JP3155789B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to an image forming apparatus including a compression unit, a storage unit, and a reproduction unit for image information.

[0002]

2. Description of the Related Art FIG. 33 is a block diagram of a main part of a conventional image forming apparatus. An image reading unit 901 is a photoelectric conversion element
Signal amplification, black level correction, shading correction, and A / D of document information (analog signal) read by (CCD) etc.
The image processing unit 902 performs the conversion.
This block performs gamma correction, MTF correction, main scanning, electric scaling, and the like on the D-converted digital signal. Also, the image data output from the image processing unit 902 may be 1-bit binary data or 4-bit multi-valued data. The memory 903 employs a configuration using an image frame memory, and has an image control circuit of an electric control unit (not shown), that is, an editing function such as trimming, masking, white / black inversion, and mirroring which are generally required. It is connected as an image memory unit to the image control circuit. This memory 9
Use of No. 03 is to input the data after image processing to the memory once, and to output images without outputting the image multiple times by the scanner when outputting a plurality of images, to obtain an image without deterioration in image quality Can be. The data stored in the memory 903 is output to the image output unit 904 to perform image formation and the like.

FIG. 34 is a block diagram of a main part of another conventional image forming apparatus. This is different from the above conventional example in that the connection between the memory block 906 and the image processing block 907 is switched. This is the memory block 906
After inputting the data after A / D conversion (for example, 6-bit data), the image data is read from the memory block 906 when a plurality of output data is desired as described above,
Thereafter, the image processing is performed. Therefore, by storing the data after A / D conversion in the memory block 906, it is possible to change the IPU parameters without scanning many times, such as when it is desired to change the image quality of a desired copy for the same original. .

However, in the former conventional example, for example, in the case of multi-value processing, 4 bits are required, and therefore 297 mm × 15.7.
Book × 420mm × 15.7 book × 4bit ≒ 16Mbyte
In the latter conventional example, for example, when the data after A / D conversion is 6 bits, the read A3 size is converted into 400 dpi, and 297
mm × 15.7 pcs × 420mm × 15.7 pcs × 6bit
A memory capacity of $ 24 Mbytes is required. Therefore, both have the disadvantage that a large capacity memory is required and the cost is increased. Therefore, an image forming apparatus capable of avoiding an increase in memory capacity has been developed at present.

FIG. 35 is a block diagram of a main part of a conventional image forming apparatus which avoids an increase in memory capacity. This is, for example, a binary compression block 9 for compressing document information read by an image reading unit (not shown) at a stage preceding the memory block 911.
10 and a binary expansion block 512 for expanding the compressed document information at the subsequent stage. As a binary compression method by the binary compression block 910, MH, MR, MMR, or the like, which is an existing technology, is adopted.

[0006]

However, even in the image forming apparatus having the above-described conventional binary compression block 910 and binary expansion block 912, if the number of originals exceeds a predetermined number, the memory capacity naturally becomes insufficient. The copying operation may be interrupted on the way. Further, when copying a plurality of originals while compressing the same, all the originals are uniformly compressed at a predetermined compression ratio, so that an original requiring high image quality is copied at a lower resolution. Further, when it is impossible to store the document information of all the documents in the memory, the user cannot be informed of this.

[0007] The present invention has been made in view of such a problem, it will document quality is required in multi Utsushichu is to be able to prevent deterioration in the image quality by reducing the compression ratio was the first object, a second object thereof is to be informed this to the user when the memory capacity by increasing changing the compression ratio of the original information is insufficient.

[0008]

[0009]

A first object of the present invention is to provide a circulating document conveying means capable of repeatedly circulating a bundle of documents one by one on a contact glass and feeding paper, and a reading means for reading image information of a document. An image forming apparatus including at least compression means for compressing the read image information, storage means for storing the compressed image information, and decompression means for decompressing the stored image information; input means that can be specified for the operation unit page to be copied in the image quality mode, the and a comparative determination unit for comparing and judging the page of the page entered conveyed document to the contact on the glass by the input means 1 This is achieved by the following means. In addition,
A second means for controlling a compression ratio of image information to be reduced when a page inputted by the input means coincides with a page of a document conveyed onto the contact glass; It is also achieved by means.

A second object of the present invention is to provide a circulating document conveying means capable of repeatedly circulating a document bundle one by one on a contact glass and feeding the sheet, reading means for reading image information of the document, and reading the read image information. A compression unit for compressing the compressed image information, a storage unit for storing the compressed image information, and an expansion unit for expanding the compressed and stored image information. Determining means for determining, changing means for changing the compression ratio of the image information based on the determination result of the determining means, detecting means for detecting that the compression ratio of the image information has reached a predetermined value, compression ratio is achieved by the third means and a display means for displaying to the user that has reached a predetermined value. Further, in the third means, when the image information exceeds the storage capacity of the storage means even if the compression ratio is changed, the control is performed such that the display is displayed on the display means so as to divide the original and perform a copying operation. This is also achieved by a fourth means provided with means.

[0011]

[0012]

According to the first means, for example, when the document is sequentially paper feed on the contact glass, and a page of the document fed onto the page and the contact glass comparative determination unit is input by the input means By comparing and determining, it is determined whether or not the document fed onto the contact glass is a document requiring the high image quality mode. Thus, when it is determined that the document fed onto the contact glass is a document requiring the high image quality mode, the compression ratio of the document can be changed to a low value. Can be prevented from deteriorating the image quality at the time of copying a document requiring the following. According to the second means, when the page inputted by the input means coincides with the page of the document fed onto the contact glass, the control means activates the changing means to automatically reduce the compression ratio of the image information. Therefore, it is possible to automatically avoid deterioration in image quality when copying a document requiring high image quality while continuously feeding many documents.

According to the third means, when the image information read from the document is compressed and stored in the storage means, when the determination means determines that the storage capacity of the storage means is insufficient, for example, The means changes to increase the compression ratio of the image information, and the detecting means detects the current compression ratio. Here, when it is detected that the compression ratio of the image information has reached the predetermined value, the fact that the compression ratio of the image information has reached the predetermined value is displayed to the user via the display means. This allows the user to know that the storage capacity of the storage unit may be insufficient when copying the document bundle. According to the fourth means, when a series of image information exceeds the storage capacity of the storage means even if the compression ratio of the image information is changed once the storage capacity of the storage means is insufficient, the document is divided by the control means. Is displayed to the user via the display means to perform the copying operation, so that the user can be surely informed that the storage capacity of the storage means has run short. You can know if you should do the work.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a configuration diagram of the entire digital copying machine according to the embodiment of the present invention. First, a schematic configuration of the digital copying machine according to the present embodiment will be described with reference to FIG. As shown in the figure, the digital copying machine has four units: a copying machine main unit (I), an automatic document circulating and feeding device [RDH] (II), a sorter (III), and a duplex reversing unit (IV), and further a transmission. It comprises a control unit, an image scanner unit, and an image compression storage / reproduction unit.

The copying machine main body (I) includes a scanner section, a writing section, a photoconductor section, a developing section, a paper feeding section, and the like. Next, the configuration and operation of each unit will be described.

