JPS6346425B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for fixing a toner image onto paper by heating and drying the paper supporting the toner image in a wet type electronic copying machine.

Conventionally, as shown in FIG. 1, a hot plate 3 is fixed between two side plates 1 and 2, and a guide roller 4 is placed on top of this hot plate 3 at a small distance and can be rotated by the side plates 1 and 2. The shaft 4 of this guide roller 4
One end of a is rotatably supported by a bearing 5 fixed to the side plate 1, and a guide roller 4 is attached to a rotating shaft 7 rotatably supported by a bearing 6 fixed to the other side plate 2.
A gear 8 for driving is fixed to one end of the rotating shaft 7, and the rotating shaft 7 is engaged with the other end of the shaft 4a.
is hollow and has a locking projection 7a on its inner wall, and a groove that engages with the locking projection 7a is formed at the end of the shaft 4a of the guide roller 4 that is engaged with the rotating shaft 7. , the shaft 4a of the guide roller 4 is slidably attached to the bearing 5 and the rotating shaft 7, a spring 10 is provided between the guide roller 4 and the bearing 5, and 2.
A fixing device is known in which the guide roller 4 can be removed upward as shown by the dotted chain line, and an exterior upper cover 11 is attached to the copying machine main body on the side plates 1 and 2 so as to be rotatable up and down. ing.

However, in this fixing device, when a paper supporting a toner image is jammed inside the fixing device and the paper is jammed, when taking out the paper, the upper cover 11 is rotated upward, and then the guide roller 4 is pressed against the spring with a finger. 10
The shaft 4a must be removed from the rotating shaft 7 by pushing in the direction of the bearing 5 against the pressure, and the guide roller 4 must be rotated upward and removed as shown by the two-dot chain line. Because it is heated up,
There is a drawback that the work of removing the jammed paper is complicated and that the hands and fingers become heated during the work and become painful.

The object of the present invention is to make it very easy to take out jammed paper without heating your hands and fingers, and to keep the minute distance between the guide roller and the hot plate constant. It is an object of the present invention to provide a fixing device that can maintain the driving force and reliably transmit the driving force to the guide roller.

In the present invention, a holding member is attached to the exterior upper cover of the copying machine body, which is rotatable up and down so that it can take an open position and a closed position. It is held so as to be movable up and down by a fixed distance with respect to the cover, and a positioning member is formed on the bearing, and as the exterior upper cover is rotated up and down, the guide roller is moved up and down with respect to the hot plate, and the exterior When the upper cover is placed in the closed position, the positioning member contacts a predetermined stationary member to determine the position of the guide roller, and the driven gear is fixed to the shaft of the guide roller to move the driven gear downward. The guide roller is characterized by transmitting the rotational force of the drive gear in the pressing direction to prevent the guide roller from lifting up due to the influence of the drive force or pieces of paper when passing the paper.

The present invention will be explained in detail below based on the embodiments shown in FIGS. 2 to 5.

In FIG. 2, reference numeral 12 indicates a drum-shaped photoreceptor, and this drum-shaped photoreceptor 12 is indicated by the arrow a.
rotated in the direction In addition to the transfer charger 13, an exposure device, a wet developing device, a cleaning device, etc. (not shown) are arranged near the photoreceptor 12.

A guide plate 1 is provided below the transfer charger 13.
4 and 15 are arranged, and these guide plates 1
Reference numerals 4 and 15 guide a transfer paper 16 sent from a paper feeder (not shown) toward the photoreceptor 12 . The guide plate 14 may be formed integrally with the transfer charger 13. The transfer charger 13 discharges electricity onto the transfer paper 16 that is in contact with the surface of the photoreceptor 12, and transfers the toner image formed on the photoreceptor 12 onto the transfer paper 16 by Coulomb force. A turn roller 17 is arranged above the transfer charger 13, and two pulleys 18 are arranged above this turn roller 17, and a turn belt 19 is attached to these pulleys 18 so that the lower surface of the turn roller 17 is connected to the upper surface of the turn roller 17. It is attached so that it comes into pressure contact with the One end of the transfer paper 16 on which the toner image has been transferred is separated from the photoreceptor 12 by a separation piece, and the separated portion of the transfer paper 16 is held between the turn roller 17 and the turn belt 19, thereby removing the transfer paper 16. is separated from the photoreceptor 12, and the transfer paper 16 is sent in the direction of arrow b by the rotational force of the turn roller 17 and the moving force of the turn belt 19. A turn guide plate 20 is provided near the turn roller 17, and the transfer paper 16 sent from the turn roller 17 is guided by the turn guide plate 20. A heating plate 21 such as a self-controlled ceramic heater is arranged on the turn guide plate 20 on the side in the direction in which the transfer paper 16 is fed.

A contact glass 22 on which a document is placed is arranged above the photoreceptor 12. A support shaft 23 is arranged near the contact glass 22, and this support shaft 23 is fixed to the main body of the copying machine. An exterior upper cover 24 is attached to the support shaft 23.
It is rotatably attached to the main body of the copying machine so that it can take an open position and a closed position. A cover support member 25 is arranged to support the tip of this upper exterior cover 24.

