JPH0511261Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a paper feeding device for a copying machine that is capable of double-sided copying and composite copying.

<Prior Art> In a conventional copying machine, as shown in FIGS. 5 and 6, the transfer machine 1 performs normal one-sided copying, and then is sent to a conveyance path for automatic double-sided copying and composite copying.
The paper is stored on the intermediate tray 2, re-fed to the image forming section by the pull-in roller 3 arranged above the intermediate tray 2, and then transferred, conveyed, fixed, and outputted from the machine. .

<Problems to be solved by the invention> In the copying machine described above, for example, when refeeding paper from the intermediate tray 2 during composite copying, the upper There was a problem in that the toner on the transfer paper 1 was reversed onto the back side of the transfer paper 1 below and smeared. Copying machines with different paper paths may get dirty when making double-sided copies. It is impossible to completely prevent this problem with the current mechanism, and the only way to alleviate this problem is to use a pull-in roller.
Although it is possible to weaken the pressing force of the roller 3, lower the hardness of the roller 3, or shorten the pressing time, all of these methods result in unstable paper feeding force and paper feeding errors.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a paper feeding device for a copying machine that can prevent adjacent transfer sheets from becoming dirty.

<Means for solving the problems> The means for solving the problems according to the present invention are shown in Figs. 1 to 4.
As shown in the figure, the copied paper 1 with an image formed on one side in the image forming section 4 is stored on the intermediate tray 2 with the image forming side facing up, and the sheet 1 is placed on the intermediate tray 2 on the side opposite to the image forming side. Screen feeding for double-sided copying, in which the paper 1 is fed to the image forming section 4 to form an image on the other side, and an image is formed on one side in the image forming section 4. The copied paper 1 is placed in the intermediate tray 2 with the image forming side facing down, and the paper 1 is fed from the intermediate tray 2 to the image forming section 4 in order to form an image on the same surface as the image forming surface. In a paper feeding device of a copying machine, which has a function of performing composite paper feeding for performing composite copying by feeding, the uppermost paper 1 accommodated in the intermediate tray 2
The uppermost sheet of paper 1 is opposed to the uppermost sheet of paper 1 and is provided so as to be able to approach and separate from the uppermost sheet of paper 1.
a first roller 5 that feeds paper from the middle tray 2; and a lowermost paper 1 accommodated in the intermediate tray 2.
A second roller 6 is provided in contact with the sheet 1 and is rotated to feed paper from the bottom paper 1, and a second roller 6 that feeds the paper from the bottom paper 1 by being rotationally driven; A first function of pressing and rotationally driving the second roller 6 and stopping the rotation of the second roller 6, and a first function of rotating the second roller 6 that presses against the paper 1 at the bottom of the intermediate tray 2 during composite copying and also rotating the first roller 5. The paper feeding roller drive control device 7 has a second function of bringing the roller into pressure contact with the uppermost paper 1 and stopping its rotation.

<Function> In the above problem solving means, when double-sided copying is performed, the first roller 5 is brought into pressure contact with the topmost paper 1 of the intermediate tray 2, and the first roller 5 is driven to form an image from the topmost paper 1. Feeding is carried out to section 4.
At this time, the second roller 6 remains stopped.

When performing composite copying, the first roller 5 is brought into pressure contact with the paper 1 at the top of the intermediate tray 2. and,
The second roller 6 is driven, the first roller 5 remains stopped, and the sheet of paper 1 at the bottom is fed to the image forming section 4.

In this way, in double-sided copying, the first roller 5 contacts the surface 1a of the paper 1 on which an image has been formed, and in composite copying, the first roller 5 contacts the surface 1a of the paper 1 on which an image has been formed.
Since the second roller 6 comes into contact with the back surface 1b of the sheet 1, it is possible to prevent the toner from being transferred to the adjacent sheet 1.

<Example> The following is a first example of the paper feeding device of the copying machine of the present invention.
This will be explained based on the drawings to FIG. FIG. 1 is an explanatory diagram of the operation of the main parts of a paper feeding device of a copying machine according to an embodiment of the present invention during double-sided copying, FIG. 2 is an explanatory diagram of the operation of the main parts during composite copying, and FIG. The control block diagram in FIG. 4 is also an overall vertical sectional side view of the copying machine.

As shown in the figure, the present invention includes a first roller (upper feed roller) 5 that presses against the surface 1a of the transfer paper 1 loaded on the intermediate tray 2 and feeds the transfer paper 1 to the image forming section 4. , a second roller (lower feed roller) 6 that presses against the back surface 1b of the transfer paper 1 loaded on the intermediate tray 2 to feed the transfer paper 1 to the image forming section 4; . 6 and a second function of rotating the first roller 5 and stopping the first roller 5.

