JP3155784B2 - Image coding 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 encoding apparatus suitable for an image transmitting apparatus such as a digital copying machine and a facsimile, and an image filing apparatus.

[0002]

2. Description of the Related Art With the recent development of semiconductor technology and the expansion of application fields, the capacity and cost of memories have been increased, and the development and standardization of image data encoding / decoding technologies, and encoding / decoding have been performed at high speed. As the development of processors for processing is advanced, image data encoding / decoding techniques are applied to digital copiers and the like, and image data of many originals can be held in a memory having a small capacity.

For example, in a digital copying machine, when a large number of copies are made from one document, the document to be copied is read by a scanner and the image data is stored in a memory, so that the document is read only once. Since the time required for the scanner to reciprocate can be omitted, the number of copies per unit time can be increased without increasing the speed of the photoconductor. Also, since the image data is held in the memory, for example, the occurrence of paper jam on the transfer paper,
Even if the copy cycle is interrupted due to the consumption of transfer paper or toner, copying can be resumed without reading the original again.

Further, when a large number of originals are successively copied, when the scanner reads the previous original and the next original is set, the next original is read and the image data is read until the previous original is completed. Since the data can be stored in the memory, the time loss accompanying the replacement of the original can be reduced, and therefore, the processing capacity per unit time can be substantially improved. When this function is used, the registered document and its copy mode can be automatically executed one after another until copying of the document is completed, so that the user waits in front of the copying machine to copy the document. There is no need to set the original and its copy mode for each copy.

Further, in the case of interrupt copying for a large number of copies, the remaining copying can be resumed after the interrupt is completed by the image data held in the memory, so that an emergency interrupt can be flexibly dealt with. be able to. Further, in a copier equipped with an automatic document feeder (RDH) that circulates a document and conveys it on a platen, the document is repeatedly conveyed and damaged when the number of copies is large. This can prevent the original from being damaged. Also, when a plurality of originals are edited and a new original is created and recorded, the memory can be used to improve the degree of freedom of editing.

Conventionally, in this type of image coding apparatus, as shown in, for example, Japanese Patent Application Laid-Open No. 2-36960, image data is coded on a page basis by a predetermined coding method, and coded information is stored in a fixed capacity. It is configured to be held in a memory.

[0007]

However, in the above-mentioned conventional image coding apparatus, since the capacity of the memory is fixed, for example, only eight pages of image data are stored in the memory for ten originals. If the copying is not possible, after the copying of eight originals is completed, the remaining two pieces of image data must be stored in the memory and copying must be restarted, resulting in a problem of poor efficiency.

The present invention has been made in view of the above-mentioned conventional problems, and has
Reads and encodes the image of the manuscript after scaling it,
It is an object of the present invention to provide an image encoding device capable of efficiently storing image data of a plurality of documents in a small-capacity memory when storing the image data in a memory.

[0009]

In order to achieve the above object, a first means quantizes and encodes image data by using quantization parameters having different compression ratios, and encodes the image data by the encoding means. Storage means for storing the encoded code, and reading and encoding the image of a plurality of originals at variable magnification
And, in the case of storing the codes in the storage means, control means for the signs of all of the document to change each document according to the magnification ratio of the quantization parameter of the coding means so as to be stored in said storage means And characterized in that:

[0010] second means, the control means in the first means, by determining the amount of code of the document read by zooming by prescanning, the codes of all of the document scaling the It is characterized in that the quantization parameter of the encoding means is changed for each document according to the scaling factor so as to be stored in the storage means.

[0011]

[0012]

[0013]

According to the first means, the quantization parameter is changed to the variable magnification.
It is changed for each document according Runode, involved in the magnification of the original document
Image data of a plurality of documents in the memory of Razz small capacity can store efficiently.

In the second means, the magnification is changed by pre- scan.
Since the code amount of each document read by is determined, even when the code amount of each original are different, also the magnification of the document
Regardless , image data of a plurality of originals can be efficiently stored.

[0015]

[0016]

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of an image encoding apparatus according to the present invention, FIG. 2 is a block diagram schematically showing an image forming apparatus provided with the image encoding apparatus of FIG. 1, and FIG. 3 is a block diagram of FIG. FIG. 4 is an explanatory diagram showing the operation of the reading unit, FIG. 4 is an explanatory diagram showing the DCT coefficients in FIG. 1, FIG. 5 is an explanatory diagram showing the quantization matrix in FIG. 1, and FIG. 6 describes the operation of the image encoding device in FIG. It is a flowchart for performing.

First, an image reading section 501 shown in FIG. 2 reads an original set on an original platen of a digital copying machine as will be described later at an equal or variable magnification by a line CCD, and outputs a read signal at a predetermined level. After the A / D conversion, the signal is subjected to shading correction according to variations in the characteristics of the illumination system and the sensitivity of the CCD, and is output to an encoding unit 502 as shown in detail in FIG. In FIG. 1, an encoding unit 501
The block reading unit 701 reads an image for each block of, for example, 8 × 8 pixels as shown in FIG.
The DCT (discrete cosine transform) transform unit 702 transforms the DCT coefficient value y _uv of the original pixel x _{ij according} to Equation 1.

(Equation 1)

As shown in FIG. 4, the DCT coefficient is such that the coefficient (0, 0) indicates the average density in the block, and the other coefficients (0, 1), (0, 1) ) Indicates the ratio of the low-frequency component in the block, and the higher-order coefficient indicates the ratio of the high-frequency component in the block. Therefore, the coefficient of (0,0) is a DC component, and the other coefficients are AC components. (1,0), (2,0),
Coefficients in the u direction from (3, 0) indicate the rate of change in density in the main scanning direction, and are (0, 1), (0, 2), (0, 3).
The coefficient in the v-direction indicates the magnitude of the density change in the sub-scanning direction. Furthermore, (1,1), (2,2), (3,3) ~
The coefficient in the oblique direction indicates the magnitude of the component in which the density change in the main scanning direction and the density change in the sub-scanning direction overlap.

