JPS61178351A - Paper supply and feed device in copying machine - Google Patents

Abstract

PURPOSE:To reduce copying time to speed up copying by restricting the stopping time of feed means in which its rotation is controlled by the output of a detector in a paper supply and feed device to the minimum required for forming a deflection in a copy paper. CONSTITUTION:A copying machine is provided with a copy paper detector K and feed means 8,the latter being arranged downstream with respect to the former in a paper feed direction, on a path from paper supply means 7 to a photosensitive member 1 and is adapted to form a deflection in a copy paper and correct its leading edge on the upstream side of the feed means 8. In such copying machine, the rotation of the feed means 8 is adapted to be stopped for at least a time t1+t2 after the copy paper detector K detects the copy paper. That is, the feed means 8 is not rotated during the time which is the sum of the time t1 sufficient for feeding the copy paper from the downstream side detecting limit position of the detector K to the feed means 8 and the time t2 required for feeding the copy paper from the upstream side detecting limit position to the downstream side detecting limit position both of the detector K.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides a copy paper detector on the way of feeding paper from a paper feeding means to a photoreceptor, and a conveying means downstream of the copy paper detector in the conveying direction. The present invention relates to a paper feeding and conveying device for a copying machine, which is provided with a paper sheet and is configured to bend the copy paper on the upstream side of the conveying means and correct the leading edge of the copy sheet.

(Prior Art) Generally, in an electrostatographic copying machine, copy paper is conveyed in synchronization with the driving of an optical system.
For example, when the paper feed roller installed near the paper cassette rotates, the paper feeding force may become unstable due to friction between the paper feed roller and the copy paper. Since the copy paper may be transported obliquely to the transport direction, the leading edge of the copy paper should be in contact with the nimp position of a stationary transport means, for example, a pair of transport rollers. By bending the copy paper, the leading edge of the copy paper is corrected during transportation.

That is, a copy paper detector is provided on the upstream side of the pair of transport rollers, and the detector detects the copy paper and the pair of transport rollers starts rotating after a predetermined period of time to correct the leading edge. The deflection was created on the upstream side of the pair of transport rollers. In conventional copying machines of this type, the time t is set relatively large in order to ensure that the necessary deflection is formed on the upstream side of the pair of conveying rollers.

(Problem to be Solved by the Invention) However, if the above-mentioned time t is increased, bending will inevitably occur, but the conveyance of the copy paper will be stopped accordingly, which is not preferable from the viewpoint of increasing the speed of copying. .

On the other hand, there are variations in the operating characteristics of the copy paper detector, and it is not effective to set the above-mentioned time t while ignoring this variation.

The present invention has been made with the above-mentioned matters in mind, and is capable of forming the necessary deflection on the upstream side of the conveying means,
Moreover, the time t is set to the minimum necessary amount even when the variation in the operation of the copy paper detector is sufficiently overcome,
The purpose is to increase the speed of copying and to effectively correct the leading edge of copy paper.

(Means for Solving the Problems) In order to achieve the above object, the present invention is configured such that the rotation of the conveying means is stopped for the time tl+tz shown below after the copy paper detector detects the copy paper. ing.

tl; Time sufficient to convey the copy paper from the downstream detection limit position of the copy paper detector to the conveyance means to form a predetermined deflection on the upstream side of the conveyance means.

t2: Time required for the copy paper to be conveyed from the upstream detection limit position to the downstream detection limit position of the copy paper detector.

In the above, the upstream detection limit position of the copy paper detector refers to the most upstream position where the copy paper detector detects the copy paper being conveyed and outputs a detection signal, and also refers to the downstream position Similarly, the detection limit position refers to the most downstream position at which the detection signal is output. For example, if we take a detector structure that combines a photointerrupter P, 1 and an actuator AC in the embodiment described later and explain it in detail (see Figs. 3 and 4), the detection RK will be , when actuator AC is at position @UL when the copy paper is being conveyed, position 4 ÷
There are cases where it is turned on when it is at 1 → ML, there are cases where it is turned on when it is at position DL, etc., and position tftUL is the upstream detection limit position and position DL is the downstream detection limit position (for details, refer to the examples below). .

