Papst Licensing GmbH & Co., KG.
`Petitioner - Apple, Inc.
`Patent Owner - Papst Licensing GmbH & Co., KG.
`IPR2016-01841
`EXH. 2001
`
`1
`
`

`
`U.S. Patent
`
`Apr. 16, 1996
`
`Sheet 1 of 7
`
`5,508,821
`
`2
`
`

`
`U.S. Patent
`
`Apr. 16, 1996
`
`Sheet-2 of 7
`
`5,508,821
`
`IMAGE
`
`MEMORY 0I -1
` 60
`
`SELECTOR
`
`SCQ BUS
`
`
`
`
`
`NONVOLSCSI64MEMORYCTRL
`
`PWP
`
`ENCD
`
`63
`
`43
`
`42
`
`o #
`
`7"
`
`V M
`mCY)
`
`36illgiii
`35IMMM37
`
`3
`
`

`
`U.S. Patent
`
`Apr. 16, 1996
`
`Sheet 3 of 7
`
`5,508,821
`
`#SCANNER PARAMETER FILE EXAMPLE
`
`#AREA PAFIAMETER(inch)
`# X.Y,XL.YL
`1.2
`2.4
`5.5
`6.3
`
`#ZOOMING PARAMETER(%) XZ,YZ
`100
`150
`
`#IMAGE PROCESSING PARAMETER
`SIMPLE BI-LEVEL IMAGE
`
`->0
`
`->1
`BI-LEVEL COMPRESSION IMAGE(MH)
`—>2
`BI-LEVEL COMPRESSION IMAGE(MR)
`—>3
`BI-LEVEL COMPRESSION lMAGE(MMR)
`->4
`ERROR DIFFUSION BI-LEVEL IMAGE
`->5
`88|TS GRAY SCALE -IMAGE
`88ITS.GRAY SCALE COMPRESSION IMAGE —>6
`
`GAMMA TRANSFER PARAMETER
`LINEAR
`->0
`DENSITY
`->1
`DATE SETTABLE —>2
`
`#GAMMA TRANSFER DATA TABLE
`
`#DATA MUST BE 0 (=.255) =
`32
`00101710 20 24 27 2A 2
`37 3A 3C 3E
`O 30
`54 56 57 59
`40 42 44 48 47 49 4B 4D 4E 50 51
`87
`5 66
`6 BASB 8C8D
`5A5C5D5E80 61 62 646
`7A
`79
`7C 7D 7E 7F
`GF 70 71 72 73 74 75876 77
`89
`A 8B 8C 8D 8E
`80 81 82 83 84 85 86 87 87 88
`8F 90 91 91 92 93 94 95 96 97 97 98 99 9A 9B 9C
`9C 9D 9E 9F A0 A0 A1 A2 A3 A4 A4 A5 A6 A7 A7 A8
`A9 AAAAABACADADAEAF B0 B0 B1 B2 B3 B3 B4
`B5 B5 B6 B7 B7 B8 B9 BA BA BB BC BC BD BE BE BF
`C0 C0 C1 C2 C2 C3 C4 C4 C5 C6 C6 C7 C7 C8 C9 C9
`CA CB CB CC CO CD CE CE CF D0 D0 D1 D1 D2 D3 D3
`D4 D4 D5 D6 D6 D7 D7 D8 D9 D9 DA DA DB DC DC DD
`DD DE DE DF E0 E0 E1 E1 E2 E2 E3 E4 E4 E5 E5 E6
`E6 E7 E7 E8 E9 E9 EA EA EB EB EC EC ED ED EE EE
`EF F0 F0 F1 F1 F2 F2 F3 F3 F4 F4 F5 F5 F6 F6 F7
`F7 F8 F8 F9 F9 FA FA FB FB FC FC FD FD FE FE FF
`
`7 8
`
`3 5
`
`4
`
`

`
`U.S. Patent
`
`Apr. 16, 1996
`
`Sheet 4 of 7
`
`5,508,821
`
`Fig. 5
`
`SYS.PREPARED
`
`“mkfs”
`COMMAND
`
`MOUNT
`
`HLE SYS.
