U.S. patent application number 10/985694 was filed with the patent office on 2005-05-19 for image-forming apparatus.
This patent application is currently assigned to Canon Kabushiki Kaisha. Invention is credited to Kato, Hitoshi, Kawamura, Takuya, Sasaki, Ichiro, Serizawa, Masahiro, Takahashi, Keita, Watanabe, Naoto, Watanabe, Takahiro.
Application Number | 20050104272 10/985694 |
Document ID | / |
Family ID | 34567332 |
Filed Date | 2005-05-19 |
United States Patent
Application |
20050104272 |
Kind Code |
A1 |
Watanabe, Takahiro ; et
al. |
May 19, 2005 |
Image-forming apparatus
Abstract
An image forming apparatus capable of grouping a plurality of
sheet storage units for feeding sheets of a same type in an image
forming operation. The image forming apparatus includes a plurality
of storage units for storing sheets and a sheet feeder operable to
feed the sheets from the plurality of storage units. The apparatus
also includes a grouping unit allowing a user to group the storage
units based on the type of sheets. A controller controls the sheet
feeder to feed sheets from the group of storage units such that
when one storage unit becomes empty, the controller controls the
sheet feeder to feed sheets from another storage unit of the group
of storage units.
Inventors: |
Watanabe, Takahiro; (Chiba,
JP) ; Watanabe, Naoto; (Chiba, JP) ;
Takahashi, Keita; (Chiba, JP) ; Sasaki, Ichiro;
(Ibaraki, JP) ; Serizawa, Masahiro; (Ibaraki,
JP) ; Kato, Hitoshi; (Ibaraki, JP) ; Kawamura,
Takuya; (Tokyo, JP) |
Correspondence
Address: |
Canon U.S.A. Inc.
Intellectual Property Department
15975 Alton Parkway
Irvine
CA
92618-3731
US
|
Assignee: |
Canon Kabushiki Kaisha
Tokyo
JP
|
Family ID: |
34567332 |
Appl. No.: |
10/985694 |
Filed: |
November 10, 2004 |
Current U.S.
Class: |
271/9.05 |
Current CPC
Class: |
B65H 7/20 20130101; B65H
3/44 20130101; B65H 2220/01 20130101; B65H 2511/40 20130101; B65H
2511/40 20130101 |
Class at
Publication: |
271/009.05 |
International
Class: |
B65H 003/06; B65H
003/44; B65H 005/26 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 13, 2003 |
JP |
2003-384327 |
Claims
What is claimed is:
1. An image-forming apparatus operable to form images on sheets in
an image forming operation, comprising: a plurality of storage
units configured to store the sheets; a sheet feeder operable to
feed the sheets from the plurality of storage units; a controller
operable to group the plurality of storage units into a group of
storage units and controlling the sheet feeder to selectively feed
the sheets from the group of storage units in the image forming
operation.
2. The image-forming apparatus according to claim 1, wherein the
controller groups the plurality of storage units in accordance with
a sheet type.
3. The image-forming apparatus according to claim 1, wherein the
controller comprises a selecting unit operable to select a storage
unit from the plurality of storage units to be classified into the
group of storage units.
4. The image-forming apparatus according to claim 3, wherein the
selecting unit is configured to select at least two storage units
to be classified into the group of storage units.
5. The image-forming apparatus according to claim 3, wherein the
controller is configured to group the plurality of storage units
into at least two groups of storage units.
6. The image-forming apparatus according to claim 3, wherein the
selecting unit includes a selection key facilitating selecting the
storage unit to be classified into the group of storage units.
7. The image-forming apparatus according to claim 6, further
comprising a main body including an operating unit, wherein the
selecting key is provided on the operating unit.
8. The image-forming apparatus according to claim 1, further
comprising a main body, wherein the sheet feeder is detachably
attached to the main body, and wherein the plurality of storage
units are housed in the sheet feeder.
9. The image-forming apparatus according to claim 8, wherein the
sheet feeder includes a plurality of sheet feeders connected in
series to the main body.
