JP2002200792A - Perfecting printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a perfecting print having a stabilized print quality by preventing occurrence of sheet jam, incomplete print, and the like, expected in rear surface print without requiring an operation for altering set values at the time of extension of an apparatus. SOLUTION: Means for storing rear surface print conditions ROM is provided independently in an inverter 51 performing perfecting print and when the printer body performs rear surface printing, rear surface print conditions in the means for storing rear surface print conditions are referred.

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 The prior art is disclosed, for example, in Japanese Patent Application Laid-Open No. 9-404.
No. 03 invents a method for increasing the printing speed of double-sided printing. Also, in Japanese Patent Application Laid-Open No. 05-016438,
An additional double-sided printing mechanism has been invented, which is additionally provided outside the apparatus main body and re-feeds the paper on which one-side printing has been performed to the main body.
In these prior arts, there is no independent reversing device control means, storage means, etc. inside the double-sided printing mechanism which is a paper reversing device. In the case of printing, two operations are performed, and the processing may be complicated. Also, no consideration is given to preventing a decrease in print quality on the back surface, which is expected to occur when performing double-sided printing.

[0003]

Generally, in a double-sided printing apparatus, a sheet printed on one side is reversed and printing is performed again. The paper printed on one side may be slightly deformed due to the adhesion of ink or toner, etc., and therefore, when the back side printing is performed, paper jams, transfer abnormalities, and the like are expected. Therefore, in the case of back side printing, it is necessary to perform printing under the printing conditions with respect to the front side.

[0004] In addition, if a double-sided printing device is added as an option to a single-sided printing device that is shipped later, if the printing condition settings on the back side are not optimized, paper jams, abnormal transfer, and the like may occur. Expected to occur. When such a problem occurs, a user or a service person operates a panel, a button, etc., which are operation / display means provided in the printing apparatus main body, and changes the setting of the printing condition and the transfer condition to an optimum one. Requires a series of work. As described above, a problem is to prevent paper jams and abnormal transfer during double-sided printing from occurring, and to prevent operations such as changing settings of the printing apparatus.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a printing apparatus in which single-sided printing is performed, reversed by a paper reversing device, and sent to a printing device again to perform double-sided printing. As a method for optimizing the difference in printing conditions on the back side, an external storage means for storing printing conditions for back side printing is provided in the paper reversing device, and the printing apparatus main body control means uses the communication means using communication means. The printing apparatus main body control means can refer to the contents of the external storage means, and can perform printing using the optimum printing conditions for backside printing. As a result, when performing double-sided printing by adding a paper reversing device to a single-sided printing device, it is not necessary to change the setting of printing conditions for backside printing, and paper jams and transfer abnormalities can be prevented beforehand. The above problem is solved.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The operation of one embodiment of the present invention will be described below with reference to FIG.

The printing apparatus main body 21 includes developing devices 1 to 4,
Mainly includes an optical unit 5, a charger 8, a photosensitive belt 18, a transfer drum 17, a registration roller 11, a transfer roller 12, a static eliminator 14, a fixing unit 15, a paper discharge roller 13, and paper cassettes a6, b7, and a switch a35. It is a component.
The anti-transfer paper device 22 includes transport rollers a33, b34, c37,
The paper sensors c31 and d32, the solenoid a27, the solenoid b28, and the switch b36 are main components.

