JPS63282770A - Printer - Google Patents

Abstract

PURPOSE:To improve the time efficiency of printing, to miniaturize a printer, and to execute printing at a high speed by executing the printing to the whole form, while operating continuously each part constituting the printer without operating it intermittently. CONSTITUTION:A process unit 20 is placed to be movable in the axial direction of a drum 7, so as to be opposed to the drum 7 to which a form 8 of a printer is wound round. On this unit 20, a driving pulley 21, and an endless OPC belt 22 which is wound round to a guide mechanism 27 consisting of many guide pins 27A-27F are provided. Length of this belt 22 is set to almost the same length as the peripheral length of the drum 7, and the belt 22 is driven at the same speed as the drum 7 by a driving motor (not shown in the figure). Also, the width of the belt 22 is set to 1/several - 1/scores of length in the axial direction of the drum 7, in which printing of a singular or plural line unit can be executed. Moreover, a charger 23, an LED head 24, a developing device 25, a cleaner 26, etc. are placed along the outside periphery of the belt 22.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a printer that forms characters, codes, figures, etc. on paper, and particularly relates to a printer that repeatedly prints line by line on paper wound around a drum. The present invention relates to a printer suitable for serial printing that prints one sheet of paper.

[Conventional technology]

A holding part that holds the leading edge of the paper is formed on the outer periphery of the drum,
The leading end of the paper is held in this holding part, and the paper with a length shorter than the circumference of the drum is wound around the outer circumference of the drum.
Printers that transfer a toner image formed on a WI image carrier such as a C-belt to paper on this drum have been known for a long time, but conventional printers print one sheet of paper at a time. There were many page printers.

7A and 7B show a conventional example of this type of printer, in which a pair of pulleys 1A and 1B having a horizontal @ line are shown.
On the outer periphery of the OPC belt 2, which is wound so as to be able to travel, there is a charger 3 as an example of a mechanism, which uniformly charges the OPC belt 2 and makes the OPC belt 2 ready for writing. , an LED head 4 as an example of a writing mechanism that forms an electrostatic latent image on the OPC belt 2.
, a developing device 5 that attracts toner to the electrostatic latent image formed on the OPC belt 2 and makes it visible; a static elimination lamp (not shown) that removes the residual potential on the OPC belt 2; Cleaner 6 etc. to remove is OPC.
They are arranged in this order along the running direction of the belt 2.

A pulley 1 to which the toner image produced by the developer 5 is adsorbed.
The OPC belt 2 at the outer circumferential portion of B is provided with a drum 7 having an axial length that is approximately the same as the width of the OPC belt 2.
They are arranged in contact or adjacently with a small gap so that they can rotate in both forward and reverse directions at a circumferential speed equal to the running speed of the C-belt 2. A holding part (not shown) that holds the leading edge of the paper 8 is formed on the outer periphery of the drum 7. A holding part (not shown) that holds the leading edge of the paper 8 is formed on the outer periphery of the drum 7. It is designed to be able to wind paper 8 of a length. The transfer may be performed by applying a voltage between the pulley 1B holding the OPC belt 2 and the drum 7 to electrostatically transfer the toner image on the OPC belt 2 to the drum 7, or by pressing the OPC belt 2 and the drum 7 together. This is done by making the surface of the drum mesh-like and installing a corotron on the inner periphery to generate an electrostatic attraction force to the toner.

In order to eliminate misalignment of the printing position on the paper 8, the OPC belt 2 and the drum 7 are driven by the same motor (not shown). A clutch is provided between the motor and the OPC belt 2, so that the drive of the motor is not transmitted to the OPC belt 2 when the paper 8 is wound around the drum 7 and when it is uncoiled. Furthermore, since the interlocking between the OPC belt 2 and the drum 7 needs to be highly precise, when using gears to transmit the drive from the motor, the magnitude of backlash should be set to less than a fraction of one pixel. It is also necessary to make the rotational unevenness of both the same or less.

Furthermore, it is necessary to stop the OPC belt 2, rotate only the drum 7, wind the paper 8 around the drum 7, and then drive the OPC belt 2 and drum 7 at a good timing to eliminate misalignment of the printing position. Therefore, a high-precision encoder (not shown) is provided to detect the rotation angle of the drum 7, and the rotation angle of the drum 7 detected by this encoder reduces the deviation of the printing position to less than a fraction of one pixel. It has become so.

