JPH0456980A - Printer - Google Patents

Abstract

PURPOSE:To prevent the curvature of a recording sheet from occurring by providing a linearly formed ejection paper guide plate at a print sheet ejection side and a guide means which changes the ejecting direction of the recording sheet at the downstream side of the ejection paper guide so as to nearly conform to a tangent direction at the contact point of a fixing roller and a pressurizing roller. CONSTITUTION:A heating roller 27 incorporating a heater 26 and the pressurizing roller 28 whose surface can be deformed elastically are arranged in an elastically pressurized state, and also, a separation claw 29 is comprised at the ejection side of the recording sheet by bringing into contact with the heating roller 27. The recording sheet ejected immediately after from a fixing device 25 is abutted with the linearly formed ejection paper guide plates 30, 31, and is cooled by the ejection paper guide plates 30, 31 as correcting the curvature, which recovers the strength of the sheet, and after that, it is bent in a prescribed direction by curved surface guide plates 32, 33. Therefore, a printed recording sheet can be ejected outside a printer in a state in straight shape. Thereby, the curl of the recording sheet can be prevented from occurring.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a printing device that scans a photoreceptor drum with a light beam modulated by print data to form an image. Regarding the structure of the conveyance route.

(Prior Art) A printing device using an electrophotographic process scans a laser beam based on a print data signal to form a latent image on the surface of a photoreceptor drum, and prints by adhering toner to this latent image. It is configured to transfer a toner image onto a sheet of paper, pass the printing sheet through a fixing roller kept in a high temperature state, and fuse the toner to the printing sheet. As the printing paper passes between the fixing rollers, it is heated to about the toner melting temperature, so if the printing paper is changed in its conveying direction to the straight edge ejected from the pressure roller, the printing paper will curve in the changed direction. A phenomenon occurs in which the liquid is discharged without leaving it.

In particular, as shown in FIG. 5, the recording paper supply mechanism A is provided on the upper part, and the printing path B is set in the vertical direction, and a thermal fixing device [ Dv! In a distributed type printing device,
Since the recording paper is ejected from the fixing device HD almost vertically, it is necessary to change the direction to a horizontal direction in order to facilitate handling of the printed recording paper. For this reason, a guide plate F for changing direction is provided on the downstream side of the heat fixing device @D.

However, as mentioned above, the recording paper immediately after leaving the fixing device 1D is extremely hot, so it tends to become curly. There is a problem that the paper curls.

In order to solve this problem, the connecting part G of the recording paper M is made vertical, and this part is set to a length that allows the recording paper to be cooled sufficiently and is opened when necessary. I'm here.

(Problems to be Solved by the Invention) For this reason, there is a problem in that the distance in the vertical direction from the fixing device No. to the paper discharge port H increases, and the height of the printing apparatus increases.

The present invention has been made in view of these problems, and its purpose is to provide a novel method that can prevent the recording paper from curving by shortening the vertical distance from the ejection port of the fixing device. An object of the present invention is to provide a printing device M equipped with a guide structure.

(Means for Solving the Problems) In order to solve these problems, the present invention includes a photosensitive drum that forms a latent image based on print data, a developing device that converts the latent image into a toner image, and a developing device that converts the latent image into a toner image. , comprising a transfer means for transferring the toner image onto the printing paper, and a heat fixing means consisting of a heat generating roller and a pressure roller for thermally fusing the toner transferred to the printing paper, wherein the fixing roller and the pressure roller are brought into contact with each other. A linear discharge paper guide plate is provided on the printing paper discharge side so as to substantially coincide with the tangential direction at the point, and a guide means for changing the recording paper discharge direction is provided on the downstream side of the paper discharge paper guide plate. I decided to set it up.

(Function) The recording paper immediately after being ejected from the fixing means is brought into contact with a straight-shaped ejected paper guide plate to straighten the curvature, and is then cooled by the ejected paper guide plate to change the stiffness of the paper! Since the recording paper is bent in a predetermined direction, the printed recording paper is ejected from the printing apparatus in a straight state.

(Example) Therefore, the details of the present invention will be explained below based on an illustrated example.

FIG. 1 shows an example of a bluffing device using an electrophotographic process to which the paper ejection guide of the present invention is applied. 2, in this example 21! a stacker 3.4 for stocking printing papers P and P' of similar sizes;
It is provided with a big-a-umbrella roller 5.6 for taking out printing sheets one by one, and is configured to feed the printing sheets to the paper feed lower.

A paper detector 8 is disposed below the paper feed lower to detect that printing paper P is set, and below this is a gate row 59 that sends the leading edge of the paper to a photosensitive drum positioned at a predetermined position. .9 is arranged.

