JPS6132220B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a feeding control device for a sheet feeding device that feeds a plurality of sheets stacked on a sheet loading table one by one.

As this type of sheet feeding control device, for example, Japanese Patent Application Laid-open No. 48-78941 (Japanese Patent Publication No. 56-51344)
There is something written in. This publication describes in detail the case where the sheet feeding control device is used in a copying machine. According to this sheet feeding control device, a detection means is provided for detecting when the number of sheets on the sheet loading table, for example, paper on the paper feeding tray, has decreased to a predetermined remaining number, and the detection means detects when the number of sheets on the sheet loading table, for example, paper on the paper feeding table, has decreased to a predetermined remaining number. During the previous copying operation that occurred prior to
When this detection means detects that the number of papers on the paper feed tray has decreased to a predetermined remaining number, the subsequent copying operation is prohibited unless paper is replenished. On the other hand, once paper feeding has started, if the above-mentioned detection means detects that the number of remaining papers has decreased to the predetermined number while continuing paper feeding, paper feeding will continue until the paper runs out regardless of the detection result. continue.

According to this conventional sheet feeding control device, as long as paper feeding continues, paper feeding continues until all of the plurality of sheets on the paper feeding tray are used up. However, in general paper feeding work, when the number of remaining papers on the paper feeding tray decreases to a small number of sheets, for example around 10 to 15, some or all of those remaining papers are In many cases, paper is fed repeatedly, that is, double feeding occurs, and paper feeding becomes unstable. In this case, smooth continuous paper feeding may not be possible, and there is a risk of causing a so-called jam.

In view of the above points, it is an object of the present invention to provide a sheet feeding control device that can prevent double feeding, jams, etc., and achieve smooth and stable sheet feeding.

This purpose includes a detection means for detecting that the number of sheets on the sheet mounting table has decreased to a predetermined remaining number;
When this detection means detects that the number of sheets on the sheet mounting table has decreased to a predetermined remaining number,
This is achieved by providing a control means for stopping the feeding of sheets from the sheet mounting table.

The present invention will be explained below using examples.

FIG. 1 is a schematic diagram of a plurality of sheet loading stands, such as a paper feed stand, in a copying machine to which the present invention is applied, and shows a case where there are three paper feed stands in the case of a copying machine. .

In FIG. 1, 1, 2, and 3 indicate first, second, and third paper feed trays, and 4 indicates a double-sided tray, respectively. Sheets of different or the same size, such as transfer paper 16, are stacked on the first, second and third paper feed trays 1, 2 and 3.

On the other hand, reference numeral 5 denotes a photoreceptor drum, which is called and used to transport the transfer paper 16 on the paper feed table between the transfer charger section that transfers the electrostatic image on the photoreceptor drum 5 and the photoreceptor drum 5. rollers 6-1, 6-2 and 6-3, separation roller pairs 7-1 and 7-2,
7-3 and 7-4, 7-5 and 7-6, 7-
7 and 7-8, feed roller pair 8-1, 8-
2, 8-3 and 8-4, diagonal rollers 9 and 1
0, the registration rollers 11 are arranged in this order, and if the selected paper feed tray is the second paper feed tray 2, the calling roller 6-2 rotates and moves to the second paper feed tray. The upper transfer paper is picked up one by one by the calling roller 6.
-2 and passes between the pair of separation rollers 7-3 and 7-4, and the pair of delivery rollers 8-2 and 8-2.
-1, is conveyed by diagonal rollers 9 and 10, and registration rollers 11, and is conveyed to the transfer charger section.

Further, the transfer sheet on which the electrostatic image has been transferred in the transfer charger section is conveyed by a conveyor belt 12, and is further discharged through a fixing roller 13 to a sheet discharge unit 14 where the image is fixed. Note that when double-sided transfer is performed, the paper is discharged to the double-sided tray 4, and after being transferred and fixed again in the same manner as described above, the paper is discharged to the paper discharge unit 14. 15 is a paper discharge tray.

