JPH08276625A - Both-side print apparatus - Google Patents

Abstract

PURPOSE: To simplify construction and improve efficiency by providing a plurality of paper discharge trays and, during both-side printing, using one of the paper discharge trays as a paper feed tray for both-side printing. CONSTITUTION: A paper sheet 4 fed from a cassette 7 to a print unit 1 by a paper feed roller 8 is caused to make a U-turn after transfer, and conveyed from above the print unit 1 to a fixer 6. After fixation, a switch jaw 13 switches the paper conveyance course over the course to a paper discharge tray 12 and the re-feed course for reverse-side printing. For reverse-side printing, a manual paper feed tray 17 for manual paper feeding is used as a re-feed tray. When a paper sheet falls on the manual paper feed tray 17, a paper presence sensor disposed in the manual paper feed tray 17 turns on. If the paper presence sensor 19 and a paper jam sensor 22 simultaneously turn on, it is determined that the both-side printing operation is completed, and the switch jaw 13 is switched for conveyance to the paper discharge tray 12. A front panel is used to select the manual feed mode or the both-side copy mode.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to both printing devices.

[0002]

2. Description of the Related Art In a conventional double-sided printing printer,
There are many parts such as two printing parts for front and back sides, complicated paper transport mechanism for double-sided printing, dedicated tray for double-sided printing, many sensors, etc. And the system was complicated and expensive.

[0003]

SUMMARY OF THE INVENTION The present invention aims to solve these problems of the prior art and provides a system having a simple structure and no waste.

In order to solve the above-mentioned problems, the present invention is a double-sided printing apparatus which performs double-sided printing using a common printing section, is provided with a plurality of paper discharge trays, and one of them is used for double-sided printing. To function as a paper feed tray for. Specifically, the means for causing the paper discharge tray to function as a paper feed tray for double-sided printing is controlled by the plurality of paper discharge tray selection switching means.

Further, in a double-sided printing apparatus that performs double-sided printing using a common printing unit, a manual feed tray provided separately from the paper discharge tray functions as a paper re-feed guide during double-sided printing, and the angle of the tray is changed. A sensor is provided to control so that double-sided printing can be automatically performed by changing the.

[0006]

With the above construction, the discharge tray can always be used as a two-bin machine, and can function as an intermediate tray during double-sided printing during double-sided printing. Further, the discharge tray can be used as a guide plate for manual feeding.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. In the figures, the same parts are designated by the same reference numerals.

FIG. 1 is a schematic explanatory view of an embodiment of the present invention.

The double-sided printing system of the present embodiment has a printing unit 1.
As the toner is accommodated and the toner carrier 2 is rotated on the surface, a bias controlled by print data is supplied to the toner passage hole formed in the mesh electrode 3 facing the toner passage hole to control passage of the toner. An example of a printer that controls and transfers a toner image corresponding to print data to the conveyed paper 4 by the back electrode 5 arranged on the back side of the paper and fixes the toner image by the fixing device 6 has been exemplified. The present invention can also be applied to the electrophotographic printers.

Reference numeral 7 is a cassette for stacking and accommodating paper, and 8
Is a paper feed roller, 9 is a registration roller, 10 is a paper feed sensor, 11 is a jam sensor, 12 is a paper ejection tray, and 13 is a paper conveyance direction switching claw for printing on the back side to enable double-sided printing. The paper whose conveyance direction has been switched is guided to the lower paper ejection tray 14, and then the registration roller 15
Is conveyed so that the back side is printed by the printing unit 1 via the conveyance roller 16 and the registration roller 17. The lower paper ejection tray 14 also functions as a second paper ejection tray different from the paper ejection tray 12 when back side printing is not performed. That is, the switching claw 13 operates to switch between the two-stage discharge trays during single-sided printing. At the time of printing on the back side, the lower-stage discharge tray 14 is used as a tray for printing on the back side. At this time, the lower tray has a paper presence / absence sensor and issues a paper removal alarm if paper remains for single-sided printing. Here, the registration roller 15 also serves as a switch for manual feeding.

The paper presence / absence sensor (not shown) of the lower tray 14 is always open. If the paper falls, the sensor turns on, indicating that the paper has arrived. At this time, if there is an auxiliary transport roller (not shown), it is turned on. The registration roller 15 used for printing on the back surface is turned on, and when the paper is supplied, the paper presence sensor is turned off, and the presence or absence of a paper jam is confirmed using this timing.

The switching jam 13 has a paper jam sensor 2
2 is provided so that one sensor 22 can detect even if it passes through the upper and lower surfaces of the switching claw 13.
When the back side paper feed registration roller 15 starts moving, the back side conveying roller 16 moves. Manual feed paper feeding from the lower paper ejection tray 14 is also possible by selecting a switch on the front panel. When the back side is printed, if the paper with the front side printed drops from the upper side, a paper squeezing claw (not shown) stands up, and the paper is shunted to match the print position reference.