Adjacent to the drum 7, a paper discharge tray 10 and a paper cassette 9 are arranged at intervals in the vertical direction so as to face the drum 7 in the axial direction of the drum 7. A hopping roller 11 is disposed above the paper cassette 9 and feeds out sheets of paper 8 one by one that are stacked in the paper cassette 9. The paper is transported in the direction of the drums 7 by transport rollers 12.12 disposed between the drums 7. Further, a fixing device 13 for fixing the toner image attached to the paper 8 to the paper 8 is disposed on the drum 7 and the paper discharge tray 10 . This fixing device 13 is composed of a heat roller 514 and a pressure roller 15 that are in pressure contact with each other. The axial position of .15 coincides with said drum 7.

According to the above-described configuration, first, the paper 8 is fed out from the paper cassette 9 by the hopping roller 11, and is transported toward the drum 77I by the transport rollers 12. Then, the motor is driven to rotate the drum 7 clockwise to wind the paper 8 on the drum 7.The encoder detects the rotational position of the drum 7, and the motor rotates in synchronization with the rotational position of the drum 7. The drive is transmitted to the OPC belt 2 and the OP
The C belt 2 is made to run in the counterclockwise direction in the figure, and the charger 3 applies a uniform charge to the OPC belt 2 to make the OPC belt 2 ready to be loaded.
A predetermined writing corresponding to image information is performed on the charger 3 by the D head 4 to form an electrostatic latent image on the OPC belt 2, and toner is attached to the vP electrostatic latent image on the OPC belt by the developer 5 to form the OPC belt. A toner image is formed on 2. Then, the toner image on the OPC belt 2 is applied to the pulley 1.
When conveyed in direction B, the drum 7 on which the paper 8 is wound continues to rotate in synchronization with the running of the OPC belt 2, so that the toner image on the OPC belt 2 is transferred to the drum by a transfer device (not shown). The image is transferred to a predetermined position on paper 8 wound around paper 7. In this way, the toner images on the OPC belt 2 are sequentially transferred onto the paper 8 on the drum 7.
When the toner image has been completely transferred onto one sheet of paper 8, the drum 7 is reversed and the paper 8 wound around the drum 7 is transferred from the rear end to the heat roller of the fixing device 13 via the conveyance rollers 12, 12. 14 and pressure roller 15, and gradually discharges the paper 8 toward the paper discharge tray 10 while fixing the toner image adhering to the paper 8 onto the paper 8. and,
When the paper 8 on the drum 7 is separated from the drum 7 to its leading edge, the paper 8 is released from the holding section of the drum 7, and the paper 8 is passed through the fixing device 13 to the leading edge, and then placed in the paper output tray 10. Discharge.

On the other hand, the OPC after transferring the toner image onto the paper 8 of the drum 7
The residual potential on the belt 2 is removed by a static elimination lamp (not shown), and the residual toner on the OPC belt 2 is removed by the cleaner 6, thereby completing one process.

Note that in order to perform color printing using a plurality of developing devices 5 for color printing, the OPC belt 2 and the drum 7 are rotated continuously, and the monochrome toner image formed on the OPC belt 2 is sequentially transferred to the drum 7. Transfer it to the upper paper 8.

(Problem to be solved by the invention) By the way, in the conventional printer mentioned above, OPC
The width of the belt 2 and the developing device 5 was made almost equal to the axial length of the drum 7, that is, the width of the paper 8, but the width of the OPC belt 2 and the developing device 5 is limited due to reasons such as processing thereof. Therefore, it is difficult to print on the large size paper 8.

Therefore, the present applicant has already proposed a printer that uses an endless latent image carrier whose width is narrower than the width of the paper to reduce the overall structure and which is also capable of printing on large size paper. ing.

The present invention further improves the above-mentioned proposal, and allows printing on the entire paper while operating the constituent parts continuously without intermittent operation, thereby achieving high printing time efficiency and high-speed printing. It is an object of the present invention to provide a printer which enables further miniaturization of the configuration and has an extremely good print finish.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention includes an endless belt-shaped latent image carrier that can run freely, and a sheet of paper having a width larger than the width of the latent image carrier, which is wound around an outer part while being inclined in the axial direction. A rotatable drum and the latent image carrier are inclined in the axial direction by the same angle as the paper and are adjacent to each other so that the toner image formed on the latent image carrier can be transferred onto the paper. The image forming apparatus is characterized in that the image forming apparatus has a guide compensation mechanism that causes the image to run, and that the latent image carrier and the drum are provided so as to be relatively movable in the axial direction of the drum in the transfer section.

