JP2000327233A - Perfecting press printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce waiting time and improve printing efficiency by allowing sheets to be fed so that at least a part of each of two sheets is included in a passage from a merging part between a sheet passage and a transportation passage to a changeover apparatus. SOLUTION: In perfecting press, when a first surface is printed, a sheet is inverted. In an inverting process of the first sheet, a changeover apparatus 17 is lifted down by a solenoid 171, and the sheet is taken on the side of an inverting/paper-feeding device 26 and is transported to an inverse temporary storing portion 9. Next, the changeover apparatus 17 is lifted up at a timing when the sheet perfectly passes through the changeover apparatus 17, and the sheet is fed toward a paper detector 172. When the paper detector 172 senses the tip of the sheet, the sheet is fed toward a paper detector 29 after a certain period. In a certain period after the paper detector 172 senses the rear end of the sheet, a transportation roller 16 is stopped. When the paper detector 29 senses the sheet, a transportation roller 177 is also stopped to accumulate the sheet, and a printing device body 25a starts a printing of the next sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a printing device,
In particular, it relates to a double-sided printing device.

[0002]

2. Description of the Related Art As a method of feeding paper in a two-sided printing apparatus, it has been known that one sheet discharged from a printing apparatus main body is inverted by an anti-transfer paper apparatus and supplied to the printing apparatus main body again. I have.

[0003] In such an apparatus, when the printing apparatus main body prints the front side of the paper and the transport time in the non-transfer paper apparatus is longer than the time that the back side can be printed, the printing apparatus main body supplies the paper. There will be a waiting time until it is done. Further, when high-speed conveyance is performed to shorten the conveyance time in the non-transfer paper device, a load is applied to the sheet, and the sheet may be damaged.

[0004]

In general, the paper transport section installed outside the printing apparatus for double-sided printing has a long paper transport path due to the restriction of the printing apparatus main body. For this reason, the waiting time of the printing apparatus main body caused by the length of the transport time is a problem. SUMMARY OF THE INVENTION An object of the present invention is to provide a double-sided printing apparatus having a short waiting time and improved printing efficiency.

[0005]

In order to achieve the above object, according to the present invention, there is provided a sheet cassette for storing sheets, a recording member on which a toner image is formed based on image information, and a toner image formed on the sheet. A paper path for feeding the paper to the recording body to transfer the paper, a fixing device for fixing the toner image,
A reversing path for reversing the fixed sheet in order to transfer the toner image to the other surface of the sheet on which the toner image is fixed; a transport path for feeding the reversed sheet to the first path; A switch for selecting whether to feed the sheet passing through the fixing device to the reversing path or to feed the sheet fed to the reversing path to the transport path; The paper can be fed so that at least a part of each of the two papers is included in the path from the junction of the conveyance path to the switch.

Preferably, the first sheet is contained in a relatively upstream portion in a path from a junction of the sheet path and the conveyance path to the switch, and a relatively downstream part in the path. Can be sent so as to include the second sheet.

More preferably, the toner image is transferred to a third sheet in a state where at least a part of each of the two sheets is included in a path from a junction of the sheet path and the transport path to the switch. Paper can be sent as much as possible.

[0008] More preferably, a first roller and a second roller that can rotate independently of each other are arranged in the transport path, and the two sheets are independently fed by the first and second rollers. It is possible.

Alternatively, one copy of the paper is retained at a lower portion of the paper transport unit, and another copy of the paper discharged from the printing apparatus main body is turned over by the paper draw-in unit and the upper portion of the paper transport unit is turned over. After the stagnation, control is performed to simultaneously feed the two sheets of paper toward the printing apparatus main body. At this time, the paper located at the lower portion of the non-transfer paper device is fed to the printing apparatus main body, and the paper located at the upper portion of the non-transfer paper device moves to the lower portion of the non-transfer paper device. At this time, since there is no paper above the transfer paper device, it is possible to reverse the paper discharged from the printing apparatus main body again. By performing these controls, paper feeding (printing on the front side) from the printing apparatus main body and paper feeding (printing on the back side) from the non-transfer paper device can be performed alternately and continuously.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.