10. An image-forming apparatus operable to form images on sheets,
comprising: a main body; a plurality of sheet cassettes configured
to store the sheets; and at least one sheet deck connected in
series to the main body and housing the plurality of sheet
cassettes, the sheet deck operable to feed the sheets from the
sheet cassettes, wherein the plurality of sheet cassettes are
classified into at least one group of sheet cassettes, and
responsive to one of the sheet cassettes in the group of sheet
cassettes being empty, the sheet deck feeds the sheets from another
one of the sheet cassettes in the group of sheet cassettes.
11. The image-forming apparatus according to claim 10, wherein the
plurality of sheet cassettes is classified into the group of sheet
cassettes in accordance with a kind of sheets stored by the sheet
cassettes.
12. The image-forming apparatus according to claim 11, wherein the
kind of sheets includes a size of the sheets.
13. The image-forming apparatus according to claim 10, further
comprising a selecting unit operable to select the sheet cassette
to be classified into the group of sheet cassettes.
14. A method for feeding sheets in an image forming apparatus
comprising: providing a plurality of cassettes configured to store
the sheets; grouping the plurality of cassettes into a group of
cassettes; and feeding the sheets from one of the cassettes in the
group of cassettes, and when the one of the cassettes is empty,
feeding from another one of the cassettes in the group of
cassettes.
15. The method according to claim 14, wherein the grouping step
includes grouping the plurality of cassettes in accordance with a
type of sheets stored in the cassette.
16. The method according to claim 14, wherein the grouping step
includes grouping at least two cassettes in the group of
cassettes.
17. The method according to claim 14, wherein the grouping step
includes grouping the plurality of cassettes into at least two
groups of cassettes.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from Japanese Patent
Application No. 2003-384327 filed Nov. 13, 2003, which is hereby
incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to image-forming apparatuses,
and more specifically relates to an image-forming apparatus
including a main body and a sheet-feeding device attached to the
main body, the sheet-feeding device containing a plurality of sheet
storage units for storing sheets.
[0004] 2. Description of the Related Art
[0005] Recently, the print-on-demand (POD) market has been growing
fast. Accordingly, it is necessary to increase the capacity of
sheet-storing sections of the image-forming apparatuses to be fed
to image-forming sections. In order to increase the capacities of
the sheet-storing sections, PCT Japanese Translation Patent
Publication No. 2001-506212 discloses an image-forming apparatus
including a main body and a sheet-feeding device attached to the
main body, the sheet-feeding device containing a plurality of paper
cassettes which functions as sheet storage units.
[0006] In such a known image-forming apparatus including the
sheet-feeding device, if one of the paper cassettes becomes empty
while a job is being processed, an automatic cassette changer
starts feeding the sheets from another paper cassette, as described
in Japanese Patent Laid-Open No. 5-92831, depending on two types of
information: size information of the sheets stored in the paper
cassettes and information regarding the kind of the sheets, such as
normal paper, recycled paper, cardboard paper, and overhead
projector (OHP) sheets (hereafter called material information).
[0007] For example, with reference to FIG. 8, an image-forming
apparatus 1000 includes a main body 1001 and three sheet-feeding
devices 1110 to 1112 containing paper cassettes A1 to A3, B1 to B3,
and C1 to C3, respectively. The paper cassettes A1 to A3, B1, and
C1 store sheets of A4-size normal paper, and the remaining paper
cassettes store sheets of A4-size recycled paper. In this case, it
is recognized that the sheets stored in the paper cassettes A1 to
A3, B1, and C1 are identical with respect to the size information
and the material information.
[0008] When, for example, a job that requires a large amount of
A4-size normal paper is processed, the sheets (normal paper) are
first fed from the paper cassette A1, which is nearest to the main
body 1001 of the image-forming apparatus 1000. Then, when the paper
cassette A1 becomes empty, an automatic cassette changer starts
feeding the sheets from the paper cassette A2. Then, when the paper
cassette A2 also becomes empty, the automatic cassette changer
starts feeding the sheets from the paper cassette A3. In this
manner, the paper cassette from which the sheets are fed is changed
successively.
