JP2002173234A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device for preventing paper jam while maintaining high-speed processing. SOLUTION: The thickness of paper sheets is detected by a sheet thickness detecting roller 229 as detecting means. The paper sheets, if discriminated to be regular paper sheets, are carried (by first carrying means) in the state of laying the rear ends of the preceding sheets on the front ends of the following sheets and, if discriminated to be thick paper sheets, are carried (by second carrying means) in sheet-to-sheet spaced relation.

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 for forming an image on a conveyed sheet.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus for forming an image on a sheet to be conveyed includes a copying machine, a printer and a facsimile, all of which feed a sheet (paper) on which an image is formed. A function for carrying is provided.

In general, sheets are stacked on a cassette for stacking the sheets, and the sheets are separated and fed one by one by a feeding means (feed roller or the like), and the fed sheets are conveyed. Means (transport rollers such as registration rollers)
Thus, the sheet is conveyed in accordance with the image forming timing by the image forming unit.

[0004] When sheets are continuously fed from a cassette, a sheet feeding / conveying control that continuously conveys a sheet (a sheet interval) between a preceding sheet and a sheet to be fed next is performed. Was common.

In recent years, in order to realize high-speed paper feeding,
From the cassette to the registration roller, the sheet is continuously conveyed with the rear end of the previous sheet and the front end of the next sheet superimposed on each other. Overlap transport control for performing transport has come to be used.

[0006]

However, in the case of the above-described prior art, the following problems have occurred.

As described above, when the overlapping conveyance control is used, the processing time can be shortened by realizing the high-speed paper feeding. However, when the paper such as the thick paper is conveyed in an overlapped state, the overlapped portion of the paper and the paper is removed. Since the thickness is increased, the paper cannot be fed by the thick paper detection and conveyance roller, and a paper jam may be caused.

As a result, there is a case where time is required to correct a paper jam and sheets are wasted.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and it is an object of the present invention to provide an image forming apparatus capable of preventing a paper jam while maintaining high-speed processing. .

[0010]

In order to achieve the above object, according to the present invention, an image forming means for forming an image on a sheet to be conveyed, and a plurality of sheets are continuously formed from the stacked sheets. When transported toward the image forming means,
A first conveyance unit that conveys a part of continuous sheets in an overlapped state, and does not stack continuous sheets when a plurality of sheets are continuously conveyed from the stacked sheets toward the image forming unit. An image forming apparatus comprising: a second conveying unit that conveys the sheet in a state; and a detecting unit that detects a thickness of a sheet to be conveyed, wherein the first conveying unit and the second conveying unit detect the thickness of the sheet to be conveyed based on a detection result by the detecting unit. It is characterized by switching to one of the two transport means.

Here, the state in which the sheets are not overlapped includes a case where a gap is provided between successive sheets, and a case where the trailing edge of the preceding sheet is in contact with the leading edge of the succeeding sheet.

Therefore, if the sheet is conveyed by the first conveying means, the processing speed is reduced by the amount by which a part of the sheet is superimposed and conveyed, and if the sheet is conveyed by the second conveying means, there is no overlapped portion of the sheet. Paper jam due to too thick paper can be prevented.

When the detecting means detects that the sheet to be conveyed is thicker than a predetermined thickness, the sheet may be conveyed by the second conveying means.

When the detecting means detects that the sheet to be conveyed has a thickness equal to or less than a predetermined value, the sheet may be conveyed by the first conveying means.

Further, according to the present invention, there is provided a feeding means for separating and feeding one sheet from a stacked sheet, and an image forming means for forming an image on the sheet fed by the feeding means. Conveying means for conveying the sheet fed by the feeding means in accordance with the image forming timing by the image forming means; detecting means for detecting the thickness of the conveyed sheet; When performing image formation, it is determined whether or not a sheet is to be conveyed in a state of being partially overlapped, based on a detection result by the detection unit, and according to the determination result, the feeding unit and / or conveyance is performed. Control means for controlling the means.

[0016]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The materials, shapes, relative arrangements, and the like are not intended to limit the scope of the present invention only to them unless otherwise specified.

