JP3457685B2 - Digital copier - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital copying apparatus that temporarily encodes image data, stores it in a memory, decodes it, and outputs it. More specifically, the present invention relates to a digital copying apparatus which improves the processing time of first copy. Regarding

[0002]

2. Description of the Related Art As one of digital copying apparatuses, an apparatus having a function of holding image data read by a scanner in a memory has been developed. The digital copying apparatus having such a function has the following advantages as compared with a copying apparatus which forms an image using directly read image data.

Scan the original to be copied with a scanner,
Since the image data is stored in the memory, when copying a large number of originals, it is only necessary to read the originals the first time and use the data held in the memory for the second and subsequent copies. You can Therefore, it is not necessary to wait for the original reading scanner to return to the position where the reading is started before performing the next reading, and it is possible to omit the time required for the scanner to return to the predetermined position and continuously perform copying. In other words, without increasing the speed of the photoreceptor,
The number of copies per unit time can be increased.

Further, since the image data of the original document to be copied is held in the memory, some trouble may occur, for example, when a jam of the recording paper occurs, when the supply of the recording paper or toner is used up, and other abnormalities occur. Even if it is necessary to interrupt the copy cycle, such as when it occurs, you can restart copying of the specified document without reading the document again, and perform the copy that was insufficient due to the interruption. You can

Even when a large number of sheets are continuously copied,
When the scanner finishes reading the document, the document can be set next, read in advance, and stored in the memory. Therefore, it is possible to eliminate the loss of time due to the replacement of originals, and it is possible to substantially improve the processing capacity per unit time.

Further, in a digital copying machine equipped with a recycle ADF (automatic document feeder) which repeatedly sends an original document to a document table and repeats copying, the damage of the original document due to the increase in the number of times the original document is sent is a problem. However, when the image data is held in the memory, the recycled ADF is used without damaging the original by holding the image data in the memory with one document feed and then using the data read from the memory. The same copying as can be done.

Further, even when data of a plurality of originals is edited to create a new original and an image is formed, if the image data of the original is held in the memory, the data can be selected from the data and used. Therefore, the degree of freedom is increased as compared with the conventional editing by cutting and pasting a document.

However, in order to realize such a function, a large amount of memory that can be accessed at high speed is required. Therefore, from the viewpoint of cost and size of the memory device, it has been a long time as a copying machine for general office work. It was not realized.

On the other hand, with the recent development of semiconductor technology and expansion of fields of use, memory capacity is increased and cost is reduced, image data is encoded and decoded, and image data is encoded and decoded at high speed. By developing a processor that can be performed,
An apparatus that once encodes image data, stores it in a memory, and decodes and outputs the image data, for example, a "printing apparatus" of Japanese Patent Application Laid-Open No. 2-36960 has been developed. This device compresses image data so that the memory can be efficiently used by compressing the image data, thereby increasing the cost of the device without increasing the size of the memory device. Rather, it provides an apparatus having a function of holding image data read by a scanner in a memory.
Further, it is possible to hold a sufficient number of original image data in the memory with a small amount of memory.

[0010]

However, according to the conventional apparatus for encoding image data, storing it in the memory, decoding it, and outputting it, the image data is encoded / decoded in page units, and at least 1 Decoding cannot be started until the page data has been encoded. Therefore, if such encoding / decoding is directly applied to the digital copying apparatus, the original is set, the original is copied, and the first sheet is copied. There was a problem that the time until the eye copy was completed (first copy time) was long. This is because the memory cannot be read when the memory for encoding and writing the image data is in the write mode.

Further, according to the conventional apparatus which encodes image data, stores it in the memory, decodes it, and outputs it, the scale factor at the time of encoding is fixed. In other words, the image data is compressed. Since the rate is fixed, there is a problem that it is not possible to change the efficiency of use of the memory and to adjust the image quality of the output image after encoding / decoding.

Further, in the conventional digital copying apparatus having the function of holding the image data read by the scanner in the memory, the function of holding the image data in the memory is simply added to the conventional digital copying apparatus. However, there is a problem that holding the image data in the memory is not sufficiently reflected in operability and convenience.

The present invention has been made in view of the above, and it is a first object of the present invention to avoid increasing the time until the first copy is completed (first copy time) and maintain high-speed processing. The purpose of.

The present invention has been made in view of the above, and it is a second object of the present invention to change the use efficiency of the memory and adjust the image quality of the output image after encoding / decoding. To aim.

Further, the present invention has been made in view of the above, and by holding the image data in the memory,
A third object is to improve operability and convenience .

[0016]

[0017]

SUMMARY OF THE INVENTION The present invention is to achieve the above Symbol purpose, a reading means for reading an original electrical, encoding means for encoding the image data read, coding by the coding means Decoding operation of the decoding means in a digital copying apparatus provided with a code storage means for storing the encoded image data and a decoding means for decoding the encoded image data stored in the code storage means. (EN) A digital copying apparatus provided with a control means for reading a new original by using a reading means, encoding it using an encoding means, and writing to a code storage means during execution.

In order to achieve the third object of the present invention, the reading means for electrically reading the original, the coding means for coding the read image data, and the coding means are used for coding. In a digital copying apparatus provided with a code storage unit for storing image data and a decoding unit for decoding the encoded image data stored in the code storage unit, during a decoding operation of the decoding unit. , Based on the designation of a new copy mode of the original, the corresponding original is read by using the reading means, encoded by the encoding means, and the copy mode designated at the time of writing to the code storage means is also added. The present invention provides a digital copying apparatus provided with a control means for storing. Incidentally, when the image formation of the original document during the decoding operation is completed, the control means reads the sequentially stored copy mode and image data, and controls the image forming operation based on the read mode. Is desirable. In addition, the control means, while executing the decoding operation of the decoding means, after interrupting the image forming operation due to an abnormality,
When the abnormality is recovered, it is desirable to execute the image formation of the number insufficient due to the interruption based on the stored image data, the copy mode, and the number of copies already completed at the time of the interruption.

In order to achieve the third object of the present invention, the reading means for electrically reading the original, the coding means for coding the read image data, and the coding means are used for coding. In a digital copying apparatus including a code storage unit for storing image data and a decoding unit for decoding the encoded image data stored in the code storage unit, a copy mode of a document stored in the code storage unit. And a management table for storing, and during execution of the decoding operation of the decoding means, based on the designation of the copy mode of the new original, the corresponding original is read using the reading means and encoded using the encoding means, The present invention provides a digital copying apparatus having a control means for writing to a code storage means and storing a copy mode in a management table. Incidentally, when the image formation of the original document during the decoding operation is completed, the control means reads the sequentially stored copy mode and image data, and controls the image forming operation based on the read mode. Is desirable. Further, the control means, when the decoding operation of the decoding means is being executed, after interrupting the image forming operation due to an abnormality, when the error recovers, the image data stored, the copy mode, and the completion at the time of interruption are already completed. It is desirable to execute the image formation of the number of sheets which is insufficient due to the interruption based on the number of copied sheets. Further, it is preferable that the control unit executes the image formation of the image data stored in the code storage unit after executing the image formation of the number of sheets which is insufficient due to the interruption.

In order to achieve the third object of the present invention, the reading means for electrically reading the original, the coding means for coding the read image data, and the coding means are used for coding. In a digital copying apparatus including a code storage unit that stores image data and a decoding unit that decodes the encoded image data stored in the code storage unit, the image data is encoded by the encoding unit. If it cannot be performed, or if encoding cannot be performed during encoding, the image data stored in the code storage means is cleared or decoded to form an image, and then the encoding means,
A digital copying apparatus provided with a code storage means and a control means for forming an image by using image data from a reading means without passing through a decoding means.

