JPH0969937A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the dead time by successively processing read input, encoding, decoding, and rotated/unrotated image formation output. SOLUTION: When scanner input of a 1st page is started, image data read by a scanner 13 are written in an image area 28a of a page memory 28. At the same time, the encoding process is started and the image data written in the image area 28a of the page memory 28 from the scanner 13 are encoded sequentially. The encoding process is much faster than the input speed of the scanner 13, so the encoding of the page is completed almost at the same time with the end of the input by the scanner 13. The encoded data (compressed data of an unrotated image) as the encoding output are written in a code area 28b of the page memory 28. When the encoding of the unrotated image is completed, the image which is already written in the image area 28a of the page memory 28 by the scanner 13 is read out in the rotational direction and the rotated image is encoded.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an image forming apparatus such as a digital copying machine having a page memory.

[0002]

2. Description of the Related Art In recent years, image information has been easily handled as digital data.

Digital PP is a device to which these are applied.
There is C (plain paper copier). This is the conventional analog P
Unlike a PC, the reflected light from the original is not optically guided to form an image on the photoconductor. The reflected light from the original is once C
After being read as an electric signal by the CD sensor, it is converted into a digital signal. The document once digitized is subjected to various processes and then output to paper by a laser printer.

By once converting an original image into a digital signal, various processing such as correction of input characteristics from a CCD sensor and output characteristics to a laser printer, enlargement / reduction, partial erasure / out-of-frame erasure can be performed by signal processing. Becomes

Further, the image converted into a digital signal can be efficiently stored by compressing the data amount by performing an encoding process. The accumulated images can be decoded into the original images in any order desired to be printed out, and can be output to an arbitrary number of laser printers.

Conventionally, these rearrangements have been performed mechanically by using a sorter or a stacker for the copied print output, so that enlarging the device and increasing noise are unavoidable. Further, in order to print a plurality of sheets, it is necessary to repeatedly perform a copying operation.

In addition, an image memory (work area, image area) for one page is prepared on the page memory, and an image (encoded data) that is coded and accumulated in the file area (code area) of the scanner or page memory is stored. ) Is once expanded on the image memory of the page memory and then the reading method of the image memory is changed to 90 degrees, 180 degrees, 2
A rotated image of 70 degrees can be output.

By rotating and outputting the image, the paper is always output in the same direction regardless of the direction in which the original is placed,
By outputting the data alternately in the vertical and horizontal directions, it is possible to distinguish a plurality of cuts by the direction of the paper.

Further, the image from the scanner or the coded and accumulated image is reduced and expanded in a multi-page image memory, so that the images of a plurality of pages can be printed on one sheet in a linked copy. At the time of this concatenated copying, since the length and width of the paper change depending on the number of concatenated sheets, it is necessary to rotate and output the image.

In order to rotate and output an image, it is necessary to write the original image into the image memory once and then read out the image memory so that the image is rotated.

Since the writing direction and the reading direction are different, the next image cannot be written in the image memory during this reading, and the rotation reading cannot be performed unless the original image is completely developed. Due to this waiting time, the processing speed decreased when the rotation output was performed.

In order to eliminate this waiting time, an image memory for two pages is prepared, and while one image memory is rotating and reading out, the next image is read from the other vacant image memory. expand. In this way, by having two pages of image memory, it is possible to develop and rotate the image before rotation at the same time. By alternately performing this, it is possible to continuously perform the processing without waiting for each other's processing. Is possible.

In order to perform the above continuous processing, an image memory for two pages is required. In order to copy a document with high image quality, it is necessary to increase the resolution when reading the document or printing an image on a laser printer. Naturally, as the resolution increases, the capacity of the image memory required for the resolution increases enormously. For example, A4 size original is 400dp
The image memory size required when one page is read as black and white data of 1 bit per pixel at a resolution of i is about 2 Mbytes, and at a resolution of 600 dpi is about 4.4.
It becomes Mbyte. When read as 8-bit grayscale data per pixel,
The size will be doubled and huge.

As described above, in order to record the image data, a very large amount of memory is required. If two pages are required, there is a drawback that the problems such as increase in cost, increase in the number of parts, increase in power consumption, and increase in device size cannot be avoided.

[0015]

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned drawbacks, it is possible to successively process read / input, encoding, decoding, and rotated / non-rotated image forming output in an image memory for one page. An object of the present invention is to provide an image forming apparatus that can be used.

[0016]

According to another aspect of the present invention, there is provided an image forming apparatus for reading image data of an original document, and storing the image data read by the reading unit in an image memory for storing one page of image data. One storage means, a first reading means for reading the image data stored in the image memory by the first storage means in a non-rotating direction and a rotating direction, and a non-rotating direction read by the first reading means. Coding means for respectively coding the image data and the image data in the rotation direction, and the non-rotational and rotation direction code data coded by the coding means are respectively stored in a code memory for storing code data for a plurality of pages. Second storage means for selectively decoding the code data in the non-rotational direction or the rotation direction stored in the code memory by the second storage means into image data Decoding means for, third storage means for storing the image data in the non-rotating direction or the direction of rotation is decoded by the decoding means in the image memory, the third
Second reading means for reading the image data in the non-rotational direction or the rotation direction stored in the image memory by the storage means of
And image forming means for forming an image on the image forming medium using the image data in the non-rotating direction or the rotating direction read by the second reading means, and the image data stored in the image memory is After being read in the non-rotational direction by the reading means of No. 1 and encoded by the encoding means,
The image data stored in the image memory is read in the rotational direction by the first reading means and encoded by the encoding means.

The image forming apparatus of the present invention comprises a reading means for reading the image data of the original, a first storage means for storing the image data read by the reading means in an image memory for storing image data for one page, and First reading means for reading the image data stored in the image memory by the first storage means in the non-rotating direction and the rotating direction, the image data in the non-rotating direction read by the first reading means, and the rotating direction. Coding means for respectively coding image data, and second storage means for respectively storing the code data in the non-rotational direction and the rotation direction coded by this coding means in a code memory for storing coded data for a plurality of pages. Decoding means for selectively decoding the non-rotating direction or rotating direction code data stored in the code memory by the second storage means into image data. Third storage means for storing in the image memory the image data in the non-rotational direction or the rotation direction decoded by the decoding means, and the non-rotational direction or the rotation direction stored in the image memory by the third storage means. The image forming apparatus includes a second reading unit for reading image data, and an image forming unit for forming an image on an image forming medium using the image data in the non-rotating direction or the rotating direction read by the second reading unit. The image data stored in the image memory by the first storage means and the image data stored in the image memory by the first reading means in the non-rotational direction are simultaneously stored and stored in the image memory. The image data stored in the image memory is read by the first reading means after the image data is read in the non-rotational direction by the first reading means and coded by the coding means. It is adapted to encode the read in the direction of rotation Te encoding means.

The image forming apparatus of the present invention comprises a reading means for reading the image data of the original, a first storage means for storing the image data read by the reading means in an image memory for storing the image data for one page, and First reading means for reading the image data stored in the image memory by the first storage means in the non-rotating direction and the rotating direction, the image data in the non-rotating direction read by the first reading means, and the rotating direction. Coding means for respectively coding image data, and second storage means for respectively storing the code data in the non-rotational direction and the rotation direction coded by this coding means in a code memory for storing coded data for a plurality of pages. Decoding means for selectively decoding the non-rotating direction or rotating direction code data stored in the code memory by the second storage means into image data. Third storage means for storing in the image memory the image data in the non-rotational direction or the rotation direction decoded by the decoding means, and the non-rotational direction or the rotation direction stored in the image memory by the third storage means. The image forming apparatus includes a second reading unit for reading image data, and an image forming unit for forming an image on an image forming medium using the image data in the non-rotating direction or the rotating direction read by the second reading unit. Storing the image data in the image memory by the first storage means and reading the image data stored in the image memory in the non-rotational direction by the first reading means from the image memory by the first reading means. Of the image data stored in the image memory are controlled simultaneously so that the number of data transfers to the image memory does not exceed the number of data transfers to the image memory by the first storage means. Data is read in the non-rotational direction by the first reading means and coded by the coding means, and then the image data stored in the image memory is read in the rotation direction by the first reading means and coded by the coding means. It is like this.

The image forming apparatus of the present invention comprises a reading means for reading the image data of the original document, a first storage means for storing the image data read by the reading means in an image memory for storing the image data of one page, and First reading means for reading the image data stored in the image memory by the first storage means in the non-rotating direction and the rotating direction, the image data in the non-rotating direction read by the first reading means, and the rotating direction. Coding means for respectively coding image data, and second storage means for respectively storing the code data in the non-rotational direction and the rotation direction coded by this coding means in a code memory for storing coded data for a plurality of pages. Decoding means for selectively decoding the non-rotating direction or rotating direction code data stored in the code memory by the second storage means into image data. Third storage means for storing in the image memory the image data in the non-rotational direction or the rotation direction decoded by the decoding means, and the non-rotational direction or the rotation direction stored in the image memory by the third storage means. The image forming apparatus includes a second reading unit for reading image data, and an image forming unit for forming an image on an image forming medium using the image data in the non-rotating direction or the rotating direction read by the second reading unit. Storing the image data in the image memory by the first storage means and reading the image data stored in the image memory in the non-rotational direction by the first reading means, the read address by the first reading means is The image data stored in the image memory is controlled so as to be less than the storage address by the first storage means, and the image data stored in the image memory is not rotated by the first reading means. After encoding by the read Te encoding means countercurrent, so as to encode the encoding means reads out the rotational direction of the image data stored in the image memory by the first reading means.

The image forming apparatus of the present invention comprises a reading means for reading the image data of the original, a first storage means for storing the image data read by the reading means in an image memory for storing the image data of one page, and First reading means for reading the image data stored in the image memory by the first storage means, coding means for coding the image data read by the first reading means, and coding by this coding means. Second storage means for storing the generated code data in a code memory for storing code data for a plurality of pages, and decoding means for decoding the code data stored in the code memory by the second storage means into image data. Third storage means for dividing the image data decoded by the decoding means and storing the divided image data in the image memory, and dividing and storing the image data in the image memory by the third storage means Second reading means reads the image data selectively to a non-rotating direction or the rotational direction, and the second
Image forming means for forming an image on the image forming medium using the image data in the non-rotating direction or the rotating direction read by the reading means of the third storing means to one of the divided areas of the image memory. The storage of the decoded image data and the reading of the image data stored in the other divided area of the image memory by the second reading means in the rotation direction are simultaneously performed.

The image forming apparatus of the present invention comprises a reading means for reading the image data of the original, a first storage means for storing the image data read by the reading means in an image memory for storing the image data of one page, and A first reading unit that divides the image data stored in the image memory by the first storage unit into a plurality of areas and reads the image data, and the image data divided by the first reading unit into the plurality of areas. Coding means for respectively coding, second storage means for storing code data corresponding to a plurality of areas coded by the coding means in a code memory for storing code data for a plurality of pages, and the second storage means. Decoding means for decoding coded data corresponding to the plurality of areas stored in the code memory by the storage means into image data, and corresponding to the plurality of areas decoded by the decoding means. Third storage means for dividing the image data and storing it in the image memory, and image data corresponding to a plurality of areas divided and stored in the image memory by the third storage means is selectively rotated in a non-rotating direction or rotated. Direction reading means, and image forming means for forming an image on an image forming medium using the image data in the non-rotating direction or the rotating direction read by the second reading means. The divided storage of the decoded image data corresponding to one area in the image memory by the third storage means and the rotation direction of the image data corresponding to the other area stored in the image memory by the second reading means Are read at the same time.