An image forming apparatus according to an embodiment of the present invention will be described with reference to FIGS. It should be noted that the image forming apparatus can be applied to various devices such as a printer and a facsimile. In the following description, as an example, a digital copying machine will be described as a line.

FIG. 1 is a block diagram showing a configuration of an image forming apparatus (digital copying machine) according to an embodiment of the present invention.

The reader unit 1 reads an image of a document and outputs image data corresponding to the document image to the image memory unit 3. The printer unit 2 forms an image corresponding to the image data from the image memory unit 3 on a sheet.

The image memory unit 3 compresses the image data transferred from the reader unit 1, stores the compressed image data, and expands the stored compressed image data to expand the image data. The image data is transferred to the printer unit 2.
Further, it transfers the stored image data to the external I / F processing unit 4, or stores the image data transferred from the external I / F processing unit 4.

The external I / F processing section 4 performs predetermined processing on the image data transferred from the image memory section 3 and then outputs the processed data to an external device, or performs predetermined processing on the image data sent from the external device. The image data is processed and transferred to the image memory unit 3.

The automatic document feeder 6 is connected to the reader unit 1 and feeds the placed document to a predetermined position.

FIG. 2 is a schematic sectional view of an image forming apparatus (digital copying machine) according to an embodiment of the present invention.

In the figure, reference numeral 200 denotes a digital copying machine main body, and reference numeral 6 denotes an automatic document feeder (DF). Reference numeral 201 denotes a platen glass serving as a document mounting table, and 202 denotes a scanner, which includes a document illumination lamp 203, a scanning mirror 204, and the like.

When an image is read by placing an original on the platen glass 201, the scanner 202 is reciprocally scanned in a predetermined direction by a motor (not shown), and reflected light of the original is scanned by scanning mirrors 204 to 206. An image is formed on the CCD sensor in the image sensor unit 208 through the lens 207 via the lens 207.

An exposure control unit 209 includes a laser, a polygon scanner, and the like.
It is converted into an electric signal in the image sensor unit 208,
A modulated laser beam 219 is applied to the photosensitive drum 211 based on an image signal on which predetermined image processing described later has been performed.

Around the photosensitive drum 211, a primary charger 212, a developing device 213, a transfer charger 216, a pre-exposure lamp 214, and a cleaning device 215 are provided.

In the image forming section 210, the photosensitive drum 211 is rotated by a motor (not shown) in the direction of the arrow shown in the figure, and after being charged to a desired potential by the primary charger 212, the exposure control section 209 is controlled. Is irradiated, and an electrostatic latent image is formed.

The electrostatic latent image formed on the photosensitive drum 211 is developed by the developing device 213 and visualized as a toner image.

On the other hand, pick-up rollers 225, 226, 2 from the right cassette deck 221, the left cassette deck 222, the upper cassette 223 or the lower cassette 224.
Sheets (transfer sheets) fed by the sheets 27 and 228 are sheet thickness detecting rollers 229, 230, 231, 232, and 2 as detecting means having a detecting function of detecting the sheet thickness.
80, 281, 282, 283, 284,
The toner image is fed to the transfer belt by the registration roller 233 while taking the image forming timing, and the visualized toner image is transferred onto the sheet by the transfer charger 216.

After the transfer, the photosensitive drum 211 is cleaned of residual toner by the cleaning device 215, and residual charge is erased by the pre-exposure lamp 214. The transferred sheet is separated from the photosensitive drum by a separation charger 217 and sent to a fixing device 235 by a transfer belt 234.

The unfixed toner image on the sheet is fixed by pressure and heat by the fixing device 235, and the sheet on which the image has been fixed is discharged to the outside of the digital copying machine main body 200 by the discharge roller 236. .

The digital copying machine main body 200 has, for example, 4
A deck 250 capable of storing 000 sheets is provided. The lifter 251 of the deck 250 rises according to the amount of the sheet so that the sheet always contacts the pickup roller 252, and the sheet is sent to the main body by the sheet feeding roller 253. Also, it can accommodate 100 sheets,
Equipped with a multi-bypass 254.

