JP2003095468A - Paper feeder - Google Patents

Abstract

(57) [Abstract] [Problem] To provide a paper feeder which can easily separate and convey paper, and can realize a reduction in size and speed of a motor. In a sheet feeding and transporting apparatus for transporting a plurality of papers while shifting the paper ends thereof by a predetermined distance, first transporting means for transporting the plurality of papers which have been transported in an overlapped manner by a first roller. A second transporting means for transporting the plurality of papers from the first transporting means, and transporting at least one of the plurality of papers with a second roller; First sensor means for indicating that the sheet is being conveyed is provided, and the second conveying means is driven based on a detection signal from the first sensor means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding / conveying device such as a copying machine.

[0002]

2. Description of the Related Art Recently, in the copying machine, there is a strong demand from the market for higher speed and smaller size.

[0003]

However, in order to satisfy the above requirements, for example, the drive motor of the paper transport system must be made faster and smaller, and the load on the motor is becoming larger.

The present invention has been made in view of the above circumstances, and a purpose thereof is to easily separate and convey sheets,
It is an object of the present invention to provide a paper feed / conveyance device capable of realizing downsizing and speed reduction of a motor.

[0005]

In order to achieve the above-mentioned object, the present invention is a sheet feeding and conveying apparatus that conveys a plurality of sheets by stacking them while shifting the paper end portions of the sheets by a predetermined distance. First transporting means for transporting the above-mentioned sheets by the first roller, the plurality of sheets are transported by the first transporting means, and at least one of the plurality of sheets is transported by the second roller. A second conveyance unit and a first sensor unit that indicates that the leading portion of the sheet is conveyed to the second roller are provided, and the second conveyance unit is based on a detection signal from the first sensor unit. It is characterized by being driven.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a diagram for explaining a copying operation of a copying machine equipped with a sheet feeding and conveying device according to the present invention.

In the copying machine shown in FIG. 1, when a print operation is instructed, two sheets of paper stored in the upper paper feed cassette 101 are stacked by the pickup roller 103 with their leading ends displaced by a predetermined distance. Transport roller 10
At the same time, it is conveyed by the rollers 7 and 108 and is conveyed to the pre-separation roller 109. If the paper feed from the lower paper feed cassette 102 is selected, similarly, the paper stored in the lower paper feed cassette 102 is stacked and fed by the pickup roller 104 with the front end of the paper being shifted by a predetermined distance, and then conveyed. Laura 1
05, 106, 107, and 108 are simultaneously conveyed to the separation roller 109.

The two sheets of paper stacked by the pre-separation roller 109 and the separation roller 110 are separated one by one,
At this time, the registration roller 111 is stopped, and the paper is pressed against the registration roller 111 so as to form a loop and then stopped. As a result, the skew of the paper is corrected. In response to the stop, the photosensitive drum 119 is rotated, the photosensitive drum 119 is charged by the primary charging device 112, a latent image of the image to be printed on the photosensitive drum 119 is formed by the laser 113, and the toner is photosensitive drum by the developing device. 119. The registration roller 111 is driven in synchronization with the rotation of the photosensitive drum 119 so that the leading edge of the latent image and the leading edge of the sheet are aligned, and the sheet is conveyed to the photosensitive drum 119. Transfer the toner of to the paper.

Unnecessary toner on the photosensitive drum 119 is removed by the cleaner 116 to prepare for the next latent image. Then, the sheet is sent to the fixing roller 117, the toner is fixed on the sheet, and the sheet on which the toner is fixed is ejected by the sheet ejection roller 118.
Thus, the paper is discharged and the printing operation is completed.

Next, the sheet separation / conveyance of the present invention will be described.

FIG. 2 is a block diagram of roller control relating to sheet separation / conveyance. Reference numeral 200 is a control unit for controlling the entire system, 201 is a roller control unit for controlling each roller, and 20 is a roller control unit.
3, 205, 207 are motors for rotating the pre-separation rollers, 202, 204, 206 are roller control units 201.
From the drive signals from moke 203, 205, 2 respectively
A driver for driving 07, 208, 210, 21
Reference numeral 2 is a sensor for determining the presence or absence of paper.

FIG. 3 shows the structure of each roller, in which the rotational driving force from the motor 301 is directly transmitted to the roller 304, and also transmitted to the roller 305 by the gears 302 and 303, whereby the respective rollers have the same rotation directions but opposite directions. It is driven at a speed and a certain amount of pressure is applied between the rollers, so that the intervening sheets are conveyed at the same speed in their rotational direction without slipping.

Next, the operation of the sheet feeding and conveying apparatus according to the present invention will be described with reference to FIGS. 4 and 5.

FIG. 4 is a diagram for explaining the separation state of the sheets, FIG.
Is a timing chart showing the driving timing of each sensor and each motor. In each sensor, "H" indicates a paper present state, "L" indicates no paper present, and each motor indicates "H" in a driven state and "L". "Indicates a stopped state.

When a paper conveyance instruction is received from the conveyance start signal from the control unit 200, the roller control unit 201 enters a standby state, and when the paper is conveyed and the sensor 208 detects the paper, the motor 203 is driven and before separation. Roller 10
9 is conveyed to the sheet 9 (state in FIG. 4A), the sensor 210
When the sheet is detected by, the moke 205 is driven, the motor 203 is driven until the leading sheet enters the separation roller 110 for a predetermined time (state in FIG. 4B), and the motor 203 stops.

The motor 205 is continuously driven and the sensor 2
A predetermined time from when the leading sheet of the sheet 12 is detected to when the leading edge of the sheet hits the registration roller 111 and forms a light loop is set in advance, and the motor 205 is driven for that period of time. It is stopped (state in FIG. 4C). As a result, it is possible to perform sheet registration and skew feeding.

At the timing when the motor 205 stops, the roller control unit 201 sends a registration-on signal indicating the completion of registration registration to the control unit 200, and the control unit 200 starts the latent image operation at the timing of the signal, and the latent image is formed on the sheet. In order to transfer the image, the timing of the photosensitive drum 119 is measured and a print start signal is sent to the roller control unit 201. Upon receiving the print start signal, the roller control unit 201 drives the motor 205 and the motor 207 immediately to convey the leading sheet to the photosensitive drum 119.

When the sensor 212 indicating that the leading sheet has passed through the separation roller 110 has become "L", the motor 207 is driven for a predetermined time until the leading sheet passes through the registration roller 111, and is stopped after a lapse of time. It The motor 203 is driven at the same timing, the rear sheet is conveyed to the separation roller 110, and the sensor 212 is "H" (paper present state).
From the time when the first sheet is used, the leading sheet is driven for a predetermined time, and is abutted against the registration roller 111 so as to form a loop (state in FIG. 4E).

Then, a registration signal is sent to the control unit 200, the motors 205 and 207 are driven by the print start signal at the next transfer timing, and the rear sheet is sent to the photosensitive drum 119 to perform a series of transfer and fixing operations. Done,
The print operation is completed. Further, when the sensor 212 indicating that the rear sheet is pulled out becomes “L”, the moke 205
Is stopped, and the motor 207 is driven for a predetermined time from the time of becoming "L" until the paper leaves the registration roller 111, and is stopped after a lapse of time.

[0021]

As is apparent from the above description, according to the present invention, in the sheet feeding and conveying device that conveys the plurality of sheets in a stacked manner by shifting the paper end portions of the plurality of sheets by a predetermined distance, the plurality of sheets that have been superposed are sent. First conveying means for conveying the sheets of paper by the first roller and the plurality of sheets of paper are conveyed from the first conveying means, and at least one of the plurality of sheets of paper is conveyed by the second roller. A second conveying unit and a first sensor unit that indicates that the leading portion of the sheet is conveyed to the second roller are provided.
Since the second conveying means is driven based on the detection signal from the first sensor means, the paper can be easily separated and conveyed, and the motor can be downsized and the speed can be reduced. can get.

[Brief description of drawings]

FIG. 1 is a block diagram showing a printing process of a copying machine provided with a paper feeding and conveying device according to the present invention.

FIG. 2 is a block diagram showing a configuration of a roller control system of the sheet feeding / conveying device according to the present invention.

FIG. 3 is a roller configuration diagram of a sheet feeding and conveying device according to the present invention.

FIG. 4 is a diagram illustrating a separated state of sheets.

FIG. 5 is a timing chart showing the drive timing of each sensor and each motor in the paper feeding and conveying apparatus according to the present invention.

[Explanation of symbols]

109 Roller before separation 110 separation roller 111 cash register 201 Roller controller 203, 205, 207 Motor 208, 210, 212 Paper detection sensor

Continued front page    F term (reference) 2H072 AA03 AA13 AA14 AA24 AA29                       AB04 AB07 CA01 CB09                 3F048 AA02 AB01 BA05 BB02 CC03                       CC07 CC17 DA06 DA07 EB15                       EB16 EB24 EB30                 3F049 AA01 CA00 DA12 EA23 EA24                       EA27 LA02 LB03                 3F101 LA02 LB03                 3F343 FA02 FB02 FC01 FC03 JD04                       JD09 JD34 JD40 KB05 KB17                       KB20

Claims (5)

[Claims] 1. A paper feeding / conveying device that conveys a plurality of papers by stacking them by shifting a paper end portion of the papers by a predetermined distance, and first conveys the plurality of papers that have been superposed by a first roller. A conveying unit, a second conveying unit that conveys the plurality of sheets from the first conveying unit, and conveys at least one of the plurality of sheets by a second roller; and a sheet leading end on the second roller. First indicating that a unit is being transported
2. A sheet feeding and conveying apparatus, characterized in that the sensor means is provided, and the second conveying means is driven based on a detection signal from the first sensor means. 2. The sheet feeding / conveying apparatus according to claim 1, wherein the first conveying means is stopped based on a detection signal from the first sensor means. 3. A second sheet indicating that the sheet has been conveyed by the second conveying means and the sheet has come out of the second roller.
2. The sheet feeding / conveying apparatus according to claim 1, wherein said sensor means is provided, and said first conveying means is driven based on a detection signal from said second sensor means. 4. The sheet feeding / conveying apparatus according to claim 3, wherein the first conveying unit is stopped after a predetermined period of time has elapsed since the detection signal from the second sensor unit was input. 5. A length of paper in the carrying direction is A, and a shift amount of papers fed in a stack in the carrying direction is B.
2. The sheet feeding / conveying apparatus according to claim 1, wherein the first and second inter-roller distances L are set so that AB <L <A, where L is the distance between the rollers.