The printing apparatus main body 25 includes developing units 1 to 4,
Optical unit 5, charger 8, photosensitive belt 22, recording medium (or transfer drum) 21, registration roller 1
2, the transfer roller 13, the static eliminator 15, the fixing device 19, the paper discharge roller 18, and the paper feed cassette 6 are main components. The control block diagram is shown in FIG. The control blocks are roughly two blocks of a printing apparatus main body control section 30 and a non-transfer paper apparatus control section 31. The printing device main unit control unit 30 exchanges data with the host, an I / F unit, an exposure, a development, a fixing unit, a motor as a power source, a drive unit of a solenoid, an operation unit, a display unit, a paper supply unit, It comprises a sequence control unit for controlling some detectors and the like and a paper reversal control unit. Further, the control unit 31 includes a motor as a power source, a drive unit of a solenoid, some detectors, and the like, and is operated by a signal from the sheet reversal control unit.

The operation of the printing device main body 25 and the non-transfer paper device 26 will be described.

The charger 8 uniformly charges the photosensitive belt 22 in response to a print start signal from a host (not shown). The optical unit 5 draws a latent image on the photosensitive belt 22 based on print data sent from the host. The drawn latent image is developed by any one of the developing units 1 to 4, and the colored particles in the developing unit are applied on the photosensitive belt 22. The photosensitive belt 22 is rotated by a driving source not shown here, and the photosensitive belt 2 is placed on the transfer drum 21.
2. Transfer the colored particles on 2. The photosensitive belt 22 is neutralized by the erase lamp 160, and the excess colored particles remaining on the photosensitive belt 22 are removed by the cleaner 23, and charged again by the charger 8. In the case of color printing, this process is repeated a plurality of times while switching the developing device. On the transfer drum 21, a visible image is formed by colored particles of a single color or a plurality of colors, and the paper 27 is supplied from the paper feed cassette a 6 or the paper feed cassette b 7 at the time when the desired transfer is completed or in advance. It is pulled out by the paper feed roller a10 or the paper feed roller b24, and stands by at the registration roller 12. After detecting the sheet by the detector 161, the sheet feeding roller a10 or the sheet feeding roller b24 stops at a predetermined time (the section from the sheet feeding roller a10 to the transfer drum 21 is referred to as a sheet path). Transfer drum 2
The timing of the position of the visible image formed on the sheet 1 coincides with the transfer position on the sheet, and the registration roller 12
The paper which has been waiting at the position starts conveying again, and the visible image is transferred to the paper side at the transfer roller 13. The paper is separated from the transfer drum 21 by the neutralizer 15, and the colored particles are fixed to the paper by the fixing device 19. In the case of printing on only one side, the switching device 17 does not operate and the paper is discharged to the paper discharge tray 28 side. In the case of the first side (front side) of double-sided printing, the sheet is reversed. For the first reversing process, the solenoid 1
71 operates, the switch 17 is lowered to the lower side in FIG.
The paper is taken into the non-transfer paper device 26 side, and the paper guide 1
4. The sheet is conveyed by the conveying roller a16 to the reversing temporary storage section 9 above the discharge section of the printing apparatus main body 25 (the path of the reversing temporary storage section is referred to as a reversing path). The solenoid 171 is operated at a timing when the sheet completely passes through the switch 17, and the switch 17 is raised upward in FIG. Next, the transport roller a16 is driven so as to feed the paper in the direction of the paper detector a172 (the paths for returning to the registration rollers 12 are referred to as transport paths). The conveyance roller b177 is driven so as to feed the paper in the direction of the paper detector b29 after a predetermined time from the detection of the head of the paper by the paper detector a172. The transport roller a16 and the transport roller b177 each have a separate and independent drive source (motor). Further, the conveyance roller a16 is stopped after a predetermined time from the detection of the trailing edge of the sheet by the sheet detector a172. When the sheet detector b29 detects a sheet, the conveying roller b1
Stop 77 and let the paper stay.