In FIG. 2, reference numeral 237 denotes a paper discharge flapper, which switches the path between the transport path 238 and the discharge path 243. Reference numeral 240 denotes a lower transport path, which is a discharge roller 236.
From the sheet sent out from the reversing path 239,
The sheet is turned over and guided to the refeeding path 241.

The paper feed roller 2 from the left cassette deck 222
The sheet fed by 30 is also guided to the refeed path 241. Reference numeral 242 denotes a re-feed roller that re-feeds the sheet to the image forming unit 210.

The paper discharge flapper 237 is disposed in the vicinity of the paper discharge flapper 237, and the discharge path 243 is formed by the paper discharge flapper 237.
This is a discharge roller for discharging the sheet switched to the side to the outside of the apparatus.

During double-sided recording (double-sided copying), the discharge flapper 237 is raised, and the copied sheet is guided to the re-feeding path 241 via the transport path 238, the reversing path 239, and the lower transport path 240. At this time, the entire rear end of the sheet is pulled out of the conveyance path 238 by the reversing roller 245, and the sheet is pulled into the reversing path 239 to a position where the sheet is bitten by the reversing roller 245. To send out.

When the sheet is reversed and discharged from the main body, the discharge flapper 237 is raised upward and the reversing roller 24 is rotated.
5, the trailing edge of the sheet is drawn into the reversing path 239 to a position where the rear end of the sheet remains in the conveying path 238,
5 is reversed, the sheet is turned over and sent out to the discharge roller 244 side.

Reference numeral 290 denotes a digital copying machine main body 200.
This is a sheet discharge processing device that closes the sheets discharged from the printer, and stacks and discharges the sheets discharged one by one on the processing tray 294.

When the discharge of a part of the image formation is completed, the sheet bundle is stapled and discharged to the discharge tray 292 or 293.
Discharge in bundles. The discharge tray 293 is controlled to move up and down by a motor (not shown), and moves to the position of the processing tray before the image forming operation starts.

Reference numeral 291 denotes a paper tray on which separator sheets to be inserted between the discharged sheets are stacked, and 295 denotes a Z-folding machine for Z-folding the discharged sheets. Reference numeral 296 denotes a bookbinding machine that binds a part of the discharged sheets to the center and staples them to perform bookbinding. The bound sheet bundle is discharged to a discharge tray 297.

FIG. 3 is a control block diagram in the digital copying machine.

Reference numeral 171 denotes a CPU for performing basic control of the digital copying machine.
74, a work RAM 175 for performing processing, and an input / output port 173 are connected by an address bus and a data bus. The input / output port 173 is connected to various loads (not shown) such as a motor and a clutch, which control the digital copier main body 200, and inputs (not shown) such as a sensor for detecting the position of the paper.

The CPU 171 controls input / output sequentially through the input / output port 173 according to the contents of the ROM 174, and executes an image forming operation. An operation unit 172 is connected to the CPU 171 and controls a display unit and a key input unit of the operation unit 172. The operator switches the display of the image forming operation mode, the scanner reading mode, and the print output mode through the CPU 1 through the key input unit.
71, and the CPU 171 sets the digital copier body 20
A state of 0 or an operation mode setting by key input is displayed.

The CPU 171 includes the image sensor unit 20
Image processing unit 1 that processes the signal converted into an electric signal in 8
And an image memory unit 3 for storing processed images.

Next, according to FIG.
0 will be described in detail. FIG. 4 is a block diagram of the image processing unit.

The original image formed on the CCD sensor via the lens 207 is input as black luminance data, and is converted into an analog electric signal by the CCD sensor. The converted image information is input to an analog signal processing unit (not shown), and after sample and hold, dark level correction, and the like are performed, the A / D conversion unit 501 performs analog-to-digital conversion (A / D conversion). Then, the digitized signal is subjected to shading correction (correction of variations in a sensor for reading a document and light distribution characteristics of a document illumination lamp). After that, the data is sent to the log conversion unit 502.