[Scanner Unit] A first scanner equipped with a reflecting mirror 1, a light source 3, and a first mirror 2 and moved at a constant speed, and a second mirror 4 and a third mirror 5 are mounted on the first scanner. A second scanner that moves following the first scanner at half the speed of the scanner. An original on the contact glass 9 by the first scanner and the second scanner
(Not shown) is optically scanned, and the reflected image is guided to a lens 7 via a color filter 6 to be formed on a one-dimensional solid-state imaging device 8. A fluorescent lamp, a halogen lamp, or the like is used as the light source 3, and a fluorescent lamp is generally used because the wavelength is stable and the life is long. In this embodiment, the reflecting mirror 1 is attached to one light source 3.
Two or more light sources 3 may be used. Since the solid-state imaging device 8 has a constant sampling clock, the fluorescent lamp has an adverse effect on the image unless it is turned on at a higher frequency. As the solid-state imaging device 8, a CCD is generally used. Since the image signal read by the solid-state imaging device 8 is an analog value, the analog / digital (A
/ D) Converted and various image processing on the image processing board 10
(Binarization, multi-level gradation processing, scaling processing, editing, etc.), and converted into a digital signal as a set of spots.
In this embodiment, in order to obtain color image information, a color filter 6 that transmits only necessary color information is disposed in the middle of the optical path guided from the document to the solid-state imaging device 8 so as to be able to enter and exit. The color filter 6 is moved in and out in accordance with the scanning of the original, and each time the functions such as multiple transfer and double-sided copy are operated, various kinds of copies can be created.

[Write Unit] The image information after image processing is
The light is written on the photosensitive drum 40 in the form of a set of light points by raster scanning of laser light in the optical writing unit. FIG. 3 is a plan view showing the writing section, and FIG. 4 is a side view thereof. The laser light emitted from the semiconductor laser 20 is collimated by the collimating lens 2.
The light beam is changed to a parallel light beam by 1 and is shaped into a light beam of a predetermined shape by the aperture 32. The shaped laser beam is the first
The light enters the polygon mirror 24 in a form compressed in the sub-scanning direction by the cylinder lens 22. The polygon mirror 24 has an accurate polygon, and is rotated by a polygon motor 25 at a constant speed in a constant direction. This rotation speed is determined by the rotation speed of the photosensitive drum 40, the writing density, and the number of surfaces of the polygon mirror 24. Polygon mirror 2
The reflected light of the laser light incident on 4 is deflected by the rotation of the polygon mirror 24. The deflected laser light is f
sequentially enter the θ lenses 26a and 26b. fθ lens 2
Reference numerals 6a and 26b denote scanning light beams having a constant angular velocity,
An image is formed so as to be a minimum light spot on the top, and a surface tilt correction mechanism is also provided. The laser light that has passed through the fθ lenses 26a and 26b is guided outside the image area by the synchronization detection mirror 29 to the synchronization detection light input section 30, and is propagated to the sensor section by an optical fiber, and a synchronization signal for generating a cue signal in the main scanning direction is generated. One line of image data is output after a certain time from the output, and one image is formed by repeating this process.

[Photosensitive Part] A sightseeing layer is formed on the peripheral surface of the photosensitive drum 40. Semiconductor laser (wavelength 780mm)
Organic photoreceptor (OPC) as a tourist layer sensitive to
a-Si, Se-Te and the like are known, and the organic photoconductor (OPC) is used in this embodiment. Generally, in the case of laser writing, a negative / positive (N
/ P) process and a positive / positive (P /
P) process, and in this embodiment, the former N /
The P process is adopted. The charging charger 41 is a scorotron type having a grid on the photoconductor side.
The surface of the photoreceptor drum 40 is uniformly (-) charged, and the image forming section is irradiated with laser light to lower the potential of the portion. Then, the background portion on the surface of the photoconductor drum 40 becomes −750 to −80.
At 0 V, the potential of the image portion becomes about -500 V, and an electrostatic latent image is formed on the surface of the photosensitive drum 40. This is applied to the developing roller by the developing devices 42a and 42b at -500 to -600V.
And a charged toner is attached to (−) to visualize the electrostatic latent image.

[Developing Unit] The apparatus of the present embodiment includes a main developing unit 4
2a and a sub-developing device 42b. In the case of a single black color, the sub-developing device 42b and the toner replenishing device 43b are detached. In the present embodiment having two developing units, the toner replenishing unit 43 paired with the main developing unit 42a
a into the toner supply unit 43b, which is paired with the sub-developing unit 42b.
During the development of a color, the development is selectively performed by changing the position of the main pole of the developing device of another color. This development can be combined with the reading of color information by switching the color filter 6 of the scanner, the multiple transfer of the feeding / conveying system, and the double-sided copying function to perform multifunctional color copying and color editing. For the development of three or more colors, there is a method of arranging three or more developing devices around the photosensitive drum 40, or a revolver method of rotating and switching the three or more developing devices. The images visualized by the developing devices 42a and 42b are transferred to the paper surface synchronized with the photosensitive drum 40 by the transfer charger 44 from the back surface of the paper (+).
Is transferred and transferred. The transferred paper is transferred to the separation charger 4 held integrally with the transfer charger 44.
At 5, an alternating current is applied to separate the photosensitive drum 40 from the photosensitive drum 40. The toner remaining on the photoconductor drum 40 without being transferred to the paper is scraped off from the photoconductor drum 40 by the cleaning blade 47 and collected in an attached tank 48. Further, the pattern of the potential applied to the photosensitive drum 40 is erased by irradiating light with the electric charge reducing lamp 49. A photo sensor 50 is provided immediately after the development.
The photo sensor 50 includes a pair of a light emitting element and a light receiving element, and detects the reflection density on the surface of the photosensitive drum 40. In this method, a certain pattern (for example, a pattern of black or halftone dots) is written in a position corresponding to the reading position of the photo sensor by the optical writing unit, and after developing this, the reflectance of the pattern unit and the photoreceptor drum other than the pattern unit are developed. The density of the image is determined from the reflectance ratio of 40, and if the image is light, a toner supply signal is output. In addition, the fact that the density does not increase even after replenishment can be used to detect the lack of the remaining amount of toner.

[Sheet Feeding Unit] In this embodiment, a plurality of cassettes 6
Papers 0a, 60b, and 60c are transferred through the refeeding loop 72 so that double-sided copying or refeeding is possible. When the start button is pressed after one cassette 60 is selected from the plurality of cassettes 60a, 60b, 60c, the paper feed rollers 61 (61a, 61b, 61c) near the selected cassette 60 rotate. Then, the paper is fed until the leading end of the paper hits a resist row 62 or the like. Although the registration roller 62 is stopped at this time, the registration roller 62 starts rotating at a timing corresponding to the image position formed on the photosensitive drum 40 and feeds the paper around the photosensitive drum 40. Thereafter, the toner image is transferred at the transfer section, and the paper is suction-conveyed by the separation / conveyance section 63, and the toner image transferred by the fixing roller including a pair of a heat roller 64 and a pressure roller 65 is transferred to the paper surface. Settle on top. The paper transferred in this manner is transferred to the switching claw 67 during normal copying.
In the case of multiple copying, the sheet passes through the lower sheet re-feeding loop 72 without being changed by the switching claws 68 and 69, and is again registered with the registration roller 62. Led to. In the case of double-sided copying, the case of performing only with the copying machine body (I) and the case of the double-sided reversing unit (I
There are two cases where V) is used. Here, the former case will be described. The paper guided downward by the switching claw 67 is further guided downward by the switching claw 68, and is guided by the next switching claw 69 to the tray 70 further below the sheet re-feeding loop 72.
Then, the sheet is fed again in the reverse direction by the reversal of the roller 71.
The switching of the switching claw 69 leads to the refeeding loop 72,
It is fed to a registration row 62 or the like.