In order to achieve the third object of the present invention, the reading means for electrically reading the original, the coding means for coding the read image data, and the coding means are used for coding. In a digital copying apparatus including a code storage unit for storing image data and a decoding unit for decoding encoded image data stored in the code storage unit, an overflow occurs in the code storage unit. In this case, there is provided control means for interrupting the reading by the reading means, decoding all the image data stored in the code storing means to form an image, then clearing the code storing means, and restarting the reading by the reading means. A digital copying machine is provided.

[0022]

[0023]

[0024]

In the digital copying apparatus of the present invention, the reading means
Image data read by the document and the encoding means
And the code storage means encodes the encoded image data.
Encoded image data stored and decoded means stored
While the decoding operation of the decoding means is being executed , the control means reads a new original document using the reading means, encodes it using the encoding means, and writes it in the code storage means.

Further, during execution of the decoding operation of the decoding means, the control means reads the corresponding original using the reading means based on the designation of the copy mode of the new original and encodes it using the encoding means. Then, the copy mode designated at the time of writing to the code storage means is also stored.

Further, during execution of the decoding operation of the decoding means, the control means reads the corresponding original using the reading means based on the designation of the copy mode of the new original and encodes it using the encoding means. Then, the copy mode is written into the code storage means and the copy mode is stored in the management table.

Further, when the image formation of the original document during the decoding operation is completed, the control means reads the sequentially stored copy mode and image data, and performs the image forming operation based on the read mode. Control.

Further, the control means interrupts the image forming operation due to an abnormality during execution of the decoding operation of the decoding means, and then restores from the abnormality, the stored image data, copy mode, and interruption time point. In step S3, the image formation of the number insufficient due to the interruption is executed based on the number of copies already completed.

Further, the control means executes the image formation of the image data stored in the code storage means after executing the image formation of the number of sheets which is insufficient due to the interruption.

The control means clears the image data stored in the code storage means when the image data cannot be encoded by the encoding means, or when the image data cannot be encoded during the encoding. After the image is formed by decoding, the image is formed by using the image data from the reading means without passing through the encoding means, the code storage means, and the decoding means.

When an overflow occurs in the code storage means, the control means interrupts the reading by the reading means, decodes all the image data stored in the code storage means to form an image, and then codes the code. The storage means is cleared and the reading by the reading means is restarted.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the digital copying apparatus of the present invention will be described below with reference to the drawings. Details of the encoding unit, the decoding unit, and the code storage unit (principal part of the present invention) will be described in detail in the order of specific operations.

Schematic Configuration of Digital Copier FIG. 1 shows a schematic configuration of a digital copier according to the present embodiment. The digital copier is roughly classified into a copier body 100, an automatic document feeder (ADF) 200, and It is composed of four units, a sorter 300 and a double-sided reversing unit 400.

FIG. 2 shows the construction of the copying apparatus main body 100, which comprises a scanner section, a writing section, a photoconductor section, a developing section, a paper feeding section, and the like. Hereinafter, the configuration and operation of each of these parts will be described in detail.

[Scanner Unit] The scanner unit is equipped with the reflecting mirror 101, the light source 102, and the first mirror 103, and moves at a constant speed.
Scanner and second mirror 104 and third mirror 105
And a second scanner which moves following the first scanner at a speed half that of the first scanner.
An original (not shown) on the contact glass 106 is optically scanned by the first scanner and the second scanner,
The reflected image is guided to the lens 108 via the color filter 107 and imaged on the one-dimensional fixed image pickup element 109.

A fluorescent lamp or a halogen lamp is used as the light source 102, but a fluorescent lamp is generally used because of its stable wavelength and long life. In this embodiment, the reflecting mirror 101 is attached to one light source 102, but two or more light sources 102 may be used. Since the fixed image pickup device 109 described above has a fixed sample clock, the fluorescent lamp will adversely affect the image unless it is lit at a higher frequency.

The fixed image pickup device 109 is generally a CC
D is used. Since the image signal read by the fixed image pickup device (hereinafter, referred to as CCD image pickup device) 109 is an analog value, analog / digital (A / D) conversion is performed.
Various kinds of image processing (for example, binarization processing, multi-value processing, gradation processing, scaling processing, editing processing, etc.) are performed on the image processing board 110, and converted into digital signals as a set of spots.

In order to obtain color image information, in the present embodiment, a color filter 107 that allows only the necessary color information to pass through is arranged so that it can be taken in and out along the optical path guided from the document to the CCD image pickup device 109. The color filter 107 is moved in and out in accordance with the scanning of the original, and the functions such as multiple transfer and double-sided copy are activated each time, so that various kinds of copies can be created. The marker on the original image can be read in the copy mode.

[Writing Section] The image information after the image processing is written on the photosensitive drum 111 in the writing section in the form of a set of light spots by raster scanning of laser light. A He-Ne laser is conventionally used as this laser light source. The He-Ne laser has a wavelength of 633 nm and is used because it is well matched with the sensitivity of the copying photoconductor. However, the laser light source itself is very expensive and the device cannot be directly modulated, which complicates the apparatus. In recent years, semiconductor lasers that are inexpensive and capable of direct modulation have been used in recent years due to the increased sensitivity of the photoconductor in the long wavelength region. Also in this embodiment, this semiconductor laser is used as a laser light source.

3 (a) and 3 (b) are a plan view and a side view of the writing section, in which the laser light emitted from the semiconductor laser 112 is converted into a parallel light flux by the collimator lens 113, and the aperture 114 is used. It is shaped into a light beam with a fixed shape. The shaped laser light enters the polygon mirror 116 in a form compressed by the first cylinder lens 115 in the sub-scanning direction.

The polygon mirror 116 has an accurate polygonal shape and is rotated by a polygon motor 117 in a fixed direction at a fixed speed. The rotation speed is the rotation speed of the photosensitive drum 111, the writing density, and the polygon mirror 11.
It is determined by the number of faces.

The reflected light of the laser light incident on the polygon mirror 116 is deflected by the rotation of the polygon mirror 116. The deflected laser light is reflected by the fθ lens 118.
A and 118b are sequentially incident. fθ lens 118a, 1
Reference numeral 18b converts scanning light having a constant angular velocity so as to scan the photoconductor drum 111 at a constant speed, and forms an image so as to form a minimum light spot on the photoconductor drum 111, and further has a face tilt correction mechanism. ing.

The laser light that has passed through the fθ lenses 118a and 118b is guided to the synchronization detection sensor 120 by the synchronization detection mirror 119 outside the image area, and after a certain time has elapsed from the time when the synchronization signal for issuing the cue signal in the main scanning direction is issued, the image is obtained. Data is 1
Lines are output, and this is repeated thereafter to form one image.

[Photosensitive Member] A photosensitive layer is formed around the photosensitive drum 111.
As a photosensitive layer having sensitivity to a semiconductor laser beam (wavelength 780 nm), an organic photoconductor (OPC), α-Si, Se-
Te and the like are known, and in this embodiment, an organic photoconductor (OP
C) is used. Generally, for laser writing,
Negative / positive (N / P) process of shining light on the image area,
2 of positive / positive (P / P) process of shining light on the background
There is a street, and in this embodiment, the former N / P process is adopted.

The charging charger 121 is of a scorotron type having a grit on the photosensitive member side, uniformly (-) charges the surface of the photosensitive drum 111, and irradiates the image forming portion with a laser beam to adjust the potential of the portion. Drop it. Then, the background portion of the surface of the photoconductor drum 111 is -750 to -800.
V, the image portion has a potential of about -500 V, and an electrostatic latent image is formed on the surface of the photosensitive drum 111. This is applied to the developing roller by the developing units 122a and 122b from -500 to -60.
A bias voltage of 0 V is applied to attach (-) charged toner to make the electrostatic latent image visible.