The log conversion unit 502 stores an LUT for converting the input luminance data into density data, and outputs a table value corresponding to the input data to convert the luminance data into density data. Convert.

After that, the image is scaled to a desired magnification by the scaling unit 503 and input to the γ correction unit 504. γ
When outputting the density data, the correction unit 504 performs conversion using an LUT in consideration of the characteristics of the printer, and adjusts the output according to the density value set by the operation unit.

After that, it is sent to the binarizing section 505. The binarization unit 505 binarizes the multi-value density data, and the density value becomes “0” or “255”. The 8-bit image data is binarized and converted into 1-bit image data of “0” or “1”, and the amount of image data stored in the memory is reduced.

However, when the image is binarized, the number of gradations of the image is changed from 256 gradations to two gradations. Therefore, binarization of image data having a large number of halftones such as a photographic image generally deteriorates the image. Remarkable. Therefore, it is necessary to perform pseudo halftone expression using binary data. Here, an error diffusion method is used as a method for pseudo-halftone expression using binary data.

According to this method, when the density of a certain image is larger than a certain threshold value, it is determined that the density data is "255", and when the density is less than a certain threshold value, it is determined that the density data is "0". In this method, the difference between the actual density data and the binarized data is distributed to surrounding pixels as an error signal. The distribution of the error is performed by multiplying a weight coefficient on a matrix prepared in advance by the error generated by the binarization and adding the result to surrounding pixels.

As a result, the density average value of the entire image is preserved, and the halftone can be represented in a pseudo binary manner. The binarized image data is sent to the image memory unit 3, where the image is stored. Also, it is input from the external I / F processing unit 4. Image data from the computer is sent to external I /
Since it is processed as binary image data by the F processing unit,
It is sent to the image memory unit 3 as it is.

The image memory unit 3 has a high-speed page memory and a large-capacity memory (hard disk) capable of storing a plurality of page image data. The plurality of image data stored in the hard disk is stored in the digital copier main body 20.
The output is performed in the order corresponding to the editing mode specified by the operation unit of “0”.

For example, in the case of sorting, images of a document bundle read from the DF 6 are sequentially output. The image data of the document once stored is read from the hard disk, and this is repeated a plurality of times and output. Thereby, it can play the same role as a sorter having a plurality of bins.

The image data output from the image memory unit 3 is sent to a smoothing unit 506 in the printer unit 2.
The smoothing unit 506 performs data interpolation so that the line ends of the binarized image are smoothed, and the exposure control unit 2
09 to output image data. The exposure control unit 209 forms image data on a sheet by the above-described processing.

Next, details of the image memory unit 3 will be described with reference to FIG.

The image memory section 3 writes a binary image from the external I / F processing section 4 and the image processing section 170 via a memory controller section 302 to a page memory section 301 composed of a memory such as a DRAM. The external I / F processing unit 4 reads out images to the printer unit 2 and accesses the hard disk 304 as a large-capacity storage device for inputting and outputting images.

The memory controller 302 generates a DRAM refresh signal for the page memory 301, and arbitrates access to the page memory 301 from the image I / F processor 4, image processor 170, and hard disk 304. I do. Further, according to the instruction of the CPU 171,
It controls a write address to the page memory unit 301, a read address from the page memory unit 301, a read direction, and the like. Accordingly, the CPU 171 controls the function of laying out a plurality of document images in the page memory unit 301 and outputting them to the printer unit, the function of cutting out and outputting only a part of the image, and the image rotation function.

Next, according to FIG. 6, the external I / F processing unit 4
Is described. As described above, the external I / F processing unit 4
Via the image memory unit 3, the binary image data of the reader unit is processed by the external I / F processing unit, and the binary image data from the external I / F is transmitted via the image memory unit 3 to the printer unit 2.
To form an image.

The external I / F processing unit 4 includes a core unit 406, a facsimile unit 401, a hard disk 402 for storing communication image data of the facsimile unit, and an external computer 1
Computer interface unit 403 connected to
And a formatter unit 404 and an image memory unit 405.