FIG. 5 is a side sectional view showing the overall structure of the RDH 200. As shown in FIG. The RDH 200 is provided in a cover-type case that covers the contact glass 9 provided on the top surface of the copying machine main body, and is provided over a range excluding the right and left ends of the upper portion thereof.
1 and a paper feed unit 270 provided at the left end in the figure and comprising a paper feed mechanism for sequentially feeding one sheet at a time from below the sheet bundle placed on the paper feed table 201 onto the contact glass 9.
And the lower running portion slides over the entire length of the upper surface of the contact glass 9 and conveys the original fed from the paper feeding portion to a predetermined original exposure position of the contact glass 9 and discharges the original from above the contact glass 9 after exposing the original. Transport section 271 having a transport belt 212 to be rotated, a reversing section 272 for reversing the document sent from the transport section 271, and a return section 273 for returning the document reversed by the reversing section 272 onto the document bundle on the sheet feeding table 201. Are provided.

Hereinafter, each of the sheet feeding unit, the conveying unit, the reversing unit, and the return unit will be described in order.

<Sheet Feeding Unit> Side fences 202 are provided on both left and right sides of the sheet feeding table 201 with respect to the transport direction within the minimum placing range of the front part. Paper feed table 201
In the vicinity of the front end in the paper feeding direction, two call rollers 203a and 203b having a missing circle portion are provided in front and rear with respect to the transport direction at positions where they do not protrude from the document placing surface when the missing circle portion is located above. ing. As shown in FIG. 6, a photoelectric sensor 262 is provided at the shaft end of each of the call rollers 203a and 203b.
Plate 2 having slit 261 detected by
60 and a positioning plate 263 having a concave portion at a position corresponding to the missing circle portion of the calling roller.
A pressing roller 264 urged by a spring is engaged with the peripheral edge of 3. With these mechanisms, two call rollers 20
Reference numerals 3a and 203b rotate synchronously so that the missing circles are in parallel with each other at the same phase, and the slit plate 261 and the photoelectric sensor 262 detect a rotation angle at which the sheet feeding table 201 and the missing circle are on the same plane. Then, the positioning is stopped by the positioning plate 263 and the pressing roller 264, and is held at that position. Above the call roller 203a, there is provided a pressing plate 204 which is driven by a solenoid (not shown) and pushes down the leading end of the document at a position indicated by a chain line in FIG. 5 to press the call roller 203a. Above the holding plate 204, as shown in FIGS.
A stopper 205 is provided which rotates about the rear end as a fulcrum by 67 and is displaced between a retracted position shown by a broken line and an operating position shown by a solid line in FIG. Stopper 2 in operating position
The toe 05 is in contact with the upper surface of the table 201 or the upper surface of the set of originals (see FIG. 8). And has a function of correcting skew by abutting the leading edge of a document to be read. The document bundle pressed by the press roller 203a by the holding plate 204 is
As a and 203b rotate synchronously, they are reliably transported to the separation unit. In FIG. 5, reference numeral 206 denotes a document set sensor which detects that a document bundle has been set on the table 201, and, based on the detection signal, reads out the page roller 203.
The document bundle is conveyed to the position shown in FIG. The call rollers 203a and 203b also have a function of reliably feeding the lowest sheet of the document bundle at the above position in cooperation with a separation unit including the endless belt 207 and the separation roller 208. The separation roller 208 rotates at a speed at which the peripheral speed becomes the document conveyance speed in the direction in which the document is moved in the conveyance direction. On the other hand, the endless belt 207 presses over the circumferential length on the peripheral surface of the separation roller 208, and 5 (in the direction indicated by arrow A in FIG. 5) at a low speed of, for example, about 1/20 of the document conveying speed, and the friction coefficient between the separation roller 208 and the document, By appropriately setting the friction coefficient between the originals and the friction coefficient between the originals, if only one original is sent from below the original bundle by the call rollers 203a and 203b, the pull-out rollers 209 and 210 on the downstream side are used as they are. And when there are two or more sheets, only the lowest one sheet is separated and pulled out rollers 209, 210
Conveyed toward. The separation roller 208 has a built-in one-way clutch, and has pull-out rollers 209 and 21.
When the document is conveyed at 0, even if the separation roller 208 is turned off, the document is conveyed at a predetermined speed by rotating the separation roller 208 to reduce the document conveyance load. The separation roller 208 is turned on and off by a clutch (not shown),
A registration sensor 211 provided at a discharge unit from the printer to the conveyance unit 271 also serves as a detection unit for detecting the trailing edge of the document and controlling to stop the document at a predetermined exposure position on the contact glass 9. Pull-out roller 20 described above
The shafts 9 and 210 have a pulse encoder 280 provided with a plurality of slits via gears, and a photosensor 281 for detecting the slits is provided (see FIG. 9). Further, a photo sensor 281 and a width detection sensor 282 for detecting the width of the document are provided at the positions shown in FIG. The width detection sensor 282 is located between the B5 vertical size and the A4 vertical size as shown in FIG. 10, and the length in the transport direction is counted by the pulse encoder 280 and the photosensor 281 to count pulses. Determine the document size.

Next, the document size determination processing will be described with reference to the flowcharts shown in FIGS. The pulse encoder 280 is formed so as to correspond to a transport distance of 0.5 mm per pulse, and the size of the transportable document is determined by A5 portrait, B5 portrait / horizontal, as shown in FIG.
Seven sizes of A4 portrait and landscape, B4 portrait and A3 portrait are possible. That is, first, after confirming that the registration sensor 211 is ON (S11-01), the width detection sensor 2
It is confirmed that 82 is ON (S11-02).
When the width detection sensor 282 is ON, the encoder pulse counting is started after setting the size sensor flag.
When the width detection sensor 282 is OFF (S11-03, 05), the encoder pulse counting is started after clearing the size sensor flag (S11-04, 05). Thereafter, when it is confirmed that the registration sensor 211 is turned off (S11-06), the encoder pulse counting is terminated.
(S11-07). When the state of the size sensor flag and the pulse count value are determined in this way, the next document size determination process is started. That is, the size sensor flag = 0
If the pulse counter is greater than 466, it is determined that the size is the B5 vertical size (S11-08, 09, 10),
If the pulse counter is equal to or less than 466, it is determined that the size is the A5 vertical size (S11-08, 09, 11). On the other hand, when the size sensor flag = 1, the pulse counter> 78
If it is 0, it is determined that it is A3 size (S11-0).
8, 12, 13), B if pulse counter> 660
4 size (S11-08, 12, 1).
4, 15), and if the pulse counter is greater than 506, it is determined that the size is A4 vertical size (S11-08, 12, 14, 14).
16, 17), if the pulse counter is greater than 391, it is determined that the size is A4 horizontal size (S11-08, 12, 1).
4, 16, 18, 19), if the pulse counter ≦ 391, it is determined that the size is the B5 horizontal size (S11-0).
8, 12, 14, 16, 18, 20). When the document size is determined, the information of the determination result is transmitted to the main body (S11-21), and this flowchart ends. Such determination of the document size is performed every time the document is fed.

<Conveying Unit> The conveying unit 271 is a single wide conveying belt 2 wound around a pair of rollers 265 and 266.
The lower running portion is pressed against the contact glass 9 by a plurality of pressure rollers 213, and conveys the original sent from the paper feeder 270 to a predetermined exposure position. 272.

