JPH0126973B2 - - Google Patents

Description

TECHNICAL FIELD The present invention relates to a paper feed control device, and more particularly, to a paper feed control device for copying machines, printers, etc. that can selectively feed paper one sheet at a time from a plurality of paper feed sections. .

BACKGROUND ART Conventionally, electrophotographic copying machines and printers, particularly printers that print out computer output, often continuously copy a large number of sheets (100 to 500 sheets) at a time. however,
Copying machines and printers, especially small ones, are mainly equipped with automatic paper feed cassettes that can be attached to and removed from the paper feed section.
It can only hold about 1 sheet. Therefore, when making a large amount of continuous copying, there is an inconvenience that copying paper runs out midway and the copying process is interrupted, and the copying paper has to be replenished many times, which is cumbersome.

On the other hand, in the case of a paper feed control device that allows automatic paper feed cassettes to be attached and detached to multiple paper feed sections, one of the paper feed sections is automatically selected when the power is turned on, and the selected paper feed It is possible to feed paper from the
A so-called priority designation method is adopted. This priority designation method can be broadly divided into a paper source designation method and a size designation method. The paper feed section designation method is a method of automatically selecting a specific paper feed section, such as the topmost paper feed section, when the power is turned on. The size designation method is a method of dynamically selecting a paper feed section in which a cassette loaded with copy paper of a specific size is installed.

If the paper source specification method is used, a cassette loaded with copy paper of the most frequently used size is attached to the priority specified paper source; if the size specification method is used, the priority specified size (the most The cassette loaded with copy paper of the most frequently used size is usually installed in the top paper feed section, which is the easiest to replace. It tends to be larger than that of the paper feed section.

Therefore, in conventional paper feed control devices, the frequently used paper feed section (for example, the paper feed roller) wears out faster than other paper feed sections, making it inefficient in terms of device repair cycles. It has its drawbacks. These drawbacks are particularly noticeable when continuous copying of a large number of sheets as described above is frequently performed, and at the same time, replenishing copy paper also takes time and effort.

OBJECT OF THE INVENTION Accordingly, an object of the present invention is to solve the problem when continuous copying is performed, when sheets of the same size are loaded in multiple stages of paper feed units, and when continuous copying is performed,
To provide a paper feeding control device that changes the paper feeding section every time one sheet of paper is fed, prevents only the special paper feeding section from being consumed early, and allows paper to be replenished with sufficient margin. It's about doing.

SUMMARY OF THE INVENTION In order to achieve the above object, a paper feed control device according to the present invention is a paper feed control device for a copying machine, a printer, etc. that can selectively feed paper one sheet at a time from a plurality of paper feeding sections. In the above, it is determined by the determining means for determining the size of the paper loaded in the paper feeding section of each stage, and the determining means that the paper of the size to be fed is loaded in the paper feeding section of the plurality of stages. When continuous copying is performed, the paper source is changed each time a sheet is fed, and the paper is fed sequentially from the paper feed sections of all stages loaded with paper of the same size. The invention is characterized by comprising: a control means for controlling.

Embodiment FIG. 1 shows an embodiment of a paper feed control device according to the present invention, which is applied to a powder image transfer type electrophotographic copying machine.

That is, the paper feed units 10 and 20 are installed in two stages, and the automatic paper feed cassettes 11 and 21 are removable, respectively. Copy sheets S and S loaded in each cassette 11 and 21 are fed to the right in FIG. 1 by selectively rotating one of the paper feed rollers 12 and 22 counterclockwise. The paper is placed on hold, waits for a while at the first registration roller 30, is conveyed to the right by the rotation of this roller 30, waits again at the second registration roller 31, and is conveyed to the transfer section A by the rotation of this roller 31. be done.

On the other hand, the photoreceptor drum 32 can be driven to rotate in a counterclockwise direction, and is surrounded by a well-known charging charger 33, an exposure means 34, a developing device 35, a transfer charger 36, a separation charger 37, a cleaner device 38, and an eraser lamp. 39 have been installed. The copy paper S has the toner image transferred thereto at the transfer section A, is immediately separated from the photoreceptor drum 32, is conveyed to the right, and is discharged outside the machine via a fixing device (not shown).

Further, empty detection sensors 13 and 23 and copy paper size determination sensors 14 and 24 for copy sheets S and S are installed in the paper feed sections 10 and 20, respectively, and in the conveyance path leading to the first registration roller 30, Misfeed detection sensors 15 and 25 are installed. Empty detection sensors 13 and 23 are for detecting when the copy sheets S are running out in the cassettes 11 and 21, and use photocouplers, microswitches, etc. consisting of reflective light emitting/receiving elements.
The size discrimination sensors 14 and 24 are a plurality of microswitches that correspond to irregularities (not shown) according to the size identification code provided on the front surface of the cassettes 11 and 21, for example, and are controlled depending on their on/off states. This is used to indirectly determine the size of the copy paper S loaded in the cassettes 11 and 21, and at the same time,
When all the microswitches are off, it is detected that the cassettes 11 and 21 are not attached to the paper feed sections 10 and 20. Note that if the size identification code is formed by an array of magnets or an optical mark, a reed switch, a photo sensor, or the like can be used as the sensor itself.

