JPH0818724B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Purpose of the invention [Industrial field of application] The present invention relates to an image forming apparatus such as a laser beam printer or an electrophotographic copying machine, and particularly to an image on one side or both sides of a sheet material such as transfer paper. The present invention relates to a formable image forming apparatus.

[Conventional technology]

Hereinafter, a laser beam printer using an electrophotographic process will be described as an example.

FIG. 8 is a sectional view showing a schematic configuration of a conventional laser beam printer capable of printing (image forming) on one side or both sides of a sheet material.

In the figure, 1 is a main body of the apparatus, and 2 is a photosensitive drum as an image carrier provided in the main body 1, which is rotationally driven at a predetermined peripheral speed in the direction of arrow a in the figure.

Around the photosensitive drum 2, known process devices such as a charger 3, a developing device 4, a transfer / separation charger 5, and a cleaner 6 are arranged.

Reference numeral 7 denotes a semiconductor laser that emits laser light based on an image signal (print signal) input from a host computer (not shown) or the like. Reference numeral 8 denotes laser light L emitted from the semiconductor laser 7 and a mirror 9 formed by a rotating polyhedron. The scanner scans the photosensitive drum 2 via the scanner.

10 is a feeding cassette containing a sheet material S such as transfer paper,
11 is a feeding roller that feeds one sheet material from the cassette 10, 12 is a guide plate for the sheet material S, and 13a and 13b are transfer charge separately from the drum 2 in synchronization with the rotation of the photosensitive drum 2. Registration rollers for feeding the sheet material to and from the device 5, 14 are sheet material conveying belts, 15 are fixing devices, 16a and 16b are sheet material discharge rollers, and 17 is a discharge tray.
The sheet material main transport path P1 is constituted by.

P2 is a sheet material sub-conveyance path that reverses the sheet material that has finished image formation on one side along the main conveyance path P1 and guides it again to the main conveyance path P1 when forming images on both sides of the sheet material S. The guide plates 18a, 18b, 19a, 19b, 20a, 20b, and the pair of conveying rollers 21a, 21b, 22a, 22b. twenty three
Is a flapper for guiding the sheet material to the sub-conveyance path.

When an image is formed on one side of the sheet material S in the above configuration, the flapper 23 is at the solid line position in the figure, a print start signal is input from a host computer (not shown), etc. (Print)
The operation is started. Then, the laser light emitted from the semiconductor laser 7 is scanned by the scanner 8 based on the image signal, and the photosensitive drum surface uniformly charged by the charger 3 is irradiated with the laser light via the mirror 9 to form a latent image. It is formed and developed by the developing device 4. At the same time, the sheet material S sent out from the feeding cassette 10 one by one is conveyed along the main conveyance path P1, and when passing between the photosensitive drum 2 and the transfer / separation charger 5, the sheet material S on the photosensitive drum 2 is conveyed. The developed image is transferred onto the sheet material, fixed by the fixing device 15, and discharged onto the discharge tray 17 by the discharge rollers 16a and 16b with the image surface facing upward.

Further, when images are formed on both sides of the sheet material, an image is formed on one side of the sheet material S by the same process as above with the flapper 23 positioned as shown by the solid line in the figure, and the trailing edge of the sheet material is When passing the flapper 23, the flapper 23 moves to the chain line position in the figure by a signal from a detection means (not shown), and at the same time, the discharge rollers 16a and 16b rotate in the opposite direction and the sheet material switches back to the sub-transport path P2. Be guided. Its sub-transport route
The sheet material guided into P2 is the transport rollers 21a, 21b, 22a.
・ Introduced from the upstream side of the registration roller pair 13a ・ 13b through the guide plates 18a ・ 18b, 19a ・ 19b, 20a ・ 20b by the 22b again with the image surface facing downward in the main conveyance path P1.
An image is formed on the surface opposite to the image surface by the same process as described above and is discharged onto the discharge tray 17.

Further, in the above-mentioned conventional laser beam printer, when the sheet material is jammed in the main conveyance path P1 or the sub-conveyance path P2, it is configured so that a part of the members constituting each conveyance path can be moved to open each conveyance path. For example, when a sheet material is jammed in the main transport path P1, the transfer separation charger 5 and the sheet material transport belt 14 are integrally rotated as shown by the chain line in FIG. 8 to remove the jammed sheet material. To do.
Further, when the sheet material is jammed in the sub-conveyance path P2, all or part of the guide plates 18a and 19a are moved as shown by the chain line in the figure to remove the jammed sheet material.