<Reversing Unit> The reversing unit 272 includes a reversing roller 215 provided along a reversing guide, a pressure roller 216 pressed against the reversing roller 215, and a position shown by a solid line and a position shown by a broken line in FIG. And a switching claw 214 that can be displaced between them. The switching claw 214 is switched to the position indicated by the broken line in the double-sided original mode, and when discharging the double-sided exposed original in the single-sided original mode or the double-sided original mode in which the single-sided exposed original is turned upside down and sent to the transport unit 271 again. The switching claw 214 is located at a position shown by a solid line in the drawing, and is discharged to the return portion 273. Pressing roller 216 and switching claw 2
14 and the reversing sensor 2 facing the reversing roller 215.
17 is provided, and thereby, the drive timing of the transport belt 212 is controlled. The transport belt 212 and the reversing roller 215 are each driven by a single motor (not shown).

<Return Unit> The return unit 273 is connected to a paper discharge unit 218 movable on the paper feed table 201 in the document transport direction and a rear portion of the paper discharge unit 216 in the transport direction. A guide plate and a reversing unit 27 that expand and contract in response to form a document re-feeding path between the sheet discharging unit 218 and the upper surface of the sheet feeding table 201 at the rear side.
And an intermediate belt 227 for transporting the document discharged from the sheet feeding unit 2 to the sheet discharging unit 218.
The above-mentioned guide plates are a plurality of (three in this example) guide plates 221, 222,
223, the guide units 221, 222, and 223 are changed so as to expand and contract by moving the paper discharge unit 218. Each guide plate 22
Reference numerals 1, 222, and 223 are sequentially overlapped outward in the document conveying direction so that the front end of the document conveyed in the reverse feeding path is not caught by the overlapping portion of the guide plates.
Above the respective guide plates 221, 222 and 223, exterior covers 224, 225 and 226 are fixed to the rising portions formed by bending the rear ends of the respective guide plates upward, and overlap each other similarly to the guide plates. It is provided to be able to expand and contract together. The paper discharge unit 218 is shown in FIGS.
As shown in the figure, the document discharged from the outlet 230 of the reversing unit 272 is directly picked up, or the document conveyed by the intermediate belt 227 on the table 201 which is the re-feeding surface of the re-feeding path is scooped up and the output port at the upper front end thereof A lower guide 229 which is inclined upward before being guided to the front, an upper guide which is provided at a certain distance from the lower guide 229 and which is formed as a front end of the guide plate 221, and an inlet and an outlet of a paper discharge unit transport path formed therebetween. And a discharge roller pair 219 ", 219 'provided in each section, and a motor 220 for driving these discharge rollers.
The front part of the outer cover 224 is an outer cover of the paper discharge unit 218. The intermediate belt 227 is the reversing unit 2
72, a plurality of sections are provided in the width direction so that the upper surface of the upper running portion is flush with the upper surface of the document table 201. When the guide plate 222 is extended, the position facing each strip of the intermediate belt 227 is shown in FIG.
4, a driven roller 228 is provided via a leaf spring as shown in FIG. 15, and when the guide 222 is pulled out in the direction of arrow B and comes above the intermediate belt 227, the driven roller 228 is moved by the force of the leaf spring. When the guide plate 222 moves in the direction of arrow C in FIG. 16 and retracts backward from above the intermediate belt 227, the driven roller 228 projects above the table surface. The member 231 is jumped up and retracted from the intermediate belt 227, and is stored behind the reversing portion outlet 230 as shown in FIG. In this state, the largest size document discharged from the reversing unit outlet 230 is driven by the driven roller 228 and the guide plate 22.
2, 223 ', without being hindered by the discharge roller pair 219 ", 219', and discharged from the front end onto the document bundle placed on the document table.
The skew is corrected by colliding with the stopper 205, and the sheet is stacked on the document bundle. The positioning of the paper discharge unit 218 corresponding to the document size is performed by the automatic document circulating and feeding device RDH20.
This can be easily performed by engaging a click pin 245 provided on the front side of the paper discharge unit with a click groove 251 provided at a position corresponding to the standard paper size of the front side frame of No. 0. Click groove 25 of click pin 245
1 or the inner surface of the frame can be easily operated by operating a lever 252 provided on the front end face of the paper discharge unit 218, and the paper discharge unit 218 can be easily moved and engaged with a required position. .

<Description of Operation> FIG. 1 shows a document feeding operation by the automatic document feeder RDH 200 having the above configuration.
This will be described with reference to a flowchart shown in FIG. First, the leading end of the document stack stacked in page order with the image surface facing upward is placed on the sheet feeding table 201 by abutting against the stopper 205, and then the side fence 202 is moved to hold both sides of the document stack. . Thereafter, the paper discharge unit 218 is set at a position suitable for the document size. When it is confirmed that the document set sensor has been turned on (S17-01) and the transmission of the paper feed signal is confirmed by turning on the print key,
(S17-02), the stopper claw solenoid and the presser plate solenoid are turned on (S17-03). As a result, the stopper 205 retreats from the leading end of the original bundle, and the pressing plate 204 calls the original bundle and presses it against the rollers 203a and 203b. Due to the rotation of the page rollers 203a and 203b, the document bundle is fed so as to form a wedge shape which is advanced in order from the lowest document. Further, when the feeding timer is operated and it is confirmed that the predetermined time X has elapsed (S17-04), the feeding motor and the conveying belt motor are turned on (S17-05). Only the lowest document is separated by the operation of the endless belt 207 and the separation roller 208 and sent to the pull-out roller 209.
When the leading edge of the document is detected by the registration sensor (S17-0)
6), the paper feed clutch and the presser plate solenoid are turned off (S17-07). When the driving of the separation roller 208 is stopped by the clutch, the original is conveyed to the contact glass 9 only by the pull-out roller 209, and further conveyed on the contact glass 9 by the conveyance belt 212. The call rollers 203a and 203b are the photoelectric sensors 2 shown in FIG.
When the slit 62 detects the slit 261 of the slit plate 260, the drive is cut off, and the operation is stopped in a state where the missing circular surface coincides with the surface of the sheet feeding table 201. After the registration sensor 211 detects the trailing edge of the document, the count value of the timing pulse becomes X
_When it is confirmed that the number has reached ₂ (S17-08), the transport belt 212 rotates in the reverse direction and strikes the original against the scale 268. Thereafter, when the conveyance belt motor and the stopper claw solenoid are turned off (S17-09), this document feeding flow is terminated, the document whose skew has been corrected is stopped at a predetermined exposure position, and the document exposure scan is performed. Done.

When the exposure scan is completed and the transmission of the document discharge signal is confirmed (S18-01), the transport motor, the inversion motor, and the discharge motor are turned on (S18-02). As a result, the transport belt 212 rotates forward again, and the original is
The document is sent to U and makes a U-turn, and the single-sided or double-sided original and the double-sided exposed original enter the return portion 273, and the intermediate belt 227 and the sheet feeding table 201 and the retractable guide plates 221, 222, 223 according to the original size. And is scooped up by the lower guide 229 of the paper discharge unit 218, and is discharged by the paper discharge rollers 219 ″,
At 219 ′, the original is discharged onto the original bundle on the paper feed table 201. Thus, the reversing sensor is turned on (S18).
-03), the paper discharge sensor is turned on (S18-04), and when the paper discharge sensor is turned off (S18-05), the paper discharge motor and the reverse motor are turned off (S18-06). If the original is fed after this (S18-0)
7) The document discharge flow is terminated as it is. If the document feeding is completed (S18-07), the transport motor is turned off.
FF is performed (S18-08), and the document discharge flow ends. On the other hand, at a predetermined timing after the paper discharge sensor 214 of the paper discharge unit 218 detects the leading edge of the document, the stopper 205 abuts on the document bundle as shown in FIG. Is the stopper 20
By colliding with 5, the skew is corrected and stacked.

Note that, as shown in FIG.
If a rib 1a having an appropriate height is formed on the upper surface of the sheet with a claw provided at a distance from the stopper 205, the document placed on the sheet feeding table 201 is pressed by the stopper claw. The paper ejected from the paper ejection unit 218 hits the stopper 205
It is prevented from getting underneath. If the partition plate 241 is placed first on the bundle of originals, the partition plate sensor 243 detects that the partition plate 241 is at the lowest position, so that it is possible to detect that the document has made one round. Although the completed manuscript has been arranged to some extent, it is not enough and may be in a wavy state. Therefore, it is preferable to rotate the call rollers 203a and 203b before the next paper feeding operation to apply vertical vibration to the original so that the original is adjusted. At this time, the holding plate 204 and the stopper 205 are retracted to a position away from the original, and the call rollers 203a, 203
3b generates a conveying force in the conveying direction, so that the front end of the document bundle is separated by the separation roller 208 and the endless belt 20.
7 is advanced to the vicinity of the press contact portion 7 and is arranged in a wedge shape in which the tips are retracted in order from the lowest. As a result, the document bundle is reset so as not to hinder refeeding, and the next feeding operation is started according to the feed signal.

[Sorter (III)] The sorter (III) is an apparatus for selectively feeding copy sheets discharged from the copying machine body (I), for example, in page order, page by page, or to bins 111a to 111x set in advance. . The copy paper fed by the plurality of rollers rotated by the motor 110 is moved to the selected bin 11 by switching the pawls near the entrance of each bin 111.
It is led to 1.

[Duplex Reversing Unit (IV)] As described above, the copying machine main unit (I) can perform only two-sided copying for each sheet. However, by attaching this duplex reversing unit (IV),
It is possible to make double-sided copies at once. When a plurality of sheets are to be collectively subjected to double-sided copying, the paper guided downward by the discharge rollers 66 is switched by the next switching claw 67 to the double-sided reversing unit (I
V). The paper that has entered the duplex reversing unit (IV) is accumulated on the tray 123 by the paper ejection rollers 120.
At this time, the length and width of the copy paper are aligned by the feed roller 121 and the side alignment guide 122. The copy sheets stacked on the tray 123 are re-supplied by the re-feed roller 124 during backside copying. At this time, the sheet is guided directly to the refeeding loop 72 by the switching claw 69. In FIG. 1, 27 is a mirror, 28 is a dustproof glass, 31 is a lens holding unit,
6 is a separation claw, 80 is a main motor, 81 is a fan motor.

[Electrical control unit]
One CPU performs sequence-related control, and the other CPU performs operation-related control. Both CPUs are connected by a serial interface (RS232C). 19 and 20 are circuit diagrams of the control unit. First, the sequence control will be described. The sequence includes a paper size sensor 301, a sensor 302 relating to paper conveyance such as paper ejection detection and registration detection, a double-sided unit 303, a high voltage power supply unit 304, a relay 305, for setting and outputting conditions for paper conveyance and image formation. Solenoid 306,
A driver 307 such as a motor, a sorter unit 308, a laser beam, a scanner unit 309, and the like are connected. In terms of sensors, paper size sensors that detect the size and orientation of the paper loaded in the paper cassette and output an electrical signal according to the detection result, sensors related to paper conveyance such as registration detection and paper ejection detection, oil end and toner There is an input from a sensor that detects the presence or absence of a supply such as an end, and a sensor that detects a mechanical abnormality such as a door open or a fuse blown. In the duplex unit 303, a motor for aligning the paper width, a paper feed clutch, a solenoid for changing the transport path, a paper presence / absence detection sensor, a side face home position sensor for aligning the paper width, and a sensor for paper transport and so on. High voltage power supply unit 30
Reference numeral 4 applies a predetermined high voltage to each of the charging charger, the transfer charger, the separation charger, and the developing bias electrode by a duty obtained by the PWM control. The driver 307 includes a paper feed clutch, a registration clutch, a counter, a motor, a toner supply solenoid, a power relay, a fixing heater, and the like. Sorter unit 308
Are connected by a serial interface, and the paper is conveyed at a predetermined timing according to a signal from the sequence and discharged to each bin. The analog input includes a fixing temperature, a photo sensor input, a monitor input of a laser diode, and a reference voltage of the laser diode. On / off control or phase control of the heater is performed so that the temperature of the fixing unit becomes constant by an input from a thermistor in the fixing unit. As for the photo sensor input, a photo transistor pattern formed at a predetermined timing is input by a photo transistor, and the density of the pattern is detected, thereby controlling ON / OFF of a toner supply clutch to control toner density. The toner end is also detected based on the density. As a mechanism for adjusting the power of the laser diode to be constant, an A / D converter and an analog input of a CPU are used. This is a preset reference voltage (this voltage is 3 m
w) is controlled so that the monitor voltage when the laser diode is turned on matches.

Next, operation-related control will be described. The main CPU 310 controls a plurality of serial ports and the calendar IC 311. In addition to the sequence control CPU 312, a scanning unit, a scanner, an application, an editor, and the like are connected to the plurality of serial ports. The operation unit has a display for displaying the key input of the operator and the state of the copying machine, and informs the main CPU 310 of the information of the key input by serial transmission. The main CPU 310 determines whether the display of the operation unit is turned on or off based on this information, and serially transmits the display to the operation unit. The operation unit turns on the display unit based on information from the main CPU 310,
Turn off the light. The scanner section performs serial transmission processing of information on scanner servo motor drive control, image processing, and image reading to the main CPU 310, and further performs interface processing between the RDH 200 and the main CPU 310. The applications are external devices (fax, printer, etc) and the main CPU 310.
Interface for exchanging preset information contents. The editor is a unit for inputting an editing function, and serially transmits image editing data (masking, trimming, image shift, etc) input by the operator to the main CPU 310. Calendar IC3
Reference numeral 11 stores a date and time.
Since it can be called at any time at 0, the ON / OFF of the machine can be timer-controlled by displaying the current time on the operation unit display and setting the ON / OFF time of the machine. The gate array 313 receives image data (DA) in the following three directions according to a select signal from the main CPU 310.
TA1, DATA2, or DATA13-10, D
ATA 23 to 20) and a synchronization signal.

On the other hand, the scanner control circuit 314 converts an image signal continuously transmitted in 2-bit parallel (binary) and 12-bit parallel (multi-valued) from the scanner into a synchronization signal PMSYNC from the laser beam scanner unit 309. And outputs it to the image control circuit 315. In addition, image information continuously transmitted in 2-bit parallel (binary) from the scanner is output to the application 316. The application 316 outputs the input image data to an external device. Also, image information transmitted in 2-bit parallel (binary) from an external device is transmitted to a laser beam scanner unit 3.
In synchronization with the synchronizing signal PMSYNC from the control signal 09, the signal is output to the image control circuit 315.

[Image Scanner Unit] FIG. 21 is a block diagram of the image scanner unit. An analog image signal output from the CCD image sensor 407 is amplified by a signal processing circuit 451 and converted into a digital multi-level signal by an A / D converter 452. This signal is subjected to correction processing by the shading correction circuit 453, and is applied to the signal separation circuit 454. The image information input to the signal separation circuit 454 is processed and separated into a binary image component signal such as a character and a halftone image component signal. The binary image component signal is applied to a binarization processing circuit 456, and the halftone image component signal is applied to a multi-level processing circuit 455. The binarization processing circuit 456 converts the input multi-valued data into binary data using a preset fixed threshold value.
The multi-value processing circuit 455 determines input data based on a preset threshold value for each scanning position, and outputs 16-value data including halftone information.

The scanner control circuit 460 controls the lamp control circuit 458, the timing control circuit 459, the electric scaling circuit 461, and the scanner drive motor 465 according to the support from the printer control unit. The lamp control circuit 458 performs ON / OFF control and light amount control of the exposure lamp 402 according to an instruction from the scanner control circuit 460. A rotary encoder 466 is connected to the drive shaft of the scanner drive motor 465, and the position sensor 462 detects the reference position of the sub-scanning drive mechanism. The electric scaling circuit 461 performs an electric scaling process on the multi-valued image data and the binarized image data according to the main-scanning-side magnification data set by the scanner control circuit 460. The timing control circuit 459 includes the scanner control circuit 46
Each signal is output according to the instruction from 0. That is, when reading is started, a transfer signal for transferring one line of data to the shift register and a shift clock pulse for outputting the data of the shift register one bit at a time are applied to the CCD image sensor 407. For the image reproduction system control unit, the pixel synchronization clock pulse CLK, the main scanning synchronization pulse LSNC, and the main scanning effective period signal LGA
Output TE.

The pixel synchronization clock pulse CLK is C
This signal is almost the same as the shift clock pulse given to the CD image sensor 407. Also, the main scanning synchronization pulse L
The signal SYNC is almost the same as the main scanning synchronization signal PMSYNC output from the beam sensor of the image writing unit. However, the output is prohibited when the image is not read. The main scanning valid period signal LGATE is the output data DA
TA1, DATA2, DATA10-13, DATA2
It goes to a high level H at the timing when 0 to 23 are regarded as valid data. In this example, the CCD image sensor 407 outputs valid data of 4800 bits per line. The output data DATA1 is data of each odd-numbered pixel, and the output data DATA2 is data of each even-numbered pixel. Scanner control circuit 460
Receives a read start instruction from the printer control unit, turns on the exposure lamp 402, starts driving the scanner drive motor 465, controls the timing control circuit 459, and controls the CCD.
Start reading the image sensor. Further, the sub-scanning effective period signal FGATE is set to a low level when the time required to scan the maximum reading length (in this example, the size in the longitudinal direction of the A size) in the sub-scanning direction has elapsed after being set to the high level H. L.

[Image Compression Storage / Reproduction Unit] FIG. 22 is a block diagram of the image compression storage / reproduction unit. The multi-level compression unit 514 includes the electric scaling circuit 461 shown in FIG.
Compress data from. The memory 515 stores the data compressed and encoded by the multi-level compression unit 514. The multi-level decompression unit 517 includes the multi-level compression unit 51
4, the data is output to the writing unit by performing the compounding. Memory management unit 518, CPU 51
9 controls the operation of the memory 515. Also, the CPU 51
Reference numeral 9 denotes monitoring of the memory capacity and control of changing the scale factor of the multi-level compression unit 514 and multi-level decompression unit 517 when the memory capacity is insufficient, detection of a high-quality mode designation page, and control of change of the scale factor for the high-quality mode. ,
When the memory capacity becomes insufficient after the change of the scale factor, a control or the like for urging the operator to perform the copying operation by dividing the memory is performed.

Here, a general method of multi-level compression will be described. FIG. 23 is a detailed block diagram of the encoding unit and the decoding unit. The coding method used here is a discrete cosine transform (DCT) coding method. First, the block reading unit 701
24, an image is read for each 8 × 8 pixel block as shown in FIG. 24, and is converted into a DCT-based numerical value by the DCT conversion unit 702. The DCT transform is defined by equation (1) shown in FIG.
In Expression (1), Xij is an original pixel, and Yuv is a conversion coefficient.

The coefficients output from the DCT transform section 702 are linearly quantized by the quantization section 703 with different quantization step sizes for each coefficient to obtain a quantized coefficient. At this time, the quantization step size for each coefficient is determined by changing the value of the scale factor set by the scale factor control unit 705 to the quantization matrix stored in the quantization matrix storage unit 706, thereby obtaining the code amount or the decoded image. Control quality. Here, the quantization matrix is adapted to finely quantize low-order coefficients in accordance with human visual characteristics, for example, as shown in FIG.
As for the quantization coefficient, a short code is assigned to a coefficient with a high appearance frequency in the Huffman encoding unit 704, and a long code is assigned to a coefficient with a low appearance frequency, so that the code amount is reduced as a whole. 707.

When outputting an image, the code is read out by the code storage unit 707, the value of the quantized system value is assigned to the code by the Huffman decoding unit 708, and the value is inversely quantized by the inverse quantization unit 709. Perform quantization. At this time, the quantization step size in the inverse quantization multiplies the quantization matrix stored in the quantization matrix storage unit 706 by the value of the scale factor set by the scale factor control unit 705, as in the case of the encoding. Required. Inverse quantization unit 70
The DCT coefficient output at 9 is converted into image data by an inverse DCT converter 710. The calculation formula is the formula (2) shown in FIG.
It is as follows. In equation (2), G (u, v): decoding conversion coefficient (u, v = 0,
1,..., N−1) g (i, j): decoded image signal (i, j = 0, 1,..., N−)
1).

The inversely DCT-transformed data is output by the block writing unit 711 for each block. The image data output for each block is stored in one block line memory (not shown) (one block line is an example of a block continuing in the main scanning direction, and here is eight lines because one block is 8 × 8 pixels). When the data is stored and one block line memory is full, the data is output line by line.

In the above description, the block size for encoding and decoding is 8 × 8, but another size may be used. For example, the vertical and horizontal sizes such as M × N may be changed. Also, here, a two-dimensional discrete cosine transform is used as the orthogonal transform, but any other orthogonal transform, such as an Agumar transform, that performs a transform from the spatial domain to the frequency domain, may be used. Can be. In the above description, although not specifically defined as an image signal, a multi-valued black-and-white image, each color component image of RGB, luminance / color difference such as Y, (RY), (BY), etc. All the signals are included in this image signal. Similarly,
The present invention can be applied to an inter-frame difference signal in a moving image such as a television signal, and a sufficient effect can be obtained. References on this inter-frame difference signal are:
"Television Bandwids Compression
Transmission by Motion Montpasified Interframe Coding (Television
Bandwidth Compression transmission by Motion-compe
nsated Interframe Coding) '' IEEE Communication Maga
zine), November 1982, pp. 24-30.

In the present invention, by using an image compression storage / reproduction unit adopting the above-mentioned multi-value compression method, when encoding an image, the memory 515 can be effectively used, and the scale of the decoded image can be reduced. Since the control of the factor is important, the portion where the density change is small in the image to be encoded is reduced by increasing the scale factor and increasing the quantization step size to reduce the code amount.
Increase the compression ratio. This reduces the amount of memory 515 used. Conversely, in a portion where the density change is sharp, the scale factor is reduced and the quantization step size is reduced, so that the code amount is increased, the compression ratio is reduced, and a good image is obtained. By controlling such a scale factor, the focus is on increasing the productivity by copying many originals at one time.

<Description of Operation> Next, the operation of the image compression storage / reproduction unit will be described. FIG. 28 is a flowchart showing the operation of monitoring the memory capacity and changing the scale factor when the memory capacity is insufficient. First, in a state where the original bundle is set on the RDH 200, the operator operates the copy switch 8 of the operation unit 800 shown in FIG.
01 is pressed (S28-01), the CP of the scanner unit is pressed.
U issues a command to feed one document on contact glass 9 to RDH, and RDH 200 starts driving.
(S28-02). When one document is fed onto the contact glass 9, the document is scanned by the scanner (S2).
8-03). The image data is subjected to shading correction, signal separation processing, multi-level conversion processing, and electrical scaling processing by the image scanner unit, and then transmitted to the multi-level compression unit 514, subjected to DCT compression processing, and further encoded. Is performed (S28-04). Then, the encoded code data is stored in the memory 515 (S28-05). At this time, a predetermined value is used as the scale factor.
After the encoded data is stored in the memory 515, the memory management unit 518 reads the write end address and transmits the read end address to the CPU 519. The CPU 519 determines whether or not the capacity of the memory 515 is over based on the end address (S28-06). If the capacity is not exceeded, it is determined whether or not the next document is present on the sheet feeding table 201 of the RDH 200 (S28-07). If there is no next manuscript, the flow is terminated as it is.
Returning to -52, the same processing is performed. On the other hand, when the capacity is over, the RDH 200 is driven to the initialization state (S28-08). The initialization state means that the originals are circulated so that the original of the first page is at the top of the feed table 201 of the RDH 200, and the original original is set. During this processing, the memory management unit 51
By the operation of 8, the data stored in the memory 515 is temporarily deleted (S28-09). Next, in order to increase the compression ratio of the image data, the value of the scale factor is changed to a value larger than the current value (S28-10). After changing the scale factor, the process returns to S28-02. By repeating this series of processes, the image data of all the originals is compressed and decoded and stored in the memory 515, and the flow of image reading ends.

Scanning of the original, input of the memory, etc. are performed while determining the memory capacity as described above. When it is determined that the memory 515 has exceeded the capacity, the RDH 200 is driven to the initial state and the data in the memory 515 is erased. Since the scale factor is changed to a large value in preparation for the next image reading, the capacity of the memory 515 can be prevented from being exceeded when the next image is read. Further, the scale factor can be increased stepwise each time the capacity of the memory 515 is determined to be over, so that the image information is limited to the limited memory 515.
The memory 515 can be effectively stored, and the workability of the copying operation can be improved.

FIG. 30 is a flow chart showing the operation of reading an image while detecting the mode of each original from the bundle of originals and setting the scale factor. First, the user sets the original bundle to the original feed table 201 of the RDH 200.
When set on the upper side, if there is an original to be copied in the high image quality mode as shown in FIG.
A message prompting the user to input with the numeric keypad 802 of 0 is output to the display unit 803. Any number of pages can be specified. When the copy switch 801 is depressed after setting the document on the RDH and specifying the high image quality mode page (S30-01), the RDH 200 circulates the document and counts the number of the document bundle (S30-02). As described above, this is a mechanism in which the RDH 200 sets a document with the document surface facing upward and feeds the document from the bottommost document (the last page). To determine the number of pages, the CPU 519 is first notified. Thereafter, the CPU 519 issues a document feed command to the RDH 200 (S30-03). As a result, the contact of one document is conveyed onto the lath 9. When the document is conveyed, it is determined whether the current document is a document for which the high image quality mode is designated (S30-04). This determination is made, for example, by counting down from the last page the page number of the document fed to the lath 9 and checking whether the number of pages matches the high image quality mode designated page designated by the ten key 802 operation. It is performed by determining whether or not it is. If the result of the determination is that the document has been designated for the high image quality mode, a scale factor for the high image quality mode is set (S30-05). The scale factor at this time is preset with a value smaller than the scale factor in the normal mode. As a result, the compression ratio at the time of compressing the image information decreases, and an image with high reproducibility can be obtained. Here, the IPU parameters may be changed together with the change of the scale factor. On the other hand, if the original is not the high-quality mode specified, the scale factor for the normal mode is set (S30-
06). Thereafter, the original is scanned by the scanner (S30).
-07), the image data is subjected to shading correction, signal separation processing, multi-level processing, and electric scaling processing by the image scanner unit, and then transmitted to the multi-level compression unit 514, where DCT compression processing is performed. Further encoded
(S30-08). The encoded code data is stored in the memory 51.
5 (S30-09). This S30-02 to S3
When the processing of 0-09 is performed for all the originals, the image reading flow ends. Although the description of the writing is omitted, similarly to the reading, the data is decrypted by the set scale factor.

Before scanning the original and storing the compression code data in the memory 515 in this manner, it is determined whether the original is in the normal mode designation or the high image quality mode designation, and the scale factor corresponding to the mode designation is determined. Is set, when continuous copying of a document bundle is performed, deterioration of the image quality of the high image quality mode designated page included in the document bundle can be automatically avoided.

FIG. 31 is a flow chart showing the operation when the memory capacity is insufficient after the change of the scale factor and the operator is urged to divide and perform the copying operation. First, when the copy switch 801 is pressed by the operator in a state where the bundle of documents is set on the RDH 200 (S31-01), the CPU of the scanner unit sends the RDH2
00, a command to feed one document on the lath 9 is issued, and the RDH 200 starts driving (S31).
-02). When one document is fed onto the contact glass 9, the document is scanned by the scanner (S31-0).
3). The image data is subjected to shading correction, signal separation processing, multi-level conversion processing, and electric scaling processing by the image scanner unit, and then transmitted to the multi-level compression unit 517, subjected to DCT compression processing, and further encoded. (S
31-04). Then, the encoded code data is stored in the memory 515 (S31-05). At this time, a predetermined value is used as the scale factor. After the encoded data is stored in the memory 515, the memory management unit 518 reads the write end address and transmits it to the CPU 519. The CPU 519 determines whether or not the capacity of the memory 515 is over based on the end address (S31-06). If the capacity is not over, it is determined whether or not the next original is present on the paper feed table 201 of the RDH 200 (S31-07). If there is no next original, this flow is terminated as it is, but if there is a next original, the process returns to S31-02 and the same processing is performed. On the other hand, when the capacity is over, the RDH 200 is driven to the initialization state (S31-08). The initialization state means that the originals are circulated so that the original of the first page is on the top of the paper feed table of the RDH 200, and the original original is set. During this processing, the memory management unit 5
By the operation of 18, the data stored in the memory 515 is temporarily deleted (S31-09). Next, in order to increase the compression ratio of the image data, the value of the scale factor is changed to a value larger than the current value (S31-10), and it is determined whether the value of the converted scale factor has reached the upper limit. (S31-11). If the current scale factor value has not reached the upper limit, the process returns to S31-02 and the same processing is performed. So that the display unit 8
03 is displayed to urge the operator to perform the copying operation by dividing the original document twice (S31-12). Then, when the value of the scale factor is changed to the initial value (the value at which the compression ratio becomes the minimum) (S31-03), the process returns to S31-01 and waits until the copy switch is pressed again. In the above series of processing, the image reading is ended when the image data is stored so that the memory capacity does not become excessive.

When it is determined that the value of the scale factor has reached the upper limit when the scale factor is changed due to the capacity of the memory 515 having been exceeded,
Since the image is divided and displayed on the display unit 803 of the operation unit 800 to prompt the user to perform the copying operation, the user can know that the capacity of the memory 515 is insufficient and a good image cannot be obtained. It is possible to know what operation should be performed when the memory capacity is insufficient.

[0052]

[0053]

[0054]

Effect of the Invention According to the first invention, by comparing determines the pages of the document fed onto the page and a contact glass of the document image quality mode is designated, is fed onto the contact glass It is determined whether or not the original is a document requiring the high image quality mode. Therefore, it is possible to change the compression ratio to a low value for an original requiring the high image quality mode. It is possible to avoid the deterioration of the image quality when copying the original to be performed.

According to the second aspect , when the page of the document for which the high image quality mode is specified matches the page of the document fed onto the contact glass, the control means activates the change means to change the image information. Since the compression ratio is automatically reduced, it is possible to automatically avoid deterioration of the image quality of a document requiring a high image quality mode while continuously copying many documents.

According to the third aspect of the invention, when the image information read from the original is compressed and stored in the storage means, the determination means runs short of the storage capacity of the storage means. When the detection means determines that the current compression rate has reached a predetermined value, the detection means displays the fact that the compression rate has reached a predetermined value to the user via the display means. Therefore, the user can be notified that the storage capacity of the storage means is insufficient and a good image cannot be obtained.

According to the fourth aspect , when a series of image information exceeds the storage capacity of the storage means even if the compression ratio of the image information is changed due to the shortage of the storage capacity of the storage means, the document is deleted by the control means. The user is notified via the display means that the copying operation is to be performed in a divided manner, so that the user can know that the storage capacity of the storage means is insufficient. You can know if you should do the work.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a partial configuration of a digital copying machine according to an embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating another configuration of a part of the digital copying machine according to the embodiment of the present invention.

FIG. 3 is a plan view showing a configuration of a writing unit of the digital copying machine of the embodiment.

FIG. 4 is a side view illustrating a configuration of a writing unit.

FIG. 5 is a side cross-sectional view illustrating the entire configuration of the automatic document circulation and feeding device.

FIG. 6 is a perspective view showing a mechanism of a call roller of the automatic document circulating and feeding apparatus.

FIG. 7 is a side view illustrating a configuration of a stopper of the automatic document circulation and feeding device.

FIG. 8 is an enlarged side view illustrating a sheet feeding unit of the automatic document circulation and feeding device.

FIG. 9 is a perspective view showing a mechanism of a pull-out roller of the automatic document circulating and feeding apparatus.

FIG. 10 is a diagram showing a specific example of an arrangement position of a width detection sensor of the automatic document circulation and feeding device.

FIG. 11 is a flowchart illustrating an operation of document size determination.

FIG. 12 is a flowchart illustrating an operation of document size determination.

FIG. 13 is an enlarged view of a sheet discharging unit of the automatic document circulating and feeding apparatus.

FIG. 14 is an enlarged perspective view of a sheet discharging unit of the automatic document circulating and feeding apparatus.

FIG. 15 is a diagram illustrating an operation state of a paper discharge unit of the automatic document circulating and feeding apparatus.

FIG. 16 is a diagram illustrating an operation state of a paper discharge unit of the automatic document circulating and feeding apparatus.

FIG. 17 is a flowchart illustrating a document feeding operation performed by the automatic document feeder.

FIG. 18 is a flowchart showing a document discharging operation performed by the automatic document circulating and feeding apparatus.

FIG. 19 is a block diagram illustrating a partial configuration of a transmission control unit.

FIG. 20 is a block diagram illustrating another configuration of another part of the transmission control unit.

FIG. 21 is a block diagram illustrating a configuration of an image scanner unit.

FIG. 22 is a block diagram illustrating a configuration of an image compression storage / reproduction unit.

FIG. 23 is a block diagram showing a general method of multi-level compression.

FIG. 24 is a diagram illustrating a specific example of reading an image for each 8 × 8 pixel block.

FIG. 25 is a diagram showing a mathematical expression defining a DHT transform.

FIG. 26 is a diagram illustrating a specific example of a quantization matrix.

FIG. 27 is a diagram showing a mathematical expression defining an inverse DHT transform.

FIG. 28 is a flowchart showing the operation of monitoring the memory capacity and changing the scale factor when the memory capacity is insufficient.

FIG. 29 is a diagram showing a specific example when a display prompting an instruction for a page of a document to be copied in the high image quality mode is displayed on the display unit on the operation unit.

FIG. 30 is a flowchart showing an operation when reading an image while detecting the mode of each original from the bundle of originals and setting a scale factor.

FIG. 31 is a flowchart showing an operation for prompting an operator to divide and perform a copying operation when a memory capacity becomes insufficient after changing a scale factor.

FIG. 32 is a diagram showing a specific example of a case where a display prompting the operator to perform a copying operation is displayed on the display unit on the operation unit.

FIG. 33 is a diagram showing a conventional technique.

FIG. 34 is a diagram showing another conventional technique.

FIG. 35 is a view showing still another conventional technique.

[Explanation of symbols]

 9 Contact glass 200 Circulating original conveying means 400 Reading device 514 Compressing means 515 Storage means 517 Decompression means 518 Changing means 519 Control means 802 Display means

──────────────────────────────────────────────────続 き Continuing on the front page (72) Yoshimichi Kanda Inventor Ricoh 1-3-6 Nakamagome, Ota-ku, Tokyo (72) Inventor Gen Ichimura 1-3-3 Nakamagome, Ota-ku, Tokyo No. 6 Inside Ricoh Co., Ltd. (72) Inventor Oji Maruyama 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Koichi Noguchi 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Inventor Shinji Yamakawa 1-3-6 Nakamagome, Ota-ku, Tokyo Co., Ltd. Toshihiko Kuroi (72) Inventor Toshihiko Kuroi 1-3-6, Nakamagome, Ota-ku, Tokyo Co., Ltd. Inside Ricoh Company (72) Inventor Yasuyuki Nomizu 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh (72) Inventor Katsura Nomura 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company JP-A-2-104078 (JP, A) JP-A-2-8967 (JP, A) JP-A-61-135286 (JP, A) JP-A-5-64011 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04N 1/41-1/419 H04N 1/21 H04N 1/00

Claims (4)

(57) [Claims] 1. A circulating document conveying means capable of feeding a document bundle by repeatedly circulating the document bundle one by one on a contact glass, a reading means for reading image information of a document, and an image information read by the reading means. In an image forming apparatus including at least compression means for compressing, storage means for storing the image information compressed by the compression means, and decompression means for decompressing the image information stored in the storage means, a high-quality mode Input means of an operation unit capable of designating a page to be copied, and comparison determining means for comparing and determining a page input by the input means and a page of a document conveyed onto the contact glass. Image forming device. 2. The image forming apparatus according to claim 1 , wherein
An image forming apparatus further comprising a control unit for controlling a compression ratio of image information to be reduced when a page input by the input unit matches a page of a document conveyed onto the contact glass. apparatus. 3. A circulating document conveying means capable of feeding a document bundle by repeatedly circulating the document bundle one by one on a contact glass, reading means for reading image information of the document, and transferring the image information read by the reading means. An image forming apparatus comprising at least compression means for compressing, storage means for storing the image information compressed by the compression means, and decompression means for decompressing the image information stored in the storage means. Determining means for determining the storage capacity; changing means for changing the compression ratio of the image information based on the determination result of the determining means; and detecting means for detecting that the compression ratio of the image information has reached a predetermined value. Display means for displaying to the user that the compression ratio of the image information has reached a predetermined value. 4. The image forming apparatus according to claim 3 , wherein
When the image information exceeds the storage capacity of the storage unit even when the compression ratio is changed, the image processing apparatus further includes control means for controlling the display so that the original is divided and the copy operation is performed on the display unit. Image forming apparatus.