JP2000162920A - Image processor, fixing control method and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the curl amount of transfer paper and to improve the transfer paper stacking ability of a stacking tray by setting fixing temperature in accordance with the detected number of ejected paper. SOLUTION: The controlled temperature of a fixing device is set to standby temperature, and copying is started. When elapsed time from a previous copying job is over a specified time, the total number of ejected paper and the number of job paper till the previous copying job are cleared (S1 to S5). When the first transfer paper is ejected, the number of job paper ejected in the copying job at this time and the total number of ejected paper are counted, and when copying is not finished, whether or not the number of job paper exceeds the specified number is discriminated (S6 to S8). In the case of exceeding the specified number, whether or not the number of ejected paper attains the specified number of paper at a next level is discriminated. In the case of attaining the number of paper at the next level, the new controlled temperature lower by one step is set (S9 and S10). When the stacking amount of a paper ejecting tray is increased, the controlled temperature of the fixing device is made low and the curl amount of transfer paper is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image processing apparatus, a fixing control method, and a storage medium.

[0002]

2. Description of the Related Art Conventionally, an image processing apparatus such as a digital copying machine having a memory such as a hard disk for storing a plurality of image data is known. This image processing apparatus can store the original image of the entire copy job in the memory, read the image data from the memory in order from the first output image of the copy job, and form the desired number of copies by the electronic sort function. It is.

In the image processing apparatus having the electronic sorting function, the sheets are sorted one by one when they are discharged from the image processing apparatus. Therefore, the sheets are discharged after being discharged using a sheet post-processing apparatus having a plurality of trays. There is no need to sort each tray individually. Therefore, a desired number of copies can be directly stacked on the same tray.

[0004]

However, when a large number of sheets are stacked on the same tray, a problem arises in that the sheets cannot be properly aligned at the time of stacking due to the effect of curl generated when the sheets are thermally fixed. I was

On the other hand, it is known that the curling amount of the sheet can be reduced by lowering the fixing temperature when the sheet is thermally fixed.

Accordingly, the present invention provides an image processing apparatus, a fixing control method, and a memory capable of performing alignment well and improving sheet stackability when a large number of sheets are stacked on the same discharge tray. The purpose is to provide a medium.

[0007]

In order to achieve the above object, an image processing apparatus according to the first aspect of the present invention has a fixing means for fixing an image on a sheet at a set fixing temperature. An image processing apparatus for discharging a fixed sheet, comprising: a discharged sheet number detecting unit for detecting a discharged sheet number of the sheet; and a fixing temperature setting unit for setting the fixing temperature according to the detected discharged sheet number. It is characterized by.

According to another aspect of the present invention, there is provided an image processing apparatus comprising: a fixing unit for fixing an image on a sheet at a set fixing temperature; and a stacking unit on which the sheet is stacked, wherein the sheet is fixed on the stacking unit. An image processing apparatus for discharging a sheet, a load amount detecting means for detecting a load amount of sheets loaded on the load means, and a fixing temperature setting for setting the fixing temperature according to the detected sheet load amount. Means.

According to a third aspect of the present invention, in the image processing apparatus according to the first or second aspect, a fixing temperature detecting unit for detecting a temperature of the fixing unit, and the detected temperature is set to the set temperature. And a temperature control unit for controlling the fixing temperature to be adjusted.

In the image processing apparatus according to a fourth aspect of the present invention, in the image processing apparatus according to the first aspect, the fixing temperature setting means changes the set fixing temperature in accordance with the detected increase in the number of discharged sheets. It is characterized in that it is lowered.

According to a fifth aspect of the present invention, in the image processing apparatus according to the second aspect, the fixing temperature setting means sets the fixing temperature in accordance with the detected increase in the load amount. It is characterized in that it is lowered.

According to a sixth aspect of the present invention, in the image processing apparatus according to the first or fourth aspect, the discharged sheet number detecting means initializes the detected discharged sheet number at the start of operation. Features.

According to a seventh aspect of the present invention, in the image processing apparatus according to the sixth aspect, when the operation has been stopped for a predetermined time or more, the discharged sheet number detecting means detects the discharged sheet number when the operation is restarted. Is initialized.

According to an eighth aspect of the present invention, in the image processing apparatus according to the fourth aspect, after the operation is started, the fixing temperature setting means keeps the fixing temperature until the detected number of discharged sheets reaches a predetermined number. Is not lowered.

According to a ninth aspect of the present invention, in the image processing apparatus according to the first or second aspect, it is set whether or not to change the fixing temperature set by the fixing temperature setting means. A change setting means is provided.

According to a tenth aspect of the present invention, in the fixing control method for fixing an image on a sheet at a set fixing temperature before the sheet is discharged from the image processing apparatus, the number of discharged sheets is detected. And setting the fixing temperature according to the detected number of discharged sheets.

The fixing control method according to claim 11, wherein the image is fixed on the sheet at a set fixing temperature before the sheet is discharged to the tray on which the sheet is stacked. And a step of setting the fixing temperature according to the detected amount of loaded sheets.

A storage medium according to a twelfth aspect is executed by a CPU in an image processing apparatus, and a program for fixing an image on a sheet at a set fixing temperature before being discharged from the image processing apparatus. In the stored storage medium, the program includes a step of detecting the number of discharged sheets and a step of setting the fixing temperature according to the detected number of discharged sheets.

According to a thirteenth aspect of the present invention, the storage medium is executed by a CPU in the image processing apparatus and fixes an image on a sheet at a set fixing temperature before the sheet is discharged to a tray on which the sheet is stacked. In the storage medium storing the program, the program includes: a step of detecting a stacking amount of the sheets stacked on the tray; and a step of setting the fixing temperature according to the detected stacking amount of the sheets. It is characterized by including.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an image processing apparatus, a fixing control method, and a storage medium according to the present invention will be described. The image processing apparatus according to the present embodiment is applied to a digital copying machine.