[0009] On the other hand, in the POD market, a user may bring
various kinds of normal paper in addition to normal paper
designated by the manufacturer of the image-forming apparatus. The
sheets of normal paper brought in by the user can be arbitrarily
stored in any of the paper cassettes A1 to A3, B1 to B3, and C1 to
C3. For example, as shown in FIG. 9, the sheets of normal paper
brought in by the user are stored in the paper cassettes A2, B1,
and C1.
[0010] However, in the known image-forming apparatus which includes
the sheet-feeding device and which distinguishes the normal paper
and the recycled paper from each other on the basis of the material
information, the normal paper designated by the manufacturer and
the normal paper brought in by the user are determined as
identical. In other words, the normal paper brought in by the user
and stored in the paper cassettes A2, B1, and C1 cannot be
distinguished from the normal paper designated by the manufacturer
on the basis of the material information.
[0011] Therefore, if the automatic cassette changer successively
feeds the sheets from the paper cassettes A1, A2, and A3, in that
order while a single job is being processed, an image will be
formed on different kinds of sheets (normal paper designated by the
manufacturer and normal paper brought in by the user) and the
quality of the obtained products will vary.
SUMMARY OF THE INVENTION
[0012] The present invention is directed to an image-forming
apparatus capable of forming an image on the same kind of sheets
even when a plurality of kinds of sheets are stored in different
sheet storage units.
[0013] In one aspect of the present invention, an image-forming
apparatus includes a plurality of storage units for storing sheets
and a sheet feeder operable to feed the sheets from the plurality
of storage units. The image-forming apparatus also includes a
controller operable to group the plurality of storage units into a
group of storage units and controls the sheet feeder to selectively
feed the sheets from the group of storage units. In an image
forming operation of the apparatus, when one of the sheet storage
units in a group becomes empty, the sheets are fed from another one
of the sheet storage units in the group. According to another
aspect of the present invention, an image forming apparatus
includes a main body; a plurality of sheet cassettes configured to
store the sheets; and at least one sheet deck connected in series
to the main body and housing the plurality of sheet cassettes, the
sheet deck operable to feed the sheets from the sheet cassettes,
wherein the plurality of sheet cassettes are classified into at
least one group of sheet cassettes, and responsive to one of the
sheet cassettes in the group of sheet cassettes being empty, the
sheet deck feeds the sheets from another one of the sheet cassettes
in the group of sheet cassettes.
[0014] According to yet another aspect of the present invention, a
method for feeding sheets in an image forming apparatus includes
providing a plurality of cassettes configured to store the sheets;
grouping the plurality of cassettes into a group of cassettes; and
feeding the sheets from one of the cassettes in the group of
cassettes, and when the one of the cassettes is empty, feeding from
another one of the cassettes in the group of cassettes.
[0015] Further features and advantages of the present invention
will become apparent from the following description of the
preferred embodiments with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a schematic diagram showing a printer as an
example of an image-forming apparatus including sheet decks
according to one embodiment of the present invention.
[0017] FIG. 2 is a schematic diagram showing the main body of the
printer shown in FIG. 1.
[0018] FIG. 3 is a flowchart showing a process of grouping paper
cassettes in the printer in accordance with one embodiment of the
present invention.
[0019] FIGS. 4A and 4B are diagrams showing screens displayed on a
display of an operating unit provided on the main body of the
printer shown in FIG. 1.
[0020] FIGS. 5A and 5B are diagrams showing other screens displayed
on the display of the operating unit shown in FIG. 1.
[0021] FIGS. 6A and 6B are diagrams showing other screens displayed
on the display of the operating unit shown in FIG. 1.
[0022] FIG. 7 is a diagram showing another screen displayed on the
display of the operating unit shown in FIG. 1.
[0023] FIG. 8 is a schematic diagram showing a known image-forming
apparatus including sheet decks.
[0024] FIG. 9 is a diagram showing an example of a manner in which
sheets are stored in the known image-forming apparatus.
DESCRIPTION OF THE EMBODIMENT
[0025] An embodiment of the present invention will be described in
detail below with reference to the accompanying drawings.
