JPH0912200A - Image forming device - Google Patents

Abstract

(57) Abstract: A sheet is discharged in a state in which an image forming surface faces upward or downward according to a command from an image generating device. According to a command input from an image generation device, a conveyance control unit controls a conveyance destination by a deflector to eject a sheet with an image forming surface facing upward or downward.

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 that forms an image on a sheet based on image data output from an image generating apparatus.

[0002]

2. Description of the Related Art In recent years, analog and digital image forming apparatuses have come into wide use.
In particular, in a digital image forming apparatus using a laser beam, a single printer can be shared by a plurality of users by forming a local area network for transmitting image information to an external host computer or the like via a communication line. .

By the way, some printers are of a type that ejects recording paper facedown (printing surface is facing downward) and another type that ejects recording paper faceup (printing surface is facing upward). There is a printer.

The face-down type printer has an advantage that the pages are stacked in the correct page order in a general printing method in which the first page is sequentially printed, but on the other hand, in order to confirm the printing result of the recording paper, the recording paper is printed one by one. Since it has to be turned upside down and the face-up recording paper coming out of the printer section is passed through a curved conveyance path in order to be reversed, it has the disadvantage that the recording paper will curl.

The face-up type printer has an advantage that it is easy to check the print result of the discharged recording paper and the recording paper is hard to curl, but in the general printing method described above, the sheets are stacked in reverse page order. This has the disadvantage that the user has to manually change pages.

[0006]

When a plurality of users share one printer due to the networking as described above, the needs of both the user who ejects face down and the user who eject face up are met. The problem arises that it must be possible.

The present invention has been made in order to solve the above problems, and provides an image forming apparatus capable of discharging a sheet with the image forming surface facing upward or downward according to a command from the image generating apparatus. The purpose is to do.

[0008]

According to the present invention, in an image forming apparatus for forming an image on a sheet based on image data output from an image generating apparatus, the sheet on which the image is formed faces the image forming surface upward. A first transporting means for discharging and stacking onto the first stacking section and a second transporting means for discharging and stacking the image-formed sheet onto the second stacking section with the image forming surface facing downward; A deflecting unit that selectively conveys the formed sheet to either the first conveying unit or the second conveying unit, and selects one of the first stacking unit and the second stacking unit. An input unit for inputting a command for inputting from the image generating apparatus, and a control unit for controlling the destination of the conveyance by the deflecting unit according to the command input by the input unit, and the sheet from the image generating apparatus. Ko There is provided an image forming apparatus characterized by discharging the image forming surface facing upward or downward state according to command.

[0009]

1 is a block diagram of the basic configuration of an image forming apparatus showing an embodiment of the present invention.

In the figure, reference numeral 1 is a paper feeding means for feeding a recording medium (hereinafter referred to as recording paper) to an image forming section (not shown). The paper feeding unit 1 has a plurality of paper feeding units and can feed a large amount of recording papers of different sizes and recording papers of the same size. Reference numeral 2 denotes a sheet discharging unit that stacks recording sheets on which an image has been formed. The paper discharge unit 2 has a plurality of paper discharge units, and stacks recording paper on which image formation has been completed. 3 is a paper feeding / discharging means,
Since it has a paper feed section and a paper ejection section and images are formed on both sides of the recording medium, the recording medium that has completed single-sided image formation is temporarily retained (paper ejection) and the recording sheet is fed again to the image forming section. To do.

Reference numeral 4 denotes a conveyance state detecting means for monitoring the conveyance state of the recording paper. The conveyance state detection unit 4 is provided at a predetermined position on the recording paper conveyance path to detect a paper jam and
The stop state of the recording paper is detected in order to set the paper feed timing. An external device 5 sends image data. 6
Is a conveyance control means, and when the paper is ejected to the paper feed / ejection means 3, the designated recording paper is preferentially conveyed to the paper feed / ejection means 3.

The above-mentioned items 1 to 4 and 6 excluding the external device 5 are collectively called a printer. Hereinafter, the operation of each unit will be described.

When the printer receives image information (including control data, mode selection data, image data, etc.) sequentially sent from the external device 5, the conveyance control means 6 interprets the mode selection data and feeds the paper. A paper feed command for feeding a recording paper of a desired size from any one of the paper feed units of the means 1 is sent to the paper feed means 1. An image is sequentially formed on the recording paper fed at a predetermined interval in accordance with the paper feeding command in accordance with the image data in the image forming unit.

Further, the conveyance control means 6 preferentially conveys the recording paper designated to be discharged to the paper supply / discharge means 3 to the paper supply / discharge means 3, and skips the conveying operation to the other paper discharge means 2. , Smoothly execute the double-sided image forming operation.

FIG. 2 is a perspective view showing the outline of the image forming apparatus of the present invention.

In the figure, reference numeral 11 denotes an image forming unit, which prints an image signal sent from the image processing apparatus 12. 1
Reference numeral 2a denotes an operation panel that displays the states of the image forming unit 11 and other units, and is provided in the image processing apparatus 12. Paper feed cassettes 13 and 14 are attached to the image forming unit 11 and feed recording sheets of different sizes to the image forming unit 11. 15 is a paper deck, which has a large capacity (for example, 200
0 sheets of recording paper can be stored at once.

Reference numeral 16 denotes a double-sided printing device (double-sided unit) corresponding to the paper feeding / discharging means 3 shown in FIG. 1, which forms an image on both sides of the recording paper. (Paper is discharged), and the image forming unit 11
Feed the recording paper to. A vertical transport unit 17 sorts the recording paper output from the image forming unit 11 to the double-sided printing device 16 or the two-stage tray 18. The vertical transport unit 17 has a face-up tray 19, the two-stage tray 18 has output trays 18a and 18b formed of the same member, and is located in a vertical direction opposite to the recording paper transport direction by a driving unit (not shown). A fixed amount of movement is possible, and four types of image formation can be executed at one time.

FIG. 3 is a sectional view showing the internal structure of the image forming apparatus shown in FIG.

In the figure, reference numerals 21a to 21c denote paper feed rollers, which feed the recording paper from the paper feed cassettes 13 and 14 and the paper deck 15. A registration roller 22 temporarily stops the fed recording paper and adjusts the leading edge of the image and the image forming start position of the recording paper. A photosensitive drum 23 forms a latent image by laser beam scanning. 24 is a fixing roller,
The toner image developed by heat and pressure is fixed.