On the other hand, taking the first paper feed tray as an example, as shown in FIG. The paper feed tray 1 is configured to move up and down. Further, a detection fitting 26 is fixed to the other end of the arm 23 which is swingably provided around one end,
One end of the detection fitting 26 is in contact with the top surface of the transfer paper 16 on the paper feed table, the other end is opposed to the height detection micro switch 29, and the top surface of the transfer paper 16 is in contact with the calling roller 6-1. When pressed, the other end of the detection metal fitting 26 hits the height detection micro switch 29, and the height detection micro switch 29 is turned on. Therefore, by raising and lowering the paper feed tray 1 by the motor 17, the transfer paper 1 on the paper feed tray 1 is moved up and down.
6 is maintained in pressure contact with the calling roller 6-1.

An actuator 32 is fixed to the paper feed tray 1, and when there are 10 to 15 sheets of transfer paper on the paper feed tray 1, the top of the transfer paper 16 is connected to the calling roller 6-1. A near-end detection microswitch 35 serving as a first detection means is arranged so as to be turned on by an actuator 32 when the paper feed table rises to the abutting position. moreover,
A transfer paper presence/absence detection sensor 38 serving as a second detection means for detecting the presence or absence of the transfer paper 16 is fixed to the detection fitting 26 .

As shown in FIG.
A phototransistor 44 receives the reflected light, and a light-absorbing paint is coated on the paper feed table 1, and the transfer paper 16
When there is no transfer paper, the amount of light reflected from the light emitting element 41 decreases, and the phototransistor 44 is not sensitive, and the absence of the transfer paper is detected.

The above description has been made using the first paper feed tray 1 as an example, but the same applies to the second and third paper feed trays 2 and 3, and in FIGS. 2 and 3 ( )
Each motor, sensor, micro switch, etc. shown in the figure is provided.

a motor 17 that drives the paper feed trays 1, 2, and 3;
18, 19 and the control circuit of the main motor 47 is the fourth
It is configured as shown in the figure. Motor 17, 18, 19
is a reversible motor, and solid state relays SSR1-1, SSR2-1, SSR3 are connected to its forward rotation terminals.
Solid state relay SSR with -1 as reverse side terminal
Connect 1-2, SSR2-2, and SSR3-2, respectively, and connect solid state relays SSR1-1 and SSR2.
-1, SSR3-1 input terminals 1-1, 2-1, 3
By giving input to −1, forward rotation and
Solid state relay SSR1-2, SSR2-
2, SSR3-2 input terminal 1-2, 2-2, 3-
The motor 47 is a main motor and is connected to rotate in the normal direction by applying an input to input terminals 0-1 of the solid state relay SSR0. Note that C0,
C1, C2, and C3 are starting capacitors.

Next, a case will be described in which paper feeding is controlled by a microcomputer system using each of the above-mentioned detection signals and control signals. This microcomputer system acts as a control means for controlling the feeding of transfer paper.

FIG. 5 shows a block diagram of this microcomputer system. A central processor unit (hereinafter referred to as CPU) 48, a read-only storage device (hereinafter referred to as ROM) 49, a readable/writable storage device (hereinafter referred to as RMM) 50,
A first computer system composed of an input/output interface adapter (hereinafter referred to as IOA) 51 is responsible for executing sequence control of the copying machine, and includes a CPU 53, a ROM 54, a RAM 55,
A second computer system configured with the IOA 56 shares control of data input/output of the copying machine. A multiprocess system is necessary for the following reasons. In other words, when it becomes high-speed and multi-functional, one
The CPU may not be able to keep up with the load due to the heavy load. This is because distributing tasks is more efficient and improves the reliability of the entire system.

Reference numeral 52 indicates a system bus line of the first computer system, and reference numeral 57 indicates a system bus line of the second computer system. An OR gate 58 receives the outputs of the IOAs 51 and 56, and the output of the OR gate 58 connects the system bus lines 52 and 57. Independent bus line switching device 5
It has 9.

