JPH0891643A - Image forming device - Google Patents

Abstract

PURPOSE: To easily perform the manual double-side printing without generating the condition that an operator feels confusion. CONSTITUTION: In the case where a double-side carrying unit 101 is not connected to a printer main body 100 when the double-side printing command is output, the cassette paper feeding command is output so as to feed the paper from a paper feeding cassette 33, and the single-side printing process is carried out, and the surface of the paper is printed, and the paper is discharged outside of a device. Continuously, a message indication for turning over the printed paper and for inserting it into a manual tray 50 is displayed in a display unit 53. Setting of the paper on the manual tray 50 is confirmed on the basis of the output of a sensor, and a manual paper feeding roller 34 is driven by the manual paper feeding command, and the paper on the manual tray 50 is pulled into the device, and the back surface of the paper is printed, and the paper is discharged outside of the device. In the case where the signal receiving data is left more, printing of the surface of the paper by the cassette paper feeding and printing of the back surface thereof by the manual paper feeding are carried out each other.

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 having a double-sided printing function capable of printing on both sides of paper.

[0002]

2. Description of the Related Art In recent years, there has been a great demand for image forming apparatuses to provide a printer with a double-sided printing function from the viewpoint of ecology (resource saving). In particular, since a page printer using an electrophotographic technique such as a laser beam printer often uses a large amount of paper, the double-sided printing function is becoming especially important for the page printer. Conventionally, the following two methods have been used to perform double-sided printing.

First, as a first method, the paper loaded in the paper cassette or the paper tray is fed to the printing unit,
For the paper feed, the paper is first printed on the front side of the paper according to a predetermined printing process, then the paper whose printing on the front surface is finished is reversed by a switchback operation, and the reversed paper is fed again to the printing section. Then, the back side of the paper is printed by the same printing process as above. This first method can automatically perform double-sided printing without the intervention of an operator.

The second method is a method in which an operator intervenes. The printer prints on the surface of the paper fed from the paper cassette or the paper tray, and then once stops the printing operation. Next, the printer prompts the operator to set the already printed paper on the paper cassette or paper tray by manually reversing it on the display or alarm buzzer, etc. Is printed. In this way, the front surface and the back surface of the paper are printed alternately.

Generally, the above-mentioned first method is called an automatic double-sided method, while the second method is called a manual double-sided method.

[0006]

However, the above-mentioned conventional automatic double-sided system and manual double-sided system have the following drawbacks.

In the automatic double-sided method, it is necessary to carry out a switchback operation for the paper which has been printed once and convey the paper to a place for re-feeding. For this operation, it is necessary to convey the printing paper over a distance of one or more sheets. In particular, an electrophotographic printer has a relatively large size as compared with other types of printers, and therefore the distance from printing to re-feeding is very long. When the paper is conveyed over a long distance, the paper becomes skewed. Therefore, in the automatic double-sided method, it is necessary to provide a mechanical mechanism for correcting the skew of the paper once printed, which is structurally complicated and expensive.

On the other hand, in the manual printing method, the operator naturally sets the paper in the paper feeding section each time printing is performed, and sequentially issues a printing command to the printer (for example, a work of pressing an operation key of the printer). It was necessary and had the drawback of being very annoying.

The present invention has been made in view of the above points, and an object of the present invention is to provide an image forming apparatus which allows an operator to easily perform manual double-sided printing without being confused with the operation. Especially.

[0010]

In order to achieve the above object, the present invention is directed to an image processing means for generating print image information based on information received from an external information processing device, and to convey a stacked paper sheet. 1 sheet feeding means, and a second sheet feeding means for conveying the sheet manually received from the operator,
A printing unit that forms a print image on the paper conveyed from the first or second paper feeding unit based on the output information of the image processing unit, and drives the first paper feeding unit according to a double-sided printing command. Then, the printing means executes the printing processing on one surface of the paper, and after confirming the manual feeding, the second paper feeding means is driven to execute the printing processing on the other surface of the same paper by the printing means. And a control unit that repeats the control operation until the output information is exhausted.

