JPH1048900A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate trouble of putting copying papers ejected to each paper ejection tray in page order in a copying machine capable of forming images on plural sheets of copying paper carried in parallel. SOLUTION: When plural sheets of copying paper where copying has been finished are respectively ejected in parallel to a 1st paper ejection tray 61 and a 2nd paper ejection tray 62, a driving belt 654 is rotated by a pulse motor PM3. Thus, a projection 653 is moved in the direction of an arrow C, the copying paper on the tray 62 is pressed by the projection 653 and moved to the 1st tray 61. For example, in the case of copying by distributing the original read by an image read part to carrying paths corresponding to the trays 61 and 62 in reading order of the original, moving operation to eject the paper is executed every time the paper is ejected to each tray in parallel, so that the copying paper where copying has been finished is stacked on the tray 61 in the reading order of the original, and the trouble that the copying paper is manually put in page order is eliminated.

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, such as a copying machine or a laser printer, capable of simultaneously forming an image on a plurality of recording sheets fed in parallel.

[0002]

2. Description of the Related Art Recently, especially in the field of digital copying machines, there has been a demand for high-speed processing in order to make a large number of copies in a short time with the spread of digital copying machines. In order to achieve high-speed copying, it is necessary to increase the speed of the operation of the internal mechanical parts, for example, the rotation of the photosensitive drum and the conveyance of the copy paper. From the viewpoint of handling, there is a certain limit in increasing the speed of such mechanical parts.

[0003] For example, Japanese Patent Application Laid-Open No. Hei 2-24673 discloses a copying machine in which two copy sheets are conveyed in parallel and an image is formed on each copy sheet at the same time. FIG.
3 is a perspective view showing a main part of an image forming unit of the copying machine. Two electrostatic latent images are formed at image forming positions Sa and Sb on the surface of the photosensitive drum 902 by exposure scanning by the optical system 901, and the electrostatic latent images are developed by a developing device (not shown) to thereby form the photosensitive drum 902. Two toner images are formed on the surface.

On the other hand, a copy paper 9
04a and 904b are set in parallel, and these copy papers are fed in parallel by a conveyor belt 903 in synchronization with the image forming operation on the surface of the photosensitive drum 902, and the electrostatic force of the transfer charger 905 is set. As a result, the toner images at the image forming positions Sa and Sb are transferred onto the respective copy sheets.

Thereafter, the toner image is fixed on the copy paper by a fixing device (not shown) and is discharged onto a discharge tray (not shown). In such a copying machine capable of parallel transfer, it is possible to simultaneously transfer to two copy sheets in one image forming operation, so that the processing speed of the copy is doubled. can do.

[0006]

However, in the above-described conventional copying machine capable of parallel transfer, when an image is formed on copy paper conveyed in parallel, the image is formed as it is on the front side and the back side of the discharge tray. Depending on the type of copying, a work of rearranging the copied copy sheets on the tray in a predetermined page order (this work is hereinafter referred to as “item alignment”) is required separately.

That is, when a plurality of copies of the same image are to be made, the stack of two copied copy papers on the paper discharge tray may be directly overlapped to form one. For example, an automatic document feeder may be used. Considering a case where a plurality of originals are read in succession, and the originals are read and copied separately in the order of the readout into the front transport path and the rear transport path, an odd number of pages of the original document are displayed in the output tray. The copied copy sheets of the even-numbered pages are discharged separately to the near side and the back side, and it is necessary to rearrange these copied copy sheets in page order. This work is troublesome even if the number of copies is small, and the greater the number of copies, the worse the work efficiency becomes. In this case, not only does the meaning of introducing a copier by parallel transport for speeding up the copying process be reduced to half, but rather the work becomes complicated and the efficiency of office work is hindered.

To solve such a problem, for example,
In a copying machine capable of parallel transfer disclosed in JP-A-61-188357, after an image is formed on a copy sheet at a transfer position of an image forming section, the copy sheet is driven by a driving roller to a discharge tray. Conveying, and by sequentially reducing the diameter of the drive roller along the axial direction, changing the conveying direction of one or both copy papers so that they approach each other, and in a state where both copy papers partially overlap The paper is discharged onto the paper discharge tray.

However, according to such a configuration, by changing the diameter of the drive roller, the amount of feed inside and outside of one copy sheet is changed to forcibly change the direction. There is a possibility that wrinkles and the like may be generated due to the application of a force in a twisting direction, and if the direction is simply changed, only a part of both of the discharged copy papers is overlapped at most, and the copy papers are completely overlapped with each other This is difficult, and the edges of the copy sheets are manually aligned. However, if the number of discharged copy sheets is large, this operation is also troublesome.