[Developing Section] The color copying apparatus of this embodiment is provided with two developing devices, a main developing device 122a and a sub-developing device 122b, as shown in the drawing. In the case of a black color, the sub-developing device 122b and the toner replenishing device 123b are removed. In this embodiment having two developing devices, black toner is put in the toner replenishing device 123a which is paired with the main developing device 122a, and the sub-developing device 122 is used.
By inserting the color toner into the toner replenishing device 123b paired with b, the development is selectively performed by changing the main pole position of the multi-color developing device during the development of one color.

This development is performed by the color filter 107 of the scanner.
It becomes possible to read color information by switching between, and to perform multi-function color copying and color editing by combining with the multi-transfer of the paper transport system and the double-sided copying function. For developing three or more colors, a method of arranging three or more developing devices around the photosensitive drum 111,
There is a revolver system in which three or more developing devices are rotated and switched.

The image visualized by the developing devices 122a and 122b is transferred onto the recording paper, which is synchronized and sent to the photoconductor drum 111, from the back surface of the paper by being charged with (+) by the transfer charger 123. To be done. The transferred recording paper is subjected to AC neutralization by a separation charger 124 which is integrally held with the transfer charger 123, and the photosensitive drum 1
Separated from 11.

On the other hand, the toner remaining on the photosensitive drum 111 without being transferred onto the recording paper is cleaned by the cleaning blade 12.
It is scraped off from the photoconductor drum 111 by 5 and collected by the attached tongue 126. Further, the photosensitive drum 111
The potential pattern remaining in the area is erased by irradiating the static elimination lamp 127 with light.

[Paper Feeding Unit] In this embodiment, a plurality of cassettes 128a, 128b, 1
28c, and a re-feeding loop 12 for recording paper that has been transferred once
It is possible to perform double-sided copying or re-feeding through the sheet 9.

A plurality of cassettes 128a, 128b, 12
When one of the cassettes 8c is selected and a predetermined start button is pressed, the paper feed rollers (130a, 130b, 130c) near the selected cassette
Is rotated and is fed until the leading end of the recording paper hits the registration roller 131. At this time, the registration roller 131
Is stopped, the rotation is started at the timing of the image position formed on the photoconductor drum 111, and the recording paper is fed to the periphery of the photoconductor drum 111. After that, the toner image on the recording paper is transferred at the transfer unit, and the separation / conveyance unit 132
The toner image transferred by suction is fixed on the recording paper by a fixing roller composed of a pair of heat roller 133 and pressure roller 134.

The recording paper thus transferred is guided to the paper exit on the sorter 300 side (see FIG. 1) by the switching claw 135 during normal copying. On the other hand, during multiple copy,
The direction is not changed by the switching claws 136 and 137, passes through the lower sheet re-feeding loop 129, and is guided to the registration roller 131 again.

When performing double-sided copying, the copying apparatus body 10
There are two cases, that is, the case where only 0 is used and the case where the double-sided reversing unit 400 (see FIG. 1) is used. Here, the former case will be described. The recording paper guided downward by the switching claw 135 is further guided downward by the switching claw 136, and then sent by the switching claw 137 to a tray (not shown) further below the re-feeding loop 129. By reversing the roller 138, it is fed again in the opposite direction, and by switching the switching claw 137, it is guided to the refeeding loop 129 and fed to the registration roller 131.

[ADF] FIG. 4 shows the configuration of the ADF 200. The ADF 200 automatically guides the originals one by one onto the contact glass 106 and automatically ejects the originals after copying. A stack of documents (not shown) placed on the document feed tray 201 is aligned in the width direction of the documents by the side guides 202.
The placed originals are separated and fed one by one by the paper feed roller 203, and the contact glass 1 is rotated by the rotation of the conveyor belt 204.
It is carried to a predetermined position on 06 and positioned.

When the copying of the predetermined number of sheets is completed, the original is discharged to the discharge tray 205 by the rotation of the conveyor belt 204 again. Although not described in detail, the side guide 20
By counting the position of 2 and the feeding time of the original,
The document size is being detected.

[Sorter] FIG. 5 shows the structure of the sorter 300. Sorter 300 is
The recording paper discharged from the copying apparatus main body 100 is, for example,
It is a device for sorting in page order, sorting for each page, or selectively feeding to preset bins 301a to 301x. The recording paper conveyed by a plurality of rollers rotatably driven by the motor 302 is
By switching a claw (not shown) near the entrance of a to 301x, it is guided to the selected bins 301a to 301x.

[Double-Sided Reversing Unit] FIG. 6 shows the structure of the double-sided reversing unit 400. As described above, the copying apparatus main body 100 side can perform only double-sided copying for each sheet, but by providing the double-sided reversing unit 400, it is possible to perform double-sided copying collectively.

When making a double-sided copy collectively for a plurality of sheets, the recording paper which has been fixed in the copying apparatus main body 100 (see FIG. 2) is transferred to the double-sided reversing unit 400 via the switching claws 135 and 136. Sent. The recording paper that has entered the double-sided reversing unit 400 is accumulated on the tray 402 by the paper discharge roller 401. At this time, the recording paper is fed vertically and vertically by the feed roller 403 and the side alignment guide 404.
The sides are aligned. The recording sheets accumulated on the tray 402 are re-fed by the re-feeding rollers 405 when the back side is copied. At this time, the recording paper sent to the copying apparatus main body 100 side is directly guided to the re-feed loop 129 by the switching claw 136 and the switching claw 137 (see FIG. 2).

Overall Configuration of Control System FIG. 7 is a block diagram showing the overall configuration of the control system in the digital copying apparatus according to this embodiment. In the figure,
Reference numeral 701 is a main control board for controlling the entire digital copying apparatus, 702 is an ADF control board for controlling the ADF 200, 703 is a sorter control board for controlling the sorter 300, and 704 is a double-sided reversing unit 400. A double-sided control plate, 705 is a paper feed control plate for performing various controls of the paper feed unit,
706 is an application system, 707 is a sensor such as a fixing sensor, a density sensor, and a registration sensor.
Reference numeral 708 denotes fans such as an APL fan and an exhaust fan.
9 is a counter such as a total counter or a key counter,
A fixing thermistor 710 detects the surface temperature of the fixing roller.

Further, 711 is an LD control plate for controlling the semiconductor laser 112, 712 is a PWM control plate, 713 is a drive plate for driving the polygon motor 117, 714 is a drive plate for driving the main motor 714a, and 715 is a fixing roller. Fixing heater and thermal fuse to prevent overheating, 7
16 is an AC drive plate that serves as an AC power source for a fixing heater,
Reference numeral 717 is a DC power source that rectifies the AC from the AC driver 716 to DC and serves as a drive source for each DC driving component. Reference numeral 718 is a toner replenishment SOL (solenoid) of the developing unit, abutting of the cleaning blade 125 to the photosensitive drum 111, and Blade SOL (solenoid) for separating operation, first
˜3 pickup SOL (solenoid), first and second lock SOL (solenoid), and 719 are registration rollers 13
Registration CL (clutch) for drivingly transmitting to No. 1, rising relay CL (clutch), first to third sheet feeding CL (clutch), 7
20 is a sensor related to the sheet feeding unit, 721 is an intake fan, 7
Reference numeral 22 denotes a transport fan that sucks the recording paper of the separation transport unit 132.

Further, 723 is each sensor of the sorter 300, 724 is a drive motor for rotationally driving each roller of the sorter 300, and 725 is each bin 301a of the sorter 300.
Solenoids for switching the recording paper entry to ˜301x, 726 solenoids of the double-sided reversing unit 400,
727 is a clutch of the double-sided reversing unit 400, 728
Is a jogger motor for aligning sheets of the double-sided reversing unit 400, 729 is each sensor of the double-sided reversing unit 400, 730 is each sensor of the ADF 200, and 731 is AD.
F200 solenoids, 732 is a motor that rotationally drives each transport roller of the ADF 200, and 733 is an ADF2
A switch for detecting the setting state of 00 and a switch for switching the paper thickness of the document, and 734 is a display unit for displaying the number of documents of the ADF 200, a jam condition, and the like.

