JP3378642B2 - Image forming apparatus provided with jam processing mechanism - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a facsimile or a laser printer, and more particularly, an image forming apparatus having a mechanism for easily removing a sheet such as copy paper when the sheet is jammed. It relates to the device.

[0002]

2. Description of the Related Art Image forming apparatuses are roughly classified into an image forming section centering on a photoconductor and the like, and a transfer sheet on which a toner image on the photoconductor is to be transferred is conveyed from a paper feed section to a paper discharge section. There is a transporting part for each and other parts. When a paper jam occurs at any part of the transport unit and a so-called jam occurs, the transport unit is generally moved from the transport position to the release position in order to remove the paper.

A specific example of the releasing method will be described with reference to the drawings. For example, as shown in FIG. 6A, a transfer sheet (not shown) on which a toner image is transferred from the photoconductor 12 by the transfer device 21 is Normally, the sheet conveying device 27 is guided and sent to the fixing device 28, the toner image is heated and fixed, and then discharged to the outside of the machine. It is lifted by 50 to the transport position. Then, when a paper jam occurs, as shown in FIG.
As shown in (b), the transport releasing device 50 is folded to move the entire transporting device 27 to the release position, and a working space for removing the jammed paper is secured above the transporting device 27.

Alternatively, as shown in FIG. 7A, in a normal state, a conveyance releasing device 51 which supports the sheet conveying device 27 at the conveying position, and when a paper jam occurs, tilts the supporting rod to convey the conveying device. 27 is tilted as shown in FIG. 7B to create a work space for removing jammed paper.

[0005]

However, in the method of removing the jammed paper by the releasing operation of the conveying device shown in FIGS. 6 and 7, when the conveying device 27 moves to the releasing position, the conveyance is performed. In order to secure a space for processing above the device 27, it is necessary to increase the amount of movement thereof. Given that movement, a sufficient space for retracting the transport device should be provided in advance below the transport device. Must be placed. This means that the machine as a whole will become large in the height direction.

Particularly in recent years, a so-called front-loading type image forming apparatus has become widespread in which a paper feed tray is provided in the lower part of the machine for improving operability and transfer paper replenishment work can be performed from the front side of the machine. Yes, there are increasing factors that increase the height of the machine. That is, in such a front loading method, the paper feeding tray is configured so as to be superposed on the lower side of the machine body, rather than being fitted with the paper feeding tray from the side of the machine body unlike the conventional side loading method. , The whole machine must be expensive if there are various mounting sizes. This method makes it easy to replenish the transfer paper and reduces the machine occupancy area by eliminating the protrusion in the lateral direction of the main body, but the increased height allows the original to be placed on the original placement surface. The workability of placing the is reduced. Particularly for a book document or the like, it is necessary to press the document on the document placement surface, which makes the work difficult.

On the other hand, if the height of the document placing surface is limited to ensure operability, the space for removing the jammed paper is inevitably narrowed when the conveying device is released, and the removing work becomes difficult. There is a drawback that a piece of paper remains in the machine, or there is a high risk of injuring a surrounding unit or the like while performing work while putting a hand in the machine.

In view of the above drawbacks, the present invention provides an image forming apparatus which secures a working space when releasing the conveying device, suppresses the height of the machine body to a necessary minimum, and has a good document setting property. The task is to do.

[0009]

According to the present invention, in order to solve the above-mentioned problems, an image forming apparatus includes a shielding member which defines a boundary of a conveying portion below a sheet conveying device, and a sheet conveying device which is supported by the shielding member. A portion of the shielding member that has a conveyance releasing member that moves between a conveyance position and a releasing position and that abuts the sheet conveying device when the sheet conveying device is at the releasing position is made of a flexible material.

Further, there is provided a shielding member which defines a boundary of the conveying portion below the sheet conveying device, and a conveyance releasing member which is supported by the shielding member and moves the sheet conveying device between a conveying position and a releasing position. Even if the shielding member, which is composed of two members that are jointly connected to each other, is configured to move so as to promote the movement stroke of the sheet conveying device when the sheet conveying device moves to the release position, Solve the problem.