`
`WRITE TO
`PARA FKE
`
`UNMOUNT
`
`HLE SYS.
`
`READ
`
`IMAGE DATA
`
`PARA.
`
`SHOULD BE
`
`CHANGED
`
`5
`
`

`
`U.S. Patent
`
`Apr. 16,1996
`
`Sheet 5 of 7
`
`5,508,821
`
`TF/'g_ 5
`
`HEHHEEHEI
`Hflfiiflflfififl
`IMHEIEMHI
`llfl¥IHMHE
`
`cytinder group 5
`r“-r“ - —*
`
`cylinder group n
`
`&EHMHlfll%H
`IMMHHMHEEH
`IIIH¥lfiEII
`
`data btocks
`
`‘
`
`6
`
`

`
`U.S. Patent
`
`Apr. 16, 1996
`
`I Sheet 6 of 7
`
`5,508,821
`
`Fig.8
`
`SCSI BUS
`
`CPU BUS
`
`IMAGE
`MEMORY
`
`PRINTER
`CLRL
`
`LASER
`DRIVER
`
`NONVOL.
`MEMORY
`
`#PRINTER PARAMETER FILE EXAMPLE
`
`#PAPER O—>A4 ‘I-> B4
`
`0 #
`
`PRINTING DIRECTION O-> PORTRAIT 1~>LANDSCAPE
`
`PRINT VOLUME
`
`O #
`
`1
`
`7
`
`

`
`U.S. Patent
`
`Apr. 16, 1996
`
`Sheet 7 of 7
`
`5,508,821
`
`Fig. 10
`
`SYS.PREPARED
`
`"mkfs"
`COMMAND
`
`MOUNT
`
`FILE SYS.
`
`WRITE TO
`PARA HLE
`
`UNMOUNT
`FILE SYS.
`
`MOUNT
`
`AGAIN
`
`WRITE
`IMAGE DATA
`
`PARA.
`
`SHOULD BE
`CHANGED
`9
`
`8
`
`

`
`5,508,821
`
`1
`IlVI.AGE SCANNER AND IIVIAGE FORMING
`APPARATUS WITH AN INTERFACE FOR
`CONNECTION WITH AN EXTERNAL
`COMPUTER
`
`BACKGROUND OF THE INVENTION
`
`1. Field of the Invention
`
`The present invention relates generally to an image han-
`dling apparatus, and more particularly to an image scanner
`and to an image forming apparatus both for transferring data
`to and from an external host apparatus via an interface.
`2. Description of the Prior Art
`A computer is generally operatively connected to several
`peripheral devices such as, for example, a magnetic disc, a
`magnetic tape, a printer or the like. Recently, a small
`computer system interface (SCSI) is standardized as an
`interface means for carrying out high-speed data transfer.
`Through the standardization, the SCSI is in wide practical
`use today as an interface for various computers.
`By virtue of marked improvement in performance of
`small computers, e.g. workstations, the development from
`character codes to bit-map data, which has hitherto been
`carried out in a printer,
`tends to be carried out
`in the
`computer using outline font data which the computer has.
`Whereas the technique of developing, for example, fonts to
`the bit-map data in the computer has advantages in adding
`other fonts, the use of the SCSI is inevitably required for
`high-speed data transfer because the quantity of data to be
`transferred from the computer to the printer is increased.
`In applications where an image scanner or an image
`forming apparatus is connected to an SCSI of a computer
`employed as ahost computer, and parameter setting for such
`apparatus or image data transfer is carried out by the
`computer,
`the computer is required to have a software
`“device driver" for the apparatus connected thereto.
`Because image scanners or image forming apparatus are
`not standardized in kind of parameters which can be set or
`in functions,
`the device driver therefor is not generally
`contained in an operating system (OS) of the computer.
`Accordingly, it is necessary to prepare the device driver for
`the image scanner or the image forming apparatus connected
`to the host computer.
`Under the present conditions discussed above, however,
`in order to enable a certain image scanner or image forming
`apparatus to be connected to any one of various types of host
`computers, it is necessary to prepare a device driver for each
`type of host computer. As aresult, the problem arises that the
`preparation of the device driver requires much labor and
`increases costs.