Since the reversing process of the next sheet can be performed after the transport roller a16 stops after the paper detector a172 detects the paper, the printing apparatus main body 25 is designed to perform the reversing process immediately after the transport roller a16 stops. Then, printing (front side) of the next sheet is started. Subsequently, the reversing process of the first sheet is performed in the same manner. However, if the preceding sheet already exists in the non-transfer sheet device, the sheet is detected by the sheet detector
The operation of driving the 177 is not performed, and the paper stays in the upper portion of the non-transfer paper device.

When the paper is present at the upper and lower portions of the anti-transfer paper device, the printing device main body 25 starts printing (front side) the next paper. When the paper has passed the registration roller 12, the transport roller a16 and the transport roller b177 are simultaneously driven to move the paper at the upper portion of the non-transfer paper device to the lower portion, and to transfer the paper at the lower portion of the non-transfer paper device to the printing device main body 25.
To the registration rollers 12. Thereafter, print processing is performed in the same manner as in one-sided printing, and the paper is discharged to the paper discharge tray 28. At this time, since only one sheet remains in the lower portion of the non-transfer paper device, the front sheet can be stored in the upper portion of the non-transfer paper device. Thereafter, the above processing is repeated, and continuous printing on the front and back sides of the paper can be performed alternately.

FIG. 3 to FIG. 7 show the state of conveyance of paper in the non-transfer paper device. FIG. 3 shows a state in which the paper stays at the lower part of the non-transfer paper device after the first (front) printing. FIG. 4 shows a state in which, after the printing of the second sheet (front side), the sheets remain at the upper and lower portions of the anti-transfer paper device. FIG. 5 shows a state during printing of the third sheet (front side). FIG. 6 shows a state in which after the third sheet has passed through the registration roller 12, the first sheet is fed, and the second sheet is moved from the upper portion to the lower portion of the non-transfer paper device. FIG.
Indicates that the first sheet (back side) is being printed, the second sheet is staying at the lower portion of the non-transfer paper device, and the third sheet is in the reverse process. Thereafter, the first sheet is discharged, the second sheet stays at the lower portion of the transfer paper device, and the third sheet stays at the upper portion of the transfer paper device. The state of FIG. 7 is repeated.

[0017]

As described above, according to the present invention,
The waiting time is short, and the printing efficiency is improved. Specifically, since printing on the first side (front side) of the paper and printing on the second side (back side) can be performed continuously, there is no waiting time for paper reversal, and high-speed double-sided printing is possible. Become.

[Brief description of the drawings]

FIG. 1 is a sectional view of a printing apparatus according to an embodiment of the present invention.

FIG. 2 is a control block diagram of the printing apparatus showing one embodiment of the present invention.

FIG. 3 is a diagram illustrating a state in which paper remains at a lower portion of a non-transfer paper device after printing of a first sheet (front side).

FIG. 4 is a diagram showing a state in which sheets stay at the upper and lower portions of the anti-transfer paper device after the second sheet (front side) is printed.

FIG. 5 is a diagram showing a state during printing of a third sheet (front side).

FIG. 6 is a diagram showing a state in which the first sheet is fed and the second sheet is moved from the upper portion to the lower portion of the non-transfer sheet device after the third sheet has passed through the registration roller 12.