The facsimile unit 401 is a modem (not shown)
, And receives facsimile communication data from the public line and transmits facsimile communication data to the public line.

The facsimile unit 401 stores a facsimile image on the hard disk 402 such as transmitting a facsimile at a specified time or transmitting image data in response to an inquiry of a specified password from a partner, which is a facsimile function. Perform processing.

Thus, once the image is transferred from the reader unit 1 to the facsimile unit 401 and the facsimile hard disk 402 via the image memory unit 3, the reader unit 1 and the image memory unit 3 are used for the facsimile function. No fax transmission can be performed. The computer interface unit 403 is an interface unit that performs data communication with an external computer, and includes a local area network (hereinafter, LAN), a serial I / O
F, SCSII / F, Centro I / F for printer data input, etc.

Via this I / F, the statuses of the printer unit and the reader unit are notified to an external computer, and an image read by the reader unit 1 is transferred to the external computer according to instructions from the computer.

Also, print image data is received from an external computer. Since the print data notified from the external computer via the computer interface unit 403 is described in a dedicated printer code, the formatter unit 404 converts the code into an image in the printer unit 2 via the image memory unit 3. Convert to raster image data to be performed.

The formatter unit 404 develops raster image data in the image memory unit 405.

The image memory unit 405 is used as a memory in which the formatter unit 404 expands raster image data.

The image memory unit 405 stores the image of the reader unit in the computer interface unit 403.
To an external computer via a PC (image scanner function)
In this case, it is also used when the image data sent from the image memory unit 3 is once expanded in the image memory unit, converted into a format of data to be sent to an external computer, and sent out from the computer interface unit 403.

The core unit 406 includes a facsimile unit 401,
It controls and manages data transfer among the computer interface unit 403, the formatter unit 404, the image memory unit 405, and the image memory unit 3. Thus, even if the external I / F processing unit 4 has a plurality of image output units or the image memory unit 3 has only one image transfer path, the core unit 40
Under the management of No. 6, exclusive control and priority control are performed, and image output is performed.

Next, conveyance control in the image forming apparatus according to the present embodiment will be described with reference to FIGS. 7, 8, 9 and 10. FIG.

FIGS. 7, 8 and 9 are explanatory views for explaining how the sheet is fed (conveyed). The sheet fed from the right cassette deck 221 and transferred by the photosensitive drum 211 is shown in FIGS. 3 is a cross-sectional view of the transport unit in the state shown in FIG.

In FIG. 7, a sheet thickness detecting roller 229 serving as a detecting means conveys a sheet in the conveying direction for each sheet fed from the right cassette deck 221 and, at the same time, arbitrarily selects a pair of sheets according to the sheet thickness. The roller is opened and closed, and the thickness of the sheet is detected based on the degree of opening.

The paper thickness detecting roller 229 outputs an output value of 0 to 255. If the output value is 0 to 64, it is determined that the sheet is 79 g / mm (thin paper) paper, and the output value is If it is 65 to 80, it is determined to be 105 g / mm paper (plain paper), and if the output value is 81 to 106, it is 163 g / mm.
Judge as paper (thick paper), and if it is 107 or more, 209 g /
It is determined that the paper is mm paper (ultra thick paper).

In FIG. 7, the sheet thickness detection output of the first to fourth sheets is 70, which is 105 g / mm.
FIG. 6 is a cross-sectional view of a conveyance unit showing a state of a sheet when it is determined that the sheet is plain paper.

In this case, the first to fourth sheets are fed from the right cassette deck 221, and a part of each successive sheet is overlapped, that is, the rear end of the preceding sheet Is conveyed in a state where the leading edge of the succeeding next sheet is overlapped (first conveying means).

As shown in the first and second sheets in FIG. 7, when the previous sheet is fed into the image forming section (transfer section) by the registration roller, the interval between the next sheet and the next sheet is increased. Is emptied.

If the sheet thickness detection output of the fifth sheet is 100, it is determined that the fifth sheet is a thick sheet.

The transport control in such a case, that is, when it is determined that the sheet is a thick sheet during paper feeding will be described with reference to FIG.