`
`SUMMARY OF THE INVENTION
`
`The present invention has been developed to overcome
`the above-described disadvantages.
`It is accordingly an object of the present invention to
`provide an improved image handling apparatus, for example
`an image scanner or an image forming apparatus, which
`requires no preparation of any new device driver.
`In accomplishing the above and other objects, an image
`scanner according to the present invention comprises means
`for reading an image, an interface means for connecting the
`image scanner to an external host apparatus, and a file
`system emulation means for emulating a file system con-
`tained in the external host computer.
`
`2
`When the present invention is applied to an image form-
`ing apparatus, the read means is replaced with an image
`forming means for forming an image on a recording
`medium.
`
`Because an operating system of a computer constructs a
`file system in a hard disc, there invariably exists a device
`driver for the hard disc.
`
`As discussed hereinabove, because the image scanner or
`image forming apparatus according to the present invention
`is provided with the file system emulation means, the control
`of the apparatus or the transfer of image data can be carried
`out using the device driver for existing hard discs. Further-
`more, because the operating system is provided with various
`commands or system calls which are utilized to access to the
`file system, development of application software for use in
`a host computer operatively connected to the image scanner
`or image forming. apparatus is facilitated.
`In applications where the image scanner or image forming
`apparatus according to the present invention is connected to
`an external host computer, it is not necessary to prepare the
`device driver for each type of computer if the file system of
`the computer is the same. In short, the apparatus can be
`connected to any one of various types of computers having
`the same file system, e.g. any one of all computers having
`software called the “UNIX” as an operating system.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The above and other objects and features of the present
`invention will become more apparent from the following
`description of preferred embodiments thereof with reference
`to the accompanying drawings, throughout which like parts
`are designated by like reference numerals, and wherein:
`FIG. 1 is a perspective view of an image scanner accord-
`ing to the present
`invention which is connected to an
`external host computer;
`FIG. 2 is a schematic sectional view of the image scanner
`of FIG. 1;
`FIG. 3 is a block diagram of the image scanner of FIG. 1;
`FIG. 4 is a programmed file that is read by the computer
`when parameters are set in;
`FIG. 5 is a flowchart indicating the procedure at the time
`the image scanner is controlled by a workstation;
`FIG. 6 is a schematic view indicating the layout of a file
`system contained in die workstation;
`FIG. 7 is a perspective view of an image forming appa-
`ratus according to the present invention which is connected
`to an external host computer;
`FIG. 8 is a block diagram of the image forming apparatus
`of FIG. 7;
`FIG. 9 is a programmed file that is read by the computer
`when parameters are set in; and
`FIG. 10 is a flowchart indicating the procedure at the time
`the image forming apparatus is controlled by a workstation.
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENTS
`
`Referring now to the drawings, there is shown in FIG. 1
`an image scanner 20 embodying the present invention. The
`image scanner 20 is connected to an external host computer
`via an SCSI bus 22. In FIG. 1, the external host computer is
`a workstation 21 having the “UNIX” as an operating system.
`Ahard disc in which a file system for the workstation 21 has
`been formulated is accommodated in the workstation 21 and
`
`9
`
`

`
`5,508,821
`
`3
`is connected to the SCSI bus 22 inside the workstation 21.
`
`FIG. 2 schematically depicts the internal construction of
`the image scanner 20 according to the present invention. The
`image scanner 20 comprises a document platform 1 made of
`glass on which a document 2 is to be placed with the image
`surface thereof directed downwards, a document cover 3 to
`be overlaid on the document 2 to hold the document 2, and
`a scanning unit 6 comprising a fluorescent lamp 4 and a
`reflection mirror 5. The scanning unit 6 is driven by a motor
`(not shown) and is moved in a direction shown by an arrow
`S at a constant speed to carry out sub-scanning with respect
`to the document 2. The image scanner 20 further comprises
`a half-speed unit 7, a lens 10, and a line-type CCD image
`sensor 31. The half-speed unit 7 comprises two mirrors 8 and
`9. During scanning, when the scanning unit 6 is moved in the
`direction of the arrow S, the hall"-speed unit 7 is moved in
`a direction shown by an arrow T at a speed half of the
`scanning unit 6. Reflected light from the document 2 is
`further reflected by the mirrors 5, 8, and 9, and is focused on
`the CCD image sensor 31 by the lens 10 for image forma-
`tion. The CCD image sensor 31 carries out main—scanning in
`the line direcfion with respect to the reflected light from the
`document 2 to convert it to an electric signal.