In FIG. 1, the DCT coefficient value transformed by the DCT transform section 702 is linearly quantized by a quantization section 703 with a quantization step size having a different size for each coefficient, and a quantized coefficient is calculated. . This quantization step size is obtained by multiplying a quantization matrix stored in the quantization matrix storage unit 706 in advance by a scale factor set by the scale factor control unit 705,
By controlling the scale factor, the code amount and the image quality at the time of decoding are controlled. Here, the quantization matrix is set so as to finely quantize low-order coefficients so as to match human visual characteristics as shown in FIG.

The quantized coefficients quantized by the quantizing section 703 are assigned a short code to a coefficient having a high appearance frequency by the Huffman encoding section 704, and a long code is assigned to a coefficient having a low appearance frequency. Is reduced,
It is stored in the memory 712 of the code storage unit 707. A code storage unit 707 is a memory management unit (MMU) that manages the number of pages and the amount of information of data stored in the memory 712.
The memory management unit 713 and the scale factor control unit 705 are provided with a main CPU (central processing unit) of an image forming apparatus in which the image encoding apparatus is used, for example, a main CPU 6 of a digital copying machine as described later.
02.

In the main CPU, the relationship between the scale factor and the quantization matrix and the code amount in the case of one standard document is preset for each document size.
When the codes of a plurality of originals are stored in 2, the scale factor and the quantization matrix of each original are instructed to the scale factor control unit 705 as described later.

Huffman decoding section 708 of decoding section 503
Assigns a coefficient value after quantization to the code read from the memory 712, and then the inverse quantization unit 709 inversely quantizes the coefficient value to calculate a DCT coefficient. The quantization step size in the inverse quantization is the same as that of the encoding, and the quantization factor stored in the quantization matrix storage unit 706 and the scale factor control unit 7
05 is multiplied by the scale factor.

The inverse DCT transform section 710 includes an inverse quantization section 709
Is converted into original image data, and the block writing unit 711 outputs this image data for each block. The image data for each block is stored in a line memory (not shown) for eight lines. When the image data is stored in all the areas of the line memory, the image processing unit 504 shown in FIG. Is output. The image processing unit 504 performs a predetermined process such as a halftone process, and then records the image on a sheet or the like by the image output unit 505.

Next, the operation of the image coding apparatus of FIG. 1 will be described with reference to FIG. In this embodiment, before reading,
The number and size of originals can be input via an operation unit of a digital copying machine, which will be described later.
H), the number and size of the document are detected. That is, since the number and size of the originals are known before reading, the approximate code amount per original stored in the memory 712 is approximately the capacity of the memory 712 / the number of originals.

First, in step S101, the main CPU of the image forming apparatus uses a scale factor and a quantization matrix, that is, standard quantization, such that the code amount per document according to the size becomes the capacity of the memory 712 / the number of documents. The parameter is notified to the scale factor control unit 705, and the scale factor control unit 705 selects a scale factor and a quantization matrix according to the standard quantization parameter.

Next, the first document is read by the image reading unit 501 (step S102), encoded by the encoding unit 501 using the standard quantization parameters (step S103), and stored in the memory 712 (step S102).
104). In the subsequent step S105, the memory management unit 713 transmits the code amount of the first document stored in the memory 712 to the main CPU, and the main CPU determines whether or not the code amount is the capacity of the memory 712 / the number of documents. Determine.

If the code amount of the first original is larger than the capacity of the memory 712 / the number of originals, the main CPU notifies the scale factor control unit 705 of a quantization parameter that reduces the code amount of the next original. On the other hand, when the code amount of the first document is smaller than the capacity of the memory 712 / the number of documents, a quantization parameter for increasing the code amount of the next document is notified to the scale factor control unit 705, and the scale factor The control unit 705 selects a scale factor and a quantization matrix according to the quantization parameter (step S106). If the code amount of the first document is equal to the capacity of the memory 712 / the number of documents, the quantization parameter is not changed. Hereinafter, step S
In the loop from 101 to S107, quantization is performed while changing the quantization parameter of each document, and the quantization is sequentially stored in the memory 712.

Therefore, according to the above embodiment, the memory management unit 713 detects the code amount for each document,
Since the scale factor control unit 705 selects an appropriate scale factor and quantization matrix, image data of a plurality of originals can be stored in a small-capacity memory.

Next, a second embodiment will be described with reference to FIG. FIG. 7 is a flowchart for explaining the operation of the second embodiment. In the first embodiment, since the code amount of each document is detected and the scale factor and quantization matrix of the next document are selected, when the code amount of each document is large, the code amount gradually decreases and the image quality is reduced. Gradually deteriorates for each document, and if the code amount of the last document is extremely large, all codes cannot be stored in the memory 712. Therefore, in the second embodiment, the code amount is detected in advance by pre-scanning the document.

First, in step S111, the scale factor and the quantization matrix, that is, the standard quantization parameter, are set to the scale factor control unit 705 so that the code amount per document according to the size becomes the capacity of the memory 712 / the number of documents. And the scale factor control unit 705 selects a scale factor and a quantization matrix according to the standard quantization parameter.

Next, the first document is read by the image reading unit 501 (step S112), encoded by the encoding unit 501 using the standard quantization parameters (step S113), and stored in the memory 712 (step S112).
114). In the following step S115, the memory management unit 713 transmits the code amount of the first document stored in the memory 712 to the main CPU, and the main CPU determines whether or not this code amount is the capacity of the memory 712 / the number of documents. Determine.

When the code amount of the first original is equal to the capacity of the memory 712 / the number of originals, the main CPU instructs to encode the next original without changing the quantization parameter. On the other hand, if the code amount of the first document is larger than the capacity of the memory 712 / the number of documents in step S116, a quantization parameter that reduces the code amount of the first document is set to the scale factor control unit 7.
When the code amount of the first document is smaller than the capacity of the memory 712 / the number of documents, a quantization parameter for increasing the code amount of the first document is notified to the scale factor control unit 705. Then, the original is prescanned again (steps S116 and S117). Hereinafter, in the loop shown in steps S111 to S117, quantization is performed up to the final document while changing the quantization parameter by pre-scanning so that the code amount of each document becomes equal (step S118), and sequentially stored in the memory 712.

Therefore, according to the above embodiment, when the code amount of each document is large, the code amount of each document is controlled so as to be the code amount of the standard document, so that the image quality gradually deteriorates for each document. Also, even when the code amount of the last document is extremely large, all codes can be stored in the memory 712. If the detected code amount is extremely different from the predicted code amount, the same document may be pre-scanned a plurality of times to control the code amount of each document to be equal to that of the standard document. it can.