[For production]

According to the present invention, a latent image carrier whose width is much narrower than the axial length of the drum is moved by a guide mechanism to a sheet of paper wound around the outer periphery of a drum in a state inclined to the axial direction of the drum. The latent image carrier is formed on the latent image carrier by making the drum adjacent to the paper so as to be inclined at the same angle as the paper, and further moving the drum and the latent image carrier relative to each other in the axial direction of the drum in the transfer section. Transfer the toner image onto paper. As a result, the toner image is transferred to the entire sheet of paper wound around the drum while continuously moving in a spiral manner with the width of the latent image carrier.

〔Example〕

The present invention will be explained below with reference to embodiments shown in the drawings. Note that the same components as those of the conventional device described above are denoted by the same reference numerals in the drawings, and the explanation thereof will be omitted.

FIGS. 1 and 2 show an entire embodiment of the present invention, and the printer shown in FIGS. 1 and 2 is a printer that forms a toner image using an electrophotographic method.

In FIGS. 1 and 2, a process unit 2 is arranged to face a drum 7 that winds a paper 8.
0 is disposed so as to be movable in the axial direction of the drum 7 as a whole, and this process unit 20 is connected to a drive pulley 21.
and a large number of guide bins 27A, 27B, 27G, 27D,
An endless O as an example of a latent image carrier wound around a guide mechanism 27 (details will be described later) consisting of 27E and 27F.
A PC belt 22 is provided. The length of this oPC belt 22 is approximately equal to the circumferential length of the drum 7, and
These drum 7 and OPC belt 22 are driven by the same motor (not shown) so that they can rotate accurately at a constant speed. Further, the OPC belt 22 can be in a state where the drive of the motor is not transmitted by a clutch (not shown). Furthermore, even if the OPC belt 22 moves in the axial direction of the drum 7, the rotation of the motor is always transmitted to the OPC belt 22.
The rotation of the motor is transmitted to the PC belt 22 via a spline or the like. Said OPC belt 2
The width of the OPC belt 22 is set to be a fraction to several tenths of the axial length of the drum 7 in order to perform printing in single or multiple line units (serial printing). A charger 23 and an LED head 24 each have a width corresponding to the width of the OPC belt 22 on the outer periphery.
, a transfer device 25, a transfer device (not shown), a static elimination lamp, a cleaner 26, etc. are arranged in this order along the running direction of the OPC belt 22, which runs counterclockwise in FIG. Each one of these! The device is supported by a frame (not shown) and can move together with the OPC belt 22 in the axial direction of the drum 7.

The charger 23 is an example of a @Ibl control mechanism that uniformly charges the OPC belt 22 and makes the OPC belt 22 optically writable.
The D head 24 is an example of a writing mechanism that forms an electrostatic latent image on the OPC belt 22 that is uniformly charged by the charger 23.

Further, in this embodiment, the paper 8 can be wound around the outer peripheral surface of the drum 7 at an angle θ with respect to the axial direction of the drum 7. This angle θ is de.

When one thread is cut on the outer peripheral surface of the ram 7, the lead of the thread is made equal to the width of the OPC belt 22. To explain further, as shown in FIGS. 3, 4, and 6, the drum 7 is formed by concentrically extending an inner drum 7A serving as a driving side and an outer drum 7B serving as a driven side. Both drums 7A and 7B each have a slit-shaped paper insertion hole 28A inclined at an angle θ with respect to the axial direction.
.