Whether the back side printing or the front side printing is detected by the paper jam sensor 22, the position of the switching claw 13 is automatically set.

The manual feed is a manual feed tray 1.
7, the auxiliary conveyance roller 18, and the paper presence sensor 19 convey and control. Reference numeral 20 is a sensor for controlling the feeding of the paper at the time of printing on the back surface. Reference numeral 21 is a cassette provided separately from the cassette 7.

Therefore, as indicated by the arrow in the figure, the paper conveyance direction is controlled, and single-sided printing and double-sided printing are executed.

FIG. 3 shows the switching claw 13 and the sensor 22.
FIG. The switching claw 13 is integrally provided with a sensor 22 that can detect the movement of the paper on the upper and lower surfaces thereof.

FIG. 2 is a schematic explanatory view of another embodiment of the present invention.

In the construction of the double-sided printing apparatus of this embodiment, the paper 4 fed from the cassette 7 to the printing unit 1 by the paper feed roller 8 makes a U-turn after transfer and is fixed from above the printing unit 1. The sheet is conveyed to the container 6, and after fixing, it is switched by the switching claw 13 to the sheet discharge tray 12 or re-feeding for back side printing. When printing on the back side, the manual feed tray 17 for manual feed is used as a refeed tray. At this time, the paper feed sensor 1 is placed on the tray 17 for manual feed.
9 is installed, and the sensor 19 is turned on when the paper falls. At this time, if there is the auxiliary transport roller 18, this is turned on. At this time, a centering claw (not shown) in the manual feed acts to align the paper feed end faces. The paper present sensor 19 is always open, and is closed when the paper falls. Paper jam sensor 22
When the paper presence sensor 19 is turned on at the same time, it is determined that double-sided printing is completed, and the switching claw 13 is switched to the paper discharge tray 12 side. The manual feed or duplex copy is set on the front panel. The paper jam sensor 22 operates as the paper jam cassette, the back surface printing system, and a paper jam sensor at the time of manual feeding. The paper jam sensor 22 provided on the switching claw 13 has a structure in which one sensor can detect whether the paper jam sensor 22 passes through the front surface or the back surface of the claw 13. If the paper jam is normal or abnormal, after passing a predetermined paper jam switch 23, the next paper jam switch 22
Check the time until it passes by using the internal clock.

[0019]

As described above, according to the configuration and method of the present invention, the discharge tray can be used as a 2-bin machine at all times, and can function as an intermediate tray during double-sided printing during double-sided printing. I can. Further, the discharge tray can be used as a guide plate for manual feeding.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of an embodiment of the present invention.

FIG. 2 is a schematic explanatory view of another embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a switching claw 13 and a sensor 22.

[Explanation of symbols]

 1 Printing Part 2 Toner Carrier 3 Mesh Electrode 4 Paper 5 Back Electrode 6 Fixing Device 7 Cassette 8 Paper Feed Roller 9 Registration Roller 10 Paper Feed Sensor 11 Jam Sensor 12 Paper Ejection Tray 13 Switching Claw 14 Lower Ejection Tray 15 Registration Roller 16 Conveyance roller 17 Registration roller 18 Auxiliary conveyance roller 19 Paper present sensor 20 Sensor 21 Cassette 22 Sensor 23 Paper jam switch

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Claims (6)

[Claims] 1. A double-sided printing apparatus that performs double-sided printing using a common printing unit, is provided with a plurality of paper discharge trays, and one of the paper discharge trays functions as a paper feed tray for double-sided printing during double-sided printing. A double-sided printing device characterized in that 2. A double-sided printing apparatus according to claim 1, wherein the means for causing the paper discharge tray to function as a paper feed tray for double-sided printing is controlled by a plurality of paper discharge tray selection switching means. . 3. A double-sided printing apparatus according to claim 2, wherein said switching means is integrally provided with a sensor capable of detecting movement of the paper on the upper and lower surfaces thereof. 4. The double-sided printing device according to claim 2, wherein the paper jam switch for manual feeding and the paper jam switch for backside printing are used in common. 5. The double-sided printing apparatus according to claim 1, wherein a switch provided on the paper discharge tray is used as a paper discharge presence / absence sensor to initially check whether the double-sided printing function is possible. 6. In a double-sided printing apparatus that performs double-sided printing using a common printing unit, a manual feed tray provided separately from a paper discharge tray functions as a paper re-feed guide during double-sided printing, and the angle of the tray is set. A double-sided printing device, which is provided with a sensor that controls so that double-sided printing can be automatically performed by changing.