Next, a third embodiment will be described with reference to the flowchart shown in FIG. In the first and second embodiments, the image data read at the same size is encoded and stored in the memory 712. However, the image data read at the same magnification is compressed at the same size as that at the same size. D at rate
Since encoding by CT conversion increases the code amount, it becomes impossible to store the codes of all the originals in the memory 712, and on the other hand, the image data read in a reduced scale is compressed at the same compression ratio as in the case of the same size. When the encoding is performed by the DCT transform, the code amount is reduced, so that the efficiency of the memory 712 is reduced. Therefore, in the third embodiment, an optimal quantization parameter is set for each document according to the number, size, and magnification of the documents.

First, in step S121, the scale factor and the quantization matrix are set by the main CPU of the image forming apparatus so that the code amount per document according to the size and the magnification is equal to the capacity of the memory 712 / the number of documents. That is, the standard quantization parameter is notified to the scale factor control unit 705, and the scale factor control unit 705 selects a scale factor and a quantization matrix according to the standard quantization parameter.

Next, the first document is read by the image reading unit 501 (step S122), and is coded by the coding unit 501 with the standard quantization parameter corresponding to the above-mentioned magnification (step S123), and is stored in the memory 712. (Step S124). In the following step S125,
The memory management unit 713 transmits the code amount of the first document stored in the memory 712 to the main CPU, and
The PU determines whether the code amount is the capacity of the memory 712 / the number of documents.

When the code amount of the first original is larger than the capacity of the memory 712 / the number of originals, the main CPU determines the quantization parameter corresponding to the size and the scaling factor so that the code amount of the next original is reduced. Is notified to the scale factor control unit 705. On the other hand, if the code amount of the first document is smaller than the capacity of the memory 712 / the number of documents, the code amount of the next document is increased according to the size and the magnification. The quantization parameter is notified to the scale factor control unit 705, and the scale factor control unit 705 selects a scale factor and a quantization matrix according to the quantization parameter (step S126). If the code amount of the first document is equal to the capacity of the memory 712 / the number of documents, the quantization parameter is not changed. Hereinafter, step S1
In a loop shown in 21 to S127, quantization is performed up to the final document while changing the quantization parameter of each document,
The data is sequentially stored in the memory 712.

Therefore, according to the third embodiment,
Since the optimal quantization parameter is set for each document in accordance with the number, size, and scaling factor of the documents, image data of a plurality of documents can be efficiently stored in a memory having a small capacity regardless of the scaling factor. .

Next, a fourth embodiment will be described with reference to FIG. In pre-scanning in a normal copying machine, in order to improve the throughput, the scanning speed of the document is set higher than the scanning speed of the document, and the size and background density of the document are detected. However, as described above, in the compression method based on the DCT transform, the compression ratio varies depending on the scaling ratio, so that the speed of the prescan cannot be reduced. Therefore, in the fourth embodiment, the original is prescanned at the same speed, and the code amount is detected in advance.

First, in step S131, the code amount per document according to the size and the magnification is stored in the memory 71.
The scale factor and the quantization matrix, that is, the standard quantization parameter, are notified to the scale factor control unit 705 so that the capacity / number of documents becomes 2, and the scale factor control unit 705 transmits the scale factor and the quantum value according to the standard quantization parameter. Select the activation matrix.

Next, the first document is read by the image reading unit 501 (step S132), encoded by the encoding unit 501 using the standard quantization parameters (step S133), and stored in the memory 712 (step S132).
134). In the subsequent step S135, the memory management unit 713 transmits the code amount of the first document stored in the memory 712 to the main CPU, and the main CPU determines whether or not this code amount is the capacity of the memory 712 / the number of documents. Determine.

When the code amount of the first original is equal to the capacity of the memory 712 / the number of originals, the main CPU instructs to encode the next original without changing the quantization parameter. On the other hand, if the code amount of the first document is larger than the capacity of the memory 712 / the number of documents in step S135, the quantization parameter corresponding to the size and the scaling factor is scaled so that the code amount of the first document is reduced. The factor control unit 705 is notified, and if the code amount of the first document is smaller than the capacity of the memory 712 / the number of documents, the code amount of the first document is increased so as to increase the code amount of the first document. The quantization parameter is notified to the scale factor control unit 705, and the original is pre-scanned again (step S136).

Hereinafter, in the loop shown in steps S131 to S137, the code amounts of the respective originals are set to be equal.
By pre-scanning, while changing the quantization parameter according to the size and the magnification (step S137), the quantization is performed up to the last document (step S138), and the memory 7 is sequentially stored.
12 is stored.

Therefore, according to the above embodiment, when the code amount of each document is large according to the enlargement ratio, control is performed so that the code amount of each document becomes the code amount of the standard document according to the magnification. In addition, the image quality does not gradually deteriorate for each document, and all codes can be stored in the memory 712 even when the code amount of the last document is extremely large. Further, even when the code amount decreases due to the reduction ratio, the memory 7
12 can be controlled to an effectively usable code amount,
When the detected code amount is extremely different from the predicted code amount, the same document may be pre-scanned a plurality of times to control the code amount of each document to the code amount of the standard document. it can.

Next, a digital copying machine to which the image forming apparatus of the present embodiment is applied will be described in detail with reference to FIGS. 10 is a side view showing the entire configuration of the digital copying machine, FIG. 11 is a plan view showing the detailed configuration of the writing unit of FIG. 10, FIG. 12 is a side view showing the writing unit of FIG.
13 is a side view showing a detailed configuration of the automatic document feeder (RDH) of FIG. 10, FIG. 14 is a perspective view showing a main part of the paper feeding mechanism of FIG. 13, and FIG. 15 is a paper feeding mechanism of FIG. 16, FIG. 16 is an enlarged side view showing a detailed configuration of the paper feeding mechanism of FIG. 13, FIG. 17 is a perspective view showing a mechanism for detecting the length of the original, and FIG. 18 is an explanation showing an original width detecting sensor. FIGS. 19 and 20 are flowcharts for explaining the document size detecting operation, FIG. 20 is a side view showing an extended state of the return mechanism of FIG. 13, and FIG. 21 is a side view showing an intermediate state of the return mechanism of FIG. 22 is a side view showing a contracted state of the return mechanism of FIG. 13, FIG. 23 is a perspective view showing a detailed configuration of the paper discharge unit of FIGS. 20 to 22, and FIG. Flowchart for explaining the operation of the apparatus (RDH), FIG. Is a block diagram showing a control unit of the digital copying machine of FIG. 10.

