JPH05105321A - Image forming device - Google Patents

Abstract

PURPOSE:To enable the continuation of image forming action even in the full state of a paper discharge tray by allowing an intermediate tray for double-side image formation to be used as a paper discharge tray or a paper supply tray. CONSTITUTION:When a paper discharge tray 8 becomes full of sheets, a paper discharge filler 22 is lifted, so that the full state of the paper discharge tray 8 is detected. Track changing claws 21, 16 are switched, and an intermediate tray 5 is locked so as not to be pulled out of a printer. Sheets from a selected paper discharge tray are printed, and after discharging these sheets to the intermediate tray 5 through double-side carrier path 19 of a double-side unit 4, the use of the intermediate tray 5 in place of the paper discharge tray is displayed on a control panel. Upon the termination of the job, the lock of the intermediate tray 5 is released, and whether or not the printed sheets are taken out of the intermediate tray 5 is checked. The display to the control panel is then released, and the track claw 21 is switched to perform reset into a main routine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a laser printer or a copying machine, and more particularly to an image forming apparatus having an intermediate tray for double-sided image formation.

[0002]

2. Description of the Related Art In a conventional image forming apparatus such as a laser printer, when an image-formed sheet stacked on a discharge tray is full, a discharge jam is prevented and a sheet is not dropped from the discharge tray. Therefore, the image forming operation is temporarily stopped so that the subsequent printing is not executed until the paper on the paper discharge tray is removed.

On the other hand, although the frequently used paper is set in the paper feed tray of the image forming apparatus, when the required paper is not set, the currently set paper is fed. It has been practiced to remove the paper from the paper tray and set the required paper newly.

[0004]

However, in such a conventional image forming apparatus, when the image-formed sheet on the sheet discharge tray becomes full, the image forming operation is stopped even during the job, and therefore the page is not formed. In many cases, the shortage was noticed later, and it was troublesome because the image formation was redone.

In particular, when a printer is used on a network or the like, the operator (user) is often not near the printer, so that even if the image-formed sheet on the discharge tray becomes full, the operator will notice it. However, other operators cannot use the printer, resulting in a decrease in the efficiency of printing work.

On the other hand, the replacement work of paper when the required paper is not set in the paper feed tray is very troublesome. For example, the first page of a letter may be preprinted with the company name, or the cover of the report may be preprinted with the format. It was very troublesome to replace the paper in the paper feed tray every time when printing other pages.

In particular, when a printer is used in a network or the like, the operator is often not near the printer, so that the operator frequently reciprocates between the host device and the printer, and other operators use paper. However, the efficiency of the printing work was reduced, for example, printing was done without noticing that the printing was replaced, and the printing is performed again.

The present invention has been made in view of the above problems, and it is possible to continue the image forming operation even when the image formed sheet on the discharge tray is full.
Even if the desired paper is not stored in the paper tray,
It is also an object to enable image formation by using a desired sheet without replacing the sheet in the sheet feeding tray.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an image forming apparatus having an intermediate tray for double-sided image formation, when the paper on the discharge tray is full. Paper discharge full detection means for detecting, a means for switching the paper conveyance path so as to discharge the paper on which the image forming processing is completed to the intermediate tray when the paper is full by the means, and the intermediate tray A means for making it possible to take out the sheets stacked on the paper and a means for notifying the operator that the paper has been discharged to the intermediate tray instead of the paper discharge tray are provided.

Further, the intermediate tray is provided so as to be able to supply the paper from the outside, a means for setting the size of the paper supplied to the intermediate tray, a means for setting the paper supply source to the intermediate tray, and the means. When the setting by
There is also provided an image forming apparatus provided with means for switching a paper feed path so as to feed paper from an intermediate tray to an image forming unit.

[0011]

According to the first aspect of the invention, when the paper on the paper discharge tray is full, it is detected and the paper conveyance path is arranged so that the paper for which the image forming process is completed is discharged to the intermediate tray. At the same time as switching, the operator was informed that the paper was discharged to the intermediate tray instead of the paper discharge tray, and the sheets stacked on the intermediate tray could be taken out, so that the image-formed paper on the discharge tray became full. Can continue the image forming operation.

Further, according to the second invention, when the size of the paper fed to the intermediate tray provided so that the paper can be fed from the outside is set, and the paper supply source is set to the intermediate tray. Since the paper feeding path is switched so that the paper is fed from the intermediate tray to the image forming unit, even if the desired paper is not stored in the paper feeding tray, it is possible to perform the desired operation without replacing the paper in the paper feeding tray. You can use this paper to form images.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be specifically described below with reference to the drawings. 2 is a front view showing an example of the external appearance of a laser printer according to an embodiment of the present invention, FIG. 3 is a block diagram showing the outline of the internal mechanism thereof, and FIG. 4 is a block diagram thereof.

