U.S. patent application number 14/790050 was filed with the patent office on 2016-07-21 for image forming apparatus performing image quality adjustment based on period image forming assembly unloaded and forming final image while image forming assembly replaced.
This patent application is currently assigned to FUJI XEROX CO., LTD.. The applicant listed for this patent is FUJI XEROX CO., LTD.. Invention is credited to Junichi ISHIBASHI, Yuki SEKURA, Satoshi TANAKA.
Application Number | 20160210540 14/790050 |
Document ID | / |
Family ID | 56408110 |
Filed Date | 2016-07-21 |
United States Patent
Application |
20160210540 |
Kind Code |
A1 |
TANAKA; Satoshi ; et
al. |
July 21, 2016 |
IMAGE FORMING APPARATUS PERFORMING IMAGE QUALITY ADJUSTMENT BASED
ON PERIOD IMAGE FORMING ASSEMBLY UNLOADED AND FORMING FINAL IMAGE
WHILE IMAGE FORMING ASSEMBLY REPLACED
Abstract
An image forming apparatus includes individually replaceable
image forming assemblies forming images of different colors; a
storage portion that stores time when at least one image forming
assembly currently loaded into the apparatus is unloaded; a
calculating portion that calculates an unloaded-engine storage
period, time elapsed from when a newly loaded image forming
assembly is unloaded last time to when the image forming assembly
is newly loaded; and a controller that performs image quality
adjustment depending on the unloaded-engine storage period
calculated before the newly loaded image forming assembly is used
for image formation. The apparatus receives image data of an image
that contains a color other than colors that currently loaded image
forming assemblies form. The apparatus forms a final image based on
the image data on a sheet through image forming operations on the
same sheet while at least one of the loaded image forming
assemblies is replaced.
Inventors: |
TANAKA; Satoshi; (Kanagawa,
JP) ; ISHIBASHI; Junichi; (Kanagawa, JP) ;
SEKURA; Yuki; (Kanagawa, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FUJI XEROX CO., LTD. |
Tokyo |
|
JP |
|
|
Assignee: |
FUJI XEROX CO., LTD.
Tokyo
JP
|
Family ID: |
56408110 |
Appl. No.: |
14/790050 |
Filed: |
July 2, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04N 1/00082 20130101;
G03G 21/1892 20130101; G06K 15/1805 20130101; G03G 2215/0132
20130101; G03G 2221/1892 20130101; H04N 1/50 20130101; H04N 1/603
20130101; H04N 1/2338 20130101; H04N 1/2346 20130101; G06F 3/1208
20130101; H04N 1/00023 20130101; H04N 1/2392 20130101; G06F 3/1255
20130101; G06K 15/1822 20130101; H04N 1/0005 20130101; H04N 1/00037
20130101; H04N 1/506 20130101; G06K 15/407 20130101; H04N 1/6008
20130101; G06K 15/1878 20130101; H04N 1/2376 20130101 |
International
Class: |
G06K 15/02 20060101
G06K015/02; G06F 3/12 20060101 G06F003/12 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 16, 2015 |
JP |
2015-006309 |
Claims
1. An image forming apparatus, comprising: a plurality of
individually replaceable image forming assemblies forming images of
different colors; a storage portion that stores a time point at
which at least one of image forming assemblies currently loaded
into the apparatus is unloaded; a calculating portion that
calculates an unloaded-engine storage period, which is time elapsed
from a time point at which a newly loaded image forming assembly is
unloaded last time to a time point at which the image forming
assembly is newly loaded; and a controller that performs image
quality adjustment depending on the unloaded-engine storage period
calculated by the calculating portion before the newly loaded image
forming assembly is used for image formation, wherein the apparatus
receives an input of image data of an image that contains a color
other than colors that currently loaded image forming assemblies
form, and wherein the apparatus forms a final image based on the
image data on a sheet through a plurality of image forming
operations on the same sheet while at least one of the image
forming assemblies loaded into the apparatus is replaced.
