Image processing device

An image processing portion for conducting the specified processing of an image to be reproduced by an image forming portion based on the processed image data is constructed as a single control portion. Consequently, the development of a variety of digital copying machines requires preparation of specially designated control boards according to levels of the products. This makes machines expensive and requires users to pay a considerable initial cost. An image processing device of the present invention is provided with an image information inputting means for inputting image information as a first level image, a main image-processing board for conducting the specified processing of the input image information of the first revel image, a sub image-processing board for conducting the specified processing of the image information processed by the main image processing board and outputting the information as a second level image, and a means for reproducing an image according to the image information processed by the main image-processing board or the sub image-processing board. These boards are independent from each other in the circuit configuration.

BACKGROUND OF THE INVENTION 
The present invention relates to an image processing device such as a 
digital copying machine that conducts specified processing of image 
information read from an original by a scanning portion or image 
information transmitted over a communication channel from the outside and 
outputs a processed image by a printer portion. 
Recently, the spread of digital data processing apparatuses such as 
personal computers, digital camera and portable information terminals 
using the digital technology has been accelerating globally. In the market 
for copying machines, many manufacturers are offering digital copying 
machines that can digitally process original images and output digital 
image information to meet an increasing demand of users for devices 
realizing easy reproduction and high-quality printing of photographs and 
originals without deterioration of the initial image quality. 
The market circumstance stimulates manufactures to put on the market 
multifunctional digital copying machines that have facsimile and printer 
functions allowing multiple access. 
However, the digital copying machines are expensive as compared with 
conventional analog copying machines because the digital machines must 
electrically read an original image and process the read image in the form 
of electronic data. 
Namely, the digital copying machine is a combination of expensive 
components such as a reading device for electrically reading an original 
image, an image processing device for processing the electrically read 
image as electronic data and an optical scanning type recording device 
(e.g., a laser scanner) and so on. Therefore the further spread of the 
digital copying machines (e.g., a replace from the conventional analog 
machines or a increase of the digital machines) now slows down. 
The image-processing portion in particular is very expensive and increases 
a total cost of the digital copying machine. 
Japanese Laid-open Patent Publication No. 62-82768 discloses an image 
processing device which is capable of high-speed processing of 
high-resolution image data by using a printer control section composed of 
a print head control portion having a first CPU for modulating beams in 
accordance with image data, an electrophotographic control portion having 
a second CPU for controlling an electrophotographic process to reproduce 
an image on paper, an interface control portion having a third CPU for 
syncronizing the operation of the printer-head control portion with the 
operation of the electrophotographic control portion. 
The publication describes a method whereby an image forming device has a 
plurality of control units used for control of respective working portions 
of the device and is provided with a specific timing control portion for 
assuring synchronous operations of the control units. 
The technical content of the above Publication consists in that 
image-processing portion for conducting processing of an image according 
to image data from an image forming portion is constructed as a single 
control unit. 
To supply a variety of the digital copying machines, it is therefore 
necessary to prepare specific control boards depending upon the 
specifications of the goods. This may burden users with an increased 
initial cost of the goods and manufactures with time and cost of 
development. The need for additional control for synchronizing the 
respective processing portions is also a problem in costs. 
Accordingly, the present invention is directed to a variety of digital 
copying machines from an inexpensive standard type copying machine capable 
of producing high-quality copies to a high-grade digital copying machine 
provided with a variety of functions, which are developed on a basis of a 
digital copying machine having minimum necessary functions, which can be 
modified with separate options of components for specific digital image 
processing functions to satisfy all the market demands and users' needs. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a digital copying 
machines that can be modified by adding options whenever user requests. 
It is another object of the present invention to provide an image 
processing device which comprises an image information inputting means for 
inputting image information as a first level image, a first 
image-processing means for conducting specified processing of the image 
information inputted as the first level image, a second image-processing 
means for receiving the image information processed by the first 
image-processing means and conducting specified processing of the image 
information as a different second level image and an image-information 
reproducing means for reproducing an image from the image information 
processed by the first image-processing means or the second 
image-processing means and i s featured in that the first image-processing 
means and the second image-processing means are formed separately from 
each other in the circuit configuration. 
