JPH01185680A - Sheet conveying device - Google Patents

Abstract

PURPOSE:To make the conveyance of recording paper secure by reinforcing both ends of an endless belt, transmitting rotating and driving force from a rotating and driving mechanism to a rivet perforated at prescribed intervals and rotating the endless belt. CONSTITUTION:Both ends of the endless heat-resistant belt 60 are reinforced with a reinforcing member 14, and the belt is rotated and driven by the engagement of the perforated rivet 15 fitted to the reinforced ends at prescribed intervals with a driving roll 16 with a sprocket. The recording paper 4 with an unfixed image is conveyed in condition where it is attracted on the endless heat-resistant belt 60 by suction from a suction hole provided on a part in contact with said belt 60 on a roll. The belt 60 rotates without being twisted, and the recording paper 4 is conveyed toward an eject port without being retained in a space formed between planar heaters 7 and 8.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fixing device for an image forming apparatus that fixes an unfixed image on recording paper using a planar heater.

[Conventional technology]

Conventionally, an electrophotographic image forming apparatus consists of a planar heater and a recording paper conveyance mechanism, and the recording paper on which an unfixed image is formed is fed into the space in which the planar heater is installed at a predetermined speed to fix it. There are some that use a fixing device.

FIG. 7 is a schematic configuration diagram showing one of the conventional configurations of a recording paper transport mechanism in such a fixing device. 32 and the guide groove 34 of the drive roller 533 are engaged, and the endless belt 31 is rotated in the direction of the arrow by sliding contact between the curved surface of the drive roller 33 and the inner peripheral surface of the endless belt 31. .

FIG. 8 is a schematic configuration diagram showing another example, in which the chain 3 rotates by engaging with the sprocketed drive roller 35, 36.
7.38 are arranged at both ends of the roller in the axial direction, and
A spring 39 is stretched between chains 37 and 38 at a predetermined interval, and the endless belt 31 is rotated by sliding contact with the spring 39.

(Problem to be Solved by the Invention) However, in the conveyance mechanism shown in FIG. 7, if there is an error in the outer diameter of both ends of the drive roller 33, a difference occurs in the conveyance amount of both ends, and the difference accumulates. This causes a problem in that the endless belt 31 is twisted and the recording paper cannot be conveyed normally.

On the other hand, in the conveyance mechanism shown in Fig. 8, two pairs of chains 38, 38
Since a large number of springs 39 must be tensioned, the number of assembly steps increases, which is economically undesirable.

SUMMARY OF THE INVENTION An object of the present invention is to provide an economically constructed fixing device that can reliably transport recording paper.

[Means for Solving the Problems] The present invention reinforces both ends of an endless belt with a reinforcing material, attaches hole rivets at predetermined intervals, and applies rotational driving force from a rotational drive mechanism to the hole rivets. The transmission is transmitted to rotate an endless belt.

[Function] Both ends of the endless belt are reinforced with reinforcing materials,
The reinforcing portion is rotated by engagement between the perforated rivet and the rotational drive mechanism.

Therefore, even if the endless belt itself has a certain degree of flexibility, it can rotate without twisting and can reliably convey the recording paper in a normal state.

Further, since the structure is simply reinforced with a reinforcing material and the perforated rivets are attached, the structure is simple and can be constructed at low cost.

[Embodiment] FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a perspective view of a paper conveyance mechanism.

In FIG. 1, an electrostatic latent image formed on the surface of a photoreceptor 1 is developed by a developing device 2, and then transferred onto a recording paper 4 by a transfer device 3. The recording paper 4 on which the image has been transferred is transported by a transport device 5 toward a fixing device 6 for fixing.

The fixing device 6 is provided with an endless heat-resistant belt 60 that is located on an extension of the conveyance device 5 and circulates in a square shape. Two pairs of planar heaters 7.8 are disposed above and below the upper flat portion of the endless heat-resistant belt 60 on which the recording paper 4 is placed and conveyed, and the unfixed image transferred to the recording paper is transferred to these heaters. fixed by two planar heaters 7.8,
It is discharged to the discharge port by the next-stage conveyance device 9.

In this case, the planar heater 7.8 has a heating material 10.8 around it.
A waveguide 12 for detecting the presence or absence of recording paper using ultrasonic waves is located at the center of the dome.
．． 13 is disposed with its opening facing the recording paper conveyance surface.

On the other hand, the endless heat-resistant belt 60 is made of, for example, glass fiber cloth, and both ends of the belt in the width direction are reinforced with reinforcing materials 14, as shown in FIG. Further, holes are made in the reinforcing member 14 at equal intervals, and perforated rivets 15 are attached to the holes. This perforated rivet 15 comes with a sprocket! III roller 16 and heat-resistant belt 60
The entire unit is rotated in the recording paper transport direction. Here, the drive O-ra 16 with a sub-O-ket is the heat-resistant bell]
The heat-resistant belt 60 is arranged to engage with the perforated rivet 15 at one corner of the inner circumferential side of the circular circulation path in the shape of a square, and a predetermined tension is applied by the tensicon roller 17 at the other corner. Rotate it in the shape of the mouth. Further, at the two corners of the upper flat part on which the recording paper 4 is placed and conveyed, O-ra 1B and 19 that rotate in contact with the inner peripheral surface of the heat-resistant belt 60 are provided.
is installed. Further, on the inner circumferential side of the heat-resistant belt between the drive row 516 and the tension roller 17, there are two drawer rails 20 and 21 for drawing out the heat-resistant belt 60 and the rotational drive mechanism such as the drive roller 16 to the outside. It is provided.