[0026] FIG. 1 is a schematic diagram showing a printer as an
example of an image-forming apparatus including sheet-feeding
devices according to one embodiment of the present invention.
[0027] With reference to FIG. 1, a printer 400 includes a main body
410, a scanner 407 placed on the main body 410, and a plurality of
(three in the present embodiment) sheet decks 110 to 112 attached
to the main body 410 and serving as sheet-feeding devices. The
sheet decks 110 to 112 are connected to each other in series.
[0028] As shown in FIG. 2, the scanner 407 for reading an original
document (not shown) includes carriages 314 and 315. The carriage
314 carries light sources 303 and 304, such as halogen lamps and
fluorescent lamps, for illuminating the original document, umbrella
reflectors 305 and 306 for converging the light from the light
sources 303 and 304 onto the original document, and a mirror 307.
The carriage 315 carries mirrors 308 and 309. The original document
is placed on a document table glass 301 by a document feeder (DF)
302. When an image of the original document is read, the carriage
314 is moved in the direction shown by the arrow at a velocity V
while light is emitted from the light sources 303 and 304. The
carriage 315 is also moved in the direction shown by the arrow at a
velocity V/2, so that the entire area of the original document is
scanned.
[0029] The light scanning the original document is reflected by the
mirrors 307 to 309, passes through a lens 310, and forms an image
on a CCD 316. Then, the image of the original document is read out
by the CCD 316, converted into an electrical signal by an
image-processing unit 312, and is transmitted to exposure devices,
which will be described below.
[0030] In FIG. 2, reference numeral 100 denotes an operating unit
provided on the top surface of the printer's main body 410,
reference numeral 311 denotes a substrate on which the CCD 316 is
mounted, and reference numeral 313 denotes an interface (I/F) for
communicating with another image-processing unit (IPU) or the like.
Although the document feeder (DF) 302 is provided in the present
embodiment, a mirror face plate may also be provided in place of
the document feeder 302.
[0031] The printer's main body 410 includes an image-forming
section 411 where an image is formed on a sheet, a sheet-conveying
device 412 for conveying the sheet fed from one of the sheet decks
110 to 112 to the image-forming section 411, and a fixing device
334 for fixing the image formed on the sheet.
[0032] The image-forming section 411 includes image-forming units
317 to 320. The image-forming units 317 to 320 respectively include
photosensitive drums 342 to 345 which function as image carriers
for yellow, magenta, cyan and black toner images; charging devices
321, 324, 327, and 330 for uniformly charging the surfaces of the
respective photosensitive drums; exposure devices 210 to 213
provided with LED arrays for irradiating the respective
photosensitive drums with laser beams on the basis of image
information in order to form electrostatic latent images on the
respective photosensitive drums; and developing devices 322, 325,
328, and 331 for developing the electrostatic latent images with
toner as toner images.
[0033] The developing devices 322, 325, 328, and 331 respectively
include toner storage reservoirs 322a, 325a, 328a, and 331a
containing black, cyan, magenta, and yellow toners and sleeves 345
to 348 which are in contact with the surfaces of the respective
photosensitive drums. The sleeves 340, 346, 347 and 348 are rotated
by driving devices (not shown) while a developing bias voltage is
applied by developing-bias power supplies (not shown), and thereby
the electrostatic latent images are developed.
[0034] In addition, transfer rollers 323, 326, 329, and 332 are
disposed inside a transfer conveyor belt 333, which functions as an
endless sheet-conveying member for conveying the sheet, such that
the transfer conveyor belt 333 is nipped between the four
photosensitive drums 342 to 345 and their respective transfer
rollers 323, 326, 329, and 332.
[0035] The transfer rollers 323, 326, 329, and 332 are connected to
transfer-bias power supplies (not shown), and a transfer bias is
applied to the sheet from the transfer rollers 323, 326, 329, and
332 via the transfer conveyor belt 333. Then, when the transfer
bias is applied to the sheet which is being conveyed by the
transfer conveyor belt 333 while the sheet is in contact with the
photosensitive drums 342 to 345, the toner images of four colors on
the photosensitive drums 342 to 345 are successively transferred
onto the sheet. Accordingly, a multi-color image is formed on the
sheet.