28B is drilled. Inside one of the inner drums 7A, there is a stopper against which the leading edge of the paper 8 inserted near the paper insertion hole 28A contacts and tilts the winding state of the paper 8 around the drum 7 by an angle of 0. 29 is fixed. By rotating the inner drum 7A in the direction of the arrow in FIG.
The drums 7A and 7B are sandwiched between the rotational direction trailing edge 30A of one paper insertion hole 28A and the rotational direction leading edge 30B of the other paper insertion hole 28B, and further rotate in the direction of the arrow in the figure. is wound around the outer peripheral surface of the outer drum 7B. Further, as shown in FIGS. 3 and 4, both drums 7A and 7B are applied with a rotational force for relative rotation in the direction opposite to the direction of the arrow by a spring 34 interposed at the end of the shaft. In this way, the paper 8 is inserted into the paper insertion holes 28A and 28B of both drums 7A and 7B which are inclined at an angle θ with respect to the axial direction.
In order to smoothly feed the paper, the paper cassette 9, hopping roller 11, and transport roller 12 of the paper feed system, and the transport roller 12, fixing device 13, and paper ejection tray 10 of the paper ejection system are also tilted by an angle θ. It is set up. Further, as shown in FIG. 6, the paper 8 is transferred from the paper feed system to the paper insertion holes 28 of both drums 7A and 7B.

28B, or the paper 8 on which the toner image has been transferred.
A fixed guide 31 and a movable guide 32 are provided to guide the paper to the paper discharge system. One movable guide 32 is
33 as the center, it can freely swing between the solid line position and the broken line position in the figure.

Further, the guide mechanism 27 transfers the toner image formed on the OPC belt 22 onto the paper 8 which is wound at an angle with respect to the axial direction of the drum 7 in parallel with the axial edge of the paper 8. Yes, multiple guide bins 27A...27
F causes the OPC belt 22 to travel in a zigzag pattern, and the OPC belt 22 can be transferred at an intermediate portion between the two outermost guide bins 27G and 27D at an angle θ to a plane perpendicular to the axis of the drum 7. The paper 8 is placed adjacent to the drum 7 and the paper 8 wound around the drum 7 in the same state.

Note that before the toner image is transferred from the OPC belt 22 to the paper 8, the guide bin 27B that guides the outer circumferential side of the OPC belt 22 contacts and guides only the widthwise both ends of the OPC belt 22 where the toner image is not formed. I'm trying to do it. Further, the guide mechanism 27 may have a configuration other than that shown in the drawing.

Next, the operation of this embodiment will be explained.

To perform printing using the configuration of the embodiment described above, first,
The process unit 20 is positioned so as to face one end of the drum 7 in the axial direction, and the hopping roller 11 feeds out the paper 8 from the paper cassette 9.
The sheet 8 is conveyed in the direction of the drum 7 by the conveyance row 512.12, and the leading edge of the sheet 8 is sequentially inserted into the sheet insertion hole 288.28A of both drums 7B and 7A through the fixed guide 31 and the movable guide 32 located at the solid line position in FIG. Stopper 29
It comes into contact with the Rotate the inner drum 7A in the direction of the arrow in FIG. 6 to open both paper insertion holes 28A.

28B rotational direction leading edge 30A and rotational direction leading edge 3
The leading end of the paper 8 is clamped and held by the 0B. As a result, the paper 8 is held on the outer peripheral surface of the drum 7 at an angle θ with respect to the axial direction of the drum 7. After that, movable guide 3
2 to the dashed line position, rotate the inner drum 7A to rotate the drum 7 in the clockwise direction in FIG. The OPC belt 22 starts rotating in synchronization with the paper 8 on the drum 7 as detected by the I encoder, and when the rotational speed of the drum 7 and the OPC belt 22 reaches a predetermined rotational speed, the OPC belt 22 is started by the charger 23. The OPC belt 2 is uniformly charged with the belt 22.
The OPC belt 2 is set in a writable state, and the LED head 24 performs writing according to the print command.
An electrostatic latent image is formed on the oPC belt 22, and toner is applied to the electrostatic latent image on the oPC belt 22 by a developing device 25 to make it visible. Then, the toner image on the OPC belt 22 is conveyed in the direction of the guide mechanism 27, and transferred by a transfer device (not shown) to the transfer start position of the paper 8 wound around the drum 7. . At the same time as the transfer at this transfer start position is performed, the process unit 20
is moved in the axial direction of the drum 7 by the width of the OPC belt 22 during one rotation of the drum 7, and the OPC
Transferring the toner image from the belt 22 to the paper 8 is continuously performed over the entire paper 8 while moving the position in a spiral manner. Therefore, after transferring the toner image onto the paper 8, the OPC belt 22 is allowed to run continuously without stopping and is used for the next transfer.

That is, after the transfer is completed, the residual potential on the OPC belt 22 is removed by a static elimination lamp (not shown), and the residual toner on the OPC belt 22 is further removed by the cleaner 6.