In this laser printer, reference numeral 1 denotes a laser printer main body, and a lower paper feed tray 2 and an upper paper feed tray 3 capable of accommodating papers of different sizes in the main body 1.
Each is detachably equipped. In FIG. 2, reference numeral 4 denotes a double-sided unit, which is provided with a reversing path for reversing the front and back sides of a sheet when performing double-sided printing, and an intermediate tray 5 for temporarily storing the sheet on which one side has been printed. In this embodiment, the intermediate tray 5 can also be used as a paper discharge tray and a paper feed tray.

An operation panel 6 is provided with a display for displaying messages such as printer status and keys for setting various modes. Reference numeral 7 denotes an upper door, which is opened and closed so that jammed paper generated in the paper transport path of the main body 1 and the duplex unit 4 can be removed, consumables can be replaced, and malfunctions can be repaired. ing.
8 is a discharge tray for stacking printed sheets, and 9
Is a front door that can be opened and closed so that consumables can be replaced and repairs can be made.

In FIG. 3, reference numerals 10 and 12 denote a paper end of the lower paper feed tray 2 and an upper paper feed tray of the upper paper feed tray 3, and a lower paper feed filler for detecting that the paper has risen to a paper feed position. It is a filler. Reference numerals 11 and 13 denote a lower paper feed roller and an upper paper feed roller for feeding the paper from the lower paper feed tray 2 and the upper paper feed tray 3, respectively. Reference numeral 14 denotes an intermediate tray filler, which indicates that the paper end of the intermediate tray 5 (when used as a paper feed tray), paper full (when used as a paper discharge tray), and that the paper has risen to the paper feed position during the paper feed operation. It is for detection.

Reference numeral 15 denotes an intermediate tray feeding / discharging roller, which feeds the paper sent from the double-sided conveying path 19 of the duplex unit 4 to the intermediate tray 5 or sends the paper from the intermediate tray 5 to the registration roller 17 of the main body 1. .. Reference numeral 16 is a paper path changing claw for switching the conveyance of the paper from the double-sided conveyance path 19 to either the intermediate tray 5 or the intermediate tray 5 to the registration roller 17.

Reference numeral 17 denotes a registration roller for synchronizing (aligning) the sheet and the toner image on the photosensitive drum 20, and 18 a transfer charger for transferring the toner image on the photosensitive drum 20 to the sheet. , 19 are double-sided conveying paths for returning the sheet, for which single-sided printing has been completed, to the paper feeding position when performing double-sided printing.

Reference numeral 20 is a photosensitive drum for forming a toner image from an electrostatic latent image on the surface by an electrophotographic process. Reference numeral 21 is a paper discharge tray 8 or a double-sided conveying path 19 of the double-sided unit 4 for the paper sent from the fixing unit 24. , A paper path changing claw for switching the conveyance to either
Is a paper discharge filler for detecting that the paper more than the specified size is stacked (paper discharge tray is full), 23 is a paper discharge roller for sending the printed paper to the paper discharge tray 8, and 24 is electrostatically transferred to the paper. And a fixing unit for fixing the toner image.

Numeral 25 is a static elimination lamp for irradiating light on the photosensitive drum 20 to remove residual charges in preparation for the next printing, and 26 is a low voltage power for a control circuit and motor drive, and for a charger. Is a power source that supplies high-voltage power and AC power for the fixing heater, and 27 is a cleaning unit that collects the toner remaining on the photosensitive drum 20 after transfer and stores the collected toner.

Reference numeral 28 is a main charger for uniformly charging the surface of the photosensitive drum 20 prior to the formation of an electrostatic latent image.
Reference numeral 9 is a developing unit for developing the electrostatic latent image on the photosensitive drum 20 with toner, and 30 is a toner cartridge for supplying toner to the developing unit 29.

Reference numeral 31 denotes an optical writing unit, which is composed of a laser diode (LD), an LD driver, a polygon mirror, a motor, an optical system, etc., which are not shown, and the photosensitive drum 20.
The laser light is scanned according to the dot image information from the controller 32 in order to form an electrostatic latent image corresponding to the print image thereon. A controller 32 analyzes data received from the host device, converts it into dot image information and sends it to the engine control unit 33 in the print engine, and sends commands and statuses to the host device and engine control unit 33. Communicate.

