JPS61136860A - Double side copying machine - Google Patents

Abstract

PURPOSE:To make paper alignment performable in an accurate manner, by detecting that a rear end of paper is separated from a discharge roller with certainty and dropped on an intermediate tray, while making a sponge roller and a side fence into operation. CONSTITUTION:At first, a sponge roller 26 is situated in a turnout position shown in broken lines, while side fences 28 are separated as far as a distance l3 with each other and situated in each end part at both sides of an intermediate tray 23. Transfer paper S of width l2 drops toward an arrow B, and when it passes through height of each small hole 41 of these side fences 28, it intercepts an optical path between a light source 40a and a light receiving element 40b and detected. With this detection signal, the roller 26 is displaced to a full line position, conveying the transfer paper S toward a stopper 27. And, after the elapse of time reaching to the stopper 27, the roller 26 is made to go up to a position of the broken line. Then, these fences 28 are moved with each other, and sheets of the transfer paper S are sligned at the central position. Next, the sponge roller 26 is made to go down again, aligning the transfer paper S, and these fences 28 is restored whereby the roller 26 is made to go up, thus sheets of paper are accurately aligned.

Description

Detailed Description of the Invention Technical Field The present invention involves discharging transfer sheets that have undergone single-sided copying one by one onto an intermediate tray, aligning them at predetermined positions on the intermediate tray in the conveying direction and in the width direction perpendicular to the conveying direction. This invention relates to a double-sided copying machine in which sheets are loaded and re-fed for back-side copying.

In conventional double-sided copying machines, the transfer paper on which one-sided copying has been completed is ejected and stacked on an intermediate tray, and after the original is turned over or replaced, the transfer paper on the intermediate tray is re-fed so that the back side faces the photoreceptor. It is designed to make a copy of the back side of the paper and eject it outside the machine.

FIG. 4 shows an example of a conventional double-sided copying machine, in which a copying machine main body 1 is placed on a double-sided unit 2. As shown in FIG. The main body of the copying machine is no different from a normal copying machine; it has a contact glass on the top, an exposure system 12 below it, a photoreceptor drum 13 below it, and predetermined copying process equipment around it. A paper feed section 14 is provided on one side of the paper feed section. Paper is fed from the paper feed section to the transfer section 15 of the photoreceptor drum 13, and the toner image formed on the photoreceptor drum 13 is transferred to the fixing section 16.
The image is fixed at , and is ejected from the ejection port 17 .

The duplex unit 2 is provided with an inlet 21 opposite to the outlet 17 of the copying machine main body 1, and paper is ejected into a path to be ejected to a paper ejection tray 22 outside the machine and to an intermediate tray 23. A branch claw 24 for selectively switching the conveying direction is provided inside the receiving port 21. A discharge row 225 is provided at the end of the path leading the paper to the intermediate tray 23.

In this device, a discharge roller is provided above near the discharge end of the intermediate tray 23, and the paper discharged from the roller and dropped onto the intermediate tray can be brought into contact with and separated from the upper surface of the paper by a sponge roller 26 that is driven counterclockwise in the figure. The rear end of the ejected paper is fed first until it comes into contact with a stopper 27 that is retractably provided at the right end of the intermediate tray 23, and then the sponge roller 26 is retracted from the top surface of the paper, and the paper is ejected from the intermediate tray. 2
3. After being aligned at a predetermined position in the width direction by the side fences that are movable in the direction perpendicular to the paper transport direction on both sides of the top surface, the top surface is held down again using the sponge rollers 26 to prevent it from moving. The side fence 28 is moved away from the side of the paper, and then the sponge roller 26 is retracted to the position shown by the broken line. In the retracted position, the sponge roller 26 occupies a position where it does not interfere with the paper discharged from the discharge roller 25.

At the upper part near the front end of the intermediate tray 23, a paper refeeding roller 29 is provided so as to be able to approach and separate from the upper surface of the stack of sheets stacked thereon. It extends to the upper surface of the vicinity, and conveyance rollers are provided along the way at a distance necessary for conveying the paper.