The operation of the printing device main body 21 and the sheet reversing device 22 will be described. The charger 8 uniformly charges the photosensitive belt 18 in response to a print start signal from a host (not shown). The optical unit 5 draws a latent image on the photosensitive belt 18 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 18. The photosensitive belt 18 is rotated by a driving source (not shown), and transfers the colored particles onto the transfer drum 17 onto the photosensitive belt 18. Photosensitive belt 18
Is neutralized by the erase lamp 25 and the photosensitive belt 1
Excess colored particles remaining on the surface 8 are removed by the cleaner 19 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. A visible image is formed on the transfer drum 17 by colored particles of a single color or a plurality of colors, and the paper 23 is fed from the paper feed cassette a6 or the paper feed cassette b7 at the time when the desired transfer is completed or in advance. It is pulled out by the roller a9 or the paper feed roller b10, and stands by at the registration roller 11. After a sheet is detected by the sheet sensor a29, the sheet feeding roller a10 or the sheet feeding roller b10 stops at a predetermined time. At a timing when the position of the visible image formed on the transfer drum 17 coincides with the transfer position on the sheet, the sheet waiting at the registration roller 11 starts to be conveyed again, and the sheet at the transfer roller 12 starts. To transfer the visible image to the paper side. The paper is separated from the transfer drum 17 by the neutralizer 14, and the colored particles are fixed to the paper by the fixing device 15. When printing on one side only,
The switch a35 does not operate, and the sheet is discharged to the discharge tray 24 side.

In the case of double-sided printing, the solenoid a27 operates, the switch a35 moves to the right in FIG. 1, guides the sheet into the sheet reversing section 20, and the sheet is reversed by the transport roller a33 at the lower portion of the reversing device. Conveyed to the section 20. In the sheet reversing section 20, when the sheet sensor d32 detects the sheet, the sheet is fed by a predetermined amount to the left in FIG. 1, the solenoid b28 is operated, the switch b36 moves upward in FIG. 1, and the transport roller b34 is rotated in reverse. Then, the rear end of the sheet is fed to a position near the conveyance roller c37 near the main body sheet feeding port. Thereafter, the transport roller b is rotated at an appropriate timing, and the paper is sent to the transport roller c37. The transport roller c37 waits when the paper is fed to the registration roller 11. After that, transfer, peeling and fixing are performed in the same procedure as for single-sided printing.
Without switching the switch a35, the paper is discharged to the paper discharge tray 24, and the double-sided printing is completed.

FIG. 2 shows a control block diagram thereof. The control blocks are roughly two blocks of a printing device main body control unit 50 and a sheet reversing device control unit 51. The printing device main unit control unit 50 exchanges data with the host, an I / F unit, an exposure, a development, a fixing unit, a motor as a power source, a solenoid driving unit, an operation / display unit, a paper feeding unit, It is composed of several paper sensors and the like. In the above-described printing operation, the transfer voltage for single-sided printing and the static elimination voltage of the static eliminator are stored in the data storage unit in the printing apparatus main body control unit 50, and the data stored during the printing operation is read. However, each voltage is generated. The data storage unit is an EE that can electrically erase and write data.
A PROM (Electrically Erasable Programming ROM) is used. The data stored in the data storage unit is
Data can be changed and stored using buttons, screens, and the like on the display unit. Further, it has a connection detecting unit for detecting that the sheet reversing mechanism is attached, and a serial communication interface for exchanging data with the sheet reversing device control unit 51.

Next, the sheet reversing device control section 51 includes a CPU,
One-chip microcomputer having a built-in ROM, RAM, serial communication interface, a solenoid drive circuit for operating the switches a35 and b36, and transport rollers a33 and b3 for transporting the paper in the paper reversing unit 20
A driving circuit for driving a motor as a driving source 4 and a sheet sensor input for detecting a sheet are provided, and all the conveyance control of the sheet fed into the sheet reversing device is performed in the sheet reversing device control section. Specifically, this is performed by exchanging various commands on a serial communication line connecting the printing apparatus main body control unit 50 and the reversing device control unit 51. Hereinafter, the command transmitted by the printing apparatus main body control section 50 and the operation of the reversing apparatus control section 51 which has been received will be described.

First, the following commands are issued during the duplex printing operation. (1) Switch-a activation instruction: The solenoid a27 is driven to switch the switch a35 to the reversing device side. Further, a motor is driven to rotate the transport roller a33. (2) Switch a end command: The solenoid a 27 is turned off to switch the switch a 35 to the main unit side. (3) Paper feed command: A motor is driven to transfer the paper stopped after the reversal to the transport roller c37 using the transport roller b34.

