JPH02248968A - Both surface image forming device - Google Patents

Abstract

PURPOSE:To quickly restart both surface printing by automatically ejecting the residue recording paper in the both surface printing device outside a carrying path of the both surface printing device and only removing a jammed piece of paper after a generation of jamming inside the image forming device. CONSTITUTION:A changeover means 28 to eject the residue recording paper 2'' inside the both surface printing device outside the carrying path provided on one edge of a paper refeeding carrying bath b of the both surface printing device, when jamming is generated inside the image forming device, and an exclusive ejecting means 29 for ejecting the residual paper when the changeover means 28 is activated are provided. Therefore, when jamming is generated inside the image forming device, the residue recording paper inside the both surface printing device is ejected through the changeover means or an inverted carrying path a by a paper refeeding carrying path b, and only removal of the jammed piece of paper inside the image forming device is necessary. Thus, the both surface printing action can be restarted in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention provides a double-sided image forming apparatus in which one image forming apparatus (
The present invention relates to a device for discharging residual recording paper in a single-sided printing device when a jam occurs in the main body.

(Prior Art) Modes for forming double-sided images in copying machines, printers, etc. can be roughly divided into the following two modes.

(A) Copying multiple double-sided originals (copying machine).

(B) Copying a portion of a double-sided original (copy machine) or printing a series of printouts sequentially on both sides (printer).

In mode (A), images can be formed on both sides efficiently by forming images on the front side of a required number of sheets and then continuously forming images on the back side.

In addition, in mode (B), since images are formed sequentially, it is necessary to form images in the order of, for example, front->back->front->back, and it is difficult to improve efficiency.

To explain a double-sided image forming apparatus using a laser printer as an example, as shown in FIG. (1) (Main body) A double-sided printing device (II) for reversing recording paper is arranged in the lower stage.

The purpose of this is to perform image formation in the above mode (B), and to improve the efficiency, for example.

Front→Front→Front→Back→Front→Front→・・・・・・→Front→Back→Back→
While simultaneously transporting multiple sheets (three sheets in the above example) into the one-sided printing device and the image forming device in order such as the back side,
Perform image formation on both sides.

The pages according to this example are 1→3→5→■→7→■
→ 9 → ... → ■ → σ King ■ → σ King 1 (the numbered circle is the back).

1 image forming device (1
) in the registration roller pair 4 (jam paper 2'
) occurs (as illustrated in Figure 4), there is also residual recording paper 2'' in the double-sided printing device (n) other than the image forming device (2) as described above, and in the above example there are 3 sheets, and which Since it is not known whether a portion of the paper is jammed or not, it is necessary to remove paper other than the jammed paper as jammed paper.

Also, Special Publication No. 61-23550 (Double-sided copying control device)
When performing single-sided copying, some machines are equipped with an intermediate tray for storing the back side copy after the front side copy. This is suitable for image formation in mode (A) above, and if a jam occurs in the image forming device, the system will restart after clearing the jam and depending on whether there is recording paper that has been copied on the back side in the intermediate tray. You can easily determine which pages should be copied on the back side.

(Problem to be Solved by the Invention) However, in the case of a laser printer without an intermediate tray, such as the above-mentioned laser printer, it is necessary to remove all the recording paper in the image forming device and the double-sided printing device as jammed paper. Not only is it time consuming, but recording paper is wasted.

According to the present invention, after a jam occurs in an image forming apparatus, the residual recording paper remaining in the duplex printing apparatus is automatically discharged to the outside of the conveyance path in the duplex printing apparatus, and only the jammed paper is removed. The purpose is to enable double-sided printing to be resumed quickly.

(Structure and operation) In order to achieve the above object, the present invention provides a double-sided image forming apparatus equipped with a double-sided printing device that reverses recording paper printed on one side by the image forming apparatus and refeeds the paper to the image forming apparatus. A switching means for discharging residual recording paper in the duplex printing device to the outside of the conveyance path, provided at one end of a paper refeeding conveyance path in the duplex printing device when a jam occurs in the image forming device; The present invention is characterized by comprising a dedicated ejecting means for ejecting the remaining recording paper when the means is activated.

The present invention is also characterized in that the conveyance path for switch-packing and reversing the recording paper in the single-sided printing device is also used as the ejection conveyance path for the remaining recording paper in the double-sided printing device when a jam occurs in the image forming device.

With the above configuration, when a jam occurs in the image forming apparatus, the present invention allows the paper refeeding path to eject the remaining recording paper in the duplex printing device through the switching means or the reversing conveyance path, resulting in a single double-sided image. It is only necessary to remove the jammed paper in the forming device, and double-sided printing can be resumed in a short time.