It is another object of the present invention to provide an image 
processing device in which the first image-processing portion is provided 
with an image-writing control portion for control of image information 
writing by the image-reproducing means. 
It is another object of the present invention to provide an image 
processing device in which the first image-processing portion is provided 
with a central processing unit for control of the first image-processing 
portion and the second image-processing portion. 
It is another object of the present invention to provide an image 
processing device in which the image information inputted from the 
image-information inputting means and processed by the first 
image-processing means is multivalued-image information and the image 
information processed by the second image-processing means is binary image 
information. 
It is another object of the present invention to provide an image 
processing device in which the second image-processirng means is further 
provided with an input portion for receiving an image transmitted from a 
facsimile and/or a printer and the facsimile image or the printed image 
inputted through the input portion is processed as a binary image.

PREFERRED EMBODIMENT OF THE INVENTION 
Referring to accompanying drawings, preferred embodiments of the present 
invention will be described below in detail. 
FIG. 1 is a sectional view showing an entire system of a digital copying 
machine. 
As shown in FIG. 1, the digital copying machine 10 is composed mainly of a 
scanner section 11 and a laser recording section 12. 
The scanner section 11 consists of a document setting table 15 made from a 
transparent glass, a both-sides automatic document feeder (RADF) 16 for 
automatically transferring document to the document setting table 15 and a 
scanner unit 20 (document image reading unit) for reading an image of the 
original document set on the document setting table 15. The original image 
read by the scanner portion 11 is transferred as image data to an image 
inputting portion (described later). 
A paper storing/feeding portion has a first cassette 31, a second cassette 
32, a both-sides copying unit 33 and a multi-format paper feeding tray 34. 
The cassettes accommodate piles of different format-size sheets of 
recording paper respectively. When a user selects a desired cassette, 
paper sheets of the desired format size will be fed periodically one by 
one from the top of the pile in the cassette and transferred along a paper 
feeding path 35 to an image forming portion of the laser printer section 
12. 
The RADF 16 is a document feeding device that automatically feeds originals 
one by one at due time-intervals from a plurality of original documents 
put on a document feeding tray to the document setting table 15 of the 
scanner unit 20. 
The RADF 16 has two different document-transporting paths one for 
one-side-printed documents and the other for both-side-printed documents, 
which paths can be selected using selecting means by a user. This RADF 16 
uses a known art and will not be further explained. 
The scanner unit 20 consists of: a first scanning unit 20a including a lamp 
reflector assembly 21 for illuminating the surface of an original document 
and a first reflecting mirror 22a for reflecting the reflected (image) 
light from the original document toward a photoelectric conversion element 
(i.e., a charge coupled device CCD) 24; a second scanning unit 20b 
including a second and third reflecting mirror 22b and 22c for directing 
the reflected light (of the original document image) to the CCD 24; an 
optical lens 23 for imaging the reflected light image of the original 
document on the surface of the CCD 24; and the CCD 24 for converting the 
received image into an electrical image signal. 
In the scanner section 11, a document to be read is placed on the document 
setting table 35 and scanned by the scanner 20 moving along the bottom 
surface of the table. This is realized by th scanner unit 20 in 
cooperation with the RADF 16. 
Image data obtained by reading the original image by the scanner unit 20 is 
transferred to an image processing section (to be described later) that in 
turn processes the received image data and transmits the processed image 
data to a laser recording unit 26. The image data is then reproduced as a 
visible image on a light-sensitive drum 28, transferred to the paper and 
fixed thereon through the electrophotographic (xerographic) process. 
The laser printer section 12 is provided with paper storing/feeding 
portion, laser writing unit 26 and an electrophotographic processing unit 
27 for forming an image. 
The laser writing unit 26 includes a semiconductor laser capable of 
emitting laser light corresponding to the image data recorded in the 
memory, a polygonal mirror for deflecting the laser light at an 
equiangular-velocity and a lens f-.theta. for correcting the laser light 
deflected at the equiangular-velocity so that the laser light may be 
deflected at an equivelocity on the light-sensitive drum 28 of the 
electrophotographic process portion 27. 