Referring also to FIG. 4, an engine control unit 33 controls the print engine mechanism unit 35 and communicates with the controller 32. Reference numeral 34 denotes a print engine (printer to controller 32) for executing printing.
35 is a print engine mechanism section mainly composed of mechanical parts centering on the photosensitive drum 20 shown in FIG.

Reference numeral 36 is an LD driver for controlling the laser diode LD included in the optical writing unit 31, reference numeral 37 is a vacuum fan for cooling the inside of the printer and suctioning and transporting the paper, and reference numeral 38 is an option such as a large-volume feed tray. A paper feeding unit 39 is an optional paper discharging unit such as a mail box.

Reference numeral 40 is an optional memory such as a memory card, font cartridge, or emulation card for expanding the function of the controller 32, and 41 is an optional hard disk for expanding the function of the controller 32.
A drive device (HDD) 42 is a host device which is a higher-level device of the printer.

FIG. 5 is a layout diagram showing an example of the configuration of the operation panel 6, 43 is an LCD panel for displaying the printer status and a menu for setting the mode in a character string, and 44 is an instruction for the printer operation. A group of operation switches for setting the mode and setting the mode, and a group of LED indicators 45 for displaying the status of the printer.

FIG. 6 is a perspective view showing an example of the intermediate tray 4, and 46 indicates to the engine control unit 33 the size of the paper supplied to the intermediate tray 5 when the intermediate tray 5 is used as a paper feed tray. It is a size detection plate for. A photocoupler array (not shown) is attached to the print engine 34 shown in FIG. 4 at a position corresponding to the size detection plate 46, and the paper size can be detected by each shape as shown in FIG. it can.

A lock claw 47 for locking the inside of the print engine 34 is formed on the side surface of the intermediate tray 5. For example, if the intermediate tray 5 is pulled out during double-sided printing, double-sided printing cannot be performed (described later).
Is locked using this lock claw 47 so that it cannot be pulled out. 48 pulls out the intermediate tray 5,
It is a handle for setting.

Reference numeral 49 denotes a push-up plate which lifts the paper so that the uppermost paper comes into contact with the intermediate tray feeding / discharging roller 15 when the paper is fed. In addition, it is usually lowered,
When the paper is fed, it is lifted by a mechanism (not shown) of the print engine.

Here, an example of the lock mechanism of the intermediate tray 5 is shown in FIG. 50 is a lock lever, which is a solenoid 51
Is engaged with the lock claw 47 of the intermediate tray 5 by
The intermediate tray 5 is prevented from being pulled out from the printer during a normal double-sided printing operation.

Under the control of the engine control unit 33, the solenoid 51 attracts the lock lever 50 and rotates it as shown in FIG. 8A so that the intermediate tray 5 cannot be pulled out. When the solenoid 51 is not operated, the lock lever 50 is pivotally returned by the spring 52 as shown in (b), and the intermediate tray 5 can be pulled out and set.

The operation of the laser printer during double-sided printing will now be described. When a "double-sided print mode" is instructed by a command from the host device 42 or the operation switch group 44 of the operation panel 6, the controller 32 causes the engine 32 to operate. The control unit 33 is instructed to enter the “double-sided print mode”. As a result, the engine control unit 33 turns on the solenoid 51 to attract the lock lever 50 and engage the tip of the lock lever 50 with the lock pawl 47 as shown in FIG. It is locked so that it cannot be pulled out from.

When print data and control commands for two pages are transmitted from the host device 42, a command from the host device 42 in the upper paper feed tray 3 or the lower paper feed tray 2 or an operation switch group of the operation panel 5. The paper is fed from the paper feed tray selected by 44. At this time, the paper path changing claw 21 in FIG. 3 is set to the position indicated by the broken line in FIG. 3 under the control of the engine control unit 33, and the paper conveyed from the fixing unit 24 for which one-sided printing is finished is the duplex unit 4 Is sent to the double-sided conveying path 19.

The paper path changing claw 16 is also set to the position indicated by the solid line in FIG. 3 under the control of the engine control unit 33, and the paper passing through the double-sided conveying path 19 is sent to the intermediate tray 5. Then, when the trailing edge of the paper passes through the paper path changing claw 16, the paper path changing claw 16 is switched to the position indicated by the broken line, the intermediate tray feeding / discharging roller 15 rotates in the reverse direction, and the paper is registered in the main body 1. The paper is fed again toward the roller 17.
At this time, the paper path changing claw 21 is switched to the position indicated by the solid line, and the paper that has been conveyed from the fixing unit 24 and has completed double-sided printing is sent to the paper discharge tray 8.