[First Embodiment] FIG. 1 is a block diagram showing a configuration of a fixing unit of a digital copying machine according to a first embodiment. The fixing unit includes a CPU 171, a fixing device 235, and a sheet discharge counter 280. The fixing device 235 includes a heater 281, a thermistor 282, an A / D converter 283, and a driver 284.

The CPU 171 performs a process for determining the temperature of the fixing device 235, and sets a temperature control temperature to be described later for the driver 284.

The heater 281 is a member for heating the fixing unit 235 in accordance with a control signal from the driver 284.
The thermistor 282 detects the temperature of the fixing device 235,
The D converter 283 converts an analog signal corresponding to the temperature detected by the thermistor 282 into a digital value,
Output to PU171. The driver 284 is a CPU 171
The control signal is output to the heater 281 in accordance with the setting of the temperature control temperature from.

Reference numeral 280 denotes a sheet discharge number counter which counts the number of sheets discharged every time a sheet is discharged from the main body of the image processing apparatus, and notifies the CPU 171 of the count.

FIG. 2 is a sectional view showing the internal structure of the digital copying machine. In the figure, reference numeral 200 denotes a digital copying machine main body, and reference numeral 6 denotes an automatic document feeder (ADF). Reference numeral 201 denotes a platen glass as a document table. Reference numeral 202 denotes a scanner, which includes a document illumination lamp 203 and a scanning mirror 20.
4 etc.

The scanner 2 is driven by a motor (not shown).
02 reciprocally scans in a predetermined direction, and the reflected light of the original is transmitted through a lens 207 via scanning mirrors 204, 205, and 206 to form an image on a CCD sensor in an image sensor unit 208.

Reference numeral 209 denotes an exposure control unit composed of a laser, a polygon scanner, or the like. The exposure control unit 209 is converted into an electric signal by the image sensor unit 208, and is modulated based on an image signal subjected to predetermined image processing described later. Light 219 is applied to the photosensitive drum 211.

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 21
1 is rotated in the direction of arrow a in the figure by driving a motor (not shown), and after being charged to a desired potential by the primary charger 212, the laser light 219 from the exposure control unit 209.
Is irradiated to form an electrostatic latent image. Photoconductor drum 21
The electrostatic latent image formed on 1 is developed by the developing device 213 and is visualized as a toner image.

On the other hand, pick-up rollers 225, 226, and 2 from the right cassette deck 221, the left cassette deck 222, the upper cassette 223, or the lower cassette 224.
Transfer paper fed by the feed rollers 27 and 228
The toner image is sent to the main body by the transfer rollers 29, 230, 231 and 232, is fed to the transfer belt by the registration roller 233, and is transferred to the transfer paper by the transfer charger 216. After the transfer, the photosensitive drum is moved to the cleaner device 2.
15 removes the residual toner, the pre-exposure lamp 214
Removes the residual charge.

The transfer paper after the transfer is separated from the photosensitive drum 211 by the separation charger 217 and the transfer belt 23
4 to the fixing device 235. In the fixing device 235, fixing is performed by applying pressure and heat, and the toner is discharged out of the main body 200 by a discharge roller 236. The main body 200 is equipped with a deck 250 capable of storing, for example, 4000 transfer papers. The lifter 251 of the deck 250 rises according to the amount of the transfer paper so that the transfer paper always contacts the pickup roller 252, and the transfer paper is fed into the main body by the paper feed roller 253. Further, the main body 200 is equipped with a multi-bypass 254 capable of storing 100 transfer papers.

Reference numeral 237 denotes a paper discharge flapper,
The path on the 38 side and the path on the discharge path 243 side are switched. 240
A lower conveyance path guides the transfer sheet sent out from the sheet discharge roller 236 through the reversing path 239 to turn the transfer sheet upside down and guide it to the re-feeding path 241. The transfer paper fed from the left cassette deck 222 by the paper feed roller 230 is also guided to the refeed path 241. Reference numeral 242 denotes a transfer sheet,
Is a paper re-feed roller for re-feeding paper. A discharge roller 244 is disposed near the discharge flapper 237 and discharges the transfer paper switched to the discharge path 243 by the discharge flapper 237 to the outside of the apparatus.

During double-sided recording (double-sided copying), the discharge flapper 2
37 is moved upward to transfer the copied transfer paper to the transport path 23.
8, leading to the re-feeding path 241 via the reversing path 239 and the lower conveying path 240. At this time, the rear end of the transfer paper is completely pulled out of the transport path 238 by the reversing roller 245, and is pulled into the reversing path 239 to a position where the transfer paper is bitten by the reversing roller 245. Send to pass 240.

On the other hand, when the transfer paper is to be inverted and discharged from the main body 200, the discharge flapper 237 is raised upward, and the rear end of the transfer paper is conveyed by the reversing roller 245 to the transport path 238.
The transfer paper is turned over and sent out to the discharge roller 244 side by pulling the transfer paper up to the position where it remains in the reverse path 239 and reversing the reverse roller 245.

Reference numeral 290 denotes a paper discharge processing device that closes the transfer papers discharged from the digital copying machine main body 200 in a line, and stacks the transfer papers discharged one by one on the processing tray 294 and aligns them. When the discharge of a part of the image formation is completed, the transfer paper bundle is stapled and discharged to the discharge trays 292 and 293 as a bundle.

The output tray 293 is a motor (not shown).
Can be moved in the vertical direction by the driving of the image forming apparatus. The image forming apparatus moves to a position corresponding to the processing tray 294 before the start of the image forming operation, and then, as the discharged transfer papers are stacked, the height of the paper surface increases. It is moved to the position of the processing tray 294.