[0013] Further, there are the following commands periodically transmitted regardless of whether the sheet reversing device is operating or stopped. (4) Sensor information inquiry: The sensor level in the paper reversing device is transmitted. The printer controller is used to determine a paper jam. (5) Inquiry of paper jam information: When it is determined that the paper does not reach the paper sensor within a predetermined time during paper conveyance in the paper reversing device, it is determined that the paper is jammed and the operation of the paper reversing device is performed. It stops and notifies the printing device main body control unit. (6) Inquiry of failure information: When there is an abnormality in the sheet reversing device, it notifies the printing device main body control unit.

As described above, the properties of the paper printed on one side and inverted for the printing on both sides are changed due to the curl of the paper and the adhesion of toner. Therefore, the same printing conditions as the front surface are used for the back surface printing, specifically, the transfer roller 1
In most cases, printing cannot be performed well with the transfer voltage of 2 and the discharge voltage of the discharger 14 for peeling. Therefore, in a printing apparatus that performs double-sided printing, the following is used as a command transmitted by the printing apparatus main body control unit 50 as a method that takes into account printing conditions during backside printing. (7) Inquiry of backside printing condition set value: The backside printing condition set value stored in the ROM in the paper reversing device control unit 51 is notified to the printing device main body control unit 50. Normally, the setting values are stored in a ROM in which the operation of the sheet reversing device 22 is stored in the form of program data.
This is realized by storing the set value of the static elimination voltage data.

FIG. 3 is a flowchart showing a printing operation performed by the printing apparatus main body control unit 50. (A) Wait for print request from host. (B) developing image data from the host onto a photosensitive belt,
The toner is transferred using a developing device and transferred onto a transfer drum. (C) Judge whether the printing is front side printing or back side printing. Go to (d) for front side printing. Go to (f) for back side printing. (D) Paper is fed from the paper feed cassette a6 or b7. (E) Reading the set values of the transfer voltage and the static elimination voltage from the storage unit. Then go to (i). (F) Send a paper feed command to the reversing device control unit 51. The reversing device control unit 51 that has received the signal activates the motor, rotates the transport roller b34, and delivers the sheet to the transport roller c37. (G) Send a back side printing condition setting value inquiry to the reversing device control unit 51. The reversing device control unit 51 that has received the ROM
The back side printing condition set value stored in the printer is read and transmitted to the printing apparatus main body control unit 50. (H) Waiting for reception of the back side printing condition set value sent from the reversing device control unit 51. When reception ends, go to (i). (I) The transfer voltage and the static elimination voltage are determined from the set values. (J) The transfer by the transfer roller 12, the charge elimination by the charge eliminator 14, and the fixing by the fixing unit 15 are performed. (K) Determine whether printing is completed. If printing is completed (m)
What. When printing on the back side, go to (l). (L) Send a switch a activation instruction. The reversing device control unit 51 that has received the signal activates the solenoid a27. Then, the switch a35 moves to the right in FIG. 1, and the sheet is sent to the sheet reversing device 22. Thereafter, when the conveyance is completed, the process returns to the process (a). (M) Send a switch a end command. The reversing device control unit 51 that has received the signal turns off the solenoid a27. Then, the switch a35 moves to the left side in FIG.
It is discharged to 4. This completes the printing.

As described above, according to the present invention, when a sheet reversing device is added to a single-sided printing device to perform double-sided printing, no manual operation is required to change the setting of the backside printing condition.

Further, as another embodiment, in a printing apparatus in which a sheet reversing device control section is not provided in a sheet reversing apparatus and a sheet reversing apparatus is controlled by a printing apparatus main body control section, an external storage means is provided in the sheet reversing apparatus. The same effect can be obtained if only the ROM is provided so that the main body control unit can refer to and update.