Subsequently, in order to perform the subsequent transfer continuously, the charger 23 uniformly charges the OPC belt 22 in the same manner as described above, and the LED head 24 performs writing in accordance with the next printing command to transfer the data to the OPC belt 22. An electrostatic latent image is formed, and a developing device 25 applies toner to make it visible. Then, the toner image on the OPC belt 22 is transferred to the position of the next row of paper 8 on the drum 7 by the guide mechanism 27 in the same manner as described above.

In this manner, the toner image is transferred to the entire surface of the paper 8, and then the movable guide 32 is returned to the position shown by the solid line in FIG. 6, and the drum 7 is reversed to discharge the paper 8 to the paper discharge system.

The paper 8 ejected to the paper ejection system has the transferred toner image fixed thereon while passing between the heat roller 14 and the pressure roller 15 of the fixing device 13 , and is then ejected to the paper ejection tray 10 .

According to this embodiment, the process unit 20 is continuously moved in the axial direction of the drum 7, and the entire paper 8 is heated.
Since the toner image is continuously transferred from the PC belt 22, the time efficiency of printing is increased and high-speed printing is achieved. The paper 8 on the drum 7 allows for intermittent movement, compared to one in which the process unit 20 is moved intermittently.
There is no need to provide a blank space in the circumferential direction where the drum 7 is not wound, and the drum 7 can be made small in diameter to further reduce the size of the overall structure. In addition, since continuous transfer is now possible, it is possible to improve the accuracy of the continuity between the transfer parts of adjacent lines transferred by the narrow OPC belt 22, and to faithfully follow printing commands. It is possible to reproduce high-quality printing.

In the above embodiment, the case of monochrome printing was explained, but a plurality of developing devices each capable of supplying cyan, yellow, magenta, and black toners are used in OPC.
The toner image of each color is transferred onto the paper 8 in a superimposed manner, and then the fixing device 1
3 may be used to fix the image and perform color printing.

Further, in the embodiment described above, only the guide mechanism 27 portion of the process unit 20 is provided to be inclined with respect to the drum 7, but the entire process unit 20 may be provided to be inclined.

In addition, in the embodiment described above, the process unit 2
0 in the axial direction of drum 7! However, the process unit 20 may be fixedly disposed and the drum 7 may be moved, or both the drum 7 and the process unit 20 may be moved. Furthermore, the present invention is not limited to the embodiments described above, but can also be applied to electrostatic or magnetic printing, and can be modified in various ways as necessary.

〔Effect of the invention〕 .

As explained above, according to the present invention, it is possible to print on the entire sheet of paper while continuously printing 9J without operating each component intermittently, resulting in high printing time efficiency and high-speed printing. It is possible to further reduce the size of the structure, and the print finish is also extremely good.

[Brief explanation of drawings]

1 to 6 show an embodiment of the printer according to the present invention, in which FIG. 1 is a schematic front view, FIG. 2 is a plan view, and FIG. 3 is an enlarged view of the blade in FIG. Figure 4 is a plan view of Figure 3, Figure 5 is a perspective view of the guide mechanism, the sixth factor is an enlarged cross-sectional view of the paper holding section of the drum, and Figures 7A and B are schematic front views of the printer with a sub-freezer. FIG. 2 is a diagram and a plan view. 2.22...OPC belt, 3,23...Charger, 4.21" LED head, 5.258.25b, 2
5C, 25d...Developer, 6,26...Cleaner,
7...Drum, 8...Paper, 9...Paper cassette, 10...Output tray, 13...Fixer, 20...
・Process unit, 27--Guide 1le4.28
A, 28B... Paper insertion hole, 29... Stopper, 3
0A... Tip edge in rotational direction, 30B... Tip edge in rotational direction. Applicant's agent Shunsuke Nakao Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] a latent image carrier in the form of an endless belt, a drum having a width larger than the width of the latent image carrier, and a drum on which a sheet of paper having a width greater than the width of the latent image carrier can be wound around the outer periphery; a guide mechanism that is inclined in the axial direction by the same angle as the paper and runs adjacent to the latent image carrier so that the toner image formed on the latent image carrier can be transferred onto the paper; A printer characterized in that the body and the drum are provided so as to be relatively movable in the axial direction of the drum in the transfer section.