Reference numeral 25 is a deflector, which distributes the recording paper to the double-sided printing device 16 or the vertical transport unit 17. A sensor 26 detects the recording paper fed to the double-sided printing device 16. Reference numeral 27 denotes an intermediate tray, which functions as a paper discharge unit that retains the recording paper having an image formed on one side of the recording paper.
It functions as a paper feeding unit that re-feeds the recording paper in response to a feeding command from the image processing apparatus 12.

A paper feed roller 28 feeds the discharged recording paper to the intermediate tray 27. Reference numeral 29 denotes a re-feed roller, which temporarily stops the recording sheet fed from the intermediate tray 27 and controls the conveyance timing. Reference numeral 30 denotes a sensor, which detects the conveyance state of the recording paper fed from the intermediate tray 27. Reference numeral 31 is a deflector which controls the conveyance direction of the recording paper. Reference numeral 32 denotes a sensor, which detects a recording sheet to be switched back (described later). Reference numeral 33 is a roller, which again conveys the recording paper conveyed to the switchback mechanism to the deflector 3
It is conveyed in the direction of 4. Reference numeral 35 is a deflector, which controls the conveying direction in order to eject the recording paper to the face-up tray 19. Reference numeral 20 is a paper discharge roller. Hereinafter, the operation will be described.

Paper feed cassettes 13 and 1 in the image forming section 11
4 or paper deck 1 mounted on double-sided printing device 16
One of the recording sheets accommodated in the sheet 5 is controlled by a control signal from the image processing apparatus 12, for example, the paper deck 15
Is selected and the paper is fed by rotating the paper feed roller 21c. Then, the fed recording paper reaches the registration rollers 22, is temporarily stopped, and is fed again according to a timing signal from the image processing apparatus 12, and at the same time, the image processing apparatus 1
An electrostatic latent image is formed on the photosensitive drum 23 by a known laser scanning optical system according to the image signal (image data) sent from the image forming apparatus 2, and the toner visualizes the electrostatic latent image.
After being transferred to the recording paper, the developing roller 24 fixes the developed toner image on the recording paper. The recording paper on which the toner image has been fixed is distributed by the deflector 25 to either the vertical transport unit 17 or the double-sided printing device 16. For example, when the deflector 25 is driven upward, the recording paper is conveyed to the double-sided printing device 16. Double-sided printing device 1
The sensor 26 detects the leading edge of the recording paper fed to the recording sheet 6, and the intermediate tray 2 is fed at a timing based on the detection.
Sent to 7. Then, the recording sheet sent to the intermediate tray 27 is re-fed by the sheet feeding roller 28 and the sheet re-feeding roller 29, and is automatically fed to the position where the sensor 30 is arranged and stopped.

When the double-sided printing device 16 is selected as the paper feed unit, the recording paper stopped at the position of the sensor 30 is fed and printed again on the second side (back side). Then, the deflector 25 is driven in a direction in which the recording paper having passed through the fixing roller 24 is not fed to the double-sided printing device 16, and the recording paper is conveyed upward. When the recording paper conveyed upward is, for example, the recording paper fed from the double-sided printing device 16, the deflector 31 is driven in response to a command from the image processing device 12, and the direction in which the sensor 32 is arranged. The recording paper is pulled in.

When the trailing edge of the recording paper is detected by the sensor 32, the rotation direction of the roller 33 is reversed and the deflector 31 is turned off to convey the recording paper in the direction of the deflector 34. The operation of pulling the recording sheet by the deflector 31 and reversing the leading edge and the trailing edge of the recording sheet (movement indicated by arrow A) is called switchback. This switchback operation is originally performed on the recording paper fed from the double-sided printing device 16, and it is not necessary to directly switch back the recording paper from the paper feed cassettes 13 and 14, the paper deck 15, and the like.
Because the output trays 18a and 18b, which are normally used in the two-stage tray 18, are stacked face down, in order to correctly stack them in the page order sent from the image processing apparatus 12, one side, This is because, in any case, the double-sided printing paper must be stacked so that the first printed surface always faces downward.

Therefore, the recording paper fed from the double-sided printing device 16 must be always switched back. Further, when the recording paper fed from the double-sided printing device 16 is continuously conveyed, the switchback operation must be instantaneously executed during the interval between the recording papers. Depending on the material and the state (for example, the state where the paper is curled), a jam may be induced, so that the switchback operation can be skipped.

The recording paper which has completed the switchback operation is
The one-sided printing paper is output to the face-up tray 19 and the output trays 18a and 18b by the deflector 34 or the deflector 35 depending on the destination of the paper. At this time, the output trays 18a and 18b are offset. That is,
When the image processing device 12 issues a command to move the recording paper in the vertical direction opposite to the conveying direction, the output trays 18a and 18b are moved at a predetermined timing. Hereinafter, the control configuration of the image forming apparatus will be described with reference to FIG.

FIG. 4 is a block diagram showing the control arrangement of the image forming apparatus according to the present invention.

In the figure, reference numeral 41 denotes a microprocessor (CPU) which performs various calculations and logical judgments for image reception and image recording, and controls each component connected to the bus B1 via the bus B1. Reference numeral 42 denotes a first serial circuit, and the image processing apparatus 1 is connected through the transmission cable CBL1.
The communication processing for receiving the control command sent from the device 2 and outputting the response information in reverse is performed.

43 is a timer circuit, 44 is a control memory (R
OM) describes the control procedure of the CPU 41. 45
Is a random access memory (RAM) and is a bus B
Temporary storage of data from components connected to 1 and CPU
It is used as a work memory of 41. 46 is an input / output port, 47 is an input interface, and 48 is a drive circuit, which drives a load such as a motor or a high-voltage transformer (not shown). The input interface 47 and the drive circuit 48 are connected to the input / output port 46 via the bus B2.

From the image processing device 12 to the transmission cable CBL
The serial signal transmitted through 1 is received by the first serial circuit 42 of the image forming unit 11, and processed by the CPU 41. The CPU 41 operates according to the control program of the ROM 44, drives the above-mentioned components 42 to 46, and controls the entire device on the image information receiving side.

Reference numeral 49 is a laser driver for image signal / VD
The semiconductor laser 50 is driven according to O (hereinafter, "/" is added to the signal that becomes active low). Reference numeral 51 is a collimator lens that collimates the laser light emitted from the semiconductor laser 50. A polygon mirror 52 reflects laser light. In the case of 53, the f-θ lens scans the photosensitive drum 23 with the laser light reflected by the polygon mirror 52 at a constant speed. The image signal / VDO sent from the image processing device 12 is supplied to the laser driver 49, and converted into laser light by the semiconductor laser 50.

