JPS6113273A - Flash fixing device - Google Patents

Abstract

PURPOSE:To perform fixing without variance with a relatively small electric power by putting a recording paper, to which a toner image is transferred, on a belt carried to a face irradiated with flash lamps and electrifying the belt and bringing it into contact with a heat roll. CONSTITUTION:A recording paper 2 to which the toner image is transferred from a photosensitive body 1 is put on a transporting belt 3 having a suction device 5 and is transported to a flash fixing device 4 and is put on a carrying belt 6. The carrying belt 6 is turned in the direction of an arrow A by a heat roll 10 and an auxiliary roll 11, and the roll 10 is not only heated by a heater 12 but also electrified uniformly by a corona discharger 14. An oxidation preventing coating 13 is provided on the surface of the roll 10. The flash fixing device 4 has a reflecting mirror 9, flash lamps 7, and a heat insulating transparent member 8. Thus, the recording paper 2 is attracted to the belt to perform fixing without variance with a relatively small electric power.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image recording apparatus such as a facsimile, a copier, or a printer that forms a toner image on a recording paper and fixes this toner image on the recording paper, and particularly relates to an image recording apparatus such as a facsimile, a copying machine, or a printer. It concerns the theorem device.

Conventional technology For example, in an electrophotographic copying machine, an optical image of a document is exposed onto a photoreceptor to form an electrostatic latent image on the photoreceptor, and this electrostatic latent image is transferred to fine particles called toner. The developed toner image is transferred onto recording paper, and then this toner image is fixed onto the recording paper. Conventionally, when fixing such a toner image, the toner is heated by heating means such as a heat roll or an infrared lamp. A method of forming a fusion layer on recording paper was mainly adopted.

However, in such conventional fixing methods, the toner and the recording paper are heated in almost the same 1ML degree environment, so if the control is incorrect, there is a risk that the recording paper will burn or burn, causing a lump. . For this reason, flash fixing has been proposed, but this flash fixing involves instantaneously absorbing the flash energy of a flood lamp into the toner on the recording paper, raising the temperature of the toner itself above its melting point, and fixing it on the recording paper. In flash fixing, the recording paper itself reflects most of the flash light irradiated onto it, and if it is close to white, it will reflect more than 80 inches in the visible light range and surrounding near-infrared and ultraviolet ranges. The reflected light reaches the toner and contributes to an increase in the temperature of the toner.

Therefore, the temperature rise of the recording paper itself is very small compared to conventional heating methods (there is no risk of the recording paper being scorched or burned as mentioned above. However, on the other hand, the toner absorbs enough energy and melts. However, since there is almost no temperature rise in the recording paper itself, the toner does not penetrate into the recording paper, so the theorem is bad (
Furthermore, if the amount of flash radiation is made too large in order to improve fixing performance, toner may scatter, causing a decrease in image density and increasing power consumption.

Therefore, it has been proposed to preheat the recording paper to near the melting point of the toner before flash irradiation.In this case, in terms of power consumption, it is recommended to Power W is the sum of preheating power and minimum necessary flash power.

However, it can be said that preheating is effective when the flash power W2 is smaller than the minimum required flash power W2 to obtain sufficient fixing without preheating.

Conventional methods for preheating recording paper have been proposed, but for example, Japanese Utility Model Application Publication No. 56-38355 discloses a fixing device in which a heating plate is brought into close contact with the back side of the visible image surface of recording paper. has been disclosed, and also Japanese Patent Application Laid-Open No. 52-129439
The publication discloses an FC fixing device in which a conveyor belt is heated by preheating.

In such a preheating type flash fixing device, the temperature of the paper at the time of flash flash is an important factor.For example, as in the former of the above-mentioned publication, there is a heating plate below the flash lamp, and the recording paper is placed on top of it. Ideally, the recording paper should be in close contact with the heating plate so that the entire surface is at a uniform temperature.
It is a shame that it is kept as such. However, when the temperature of the heating plate is 110℃, the surface temperature on the Franche lamp side of recording paper with a thickness of 0.08mm is usually around 70 to 80℃, but if the recording paper rises slightly, , the raised part is 7
The temperature is much lower than 0 to 80 degrees Celsius, and this area is known as flutter, where the adhesion between the toner and the recording paper is poor during flashing (flashing occurs after a certain amount of adhesion, resulting in uneven fixing. How to eliminate this uneven fixing) It is possible to increase the degree of adhesion between the recording paper and the heating plate, but if the two are brought into close contact with each other too closely, the conveyance performance of the recording paper will decrease due to an increase in frictional resistance. is extremely difficult.

As in the latter of the above-mentioned publication, if a conveyor belt is provided and the conveyor belt is heated with 5 VC, the conveyance of the recording paper will be improved, but if the belt is heated with a hot plate, the close contact between the belt and the hot plate will be poor. This becomes a problem, and if there is any unevenness in this degree of adhesion, there is a possibility that the same fixing unevenness as described above will occur as a result. In addition, when heating the belt with a heater, etc., if the distance between the heater and the belt is close, the temperature of the belt may rise close to its heat-resistant temperature, and if the distance is far, the heat transfer efficiency will be poor. If a part of the recording paper lifts off the belt surface, the temperature rise in that part will not be sufficient (this will cause uneven fixing as described above).

Problems to be Solved by the Invention Therefore, the present invention improves the above-mentioned conventional 7-ray fixing device with preheating, so that the recording paper is heated to a uniform temperature, so that uneven fixing does not occur. , and has high heat transfer efficiency.
It is an object of the present invention to provide a flash fixing device that consumes less power as a whole.Means and effects for solving the problems Therefore, the fludge fixing device of the present invention moves the recording paper to a position below the flash lamp. It has a conveyor belt that conveys, a charger that charges the conveyor belt, and a heating roller that comes into close contact with the conveyor belt and heats the conveyor belt.

According to the present invention, the conveyor belt is uniformly heated and heated by the heating roller that rotates together with the conveyor belt, and the recording paper is attracted by static electricity and adheres to the conveyor belt whose temperature has been uniformly raised. The temperature rise of the recording paper itself becomes uniform, and uneven fixing does not occur. Therefore, the amount of flash radiation is small and the power consumption required for this is also reduced.

In addition, good adhesion between the heating rollers and the conveyor belt, and between the conveyor belt and the recording paper improves the heat transfer efficiency between these parts, so less electricity is required for preheating (and overall consumption is reduced). Power decreases.

Example The present invention will be described below with reference to embodiments shown in the accompanying drawings.

FIG. 1 shows an embodiment in which the present invention is applied to an electrophotographic copying machine, in which a recording paper 2 on which a toner image has been transferred by a photoreceptor 1 is transported to a flash fixing device 4 by a transport belt 3. Usually, the transfer belt 3 is equipped with a suction device 5 and the recording paper 2
is sucked onto the belt surface by the vacuum action of this suction device 5 and transferred.

The recording paper 2 that has reached the flash fixing device 4 is transferred to the conveyor belt 6
The image is conveyed to the fixing position below the flash lamp 7 by the image forming apparatus.

In the present example, two flash lamps 7 are provided, but the flash lamp 7 may be composed of one flash lamp, three flash lamps, or a plurality of three or more flash lamps. 8 is a heat-resistant transparent member for preventing the flash lamp 7 from becoming dirty. 9 is a reflective member.

The conveyor belt 6 is stretched between a heating roller 1o and an auxiliary roller 11, and the heating roller 1o is made of a material with good thermal conductivity, and is usually a metal roller. The heating roller 1o is heated from inside by the heater 12, and as described above, it has good thermal conductivity, so it is heated to a uniform temperature.

Anti-oxidation coating 1 is applied to the surface of heating roller 1o.
3 is applied to prevent uneven heat transfer to the conveyor belt 6 due to changes in the state of the roller surface due to oxidation or the like.

A DC corona discharger (charger) 14 is disposed outside the portion of the conveyor belt 6 that is connected to the heating roller 1o. Therefore, the surface of the conveyor belt 6 is charged by the discharge of the discharger 14 while passing through the heating roller 1o, and the recording paper 2 is brought into close contact with the surface VLt1 of the conveyor belt 6 by electrostatic action. For this reason, the conveyor belt 6 is usually made of heat-resistant rubber or the like having high insulation performance. In addition, the conveyor belt 6 is not divided in the width direction, and there are no seams.
It is evenly molded throughout.

Since the present embodiment is configured as described above, the conveyor belt 6 is connected to the heating roller 1 which is uniformly heated by the heater IIC.
0, the recording paper 2 is heated to a uniform temperature by being in close contact with the conveyor belt 6vc, and since the recording paper 2 is tightly attached to the conveyor belt 6vc by static electricity, the temperature of the recording paper 2 is also increased with a uniform temperature distribution. Since the toner is exposed to the flash light from the 7-ray sea lamp 7 in such a uniform temperature state, the melt-resistant toner penetrates and adheres well to the surface of the recording paper 2 at any location on the recording paper 2, and does not cause uneven fixing. .

In addition, the heat of the heater 12 is transferred to the heating roller 10 and the conveyor belt 6.
Since the heat is effectively transmitted to the recording paper 2 through the heat exchanger, the power required for preheating is reduced.

FIGS. 2 to 8 each show other embodiments of the present invention. In these drawings, the same reference numerals are given to the same parts as in FIG. 1, and redundant explanation will be omitted below.

In FIG. 2, a heater 15 is also provided inside the auxiliary roller 11, which is effective in heating the conveyor belt 6 when the heating roller 10 and the auxiliary roller 11 are close to each other.

In FIG. 3, a static eliminator 16 consisting of an AC or DC corona discharger is installed near the auxiliary roller 11 to eliminate static electricity every time the conveyor belt 6 rotates, thereby preventing the belt 6 from becoming excessively charged. It is.

In FIG. 4, a DC corona discharger 141 is disposed above the recording paper 2 at the entrance of the flash fixing device 40, and this discharger 14. Accordingly, the recording paper 2 and the conveyor belt 6 are charged.

FIG. 5 shows the apparatus shown in FIG. 4 except that a static eliminator 16 similar to that shown in FIG. 3 is provided.

FIG. 6 shows a combination of the charger 14 shown in FIG. 1 and the charger 14° shown in FIG. 4, and FIG. 7 shows the charger 14 in which the static eliminator 16 is added.

FIG. 8 shows a case in which the static eliminator I6 consisting of a DC or AC corona discharger in FIG. 5 is replaced with a static eliminator brush 17 etc. that does not use electrical energy. You can use a brush etc.

In addition, in the present invention, as described above, since electrostatic force is used to bring the recording paper 2 into close contact with the heated conveyor belt 6, the recording &2 remains charged immediately after fixing, and the recording paper 2 remains charged. This tends to cause problems in the subsequent conveyance of the recording paper. Therefore, as shown in FIGS. 9 and 10, a DC or AC corona discharger 18 or a static eliminating brush 19 is used to remove the recording paper from the recording paper.
It is desirable to eliminate static electricity.

Effects of the Invention As described above, in the present invention, the recording paper is brought into close contact with the conveyor belt, which is heated to a uniform temperature through close contact with the heating roller, by electrostatic force, so that the recording paper is fixed at the fixing position M below the flash lamp. is preheated to a uniform temperature, and uniform fixing without uneven fixing can be obtained with relatively little flash energy.

Furthermore, since the efficiency of heat transfer from the heating roller to the recording paper via the conveyor belt is high, the preheating power is also small, and the overall power consumption is reduced.

[Brief explanation of the drawing]

FIG. 1 is a side view of essential parts showing one embodiment of the present invention applied to an electrophotographic copying machine, FIGS. 2 to 8 are drawings similar to FIG. 1 showing other embodiments, and FIG. Figure and 10th
The figure is a similar drawing showing a recording paper charge eliminating means. DESCRIPTION OF SYMBOLS 1... Photoreceptor, 2... Recording paper, 3... Transfer belt, 4... Fludge fixing device, 5... Suction device, 6
...Conveyor belt, 7...Flash lamp, 8...
- I-resistant transparent S material, 9... Reflective member, 10... Heating roller, 11... Auxiliary roller, 12... Heater, 13
... coach ink, 14 ... DC corona discharger (charger), 15 ... heater, 16 ... static eliminator, 17.
... Static elimination brush, 18... Corona discharger, 19...
Static elimination brush.

Claims (1)

[Claims] A flash fixing device that fixes an unfixed toner image on a recording paper by flash energy of a flash lamp includes a conveyor belt that conveys the recording paper to a position below the flash lamp, a charger that charges the conveyor belt, and the conveyor belt. 1. A flash fixing device comprising: a heating roller that heats the conveyor belt in close contact with the conveyor belt.