Alternatively, the sheet conveying device includes a shielding member that defines a boundary of the conveying portion below the sheet conveying device, and a conveying canceling member that is supported by the shielding member and that moves the sheet conveying device between a conveying position and a releasing position. Even if it is configured such that the position of the shielding member to be brought into contact when the is moved to the release position is opened, and the cover having the recessed portion so as to cover the opened position is placed on the shielding member, Solve the problem.

In this case, the paper feed tray portion is provided below the paper conveying device with the shielding member interposed therebetween, and the recessed portion of the cover projects into the paper feed tray portion, so that the cover is opened when the paper feed tray portion is attached or detached. Suitably, it can be lifted.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described based on the embodiments shown in the drawings.

In FIG. 1 showing a color copying machine as an image forming apparatus to which the present invention can be applied, the copying machine is provided with a scanner section 1 for reading an original document and a digital output signal sent from the scanner section 1. It comprises an image processing section 2 for electrically processing and a printer section 3 for forming an image on a transfer sheet based on image recording information of each color from the image processing section 2.

The scanner section 1 has a lamp 5 for scanning and illuminating an original on the original table 4, for example, a halogen lamp.
The reflected light from the document when illuminated by the lamp 5 enters the imaging lens 9 via the mirrors 6, 7 and 8. The image light is imaged by the imaging lens 9 on the 3-line CCD 10 which is an image information reading unit, and is converted into a digital signal for each of red, green and blue components and output.

The digital signals of the red, green and blue components output from the scanner section are sent to the image processing section 2 where they are subjected to necessary processing and recorded information of each color, that is, black, cyan, magenta and yellow. Is converted to a signal.

The recording information converted by the image processing unit 2 is input to the printer unit 3 and sent to the laser light emitting device 11. The image forming unit of the printer unit 3 of the copying machine shown in FIG. 1 includes a laser light emitting device 11, a photoconductor 12, and a charging device 1.
3, a developing device 14, an intermediate transfer device 15, and a cleaning device 16. The developing device 14 has black, cyan, magenta, and yellow developing units (14Bk, 14C, 14M, and 14Y) corresponding to recorded information.
It is rotatably supported by the main body, and if necessary, the developing portion for each color can be moved to a position where the latent image formed on the photoconductor 12 is visualized (position 14Bk shown in FIG. 1). There is. Further, a density sensor 17 for detecting the image density on the developed photoconductor is arranged on the downstream side of the developing device 14, and the density signal from the density sensor 17 can be used to replenish toner in the developing section and change the developing conditions. Then, the image density is controlled so that the image density is appropriately maintained. The intermediate transfer device 15 is a driving roller 1.
8 and an intermediate transfer belt 19 supported by driven rollers, a belt transfer device 20, an image synchronization sensor 22, a paper transfer device 21, and the like. The image developed on the photoconductor 12 is transferred onto the intermediate transfer belt 19 by the belt transfer device 20, and further transferred onto the transfer paper by the paper transfer device 21.

In the case of forming a color image, it is necessary to superimpose the recording information of each color, but in this apparatus, the color is superposed on the intermediate transfer belt 19. In FIG. 1, the black developing unit 14Bk is at the developing position, and the laser light emitting device 11 forms a black latent image on the photoconductor 12 according to the black recording information output from the image processing unit 2. The black latent image on the photoconductor 12 is visualized by the developing unit 14Bk and transferred onto the intermediate transfer belt 19 by the belt transfer device 20. The image formation at this time is started according to the detection signal of the position in the feeding direction on the belt by the image synchronization sensor 22. When the transfer of the black image onto the intermediate transfer belt is completed, the developing device 14 rotates, for example, the cyan developing portion 14C moves to the developing position, and the laser emitting device 11 causes the cyan recording information to follow the detection signal of the image synchronization sensor 22. Start forming. Thereafter, the same operation is repeated for each color to form a superimposed color image on the intermediate transfer belt 19, and thereafter, the paper transfer device 21 transfers the color image onto the transfer paper. Belt cleaning device 23
Is retracted to the retracted position during the color image forming operation,
After the image on the belt is transferred to the transfer paper, it moves to the operating position to collect the toner remaining on the belt to prepare for the next image operation.