(Example) Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a sectional view schematically showing a copying machine 100 to which the present invention is applied, and FIG. 2 is a sectional view showing main parts of a paper feeding and conveying device. In the figure, reference numeral 1 denotes a right cylindrical photoconductor, and a charging device 2, a developing device RFI 3, and a transfer device 4 are arranged in sequence near the circumference of the photoconductor according to the rotation direction (indicated by an arrow in the figure). 5 is a paper feed cassette, and 6 is copy paper. 7 is a paper feed roller provided near the paper feed cassette 5.

Reference numeral 8 denotes a conveying means having a function as a registration roller whose rotation is controlled in synchronization with the toner image formed on the photoreceptor 1, and is a pair of conveying rollers consisting of a main roller 8a and a subordinate roller b. Although not shown, the paper feed roller 7 and the main roller 8a are each pivotally attached to a rotating shaft having a spring clutch, which is a known means, and by controlling the spring clutch with a solenoid, the rotating shaft can be connected to the rotating shaft. It is configured to be able to transmit and release the drive between the rollers.

K is a copy paper detector (hereinafter referred to as a detector) provided near the upstream side of the conveying means 8. For example, as shown in FIG. 3 (5) and (B), this detector combines a photointerrupter PI and an actuator AC,
The copy paper comes into contact with the actuator AC, presses it, rotates the light shielding plate S provided between the light emitting side and the light receiving side of the photointerrupter PI, and turns on the photointerrupter PI.
The one that is made to do so is used. R is a connecting piece that connects the actuator AC and the light shielding plate S. Then, as the copy paper advances in the direction of the arrow Y in FIG. 3(5), the actuator AC rotates, and the light shielding plate S rotates.

In addition to the above-mentioned detector, for example, a limit switch or a microswitch having an actuator may be used as the detector. Alternatively, a photosensor may be used.

Thus, after the detector K detects the copy paper, the conveying means 8 operates at least during the time tl-)-t2 shown below.
The rotation is configured to stop.

Here, time t1 is the downstream detection limit position DL of the detector.
(hereinafter referred to as DL, see Figure 4) to the conveying means 8
The time t2 refers to the time sufficient to convey the copy paper to the upstream side of the conveying means 8 to form a predetermined deflection, and the time t2 is the upstream detection limit position UL (hereinafter referred to as the position) of the detector. UL refers to the time required for a copy sheet to be conveyed from position DL (see FIG. 4N) to position DL.

The reason why the position DL is used as a reference when setting the time tl is as follows. When setting the time required to form a predetermined deflection on the upstream side of the conveyance means 8 after the detector is turned on, there are two ways to set the time required to form a predetermined deflection on the upstream side of the conveying means 8: one is based on position @UL, and the other is based on position [DL]. It will be done. If iUL is used as a reference, the above-mentioned deflection becomes larger than necessary, which becomes a major hindrance to increasing the speed of copying. On the other hand, when the time tl is set based on the position DL, the deflection Wl formed on the upstream side of the conveyance means 8 is equal to or less than a predetermined value.

In this case, there is no problem if the deflection Wl is always a predetermined amount, but a problem occurs when it is less than the predetermined amount.

The magnitude of this deflection is due to variations in the operating characteristics of the detector, and as shown in FIG. Therefore, in the present invention, after the detector K detects the copy paper, the rotation of the conveying means 8 is stopped for at least the time tl-1-t2, so that the detector K is in the position [
A predetermined deflection is created even when the UL is turned on.

9 is a conveyor belt, 10 is a fixing device, 11 is a discharge/roller pair, and 12 is a tray. Reference numeral 13 denotes a document placement section provided on the top surface of the main body of the copying machine 100. Although not shown, an operation panel including a human-powered numeric keypad, a print button, etc. is provided near the document placement section 13.

Reference numeral 14 denotes an optical system for exposing the IQ document, which includes a light source 15, an anti-IJ m16, 17, 18, a lens system 19, etc. Then, the original f2 canter 13 on which the original is placed is X-Y
By moving in the direction, the original is exposed and an electrostatic layer image of a predetermined magnification is formed on the photoreceptor 1.

Next, the operation of the above embodiment will be explained with reference to FIGS. 1, 2, and 4 (A), (H), and (C1).