The electrophotographic processing portion 27 includes a light-sensitive 
drum 28 around which an electrically charging means, a developing means, a 
toner-image transferring means, a paper stripping means, a cleaning means, 
electrically discharging means, and a toner-image fixing device 29 are 
disposed according to a known arrangement. A paper transporting path is 
provided downstream at the outlet of the toner-image fixing device 29 and 
branches into a path 37 extending to a post-processing device 14 and a 
path 38 extending to a both-sides copying unit 23. 
According to image data read from the image memory, the laser unit 26 emits 
arid scans laser light to form a latent image on the light-sensitive drum 
28. The latent image on the drum is developed with toner and transferred 
onto a paper sheet fed from a multistage paper-feeding portion. The toner 
image is fixed by heat on the paper sheet while passing the fixing device. 
The paper sheet with a toner image fixed thereon passes the outlet of the 
fixing device 29 and is delivered via the path 30 to the post-processing 
unit 14 or via the path 38 to a cassette 33 for paper-sheets to be further 
printed on its reverse side. 
The construction and functions of an image processing portion for 
conducting processing of image information read from an original in the 
digital copying machine 10 will be described below: 
FIGS. 2A and 2B are block diagram showing a whole construction of the 
component units and an image processing portion included in digital 
copying machine 10 shown in FIG. 1. A main central processing unit (CPU) 
401 disposed at the center of the components controls the operation of the 
whole system in cooperation with central processing units (CPU) of 
respective component units of the machine. 
As shown in FIGS. 2A and 2B, the control system is composed mainly of an 
operation-panel board 100 shown above right for control of an operation 
panel, a machine control board 200 disposed above left for control of 
component units of the digital copying machine 10, a CCD board 300 shown 
below left for control of electrically reading an image from an original 
converting the image into electronic data, an image processing board 400 
shown at the center for carrying-out the particular processing of the 
electronic image data from the CCD board 300, a sub image-processinag 
board 500 for carrying-out the particular processing of the image data 
from the main image-processinig board, original image and a group of 
extended boards 600 (e.g., a printer board, a facsimile board, a extended 
function board) shown below right and connected through an interface to 
the sub image-processing board 500. 
The control actions of the respective control boards will be described as 
follows: 
Operation Panel Board 
The operation panel board 100 is basically controlled by a sub central 
processing unit (CPU) 101 and controls input operations from an LCD 
display 104 and from operation keys 105 on the operation panel 103. A 
memory 102 is provided for storing data input from the operation keys 105 
and various kinds of control information to be displayed on the LCD 104 on 
the operation panel. 
In this arrangement, the sub-CPU 101 receives and transmits control data 
from/to the main control CPU 401 and controls actions of the digital 
copying machine 10. The main CPU 401 transfers a control signal showing a 
current working state of the digital copying machine 10 to the sub-CPU 101 
that indicates the current state of the machine on a screen of the LCD 
104. 
Machine Control Board 
The machine control board 200 works under the control of the sub-CPU 201 
and controls the operation of an automatic document-feeder 203 (ADF/RADF), 
a reading scanner section 204 for reading a document image, a processing 
section 205 for reproducing an image from image information, a recording 
paper feeding section 206 for periodical feeding a recording paper sheet 
from a sheet-cassette to the processing section 205, a both-side printing 
unit 207 for reversing a paper sheet printed surface down and feeding it 
to the processing section 205 for printing the reversed surface of the 
paper sheet, and a finisher 208 for conducting post-processing (e.g., 
stapling) of the printed paper sheets. 
CCD board 
The CCD board 300 includes a charge-coupled device (CCD) 301 for 
electrically reading an image from an original document, a CCD driving 
circuit (CCD gate array) 302 for driving a CCD 301, an analog circuit 303 
for adjusting a gain of analog data and an analog-to-digital converter 304 
for converting analog data from the CCD 301 to digital signals and 
outputting the digital signals as electronic data for further processing. 
The CCD board 300 works under the control of the main CPU 401. 
