JPS6029772A - Conveying and fixing device for sheet paper - Google Patents

Abstract

PURPOSE:To prevent sheet paper from being crumpled when conveyed to a fixing device by providing a guide plate for conveyance which has a convex surface and an upper guide member which gives the paper flatness opposite on a conveyance path for the sheet paper after separation. CONSTITUTION:The guide plate 10 for conveyance and guide plate 14 are provided in combination to give flatness the sheet paper 7 being conveyed after separation from a photosensitive drum 1, and a front edge of the sheet paper 7 after separation touches to the slanting surface of the guide plate 10 for conveyance firstly and is conveyed toward the upper guide member 14, but curved along the convex curved-surface part 11 by its own weight. If the sheet paper 7 is too stiff not to curve along the curved-surface part 11, the front edge of the sheet paper 7 abuts on the upper guide plate 14 to be bent, and sent to the fixing device 15 while shaped along the guide plate 10 for conveyance momentarily.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a sheet conveying and fixing device, and in particular, after transferring a toner image to a sheet in an electronic copying device, This relates to a sheet conveying and fixing device used to completely peel off a sheet, convey it to a fixing section, and fix it.

[Background of the invention]

Conventionally, the sheet of paper after peeling was moved away from the photosensitive drum and then conveyed along a flat conveyance path. is difficult to transport, and when inserted into the fixing device, the fixing roller
This method has the disadvantage that the leading edge of the sheet cannot be inserted uniformly, resulting in wrinkles.

[Purpose of the invention]

The present invention is designed to prevent wrinkles from forming on a sheet of paper in an electronic copying device, from peeling off a sheet of paper after transfer of a toner image to transporting and fixing the toner image to a fixing section of a fixing device. Its purpose is to provide a conveyance and fixing device for sheets of paper.

[Summary of the invention]

The configuration of the sheet conveying and fixing device according to the present invention is such that after peeling off the transferred sheet from the photosensitive drum in an electronic copying device,
In a sheet conveyance and fixing device that transports the transfer sheet to a fixing section and fixes the transfer sheet, a convex curved surface portion that gives a curved surface when conveying the transfer sheet is placed on the feeding side. a conveying guide plate formed in a shape and disposed at a position close to the roller side of the fixing section; and a conveying guide plate disposed opposite to the conveying guide plate so as to impart flatness to the sheet. A conveying section is constituted by the upper guide member provided.

In addition, the following is added.

In other words, conventionally, the peeled sheets are conveyed through a concave or flat conveying path, so the posture of the sheet can be determined by simply relying on the posture of the sheet itself. It was difficult to control the shape of the curvature.

However, in the present invention, a convex conveyance path is formed, a sheet of paper after peeling is made to align with the curved surface of the convex shape to once form a curved surface, and by forming this curved surface, the sheet of paper is At the same time, the leading part side in the direction of travel from the curved surface becomes flat, so under this situation, the sheets are inserted into the fixing device to completely prevent the occurrence of wrinkles.

[Embodiments of the invention]

An embodiment according to the present invention will be described with reference to the drawings.

Here, FIGS. 1 and 2 are partially cutaway side views showing the operation of a sheet conveyance and fixing device according to an embodiment of the present invention, and FIG. FIG. 4 is a perspective view of the portion, and FIG. 4 is an explanatory diagram of the configuration of the fixing section, and FIGS. 5 to 8 are schematic configuration diagrams together with explanation of sheet conveyance.

In the figure, 1 is a photosensitive drum, 2 is a conductive drum, 3 is a photosensitive layer,
4 is a metal guide plate, 5 is a mylar part, 6 is a fulcrum, 7 is a sheet of paper, 7' is a curved surface, 8 is a corona discharger for transfer,
9 is a corona discharger for peeling, 10 is a conveyance guide plate, 11 is a convex curved surface, 12° and 13 are tip parts, 14 is a guide plate related to the upper guide member, and 15 is a fixing plate related to the fixing part. In the device, 16 is a heat roller, 17 is a pressure roller, 18° and 19 are gears, and 20.21 indicates wrinkles related to slack.

The conveyance guide plate 10 and the guide plate 14 described above constitute a conveyance device related to the conveyance section.

Therefore, in explaining this embodiment, a description of the steps of a known electronic copying machine will be omitted, but the parts of the peeling device that are particularly relevant are belt peeling and AC An embodiment relating to the combined use of the corona static elimination method will be described.

That is, in FIGS. 1 and 2, the photosensitive drum 1 is the conductive drum 2.
and a photosensitive layer 3, and when in operation, rotates in the direction of the arrow shown in the figure.

A metal guide plate 4 of a predetermined width and thickness is supported by a fulcrum 6 on the peripheral surface of the front edge of the photosensitive drum 1, and is slid onto the surface of the photosensitive layer 3 via a Mylar portion @5 of a predetermined size. The sheet 7 is scraped and guided along the side edges of the sheet 7 that is fed synchronously with the image formed on the photosensitive drum 1, so that the sheet 7 is forcibly peeled off from the metal guide plate 4 side. It is something to do.

