Electrical computers and digital data processing systems: input/ – Intrasystem connection – Bus access regulation
Reexamination Certificate
1998-12-18
2001-05-29
Auve, Glenn A. (Department: 2181)
Electrical computers and digital data processing systems: input/
Intrasystem connection
Bus access regulation
C710S120000
Reexamination Certificate
active
06240481
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus which is preferably applied to an image processing apparatus such as a copying machine, a printer and a facsimile machine. To be more precise, the invention relates to an apparatus wherein a 3-way interface means is connected to an image memory and data bus which is split into two, and after control instruction is given to the interface means, input and output of an image acquisition means and an image reproduction means are controlled on a time series basis by the control instruction independently of the control means so that the control means can execute another data processing.
Recently, a digital copying machine which forms an image based on image data acquired from a document image has been put to practical use. In the copying machine of this type, image information of a document is read by a scanner or the like, and image information of the document is stored temporarily in an image memory. Then, the image information stored in the image memory is subjected to image processing such as image reduction, image enlargement and rotation, to meet a user's demand. Due to this, an image of the document can be printed on a prescribed transfer sheet, based on the image data which have been subjected to image processing.
A digital copying machine of this kind, on the other hand, is equipped with a memory with large capacity for storing image information of a document temporarily, and it needs a technology of efficient data transmission for the image information.
FIG. 7
is a block diagram showing an example of the structure of image forming apparatus
500
of a conventional type employing an image memory of this kind. This image forming apparatus
500
is equipped with CPU bus
1
shown in FIG.
7
. The CPU bus
1
is connected to system control means
2
, image memory
3
, direct memory access controller (hereinafter referred to as DMAC)
4
, image acquisition means
5
and image reproduction means
6
.
The system control means
2
connected to CPU bus
1
has therein CPU
2
a
, ROM
2
b
, RAM
2
c
and user interface section
2
d
. CPU
2
a
is an IC which conducts overall control of the image forming apparatus
500
, and its control program is stored in ROM
2
b
. RAM
2
c
is a memory used temporarily when CPU
2
a
conducts operation, and it is needed for execution of control program.
For example, when control instruction such as a startup directive is outputted to image acquisition means
5
or image reproduction means
6
, the control instruction is written in RAM
2
c
by CPU
2
a
, and after that, when an end of writing of image data is notified, those corresponding to the control instruction are verified.
User interface section
2
d
is one which is needed for interface between the present apparatus and a user, and the instruction of the user interface section makes CPU
2
a
to execute prescribed data processing. Image memory
3
connected to CPU bus
1
is a memory with a relatively large capacity corresponding to plural pages, and it also stores code data by conducting coding processing, though this is not shown. DMAC
4
is one which executes data transmission between devices without interposition of CPU
2
a
, and compared with CPU
2
a
, it can transmit data at higher speed.
Image acquisition means
5
connected to the CPU bus
1
has therein scanner-use interface
5
a
, scanner section
5
b
and page memory
5
c
. The scanner-use interface
5
a
conducts control for driving of scanner section
5
b
and control for writing and reading of image data (DATA) in page memory
5
c
. The page memory
5
c
is a memory for storing image data in quantity equivalent to one page coming from scanner section
5
b
, and it is needed for adjustment of data transmission speed between the scanner section
5
b
and CPU
2
a
and for improving use efficiency for CPU bus
1
. Since the page memory
5
c
is provided to adapt with the speed of the scanner, the page memory
5
c
needs not have the capacity for full or all pages.
Further, image reproduction means
6
connected to CPU bus
1
has therein printer-use interface
6
a
, page memory
6
b
and printer section
6
c
. The printer-use interface
6
a
conducts control for driving of printer section
6
c
and control for writing and reading of image data in page memory
6
b
. The page memory
6
b
is a memory for storing data to be written in printer section
6
c
in quantity equivalent to one page, and it is needed for adjustment of data transmission speed between the printer
6
c
and CPU
2
a
and for improving use efficiency for CPU bus
1
. As same as the case for the scanner, the page memory Sc needs not have the capacity for full or all pages.
Next, operations of the image forming apparatus
500
will be explained. First, copying operations for a single document will be explained. First of all, when instruction for one page copy is received from user interface section
2
d
, scanner driving is instructed from CPU
2
a
to image acquisition means
5
. In the scanner-use interface
5
a
which has received that instruction, the scanner section
5
b
is driven and image data of a document is acquired from scanner section
5
b
, and that image data are stored in page memory
5
c
in succession. When image data equivalent to one page are stored in page memory
5
c
, the scanner-use interface
5
a
notifies an end of image data reading to CPU
2
a.
CPU
2
a
which has received the notification gives to DMAC
4
the instruction for transmitting image data from scanner-use interface
5
a
to printer-use interface
6
a
. Then, image data equivalent to one page are transmitted from scanner-use page memory
5
c
to printer-use page memory
6
b
. When this transmission of image data for one page has been finished, an end of transmission is notified from DMAC
4
to CPU
2
a
. Then, printer driving is instructed from CPU
2
a
which has received the aforesaid notification to image reproduction means
6
. Then, image data are read from page memory
6
b
by printer-use interface
6
a
which has received the aforesaid instruction, and the image data are outputted to printer section
6
c
. On the printer section
6
c
, it is possible to copy an image of a document on a transfer sheet or the like based on image data for one page.
Next, operations for making plural sets of copies for plural documents will be explained. First, scanner driving is instructed to image acquisition means by CPU
2
a
which has received the instruction from user interface section
2
d
. On the scanner-use interface
5
a
which has received the instruction, when image data equivalent to one page acquired by scanner section
5
b
have been stored in page memory
5
c
, an end of reading of image data equivalent to one page is notified to CPU
2
a
from scanner-use interface
5
a
. Then, data transmission is instructed to DMAC
4
by CPU
2
a
which has received the notification, thereby, image data stored in page memory
5
c
are transmitted to image memory
3
.
A series of aforesaid operations are repeated for the number of times equivalent to the number of documents, and all image data are stored in image memory
3
. After that, image data thus stored are transmitted to printer-use interface
6
a
by the instruction of CPU
2
a
. In this case, when image data equivalent to one page are stored by DMAC
4
in printer-use page memory
6
d
from image memory
3
, printer startup is instructed to printer-use interface
6
a
from CPU
2
a.
When image data equivalent to one page are outputted to printer section
6
c
by printer-use interface
6
a
which has received the instruction stated above, an end of printing is notified to CPU
2
a
. Then, transmission of image data on the succeeding page is instructed to DMAC
4
from CPU
2
a
which has received the notification, whereby printing is started.
When a series of aforesaid operations are repeated for the number of times equivalent to the number of documents, copies for the first set are finished. Since plural sets of copies are instructed to CPU
2
a
in this examp
Auve Glenn A.
Frishauf, Holtz Goodman, Langer & Chick, P.C.
Konica Corporation
LandOfFree
Data bus control for image forming apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Data bus control for image forming apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Data bus control for image forming apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2513626