Further, according to one aspect of the present invention, the control means drives the first paper feeding means to cause the printing means to perform a printing process on one surface of the paper, and thereafter, the control means outside the machine. It is possible to use a display means to give a message instruction to invert the printed paper discharged to the sheet by hand and place it on the manual feed tray of the second paper feeding means.

Further, as another aspect of the present invention, the image forming apparatus reverses the paper printed by the printing means, and reversely feeds the paper to the printing means again to print the back surface of the paper. It is detachable from the apparatus, and the control means determines whether or not the reverse sheet feeding device is mounted, and executes the control operation when the reverse sheet feeding device is not mounted. it can.

Further, as another aspect of the present invention, the control means controls the image processing means to generate print image information of all odd pages and drives the first paper feeding means to perform the printing. Means for collectively executing the printing processing of all the odd pages on the surface of the paper, and then controlling the image processing means to generate the printing image information of all the even pages to generate the second feeding means. It is possible to control to drive all the even-numbered pages on the back surface of the paper by the printing means at the same time.

[0014]

According to the present invention, the image processing apparatus for generating the print image information based on the information received from the external information processing apparatus, the first sheet feeding apparatus for conveying the stacked sheets, and the sheet manually received from the operator A second paper feeding device for feeding the paper; and a printing device for forming a print image on the paper fed from the first or second paper feeding device based on the output of the image processing device. When a double-sided printing command is issued to the image processing device by a key input instruction from the information processing device or the operator, the first paper feeding device is operated, and then the operator is instructed to perform a manual feed operation on the back surface, Operate the paper feeder.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(First Embodiment) First, a first embodiment of the present invention will be described. In this embodiment, the present invention is applied to a laser beam printer. The circuit configuration of the control unit of the laser beam printer is shown in FIG. In FIG.
The laser beam printer can be roughly divided into an image control unit 1 and an engine control unit 2. The image control unit 1 receives image data encoded by an external host computer,
The code data is converted into bit-mapped pixel data, and the pixel data is sent to the engine control unit 2. Further, the engine control unit 2 has a role of forming a toner image on the front surface or the back surface of the recording material paper according to the pixel data received from the image control unit 1.

FIG. 2 shows the internal structure of the laser beam printer of the first embodiment.

In FIG. 2, reference numeral 100 denotes a main body of the laser beam printer, and 101 is a double-sided conveyance unit detachable from the main body 100. The operation of the embodiment of the present invention will be described below with reference to FIGS. In addition, the same code | symbol is attached | subjected to the common component part in FIG.1 and FIG.2.

In FIG. 1, the image control unit 1 has a CPU (central processing unit) 7 as a control means. The CPU 7 has an external I / O (input / output unit) 3, a pixel data RAM ( Random access memory) 4, program ROM (read only memory) 5, code storage R
The AM6, the DMA (direct memory transfer) controller 8, the engine control I / O 9 and the display unit 52 are connected to each other via the internal bus 11. The internal bus 11 is composed of a data bus, an address bus, and a control bus, and the CPU 7 can access each device.

The image controller 1 has an external interface 10
(For example, Centronics parallel interface or RS232C serial interface) receives coded image data. The code data is input to the external I / O3.