The laser light emitted from the semiconductor laser 50 is focused by a collimator lens 51, reflected by a polygon mirror 52 rotating at a high speed, and scanned in a main scanning direction (arrow Y direction) parallel to the photosensitive drum 23. Polygon mirror 52
After the light amount is corrected by the f-θ lens 53, the laser light scanned by is irradiated onto the photosensitive drum 23 rotating in the sub-scanning direction to form a latent image corresponding to the image signal / VDO. The latent image is developed with a developer by the electrostatic recording method, and transferred and fixed on a recording paper. Then, as described above, the recording paper passes through the vertical transport unit 17 and is transported to the double-sided printing device 16 or the two-stage tray 18. Further, an optical fiber 54 arranged on the side of the photosensitive drum 23 before the photosensitive drum 23 is irradiated with the laser beam scanned by the polygon mirror 52.
To the image processing device 12 as a horizontal synchronizing signal BD.

In addition to the first serial circuit 42 for performing communication processing with the image processing device 12, a second serial circuit 56 for communicating with the double-sided printing device 16 through the transmission cable CBL2 is provided in the image forming section 11. Transmission cable CB
It has a third serial circuit 57 that communicates with the two-stage tray 18 through L3, and each is connected to the CPU 41 by a bus B1.

The second serial circuit 56 of the image forming section 11
The serial circuit 58 in the double-sided printing device 16 connected by the transmission cable CBL2 is connected to the CPU 59, the ROM 60, the RAM 61, the input / output port 62 and the bus B3 as in the inside of the image forming unit 11. 2-tier tray 1
Since 8 has the same structure as that of the double-sided printing device 16, the description thereof will be omitted.

Next, referring to FIG. 5, a signal sequence for controlling each section of the image forming section 11 will be described.

FIG. 5 is a diagram for explaining the interface between the image processing device 12 and the image forming section 11 shown in FIG.

In the figure, a signal PPRDY is a signal for informing the image processing apparatus 12 that the image forming unit 11 is powered on. The signal CPRDY is the image processing apparatus 1
This is a signal for informing the image forming unit 11 that the power supply No. 2 is turned on. The signal / RDY is a signal indicating that the image forming unit 11 is in a state in which the printing operation can be started if the image forming unit 11 receives a signal / PRNT to be described later from the image processing apparatus 12. For example, when the paper cassette runs out of paper, 0 "
(1ow).

The signal / PRNT is a signal for the image processing apparatus 12 to instruct the image forming unit 11 to start an image forming operation, or a signal to instruct the image forming unit 11 to continue image formation when the image forming unit 11 is forming an image. is there. For the signal / VSREQ, both the signal / RDY and the signal / PRNT are "1" (hi
gh), and the image forming unit 11 outputs a signal / VS which will be described later.
This signal indicates that the preparation for receiving the YNC has been completed.

The signal / VSYNC is a vertical (sub-scanning direction synchronizing signal) of the printed image, and is used by the image processing device 12 to cause the image forming unit 11 to synchronize the leading edge of the image on the photosensitive drum 23 with the recording sheet. The signal / VDO is an image output by the image processing device 12, and the image forming unit 11
Outputs "1" (high) of this signal to the black of the output image,
Image formation is performed with "0" (low) as white.

The signal SC is a command signal (command signal) from the image processing apparatus 12 to the image forming unit 11 and the image forming unit 11
Is a bidirectional serial 8-bit signal for transmitting and receiving a status notification signal (status signal) from the image processing apparatus 12 to the image processing apparatus 12. Both the image processing apparatus 12 and the image forming unit 11 receive a clock signal / SCLK described later to capture this signal.
Is used. Further, since it is a bidirectional signal, a signal / SBSY and a signal / CBSY which will be described later are used for input / output control. The command signal is a serial signal composed of 8 bits, and for example, the face-up tray 19, the output trays 18a and 18b, and a movement command for the tray can be issued by the command signal. Further, a cassette paper feed command for feeding recording paper from the paper feed cassettes 13 and 14,
Paper feed command from paper deck 15 and double-sided printing device 1
6 includes a paper feed command and the like. The / SC signal line is an example of the input means of the present invention.

The status signal is a serial signal consisting of 8 bits. For example, the printer is in a wait state in which the temperature of the fixing device has not reached a printable temperature, a jam has occurred, and the paper cassettes 13 and 14 are out of paper. Is a signal for notifying the image processing device 12.

Both the status signal and the command signal are made up of 8 bits, and the most significant bit (1st bit) is sent out on the / SC signal line. The least significant bit (8th bit) has odd parity for both the status signal and the command signal.

The command signal is coded from the most significant bit (1st bit) to the 8th bit excluding the parity bit. The command includes a status request command that requests the image forming unit 11 for information about the device, a status request command that requests the image forming unit 11 to execute an operation, and an execution command that requests the image forming unit 11 to execute an operation. There is.

The signal / SCLK is a synchronous clock pulse signal for the image forming section 11 to work on the command signal or for the image processing apparatus 12 to fetch the status signal. The signal / SBSY is the signal / SC and the signal / SC before the image forming unit 11 transmits the status signal.
This is a signal for occupying LK. The signal / CBSY is a signal for occupying the signal / SC and the signal / SCLK before the image processing device 12 transmits the command signal.

Next, the image forming section 11 and the image processing apparatus 12
The interaction between and is explained.

Now, it is assumed that the power switch (not shown) of the printer is turned on and the power switch of the image processing apparatus 12 is turned on. At this time, the image forming unit 11 initializes the internal state of the printer and then outputs the signal / PPRDY.
Is transmitted to the image processing apparatus 12. In this initial state, the image forming unit 11 initializes the paper feed mode to the cassette paper feed mode.

On the other hand, the image processing device 12 initializes the internal state and then transmits the signal CPRDY to the image forming section 11. After that, when the printer becomes a printable state, for example, when the temperature of the surface of the fixing roller reaches a temperature at which fixing is possible, a signal / RDY is transmitted to the image processing apparatus 12. In response to this, the image processing device 12 transmits a signal / PRNT to the image forming unit 11 as necessary.
The image forming unit 11 rotates the photosensitive drum 23 according to the signal / PRNT to uniformly initialize the potential on the surface of the photosensitive drum 23, and in the cassette sheet feeding mode, for example, rotates the sheet feeding roller 21, The leading edge of the recording paper is conveyed to a registration shutter (not shown) of the registration roller 22.

When the printer is ready to accept the image signal / VDO, the signal / VSREQ is sent to the image processing apparatus 1.
Send to 2. The image processing device 12 outputs the signal / V
The signal / VSYNC is transmitted to the image forming unit 11 in response to the reception of the SREQ. The image forming unit 11 outputs the signal / V
In response to the reception of SYNC, the registration shutter is driven in synchronism with this, and the transport path closed state is released. After outputting the signal / VSYNC, the image processing device 12 sequentially transmits the image signal / VDO to be recorded to the printer in synchronization with the horizontal synchronizing signal / BD transmitted from the image forming unit 11. The image forming unit 11 forms a latent image on the photosensitive drum 23 by controlling the semiconductor laser 50 to be turned on / off by the laser driver 49 according to the image signal / VDO, and the photosensitive drum 23 is formed by a developing device (not shown). Toner (developer) is adhered to and developed to be transferred onto the conveyed recording paper and fixed by the fixing roller 24.

Next, the status request command and the execution command will be described with reference to FIGS.

FIG. 6 is a diagram for explaining the status request command in the image forming apparatus according to the present invention.

In the figure, SR0 to SR12 are instruction codes. When the instruction code SR0 (basic status request command) is output to the image forming unit 11, the image forming unit 11
Is an image forming unit 11, a double-sided printing device 16, a two-stage tray 1
Basic status such as 8 is returned as status (Fig. 7
Will be explained).

When the instruction code SR1 (operator call status request command) is output to the image forming section 11,
The image forming unit 11 returns a call that can be restored by the operator of the image forming unit 11 as a status. Command code SR2 (serviceman call status request command)
Is output to the image forming unit 11, the image forming unit 11 returns a call, which the operator of the image forming unit 11 cannot repair, as a status.

When the instruction code SR3 (paper feed cassette paper size status request command) is output to the image forming unit 11, the image forming unit 11 returns a call for obtaining paper size information of the paper feeding cassette 14 as a status. When the instruction code SR4 (paper cassette paper size status request command) is output to the image forming unit 11, the image forming unit 11
Returns a call for obtaining the paper size information of the paper feed cassette 13 as a status.

When the command code SR5 (paper deck paper size status request command) is output to the image forming section 11, the image forming section 11 returns a call for obtaining the paper size information of the vapor deck 15 as a status. When the instruction code SR6 (paper discharge function status request command) is output to the image forming unit 11, the image forming unit 11 returns a call for knowing the function of the paper discharging unit connected to the image forming unit 11 as a status.

When the instruction code SR7 (call generation unit status request command) is output to the image forming unit 11, the image forming unit 11 calls which of the image forming unit 11, the double-sided printing device 16, and the two-stage tray device 18 is called. Taka is returned as status.

When the instruction code SR8 (designated sheet feeding unit status request command) is output to the image forming unit 11, the image forming unit 11 returns the sheet feeding unit designated by the execution command (EC0 to EC3) as the status. To do.

When the instruction code SR9 (paper feed unit configuration status request command) is output to the image forming unit 11, the image forming unit 11 returns the paper feeding means connected to the image forming unit 11 as a status. When the instruction code SR10 (double-sided printing device status request command) is output to the image forming unit 11, the image forming unit 11 returns the call content of the double-sided printing device 16 as a status.

When the instruction code SR11 (two-stage tray call status request command) is output to the image forming unit 11, the image forming unit 11 returns the call contents of the two-stage tray 18 as the status. Instruction code SR12 (2
Image tray 1)
After outputting to 1, the image forming unit 11 returns the status of each tray of the two-stage tray 18 as a status.

FIG. 7 is a diagram for explaining execution commands in the image forming apparatus according to the present invention.

In the figure, EC0-EC4 are instruction codes. The instruction code EC0 (paper feed cassette paper feed designation execution command) designates feeding of recording paper from the paper feed cassette 14. The instruction code EC1 (paper feed cassette feed designation execution command) designates feeding of recording paper from the paper feed cassette 13. The command code EC2 (vapor deck paper feed designation execution command) designates feeding of recording paper from the paper deck 15.

The instruction code EC3 (double-sided printing device execution command) designates paper feeding from the double-sided printing device 16.
The instruction code EC4 (destination designation execution command) is used for each tray of the two-stage tray 18 and the face-up tray 19,
Designation of conveyance to the double-sided printing device 16 is performed.

8 to 11 are diagrams showing an example of the bit data indicating the status contents returned in correspondence with the status request codes SR0 to SR12 shown in FIG.
Each status is composed of 8 bits, and the least significant bit (8th bit) is an odd parity bit. Each bit is "1" when an event has occurred and "0" when no event has occurred. In addition, FIG.
In FIG. 12, st is ST, nd is ND, and rd is R.
D and th are described as TH.

FIG. 8A shows the bit data of the basic status, which generally shows the states of the image forming unit 11, the double-sided printing device 16, the two-stage printing tray 18, etc., and includes the status request code (SR0) or the execution command. When the image processing apparatus 12 outputs EC0 to EC4, the image forming unit 11 outputs them.

The 1st bit of the instruction code SR0 is "0".
It is. The 2nd bit indicates a print request, which becomes “1” when the signal / PRNT (a signal for instructing the image forming unit 11 to start feeding) allows the sheet to be fed, either after receiving the signal / PRNT or after the signal / PRNT is received. / PRNT
When the image forming unit 11 cannot start the paper feeding operation even if is input, “0” is set.

The 3rd bit indicates that the recording paper is being conveyed, and when the recording paper is present in the image forming unit 11, the double-sided printing device 16, and the two-stage tray 18 (hereinafter, 11, 11, 18 are collectively referred to as a system). It becomes "1". Then, when all the recording papers existing in the system are normally output to the respective trays (face-up tray 19, output trays 18a, 18b), or when the conveyance operation is stopped due to a jam or the like,
It becomes "0".

The 5th bit becomes "1" when the image forming section 11 is in the wait state due to the low temperature of the fixing device or the like, and becomes "0" when the wait is completed. The 7th bit is set to "1" when an error occurs in the system, that is, when "1" is set to any of the 2nd, 3rd, and 4th bits of the call generation unit status.

8 (b) and 8 (c) show the basic contents of the operator call status and service man call status of the image forming section 11, but since they are not directly related to the present invention, the description will be omitted. Omit it.