The image forming apparatus of the present invention reads a bit image image from a document, stores the read bit image image in an image area for one page of the page memory, and stores the bit image image stored in this image area. The compressed image is stored in the code area of the page memory, the compressed image stored in this code area is decompressed into a bit image image and stored in the image area, and the bit image image stored in this image area is used to form an image forming medium. In the above image forming, when compressing the bit image image stored in the image area and storing it in the code area of the page memory, the bit image image stored in the image area is not rotated as it is. Read out, compress and store in the code area of the page memory, and rotate the bit image stored in the image area. Storage means for reading out, compressing and storing in a different area of the code area of the page memory, and selectively reading the non-rotated compressed image or rotated compressed image stored in the code area by this storage means. The reading means and the non-rotated compressed image or the rotated compressed image read by the reading means are expanded into a bit image image and stored in the image area, and the bit image image stored in this image area is used to store the compressed image. It is composed of an image forming means for forming an image on an image forming medium.

The image forming apparatus of the present invention reads a bit image image from a document, stores the read bit image image in an image area of one page of the page memory, and stores the bit image image stored in this image area. The compressed image is stored in the code area of the page memory, the compressed image stored in this code area is decompressed into a bit image image and stored in the image area, and the bit image image stored in this image area is used to form an image forming medium. In the above image forming, the compressed image stored in the code area is expanded into a bit image image and stored in a partial area of the image area, and is stored outside the partial area of the image area. The decompressed bit image image is read out in the rotation direction at the same time, and the read out bit image image is read out. And performs image formation on the image forming medium.

The image forming apparatus of the present invention reads a bit image image from a document, stores the read bit image image in an image area for one page of the page memory, and stores the bit image image stored in this image area. The compressed image is stored in the code area of the page memory, the compressed image stored in this code area is decompressed into a bit image image and stored in the image area, and the bit image image stored in this image area is used to form an image forming medium. In the above image formation, when compressing the bit image image stored in the image area and storing it in the code area of the page memory, it is divided into a part of the image area and a part of the outside of the area. Bit image images are compressed and stored as two compressed images in the code area of the page memory. Second storage means for expanding one of the compressed images and the other compressed image into bit image images and storing them in a partial area of the image area and outside the partial area. An expanded bit image stored in a part of the image area or in a part of the image area when the bit image image is stored in the part of the area or outside the part of the area. It is composed of reading means for simultaneously reading the image in the rotation direction, and image forming means for forming an image on the image forming medium using the rotated bit image image read by the reading means. .

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

That is, the present invention is a copy (PPC),
An embodiment of a composite image forming apparatus having three functions of facsimile (FAX) and printer (PRT) will be described.

FIG. 1 is a schematic block diagram showing the internal structure of a digital copying machine as an example of the image forming apparatus of the present invention.

As shown in FIG. 1, the digital copying machine is provided with an apparatus main body 110, and inside the apparatus main body 110, a scanner 13 functioning as a reading means described later and a printer 15 functioning as an image forming means are provided. ing.

On the upper surface of the apparatus main body 110, an object to be read,
That is, the document placing table 112 made of transparent glass on which the document D is placed is provided. An automatic document feeder 107 (hereinafter, referred to as an ADF) for automatically feeding a document onto the document table 112 is provided on the upper surface of the apparatus main body 110. The ADF 107 is provided so as to be openable and closable with respect to the document table 112, and also functions as a document holder for bringing the document D placed on the document table 112 into close contact with the document table 112.

The ADF 107 includes a document tray 108 on which the document D is set, an empty sensor 109 for detecting the presence or absence of the document, a pickup roller 114 for taking out the documents one by one from the document tray 108, and a sheet feeding roller for conveying the taken out documents. 115, a pair of aligning rollers 116 for aligning the leading edge of the document, and a conveyor belt 118 arranged so as to cover almost the entire document placing table 112. The plurality of originals set upward on the original tray 108 are sequentially taken out from the bottom page, that is, the last page, are aligned by the aligning roller pair 116, and are placed on the original by the transport belt 118. The sheet is transported to a predetermined position on the table 112.

In the ADF 7, at the end portion on the opposite side of the aligning roller pair 116 with the conveyor belt 118 interposed,
Reversing roller 120, non-reversing sensor 121, flapper 12
2. Discharge rollers 123 are provided. A document D whose image information has been read by a scanner 13, which will be described later, is sent out from the document placing table 112 by a conveyor belt 118, and passes through a reversing roller 120, a flapper 121, and a sheet discharging roller 122, and a document discharging section on the upper surface of the ADF 7. It is discharged onto 124. When reading the back surface of the document D, by switching the flapper 122, the document D conveyed by the conveyor belt 118 is reversed by the reversing roller 120, and then again conveyed by the conveyor belt 118 to a predetermined position on the document table 112. Sent.

The scanner 1 installed in the apparatus main body 110
Reference numeral 3 denotes an exposure lamp 125 as a light source for illuminating the original D placed on the original mounting table 112, and a first mirror 126 for deflecting the reflected light from the original D in a predetermined direction. Lamp 125 and first mirror 12
Reference numeral 6 is attached to a first carriage 127 disposed below the document table 112.

The first carriage 127 is the original table 1
12, and is reciprocally moved below the document table 112 by a drive motor via a toothed belt or the like (not shown).

Below the document table 112, the second carriage 12 movable in parallel with the document table 112.
8 are provided. On the second carriage 128, there are provided second and third mirrors 130 and 131 for sequentially deflecting the reflected light from the document D deflected by the first mirror 126.
Are mounted at right angles to each other. The second carriage 128 is driven by the first carriage 127 by a toothed belt or the like that drives the first carriage 127, and the original is loaded on the first carriage 127 at half speed. It is moved in parallel along the table 112.

Below the document table 112, a second
An imaging lens 132 that focuses the reflected light from the third mirror 131 on the carriage 128 and a CCD sensor 134 that receives the reflected light focused by the imaging lens 132 and photoelectrically converts the reflected light are provided. . The imaging lens 132 is
It is movably arranged in the plane including the optical axis of the light deflected by the third mirror 131 via a driving mechanism, and by moving itself, the reflected light is imaged at a desired magnification. And
The CCD sensor 134 photoelectrically converts the incident reflected light,
An electric signal corresponding to the read original D is output.

On the other hand, the printer 15 is equipped with a laser exposure device 140 which functions as a latent image forming means. The laser exposure device 140 includes a semiconductor laser 141 as a light source.
And a polygon mirror 136 as a scanning member that continuously deflects the laser light emitted from the semiconductor laser 141.
Also, a polygon motor 137 may be used as a scanning motor for rotating and driving the polygon mirror 136 at a predetermined rotation number described later.
And an optical system 142 that deflects laser light from the polygon mirror and guides the laser light to a photosensitive drum 144 described later. The laser exposure apparatus 140 having such a configuration is fixedly supported by a support frame (not shown) of the apparatus main body 110.

The semiconductor laser 141 is ON / OFF controlled according to image information of the document D read by the scanner 13 or facsimile transmission / reception document information, and this laser light is exposed through the polygon mirror 136 and the optical system 142. The photosensitive drum 1 is directed toward the body drum 144.
An electrostatic latent image is formed on the peripheral surface of the photosensitive drum 144 by scanning the 44 peripheral surface.

Further, the printer 15 has a rotatable photosensitive drum 144 as an image bearing member disposed substantially in the center of the apparatus main body 110, and the peripheral surface of the photosensitive drum 144 from the laser exposure device 140. The desired electrostatic latent image is formed by exposure with laser light. Around the photosensitive drum 144, a charging charger 145 for charging the peripheral surface of the drum to a predetermined charge, and a toner as a developer is supplied to the electrostatic latent image formed on the peripheral surface of the photosensitive drum 144 by supplying a desired toner. Developing device 146 for developing with image density, peeling charger 147 for separating transfer material fed from a paper cassette described later, that is, copy paper P from photosensitive drum 144
And a transfer charger 148 for transferring the toner image formed on the photosensitive drum 144 onto the sheet P, and a peeling claw 1 for peeling the copy sheet P from the peripheral surface of the photosensitive drum 144
49, a cleaning device 150 for cleaning the toner remaining on the peripheral surface of the photosensitive drum 144, and a static eliminator 151 for removing static from the peripheral surface of the photosensitive drum 144 are arranged in this order.

An upper cassette 152, a middle cassette 153, and a lower cassette 154, which can be pulled out from the apparatus main body, are arranged in a laminated state in the lower part of the apparatus main body 110, and copy sheets of different sizes are stored in each cassette. It is loaded. A large-capacity feeder 155 is provided on the side of these cassettes, and the large-capacity feeder 155 has a copy paper P of a size frequently used, for example, A.
Approximately 3000 sheets of 4-size copy paper P are stored. Further, above the large-capacity feeder 155, a paper feed cassette 157 which also serves as a manual feed tray 156 is detachably mounted.

A transport path 158 extending from each cassette and the large-capacity feeder 155 through the transfer portion located between the photosensitive drum 144 and the transfer charger 148 is formed in the main body 110 of the apparatus, and the end of the transport path 158 is formed. Is provided with a fixing device 160 having a fixing lamp 160a. A discharge port 161 is formed on a side wall of the apparatus main body 110 facing the fixing device 160, and a single tray finisher 180 is mounted on the discharge port 161.

Upper cassette 152, middle cassette 15
3, pickup rollers 163 are provided near the lower cassette 154, the paper feed cassette 157, and near the large-capacity feeder 155 to take out the sheets P one by one from the cassette or the large-capacity feeder. Also,
The transport path 158 is provided with a large number of paper feed roller pairs 164 for transporting the copy paper P taken out by the pickup roller 163 through the transport path 158.

In the conveying path 158, the photosensitive drum 144
A registration roller pair 165 is provided on the upstream side of. The registration roller pair 165 corrects the inclination of the taken-out copy sheet P and aligns the leading edge of the toner image on the photosensitive drum 144 with the leading edge of the copy sheet P.
The copy paper P is fed to the transfer unit at the same speed as the moving speed of the peripheral surface of the photosensitive drum 144. In front of the registration roller pair 165, that is, on the side of the paper feed roller 164, the copy paper P
A pre-aligning sensor 166 is provided to detect the arrival of the.

The copy sheets P picked up one by one from each cassette or the large-capacity feeder 155 by the pickup roller 163 are sent to the registration roller pair 165 by the paper feed roller pair 164. And copy paper P
Is sent to the transfer unit after the front end is aligned by the registration roller pair 165.

At the transfer portion, the developer image formed on the photosensitive drum 144, that is, the toner image is transferred onto the paper P by the transfer charger 148. The copy paper P on which the toner image has been transferred is peeled off from the peripheral surface of the photosensitive drum 144 by the action of the peeling charger 147 and the peeling claw 149, and the transport belt 16 forming a part of the transport path 52.
7 to the fixing device 160. Then, after the developer image is fused and fixed on the copy paper P by the fixing device 160, the copy paper P is ejected onto the finisher 180 through the ejection port 161 by the paper feed roller pair 168 and the paper ejection roller pair 169.

Below the conveying path 158, the fixing device 160 is provided.
An automatic double-sided device 170 is provided for reversing the copy paper P that has passed through and feeding it again to the registration roller pair 165.
The automatic duplexing device 170 includes a temporary stacking unit 171 for temporarily stacking the copy sheets P, and a reversing path 172 that branches off from the transport path 158 and turns the copy sheet P that has passed through the fixing device 160 to guide the copy sheet P to the temporary stacking unit 71. And a pickup roller 1 for taking out the copy papers P accumulated in the temporary accumulation section one by one.
73, and a paper feed roller 175 for feeding the taken out paper to a pair of registration rollers 165 through a conveyance path 174. Further, a copy sheet P is supplied to the discharge port 161 or the reverse path 1 at a branch portion between the transport path 158 and the reverse path 172.
A sorting gate 176 for selectively sorting is provided at 72.