Further, according to such a superposition method, it is uncertain which of the copy papers conveyed in parallel at the same time is vertically overlapped, and there is no guarantee that the copy papers are surely overlapped in the page order. In order to solve this problem, according to the publication, processing is performed by delaying the conveying speed of one copy sheet. However, in this case, the copy processing speed is limited by the slower transport speed, and there is no point in employing a parallel transport copier for high-speed copy processing.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and in an image forming apparatus capable of forming a plurality of images in one image forming operation, the image forming apparatus is capable of forming a plurality of images without reducing the processing speed. It is an object of the present invention to provide an image forming apparatus in which items on a recording sheet on which an image is formed can be easily arranged.

[0012]

In order to achieve the above object, the present invention provides an image forming means for forming a plurality of images in parallel in a direction substantially perpendicular to a recording sheet conveying direction, and a plurality of recording sheets. Paper feed means for supplying the recording sheet on which the image has been formed to a paper output tray, and a paper feeding means for supplying the image forming recording sheet to a paper output tray in parallel. In an image forming apparatus capable of forming an image on a plurality of recording sheets by a forming operation, a tray surface corresponding to at least one transport path among the discharge trays is a tray surface of a discharge tray corresponding to another transport path. Higher and the recording sheet discharged to the higher discharge tray is moved in a direction orthogonal to the discharge direction,
It is characterized by having a paper discharge moving means for transferring to a lower paper discharge tray.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image forming apparatus according to the present invention will be described below using a digital copying machine as an example. (1) Overall Configuration of Digital Copier FIG. 1 is a diagram showing the overall configuration of the digital copier (hereinafter, simply referred to as “copier”).

As shown in FIG. 1, the copying machine includes an automatic document feeder 10 that automatically feeds a document, an image reading unit 30 that reads an image of the fed document, and a read image on a copy sheet. And a printer unit 40 that reproduces the data. The automatic document feeder 10 includes a document feed tray 11 for setting a document, a paper feed roller 12, a separating roller 13,
Release pad 14, guide 15, registration roller 16, transport belt 17, paper discharge roller 18, and document discharge tray 1
9 and the like, and the driving motor M
By driving the original at 3, the maximum size of, for example, A4-size documents set in parallel on the document feed tray 11 can be conveyed to the image reading unit in parallel in the vertical direction.

As shown in the external perspective view of FIG. 2, the document feed tray 11 is provided with two document guides 11a and 11b standing in parallel with the direction of document transport. , 22b to the document guide 1
1a and 11b can be set together.
The document guides 11a and 11b are configured to be movable in a direction orthogonal to the document transport direction according to the size of each document placed.

Document detection sensors SE4a and SE4b (FIG. 1) for detecting the presence or absence of the document are provided at positions on the document feed tray 11 where the two document bundles are placed. These document detection sensors SE4a and SE4b are, for example, reflection-type photoelectric sensors composed of a combination of a light emitting element and a photoelectric conversion element, and emit light when a document is placed at the position of each sensor of the document feed tray 11. Light emitted from the element is reflected on the original surface and detected by the photoelectric conversion element, and the presence or absence of the original is determined based on the detection signal.

When the original bundle is placed on the near side or the rear side of the original feed tray 11, the original located at the bottom of the original bundle is fed by the feed roller 12, the separating roller 13, and the separating roller 13, respectively. The sheet 14 is fed downward along the guide 15 by the pad 14, further conveyed by the registration roller 16 and the conveyance belt 17 to a predetermined document reading position set on the platen glass 35, and scanned by the scanner 31 of the image reading unit 30. After the transfer belt 1
The paper is sent to the right in FIG. 1 by a paper 7 and is discharged onto a document discharge tray 19 via a paper discharge roller 18.

Further, when reading the back side of the original,
The transport path of the document is switched to the reversing roller 21 by the switching claw 20, the document is reversed by the reversing roller 21, transported again to the platen glass 35, and further transported by the transport belt 17 to the document reading position of the platen glass 35. Then, after being read by the image reading unit 30, the next document is conveyed in the same manner as described above.

The image reading section 30 includes a scanner motor M2.
There is a scanner 31 that moves in the direction of the arrow in FIG. The scanner 31 includes an exposure lamp 32 for irradiating a document, a rod lens array 33 for condensing light reflected from the document, and a contact-type CCD image sensor (hereinafter, referred to as a CCD image sensor) for converting the condensed light into an electric signal. (Hereinafter simply referred to as “CCD sensor”) 34.

The image of the original illuminated by the exposure lamp 32 of the scanner 31 is photoelectrically converted by the CCD sensor 34 into an electric signal, and the image data obtained by this is A / D converted by the control unit 100 and converted into a digital signal. After being subjected to necessary corrections for improving the image quality, the signals are stored in an image memory 131 (see FIG. 5) in the control unit 100, read out as necessary, and converted into drive signals for the laser diode 41. Is done.