(Example) FIG. 1 is a longitudinal sectional view of a laser printer in which the present invention is implemented.

To give an overview of the operation of this printer, there are 9 image forming devices.
(1) Paper feed tray IA, IB or bulk paper feed tray I
The recording paper 2 fed from any one of the paper feed rollers 3A, 3B, or 3C is timed by a pair of registration rollers 4, and is delivered to a drum-shaped photoconductor 5 (POC), which is an example of a photoconductor. transported.

The photoreceptor 5 is rotated clockwise, and at this time, the photoreceptor 5
The surface is charged by a charging charger 6, and an electrostatic latent image is formed on the photoreceptor 5 by being irradiated with a light beam from an optical unit 7, which is an optical writing device that modulates an image signal into a light beam. be done.

When this latent image passes through the developing unit 8 that forms the toner layer, it is made visible by the toner, and this visible image is transferred by the transfer charger 9 to the recording paper 2 that is conveyed to the photoreceptor 5, and is then transferred. The visible image on the recording paper is fixed by a fixing device [1G.

Then, the recording paper 2 that has exited the fixing device [10] is transferred to the paper transport roller 1.
1 and the switching claw 12 to discharge the paper to any of the paper discharge trays 13, 14, and 15 on the image forming apparatus t(1) side.

Or a double-sided printing device! (n).

That is, in the case of single-sided printing, the recording paper printed on one side is placed on the paper output trays 13 to 15 under the control of the electrical equipment section 16 (which includes an engine board 17 for controlling the print sequence and a controller board 18 having an image processing section). is discharged.

Further, in the case of double-sided printing, the switching claw 12 is switched by the control section of the electrical equipment section 16, and the recording paper 2 is conveyed to the conveying path a side on the reversing roller 19 side. Then, the recording paper 2 sent to the conveyance path a by the first reversing roller 19 is moved one by one to the conveyance path side formed by the conveyance rollers 22A and 22B by the operation of the first reversing claw 21. It is then transported by switchback. That is, the side printed on one side of the recording paper 2 is reversed, and the paper is fed by the paper feed roller 23 to the pair of registration rollers 4 in order to record on the other side to be printed.

The electrical equipment section 16 described above includes a master CPU 160 and a slave CPU 16, as shown in the block diagram in FIG.
1, one image forming device (1) is controlled by a master CPU 160, and one double-sided printing device (II) is controlled by a slave CPU.
161. The slave CPU 161 operates according to commands sent from the master CPU 160 via serial communication.
PU is an image forming device! A main motor 26, a solenoid such as a switching pawl 12, which drives mechanical parts in the image forming apparatus t(1) based on input from various sensors (for example, 1 image density detection sensor 24 and recording paper leading edge detection sensor 25) of (I) , provides output to the clutch of the mechanical part.

The slave CPU also controls the duplex motor 20 in the duplex printing apparatus based on inputs from various sensors (paper detection sensors for transport paths a and b, etc.) in the duplex printing apparatus W(II). Mass paper feed motor 27. Switching claw 21. It provides output to a solenoid such as the switching pawl 28 (FIG. 3).

FIG. 3 shows an embodiment of the present invention, in which a residual recording paper 2' is placed at a position slightly away from the conveyance roller 22B (at the right end in the drawing) on the conveyance path of the double-sided printing device f(II) in the conveyance direction. A switching claw 28 is arranged, and a dedicated residual recording paper discharge port 29 is provided below the switching claw 28. The switching pawl 28 is controlled by the slave CPU 161 shown in FIG. 2, and normally is at the position shown by the broken line, and the recording paper is conveyed to the image forming apparatus (1) by the paper feed roller 23, but as shown in FIG. When jammed paper 2' occurs, the position is switched to the solid line position, and the remaining recording paper 2'' is ejected to the dedicated ejection port 29.

Next, the operation will be explained. When a jam occurs in the image forming device ff1(1), the jammed paper 2' is located in front of the pair of registration rollers 4 as shown in FIG. 4, and is displayed on the operation panel. In this case, the master CPU 160 in FIG. 2 stops the main motor 26, and the WI side printing device! (n) The slave CPU instructs the slave CPU 161 to stop.
U stops the operation of the duplex motor 20, checks the remaining recording paper 2', and operates the switching claw 28 if it is on the transport path a or b.

Switch from the dashed line position to the solid line position. and 1 reversing roller 19. The conveyance rollers 22A and 22B are rotated normally by the slave CPU, and the remaining recording paper 2'' is moved from FIG. 3 (1) to (2).
), and the paper is discharged as shown in FIG. 3 (3) through a dedicated discharge port 29.