[0036] The sheet-conveying device 412 includes a driving roller
348a, driven rollers 348b to 348d, and the transfer conveyor belt
333 which is stretched around the rollers 348a to 348d such that it
faces the photosensitive drums 342 to 345. The sheet-conveying
device 412 functions as a sheet carrier. The sheet
electrostatically adheres to the outer peripheral surface of the
transfer conveyor belt 333 which faces the photosensitive drums 342
to 345. The transfer conveyor belt 333 is rotated by the driving
roller 348a so as to bring the sheet into contact with the
photosensitive drums 342 to 345. Accordingly, the sheet, which is
electrostatically adhered to the rotating transfer conveyor belt
333, is conveyed to transfer positions corresponding to the
photosensitive drums 342 to 345. The toner images on the
photosensitive drums 342 to 345 are transferred onto the sheet.
[0037] The sheet is charged by an adhesion charging device 446 as
the sheet passes between the adhesion charging device 446 and the
driven roller 348d, and accordingly the sheet adheres to the
transfer conveyor belt 333. In addition, a front-end detection
sensor 447 detects the front end of the sheet on the transfer
conveyor belt 333, and a detection signal obtained from the
front-end detection sensor 447 is transmitted to the scanner 407
and is used as a sub-scanning synchronization signal when a YMCK
electrical signal (video signal) is transmitted to the
image-forming section 411 (that is, to the exposure devices 210 to
213 in the image-forming section 411) from the scanner 407. In
addition, a separation charging device 350 is used for preventing
degradation of the image due to a separation discharge when the
sheet is separated from the transfer conveyor belt 333.
[0038] As shown in FIG. 1, the sheet decks 110 to 112, which
function as the sheet-feeding devices, include paper cassettes A1
to A3, B1 to B3, and C1 to C3, respectively, for storing sheets. In
the present embodiment, the sheet decks 110 to 112 have an
identical structure, and are detachably connected to each other.
Accordingly, sheets can be arbitrarily stored in any of the paper
cassettes A1 to A3, B1 to B3, and C1 to C3. An operation of feeding
the sheets from the paper cassettes A1 to A3, B1 to B3, and C1 to
C3 in the sheet decks 110 to 112, respectively, is adequately
controlled by a controller C.
[0039] Although three sheet decks are connected in the present
embodiment, the number of sheet decks may be increased or reduced.
In addition, the order in which the sheet decks are connected may
also be changed. In FIG. 2, reference numerals 336 and 337 denote
registration rollers used for conveying the sheet fed from one of
the sheet decks 110 to 112 in synchronization with an image-forming
operation.
[0040] Next, the image-forming operation performed in the printer
400 having the above-described structure will be described
below.
[0041] First, in the scanner 407, the carriages 314 and 315 are
moved in the directions shown by the arrows while light is emitted
from the light sources 303 and 304, so that the entire area of the
original document is scanned. The light scanning the original
document is reflected by the mirrors 307 to 309, passes through the
lens 310, and forms an image on the CCD 316. Then, the image of the
original document is read out by the CCD 316, converted into the
YMCK electrical signal by the image-processing unit 312, and is
transmitted to the exposure devices 210 to 213.
[0042] The YMCK image signal generated in the image-processing unit
312 is transmitted to the exposure devices 210 to 213 at
predetermined times by adjusting the differences between distances
from the front-end detection sensor 447 to the image-forming units
317 to 320 by a delay process based on the front-end detection
signal obtained from the front-end detection sensor 447.
[0043] Then, the surfaces of the photosensitive drums 342 to 345
are uniformly charged by the charging devices 321, 324, 327, and
330, respectively, and are scanned by laser beams emitted from the
exposure devices 210 to 213, respectively, in accordance with the
image information at predetermined times corresponding to the
detection signal obtained from the front-end detection sensor 447.