A photoreceptor drum 11 is disposed downstream of the gate roller 9.9 and rotates in the direction of the arrow in the figure and receives writing with a beam of light from the light beam control mechanism 10. Surroundings include a power storage device 12, a toner sleeve 14 of a developing device 113, a transfer device M15, and a toner recovery device 116.
, an eraser 17 is disposed, and a photosensitive drum 11 is arranged in the middle.
A fixing device 18 for fixing the toner transferred to the printing paper is disposed below the mark 41J.

[8 is a heating roller 20 with a built-in heater 19,
A pressure roller 21 is disposed in a resilient state across a printing paper conveyance path, and a paper discharge guide 23 is arranged so as to be connected to a paper discharge port 22 of the pressure roller 21 .

FIG. 2 shows the main parts of the paper ejection guide that the present invention makes precise. In the figure, numeral 25 is the aforementioned fixing device,
6 and a pressure roller 28 whose surface is elastically deformable are disposed in a resilient state, and a separating claw 29 is brought into contact with the heating roller 27 on the recording paper discharge side. ing.

In the figure, reference numeral 3o denotes a first ejected paper guide plate that extends linearly so as to be in contact with the recording paper ejected along the bisecting claw 29, and a second ejected paper guide plate that is arranged opposite to this and is aligned with the recording paper that is ejected along the bisecting claw 29. The guide plate 31 constitutes a guide member that guides the recording paper immediately after fixing.

The inner surface 30a of the first paper discharge guide plate 3o is heated by heating 0-ra 2.
7 and the pressure roller 28 at the point of contact with the tangent S at the point of contact with the pressure roller 28. , curved guide plates 33, 34 for directing the recording paper toward the discharge port of the drawing main body are affected.

Returning to FIG. 1 again, numerals 40, 41, and 42 in the figure are paper ejection rollers, and on the side where the paper curls, two rollers 40, 41 are arranged horizontally close to each other in parallel to the conveyance path. At the same time, a third roller 42 is arranged in pressure contact between these two rollers 40 and 41 so as to face each other, and rotational driving force is transmitted to at least one of these rollers 4o and 41.42. is configured to do so.

In this embodiment, when a print command is output, the printing paper P stored in the stacker section 3.4 of the paper feeder M1 is pulled out to the paper feed lower by the pickup roller 5.6, and the leading end is transferred to the gate roller. 9.9, and then sent out toward the photosensitive drum 11 by the gate roller 9.9.

Transfer device! ]5 The recording paper to which the toner was transferred is
It receives heat from the heating roller 27 and pressure roller 28 of the fixing device M25 and is heated to a temperature that allows toner welding, thereby fixing the toner on the surface onto the recording paper.

The recording paper that has passed through the heating roller 27 is separated from the heating roller 27 by a separating claw 29, and enters the discharge paper guide plates 3o and 31 in a curved state so that the surface of the heating roller is concave. At this time, the printing paper, which is curved so that the print side is concave, moves while contacting the surface 30a of the first discharge paper guide plate 3° while maintaining the temperature at which toner can be welded, so that the paper is discharged. The curve is corrected into an iiiwA shape in accordance with the linear shape of the paper guide plate 30, and as it moves downward, heat is removed by the discharged paper guide plate 30 and the curved guide plate 32 is cooled.
．． 33, the recording paper has not been sufficiently cooled and has recovered its elasticity, so-called stiffness, so it is temporarily bent by the curved guide plates 32, 33. However, when the paper is discharged from the discharge port to the tray 24, it recovers to a flat plate shape.

Incidentally, any bends in the recording paper that are not corrected by the first ejected paper guide plate 30 or caused by the curved guide plates 32, 33 are corrected by the ejected paper O-ra 40, 41, 42, so that they are not removed from the apparatus. When it is discharged, it does not cause curls.

FIG. 3 shows a second embodiment of the paper discharge guide of the blinking device of the present invention, in which reference numeral 50 indicates an M2 paper discharge paper provided opposite to the first paper discharge guide plate 30. The guide plate is configured such that the leading end 50a is slightly bent so as to protrude more roughly toward the heating roller 26 side than the extension line of the surface 30a of the first discharged paper guide plate 3o.

51 and an upper curved guide plate provided on the ejection side of the ejected upper paper guide plate 52, the leading end, that is, the recording paper entrance side, is closer to the heating roller 39 than the recording paper contact surface of the ejected paper guide plate 51.
It has a single layer that protrudes from the side.

In this embodiment, the heating roller 27, the pressure roller 528
As described above, the recording paper P that has exited the recording paper P moves while contacting the surface 30a of the first discharged paper guide plate 30, and is transferred to the fixing snowmaking 35.
The paper is cooled by the first discharge paper guide plate 30 while being corrected from curling, and then enters the curved guide plates 51 and 52.