The printer unit 40 includes an optical system for exposing the surface of the photosensitive drum 47 around the photosensitive drum 47, an image processing system for visualizing the exposed image and reproducing the image on copy paper,
It comprises a paper feed system for supplying the copy paper. The output of the laser diode 41 of the optical system is modulated by the drive signal output from the control unit 100, and the output laser light passes through the collimator lens 42 and becomes parallel light. The light is reflected by the mirror surface of the polygon mirror 43 rotated through the fθ lens 45 and further reflected by the return mirrors 46a and 46b to expose the surface of the photosensitive drum 47 in its axial direction (main scanning direction). Then, scanning is performed, and predetermined electrostatic latent images are written at the image forming positions Sa and Sb (see FIG. 3).

FIG. 3 is a perspective view showing the structure of the photosensitive drum 47 in the printer unit 40 and the essential parts around it. For convenience of explanation, the folding mirror 46 shown in FIG.
a, 46b, a cleaner 48, an eraser lamp 49, a transport belt 53, etc. are omitted, and a polygon mirror 43 is provided.
Also, only the reflection surface is shown. As shown in the figure, an SOS sensor 58 for detecting when a laser beam is incident at a scanning angle slightly smaller than the scanning angle of the image forming position Sb of the photosensitive drum 47 is provided. This SOS
The sensor 58 is composed of a photoelectric conversion element such as a photodiode, and the laser light reflected by the polygon mirror 43 is reflected by f
After passing through the θ lens 45 and entering the SOS sensor 58, it is converted into an electric signal and sent to the control unit 100 as an SOS signal. Printer control unit 140 of control unit 100
FIG. 6 shows the image forming position S in response to the SOS signal.
The timing of starting image writing for each of a and Sb is determined.

A charging charger 50, a developing device 51, and a transfer charger 54 constituting an image processing system are disposed around the photosensitive drum 47 in parallel with the rotation axis thereof. An image is formed on paper. That is, the photosensitive drum 47 is cleaned by a cleaner 48 (see FIG. 1) to remove residual toner on the surface of the photosensitive member before being exposed to the laser light, and is further irradiated with an eraser lamp 49 to remove electricity. When the photosensitive drum 47 is exposed to light while being uniformly charged, an electrostatic latent image is formed on the surface of the photosensitive drum 47. Each electrostatic latent image is developed by the developing unit 51, and a predetermined toner image is formed at each of the image forming positions Sa and Sb on the surface of the photosensitive drum 47. This developing device 51
Is, for example, a two-component developing device, which stirs the toner and carrier housed inside to give a charge to the toner,
This toner is transferred to the photosensitive drum 4 via the developing roller 511.
The surface is supplied and developed.

The paper cassettes 52a and 52b store copy papers 352a and 352b of A4 size in this copying machine, and the copy papers 352a and 352b are fed by paper feed rollers 353a and 353b and a timing roller 354, respectively. The paper is fed in parallel, and is conveyed to a transfer position below the photosensitive drum 47 by the conveyance belt 53 (FIG. 1).

A transfer charger 54 is provided on the rear side of the portion of the conveyor belt 53 which comes into contact with the photosensitive drum 47. The transfer charger 54 generates an electric charge and generates a toner image formed on the photosensitive drum 47 by the electrostatic force. Transfer onto each copy paper.
The toner image transferred to each copy paper 352a, 352b is
Since it is in an unstable state where it is immediately peeled off when it is touched, it is transported to the fixing device 56 by the transport belt 55. The fixing device 56 fixes the toner between the paper fibers by pressing each copy paper 352a, 352b while heating it with a fixing roller 561 having a built-in heater. The copy paper 352a, 352b after fixing is discharged from the discharge outlet 59 to the first and second discharge trays 61, 62 of the discharge unit 60 by the discharge roller 57.

As shown in the external perspective view of FIG. 2, the discharge unit 60 includes first and second discharge trays 61 and 62 corresponding to the front and back paths of copy paper conveyed in parallel. , Each of which can be moved up and down, and whose tray surface 61
The heights of a and 62a can be changed. FIG. 4 is a front view of the discharge unit 60 as viewed from the direction of arrow A in FIG. In this figure, for convenience of explanation, the side wall of the copying machine main body is not shown, and only the outline and the position of the paper discharge port 59 are shown by broken lines.

The bases 611, 621 of the first and second discharge trays 61, 62 are respectively provided with tray elevating devices 63, 64.
And is held so as to be movable only in the vertical direction along a rail (not shown), and the bolts 631 and 641 are respectively driven by the driving devices 632 and 641.
By rotating at 642, it is possible to move up and down by the screw feed action.