Reference numeral 298 denotes a tray lower limit sensor for detecting the lower limit of the paper discharge tray 293.
The detection is performed when 00 transfer papers are stacked. Reference numeral 291 denotes a paper tray on which separator sheets to be inserted between the discharged transfer sheets are stacked. Reference numeral 295 denotes a Z-folding unit that Z-folds the discharged transfer paper. Reference numeral 296 denotes a bookbinding machine that binds a part of the discharged transfer papers into a center and collectively staples the papers, and discharges the bound paper bundle to a discharge tray 297.

FIG. 3 is a block diagram showing a configuration of a control unit provided in the digital copying machine main body 200. In the figure, 171 performs basic control of the digital copier 200.
The CPU 171 is connected to a ROM 174 in which a control program is written, a RAM 175 as a work memory, an input / output port 173, and the like via an address bus and a data bus. Further, to the input / output port 173, various loads such as a motor and a clutch for driving each unit in the digital copying machine main body 200 and a sensor for detecting the position of the paper are connected.

The CPU 171 performs input / output control sequentially through the input / output port 173 according to the control program stored in the ROM 174 to execute an image forming operation.
An operation unit 172 is connected to the CPU 171, and the CPU 171 controls a display unit and a key input unit of the operation unit 172. The operator instructs the CPU 171 to switch the display between the image forming operation mode, the scanner reading mode, and the print output mode via the key input unit.
1 displays the state of the digital copier main body 200 and the operation mode setting by key input. Further, the CPU 171 includes an image processing unit 170 that processes a signal converted into an electric signal by the image sensor unit (CCD sensor) 208,
And an image memory unit 3 for storing processed images.

FIG. 4 is a block diagram showing the configuration of the image processing section 170. CCD sensor 20 through lens 207
The original image focused on 8 is input as black luminance data, and is converted into an analog electric signal by the CCD sensor 208. The converted image information is input to an analog signal processing unit (not shown), and sample and hold,
After the dark level is corrected, the signal processing unit 501
After the analog-to-digital conversion (A / D conversion) and shading correction of the digitized signal (variation of the sensor for reading the original and correction of the light distribution characteristic of the original illumination lamp) are performed, the signal is sent to the log converter 502. Can be

An LUT (look-up table) for converting the input luminance data into density data is stored in the log converter 502, and the log converter 502 outputs a table value corresponding to the input data. To convert the luminance data into density data. The image of the converted density data is scaled to a desired magnification by a scaling processing unit 503 and input to a γ correction unit 504.

When outputting density data, the γ correction unit 504 performs conversion using an LUT in consideration of the characteristics of the printer.
The output is adjusted according to the density value set on the operation unit.
The density data subjected to the output adjustment is sent to the binarization unit 505.

In the binarizing section 505, the multi-valued density data is
It is converted into a value, 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 an image is binarized, the number of gradations of the image is changed from 256 gradations to two gradations. Therefore, when binarizing image data having a large number of halftones such as a photographic image, the image is generally significantly deteriorated. So 2
It is necessary to perform pseudo halftone expression using value data.
Here, an error diffusion method is used as a method for pseudo-halftone expression using binary data.

In the error diffusion method, when the density of a certain image is larger than a certain threshold value, the density data is determined to be "255". When the density is equal to or less than a certain threshold value, the density data is determined to be "0". After the binarization, 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 maintained, and the halftone can be represented in a pseudo binary manner.

The binarized image data is stored in the image memory 3
Sent to and stored. Further, the image data from the computer input from the external I / F processing unit 4 is
Since it has been processed as binary image data by the F processing unit 4, it is sent to the image memory unit 3 as it is.

The image memory section 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, the images of the document bundle read from the ADF 6 are sequentially output. By reading out the image data of the document once stored from the hard disk and repeating and outputting the image data a plurality of times, the sorter having the plurality of bins can play the same role.

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 interpolates the data so that the line ends of the binarized image become smooth, and outputs the image data to the exposure control unit 209. The exposure control unit 209 forms image data on transfer paper by the above-described processing.

FIG. 5 is a block diagram showing the configuration of the image memory unit 3. The image memory unit 3 writes binary image data from the external I / F processing unit 4 and the image processing unit 170 via a memory controller unit 302 to a page memory unit 301 including a memory such as a DRAM, The F processing unit 4 reads image data to the printer unit 2 and performs input / output access of image data to the hard disk 304 which is a large-capacity storage device. Memory controller 302
Generates a DRAM refresh signal for the page memory 301, and outputs an external I / F processor 4, an image processor 1
70, page memory 301 from hard disk 304
Mediate access to. Further, according to an instruction from the CPU 171, a write address to the page memory unit 301,
The read address and the read direction from the page memory unit 301 are controlled. Thereby, the CPU 171
Controls a function of performing layout processing for arranging a plurality of document images in the page memory unit 301 and outputting the result to the printer unit, a function of cutting out and outputting only a part of the image, or an image rotation function.

FIG. 6 is a diagram showing the configuration of the external I / F processing unit 4. The external I / F processing unit 4 fetches the binary image data of the reader unit 1 through the image memory unit 3 as described above, and outputs the binary image data through the image memory unit 3 to the printer unit. 2 to perform image formation. 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, a computer interface unit 403 connected to the external computer 11, a formatter unit 404, and an image memory unit. 405 are provided.

The facsimile unit 401 is connected to a public line via 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 performs processing by storing a facsimile image in the hard disk 402, such as performing facsimile transmission at a specified time or transmitting image data in response to an inquiry about a specified password from a partner as a facsimile function.

Thus, after 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 not used for the facsimile function. , Can send fax.

The computer interface unit 403 is an interface unit for performing data communication with an external computer, and is a local area network (LA).
N), serial I / F, SCSII / F, and Centronics I / F for data input of a printer. Via this I / F, the statuses of the printer unit and the reader unit are notified to an external computer, and the image read by the reader unit 1 is transferred to the external computer according to instructions from the computer. Further, it receives print image data 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 a raster image to be formed by the printer unit 2 via the image memory unit 3. Convert to image data.