`As shown in FIG. 3, the CCD 31 reads the reflected light
`from the document 2 at a resolution of 400 dpi, converts it
`to the electric signal, and outputs an analogue image signal
`32. The analogue image signal 32 is then amplified by an
`amplifier 33 and is converted to a digital image signal 35 by
`an 8-bit A/D converter 34. A garrrrna transfer circuit 36
`carries out digital-to-digital conversion for conversion of the
`gradation characteristic,
`thereby converting the digital
`image signal 35 to an image signal 37. The gamma transfer
`circuit 36 is comprised of a look—up table formulated by the
`use of a RAM. The RAM is connected to a CPU bus 51 of
`a CPU 50, and data stored therein can be set by the CPU 50.
`Accordingly, the conversion characteristic of the gamma
`transfer circuit 36 can be changed by the CPU 50.
`A zooming circuit 38 carries out a zooming operation in
`the direction of main—scanning by interpolating or thinning
`out the image signal 37, and outputs an image signal 39. The
`CPU 50 sets the zooming rate of the zooming circuit 38 via
`the CPU bus 51. The zooming operation in the sub-scanning
`direction is carried out by changing the speed of movement
`of the scanning unit 6 shown in FIG. 2. A trimrrring circuit
`40 carries out a trimming operation wherein only part of the
`image signal 39 that is indicative of a predetermined rect-
`angular region on the document 2 is made effective, and
`outputs an image signal 41. The trimming circuit 40 is
`connected to the CPU bus 51 of the CPU 50, and the
`trimming region can be set by the CPU 50.
`A binary circuit 42 compares the image signal 41 with a
`predetermined threshold value and outputs a binary image
`signal 43. The threshold value can be set by the CPU 50. A
`compression circuit 44 encodes and compresses the binary
`image signal 43 and outputs a compressed binary image
`signal 45. The compression circuit 44 carries out the encod-
`ing using any one of three binary image encoding methods:
`MH; MR; and MMR. The selection of an appropriate
`compression method is carried out by the CPU 50. A
`pseudo-half-tone processor 46 processes the image signal 41
`using the error dififusion method and outputs an image signal
`47. An encoder 48 encodes and compresses the image signal
`41 and outputs’ an encoded image signal 49.
`A selector 60 selects an appropriate signal from among
`the compressed binary image signal 45, the binary image
`signal 43, the image signal 47, the image signal 41, and the
`
`4
`encoded image signal 49. After the selection, the selector 60
`outputs an image signal 61. The appropriate signal selection
`is carried out by the CPU 50 via the CPU bus 51. An image
`memory 62 stores the image signal 61 selected by the
`selector 60. Because the image memory 62 is connected to
`the CPU bus 51, the image memory 62 is freely accessible
`from the CPU 50 and an SCSI controller 64. A data counter
`65 counts the quantity of image data to be read and that of
`image date actually stored in the image memory 62. Indi-
`vidual values counted can be read from the CPU 50 via the
`CPU bus 51.
`
`Data stored in a nonvolatile memory 63 can be read or
`rewritten by the CPU 50 via the CPU bus 51. The SCSI
`controller 64 is a controller, controlled by the CPU 50, for
`carrying out data transfer to and from the external host
`computer via the SCSI.
`The operation of the workstation 21 and the image
`scanner 20 at the time the image scanner 20 is controlled by
`the workstation 21 is discussed hereinafter.
`
`The image scanner 20 emulates the file system of the
`“UNIX” as if it were a hard disc. Accordingly, the image
`scarmer 20 looks like the hard disc from the workstation 21
`and can be handled as the hard disc.
`
`The image scanner 20 according to the present invention
`is controlled by the workstation 21 as follows.