The driving devices 632 and 642 have pulse motors PM1 and PM2 built therein, respectively, and rotate the respective pulse motors PM1 and PM2 by means of a power transmission mechanism (not shown) such as gears and the above-mentioned bolts 631 and 641. To be driven to rotate. SE6-S
E8 is a reflection-type photoelectric sensor installed on the wall surface of the copying machine main body. SE7 and SE8 are reference positions (hereinafter, referred to as "tray") indicated by the first and second discharge trays 61 and 62, respectively. SE6 is a tray detection sensor for detecting that the sheet is at the reference position.) SE6 is a sheet discharge amount for detecting the height of the sheet discharged to the first sheet discharge tray 61 and increasing. It is a detection sensor.

The position detected by the sheet discharge amount detection sensor SE6 is the second sheet discharge tray 6 at the tray reference position.
2 is set lower than the tray surface 62a, the distance between the detection position of the discharge amount detection sensor SE6 and the tray surface 61a of the first discharge tray 61 is d1, the discharge port 59 and the second discharge tray. The distance from the tray surface 62a of 62 to d2
Then, it is set so that d1 <d2. As described later, paper is discharged in parallel to each of the first paper discharge tray 61 and the second paper discharge tray 62, and the first paper discharge tray 61 is discharged.
Is increased by the paper discharge amount detection sensor SE6 and the first paper discharge tray 61
And the second discharge tray 62 are simultaneously lowered by the same amount, but since d1 <d2 is set, when the discharge amount of the first discharge tray 61 is detected by the discharge amount detection sensor SE6, The discharge height of the second discharge tray 62 does not reach the discharge port 59, and by lowering both the discharge trays 61 and 62 by the same amount, the respective discharge trays 61 and 6 are always maintained.
2 can be made lower than the paper discharge port 59, thereby enabling a smooth paper discharge operation.

SE9 is a tray surface coincidence detection sensor comprising a photoelectric conversion element provided at the end of the second discharge tray 62 (see FIG. 5). A light emitting element provided at a position corresponding to the tray surface coincidence detection sensor SE9, for example, the light emitting diode LED1
And outputs a predetermined detection signal in response to the light from the tray surfaces 61a, 62 of the first and second discharge trays 61, 62.
It can be determined that the heights of “a” match.

The second paper discharge tray 62 is provided with a paper discharge moving mechanism 65 for moving the copied copy paper discharged onto the second paper discharge tray to the first paper discharge tray 61 and aligning them. I have. FIG. 5 is a perspective view of the discharge unit 60 as viewed from the direction of arrow B in FIG. 2, and the first and second discharge trays 61,
62, only the tray surfaces 61a and 62b are shown.

As shown in the drawing, the paper discharge moving mechanism 65 includes a driving belt 654 and a driving roller 651 and a driven roller 652.
And the driving roller 651 is driven by a pulse motor PM3.
, The driving belt 654 is rotated in the direction of arrow C. The drive belt 6
On the surface of the projection 54, a projection 65 projecting upward from a gap provided by dividing the tray surface 62a into front and rear portions substantially at the center thereof.
3 is fixed, moves with the rotation of the drive belt 654, and pushes the copied copy paper discharged to the tray surface 62a in a direction orthogonal to the discharge direction to move the copy paper to the first paper discharge tray 61. On the side of the first paper output tray 61,
A guide plate 61b is provided to prevent the moved copy paper from falling too far.

SE10 and SE11 provided on each of the tray surfaces 61a and 62a are paper discharge detection sensors each composed of a photoelectric sensor, and detect the copied copy paper discharged on each of the trays 61 and 62. To the discharge unit control unit 150 described later. These functions will be described later. Also, SE1a, SE1b, SE1 in FIG.
2a and SE2b and SE3a and SE3b in FIG. 1 are jam detection sensors that detect the copy paper conveyed to the respective conveyance paths, and the rear edge of the paper is detected even after a predetermined time from the detection of the front edge. If not detected, the control unit 1
00 is determined to be a paper jam (jam).

In addition to the paper cassettes 52a and 52b, a paper cassette 52c (FIG. 1) for horizontally storing A3 size paper is installed as a paper cassette. For example, a paper size detection sensor (not shown) including a photoelectric sensor and a limit switch is provided, and based on the detection signal, the printer control unit 140 of the control unit 100 selects a necessary paper cassette and feeds the paper. The roller 353a, 353b or 353c is driven to execute sheet feeding.

Further, an operation panel 36 for setting various copy modes by an operator is provided at an easy-to-operate position (broken line in FIG. 1) on the front surface of the image reading section 30. Is set with a numeric keypad for inputting the number of copies and a copy magnification, a start key for starting a copy operation, a display unit for displaying a set copy mode, and the like, and a term alignment mode (described later). Item setting key is provided. (2) Configuration of Control Unit 100 Next, the configuration of the control unit 100 installed inside the copying machine will be described with reference to the block diagram of FIG.

As shown in FIG. 1, the control unit 100 includes an image reading control unit 110, an image signal processing unit 120, a memory control unit 130, a printer control unit 140, a discharge unit control unit 150, a main control unit. 160 and others. Each control unit is configured around a CPU, and each of the ROs stores a program necessary for each control.
M and RAM serving as a work area when executing programs
Are provided, and data and commands are mutually transmitted and received via the command line CL.

