P is jammed on the bottom side of the stacker 61, the stacker 61
By opening upward, the carry-in path 62 is opened, the paper P jammed in this area is removed, and maintenance and inspection etc. are performed in the same manner.

In the above embodiment, a configuration was described in which the guide bodies 66 and 67 were attached to the bottom surface of the stacker 61 and the base 1a to guide the paper P. It may also be a configuration.

In addition, it goes without saying that the present invention can be modified in various ways without departing from the gist thereof.

[Effects of the Invention] As described above, according to the present invention, the paper passes through the fixing device below the paper conveyance path that reaches the fixing device via the image transfer section formed between the image carrier and the transfer device. In an image forming apparatus that includes a built-in paper transport device that can temporarily accumulate sheets of paper in a stacker and guide them to the image transfer section again, the image forming apparatus is configured such that the paper passes through the lower surface side of the stuffer 4 that temporarily accumulates the sheets of paper. A large space is provided on the upper surface side of the stacker, and jam removal can be easily performed without increasing the height of the entire image forming apparatus. Further, the guide body can be directly attached to the bottom plate of the stacker and the apparatus main body, and the bottom plate of the stacker and the apparatus main body can also be used as a guide means, thereby reducing costs by reducing the number of parts.

Furthermore, since the stacker is made movable, the lower surface side of the stacker can be opened by moving the stacker upward, and jams in the carry-in path formed on the lower surface side of the stacker can be easily cleared.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and Fig. 1 is a schematic exploded perspective view with some of the main components of the paper conveying device, which is the main part, omitted, and Fig. 2 shows the platen cover opened. FIG. 3 is a schematic longitudinal sectional front view of the entire image forming apparatus, and FIG. 4 is a schematic perspective view with some of the main components of the paper conveyance device being omitted. 5 is a diagram showing the configuration of the paper conveyance merging section, FIGS. 6 to 9 are diagrams showing the different operating states of the paper transport merging section, and FIG. 10 is an explanation showing the operating state during double-sided copying. figure,
FIG. 11 is an illustration of the main parts showing the operating state during double-sided copying. DESCRIPTION OF SYMBOLS 1... Apparatus main body, 1a... Base, 3... Paper conveyance device (ADD) 20... Image carrier (photoreceptor) 4
24... Transfer device, 30... Image transfer section, 32...
Paper conveyance path, 34... Fixing device, 61... Stacker, 62... Carrying in path, 66.67... Guide body, P.
...Paper. Applicant's Representative Patent Attorney Takehiko Suzue

Claims (2)

[Claims] (1) The paper that has passed through the fixing device is temporarily stacked in a stacker below the paper conveyance path that passes through the image transfer section formed between the image carrier and the transfer device and reaches the fixing device, and is transferred to the image transfer section again. 1. An image forming apparatus having a built-in paper conveying device that can be guided, the image forming apparatus being configured such that the paper passes under a stacker that temporarily accumulates the paper. (2) The image forming apparatus according to claim 1, wherein the stacker is movable.