Referring to FIG. 10, the digital copying machine includes a copying machine main body (I) and an automatic document circulating and feeding device (RD).
H) (II), sorter (III) and double-sided reversing unit (IV)
Are roughly constituted by the four units. The copier body (I) includes a scanner unit, a writing unit, a photoconductor unit,
A developing unit, a paper feeding unit, and the like are provided. The details will be described below.

The scanner section is provided with a reflecting mirror 1, a light source 3, and a first mirror 2, and moves at a constant speed in the sub-scanning direction. A first scanner is provided with a second mirror 4 and a third mirror. A second scanner that moves in the sub-scanning direction at half the speed of one scanner. An original (not shown) on the contact glass 9 by the first scanner and the second scanner
Is optically scanned, and the reflected light is imaged on the light receiving surface of the one-dimensional solid-state imaging device 8 via the color filter 6 and the lens 7.

In general, a CCD is used as the solid-state imaging device 8. Since the image signal read by the solid-state imaging device 8 is analog, it is A / D converted, and is binarized and multi-valued by a processing circuit mounted on the image processing board 10 as shown in FIGS. Various processes such as key processing, scaling processing, and editing are performed. In order to obtain a color signal, a color filter 6 is arranged so as to be freely put in and out of the optical path. This color filter 6 is put in and out of the optical path in accordance with the scanning of the original so that various kinds of copying such as multiple transfer and double-sided copying can be performed. Done.

The image information after the image processing is written on the photoreceptor 40 in the form of a set of light points by raster scanning of a laser beam in a writing section as shown in detail in FIGS. The laser light emitted from the semiconductor laser 20 is
The light beam is shaped into a parallel light beam by the collimator lens 21, passes through the aperture 32, is shaped into a light beam having a predetermined shape, and is then compressed in the sub-scanning direction by the first cylinder lens 22 and enters the reflection surface of the polygon mirror 24.

The polygon mirror 24 is formed in an accurate polygon, and is rotated by a polygon motor 25 in a predetermined direction at a constant speed. The rotation speed is determined by the rotation speed of the photoconductor 40, the writing density, and the number of surfaces of the polygon mirror 24. The laser light incident on the reflection surface of the polygon mirror 24 is deflected at a constant angular velocity, and then corrected by the f-θ lenses 26a and 26b so as to scan the photoreceptor 40 at a constant velocity. The f-θ lenses 26a, 26
6b also has a tilt correction function.

The laser light corrected by the f-.theta. 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 guided to the sensor by an optical fiber. Then, after a predetermined time from the cue signal in the main scanning direction synchronized with the detection signal, image data for one line is output. Thereafter, by repeating this operation, an electrostatic latent image of one image is Formed on 40.

On the peripheral surface of the photoconductor 40, a photoconductor layer is formed. Organic photoreceptors (OPC), as photoreceptor layers sensitive to semiconductor lasers having a wavelength of 780 nm,
Although α-Si, Se-Te, and the like are known, an organic photoconductor (OPC) is used in this embodiment. Here, when writing with the semiconductor laser 20, there are known a negative / positive process of irradiating the image portion with light and a positive / positive process of irradiating the background portion with light. Writing is performed by a positive process.

In FIG. 10, a scorotron system having a grid on the photoconductor 40 side is used as the charging charger 41, and the surface of the photoconductor 40 is uniformly (-) charged, and the image forming area is irradiated with laser light. The potential of the region is reduced. Therefore, the potential of the background area of the photoconductor 40 becomes -7.
50 to -800 V, while the potential of the image area is -5.
Since the voltage is about 00 V, an electrostatic latent image is formed on the surface of the photoconductor 40.

The developing devices 42a and 42b are connected to a developing roller.
A bias voltage of 500 to -600 V is applied, and (-)
The electrostatically charged toner is visualized by adhering the charged toner to the image area of the photoconductor 40. The developing section of the present embodiment includes two main developing units 42a and sub developing units 42b.
The toner can be selectively developed by filling the toner replenisher 43a corresponding to 2a with black toner and filling the toner replenisher 43b corresponding to the sub-developing device 42b with color toner.

The transfer paper is conveyed to the position of the transfer charger 44 in synchronization with the photoreceptor 40, and the transfer charger 44 charges the back surface of the transfer paper to (+) with the toner image visualized by the developing units 42a and 42b. Is transferred onto transfer paper. The transfer paper onto which the toner image has been transferred is separated by a charger 4.
5 and is separated from the photoreceptor 40 by AC static elimination. The remaining toner on the photoreceptor 40 is removed by the cleaning blade 47 and collected in the tank 48. The remaining charge on the photoreceptor 40 is discharged by irradiating the charge on the photoreceptor 40 with a discharge lamp 49.

Incidentally, downstream of the developing devices 42a and 42b,
A photo sensor 50 for detecting the reflection density on the photoreceptor 40 is provided. The photo sensor 50 includes a density of a pattern such as black or a halftone dot formed and developed by the writing unit and a density other than the pattern. And outputs a toner replenishment signal when the density of the toner image is low by detecting the density of the toner image, or outputs an insufficient toner remaining signal.

The paper feeding section includes a plurality of cassettes 60a, 60b,
60c, and is configured to perform double-sided copying and re-feeding by guiding the paper once transferred to the transfer position via the re-feeding loop 72. This cassette 60
When one of a to 60c is selected and the copy start button is pressed, the corresponding paper feed rollers 61a, 61b, 61
c is rotated, and the leading end of the transfer paper is
Is transported until it comes into contact with. Then, the registration roller 6
2 starts rotation so that the toner image on the photoconductor 40 and the transfer paper are synchronized, and the above-described transfer is performed.