While the copying machine is on standby, the paper feed roller 7 and the conveying means 8 are stopped. When the print button is pressed, the paper feed roller starts rotating in the direction indicated by the arrow in FIG. As a result of this rotation, the uppermost copy paper 6 in the paper feed cassette 5 is sent out toward the conveyance means 8 along the guide member. The detector K is turned on until the leading edge of the copy paper t' comes into contact with the nip position of the conveying means 8.

Note that, after the elapse of time tl-)-t2, the paper feed roller 7 stops, but the latent image formed on the surface of the photoreceptor 1 is developed by the developing device 3 as the photoreceptor 1 rotates, and a toner image is formed. When the distance between the leading edge of this toner image and the transfer device @4 matches the distance between the leading edge of the copy paper 6 held in the conveyance means 8 and the transfer device 4, the conveyance means 8 It begins to rotate.

Here, there are roughly three timings at which this detector K turns ON, and for each case, Fig. 4 (5) and (
B), (Qt- will be explained with reference to

■ As shown in (5) of the same figure, when the actuator AC of the detector comes to the position DL, if the detector K is turned on, the copy paper 6 is the most in the conveying means 8 at the time of turning on. Until the transport means 8 rotates in accordance with the exposure timing of the optical system, a deflection Wl is formed on the upstream side of the transport means 8, and the leading edge of the copy paper 6 is corrected.

■ As shown in the same figure (B), if the detector K is turned on when the actuator AC is at the position ML intermediate between the positions UL and IDL, if the leading edge of the copy paper 6 is in the above-mentioned ■ Since the copy paper 6 is not closer to the conveying means 8 than the above, a deflection Wl smaller than the above-mentioned deflection Wl is formed on the upstream side of the conveying means 8, and the leading edge of the copy paper 6 is corrected.

(J, As shown in the same figure (C), actuator A
If the detector K is turned ON when C comes to the position UL, the recorded time tl + t2 is the time when the copy paper 6 is conveyed from the position LIL to the position DL, and further conveyed from the position DL to the conveyance means 8. Since this is a sufficient time to form a predetermined deflection on the upstream side of the conveying means 8, the deflection W3 is formed on the upstream side of the conveying means 8 also in this case. Although this deflection W3 is smaller than the deflection Wl, it is large enough to correct the leading edge of the copy paper 6, so that a predetermined leading edge correction is performed.

As described above, in any of the cases ① to ②, the predetermined deflection W,, Wl on the upstream side of the conveying means 8.

W3 is formed, and the leading edge of the copy paper 6' being conveyed is corrected.

(The following is a margin, continued on the next page) In the above embodiment, only one conveying means 8 that functions as a registration roller is provided on the way to feed and convey the paper, but there is also a conveyance means 8 upstream or downstream of this conveyance means 8 that functions as a registration roller. Other conveying means that do not have this function may also be provided.

(Effects of the Invention) As detailed above, according to the present invention, the stop time of the conveying means whose rotation is controlled by the output of the detector can be minimized to the minimum required to form a deflection. Compared to this type of copying machine, the time required for copying is shortened, and the speed of copying is promoted accordingly. Furthermore, since a predetermined amount or more of deflection can always be formed on the upstream side of the conveyance means, the leading edge of the copy sheet being conveyed can be reliably corrected.

[Brief explanation of drawings]

FIG. 1 is a sectional view schematically showing a copying machine to which the present invention is applied;
FIG. 2 is a cross-sectional view showing the main parts of the paper feeding and conveying device according to the present invention, FIG. (B) and (C) are operation explanatory diagrams. DESCRIPTION OF SYMBOLS 1...Photoreceptor, 8...Transportation means, K...Copy paper detector.

Claims (1)

[Scope of Claims] A copy paper detector and a conveyance means are provided on the downstream side of the copy paper detector in the conveyance direction of the copy paper detector on the way of paper feeding from the paper feed means to the photoreceptor, and copying is performed on the upstream side of the conveyance means. In a copying machine that corrects the leading edge of paper by forming a bend in the paper,
A paper feeding and conveying device for a copying machine, characterized in that the rotation of the conveying means is stopped at least for a time t_1+t_2 shown below after the copy paper detector detects the copy paper. t_1, a time sufficient to convey the copy paper from the downstream detection limit position of the copy paper detector to the conveyance means to form a predetermined deflection on the upstream side of the conveyance means; t_2: Time required for the copy paper to be conveyed from the upstream detection limit position to the downstream detection limit position of the copy paper detector.