Accordingly, latent images are formed on the surfaces of the
photosensitive drums, and these latent images are developed by the
developing devices 322, 325, 328, and 331, so that yellow, magenta,
cyan, and black toner images are formed on the surfaces of the
respective photosensitive drums.
[0044] In addition, in parallel to the operation of forming the
toner images, a sheet is fed from one of the paper cassettes A1 to
A3, B1 to B3, and C1 to C3, and is conveyed by the registration
rollers 336 and 337 in synchronization with the image-forming
operation. Then, the sheet is charged by the adhesion charging
device 446 so that it adheres to the transfer conveyor belt 333.
The sheet is conveyed to the transfer positions, where the transfer
conveyor belt 333 is pressed against the photosensitive drums 342
to 345, by the transfer conveyor belt 333.
[0045] When the sheet is conveyed to the transfer positions, the
toner images of the respective colors formed on the photosensitive
drums 342 to 345 are successively transferred onto the sheet by the
transfer rollers 323, 326, 329, and 332 disposed at the transfer
positions and receiving voltages of a polarity opposite to that of
the toner. Then, a charge/discharge device 349 removes the
electrostatic charge from the sheet on which the toner images of
four colors are superimposed. The sheet is separated from the
transfer conveyor belt 333. The sheet is charged by a pre-fix
charging device 352 in order to increase the adhesion force of the
toner and thereby prevent degradation of the image, and is then
conveyed to the fixing device 334.
[0046] The fixing device 334 heats and pressurizes the sheet so
that the un-fixed toner image is fixed on the sheet as a full-color
image. Then, the sheet on which the toner image is fixed as a
full-color image is outputted and placed on an output tray 335. The
toner remaining on the photosensitive drums after the transfer
process is collected into a cleaner device 360 by a cleaner blade
361.
[0047] As described above, in the POD market, sheets of normal
paper brought in by a user may be stored in one or more of the
paper cassettes A1 to A3, B1 to B3, and C1 to C3, in addition to
the sheets of normal paper designated by the manufacturer of the
printer. In such a case, if one of the paper cassettes becomes
empty and an automatic cassette changer starts feeding the sheets
from another paper cassette, there is a risk that the image will be
formed on different kinds of sheets and the quality of the obtained
products will vary.
[0048] Therefore, in the present embodiment, the user can group
some of the paper cassettes A1 to A3, B1 to B3, and C1 to C3
together, so that even when different kinds of sheets are stored in
the paper cassettes A1 to A3, B1 to B3, and C1 to C3, the same kind
of sheets are fed to the image-forming section 411 and the image is
formed on the same kind of sheets.
[0049] Next, an operation of grouping the paper cassettes A1 to A3,
B1 to B3, and C1 to C3 will be described below with reference to
the flowchart shown in FIG. 3.
[0050] When, for example, sheets of normal paper designated by the
manufacturer and sheets of normal paper brought in by the user are
stored in the paper cassettes as A4-size sheets, the controller C
displays a grouping key 102 on a display 101 of an operating unit
100, as shown in FIG. 4A, for the operation of grouping the paper
cassettes A1 to A3, B1 to B3, and C1 to C3.
[0051] Next, when the user presses the grouping key 102, the paper
cassettes A1 to A3, B1 to B3, and C1 to C3 are displayed as shown
in FIG. 4B (Step 101). In addition, a message prompting the user to
select some of the paper cassettes A1 to A3, B1 to B3, and C1 to C3
is also displayed. Then, in response to this message, the user
selects some of the paper cassettes A1 to A3, B1 to B3, and C1 to
C3 by pressing selection keys 104 corresponding to the paper
cassettes A1 to A3, B1 to B3, and C1 to C3.
[0052] For example, when the sheets of A4-size normal paper brought
in by the user are stored in the paper cassettes A2, B1, and C1, as
shown in FIG. 1, the user selects the paper cassettes A2, B1, and
C1 by pressing the selection keys 104 corresponding to the paper
cassettes A2, B1, and C1, as shown in FIG. 5A. Then, when the
selecting step is finished, the user presses an OK key 103. If
grouping is not performed, for example, if none of the selection
keys 104 nor the OK key 103 is pressed for a predetermined period
of time, the process ends and a normal job is started.
[0053] In the present embodiment, at least two paper cassettes are
grouped together. Therefore, when a first paper cassette is
selected as one of the paper cassettes to be grouped together (that
is, when the result of Step 102 is Y), it is determined whether or
not a second paper cassette is selected (Step 103).
[0054] Then, when the paper cassettes A2, B1, and C1 are selected
using the corresponding selection keys 104, that is, when at least
two paper cassettes are selected (when the result of Step 103 is
Y), the user presses the OK key 103. Accordingly, the selected
paper cassettes A2, B1, and C1 are grouped together (Step 104).
FIG. 5B shows the state in which the selected paper cassettes are
grouped together.
[0055] Then, if the grouping operation is to be continued, the
process returns to Step 102 from Step 105, and the above-described
steps are repeated. For example, when the sheets of A4-size normal
paper designated by the manufacturer are stored in the paper
cassettes A1 and A3, as shown in FIG. 1, the user selects the paper
cassettes A1 and A3, as shown in FIG. 6A, and presses the OK key
103. In such a case, two groups are set as shown in FIG. 6B.
[0056] Then, when, for example, the two groups are set as described
above, the paper cassettes A2, B1, and C1 are displayed as group 1,
the paper cassettes A1 and A3 are displayed as group 2, and the
remaining paper cassettes are displayed as other, as shown in FIG.
7. When a cancel key shown in FIGS. 6A and 6B is selected, the
display 101 returns to that shown in FIG. 4A.
[0057] Thus, the paper cassettes are classified (grouped) in
accordance with the kind of sheets stored therein. Accordingly, if
group 1 or group 2 is selected using group-selection keys 105
before starting a job, even when one of the paper cassettes becomes
empty while the job is being processed, the auto cassette changer
can start feeding the sheets from another paper cassette which
belongs to the same group (the paper cassettes A2, B1, and C1 when
group 1 is selected). As a result, the same kind of sheets is
continuously fed to the printer's main body 410.
[0058] As described above, some of the paper cassettes A1 to A3, B1
to B3, and C1 to C3 are classified into a group, and when one of
the paper cassettes of this group becomes empty, the sheets are fed
to the printer's main body 410 from another one of the paper
cassettes of this group. Accordingly, the image is formed on the
same kind of sheets, and the products of constant quality are
obtained. Once the grouping operation is performed, it is not
necessary to perform the grouping operation again as long as the
same kind of sheets is stored in the paper cassettes which are
grouped together.
[0059] Although the sheets of normal paper brought in by the user
and arbitrarily stored in the paper cassettes A1 to A3, B1 to B3,
and C1 to C3 have the same size (A4-size) according to the
above-described embodiment, the present invention is not limited to
this, and may also be applied to the case in which sheets of
different sizes, such as A4 and A3, and the same material are
arbitrarily stored in the paper cassettes. For example, even when
sheets of A4-size normal paper and A3-size normal paper are brought
in by the user and arbitrarily stored in the paper cassettes
arbitrarily and a job using both the A4-size and A3-size sheets is
processed, products of constant quality can be obtained by grouping
the paper cassettes A1 to A3, B1 to B3, and C1 to C3 in accordance
with the kind of the sheets.
[0060] In the above-described embodiment, the display 101 for
displaying the paper cassettes A1 to A3, B1 to B3, and C1 to C3,
the grouping key 102, the OK key 103, etc., is disposed on the
operating unit 100 which is provided on the printer's main body
410. However, the present invention is not limited to this, and the
display may also be shown on a screen of a personal computer which
is connected to the printer via a network controller (not
shown).
[0061] While the present invention has been described with
reference to what are presently considered to be the embodiments,
it is to be understood that the invention is not limited to the
disclosed embodiments. On the contrary, the invention is intended
to cover various modifications and equivalent arrangements included
within the spirit and scope of the appended claims. The scope of
the following claims is to be accorded the broadest interpretation
so as to encompass all such modifications and equivalent structures
and functions.
* * * * *