FIG. 7 is a diagram illustrating a state in which the first sheet (back side) is being printed, the second sheet is staying at the lower portion of the transfer paper device, and the third sheet is in a reversing process.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Developing device 1, 2 ... Developing device 2, 3 ... Developing device 3, 4 ... Developing device 4, 5 ... Optical unit, 6 ... Paper cassette 1, 7 ... Paper cassette 2, 8 ... Charging device, 9 ... Reversal temporary storage unit, 10
.., Paper feed rollers 1, 12, registration roller, 13, transfer roller, 14, paper guide, 14-a, paper regulation guide section, 15, static eliminator, 16, transport rollers a, 16-a, first transport roller Pair, 16-a-1 ... one roller, 16
-A-2: the other roller, 16-b: the second conveying roller pair, 17: switch, 18: paper discharge roller, 19: fixing device,
20, 23 cleaner, 21 transfer drum, 22 photosensitive belt, 24 paper feed roller 2, 25 printing device body, 2
6 anti-transfer paper device, 27 paper, 28 discharge tray, 2
9 ... paper detector b, 30 ... printing device main body control unit, 31 ...
Anti-transfer paper device controller, 160 ... Erase lamp, 161
Detector 171 Solenoid 172 Paper detector a 173 Paper discharge detector 176 Paper guide 177
... Transport roller b.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akira Shimizu 1-1-1 Higashitaga-cho, Hitachi City, Ibaraki Prefecture Inside the Taga Headquarters, Electrical Equipment Division, Hitachi, Ltd. (72) Inventor Yoshio Ouchi Higashi Hitachi City, Ibaraki Prefecture 1-1-1, Tagacho, Hitachi, Ltd.Electrical Equipment Division, Taga Headquarters (72) Inventor Kazuhiro Wakamatsu 1-1-1, Higashitagacho, Hitachi City, Ibaraki Prefecture Hitachi, Ltd.Electrical Equipment Division, Taga Headquarters (72) Inventor Satoshi Narita 1-1-1, Higashitaga-cho, Hitachi City, Ibaraki Prefecture F-term (reference) 2H028 BA06 BA09 BA16 BB02 3F053 BA03 BA12 BA14 BA18 LA07 LB01 3F100 AA02 CA12 CA14 DA01 EA07

Claims (5)

[Claims] A sheet cassette for storing sheets, a recording member on which a toner image based on image information is formed, a sheet passage for sending the sheet to the recording member for transferring the toner image onto the sheet, A fixing device for fixing the toner image; a reversing path for reversing the fixed sheet to transfer the toner image to the other surface of the sheet on which the toner image is fixed; A transport path for feeding the paper to the path, and a switch for selecting whether to feed the paper that has passed through the fixing device to the reverse path, or to feed the paper that has been fed to the reverse path to the transport path. And a paper feeder so that at least a part of each of the two papers is included in a passage from the junction of the paper passage and the transport passage to the switch. Double-sided printing device. 2. The apparatus according to claim 1, wherein the first sheet is contained in a relatively upstream portion of a path from a junction of the sheet path and the transport path to the switch, and the first sheet is contained in the path. A double-sided printing apparatus capable of feeding a second sheet in a downstream portion. 3. The toner as claimed in claim 1, wherein at least a part of each of the two sheets is included in a path from a junction of the sheet path and the transport path to the switch. A double-sided printing apparatus characterized in that an image can be transferred so that the image can be transferred. 4. The apparatus according to claim 1, wherein a first roller and a second roller which are rotatable independently of each other are arranged in the transport path, and the two sheets are independently rotated by the first and second rollers. A double-sided printing device characterized in that it can be fed to a printer. 5. A paper discharge switching section, a paper transport section, and said paper transport section include a first transport roller pair and a second transport roller pair, wherein said first and second transport roller pairs are respectively provided. A two-sided printing apparatus having an independent drive source, the paper transport unit having a length capable of storing two or more sheets of paper, having a paper draw-in unit, and a reversing drive unit, including a non-transfer paper device; After one part of the paper stays in the lower part of the paper transport part, and another part of the paper discharged from the printing apparatus main body is inverted in the paper draw-in part and stays in the upper part of the paper transport part, Controlling to simultaneously feed the two sheets of paper toward the printing apparatus main body.
Double-sided printing device.