2. The image forming apparatus according to claim 1, wherein the
controller performs image quality adjustment, in response to
loading of the newly loaded image forming assembly, on only the
newly loaded image forming assembly among all the image forming
assemblies loaded into the image forming apparatus.
3. The image forming apparatus according to claim 1, wherein the
storage portion stores a time point at which previous image
formation on a sheet has been performed, wherein the calculating
portion calculates an intermediate-image storage period, which is
time elapsed from the time point at which the previous image
formation on the same sheet has been performed to a time point at
which current image formation on the same sheet is to be performed,
and wherein the controller adjusts image forming conditions in the
current image formation on the same sheet depending on the
intermediate-image storage period calculated by the calculating
portion.
4. The image forming apparatus according to claim 2, wherein the
storage portion stores a time point at which previous image
formation on a sheet has been performed, wherein the calculating
portion calculates an intermediate-image storage period, which is
time elapsed from the time point at which the previous image
formation on the same sheet has been performed to a time point at
which current image formation on the same sheet is to be performed,
and wherein the controller adjusts image forming conditions in the
current image formation on the same sheet depending on the
intermediate-image storage period calculated by the calculating
portion.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and claims priority under 35
USC 119 from Japanese Patent Application No. 2015-006309 filed Jan.
16, 2015.
BACKGROUND
Technical Field
[0002] The present invention relates to image forming
apparatuses.
SUMMARY
[0003] According to an aspect, an image forming apparatus includes
multiple individually replaceable image forming assemblies forming
images of different colors, a storage portion that stores a time
point at which at least one of image forming assemblies currently
loaded into the apparatus is unloaded, a calculating portion that
calculates an unloaded-engine storage period, which is time elapsed
from a time point at which a newly loaded image forming assembly is
unloaded last time to a time point at which the image forming
assembly is newly loaded, and a controller that performs image
quality adjustment depending on the unloaded-engine storage period
calculated by the calculating portion before the newly loaded image
forming assembly is used for image formation. The apparatus
receives an input of image data of an image that contains a color
other than colors that currently loaded image forming assemblies
form. The apparatus forms a final image based on the image data on
a sheet through a plurality of image forming operations on the same
sheet while at least one of the image forming assemblies loaded
into the apparatus is replaced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Exemplary embodiments of the present invention will be
described in detail based on the following figures, wherein:
[0005] FIG. 1 is a schematic diagram of the external appearance of
a printer;
[0006] FIG. 2 is an inner configuration diagram of the printer
whose external appearance is illustrated in FIG. 1;
[0007] FIG. 3 is a flowchart of a printing operation;
[0008] FIG. 4 is a flowchart of an engine replacement;
[0009] FIG. 5 illustrates an example of an error message;
[0010] FIG. 6 illustrates another example of an error message;
[0011] FIG. 7 illustrates an example of an engine replacement
message;
[0012] FIG. 8 illustrates another example of an engine replacement
message;
[0013] FIG. 9 illustrates another example of an engine replacement
message;
[0014] FIG. 10 illustrates another example of an engine replacement
message; and
[0015] FIG. 11 is a flowchart of another example of a printing
operation different from the operation illustrated in FIG. 3.
DETAILED DESCRIPTION
[0016] Exemplary embodiments of the invention are described
below.
[0017] FIG. 1 is a schematic diagram of the external appearance of
a printer 100. The printer 100 is an exemplary embodiment of an
image forming apparatus. A notebook personal computer (abbreviated
to "notebook PC", below) 200 is connected to the printer 100.
[0018] The printer 100 includes a drawer-type sheet tray 110 at a
lower portion. This sheet tray 110 contains a stack of multiple
sheets for printing.
[0019] The printer 100 includes a drawer-type engine loading frame
120 at a portion above the sheet tray 110. Four image forming
engines 130 (see FIG. 2) are loaded onto the engine loading frame
120. These four image forming engines 130 are individually loadable
onto or unloadable from the engine loading frame 120. These engines
correspond to examples of image forming assemblies.