FIG. 8 shows that the fifth sheet is determined to be thick paper, and
FIG. 9 is a cross-sectional view illustrating a state of a sheet when a sheet is fed.

As shown in the figure, the third to fifth sheets are conveyed in a partially overlapping state as described above.
The image is being transferred while being spaced from the first sheet.

Here, the sixth sheet is conveyed without overlapping with the fifth sheet (switching from the first conveying means to the second conveying means). That is, control is performed so that the leading end of the sixth sheet is fed with an interval (paper interval) from the trailing end of the fifth sheet (second conveying unit). In addition,
In the illustrated example, the case where the paper feed control is performed with a space between the papers is shown.

Thereafter, as shown in the cross-sectional view of FIG. 9, the sheet is conveyed between the sixth sheet, the seventh sheet, and the eighth sheet and the conveyance control is performed (second conveyance means).

Next, the operation flow of the image forming apparatus according to the present embodiment will be described with reference to the flowchart of FIG.

The flow of FIG. 10 is a flow for feeding a predetermined number of sheets from the right cassette deck from the start of sheet feeding.

First, a count variable for counting a predetermined number of fed sheets is set to 1 (S1001). Next, the first sheet is fed at a constant speed by driving the sheet thickness detection roller 229 at a speed similar to the transport speed of the sheet thickness detection rollers 283 and 284 (S1002).

Next, in step S1002, the thickness of the fed sheet is detected. Here, if the output of the paper thickness detection is 81 or more, it is determined that the paper is thick paper. If the output value is less than 80, it is determined that the paper is not thick paper.
(S1003).

If it is not determined that the sheet is a thick sheet, the first sheet fed is waited for the trailing edge of the sheet to pass through the sheet thickness detecting roller by the sheet thickness detecting roller (S1004). Is passed, the count variable is incremented (+1) (S1005), and it is determined whether a predetermined number of sheets has been fed (S1006).

If the predetermined number of sheets has not been reached, the sheet thickness detecting roller 229 is driven at a speed higher than the conveying speed of the sheet thickness detecting rollers 283 and 284, and the leading end of this sheet is moved forward by one. (S1007).

Thereafter, S1003 to S1007 are repeated.

Next, if it is determined in S1003 that the sheet is thick paper, the first fed sheet is waited for the trailing edge of the paper to pass through the paper thickness detection roller by the paper thickness detection roller (S1003).
8) When the trailing edge of the sheet has passed, the count variable is incremented (+1) (S1009), and it is determined whether a predetermined number of sheets has been fed (S1010).

If the predetermined number of sheets has not been reached, the sheet thickness detection roller 229 drives the next sheet at a speed similar to the transport speed of the sheet thickness detection rollers 283 and 284, and the next sheet is fed. The sheet is fed at a constant speed with a sheet interval (S1011).

Thereafter, S1008 to S1011 are repeated until a predetermined number of sheets have been fed in S1010.

In the above description, a case has been described in which, after it is determined that the sheet being conveyed is thick paper, control is performed to convey the sheet at an interval (second conveyance control). If it is determined that the middle sheet is normal paper, control may be performed to convey the sheet while overlapping a part of the sheet again (first conveyance control).

In the above description, a case where the present invention is applied to an electrophotographic image forming apparatus has been described. However, the present invention can be applied to an image forming apparatus of another type.

That is, in the case of the above-described electrophotographic image forming apparatus, the feeding and transport control from the feeding section to the transfer section serving as the image forming section is characterized by, for example, In the case where the present invention is applied to an ink jet type image forming apparatus, the present invention can be applied to feeding and transport control from a sheet feeding unit to an ink ejection unit.

[0097]

As described above, according to the present invention, when a plurality of sheets are conveyed continuously, the sheets may be conveyed in a state where a part of the sheets are superimposed, Since the paper is conveyed without any paper, paper jams can be prevented while maintaining high-speed processing.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of an image forming apparatus according to an embodiment of the present invention.

FIG. 3 is a control block diagram in the digital copying machine.

FIG. 4 is a block diagram of an image processing unit.