Main Image-Processing Board 
The main image-processing board 400 works under the control of the main CPU 
401. It includes a multivalued image-processing portion 402 for receiving 
the electronic data of the original image and processing the data in the 
multivalued state so as to represent a desired gradation of the image 
through steps of shading correction, optical-density correction, area 
separation, filtering, MTF correction, resolution transform, electronic 
zooming (variable-power processing) and gamma correction steps, a memory 
403 for storing processed image data and/or various kinds of control data 
for processing, and a laser control unit 404 for control of transferring 
the processed data to a laser writing unit 26 for reproducing the original 
image according to the processed electronic data. 
Sub Image-Processing Board 
The sub image-processing board 500 is connected through a connector to the 
main image-processing board 400 and includes a binary-image processing 
unit 501 controlled by the main CPU 401 provided on the main image 
processing board, a memory for storing binary processed image information 
and/or control data for processing, a gate array 502 for control of the 
memory, a hard disk for storing information of a plurality of original 
images to be repeatedly read out for copying the desired number of copy 
products, a gate array 503 for control of the hard disk a SCSI as external 
interface, a gate array 504 for control of the SCSI. 
The binary-image processing unit 501 is composed of a converting portion 
for converting multivalued image-information into binary image 
information, an image-turning portion for rotation of an image, and a 
zooming processing portion for changing a scale factor of the binary 
image. It is also provided with a facsimile interface for receiving and 
transmitting a facsimile image over a communication line. 
Extended Boards 
The extended board group 600 is composed of, e.g. a printer board 601 for 
receiving data from a personal computer and outputting the same in printer 
mode from a printing section of the copying machine, a function expanding 
board 602 for expanding edit-functions of the digital copying machine for 
further effective use of the features of digital printing, and a facsimile 
board 603 for enabling image-information transmitted from a remote 
terminal to be output from the printer of the digital copying machine. 
The image processing operation of the image-processing device for the 
digital copying machine will he described below in copier, facsimile and 
printer modes respectively. 
Copier Mode 
In the digital copying machine 10, original documents put on the RADF 16 
are automatically fed one by one to a document setting table 15 of the 
scanner unit 20. Each original document image is read and converted by the 
scanner unit 20 into 8-bit electronic data which is then transferred to 
the main image-processing board 400. 
In the main image-processing board 400, the electronic data is processed as 
8-bit electronic image data by the multivalued-image processing portion 
402 according to a predetermined procedure. 
The 8-bit electronic data subjected to the processing (e.g., gamma 
correction) is transferred through laser control portion 404 to the laser 
writing unit 26. The original image read by the scanner section 11 of the 
digital copying machine 10 is output as a copied image having a gradation 
from the laser recording portion 12. 
Electronic RDH Function in the Copy Mode 
Original documents put on the RADF 16 are automatically fed one by one to a 
document setting table 15 of the scanner unit 20. Each original image is 
read and converted by the scanner unit 20 into 8-bit electronic data that 
is then transferred to the main image-processing board 400. 
In the main image-processing board 400, the electronic data is processed as 
8-bit electronic image data by the multivalued-image processing portion 
402 according to a predetermined procedure. 
The 8-bit electronic data is transferred from the main image-processing 
board 400 (through the connector 405) to the sub image-processinig board 
500 (through the connector 505). Then the data is subjected to error 
diffusion processing and converted into 2-bit (binary) electronic image 
data in a multivalued image-to-binary image conversion portion of a binary 
image processing portion 501. 
The conversion of 8-bit electronic image data into 2-bit electronic image 
data with error diffusion processing is conducted in such a way that the 
image may not suffer deterioration of its quality. The conversion may 
bring an advantage of saving the memory capacity of the system. 
The binary-bit electronic image data of each original is transferred to and 
temporarily stored in a hard disk memory 503. 
When all original documents put on the RADF 16 were fed and read by the 
scanner, the binary-bit electronic image data stored in the hard disk 503 
is read out repeatedly by the required number of copies under the control 
of the gate array control and transferred again to the main 
image-processing board 400 through the connectors 405 and 505. The data is 
subjected to gamma correction on the board 400 and then transferred to the 
laser writing unit 26 through the laser control portion 404. 
Although the embodiment is intended to repeatedly read a set of the images 
by the desired number of copies after having read and stored all original 
document images, it may be modified to output first series of images just 
after a set of images to be copied first has been prepared. 