When performing double-sided copying, the copy sheet P that has passed through the fixing device 160 is guided to the reversing path 172 by the sorting gate 176, and is temporarily reversed in the reversing state.
After being temporarily accumulated in the pickup roller 173, the pickup roller 173
Then, the paper is fed to the registration roller pair 165 through the conveyance path 174 by the paper feed roller pair 175. Then, after the copy paper P is aligned by the registration roller pair 165,
The sheet is sent to the transfer section again, and the toner image is transferred to the back surface of the copy sheet P. Thereafter, the copy paper P is transferred to the transport path 158,
The sheet is discharged to the finisher 180 via the fixing device 160 and the sheet discharging roller 169.

The finisher 180 staples and stores the discharged documents having a partial structure in a unit. One sheet of copy paper P to be stapled 161
Each time the paper is discharged from the printer, the guide bar 181 aligns the paper toward the side to be stapled. When all the sheets have been ejected, the paper holding arm 152 suppresses a part of the ejected copy sheets P, and the stapler unit 183 performs stapling. Thereafter, the guide bar 181 is lowered, and the copy paper P on which stapling has been completed is partially completed by the finisher discharge roller 185 in the finisher discharge tray 1.
84. The lowering amount of the finisher discharge tray 184 is determined to some extent by the number of copy sheets P to be discharged, and decreases stepwise each time the copy paper P is discharged in a unit. Further, the guide bar 181 for aligning the copy paper P to be discharged is located at such a height that it does not hit the already stapled copy paper P placed on the finisher discharge tray 184.

Further, the finisher discharge tray 184 is
In the sort mode, it is connected to a shift mechanism (not shown) that shifts every part (for example, in four directions of front, rear, left and right).

FIG. 2 is a block diagram showing the overall structure of the image forming apparatus. This apparatus is a basic unit 1 for executing a basic copying function, and temporarily stores image data when the apparatus is connected to another system. To store the image data input from the system basic unit 2 having a page memory or the like for storing the image data when the image data is edited / processed and copied, and electronically and semipermanently storing the image data. System having the optical disk device, etc., and having control means for converting the image data and the control data into the control system and the image format of the other system when the image data or the control data is exchanged with the other system. The expansion unit 3 is composed of three systems.

The basic unit 1 and the system basic unit 2 are connected by a basic system interface 4 for exchanging control data and a basic image interface 5 for exchanging image data.

The system basic unit 2 and the system expansion unit 3 are connected by an expansion system interface 6 for exchanging control data and an expansion image interface 7 for exchanging image data.

That is, the basic unit 1 and the system expansion unit 3 are not directly connected to each other, and control data and image data are always exchanged with the system basic unit 2.
Is to be done through.

This image forming apparatus has three types depending on whether the system basic unit 2 and the system expansion unit 3 are connected or not.
Can take two forms.

In other words, the first mode has a configuration of only the basic unit 1, and the basic function in this configuration is a copying function, and copying processing involving simple editing processing such as enlargement / reduction processing and masking / trimming processing is performed. Is possible.

The second form is a form in which the system basic unit 2 is connected to the basic unit 1. In this form, in addition to the copying function in the basic unit 1, a page memory for temporarily storing image data is used. Editing processing such as image rotation processing and combining processing of a plurality of images is possible. The system basic unit 2 includes a system extension unit 3
F which constitutes communication line control means such as a facsimile
It is possible to connect a printer controller 9 for using the printer of the AX (facsimile) unit 8 and the basic unit 1 as a remote printer of a control device such as an external personal computer.
Can transmit an image to another system or device via a communication line, or can receive image data from another system or device via a communication line. And printed out by a printer described later.

The third form is a form shown in FIG. 2 in which the basic unit 1, the system basic unit 2 and the system expansion unit 3 are connected.

In this embodiment, in addition to the functions of the first and second embodiments, a data storage / management function of electronically and semi-permanently storing image data and managing the stored image data, a local area network described later (LAN) A transmission / reception function of image data by LAN for transmitting an image from the line control means to another system or device via the LAN line, and conversely receiving image data from the other system or device via the LAN line, A printer function that converts the print control code sent from a personal computer via a general-purpose interface into image data and prints out the image data from the printer of basic unit 1 via the page memory of system basic unit 2 is possible. Becomes

As shown in FIG. 3, the basic unit 1 includes a system CPU 11 which constitutes a main body of a control unit, a control panel 12 which includes an operation unit and a display unit, and an image scanner 1 as an input unit for reading an image from a document.
3. Image processing circuit 14 and printer 1 as output means
It is composed of 5. The system CPU 11 is connected to a control panel 12, a scanner 13, an image processing circuit 14, and a printer 15 as an output unit for performing image formation output through a basic system bus 16, and controls these. This basic system bus 16
Is connected to the basic unit system interface 4.

The scanner 13 has a CCD line sensor (not shown) consisting of a plurality (one line) of light receiving elements arranged in a row, and an image of the document placed on a document table (not shown). Is read line by line according to the instruction from the system CPU 11, and the grayscale of the image is digitally displayed in 8 bits.
After being converted into data, it is output to the image processing circuit 14 via the scanner interface as time-series digital data together with a synchronization signal.

The printer 15 is composed of a laser optical system (not shown) and an image forming unit (not shown) in which an electrophotographic system capable of forming an image on a transfer sheet is combined, and an image is formed in accordance with an instruction from the system CPU 11. Processing circuits 14 to 4
Bit digital image data is input in synchronization with a synchronization signal via a printer interface, and an electrostatic latent image is formed on a photosensitive drum (not shown) by a laser beam having a pulse width corresponding to the size of the image data. After the formation, the electrostatic latent image is visualized by a visualizing unit (not shown), the image visualized by a transfer unit (not shown) is transferred to a transfer paper, and is fixed on the transfer paper by a fixing unit (not shown). Is fixed and the transfer paper is output.

The control panel 12 is composed of an operation section for setting operation modes and parameters of the apparatus and a display section for displaying a system state or a picture image stored in the page memory of the system basic unit 2.

The system CPU 11 also controls each part of the system basic unit 2 described later.

As shown in FIG. 6, the image processing circuit 14 includes a smoothing edge emphasizing circuit 14a and an editing / moving circuit 14.
b, an enlargement / reduction circuit 14c and a gradation conversion circuit 14d.

The smoothed edge emphasizing circuit 14a removes noise mixed in during image reading by the smoothing circuit, and sharpens the edges which are blurred due to the smoothing by the edge emphasizing circuit.

The editing / moving circuit 14b is a block for performing a simple editing process on a line-by-line basis, and performs, for example, a moving process in the line direction and a masking / trimming process.

The enlarging / reducing circuit 14c performs the enlarging / reducing process by repeating the pixels according to the designated scaling ratio or by combining the thinning process and the interpolation process.

The gradation conversion circuit 14d uses the area gradation method to read one pixel of 8 bits by the scanner 13.
Is converted to a designated number of gradations. The gradation-converted image data is 1 which is the bit number of the printer.
The image data of 4 bits is sent to the printer 15 or the system basic unit 2 via the scanner data bus 17 and the basic section image interface 5.

The correction of the non-linearity of the input / output characteristics of the printer 15 is performed at the same time when the gradation processing is performed using the area gradation method.

As shown in FIG. 4, the system basic unit 2 includes a page memory 28 for storing bit image data read by the scanner 13 as image data, encoded data obtained by compressing the image data, etc., and the basic unit 1 in the basic unit 1. Of the system control circuit 21 and the page memory 28 which control communication of control information between the system CPU 11 and the CPU in the system expansion unit 3 and control access to the page memory 28 from the basic unit 1 and the system expansion unit 3. A page memory address control circuit 26 for generating an address, an image bus 29 for transferring data between devices in the system basic unit 2, and a data transfer between the page memory 28 and other devices via the image bus 29. Page memory data control to control the data transfer of It is provided with a circuit 27.

The page memory 28 has an image area (work area, image memory) 28a for storing image data for one page, and a code area (file area) 28b for storing compressed data for a plurality of pages. It consists of

Further, the image data I / F 210 that interfaces the image data when transferring the image data to and from the basic unit 1 through the basic part image interface 5, and the image data when the image data is transmitted to a device having a different resolution. Resolution conversion Binary rotation for converting the resolution of another device, converting image data received from a device with a different resolution to the resolution of the printer 15 of the basic unit 1, and performing 90-degree rotation processing of binary image data. The circuit 212 compresses the image data input for a device for compressing and transmitting the image data such as facsimile transmission or optical disk storage, or compressing the input image data via the printer 15. A compression / expansion circuit 211 that expands for visualization is provided.

FO in which character fonts are stored
A system memory (ROM) including an NT memory, a work memory for temporarily storing control information used by the system CPU 11, a program memory for storing a processing program for performing processing using the system basic unit 2, and the like. / RAM) 24, a system D for performing high-speed data transfer between devices of the basic system bus 16
MA controller 23, exchanges control information between printer controller 9 and system CPU 11,
A printer controller interface 213 for interfacing the control information and image data when transferring image data between the printer controller 9 and the image bus 29 is provided.

Furthermore, the system control circuit 21 is connected to the system CPU 11 and the C of the system expansion unit 3.
A communication memory 25 for storing control information when communicating control information with the PU, an image data I / F 21
0, and a multi-valued rotation memory 214 used when outputting image data from the printer 15 by rotating the image data by 90 degrees or 180 degrees.

The FAX unit 8 and printer controller 9 are optionally connected.

As shown in FIG. 5, the system expansion unit 3 connects each internal device to the expansion system bus 43.
An extended CPU 31 for controlling data transfer on the extended system bus 43, a general-purpose ISA bus 44, an ISA bus controller 33 for interfacing the extended system bus 43 and the ISA bus 44, Storage means connected to the extension system bus 43 for electronically storing image data, for example, a hard disk device 35, a hard disk interface 34 as an interface thereof, and the ISA bus 4
Storage means for electronically storing image data, such as an optical disk device 38, an optical disk interface 37 as an interface thereof, a local area network line controller (LAN) 41 for realizing a LAN function, a printer function Controller, a G4 / FAX control circuit 39 having a G4 / FAX control function, an extended SCSI interface 42 used when connecting a SCSI specification device, and an image from the printer controller controller 40 An extension image bus 45 for outputting data to the system basic unit 2 via the extension image interface 7, and an interface for exchanging data between the extension system bus 43 and the extension image bus 45. Bag Consisting of Amemori 36.

Incidentally, the optical disk interface 3
7, optical disk device 38, G4 / FAX control circuit 39,
The printer controller controller 40, the local area network line controller 41, and the extended SCSI interface 42 are optional,
It is configured so that it can be attached to and detached from.

The optical disk device 38 is connected to the ISA bus 44 through the interface 37, and the expansion C
The PU 31 uses the SCSI command to extend the system bus 43, the ISA bus controller 33, and the ISA bus 4.
4, the optical disk device 38 is controlled.

The local area network line control device 41 controls the communication of control data and image data with other devices on the network based on the protocol of the connected network system, LAN.
It is composed of a shared memory for temporarily storing communication control data and image data from the system, or control data and image data from the system expansion bus, and a system expansion bus interface.

Printer controller controller 40
Interfaces a parallel interface conforming to Centronics for exchanging control codes and image data with a personal computer, and a system extension unit image bus 45 for transferring bit image data to the page memory 28 of the system basic unit. A system expansion image bus interface, an image data transfer control unit for controlling the transfer of image data in the apparatus, a control code from a personal computer, and an expansion CP via an expansion unit system bus 43 and an ISA bus 44.
Control means for notifying U31 of control information, interpreting a print control code from a personal computer, converting the bit information into bit information, and storing the bit information in a memory in the apparatus; a system expansion bus for interfacing with an ISA bus 44 Interface.

Next, the structure and function of the main part in the system basic unit 2 will be described in detail.