[Problems to be solved by the invention]

However, in the above-mentioned conventional example, when the member on the main transport path P1 side is opened, it hits the member on the sub transport path P2 side, and conversely, when the member on the sub transport path P2 side is opened, the main transport path P1 is reached.
Since it will hit the member on the side, it is not possible to move the conveyance guide member etc. greatly, it is very difficult to remove the sheet material on the conveyance path, especially when the sheet material is torn or a small size sheet material is jammed. Was a problem. Also, in order to open the transport path widely, the members that make up the transport path are divided into several units, each of which can be independently opened, and the transport path can be widened as much as possible. When a plurality of sheet materials are jammed or stopped in the print, there is also a problem that the guide plates and units of the respective conveyance paths have to be moved to be in an open state. Further, after removing the jammed sheet material, there is a risk of forgetting to return the guide plate and the like to the normal state.

 The present invention aims to solve the above problems.

B. Configuration of the Invention [Means for Solving the Problems] The present invention is directed to a sheet material main conveyance path from the sheet material feeding section to the final or intermediate sheet material discharging section via the image forming section, and both sides. A sheet material sub-conveyance path that guides the sheet material on which one side is imaged again through the main conveyance path at the time of image formation to the main conveyance path, and a part of the members forming the sub-conveyance path is formed. An integrated first sheet material conveying system unit and a second sheet material conveying system unit in which a member other than the above-mentioned members constituting the sub-conveying route and a part of the member constituting the main conveying route are integrated. It is characterized in that the main transport path and the sub transport path can be opened by being configured to be rotatable outwardly with respect to the main body.

[Action]

A first sheet material conveying system unit in which a part of a member forming a sheet material sub-conveying path is integrated, and a member forming a sub-conveying path other than the above and a part of a member forming a main conveying path are integrated. The second sheet material conveying system unit,
Since the main conveyance path and the sub-conveyance path can be opened so as to be rotatable outward with respect to the apparatus main body, the members forming the both conveyance paths do not interfere with each other, and are simple. It is possible to open both transport paths greatly by the operation.

〔Example〕

FIG. 1 is a sectional view of a schematic structure of a laser beam printer as an image forming apparatus showing a first embodiment of the present invention. The same members as those in FIG. The description is omitted.

The sheet material feeding cassette 10 is arranged at the bottom of the apparatus main body 1, and a main conveyance path P1 from the cassette 10 to the sheet material discharging portion via the image forming portion is provided substantially vertically from bottom to top. ing.

On the upper part of the main conveyance path P1, the first discharge roller pair 23a.2 for discharging the image surface formed on the sheet material S face down in the process of passing through the conveyance path P1.
3b and the first discharge tray 24, and a second discharge roller pair 25a.2 for discharging with the image surface facing upward (face up)
5b and a second discharge tray 26 are provided, and first and second flappers 27, 28 are arranged at the sheet material entrance portion to each discharge roller pair 23a, 23b, 25a, 25b.

Further, the sub-conveyance path that inverts the sheet material from the sheet material discharge portion side of the main conveyance path P1 and guides it again to the sheet material P1
P2 is provided outside the main transport path P1 and substantially parallel to it.

In the above configuration, when an image is formed only on one side of the sheet material, the image is formed on one side of the sheet material in the process of the sheet material S sent from the feeding cassette 10 passing through the sheet material P1. Is formed and is discharged to the outside of the apparatus. At that time, by setting the first flapper 27 to the solid line position, the sheet material is guided by the flapper 27 and is discharged from the first discharge roller pair 23a. The image can be discharged onto the discharge tray 24 with the image surface facing downward. Alternatively, by setting the first flapper 27 to the chain line position and the second flapper 28 to the chain line position, the second discharge roller pair 25a and 25b can
The image can be discharged onto the discharge tray 26 of FIG.

Further, when images are formed on both sides of the sheet material, for example, a sheet on which one side is imaged via the main transport path P1 with the first flapper 27 in the solid line position and the second flapper 28 in the chain line position. The material is switched back by the first pair of discharge rollers 23a and 23b to be guided to the sub-conveyance path P2, and again through the main conveyance path P1 to form an image on the surface opposite to the above-mentioned image surface, and then the first discharge. Roller pair 23a and 23b to first discharge tray
Discharge onto 24. Alternatively, with the first flapper 27 and the second flapper 28 in the chain line position, an image is formed on one side of the sheet material and switched back by the second pair of discharge rollers 25a and 25b, and the second flapper 28 is removed. The solid line position is led to the sub-conveyance path P2, images are formed on both sides of the sheet material through the main conveyance path P1, and the second flapper 28 is returned to the chain line position to make the second line.
The sheet is discharged from the pair of discharge rollers 25a and 25b to the second discharge tray 26.

2 and 3 show a state in which the main conveyance path P1 and the sub-conveyance path P2 in the image forming apparatus of FIG. 1 are opened.