The CPU 7 stores the code input via the external I / O 3 in the RAM as the image data transmission preparation process.
6, the code data is converted into pixel data according to a predetermined format, and the pixel data is stored in a specific address of the RAM 4. This RAM
Reference numeral 4 is a so-called bitmap memory. A program for converting code data into pixel data is stored in the ROM 5. The conversion and storage are performed as described above, and the CPU 7
Confirms that the engine control unit 2, which will be described later, can receive data, and activates the DMA controller 8. Next, the DMA controller 8 reads out the pixel data stored in the RAM 4 exclusively from the internal bus 11 from a predetermined address. When the DMA controller 8 becomes active, the CPU 7 and the DMA controller 8 alternately occupy the internal bus 11. The DMA controller 8 reads pixel data from a predetermined address of the RAM 4 and converts the pixel data into serial data. D
The MA controller 8 is then operated by the engine control unit 2 which will be described later.
The serialized image signal 14 is sent to the engine controller 2 in synchronization with the horizontal synchronizing signal received from the engine controller 2. The engine controller 2 forms a toner image according to the image signal 14.

As described above, the image control unit 1 converts the image data received from the outside into a serialized (that is, rasterized) image signal, and sends the signal to the engine control unit 2. In addition, the image controller 1 also has a role of instructing the engine controller 2 to execute a specific operation of the engine controller 2 via the serial communication line 12. The command for the operation is sent by the engine control I / O 9 to the one-chip microcomputer 15 as the image forming control means and the paper feed control means. Further, the image control unit 1 can know the internal information of the engine control unit 2 via the serial communication line 12.

The one-chip microcomputer 15 in the engine control unit 2 detects through the various sensors 26 whether or not the double-sided conveyance unit 101 of FIG. 2 is attached to the printer body 100, and the presence or absence of the attachment is serially communicated. Line 12
The image control unit 1 is notified via.

It is assumed that the image controller 1 receives a double-sided printing command from the host computer via the external interface 10. Next, when the CPU 7 determines that the code data received from the host computer has reached one page and that the double-sided transport unit is not installed, the CPU 7 determines that the one-chip microcomputer via the engine control I / O 9. A cassette paper feed command is sent to 15.

When the one-chip microcomputer 15 receives this cassette paper feed command, it activates the laser scanner motor driver 21 and rotates the laser scanner motor 22. At the same time, the one-chip microcomputer 15 activates the main motor driver 23, rotates the main motor 24, and rotates the photosensitive drum 38, the heating roller 28, and the pressure roller 43. Further, the main motor 24 also has a role of conveying the paper.

When the one-chip microcomputer 15 detects that the number of rotations of the laser scanner motor 22 reaches a predetermined value, it outputs a laser forced lighting command to the laser control circuit 16. The laser control unit 16 drives the laser driver 17 by this command, and the semiconductor laser 1
8 emits light. A laser beam emitted from the semiconductor laser 18 is applied to a rotating polygon mirror 44 by a laser scanner motor 22, and the beam is reflected by the reflecting mirror 3.
Scan over 7. The beam reflected by the reflection mirror 37 scans the photosensitive drum 38. That is, the output beam of the semiconductor laser 18 scans the surface of the photosensitive drum 38 by the polygon mirror 44. On the other hand,
A part of the reflected beam of the polygon mirror 44 is incident on the beam receiving element 20. The beam incident on the beam receiving element 20 is converted into an electric signal, and the beam detection circuit 1
It is converted into a digital pulse signal by 9.

The pulse signal output from the beam detection circuit 19 enters the laser control circuit 16, and the pulse signal is sent to the image control unit 1 as the horizontal synchronizing signal 14. Once the laser control circuit 16 can output the horizontal synchronization signal, the semiconductor laser 18 is partially stopped so that the semiconductor laser 18 is forcibly stopped from being fully turned on and the laser beam scans only the vicinity of the beam receiving element. Turn on the light.