As shown in FIG. 7, the system control circuit 21 includes a communication memory access control circuit 401 for controlling communication of control information between the system CPU 11 and the extended CPU 31, and a communication memory for interfacing with the communication memory 25. A page memory access control circuit 4 for controlling access to the page memory 28 from the interface 402, the basic unit 1 and the system expansion unit 3.
03, the basic unit 1 via the basic system bus 16
A basic part system bus interface 405 for decoding control information and image information sent from the system CPU 11 at the same time and distributing the control information or image information to blocks in the corresponding system basic unit 2; Extension unit 3
A system expansion bus interface 406 for decoding addresses that simultaneously transmit control information and image information from the CPU and allocating them to corresponding blocks in the circuit, and a means for enabling page memory access on the basic system bus 16 (in the basic unit) (The CPU 11 of the system expansion unit 3) and the means capable of accessing the page memory on the system expansion bus 43 (the CPU of the system expansion unit 3).
31 and the DMA controller 32) access the image data in the page memory 28 via each system bus when the page memory access control circuit 40
3 and a page memory interface 404 for interfacing image data between the page memory 28.

The communication memory access control circuit 401 includes the CPU 11 of the basic unit 1 and the system expansion unit 3
The CPU 31 controls access to the communication memory 25 when the control code is transferred to and from the communication memory 25 via the communication memory interface 402 in the system control circuit 21.

The communication memory 25 is C of the basic unit 1.
The data is mapped in the memory space of the PU 11 and the CPU 31 of the system extension unit. Data can be read from and written to the communication memory 25 by accessing a specific area.

Communication memory access control circuit 401
8 includes an arbitration circuit 410, a communication memory access sequencer 412, a bidirectional selector 413, and an interrupt control circuit 414, as shown in FIG.

The arbitration circuit 410 is the C of the basic unit 1.
The priority control of the communication memory access between the PU 11 and the CPU 31 of the system extension unit 3 is performed. CPU 11 of the basic unit 1 and CPU 31 of the system expansion unit 3
When the user accesses the communication memory 25 at the same time, one of them is permitted based on the set priority,
Make the other access wait.

Communication memory access sequencer 412
Outputs a read or write control signal to the communication memory 25 based on the request from the permitted CPU.

The bidirectional selector 413 is used by the arbitration circuit 4
Based on the arbitration result of step 10, the address to the communication memory 25 output from the permitted control means is output to the communication memory 25 in synchronization with the timing signal output from the communication memory access sequencer 412. In the write operation, the permitted CPU outputs communication information (data) output together with the address to the communication memory 25 together with the address information. In the read operation, the permitted CP
The communication information read from the communication memory 25 is input according to the address from the U to the communication memory 25 and the timing signal output from the communication memory access sequencer 412, and is output to the permitted CPU.

The page memory access control circuit 403
As shown in FIG. 9, the arbitration circuit 430 includes a arbitration circuit 430, data registers 431, 432, 436, and 437, an address register 433, a bidirectional select 434, and a page memory access sequencer 435.

The arbitration circuit 430 controls the page memory access priority of the CPU 11 of the basic unit 1 and the CPU 31 of the system expansion unit 3. When the CPU 11 and the CPU 31 simultaneously access the page memory 28, one of the CPUs 31 and 31 may be used based on the set priority.
Is permitted, and the access of the other CPU is made to wait.

The page memory access sequencer 43
5 is a page memory 2 based on a permitted CPU request.
A read or write control signal for 8 is output to the address control circuit 26.

The bidirectional selector 434 has the arbitration circuit 4
Based on the arbitration result of 30, the address for the page memory 28 output by the permitted CPU is output to the address control circuit 26 in synchronization with the timing signal output by the page memory access sequencer 435. In the write operation, the permitted CPU outputs information (data) output together with the address to the data control circuit 27 together with the address information. Further, in the read operation, the image data read from the page memory 28 is input via the data control circuit 27 in accordance with the address to the page memory 28 from the permitted CPU and the timing signal output from the page memory access sequencer 435, Output to the permitted CPU.

The data register 431 and the data register 432 are registers for temporarily storing data when the basic unit 1 accesses the page memory 28, and the address register 433 is an address of the page memory 28 output by the basic unit 1. Is a register for temporarily storing.

Here, when the basic unit 1 uses the data register 431 to access the page memory 28, the address output by the basic unit 1 is temporarily stored in the address register 433 and the address control circuit 26
Is output to the page memory 28 via the. On the other hand, when the basic unit 1 uses the data register 432 to access the page memory, the address output by the basic unit 1 is ignored, and the address generator of the address control circuit 26 pages the address based on the setting information. Output to the memory 28.

The data register 436 and the data register 437 are registers for temporarily storing data when the system expansion unit 3 accesses the page memory 28. When the system expansion unit 3 accesses the page memory 28, The address generator of the two register address control circuit 26 outputs the address to the page memory 28 based on the setting information.

The system DMA controller 23 of the basic unit 1 is a controller for transferring data between devices on the basic system bus 22 at high speed by hardware without the intervention of the CPU 11 of the basic unit 1.

As the processing for transferring data using the system DMA controller 23, the compressed data (code data) is transferred between the page memory 28 and the FAX unit 8 in the FAX transmission / reception processing, and the image on the page memory 28 is controlled. There are transfer of image data between the page memory 28 and the control panel 12 for displaying on the panel 12, data transfer between the system memory 24 and the control panel 12 for displaying an operation screen on the control panel 12, and the like.

The address control circuit 26 for generating the address of the page memory 28 is, as shown in FIG. 10, a transfer control sequencer 610 for executing various transfer sequences in response to a request from the image bus, an image bus request and a system bus. Arbitration unit 6 that arbitrates the request of
11, an address generator 612 that generates various memory addresses of a plurality of channels in the transfer from the image bus, a selector 613 that switches an address output from the address generator 612 and a system address, a DRAM
DRAM control section 61 for generating the address and control signal of
4.

The address control circuit 26 receives a memory access request from two systems, an image bus and a system bus. This request is arbitrated by the arbitration unit 611, and the data transfer process on the side that has won the arbitration is performed.

When the request on the system bus side wins the arbitration, the system address selected by the selector 613 is input to the DRAM control unit 614. DRAM
The control unit 614 converts the input address into a DRAM address and generates a control signal necessary for reading and writing.

Further, an address channel signal is input to the transfer control sequencer 610 together with a request from the image bus, and one is selected from a plurality of address generators in the address generator 612. When the request on the image bus side wins arbitration, the memory address of the selected channel is output from the address generation unit 612, and the DRAM control unit 61
4 is input.

The address generation unit 612, as shown in FIG. 11, includes a 4-channel two-dimensional address generator 63.
1, 632, 633, 634, 2-channel FIFO
It comprises a selector 637 for selecting one of the memory addresses generated by the address generators 635 and 636 and a channel select signal from the transfer sequencer.

Each of the two-dimensional address generators 631 to 63
4 can generate various addresses. For example, FIG.
It is also possible to sequentially generate addresses in the X direction in synchronization with the clock from the transfer control sequencer, as shown in (a). It is also possible to sequentially generate addresses in the opposite direction of the Y direction by changing the parameters, as shown in FIG.

Further, the start address and the main scanning width (XW) of one line can be arbitrarily set according to the paper size of the original.

[0104] Such various addresses can be generated.
By using the dimensional address generator, transfer to any rectangular area of the page memory 28, rotation reading or repeated reading, and two-dimensional address generator
By using the channels, it is possible to move, rotate, vertically / horizontally convert, repeat, and edit images such as mirror images between arbitrary areas of the page memory 28.

FIFO address generators 635 and 636
Generates a FIFO address for using the page memory 28 as a FIFO memory and a status required for FIFO control.

The status is FIFO full (FI
FO area is full of unread data), FIFO
There are an empty state (a state in which there is no unread data in the FIFO area) and a FIFO half state (a state in which half or more unread data exists in the FIFO area). Also, the system CP
By reading the FIFO register from U11, it is possible to know the amount of data and free space in the FIFO.

By performing FIFO control using these statuses, the devices on the image bus 29
Alternatively, from the device of the image bus 29 to the system bus 22
When the data is transferred to the memory, differences in the transfer speed and transfer timing can be absorbed by the FIFO memory, and high-speed data transfer is possible.

Further, the FIFO address generators 635, 6
When the FIFO control is not performed, 36 can be used as a one-dimensional address generator for two channels per channel.

The detailed structure of the FIFO address generators 635 and 636 will be described with reference to FIG. FIF
The O address generator is a one-dimensional address generator channel A4601, a channel B4603, start address setters A4602, B4604, FIFO for giving a start address to each one-dimensional address generator.
It is composed of a status generator 4605 and a FIFO area size setting unit 4606.

The one-dimensional address generator 4601 is incremented by the count up signal each time one transfer is completed. Therefore, it is possible to write or read data to consecutive addresses in the memory.

The address generators 635 and 635 have a mode in which continuous one-dimensional addresses are generated, and when the address reaches the size of the FIFO area from the start address, the address is returned to the start address in the next transfer. There are two modes, a FIFO address mode for generating addresses.

In the FIFO address mode, a write address for FIFO control is generated in one channel, and an address for FIFO control is generated in another channel.

The FIFO status generator determines the FIFO from the addresses of two channels and the size of the FIFO area.
Generates a status indicating the state of the data in the area.

The statuses are FIFO full and FIF
There are two, O empty.

The FIFO full indicates a state in which the unread data is full in the FIFO area, and new data cannot be written. Therefore, the FIFO full signal is used to prohibit the data writing.

The FIFO empty indicates a state in which there is no unread data in the FIFO area, and the data cannot be read any more. Therefore, the reading of the data is prohibited by using this FIFO empty signal.

By thus controlling the transfer using the FIFO address mode, a part of the memory can be transferred to the FIFO.
High-speed data transfer can be performed by using it as an O region and absorbing the difference in writing and reading speeds.

FIG. 14 shows the page memory 28 (image area 2
8a) is a conceptual diagram in the case of two-dimensional access.

Assuming that one access width (64 bits in the figure) of the page memory 28 is one column, one line is configured by an integral multiple of one column. Columns continuous in the X direction on the same line are page memory 2
The linear addresses of 8 are continuous, and the linear addresses of the last column of the line and the first column of the next line are continuous.

FIG. 15 is a block diagram of the page memory 28 of FIG.
The dimensional memory is written in linear addresses.

As shown in FIG. 16, the data control circuit 27 performs data transfer between devices on the image bus 29 in the system basic unit 2 and data transfer between devices on the image bus 29 and the page memory 28. The image data transfer control unit 701 for controlling, the image processing unit 702 for executing bit block transfer and various raster operations (logical operations), the CPU 11 of the basic unit 1 or the CPU 31 of the system expansion unit 3 are connected via the system control circuit 21. A system interface 703 that interfaces data when accessing (reading / writing) the page memory 28, and the image data transfer control unit 701 based on the page memory access arbitration result of the address control circuit 26 in the writing process to the page memory 28. To C of and or data from a device on the image bus 29 sent to, or system interface 703 is sent via the come CPU (basic unit 1 of the CPU11 or system expansion unit 3
A selector 704 for selecting data from the PU 31).
In the process of reading data from the page memory 28, data is sent to a device on the image bus 29 via the image data transfer control unit 701 based on the page memory access arbitration result of the address control circuit 26, or the system interface 703 And a selector 705 for selecting whether to send data to the CPU (the CPU 11 of the basic unit 1 or the CPU 31 of the system expansion unit 3) via the CPU.

Next, the control of the image data transfer control unit 701 shown in FIG. 16 will be described. The image data transfer mode controlled by the image data transfer control unit 701 includes the following two modes.

One form is data transfer between I / O devices on the image bus 29 of the system basic unit 2, both source (transfer source) / destination (transfer destination) are on the image bus 29, and the image is transferred from the source. The data transfer control unit 701 includes two cycles of a read cycle for fetching data into the data buffer and a write cycle for writing data in the data buffer to the destination.

Another form is the system basic unit 2
I / O device on image bus 29 and page memory 28
The data transfer between the I / O device and the data buffer in the image data transfer controller 701 and the data transfer cycle between the data buffer and the page memory 28 include two cycles.

Since the page memory 28 and the data buffer are independent of the image bus 29, the two cycles can operate in parallel.