The transfer paper separated from the photoreceptor 40 is sucked and conveyed by the separation conveyance section 63, and
4, 65 fixes the toner image. This transfer paper is guided to the discharge port on the sorter (III) side in the case of normal single-sided copying, and in the case of multiple copying, the switching claw 6 is used.
8, 69 return to the position of the registration roller 62 via the lower re-feeding loop 72 without changing the copy surface. In the case of double-sided copying, the copy side is reversed by the copier body (I) or the duplexing reverse unit (IV). In the former case, the switching pawls 68, 69 and 71 guide the roller 70 to the tray 70 below the paper re-feeding loop 72,
Is returned in the opposite direction by the reversal, and is guided to the re-feeding loop 72 by the switching of the switching claw 69, and is returned to the position of the registration roller 62.

Next, a detailed configuration of the automatic document feeder (RDH) will be described with reference to FIGS. As shown in FIG. 13, the RDH (III) has a cover-shaped case that covers the contact glass 9 of the copier body (I). A table 201, a paper feed mechanism 270 for sequentially feeding the originals on the paper feed table 201 from below in the direction of the contact glass 9, and transporting the originals fed by the paper feed mechanism 270 to a predetermined exposure position on the contact glass 9. And a conveyor belt 2 to be discharged from the contact glass 9 after exposure.
12, a reversing mechanism 272 for reversing the surface of the document discharged by the transport mechanism 271, and a document reversed by the reversing mechanism 272.
And a return mechanism 273 for returning the original to a position above the original stack.

Side fences 202 are provided on both left and right sides of the sheet feeding table 201 along the transport direction in the minimum document placing range in front. Paper feed table 2
In the vicinity of the front end of the sheet feeding direction No. 01, two call rollers 203a and 203b having a missing circle are arranged along the transport direction, and the call rollers 203a and 203b are arranged such that the missing circle faces upward. , So as not to protrude above the document placing surface.

As shown in FIG. 14, a slit plate 260 having a slit 261 and a positioning plate 263 for positioning the missing circle portion are attached to the axes of the call rollers 203a and 203b. The slit 261 of the slit plate 260 is detected by the photoelectric sensor 262, and the positioning plate 263 has a pressing roller 26 urged by a spring.
4 are configured to engage. Calling roller 20
The slits 261 and the photoelectric sensor 162 detect a rotation angle at which the sheet feeding table 201 and the missing portion are on the same plane so that the missing portions 3a and 203b rotate in the same phase, and call rollers 203a and 203b. Is stopped, and the calling roller 203 is moved by the positioning plate 263 and the pressing roller 264.
a, 203b is positioned at the stop position.

As shown by the dashed line in FIG. 13, a pressing plate 204 for pressing down the leading end of the original and pressing against the calling roller 203a is provided above the calling roller 203a.
The pressing plate 204 is driven by a solenoid (not shown). As shown in FIG.
1, between the retracted position indicated by the broken line and the operation position indicated by the solid line, the solenoid 267 (see FIG.
A stopper 205 that moves according to 5) is provided.
In the operating position, the toe of the stopper 205 abuts on the upper surface of the sheet feeding table 201 or the upper surface of the set of document bundles as shown in FIG. The skew is corrected by colliding the leading edge of the document returned on the sheet feeding table 201.

The pressing roller 203 is pressed by the pressing plate 204.
The document bundle pressed by the a
3b rotates synchronously, and is reliably conveyed to a separation position. The document set sensor 206 detects that the document bundle has been set on the sheet feeding table 201, and according to this detection signal, the call rollers 203a and 203b rotate by a fixed amount, and the document bundle is conveyed to the separation position shown in FIG. You.

The call rollers 203a and 203b are
In cooperation with a separation mechanism composed of an endless belt 207 and a separation roller 208, the lowermost sheet of the document bundle located at the separation position is fed. The separation roller 208 rotates in the document conveying direction, and the endless belt 207
08, the separation roller 208 rotates in the opposite direction (arrow A in FIG. 13) at a speed of, for example, 1/20. Therefore, by appropriately setting the coefficient of friction between the separation roller 208 and the document, the coefficient of friction between the endless belt 207 and the document, and the coefficient of friction between the documents, one page of the document sent out by the call rollers 203a and 203b can be formed. In the case of (1), the sheet is directly conveyed in the direction of the pull-out rollers 209 and 210 on the downstream side, and in the case of two or more sheets, only the lowest one sheet is separated and conveyed.

The separation roller 208 has a built-in one-way clutch (not shown). When the registration sensor 211 provided at the discharge position of the paper feeding mechanism 270 detects the leading end of the document, the clutch is turned off and the document is pulled out. Roller 20
The wafer is conveyed to a predetermined exposure position on the contact glass 9 by 9, 210. Further, the clutch is configured to reduce the transport load on the pull-out rollers 209 and 210 when the driving of the separation roller 208 is turned off. When the registration sensor 211 detects the trailing edge of the document, the document is controlled so as to stop at a predetermined exposure position.

As shown in FIG. 17, a pulse encoder 280 provided with a plurality of slits is mounted on the shaft of the pull-out roller 209 through a gear to detect the length of the original. A photo sensor 281 is provided to detect the A photo sensor (width detection sensor) for detecting the width of the document as shown in FIG. 13 is provided near the pull-out rollers 209 and 210.
282 are arranged. FIG. 18 shows the width detection sensor 282.
As shown in detail in FIG. 5, it is arranged between the B5 vertical size and the A4 vertical size.

The size of the original is detected by the length detected by the photo sensor 281 and the width detected by the photo sensor 282, and FIG. 19 is a flowchart showing the detailed detection operation. As shown in FIG. 18, there are seven types of document sizes that can be transported by the RDH: A5 portrait, B5 portrait and landscape, A4 portrait and landscape, B4 portrait and A3 portrait.
The pulse encoder 280 is formed so that one pulse corresponds to a transport distance of 0.5 mm.

In FIG. 19, the length of the document is detected by counting the number of pulses while the registration sensor 211 is on (steps S1 to S7). When the registration sensor 211 is on, the size sensor flag is set to "1" when the width detection sensor 282 is on (step S3), and is cleared to "0" when it is off (step S3). S4). When the registration sensor 211 is turned off, the counting of the pulses is terminated (step S6,
S7) The process proceeds to step S8 and the subsequent steps to determine the size.