In the figure, U1 is a first sheet material conveying system unit (hereinafter, referred to as a first unit) in which a part of members constituting the sub-conveying path P2 is integrated, and in the illustrated example, a part of the sub-conveying path P2 is formed. A common supporting member 29 for the constituent guide plates 18b, 19b, 20b and a part of the guide plate 19a and the conveying rollers 21b, 22a, 22b.
It is provided integrally with.

The above-mentioned first unit U1 is attached to the apparatus main body 1 so as to be rotatable around a support shaft 30. Reference numeral 31 is a first locking lever for holding the unit U1 in a closed state with respect to the apparatus main body 1, and is configured to engage and disengage with a locking pin 32 provided in the apparatus main body 1.

U2 is a second sheet material conveying system unit (hereinafter, referred to as a second unit) in which a member other than the above-mentioned member forming the sub-conveying path P2 and a part of the member forming the main conveying path P1 are integrated, In the illustrated example, the guide plates 18a and 20a other than the above which configure a part of the sub-transport path P2, a part of the guide plate 19a and the transport roller 21a, and the registration roller 13b and a sheet material which configure a part of the main transport path P1. The conveyor belt 14 and the transfer / separation charger 5 are integrally provided on a common support member 33.

The second unit U2 has a support shaft 34 attached to the first unit U1.
It is attached so as to be rotatable around. Reference numeral 35 is a second locking lever for holding the second unit U2 in a closed state with respect to the first unit U1, and is configured to be engaged with and disengaged from a locking pin 36 provided in the first unit U1. .

The locking pin of the first locking lever 31 from the state shown in FIG.
The engagement with the locking pin 32 is released by picking up the end portion 31b opposite to the engagement portion 31a with the first unit U1.
2 is rotated around the support shaft 30 together with the second unit U2 as shown in FIG. 2, the main conveyance path P1 is largely opened, and the sheet material jammed in the conveyance path P1 can be easily removed. .

Further, when the second locking lever 35 is picked up from the state shown in FIG. 2, the engagement with the locking pin 36 is released, and the second unit U2 is rotated around the support shaft 34 as shown in FIG. By doing so, the sub-conveyance path P2 is opened, and the sheet material jammed in the path P2 can be easily removed. After removing the jammed sheet material, the first and second locking levers are turned by rotating the first unit U1 toward the main body of the apparatus.
31 and 35 are automatically engaged with the locking pins 32 and 36, respectively, and are held in the state of FIG.

As described above, by integrally moving the first and second units U1 and U2 toward the outside of the apparatus main body 1, it is possible to widen the respective conveyance paths P1 and P2 and perform maintenance work such as jam clearance. It is possible to significantly improve the sex. Also, since the opening and returning operations of the units U1 and U2 are simple and few, the members that make up the sheet material conveying path are divided into several parts as in the conventional case, and each unit is opened and jammed. As compared with the operation of returning to the transporting state, it is possible to shorten the time and prevent the operator from forgetting to remove jammed paper and forgetting to return the unit or the like.

FIG. 4 shows a second embodiment of the present invention, which is between the apparatus main body 1 and the second unit U2 and the first and second units U1 and U2 in FIGS. Wires 37a and 37b for holding both units in an open state are provided between them. 38a to 38c are fixing pins for the wires 37a and 37b.

A locking lever 31 and a locking pin (shared with the fixing pin 38a in the figure) 32 are provided between the first unit U1 and the apparatus body 1 as in the above example. The locking lever 35 and the locking pin 36 between the second unit U1 and the second unit U2 are omitted. The other structure is the same as in the case of the above-mentioned FIGS.

From the closed state of the first and second units U1 and U2, the engagement between the locking lever 31 and the locking pin 32 is released to move the first unit U1 to the right in the figure with the support shaft 30 as the center. When rotated, both units U1 and U2 are opened in a fan shape around the support shafts 30 and 34 as shown in FIG. 4, and are held in that state by the tension of the wires 37a and 37b. The above units U1 and U2 may be configured to open around the same support shaft 30.

With the simple operation as described above, the main conveyance path P1 and the sub-conveyance path P2 are opened at the same time, and it is easy to remove the jammed sheet material due to the large opening, and the work can be completed in a short time. it can. Further, after the above removal work is completed, the locking lever 31 is automatically engaged with the locking pin 32 by rotating the first unit U1 in the direction of the apparatus main body, and the both transport paths P1 and P2 are normally closed. It can be kept in a state. Therefore, the returning operation is simple and can be completed by one operation, so that the operation is easy and there are few operation errors.

