JPS6040372A - Form-sheet transporting apparatus - Google Patents

Abstract

PURPOSE:To suppress generation of noise by detecting the thickness of a form sheet and allowing the number of revolution of a blower to be variable according to the thickness, thus increasing the transport efficiency for thick paper by increasing the number of revolution, while reducing the number of revolution for other kinds of form sheet. CONSTITUTION:A form-sheet is sent into the copying part of a photosensitive body 2 by a roll 1, and the surface of the form-sheet is treated with toner by a copying corotron 3, and then the form-sheet is adsorbed onto a tranfer belt 4 and vertically transported, and fixation is carried-out by a fixing roll 8. The revolution drive of a blower 6 is carried-out by a motor 9, and setting and control of the speed of the motor 9 are carried-out by a computer 10, and the thickness of the form sheet is detected by a form-sheet thickness detector 11 in orde to set the speed of the motor. By measuring the relation between the thickness of the form sheet and the number of revolution of the blower beforehand, the frequency and the voltage which are supplied to the motor suitable for the above retation can be selected.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device for transporting paper in paper processing devices such as copying machines and facsimile machines.

Prior art In conventional paper conveying devices that use a blower to convey paper not only horizontally but also vertically while adsorbing it to a paper belt, the number of revolutions of the blower is fixed and varies depending on the thickness of the paper. 0 Therefore, there is a limit to how much paper can be conveyed in the direction perpendicular to τ, and in order to exceed that limit, it is necessary to increase the rotation speed of the blower. If fixed, the blower always rotates at a high speed and generates noise.Object of the InventionThe present invention relates to an invention for a paper processing device [hereinafter referred to as a paper processing device] that overcomes these drawbacks. By providing paper thickness detection means, the number of rotations of the blower is automatically adjusted based on the thickness of the paper. The object of the present invention is to provide a paper processing device that can reduce the number of rotations of the blower for other types of paper and prevent noise generation while maintaining the required carrying capacity.

Ridge hitting η nose area The configuration of the present invention will be explained based on FIG.

A is a paper thickness detection means that detects the thickness of paper, and B
0 is a motor speed determining means that determines the motor speed for changing the rotation speed of the blower based on the information from the detecting means A, and 0 is a motor speed determining means that controls the motor speed based on the determination result of the determining means. This is the motor for driving the DG blower.

Since the present invention is constructed and operated as described above, the number of rotations of the blower can be automatically adjusted according to the thickness of the paper.

EXAMPLE An example of the present invention utilized in a copying machine will be described below with reference to FIGS. 2 and 3.

FIG. 2 is a schematic explanatory diagram in which the conveyance device according to the present invention is applied to vertical conveyance of paper from the transfer process to the fixing process.

Reference numeral 1 denotes a conveyance roll, which sends out the paper to the transfer process.

2 is a photoreceptor, on which a toner image is formed immediately before transfer.

Reference numeral 3 denotes a transfer corotron which, when a sheet of paper is inserted, transfers the toner by applying static electricity to the sheet itself and attracting the toner that has adhered to the surface of the photoreceptor to the sheet side.

Reference numeral 4 denotes a conveyor belt which is stretched across a pulley 5, and is provided with a large number of ItJ paper absorption belts.

Reference numeral 6 denotes a paper suction blower which sucks air from the suction pipe 7 and discharges it.

Reference numeral 8 denotes a fixing roll that keeps the toner adhering to the surface of the paper at a constant N.

With this configuration, the paper is sent to the transfer section of the photoreceptor 2 by the transport roll 1, has toner attached to its surface by the transfer flotron 3, is further attracted to the transport belt 4, and is transported vertically. τ fixing is performed by the fixing roll 8.

The blower 6 is rotationally driven by a motor 9, and the speed of the motor 9 is set and controlled by a computer 10.
The paper thickness detection device 11 detects the thickness of the paper (l+f) for setting the motor speed.