Further, 735 is a scanner motor for scanning and driving the scanner unit, 736 is a rotary encoder connected to the drive shaft of the scanner motor 735, 737 is a lamp control circuit for controlling the lighting of the light source 102, and 738 is a sub-scanning drive mechanism. HP sensor for detecting the reference position of 739, 739
Is ADFSOL (solenoid), 740 is APSSOL
(Solenoid), 741 is a fluorescent lamp heater and a thermistor for temperature control, and 742 is a high voltage power source for applying high voltage power to the charging charger 123, the separation charger 124, and the developing bias electrode (not shown). In addition, 744
Is an image processing unit (IPU) that receives an input from the CCD image pickup device 109.

8 and 9 are block diagrams of the electrical equipment control section of the digital copying machine according to this embodiment. The two diagrams are obtained by dividing one block diagram, and the two diagrams are connected to form one overall block diagram.

The control unit of the color copying machine has two CPUs. The CPU (a) controls the sequence and the CPU (b) controls the operation. The CPU (a) and the CPU (b) are connected by a serial interface (RS232C). Also, these two CPUs (a) and CPU
(B) constitutes the control unit 800 of the present invention described later.

First, the sequence control will be described.
The CPU (a) (hereinafter, referred to as a sequence) controls the timing of the recording paper conveyance, and as shown in FIG. 9, a paper size sensor, a sensor related to the paper conveyance such as discharge detection and registration detection, A double-sided control plate 704, a high voltage power supply 742, a relay driver, a solenoid driver, a motor driver, a sorter control plate 703, an optical writing unit 743, etc. are connected.

Regarding the sensor, a paper size sensor for detecting the size and direction (direction) of the recording paper loaded in the paper feed cassette and outputting an electric signal according to the detection result, resist detection, paper discharge detection, etc. Sensor for conveying recording paper,
Signals are input from a sensor that detects the presence or absence of supply such as an oil end or a toner end, or a sensor that detects a machine abnormality such as a door open or fuse blown.

Input / output signals of the double-sided control plate 704 include a motor for aligning the width of the recording paper, a paper feed clutch, a solenoid for changing the conveying path, a paper presence sensor, and a side fence for aligning the recording paper width. There are home position sensors, paper transport sensors, and so on.

The drivers include a paper feed clutch, a registration clutch, a counter, a motor, a toner replenishing solenoid, a power relay, and a fixing heater.

The sequence and the sorter control plate 703 are connected by a serial interface, and the sorter control plate 703 conveys the recording paper at a predetermined timing according to a signal from the sequence and discharges the recording paper to each of the bins 301a to 301x. There is.

The fixing temperature, the photosensor input (P sensor input), the monitor input of the semiconductor laser 112, and the reference voltage of the semiconductor laser 112 are input to the analog input section (see FIG. 8). The fixing temperature is controlled on / off by an input from a thermistor in the fixing unit so that the temperature of the fixing unit becomes constant. As for the photosensor input, a photosensor pattern created at a predetermined timing is input by a phototransistor, and a toner replenishing clutch is turned on / off to control the toner density.

The A / D converter and the analog input section of the CPU are used as a mechanism for adjusting the power of the semiconductor laser 112 to be constant. This is a preset reference voltage (the output voltage of the semiconductor laser is 3 mW
Is set so that the semiconductor laser 112
It is controlled so that the monitor voltage when the lights up is the same.

The image processing board 110 generates timing signals for masking / trimming of image data, erasing, photo sensor pattern of density sensor, etc., and outputs a video signal to the semiconductor laser 112. The gate array synchronizes the image data continuously transmitted in 2-bit parallel from the scanner unit with the synchronization signal PMSYNC from the optical writing unit 743, and further converts the image data into a 1-bit serial signal in synchronization with the image writing position signal RGATE. And outputs it to the image processing board 110.

Next, operation-related control will be described below. The main CPU (b) controls a plurality of serial ports and a calendar IC. A sequence of sequence control is connected to the plurality of serial ports, an operation unit 750, a scanner control circuit 700,
An application circuit 706, an editor, etc. are connected.

In the operation unit 750, the key input information by the operator is serially transmitted to the main CPU (b), and the display unit is turned on by the serial reception from the main CPU (b). In the scanner control circuit 700, the scanner motor 73
Drive control, image processing, and serial transmission processing of image reading information to the main CPU (b);
Interface processing between the ADF 200 and the CPU (b) is performed.

The application circuit 706 exchanges preset information through an interface with an external device (facsimile device, printer, etc.).
Further, the editor is image editing data (masking, trimming, image shift, etc.) input from the operation unit 750.
Is serially transmitted to the main CPU (b) to input the processing content of image editing. The calendar IC reads the stored date and time by the main CPU (b) at any time,
The current time is displayed on the display unit of the operation unit 750 and timer control is performed by setting the on time and the off time of the copying apparatus.

Flow of Image Data FIG. 10 is a schematic diagram showing the flow of image data in the digital copying apparatus of this embodiment. The image reading unit 801
The device is composed of the scanner unit and the scanner control circuit 700 described above. Therefore, the reading is CCD
This is performed by the image sensor 109 and the image data is output as serial data. The output image data is amplified to a predetermined level, A / D-converted, and further subjected to shading correction for compensating for the characteristics of the optical system, CCD sensitivity variations, etc., and then input to the encoding unit 802. .

The coding section 802 codes the image data by using a coding method such as discrete cosine transform (DCT) and writes the generated code in the code storage section 806 composed of a semiconductor memory. At this time, the scale factor, the quantization matrix, the Huffman coding table used for the coding, and the copy condition specified by the operator for the document ( For example, copy number, document size,
Copy size, recording paper size, etc.) is written as information.
Although not shown, the copy condition data is received from the main CPU (b) in FIG. 8 and written in the header section. In addition, for example, in the case where the encoded data file is transferred to a computer or an image file for use, it is desirable to standardize the structure of the data file so that it can be used as it is. It is better to manage with a separate management table.

When outputting the data stored in the code storage unit 806, the data (code) is decoded by the decoding unit 803, and the image processing unit 804 selectively performs halftone processing and simple binarization processing. The image is output via the image output unit 805. The control unit 800 controls the timing of each of the above-described units, and is configured by the two CPUs (a) and (b) shown in FIGS. 8 and 9.

The image processing unit 804 is composed of the image processing board 110 shown in FIG.
Reference numeral 5 corresponds to a [writing section], a [photosensitive section], and a [developing section] of the schematic construction of the digital copying apparatus.

The flow of image data in the above configuration will be described. When outputting the image of the original document that is currently being encoded, the decoding unit 803 controls the timing of the control unit 800 so that the encoding unit 802 uses the scale factor, the quantization matrix, and the scale factor that are currently used for encoding.
The Huffman coding table is received, and the coding unit 802 reads the data being written in the code storage unit 806 while coding and decodes the Huffman coding table to obtain a reproduced image and obtain the reproduced image.
Output to 4. The image processing unit 804 outputs the image data to the image output unit 805 by performing the processing necessary for forming an image by the electrophotographic method and the processing based on the instruction from the operator. The image output unit 805 is the photosensitive drum 1.
11 is written and printing is performed.