The image reading control section 110 controls the operations of the automatic document feeder 10 and the image reading section 30 to execute reading of a document. When a predetermined copy mode is set from the operation panel 36 and a copy start operation is performed, the instruction is received via the main control unit 160, and first, the document detection sensor SE4a or SE4b
The presence or absence of a document in the document feed tray 11 is checked based on the detection signal from FIG. 1 (FIG. 1).
0 is controlled to convey the original to the original reading position on the platen glass 35 of the image reading unit 30.

Thereafter, the image reading control section 110 controls the operation of each section of the image reading section 30 and causes the scanner 31 to scan to execute the document reading operation. That is, the exposure lamp 32 is turned on and the scanner motor M2 is driven and controlled to move the scanner 31, and the image data of the document read by the CCD sensor 34 is sent to the image signal processing unit 120.

The image signal processing section 120 includes an A / D converter, a shading correction section, an MTF correction section, a scaling section, a γ correction section, and the like. After being converted into a digital multi-level signal by the converter and correcting the illumination unevenness of the exposure lamp 32 and the sensitivity unevenness of the CCD sensor 34 by the shading correction unit, the MTF correction unit performs processing for improving image quality such as edge enhancement. After being subjected to scaling processing and γ correction processing by the scaling section and the γ correction section, respectively, the memory control section 130
(Image data D1).

The memory control unit 130 stores the image data D
1 is binarized or further encoded and compressed, and stored in the image memory 131 on a page basis, and image data of a target page is read from the image memory 131 in response to an instruction from the main control unit 160 ( If the data is compressed, the decompression process is performed).
40 (image data D2).

Since the scanner 31 reads a single original even when the originals are conveyed in parallel, the image data is stored in the image memory 131 in two pages in order to store the image data in page units as described above. The document must be divided into image data. Therefore, in the copying machine, a document size detection sensor (not shown) for detecting a document size is provided at a position below the platen glass 35 so as not to hinder image reading by the scanner 31. The length and width of the document conveyed to the document reading position on the glass 35 and the presence or absence of a gap between the two documents conveyed in parallel are detected. Memory control unit 1
30, based on the detection signal from the document size detection sensor, determines whether the document is parallel-conveyed, one-sided conveyance only on the back side or front side, or a large document through the center, based on the detection signal from the document size detection sensor. , The memory is controlled so that the original is written into the image memory 131 in page units.

The printer control section 140 controls the operation of each section of the printer section 40 based on a control program stored in an internal ROM and executes printing on the image data D2 read from the image memory 131. That is, in addition to controlling the rotation of the polygon motor 44, the timing of the output of the drive signal to the laser diode 41 is determined while counting the clock pulses generated from the internal clock pulse circuit in response to the SOS signal from the SOS sensor 58. This controls the writing start position on the photosensitive drum 47 to form an electrostatic latent image at a predetermined position.

Further, detection signals from various sensors are input to the printer control unit 140, which controls a paper feeding operation from each paper cassette and an operation of the above-described image processing system, and prints a copy paper. Is performed. The discharge unit control unit 150 controls the operation of each unit of the discharge unit 60, and drives the CPU 151 and the pulse motors PM1 to PM3 under the control of the CPU 151 as shown in the block diagram of FIG. First to third pulse motor driving circuits 152 to 154
, A ROM 155 for storing the control program, and a RAM 156 for temporarily storing the current operation state, the contents of instructions from the main control unit 160, and the like.

The CPU 151 receives the detection signals of the above-described detection sensors SE6 to SE11. Upon receiving these detection signals, based on a control program in the RAM 156, the first and second tray lifting devices 63 are received. , 64 to control the height of each of the paper discharge trays 61, 62,
Alternatively, the operation of the paper discharge moving mechanism 65 is controlled to move the copied copy paper discharged onto the second paper discharge tray 62 to the first paper discharge tray 61 as necessary, and execute the item alignment mode described later. I do.

The main control unit 160 receives various key inputs from the operation panel 36 and reports the set copy mode to each of the control units 110 to 150, or sends a communication from each of the control units 110 to 150. In response to this, necessary contents are displayed on the display unit of the operation panel 36, and the timing of each operation is instructed to each of the control units 110 to 150, so that the entire unit is uniformly controlled and smooth copying is performed. Implement the operation. (3) Control Operation of Discharge Unit Control Unit 150 Next, the control operation of the discharge unit control unit 150 is performed, for example, in a case where an A3-size original is read and copied at the same magnification, and in a case where an A4-size original is read and parallel. The case of copying at the same magnification by transport will be described with reference to the flowcharts of FIGS.