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, or when the image of the reader unit 1 is sent to an external computer via the computer interface unit 403 (image scanner function). It is also used as a memory for temporarily expanding the image data sent from the image memory unit 3, or is also used when the data is sent from the computer interface unit 403 after being converted into a data format to be sent to an external computer.

The core unit 406 includes a facsimile unit 401,
It controls each 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,
Under the management of the core unit 406, exclusive control and priority control are performed, and an image is output.

FIG. 7 is a sectional view showing the structure of the automatic document feeder (ADF) 6. As shown in FIG. In the figure, reference numeral 601 denotes a paper feed roller, and a document bundle 621 placed on a document tray 620.
The document on the uppermost surface of the document bundle 621 is fed by being dropped on the paper surface and rotated. Reference numeral 611 denotes a stopper, which protrudes before the start of document feeding. The document bundle 621 is restricted by the stopper 611 and cannot advance downstream.

The original fed by the paper feed roller 601 is separated into one sheet by the operation of the separation roller 602 and the separation belt 603. Separation is achieved by the well-known retard separation technique. A conveyance roller 604 conveys the document separated by the separation roller 602 and the separation belt 603 to the registration roller 605. The document is abutted against the registration roller 605 to form a loop, thereby eliminating skew in document conveyance.

Below the registration roller 605, there is provided a reversing paper feeding flapper 613 for guiding the document passing through the registration roller 605 to a paper feeding path 652, which is a conveyance path to the platen 201, or to a reversing entrance path 653. Are located. 614 is a first reversing roller. 615
Is a second reversing roller, which rotates when reversing the original. Reference numeral 612 denotes a reversing flapper,
The document coming from the direction 15 is guided to the reversing path 650 or the re-feeding path 651.

Reference numeral 606 denotes a belt driving roller for driving a feeding belt 607 for arranging a document on the platen 201. The feeding belt 607 is in contact with the platen 201. 617, a paper feed / discharge roller,
Document feeding and discharging and feeding belt 60 fed from document 22
The document fed by the printer 7 is discharged to a document discharge port 623.

Reference numeral 616 denotes a paper discharge flapper, which guides a document to a manual feed / discharge path 654 or a document discharge path 655. The paper discharge flapper 616 operates so that the document is not discharged toward the manual paper discharge port 622 when the document is discharged. 61
A manual feed / discharge roller 9 feeds / discharges a manual document. Reference numeral 618 denotes a paper discharge roller for discharging a document.

Further, three sensors 608, 609 and 610 are arranged below the document tray 620. 61
Reference numeral 0 denotes a document set detection sensor including a transmission type optical sensor that detects that the document bundle 621 has been set. 60
Reference numeral 8 denotes a document trailing edge detection sensor including a reflection type optical sensor for determining whether the document is a half-size document. Reference numeral 609 denotes a final document detection sensor which is provided between the document set detection sensor 610 and the document trailing edge detection sensor 608 and is a reflection type optical sensor for determining whether or not the document being transported is the final document.

Reference numerals 624, 625, and 626 denote original size detection sensors for detecting the size of the original being conveyed.
Three documents are arranged side by side in the width direction of the document. Based on the output values of these three document size detection sensors 624, 625, and 626, the document width is detected in three stages, and whether the width is A or B,
4 and A5 are determined. Also, the original length is detected based on the passage time of the original. This makes it possible to accurately detect the size of each document even if the document bundle includes documents of different sizes. However, the document bundle is placed so that the back side in the document width direction is aligned.

Next, the operation of the automatic document feeder 6 when reading both sides of a document on which double-sided printing has been performed (double-sided document) will be described. FIGS. 8 and 9 show the operation of the automatic document feeder 6 when reading both sides of a two-sided document. When the automatic document feeder 6 is instructed to start feeding double-sided documents,
The stopper 611 descends, and the paper feed roller 601 further falls on the upper surface of the document (see FIG. 8A).

By the operation of the paper feed roller 601, the separation roller 602, the separation belt 603, and the conveyance roller 604, only one document is separated from the uppermost surface of the document bundle 621 and fed to the registration roller 605 (FIG. B)). At this time, the reversing sheet feeding flapper 613 is set in a direction for transporting the document to the reversing path. In order to facilitate understanding, the leading edge of the document is "2" and the trailing edge is "1" in the figure.
It is represented by

When the registration roller 605 rotates, the original is conveyed to the position shown in FIG. 9A via the path shown in FIG. 8C. From here, the driving directions of the first reversing roller 614 and the second reversing roller 615 are reversed, the document is fed onto the platen 201, and stops at the position shown in FIG. 9B.

When the reading of the original is completed at this position,
As shown in FIG. 9C, the original is turned over via the re-feeding path 651 and is again fed onto the platen 201 as shown in FIG. 9D.

Similarly, when the reading of the document is completed, the document is fed rightward and discharged from the document discharge port 623 to the outside of the automatic document feeder 6. By repeating the above operation, the double-sided document can be separated one by one from the uppermost surface, both sides can be read, and the paper can be discharged with the upper surface facing down (face down).

Next, the scanner 202 is fixed at a predetermined position, and the operation of the original reading system (flow reading) for reading the image by moving the original is described in the case where the original is only the small size and the case where the large size is included. Will be described separately.

In the present embodiment, the small size is a size at which the document trailing end detection sensor 608 does not detect a document when the document bundle 621 is placed on the document tray 620, and the large size is a size at which the document bundle is placed on the document tray 620. When the document 621 is placed, the size of the document is detected by the document trailing edge detection sensor 608.

FIG. 10 is a diagram showing the flow reading operation of a small-sized document. First, the flow-reading of a small-sized document will be described. FIG. 10 is a diagram illustrating a flow-reading operation of a small-sized document. The operation until the document reaches the registration roller 605 is described in FIG.
This is as shown in (A) and (B). In the case of skimming,
Further, as shown in FIG.
13 guides the document onto the platen 201. The document is conveyed at a predetermined speed above point A in the figure, and the document image is read by the scanner 202 waiting below point A (see FIG. 10B). Here, point A is defined at the position where the trailing edge of the small-sized document has passed the registration roller 605. The document is conveyed to the right in the figure as it is, and is discharged from the document discharge port 623 to the outside of the automatic document feeder 6 (see FIG. 10C).