[0018]

According to the present invention, when a double-sided printing mechanism is added to a single-sided printing apparatus, the printing conditions for backside printing are automatically set. And not. In addition, by having all the setting conditions for backside printing on the double-sided printing mechanism side, it is not necessary to match and store the appropriate setting values for backside printing on the single-sided printing device body side, so effective use of memory devices etc. Becomes possible. Further, it is not necessary to use a single-sided printing device to set the optimum printing conditions for paper for double-sided printing, and the effect of shortening the development period of a single-sided printing device capable of adding a double-sided printing mechanism is eliminated. is there. As described above, the present invention is particularly effective for a printing apparatus that performs double-sided printing by adding a double-sided printing apparatus to a single-sided printing apparatus. Prevent
It is possible to provide double-sided printing with stable printing quality.

[Brief description of the drawings]

FIG. 1 is a structural diagram of an example of an embodiment of the present invention.

FIG. 2 is a block diagram illustrating an example of an embodiment of the present invention.

FIG. 3 is a flowchart of print control.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Developer a, 2 ... Developer b, 3 ... Developer c, 4 ... Developer d, 5 ... Optical unit, 6 ... Paper cassette a, 7 ... Paper cassette b, 8 ... Charger, 9 ... Paper feed rollers a, 10 ...
Paper feed rollers b, 11: registration roller, 12: transfer roller, 13: paper discharge roller, 14: static eliminator, 15: fixing device,
DESCRIPTION OF SYMBOLS 16 ... Cleaner, 17 ... Transfer drum, 18 ... Photosensitive belt, 19 ... Cleaner, 20 ... Paper reversing part, 21 ... Printing device main body, 22 ... Paper reversing device, 23 ... Paper, 24 ... Discharge tray, 25 ... Erase lamp , 26 ... paper ejection sensor, 2
7 Solenoid a, 28 Solenoid b, 29 Paper sensor a, 30 Paper sensor b, 31 Paper sensor c, 3
2 Paper sensor d, 33 Transport rollers a, 34 Transport rollers b, 35 Switchers a, 36 Switchers b, 37 Transport rollers c, 50 Printer control unit, 51 Paper reversing unit control Department.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 21/00 376 B41J 29/00 B (72) Inventor Nobuaki Fukasawa 1-1-1, Higashitaga-cho, Hitachi City, Ibaraki Prefecture No. 1 F-term in the Hitachi, Ltd. Electrical Equipment Division (Reference)

Claims (3)

[Claims] 1. A printing apparatus main body for performing single-sided printing, a main body control means for controlling the printing apparatus main body, and a discharge destination switching unit for sending a single-sided printed sheet to a sheet reversing apparatus when performing double-sided printing. Invert the sheet printed on one side to perform double-sided printing and send it to the main unit again, the paper retraction unit that sends the paper sent from the sheet reversing unit to the printer main unit, and the sheet reversing unit. Yes, paper reversing device control means for controlling the paper reversing device, communication means for communicating between the main body control means and the reversing device control means, and the printing device main body, wherein printing conditions of the printing device are stored as set values. Main body storage means, operation / display means capable of changing the set value of the printing condition data, and
External storage means for storing the printing conditions of the printing apparatus main body, and in the printing apparatus having the above, when performing single-sided printing, printing is performed according to the contents of the main body storage means, and the sheet is sent to the sheet reversing unit to perform double-sided printing. In this case, the main body control means is inverted by the paper reversing unit and sent by the communication unit via the paper reversing unit control unit, referring to the printing conditions stored in the external storage unit provided in the paper reversing unit. Double-sided printing device that can print incoming paper under optimal printing conditions. 2. A printing apparatus according to claim 1, wherein said sheet reversing device is detachable as required. 3. The printing apparatus according to claim 1, wherein
A two-sided printing apparatus characterized in that the main body control means can refer not only to the contents in the external storage means but also to update the contents of the main body storage means as needed.