First, in FIG. 8, the CPU 151 of the discharge unit control section 150 determines the paper size of the copy paper selected in the copy operation (step S).
1). As described above, since the document size is determined based on the detection signal of the document size detection sensor provided below the platen glass 35, the document size is determined based on this and the magnification (actual magnification in this example) specified from the operation panel 36. The size of the copy paper to be fed is determined by the printer control unit 140, and the CPU 1
51 obtains the information via the command line CL, so that the fed copy paper is A3 size or A4 size.
It can be easily determined whether or not the two sheets are conveyed in parallel.

When a large A3 size copy sheet is discharged, the heights of the tray surfaces 61a and 62a of the first discharge tray 61 and the second discharge tray 62 need to be matched. Second pulse motor drive circuit 153
Through the pulse motor PM2 of the second tray elevating device 64
Is driven to lower the second discharge tray 62, and when the tray surface coincidence detection sensor SE9 receives the light beam from the light emitting diode LED1 and obtains the detection signal, the height of both tray surfaces 61a, 62a And stops descending (steps S2, S3, S4, S5).

The copy operation is executed under the control of the printer control unit 140, and the copied A3-size copy paper is discharged onto the first and second discharge trays 61 and 62. The discharge amount increases and the discharge port 59 (FIG. 4)
If the height of the sheet is detected by the sheet discharge amount detection sensor SE6, the first and second tray elevating devices 6 are moved.
3 and 64 to lower the first and second discharge trays 61 and 62 by the same amount, for example, 1 cm (step S).
6, S7). In addition, this descending amount is determined by each tray elevating device 6.
By counting the number of drive pulses applied to the 3, 64 pulse motors PM1, PM2, the CPU 151 can easily control them.

The first and second discharge trays 61, 6
2 is performed as necessary until all copying is completed, and when the copying is completed, the sheet discharge detection sensor SE10
By the detection signal of (SE11), the discharge tray 61,
It is determined whether or not the discharged paper on 62 has been removed by the operator (steps S8, S9). When it is determined that the discharged sheet has been removed, the process proceeds to FIG. 9, and the operation of step S10 and thereafter is performed to perform control to return each of the discharged trays 61 and 62 to the tray reference position shown in FIG. That is, first, it is determined based on the detection signal from the tray detection sensor SE7 whether or not the first discharge tray 61 is at the tray reference position (step S10). To raise the first tray 61, and stop the raising when the tray detection sensor SE7 detects the first discharge tray 61 (steps S11, S12, S1).
3).

For the second discharge tray 62 as well, it is determined by the tray detection sensor SE8 whether or not the second discharge tray 62 is at the tray reference position (step S14). The discharge tray 62 is raised, and the tray detection sensor SE8 is set to the second discharge tray 6.
2 is detected (steps S15 and S1).
6, S17). As a result, the first and second discharge trays 6
1, 62 return to the tray reference position as shown in FIG.

In this copying machine, the state in which the first paper discharge tray 61 and the second paper discharge tray 62 are provided with a step is set as the tray reference position in ordinary office work. This is because the size copy is extremely rare, and the A4 size copy is overwhelmingly large. The reason why the first paper discharge tray 61 on the front side is made lower is to make it easier for the operator to discharge paper.

Returning to FIG. 8, in step S2, A4
If it is determined that the copy paper of the size is conveyed in parallel, it is determined whether or not the item alignment mode is set each time the copied copy paper is discharged to each of the trays 61 and 62 (step S1). S18). Here, the term alignment mode is set by the operator operating the term alignment setting key on the operation panel 36, and the copied copy sheets discharged in parallel are arranged in the page order according to the document. This is a mode for aligning them.

More specifically, for example, when a document of 20 pages is copied, the item alignment mode is executed as follows. When a document bundle is set with the document face up on the front (or back) side of the document feed tray 11 of the automatic document feeder 10, the image reading unit 30 starts from the bottom 20th page of the document bundle. , And reading is started, and the originals are read in the order of the 19th page, the 18th page, and so on, and written in the image memory 131 in that order. In parallel with this memory writing, image data of two originals is read from the image memory 131 in the order of writing, and in the image processing system, for example, the 20th page is located at the image forming position Sa on the near side (see FIG. 3). An image of the document is formed on the image forming position Sb on the back side, and an image of the document on the 19th page is formed, and the copied copy paper is discharged to the first and second discharge trays 61 and 62, respectively. Hereinafter, such a copying operation will be repeated.
The copy paper on which the even-numbered pages of the document are copied is discharged to the discharge tray 61, and the copy paper on which the odd-numbered pages of the document are copied is discharged to the second discharge tray 62, respectively. However, when the item alignment mode is set in step S18, first, whether or not the copy sheet has been discharged to the second discharge tray 62 is detected by the discharge detection sensor SE11.
After a lapse of a predetermined time, the protrusion 653 of the paper discharge moving mechanism 65 is moved to the position shown in FIG.
Is rotated once in the direction of the arrow to move the copy paper discharged to the second discharge tray 62 in the direction of the first discharge tray 61, and overlaps the copy paper already discharged to the second discharge tray 62. The operation is performed (steps S19 to S21). In the above example, since the copy sheet on which the twentieth page of the document has been copied is discharged to the first discharge tray 61 with its copy surface facing up, the copy paper is discharged to the second discharge tray 62. The copy paper on which the ejected original of the nineteenth page is copied is overlaid. By repeating this paper discharge movement operation for each parallel paper discharge until the copy is completed, the first paper discharge tray 61
Copy papers copied in the order of the read pages of the original will be stacked on the top, so there is no need for the operator to rearrange the copy paper discharged separately corresponding to each transport path in the page order as in the past. It becomes unnecessary.