At this time, the back side of the recording paper, that is, the side on which printing is not performed, is pushed toward the heating roller 26 by the tip 50a of the second ejected paper guide plate 50, so that the recording paper P is moved toward the first ejected paper guide. The surface facing the plate 3o is pressed against the first discharge paper guide plate 3o. This allows curl correction and cooling to be performed even more effectively.

Figure 4 shows a third embodiment of the present invention, in which reference numerals 55 and 56 indicate the first and second discharge paper guide plates 30.
A pull-out roller provided at the discharge port 31, at least the surface of which is made of a material with a small friction coefficient such as fluororesin, and whose contact point is the inner surface 3 of the first discharge paper guide plate 30.
N is arranged so that it is located slightly closer to the heating roller 27 than 0a.
and these circumferential speeds are the rollers 27 and 28 of the fixing device.
It is rotationally driven by a drive source (not shown) so that it becomes larger than the size of the main body. Note that numerals 57 and 58 in the figure indicate curved guide plates.

In this embodiment, the recording paper leaving the fixing device 18 is
The pull-out roller 55.5 is cooled while being in contact with the first ejected sheet guide plate 30 while being corrected from curling in the fixing device 18.
Enter 6. As a result, the recording paper P is held at one end by the rollers 27, 28 of the fixing device, and at the other end by the pull-out rollers 55, 56, which rotate at a faster circumferential speed than the rollers 27, 28 of the fixing device. Because it is being pulled, the first
The inner surface 30a of the ejected paper guide plate 30 is forcibly pressed against the inner surface 30a of the ejected paper guide plate 30. Therefore, the recording paper is cooled while the curl in the fixing device is corrected by the first ejected paper guide plate.

Of course, even if the peripheral speed of the rollers 55.56 is faster than that of the rollers 27.28 of the fixing device, the rollers 55.56.
Since the surface of the recording paper 56 is made of a material with a small coefficient of friction, the recording paper will not slip between itself and the recording paper and be damaged, and the recording paper will not be forcibly pulled out of the fixing device.

Note that if the airflow from the fan 6o provided in the main body of the printing apparatus is guided to the first discharged paper guide plate 30 through the duct 61 to forcibly cool the first discharged paper guide plate 3o,
The lengths of the first and second discharge paper guide plates can be shortened.

In this embodiment, the first ejected sheet guide plate and the separating claw 29 of the fixing device are constructed as separate members, but they may also be constructed as a single member.

(Effects of the Invention) As explained above, in the present invention, a photosensitive drum that forms a latent image based on a printing disk f, a developing means that converts the latent image into a toner image, and a printing paper f that forms a latent image based on the toner image. It is equipped with a transfer means for transferring the image, and a heat fixing means consisting of a heat generating roller and a pressure roller that heat-fuses the toner transferred to the printing paper.
An M-line shaped discharge sheet guide plate is provided on the printing paper discharge side so as to substantially coincide with the linear direction, and a guide means for changing the recording paper discharge direction is provided downstream of the discharge sheet guide plate. In the high temperature state of the fixing straight boar, the recording paper 8 is brought into contact with the linear discharge paper guide plate to straighten the bending, and is then cooled by the discharge paper guide plate to restore the stiffness of the paper and its edge to the predetermined position. It is possible to bend the printed recording paper in the straight direction and discharge it out of the printing device in a straight state, eliminating the need for a long cooling path and reducing the height of the printing device main body of the device.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an embodiment of a printing device using a guide plate of the present invention, FIG. 2 is a cross-sectional view of main parts of the present invention, and FIG. FIG. 5 is a sectional view showing a conventional printer device W. FIG. 1...Paper feeder W1 2...Printing device main body 3.4...Stacker 5.6...Pickup roller 9...Gate roller 11...Photoconductor drum 18 ... Fixing device M 27 ... Heating roller 28 ... Pressure roller 29 ... Separation claw 30.37 ... Paper ejection sheet guide plate 32.33 ... Curved guide Applicant: Seiko Even Co., Ltd. Agent: Patent attorney: Katsuhiko Kimura, Kaji Nishikawa

Claims (1)

[Claims] a photosensitive drum that forms a latent image based on print data;
A developing device that converts the latent image into a toner image, a transfer device that transfers the toner image onto printing paper, and a heat fixing device that includes a heating roller and a pressure roller that heat-fuses the toner transferred to the printing paper. In this case, a linear discharge paper guide plate is provided on the printing paper discharge side, and a linear discharge paper guide plate is provided on the downstream side of the paper discharge paper guide plate so as to substantially coincide with the tangential direction at the contact point of the fixing roller and the pressure roller. A printing device equipped with a guide means for changing the direction in which recording paper is ejected.