The programs stored in the first and second computer system ROMs 49 and 54 are sequentially executed. RAM50,55 is IOA48,56
The signal data input from CPU4 is input.
8 and 53 process data in RAMs 50 and 55 as operands of instructions. Furthermore, the system bus lines 52 and 57 can be disconnected or connected as necessary to allow the CPU to operate without restrictions. System bus lines 52 and 57 are typically separate and independent and act as dedicated system bus lines for the first and second computer systems. and IOA5 when transferring data across first and second computer systems.
1 and 56 actuate the OR gate 58 to connect the system bus lines 52 and 57 by the bus line switching device 59 and use them as a common bus line for the first and second computer systems. In this case, one of the CPUs 48 or 53 is placed in a stopped state to prevent contention between the CPUs 48 and 53. Furthermore, when the data transfer is completed, the system bus line 52 is returned to its original state.
The connection between the and
It is acknowledged by the polarity of the output signal of IOA 51 or 56.

FIG. 6 shows input/output signals between the IOAs 51 and 56 when a programmable peripheral interface adapter such as Intel's 8255 is used for the IOAs 51 and 56. Programmable peripheral interface
The 8255 has three 8-bit input/output ports, A, B, and C, and has a function that allows programmable operation of the A, B, and C input/output ports by controlling signals sent from the CPU, ie, programs. There is.

FIG. 6a shows the input signal of the IOA 51. The signal input to the IOA 51 is the signal a1 of the height detection microswitches 29, 30 and 31 of the transfer paper 16 on the first, second and third paper feed tables.
0, a13 and b10, as well as signals a11, a of the transfer paper presence/absence detection sensors 38, 39 and 40.
14 and b11, near-end detection micro switches 35, 36, and 37 signals a12, a1
5 and b12, transfer paper presence/absence signals b13 and b14 for the double-sided tray, selection commands for the first, second and third paper feed trays 1, 2 and 3, non-selection commands c1
0, c11, c12, c13, c14 and c1
It is 5.

FIG. 6b shows a portion of the output signal from IOA 56. Output signals from the IOA 56 drive the motors 17,
Forward rotation signals a20, a22, a of 18 and 19
24, reverse rotation signals a21, a23, a25, and forward rotation signal a26 of the main motor 47. The forward rotation signal and reverse rotation signal are input to the corresponding solid state relays in FIG. 4, respectively.

Further, FIG. 7 is a diagram showing input/output signals of other IOAs connected to the system bus line 57. Ports 0 to 6 of this IOA are numerical decoding terminals a of the 7-segment numerical display tube LED0 to LED5, respectively.
Transistor amplifier u with Darlington connection to ~g
Connected through 0~u6, ports 7~12 of IOA are respectively 7 segment numeric display tube LED0~LED
The 7-segment numerical display tubes LED0 to LED2 display the 3-digit number of copies, and the 7-segment numerical display tubes LED3 to
The LED 5 is arranged to display the number of copies to be processed in 3 digits. On the other hand, the number of copies can be set by using the extension line of the number decoding terminals a to d of the 7-segment number display tube.
Key switches SW0 to SW9 are connected in a matrix to the input line of port c, and the key switches SW0 to SW9 perform the operation. key switch
The states of SW0 to SW9 are read into the CPU and displayed on the 7-segment numerical display tubes LED0 to LED2. The number of copies to be made is determined by subtracting the set number of copies from the set number of copies by providing a microswitch that is activated by the passage of the transfer paper past the fixing roller, and inputting the output of this microswitch to the CPU. You can get it by going.

Next, FIG. 8 shows a flowchart of paper feeding control performed by this computer system.