FIGS. 9D to 9F show the paper feed cassette 1.
4, 13, a status indicating the size of the recording paper set in the paper deck 15, which is data to which a predetermined 6-bit code (20 to 25 bits) and a parity bit are added. 10G shows the bit data (corresponding to the instruction code SR6) of the paper discharge unit function status, and the 4th bit is the double-sided printing device 1 in the image forming unit 11.
When 6 is connected, it becomes “1” and the image forming unit 11
When the double-sided printing device 16 is not connected to, it becomes "0". In addition, 5th to 7th indicate the connection state of the paper discharge unit and "001 when the two-stage tray 18 is connected.
(Binary code) ", and if the paper ejection unit is not connected, it will be" 000 (binary code) ". Even if some paper ejection unit is connected, if the paper ejection unit is not powered on, Since the power has not been turned on, "111
(Binary code) "is set.

FIG. 10H shows bit data of the call generation unit call status (corresponding to the instruction code SR7), and the 2nd bit indicates when a call is generated in the image forming section 11, that is, operator call and service. When any bit data of the man status request command (SR1, SR2) becomes "1", this bit becomes "1". The 3rd and 4th bits are the double-sided printing device 16 and the two-stage tray 1 which is one of the paper discharge unit.
Set when a call occurs at 8. That is,
When "1" is set to any one of the 4th to 7th bits of the double-sided printing device call status request command to be described later, "1" is set to the 3rd bit of this status, and the 2nd tray call status request command When "1" is set to any one of the 4th to 6th bits, "1" is set to the 4th bit of this status.

The bit data of the designated paper feed unit status (corresponding to SR8) in (i) of FIG. 10 is shown to indicate which one of the paper feed stages is designated by the execution commands EC0 to EC4. is there. 2nd of this status
When the paper feed unit in which "1" is set in the 5th bit receives the next signal / PRNT, the recording paper is fed.

FIG. 11 (j) shows bit data of the paper feed unit configuration status (corresponding to SR9), and "1" is set to the bit corresponding to each function. In this embodiment,
2nd to 4th bits are all "1".

FIG. 11 (k) shows bit data of the double-sided printing device call status (corresponding to SR10), and the 3rd bit of this status indicates skipping of the double-sided printing device 16. That is, when this bit is “1”, the double-sided printing device 16 is instructed to convey the recording paper to the double-sided printing device 16 by designating the destination (described later).
This bit becomes "1" when the data is not conveyed to and output to the two-stage tray 18. This is already a double-sided printing device 1
The recording paper exists inside the recording medium 6, and the recording paper having a different size from the recording paper is conveyed to the double-sided printing device 16 to prevent the paper jam from occurring.

Further, when a predetermined number or more of recording sheets are conveyed to the intermediate tray 27, this bit becomes "1". 4
When the th bit is "1", it indicates that the recording paper remains on the intermediate tray 27. This bit becomes "1" when there is recording paper other than when the paper is being conveyed to the intermediate tray 27 (when the basic status 3rd bit is "1").
Paper is being conveyed to the intermediate tray 27 (3rd of status "0")
This bit becomes "0" when there is no recording paper other than when the bit is "1".

The 5th bit has a value of "1" when a jam occurs in the double-sided printing device 16, and has a value of "0" when the jam is cleared or in a normal state.
The 6th bit has a value of "1" when the conveyance path is released for removing jammed paper in the system, etc., and has a value of "0" when normally closed.

The 7th bit is set when the intermediate tray 27 is full, that is, when a specified number of recording sheets are stacked.
This bit becomes "1", and when there is no recording sheet on the intermediate tray 27, this bit becomes "0".

FIG. 11 (l) shows bit data of the two-stage tray call status (corresponding to SR11), the 3rd bit of this status indicates the destination skip, and is recorded in the destination designated by the destination designation (described later). If the paper is not ejected, this bit becomes "1". Further, when the recording paper fed from the double-sided printing device 16 is switched back, if the recording paper on which only one side is printed is continuously conveyed from the image forming section 11, the switch back operation is required. Since it takes time, if the switchback operation is not executed for single-sided printing paper, it will cause a jam due to overlapping with the previous recording paper (recording paper being switched back).
In order to avoid this,
Force a switchback operation.

At this time, the 3rd bit of this status is set to "1" to indicate that the switchback has been skipped. Further, even when a mode (not shown) or the like provided in the two-stage tray 18 is designated as a mode in which the switchback operation is not executed, the 3rd bit of this status becomes "1". The 4th bit of this status is a bit indicating a shift error and is output to the output trays 18a, 18
If b is not shifted normally, this bit is "1".
Becomes

A motor (not shown) is used to shift the output trays 18a and 18b,
Whether or not a and 18b have moved to the normal position is detected by a lever attached to a movable part of each output tray 18a and 18b and a photo interrupter attached to the system body (neither is shown). Then, when the output trays 18a and 18b have not moved within a fixed time from the start of movement, this bit becomes "1",
This bit is "1" if the movement is normal. 6
Since the th and 7th bits are essentially the same as the bit data of the above-mentioned double-sided printing device call status request command (see (k) of Z11), description thereof will be omitted.

FIG. 11 (m) shows bit data of the two-stage tray status status (corresponding to SR12), 3rd bit and 4th bit are destinations of recording paper designated by the execution command EC4, and output trays 18a, 18b. Alternatively, the state of the face-up tray 19 is shown. Especially,
If the contents of the 3rd and 4th bits are "00", it means that the tray is empty, if it is "01", it means that the tray is being accessed, and if it is "11", it means that the tray is being accessed. Indicates that the tray is full. However,
Since the face-up tray 19 also has the meaning of a sample tray, the state of the face-up tray 19 is “01”.
Is set to be Further, the 2nd bit of this status becomes "1" when the recording paper having the first surface printed is sent to the double-sided printing device 16 and passes through the intermediate tray 27 to reach the position of the sensor 30. When the feeding signal from the image forming unit 11 is received, or the sensor 3
When there is no recording paper at the 0 position, it is "0".

FIG. 12 is a diagram for explaining the execution command indicating the destination of the fed recording paper in the image forming apparatus according to the present invention, and corresponds to the case where the command is composed of 2 bytes.

As shown in FIG. 12 (a), for example, 94 "h" is output at the first byte, the basic status is returned from the image forming section 11 correspondingly, and then 2
Specify the destination by bi-fold. The 2nd bit of the second byte shown in FIG. 12B is a destination designation bit for causing the double-sided printing device 16 to convey the recording paper. When this bit is “1”, the fed recording paper is double-sided. It is returned to the printer 16. At this time, whatever the 3rd, 6th, and 7th bits are, the 2nd bit has priority and the other bits are ignored. However, when the recording paper is the recording paper fed from the double-sided printing device 16, the recording paper is printed on the same surface, that is, the surface on which the image is formed. Set to eject.

Further, the 3rd bit of this execution command is for instructing the tray shift indicated by the 6th and 7th bits which will be described later, and when this bit is "1", the shift position (from the back side of FIG. 3). A predetermined amount is moved in the direction toward the front surface, and when it is “0”, it means a home position (moved by a predetermined amount in the rear surface direction in FIG. 3).

Furthermore, 6th and 7t of this execution command
The h bit is a bit that designates the output trays 18a and 18b and the face-up tray 19. When these bits are "00", the destination of the recording paper is the face-up tray 19, and when the bit is "01", the recording paper is When the destination is "10", the destination of the recording paper is designated as the output tray 18b.

Next, referring to FIG. 13, the image forming section 1
Information exchange between 1 and the double-sided printing device 16 will be described.

FIG. 13 is a diagram for explaining the instruction codes exchanged between the image forming section 11 and the double-sided printing device 16 shown in FIG.

FIG. 13A is a diagram for explaining the information sent from the image forming section 11 to the double-sided printing device 16, and is constituted by each information code D00 to D09 (8-bit data with odd parity). Has been done.

The information code D00 (image forming unit ready command) is data indicating that the image forming unit 11 is ready to print. The information code D01 (image forming unit jam command) is a command indicating that a jam has occurred in the image forming unit 11 and the two-stage tray 18. Information code D02
(Discharge Signal Command) This is a command indicating that the recording paper is discharged from the image forming unit 11.

The information code D03 (start command) is a start command for driving the drive means (not shown) of the recording paper transport system. Information code D04 (paper feed designation command) is a command for selecting the double-sided printing device 16 or the paper deck 15.

The information codes D05 to D09 (paper size designation commands) are commands indicating the size of the recording paper being conveyed in the double-sided printing device 16.

FIG. 13B corresponds to an instruction code sent from the double-sided printing device 16 to the image forming section 11,
It is composed of information codes D10 to D24.

The information code D10 (exit paper present command) is a command indicating that the recording paper can be fed from the double-sided printing device 16. Information code D11 (feeding command) is a command indicating that the recording paper is being conveyed from the double-sided printing device 16. The information code D12 (paper deck connection command) is a command indicating that the vapor deck 15 is connected.

The information code D13 (double-sided printing device connection command) is a command indicating that the double-sided printing device 16 is connected. The information code D14 (paper deck paper no command) is a command indicating that there is no recording paper in the paper deck 15. Information code D15 (Intermediate tray paper existence command)
Is a command indicating that recording paper is present in the intermediate tray 27.

The information code D16 (double-sided printing device jam command) is a command indicating that a jam has occurred in the double-sided printing device 16. The information code D17 (double-sided printing device door opening command) is a command indicating that the door of the double-sided printing device 16 is in an open state. The information codes D18 to D22 (paper deck paper size command) are commands indicating the size of the recording paper accommodated in the paper deck 15.

The information code D23 (double-sided printing device skip command) is a command for preventing the double-sided printing device 16 from conveying the recording paper. The information code D24 (intermediate tray full command) is a command indicating that the intermediate tray 27 has reached the specified number.

Next, referring to FIG. 14, the image forming section 1
Information exchange between the first and second trays 18 will be described.

FIG. 14 is a diagram for explaining instruction codes exchanged between the image forming section 11 and the two-stage tray 18 shown in FIG.

FIG. 14A corresponds to the instruction code sent from the image forming section 11 to the two-stage tray 18 via the transmission cable CBL3, and the information codes D30 to D41.
It is composed of

The information code D30 (image forming section ready instruction) is an instruction indicating that the image forming section 11 is in a printable state. Information code D31 (paper discharge command)
This indicates that recording paper is output from the image forming unit 11. The information code D32 (start command) is a command to start driving of a driving unit (not shown) that conveys the recording paper.

Information codes D33 to D34 (destination instruction)
Is a command indicating the discharge destination of the recording paper. Information code D3
5 (shift command) is a command indicating whether or not the output tray is shifted. Information codes D36 to D40 (paper size command)
Is a command indicating the size of the recording paper being conveyed through the image forming unit 11.

The information code D41 (paper feed section designation command) is
This is a command indicating the paper supply source of the discharged recording paper.

FIG. 14B corresponds to an instruction code sent from the two-stage tray 18 to the image forming section 11 via the transmission cable CBL3, and information codes D50 to D60.
It is composed of The information code D50 (recording paper conveyance command) is a command indicating that the recording paper is being conveyed to the two-stage tray 18. The information code D51 (shift error command) is a command indicating that a shift error has occurred in the two-stage tray.

The information code D52 (jamming command) is a command indicating that a jam has occurred in the two-stage tray 18. The information code D53 (door open command) indicates that the door (not shown) of the two-stage tray 18 is open. The information codes D54 to D55 (output tray status command) are commands indicating the status of the output tray 18a.

Information codes D56 to D57 (output tray status command) are commands indicating the status of the output tray 18b. The information codes D58 to D59 (face-up tray state command) are commands indicating the state of the face-up tray 19. Information code D60 (Destination skip command)
Is a command indicating the skipped state of the recording paper.

Next, the control operation of the image forming section 11 shown in FIG. 3 will be described with reference to FIG.

FIG. 15 is a flow chart showing an example of the operation of the control means of the image forming apparatus according to the present invention. Note that (1) to (26) indicate each step.

The image forming unit 11 checks the system such as the double-sided printing device 16, the paper deck 15, the two-stage tray 18 (1), and the paper discharge unit function status and the paper feeding unit shown in FIG. Set / reset configuration status bit data. Next, the ready state of the entire system is checked (2), and it is checked whether jam has already occurred or whether the door of the double-sided printing device 16 or the like is opened.

Specifically, the bit data of the call status in the image forming section 11, that is, the operator call status shown in FIG. 8B and the serviceman call status shown in FIG. 8C are checked. , Check whether the event for each bit has occurred.

For the double-sided printing device 16, FIG.
3 (b), whether or not an event corresponding to the information code D14 to D17 has occurred, and the two-stage tray 18
For the information codes D51 to D shown in FIG.
It is checked whether or not an event corresponding to 53 has occurred, and each bit data of the double-sided printing device call status and the two-stage tray call status shown in (k) of FIG. 11 is set according to their contents.

Next, it is judged whether or not the system is in the ready state (3), and if NO, the signal / RDY is not sent and the system waits until the ready state is released (4).

On the other hand, if the judgment in step (3) is YES, the signal / RDY is sent to the image processing device 12 (5). It waits for the signal / PRNT to be sent from the image processing device 12 to the image forming unit 11 (6), and when sent, the photosensitive drum 23 performs a pre-rotation operation (the surface of the photosensitive drum 23 is stopped to form a clear image). (Rotating operation for electrically uniforming) is started (7), and then a start signal is sent to the double-sided printing device 16 and the two-stage tray 18 (8).
This start signal means an event of the information code D03 shown in FIG. 13A and the information shown in FIG. 14A.

Next, the completion of the pre-rotation is awaited (9), and when it is completed, the paper feeding section is checked (10). The check of the paper feed unit is to check which of the execution commands (designate paper feed) EC0 to EC3 shown in FIG. 7 is received last.

For example, when the execution command EC2 and the execution command EC3 are received in this case, that effect is shown in FIG.
The information code D04 shown in (a) of 3 is set and the double-sided printing device 16 is notified. However, if there is no recording sheet in the transport path, the execution command EC3 is ignored.

Next, the destination is checked (11). This destination check is performed by checking the execution command EC4 shown in FIG. Then, the paper feeding operation is started (12) and the print request (signal / P
RNT) is turned off (13). Next, it waits until the recording paper is fed to a predetermined position (14), and at the time of feeding, the signal / VSREQ is sent from the image forming section 11 to the image processing device 12 (15), and the recording paper is fed. Stop once (1
8).

Next, the signal / VSYNC input is awaited (17), and when the signal / VSYNC is input, the conveyance of the recording paper is restarted (18). Next, it waits for the recording paper, which is transferred at a predetermined timing and fixed by the fixing roller 24, to be conveyed to the discharge section of the image forming section 11 (19), and when it is conveyed, the discharge signal output sequence is executed. Do (2
0). Then, it is checked whether or not the recording paper is ejected from the image forming section 11 (21), and if ejected, the signal / PRNT for feeding the next recording paper is sent to the image processing apparatus 12.
Waits until it is sent to the image forming unit 11 (22),
If YES, the process returns to step (10), and if NO, the process waits until all the recording sheets on the system transport path are transported (23), that is, the information code D11 and the information code D11 shown in FIG. After the information code D50 shown in (b) of FIG. 14 is adjusted and all the recording sheets on the conveyance path have been conveyed to each designated tray, the 3rd bit of the basic status request command is set to "0".

Next, it is judged whether or not the conveyed recording paper is one fed from the double-sided printing device 16 (24), and N
If O, proceed to step (26), YES, that is,
If the paper is fed from the double-sided printing device 16 and the execution commands EC0 to EC2 shown in FIG. 7 are not output, it is automatically changed to the lower-stage paper feeding (paper feeding from the paper feeding cassette 14) (25).

Next, in order to stop the transport driving means of the entire system, stop signals are output to the double-sided printing device 16 and the two-stage tray 18 (26). That is, the information code D03 shown in FIG. 13A and the information code D32 shown in FIG. 14A are reset.

FIG. 16 is a flow chart showing details of the paper discharge signal output operation executed in step (20) of the flow chart shown in FIG. Note that (31) to (3)
4) shows each step.

It is determined whether or not the 2nd bit of the bit data of the second byte shown in FIG. 12B is "1" (3
1) If YES, ignoring the other bits, preferentially send the information code D02 shown in FIG. 13A to the double-sided printing device 16 and end the control (32).

On the other hand, if the judgment in step (31) is NO,
That is, if the destination of the recording paper is the two-tier tray 18,
3r of the bit data of the second byte shown in (b) of 2
The contents of the d, 6th, and 7th bits are notified to the two-stage tray 18 with the information codes D33 to D35 shown in FIG. 14A, that is, the shift / destination of the recording paper (3
3), a paper discharge signal (information code D3 shown in FIG. 14A)
1) is transmitted (34).

Next, referring to FIG. 17, the double-sided printing device 1
The control operation of No. 6 will be described.

FIG. 17 is a double-sided printing device 16 shown in FIG.
4 is a flowchart for explaining the control operation of FIG. In addition,
(51) to (70) indicate each step.

The system waits for each unit in the double-sided printing device 16 to be in a ready state (51), and then waits for a star signal to be sent from the image forming unit 11 (52). That is, the information code D03 shown in FIG. 13A is "1".
When the start signal is sent out, the recording paper feeding drive means (not shown) in the double-sided printing device 16 is driven (53), the paper ejection signal is waited (54), and the paper ejection signal is sent. If received, it is judged whether or not the recording paper is already present in the double-sided printing device 16 (55). If NO, the deflector 25 is turned on, and the recording paper is pulled into the double-sided printing device 16 and the process proceeds to step (62) ( 56), if YES, it is judged whether the size of the existing recording paper matches the size of the recording paper to be fed next (57). If YES, the process proceeds to step (56), and if NO, further skips. It is judged whether or not the mode is set (58). If NO, it is recognized that a jam has occurred, the double-sided printing device 16 is stopped, and the control ends (59).

On the other hand, the judgment in step (58) is YES.
If so, the deflector 25 is turned off (60), the skip mode is notified, and the control ends (61).

Then, in step (62), it is judged whether or not the number of recording sheets stacked on the intermediate tray 27 reaches the specified number, and if NO, the process proceeds to step (66), YES.
If so, it is determined whether or not it is the notification mode (63).
If NO in this determination, it is recognized that a jam has occurred, the double-sided printing device 16 is stopped, and the control ends (64). If YES, it is notified that the intermediate tray 27 is full (65). Next, waiting for the recording paper to be conveyed to the position of the sensor 30 (66), and when it is conveyed, there is an exit paper,
That is, the information code D10 shown in FIG. 13B is set (67).

Next, it waits for a feeding instruction from the image forming section 11 (68). When the feeding instruction is issued, feeding of the recording paper is started (69), and exit paper is turned off. And control is terminated (70).

Next, the operation of the two-stage tray 18 shown in FIG. 3 will be described with reference to FIG.