Next, the flow reading of a document including the large size will be described. FIG. 11 is a diagram illustrating a flow reading operation of a document including a large size. Original is a registration roller 6
8 (A) and 8 (B) described above.
As shown in FIG. In the case of drift reading, FIG.
As shown in (A), the reverse feeding flapper 613 guides the document onto the platen 201. The original is conveyed at a predetermined speed above the point B in the figure, and the scanner 2 which stands by below the point B
02 reads the image of the document. Here, the point B is defined at a position where the rear end of the large-sized document has passed the registration roller 605. The document is conveyed to the right in the figure as it is, and is discharged from the document discharge port 623 to the outside of the automatic document feeder 6 (see FIG. 11B).

On the other hand, in the case of fixed original reading in which an image is read by moving the scanner 202, the rear end of the original is
01 (the position shown in FIG. 9D)
Is placed on the original.

FIG. 12 shows how the orientation of the document bundle 621 set on the document tray 620 of the automatic document feeder 6 corresponds to the direction of the document bundle 621 conveyed and discharged to the document discharge port 623. FIG.

The original shown on the left side of FIG.
The document bundle 621 is set in the document bundle 20. The document is conveyed in order from the topmost document numbered 1, and is output with its front and back reversed. Therefore, as shown on the right side of the figure, the topmost document is reversed and discharged as the bottom surface. You.

The temperature setting process of the fixing device of the digital copying machine having the above configuration will be described. FIG. 13 is a diagram showing a table of the regulated temperature of the fixing device according to the operation state of the digital copying machine. The temperature adjustment temperature is a target fixing temperature when the temperature of the fixing device is controlled to be constant, and is set to a temperature that does not cause fixing defects.

When the digital copying machine is in the standby state, the temperature control temperature is set to the normal set temperature of 205 ° C. so that the copying operation can be performed immediately. During copying, the temperature control temperature is divided into level 1 to level 4 depending on the number of sheets of transfer paper discharged. Since the influence of curl of the transfer paper does not appear during the stacking of up to 1000 sheets, the temperature control temperature is set to 205, which is the normal set temperature, as Level 1.

If the number of sheets exceeds 1,000, the influence of the curl of the transfer paper during stacking appears.
Up to the number of sheets, it is set to 190 ° C as level 2 and 1051
The level 3 is set to 185 ° C. from the number of sheets to 2000 sheets.

Here, the level 2 is from 205 ° C. set as the level 1 to 185 ° C. set as the level 3
When the temperature is lowered, the intermediate temperature is set so as to make a smooth transition. When the temperature is lowered directly, there is a meaning of preventing the fixing temperature from dropping below 185 ° C. and causing defective fixing.

For 2000 or more sheets, the level 4 is set to 205 ° C. again. This assumes a case where the number of sheets that can be stacked on the sheet discharge tray is 2000, but stacking is still possible, that is, a case where the transfer paper has been removed during copying by the user.

When a certain time has elapsed from the end of the previous copy at the start of the copy, the count of the number of discharged sheets is cleared, but the next copy is started immediately after the end of the previous copy. In this case, the count of the number of discharged sheets is not cleared in consideration of the case where the transfer sheet is not removed. If not cleared, even if the number of discharged sheets has already reached the specified number when copying starts, instead of setting the temperature at that level immediately, the next level is output after the specified number of sheets are discharged. Set the temperature to be adjusted. This is to prevent the occurrence of a fixing failure as described above, for example, when the temperature is immediately lowered from the standby state to 185 ° C., which is the regulated temperature as level 3.

When the digital copying machine is in a power saving mode for saving power consumption when stopped, the temperature control temperature is set to 100 ° C. so that the standby state can be returned in a short time when the power saving mode is canceled.

FIG. 14 is a flowchart showing a temperature control temperature setting procedure for determining the temperature of the fixing device. This processing program is stored in the ROM 174 in the control unit, and its execution is started by the CPU 171 as soon as the power is turned on.

First, the regulated temperature of the fixing unit 235 is set to 205 ° C., which is the temperature during standby (step S).
1). It is determined whether or not copying has started (step S2). If copying has started, it is determined whether or not a predetermined time has elapsed since the previous copy job (step S3). Here, the predetermined time is a time used to determine whether or not the transfer paper has been removed when the next copy is started after the end of the previous copy.

If the predetermined time has elapsed, the total number of discharged sheets up to the previous copy job is cleared (step S4). Further, the number of jobs is cleared (step S
5). Here, the number of jobs counts the number of sheets discharged in the current copy job, and is always cleared at the start of a new copy job. When the power is turned on and the first copy is performed, the number of discharged sheets is cleared as an initial setting in step S4. On the other hand, if the predetermined time has not elapsed in step S3, the process proceeds to step S5 without clearing the number of discharged sheets.

Subsequently, when the first transfer sheet is discharged, the number of jobs discharged in the current copy job and the total number of discharged sheets are counted (step S).
6). Then, it is determined whether or not the copying has been completed (step S7). When the copying is completed, the copying machine is in a standby state until the next copy job is started.

On the other hand, if the copying has not been completed, it is determined whether or not the number of jobs has exceeded a predetermined number. here,
As described above, even if the number of discharged sheets has already reached the specified number when copying is started, the predetermined number of sheets is immediately set to the temperature control temperature at that level to cause a fixing failure, as described above. The number is set to prevent such a situation, and is, for example, 20.