By the way, in this laser printer, in order to arrange the page order of the discharged sheets, the printing order is as follows: second page → first page → fourth page → third page. In addition to the normal double-sided print mode for printing, an interleaved double-sided print mode in which the print order is set to the second page → the fourth page → the first page → the third page in order to increase the throughput can also be used. ..

When the interleaved double-sided print mode is used, one side of the intermediate tray 5 is placed on the intermediate tray 5 depending on the data transmission order from the host device 42, the data processing speed of the controller 32, the paper feeding order of the print engine, and the like. Multiple sheets of paper that have been printed are stored. Further, even in the double-sided copy mode (same printing is performed for a plurality of copies), it is necessary to temporarily store the paper on which the one-sided printing is finished in the intermediate tray 5. For these purposes, the intermediate tray 5 is generally structured to store a plurality of sheets of paper.

Next, the processing by the engine control unit 33 when the intermediate tray 5 is used as a paper discharge tray will be specifically described with reference to FIG. In this laser printer, when the paper in the paper ejection tray 8 becomes full (paper ejection is full) during printing, the paper ejection port of the printer is blocked and a paper ejection jam occurs, or the ejected paper is ejected from the paper ejection tray. In order to prevent the sheets from falling out of the sheet 8 and being lost, or the page order not being aligned, a sheet discharge filler 22 for detecting the amount of sheets stacked on the sheet discharge tray 8 is attached.

The routine of FIG. 1 starts when called from a main routine (not shown) during printing.
First, it is checked whether or not the paper in the paper discharge tray 8 is full, and if it is not full, the paper is fed from the selected paper feed tray to execute printing, and the paper is discharged from the paper discharge tray 8
The sheet is discharged to, and the above processing is repeated until the job is completed.

After that, when the paper in the paper discharge tray 8 is full, the paper discharge filler 22 is lifted to detect that the paper in the paper discharge tray 8 is full, and the paper path changing claw 21 is set to the position shown in FIG. The paper path changing claw 16 is switched to the solid line position and the solenoid 5
1 is turned on, the lock lever 50 is rotated counterclockwise against the spring 52 as shown in FIG. 8A, and the tip end of the lock lever 50 is engaged with the lock claw 47. The intermediate tray 5 is locked so that it cannot be pulled out from the printer.

When this is completed, the paper from the selected paper feed tray is printed, the paper is discharged to the intermediate tray 5 through the double-sided conveying path 19 of the double-sided unit 4, and then the LCD panel 43 of the operation panel 6 is operated. A message indicating that the intermediate tray is used instead of the paper discharge tray is displayed to notify the operator (may be notified by a buzzer or the like) so that the operator does not forget to take out the printed paper from the intermediate tray 5, The above processing is repeated until the job is completed.

When the job is completed, the solenoid 51 is turned off, so that the lock lever 50 is rotated clockwise by the spring 52 as shown in FIG. The intermediate tray 5 is released from the lock claw 47 and is unlocked. Next, it is checked whether or not the printed paper is taken out from the intermediate tray 5, and when it is taken out, the operation panel 6
The above display (display indicating that the intermediate tray is used instead of the paper discharge tray) is canceled, the paper path changing claw 21 is switched to the position shown by the solid line in FIG. 3, and the process returns to the main routine (not shown).

Next, when the intermediate tray 5 is used as a paper feed tray, the operator supplies the required paper to the intermediate tray 5, attaches the size detection plate 46 indicating the paper size, and then Set the intermediate tray 5 in the printer. Further, a command from the host device 42 or the operation switch group 44 of the operation panel 6 sets the paper supply source to the intermediate tray 5.

As a result, the engine control unit 33 switches the paper path changing pawl 16 to the position indicated by the broken line in FIG. 3 so as to feed from the intermediate tray 5, and then feeds the paper from the intermediate tray 5 to perform printing. .. FIG. 10 shows the flow of the specific processing. As described above, the intermediate tray 5 can also be used as a paper feed tray like the upper paper feed tray 3 or the lower paper feed tray 2.

As described above, according to this embodiment, when the paper on the paper discharge tray 8 is full, it is detected that the paper on which the printing is finished is discharged to the intermediate tray 5. As the conveyance path is changed, the operator is informed that the paper is discharged to the intermediate tray 5 instead of the paper discharge tray 8, and the sheets stacked on the intermediate tray 5 can be taken out. Printing will not be interrupted even if the upper paper is full,
The efficiency of printing work increases.