FIG. 18 is a flow chart for explaining the control operation of the two-stage tray 18 shown in FIG. In addition, (7
1) to (84) show each step.

First, the ready of each part in the two-stage tray 18 is waited for (71), and the start signal is waited for from the image forming section 11 (72). When the start signal is sent, 2 The tray 18 is driven (73).
Next, when a paper discharge signal is waited (74) and the paper discharge signal is received, at that time, the received destination is checked (7).
5).

Then, it is judged whether the paper feeding unit of the received recording paper is the double-sided printing device 16 by checking the information code D41 shown in FIG. 14A (76), and Y
If it is ES, the process proceeds to step (81), and if NO, it is further determined whether or not the recording sheet immediately before the received recording sheet has executed the switchback operation (77). In this determination, if the immediately preceding recording sheet is a recording sheet that has not executed the switchback operation, the switchback operation is not executed (78) and the process proceeds to step (82).

On the other hand, if it is judged in the step (77) that the immediately preceding recording paper is the recording paper for which the switchback operation has been executed, it is judged whether or not a jam has occurred (79), and if NO, the process returns to the step (78). , YES, the notification that the switchback operation is not executed, that is, the information code D60 shown in FIG. 14B is set (80).

Then, the switchback operation is executed (8
1), the deflectors 34 and 35 are controlled by the destination assigned in step (75) (82), and the recording paper is conveyed to the destination tray. Next, it waits for the recording paper to be ejected to the tray (83), and when the recording paper is ejected, the number of ejected recording papers is counted and the control ends (8
4).

Next, the ready check operation of the two-stage tray 18 in step (71) shown in FIG. 18 will be described with reference to FIG.

FIG. 19 shows the two-stage tray 18 shown in FIG.
5 is a flowchart showing an example of the ready check operation of FIG. Note that (91) to (97) indicate each step.

First, the output tray 18a is selected (9
1), it is checked whether or not the output tray 18a is in the home position described above (92), and if YES, the process proceeds to step (96), and if NO, the output tray 18a.
Shift to move to the home position (9
3).

Next, it is judged whether the output tray 18a has moved to the home position within a fixed time, that is, whether the shift has ended (94). If YES, that is, if the output tray 18a has moved to the normal position, step (96). ), If NO, a shift operation error is notified (95).

Then, it is checked whether the output tray 18b is located at the home position (96), and Y
If it is ES, the control is terminated, and the subsequent step operations shown in FIG. 18 are executed.

On the other hand, if the judgment in step (96) is NO, the output tray 18b is selected (97), and step (9)
Returning to 2), the operation after step (92) is executed.
As described above, the output tray 18a of the two-stage tray 18,
Since 18b is accompanied by a shift operation, when the power is turned on, the output tray 18a, 18b is moved to the home position in advance so that the recording paper discharge operation can be accurately executed.

In the above embodiment, the case where the recording paper conveyance control is executed by 8-bit data has been described, but other numbers of bits may be used.

[0139]

As described above, according to the present invention,
Since the sheet on which the image is formed based on the image data output from the image generating apparatus is discharged with the image forming surface facing upward or downward in accordance with the command from the image generating apparatus, the user may discharge the image forming surface upward. You can easily instruct whether to eject paper downward, and immediately respond to various needs such as users who place importance on page order, users who emphasize print result confirmation, and users who want to minimize sheet curl. There is an effect that can be.

[Brief description of the drawings]

FIG. 1 is a basic configuration block diagram of an image forming apparatus showing an embodiment of the present invention.

FIG. 2 is a perspective view showing an outline of an image forming apparatus of the present invention.

3 is a cross-sectional view showing an internal structure of the image forming apparatus shown in FIG.

FIG. 4 is a block diagram showing a control configuration of the image forming apparatus according to the present invention.

5 is a diagram illustrating an interface between the image processing apparatus and the image forming unit illustrated in FIG.

FIG. 6 is a diagram illustrating a status request command in the image forming apparatus according to the present invention.

FIG. 7 is a diagram illustrating an execution command in the image forming apparatus according to the present invention.

8 is a diagram showing an example of bit data indicating status contents returned in response to the status request code shown in FIG.

9 is a diagram showing an example of bit data indicating status contents returned in response to the status request code shown in FIG.

10 is a diagram showing an example of bit data indicating the status contents returned in response to the status request code shown in FIG.

FIG. 11 is a diagram showing an example of bit data indicating status contents returned in response to the status request code shown in FIG. 6;

FIG. 12 is a diagram illustrating an execution command indicating a destination of a fed recording sheet in the image forming apparatus according to the present invention.

FIG. 13 is a diagram illustrating instruction codes exchanged between the image forming unit and the double-sided printing device shown in FIG.

FIG. 14 is a diagram illustrating instruction codes exchanged between the image forming unit and the two-stage tray shown in FIG.

FIG. 15 is a flowchart showing an example of a control operation of the image forming apparatus according to the present invention.

16 is a flowchart showing details of a paper discharge signal output operation executed in the flowchart shown in FIG.

17 is a flowchart illustrating a control operation of the double-sided printing device shown in FIG.

18 is a flowchart illustrating a control operation of the two-tier tray shown in FIG.

FIG. 19 is a flowchart showing an example of a ready check operation of the two-tier tray shown in FIG.

[Explanation of symbols]

 1 Paper Feeding Means 2 Paper Ejecting Means 3 Paper Feeding and Ejecting Means 4 Conveyance State Detecting Means 5 External Device 6 Conveying Control Means 11 Image Forming Part 12 Image Processing Device, 13 Paper Feeding Cassette 14 Paper Feeding Cassette 15 Paper Deck 16 Double-sided Printing Device 17 Vertical transport unit 18 Two-stage tray 18a Output tray 18b Output tray

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Kaoru Seto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kenjiro Hori 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Within the corporation

Claims (1)

[Claims] 1. An image forming apparatus for forming an image on a sheet based on image data output from an image generating apparatus, wherein the sheet on which the image is formed is discharged to a first stacking portion with the image forming surface facing upward. And first stacking means for stacking the image-formed sheets on the second stacking section with the image-formed surface facing downward, and the first transporting means for stacking the image-formed sheets on the first stacking means. Deflection means for selectively carrying to any one of the second carrying means and the second carrying means, and a command for selecting one of the first stacking section and the second stacking section. Input means for inputting from the image generating device, and control means for controlling the destination of the conveyance by the deflecting means according to the command input by the input means. Image forming apparatus characterized by discharging surface upward or downward state.