The copying machine C has a first paper feed path 8 for feeding the transfer paper 1 fed from the paper cassette main body K to the image forming section 4, and a fixing section 9 for fixing the toner. It has a paper feed belt 10 that feeds paper, a conveyance roller 11 that conveys the transfer paper 1 after fixing to the outside of the machine, and the like.

A support box 12 for supporting the copying machine is provided below the copying machine, and a connection box 13 for connecting the support box 12 and the copying machine C in communication at the side is provided. A second paper feed path 14 for automatic double-sided copying and composite copying is formed in the junction box 13, and the second paper feed path 14 is connected to a third paper feed path 15 for double-sided copying and for composite copying. The confluence 17 of both paths 15 and 16 communicates with the fifth sheet feeding path 18 of the support box 12, and the lower side of the fifth sheet feeding path 18 An intermediate tray 2 is disposed at , and the intermediate tray 2 is communicatively connected to the first paper feed path 8 .

The intermediate tray 2 includes a flat wall 19 for storing the transfer paper 1, and an upwardly inclined slanted wall 20 integrally formed on the paper feeding side of the flat wall 19.

The first roller 5 is arranged above the flat wall 19, and the third roller 21 (paper feeding roller) is arranged on the paper feeding side of the first roller 5 and above the slanted wall 20.
The rollers 5 and 21 have their respective rotation shafts 5a and 21a connected by an arm 22. One end of the arm 22 is rotatably fitted onto the rotating shaft 5a of the first roller 5, and the other end of the arm 22 is fitted onto the rotating shaft 21a of the third roller 21.
It is rotatably fitted on the outside.

As shown in FIG. 1, the pressure rotation mechanism of the first roller 5 and the second roller 6 is supported by the arm 22, a pressing piece 21a formed at the upper end on the paper feeding side, and the copying machine main body. A spring hanging piece A1 is rotatably supported around axis A and has a lower end in contact with the pressing piece 21b, and a spring hanging piece A1 is interposed between the lower end of the spring hanging piece A1 and the pressing piece 21b to rotate the arm 22. A tension spring S swings under pressure in the pressure direction (counterclockwise) around the shaft 21a, and a tension spring S is connected to the upper end of the spring hanging piece 21b and resists the tensile force of the tension spring S when the spring hanging piece 21b is turned on. and a solenoid S1 for swinging the arm in the non-pressurizing direction (clockwise rotation direction) around the support shaft A.

The second roller 6 is fixedly supported by a rotating shaft 6a at a position opposite to the first roller 5, and is mounted on a flat wall 19.
The outer circumferential portion 6b thereof slightly protrudes from the hole 23 formed in the flat wall 19.
A fourth roller 24 (judging roller) is rotatably supported by a shaft 24a at a position opposite to the second roller 6, and is disposed below the inclined wall 20, and its outer peripheral portion 2
4b slightly protrudes from the hole 25 formed in the inclined wall 20 and comes into contact with the outer peripheral portion 21b of the third roller 21. The rotating shafts 5a, 6a, and 21a of the first, second, and third rollers 5, 6, and 21 are operatively connected to a drive chain of the copying machine via, for example, an electromagnetic clutch.

The control device 7 is a general one-chip microcomputer that has a program ROM, data RAM, ALU, etc. inside, and is driven by a reference clock oscillator. The control device 7 has a composite copying switch 26 and a double-sided copying switch 27 connected to its input side, and a drive opening circuit for each clutch of the control first roller 5, second roller 6, and third roller 21 to its output side. has been done.

The control device 7 controls the duplex copying switch 27.
A first function outputs a drive signal to each clutch of the first roller 5 and third roller 21 by an ON signal, and a drive signal is output to each clutch of the second roller 6 and third roller 21 by an ON signal of the composite copying switch 26. It also has a second function of outputting a drive signal.

In the above configuration, for example, when the user presses the duplex copying switch 27 and sets the number of copies to seven, the transfer paper 1 fed from the paper feed cassette main body K
is sent to the image forming section 4 through the first paper feed path 8, forms an image on the surface of the transfer paper 1, is fed to the fixing section 8, where the toner is fixed on the surface, and the toner is fixed on the surface of the transfer paper 1.
The second paper feed path 14, the third paper feed path 15, and the support box 12
The paper passes through the fifth paper feed path 18 and is stored face up on the intermediate tray 2. At this time, arm 2
Since the solenoid 2 is ON, the first roller 5 does not move upward and prevent the transfer paper 1 from entering. When seven single-sided copies have been completed, the control device 7 outputs an output to rotate the first roller 5 and the third roller 21. At the same time, the solenoid is turned OFF, and the arm 22 is moved downwardly around the rotating shaft 21a of the third roller 21 in the direction in which the first roller 5 presses the transfer paper 1, and the arm 22 is moved downward by the force of the pressure spring in the direction in which the first roller 5 presses the transfer paper 1. The paper is re-fed to the first paper feed path 8 starting from the highest one among the paper sheets.

Also, when the user presses the composite copy switch 26, the transfer paper 1 fed from the paper cassette main body K is
is sent to the image forming unit 4 through the first paper feed path 8, forms an image on the surface of the transfer paper 1, is fed to the fixing unit 9, where the toner is fixed, and is transferred to the second paper feed of the connection box 13. The transfer paper 1 passes through the paper path 14, the fourth paper feed path 16, and the fifth paper feed path 18 of the support box 12, and is stored on the intermediate tray 2 with the surface of the transfer paper 1 facing down. At this time, since the solenoid of the arm 22 is ON, the first roller 5 moves upward and does not prevent the copying machine 1 from entering. Then, when the copying of the set sheet is completed, the control device 7 outputs an output to drive the second roller 6 and the third roller 21, and feeds the transfer paper 1 from the lowest one to the first paper feed path 8. . At this time, arm 22
is moved downward by the force of the pressure spring, and the first roller 5 is
The third roller 21 rotates about the rotating shaft 21a in the direction of pressing the transfer paper 1 and presses the copying machine 1 from above, but the rotation is stopped.

As mentioned above, in the case of double-sided copying, the first roller 5
In the case of composite copying, the paper is fed from the lowest transfer paper 1 by the second roller 6, so that it is transferred to the adjacent transfer paper 1 by the pressure of the roller. Almost no toner transfer occurs.

It should be noted that the present invention is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention.

<Effects of the invention> As is clear from the above description, according to the invention, the tray is provided facing the uppermost sheet of paper stored in the intermediate tray and capable of approaching and separating from the uppermost sheet of paper,
The first roller is rotatably driven to feed paper from the topmost paper, and the first roller is provided in contact with the bottommost paper stored in the intermediate tray. a second roller for printing the paper, and during double-sided copying, the first roller on the intermediate tray is brought into pressure contact with the uppermost sheet of paper and driven to rotate, and the rotation of the second roller is stopped;
During composite copying, the second roller that comes into pressure contact with the bottom sheet of the intermediate tray is rotated, and the first roller comes into pressure contact with the topmost sheet of paper and stops rotating. One roller comes into contact with the other, and in composite copying, the second roller comes into contact with the back side of the paper on which the image has been formed, which has the excellent effect of preventing toner from being transferred to the adjacent transfer paper. There is.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the operation of the main parts of a paper feeding device of a copying machine according to an embodiment of the present invention during double-sided copying, FIG. 2 is an explanatory diagram of the operation of the main parts during composite copying, and FIG. FIG. 4 is a general longitudinal sectional side view of the copying machine, FIG. 5 is an operational explanatory diagram showing a paper feeding device of a conventional copying machine, and FIG. 6 is an enlarged detailed view of the main parts thereof. 1...Transfer paper, 1a...Surface of transfer paper, 1b...
... Back side of transfer paper, 2 ... Intermediate tray, 4 ... Image forming section, 5 ... First roller, 6 ... Second roller, 7 ... Control device, 8 ... First paper feed path, 9 ... …
Fixing unit, 12... Support box, 13... Connection box, 15
...Third paper feed path, 16...Fourth paper feed path, 18...
Fifth paper feed path, 21...Third roller, 21a...
Rotation shaft of the third roller, 24...fourth roller,
26...Composite copy switch, 27...Double-sided copy switch.

Claims (1)

[Claims for Utility Model Registration] Copied paper with an image formed on one side in the image forming section is stored on an intermediate tray with the image forming side facing up, and the sheet is placed on an intermediate tray opposite to the image forming side from the intermediate tray. Two-sided paper feeding for double-sided copying, in which the paper is fed to the image forming unit to form an image on the other side, and a double-sided paper feeding system, in which the paper is fed to the image forming unit to form an image on one side, and the other Composite copying is performed by placing sheets of paper in the intermediate tray with the image forming surface facing down, and feeding the sheets from the intermediate tray to the image forming section to form an image on the same surface as the image forming surface. In a paper feeding device for a copying machine, which has a composite paper feed function for the above-mentioned intermediate tray and a function to perform the following, the above-mentioned intermediate tray is provided with a paper feeding device that faces the uppermost sheet of paper stored in the intermediate tray and is movable toward and away from the uppermost sheet of paper. , a first roller that is rotationally driven to feed paper from the topmost sheet; and a first roller that is provided in contact with the bottommost sheet of paper stored in the intermediate tray, and that is rotatably driven to feed the bottommost sheet of paper. a second roller that feeds the paper from the uppermost sheet; a first function that presses the first roller on the intermediate tray against the uppermost sheet of paper during double-sided copying and rotationally drives the second roller; and a first function that stops the rotation of the second roller; a paper feed roller drive control device having a second function of rotating a second roller that is in pressure contact with the paper at the bottom of the intermediate tray and stopping the rotation by bringing the first roller into pressure contact with the paper at the top of the intermediate tray; A paper feeding device for a copying machine characterized by the following.