FIG. 5 is a block diagram of an image memory unit.

FIG. 6 is a block diagram of an external I / F processing unit.

FIG. 7 is an explanatory diagram illustrating a state of sheet conveyance.

FIG. 8 is an explanatory diagram illustrating a state of sheet conveyance.

FIG. 9 is an explanatory diagram illustrating a state of sheet conveyance.

FIG. 10 is a flowchart showing a flow of an operation of the image forming apparatus according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reader part 2 Printer part 3 Image memory part 4 External I / F processing part 6 Automatic document feeder 170 Image processing part 172 Operation part 173 I / O port 200 Digital copier main body 201 Platen glass 202 Scanner 203 Document illumination lamp 204 Scanning mirror 207 Lens 208 Image sensor unit 209 Exposure control unit 210 Image forming unit 211 Photoconductor drum 212 Primary charger 213 Developing unit 214 Pre-exposure lamp 215 Cleaning device 216 Transfer charger 217 Separator charger 219 Laser light 221 Right cassette deck 222 Left Cassette deck 223 Upper cassette 224 Lower cassette 225, 226, 227, 228 Pickup roller 229 Paper thickness detection roller 230 Feed roller 233 Registration roller 234 Transfer belt 235 Fixing 236 Discharge roller 237 Discharge flapper 238 Convey path 239 Reverse path 240 Convey path 241 Refeed path 243 Discharge path 244 Discharge roller 245 Reverse roller 250 Deck 251 Lifter 252 Pickup roller 253 Feed roller 283, 284 Paper thickness detection roller 292 Discharge Paper tray 293 Output tray 294 Processing tray 297 Output tray 301 Page memory 301 Page memory section 302 Memory controller section 304 Hard disk 401 Facsimile section 402 Hard disk 403 Computer interface section 404 Formatter section 405 Image memory section 406 Core section 501 Conversion section 502 Conversion section 503 Scaling processing unit 504 Correction unit 505 Value conversion unit 506 Smoothing unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 15/00 518 G03G 15/00 518 F term (Reference) 2H072 AA07 AA12 AA16 AA22 AA32 AB07 BA12 BA13 CA01 CA02 CA05 3F048 AA03 AA04 AA05 AB01 BA06 BB03 DA04 DA06 DC01 3F101 LA03 LA05 LA07 LB03 3F102 AA07 AA10 AA11 AB01 AB02 BA02 BB02 CA01 CB00 DA08 EA03 FA08 3F343 FA02 FB02 FB03 FC05 GA01 GB01 GC01 HA14 JA15 MC03 MB13

Claims (4)

[Claims] An image forming means for forming an image on a sheet to be conveyed, and a part of a continuous sheet when a plurality of sheets are continuously conveyed from a stacked sheet toward the image forming means. A first conveying unit that conveys the sheets in a stacked state, and a second unit that conveys the continuous sheets in a non-overlapped state when a plurality of sheets are continuously conveyed from the stacked sheets toward the image forming unit. An image forming apparatus comprising: a conveying unit; and a detecting unit configured to detect a thickness of a sheet to be conveyed. An image forming apparatus characterized in that the image forming apparatus is switched to one of the two modes. 2. The image forming apparatus according to claim 1, wherein when the detecting unit detects that the sheet to be conveyed is thicker than a predetermined thickness, the sheet is conveyed by the second conveying unit. . 3. The image forming apparatus according to claim 1, wherein when the detecting unit detects that the sheet to be conveyed has a thickness equal to or less than a predetermined thickness, the sheet is conveyed by the first conveying unit. . 4. A feeding means for separating and feeding one sheet from a stacked sheet; an image forming means for forming an image on the sheet fed by the feeding means; Conveying means for conveying the fed sheet while adjusting the image forming timing by the image forming means; detecting means for detecting the thickness of the conveyed sheet; Control means for judging whether or not the sheet is to be conveyed in a superimposed state based on the detection result by the detection means, and controlling the feeding means and / or the conveyance means in accordance with the judgment result; An image forming apparatus comprising: