JPH1097112A - Image forming device and method for image forming - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent from double printing, and to facilitate judging of the rear side and the newly image formed surface, at the time of image forming by reusing the rear side of the only one-side printed paper sheet. SOLUTION: A main CPU controls the whole of this electronic copying machine 1 by transport-feeding copying papers P being set in a state of the rear side up on feeding trays 31a, 31b and 31c, or a large number of papers feeding part 47 at the time of copying operation, reading the A side of transported paper sheet P by a sensor 137, reading the B side by the sensor 138, finding out whether A side and B side of the paper sheet P is severally blank or not from respective read-out signal, printing the read-out image of the scanner part by a printer part 3 on the A side or B side of the paper sheet P being found out as a blank paper, printing the rear side mark on the rear side and paper-ejecting on a bin 76a of a unit 74, or paper-ejecting on the bin 76d while passing through the printer part 3 without printing in the case the A side and B side of the paper sheet P are already printed.

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 an electronic copying machine for forming an image of a document read by a scanner section by a printer section, and an image forming method.

[0002]

2. Description of the Related Art Conventionally, when a sheet on which only one side is printed due to misprinting or miscopying (hereinafter referred to as "backing paper") is reused in an electronic copying machine such as an image forming apparatus, the backing paper is used. When the paper has accumulated to some extent, the front and back sides of the backing paper are aligned, and the unprinted surface is set in the paper feeding device (paper feeding tray) so that the printing surface becomes a new printing surface.

However, when back paper such as miscopy paper is collected and reused as paper for an electronic copier, some paper may be set upside down even if the back paper is oriented. In this case, if the copy was performed as it was, the page of the sheet was double-printed as shown in FIG. Further, even if the copied paper is mixed with the backing paper on both sides, the same problem occurs. When the user collects the backing paper and carefully sets it in the paper feed tray, it is necessary to confirm the confirmation strictly. However, this puts a burden on the user, and in turn, may avoid using the backing paper. In addition, when a copy is made on the backing paper, the copy output looks like a two-sided copy at first glance.
As shown in (b), it was difficult to determine which was the back side and which was the newly copied side. Especially when circulating only one document, there is a possibility that a serious mistake may occur.

[0004]

As described above, when backing paper such as miscopy paper is collected and reused as paper for an electronic copying machine, some of the paper may be turned over even if the backing paper is oriented. The paper may be set upside down, and if you copy as it is, the page of that paper will be double printed, and the same problem will occur even if the paper that has been copied on both sides is mixed with the backing paper. Output looks like a two-sided copy, so it is difficult to determine which side is the back side and which is the newly copied side, which can lead to serious mistakes, especially when circulating only one document. There was a problem.

Therefore, the present invention prevents double printing when reusing the back side of a sheet on which only one side is printed, and makes it possible to easily determine the back side and the newly formed side. It is an object of the present invention to provide an image forming apparatus and an image forming method that can be used.

[0006]

According to the present invention, there is provided an image forming apparatus for forming an image on a sheet supplied from a supply unit, the surface of the sheet supplied from the supply unit on which an image is to be formed. Reading means for reading the image of the image forming apparatus, detecting means for detecting whether or not an image has already been formed on the image forming surface from the image read by the reading means, and detecting that the image has not been formed by the detecting means Image forming means for forming an image on the sheet detected by the detecting means, a sheet discharging means for discharging the sheet on which the image is formed by the image forming means to a predetermined position, and And control means for performing control to discharge the sheet detected by the detection means to a position different from a predetermined position where the sheet is discharged by the discharge means when it is detected that the sheet is formed. .

An image forming apparatus according to the present invention is an image forming apparatus for forming an image on a sheet supplied from a supply unit, wherein the reading unit reads an image on a surface of the sheet supplied from the supply unit on which an image is to be formed. Detecting means for detecting whether or not an image has already been formed on the image forming surface from the image read by the reading means; and detecting when the detecting means has detected that the image has not been formed. First image forming means for forming an image on a sheet detected by the means, reversing means for reversing the sheet on which the image is formed by the first image forming means, and image of the sheet reversed by the reversing means A second image forming means for forming an image indicating the back surface on the back surface of the surface on which the image is formed, and a sheet on which the image indicating the back surface is formed by the second image forming means is placed at a predetermined position. Eject paper A paper unit and a control for discharging the sheet detected by the detection unit to a position different from a predetermined position where the sheet is detected by the discharge unit when the detection unit detects that an image is formed. And control means for performing the control.

An image forming apparatus according to the present invention is an image forming apparatus for forming an image on a sheet supplied from a supply unit, wherein the first unit reads an image on a surface of the sheet supplied from the supply unit on which an image is to be formed. Reading means, a second reading means for reading an image on the back side of a sheet read by the first reading means, and a back side image read by the second reading means and reading by the first reading means Detecting means for detecting whether or not an image has already been formed on the image forming surface and the back surface from the image on the image forming surface, and detecting that no image has been formed on the image forming surface by the detecting means An image forming unit that forms an image on the sheet detected by the detecting unit, a sheet discharging unit that discharges the sheet on which the image is formed by the image forming unit to a predetermined position, Image formation on image formation surface When it is detected that the image is not formed on the back side, the sheet detected by the detection unit is reversed, an image is formed on the back side by the image forming unit, and the sheet is discharged to a predetermined position by the discharge unit. A first control unit for controlling discharge, and a sheet detected by the detection unit when the detection unit detects that an image has been formed on the image forming surface and the back surface by the discharge unit. And a second control unit for controlling discharge of the sheet to a position different from the predetermined position where the sheet is discharged.