The transfer paper P is supplied from a so-called front loading type paper feed tray section 24 or a manual paper feed section 25 which is constructed so as to be pulled out and supplied to the front side of the apparatus, and its leading end is aligned by a registration roller 26. Then, the image is sent to the transfer portion area at the same timing, and the toner image on the intermediate transfer belt 19 is transferred by the paper transfer device 21. Then, the transfer paper P having the image transferred on the upper surface is sent to the fixing device 28 by the paper conveying device 27, the toner image is heated and fixed by the fixing device 28, and is discharged to the outside by the discharging roller 29. . The paper feed tray section 24 has a certain height because it requires a certain amount of paper stacking capacity and a vertical stack stroke to bring the leading edge region of the paper into contact with the pickup roller. Must be

Below the conveying device 27 and the fixing device 28, a main body side plate is used as a shield plate 31 for preventing foreign matters such as toner and paper dust from falling from the image forming unit onto the transfer paper P. Is attached so as to cover the paper feed tray section 24.

On the shielding plate 31, as shown in detail in FIG. 2, the transport device supporting plates 32, which are transport releasing members, are rotatably supported by the mounting members 33 located at both ends. An operating handle 34 projects to the side of the support plate 32. Further, an opening is provided on the left side of the support plate 32 on the shield plate 31, that is, on the downstream side of the transfer device 27 as viewed in FIG.
A highly flexible member 35 such as rubber is fixed by a fixing frame 36 so as to cover the opening and prevent a gap from being formed in the opening.

In the structure in which the opening provided in the shield plate 31 is covered with the flexible member 35 as described above, when the support plate 32 is tilted down and the sheet conveying device 27 is moved to the release position, as shown in FIG. In addition, the transport device 27 moves downward on the downstream side with the upstream side of the sheet transport as a fulcrum. At that time, the drop-side end of the transport device 27 contacts the rubber sheet 35 attached to the shielding plate 31, and the rubber sheet is easily deformed downward due to the weight of the transport device. Can be moved to a position lower than the position where the shield plate 31 is attached, and the space above the transport device 27 is large enough for jam clearance.

FIG. 4 shows a different configuration. Similar to the above example, the shielding plate 31 is provided with an opening, and the opening is rotatable about the fulcrum 38 and covers the opening at both ends of the rotation ( In the example shown,
A separate shield plate piece 37 having a substantially L-shaped plane is arranged. It goes without saying that the protruding portion 37a of the shield plate piece 37 should be of a length that does not interfere with the sheet transport operation when the transport device 27 is at the transport position. A spring 41 is attached between the spring anchor portion 39 of the shield plate piece 37 and the spring anchor portion 40 of the main body shield plate 31, and a fulcrum 38
The shield plate piece 37 is urged in a clockwise direction with respect to the rotation center, in other words, in a lifting direction.

When the transport device support plate 32 is rotated clockwise to release the transport device 27 from the transport position, the sheet transport downstream end of the transport device 27 contacts the shield plate piece 37,
The shield plate piece 37 has a spring 41 depending on the weight of the transfer device.
By rotating counterclockwise about the fulcrum 38 against the urging force of, the drop side end of the transport device 27 is positioned below the shield plate 31.

When the above-described structure is applied to the image forming apparatus shown in FIG. 1, the sheet conveying apparatus is inserted into the upper space of the sheet feeding tray portion 24 at the time of releasing, and the space inside the machine can be effectively used. Becomes If the lower part of the sheet conveying device is the base of the machine body, the space of the paper feed tray cannot be used, but in such a case, rubber feet are usually attached to the bottom surface of the machine body and the machine body is attached. Since it is lifted, the dead space may be used, or the dead space between the main body mounting table and the base may be used.