The original image read by the scanner section 11 of the digital copying 
machine 10 is output as a copy image having a gradation from the laser 
recording portion 12. 
Printer Mode 
An image transmitted over a network from an external terminal (e.g., a 
personal computer) connected thereto is developed to a unit-page image on 
the printer board 601 and then transferred through the interface SCSI 504 
to the sub image-processing board 500 wherein the data is stored in the 
hard disk memory 503. 
The image developed to a page image on the printer board 601 is transferred 
to the sub image-processing board 500 wherein it is not subjected to 
binary image processing and is temporarily stored in the hard disk memory 
503. 
The binary image processing is not made on the page image when being read 
from the hard disk memory 503. 
The page images stored in the hard disk 503 are read therefrom in the order 
of specified page numbers and transferred to the main image-processing 
board 400 wherein they are subsequently subjected to gamma correction. The 
laser control 404 controls the laser unit (LSU) 26 for writing the images 
to be reproduced. 
Facsimile Mode 
The facsimile mode includes processing for transmitting an original image 
to a remote communication party and processing for receiving an original 
image from a remote communication party. 
The procedure of transmitting original images to the remote terminal is 
described first as follows: 
Originals (separate sheets of a document) set on the RADF 16 are 
automatically fed one by one to a document setting table 15 of the scanner 
unit 20. Each original image is read and converted by the scanner unit 20 
into 8-bit electronic data that is then transferred to the main 
image-processing board 400. 
In the main image-processing board 400, the electronic data is processed as 
8-bit electronic image data by the multivalued-image processing portion 
402 according to a predetermined procedure. 
The 8-bit electronic data is transferred from the main image-processing 
board 400 (through the connector 405) to the sub image-processing board 
500 (through the connector 505). Then the data is subjected to error 
diffusion processing and converted into 2-bit (binary) electronic image 
data in a multivalued image-to-binary image conversion portion of a binary 
image processing portion 501. 
The conversion of 8-bit electronic image data into 2-bit electronic image 
data with error diffusion processing is conducted in such a way that the 
image may not suffer deterioration of its quality. The biniary-bit images 
of the originals to be transmitted are compressed in a specified format 
and stored in the memory 502. 
After establishment of communication line with the remote party, the 
original images compressed in the specified format are read from the 
memory 502 and transferred to the facsimile board 603 wherein the images 
are subjected to necessary processing (e.g., changing of a compression 
format) and successively transmitted to the party over the communication 
line. 
The procedure of processing original images received from a remote terminal 
is as follows: 
A series of original document images transmitted over a communication line 
from a remote terminal is received by the facsimile board 603 that 
establishes first the communication condition and then receives the 
original document images. The received images compressed in a specified 
format are transferred to the binary image processing portion 501 through 
the interface from the sub image board 500. The transmitted images are 
reproduced as respective page images by using a companding device provided 
thereat. 
The reproduced original page images are transferred to the main 
image-processing board 400 wherein they are successively subjected to 
gamma correction. The laser control 404 controls the laser unit 26 for 
writing the images to be reproduced. 
As described above, the image processing portion for conducting the 
specified processing of image information is constructed of two separated 
image-processing boards, one of which is a main image-processing board 400 
for processing an original document image inputted through a scanner 
portion 11 in the form of multivalued image-information and the other is a 
sub image-processing board 500 for conducting the specified processing 
(including multivalue-to-binary conversion) of the multivalued image 
information transferred from the main image-processing board 400 and the 
specified processing of image information received from any external 
terminal through an external interface and then transferring the 
information to the multivalued image-processing portion (of the main 
image-processinig board). 
The main image-processing board 400 includes a laser control 404 that 
controls a laser writing unit 26 to write image information for 
reproducing an image on a light-sensitive body 28 in the 
electrophotographic process. 
In the above construction of the image processing portion, an original 
image scanned by the scanner unit 31 can be reproduced as a high-quality 
copy of the original image maintaining the feature of the multivalued 
image by laser recording portion 12. High speed output of a large number 
of original images can be carried out by using electronic reading function 
with sub image-processing board 500 and a hard disk memory 503. 