An image forming apparatus according to the present invention is an image forming apparatus for forming an image on a sheet supplied from a supply unit, wherein the first unit reads an image on a surface of the sheet supplied from the supply unit on which an image is to be formed. Reading means, a second reading means for reading an image on the back side of a sheet read by the first reading means, and a back side image read by the second reading means and reading by the first reading means Detecting means for detecting whether or not an image has already been formed on the image forming surface and the back surface from the image on the image forming surface, and detecting that no image has been formed on the image forming surface by the detecting means. A first image forming unit for forming an image on the sheet detected by the detecting unit, a reversing unit for reversing the sheet on which the image is formed by the first image forming unit, and a reversing unit for reversing the sheet on which the image is formed by the first image forming unit. Image on the paper A second image forming means for forming an image indicating the rear surface to the back surface of the the surface, the second
A sheet discharging means for discharging a sheet on which an image indicating the back side is formed by the image forming means to a predetermined position; and an image forming on the image forming surface by the detecting means, and the image forming on the back side. When it is detected that the image has not been formed, the second image forming unit forms an image indicating the back side on the sheet detected by the detecting unit, and the image is inverted by the reversing unit to form the first image. Means for forming an image by means, and controlling to discharge the sheet to a predetermined position by the sheet discharging means, and when the detecting means detects that an image is formed on the image forming surface and the back side, And a second control unit for performing control to discharge the sheet detected by the detection unit to a position different from a predetermined position where the sheet is discharged by the discharge unit.

An image forming method according to the present invention is an image forming method for forming an image on a supplied sheet, wherein an image on a surface of the supplied sheet on which an image is to be formed is read, and the read image is read from the read image. It is detected whether or not an image has already been formed on the image forming surface, and when it is detected that the image has not been formed, an image is formed on the detected sheet and discharged to a predetermined position. When it is detected that the sheet is formed, a control is performed to discharge the detected sheet to a position different from the predetermined position.

An image forming method according to the present invention is an image forming method for forming an image on a supplied sheet, wherein an image on a surface of the supplied sheet on which an image is to be formed is read, and the read image is read from the read image. It is detected whether or not an image has already been formed on the image forming surface, and when it is detected that the image has not been formed, an image is formed on the detected sheet,
When the sheet on which the image is formed is inverted and an image indicating the back side is formed on the back side of the side on which the image is formed, the sheet is discharged to a predetermined position, and when it is detected that the image is formed, A control for discharging the detected sheet to a position different from the predetermined position is performed.

An image forming method according to the present invention is an image forming method for forming an image on a sheet to be supplied. The image on the side of the sheet to be formed on which the image is to be formed and the image on the back side thereof are read. From the image on the forming surface and the image on the back surface, it is detected whether or not the image has been formed on the image forming surface and the back surface, and when it is detected that the image has not been formed on the image forming surface, the detected paper When an image is formed on the image forming surface and it is detected that the image is not formed on the back surface, the detected sheet is inverted and the image is formed on the back surface. Is formed and discharged to the predetermined position, and when it is detected that an image is formed on the image forming surface and the back surface, the detected sheet is discharged to a position different from the predetermined position. It is characterized by having done.

An image forming method according to the present invention is an image forming method for forming an image on a sheet to be supplied, wherein the image on the surface of the sheet to be formed on which the image is to be formed is read and the image on the back is read. It is detected whether or not an image has been formed on the image forming surface and the back surface from the surface and the image on the back surface, and when it is detected that the image has not been formed on the image forming surface, the detected paper An image is formed, the sheet on which the image is formed is inverted, an image indicating the back side is formed on the back side of the surface on which the image is formed, and the image is discharged to a predetermined position, and the image is formed on the image forming surface. When it is detected that the image is not formed on the back side, an image indicating the back side is formed on the detected sheet, and the sheet on which the image indicating the back side is formed is inverted. An image is formed and discharged to the predetermined position. When an image formed on the image forming surface and the back surface is detected as being, characterized by being adapted to discharge at a different position from the predetermined position the detected paper.

[0014]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows an overall configuration of an electronic copying machine as an image forming apparatus according to the present invention. The electronic copying machine 1 includes a scanner unit 2 as a reading unit and a printer unit 3 as an image forming unit.
And an automatic document feeder (ADF) 4 is mounted on the upper part.

In the automatic document feeder 4, the rear edge of the cover body 21 as a housing is attached to the rear edge of the upper surface of the apparatus body via a hinge device (not shown) so as to be openable and closable. In response, the entire automatic document feeder 4 is pivotally displaced to open the document table 5. A document feed table 22 capable of holding a plurality of documents collectively is provided on the upper surface of the cover main body 21 in a slightly rightward direction. At one end of the apparatus, there is provided a feeding means 23 for sequentially taking out the originals one by one and supplying the originals to one end (the left end in the figure) of the original table 5. The feeding means 23 includes a pickup roller 27 for taking out the document, a weight plate 28 for pressing the document against the pickup roller 27, an empty sensor 29 as a document detection sensor for detecting a setting state of the document on the document feed table 22, and the like. Are arranged. Further, a paper feed roller 32 is arranged in the direction of taking out the document by the pickup roller 27, so that the document is fed one by one without fail. On the upper surface of the document table 5, a document conveying belt 3 covering the document table 5
7 is installed. The document conveying belt 37 is formed of a white wide endless belt whose outer surface stretched over a pair of belt rollers 40, 40, and is configured to be able to run in both forward and reverse directions by a belt driving mechanism (not shown). A plurality of belt pressing rollers 41 for pressing the belt surface onto the document table 5 and a set switch for detecting the open / close state of the automatic document feeder are provided on the back side of the inner peripheral portion of the document conveying belt 37. (Not shown). Then, the document fed by the feeding means 23 is transported from one end (left end) of the document table 5 to the other end (right end). A paper discharging means 38 is provided on the right side of the apparatus. The paper discharging means 38 detects a conveying roller 44, a pinch roller 45 for pressing the document against the conveying roller 44, and a trailing end of the document sent in the paper discharging direction. A paper discharge sensor 46 or the like is provided as document detecting means for detecting the original. On the downstream side of the document discharge path,
A discharge roller 48 is provided. A gate 8 is provided in the document discharge path to guide the document upside down to the document table 5.
2 is provided so that the document can be copied on both sides.

The scanner unit 2 includes an exposure lamp 6 as a light source, a first carriage 7 provided with a mirror 15, a second carriage 9 provided with mirrors 8a and 8b for bending optical paths,
A lens 10, a CCD sensor 11 for receiving reflected light, a drive system (not shown) for changing the positions of these components, and an A / A for converting the output of the CCD sensor 11, ie, image data (information) from analog data to digital data. It is composed of a D conversion unit (not shown). The first and second carriages 7 and 9 are connected to each other by a timing belt (not shown), and the second carriage 9 moves in the same direction at half the speed of the first carriage 7. ing. Thus, scanning can be performed so that the optical path length to the lens 10 is constant. The lens 10 has a fixed focal length and is moved in the optical axis direction during zooming. In the CCD sensor 11, one pixel of the document corresponds to one element of the CCD sensor. CCD
The output of the sensor 11 is output to an A / D converter. First and second carriages 7, 9 and mirror 12
The movements of a and 12b are each performed by a stepping motor (not shown). The first and second carriages 7 and 9 are used for the operation of a timing belt (not shown) suspended between a drive pulley (not shown) and an idle pulley (not shown) connected to the rotation shaft of the stepping motor. It will be moved accordingly. The spiral shaft (not shown) of the lens 10 is rotated by a corresponding stepping motor (not shown), and is moved in the optical axis direction by the movement of the spiral.

Reference numeral 60 denotes a laser diode, which corresponds to the collimating lens 62, polygon mirror (polyhedral reflecting mirror) 64, lens 66, and reflecting mirror 6 corresponding to the laser diode 60.
The exposure device 52 irradiates the photosensitive drum 50 with a laser beam.

The printer unit 3 combines, for example, a laser optical system and an electrophotographic system capable of forming an image on transfer paper. That is, the printer unit 3 includes a photosensitive drum 5 as an image carrier rotatably supported at a substantially central portion in the apparatus.
Around the photosensitive drum 50, an exposing device 52, a developing device 54, a transfer charger 55, a peeling charger 56, a PCC charger 57, a discharging lamp 58, and a charging charger 59 are arranged in this order. The photoconductor drum 50 is configured to be uniformly charged by the charging charger 59, and outputs a laser beam from the scanner unit 2 to form an image of a document on the photoconductor drum 50, thereby forming an electrostatic image. A latent image is formed.

The electrostatic latent image formed on the photosensitive drum 50 is developed by a developing device 54, and is supplied from a paper feed cassette 30a to 30c as a paper feeding means to be described later to a paper feed roller 20, an aligning roller The developed image is transferred by the transfer charger 55 onto the copy paper P sent through the transfer paper 25. The copy paper P after the transfer by the transfer charger 55 is separated by the separation charger 56 by the AC corona discharge, and is fixed to the fixing device 7 via the transport belt.
1, the copy paper P on which the developed image is fused and fixed by the fixing device 71 is discharged by a discharge roller pair 73 to a unit 74 having a plurality of bins 76a, 76b, 76c, 76d.

On the other hand, the developer remaining on the photosensitive drum 50 after the transfer and peeling of the developed image onto the copy paper P is
The cleaning is performed by the PCC charger 57, and the potential on the photosensitive drum 50 is reduced to a certain level or less by the charge removing charger 58, thereby enabling the next copy operation.

In the case of double-sided copying in which printing is performed on both sides of the copy sheet P, the copy sheet P on which the developed image has been fused and fixed by the above-described fixing device 71 is conveyed through a conveyance path 75a, and then stacked in a stacker 75b. Is accumulated in The single-sided printed paper P stored in the stacker 75b is conveyed to the above-described transfer charger 55 via the conveyance path 75c, and the developed image is transferred to the other unprinted surface. A light reflection type paper sensor 75d is provided below the stacker 75b to detect the presence or absence of sheets stacked on the stacker 75b.

Further, an automatic double-side device (ADD) 75 as an automatic double-side reversing mechanism is constituted by the transport path 75a, the stacker 75b, the transport path 75c, and the paper sensor 75d. In the drawing, reference numerals 30a to 30c denote sheet cassettes as sheet feeding means which are detachably mounted from the front side of the apparatus main body 1 in a plurality of upper and lower stages. These paper cassettes 30a to 30c
Is a paper feed tray 3 which is a housing in which copy paper P is stored.
1a to 31c, and the paper feed trays 31a to 31c
Has a configuration in which the take-out end is inclined in the paper take-out direction.