Also, before starting copying, the operator selects from which paper feed table the transfer paper is to be fed. A slider that comes into contact with the side of the transfer paper when stacked on the paper feed tray is fixed, and the signal of this slider position is displayed as the size of the transfer paper stacked on the paper feed tray, and at the same time the computer system has been input into the storage device. According to the selection of the paper feed tray, the selection signal of the selected paper feed tray is input to the corresponding port of the c port of the IOA 51. For example, when the first paper feed tray 1 is selected, the signal c10 is inputted. . Therefore, the normal rotation signal a20 of the motor 17 is output, the motor 17 rotates in the normal direction, and the normal rotation continues until the height detection signal a10 of the first paper feed tray 1 is input, and from then on, the copies specified by the number of copies are made. The motor 17 rotates forward as the transfer paper 16 decreases from the paper feed tray 1 until the transfer paper 16 is lowered from the paper feed tray 1 to raise the first paper feed tray 1, and the height detection signal a10 of the first sheet feed tray 1 is inputted. maintained so that This means that during that period, the uppermost surface of the transfer paper on the paper feed tray 1 is in pressure contact with the pick-up roller 6-1, and that the paper continues to be sequentially fed.

Next, the required number of copies is set in step 2.
This is done by switches SW0 to SW9 in FIG.

Then, in step 3, the copy start button is pressed to start copying. For example, when calling the transfer paper 16, the clutch of the calling roller 6-1 is engaged and the calling roller 6-1 starts rotating. Thereupon, the transfer sheets 16 on the paper feed tray 1 are retrieved one by one, transferred, fixed, and copied. While copying is being performed, the uppermost surface of the transfer paper on the paper feed table 1 is raised by the motor 17 in proportion to the amount of transfer paper consumed by the paper feed table 1, as described above, and held at a predetermined position. ing.

If there is still enough transfer paper 16 on the paper feed table 1, copying is repeated until the number of copies to be processed n0 and the set number of copies n1 are equal, and in step 15, n1=n0 is detected and the copying is completed. finish.

However, there is not much remaining transfer paper 16 on the paper feed tray 1, and the near-end detection micro switch 35 is activated during copying, and when the A port signal a12 of the IOA 51 is input, the process starts at step 7.
In step 8, the remaining number of copies n1 = n0 is compared with the number of copies released when the near-end micro switch 35 is activated (near-end number of copies), which is 10 to 15 in the case of this embodiment, and in step 8 it is determined that n1 = n0 < 10. to judge. Here, when n1=n0<10, the copying machine continues to operate by feeding paper from paper feed tray 1. young
When n1=n010, another paper feed tray, for example, the second paper feed tray 2, is selected in step 9, and the process is performed in step 10.
In this step, it is determined whether the size of the transfer paper on the second paper feed tray 2 is the same as the size of the transfer paper on the first paper feed tray that is currently being copied. Therefore, if the sizes of both transfer sheets are the same, the paper feed table is switched. The motor 18 is activated by this switching signal from the paper feed tray.
The uppermost surface of the transfer paper on the paper feed tray 2 rises to a position where it comes into contact with the calling roller 6-2, paper feeding is started, and the paper continues to be fed from the paper feed tray 2 to perform copying.

Furthermore, if the size of the transfer paper on the second paper feed tray 2 is different from the size of the transfer paper on the first paper feed tray 1 in step 10, the third paper feed tray is selected in step 11. Then, in step 12, step
As in case 10, it is determined whether the sizes of the transfer sheets on the first paper feed tray 1 and the third paper feed tray 3 are the same. If the size of the transfer paper is the same, the transfer paper is switched to the third paper feed tray 3 and the transfer paper is fed from the third paper feed tray 3 in the same manner as in the case of the second paper feed tray. Also the third
The size of the transfer paper on the paper feed tray 3 is the same as that of the first paper feed tray 1.
If the size of the transfer paper is different from that of the transfer paper, step 13 indicates that there is no paper, and the process proceeds to step 14. Copying continues until all of the transfer paper remaining on 1 has been fed, and when all of the transfer paper has been fed, the transfer paper presence/absence detection sensor 38 activates and inputs the fact that there is no more transfer paper to the A port of the IOA 51. Input as signal a11. Then, in step 6, it is determined that there is no paper, and the copying machine is stopped.