FIGS. 5 to 7 show a third embodiment of the present invention, and show an example in which the main conveyance path P1 and the sub-conveyance path P2 in the first embodiment can be opened individually by one touch.
The second unit U2 in this embodiment can be opened and closed around the same support shaft 30 as the first unit U1. Further, the first locking lever 31 and the locking pin 32 for holding the first unit U1 in the closed state are between the first and second units U1 and U2, and the second unit U2 is in the closed state. Second locking lever to hold
The 35 and the locking pin 36 are provided correspondingly between the second unit U2 and the apparatus main body 1. The other structure is the first
~ It is almost the same as the case of the example of FIG.

In the above configuration, when the sheet material is jammed in the sub-conveyance path P2, the outer side of the first locking lever 31 is picked up to release the engagement with the locking pin 32, and the first unit U1 is pivoted.
By opening 30 as shown in Fig. 6, the sub-conveyance route P2
Is opened, and the sheet material jammed in the path P2 can be removed. When a jam occurs in the main conveyance path P1, the second locking lever 35 is picked up to release the engagement with the locking pin 36, and the second unit U2 is moved together with the first unit U1 to the support shaft 30. The main conveyance path P1 is opened by opening the sheet as shown in FIG. 7 around the center, and the sheet material jammed in the path P1 can be removed. Therefore, depending on the place where the sheet material is jammed, the first and second locking levers
By properly using 31 and 35, it is possible to selectively open the conveying paths P2 and P1 with one touch to easily handle the jammed sheet material.

Although the above embodiments have been described by taking the laser beam printer as an example, the present invention is not limited to this, and the same effect can be obtained by applying the present invention to a copying machine or the like capable of double-sided copying.

As described above, according to the present invention, according to the present invention, as described above, the first sheet material conveying system unit in which a part of the members constituting the sheet material sub-conveying path are integrated, and the sub-elements other than the above. A second sheet material conveying system unit, in which a member forming the conveying path and a part of the member forming the main conveying path are integrated, is configured to be rotatable outward with respect to the main body of the apparatus, and the main conveying path Since the conveyance paths can be opened, it is possible to open both conveyance paths largely without the members forming the above-mentioned conveyance paths interfering with each other, and the sheet material jammed in each conveyance path can be opened for a short time. It can be removed efficiently. Moreover, it is possible to return each transport path to the open state or return to the normal use state with a few simple operations, and it is possible to prevent operation mistakes such as forgetting to return the unit to the original position after the jam processing. effective.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a laser beam printer showing a first embodiment of the present invention, FIGS. 2 and 3 are the same drawings showing a state in which a sheet material conveying path is opened, and FIG. FIG. 5 is a sectional view of a second embodiment of the present invention, FIG. 5 is a sectional view of a third embodiment of the present invention, and FIG. 6 and FIG. FIG. 8 is a sectional view of a conventional laser beam printer. 1 is a main body of the apparatus, 2 is a photosensitive drum, 10 is a sheet material feeding cassette, 11 is a feeding roller, 23a / 23b / 25a / 25b is a sheet material discharging roller, 24/26 is a discharging tray, S is a sheet material, and P1. Is a sheet material main transport path, P2 is a sheet material sub-transport path, U1 is a first sheet material transport system unit, and U2 is a second sheet material transport system unit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-59-211059 (JP, A) JP-A-62-10660 (JP, A) JP-A-62-285838 (JP, A) JP-A-62- 88743 (JP, A)

Claims (4)

[Claims] 1. A sheet material main conveying path from a sheet material feeding section to an image forming section to a final or intermediate sheet material discharging section, and to the one-sided side after passing through the main conveying path during double-sided image formation. A sheet material sub-conveyance path for guiding the image-formed sheet material to the main conveyance path again, and a part of a member forming the sub-conveyance path is integrated;
And a second sheet material conveying system unit in which a part of the member forming the sub-conveying path other than the above and a part of the member forming the main conveying path other than the above are integrated. An image forming apparatus characterized in that the main transport path and the sub transport path can be opened by being rotatable. 2. A main transport path is opened by simultaneously rotating the first and second sheet material transport system units in the same direction with respect to the apparatus main body, and from that state, the second sheet material transport system is transported. The image forming apparatus according to claim 1, wherein the sub-conveyance path is opened by rotating the system unit in the opposite direction. 3. When the first sheet material conveying system unit is rotated, the second sheet material conveying system unit is rotated in the same direction in association with the rotation of the first sheet material conveying system unit so that the main conveying path and the sub-conveying path are formed. The image forming apparatus according to claim 1, wherein the image forming apparatus is configured to be opened at the same time. 4. A structure for selectively opening a sheet material sub-transport path or a sheet material main transport path by rotating the first sheet material transport system unit or the second sheet material transport system unit. The image forming apparatus according to claim 1, wherein: