JPS5824160A - Image forming apparatus - Google Patents

Abstract

PURPOSE:To stabilize feed of a recording sheet without enlarging the size of a machine, by arranging pairs of rollers staggered in the direction at right angles to the traveling direction of the recording sheet immediately at the rear of a roller fixing device. CONSTITUTION:Pairs of rollers comprise lower rollers 13 fixed to a lower feed roller shaft 12, upper rollers 15 fixed to an upper feed roller shaft 14, correction rollers 16 staggered somewhat inside from the outside diameter of the lower rollers 13. A recording sheet P is conveyed as shown by the alternate long and short dash line. Such pairs of rollers are arranged immediately at the rear of a roller fixing device 3. This invented method permits the recording sheet fed from an image forming device, even if curling, to be given strong toughness by the staggered roller pairs, and to travel in the desired direction, and to be stabilized in the traveling direction without enlarging the size of the machine.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming apparatus such as a copying machine, and more particularly, to an image forming apparatus such as a copying machine, etc. This is about the double-sided or multi-layer forming device.

In addition to the single-sided image forming function, a 1III image forming device has been proposed, which has a double-sided and multiple III* image forming function, for reasons such as the conventional method of reducing the bulk of the image when it is used for scanning, and the ease of viewing when reading. has been done. As an example of such an image forming apparatus,
Fig. 1 shows an example of a double-sided photographing device. In WA, 1 is a photosensitive drum, 2 is a recording sheet supply stand, 3 is a fixing device, and 4 is a stock stand. Recording sheets are fed from the supply stand. is fed to the photosensitive drum IK, and after the toner image formed thereon is transferred, the toner image is fixed by the fixing device 3, and sent out of the machine by the conveyance system. In the case of double-sided image formation, the recording sheets that have passed through the fixing device 3 and fixed with 181 IIlGII as described above are aligned and stored on the stock table 4, and then The 20th image is transferred again from the photosensitive drum IK, fixed thereon, and then transported out of the machine by the conveyance system.

The hot roller fixing method is suitable for the above-mentioned double-sided or enlarged image formation apparatus, especially for high-speed apparatus. In fixing methods other than the heated roller electrodeposition method, such as the hot plate or chamber constant deposition method, the surface on which the 11-stack Km is fixed is the back side, so it may touch the hot hot plate or wire mesh and disturb the image. Also, in the pressure fixing method using only pressure, the surface of the copy paper becomes a mirror surface after pressure fixing, so the second fixation does not go well. A heated roller fixing method is generally used for the rounding, but in the heated roller fixing method, the curling in the direction of execution of the Ie force receipt once passed through the fixing device was severe, and the paper feed p was unstable. A thin letter and the 211th.
This tendency is strong with drawing paper, and this kind of curling also occurs with the pressure roller fusing method, but in practice, while accepting the instability of curled paper feeding, the heat roller fusing method The device uses a pressure roller fixing method, and uses thick paper.The paper feeding guide is configured with a smooth large radius to avoid placing stress on the sheet, which increases the size of the machine. There were also nine flaws.

The object of the present invention is to use the heat roller fixing method or the pressure roller fixing method to stabilize the feeding of the arranged sheet without increasing the size of the machine.
! 111g1 or 1m on both sides! II image formation WAK
An object of the present invention is to provide an IJI healthy acid forming device that stabilizes the feeding of distribution sheets in a machine.

For this purpose, the present invention includes a roller fixing device. In the forming device, iliIgI! is sent out from the roller fixing device. A pair of rollers arranged in a staggered manner in a direction perpendicular to the mosquito sheet running direction is installed in the onn sheet deposition apparatus so as to impart a wavy shape parallel to the traveling direction of the sheet to the fixed recording sheet. The present invention provides an image forming apparatus in which the position immediately after the image forming apparatus is ignored.

The present invention will be explained below with reference to the drawings below in Figure 2.
I will clarify.

Figure 2 shows a heated roller fixing device used in an embodiment of the ib* forming scissors device according to the present invention. In the figure, 5 indicates a fixing roller, and 6 indicates a pressure bonding p-2. The fixing roller 5 has a heater H and an e-heater H inside, and the wattage of each is 720.
W, 80W. The pressure roller 6 also has a heater H1 inside and has a wattage of 50W. The recording sheet is fed (to the left in the figure), guided by a fixing guide 7, passed through both rollers, heated and fixed, prevented from being wrapped by an upper claw 8 and a lower claw 9, and discharged from the v-roller 10. It is sent out at 11. Immediately after fixing, P curls upward as shown by a chain line. Therefore, there is no SO in the sending direction.
11, which often interferes with the transportation of items. In a general copying machine, there is no problem because the discharge roller immediately collects the m1itr on the tray, but in a double-sided image forming apparatus as shown in Fig. 1, both m1itr and
*In order to form a single-sided K11i image, when stacking it on the stock stand 4, it is easy to get it unevenly, and it is necessary to secure the double-sided image, so each recording sheet is separated by a small wing. Since the recording sheet is guided to the stock stand 4 through the guide and the roller, the recording sheet may protrude from between the guide and the roller, and the feeding direction K11 (weak island feeding) may become unstable, and jams are likely to occur. However, with the addition of a duplex unit, it is difficult to handle jams in the equipment, and furthermore, if a sheet with an image formed on one side jams, the subsequent sequence and re-sheeting are complicated, and downtime is also reduced.
gj! Since it cannot be compared with a forming device, it must be avoided as much as possible.

The real deal! In order to eliminate the above-mentioned drawbacks, a wavy shape parallel to the traveling direction of the recording sheet (1) with the JKI image fixed thereon sent out from the roller fixing device is given. 11 A pair of rollers arranged in a staggered manner in a direction perpendicular to the sheet compliance direction is placed immediately after the O-roller fixed 5Ii roller pair. In other words, a sheet that has been curled upward (sometimes downward) by a p-ra fixing device is passed through a pair of staggered rollers while it is still hot, so that the sheet is undulated parallel to the direction of travel. It makes you lean back. An example of two pairs of rows arranged in a staggered manner is 13wA.
Shown below. The two pairs of rows shown in the figure include a lower roller 13 fixed to the lower feed roller shaft 12, an upper roller 15 fixed to the upper feed roller shaft 14, and a lower roller 13C) staggered from the outer diameter to the inner diameter. It has a fixed roller 16 inserted therein, and is fed as shown by one point S* of the recording sheet Ptli. This pair of rollers acts directly on the hot sheet of the fixer to give it some stiffness in the feeding direction, so it is best to do this within 0.5 seconds before the sheet has cooled down, as shown in Figure 2. The positions of the paper ejection rollers 10 and 11 shown in the figure are suitable. (If it cools down, it will not stick properly in the direction of travel even if it passes between the pair of rollers mentioned above.) Because the top surface is hot and has semi-molten toner on it, you should use a non-offset resin material such as Teflon. A type of eyelid type roller is suitable. In particular, it is preferable to use resins that have poor thermal conductivity and have little ability to absorb heat from the sheet.

The fourth [1] shows a modification of the above-mentioned roller pair, which includes a roller 13'j with 7 flanges on both sides and a row 215' located between the 7 flanges, and a plurality of such roller pairs can be used. A similar effect can be achieved by using The feeding of recording sheets through the fixing device is stable with the above device, but in many cases the recording sheets are hot when stacked on the stock stand 4, and the toner is semi-molten and viscous, and the next sheet is reversed. It may become sticky. To prevent this, it is possible to cool the fuser and the stock stand between them, but this requires a cooling fan, a cooling fan, a metal plate, etc., and is a problem in terms of cost and installation space. . In the embodiment shown in FIG. 3, in order to prevent such surface adhesion, the bearing 17 of the shaft 14 of the Masayo roller r) 16 is
It is configured to move in the direction shown by the arrow → in the figure. That is,
The bearing 17 is slidably supported on the side plate 18, and one end of the lever 20, which is fixed to the side plate 18 and can swing around the round shaft 19, is engaged with the C-shaped lever 21 that is integrated with the wrinkled bearing 17. Connect solenoid 80L-1 to the other end.

In such a structure, for example, solenoid BOL-1
When solenoid 80L-1 is turned on, the shaft 14 is moved to the left against the force of the spring 220, and when solenoid 80L-1 is turned off, the shaft 14 is moved to the right by the force of the spring 220.

However, as shown in FIG. 2, the lamp L and the light receiving element C-5
1 is provided, this detects the ejection of the recording sheet, and the above-mentioned solenoid SQL-1 is turned on and off for each recording sheet, then each recording sheet has a wavy shape at a different position. When the recording sheets are piled up as shown in FIG. 5, an air layer is formed between each sheet, making it difficult for them to stick together.

As described above, according to one aspect of the present invention, sticking of the stacked recording sheets can be prevented by switching the relative positions of the roller pair in the axial direction according to the passage of the recording sheets.

As described above, in the 1tii* forming apparatus of the present invention, the two pairs of rows configured as described above are provided near the fixing device, so even if the recording sheet is severely curled as shown by KAIm in FIG. The recording sheet is stretched straight in the direction of travel by the four-ra pair, and has a strong stiffness in the direction of execution, unlike conventional recording sheets. Therefore, by increasing the size of the ItIK machine, the feeding of recording sheets is stabilized.

Therefore, as shown in Fig. 1, in an image forming IT that has a double-sided or multiple image forming function in addition to a single-sided image forming function, an image is recorded on the first side and a side recording sheet is used. It is necessary to change the traveling direction of the recording sheet by switching between the conveyance system that carries it out of the machine as it is and the conveyance system that refeeds it into the machine. In order to switch the traveling direction of the recording sheet in this manner, a traveling direction switching device comprising a triangular guide 23 as shown in FIG. 6 has conventionally been used. In FIG. 6, the recording sheet is conveyed from the left side of the figure and fed to the right by the row 2, and when forming a single-sided image, the mineral guide 23 is at the solid line position and the recording sheet F is fed in the true direction. It is carried out of the machine via one of the conveyance systems (not shown), and when forming double-sided round multiple images, the guide 2
3 is at the position indicated by the broken line, and the recording sheet is sent in the direction B and sent back into the machine via another conveying thread (not shown).

In the iIiIg1 forming apparatus that uses such a conventional triangular guide to change the direction of the feeding sheet, the direction of the recording sheet fed by the conveyance roller is forcibly changed. Sheets are often not fed smoothly, resulting in ji, -yA.

According to the present invention, the recording sheet can be fed in a desired direction by changing the relative position of the pair of rollers arranged in a staggered manner without using such a triangular guide. Such an embodiment is shown in FIG.

In FIG. 7, p-ra 13 and 15 are used to transport the recording sheet in a desired direction according to the image mode selection.
．． The means for displacing the relative positions of the shafts 16 and 16 is formed by a lever 23, the shafts 12 and 14 are mounted on the shaft 23, and the lever 23 is mounted around the shaft 12. It is possible to swing. In order to swing this lever, there are solenoids 80L-2 and 1i at the upper end of the lever 23 facing each other! OL-3 is provided.

In the above structure, solenoid 80L-2.

By the operation of SQL-3, the roller 16 is displaced to the position shown by the solid line and the position shown by the broken line,
This feeds the recording sheet in the A and tiB directions.

To make the feeding direction of this recording sheet even more accurate,
A guide 24 is attached to the lever 23 mentioned above.

This die 24 may not be integrally attached to the lever 23, but may be moved simultaneously or sequentially in accordance with the movement of the roller 16. For this purpose, the cam bolt 24, which rotates in accordance with the movement axis of the roller, may be moved simultaneously or sequentially in accordance with the movement of the roller 16. It may be moved through a means to an appropriate angle for sheet conveyance.

In the embodiment shown in FIG. 7, the recording sheet is given a wavy shape parallel to the direction of travel, so it is stiffened and is neatly fed in the tangential direction of the rollers 15 and 16 and the row M) 13. , solenoid 80L-2, 8OL-3
Switch the position of the lever 23 at
- changing the relative position of 213 and the orientation of the guide 24;
W. Because the guide shown in Figure 6 does not forcefully change the feed direction, the recording sheet is fed in its respective direction very well.

Figure 8 shows an outline of the above-mentioned image forming apparatus and its operation panel, and Figure 9 shows an outline of its circuit. In FIG. 9, 28 is a power supply, sw is a switching switch, and 5QL-2°80L-3 is the above-mentioned solenoid. When the one-sided selection button 25 is pressed, the solenoid 80L-3 is energized, the roller shaft 14 is placed at the solid line position in the figure $7, and the recording sheet is fed in the true direction. Similarly, in the case of double-sided recording, when the multiple selection button 26 or 27 is pressed, the solenoid 80L-2K is energized and the recording sheet is fed in the layer direction.

The above switching is OW! You can increase the number of books and send them in one-sided, double-sided, or multiplex directions. Such an example is shown in FIG. In FIG. 1θ, 1 is a photosensitive drum, 2 is a recording sheet supply table, and 3 is a fixing device. Further, 29 is a stock stand that temporarily receives and inverts a recording sheet for double-sided image formation and sends it to a photosensitive drum; 30 is a multiplex i1i*
In this device, the position of the upper roller can be changed to island, island, etc. depending on the selection of single-sided, double-sided, or multiplex.
b.

Switch to C. At the same time, the guide 24 also moves integrally, and the recording sheets are A and B, respectively.

It is sent in the direction of the arrow C. What is important about this device is that, for example, the upper opening 2 is removably provided at positions a, b, and @ in the figure, and when it is on one side, Fib is on both sides, and a and b1 are on both sides.
In the case of multiple prizes, it is also possible to make a, b, and C work together with the roller 18, and change the feed direction so that the feed direction can be selected.

As described above, according to the present invention, even if the recording sheet fed out from the image forming apparatus is curled, the two pairs of staggered rows impart strong stiffness to the recording sheet, so that the recording sheet i The recording sheet can be immediately stretched and moved correctly in the desired direction, and the feeding of the recording sheet can be stabilized without particularly increasing the size of the machine. Furthermore, by moving the relative positions of the pair of rollers described above, the recording sheet can be extremely well fed in a desired direction without having to forcefully change the direction using a guide or the like.

[Brief explanation of drawings]

Figure 1 is a conventional double-sided machine! 2 is a diagram showing an example of the device; FIG. 2 is a diagram showing a heat roller 2 fixing device used in the device of the present invention; FIG. 3 is a sectional view showing a 4-2 pair used in the device of the present invention;
4 is a sectional view showing a modification of the pair of rollers shown in FIG. 3; FIG. 5 is a view showing an overlapping state of enlarged recording sheets; FIG. , Tuna 7 is a diagram showing the recording sheet advancing direction changing means in the device of the present invention, FIG. 8 is a diagram showing the operation panel of the device of the present invention, FIG. 9 is a schematic diagram showing the operation circuit thereof, and FIG. 10 is a diagram showing the device of the present invention. FIG. 1 is a diagram schematically showing an image forming apparatus according to. 1... Photosensitive drum 2... Recording sheet supply stand 3... Fixing device 4... Stock stand 5...
・Fixing roller 6...Pressure roller 7...Idle 8, 9...Claw 10.11...Discharge row 2 12...Lower feed roller shaft 13, 13'...Lower roller 14. ...Upper feed roller shaft 15, 15'...
Upper mouth -216-...Masei roller 17...Bearing 1
8...Flap board 19...Shaft 20...Lever 21...Pin 22...Spring
23...Guide 24-...Guide 25.26.27...Selection guitar 28...Power source 29...Stock stand 30
...Conveyance route.

Claims (1)

[Claims] α) In an image forming apparatus equipped with a row 2 fixing device,
Nine sheets are arranged in a staggered manner in a direction perpendicular to the direction of travel of the blank sheet so as to impart a wavy shape parallel to the direction of travel of the sheet to the recording sheet (K) on which the image has been fixed and which is sent out from the roller fixing device. iii. An image forming apparatus in which a pair of rollers is arranged immediately after the roller fixing device described above. (2) Add #I2 to the recording sheet on which the ij image has been fixed.
In a double-tooth or multi-image forming apparatus that forms an image, the recording sheet provided with a corrugated shape by the pair of rollers is fed to a ninth recording sheet loading section where a second image is recorded. An image forming apparatus according to claim α). (3) Claim 0 in which the relative position of the roller pair in the axial direction is changed according to the passage of the recording sheet.
).