A receiving port 18 for re-feed transfer paper is provided on the lower surface of the copying machine main body 1, facing the exit 31 of the duplex conveyance path 30, from which the re-feed transfer paper joins the paper feed path from the paper feed section 14. Route 19
is provided. When refeeding paper, move the stopper 27 to arrow A.
By tilting the intermediate tray 2 in the direction of
The sheets on the top 3 are fed into the transfer section 15 one by one.0 Now, in the conventional double-sided copying machine of this type, the paper on the ejection row 225
The sponge roller 26 and side fence 28 for aligning the single-sided copied transfer paper ejected from the intermediate tray 23 are controlled by a pulse generator installed in the copying machine main body l, and a paper detection device at the ejection row 225. A sensor 32 is provided,
When this detection sensor 32 detects the trailing edge of the paper and reaches a predetermined number of pulses, it is determined that the paper has landed on the intermediate tray 23, and when the number of pulses reaches y, the leading edge of the paper reaches the stopper 23. It is determined that the paper has been reached, and the sponge roller 26 and the side fence 28 are moved as described above and controlled to align the paper according to the program. Therefore, if the paper is stopped at the discharge roller 25 for some reason, it may cause a paper jam. In addition, if the paper and each roller slip, the paper position estimated from the pulse number and the actual paper position will deviate, causing the timing of the movement of the pants and side fences 26 and side fences to deviate from the movement of the paper. This resulted in poor paper alignment.

In order to eliminate the above problem, the paper that has fallen onto the intermediate tray 23 is actually moved to the stopper 27 by the sponge roller 26.
It is conceivable to provide means for detecting that the information is being sent to the destination. As shown in FIG. 5, this method involves providing a paper entry detection roller 32 in contact with the upper surface near the tip of the intermediate tray 23, and pivoting one end of a lever 34 that swings about a fulcrum 33 to the eccentric point of the roller 32. A photoelectric sensor 36 is actuated by a small hole provided in a light-shielding plate 35 that swings together with a lever 34 about a fulcrum 33, so that paper sent by a sponge roller 26 is detected under the entry detection roller 32. A paper entry detection mechanism has been proposed in which the entry detection roller 32 rotates due to friction when the paper enters the sheet, causing the light shielding plate 35 to swing so that the sensor 36 can detect the paper entry. However, this mechanism has many parts and takes time to assemble, and the friction between the paper and the entry detection roller 32 is so small that the roller does not rotate, and conversely, the vibration of the machine during copying may cause the light shielding plate 32 to
There is a problem where the paper oscillates and the paper is mistakenly detected as having arrived even though it has not been removed.

Purpose of the Invention The present invention has been made in view of the above-mentioned problems related to paper detection for aligning single-sided copied paper ejected to an intermediate tray in a conventional double-sided copying machine, and the present invention has been made in view of the above-mentioned problems related to paper detection for aligning single-sided copied paper ejected to an intermediate tray. To provide a double-sided copying machine capable of accurately aligning paper without jamming the paper by detecting that the paper has fallen onto an intermediate tray and operating a sponge roller and a side fence.

Structure: In order to achieve the above object, the present invention provides a double-sided copying machine equipped with an intermediate tray unit 11 equipped with the side fence having the above structure and a paper aligning member such as a sponge roller. The present invention is characterized in that a transfer paper detection means is provided at a position where it can detect the transfer paper falling onto the intermediate tray away from the rollers, and the movement of the above-mentioned paper aligning member is controlled based on the detection signal.

Hereinafter, the present invention will be explained in detail based on drawings showing embodiments thereof.

FIG. 1 is a diagram showing an embodiment in which the present invention is applied to a double-sided copying machine having the configuration described in FIG. 4.

In this embodiment, the sensor 40 detecting the entry of the paper ejected from the ejecting roller 25 into the intermediate tray is connected to the side fence 28.
It is not provided at the discharge row 225, and the control of the approach and separation of the sponge roller 26 and the movement of the side fence 28 is performed based on the detection signal of the sensor 40. The configuration and operation are the same as those shown in FIG. Therefore, the same members are given the same reference numerals, and the explanation of the functions that are obvious from the above description will be omitted.

FIG. 2 is an enlarged view showing the cross section of the intermediate tray 23 and the side fence 28 at the position of the sensor 40;
FIG. 3 is a side view of that part. The sensor 40 is a transmission type photoelectric sensor, and the side fences 28 on both sides have small holes 41 at opposing positions, and light sources 40 are installed on the outside of each small hole 41.
A and a light receiving element 40b are provided, and the light beam emitted by the light source 40a passes through the small holes 41 of the two side fences 28 and is received by the light receiving element 40b. The position of the sensor 40 in the conveyance direction is such that it can detect the vicinity of the rear end of the sheet that has left the discharge row 225 and is falling toward the intermediate tray 23 .

Initially, the sponge roller 26 is in the retracted position shown by the broken line in FIG. The paper S falls toward the intermediate tray 23 as shown by the solid line B in FIG.
The optical path between the light source 40a and the light receiving element 40b passing through the height of 1 is blocked and detected. In response to this detection signal, the sponge roller 26 is displaced to the position shown by the solid line in FIG. 1, and the transfer paper S is conveyed toward the stopper 27. The stopper 2 starts from the position directly below the position where the trailing edge of the paper leaves the discharge row 225.
After conveying the paper for the time required to convey the distance tI'c up to 7 plus the time for the slip of the paper, the sponge roller 26 is raised to the original position shown by the broken line, and at the same time the side fence and drive motor shown in FIG. 42 is rotated and moved to a predetermined central position spaced apart from each other by a distance t2 from the side fences 28t, and the transfer paper S is aligned at a predetermined position in the center of the tray 23. Then, the sponge roller 26'ft is lowered again to hold down the transfer paper S, and after returning the side fence 28 to its original position, the sponge roller 26 is retracted to the raised position to prepare for the entry of the next paper.

By repeating this operation for a predetermined number of sheets, the sheets are aligned at a predetermined position on the intermediate tray 23. It is assumed that for the final sheet, the side fence is held at the sheet alignment position separated by a distance of 4.

It should be noted that various known types of paper entry detection sensor can be used, such as the light transmission type of the Asahi light reflection type and the sonic wave detection type of the embodiment.

Effects According to the present invention, the operation of the paper alignment members such as the sponge core a and the side fence is controlled after it is detected that the transfer paper has reliably separated from the discharge roller and fallen onto the intermediate tray. , the control timing is reliable, paper jam υ can be detected reliably, and the structure is simple.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the structure of the umbrella body of a double-sided copying machine according to an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of the paper entry detection unit into the intermediate tray and the side fence, and FIG. 3 is an enlarged cross-sectional view of that part. FIG. 4 is a cross-sectional view showing the overall configuration of an example of a conventional double-sided copying machine, and FIG. 5 is a side view showing another example of conventional paper entry detection means into an intermediate tray. 23... Intermediate tray 25... Discharge roller 26... Sponge roller (paper alignment member) 27... Stopper 28... Side fence (paper alignment member) 40... Transfer paper detection means S...・Transfer paper February 14, 1985 Manabu Shiga, Commissioner of the Patent Office l Display of the case 1982 Patent Application No. 255120 2 Name of the invention Double-sided copying machine 3 Person making the amendment Relationship to the case Patent Applicant tlI location x residence x name (name) (674) Ricoh Co., Ltd. 4 agent address 2-32-4 Nishi-Shinbashi, Minato-ku, Tokyo Target of Kaji Kogyo Building 3 gI8 Roofing drawing 7, Contents of amendment No. 4 Replace the diagram with the one on the separate sheet.

Claims (2)

[Claims] (1) The transfer paper on which one-sided copying has been completed is ejected one by one from the ejection roller provided above the intermediate tray, and the paper alignment member moves and displaces the transfer paper to a predetermined paper alignment position. In a double-sided copying machine that performs alignment, a transfer paper detection means is provided at a position below the above-mentioned ejection roller and can detect the transfer paper falling away from the ejection roller and onto the intermediate tray. A double-sided copying machine characterized in that the movement of the paper aligning member is controlled by a signal. (2) The paper alignment member includes a side fence that is movable in the width direction along the upper surface of the intermediate tray and aligns the transfer paper at a predetermined position in the width direction, and the transfer paper detection means is arranged on the side fence. The double-sided copying machine according to claim 1, wherein the double-sided copying machine is provided on a side surface.