First, when the size sensor flag is set, the A3 size (steps S9 and S10)
B4 size (Steps S11 and S12), A4 vertical size (Steps S13 and S14), A4 horizontal size (Steps S15 and S16), B5 horizontal size (Steps S15 and S16)
17) is determined. On the other hand, if the size sensor flag is not set, the B5 vertical size (step S1)
8, S19), A5 vertical size (steps S18, S2
0) is determined. Finally, the result of this determination is transmitted to the digital copier body (I) (step S21), and this determination is made for each document.

Returning to FIG. 13, the transport mechanism 271 of the RDH (III) has a single wide endless transport belt 212 wound around a pair of rollers 265 and 266. The lower side of the conveyor belt 212 includes a plurality of pressure rollers 213.
Is pressed onto the contact glass 9 by the
The document from 0 is conveyed to a predetermined exposure position, and sent to the reversing mechanism 272 after the exposure is completed.

The reversing mechanism 272, as shown in FIG.
Reversing roller 21 provided along reversing guide 215a
5 and a pressure roller 216 pressed against the reversing roller 215
And a switching claw 214 displaceable between a position shown by a solid line and a position shown by a broken line downstream of the pressure roller 216. The switching claw 214 is switched to the position indicated by the broken line in the double-sided original mode, and reverses the original whose one side has been exposed, and sends it back to the transport mechanism 271. On the other hand, in the single-sided original mode and the double-sided original mode, when the double-sided exposure has been completed, the switching claw 214 is switched to the position indicated by the solid line.
The document is discharged to the return mechanism 273. A reversing roller 215 is provided between the pressure roller 216 and the switching claw 214.
A reversing sensor 217 is provided so as to face the image forming apparatus, and the driving timing of the transport belt 212 is controlled by the reversing sensor 217.

The return mechanism 273 is connected to the sheet feeding table 20.
1, a paper discharge unit 218 movable in the document conveying direction, and connected to the rear of the paper discharge unit 218 to expand and contract in accordance with the movement of the paper discharge unit 218.
It has guide plates 221, 222, and 223 that form a document conveying path between the sheet feeding table 201 and the sheet feeding table 201 behind the sheet feeding device 18, and an intermediate belt 227 for conveying the document from the reversing mechanism 272 to the sheet discharging unit 218. FIG. 20, FIG. 21,
FIG. 22 shows the extended state, the intermediate state, and the contracted state of the guide plates 221 to 223, respectively.

As shown in detail in FIGS. 22 and 23, the document discharged from the outlet 230 of the reversing mechanism 272 is guided to the discharge unit 218 directly or the document conveyed on the table 201 by the intermediate belt 227 is guided. For this purpose, a lower guide 229 that is inclined forward and upward is provided. Also, at a predetermined interval from the lower guide 229,
An upper guide formed as a front end of the guide plate 221 is provided.
At the entrance and exit of the transport path 18, there are two paper discharge rollers.
19 ′ and 219 ″ are provided.
9 ′ and 219 ″ are driven by a motor 220. A front part of the exterior cover 224 is formed as an exterior cover of the paper discharge unit 218.

The intermediate belt 227 is located in front of the exit of the reversing mechanism 272 and the upper surface of its upper running portion is
Are arranged so as to be on the same plane as the upper surface of the substrate, and are divided into a plurality of sections in the width direction. When the guide plate 222 is extended, a driven roller 228 is provided at a position facing each strip of the intermediate belt 227 via a leaf spring, as shown in FIGS. As shown in FIG. 20, the guide plate 222 is pulled out in the
7, the driven roller 228 is pressed by the leaf spring against the intermediate belt 227 to be driven, and the document is conveyed.

Further, as shown in FIG.
When 2 moves in the arrow direction C and retracts behind the intermediate belt 227, the driven roller 228 is flipped up by the member 231 projecting above the surface of the table 201 and retracts from the intermediate belt 227, as shown in FIG. Thus, it is stored behind the outlet 230 of the reversing mechanism 272. In this state, the largest size document discharged from the outlet 230 of the reversing mechanism 272 is driven by the driven roller 228, the guide plate 222,
The sheet is conveyed along the conveyance path of the sheet discharge unit 218 by the pair of sheet discharge rollers 219 ′ and 219 ″ without being hindered by the document discharge unit 23. Skew is corrected.

Here, the positioning of the paper discharge unit 218 corresponding to the document size is performed by clicking the paper discharge unit 218 in the click groove 251 provided at a position corresponding to the standard paper size in the front frame of the RDH as shown in FIG. Unit 21
8 by engaging a click pin 245 provided on the front side. Click groove 2 of click pin 245
51 or the inner surface of the frame
The operation can be performed by operating a lever 252 provided on the front end surface of the sheet ejecting unit 18, and the sheet discharging unit 218 can be moved to a predetermined position and engaged with a desired position.

Next, the operation of the above RDH will be described with reference to FIG. First, when a plurality of originals are stacked in page order such that the image surface faces upward, and the originals are placed on the paper feed table 201 such that the leading ends contact the stoppers 205, the original set sensor 206 is turned on (step S3
1). In this case, as the side fence 202 moves, both sides of the document bundle are supported.
18 moves to a position corresponding to the size of this bundle of originals.

When the copy star key of the copier body (I) is pressed to turn on the paper feed signal (step S32), the solenoid 267 of the stopper 205 and the solenoid (not shown) of the holding plate 204 are turned on (step S33). ). Therefore, the stopper 205 retracts from the leading end of the document bundle,
The holding plate 204 calls the bundle of originals and the rollers 203
a, 203b. Then, when the paper feed timer elapses a predetermined time X (step S34), the paper feed motor and the transport belt motor are turned on (step S35). Accordingly, the rotation of the call rollers 203a and 203b causes the bundle of originals to be conveyed so as to sequentially advance from the lowermost original, and only the lowermost original is separated by the endless belt 207 and the separation roller 208 so that the pullout roller 20
9 is conveyed.

Then, the leading edge of the document is
1 (step S36), the drive of the separation roller 208 is stopped by the clutch (step S3).
7). Therefore, the document is conveyed in the direction of the contact glass 9 only by the pull-out roller 209, and then conveyed on the contact glass 9 by the conveying belt 212. The calling rollers 203a and 203b stop driving in response to the detection signal of the photo sensor 262, and stop 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,
A predetermined count value of the photo sensor 262 (step S3
In step 8), the transport belt 212 rotates in the reverse direction, and the original is
8 and then stop (step S39).