Misfeed detection sensors 15 and 25 detect copy paper S in cassette 1 when the paper feed rollers 12 and 22 rotate.
In combination with a timer, it detects whether paper has been reliably fed from 1 and 21 and detects paper jams in the conveyance path leading to the first registration roller 30. In this embodiment, a micro switch is used. , a photo sensor, etc. may be used.

The signals from each of the above sensors are input to a microcomputer (CPU) as shown in FIG. 2, and predetermined calculations are performed to perform the control described below.

Here, the paper feeding operation in this embodiment will be explained according to the flowchart shown in FIG.

When it starts, it first performs idle processing in a step (1s). Idle processing is processing while the copying machine is on standby, and includes temperature control of the fixing device, various display controls, switch input processing, and the like.

Next, in step (2s), it is determined whether the request flag is "1" or not. The request flag is reset to "0" if there is no copy request, and is set to "1" if there is a copy request, for example, when a print switch is turned on. In this case, the process waits until a copy request is received, and if so, it is determined in step (3s) whether or not the double cassette mode has been selected as the paper feeding mode. In this embodiment, paper feeding modes include an upper cassette mode in which paper is fed only from the upper cassette 11, a lower cassette mode in which paper is fed only from the lower cassette 21, and a paper feeding mode in which paper is fed only from the lower cassette 21, and from both upper and lower cassettes 11 and 21, which are the object of the present invention. There is a double cassette mode for continuous copying in which paper is fed sequentially (alternately).
Select before the user turns on the print switch. Note that in order for the double cassette mode to be selected, it is necessary that copy sheets S of the same size are loaded in both the upper and lower cassettes 11 and 21.
This is determined by size determination switches 14 and 24. In this case, it is possible to automatically set the double cassette mode simply when the same size paper is loaded, but in this embodiment, we take into account that copy paper of different colors and types will be loaded. The mode is selected by a selection operation by the user. Note that even the color and type may be determined by other sensors so that the double cassette mode is automatically set when all conditions are the same.

If a mode other than the double cassette mode is selected, copy processing is performed based on another paper feeding mode in step (4s). If the double cassette mode is selected, the cassette flag is set to "1" in step (5s). The cassette flag is “1”
Instructs to feed paper from the upper cassette 11 when
When it is "0", it instructs to feed paper from the lower cassette 21.

Next, in step (6s), it is determined whether the cassette flag is "1" or not. Since the cassette flag was set to "1" in step (5s), it is determined as "YES", that is, the upper cassette 11
is given priority, and upper paper feed is displayed in step (7s).
Turns on the LED and turns off the lower paper feed display LED. Next, in step (8s), it is determined whether or not the upper cassette 11 is empty. If it is not empty, the upper paper feed clutch is turned on in step (12s), and the paper feed roller 12 is rotated to feed the paper from the upper cassette 11. Feed copy paper S.

At the same time, the cassette flag is reset to "0" in step (13s), and copy processing is performed in step (14s). Thereafter, in step (15s) it is determined whether the designated number of copies has been completed, and if not, the process returns to step (6s).

In step (6s), since the cassette flag was reset to "0" in step (13s), the determination is "NO", and the process shifts to paper feeding from the lower cassette 21. That is, in step (16s), the upper paper feed display LED is turned off and the lower paper feed display is turned off.
Turn on the LED. Next, in step (17s), it is determined whether the lower cassette 21 is empty or not.
If it is not empty, the lower paper feed clutch is turned on in step (21s), the paper feed roller 22 is rotated, and the copy paper S is fed from the lower cassette 21. At the same time, set the cassette flag to "1" in step (22s).
and perform copy processing in step (14s). Thereafter, in step (15s) it is determined whether the designated number of copies has been completed, and if not, the process returns to step (6s).

That is, in this case, the paper feed from the upper cassette 11 [steps (7s), (8s), (12s), (13s)] and the paper feed from the lower cassette 21 [steps (16s), (17s),
(21s), (22s)] will be repeated alternately. Then, when the specified number of copies is completed, the step (15s)
The result is ``YES'' and the process returns to the start.

By the way, if an empty cassette is detected in either cassette 11 or 21 during continuous copying, for example, if the upper cassette 11 becomes empty, the determination at step (8s) is ``YES'' and the lower cassette is replaced at step (9s). 21 is empty or not, and if it is not empty, the upper cassette 11 is skipped and paper is fed from the lower paper feeding cassette 21. That is, in step (10s), the upper paper feed display LED is turned off and the lower paper feed display LED is turned off.
is turned on, and in step (11s) the lower paper feed clutch is turned on to feed the copy paper S from the lower cassette 21. For the next paper feed, execute the normal bottom feed routine [steps (16s), (17s), (21s), (22s)],
Next, in step (8s), it is determined whether the upper cassette 11 is empty, and then steps (9s), (10s),
(11s) is executed to feed paper from the lower cassette 21.