[0020] The printer 100 also includes a paper exit tray unit 140,
onto which sheets on which images have been printed are ejected, at
an upper portion. The paper exit tray unit 140 has a two-level
configuration. An upper-level tray 141, which is a movable paper
exit tray (see FIG. 2), also serves as a paper supply tray that
supplies a sheet subjected to a first printing into the printer 100
so as to subject the same sheet to a second printing (subsequent
printing). The paper exit tray unit 140 is described in detail
below.
[0021] The notebook PC 200 illustrated in FIG. 1 has a function of
transmitting image data to the printer 100 and also has a function
as a user interface (UI) of the printer 100.
[0022] The notebook PC 200 includes a display screen 210, a
keyboard 220, multiple memory slots 230, and a mouse 240.
[0023] The display screen 210 displays various types of information
related to the printer 100. The keyboard 220 and the mouse 240 are
tools operated by users for inputting various commands to the
printer 100. The memory slots 230 are provided to allow various
types of external memories, including a memory card and a USB
memory, to be attached thereto. An external memory storing image
data based on which an image is printed is attached to one of the
memory slots. The image data is read from the external memory by
the notebook PC and then transmitted to the printer 100. The
printer 100 prints an image based on the transmitted image data on
a sheet taken out from the sheet tray 110 and then ejects the sheet
to the paper exit tray unit 140. In some cases, the printer 100
receives, from the notebook PC 200, image data of an image
containing colors, such as five or six colors, the number of which
is larger than the number of colors in images formed by the image
forming engines 130 loaded into the printer 100. The operation in
such a case is described in detail below.
[0024] FIG. 2 is an internal configuration diagram of a printer
whose external appearance is illustrated in FIG. 1.
[0025] The printer 100 has the drawer-type sheet tray 110 at a
lower portion. The sheet tray 110 contains a stack of unused sheets
P for printing. The sheets P in the sheet tray 110 are picked up
one by one by a pick-up roller 151 for image printing and
transported by transporting rollers 152. Sheet transportation is
described in detail below.
[0026] The printer 100 also has the drawer-type engine loading
frame 120. Four image forming engines 130 are loaded onto the
engine loading frame 120. These four image forming engines 130 are
in the form of a cartridge and individually loadable onto or
unloadable from the engine loading frame 120. The image forming
engines 130 each contain a single color toner. Each image forming
engine 130 forms a single-color-toner image using the corresponding
single color toner.
[0027] Here, when the color of each of the image forming engines
130 is to be specified, the image forming engine 130 is denoted by
a symbol `130`, which represents an image forming engine, with the
suffix of a character, such as `Y` (denoting yellow), `M` (denoting
magenta), `C` (denoting cyan), or `K` (denoting black), for
expressing the corresponding color of a toner. Although not
illustrated here, the printer 100 is also ready to accept three
image forming engines that contain toners of `G` (denoting green),
`O` (denoting orange), and `T` (denoting transparent).
[0028] In the exemplary embodiment, all the image forming engines
130 have the same configuration. Each image forming engine 130
includes a photoconductor 131, which rotates in a direction of
arrow a, a charging device 132, an exposing device 133, a
developing device 134, and a cleaner 135, which are disposed around
the photoconductor 131.
[0029] The charging device 132 uniformly charges the surface of the
corresponding photoconductor 131.
[0030] The exposing device 133 applies exposure light modulated on
the basis of the image data to the corresponding photoconductor 131
to form an electrostatic latent image on the photoconductor 131.
Each image forming engine 130 receives image data indicating a
single-color image that is to be formed with a color toner
corresponding to the image forming engine 130. The exposing device
133 applies, to the photoconductor 131, exposure light modulated on
the basis of the image data indicating the single color image.
Thus, the exposing device 133 forms an electrostatic latent image
representing the single color image on the photoconductor 131.