Accordingly, the original is stopped at a predetermined exposure position after the skew is corrected, and the image is read by the scanner section of the copying machine main body (I). Then, according to a document discharge signal from the copying machine main body (I) (step S41),
The transport belt 212 rotates forward again, and the original is rotated by the reversing mechanism 272.
Is sent to the return mechanism 273 in the case of a single-sided original and in the case of a double-sided original and both-sided exposure has been completed (step S42). Then, the original is transferred to the intermediate belt 227, the sheet feeding table 201 and the guide plate 22.
Conveyed along a conveyance path constituted by 1 to 223,
The sheet is guided by the lower guide 229 of the sheet discharging unit 218 and is discharged onto the sheet feeding table 201 by sheet discharging rollers 219 ′ and 219 ″.

In this case, after the paper discharge sensor 242 of the paper discharge unit 218 detects the leading edge of the document (step S4).
4) At a predetermined timing, the stopper 205 comes into contact with the original bundle, and the leading end of the original discharged from the paper discharge unit 218 comes into contact with the stopper 205 to correct the skew and stack the original. When the paper discharge sensor 242 detects the trailing end of the document (step S45), the paper discharge motor and the reversing motor are turned off (step S46).
If the next document is not detected, the transport motor is stopped (steps S47 and S48).

Note that, as shown in FIG.
In the case where a claw portion is formed at an interval with respect to the sheet 5 and a rib 1a having an appropriate height is formed on the sheet feeding table 201 at an interval, the original on the sheet feeding table 201 is
The document is not pushed under the stopper 205 because it is hit by the claw 05 and hits from the upper end of the rib 1a. Further, as shown in FIG. 16, when the partition plate 241 is placed on the document bundle in advance, the partition plate 241
Is detected by the partition plate sensor 243, it is possible to detect that the document bundle has made one round.

Further, the bundle of originals that have completed one cycle is aligned to some extent, but is not sufficient, and may be in a wavy state. Therefore, before the next sheet feeding operation, the pages can be aligned by rotating the call rollers 203a and 203b and applying a vertical vibration to the document bundle. in this case,
The pressing plate 204 and the stopper 205 are retracted to a position away from the document, and the leading end of the document bundle is advanced to near the pressure contact position between the separation roller 208 and the endless belt 207 by generating a force in the transport direction by the call rollers 203a and 203b. Then, the originals are arranged in a wedge shape sequentially evacuated from the lowermost original. Accordingly, the document bundle is reset so as not to hinder refeeding, and the next feeding operation is started by the feed signal.

Returning to FIG. 10, the sorter (III) selectively discharges the transfer paper discharged from the copying machine main body (I), for example, in a page order, for each page, or to a preset bin 111a to 111x. In this case, the transfer paper is conveyed by a plurality of rollers rotated by a motor 110, and is switched by bins 111a to 111
Led to 1x.

The double-sided reversing unit (IV) shown in FIG.
It is used when performing double-sided copying by inverting a plurality of transfer sheets. In this case, the transfer paper in the copying machine main body (I) is guided downward by the paper discharge roller 66 and the next switching claw 68 is provided.
To the double-sided reversing unit (IV). The paper is stacked on the tray 123 by the paper discharge roller 120, and is vertically and horizontally aligned by the feed roller 121 and the side alignment guide 122. The transfer papers accumulated on the tray 123 are returned into the copying machine main body (I) by the re-feed rollers 124,
The switching claw 69 directly guides the sheet to the sheet re-feeding loop 72.

Next, referring to FIG. 25, the copying machine body (I)
The configuration of the control unit will be described. This control unit has a CPU 601 for controlling sequence relations and a main CPU 602 for controlling operation relations.
The CPU 601 that controls the sequence relations sets and outputs conditions related to paper conveyance timing and image formation,
As shown in FIG. 5B, a paper size sensor 603 and sensors 603 related to paper conveyance such as paper ejection detection and registration detection are provided.
a, double-sided unit 604, and high-voltage power supply unit 605
And a driver 606 such as a relay, a solenoid or a motor.
And a laser beam scanner unit 608 and the like. The laser beam scanner unit 608 is connected to an image control circuit 609, and the image control circuit 609 is configured by circuits as shown in FIGS.

The paper size sensor 603 detects the size and orientation of the transfer paper loaded in the paper feed cassette, and
Reference numeral 3a detects the presence or absence of a supply such as an oil end or a toner end, and a mechanical abnormality such as a door open or a blown fuse, in addition to the sheet discharge detection and the registration. Double-sided unit 604
Has a motor and side fence home position sensor for aligning the paper width, a paper feed clutch, a solenoid for changing the transport path, a paper presence / absence detection sensor, and a sensor related to paper transport.

The high-voltage power supply unit 605 supplies a predetermined high-voltage power to the charging charger 41, the transfer charger 44, the separation charger 45, and the bias electrodes of the developing units 42a and 42b for the time of the duty obtained by the PWM control, as shown in FIG. Apply. The driver 606 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 (III) 607 is CPU 60
1 is connected via a serial interface,
The paper is conveyed at a predetermined timing according to a control signal from the CPU 601, and is discharged to each bin.

As the analog signal to be input to the CPU 601, the detection signal of the fixing temperature, the photosensor 50 for density detection, the monitor current of the laser diode 20, and the reference voltage are input. The fixing temperature is determined by the fixing mechanism (rollers 64 and 65).
The on / off control or phase control of the heater is performed so as to be constant. The detection signal of the photosensor 50 for density detection is detected by reading a pattern formed on the photoreceptor 40 with a phototransistor at a predetermined timing, a clutch for toner supply is turned on and off, and a toner is supplied. End is detected. The monitor current of the laser diode 20 is controlled so as to match a reference voltage (for example, 3 mW).

Next, the main CPU 602 for controlling the operation relation will be described with reference to FIG. 25B. The main CPU 602 controls a plurality of serial ports and a calendar IC 610. As shown, the quantization parameter is changed for each document according to the document size and the magnification. In addition to the CPU 601, an operation unit 611, a scanner control circuit 612, an application unit 613,
An editor unit 614 and the like are connected.

