JPH06156772A - Paper feeding device - Google Patents

Abstract

PURPOSE:To improve the reliability and economic efficiency of the paper feed control by simplifying the transport control for a recording paper sheet, as for a paper feeding device having a plurality of paper feeding parts. CONSTITUTION:A paper feeding device equipped with a plurality of paper feeding trays 121, 122, and 123 is equipped with a single transport passage 128 for all the recording paper sheets supplied from the paper feeding trays 121-123, paper detecting sensor 132 which is arranged in the transport passage 128 and detects the passing of the recording paper sheets, and an MPU 304 for executing the paper transport control on the basis of the detection signal supplied from the paper detecting sensor 132.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device used in an image processing apparatus such as a copying machine, a facsimile machine, a printer, etc. The present invention relates to a sheet feeding device in which a single sheet detection unit is provided in the conveyance path and the overall sheet feed timing control is executed based on the detection signal of the sheet detection unit.

[0002]

2. Description of the Related Art Generally, when a paper feeding device used in a copying machine, a page printer, or the like is provided with a plurality of paper feeding units, the conveyance paths from the paper feeding units to the registration roller units are independent from each other. It has become.

Further, as an apparatus having a conventional paper feeding means related to the present invention, firstly, Japanese Patent Laid-Open No. 59-121068.
There is an "image processing device" disclosed in the publication. This is done by connecting a plurality of image processing devices that can be used independently, prohibiting the operation of the paper feed rollers of units other than the specific unit, and supplying the mixing signal used for timing adjustment from the preceding unit. It is designed to facilitate the paper operation, and each paper feed unit has an independent structure.

Secondly, there is a "paper leading edge resist control system" disclosed in Japanese Patent Laid-Open No. 62-255357.
This is after detecting the leading edge of the fed paper with the registration sensor,
By setting the predetermined time for stopping the feeding for each of the plurality of feeding paths to be different, the abutting of the leading edge of the paper at the registration roller and the amount of deflection are optimally set, and the conveyance path to the registration roller is set. And a paper detection sensor are provided in the paper feed section.

[0005]

However, in the conventional paper feeding device as described above, when the paper feeding path to the registration roller and the paper detection sensor are provided corresponding to the paper feeding portions, respectively, When each paper feed unit executes the paper feed control of the recording paper at the same time, each paper feed unit monitors the recording paper with a different paper detection sensor, so the paper detection logic of each paper detection sensor is grasped. (One of the paper detection sensors must detect the recording paper, but the other paper detection sensor must not detect the recording paper). However, as a result, there is a problem that the control program becomes complicated and the cost becomes high.

Further, in the "image processing device" of Japanese Patent Laid-Open No. 59-121068, since the paper feed units are independently configured, the control between the paper feed units becomes more complicated. At the same time, there was a problem in high-speed paper feeding.

The present invention has been made in view of the above, and simplifies the control of recording paper conveyance in a paper feeding apparatus having a plurality of paper feeding units, and improves the reliability and economic efficiency of the paper feeding control. With the goal.

[0008]

In order to achieve the above-mentioned object, the present invention provides a paper feeding apparatus having a plurality of paper feeding means, in which all the recording papers fed from the respective paper feeding means are shared. And a paper feed control unit that is disposed in the transport path and detects the passage of the recording paper, and a paper feed control unit that executes the paper feed transport control based on a detection signal from the paper detection unit. A paper feeding device is provided.

Further, the paper feed control means, after the paper detection means detects the leading edge of the recording paper, determines the size of the recording paper to be fed and the path length from the entrance of the paper feed means to the paper detection means. Based on this, it is desirable to control the paper feed timing of the next recording paper.

Further, it is desirable that the paper feed timing corresponding to the path length from the entrance of each paper feed means to the paper detection means be different for each paper feed means.

Further, it is desirable that the sheet feeding timing of each of the sheet feeding means can be arbitrarily changed for each recording sheet size.

Further, it is desirable that the paper detecting means is arranged at a distance from the entrance of each of the paper feeding means that is shorter than a minimum size that each of the paper feeding means can carry.

[0013]

In the paper feeding apparatus according to the present invention, the paper feeding path is constructed so that the paper fed from the plurality of paper feeding means is carried by a single path, and the single paper detecting means provided in the paper feeding path. Detects the leading edge of the paper fed from each paper feeding means,
Based on the detection signal, the paper feed controller executes paper feed / conveyance control.

After the paper detecting means detects the leading edge of the paper,
The paper feed timing of the next paper to be fed is controlled based on the length of the paper to be fed in the feed direction and the feed length from the entrance of the paper feed means to the paper detection means. Further, at this time, the timing of the paper feed / transport control is arbitrarily changed for each transport length or each paper size to optimize the inter-sheet control.

Further, the paper detection means is arranged at a distance from the entrance of each paper feed means shorter than the minimum size which each paper feed means can carry, so as to correspond to the shortest paper feed timing.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an explanatory diagram showing a schematic configuration of a laser printer to which a sheet feeding device according to the present invention is applied. In the figure, the laser printer is a printer engine unit 100.
The sheet feeding section 120 and the reverse sheet discharging section 140 are configured to be large. Further, the printer engine unit 100 is composed of a laser optical system 101, an image forming system 102, a fixing unit 103 and the like.

As is well known, the laser optical system 101 is a box-shaped unit in which a semiconductor laser, a scanner motor, a polygon mirror, a cylindrical lens, an fθ lens, a mirror and the like (all not shown) are arranged at predetermined positions.

The image forming system 102 is composed of the following functional parts and units based on the electrophotographic process. Reference numeral 105 denotes a photosensitive drum that forms an electrostatic latent image, 10
6 is a registration roller that conveys the recording paper to the transfer portion while keeping timing with the image formed on the photoconductor drum 105, 107 is a charger that uniformly corona-discharges the surface of the photoconductor drum 105, and 108 is toner. Is a developing unit that performs development processing using the developing roller 108a in the developing process, and the developing roller 108a is configured to be able to apply a predetermined developing bias based on the developing process. Further, 109 is a transfer charger that executes the transfer process by corona discharge, 110 is a separation charger that executes the separation process by corona discharge, and 111 is a cleaning unit that cleans the residual toner on the surface of the photosensitive drum 105.

Further, the fixing unit 103 has a fixing heater built therein, the surface thereof is made of a heat-resistant and mold-releasing material, and the fixing roller 1 is rotated under the control of a predetermined temperature condition.
12 and a pressure roller 113 that rotates in a state of being biased with a predetermined pressure while facing the fixing roller 112. Further, reference numeral 114 is a paper discharge roller that conveys the recording paper after the fixing processing by the fixing unit 103.

Further, the paper feeding unit 120 is a large-scale paper feeding device for suspending and mounting a first paper feeding tray 121 and a second paper feeding tray 122 arranged side by side on a printer body and accommodating a large amount of recording paper. It is composed of the tray 123. Further, paper feed rollers (pickup rollers) 125, 12 for feeding the recording papers set at the uppermost entrances of the first paper feed tray 121, the second paper feed tray 122, and the mass paper feed tray 123.
6, and 127, respectively, and further, the first paper feed tray 12
1, second paper feed tray 122, and large-volume paper feed unit 12
A transport path 128 for transporting the recording paper fed from No. 3 in the direction of the registration roller 106 is configured so as to merge with each paper feed unit to form a single transport path. Further, 129, 130, and 131 are conveying rollers provided on the path of the conveying path 128, 132 are provided near the confluence of the conveying path 128, and the passage of the recording paper is optically performed by using, for example, a reflection sensor or the like. It is a paper detection sensor for detecting.

Further, the reversal sheet discharge section 140 is located above the printer engine section 100, and is composed of a conveyance path 150, conveyance rollers 141 and 142 and the like.

The basic operation of the laser printer configured as described above will be described. The laser beam modulated according to the written image data is scanned by a polygon mirror that rotates at a high speed and a constant speed, and is irradiated onto the photosensitive drum 105. On the other hand, prior to this, since the surface of the photosensitive drum 105 is uniformly charged by the charging charger 107, an electrostatic latent image corresponding to the image data is formed due to the potential distribution. The formed electrostatic latent image is visualized by the toner adhering action of the developing roller 108a of the developing unit 108.

First paper feed tray 121, second paper feed tray 1
The recording paper fed from either 22 or the large-volume paper feed tray 123 passes through the conveyance path 128 and the registration roller 1
The slant feed correction (skew correction) is performed by being abutted against 06 and temporarily stopped in a state where slack is formed by excessive feed. Next, the registration roller 106 is restarted by turning on an electromagnetic clutch (not shown) at the timing of aligning with the toner image formed on the photosensitive drum 105, and conveys the recording paper to the transfer portion. . The image information formed on the photoconductor drum 105 is transferred to this recording paper by the corona discharge of the transfer charger 109.

After that, the recording paper is separated from the photosensitive drum 105 by the separation charger 110. Further, the recording paper on which the toner image is transferred is sent to the nip between the fixing roller 112 and the pressure roller 113, which are controlled at a predetermined temperature, and is subjected to the fixing process, and then the reverse discharging unit 140 is discharged by the discharging roller 114. The sheet is conveyed to the side, the recording surface is made to face downward by the reversing sheet discharging unit 140, and the sheets are discharged to the outside of the machine in page order.
In addition, the photosensitive drum 105 after the transfer processing removes and collects the residual toner by the cleaning unit 111,
It stands by until the next image processing command is issued.

Next, the operation of the paper feeding section 120 will be described in more detail. FIG. 2 illustrates a paper feed unit 120 according to the present invention.
It is explanatory drawing which shows the conveyance path. In the figure, L1 is a transport distance from the sheet feed roller 127 of the large-volume feed tray 123 to the sheet detection sensor 132 (hereinafter, referred to as a transport path), L
Reference numeral 2 denotes a conveyance path from the paper feed roller 125 of the first paper feed tray 121 to the paper detection sensor 132, and L3 denotes a conveyance path from the paper feed roller 126 of the second paper feed tray 122 to the paper detection sensor 132. .

Further, FIG. 3 shows a paper feeding unit 120 according to the present invention.
3 is a block diagram showing a configuration of a control system of a printer engine unit 150. FIG. In the figure, the printer engine unit 10
0 according to the present invention mainly includes an MPU (microprocessing unit) 301 that controls the entire printer engine unit 100 of 301, and an I / F that connects the MPU 301 of 302 and the sheet feeding unit 120.

The control system of the paper feeding unit 120 is an I / F 303 connected to the I / F 302 on the printer engine 100 side by a handshake line, and an MPU 304 for controlling the entire paper feeding unit 120 based on a control program.
And a ROM 305 that stores a control program,
RAM 306 for storing processing results of MPU 304
A motor driver 307, a motor 308, and a clutch (for example, an electromagnetic clutch) 309 that intermittently transmits the rotation of the motor 308 at the instruction timing of the MPU 304.

The paper feed operation timing in the above configuration will be described with respect to the following items. (1) Continuous paper feed operation timing from the same tray (2) Continuous paper feed operation timing from different trays

(1) Continuous Paper Feeding Operation Timing from the Same Tray Here, a case where recording paper is continuously fed from the large-volume paper feeding tray 123 will be described. Printer engine unit 100
The paper feed command from the MPU 301 in (1) is input from the I / F 302 to the MPU 304 of the paper feed unit 120 via the I / F 303. The MPU 304 outputs a control signal to the motor driver 307 and the clutch 309 based on the paper feed command. As a result, the paper feed roller 127 is moved to the motor driver 3
The motor 308 controlled by 07 rotates and is driven in conjunction with the clutch 309. In this way, the uppermost one sheet of the recording sheets stacked in the large-volume sheet feeding tray 123 is sent to the transport path 128 by the rotation of the sheet feeding roller 127. At this time, the paper detection sensor 132 detects the leading edge of the fed recording paper and outputs the detection signal to the MPU 304. Based on the detection signal, the MPU 304 calculates the paper feed timing (paper interval control) of the next recording paper.

For example, the required sheet interval is C1, the sheet feeding linear velocity is F
1, assuming that the paper length is P1 and the transport path is L1, the next paper feed timing T1 after the detection of the leading edge of the recording paper by the paper detection sensor 132 is obtained by an equation.

T1 = C1 + (P1-L1) / F1 ...

Further, in the above, the sheet interval C1, the conveying path L1, and the sheet feeding linear velocity F1 are fixed values, respectively, and only the sheet length P1 is a variable value. That is, the paper length P1 differs depending on the size of the recording paper to be stacked. Therefore, MPU30
4 reads the data of the paper length P1 from the RAM 306, and from the fixed values in the ROM 305, the paper feed timing T1.
To perform paper feed control. It should be noted that the paper interval C1 is set to an appropriate value R depending on each paper tray or recording paper size
It is preset in the OM 305 and stored. At the sheet feeding timing T1, the next sheet feeding operation is started after reading the constant period signal from the sheet detection sensor 132.

(2) Timing of Continuous Paper Feeding from Different Tray Next, as the timing of continuous paper feeding from different trays, for example, after feeding paper from the first paper feed tray 121,
A case of feeding paper from the second paper feed tray 122 will be described. In the same manner as above, the first paper feed tray 12
The uppermost one of the recording sheets stacked in 1 is fed out by the rotation of the sheet feeding roller 125. Paper detection sensor 1
32 detects the leading edge of the fed recording paper, and the MPU 3
A detection signal is output to 04. MP based on the detection signal
U304 calculates the paper feed timing (paper interval control) of the next recording paper.

For example, the second paper feed tray 122 is far from the paper detection sensor 132 with respect to the first paper feed tray 121. Therefore, the trailing edge of the recording paper is the first paper feed tray 121.
Immediately after exiting from the control, the control for enabling the second paper feed tray 122 to perform the paper feed timing is executed.

In this case, the sheet interval C2 is unnecessary, and if the sheet feeding linear velocity of the second sheet feeding tray 122 is F2, the sheet length is P2, and the transport path is L2, the recording sheet leading edge detection by the sheet detection sensor 132 is performed. After that, the next paper feed timing T2 is obtained by an equation.

T2 = (P2-L2) / F2 ...

Further, similarly to the above, the transport path L2, the second
The feeding linear velocity F2 of the feeding tray 122 is a fixed value, and only the paper length P2 is a variable value.
Is the data of the paper length P2 in the RAM 30 in the MPU 304.
6 is read out, and calculation is performed from each fixed value in the ROM 305. Then, after the constant signal from the paper detection sensor 132 is also read at the paper feed timing T2 as described above, the paper feed from the second paper feed tray 122 is started. At this time, if the paper interval is required, the optimum value for the paper feeding unit 120 and the paper size is set in the ROM 305 in advance as described above.

By executing such a configuration and control, it is possible to randomly switch the paper feed ports in continuous paper feed from different paper feed trays or to continuously feed paper from the same paper feed port. However, the single paper detection sensor 13
It is possible to efficiently execute the paper feed control by the detection signal from 2.

The paper detection sensor 132 is attached at a shorter distance from the entrance of each paper feed tray with respect to the shortest paper size that can be carried in the carrying direction. The reason for this will be explained. In continuous sheet feeding in the same sheet feeding tray, when the sheet detection sensor 132 detects the leading edge of the recording sheet when the sheet interval is set to 0 mm, the trailing edge of the recording sheet is the inlet of the sheet feeding tray. Will pass through. Therefore, when the next recording paper is tried to be fed, the paper gap is already opened and the paper gap cannot be 0 mm. In order to deal with such a defect, the paper detection sensor 13
2 must be installed in the above position.

[0040]

As described above, the paper feeding device according to the present invention constitutes a common carrying path for carrying the recording papers fed from the plurality of paper feeding means, and is provided on the carrying path. Since the paper detection means detects the leading edge of the paper fed from each paper feeding means and the paper feeding control means executes the paper feeding / conveying control based on the detection signal, the paper feeding having a plurality of paper feeding parts This simplifies the paper transport control in the machine and improves the reliability and economy of paper feed control.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of a laser printer to which a sheet feeding device according to the present invention is applied.

FIG. 2 is an explanatory diagram showing a transport path of a sheet feeding unit according to the present invention.

FIG. 3 is a block diagram showing a schematic configuration of a control system of a paper feed unit and a printer engine unit according to the present invention.

[Explanation of symbols]

120 Paper Feeding Section 121 First Paper Feeding Tray 122 Second Paper Feeding Tray 123 Large Paper Feeding Tray 128 Conveying Path 132 Paper Detecting Sensor 304 MPU 305 ROM 306 RAM

Claims (5)

[Claims] 1. A paper feeding device having a plurality of paper feeding means, wherein a conveyance path shared by all the recording papers fed from the respective paper feeding means, and a conveyance path arranged so as to pass the recording papers. A sheet feeding device comprising: a sheet detecting unit that detects the sheet; and a sheet feeding control unit that executes sheet feeding control based on a detection signal from the sheet detecting unit. 2. The paper feed control means, after the paper detection means detects the leading edge of the recording paper, the size of the recording paper to be fed and the path length from the entrance of the paper feed means to the paper detection means. 2. The paper feeding device according to claim 1, wherein the paper feeding timing of the next recording paper to be fed is controlled based on this. 3. The paper feed according to claim 2, wherein the paper feed timing corresponding to the path length from the entrance of each paper feed means to the paper detection means is different for each paper feed means. apparatus. 4. The sheet feeding device according to claim 2, wherein the sheet feeding timing of each sheet feeding unit can be arbitrarily changed for each recording sheet size. 5. The paper detecting means is arranged at a distance from an entrance of each paper feeding means shorter than a minimum size that each paper feeding means can carry.
The paper feeder described.