Note that although the above explanation is for the case where there are three paper feed trays, the same applies to cases where there are other than three paper feed trays. Furthermore, in addition to using a microcomputer, it is of course possible to use a device having each function independently.

According to this embodiment, when the near-end detection microswitch detects that the paper on the paper feed tray has decreased to a predetermined remaining number, the paper feed tray on which the paper feed operation should be performed is moved to another paper feed tray. Switching. In other words, feeding of paper is stopped for a paper feed tray in which the number of remaining papers has decreased to a predetermined number. This avoids paper feeding instability that tends to occur when feeding remaining paper.

As is clear from the above description, according to the present invention, feeding of sheets on the sheet mounting table is stopped after leaving a predetermined number of remaining sheets, so that instability in sheet feeding such as double feeding and jams can be eliminated.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the structure of a copy paper feed tray of a copying machine to which the present invention is applied, Fig. 2 is a schematic diagram showing the mechanism of the paper feed tray and the relationship between each switch and sensor, and Fig. 3 is a transfer An explanatory diagram of the paper presence/absence detection sensor, Fig. 4 is a circuit diagram of the motor control circuit, Fig. 5 is a block diagram of an embodiment of the microcomputer system used for feeding control of the present invention, and Figs. 6 a and b. 7 is a diagram showing input and output signals of the IOA of the system of FIG. 5, and FIG. 8 is a flowchart of paper feed control performed by the microcomputer system of FIG. 5. 1, 2, 3... Sheet loading table (paper feeding table), 16
... Sheet (transfer paper), 17, 18, 19 ... Motor, 20, 21, 23 ... Belt for raising and lowering paper feed table, 29, 30, 31 ... Micro switch for height detection, 35, 36, 37 ...First detection means (near-end detection microswitch), 38, 39,
40...Second detection means (transfer paper presence detection sensor), SSR1-1 to SSR3-2, SSR0...Solid state relay, 48, 53...CPU, 4
9,54...ROM, 50,55...RAM, 5
1,56...IOA, 52,57...System bus line, u0~u12...Amplifier, LED0~
LED5...7 segment numeric display tube, SW0~
SW9...Key switch (numeric keypad).

Claims (1)

[Scope of Claims] 1. In a feeding control device for a sheet feeding device that feeds a plurality of sheets stacked on a sheet loading table one by one, the number of sheets on the sheet loading table is reduced to a predetermined remaining number. first detection means 35, 3 for detecting that
6, 37, and a control means for stopping the feeding of sheets from the sheet placing table when the first detecting means detects that the number of sheets on the sheet placing table has decreased to a predetermined remaining number. A sheet feeding control device characterized by: 2. A plurality of sheet mounting tables 1, 2, and 3, and the first sheet mounting table provided corresponding to each of the sheet mounting tables.
A patent characterized in that it has detection means 35, 36, and 37, and a control means that, when stopping sheet feeding from one sheet loading table, switches to another sheet loading table and continues sheet feeding. A sheet feeding control device according to claim 1. 3 Memory means (RAM) for storing the size of the sheets stacked on each sheet loading table; and when switching to another sheet loading table and continuing sheet feeding, the size of the sheets stored in the above storage means is stored. Based on the size, select another sheet mounting table stacked with sheets of the same size as the sheets on the one sheet mounting table whose sheet feeding has been stopped;
3. The sheet feeding control device according to claim 2, further comprising a control means that switches to the selected sheet loading table and continues feeding the sheet. 4. Second detection means 38, 39, 40 for detecting the presence or absence of sheets on each sheet placing table, and when switching to another sheet placing table to continue sheet feeding, detecting the number of sheets stored in the above storage means. When there is no other sheet stacking table stacked with sheets of the same size as judged from the size, the sheets are fed without switching the sheet stacking table until the second detection means detects that there is no sheet. 4. The sheet feeding control device according to claim 3, further comprising control means for controlling the sheet feeding.