It should be noted that the first copy is not completed until all copying is completed.
When the discharge amount of the discharge tray 61 increases and the height thereof reaches the position of the discharge amount detection sensor SE6, the CPU 151 controls the driving of the first tray lifting / lowering device 63 based on the detection signal, and the first discharge is performed. Set the height of the tray 61 to a predetermined amount, for example, 1c.
m (steps S23 and S24), and controls the height of the tray surface 61a so that the paper is discharged smoothly.

In steps S20 and S21,
One rotation of the protrusion 653 after a certain period of time has elapsed after the detection of discharge to the second discharge tray 62 is that when the discharge detection sensor SE11 detects discharge of the copy paper, each copy paper is still Completely the first discharge tray 61, the second discharge tray 62
The protrusion 653 has not been completely discharged to the top and remains as it is.
Is moved, the copy paper moves in an inclined state, and the overlap becomes worse. Therefore, the predetermined time in step S20 is at least equal to or longer than the time required for detecting the leading edge of the discharged copy sheet by the sheet discharge detection sensor SE11 and completely discharging the copy sheet onto the second discharge tray 62. Therefore, it is set appropriately within a range that does not hinder the discharge by the next copy operation. However, the paper ejection detection sensor SE11
Is set near the end of the second paper discharge tray 62 (the end opposite to the discharge direction in FIG. 5), the predetermined time can be set to “0”. In this case, Step S20 can be omitted.

When all copying is completed ("Y" in step S22), the returning operation of each of the discharge trays 61 and 62 to the tray reference position in step S10 and subsequent steps in FIG. I do. Step S18 in FIG.
In, if the term alignment mode is not set,
The copy paper discharged from each transport path is stacked on each of the paper discharge trays 61 and 62 as it is until the copy is completed, and the height of the paper discharge of the first paper discharge tray 61 is determined by the paper discharge amount detection sensor SE6 in the middle. If detected, the second discharge tray 62
Since the same amount of paper should have been ejected, the CPU 15
1 drives the first and second tray lifting / lowering devices 63 and 64 to lower both of the paper discharge trays 61 and 62 by a predetermined amount, for example, 1 cm (steps S25, S28, S29).

Then, when all copying is completed, it is determined whether or not the operator has removed the bundle of copied paper sheets on the first paper output tray 61 based on a detection signal from the paper output detection sensor SE10, and is removed. Then, the paper ejection moving mechanism 65 is driven to rotate the projection 653 once, and the second paper ejection tray 6 is rotated.
The bundle of copy papers on the second paper tray 2 is moved to the first discharge tray 61 (steps S26 and S27). As described above, the first discharge tray 61 is located on the near side as viewed from the operator.
This makes it very easy to take a stack of copied paper sheets on the back side.

Thereafter, the operation of returning each of the paper discharge trays 61 and 62 to the tray reference position in step S10 and subsequent steps in FIG. In the parallel conveyance of A4 size when the term alignment mode is not executed, for example, in order to copy a large number of the same document, the same image is formed in both conveyance paths, or the document bundle is transferred to the automatic document conveyance device 10. This is carried out when two copies are placed and a copy of the corresponding document bundle is executed in each transport path.

In the above flowchart, the operation of returning each of the paper discharge trays 61 and 62 to the tray reference position (FIG. 9) is performed after copying is completed. However, the operation of returning to the tray reference position before copying is started. May be performed before the copy operation is performed. (4) Modifications Although the image forming apparatus according to the present invention has been described based on the embodiment, it goes without saying that the content of the present invention is not limited to the above-described embodiment. Modifications are possible.

(4-1) In this embodiment, the copying machine capable of forming two images simultaneously by carrying two copy papers in parallel has been described. However, three or more copy papers are carried in parallel. The present invention is also applicable to a copying machine capable of forming an image on each copy sheet. In this case, when executing the item alignment mode, two specific adjacent conveyance paths are selected,
The same operation as described above may be performed by providing a discharge mechanism on the higher discharge tray with a level difference between the respective discharge trays, or by selecting three or more adjacent transport paths and Steps are sequentially formed in the discharge trays corresponding to the paths, and the above-mentioned discharge moving mechanism is provided except for the lowest discharge tray among these discharge trays to discharge the paper from the higher discharge tray to the lower discharge tray in order. May be executed to execute the item alignment mode.

