JPH0553462A - Transfer material conveying device for image fixing device - Google Patents

Abstract

PURPOSE:To provide a good-quality image without causing an image drift by making the suction force of a suction hole provided on an inlet guide plate larger at the end section than at the center section. CONSTITUTION:A suction hole 11 is provided on the inlet guide plate 7 of a fixing device, a sucking means 8 is provided below it, and the force sucking a transfer material 13 through the suction hole 11 is made larger at the end section than at the center section of the guide plate 7. When the transfer material 13 carrying the unfixed toner image is conveyed to the inlet guide plate 7 provided in front of a fixing roller 3, suction force is generated by the air current from the sucking means 8 provided below the suction hole 11 provided on the guide plate 7 via it, the transfer material 13 is conveyed while being sucked, the suction force is larger at the end section than at the center, thus even the dog-eared or undulatively curled transfer material 13 is kept flat and conveyed to the fixing roller 3. An image blue due to unnecessary contact between the fixing roller 3 and the transfer material 13 is prevented, and a good-quality image is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer material conveying device after transferring a toner image in an image fixing device.

[0002]

2. Description of the Related Art Most of the conventional transfer material conveying device after transferring a toner image of an image fixing device is the same as that of the embodiment of the present invention, and therefore, it will be described with reference to FIG. The above-mentioned conventional conveying device has a fixing roller 3 having a heat source inside.
And a pressure roller 9 in pressure contact therewith, and the transfer belt 13 causes the transfer material 13 to pass through the nip portion between the rollers 3 and 9 to fix the toner image on the transfer material 13. In such a structure, the entrance guide plate 7 of the fixing device may be provided with a spur that contacts the transfer material 13, or the conveyor belt 6 may be of a type that conveys by a vacuum method. In addition, 1 is a pair of discharge rollers, 2 is a separation claw, 4 is a thermistor, 5 is a separation charger, and 10 is an oil pan.

[0003]

In the conventional transfer material conveying device as described above, the transfer material 13 which has been unused for a long time is transferred to the fixing device after the transfer of the toner image. A so-called face curl that bends toward the toner side, a so-called back curl that bends toward the opposite side of the toner image, and an ear fold A and a wavy curl B occur as shown in FIG. In particular, when the transfer material 13 having the edge fold A or the wavy habit B is gripped in the nip portion between the fixing roller 3 and the pressure roller 9, there is a problem that an image flow occurs due to the contact immediately before the nip portion. is there.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the problems of the above-described conventional transporting device and to provide a transporting device which does not cause image deletion even with a transfer material having edge folds or wavy habits. It is in.

[0005]

In order to achieve the above-mentioned object, the present invention provides a suction hole in an entrance guide plate of a fixing device and an intake means below the suction hole, and the transfer material is provided by the suction hole. The end portion of the guide plate is larger than the center portion of the guide plate. Further, the width of the suction hole provided in the inlet guide plate is wider at the end portion than at the central portion. Further, the inlet guide plate has a plurality of suction holes, and the number of the suction holes is larger at the end portion than at the central portion. Further, the inlet guide plate has a plurality of suction holes, and the opening area of the suction holes is larger at the end portion than at the central portion.

[0006]

In the present invention as described above, when the transfer material carrying the unfixed toner image is conveyed to the entrance guide plate provided in front of the fixing roller, the suction hole provided in the guide plate. A suction force is generated by the air flow by the suction means provided thereunder, and the transfer material is conveyed while suctioning. However, since this suction force is larger at the end than in the center, there is a break in the ears or wavy Even the transfer material with a habit is kept flat and conveyed to the fixing roller.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiments of the present invention shown in the drawings, in the case of being similar to the above-mentioned conventional one, the same reference numerals are used for omitting the description, and mainly different parts will be explained. In FIG. 1, in a developing device (not shown), the transfer material 13 carrying the toner image is conveyed by the conveyor belt 6, the adsorption is released from the conveyor belt 6 by the separation charger 5, and enters the entrance guide plate 7. come. At this time, the air is introduced from the suction hole 11 provided in the inlet guide plate 7 and discharged from the discharge port 12 by the intake means 8 composed of a fan provided in the main body of the copying machine. The suction hole 11 of the guide plate 7 has a negative pressure, and the transfer material 13 is conveyed to the fixing roller 3 while being adsorbed along the entrance guide plate 7. 2 to 5 show the inlet guide plate 7 according to the first embodiment of the present invention.
FIG. 4 is a diagram showing the upper surface of the air suction hole 11 because the width b2 of both ends is wider than the width b1 of the central part (FIG. 4, FIG.
5) The inflow amount of the inflowing air per unit time is larger in the vicinity of both end portions than in the vicinity of the central portion, so that the suction force received by the transfer material 13 is also larger in the end portions. 3 shows the inlet guide plate 7, the fixing roller 3 and the pressure roller 9 of the first embodiment.
It is a perspective view showing.