`When the image scarmer 20 connected to the workstation
`21 is operated by the workstation 21 for the first time, the
`workstation 21 prepares a file system in the image scanner
`20, as is the ease with the hard disc. In practice, an “mkfs”
`or “newfs” command of the “UNIX” is executed. At this
`moment, the operating system provides a device file and a
`device driver required for operating the hard disc as those
`required for preparing the file system. The preparation of the
`file system enables basic infonnation of the file system to be
`written to a predetermined region, i.e. a super block of the
`hard disc (image scanner).
`In the image scanner 20, the information written to the
`super block is stored in the nonvolatile memory 63. There-
`after, when a request to read the data stored in the super
`block is sent from the workstation 21, the image scanner 20
`outputs the data stored in the nonvolatile memory 63.
`Because the information of the super block is stored in the
`nonvolatile memory 63, even if a power supply to the image
`scanner 20 is cut off, further preparation of the file system
`is no longer required.
`As dismissed above, if the preparation of the file system
`is carried out with respect to the image scanner 20, the
`workstation 21 can “mount” the image scanner 20 which
`emulates the file system, as is the case with the file system
`of the hard disc. The “mounting” operation is to establish
`linkage between the file system and device files in the hard
`disc. After the “mounting” operation, the workstation 21 can
`access to files contained in the file system prepared in the
`hard disc. The “mounting” operation is executed using a
`“mount” command of the “UNIX”.
`
`Upon completion of the “mounting” operation, when the
`file system emulated by the image scanner 20 is viewed from
`the workstation 21, one file seems to exist therein. This file
`is a parameter file required to set parameters for the image
`scanner 20. In order for the image scanner 20 to pretend to
`contain the parameter file therein, as viewed from the
`workstation 21, i—node data having information required for
`the workstation 21 to access to the parameter file are created
`in the image scanner 20 and are transferred to the worksta-
`tion 21 according to a request from the workstation 21.
`The name of the parameter file is “scan. para”. The
`attribute of the parameter file is “write only”. The parameter
`
`10
`
`

`
`5,508,821
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`5
`file is a file required to set the operation mode of the image
`scanner 20 such as, for example, the zooming ratio, the read
`area, the gamma transfer characteristic, the binary process or
`the like, and is represented using a predetermined format.
`FIG. 4 depicts one example of the parameter file. Lines
`starting from “#” are comment lines. The parameters are
`represented in the following order using numerals.
`
`(1) Read area:
`
`(2) Zoom. ratio:
`
`(3) Image process. method:
`
`(4) Gamma trans. mode:
`
`(5) Y trans. table:
`
`upper left coordinates (X, Y); length
`in the direction of X (XL); and length
`in the direction of Y (YL), (unit:
`inch)
`zooming ratio in the direction of X
`(X2); and zooming ratio in the direc-
`tion of Y (YZ), (unit: %)
`binary process or the pres-
`ence or absence of the com-
`pression process
`no transfer when 1; transfer from
`retlectance to density when 2;
`and designation of gamma transfer
`table when 3
`to be represented by hexadecimal
`numbers
`
`The workstation 21 sets the operation mode of the image
`scanner 20 by writing the parameter file to the image scarmer
`20. The writing of the parameter file for the setting of the
`operation mode of the image scanner 20 can greatly facili-
`tate the setting of the parameters of the image scanner 20.
`Because the “UNIX” operating system executes buffering
`such that data to be read from or written to the file system
`are temporarily stored in a buifer of a main memory of the
`workstation, it is necessary to “unmount” the file system in
`order to actually write the data to the hard disc. A “umount”
`command of the “UNIX” is used for this purpose.
`The image scanner 20 reads a document in accordance
`with the parameters at the time the parameter file has been
`written. At this moment, the read image data are stored in the
`image memory 62 inside the image scanner 20. When the
`quantity of the image data is greater than thecapacity of the
`image memory 62, the image data as many as the image
`memory 62 can accommodate are temporarily stored in the
`image memory 62.
`Subsequently, in order for the workstation 21 to read the
`image data from the image scanner 20, the file system to be
`emulated by the image scanner 20 is “mounted” again. As
`viewed from the workstation 21, there seem to exist two files
`in the file system emulated by the image scanner 20. One of
`them is the aforementioned parameter file “scan. para”,
`whereas the other is an image data file, the name of which
`is “image. data". The attribute of the image data file is “read
`only”.
`In order for the image scanner 20 to pretend to contain the
`image data file therein, as viewed from the workstation 21,
`the CPU 50 of the image scanner 20 creates i-node data
`having information required for the workstation 21 to access
`to the image data file and transfers them to the workstation
`21 in response to a request from the workstation 21. The size
`of the image data file as viewed from the workstation 21
`depends upon the operation mode which has been’ set in the
`image scanner 20 by writing to the parameter file. The
`workstation 21 reads the contents of this data file so that the
`image data read by the image scanner 20 may be transferred
`to the workstation 21.
`
`FIG. 5 depicts a flowchart indicating the above-described
`control procedure at the time the image scanner 20 accord-
`ing to the present invention is controlled by the workstation
`21.
`
`6
`The operation of the image scanner 20 is discussed
`hereinafter in association with the procedure of the work-
`station 21.
`
`FIG. 6 schematically depicts an ordinary layout of the file
`system of the workstafion containing therein the “UNIX” as
`the OS. First 8 KB of the file system is allocated to a boot
`block including boot programs required for booting the
`workstation 21. The next 8 KB is an area called the super
`block which is generally used to store the then conditions of
`the file system such as, for example, the number of files, the
`size of the file system and the like. The super block is
`followed by a plurality of cylinder groups. Each cylinder
`group is made up of a copy of the super block, a cylinder
`group block, an i-node table, and data blocks. Data such as
`the number of i-nodes, that of the data blocks, an i-node map
`used, or a map of empty blocks are stored in the cylinder
`data blocks. The i-node is
`information indicating the
`attribute of a file or the location of a data block in which the
`file exists. Because a directory is also handled as a file,
`i-nodes are required by the number of files and directories.
`A predetermined extent is allocated to the area of the i-node
`table including a plurality of i-nodes at the time the file
`system is first prepared.
`The image scanner 20 which emulates the file system
`having the “UNIX" and shown in FIG. 6 operates as follows.
`The operation at the time the workstation 21 prepares the
`file system is initially discussed. The file system used herein
`is a file system to be emulated by the image scanner 20. The
`workstation 21 writes to the boot block and to the super
`block positioned at the first 8 KB and at the next 8 KB of the
`file system, respectively. The CPU 50 of the image scanner
`20 stores these 16 KB data in the nonvolatile memory 63.
`When a data read request for reading the data of these blocks
`is sent from the workstation 21, the CPU 50 reads the data
`from the nonvolatile memory 63 and transfers them to the
`workstation 21. Likewise, when a data write request for
`writing data into these blocks is sent from the workstation
`21, the CPU 50 writes the data to the nonvolatile memory
`63.
`
`Thereafter, the workstation 21 writes a copy data of the
`super block to the first 8 KB of each cylinder block of the
`file system. At this moment, the CPU 50 can know from the
`data of the super block, the location of each cylinder in the
`file system. Accordingly, when the CPU 50 has received the
`copy data of the super block of the file system from the
`workstation 21, the CPU 50 discards such data. On the other
`hand, when a read request is received, the data of the super
`block are outputted from the nonvolatile memory 63. Alter-
`natively, the data of each copy of the super block may be
`stored in the nonvolatile memory 63. In this case, when a
`read request is received, the copy data of the super block are
`outputted from the nonvolatile memory 63.
`Thereafter, the workstation 21 writes to the cylinder group
`block of each cylinder group. The CPU 50 can know the
`location and size of the cylinder group block in the file
`system from the data of the super block. The CPU 50 stores
`the data of the cylinder group block in the nonvolatile
`memory 63. When a read request of such data is sent from
`the workstation 21, the CPU 50 reads the data from the
`nonvolatile memory 63 and transfers them to the worksta-
`tion 21. Likewise, when a data write request is sent from the
`workstation 21, the CPU 50 writes data to the nonvolatile
`memory 63.
