JPH04310973A - Transfer material carrying device - Google Patents

Abstract

PURPOSE:To eliminate transfer deviation and the dog-ear of a transfer material from the ejected transfer material by providing a suction deck, a suction device, a suction force adjusting means, and a mode selection means in a transfer material carrying device. CONSTITUTION:The suction deck 2, the suction device 15, the suction force adjusting means and the mode selection means are provided. In the case that a 1st mode is selected by the mode selection means, the suction force is kept at a specified value. Meanwhile, in the case that a 2nd mode is selected by the mode switching means, the suction force is made weak when the leading edge of the transfer material arrives at the vicinity of a fixing part Y. Then, the suction force in the middle of selecting the 1st mode or the 2nd mode is varied by the suction force adjusting means. Therefore, when the dog-ear of the transfer material ejected from an image forming device is caused, the suction force for the transfer material is set to be strong by the suction force adjusting means and when the transfer deviation is caused, such failure is eliminated by selecting the 2nd mode by the mode selection means.

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 for conveying a transfer material onto which toner has been transferred to a fixing section in an image forming apparatus such as a copying machine or a printer.

0002

2. Description of the Related Art In an image forming apparatus using powder toner, the toner transferred to a transfer material in a transfer section is heated and fused and fixed in a fixing section. However, in some small image forming apparatuses, the distance from the transfer section to the fixing section is shorter than the length of the transfer material, and in such image forming apparatuses, the distance between the transfer section and the fixing section is shorter than the length of the transfer material. The leading edge of the transfer material enters the fixing section, and the impact when it enters the fixing section is transmitted to the portion of the transfer material passing through the transfer section, causing so-called transfer misalignment, resulting in poor image quality. Therefore, two air suction type conveyor devices are installed between the transfer section and the fixing section in the transfer material transport direction to prevent slack in the portion of the transfer material that is transferred from the first conveyor device to the second conveyor device. An image forming apparatus in which the impact is absorbed by the slack is proposed in Japanese Utility Model Application Publication No. 138554/1983.

0003

However, the above-mentioned image forming apparatus requires two conveyor apparatuses, resulting in an increase in cost and poor space efficiency.

[0004] Therefore, the inventor of the present invention has conducted intensive research and has proposed a conveying device using a chevron-shaped suction deck. In this mountain-shaped suction deck, slack is naturally formed when the transfer material passes the top of the suction deck. That is, the transfer material lifts up from the top surface of the suction deck due to its own stiffness when passing over the top of the suction deck. Therefore, the impact when the transfer material enters the fixing section is absorbed by the slack portion and is not transmitted to the portion of the transfer material passing through the transfer section.

Incidentally, in recent years, in order to effectively utilize forest resources, the use of recycled paper (waste paper) as a transfer material has become active. However, recycled paper tends to curl more easily than non-recycled paper due to the influence of humidity and the like. Further, if the curled paper enters the fixing section as it is, there is a problem that the curled portion is bent, resulting in so-called edge folding.

Therefore, in order to eliminate the edge folding in the fixing device having the chevron-shaped suction deck, it is necessary to strongly suck the transfer material passing over the chevron-shaped suction deck so that the fixing unit is free from curls. It should be transported to
In this case, the transfer material adheres closely to the suction deck, and the necessary slack cannot be formed. Conversely, if the suction force of the transfer material is weakened, curling cannot be eliminated.

[0007]

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and includes a transfer material conveying device that is formed in a V-shape from the transfer section side to the fixing section side. A suction deck having suction holes at the hem of each of the uphill and downhill slopes, a belt that moves along the slope from the transfer section side to the fixing section side, and the air on the belt is sucked through the suction holes. , a suction device that holds the transfer material on the belt with its suction force, a suction force adjustment means that adjusts the suction force, and a first mode that maintains the suction force at the adjusted value during the conveyance process of the transfer material; A mode selection means is provided that can select one of a second mode in which the suction force is weakened when the transfer material reaches the vicinity of the fixing section.