Further, the image data transfer control unit 701 can specify the above-mentioned two types of data transfer for 8 channels, and simultaneously can transfer data for 8 channels.

The image data transfer control unit 701 shown in FIG.
7, the data buffer 740, the image bus priority control unit 741, the transfer control sequencer 742, the page memory priority control unit 743, the page memory timing control unit 744, the terminal counter 745, and the interrupt control unit 74.
6, a control bus interface 747, a parameter register 748 and an I / O buffer 749.

The data buffer 740 has the same number of data registers as the number of channels for temporarily storing the data from the source in the data transfer.

The image bus priority control unit 741 sends a data transfer request (R) from a device on the image bus 29.
EQ) is input, a device for which data transfer is permitted is determined by a predetermined priority control, and a start of data transfer is notified (ACK) to the permitted device.

The transfer control sequencer 742 generates a timing signal for data transfer between the source device and the destination device, which is determined based on the priority control result of the image bus priority control unit 741 to generate the image bus 2
Output to 9.

The page memory priority control unit 743
A request signal output from the data buffer 740 is input, and a data transfer channel between the page memory 28 and the data buffer 740 is determined based on a predetermined priority.

The page memory timing controller 744
Is the page memory 28 of the transfer channel determined based on the priority control result of the page memory priority control unit 743.
And a data transfer timing signal between the data buffer 740 and the address control circuit 26. The transfer request signal from the data buffer 740 is used when the data from the device on the image bus 29 is stored in the data buffer 740 during the write processing to the page memory 28. In the read process, when data is not stored in the data buffer 740, the data is output to the page memory priority control unit 743.

The parameter register 748 is a register for setting the transfer source, transfer destination, number of transfer bytes, presence / absence of interrupt processing at the end of transfer, etc. for each transfer channel.

The image bus 29 has a data width of 32 bits and 32 bits of data are always transferred regardless of the bit width of one pixel. For example, when writing binary (1 bit / pixel) data from the scanner 13 to the page memory 28, 32 pixel data is transferred from the image data I / F 210 to the image data transfer control unit 70 on the image bus 29 at a time.
1 to the page memory 28, and multivalued (4
When writing (bit / pixel) data to the page memory 28, data of 8 pixels is transferred on the image bus 29 at one time. The data is converted into 32 bits in each device on the image bus 29 in accordance with the number of bits of one pixel.

The data transfer priority control on the image bus 29 is based on a transfer request from a device that cannot stop or wait for data transfer, such as output processing to the printer 15 and input processing from the scanner 13. A device that can prioritize and allow transfer requests such as compression / expansion processing and resolution conversion processing to wait for data transfer is allowed only when there is no transfer request from a device with a high priority. It is decided to decide the priority according to the property of.

A timer 900 is connected to the system bus 16 shown in FIG. This timer 900 is shown in FIG.
As shown in FIG. 8, it comprises a timer control unit 901, a reference clock generation circuit 902, a reference clock frequency dividing circuit 903, and a down counter 904.

The timer control unit 901 is the system CPU 1
From 1 through the system bus 16, a division ratio of the reference clock frequency dividing circuit 902 is set, and the count start and stop of the down counter 904 are controlled.

Further, the timer control unit 901 can generate an interrupt signal to the system CPU 11 by the carry-down signal output from the down counter 904.

The reference clock generation circuit 902 generates an accurate square wave of 25 MHz by the crystal oscillator.

The reference clock frequency dividing circuit 903 is the system C.
According to the setting from the PU 11, the reference clock is frequency-divided into a frequency of 1 / n at an arbitrary frequency division ratio from 1/1 to 1/65536.

The down counter 904 is a 32-bit binary down counter which counts down in synchronization with the divided clock. The initial value of the down counter 904 is set by the system CPU 11 via the system bus 16.

Further, when carry-down (carrying down from 0) occurs in the down counter 904, the previous system C
The initial value set by the PU 11 is automatically set. The value of this down counter 904 is
1 at any time via the system bus 16.

The start and stop of the countdown of the down counter 904 are controlled by the count enable signal output from the timer control section 901.

Next, the image bus priority control unit 74 of FIG.
The detailed configuration of No. 1 will be described with reference to FIG. The image bus priority control unit 741 includes an image bus transfer request arbitration unit 910, a request mask circuit 911 for eight channels, and a request generation unit 912 for eight channels.

The request generator 912 is independent for each of the eight transfer channels. The image bus transfer request signal and the channel buffer status are input to the request generation section 912 of each channel, and when both conditions are satisfied, an internal valid transfer request is generated. Here, the image bus transfer request signal is a signal that is activated when a device connected to the image bus 29 requests data transfer on the image bus 29. The channel buffer status is a signal indicating the state of the data buffer 740 for data transfer of each transfer channel. The “empty” state where no valid data is contained in the data buffer of that channel and “the state where valid data is contained”. There are two states, "full".

In the case of device read transfer from the device of the image bus 29 to the data buffer 740, when the buffer status of the data buffer of the channel to be transferred is "empty" and the request signal from the device to that channel is active, a request is generated. An internal valid transfer request is generated from the unit 911.

Further, in the case of device write transfer from the data buffer 740 to the device of the image bus 29, there is valid data in the data buffer 740 of the channel to be transferred, the buffer status is “full”, and the device requests the channel. When the signal is active, the request generator 912 generates a valid internal transfer request.

The request mask circuit 911 controls whether or not the transfer request generated by the request generation unit 912 at the preceding stage is valid.

The transfer channel enable determines whether transfer of the channel is permitted or not.

The TC mask is for controlling the transfer amount. The number of words to be transferred is set in the terminal counter 745 in advance, and when the transfer of the predetermined number of words is completed, the TC mask becomes active and transfer of the channel is prohibited. To be done. When this transfer amount control is not performed, the TC mask is always kept inactive by setting.

The FIFO control mask controls transfer permission / prohibition of the channel when performing FIFO control.
The FIFO control mask is active to prohibit transfer, and inactive to permit transfer.

FIFO address generator 6
The system CPU 11 determines whether to perform the operation based on the FIFO status from the terminals 35 and 636, the comparison result of the transfer comparator of the terminal counter 745, or not to perform the FIFO control.
Select by setting from. When the FIFO control is not performed, the FIFO control mask is always kept inactive by setting.

The image bus transfer request arbitration unit 910 arbitrates the transfer request for eight channels generated by the request mask circuit 911, selects one channel, accepts the request to the device of the selected channel, and permits the transfer. The image bus transfer acknowledge signal indicating is output. The device that receives this acknowledge signal transfers data on the image bus 29.

The priority control of arbitration performed when transfer requests are generated from a plurality of channels is round robin control in which the priority of the previously transferred channel is lowest when channels 1 to 8 are arranged in a ring. Is going. Therefore, even if all eight channels continue to issue a transfer request, the transfer is always performed while the transfer is performed eight times, so that the transfer is performed equally for each channel.

Next, the detailed configuration of the page memory priority control unit 743 of FIG. 17 will be described with reference to FIG. The page memory priority control unit 743 includes a page memory transfer request arbitration unit 921, a request mask circuit 922 for eight channels, and a request generation unit 9 for eight channels.
23.

The request generator 923 is independent for each of the eight transfer channels. The channel buffer status is input to the request generator 923 of each channel, and an internal valid transfer request is generated when the condition of the channel buffer status is satisfied.

The channel buffer status is a signal representing the state of the data buffer 740 for data transfer of each transfer channel.
There are two states, 40, "empty" with no valid data and "full" with valid data.

From page memory 404 to data buffer 7
In the case of the memory read transfer to the memory 40, when the buffer status of the data buffer 740 of the channel to be transferred is “empty”, that is, when data can be received, the request generation unit 923 generates an internal valid transfer request.

Further, in the case of memory write transfer from the data buffer 740 to the page memory 404, when there is valid data in the data buffer 740 of the channel to be transferred and the buffer status is “full”, the request generator 923 internally A valid transfer request is generated.

The request mask circuit 922 controls whether or not the transfer request generated by the request generation unit 923 in the preceding stage is valid.

The transfer channel enable determines whether the transfer of the channel is permitted or not.

The TC mask is for controlling the transfer amount. The number of words to be transferred is set in the terminal counter 745 in advance, and when the transfer of the predetermined number of words is completed, the TC mask becomes active and transfer of the channel is prohibited. To be done. When the transfer amount control is not performed, the TC mask is always inactive depending on the setting.

The FIFO control mask controls transfer permission / prohibition of the channel when performing FIFO control,
The FIFO control mask is active to prohibit transfer and inactive to permit transfer.

FIFO address generator 6
The system CPU 11 determines whether to perform the operation based on the FIFO status from the terminals 35 and 636, the comparison result of the transfer comparator of the terminal counter 745, or not to perform the FIFO control.
Select by setting from. When the FIFO control is not performed, the FIFO control mask is always kept inactive by setting.

Page memory transfer request arbitration unit 921
Arbitrates a transfer request for eight channels generated by the request mask circuit 922, selects one channel, and outputs a selection signal (RCHN) of an address generator set for the selected channel to the address control unit 26.

The priority control of arbitration performed when transfer requests are issued from a plurality of channels is round robin control in which when channels 1 to 8 are arranged in a ring, the priority of the previously transferred channel is the lowest. Is going. Therefore, even if all eight channels continue to issue a transfer request, the transfer is always performed while the transfer is performed eight times, so that the transfer is performed equally for each channel.

Next, the terminal counter 745 shown in FIG.
The detailed configuration of will be described with reference to FIG. The terminal counter 745 counts the number of transfer words for each channel.
Transfer word counter 932 for 1, 8 channels, 2
Four transfer number comparators 9 connected to one channel
33.

The countdown signal generator 931 outputs a countdown signal to the transfer channel signal based on the arbitration result of the image bus priority controller 741 and the transfer word number counter 932 of the selected channel according to the transfer end signal.

The transfer word number counter 932 is a 32-bit binary down counter which counts down each time one transfer of the image bus 29 of the channel is completed. Here, the initial value of the counter 745 is the system CPU
11 is set via the system bus 16. When carry down (falling from 0) occurs, a terminal count signal is output.

The value of the transfer word number counter 932 can be read from the system CPU 11 at any time via the system bus 16.

The interrupt mask circuit 934 enables / disables the interrupt to the system CPU with respect to the terminal count signals for eight channels, takes the logical sum of them and outputs them as a terminal count interrupt signal. To do. Permission / non-permission of each channel is set by the system CPU 11.

The transfer number comparator 933 compares the transfer word numbers of the two channels, and when the transfer word numbers are equal, activates the output as the comparison result.

Further, the transfer count comparison 933 can perform comparison by multiplying each transfer word count to be compared by an arbitrary positive number by setting. Normally, they are used by multiplying each one.
For example, if A is set to double and B is set to 1 for two channels A and B, the comparison result becomes active when the number of A transfer words reaches 1/2 of the number of B transfer words. This comparison result is used as a control signal when performing FIFO control between two channels.

The operation of the above arrangement will be described below. First, a basic operation of inputting image data from the scanner 13 to the page memory 28 will be described. The image output data of 8 bits / pixel of the original read by the scanner 13 is passed through the image processing circuit 14 to 8 bits / pixel, 4 bits / pixel, 2 bits / pixel or 1 bit.
/ Pixel scanner image data is transferred to the image data interface 210, and a plurality of pixels (4, 8, 16, 32 pixels) of the scanner image data are collected inside the image data interface 210, and the image bus 29 is transferred as transfer data in units of 32 bits. Is transferred to the data control circuit 27 via DMA.

The data control circuit 27 is the address control circuit 2
32 bits in the address of the page memory 28 generated in step 6
The scanner image data is being written.

Next, the process of compressing the image data on the page memory 28 will be described. The page memory 28 is logically distinguished into an image area 28a for storing image data and a code area 28b for storing compressed code data.