Further, a manual sheet feeding section 43 as a sheet feeding means and a large capacity sheet feeding section 47 of 1000 sheets or more are also provided on one side of the apparatus main body 1. Then, the large-capacity paper supply unit 47
Paper tray 31 inside or paper cassette 30a-30c
The copy paper P stored in each of a to 31c is picked up by the pickup roller 81 from the uppermost layer and taken out. This pickup roller 81
The copy paper P taken out of the feed trays 31a to 31c and fed to the take-out end side of the paper feed trays 31a to 31c is separated from the feed roller 84 provided above and inside the take-out end of the feed trays 31a to 31c. Roller (or separation pad) 85
The paper is separated one by one by a paper separating unit, and is conveyed to the printer unit 3.

Next, a control system of the electronic copying machine 1 will be described with reference to FIGS. 2 shows the overall configuration of the control system of the electronic copying machine 1, FIG. 3 shows the scanner unit 2, FIG. 4 shows the control means (basic unit CPU) 311 and FIG.
6 shows the facsimile unit 312.

The control system of the electronic copying machine 1 is generally composed of two blocks. The image processing unit 314 connects the scanner unit 2 and the printer unit 3 with each other, and a facsimile (FAX) unit 312 as a facsimile function. And a basic unit 301 of the electronic copying machine 1 having the
And a page memory unit 302 as storage means for realizing a memory copy by receiving and storing the image data from the storage unit, and transferring the stored image data to the basic unit 301 again.

The basic unit 301 and the page memory unit 302 are connected by a basic unit system interface 316 for exchanging control data and a basic unit image interface 317 for exchanging image data.

Next, the basic unit 301 includes a scanner 313 as an input unit, a printer 315 as an output unit, an image processing unit (image processing unit) 314, and a facsimile unit 31.
2, and control means for controlling them (basic unit CPU)
311.

As shown in FIG. 4, the control means (basic unit CP
U) The main CPU 100 of 311 includes a sensor 137,
138, ROM 102, RAM 104, image memory 10
6. The timer memory 108, the password memory 110, the timer 112, the internal interface 122, and the external interface 124 are connected. Internal interface 1
The operation panel 114 is connected to the operation panel 11.
4, a message display 93, a numeric keypad 105, a start key 101 and the like are arranged. The external interface 124 is connected to the unit 74 and the external device 138.

Here, storage and recall of image data are performed by the main CPU 100. For example, image data read by the scanner unit 2 under the control of the scanner CPU 160 is stored in the image memory 106 according to an instruction from the main CPU 100. The mode of the instruction of the main CPU 100 is determined by an input (key input) from the operation panel 114 and is performed.

Next, a detailed configuration of the scanner section 2 will be described with reference to FIG. Scanner CP of scanner unit 2
U160 includes a lamp control unit 1 for controlling the exposure lamp 6.
64, a motor driver 16 for controlling the scanning motor 166
8. A sensor including a document size detection sensor 169, a switch, and a driving unit 172 for driving and controlling the solenoids 170 are connected to and controlled by a driving unit 172.
An A / D conversion circuit 176, a resolution conversion circuit 178, a shading correction circuit 179, an image quality improvement circuit 180, and a binarization circuit 182 for image processing of image information from the D sensor 11 are connected and controlled.

Next, the printer section 3 will be described in detail with reference to FIG. In the printer unit 3, the printer C
The PU 190 includes a main motor driver 194 for driving the main motor 192, a sensor including a paper size detection sensor 195, a switch, a driving unit 198 for driving and controlling solenoids 196, and a fixing lamp control for controlling the fixing lamp 200 of the fixing unit 71. Unit 202, charging charger 59, transfer charger 55, peeling charger 56, high-voltage output controller 212 for controlling PCC charger 57, discharging lamp controller 216 for controlling discharging lamp 58, and feed roller 2
0, a paper feed controller 224 for controlling a paper feed motor 222 for the pickup roller 81, a laser diode 60, and a modulation circuit 232 for controlling a laser drive circuit 230 for the polygon motor 228 are connected. Printer CPU
Reference numeral 190 controls each connected unit. High-voltage output control section 212, charging charger 59, transfer charger 55, peeling charger 56, PCC charger 57
Between the high-voltage transformers 59a, 55a, 5
6a and 57a are provided.

Next, the page memory unit 302 will be described with reference to FIG.
This will be described with reference to FIG. The page memory unit 302 controls access to the page memory 323 from the basic unit 301, and includes a system control unit 30 having a built-in communication memory 305.
4. Storage means for temporarily storing image data (P
M: page memory) 323, an address control unit 306 for generating an address of the page memory 323, and an image bus 3 for transferring data between devices in the page memory unit 302.
20, a control bus 321 for transferring a control signal between each device in the page memory unit 302 and the system control unit 304, and a data transfer between the page memory 323 and another device via the image bus 320. Data control means 307 for controlling data transfer; image data I for interfacing image data when transferring image data with basic unit 301 via basic unit image interface 317
/ F means 308 converts image data to a resolution of another device when transmitting image data to a device having a different resolution, or converts image data received from a device having a different resolution to the resolution of the printer unit 3 of the basic unit 301. Resolution conversion / binary rotation means 325 for converting or performing 90-degree rotation processing of binary image data, for a device that compresses and transmits or stores image data such as facsimile transmission or optical disk storage Compress image data input to
Compression / expansion means 324 for expanding the compressed image data for visualization printing is connected to the image data I / F means 308. When the image data is output from the printer unit 3, the image data is 90 degrees or -90. It comprises a multi-value rotation memory 309 which is used when rotating and outputting the data.