On the other hand, the one-chip microcomputer 15
After starting to rotate the main motor 24, the high voltage is sequentially applied to the primary charger 39, the developing device 36, and the transfer charger 40 via the high voltage generation circuit 45. Further, the one-chip microcomputer 15 starts rotating the main motor 24, and after confirming that the temperature of the heating roller 28 has risen to a predetermined value, drives the paper feed roller 51 to load it on the cassette 33. Feed the paper. The fed paper is temporarily stopped by the registration roller 35. After the conveyance paper stops at the registration rollers 35, the laser scanner motor 2
When 2 reaches the specified number of rotations and the horizontal synchronizing signal 14 can be normally output, the one-chip microcomputer 15 drives the registration roller 35. Here, the rotation of the paper feed roller 34 and the registration roller 35 is turned on / off (rotated / non-rotated) by various solenoids 25. The one-chip microcomputer 15 drives the registration roller 35 and notifies the image controller 1 that it is ready to receive an image signal via the serial communication line 12 immediately. The CPU 7 of the image control unit 1 knows this information through the engine control I / O 9 and activates the DMA controller 8. Thereby, the DMA controller 8 reads the pixel data from the RAM 4 and outputs the serial image signal 13 to the laser control circuit 16 in synchronization with the horizontal synchronizing signal 14. The laser control circuit 16 drives the laser driver 17 based on the image signal 13 so that the semiconductor laser 18 outputs a beam modulated by the image signal. This modulated beam enters the polygon mirror 44, is reflected by the reflection mirror 37, and
The surface of the photosensitive drum 38 is scanned.

The surface of the photosensitive drum 38 is charged by the primary charger 39, and the charged drum 38 is charged.
A latent image is formed on the surface of the photosensitive drum 38 by scanning the modulated laser light on the surface of the photosensitive drum 38. This latent image is converted into a toner image by the developing device 36, and is transferred onto a sheet of paper by the transfer charger 40. The conveying paper on which the toner image is placed moves on the conveying guide 42 and enters between the rotating heating roller 28 and the pressure roller 43. The toner on the conveyed paper is fixed on the paper by heat and pressure received from the heating roller 28 and the pressure roller 43. The conveyed paper on which the toner is fixed is discharged to the paper discharge tray 46 outside the printer. Further, the unnecessary toner remaining on the surface of the photosensitive drum 38 without being transferred to the paper is collected by the cleaner 41.

In the fixing process of this toner,
The surface temperature of the heating roller 28 is kept constant by the one-chip microcontroller 15. The surface temperature of the heating roller 28 is transmitted to the thermistor 29, the terminal voltage of the thermistor is transmitted to the AD converter 30, and the output value of the AD converter 30 is input to the 1-chip microcontroller 15. 1-chip microcontroller 1
Reference numeral 5 turns ON / OFF the heater driver 27 so that the output value of the AD converter 30 becomes a predetermined value. As a result, the surface temperature of the heating roller 28 is maintained at a constant value.

The printing on the front surface is completed as described above.
After this front side printing is completed, the CPU 7 causes the internal bus 11
A predetermined message is sent to the display unit 52 via.
The display unit 52 displays the message, that is, an instruction to insert the already-printed paper into the manual feed tray 50 for printing on the back side. At this time, it is also preferable to use a buzzer sound or message utterance.

According to the instruction, the operator manually turns over the paper on the paper discharge tray 46, which has already been surface-printed, and inserts it into the manual paper feed tray 50. When the 1-chip microcontroller 15 detects the presence of paper on the manual tray 50 by the manual paper sensor 53, the 1-chip microcontroller 15 notifies the image control unit 1 of the detection result via the serial communication line 12.

The image control unit 1 develops the image information on the back surface received from the host computer through the external interface 10 into bitmap information, and sends a manual paper feed command to the 1-chip microcomputer 15 through the serial communication line 12. . The 1-chip microcomputer 15 follows the manual paper feed instruction received by the manual paper feed roller 3
4 is driven to convey the paper set in the manual feed tray 50. Further, similarly to the above-described front side electrophotographic printing process, the back side printing process is performed, and the paper printed on both sides of the paper is carried out to the discharge tray 46 outside the machine.

When the image information received by the image control unit 1 via the external interface 10 is three pages or more (that is, two or more sheets of double-sided printing paper), the above-mentioned front side printing process is repeated. In this way, cassette feeding is performed when the front side of the paper is printed, and manual feeding is performed when the back side of the paper whose front side has been printed is printed. To do.