A bearing holding member 26 is fixed to the lower part of the intermediate portion of the upper exterior cover 24, and this bearing holding member 26 consists of two protruding plates that protrude downward.
A sliding hole 27 is formed at the tip of the bearing holding member 26, and a portion of the bearing 28 is inserted into the sliding hole 27 so as to be able to slide only up and down. Both ends of a shaft 30 of a guide roller 29 are supported by the bearing 28 . The end of the bearing 28 is formed larger than the sliding hole 27, and serves as a guide when the bearing 28 slides inside the sliding hole 27. A positioning protrusion 31 is formed at the lower part of the portion of the bearing 28 outside the sliding hole 27, and this positioning protrusion 31 determines the position of the guide roller 29 with respect to the hot plate 21.

At one end of the shaft 30 of the guide roller 29,
A driven gear 32 is fixed as shown in FIGS. 4 and 5. When the exterior upper cover 24 is placed on the cover support member 25, the bearing 2
8 slides downward through the sliding hole 27 due to its own weight and the weight of the guide roller 29. In this case, a bracket 33 of the hot plate 21 is arranged so as to stop the positioning protrusion 31 of the bearing 28, and the positioning protrusion 31 of the bearing 28 comes into contact with the upper surface of this bracket 33, causing heat to be generated between the guide roller 29 and the guide roller 29. Determine the distance from the plate 21.

A drive gear 34 is arranged so as to mesh with the driven gear 32 when the positioning protrusion 31 of the bearing 28 comes into contact with the bracket 33. The shaft 35 of the drive gear 34 is rotatably supported by a holding member fixed to the main body of the copying machine, and transmits the rotational force of a drive means (not shown) to the driven gear 32 to move the guide roller 29 as shown in FIG. It is rotated in the direction of the arrow at approximately the same circumferential speed as the speed of the paper 16. Due to the weight of the bearing 28, guide roller 29, shaft 30, and driven gear 32, the positioning protrusion 31 of the bearing 28 is only in pressure contact with the upper surface of the bracket 33.
is not fixed, the drive gear 34 is
As shown in FIG. 4, it is desirable to transmit a force P having a force component pushing the driven gear 32 downward at a pressure angle θ.

The exterior upper cover 24 can be rotated up and down by fingers, that is, reciprocally in the direction of arrow c in FIG. 2, and can be stopped at the position shown by the two-dot chain line. There is. The bearing holding member 26 and the guide roller 29 also rotate together with the exterior upper cover 24, and by rotating the exterior upper cover 24 up and down, the guide roller 29 can be moved up and down with respect to the hot plate 21. Can be done.

The turn guide plate 2 is rotated by the turn roller 17.
The paper 16 fed along the paper 16 passes between the heating plate 21 and the guide roller 29, and at this time, the paper 16 and the toner image are heated and dried, and the toner image is fixed on the paper 16. be done. Guide roller 29
A guide plate 36 and a guide plate 1 are provided on the traveling direction side of the paper 16.
A pair of paper ejection rollers 37 are arranged, and the paper 16 sent from the guide roller 29 is delivered to the paper ejection roller 3.
7, the paper is delivered to the paper discharge tray.

The drive gear 34 is connected to a driven gear 32 so that the guide roller 29 is not separated from the hot plate 21.
It is necessary to have a configuration that transmits rotational force to.

Further, the guide roller 29 is not limited to one in which a plurality of short rollers are attached to the shaft 30 at a predetermined interval, but may be one in which one long roller is attached to the shaft 30.

The present invention is also applicable to facsimile receivers having a wet developing device.

In the fixing device of the present invention, the guide roller can be moved up and down with respect to the hot plate by rotating the outer upper cover up and down, so that when paper is jammed in the fixing device, the jammed paper can be removed. It is very easy to take out the work, the fingers do not get heated and become painful during the work, and when the outer cover is placed in the fixed position, the minute distance between the guide roller and the hot plate remains constant. maintained. Furthermore, in the fixing device of the present invention, the driving gear transmits the rotational force of the driving means in a direction that presses the driven gear downward, so that the outer upper cover does not lift up relative to the main body of the copying machine. The driving force can be reliably transmitted to the guide roller.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side view showing an example of a conventional fixing device, FIG. 2 is a partially cutaway front view showing the fixing device of the present invention, and FIG. 3 is a partially cutaway side view showing the main parts of the same device. A front view, FIG. 4 is a partially cutaway front view showing a part of the above device, and FIG. 5 is a partially cutaway side view showing a main part of the above device. 21... Heat plate, 24... Exterior upper cover, 26... Bearing holding member, 27... Sliding hole, 28... Bearing, 29... Guide roller, 30... Shaft, 31... Positioning protrusion, 3
2... Driven gear, 34... Driving gear.

Claims (1)

[Claims] 1. A heating means arranged at a predetermined position, a guide roller arranged at a minute interval on the heating means, and a holding member that holds the guide roller.
A positioning member attached to the shaft of the guide roller, and an exterior that supports the holding member and is attached to the main body of the copying machine so that it can rotate up and down so that it can take an open position and a closed position. An upper cover, a driven gear fixed to an end of the shaft of the guide roller, and a driven gear that engages with the driven gear when the outer upper cover is in a closed position and drives the driven gear downward. A fixing device comprising: a drive gear that transmits rotational force of the means to the driven gear.