[0008]

[Operation] In the transfer material conveying device, when the first mode is selected by the mode selection means, the suction force is maintained at a predetermined value. On the other hand, when the second mode is selected by the mode switching means, the suction force is weakened when the leading edge of the transfer material reaches the vicinity of the fixing section. Furthermore, the suction force during selection of the first mode or the second mode can be varied by a suction force adjustment means. Therefore, by setting the suction force adjusting means and the mode selecting means, a conveyance state suitable for the material of the transfer material can be obtained.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 1 and 2 show a transfer material conveying device disposed between a transfer section and a fixing section in an image forming apparatus,
In this transfer material conveying device 1, the upper guide surface 3 of the suction deck 2 is formed in the shape of an "H" shape, and the top portion 4 has two sides on the transfer section side (the left side in FIG. 1) and the fixing section side (the right side in FIG. 1). Suction holes 7 and 8 are formed at the bottoms of the slopes 5 and 6, respectively.

The conveyor device 10 includes rollers 11 and 12 provided on the fixing section side and the transfer section side of the suction deck 2, respectively.
and a plurality of conveyor belts 13 wound around these rollers 11 and 12 and disposed along the upper guide surface 3 of the suction deck 2. Based on the rotation of the rollers 11, the conveyor belt 13 rotates clockwise. It is supposed to move to . Note that the conveyor belt 13 has countless holes 13a formed therein.

The suction device 15 is disposed under the suction deck 2, and the fan 1 is operated based on the drive of the motor 17.
6 rotates to suck air on the belt through the suction holes 7 and 8 of the suction deck 2 and the hole 13a of the belt 13.

The guide plate 18 is connected to the roller 11 and the fixing device 30.
A slit 19 is formed in the transfer material conveying direction.

The transfer material leading edge detection device 20 includes an actuator 21 and a switch 22. The actuator 21 is rotatably arranged under the guide plate 18, and one end thereof is inserted above the guide plate 18 through a slit 19. The switch 22 is operated when the actuator 21 detects the leading edge of the transfer material.

FIG. 4 shows a part of the operation panel of the image forming apparatus having the transfer material conveying device, and this operation panel 50
includes a recycled paper selection switch 51 and a recycled paper selection display LED.
52 are provided. The operation panel 50 also includes a suction force automatic setting switch 53, a suction force up switch 54, a suction force down switch 55, and settings made by these switches 53, 54, and 55 in order to adjust the suction force of the suction device 15. A plurality of LEDs 56 are provided to indicate the suction force.

FIG. 5 shows a control device for a transfer material conveying device.
Signals from the switch 22, various switches 51, etc. are input, and lighting signals for the LED 52, etc., and signals to the suction fan drive control circuit are output.

The basic operation of the transfer material conveying device 1 having the above configuration will be explained. In the transfer material conveyance device 1, rollers 11, 12 and conveyance belt 13 each rotate in the direction of the arrow in response to a signal from the control device CPU. Also,
The motor 17 rotates, and the suction holes 7 and 8 are opened by the fan 16.
The air above the belt is sucked through the belt hole 13a.

The transfer material P, on which the toner image has been transferred from the photoreceptor 40 at the transfer section X, is conveyed from the left side in the figure. This transfer material P moves along the upward slope 5 of the suction deck 2, and is attracted and held by the belt 13 at a portion opposite the suction hole 7. Note that the suction force F applied to the transfer material P at this time is referred to as "initial suction force." The transfer material P held by the belt 13 is conveyed in the direction of the arrow as the belt 13 moves, passes over the top 4 of the suction deck 2, and reaches the suction hole 8 of the downward slope 6.
It is again attracted to the belt 13 at the opposite part. Here, since a suction hole is not formed near the top part 4 of the suction deck and no suction force is applied to the transfer material P, the transfer material P is moved to the belt 13 based on its own stiffness. The transfer material P is lifted up, and a slack (bulge) Pa is formed in the transfer material P.