(4-2) In the above-described embodiment, the term alignment mode in the case where odd pages and even pages are shared by both transport paths and copied is described. A document of 1 to 5 pages is copied and ejected in the transport path on the back side, a document of 6 to 10 pages is copied and ejected on the near side, and finally, the ejection of the back side is ejected by a paper ejection moving mechanism. It is also possible to move the document to the paper ejection tray on the front side to align the items of the original of 1 to 10 pages. Further, the other item alignment modes can be executed by appropriately controlling the operation of the discharge unit 60 in association with the reading control from the image memory 131 by the memory control unit 130.

(4-3) In the above embodiment, the drive belt 654 is used as a mechanism for moving the projection 653 in the paper discharge moving mechanism 65. However, the present invention is not limited to such a method. For example, a linear motor is used. The protrusion 653 can be moved. Also, the protrusion 653
Is provided only at a position substantially at the center of the side of the discharged copy sheet. For example, a plurality of protrusions may be provided and moved in parallel, or the tray surface 62a
By forming itself with the transport belt, the first discharge tray 61 can be stably maintained without tilting the direction of the copy paper.
Can be moved.

Further, the first and second tray elevating devices 63 and 6
Reference numeral 4 uses the screw feed mechanism to drive the first and second discharge trays 61 and 62 up and down, respectively. However, it is a matter of course that the present invention is not limited to such an up and down method.
Each of the paper discharge trays 61 and 62 held movably in the vertical direction by a rail may be suspended by a wire, and the wire may be wound up by a drive motor and rewound to drive each paper discharge tray up and down.

(4-4) In the above embodiment, the case where the copy paper is fed has been described. However, any other recording sheet such as an OHP film sheet that can be transferred by a copying machine may be used. The present invention is applicable not only to image formation in the above-described digital copying machine but also to other image forming apparatuses such as a laser printer.

[0065]

As described above, according to the present invention, in an image forming apparatus capable of forming an image on each recording sheet conveyed in parallel on a plurality of conveying paths, the paper discharging means is provided with a paper discharging tray. The tray surface corresponding to at least one of the transport paths is set higher than the tray surface of the discharge tray corresponding to the other transport path, and the recording sheet discharged to the higher discharge tray is moved in the discharge direction. A paper ejection moving means for moving the recording sheet to the lower paper ejection tray by moving the recording sheet to the lower paper ejection tray as necessary is provided. By superimposing on the recording sheet discharged to the lower output tray, it is possible to eliminate the need for manual alignment work, which has been done manually, and to greatly improve the efficiency of office work in image formation. Can .

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of a copying machine according to an embodiment of the present invention.

FIG. 2 is an external perspective view of the copying machine.

FIG. 3 is a perspective view of the periphery of a photosensitive drum of the copying machine.

FIG. 4 is a front view showing a configuration of a discharge unit of the copying machine.

FIG. 5 is a perspective view showing a configuration of a paper discharge moving mechanism in the discharge unit.

FIG. 6 is a block diagram of a control unit in the copying machine.

FIG. 7 is a block diagram of a discharge unit control unit in the control unit.

FIG. 8 is a flowchart illustrating a control operation of the discharge unit control unit.

FIG. 9 is a flowchart continued from FIG. 8;

FIG. 10 is a perspective view showing a configuration of a main part of a conventional copier capable of parallel transfer.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 Automatic document feeder 30 Image reading unit 40 Printer unit 60 Discharge unit 61 First discharge tray 62 Second discharge tray 63 First tray elevating device 64 Second tray elevating device 65 Discharge moving mechanism 100 Control unit 150 Discharge unit Control unit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kiyoto Tsujihara 2-3-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka Inside Osaka International Building Minolta Co., Ltd. (72) Inventor Hiroshi Otsuka Azuchi, Chuo-ku, Osaka-shi, Osaka Osaka International Building Minolta Co., Ltd.

Claims (1)

[Claims] 1. An image forming means for forming a plurality of images in parallel in a direction substantially orthogonal to a conveying direction of a recording sheet, and a conveying path formed by aligning a plurality of recording sheets at positions where the respective images are formed. An image forming apparatus capable of forming an image on a plurality of recording sheets by a single image forming operation, comprising: a sheet feeding unit that supplies the recording sheet on which the image is formed to a discharge tray; In the forming apparatus, a tray surface corresponding to at least one transport path among the discharge trays is higher than a tray surface of a discharge tray corresponding to another transport path, and the higher discharge tray An image forming apparatus, comprising: a discharge moving unit that moves a discharged recording sheet in a direction perpendicular to the discharge direction and moves the recording sheet to a lower discharge tray.