It should be noted that when the paper discharge unit is out of order (for example, when the paper discharge full detection unit is out of order and the paper is constantly discharged, or when the drive system of the paper discharge unit is out of order, the paper cannot be discharged) Even when it is not possible to print, it is possible to print by using the intermediate tray 5 as a paper discharge tray.

Further, in this embodiment, when the size of the paper fed to the intermediate tray 5 is set and the paper supply source is set to the intermediate tray 5, the paper is fed from the intermediate tray 5 to the printer body 1. Since the paper feed path is switched to, it was intended without changing the paper in the paper feed tray for printing with various papers or the fact that another operator replaced the paper in the paper feed tray. The work and waste of printing on a different sheet of paper and then reprinting is reduced, and the efficiency of printing work is improved.

In this embodiment, the intermediate tray 5 has a structure similar to that of the paper feed tray so that the intermediate tray 5 can be pulled out from the printer. It is also possible to take out the paper and feed unprinted paper to the intermediate tray. Further, as a method of setting the paper size when the intermediate tray 5 is used as a paper feed tray, there is also a method of setting it by a switch or the like instead of using the size detection plate.

The embodiments in which the present invention is applied to a laser printer have been described above. However, the present invention is not limited to this, and other printers such as an LED printer and a liquid crystal shutter printer, as well as a copying machine, a facsimile machine, etc. It is applicable to various image forming apparatuses.

[0049]

As described above, according to the present invention, the image forming operation can be continued even when the image formed sheet on the discharge tray is full. Further, even when the desired paper is not stored in the paper feed tray, it is possible to perform image formation using the desired paper without replacing the paper in the paper feed tray.

[Brief description of drawings]

FIG. 1 is an intermediate tray 5 by an engine control unit 33 of FIG.
FIG. 7 is a flow chart showing a process when is used as a paper discharge tray.

FIG. 2 is a front view showing the outer appearance of a laser printer which is an embodiment of the present invention.

FIG. 3 is a configuration diagram showing an outline of an internal mechanism of the same.

FIG. 4 is a block diagram of the same.

5 is a layout diagram showing a configuration example of an operation panel 6 of FIG.

FIG. 6 is a perspective view showing a configuration example of an intermediate tray 5 of FIG.

FIG. 7 is an explanatory view showing an example of the shape of a size detection plate attachable to the intermediate tray 5.

FIG. 8 is a main-part configuration diagram showing a lock mechanism of the intermediate tray 5;

FIG. 9 is a plan view showing a state of attaching and detaching the intermediate tray 5 from above the printer.

FIG. 10 is a flowchart showing processing when the intermediate tray 5 according to this embodiment is used as a paper feed tray.

[Explanation of symbols]

1 Laser Printer Main Body 2 Lower Paper Feed Tray 3 Upper Paper Feed Tray 4 Double-sided Unit 5 Intermediate Tray 6 Operation Panel 8 Paper Ejection Tray 14 Intermediate Tray / Filler 15 Intermediate Tray / Paper Ejection Roller 16,21 Paper Path Change Claw 19 Double-sided Feed Road 22 Paper discharge filler 32 Controller 33 Engine control unit 34 Print engine 35 Print engine mechanism unit 43 LCD panel 44 Operation switch group 45 LED display group 46 Size detection plate 47 Lock claw 48 Handle 49 Push up plate 50 Lock lever 51 Solenoid 52 Spring

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display part G03G 15/00 102 8004-2H 1068530-2H 108 7369-2H

Claims (2)

[Claims] 1. An image forming apparatus provided with an intermediate tray for double-sided image formation, and a discharge full detection means for detecting when the paper on the discharge tray is full, and full paper by the means. Means for switching the paper conveyance path so that the paper on which the image forming process has been completed is discharged to the intermediate tray when it is detected, a means for allowing the paper stacked on the intermediate tray to be taken out, and a paper discharge An image forming apparatus comprising means for notifying an operator that a sheet has been discharged to an intermediate tray instead of the tray. 2. An image forming apparatus having an intermediate tray for double-sided image formation, wherein the intermediate tray is provided so as to be able to supply paper from the outside, and means for setting the size of the paper supplied to the intermediate tray. And a means for setting a paper supply source to the intermediate tray, and a means for switching a paper feed path so that the paper is fed from the intermediate tray to the image forming unit when the setting by the means is provided. Image forming apparatus.