On the other hand, when the lower cassette 21 becomes empty, the judgment in step (17s) is ``YES'', and in step (18s) it is judged whether or not the upper cassette 11 is empty, and if it is not empty, the lower cassette 21 is skipped. Upper paper feed cassette 1
Start feeding paper from 1. That is, in step (19s), the upper paper feed indicator LED is turned on and the lower paper feed indicator LED is turned off, and in step (20s), the upper paper feed clutch is turned on to feed the copy paper S from the upper cassette 11. The next paper feeding will be the normal upper paper feeding routine [steps (7s), (8s), (12s), (13s)]
Then, in step (17s), it is determined whether the lower cassette 21 is empty, and then steps (18s), (19s), and (20s) are executed to empty the upper cassette 1.
Start feeding paper from 1.

That is, when either cassette 11 or 21 becomes empty, that cassette is skipped and paper feeding continues from the other cassette. However, empty determination is performed every time paper is fed.

By the way, when both the upper and lower cassettes 11 and 21 become empty, it is judged as ``YES'' at steps (8s), (9s) or (17s), (18s), and the empty display LED is turned on at step (23s). , return to start.

That is, in this embodiment, during continuous copying, the copy sheets S are fed alternately from the upper and lower cassettes 11 and 21, so that only a specific paper feeding section is prevented from being consumed early, and the copy sheets S are There is no need to replenish each cassette 11, 21. Furthermore, even if one cassette becomes empty, this is detected and paper continues to be fed from the other cassette that is not empty. copy paper S
It is also possible to use it completely. Furthermore, if one empty cassette is replenished with copy sheets S before the other cassette becomes empty, a considerable number of copies can be made continuously.

In addition, since paper is fed sequentially from each paper feed section, even if the paper feed sections are multistage and the length of the conveyance path from each paper feed section to the transfer section is different, the rotation timing of the paper feed roller can be adjusted to match that of the single cassette mode. The copy paper is fed at an early timing and the first
If the registration rollers 30 are kept on standby, complicated control due to differences in conveyance path length is eliminated, and control becomes simple.

Furthermore, in this embodiment, the first registration roller 3
Misfeed detection sensor 1 is installed on the conveyance path leading to 0.
5,25 are installed. When feeding paper continuously from the same cassette, if a misfeed occurs, the paper feeding interval is shorter than in the sequential (alternating in this embodiment) paper feeding method as in the present invention.
Even the slightest slip in the copy paper is determined to be a misfeed and the copying operation is stopped, resulting in very large losses and is not suitable for high-volume, high-speed copying. However, in the case of the sequential paper feeding system of the present invention, even if copy paper in the upper paper feed section slips and is determined to be a misfeed, there is no need to immediately stop the copying operation; Since there is time to take measures such as rotating the upper paper feed roller again during the copying operation, there is no need to stop the copying operation due to a misfeed such as a slip. However, if a second misfeed is detected in the same sheet feeding section, the copying operation is stopped.

Note that the paper feed control device according to the present invention is not limited to the above-mentioned embodiments, and can be modified in various ways within the scope of the gist. For example, the paper feed section may have two or more stages, and various control flowcharts can be considered.

Effects of the Invention As is clear from the above description, the present invention includes a determining means for determining the size of paper loaded in the paper feeding section of each stage, and a determining means that determines the size of paper to be fed. When it is determined that multiple paper feed sections are loaded, and when continuous copying is performed, the paper feed section is changed each time a sheet is fed, and the same size paper is loaded. Since the controller is equipped with a control means that sequentially feeds paper from the paper feed sections of all stages, when performing continuous copying, paper is fed sequentially from the paper feed sections loaded with paper of the same size. Only the paper section is prevented from being consumed early, and paper can be replenished with plenty of time.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a copying machine equipped with a paper feed control device according to the present invention, FIG. 2 is a block diagram of a control section, and FIG. 3 is a control flowchart. 10, 20... Paper feeding section, 11, 21... Automatic paper feeding cassette, 12, 22... Paper feeding roller, 14,
24...Discrimination means (size discrimination sensor), S...
Paper (copy paper).

Claims (1)

[Scope of Claims] 1. In a paper feed control device such as a copying machine or a printer that can selectively feed paper one sheet at a time from paper feed sections in multiple stages, the paper loaded in the paper feed section in each stage. a determining means for determining the size; and when the determining means determines that paper of the size to be fed is loaded in multiple paper feed units and continuous copying is performed; ,1
A control means for changing the paper feeding section every time a sheet is fed and sequentially feeding paper from the paper feeding sections of all stages loaded with paper of the same size, and a paper feeding control characterized by comprising: Device.