On the other hand, when the image of the original document which has already been encoded and is written in the code storage unit 806 as a file of data for one page is output, the decoding unit 80
3 is a scale factor, a quantization matrix of the header part of the file by the timing control of the control unit 800,
The Huffman coding table and the coded image data are read from the code storage unit 806 and decoded to obtain a reproduced image and output to the image processing unit 804. The image processing unit 804 outputs the image data to the image output unit 805 by performing the processing necessary for forming an image by the electrophotographic method and the processing based on the instruction from the operator. Image output unit 80
Reference numeral 5 writes on the photosensitive drum 111 to perform printing.

Details of Encoding Unit, Decoding Unit, and Code Storage Unit Next, the details of the encoding unit 802, the decoding unit 803, and the code storage unit 806 will be described with reference to FIG. .

In the coding unit 802 of this embodiment, the discrete cosine transform coding system is used as the coding system. First, the block reading unit 802a reads an image for each 8 × 8 pixel block as shown in FIG.
In 02b, it is converted into a DCT coefficient value. The DCT transform is defined by the equation (1). Here, x _ij is the original pixel and y _UV is the conversion coefficient.

[0084]

[Equation 1]

The coefficient output from the DCT transform unit 802b is linearly quantized by the quantizing unit 802c with a different quantizing step size for each coefficient to obtain a quantized coefficient. At this time, the quantization step size for each coefficient is obtained by multiplying the quantization matrix stored in the quantization matrix storage unit 807 by the scale factor value set by the scale factor control unit 808. The code amount or the decoded image quality is controlled by changing the value of this scale factor. Here, the quantization matrix finely quantizes low-order coefficients in accordance with human visual characteristics, as shown in FIG. 13, for example. The Huffman coding unit 802d assigns a short code to a coefficient having a high appearance frequency and a long code to a coefficient having a low appearance frequency, so that the quantization coefficient is reduced as a whole. It is stored in the code storage unit 806.

In the present embodiment, the scale factor value set by the scale factor control unit 808 is designated via the operation unit 750 (scale factor designating unit in the present embodiment), and the operator externally operates. The scale factor value can be adjusted. As a result, the operator can change the usage efficiency of the memory of the code storage unit 806, adjust the image quality of the output image after encoding / decoding, and the like.

The DCT coefficient is, as shown in FIG.
The coefficient (0,0) indicates the average density of the block, and the other low-order coefficients near (1,0) and (0,1) are the low-frequency components of the block. The higher the coefficient is, the higher the high-frequency component is included. From this, the coefficient of (0,0) is called a DC component, and the other coefficients are called an AC component. Also, (1,
Coefficients in the u direction (main scanning direction) such as 0), (2,0), (3,0), ... Show the rate of change in density in the main scanning direction, and are (0,1), (0,2). , (0, 3) ... In the v-direction (sub-scanning direction), the coefficient indicates the magnitude of the component in which the density change in the sub-scanning direction and the density change in the sub-scanning direction overlap.

When outputting an image, the code storage unit 806
The Huffman decoding unit 803d assigns the value of the quantized coefficient value to the code, and the inverse quantization unit 803c inversely quantizes the value. At this time, the quantization step size in inverse quantization is obtained by multiplying the quantization matrix stored in the quantization matrix storage unit 807 by the value of the scale factor control unit 808, as in the case of encoding. DC output by the inverse quantizer 803c
The T coefficient is converted into image data by the inverse DCT conversion unit 803b and output for each block by the block writing unit 803a. The image data output for each glock is a 1-block line memory (not shown) (1 block line is a column of blocks continuing in the main scanning direction, and here, since 1 block is 8 × 8 pixels, there are 8 lines) When the 1-block line memory is full, the data is output to the image processing unit 804 shown in FIG. 10 line by line.

In the present embodiment, as described in the flow of image data, the encoded image data written in the code storage unit 806 is encoded while encoding the image data obtained by reading one original. It has the function of decoding with a delay of the number of lines corresponding to the required processing unit. Therefore, in order to realize this function, the code storage unit 806 includes a dual port memory 806a that can simultaneously perform read / write access at high speed and a RAM 8 that is a normal semiconductor memory.
It has two memories 06b and 06b.

The Huffman encoder 8 encodes the encoded data.
02d output from the multiplexer (MUX) 806
It is written in the dual port memory 806a via A of c. In parallel with writing, this data passes through A of the multiplexer (MUX) 806d, is read by the Huffman decoding unit 803d, is decoded, and is dequantized by the inverse quantization unit 803.
c, the inverse DCT conversion unit 803b, and the block writing unit 803a to output to the image processing unit 804.
This is a path of image data in the case where one original is encoded and simultaneously decoded to form an image.

When the encoding of one original is completed, the encoded file of the original is completed in the dual port memory 806a. The completion time is the time when the scanner unit of the copying apparatus operates to finish reading the original document and the scanner starts returning to the reading start position. Since the original is not read during the return, new image data is not input. Therefore, the encoding unit 802 stops operating. Multiplexer (MUX) 80 during this period
6c is switched to B, and the completed file is R in this path
Transfer to AM806b.

When an image of a file that has been encoded is formed, it is necessary to read the file from the RAM 806b. Therefore, the multiplexer (MUX) 806d is set to B.
Switch to. When decrypting this data, the parameters used for decrypting the header part of the file to be read are obtained and processed.

In the present embodiment, the parameters necessary for the decoding process are directly sent from the coding unit 802 to the decoding unit 803 when one document is coded / decoded in parallel. However, this data is the dual port memory 806
Since the data is written in the header portion when the data is written in a, it may be read from the header portion and used in the decoding unit 803.

During the scanner return period at the time of reading the original, the dual port memory 806a to the RAM 8
The dual port memory 806a is not highly integrated, and thus the unit price per bit is high and the size of the code storage unit 806 is prevented from becoming large. Memory 806a
This is because the image data obtained by encoding the capacity of 1 can be stored in a capacity for storing one page.

Specific Operation Next, a specific operation of the present embodiment will be described in the order of [encoding / decoding operation timing when copying is performed] and [image compression exception processing].

[Encoding / Decoding Operation Timing When Copying is Performed] FIG. 15 shows image encoding and decoding when four originals are set in the ADF 200 and one copy is made. The timing chart is shown and the copy start signal is
After the operator sets the original on the ADF 200 and presses the print key to start the copy operation,
A start signal of the original reading scan issued by the control unit 800, and a copy start signal for the second and subsequent sheets is ADF2.
00 is a signal set by the control unit 800 when the document reading scanner returns to the start position. This copy start signal starts reading the next document. The image reading signal indicates a period in which the image reading unit 801 outputs the image data to the encoding unit 802. The encoding indicates a period during which the read image data is encoded (that is, a period during which the encoding unit 802 is operating), and the decoding is performed while decoding the data encoded and written in the code storage unit 806. , A period during which the decrypted data is written in the photosensitive drum 111. Here, the scale factor used by the encoding unit 802 for encoding,
The quantization matrix and the Huffman coding table are configured so that the decoding unit 803 can read them, and a memory that holds coded data at the same time is a dual port memory 806a.
Then, by delaying the operation time of the decoding unit 803 for a period corresponding to the number of lines of the block for which encoding and decoding are to be processed and the number of lines of the buffer for reading, encoding of image data of the same original document is performed. And decryption are performed in parallel.

FIG. 16 shows a timing chart in the case of making two copies from each of three originals, which is an example in which it is important to finish reading the originals as fast as possible. The advantage of accelerating document input is remarkable when there are a plurality of documents and the number of copies from one document is relatively large. In such cases,
In a copying apparatus that reads the next original after copying each original (that is, a conventional copying apparatus that does not have an image memory), the copying of the set originals must be completed before the next original is copied. Since the manuscript could not be set, the operator could not leave the copying machine during this time. However, in the digital copying machine of this embodiment, the operator completes the copying of the manuscript image to be copied and the copy mode. Since the registration can be done before, the registered document can be taken away from the copying machine at the time of completing the registration, and the copying process after that can be entrusted to the copying machine.