The image data transfer control unit 701 uses, as transfer paths, two channels from the image area 28a of the page memory 28 to the image input of the compression / expansion circuit 211 and the code output of the compression / expansion circuit 211 to the code area 28b of the page memory 28. Set.

The transfer destination of the code output is the hard disk interface 34 or the optical disk interface 3.
By setting 7, a large amount of images can be recorded on a recording medium having a lower bit unit.

After the compression processing is set in the compression / expansion circuit 211, an encoding start command is executed.

The image data is read from the page memory 28 and input to the compression / expansion circuit 211. Compression / expansion circuit 2
Numeral 11 encodes the image and outputs the code to the code area 28b of the page memory 28.

Next, the expansion processing of the encoded image data into the page memory 28 will be described. In the image data transfer control unit 701, two channels from the code area 28b of the page memory 28 to the code input of the compression / expansion circuit 211 and the image output of the compression / expansion circuit 211 to the image area 28a of the page memory 28 are set as transfer paths. Further, by using the hard disk interface 34 or the optical disk interface 37 as the transfer source of the code input, it is possible to record a large amount of images stored in a recording medium with a lower unit cost per bit.

After the expansion processing is set in the compression / expansion circuit 211, a decoding start instruction is executed.

The code data is read from the page memory 28 and input to the compression / expansion circuit 211. Then, the compression / expansion circuit 211 decodes the image and outputs the image data to the image area 28 a of the page memory 28.

Next, from the page memory 28 to the printer 15
The operation of printer output to the printer will be described. First, image data is output from the page memory 28 to the printer 15.
The 32-bit image data specified by the address of the page memory 28 generated by the address control circuit 26 is transferred to the data control circuit 27 and then DMA-transferred to the image data interface 210 via the image bus 29.

In a part of the image data interface 210, the number of bits of one pixel for outputting the image data of 32 bits to the printer 15 is 4 bits / pixel or 2 bits.
The image data is converted into t / pixel or 1 bit / pixel, and transferred to the printer 15 through the image processing unit 14.

As described above, the image input operation from the scanner 13 to the page memory 28, the image data compression processing on the page memory 28, the expansion processing of encoded image data to the page memory 28, the page memory 28 A basic operation of a printer output operation to the printer 15 is performed.

Next, electronic sorting will be described with reference to FIG. The electronic sort is to read a plurality of documents to be sorted, temporarily store them in a storage device such as a semiconductor memory or a hard disk or an optical disk, and output an arbitrary number of stored images in an arbitrary order. By doing so, it becomes possible to output the page input later and arrange the page order of the print output, or to output a plurality of copies in the page order. FIG.
Is an example of electronic sorting. When four documents are sequentially input as shown in the figure, in the case of group output, the required number of copies are output in order from the last input document. Since sheets output later are jammed, originals input first are jammed at the top and output.

On the other hand, in the case of sort output, one copy is output in the reverse order of the original input, and this is repeated for the required number of copies.

Before explaining the compression / expansion operation of the present invention, the conventional compression / expansion operation will be described.

FIG. 23 shows the timing of scanner input and encoding processing.

When the scanner 13 and the encoding process proceed at the same time and the scanner 13 finishes the input of the first page, the reading preparation time ta of the next page such as the carriage back of the scanner 13 or the setting of the document by the document feeder is set. rear,
The scanner input of the next page is started, and if there are subsequent pages, the same operation is repeated to store the original image.

FIG. 24A shows the state of the image area 28a of the page memory 28 during scanner input and encoding processing.

The image data written in the image area 28a of the page memory 28 from the scanner 13 is read in the same order as it was written, and the encoding process is performed.

When the scanner input and the encoding process are simultaneously progressed, the writing control from the scanner 13 to the image area 28a of the page memory 28 is controlled so that the reading of the encoding process does not overtake.

FIG. 25 shows the timing of decoding processing and printer output during non-rotational output.

First, the first page is decrypted.

Next, the printer output of the first page and the decoding of the next page are simultaneously performed.

When the output of the first page is completed, the output of the second page is prepared such as taking in the paper, and the output of the second page and the encoding of the third page are started.

FIG. 24B shows the image area 2 of the page memory 28 for the printer output during non-rotational output and the decoding process.
8a is shown.

The page memory in which the image of the first page has already been developed is sequentially read out and output to the printer, and the image data of the decoded next page is written to the empty area already output to the printer 15.

When the printer output and the decoding process are performed simultaneously, the writing of the decoded image data of the next page to the image area 28a of the page memory 28 reads the currently output page to the printer 15. Write control is done so as not to overtake.

FIG. 26 shows the timing of the decoding process and the printer output at the time of rotation output.

First, the first page is decrypted.

Next, the image on the image area 28a of the page memory 28 is read in the rotation direction, and the rotated image data is output to the printer 15.

All the image data for one page is read out in rotation and output to the printer 15, and then the image of the next page is expanded.

FIG. 27A shows how the page memory 28 is decoded into the image area 28a. As shown in the figure, the image is decoded from the upper left to the lower right on the page memory.

FIG. 27 (b) shows a rotation reading of the decoded image data in the image area 28a of the page memory 28.
The state of printer output is shown. In this example, the image data is rotated 90 degrees clockwise, and the image data is read from the lower left to the upper right as shown in the figure.

Since the decoding order of the image writing and the rotational reading in the image area 28a of the page memory 28 is different, the decoding image of the next page cannot be written during the rotational reading, and the decoding of the next page cannot be performed. Printer output was stopped because rotation reading could not be performed until conversion was completed.

Therefore, there is a dead time tp in which no printer output is performed and a dead time td in which no decoding process is performed, resulting in a drop in system performance.

The present invention is intended to shorten the above-mentioned useless time tp and td as much as possible when performing image decoding processing and printer processing using the image area 28a of the page memory 28 for one page. Three ways to improve these are described below.

First, the first method will be described.

In the first method, when rotation is required at the time of output, the image read from the scanner 13 to the image area 28a of the page memory 28 is encoded instead of rotating and reading the decoded image for rotation output. At this time, the image is rotated and read out, and the rotated image is encoded.

Whether to encode only the non-rotated image, only the rotated image, or both the non-rotated image and the rotated image is selected depending on the direction required at the time of printer output.

If we know that only non-rotated images are needed as printer output, only non-rotated images will be encoded. Similarly, if only the rotated output is required, the rotated image is encoded.

Further, when both a non-rotated image and a rotated image are required as printer outputs, for example, when images are alternately output by non-rotated and rotated by groups, the non-rotated image and the rotated image are encoded. Encode both.

FIG. 28 shows the timing of image input of the scanner 13 and encoding of both non-rotated images and rotated images.

First, when the scanner input for the first page is started, the image data read by the scanner 13 is written in the image area 28a of the page memory 28.

At the same time, the encoding process is started and the image data written from the scanner 13 into the image area 28a of the page memory 28 is sequentially encoded.

Since the encoding process is sufficiently faster than the input speed of the scanner 13, the encoding of the same page is completed almost at the same time as the input of the scanner 13 is completed.

The coded data (compressed data of the non-rotated image) as the coded coded output is the page memory 2
8 code area 28b.

When the encoding of the non-rotated image is completed, the image area 28a of the page memory 28 has already been scanned by the scanner 13.
The image written in is read in the rotation direction and the rotated image is encoded.

The coded data (rotated image compressed data) as the coded coded output is the page memory 28.
Is written in another area of the code area 28b.

Since the image data is already in the image area 28a of the page memory 28 at the time of encoding the rotated image, the data from the scanner 13 can be encoded without waiting as in the case of encoding the non-rotated image. I can.

When the input of the first page is completed, the scanner 13 starts the input of the next page after the read preparation time ta of the next page such as the carriage back of the scanner 13 or the setting of the original by the automatic document feeder. Then, if there is a subsequent page, the same operation is repeated to store the encoded data for the original image.

[0225] The image area 28 of the page memory 28 at the time of the above-mentioned scanner input and non-rotated image and rotated image encoding processing.
The state of a will be described step by step.

FIG. 29A shows the scanner input to the image area 28a of the page memory 28 and the reading of the image data to be encoded in the non-rotational direction.

As shown in the figure, the scanner input is the page memory 2
The eight image areas 28a are line-sequentially scanned from the upper left to the lower right in the figure and written in the image area 28a of the page memory 28.

Similarly, the image data to be encoded in the non-rotational direction is read out and the images written by the scanner 13 are sequentially read out and encoded in the same order as the scanner input.

At this time, overtaking prevention control is performed for the reading of the image data to be encoded so that the reading of the image data to be encoded does not overtake the writing position of the scanner 13.

Since the encoding process is sufficiently faster than the input speed of the scanner 13, the encoding process catches up with the scanner input and waits for the next image data to be written from the scanner 13 by the overtaking prevention control.

Therefore, the scanner input for one page and the read-out encoding process for the same image are completed almost at the same time.

FIG. 29B shows reading of image data to be encoded in the rotation direction of the image area 28a of the page memory 28.

In the figure, by reading from the lower left to the upper right, 90-degree rotation reading is performed clockwise.

Therefore, the image data to be encoded is shown in FIG. 29 (c) for non-rotational reading and FIG. 29 for rotation reading.
(D).

Next, the output operation of decoding and printing the image (coded data) stored in the code area 28b of the page memory 28 in the desired order by the above-described coding process will be described.

Since the selection of rotation and non-rotation of the output image can be switched by decoding the image encoded in the direction necessary for the output image, the operation timing is the same as the conventional decoding process at the time of non-rotation output. It becomes the same as the printer output (FIG. 25).

Therefore, even when the rotated image is output, the continuous processing can be performed as in the case where the non-rotated image is output, and the processing speed can be improved.

The state of the image area 28a of the page memory 28 for the above printer output and decoding processing is also the same as the conventional decoding processing and printer output for non-rotational output ((b) in FIG. 24).

Even in the case of decoding and outputting the rotated image, the operation is the same only by using the image area 28a of the page memory 28 as a horizontally placed image.

Next, the second method will be described.

In the second method, the encoding is performed in the non-rotational direction at the same time as the scanner input, and the output image is rotated by reading the decoded image in the non-rotational direction in the rotational direction and outputting to the printer. .

Conventionally, the image area 28a of the page memory 28 is used.
While the decoded image of the next page was not written during the rotation reading of the above, the present invention does not wait for the end of the rotation reading for one page, and is already read to the printer 15 by the rotation reading. By partially writing the decoded data of the next page to the area, the rotational output of the current page and the decoding processing of the next page are simultaneously progressed to improve the processing speed.

Since the scanner input / encoding process and the non-rotating printer output / decoding process are the same as the conventional ones, the rotating printer output / decoding process having different operations will be described in detail.

FIG. 30 shows the operation timing of the rotary printer output and decoding processing.

First, the decrypted data for the entire surface of the image on the first page is written in the image area 28a of the page memory 28.

Next, the image area 28a of the page memory 28 is read out in rotation, and the rotary printer output is started.
In this example, since the decoded image data is rotated 90 degrees clockwise in the image area 28a of the page memory 28, it is rotated and output from the left half side of the image area 28a of the page memory 28.

When the entire left half on the image area 28a of the page memory 28 has been read, the left half of the second page is already read and the decoded data is written in the empty area.

Further, the printer 15 has the page memory 28.
2 when the right half of the image area 28a of
The right half of the page is read and the decoded data is written in the empty area.

When the output of the first page is completed, the printer 15 starts the output of the second page after the preparation for the output of the next page such as the taking in of the paper is completed.

The state of the image area 28a of the page memory 28 at the time of the above decoding process and output from the rotary printer will be described step by step.

FIG. 31A shows a state in which the decoded data of the entire surface of the image on the first page has been written.

Next, the image area 28a of the page memory 28 is read out in rotation and the output to the rotary printer is started.
In this example, since the decoded image data is rotated 90 degrees clockwise in the image area 28a of the page memory 28, the reading is performed from the lower left to the upper right in the figure.