`Subsequently, the workstation 21 carries out inih'alization
`with respect to the i-node table of each cylinder group. The
`CPU 50 can know the location and size of the i-node table
`
`11
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`

`
`5,508,821
`
`7
`in the file system from the data of the cylinder group block.
`"The CPU 50 discards data to be written to the i-node table.
`
`When the workstation 21 “mounts” the file system emu-
`lated by the image scarmer 20, the workstation 21 reads the
`super block, the cylinder group block, and the i-node table
`from the file system. When the CPU 50 has received a read
`request for reading the super block and the cylinder group
`block, the CPU 50 reads the corresponding data from the
`nonvolatile memory 63 and transfers them to the worksta-
`tion 21. The CPU 50 creates a root directory and i-node data
`of the parameter file “scan. para" and transfers them to the
`workstation 21.
`
`The CPU 50 knows the location of the data region of the
`parameter file in the file system from the created i-node data
`of the parameter file. Accordingly, the CPU 50 can know the
`writing of the parameter data from the workstation 21 to the
`parameter file “scan. para”. The CPU 50 makes an analysis
`of the data written to the parameter file, obtains the param-
`eters, and reads the document in accordance with the set
`operation mode.
`The read image data are stored, from the beginning of the
`image, in the image memory 62 in accordance with a read
`region set in the parameter file. When the capacity of the
`image memory 62 is less than the quantity of the image data,
`a limited quantity of image data corresponding to the
`capacity of the image memory 62 is stored. The CPU 50 can
`know from the value of the data counter 65, the quantity of
`the whole image data to be read, that of the image data stored
`in the image memory 62, and the region of the image stored
`in the image memory 62.
`After the image reading, when a read request of the i-node
`table of the file system is sent from the workstation 21, the
`CPU 50 creates the root directory, the i-node of the param-
`eter file “scan. para", and that of the image data file “image.
`data”, and transfers them to the workstation 21. The size of
`the image data file is equal to that of the whole image data
`detected by the data counter 65.
`When a read request for reading data located at a certain
`posidon in the image data file is sent from the workstation
`21, and if the requested data exist in the image memory 62,
`the CPU 50 transfers such data to the workstation 21 via the
`SCSI controller 64. If the image memory 62 contains no
`requested data, the CPU 50 reads a region of the document
`corresponding to the requested data and stores it in the image
`memory 62. Thereafter, the CPU 50 takes out the data from
`the image memory 62 and transfers them to the workstation
`21. As described above, because the image scanner 20 has an
`image memory, it can take full advantage of high-speed data
`transfer through the SCSI. Furthermore, because the image
`memory is not necessarily required to have a capacity
`suflicient to store the entire region to be read, the memory
`need not have a capacity unduly greater than that necessary.
`It is to be noted here that a magnetic storage may be used
`in place of the nonvolatile memory 63.
`FIG. 7 depicts an image forming apparatus 120 according
`to the present invention, which is connected to an external
`host computer via an SCSI bus 122. The external host
`computer shown in FIG. 7 is a workstation 121 having the
`“UNIX" as an operating system. A hard disc in which a file
`system for the workstation 121 has been formulated is
`accommodated in the workstation 121 and is connected to
`the SCSI bus 122 inside the workstation 121.
`
`FIG. 8 is a block diagram of the image forming apparatus
`120 according to the present invention.
`Data stored in a nonvolatile memory 163 can be read or
`rewritten by a CPU 150 via a CPU bus 151, An SCSI
`
`8
`controller 164 carries out data transfer to and from the
`external host computer via the SCSI and is controlled by the
`CPU 150.
`
`An image memory 152 stores bit-map image data trans-
`ferred via the SCSI bus 122 by at least one page. At the time
`the image data have been stored by one page in the image
`memory 152, a printer engine (not shown) commences an
`image forming operation, and image data 153 are outputted
`from the image memory 152 to a printer engine controller
`154 in synchronism with the operation of an image forming
`unit. The printer engine controller 154 outputs a laser
`modulation signal 155 to a laser driver 156 based on the
`image signal 153. Because the image forming unit com-
`prises a conventionally known laser printer employing a
`semiconductor laser, explanation thereof is omitted.
`The operation of the workstation 121 and the image
`forming apparatus 120 at the time the image forming appa-
`ratus 120 is controlled by the workstation 121 is discussed
`hereinafter.
`
`The image forming apparatus 120 emulates a file system
`of the “UNIX" as if it were a hard disc. Accordingly, the
`image forming apparatus 120 looks like the hard disc from
`the workstation 121 and can be handled as the hard disc.
`
`The image forming apparatus 120 according to the present
`invention is controlled by the workstation 121 as follows.
`When the image forming apparatus 120 connected to the
`workstation 121 is operated by the workstation 121 for the
`first time, the workstation 121 prepares a file system in the
`image forming apparatus 120, as is the case with the hard
`disc. In practice, an “mkfs” or “newfs" command of the '
`“UNIX” is executed. At this moment, the operating system
`provides a device file and a device driver required for
`operating the hard disc as those required for preparing the
`file system. The preparation of the file system enables basic
`information of the file system to be written to a predeter-
`mined region, i.e. a super block of the hard disc.
`In the image forming apparatus 120, the information
`written to the super block is stored in the nonvolatile
`memory 163. Thereafter, when a request to read the data
`stored in the super block is sent from the workstation 121,
`the image forming apparatus 120 outputs the data stored in
`the nonvolatile memory 163 to the SCSI bus 122. Because
`the information of the super block is stored in the nonvolatile
`memory 163, even if a power supply to the image forming
`apparatus 120 is cut ofi, further preparation of the file system
`is no longer required.
`As discussed above, if the preparation of the file system
`is carried out with respect to the image forming apparatus
`120, the workstation 121 can “mount” the image forming
`apparatus 120 which emulates the file system, as is the case
`with the file system of the hard disc.
`Upon completion of the “mounting” operation, when the
`file system emulated by the image forming apparatus 120 is
`viewed from the workstation 121, one file seems to exist
`therein. This file is a parameter file required to set param-
`eters for the image forming apparatus 120. In order for the
`image forming apparatus 120 to pretend to contain the
`parameter file therein, as viewed from the workstation 121,
`i-node data having information required for the workstation
`121 to access to the parameter file are created in the image
`forming apparatus 120 and are transferred to the workstation
`121 according to a request from the workstation 121.
`The name of the parameter file is “printer. para”. The
`attribute of the parameter file is “write only”. The parameter
`file is a file required to set the operation mode of the image
`forming apparatus 120 such as, for example, the direction of
`
`12
`
`

`
`5,508,821
`
`9
`printing (portrait or landscape), the size of recording papers
`(A4, B4 etc.),
`the number of prints, or the like, and is
`represented using a predetermined format.
`FIG. 9 depicts one example of the parameter file. Lines
`starting from “#” are comment lines. The parameters are
`represented in the following order using numerals.
`(1) Size of recording papers to be used
`(2) Direction of printing
`(3) Number of prints
`The workstation 121 sets the operation mode of the image
`forming apparatus 120 by writing the parameter file to the
`image forming apparatus 120. The writing of the parameter
`file for the setting of the operation mode of the image
`forming apparatus 120 can greatly facilitate the setting of the
`parameters of the image forming apparatus 120.
`Because the “UNIX” operating system executes buffering
`such that data to be read from or written to the file system
`are temporarily stored in a buffer of a main storage, it is
`neeessaryito “unmount” the file system in order to actually
`write the data to the hard disc.
`The image forming apparatus 120 sets the operation mode
`thereof in accordance with the parameters at the time the
`parameter file has been written.
`Thereafter, in order for the workstation 121 to write the
`image data to the image forming apparatus 120, the file
`system to be emulated by the image forming apparatus 120
`is “mounted” again. As viewed from the workstation 121,
`there seem to exist two files in the file system emulated by
`the image forming apparatus 120. One of them is the
`aforementioned parameter file “printer. para", whereas the
`other is an image data file, the name of which is “image.
`data". The attribute of the image data file is “write only”.
`In the case where the resolution of the image forming
`apparatus 120 is chosen to be 300 dpi (84.667 pmlpixel), and
`the size of recording papers and the direction of printing are
`A4 and portrait, respectively, the siz