Let us now consider the suction force exerted on the paper by the conveyor belt.

Blower rotation v! While keeping the ir constant, the adsorption area 5 (
The curve in Figure 3 shows the change in the static pressure P on the suction surface when the air volume Q is changed by changing the total area of holes on the surface of the llrt conveying belt that have effective suction capacity.
,■,■, and if the case of ■ in the blower rotation speed is LE, then ■ is 7Ll×1.2−.

(2) is the case of yL, Xl, and the number of rotations of 4.

f. The resistance curve (2) is the value of the static pressure P on the suction surface measured when the wind itQ is changed by changing the rotation speed with a paper of a certain size being suctioned.

When the number of revolutions of the τ blower is 1, the suction force F of the paper, the static pressure P1 at the intersection of the curves ■ and ■, and the suction area S are multiplied by P and S.

If we assume that the suction force required to vertically convey cardboard by suctioning it to the belt is F2=P2S, then the blower curve ■ which shows a curve ■ passing through a point on the resistance curve ■ corresponding to the static pressure P2 is τ.
Rotation speed 7LIX1. ．． 4 is obtained.

In other words, if the number of revolutions of the blower is increased by 1.41 times,
A suction force F2 is obtained, making it possible to vertically transport the cardboard.

In this way, by determining in advance the required number of rotations according to the thickness of one sheet of paper, it is possible to adjust the number of rotations of the blower to an appropriate number.

Adjustment of the rotation speed of the blower is performed by controlling the speed of the motor, in which case frequency control using a frequency converter or voltage control may be considered.

At this time, the motor speed may be set in several stages depending on the thickness of the paper, or a two-stage switching system may be used, one for thick paper of a certain thickness or higher and one for other times.

The motor speed is set based on the paper thickness using the computer 10'E or a relay circuit. That is, as mentioned above, by measuring the correspondence between the thickness of the paper and the number of rotations of the blower in advance, the frequency or voltage supplied to the motor can be selected accordingly.

Note that the paper thickness detection device 11 calculates the thickness of a bundle of several dozen sheets by dividing it by the number of sheets. Generally, the paper thickness is expressed by the paper weight corresponding to the thickness of the paper. The position of the top layer of paper drops on the set tray as the paper is fed, but by counting the number of sheets of paper that has been fed for a certain amount of the drop and setting it by 1, the thickness and weight of the paper can be increased)T T-, - (K is a constant)
It can be claimed according to the following formula. Note that a limit switch or the like may be used to detect a certain amount of decrease.

As described above, the number of rotations of one blower can be adjusted appropriately depending on the thickness of the paper.

Effects of the Invention As described above, in the present invention, since the +11iQ thickness can be detected and the rotation speed of the blower can be varied according to the thickness, the rotation speed can be increased for thick paper to improve the conveyance capacity, and other As for the paper, by reducing the number of rotations and maintaining the necessary conveyance capacity, noise can be suppressed, and constant noise can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a diagram corresponding to claims of the present invention, FIG. 2 is a schematic explanatory diagram of an embodiment according to the present invention, and FIG. 3 is a diagram showing characteristics of a blower. 1°°° Conveyance roll, 2... Photoreceptor, 3... Transfer corotron, 4... Conveyance heald, 5... Pulley, 6...
...Blower 17...Suction pipe, 8...Fixing roll,
9...Motor, IO...Computer, 11...
Paper thickness detection device. Agent: Patent attorney Nozomi Ehara (1 person)

Claims (1)

[Scope of Claims] In a paper processing apparatus having a blower Z for conveying the paper while adsorbing it to a paper belt, a paper thickness detection means for detecting the thickness of the paper and a blower Z based on information from the detection means - a motor speed determining means for determining the motor speed for changing the rotational speed of the motor; a motor speed controlling means for controlling the speed of the motor based on the determination result of the determining means; A paper processing device [/] A paper conveying device, which has the following features.