The leading edge of the transfer material P that has passed through the opposing portion of the suction hole 8 moves on the guide plate 18 toward the fixing side, and operates the actuator 21 . In the tip detection device 20, a switch 22 detects the operation of the actuator 21 and outputs the detection signal to the control device CPU.

The transfer material P that has passed through the guide plate 18 enters the fixing section Y of the fixing device 30, where the toner held on the upper surface of the transfer material P is heated and fixed. When the leading edge of the transfer material P enters the fixing section Y, the impact propagates backward through the transfer material P (in the direction of the transfer section) and is absorbed by the slack Pa near the top portion 4. Therefore, the impact is not transmitted to the portion of the transfer material passing through the transfer section X. Therefore, the toner image transferred from the photoreceptor 40 to the transfer material P at the transfer portion X is not disturbed.

Next, the control of the transfer material conveying device 1 when the recycled paper selection switch 51 and the suction force adjustment switches 53, 54, and 55 on the operation panel 50 are pressed will be explained with reference to FIG. .

(a) Mode (a) (see upper left column in Figure 6) [
SW51: OFF, SW53: ON (SW54, 55: OFF)] When the recycled paper selection switch 51 is OFF and the suction force automatic setting switch 53 is ON, the suction force F remains at the initial suction force until the end. The automatic suction force setting switch 53 is turned on by pressing it, and is also turned on automatically when the image forming apparatus is turned on. In addition, when the suction force automatic setting switch 53 is on, the suction force up switch 54 or the suction force down switch 55
is off.

(b) Mode (b) (see lower left column in Figure 6)
SW51: Off, SW53: Off (SW54 or SW
55: ON)] When the recycled paper selection switch 51 is OFF, the suction force automatic setting switch 53 is OFF, and the suction force up switch 54 or the suction force down switch 55 is ON in place of the switch 53, the operation panel 50 displays the suction The suction force F2 set by operating the force up switch 54 or the suction force down switch 55 is displayed by the LED 56.

On the other hand, in the transfer material conveying device 1, if the suction force down switch 54 is turned on, the transfer material P is in the mode (
The transfer material P is attracted to the belt 13 with a weaker force than in mode (a), and if the attraction force up switch 55 is turned on, the transfer material P is attracted to the belt 13 with a stronger force than in mode (a). Furthermore, if the suction force of the transfer material to the belt 13 is increased by the suction force up switch 54, the amount of curling when it enters the fixing section Y will be reduced, and the curling of the transfer material P that has passed through the fixing section Y will be prevented. It disappears.

(c) Mode (c) (see upper right column in Figure 6)
SW51: ON, SW53: ON (SW54 or SW
55: Off) When the recycled paper selection switch 51 is turned on and the suction force automatic setting switch 53 is turned on, the LED 52 lights up on the operation panel 50 to indicate that the recycled paper selection switch 51 is turned on. .

On the other hand, in the transfer material conveying device 1, the initial suction force is set to F1. Then, when the leading edge of the transfer material P that has passed through the opposing portion of the suction hole 8 operates the actuator 21 at time t1 and turns on the switch 22, the control device 10 controls the rotation of the motor 17 of the suction device 15 based on the ON signal. The suction force of the transfer material P is weakened to F1'. The suction force at this time is referred to as the "changed suction force."

As a result of the weakening of the suction force F (F1') as described above, the adsorption force of the transfer material P to the belt 13 is reduced, and the portion of the transfer material moving near the top portion 4 of the suction deck is further lifted up. , the slack Pa formed in the transfer material P increases. Therefore, even if the impact is large when the leading edge of the transfer material P enters the fixing section Y, this impact is reliably absorbed by the slack Pa, and no impact is transmitted to the portion of the transfer material passing through the transfer section X.