The case where the double-sided conveyance unit 101 is not attached to the printer body 100 has been described above. The case where the double-sided conveyance unit 101 is attached to the printer body 100 will be briefly described below.

In the case of the front side printing, the sheet feeding from the sheet feeding cassette 33 and the printing in the electrophotographic process are the same as in the case where the double-sided conveying unit 101 does not exist. When the printed paper is about to leave the printer body 100, the flapper 45 in the double-sided transport unit 101 operates and the paper is drawn into the transport path 55 in the double-sided transport unit 101.
Then, the paper passes between the drive rollers 47 and advances toward the switchback conveyance path 56. When the paper sensor 58 detects that the trailing edge of the paper passes through 58, the drive roller 47
Rotate in the opposite direction, which causes the paper to be reversed
It is carried to 7. Further, when the leading edge of the paper reaches the paper sensor 59, the transport rollers 48 and 49 stop.

When the image controller 1 finishes generating the backside bitmap image, the image controller 1 sends a backside paper feed command to the one-chip microcomputer 15 via the serial communication line 12. In response to this command, the 1-chip microcomputer 15 drives the transport rollers 48 and 49 again,
After that, the back surface of the paper is printed by the same electrophotographic process as described above, and is discharged to the outside of the machine. The double-sided printing operation when the double-sided transport unit 101 is connected is the same as the conventional example.

FIG. 3 is a flowchart showing the outline of the operation procedure of the first embodiment of the present invention described in detail above. The detailed contents of each step S1 to S16 are as described above, but to be sure, in brief description, there is a double-sided printing command (S1, S2), after one page of data has been developed (S3), the double-sided transport unit 101 When it is confirmed that is not connected to the printer main body 100 (S4), a cassette paper feed command is issued (S5), and a single-sided printing process by paper feed from the cassette 33 prints on the front surface of the paper and discharges it out of the machine. (S6). Then, the operator prints out the printed sheet by hand (reverses) and outputs a message instruction to the display section 52 to insert it into the manual feed tray 50 (S7). The insertion of the paper is confirmed by turning on the manual paper sensor 53 (S8), and after developing one page of data (S9),
Manual paper feed command is issued (S10), and manual paper feed roller 3
4 to drive the paper on the bypass tray 50 into the machine,
Printing is performed on the back side of the paper by the one-sided printing process, and the paper is ejected outside the machine (S11). If the received data remains (S
12) Return to step S3, and if there is no received data, the process ends.

(Second Embodiment) The flowchart of FIG. 4 shows the operation procedure of the second embodiment of the present invention. The electrical structure and mechanical structure of the second embodiment are the same as those of the first embodiment described above. The control method of the second embodiment differs from that of the first embodiment.

The contents of the second embodiment will be described below with reference to FIGS. 1, 2 and 4.

The image controller 1 receives a double-sided printing command from the host computer via the external interface 10 (S21). The image control unit 1 receives code data for a plurality of pages. If the double-sided conveyance unit 101 is not attached to the printer body 100 (S22), the image controller 1 first develops an odd page into pixel data (S2).
3). The image controller 1 instructs the engine controller 2 to feed the cassette (S24). Odd pages are continuously printed by the electrophotographic process described in the first embodiment (S25 → S26 → S24 → S25 ...), and the printed paper is ejected out of the machine.

After confirming that all the odd-numbered pages have been printed (S26), the image control unit 1 displays on the display unit 52 that the entire surface has been printed, and further reverses all the already printed paper. It is displayed so as to be set on the manual feed tray 50 (S27).