Image information received from an external device (e.g., a facsimile and a 
printer) and, particularly, processed multivalued images (holding the 
feature of the originals) transmitted from an external facsimile can be 
processed suitably (including conversion of multivalued images into binary 
images) using the various kinds of functions featuring the digital copying 
machine 10. 
The divided construction of the image processing portion makes it possible 
to line up many variations of the digital copying machines 10 to meet the 
users' needs. It is also possible to easily expand the system of the 
digital copying machine 10 working at the user's request. 
The central processing unit 401 disposed on the main image-processing board 
400 controls the sub image-processing board 500 in a whole system 
described before to achieve the consistency of sequential operations of 
respective processing portions, realizing a smooth flow of data and 
processing steps on respective portions of the machine (without missing 
any image data). 
The present invention can offer the following advantages: 
The division of image processing section (in the form of separate 
image-processing boards) according to levels or contents of image 
processing realizes simplified arrangements for control of processing 
steps and data flows in the respective image-processing portions, 
achieving effective processing of the image information. 
The provision of functional options (in the form of boards) realizes the 
supply of digital copying machines to meet the requirements of the market 
and individual users. This enables users to obtain the digital copying 
machines provided with only desired functions at a least expense. 
Furthermore, the above concept allows makers to easily offer a wide 
selection of the goods from a standard machine having the minimum 
necessary functions to a high-grade machine provided with the maximum of 
functions. This eliminates the need for using specially designed 
processing boards. 
It is also of a great advantage for users to save an initial cost by 
selecting a basic machine containing the minimum necessary 
image-processing boards that usually take a large portion of the cost of 
the components of the machine. 
Especially the image-processing device according to an aspect of the 
present invention uses two separate image-processing boards one of which 
is a main image-processing board for conducting the specified processing 
of the image information input from a scanner and outputting an image from 
a printer and the other is a sub image-processing board for conducting the 
particular processing of the image information transferred from the main 
image-processing board. This division is made in accordance with levels 
and contents of processing operations, thus realizing a simplified 
arrangement for control of processing steps and data flows in the image 
processing device and attaining effective processing of the image 
information. 
The image-processing device according to another aspect of the present 
invention is further featured in that the main image-processing board has 
a control portion that controls image-data writing by the recording 
portion to output the reproduced image from a recording section. This 
enables the main image-processing board to process the electronic image 
data in a multivalued form and output the reproduced image through a laser 
recording portion. Namely, it is possible to provide the standard digital 
copying machine that can reproduce a high-quality image of an original 
read by a scanner. 
The use of the main image-processing board provided with minimum necessary 
functions realizes an inexpensive standard digital copying machine with a 
reduced cost of the image processing portion that usually takes a large 
portion of the cost of the machine. The standard machine is also capable 
of freely extending its processing performace by adding desired options. 
The image-processing device according to another aspect of the present 
invention is featured by the provision of a central processing unit (CPU) 
on its main image-processing board, which device controls a sub 
image-processing board to assure smooth and reliable control of the image 
information while processing the main and sub boards. Both the boards 
operate in synchronism with each other by being controlled from the same 
clock, realizing smooth transfers of the image information between them. 
The image-processing device according to another aspect of the present 
invention is further featured in that the main image-processing board 
processes image information of a multivalued image and the sub 
image-processing portion processes image information of a binary image. 
This feature can simplify the control of data processing operations and 
data flows, assuring effective processing image information. 
This enables makers to easily line up a variety of digital copying machines 
by incorporating main image-processing board only for conducting the 
processing multivalued image information and by incorporating the main 
image-processing board for processing multivalued original image 
information and outputting the high-quality of reproduced image and the 
sub image-processing board for processing binary image information for use 
in a facsimile and a printer. 
The image-processing device according to another aspect of the present 
invention is featured in that the sub image-processing board processes 
image information for use in a facsimile or a printer to easily meet the 
user's requirements without any additional expense. 
Recent models of digital copying machines are featured by the ability to 
process image information transmitted over a communication line from an 
external device in the facsimile mode or the printer mode besides or, 
sometimes, in parallel with processing image information read in the copy 
mode. The use of the separate image-processing boards can assure the 
smooth control of processing and transfers of image information in 
respective modes.