If the number of jobs does not exceed the predetermined number, the process returns to step S6, and the processes from step S6 to step S8 are repeated until the number of jobs exceeds the predetermined number. On the other hand, if the number of jobs exceeds the predetermined number in step S8, it is determined whether the number of discharged sheets has reached the next level (step S9). in this way,
Only in the case where the number of jobs exceeds a predetermined number in step S8 so that the level does not advance two steps at a time, step S9
It is taken into consideration that the determination in the above is performed.

If the number of discharged sheets has reached the next level in step S9, a new temperature control temperature is set down by one step (step S10). Then, the number of jobs and the number of discharged sheets are counted (step S11). On the other hand, if the number of discharged sheets has not reached the next level in step S9,
The process directly proceeds to step S11.

Then, it is determined whether or not the copy has been completed (step S12). When the copying is completed, the process returns to the step S1, and is in a standby state until the next copy job is started. On the other hand, if the copy has not been completed in step S12, the processing from step S9 is repeated.

On the other hand, if the copying has not been started in step S2, it is determined whether or not to shift to the power saving mode (step S13). The condition for shifting to the power saving mode is when a key input is not performed from the operation unit for a certain period of time after copying is completed, or when a power saving mode shift key provided on the operation unit is pressed. If the mode is not shifted to the power saving mode, the process returns to step S2, and waits for the start of copying or the shift to the power saving mode.

If the condition for shifting to the power saving mode is satisfied in step S13, the temperature control temperature of 10 in the power saving mode is satisfied.
It is set to 0 ° C. (step S14). Thereafter, the process waits until the condition for returning to the normal mode is satisfied. Wait until the condition for returning to the normal mode is satisfied. The transition to the normal mode is performed when the power saving mode transition key is pressed. If the condition for returning to the normal mode is satisfied, step S1
The process returns to and the standby state is set.

As described above, the temperature of the fixing device can be controlled to an appropriate temperature by setting the temperature control temperature of the fixing device according to the operation state of the digital copying machine and the number of sheets discharged during copying. The setting as to whether or not to perform the temperature setting process (see FIG. 14) for changing the setting of the temperature control temperature according to the number of discharged sheets is made.
You may make it selectable with an operation part.

[Second Embodiment] The digital copying machine according to the second embodiment has substantially the same configuration as that of the first embodiment, and therefore, different components will be mainly described here.

FIG. 15 is a block diagram showing a configuration of a fixing section of a digital copying machine according to the second embodiment. The same components as those in the first embodiment are denoted by the same reference numerals.

The CPU 171 performs a process for determining the temperature of the fixing unit 235, and sets a temperature control temperature for the driver 284. The fixing device 235 includes a heater 281,
It comprises a thermistor 282, an A / D converter 283 and a driver 284. The heater 281 is the driver 2
The thermistor 282 detects the temperature of the fixing device and controls the temperature of the fixing device.
The / D converter 283 converts an analog signal corresponding to the temperature detected by the thermistor 282 into a digital value and outputs the digital value to the CPU 171. The driver 284 is a CPU 17
The control signal is output to the heater 281 in accordance with the setting of the temperature control temperature from 1.

Reference numeral 280 denotes a sheet discharge number counter which counts the number of sheets each time a sheet is discharged from the digital copier main body 200 and notifies the CPU 171 of the count. An interface 285 communicates with the sheet post-processing apparatus. Reference numeral 286 denotes a CPU that controls the sheet post-processing device. The CPU 286 receives a notification of the amount of transfer paper loaded from the loaded amount detection unit 287, and notifies the digital copying machine main body 200 of the number of transfer paper loaded via the interface 288.

The processing for setting the temperature control temperature of the fixing unit in the digital copying machine having such a configuration will be described.
Here, the temperature control temperature is set to a value similar to that of FIG. 13 described above according to the load amount notified from the sheet post-processing apparatus. Also, after the temperature control temperature is changed once, the next level of the temperature control temperature is not set until 20 transfer sheets are discharged.

FIG. 16 is a flowchart showing a temperature control temperature setting process for determining the temperature of the fixing device. This processing program is stored in the ROM 17 as in the first embodiment.
4 and is executed by the CPU 171. This processing program starts when the copy is started by pressing the copy start key of the operation unit, or when the copy is restarted from the interrupted state. Here, assuming that the apparatus is in the standby state before the start of copying, the temperature control temperature of the fixing unit is set to 205 ° C.

First, it is determined whether or not a setting for switching the temperature control temperature of the fixing unit according to the load amount is made (step S21). If it is not set to switch, the control is performed so that the temperature of the fixing unit is always maintained at 205 ° C., and the process is terminated.

On the other hand, if it is determined in step S21 that the temperature of the fixing unit is to be switched in accordance with the load, the number J of sheets discharged in the current job is cleared (step S22). Then, when one transfer sheet is discharged, the number of discharged sheets J is counted (step S23).

It is determined whether the copying has been completed by the discharge in step S23 or whether the stacking amount has exceeded 2000 sheets (step S24). If either one is satisfied, the temperature of the fixing unit is set to the standby temperature 2
The temperature is set to 05 ° C. (step S25), and the process ends.
Here, if the stacking amount exceeds 2,000 sheets, since no more sheets can be stacked, copying is interrupted, and a message to remove the transfer paper discharged to the stacking tray is displayed on the operation unit. This processing is restarted when the loaded transfer paper is removed.

On the other hand, if neither condition is satisfied in step S24, it is determined whether or not the number of discharged sheets has exceeded 20 and the stacking amount has exceeded 1000 (step S24).
26). If both conditions are satisfied, it is determined whether or not the currently set temperature regulation temperature is 205 ° C. (step S27). If the current temperature is 205 ° C,
190 ° C. is set as the new temperature control temperature, the number of discharged sheets J is cleared (step S28), and the process returns to step S23.