Then, when the paper ejection is completed, the slave CPU detects this and returns the switching claw 28 to the original position indicated by the broken line, and moves on to prepare for conveyance for the primary double-sided printing.

Further, after the remaining recording paper 2'' is discharged, the operator removes the jammed paper 2'.

In this way, the operator does not have to remove the remaining recording paper inside the duplex printing device (II).

Print operation can be performed from the next page.

Note that the areas where jams often occur are the pickup section of the recording paper 2 shown in FIG. 1 (the pickup rollers 3a to 3c in front of the paper feed rollers 3A to 3B), the vicinity of the photosensitive drum s where the image is transferred, and the fixing device. Jams are relatively limited to the image forming apparatus (1) side, such as the entrance of the printer 10, and are less likely to occur in areas where recording paper is conveyed, such as the duplex printing apparatus (n).

FIG. 5 shows another embodiment of the present invention, in which the conveyance path of a double-sided printing device I (II) is used to remove the residual recording paper 2 in the device.
A state diagram when discharging a paper is shown.

Next, the operation will be explained using the flowchart shown in FIG.

If a jam occurs as a result of the jam check, the master C
The PU 160 stops the main motor 26 of the image forming apparatus (summer) and instructs the slave CPU 161 to stop the duplex printing apparatus (II).

Slave CPU is large quantity paper feed (LCI T) motor 2
7. After the duplex (D P The case is also the same as the conventional case (step A).

Next is the 2-sided printing device! (II)Remaining recording paper 2#
If it is confirmed that there is, proceed to step B.

Slave CPU 161 is double-sided (D P
The residual recording paper 2'' on the conveyance paths a and b is discharged into the double-sided printing device (II) using the conveyance path S as shown in FIGS. 5(1) to 5(3). At the same time as the ejection ends, the double-sided motor 20 is stopped, and the master CPU 16
0 Heslep CPU 161 sends a discharge completion report,
1 image forming bag after confirming this! Jam paper 2 in (I)
' (illustrated in FIG. 4) is eliminated.

In this way, by using the conveyance path also for discharging the remaining recording paper, it is possible to reduce the size of the structure, which is advantageous in terms of cost.

(Effects of the Invention) As explained above, in the present invention, when a jam occurs in one image forming device, the remaining recording paper in the duplex printing device is automatically ejected to the outside of the conveyance path, so that the operator can You only need to focus on eliminating paper, which simplifies your work. Moreover, double-sided printing can be restarted quickly.

Furthermore, the present invention has the advantage that it can be implemented without increasing costs, since the conveying path (reversing path) for switching back the recording paper can also be used as a discharge port for the remaining recording paper.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a laser printer in which the present invention is implemented, FIG. 2 is a block diagram of the electrical equipment shown in FIG. 1, FIG. 3 is an embodiment of the present invention, and FIG. Image forming device (1
), FIG. 5 is a diagram showing another embodiment of the present invention, and FIG. 6 is a flowchart for explaining the operation of FIG. 5. (1)...Image forming apparatus (main unit), (II)...
・Double-sided printing device, 2...recording paper, 2'...
Jam paper, 2″...Residual recording paper, 4...Register roller pair, 5...Photosensitive drum, 16...Electrical equipment section, 19...Reversing roller, 20...Double-sided (D P
X) %-ta, zi-...reversal claw, 22A. 22B...Conveyance roller % 23...Paper feed roller, 2
6...Main motor, 27...Large paper feed (LCIT)
) Motor, 28... Switching claw, 29... Dedicated discharge port, a... Conveyance route (reversing route), b... Conveyance route. Figure 2 Figure 4 Figure 3 Figure 5

Claims (2)

[Claims] (1) In a double-sided image forming apparatus equipped with a double-sided printing device that reverses recording paper printed on one side by the image forming apparatus and refeeds the paper to the image forming apparatus, when a jam occurs in the image forming apparatus, the double-sided A switching means is provided at one end of the paper refeeding conveyance path in the printing device for ejecting the remaining recording paper in the duplex printing device to the outside of the conveyance path, and when the switching means is operated, the remaining recording paper is ejected. A double-sided image forming apparatus characterized by comprising a dedicated ejection means for printing paper. (2) When a paper jam occurs in the image forming apparatus, the remaining recording paper in the duplex printing apparatus can be changed to 2. The double-sided image forming apparatus according to claim 1, wherein the double-sided image forming apparatus also serves as a discharge conveyance path.