FIG. 5 shows a further different configuration. The drawing is a side sectional view of the machine body, and the left side of the drawing is the front surface of the machine body. The shield plate 31 is fixed to the rear plate 43 and the front plate 44 of the main body. The shield plate 31 is provided with an opening at a predetermined position as in the above example, and a separate opening is formed so as to cover the opening. The part cover 42 is placed on the shielding plate 31. The opening cover has the shape of a truncated pyramid if the opening is rectangular, for example. This opening cover 42
Is located below the shielding plate 31 in the sheet conveying device 27, in particular, the portion facing the end on the drop side, and has entered the space in the sheet feeding tray portion 24 located below the shielding plate 31, and conveys the sheet. When the device 27 is released, the transport device can be lowered to this position. When pulling out the paper feed tray unit 24 (in the direction of the arrow), the rear side plate 45 of the paper feed tray unit 24 is drawn.
Hits the inclined surface 46 of the cover 42, and the cover 4
If 2 is lifted, the tray part is pulled out.

[0027]

According to the present invention, a part of the shielding member that defines the boundary of the conveying portion below the sheet conveying device is made of a flexible material, or the shielding member can be moved so as to promote the movement stroke of the sheet conveying device. It is also possible to use the space inside the machine body effectively because it has a recessed part, and while maintaining the height of the entire machine to the minimum necessary, it is possible to secure a sufficient space necessary for jam handling. Became.

[Brief description of drawings]

FIG. 1 is a schematic view of a color copying machine to which the present invention is applied.

FIG. 2 is a schematic perspective view of a shielding plate according to the present invention.

FIG. 3 is a schematic diagram illustrating a state when the sheet conveyance device is moved to a release position.

FIG. 4 is a schematic diagram corresponding to FIG. 3 in another configuration.

FIG. 5 is a schematic cross-sectional view showing a relationship between a sheet conveying device, a shielding plate, and a sheet feeding tray section in another configuration.

6A and 6B are views showing a conventional transport releasing member, in which FIG. 6A shows a state in which the transport device is in a transport position, and FIG. 6B shows a state in which the transport device is in a release position. .

FIG. 7 is a view showing a conventional conveyance releasing member having another structure, and FIG.
FIG. 6A shows a state in which the transport device is at the transport position, and FIG.
(B) shows a state in which the transport device is in the release position.

[Explanation of symbols]

31 Shield 32 Conveyor support plate 33 Mounting member 34 Operating handle 35 Flexible member 36 fixed frame

Claims (4)

(57) [Claims] 1. A paper transporting device, comprising: a shielding member that defines a transporting unit boundary below a paper transporting device; and a transport releasing member that is supported by the shielding member and that moves the paper transporting device between a transport position and a release position. An image forming apparatus having a jam processing mechanism, wherein a portion of a shielding member that comes into contact with the device when the device is in a release position is made of a flexible material. 2. A shielding member having a shielding member that defines a boundary of a conveying portion below the sheet conveying device, and a conveyance releasing member that is supported by the shielding member and that moves the sheet conveying device between a conveying position and a releasing position. The jam removing mechanism is composed of two members that are articulated, and a portion of the shielding member that abuts against the sheet conveying device moves so as to promote the movement stroke when the sheet conveying device moves to the release position. An image forming apparatus provided with. 3. A sheet conveying device comprising: a shielding member that defines a boundary of a conveying portion below the sheet conveying device; and a conveyance releasing member that is supported by the shielding member and that moves the sheet conveying device between a conveying position and a releasing position. The jam treatment mechanism is characterized in that a portion of the shielding member to be brought into contact when the device moves to the release position is opened, and a cover having a recessed portion so as to cover the opened portion is placed on the shielding member. An image forming apparatus provided with. 4. A paper feed tray portion is provided below the paper conveying device with the shielding member interposed therebetween, and a recessed portion of the cover projects into the paper feed tray portion, and the paper feed tray portion is detached when the paper feed tray portion is attached or detached. The image forming apparatus according to claim 3, wherein the cover is lifted.