On the other hand, in step S27, the temperature control temperature is 205
If not, it is determined whether or not the stacking amount exceeds 1050 sheets (step S29). If the load capacity exceeds 1050 sheets, the currently set temperature control temperature is 190
It is determined whether the temperature is C (step S30). 190
If the temperature is ° C, 185 ° C is set as a new temperature control temperature, the number of discharged sheets J is cleared (step S31), and the process returns to step S23. On the other hand, if the temperature control temperature is not 190 ° C. in step S30, it is assumed that 185 ° C. has already been set, and the process returns to step S23.

On the other hand, at step S29, the load
If the number does not exceed 50, it is determined whether or not the currently set temperature regulation temperature is 190 ° C. (step S).
32). If the temperature is 190 ° C., step S2
The process returns to step 3. On the other hand, if the temperature is not 190 ° C. in step S32, 190 ° C. is set as a new temperature control temperature,
The process returns to step S23. In this case, 1
85 ° C. should have been set, for example, it is assumed that the user has removed the transfer paper from the stacking tray. Thereafter, the processing from step S23 is repeated until the copy is completed or the stacking amount of the stacking tray exceeds 2000 sheets.

As described above, the temperature of the fixing unit is controlled to an appropriate temperature by setting the temperature control temperature of the fixing unit in accordance with the amount of transfer paper stacked on the discharge tray of the sheet post-processing apparatus. be able to. Further, once the temperature adjustment temperature is changed, control is performed so that the next level of the temperature adjustment temperature is not set until 20 sheets are discharged, so that it is possible to prevent the occurrence of fixing failure. Further, it is also possible to select whether or not to perform a process of switching the temperature control temperature of the fixing device according to the load amount.

In the above embodiment, the temperature control temperature of the fixing unit is set in accordance with the detected number of discharged sheets or the amount of stacked sheets. However, both the number of discharged sheets and the amount of stacked sheets are detected to adjust the temperature. You may make it set.

The present invention may be applied to a system constituted by a plurality of devices, or may be applied to an apparatus constituted by a single device. Needless to say, the present invention can be applied to a case where the present invention is achieved by supplying a program to a system or an apparatus. In this case, by reading out a storage medium storing a program represented by software for achieving the present invention into a system or an apparatus, the system or the apparatus can enjoy the effects of the present invention.

FIG. 17 is an explanatory diagram showing a memory map of the ROM 174 as a storage medium. R as storage medium
The OM 174 includes a temperature control temperature table of the fixing device illustrated in FIG. 13, a temperature control temperature setting processing program module illustrated in FIG.
The temperature control temperature setting processing program module of FIG. 16 and the like are stored.

The storage medium for supplying the program module is not limited to ROM, but may be, for example, a floppy disk, hard disk, optical disk, magneto-optical disk,
A D-ROM, a CD-R, a DVD, a magnetic tape, a nonvolatile memory card, or the like can be used.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instruction of the program code, The case where the CPU of the function expansion board or the function expansion unit performs part or all of the actual processing, and the function of the above-described embodiment is realized by the processing.

[0110]

According to the image processing apparatus of the present invention, an image is fixed on a sheet at a fixing temperature set by a fixing unit, and when the fixed sheet is discharged, the number of discharged sheets is detected. Means for detecting the number of discharged sheets,
Since the fixing temperature is set according to the detected number of discharged sheets by the fixing temperature setting unit, when the number of discharged sheets increases and the stacking amount of the discharge tray increases, the temperature control temperature of the fixing device may be reduced. it can. Therefore, the curl amount of the transfer sheet can be reduced at the time of heat fixing, and the load of the transfer sheet on the stacking tray can be improved. in this way,
When stacking many sheets on the same output tray,
Alignment can be performed well, and sheet stackability can be improved. The same effect can be obtained in the fixing control method according to the tenth aspect and the storage medium according to the twelfth aspect.

According to the image processing apparatus of the second aspect,
An image is fixed on a sheet at a fixing temperature set by a fixing unit, and when the fixed sheet is discharged to a stacking unit, a stacking amount of the sheet stacked on the stacking unit is detected by a stacking amount detection unit. Since the fixing temperature is set in accordance with the detected amount of stacked sheets by the temperature setting unit,
As in the case of the first aspect, the curl amount of the transfer sheet can be reduced at the time of thermal fixing, and the loadability of the transfer sheet on the stacking tray can be improved. Further, when a sheet post-processing device is provided as a stacking means, when sorting is performed without sorting to each tray, the sheets can be stacked in a well-aligned manner. The same effect can be obtained in the fixing control method according to the eleventh aspect and the storage medium according to the thirteenth aspect.

According to the image processing apparatus of the third aspect,
A fixing temperature detecting unit detects the temperature of the fixing unit,
Since the temperature controller controls the detected temperature to be the set fixing temperature, the temperature of the fixing device can be accurately controlled. According to the image processing apparatus of the fourth aspect, the fixing temperature setting unit gradually decreases the set fixing temperature in accordance with the detected increase in the number of discharged sheets. It is possible to control the fixing temperature suitable for the reduction, and it is possible to prevent the fixing temperature from dropping at a stretch and causing a defective fixing by stepwise lowering. The same effect can be obtained in the image processing apparatus according to the fifth aspect.

According to the image processing apparatus of the sixth aspect,
Since the discharged sheet number detecting means initializes the detected discharged sheet number at the start of the operation, the discharged sheet number after the start of the operation can be accurately detected.

According to the image processing apparatus of the present invention,
If the operation has been stopped for a predetermined time or more, the discharged sheet number detecting means initializes the detected discharged sheet number when the operation is restarted, so that if the predetermined time has not elapsed, it is determined that the transfer paper has not been removed. By not clearing the number of discharged sheets, the accuracy of the number of discharged sheets can be ensured.

According to the image processing apparatus of the present invention,
After the start of the operation, the fixing temperature setting unit does not lower the fixing temperature until the detected number of discharged sheets reaches the predetermined number, so that it is possible to prevent the fixing temperature from dropping at once and causing a fixing defect.