(d) Mode (d) [SW51: ON, SW53: OFF (SW54 or 5
5: ON)] When the recycled paper selection switch 51 is turned on, the suction force automatic setting switch 53 is turned off, and the suction force up switch 54 or the suction force down switch 55 is turned on, the LED 52 on the operation panel 50 is turned on. It lights up to indicate that the recycled paper selection switch 51 is turned on. In addition, the suction force set by operating the suction force up switch 54 and the suction force down switch 55 is LE.
Displayed by D56.

In the transfer material conveying device 1, basically the same process as in the mode (c) is executed, including a process of changing the suction force F at which the leading edge of the transfer material P is detected by the leading edge detecting device 20 at time t1. is executed. However, the initial suction force F2 and the changed suction force F2' for the transfer material P are adjusted according to the selection of the suction force up switch 54 or the suction force down switch 55. Therefore, even if the transfer material P is recycled paper or stiff paper, the suction force is increased by the suction power up switch 54, and the transfer material P is conveyed to the fixing unit Y without curling or with no problem in the amount of curling. be able to. Further, by changing the suction force F, the impact when the leading edge of the transfer material P enters the fixing portion Y is reliably absorbed by the slack Pa, thereby preventing image quality deterioration due to transfer misalignment.

Note that in the above embodiment, the tip detection device 20
Although the suction force is weakened as soon as the leading edge of the transfer material P is detected in , the suction force may be weakened after a predetermined period of time has elapsed from the detection time t1. It is not limited to the location immediately before the fixing section Y.

Further, the leading edge detection means of the transfer material is not limited to the above-mentioned embodiment, and detects when the leading edge of the transfer material is near the fixing section based on a signal for register adjustment between the transfer material and the toner image on the photoreceptor. The arrival may be detected.

[0031]

As is clear from the above description, the transfer material conveying device according to the present invention includes a chevron-shaped suction deck, a belt that moves along the upper surface, and a hem portion of the suction deck. a suction device that suctions air on the belt through a suction hole provided in the belt and uses the suction force to hold the transfer material on the belt; a suction force adjustment means that adjusts the suction force; and a suction force adjusting means that adjusts the suction force; mode selection means capable of selecting one of a first mode in which the suction force is maintained at an adjusted value and a second mode in which the suction force is weakened when the transfer material reaches the vicinity of the fixing section; It is set up.

Therefore, if the transfer material discharged from the image forming apparatus has a bent edge, the suction force adjusting means sets the suction force of the transfer material to be strong, and if there is transfer misalignment, the second mode is selected by the mode selection means. In this way, each inconvenience can be resolved.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a transfer material conveying device.

FIG. 2 is a perspective view of a transfer material conveying device.

FIG. 3 is a perspective view of a curled transfer material.

FIG. 4 is a partial plan view of the operation panel.

FIG. 5 is a control circuit diagram.

FIG. 6 is a diagram showing a suction force setting mode.

[Explanation of symbols]

1...Transfer material conveyance device 2...Suction deck 7, 8...Suction hole 10...Conveyor device 13...Belt 15...Suction device 16...Fan 20...Tip detection device X...Transfer section Y...Fusing part P...Transfer material Pa... slackness CPU...control device

Claims (1)

[Claims] Claim 1: A transfer material conveying device that conveys the transfer material onto which the toner has been transferred in the transfer section to the fixing section is provided with: a suction deck having suction holes at the bottom of each of the slope and the downward slope; (b) a belt that moves from the transfer unit side to the fixing unit side along the slope; and (c) a suction deck that moves on the belt through the suction holes. (d) a suction device that sucks air and holds the transfer material on the belt with its suction power;
a suction force adjusting means for adjusting the suction force; (e) a first mode for maintaining the suction force at a set value during conveyance processing of the transfer material; A transfer material conveying device comprising: a mode selection means capable of selecting either one of a second mode in which the transfer material is weakened.