The image control unit 1 develops even-numbered pages of pixels (S28), and after the operator sets the front-printed sheet bundle on the manual feed tray 50 (S29), the engine control unit 2 is continuously operated. The back side printing operation is commanded (S30). In this way, double-sided printing is achieved (S31 → S32 → S30 → S31 → ...) If the double-sided transport unit 101 is attached to the printer main body 100 (S22), the double-sided printing is performed as in the first embodiment. Perform double-sided printing operation using the transport unit (S33, S3
4).

Other Embodiments In the above-described embodiments of the present invention, the case where the present invention is applied to a laser beam printer as an image forming apparatus is shown, but the present invention is not limited to this, and the present invention is a liquid crystal printer using a liquid crystal array. It is suitable for an electrophotographic printer such as an LED printer using an LED array. In addition, the present invention can be applied to all printers in which a recording head or a printing unit is provided only on one side of a sheet conveyance path and the sheet is reversed and recorded for double-sided recording. Further, it is needless to say that the present invention can be applied to a facsimile machine having such a printer built therein.

[0045]

As described above, according to the present invention,
Since the front side of the paper is printed by cassette feeding and the back side of the paper is manually fed, double-sided printing can be easily achieved without any hesitation by the operator.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration of a carrier system of an apparatus according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing the mechanical structure of the device according to the first embodiment of the present invention.

FIG. 3 is a flowchart showing an operation procedure of the first embodiment of the present invention.

FIG. 4 is a flowchart showing an operation procedure of the second embodiment of the present invention.

[Explanation of symbols]

 1 Image Control Section 2 Engine Control Section 3 External I / O 7 CPU 9 Engine Control I / O 10 External Interface 12 Serial Communication Line 15 1 Chip Microcomputer 16 Laser Control Circuit 18 Semiconductor Laser 20 Beam Receiving Element 22 Laser Scanner Motor 27 Heater Driver 28 Heat roller 33 Paper feed cassette 34 Manual feed roller 38 Photosensitive drum 44 Polygon mirror 45 Flapper 46 Paper ejection tray 47, 48, 49 Drive roller 50 Manual feed tray 51 Paper feed roller 53 Manual paper sensor 56, 57 Conveyance path 100 Printer Main body 101 Double-sided transport unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location G03G 21/00 376 (72) Inventor Tetsuo Kishida 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Kenfumi Takubo 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (4)

[Claims] 1. An image processing means for generating print image information based on information received from an external information processing device, a first paper feeding means for conveying stacked paper sheets, and a paper sheet manually received from an operator. A second paper feeding means for carrying the paper; a printing means for forming a print image on the paper carried from the first or second paper feeding means based on the output information of the image processing means; , Driving the first paper feeding means to cause the printing means to perform printing processing on one surface of the paper, and after confirming the manual feeding, driving the second paper feeding means to perform the same printing by the printing means. An image forming apparatus comprising: a control unit that repeats a control operation for executing a printing process on the other surface of the paper until the output information is exhausted. 2. The control unit drives the first paper feeding unit to cause the printing unit to perform a printing process on one surface of the paper, and then causes the operator to eject the unprinted paper to the outside of the machine. 2. The image forming apparatus according to claim 1, wherein the display unit is used to give a message instruction to reverse the sheet by hand and place it on the manual feed tray of the second sheet feeding unit. 3. The image forming apparatus is attachable to and detachable from a reversing paper feeding device that reverses the paper printed by the printing means and conveys the paper to the printing means again so as to print the back surface of the paper. 3. The image according to claim 1, wherein the control unit determines whether or not the reverse paper feeding device is mounted, and executes the control operation when the reverse paper feeding device is not mounted. Forming equipment. 4. The control means controls the image processing means to generate print image information of all odd pages, drives the first paper feeding means, and causes the printing means to print on the surface of paper. Printing processing for all odd pages is executed collectively, and then the image processing means is controlled to generate printing image information for all even pages to drive the second paper feeding means to drive the printing means. 4. The image forming apparatus according to claim 2, wherein the control is performed to collectively execute the printing processing of all the even pages on the back surface of the paper.