Here, first, the first original is read, the data is encoded, and the code storage unit 806 is used.
While copying the first sheet while writing the data on the photosensitive drum 111 while holding it at the same time and decoding it at the same time, the dual port memory 8
The scale factor, the quantization matrix, the Huffman coding table, and the coded image data used for coding are transferred from 06a to the RAM 806b. The second copy is printed by reading the encoded image data transferred to the RAM 806b and writing the image data on the photosensitive drum 111 while decoding the image data. Of course, if the dual port memory 806a has a sufficient capacity, the coded data may be directly read from the dual port memory 806a without being transferred to the RAM 806b, and may be decoded to form an image. During this time, if the scanner for reading the original reads the first original and returns to the reading start position, the next original can be read even while the printing of the previous original is being executed.

A, B, and C in the figure indicate images on which the respective processes are performed. For example, the period during which the first original A is read, encoded, and decoded is indicated as A. That is, the read signal is decoded from the time when the data of the lines for the blocks to be processed is aligned and then the encoding A is performed and the encoded data is aligned with the lines corresponding to the blocks to be decoded. Start chemical A. Data of one document is encoded and decoded in parallel, and after the decoding is completed, the dual port memory 806a reads R
The data is transferred to the AM 806b, the second print is read from the RAM 806b, is decoded, and is written on the photosensitive drum 111. Usually, the compression rate by encoding is about one tenth to several tenths. Therefore, if data is transferred between memories at the same speed as the bit stream clock of image data handled in encoding and decoding, compression will be performed. The time required for transfer decreases in proportion to the rate.

The page interval of the decoding process has a limit in reducing the interval of the recording papers due to the time required for the above transfer and the restrictions associated with the transportation of the recording papers such as paper feeding and separation of the copying apparatus. , Determined by the longer of these factors.

FIG. 17 shows an example in which the timing for starting the reading of the next most original is delayed under the condition that copying is completed in the same time as in the example shown in FIG. Therefore,
If the ADF 200 is provided and there is no merit in registering the data of the document, such timing may be used. That is, the timing of starting the reading of the next original can be set to any timing between the timings shown in FIGS.

Further, for example, in the case of a copying machine not equipped with the ADF 200, the operator sets the next original, sets copy conditions, and presses the print key to start reading the original. That is, in FIG. 16, the timing for replacing the originals and pressing the print key after reading the first original is
If it is after the copy start signal of the next original, the reading of the original is started by the print key. In this example, two copies are obtained from one original, but if the number of copies is large, copying conditions for as many originals as necessary while printing the first original, Image data can be registered in the copying machine. Further, when the printing of the document currently being printed is completed, the copy condition and the image data for the previously registered document are read, and the copying is sequentially executed. Since it is registered in advance, there is no wasted time when moving to the next copy, and as a result speedup of the copying operation is realized.

FIG. 18 shows the timing of occurrence of abnormality and restart of printing when printing is interrupted due to an abnormality. In the present embodiment, since the image data of the original is encoded and held in the code storage unit 806, some circumstances, such as occurrence of jam of recording paper, occurrence of exhaustion of supply of recording paper or toner, and other Even if the copy cycle is interrupted due to the occurrence of the abnormal condition 1 and the original document is not read again, by decoding the data in the code storage unit 806, the copy of the predetermined original document can be restarted. At this time, the control unit 800 calculates the number of copies already completed at the time of interruption and the number of copies to be deficient due to interruption from the number of copies set for the original document (stored copy conditions), and other The remaining printing is executed by setting the copy conditions. In addition, after printing is performed due to interruption, if there are further registered originals and copy conditions for them, the processing is automatically continued in sequence.

Here, FIG. 18 shows, as an example, a case where an abnormality occurs in the timing chart of FIG.
, Three cases are shown. However, it does not indicate that these occur continuously. Except for these three abnormality occurrence timings, the timing is the same as in FIG. 16 and shows the timing when there is no abnormality.

The timing of occurrence of abnormality is when writing is being performed on the photoconductor drum 111 to print the second sheet of the original A, and when reading of the second original has not yet started. This is when a jam occurs. From the position where the sensor that detects the jam at this time is installed,
It is determined whether or not the first print of the original A, which has already been written, can be used. If the jam is at a usable timing, the printing is performed after the jammed recording paper is removed. Resume and print the remaining one printout in RAM
An image is formed by reading out from 806b and decoding. Since the image reading can be performed when the printing is restarted, the image reading of the document B is also performed in parallel. Then, after the writing of the print of the original A is completed, the printing of the original B is started.

When the copy (recording paper) of the first original A is not usable, the image data is read from the RAM 806b to perform the remaining two copies, decrypted, and printed. Even in this case, the image can be read when the printing is restarted.
Image reading is also performed in parallel. Then, after the printing of the document A is completed, the printing of the document B is started.

The timing of occurrence of an abnormality is a jam when the writing is performed on the photosensitive drum 111 to print the second sheet of the original A and when the reading of the second original is started. Is the case. In this case, the control unit 800 stops the print operation, but continues the operation of the scanner that has already started reading until the reading of the document B being read is completed. The operation at the time of restarting the printing is the same as that at the timing of occurrence of abnormality, but since the reading of the document B has already been completed here, the reading of the document C is performed in parallel.

The timing of occurrence of abnormality is when the image formation is interrupted because the recording paper has been used up or the toner has run out and the next image formation cannot be performed. In this case, the image already written on the photoconductor drum 111 continues the subsequent processing and discharges it to a predetermined discharge tray, but the execution of new printing thereafter is stopped. Even in this case, the scanning that started before discharging the prints to the discharge tray is continued until the scanning is completed.
It is encoded and stored in the code storage unit 806. When the original is discharged and the reading of the original, which has been started by that time, is finished, the cause of the interruption, such as no paper, no toner, etc., is displayed, and the copying apparatus is stopped.
After that, the cause of the interruption is taken, and after the printing becomes possible, the printing of the second document B is started, and subsequently the document C is printed.

In the above description, for the sake of simplicity, the example of the abnormality occurrence timing has been described. However, the principle of the operation at the time of interruption is that the image reading unit 801 and the image output unit 805 are provided with a processing method capable of operating independently. Therefore, even if it is interrupted, the possible processing is to execute it ahead of time. Therefore, even if an abnormality occurs in the image reading unit 801 instead of the image output unit 805 and the printing is interrupted, at that time, if the printing is already started, the processing is continued until the corresponding recording paper is ejected. Will be done.

[Image Compression Exception Processing] In this embodiment, as the image compression exception processing, two exception processings are executed: an exception processing when image compression is not possible and an exception processing when memory overflow occurs. In the exceptional process when the image compression is not possible, the control unit 800 stops the reading by the image reading unit 801 when the document is read by the image reading unit 801 and then when the document cannot be encoded.
If one original document is being read, the data stored in the code storage unit 806 for the one original document currently read is invalidated and the data is cleared. In addition, the code storage unit 8
If there is data already stored in 06, it is decrypted and output via the image output unit 805. When the original is read again by the image reading unit 801 after the output is completed, the image processing unit 804 and the image output unit 805 are directly performed without performing the data compression (encoding) and the storage process in the code storage unit 806.
Output via. Therefore, even if the data cannot be compressed, it has the function of copying, so that there is an advantage that copying can be continued even if a problem occurs.

Although the document is read by the image reading unit 801 and then encoded and stored in the code storage unit 806, if an overflow occurs in the memory of the code storage unit 806, the control unit 800 Stops the reading of the original document by the image reading unit 801, and if the reading of one original document is in progress, the data stored in the code storage unit 806 for one original document being read this time is invalidated, and the data is deleted. clear. Further, if there is data already stored in the code storage unit 806, it is decoded and output via the image output unit 805. After the output is completed, the memory of the code storage unit 806 is cleared and the next reading is permitted. Therefore, even if a memory overflow occurs, there is an advantage that the copying can be continuously executed by completing the processing before the occurrence of the trouble and automatically clearing the memory by the processing of the copying apparatus itself.

Before describing the specific operation of the image compression exception processing, the operation unit 750 will be described with reference to FIG.
Image compression not possible and memory over
The display unit for notifying the flow and the document reading completion push button for inputting the completion of document reading to the copying apparatus will be described. Reference numeral 751 in the figure denotes a part of the operation unit 750, which is lit green in the image compression mode (a mode for encoding the image data), does not perform the image compression, and directly outputs the image data as in a normal copying apparatus. In the case of outputting, an image compression mode lamp 751a that lights up in red to indicate whether or not the image compression mode is in progress, and an image compression incompressible lamp 751b that lights up in red when image compression is not possible,
When the capacity of the code storage unit 806 that stores the encoded data is full, the memory is lit red in red.
A flow lamp 751c, a scale factor indicator 751d for displaying a compression ratio (scale factor) when data is encoded, and a code storage unit 806.
A memory / store number display 751e for displaying the number of originals (image data) stored in, and an original reading completion push button to be pressed when there are no more originals to be read and the controller 800 is notified of an image data output instruction. 751f.

FIG. 20 shows an example of a flow chart of the image compression exception processing, FIG. 21 shows a flow chart of the image compression impossible processing shown in FIG. 20, and FIG. 22 shows a flow chart of the memory overflow processing shown in FIG. Show.
First, it is determined whether or not there is a document to be read, and if there is a document to be read, the image reading unit 801 reads the document (S
101, S102). Next, it is determined whether or not the image compression processor (encoding unit 802) is normal, in other words, whether or not image compression is possible (S103), and if it is not normal, image compression non-processing is executed (S104). ). If it is normal, it is judged whether the memory overflows (10
5) If it is full, a memory overflow process is executed (S106). On the other hand, if the memory is not full,
Document reading completion push button 751f in S107 to S109
Image data is read, encoded, and stored until is pressed. When the document reading completion push button 751f is pressed, the image data stored in the code storage unit 806 is read and decoded in S110 to S114, and the printer (image output unit 805) outputs the set number of sheets.

In FIG. 20, S is used for simplicity of explanation.
In 107 to S114, the case where the images of all the originals are read and then output is described as an example, but as described above, it goes without saying that there is a process of decoding while encoding.

FIG. 21 shows the image compression impossibility process of S104 of FIG. First, it is determined whether or not the previous image compression was impossible (S201).
The image output unit 805 outputs the image data read in step S102.
To the printer for direct printer output (S210). On the other hand, if it was not possible last time, the image reading is stopped (S202), and it is determined whether the reading of one original has been completed (S203). If not, the one original currently read is read. Clear the data of (S20
4), RA of the code storage unit 806 in S205 to S209
All the data stored in M806b is decrypted and output by the set number.

FIG. 22 shows the memory overflow process of S106 of FIG. First, the image reading is stopped (S301), it is determined whether the reading of one original has been completed (S302), and if not completed, the data of one original read this time is cleared (S30).
3), RA of the code storage unit 806 from S304 to S308
After decoding all the data stored in M806b and outputting the set number of sheets, the RAM 80 of the code storage unit 806
6b is cleared (S309).

FIG. 23 shows a timing chart when a memory overflow occurs.

As described above, in the present embodiment, even in a digital copying apparatus that encodes image data, holds it in the code storage unit 806, and decodes it to form an image, encoding and decoding are performed in parallel. Therefore, the first copy time is not delayed. Also, since the encoding and decoding are performed in parallel, the copy interval can be shortened, and even if the processing speed of the copying process is not increased,
The processing capacity of the digital copying apparatus can be improved.

Further, since the reading of an original and the image formation can be used independently, the next original can be read in advance when forming a plurality of copies for one original. There is no time loss due to the replacement, and the processing speed of the digital copying apparatus can be substantially increased.

Further, since the copy condition for the original and its image data can be registered, a large number of originals can be registered within a short time, and the execution of the subsequent copying can be entrusted to the digital copying apparatus. At this time, in the case of the ADF, it was necessary to leave the original set in the digital copying apparatus, but in the present embodiment, the original can be brought back when leaving the digital copying apparatus. Further, since the copy condition can be set for each original, it is needless to say that all the originals can be set to be copied under the same copy condition, and different copy conditions can be set for each original. The convenience can be improved as compared with the conventional ADF.

Further, by separately managing the image data encoded and written in the code storage unit 806 and the copy condition, it is not necessary to add the data peculiar to the copying apparatus to the image file to be encoded and written. , The file structure can be standardized to be compatible with image files such as optical files, and the digital copying device can be used as an image data input device. Can be improved.

Further, by utilizing the function of encoding the image data, storing it in the code storage unit 806, decoding it and printing it, the image data of the original document and the copy conditions relating to it are displayed in the digital copying apparatus. By registering,
In addition to enabling efficient copying, even if printing is unavoidably interrupted due to recording paper jams, recording paper end, toner end, etc., digital data will be added again when the prescribed measures are taken and printing becomes possible. The remaining prints can be obtained without resetting the original document in the copying apparatus, and the registered print job can be automatically and continuously executed following the interrupted original document print.

When the image cannot be compressed, the image reading is stopped, the data already stored in the code storage unit 806 is decoded and output, and the subsequent printing encodes and decodes the image data. Without
Since the data is output directly to the printer, copying can be continued even if image compression cannot be performed.

When the memory overflows, the image reading is stopped, the data already stored in the code storage unit 806 is decoded and output, and when all the output is completed, the memory is cleared. Then, since the reading of the new original is permitted again, the copying can be automatically continued.

[0125]

As described above, in the digital copying apparatus of the present invention, the reading means for electrically reading the original, the coding means for coding the read image data, and the image coded by the coding means. a code storage means for storing data, and a decoding means for decoding the encoded image data stored in the code storage means, decoding of the decoding means
A new document is read using the reading means during operation.
Code to the code storage means and write to the code storage means.
Since it is equipped with a control means for performing cutting, operability and
The convenience can be improved. Specifically, read the manuscript
You can use the picking and image formation independently, so
When making multiple copies of an original,
Originals can be read in advance and used for replacing originals.
As a result, there is no loss of time and it is virtually digital.
The processing speed of the copying machine can be increased.

[0126]

[0127]

Further, in the digital copying apparatus of the present invention, during the execution of the decoding operation of the decoding means, the corresponding original is read by the reading means based on the designation of the copy mode of the new original, and the encoding means is used. Since the control means is provided for encoding by using, and storing the copy mode specified at the time of writing in the code storage means, the copy mode can be set for each document, and all the documents can be set in the same copy mode. Of course, it is possible to set to copy, and it is also possible to set a different copy mode for each document.
Even when compared with the case where F is used, the convenience can be further improved.

Further, the digital copying apparatus of the present invention can specify a copy mode of a manuscript stored in the code storage means, and a new manuscript copy mode can be designated during the decoding operation of the decoding means. On the basis of the above, the corresponding document is read using the reading unit and encoded using the encoding unit,
Since the control means stores the copy mode in the management table while writing to the code storage means, the image data stored in the code storage means and the copy mode are separately managed to copy to the image file to be encoded and written. Since it is not necessary to add device-specific data, a standardized file structure compatible with image files such as computers and optical files can be created, and a digital copying device can also be used as an image data input device. Therefore, the use of the digital copying apparatus can be further expanded and the convenience can be improved.