Next, the facsimile unit 312 shown in FIG.
This will be described with reference to FIG. The facsimile unit 312 is connected to a public line, and includes a modem 242 as a modem for analog line connection, CODECs 244 and 246 as encoding / decoding devices for binary image data, an EPROM 248 for a communication control program, and image data. Of the pseudo SRAM 2 backed up by the battery 250
52, a work RAM 254 used for performing various processing of image data, an additional memory 256, and an ASIC 258 for an interface for outputting facsimile reception data to the image processing unit 314.

FIG. 7 shows the structure of the operation panel 114. That is, the operation panel 114 includes the finisher key 82, the status display 83, and the paper feed cassettes 30a to 30a.
A cassette selection key 86 and a HELP key 8 as selection means for the 30c, the manual paper feed unit 43, and the large capacity paper feed unit 47;
7. Automatic paper selection key 88, automatic magnification selection key 89, zoom / 100% key 90, original size key 91, paper size key 92, message display 93, automatic density key 9
4, a manual density key 95, a preheat key 96, an interrupt key 97, an all clear key 98, a clear / stop key 99, a start key 101, a timer key 103, a ten key 105, and a communication start key 120.

The finisher key 82 is used to select a sort mode, a group mode, or a staple mode. The status indicator 83 blinks and displays various pictograms to indicate the status of the copying machine.

When the selected cassette is not the desired size, the cassette selection key 86 can be pressed to select another cassette. HELP key 87
When pressed as an operation guide key, a message indicating the operation procedure is displayed, and when pressed after setting the function, the settings can be confirmed.

The automatic paper selection key 88 is normally in the automatic paper selection mode. The size of the document set on the platen (glass) 5 is automatically detected, and a sheet of the same size is automatically selected (only the same size copy).

When an automatic magnification selection key 89 is pressed to select an automatic magnification selection mode and specify a desired paper size, the size of the original set on the original platen (glass) 5 is detected, and the copy magnification is automatically set. Is calculated.

The zoom / 100% key 90 is "25%
When the <> key is pressed, the copy magnification is reduced to 25% in increments of 1%. When the “> 800%” key is pressed, the copy magnification increases to 800% in increments of 1%. "100
Press the "%" key to return to the same size (100%).

The document size key 91 is used to set a document size. When the paper size is selected and the document size is specified, the copy magnification is automatically set.
The paper size key 92 is used to select a paper size.

The message display 93 displays the status of the electronic copying machine 1, the operating procedure, and various instructions to the user in characters and pictures. Message display 9 as display means
Reference numeral 3 has a built-in touch panel, and can set functions.

When the automatic density key 94 is selected for the automatic density, the electronic copying machine 1 automatically detects the density of the original and selects the optimum copy density. With the manual density key 95, a desired copy density can be selected in the manual density. The density can be reduced in five steps by pressing the "light" key, and the density can be reduced in five steps by pressing the "dark" key.

When this key is pressed, the preheating key 96 enters a preheating (power saving) state, and all the display lamps are turned off. To make another copy, press this button again. The interrupt key 97 is used to make an interrupt copy during continuous copying.

When the all clear key 98 is pressed, all the selected modes are cleared and the mode returns to the standard state. The clear / stop key 99 is used to correct the number of copies or to stop the copy operation.

The start key 101 is pressed to start copying. When this key is pressed, the timer key 103
At what time the power of the electronic copying machine 1 is turned on and off is displayed (when a weekly timer is set).

The ten keys 105 are used to set the number of copies to be made. The number of copies can be set from 1 to 999. The communication start key 120 is a key for instructing the start of transmission in facsimile communication.

FIG. 8 shows a transport path of the copy sheet P in the electronic copying machine 1. As described above, the copy paper P is supplied to the paper feed trays 30a to 30c,
3, the photosensitive drum 50 from any of the large capacity
Is fed to the printer unit 3 using

The backing paper is provided on the paper feed trays 30a, 30a.
b, 30c, or the large-capacity paper feeding unit 47. Also, if necessary, the manual sheet feeding section 43
, But the present invention excludes manual paper feeding.

Copy paper P is fed from the paper feed tray 30a to the paper feed path 131, from the paper feed tray 30b to the paper feed path 132,
From the paper feed tray 30c to the paper feed path 133, the large capacity paper feed unit 4
7, the paper is fed to the printer unit 3 through the paper feed path 134. Further, from the manual paper feed unit 43, the paper feed path 13
5 is conveyed to the printer unit 3. Further, the copy paper P is supplied to paper feed paths 131, 132, 133, and 134.
Are conveyed from each other, are merged and conveyed in the paper feed path 136, and are fed to the printer unit 3.

In double-sided printing, the copy paper P is conveyed on the conveyance path 75a after being printed on one side, is accumulated on the stacker 75b, and is again transferred from the stacker 75b to the conveyance path 7a.
5c is conveyed and fed to the printer unit 3, where the other side is printed. The unit 74 is a paper discharge device having a plurality of bins 76a, 76b, 76c, 76d for discharging the printed copy paper P.