FIG. 4 is a diagram of the heat-resistant belt 60 and its rotational drive mechanism viewed from six directions in FIG. The rotation axis of the drive roller 16 is the frame 22
It is coupled to a rotational drive source via a bearing 23. Further, the rotating shaft of the roller 19 is hollow, and a hole 24 for air intake is bored in a part of the roller 19 in contact with the heat-resistant belt 60. By sucking in air with a suction blower 25, the recorder 4 is attached to the heat-resistant belt 60. It is configured to be transported in an adsorbed state.

On the other hand, the inner and outer circumferential surfaces of the heat-resistant belt 60 at portions that no longer receive heat from the sheet heaters 7.8 are covered with heat insulating materials 27-29. This is to prevent a decrease in the temperature of the heat-resistant belt 60, which would increase the heat loss of the planar heater 7.degree. 8, thereby preventing the fixing performance from deteriorating.

In addition, during two time periods: when the sheet heater 7.8 is energized and after a certain period of time has passed after the energization is stopped, the heat-resistant bell i-60 is controlled to be in a rotational drive state, and only a part of it is continuous. It is controlled so that damage to the coating material etc. due to heating does not occur.

Incidentally, the sprocket wheels 16A and 16B at both ends of the sprocket-equipped drive roller 16 are connected to the roller 1, as shown in the exploded perspective view of FIG. 5 and the one-sided sectional view of FIG.
6 is attached to the rotating shaft using two wheels 41.6 with holes.
42, recesses are provided on the circumferential surface of the wheel 41 at equal angular intervals, and pins 43 are implanted in each of the recesses, and the wheel 41 is inserted between the wheel 42 and the other wheel 42.
Tighten the screw 44 from the side and fix the pin 43 M
It is a 4-story building.

In this case, the wheel 42 is attached to the roller 16 by the screw 45.
By fixing the wheel 41. to the rotating shaft 16G of the wheel 41.
42 is rotatably fixed.

Therefore, in the fixing device configured as described above, since the recording paper 4 on which the unfixed image is formed is conveyed while adsorbed onto the endless heat-resistant belt 60, the space for disposing the planar heater 7.8 is reduced. To? 11, it is fixed while being reliably conveyed toward the discharge port without being stuck. Further, the endless heat-resistant belt 60 is reinforced at both ends with the reinforcing material 14,
It is rotationally driven by the engagement of the perforated rivet 15 attached to this reinforcing portion and the drive roller 16 with a sprocket. Therefore, even if the endless heat-resistant belt itself has a certain degree of flexibility, it can rotate without twisting and can reliably convey the recording paper in a normal state. Since only the drilling rivet 15 is attached, the construction is simple and can be constructed at low cost.

(Effects of the Invention) As explained above, according to the present invention, both ends of the endless belt are reinforced with a reinforcing material, and a perforated rivet is attached.
Since the endless belt is rotated by the engagement between the perforated rivet and the rotationally driven state, the endless belt can be rotated without twisting and the recording paper can be reliably conveyed. Furthermore, since the structure is simple, it can be constructed at low cost.

[Brief Description of the Drawings] Fig. 1 is a cross-sectional configuration diagram showing one embodiment of the present invention, Fig. 2 is a perspective view of a paper conveyance mechanism, and Fig. 3 is a four-dimensional diagram of an endless heat-resistant belt.
Figure 4 is a plan view taken from the direction of the arrow in Figure 1, Figure 5 is an exploded perspective view of the drive roller with sprocket, Figure 6 is a half sectional view of Figure 5, Figures 7 and 8
The figure is a perspective view showing the configuration of a conventional paper conveying device. 4... Recording paper, 6... Fixing device, 7, 8... Planar heater, 10.11. Material, 12.1
3... Waveguide, 14... Reinforcement material, 15... Perforated rivet, 16... Drive roller with sprocket, 16
A, 16B... Sprocket wheel, 17... Tension roller, 18.19... Roller, 20.21
...Drawer rail, 25...Suction blower, 60
...Endless heat-resistant belt. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 8

Claims (1)

[Scope of Claims] A paper conveyance device comprising an endless belt having a predetermined width and a rotation drive mechanism for rotating the endless belt and conveying paper by placing the paper on the belt surface, comprising: a width of the endless belt; A paper conveyance device configured to install perforated rivets at predetermined intervals on both ends of the direction through reinforcing materials, and to transmit rotational driving force from a rotational drive mechanism to the perforated rivets to rotate an endless belt. .