According to the image processing apparatus of the ninth aspect,
Since whether or not to change the fixing temperature set by the fixing temperature setting means is set by the change setting means, the user can arbitrarily switch the fixing temperature.

According to the storage medium of the twelfth aspect, the program is executed by the CPU in the image processing apparatus, and is used to fix an image on a sheet at a set fixing temperature before being discharged from the image processing apparatus. In the storage medium storing the program, the program includes a step of detecting the number of discharged sheets and a step of setting the fixing temperature according to the detected number of discharged sheets. And expandability can be improved. The same effect can be obtained in the storage medium according to the thirteenth aspect.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a fixing unit of a digital copying machine according to a first embodiment.

FIG. 2 is a sectional view showing an internal configuration of the digital copying machine.

FIG. 3 is a block diagram showing a configuration of a control unit provided in the digital copying machine main body 200.

FIG. 4 is a block diagram illustrating a configuration of an image processing unit 170.

FIG. 5 is a block diagram showing a configuration of an image memory unit 3;

FIG. 6 is a diagram illustrating a configuration of an external I / F processing unit 4;

FIG. 7 is a cross-sectional view illustrating a configuration of an automatic document feeder (ADF) 6.

FIG. 8 is a diagram illustrating the operation of the automatic document feeder 6 when reading both sides of a double-sided document.

FIG. 9 is a diagram illustrating the operation of the automatic document feeder 6 when reading both sides of a double-sided document, following FIG. 8;

FIG. 10 is a diagram illustrating a flow-reading operation of a small-sized document only.

FIG. 11 is a diagram illustrating a flow reading operation of a document including a large size.

FIG. 12 illustrates how the orientation of a document bundle 621 set on a document tray 620 of the automatic document feeder 6 corresponds to the direction of the document bundle 621 conveyed and discharged to a document discharge port 623. FIG.

FIG. 13 is a diagram showing, as a table, temperature-adjusted temperatures of the fixing device according to the operation state of the digital copying machine.

FIG. 14 is a flowchart illustrating a temperature control temperature setting process procedure for determining a temperature control temperature of the fixing device.

FIG. 15 is a block diagram illustrating a configuration of a fixing unit of a digital copying machine according to a second embodiment.

FIG. 16 is a flowchart illustrating a temperature control temperature setting processing procedure for determining a temperature control temperature of the fixing device.

FIG. 17 is an explanatory diagram showing a memory map of a ROM 174 as a storage medium.

[Explanation of symbols]

 171 CPU 174 ROM 200 Digital copier main body 235 Fixing unit 280 Discharge sheet number counter 281 Heater 282 Thermistor 287 Stacking amount detection unit 292, 293 Discharge tray

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Nobuo Sekiguchi 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H027 DC12 EA12 2H033 AA14 BA10 CA22 CA30

Claims (13)

[Claims] 1. An image processing apparatus that has a fixing unit that fixes an image on a sheet at a set fixing temperature, and that discharges the fixed sheet, wherein a discharged sheet number detecting unit that detects the number of discharged sheets; An image processing apparatus comprising: a fixing temperature setting unit configured to set the fixing temperature in accordance with the detected number of discharged sheets. 2. An image processing apparatus, comprising: a fixing unit for fixing an image on a sheet at a set fixing temperature; and a stacking unit on which the sheet is stacked, and discharging the sheet fixed to the stacking unit. A stacking amount detecting unit configured to detect a stacking amount of sheets stacked on the stacking unit; and a fixing temperature setting unit configured to set the fixing temperature according to the detected stacking amount of the sheets. Image processing device. 3. A fixing temperature detecting means for detecting a temperature of the fixing means, and a temperature controlling means for controlling the detected temperature to the set fixing temperature. The image processing apparatus according to claim 1 or 2. 4. The image processing apparatus according to claim 1, wherein the fixing temperature setting unit decreases the set fixing temperature in a stepwise manner in accordance with the detected increase in the number of discharged sheets. 5. The image processing apparatus according to claim 2, wherein the fixing temperature setting unit decreases the set fixing temperature in a stepwise manner in accordance with the increase in the detected stacking amount. 6. The image processing apparatus according to claim 1, wherein the discharged sheet number detecting means initializes the detected discharged sheet number at the start of operation. 7. When the operation has been stopped for a predetermined time or more,
7. The image processing apparatus according to claim 6, wherein the discharged sheet number detecting unit initializes the detected discharged sheet number when the operation is restarted. 8. After the operation is started, the fixing temperature setting means includes:
5. The image processing apparatus according to claim 4, wherein the fixing temperature is not reduced until the detected number of discharged sheets reaches a predetermined number. 9. The image forming apparatus according to claim 1, further comprising a change setting unit configured to set whether or not to change the fixing temperature set by the fixing temperature setting unit.
The image processing apparatus according to any one of the preceding claims. 10. A fixing control method for fixing an image on a sheet at a set fixing temperature before the sheet is ejected from an image processing apparatus, comprising: a step of detecting the number of sheets ejected; Setting the fixing temperature accordingly. 11. A fixing control method for fixing an image on a sheet at a set fixing temperature before the sheet is discharged to a tray on which the sheet is stacked, wherein a step of detecting a stacking amount of the sheet stacked on the tray And a step of setting the fixing temperature according to the detected amount of stacked sheets. 12. A storage medium which is executed by a CPU in an image processing apparatus and stores a program for fixing an image on a sheet at a set fixing temperature before being discharged from the image processing apparatus, A storage medium comprising: a step of detecting the number of discharged sheets; and a step of setting the fixing temperature according to the detected number of discharged sheets. 13. A storage medium which is executed by a CPU in an image processing apparatus and stores a program for fixing an image to a sheet at a set fixing temperature before the sheet is discharged to a tray on which the sheet is stacked. In the storage medium, the program includes: a step of detecting a stacking amount of sheets stacked on the tray; and a step of setting the fixing temperature according to the detected stacking amount of sheets. .