Further, the side of the copy sheet P to be printed to be sent to the printer unit 3 (hereinafter, referred to as side A).
Is provided on the side of the sheet feeding path 136 on the side A, and a sensor 138 for reading the side opposite to the side A (hereinafter referred to as the side B) is provided on the side B of the sheet feeding path 136. Have been. The sensors 137 and 138 are constituted by, for example, CCD sensors.

The main CPU 100 detects whether or not printing has already been performed on the surface A (whether or not it is a blank sheet) based on the signal read by the sensor 137, and based on the signal read by the sensor 138, the printing has already been performed on the surface B. Is detected (whether or not it is a blank sheet).

Next, the printing operation using the backing paper in such a configuration will be described with reference to the flowchart of FIG. It is assumed that the backing paper is set on the paper feed tray 30a.
First, the main CPU 100 transports and feeds the copy paper P from the paper feed tray 30a during the copy operation (ST1), reads the A side of the transported paper P with the sensor 137, and
The surface is read by the sensor 138 (ST2), and it is detected from the respective read signals whether the A side and the B side of the sheet P are blank (ST3).

When the A side of the sheet P is blank, the main CPU 100 performs normal printing on the sheet P by the printer unit 3 (prints an image of a document read by the scanner unit 2), and The sheet is discharged to the uppermost bin 76a (ST4).

If the side A of the sheet P has already been printed but the side B is blank, the main CPU 100 passes the sheet P without printing by the printer unit 3 and passes through the transport path 7.
5a is conveyed and collected (stored) in the stacker 75b (ST
6), the sheet P is transported from the stacker 75b to the transport path 75c, the sheet P is reversed, and printing is performed by the printer unit 3;
Is discharged to the uppermost bin 76a (ST7).

If both sides A and B of the sheet P have already been printed, the main CPU 100 passes the sheet P without printing in the printer section 3 and discharges the sheet P as a non-applicable sheet in the normal printing of the unit 74. The paper is discharged to the lowermost bin 76d different from the bin 76a (ST8).

By the way, since the paper P printed on the back paper and discharged is apparently a two-sided copy, it is difficult to determine which side is the back side and which side is the newly copied side. Further, a mark indicating the back side (hereinafter, referred to as a back sheet mark) is printed on the back side of the paper P so that it can be easily determined. The image of the backing paper mark is stored in the image memory 106 in advance, and is read out by the main CPU 100 and formed into an image by the printer unit 3.

FIG. 10 shows an example of a backing paper mark. In FIG. 10 (a), the mark x is the backing paper mark, and in FIG. 10 (b), "Done" is the backing paper mark. Next, a printing operation for adding a backing paper mark when backing paper is used will be described with reference to the flowchart of FIG. Back paper feed tray 3
It shall be set to 0a.

First, the main CPU 100 conveys and feeds the copy sheet P from the sheet feed tray 30a during the copy operation (ST11), and detects the A side of the conveyed sheet P with the sensor 1.
37, and the surface B is read by the sensor 138 (ST1).
2) It is detected from the respective read signals whether the A side and the B side of the sheet P are blank (ST13).

When the side A of the sheet P is blank, the main CPU 100 prints the sheet P in a normal manner by the printer unit 3 (prints the image of the original read by the scanner unit 2). The paper P is transported along the transport path 75a and is accumulated (stored) in the stacker 75b (ST14).
The paper P is transported from the transport path 75c to the transport path 75c, and the inverted paper P is printed on the back paper mark by the printer unit 3 and discharged to the uppermost bin 76a of the unit 74 (ST15).

If the side A of the sheet P is already printed but the side B is blank (ST16), the main CPU 1
00, the paper P is printed on the backing paper mark by the printer unit 3, conveyed through the conveyance path 75a and accumulated (stored) in the stacker 75b (ST17).
5c is conveyed, the paper P thus inverted is subjected to normal printing by the printer unit 3 and the top bin 7 of the unit 74 is conveyed.
The sheet is discharged to 6a (ST18).

If both sides A and B of the sheet P have already been printed, the sheet P passes through the printer unit 3 without printing, and a bin 76a which is discharged as a non-applicable sheet by the normal printing of the unit 74. Discharges paper to a different lower bin 76d (ST19).

As another embodiment, an electronic copying machine 1 provided with only the sensor 137 among the sensors 137 and 138 shown in FIGS. 4 and 8 will be described. That is, in this case, it is detected whether or not only the side A of the conveyed copy sheet P, that is, the side to be printed of the copy sheet P has already been printed (whether or not it is a blank sheet). Things.

The printing operation using the backing paper in such a configuration will be described with reference to the flowchart of FIG. It is assumed that the backing paper is set on the paper feed tray 30a. The main CPU 100 transports and feeds the copy paper P from the paper feed tray 30a during the copy operation (ST21), reads the side A of the transported paper P with the sensor 137 (ST22),
From this read signal, it is detected whether or not the side A of the sheet P is blank (ST23).

If the A side of the sheet P is blank, the main CPU 100 performs normal printing on the sheet P by the printer unit 3 (prints the image of the original read by the scanner unit 2). The sheet is discharged to the uppermost bin 76a (ST24).

When the side A of the sheet P has already been printed, the main CPU 100 sends the sheet P to the printer unit 3.
Then, the paper passes without printing, and is discharged as non-applicable paper to the lowermost bin 76d different from the bin 76a discharged for normal printing of the unit 74 (ST25).

Next, a printing operation for adding a backing paper mark when a backing paper is used will be described with reference to the flowchart of FIG. It is assumed that the backing paper is set on the paper feed tray 30a. The main CPU 100 transports and feeds the copy paper P from the paper feed tray 30a during the copy operation (ST31), and reads the side A of the transported paper P with the sensor 137 (S31).
T32), it is detected from the read signal whether or not the side A of the sheet P is blank (ST33).

When the side A of the sheet P is blank, the main CPU 100 prints the sheet P in a normal manner by the printer unit 3 (prints the image of the original read by the scanner unit 2), The paper P is transported along the transport path 75a and is accumulated (stored) in the stacker 75b (ST34).
The paper P is conveyed from the conveyance path 75c to the conveyance path 75c, and the reversed paper P is printed on the back paper mark by the printer unit 3 and discharged to the uppermost bin 76a of the unit 74 (ST35).

When the side A of the sheet P has already been printed, the main CPU 100 sends the sheet P to the printer unit 3.
Then, the paper passes through without printing, and is discharged as non-applicable paper to the lowermost bin 76d different from the bin 76a discharged for normal printing of the unit 74 (ST36).

As described above, according to the embodiment of the present invention, when the back paper is set in the paper feed tray or the large-capacity paper feed section, the correct orientation is set even if the paper is erroneously set upside down. Can be printed only on the backing paper, and the paper set in the opposite direction can be discharged to a different bin from the bin that normally discharges. It can be discharged to another bin.

Also, by inverting the paper using the stacker of the automatic double-sided apparatus, even if some of the back paper is set upside down by mistake, it can be printed with the correct orientation. Further, paper on which both sides have been printed can be discharged as non-applicable paper.

Also, by turning over the sheet using the stacker of the automatic double-sided apparatus and printing a mark indicating the back side (back side mark) on the back side, the back side and the newly copied side (front side) can be easily printed. Can be determined.

Further, the sheet is reversed using the stacker of the automatic double-sided apparatus to perform normal printing and printing of a mark indicating the back side (back side mark), so that the backing paper can be oriented in either direction. Even if it is set, normal printing can be performed on the front surface (blank paper surface) and back surface mark can be printed on the back surface (printed surface).

[0074]

As described in detail above, according to the present invention,
When forming an image by reusing the back side of a sheet on which only one side is printed, an image forming apparatus and an image are provided which prevent double printing and allow the back side and the newly formed image side to be easily determined. A forming method can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an electronic copying machine according to an image forming apparatus of the present invention.

FIG. 2 is a system configuration diagram of the image forming apparatus.

FIG. 3 is a block diagram illustrating a configuration of a scanner unit.

FIG. 4 is a block diagram showing a configuration of a basic unit CPU.

FIG. 5 is a block diagram illustrating a configuration of a printer unit.

FIG. 6 is a block diagram illustrating a configuration of a facsimile unit.

FIG. 7 is a diagram showing a configuration of an operation panel.

FIG. 8 is a diagram illustrating a copy paper transport path in the electronic copying machine.

FIG. 9 is a flowchart for explaining a printing operation using a backing sheet.

FIG. 10 is a diagram illustrating an example of a back paper mark.

FIG. 11 is a flowchart for explaining a printing operation for adding a backing paper mark when backing paper is used.

FIG. 12 is a flowchart for explaining a printing operation using a backing sheet.

FIG. 13 is a flowchart for explaining a printing operation for adding a backing paper mark when backing paper is used.

FIG. 14 illustrates an example of double printing.

FIG. 15 is a diagram illustrating an example of a back side and a newly copied side.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electronic copying machine 2 ... Scanner part 3 ... Printer part 30a, 30b, 30c ... Paper feed cassette 31a, 31b, 31c ... Paper feed tray 47 ... Large capacity paper feed part 74 ... Unit 75a, 75c ... Transport path 75b ... Stacker 75 ... Automatic duplexer 76a, 76b, 76c, 76d ... Bin 137, 138 ... Sensor 100 ... Main CPU 106 ... Image memory 131, 132, 133, 134, 135, 136 ... Feeding path

Claims (8)

[Claims] 1. An image forming apparatus for forming an image on a sheet supplied from a supply unit, wherein the reading unit reads an image on a surface of the sheet supplied from the supply unit on which an image is to be formed. Detecting means for detecting whether or not an image has been formed on the image forming surface from the read image; and paper detected by the detecting means when the detecting means detects that no image has been formed. An image forming unit for forming an image on the sheet, a sheet discharging unit for discharging the sheet on which the image is formed by the image forming unit to a predetermined position, and when the detecting unit detects that the image has been formed,
An image forming apparatus comprising: a control unit configured to control discharge of a sheet detected by the detection unit to a position different from a predetermined position where the sheet is discharged by the discharge unit. 2. An image forming apparatus for forming an image on a sheet supplied from a supply unit, wherein the reading unit reads an image on a surface of the sheet supplied from the supply unit on which an image is to be formed. Detecting means for detecting whether or not an image has been formed on the image forming surface from the read image; and paper detected by the detecting means when the detecting means detects that no image has been formed. A first image forming unit for forming an image on the sheet, a reversing unit for reversing the sheet on which the image is formed by the first image forming unit, and a reversing unit for reversing the sheet on which the image is formed by the reversing unit. A second image forming unit for forming an image indicating the back side on the back side, and a sheet discharging unit for discharging a sheet on which the image indicating the back side is formed by the second image forming unit to a predetermined position And the detection When the image formation is detected as being in stage,
An image forming apparatus comprising: a control unit configured to control discharge of a sheet detected by the detection unit to a position different from a predetermined position where the sheet is discharged by the discharge unit. 3. An image forming apparatus for forming an image on a sheet supplied from a supply unit, a first reading unit for reading an image on a surface of the sheet supplied from the supply unit on which an image is to be formed, A second reading unit for reading an image on the back surface of the sheet read by the first reading unit; an image on the back surface read by the second reading unit;
Detecting means for detecting whether or not an image has already been formed on the image forming surface and the back surface from the image on the image forming surface read by the reading means; and forming the image on the image forming surface by the detecting means. An image forming means for forming an image on the sheet detected by the detecting means when it is detected that the sheet is not detected; and a sheet discharging means for discharging the sheet on which the image is formed by the image forming means to a predetermined position. When the detecting means detects that an image has been formed on the image forming surface and no image has been formed on the back surface, the sheet detected by the detecting means is inverted and the image is formed on the back surface by the image forming means. A first control unit for controlling discharge of paper to a predetermined position by the paper discharge unit; and detecting when the detection unit detects that an image is formed on the image forming surface and the back surface. Paper detected by the paper discharging means And a second control unit that controls discharge of the paper to a position different from the predetermined position where the paper is to be printed. 4. An image forming apparatus for forming an image on a sheet supplied from a supply unit, wherein the first reading unit reads an image on a surface of the sheet supplied from the supply unit on which an image is to be formed. A second reading unit for reading an image on the back surface of the sheet read by the first reading unit; an image on the back surface read by the second reading unit;
Detecting means for detecting whether or not an image has already been formed on the image forming surface and the back surface from the image on the image forming surface read by the reading means, and forming an image on the image forming surface by the detecting means. A first image forming unit that forms an image on the sheet detected by the detecting unit when it is detected that the sheet has not been detected; a reversing unit that reverses the sheet on which the image is formed by the first image forming unit; A second image forming means for forming an image indicating the back side on the back side of the surface on which the image of the sheet inverted by the reversing means is formed; and indicating the back side by the second image forming means. A sheet discharging unit for discharging the sheet on which the image is formed to a predetermined position; and detecting when the detecting unit detects that the image is formed on the image forming surface but not on the back surface. The second image on the sheet detected by the means A first image forming unit that forms an image indicating that the image is a back side by the forming unit, reverses the image by the reversing unit, forms an image by the first image forming unit, and discharges the paper to a predetermined position by the discharging unit. And a predetermined position at which a sheet detected by the detection unit is discharged by the discharge unit when the control unit detects that an image is formed on the image forming surface and the back surface by the detection unit. An image forming apparatus comprising: a second control unit configured to perform control to discharge a sheet to a position. 5. An image forming method for forming an image on a supplied sheet, comprising: reading an image on a side of the supplied sheet on which an image is to be formed; and forming an image on the image forming side from the read image. It is detected whether or not an image is formed, and when it is detected that the image is not formed, an image is formed on the detected sheet and discharged to a predetermined position. An image forming method, wherein when detected, control is performed to discharge the detected sheet to a position different from the predetermined position. 6. An image forming method for forming an image on a supplied sheet, comprising: reading an image on a side of the supplied sheet on which an image is to be formed; and forming an image on the image forming side from the read image. It is detected whether or not an image is formed, and when it is detected that the image is not formed, an image is formed on the detected sheet, and the sheet on which the image is formed is inverted to form the image. An image indicating the back side is formed on the back side of the surface, and the sheet is discharged to a predetermined position. When it is detected that the image is formed, the detected sheet is discharged to a position different from the predetermined position. An image forming method, wherein control for paper feeding is performed. 7. An image forming method for forming an image on a supplied sheet, comprising: reading an image of a side of the supplied sheet on which an image is to be formed and an image of a back side thereof; It is detected whether or not an image has already been formed on the image forming surface and the back surface from the image, and when it is detected that the image has not been formed on the image forming surface, an image is formed on the detected sheet. When the paper is discharged to a predetermined position and it is detected that the image is formed on the image forming surface and the image is not formed on the back surface,
The detected sheet is inverted to form an image on the back side and is discharged to the predetermined position. When it is detected that the image is formed on the image forming side and the back side, the detected sheet is An image forming method, wherein a sheet is discharged to a position different from a predetermined position. 8. An image forming method for forming an image on a supplied sheet, comprising: reading an image on a side of the supplied sheet on which an image is to be formed, and an image on a back side thereof; It is detected whether or not an image has already been formed on the image forming surface and the back surface, and when it is detected that the image has not been formed on the image forming surface, an image is formed on the detected sheet,
The sheet on which the image is formed is inverted and an image indicating the back side is formed on the back side of the side on which the image is formed, and the image is discharged to a predetermined position. When it is detected that the image has not been formed, an image indicating the back side is formed on the detected sheet, and an image is formed by inverting the sheet on which the image indicating the back side is formed. The sheet is discharged to the predetermined position, and when it is detected that an image is formed on the image forming surface and the back surface, the detected sheet is discharged to a position different from the predetermined position. Image forming method.