In the digital copying apparatus of the present invention, the image stored in the code storage means when the image data cannot be coded by the coding means or when the coding cannot be performed during the coding. Since the control means for performing image formation by using the image data from the reading means without passing through the encoding means, the code storage means, and the decoding means after forming the image by clearing or decoding the data has already been provided. The document stored in the code storage means is decoded and output,
Since the subsequent prints are directly output to the printer without encoding and decoding the image data, the copying can be continued even if the image compression becomes impossible.

Further, in the digital copying apparatus of the present invention, when an overflow occurs in the code storage means, the reading by the reading means is interrupted and all the image data stored in the code storage means is decoded to form an image. After that, since the control means for clearing the code storage means and restarting the reading by the reading means is provided, the image data already stored in the code storage means is decoded and output, and when all output is completed, Since the memory is cleared and the reading of a new original is permitted again, the copying can be automatically continued.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of a digital copying apparatus of this embodiment.

FIG. 2 is an explanatory diagram showing a configuration of a copying apparatus main body of this embodiment.

3A and 3B are a plan view and a side view of a writing unit.

FIG. 4 is an explanatory diagram showing a configuration of an ADF.

FIG. 5 is an explanatory diagram showing a configuration of a sorter.

FIG. 6 is an explanatory diagram showing a configuration of a double-sided reversing unit.

FIG. 7 is a block diagram showing an overall configuration of a control system in the digital copying apparatus according to the present embodiment.

FIG. 8 is a block diagram of an electrical equipment control unit of the digital copying apparatus according to the present embodiment.

FIG. 9 is a block diagram of an electrical equipment control unit of the digital copying apparatus according to the present embodiment.

FIG. 10 is a schematic diagram showing the flow of image data in the digital copying apparatus of this embodiment.

FIG. 11 is an explanatory diagram showing details of an encoding unit, a decoding unit, and a code storage unit. It is explanatory drawing which shows the 8x8 pixel block read by a block reading part.

FIG. 13 is an explanatory diagram showing a quantization matrix.

FIG. 14 is an explanatory diagram showing DCT coefficients.

[Fig. 15] Four originals are set in the ADF, and one of each is set.
6 is a timing chart of image encoding and decoding when copying one by one.

FIG. 16 is a timing chart in the case of making two copies of each of three originals.

FIG. 17 is a timing chart in the case where the timing for starting the reading of the next most original is delayed under the condition that copying is completed in the same time as in the example shown in FIG.

FIG. 18 is a timing chart for explaining the timing of abnormality occurrence and print restart when printing is interrupted due to an abnormality.

FIG. 19 is an explanatory view showing a display unit provided in the operation unit for notifying image compression failure and memory overflow, and a document reading completion push button for inputting completion of document reading to the copying apparatus. is there.

FIG. 20 is an example of a flowchart of image compression exception processing.

FIG. 21 is a flowchart of the image uncompressible process shown in FIG.

22 is a flowchart of the memory overflow process shown in FIG.

FIG. 23 is a timing chart when a memory overflow occurs.

[Explanation of symbols]

800 control unit 801 Image reading unit 802 encoder 802a block reading unit 802b DCT converter 802c Quantizer 802d Huffman coding unit 803 Encoding unit 803a Block writing unit 803b Inverse DCT transform unit 803c Dequantization unit 803d Huffman decoding unit 804 Image processing unit 805 Image output unit 806 code storage unit 806a dual port memory 806b RAM 806c, 806d Multiplexer (MUX) 807 Quantization matrix storage unit 808 Scale factor control unit

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yoshimichi Kanda 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Katsura Nomura 1-3-3 Nakamagome, Ota-ku, Tokyo No. 6 Inside Ricoh Co., Ltd. (72) Inventor Tomio Sasaki 1-3-6 Nakamagome, Ota-ku, Tokyo Incorporated (72) Shinji Yamakawa 1-3-6 Nakamagome, Ota-ku, Tokyo In stock company Ricoh (72) Inventor Midori Aida 1-3-6 Nakamagome, Ota-ku, Tokyo In-house company Ricoh (72) Prince Maruyama 1-3-6 Nakamagome, Ota-ku, Tokyo Company Ricoh (72) Inventor Shin Hidaka 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Stock Ricoh (72) Inventor Yasuyuki Nomizu 1-3-6 Nakamagome, Tokyo Ota-ku Stock Company Kouchi (56) Reference JP 60-72378 (JP, A) JP 61-164377 (JP, A) JP 59-11063 (JP, A) JP 56-10774 (JP, A) ) Actual Development Sho 62-119059 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 1/21 H04N 1/413

Claims (8)

(57) [Claims] 1. A reading means for electrically reading a document, a coding means for coding the read image data, a code storage means for storing the image data coded by the coding means, and the code storage. A decoding unit for decoding the encoded image data stored in the unit, and a new original using the reading unit during the decoding operation of the decoding unit. A digital copying apparatus comprising: a control unit that reads the data, encodes it using the encoding unit, and writes the encoded data in the code storage unit. 2. A reading unit that electrically reads a document, an encoding unit that encodes the read image data, a code storage unit that stores the image data encoded by the encoding unit, and the code storage In a digital copying apparatus provided with a decoding means for decoding the encoded image data stored in the means, during the execution of the decoding operation of the decoding means, a copy mode of a new original can be designated. On the basis of the above, there is provided a control means for reading the corresponding original document by using the reading means, encoding it by using the encoding means, and storing the copy mode designated at the time of writing to the code storage means. A digital copying apparatus characterized in that 3. A reading unit for electrically reading a document, a coding unit for coding the read image data, a code storage unit for storing the image data coded by the coding unit, and the code storage. A decoding unit for decoding the encoded image data stored in the storing unit, a management table storing the copy mode of the document stored in the code storing unit, and the decoding unit. During execution of the decoding operation of the means, the corresponding original is read by using the reading means based on the designation of the copy mode of the new original, encoded by the encoding means, and written in the code storage means. And a control means for storing the copy mode in the management table. 4. When the image formation of the original document during the execution of the decoding operation is completed, the control means reads the sequentially stored copy mode and image data and forms the image based on the read mode. digital copier according to claim 2 or 3, characterized in that to control the operation. 5. The control means interrupts the image forming operation due to an abnormality during execution of the decoding operation of the decoding means, and then returns from the abnormality when the abnormal image recovers from the stored image data, copy mode, and 3. The image forming method according to claim 2, wherein the number of images which is insufficient due to the interruption is executed based on the number of copies already completed at the time of interruption.
3. The digital copying machine according to item 3 . Wherein said control means, according to claim 5, characterized in that to perform the post-execution the number of image formation was insufficient by interrupted image formation of the image data stored in the code storage means Digital copying machine. 7. A reading unit that electrically reads a document, an encoding unit that encodes the read image data, a code storage unit that stores the image data encoded by the encoding unit, and the code storage Decoding means for decoding encoded image data stored in the means, and a digital copying apparatus comprising: when the image data cannot be encoded by the encoding means, or during encoding. When the encoding cannot be performed, the image data stored in the code storage means is cleared or decoded to form an image, and then the image data is stored without passing through the encoding means, the code storage means, and the decoding means. A digital copying apparatus comprising a control means for forming an image using image data from a reading means. 8. A reading unit for electrically reading a document, a coding unit for coding the read image data, a code storage unit for storing the image data coded by the coding unit, and the code storage Decoding means for decoding the encoded image data stored in the means, in a digital copying apparatus comprising: when an overflow occurs in the code storage means,
A control means for interrupting the reading by the reading means, decoding all the image data stored in the code storing means to form an image, clearing the code storing means, and restarting the reading by the reading means. A digital copying apparatus characterized by being provided.