The corona discharger is a direct current corona discharger as a transfer corona discharger 8, and an alternating current corona discharger as a peeling corona discharger 9, and is peeled off by guiding the side edge portions thereof, which are arranged as shown in the figure. Transfer is performed by a transfer corona discharger 8, static electricity is removed by a peeling corona discharger 9, and the toner image is electrically transferred from the photosensitive layer 3 of the sheet 7 to prevent disturbance of the toner image transferred to the sheet 7. It is used to remove the

The above-mentioned peeling is a combination of conventionally known peelings.

Conventionally, as mentioned above, the sheet of paper after peeling is kept as far away from the photosensitive drum as possible and then guided to the fixing section.
In the case of roll heaters or pressure rollers, the orientation in which the sheet is inserted into the fixing section is particularly important.
Various developments have been made to prevent the occurrence of wrinkles during fixing and to maintain the flatness of sheets.

In this respect, in this embodiment of the present invention, the configuration is characterized by the combination of the conveyance guide plate 10 and the guide plate 14, which makes it possible to easily obtain flatness of the sheet 7 during conveyance. That is.

That is, as shown in FIG. 1, the conveyance guide plate 10 is
In order to make it easier for the tip of the sheet 7 after peeling to ride, the tip 12 on the corona discharger side is raised toward a curved surface 11 formed on the feed side and at a lower comb than the discharge electrode of the peeling corona discharger 9. It is designed to form a slope.

After the curved surface portion 11 is formed, the other end portion 13 is extended flat near the contact portion of the heat roller 16 and the pressure roller 17 of the fixing device 15 that are in contact with each other.

Here, the guide plate 14 related to the upper guide section mentioned earlier
is disposed above and opposite to the conveyance guide plate 10.

Therefore, the illustrated tip 13 extends flatly without bending near the contact portion of the press-contact portion.
Alternatively, it may be placed near or above or below it.

FIG. 2 shows a state in which the sheet 7 after the first inspection is attached to the conveyance guide plate 10, and the tip of the peeled sheet 7 is attached to the conveyance guide plate 10. The paper sheet 7 hits the inclined surface and is further conveyed toward the upper guide plate 14, but due to the weight of the sheet 7, it follows the convex curved surface portion 11.

If the sheet 7 is stiff and difficult to follow the curved surface 11, the tip of the sheet 7 will come into contact with the upper guide plate 14 and the sheet 7, whose waist will be folded, will instantly , a transport guide plate 10
, as shown in Figure 1.

FIG. 3 shows the attitude of the sheet 7 at this time when it is along the conveyance guide plate 10.

As can be seen from the figure, the sheet 7 has a curved surface 7', so
The leading end becomes flat with the curved surface 7' as a boundary.

The degree of flatness of the sheet 7 determines whether or not wrinkles occur during the sheet 70 passage process during the operation of the fixing device 15, so it is important to form the curved surface 7'. The above configuration achieves such formation.

Next, an embodiment of the fixing device 15, together with its related components, will be described with reference to FIG. 4.

The heat roller 16 is a metal tube coated with Teflon on the outer periphery and has a built-in heating lamp. Although not shown, the lighting time of the heating lamp is determined by detecting the temperature on the surface. is automatically adjusted to obtain the required temperature.

The pressure roller 17 is a roller that forms a silicone layer having a required elastic force on the core metal, and presses against the heat roller 16 by applying a predetermined pressure to form a predetermined nip width. It is designed to be used for fixation.

It is appropriate that the fixing device 15 be of a type that drives the heat roller 16 and pressure roller 17 described above.

Therefore, in this embodiment, the sheet 7 is 52g'/
Even for M2 and A3 sizes, wrinkles could be prevented by setting the dimensions of each of the rollers mentioned above.

That is, as shown in FIG. 4, first, the outer diameter of the heat roller 16 at the set temperature is set to Dφ, and the pitch circle of the gear 18 fixed to the end of the roller is adjusted to match the outer diameter of the heat roller 16. Set to .

Also, the gear fixed to the pressure roller 17 is replaced with gear 1.
9, and if the gear ratio of the gear 19 to the gear 18 is 1:1.25, then the outer diameter of the pressure roller 17 is Dφmm x 1.25, and for example, the diameter of the heat roller 16 after the set temperature is 322 order,
If gear 18 is module 1 and has 32 teeth, gear 19 is 125 times larger and has 40 teeth.

The outer diameter of the pressure roller 17 is the same as that of the gears 18 and 1.
Similar to the ratio with 9, 3221 mochi x 1.25 = 40.25 m
m.

However, since the pressure roller 17 performs fixing and passes the sheet 7, the outer diameter becomes thinner by about 0.4 mm due to wear when about 50,000 sheets are fixed. Add 2mm and get 4.0.25 + 0.2 = 4
, 0.45φ111111.

That is, the ratio of the diameter of the pressure roller 17 to the diameter of the heat roller 16 at the set temperature is determined by the ratio of the diameter of the pressure roller 17 to the diameter of the heat roller 16 at the set temperature.
This is equivalent to the drive transmission ratio of 9.

When the above dimensions were set, no wrinkles occurred on sheets of 52 g/m2 and A3 size paper even when the pressurization and depressurization were changed by about 30% relative to the predetermined set pressure. It is something.

The above method prevents wrinkles from occurring in terms of the dimensions of the heat roller 16 and the pressure roller 17.

That is, the combination of the above-described flat state of the sheet 7, the above-mentioned fixing device 15, and the conveyance guide plate 10 for the sheet 7 makes it possible to perform even more stable fusing without wrinkles. It is.

Of course, there is no problem in practical use even if the fixing device 15 is not configured as described above and the transmission ratio is set close to that of the fixing device 15.

Further, in addition to the above-mentioned driving means, a driving means such as a timing boot 1 hash groove can be used, and the same drive transmission ratio can be achieved.

Next, the relationship between the positions of the paper in the configuration of the conveyance guide plate 10 and the fixing device 15 will be explained with reference to FIGS. 5 to 8.

That is, first, as shown in FIGS. 5 and 6, if the tip 13 of the conveyance guide plate 10 is lower than the pressure contact position of the heat roller 16 and the pressure roller 17, As shown in FIG. 6, a plate-shaped slack 20 is generated in the center of the sheet 7 as it is pulled out in the direction of the arrow on the left, so that the rear of the sheet 7 is particularly Just before the end passes, it is affected by the slack 20, that is, the slack 20 is continuously fed, so that it winds around the heat roller 16. If the guide plate 14 is disposed close to the heat roller 16 as in the above embodiment, the rear end of the sheet 7 may come into contact with the guide plate 14, resulting in an inappropriate situation. There is a fear.

The seventh version was designed to eliminate such problems.
The embodiment shown in FIG. 8 and FIG.

That is, as shown in FIG. 7, by bringing the tip 13 of the conveyance guide plate 10 close to the heat roller 16 side, that is, by disposing it above the position where both rollers are in contact with each other, the sheet 7 can be A slack 21 occurs on the side of the heat roller 16, and as shown in FIG. 8, the rear end of the sheet 7 passes along the unloading guide plate 10 as it passes.

That is, the tip portion 13 of the unloading guide plate 10 is loosened 21
It is sufficient that it is within the range of .

For example, when copying, if there is no image at the rear end of the sheet, there is no practical problem in inspecting it, so if the leading edge 13 is within the range of the slack 21. It may be arranged so that it is not located.

Taking all of the above into consideration, by maintaining the flatness of the sheet after peeling, making it easier to transfer it to the fixing section, and driving the heat roller and pressure roller in the fixing section, It is possible to prevent the occurrence of wrinkles on sheets of paper and to perform stable fixing depending on the sheet of paper used.

〔Effect of the invention〕

According to the present invention, in an electronic copying device, the sheet of paper is peeled off after the toner image is transferred, and then transported to a fixing unit and fixed, thereby preventing the occurrence of wrinkles on the sheet of paper. This invention can provide a sheet conveying and fixing device, and can be said to be a practically excellent invention.

[BRIEF DESCRIPTION OF THE DRAWINGS] Figures 1 and 2 show sheet conveyance according to an embodiment of the present invention,
FIG. 3 is a partially cutaway side view showing the operation of the fixing device; FIG. 3 is a perspective view of a portion related to sheet conveyance; FIG.
The configuration explanatory diagrams of the fixing section, FIGS. 5 to 8, are schematic configuration diagrams that also illustrate sheet conveyance. DESCRIPTION OF SYMBOLS 1... Photosensitive drum, 10... Conveyance guide plate, 11...
...Curved surface portion, 12.13...Tip portion, 14...Guide plate, 15...Fixing device, 16...Heat roller,
17... Pressure roller, 20.21... Wrinkles. Agent Patent attorney Kosaku Fukuda (and 1 other person)

Claims (1)

[Scope of Claims] 1. In a sheet conveying and fixing device in which the transferred sheet is peeled off from a photosensitive drum in an electronic copying device, and then the transferred sheet is conveyed to a fixing section and fixed. , a conveying guide plate having a convex curved surface portion formed on the feeding side to provide a curved surface when conveying the transfer sheet, and disposed at a position close to the roller side of the fixing section; A sheet conveyance and fixing device, characterized in that a conveyance section is constituted by an upper guide member disposed opposite to the conveyance guide plate so as to impart flatness to the sheet. 2. In the device described in claim 1, the conveyance guide plate is provided, and the opposite tip of the convex curved surface portion is fixed by the heat roller and the pressure roller of the fixing unit. A sheet conveying and fixing device which is arranged within the area of the sheets inside. 3. In the item described in claim 1, the ratio of the diameter of the pressure roller to the diameter of the heat roller of the fixing unit at the set temperature is equivalent to the drive transmission ratio in the drive means for the heat roller and the pressure roller. Or a sheet transport and fixing device set up nearby.