The operation unit 611 has a key input device for the operator and a display for displaying the status of the copying machine, and notifies the main CPU 602 of the key input information by serial communication. The main CPU 602 determines whether the display unit of the operation unit 611 is on or off based on the key input information.
The display command is notified to the operation unit 611 by serial communication. The operation unit 611 turns on or off the display according to the display command. The scanner control circuit 612 informs the main CPU 602 of information regarding drive control of the scanner servomotor, image processing, and image reading by serial communication, and performs interface processing between the RDH (II) and the main CPU 602.

The application unit 613 performs interface processing between an external device such as a facsimile or an external printer and the main CPU 602, and exchanges predetermined information. The editor unit 614 transmits image editing data such as masking, trimming, and image software input by the operator to the main CPU 602 by serial communication. The calendar IC 610 stores the current date and time and informs the main CPU 602 at any time. Therefore, it is possible to display the current time on the display of the operation unit 611 and to control the on-time and off-time of the copying machine by the timer. it can.

The gate array 615 is the main CPU 602
The image data is selectively output from the scanner control circuit 612 to the image control circuit 609, from the scanner control circuit 612 to the application unit 613, or from the application unit 613 to the image control circuit 609 according to the select signal from the scanner control circuit 612. From the scanner control circuit 612 to the image control circuit 6
When the image data is output to the sync signal PMSYNC from the laser beam scanner unit 608, the image data of the 2-bit parallel signal (in the case of binary) and the 12-bit parallel signal (in the case of multi-value) from the scanner is output. It is transmitted synchronously. When output from the scanner control circuit 612 to the application unit 613, 2
When a bit parallel signal is output and output from the application unit 613 to the image control circuit 609,
A 2-bit parallel signal is transmitted in synchronization with the synchronization signal PMSYNC.

[0095]

As described above, according to the first aspect of the present invention, there is provided a method for encoding images of a plurality of scaled originals.
The quantization parameter so that the codes of all originals are stored.
Since the data is changed for each original according to the magnification, the original
Regardless of the magnification, image data of a plurality of documents can be efficiently stored in a memory having a small capacity.

The invention according to claim 2 is based on the pre-scan.
Ri by discriminating the code amount of each document read by zooming, so that the codes of all of the document magnification is remembers
Since it changed for each document in accordance with quantization parameters to the magnification ratio, even when the code amount of each original are different, also the original
The image data of a plurality of originals can be efficiently stored regardless of the magnification .

[0097]

[0098]

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an image encoding device according to the present invention.

FIG. 2 is a block diagram schematically illustrating an image forming apparatus including the image encoding device of FIG. 1;

FIG. 3 is an explanatory diagram illustrating an operation of a block reading unit in FIG. 1;

FIG. 4 is an explanatory diagram showing DCT coefficients in FIG. 1;

FIG. 5 is an explanatory diagram showing a quantization matrix in FIG. 1;

FIG. 6 is a flowchart for explaining the operation of the image encoding device in FIG. 1;

FIG. 7 is a flowchart for explaining the operation of the image encoding apparatus according to the second embodiment of the present invention.

FIG. 8 is a flowchart for explaining the operation of the image encoding apparatus according to the third embodiment of the present invention.

FIG. 9 is a flowchart for explaining the operation of the image encoding apparatus according to the fourth embodiment of the present invention.

FIG. 10 is a side view showing the overall configuration of a digital copying machine to which the image encoding device of FIG. 1 is applied.

FIG. 11 is a plan view illustrating a detailed configuration of a writing unit in FIG. 10;

FIG. 12 is a side view showing the writing unit of FIG. 11;

FIG. 13 is a side view showing a detailed configuration of the automatic document circulating and feeding apparatus of FIG. 10;

FIG. 14 is a perspective view showing a main part of the sheet feeding mechanism of FIG.

FIG. 15 is a front view showing the sheet feeding mechanism of FIG.

FIG. 16 is an enlarged side view showing a detailed configuration of the paper feeding mechanism of FIG.

FIG. 17 is a perspective view showing a mechanism for detecting the length of a document.

FIG. 18 is an explanatory diagram illustrating a document width detection sensor.

FIG. 19 is a flowchart illustrating an operation of detecting a document size.

FIG. 20 is a side view showing an extended state of the return mechanism of FIG.

FIG. 21 is a side view showing an intermediate state of the return mechanism of FIG.

FIG. 22 is a side view showing a contracted state of the return mechanism of FIG.

FIG. 23 is a perspective view showing a detailed configuration of the paper discharge unit shown in FIGS. 20 to 22;

FIG. 24 is a flowchart for explaining the operation of the automatic document circulating and feeding apparatus of FIGS. 13 to 23;

25 is a block diagram showing a control unit of the digital copying machine shown in FIG.

[Explanation of symbols]

 702 DCT transformer 703 Quantizer 705 Scale factor controller 706 Quantization matrix storage 712 Memory 713 Memory management unit

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Motoichi Ichimura 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Yoshimichi Kanda 1-3-3 Nakamagome, Ota-ku, Tokyo No. 6 Inside Ricoh Company, Ltd. (72) Oji Maruyama 1-3-6 Nakamagome, Ota-ku, Tokyo Inventor Shinji Yamakawa 1-372 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Koichi Noguchi 1-3-6 Nakamagome, Ota-ku, Tokyo Co., Ltd. (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-61-135286 (JP, A) JP-A-5-64143 (JP, A) JP-A-5-14562 (JP, A) JP-A-5-22610 (JP, A) JP-A-4-281667 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 1/41-1/419 H04N 1 / 38-1/393

Claims (2)

(57) [Claims] An encoding unit that quantizes and encodes image data by using a quantization parameter having a different compression ratio; a storage unit that stores a code encoded by the encoding unit; Read, encode, scale,
When storing a code in the storage unit, a control unit that changes a quantization parameter of the encoding unit for each document according to a scaling factor so that codes of all the documents are stored in the storage unit. Image encoding device provided with the same. 2. The controller according to claim 1, wherein the controller determines a code amount of each of the originals read by changing the size of the original by pre-scanning, so that the codes of all the scaled originals are stored in the storage unit. Scaling the quantization parameter of the encoding means
2. The method according to claim 1, wherein the change is made for each document according to the ratio.
The image encoding device according to claim 1.