FIG. 31B shows a state in which the left half rotation reading of the image area 28a of the page memory 28 has been completed.

At this point, the left half of the image area 28a of the page memory 28 is an empty area that has already been read by the printer 15, so the image of the next page (see the figure) is added to this left half area. In the example, the decrypted data is written in the left half of the character F).

At this time, partial (left half in the example of the figure) decoding of the image of the next page and writing to the image area 28a of the page memory 28 are required, but the code data itself covers the entire image. Since it is obtained by encoding, partial writing can be performed using the following method.

[0256] If the coding method and apparatus are such that the decoding of only the part required when decoding the entire coded data into the original image can be specified, only the required part is decoded and the page memory 28 Write in the image area 28a.

If partial decoding is not possible when decoding the coded data of the entire surface into the original image, after performing a process of cutting out only a necessary portion from the decoded entire image. Write to the image area 28a of the page memory 28. Alternatively, the entire image is written in the image area 28a of the page memory 28, but the data in the image area 28a of the page memory 28 is not rewritten except for the area where writing is required. There is a method of setting the image area 28a.

For example, as a process of cutting out only a necessary part from the decoded whole image, as shown in FIG. 36, a cutout part 215 is provided between the compression / expansion circuit 211 and the image bus 29. In accordance with an instruction from the system control circuit 21, the cutout unit 215 selectively cuts out the left half, the right half, and the entire decoded data for each line expanded by the compression / expansion circuit 211. good.

In FIG. 31 (c), the output of the right half of the first page and the writing of the decoded data of the left half of the second page are completed,
It shows a state in which the left half of the second page is about to start rotational printing.

At this time, since the rotation reading is completed in the right half of the first page, the writing of the decoded data to the right half of the second page is in progress.

FIG. 31 (d) shows a state in which the rotational reading of the left half of the second page has been completed.

In the example shown in the figure, writing of the decoded data in the left half of the third page is about to be started.

After that, if there is a subsequent page, the same operation is repeated.

In this way, it is possible to perform continuous rotation print output in the same manner as non-rotation print output using the image area 28a of the page memory 28 for one page.

Next, the third method will be described.

In the third method, when rotation printer output is required, the image is divided at the time of encoding and a plurality of regions are simultaneously encoded and accumulated in order to continuously perform the rotation output at the time of output.

Therefore, when it is known that a non-rotating printer output will be obtained, the encoding process is performed without dividing the image as in the conventional case by treating the entire surface of one page as one image.

The rotation of the output image is performed by reading the image decoded in the non-rotational direction in the rotational direction and outputting it to the printer as in the second method.

Conventionally, the image area 28a of the page memory 28 is used.
During the rotation reading of, the decoded image of the next page was not written.

On the other hand, according to the present invention, the decoding of the partial next page divided at the time of encoding into the empty area which has already been read by the printer 15 in the rotation direction is not waited for until the end of the rotation reading for one page. I am writing a ghost image.

As a result, the rotation output of the current page and the decoding process of the next page are simultaneously advanced to improve the processing speed.

FIG. 32 shows the timing of image input of the scanner 13 and simultaneous encoding of the left and right halves of the input image.

The scanner input and the encoding process proceed simultaneously, and the image area 28 of the page memory 28 is read from the scanner 13.
The image data written in a is independently read out in the left half and the right half and encoded respectively.

Further, when the respective encoding processes are simultaneously advanced, the reading control is performed so that the reading of the respective encoding processes does not overtake the writing from the scanner 13 to the image area 28a of the page memory 28.

The state of the image area 28a of the page memory 28 during the above scanner input and encoding processing will be described step by step.

FIG. 33A shows the scanner input to the image area 28a of the page memory 28 and the coded reading of the left and right areas.

As shown in the figure, the scanner input is page memory 2
The eight image areas 28a are line-sequentially scanned from the upper left to the lower right in the figure and written in the image area 28a of the page memory 28.

In the encoding process, the image data written by the scanner 13 is sequentially encoded in each of the left and right areas.

At this time, the reading of the encoding is performed by the scanner 13
In order to prevent the overwriting of the writing position, the overtaking prevention control is performed for the coded reading.

Since the encoding process is sufficiently faster than the input speed of the scanner 13, each encoding process catches up with the scanner input and waits for the next image data to be written from the scanner 13 by the overtaking prevention control.

Therefore, the scanner input for one page and the read-out encoding process for the same image are completed almost at the same time.

At this time, the images coded by the respective coding processes are shown in FIGS. 33 (b) and 33 (c).

If there is a succeeding document, it is similarly divided into left and right regions, subjected to coding processing, accumulated as a code, and repeated.

Next, the output operation for decoding the images accumulated by the above-described encoding processing in the desired order, outputting them to the non-rotating printer and outputting them to the rotating printer will be described.

FIG. 34 shows the timing of the decoding processing of the divided coded image and the output of the non-rotating printer.

First, the left half and the right half of the first page are each decoded prior to the printer output.

When the decoding of the entire first page is completed, the printer output is started and the decoding of the second page is proceeded at the same time.

In the decoding of the second page, the empty area read by the printer output is decrypted and written in the empty areas of the left half and the right half by each decoding process.

Since the decoding process is sufficiently faster than the reading of the printer output, the decoding of the second page is completed almost at the same time as the output of the first page is completed.

Thereafter, the same operation for the necessary pages is repeated.

FIG. 35 (a) shows the state of the image area 28a of the page memory 28 at the time of the printer output of the first page and the decoding processing of the split-coded image of the second page.

FIG. 35B shows a state in which the printer output of the first page and the decoding of the second page have further advanced.

Since the decoding process is sufficiently faster than the reading of the printer output, the writing of the image of the decoding process catches up with the reading of the image of the printer output, so the writing of the decoding process does not overtake the reading of the printer output. Preventive control is being performed.

Method 2 is the timing of the decoding processing of the image which is divided into the left half and the right half and the output of the rotary printer.
(FIG. 30).

First, when the left half and the right half of the first page are decoded and the entire surface of the first page is decoded, the rotation reading printer output is started.

Every time one half of the image area 28a of the page memory 28 is read, one half of the next page is decoded and written into the image area 28a of the page memory 28 for the already read empty area.

After that, if there is a subsequent page, the same operation is repeated.

In this way, it is possible to perform continuous rotation print output in the same manner as non-rotation print output using the image area 28a of the page memory 28 for one page.

The difference from the method 2 in the rotation output operation is that each of the left and right regions is encoded at the time of encoding, and the region (left side or right side) required for decoding at the time of rotation output. Page memory 2
8 image areas 28a are being written.

The three methods for continuously obtaining the rotated output image by using the image area 28a of the page memory 28 for one page have been described above, but the scanner input and encoding necessary for performing these are described. The overtaking prevention control at the time of transfer for simultaneously advancing the processing, the printer output and the decoding processing will be described.

First, from the scanner 13 to the page memory 28.
The overtaking prevention control of writing the image data to the image area 28a and encoding and reading the written image data will be described.

Image area 2 of page memory 28 at this time
The state of 8a is shown in FIG.

The number of transfers from the scanner 13 to the image area 28a of the page memory 28 and the number of encoded read transfers are counted by the respective transfer word number counters 932. The transfer numbers of the two are compared by a transfer number comparison 933, and when the comparison results are equal, the coded reading is prohibited.
By doing so, it is not possible to encode more image data than that input from the scanner 13, and it is possible to prevent overtaking.

As another method, there is a method of comparing the write address and the read address to the image area 28a of the page memory 28.

Writing and reading to and from the image area 28a of the page memory 28 are performed in the image area 2 of the page memory 28.
On the physical address of 8a, since it is performed for one-dimensional continuous addresses, the relationship between each transfer number and the physical address is equivalent. In other words, having the same number of transfers is equivalent to accessing the same address.

Therefore, it is possible to prevent overtaking by comparing the coded read address and the write address of the scanner 13 and prohibiting the coded read when these are equal.

Next, the control for preventing the decoding writing of the next page from overtaking the printer output reading at the time of non-rotation output will be described.

Image area 2 of page memory 28 at this time
The state of 8a is shown in FIG.

Similar to the case of encoding, the number of transfer words for printer output reading and decoding writing is counted, and if they become equal, decoding writing is prohibited, or the reading address and writing of the image area 28a of the page memory 28 are performed. It is possible to prevent overtaking by comparing addresses and prohibiting writing when they are equal.

Next, the control for preventing the reading of the printer output during continuous rotation output from being overtaken by the writing by the decoding of the next page will be described.

Image area 2 of page memory 28 at this time
The state of 8a is shown in FIG.

First, as the transfer number of the rotational reading to the printer 15, half the transfer number of one page is set in the transfer word number counter 932, and when the transfer number is reached, the system C
An interrupt is generated for PU11.

When the rotation reading is started and the left half rotation output is completed, an interrupt is generated to the system CPU 11.

With this as a trigger, writing for decoding of the left half of the next page is started.

Since the area has already been read, it does not affect the right half image data being currently output.

When the rotation output of the entire one page, that is, the output of the remaining right half is completed, the writing for the decoding of the right half of the next page is started.

Next, the control for preventing the read of the encoded data of the left and right regions from overwriting the write from the scanner 13 to the image region 28a of the page memory 28 will be described.

Image area 2 of page memory 28 at this time
The state of 8a is shown in FIG.

The left and right areas are divided so that the transfer amount increases.

Therefore, the transfer number for reading the encoded data in each area is 1 of the write transfer number for the scanner 13.
It may be controlled so as not to exceed / 2.

Therefore, when comparing the write transfer number of the scanner 13 and the read transfer number of the encoded data, the transfer number of the encoded data is set to double, and when the transfer numbers become equal, the read of the encoded data is performed. Prohibition prevents overtaking.

The image area 28a of the page memory 28
The overwriting is prevented by comparing the scanner write address with the read address of the encoded data and prohibiting the read of the encoded data when the read address becomes equal to or more than the write address.

Finally, the control for preventing the printer output reading when non-rotationally outputting the divided and encoded images in the left and right areas from being overtaken by the writing of the decoded data of the next page will be described.

Image area 2 of page memory 28 at this time
The state of 8a is shown in FIG.

The left and right areas are divided so that the transfer amount increases.

Therefore, it is sufficient to control so that the transfer number of writing the decrypted data in each area does not exceed 1/2 of the transfer number of the printer reading.

Therefore, when comparing the respective numbers of transfers, the number of transfers of the decoded data is set to double, and when the numbers of transfers become equal, the reading of the encoded data is prohibited to prevent overtaking.

The image area 28a of the page memory 28
The passing address is prevented by comparing the write address of the decrypted data and the read output address of the printer and prohibiting the decrypted write when the write address becomes equal to or more than the read address.

As described above, the non-rotated image and the rotated image are coded / stored when the scanner is input, and the image in the required direction is decoded when the image is output. It is designed such that it is non-rotationally encoded / stored at the time of scanner input, and partially decoded in a vacant area generated at the time of rotation output. The image is divided and encoded / stored in the main scanning direction at the time of scanner input, and is decoded if a vacant area for the divided area is generated at the time of rotation output.

As a result, in the electronic sort of the digital copying machine, it is possible to continuously process the scanner input, the encoding, the decoding, and the rotation / non-rotation printer output in the image memory of the page memory of the single page.

[0331]

As described above in detail, according to the present invention, an image capable of continuously processing read input, encoding, decoding, and rotated / non-rotated image forming output in an image memory for one page. A forming device can be provided.

[Brief description of drawings]

FIG. 1 is a sectional view showing a schematic configuration of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is an overall block diagram illustrating a control circuit of the image forming apparatus.

FIG. 3 is a block diagram showing a configuration of a basic unit.

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

FIG. 5 is a block diagram showing a configuration of a system extension unit.

FIG. 6 is a block diagram illustrating a configuration of an image processing circuit.

FIG. 7 is a block diagram showing the configuration of a system control circuit.

FIG. 8 is a block diagram showing a configuration of a communication memory access control circuit.

FIG. 9 is a block diagram showing a configuration of a page memory access control circuit.

FIG. 10 is a block diagram showing the configuration of an address control circuit.

FIG. 11 is a block diagram showing a configuration of an address generation unit.

FIG. 12 is a diagram showing an example of an address generation direction of an address generation unit.

FIG. 13 is a diagram showing a configuration of a FIFO address generator.

FIG. 14 is a diagram showing the concept of two-dimensional access to a page memory.

FIG. 15 is a diagram showing a two-dimensional access to a page memory by a linear address.

FIG. 16 is a block diagram showing the configuration of a data control circuit.

FIG. 17 is a block diagram showing the configuration of an image data transfer control unit.

FIG. 18 is a diagram showing a configuration of a timer.

FIG. 19 is a block diagram showing a detailed configuration of an image bus priority control unit.

FIG. 20 is a block diagram showing a detailed configuration of a page memory priority control unit.

FIG. 21 is a diagram showing a detailed configuration of a terminal counter.

FIG. 22 is a diagram showing an example of electronic sorting.

FIG. 23 is a diagram showing the timing of conventional scanner input and encoding processing.

FIG. 24 is a diagram illustrating access to a page memory.

FIG. 25 is a diagram showing the timing of conventional non-rotating printer output and decoding processing.

FIG. 26 is a diagram showing timing of conventional rotary printer output and decoding processing.

FIG. 27 is a diagram illustrating access to a page memory.

FIG. 28 is a diagram showing the timing of scanner input and encoding processing.

FIG. 29 is a diagram illustrating access to a page memory.

FIG. 30 is a diagram showing the timing of rotary printer output and decoding processing.

FIG. 31 is a diagram illustrating access to a page memory.

FIG. 32 is a diagram showing the timing of scanner input and encoding processing.

FIG. 33 is a diagram illustrating access to a page memory.

FIG. 34 is a diagram showing the timing of non-rotating printer output and decoding processing.

FIG. 35 is a diagram illustrating access to a page memory.

FIG. 36 is a block diagram showing the configuration of a system basic unit.

[Explanation of symbols]

 11 ... System CPU 13 ... Scanner 14 ... Image processing circuit 15 ... Printer 28 ... Page memory 28a ... Image area 28b ... Code area 211 ... Compression / expansion circuit

Claims (9)

[Claims] 1. A reading unit for reading image data of an original, a first storage unit for storing the image data read by the reading unit in an image memory for storing image data for one page, and the first storage. First reading means for reading the image data stored in the image memory by the means in the non-rotating direction and the rotating direction, and the non-rotating direction image data and the rotating direction image data read by the first reading means. Coding means for respectively coding, and second storage means for respectively storing the code data in the non-rotational direction and the rotation direction coded by the coding means in a code memory for storing coded data for a plurality of pages, Decoding means for selectively decoding the non-rotating direction or rotating direction code data stored in the code memory by the second storage means into image data, and this decoding Third storage means for storing in the image memory the image data in the non-rotational direction or the rotation direction decoded by the encoding means, and the image in the non-rotational direction or the rotation direction stored in the image memory by the third storage means. A second reading unit for reading data; and an image forming unit for forming an image on an image forming medium using the image data in the non-rotating direction or the rotating direction read by the second reading unit. Then, after the image data stored in the image memory is read in the non-rotational direction by the first reading means and encoded by the encoding means, the image data stored in the image memory is rotated in the rotational direction by the first reading means. An image forming apparatus, which is read and encoded by an encoding unit. 2. A reading unit for reading image data of a document, a first storage unit for storing the image data read by the reading unit in an image memory for storing image data for one page, and the first storage. First reading means for reading the image data stored in the image memory by the means in the non-rotating direction and the rotating direction, and the non-rotating direction image data and the rotating direction image data read by the first reading means. Coding means for respectively coding, and second storage means for respectively storing the code data in the non-rotational direction and the rotation direction coded by the coding means in a code memory for storing coded data for a plurality of pages, Decoding means for selectively decoding the non-rotating direction or rotating direction code data stored in the code memory by the second storage means into image data, and this decoding Third storage means for storing in the image memory the image data in the non-rotational direction or the rotation direction decoded by the encoding means, and the image in the non-rotational direction or the rotation direction stored in the image memory by the third storage means. A second reading unit for reading data; and an image forming unit for forming an image on an image forming medium using the image data in the non-rotating direction or the rotating direction read by the second reading unit. Then, the image data stored in the image memory by the first storage means and the image data stored in the image memory by the first reading means in the non-rotational direction are simultaneously read and stored in the image memory. The read image data is read in the non-rotational direction by the first reading means and coded by the coding means,
An image forming apparatus characterized in that image data stored in an image memory is read in a rotational direction by a first reading means and encoded by an encoding means. 3. A reading unit for reading image data of a document, a first storage unit for storing the image data read by the reading unit in an image memory for storing image data for one page, and the first storage. First reading means for reading the image data stored in the image memory by the means in the non-rotating direction and the rotating direction, and the non-rotating direction image data and the rotating direction image data read by the first reading means. Coding means for respectively coding, and second storage means for respectively storing the code data in the non-rotational direction and the rotation direction coded by the coding means in a code memory for storing coded data for a plurality of pages, Decoding means for selectively decoding the non-rotating direction or rotating direction code data stored in the code memory by the second storage means into image data, and this decoding Third storage means for storing in the image memory the image data in the non-rotational direction or the rotation direction decoded by the encoding means, and the image in the non-rotational direction or the rotation direction stored in the image memory by the third storage means. A second reading unit for reading data; and an image forming unit for forming an image on an image forming medium using the image data in the non-rotating direction or the rotating direction read by the second reading unit. The storage of the image data in the image memory by the first storage means and the reading of the image data stored in the image memory by the first reading means in the non-rotational direction are performed by the image memory by the first reading means. Are controlled so that the number of data transfers from the first storage means does not exceed the number of data transfers to the image memory by the first storage means. Read out in the non-rotating direction by the reading means and encoded by the encoding means, and then the image data stored in the image memory is read in the rotating direction by the first reading means and encoded by the encoding means. Image forming apparatus. 4. A reading unit for reading image data of a document, a first storage unit for storing the image data read by the reading unit in an image memory for storing image data of one page, and the first storage. First reading means for reading the image data stored in the image memory by the means in the non-rotating direction and the rotating direction, and the non-rotating direction image data and the rotating direction image data read by the first reading means. Coding means for respectively coding, and second storage means for respectively storing the code data in the non-rotational direction and the rotation direction coded by the coding means in a code memory for storing coded data for a plurality of pages, Decoding means for selectively decoding the non-rotating direction or rotating direction code data stored in the code memory by the second storage means into image data, and this decoding Third storage means for storing in the image memory the image data in the non-rotational direction or the rotation direction decoded by the encoding means, and the image in the non-rotational direction or the rotation direction stored in the image memory by the third storage means. A second reading unit for reading data; and an image forming unit for forming an image on an image forming medium using the image data in the non-rotating direction or the rotating direction read by the second reading unit. However, the storage of the image data in the image memory by the first storage means and the reading of the image data stored in the image memory by the first reading means in the non-rotational direction are the read addresses by the first reading means. Are controlled so as to be less than the storage address of the first storage means, and the image data stored in the image memory is read in the non-rotational direction by the first reading means. The image forming apparatus is characterized in that the image data stored in the image memory is read in the rotational direction by the first reading unit and encoded by the encoding unit after being encoded by the encoding unit. 5. A reading unit for reading image data of a document, a first storage unit for storing the image data read by the reading unit in an image memory for storing image data for one page, and the first storage. First reading means for reading the image data stored in the image memory by the means, encoding means for encoding the image data read by the first reading means, and encoding means for encoding the image data. Second storage means for storing the code data in a code memory for storing code data for a plurality of pages; and decoding means for decoding the code data stored in the code memory by the second storage means into image data. Third storage means for dividing the image data decoded by the decoding means and storing the divided image data in an image memory, and an image divided and stored in the image memory by the third storage means Second reading means for selectively reading the data in the non-rotating direction or the rotating direction, and the image data in the non-rotating direction or the rotating direction read by the second reading means on the image forming medium. Image forming means for forming an image, storing the decoded image data in one divided area of the image memory by the third storage means, and the other divided area of the image memory by the second reading means. An image forming apparatus characterized in that the image data stored in the memory is simultaneously read in the rotation direction. 6. A reading unit for reading image data of a document, a first storage unit for storing the image data read by the reading unit in an image memory for storing image data for one page, and the first storage. First reading means for reading the image data stored in the image memory by dividing the image data into a plurality of areas, and encoding the image data divided into the plurality of areas read by the first reading means. Encoding means, second storage means for storing the code data corresponding to the plurality of areas encoded by the encoding means in the code memory for storing the code data for a plurality of pages, and the second storage. Decoding means for decoding the code data corresponding to the plurality of areas stored in the code memory by the means into image data, and the image data corresponding to the plurality of areas decoded by the decoding means. Third storage means for dividing the image data into the image memory and storing the image data corresponding to a plurality of areas divided and stored in the image memory by the third storage means in a non-rotational direction or rotation. Direction reading means, and image forming means for forming an image on an image forming medium using the image data in the non-rotating direction or the rotating direction read by the second reading means. Then, the divided storage of the decoded image data corresponding to one area in the image memory by the third storage means and the rotation of the image data corresponding to the other area stored in the image memory by the second reading means. An image forming apparatus in which readings in the same direction are performed simultaneously. 7. A bit image image read from a document, the read bit image image is stored in an image area for one page of a page memory, and the bit image image stored in this image area is compressed to be stored in a page memory. The compressed image stored in the code area is decompressed into a bit image image and stored in the image area, and an image is formed on the image forming medium using the bit image image stored in the image area. In the image forming apparatus, when the bit image image stored in the image area is compressed and stored in the code area of the page memory, the bit image image stored in the image area is read out without being rotated and compressed. The bit image image stored in the image area is rotated and read out and compressed. Storage means for storing in another area of the code area of the page memory, and reading means for selectively reading the non-rotated compressed image or the rotated compressed image stored in the code area by the storage means, A non-rotated compressed image or a rotated compressed image read by the reading means is expanded into a bit image image and stored in an image area, and the bit image image stored in this image area is used to form an image forming medium. An image forming apparatus comprising: an image forming unit that forms an image on the image forming apparatus. 8. A bit image image from a document is read, the read bit image image is stored in an image area for one page of a page memory, and the bit image image stored in this image area is compressed to be stored in a page memory. The compressed image stored in the code area is decompressed into a bit image image and stored in the image area, and an image is formed on the image forming medium using the bit image image stored in the image area. In the image forming apparatus, the compressed image stored in the code area is expanded into a bit image and stored in a partial area of the image area, and is expanded outside the partial area of the image area. The bit image image is read in the rotation direction at the same time, and the read rotated bit image image is used to print on the image forming medium. Image forming apparatus and performs image formation. 9. A bit image image read from an original, the read bit image image is stored in an image area of one page of a page memory, and the bit image image stored in this image area is compressed to be stored in a page memory. The compressed image stored in the code area is decompressed into a bit image image and stored in the image area, and an image is formed on the image forming medium using the bit image image stored in the image area. In the image forming apparatus, when the bit image image stored in the image area is compressed and stored in the code area of the page memory, the bit image image is divided into a part of the image area and a part outside the area. Is stored in the code area of the page memory as two compressed images, and one pressure is applied to one image stored in the code area. A second storage unit that expands the image and the other compressed image into bit image images and stores them in a partial area of the image area and outside the partial area, and the second storage unit stores one of the image areas. Rotation of a decompressed bit image image stored in a part of the image area or in a part of the image area when the bit image image is stored in a partial area or a partial area A reading means for simultaneously performing reading in the direction, and an image forming means for forming an image on an image forming medium using the rotated bit image image read by the reading means. Image forming apparatus.