6 to 8 showing a second embodiment of the present invention, a plurality of suction holes 11 are provided in the inlet guide plate 7, and a large number of suction holes 11 are formed at both ends from the central portion. As shown in FIGS. 7 and 8, the area of the portion is such that the area 2 × bo of the end portion is larger than the area bo of the central portion. The suction force that the transfer material 13 receives is increased.

9 to 11 showing the third embodiment of the present invention, the opening area of the suction hole 11 formed in the inlet guide plate 7 is as shown in FIGS. As described above, the suction force is larger at both end portions than in the central portion, as described above.

In the present invention, when the opening portion of the suction hole 11 is made to have the same size in the central portion and both end portions in order to increase the suction force of the transfer material 13, the suction force increases, but the load of the suction force is rather increased. Since the conveyance speed is reduced due to 13, the structure is made as in the above-mentioned embodiment, and the opening area is provided so as to have a desired suction force.

[0011]

As described above, the present invention is as described above, and since the suction force of the suction hole provided in the inlet guide plate is made larger at the end portion than at the central portion, it is possible to prevent the edge of the transfer material from tearing or the grain of paper. A large suction force is applied to the generated wavy wrinkles so that the whole is uniformly adsorbed by the inlet guide plate, and these edge folds and wrinkles can be made flat and conveyed to the fixing roller. Immediately before the nip portion with the pressure roller, there is an effect that a good quality image can be obtained without causing an image flow due to unnecessary contact between the fixing roller and the transfer material carrying the unfixed toner image.

[Brief description of drawings]

FIG. 1 is a partial schematic front view of a fixing device according to a first embodiment of the present invention.

FIG. 2 is a top view of the inlet guide plate of the first embodiment of the above.

FIG. 3 is a perspective view of a fixing roller, a pressure roller and an entrance guide plate of the first embodiment.

FIG. 4 is a vertical cross-sectional view showing a suction hole near a central portion of the first embodiment.

FIG. 5 is a vertical cross-sectional view showing suction holes in the vicinity of an end portion of the above first embodiment.

FIG. 6 is a top view of the inlet guide plate of the second embodiment of the above.

FIG. 7 is a vertical cross-sectional view showing a suction hole near a central portion of the second embodiment.

FIG. 8 is a vertical cross-sectional view showing a suction hole near an end portion of the second embodiment.

FIG. 9 is a top view of the inlet guide plate of the above third embodiment.

FIG. 10 is a vertical cross-sectional view showing a suction hole near a central portion of the third embodiment of the above.

FIG. 11 is a vertical cross-sectional view showing a suction hole near an end portion of the third embodiment.

FIG. 12 is a diagram showing a state in which a transfer material has a bent edge and a wavy habit.

[Explanation of symbols]

 3 Fixing roller 7 Entrance guide plate 8 Intake means 11 Suction hole 12 Exhaust hole 13 Transfer material 14 Air flow

Claims (4)

[Claims] 1. An image having a fixing roller having a heat source inside, and a pressure roller in pressure contact with the heat roller, and passing a nip portion of a roller pair that presses and abuts each other to fix a toner image on a transfer material. In the fixing device, a suction hole is provided in the entrance guide plate of the fixing device, and an air suction means is provided below the suction hole, and the force of sucking the transfer material by the suction hole becomes larger at the end portion than at the central portion of the guide plate. A transfer material conveying device characterized in that 2. The conveying device according to claim 1, wherein the width of the suction hole provided in the inlet guide plate is wider at the end portion than at the central portion. 3. The conveying device according to claim 1, wherein the inlet guide plate has a plurality of suction holes, and the number of the suction holes is larger at the end portion than at the central portion. 4. The transfer device according to claim 1, wherein the inlet guide plate has a plurality of suction holes, and the opening area of the suction holes is larger at the end portion than at the center.