[0031] The developing device 134 develops the electrostatic latent
image formed on the corresponding photoconductor 131 with a toner
to form a single-color-toner image on the photoconductor 131. The
developing device 134 includes a toner cartridge 134a. The toner
cartridge 134a contains a single-color toner corresponding to the
developing device 134. The toner in the toner cartridge 134a is
supplied into the corresponding developing device 134 for forming a
toner image. The toner cartridges 134a are individually
replaceable. When a toner in one toner cartridge 134a is used up,
the toner cartridge 134a is replaced with a new one.
[0032] An intermediate transfer unit 160 is disposed above the
image forming engines 130. The intermediate transfer unit 160
includes an endless intermediate transfer belt 161, multiple
support rollers 162 that support the intermediate transfer belt
161, four first transfer rollers 163, a cleaner 164, and a sensor
165.
[0033] The intermediate transfer belt 161 is supported by the
multiple support rollers 162 and rotates in the direction of arrow
b through a traveling path along the four image forming engines
130.
[0034] The four first transfer rollers 163 are disposed at
positions opposing the photoconductors 131 of the respective image
forming engines 130 with the intermediate transfer belt 161
interposed therebetween. The first transfer rollers 163 transfer
the toner images formed on the respective photoconductors 131 to
the surface of the intermediate transfer belt 161.
[0035] Toner images formed on the photoconductors 131 of the
respective four image forming engines 130 are sequentially
transferred in a superposed manner to the intermediate transfer
belt 161, moving in the direction of arrow b, by the operations of
the respective first transfer rollers 163.
[0036] After the toner images are transferred to the intermediate
transfer belt 161, remnants such as toners remaining on the
surfaces of the photoconductors 131 are removed by the
corresponding cleaners 135.
[0037] Each image forming engine 130 also includes a memory 136.
The memory 136 stores various types of information relating to the
image forming engine 130 such as the color of a toner used in the
image forming engine 130 or the accumulated used hours. When one
image forming engine 130 is loaded onto the engine loading frame
120 and the engine loading frame 120 is attached to the printer
100, the printer 100 reads the content of the memory 136 or, when
needed, rewrites the content of the memory 136.
[0038] The toner images sequentially transferred to the
intermediate transfer belt 161 in a superposed manner are
transferred by the operation of a second transfer roller 170 to a
sheet P that has been transported to the position of the second
transfer roller 170 at a right timing. The sheet P subjected to the
toner image transfer is heated and pressed by a fixing device 180,
so that an image constituted by the fixed toner images is printed
on the sheet P. The sheet P is then ejected by paper exit rollers
153 to the paper exit tray unit 140 through a paper outlet port
101.
[0039] After the toner image transfer, remnants such as toners
remaining on the surface of the intermediate transfer belt 161 are
removed by the cleaner 164.
[0040] The paper exit tray unit 140 has a two-level configuration
including a movable paper exit tray 141 and a fixed paper exit tray
142 under the movable paper exit tray 141. The movable paper exit
tray 141 is movable between a paper receiving position, drawn with
solid lines in FIG. 2, and a paper supplying position, drawn with a
dot-dash line in FIG. 2. The movable paper exit tray 141 is moved
between the paper receiving position and the paper supplying
position by a tray driving unit 191 controlled by a controller 190.
When receiving a sheet P on which an image has been printed, the
movable paper exit tray 141 is moved to the paper receiving
position, drawn with solid lines, to receive the sheet P. The
printer 100 occasionally performs printing on the same sheet twice,
as will be described below. In a second printing, while the paper
exit tray 141 carries the sheet P that has been ejected thereto
after the completion of a first printing, the paper exit tray 141
moves to the paper supplying position, drawn with a dot-dash line.
The sheet P on the paper exit tray unit 140 that has arrived at the
paper supplying position is fed again to the printer 100 through a
paper supply port 102 for the second printing.
[0041] Now, the transportation path along which sheets are
transported for printing is described.
[0042] For a first printing, a sheet P is picked up by the pick-up
roller 151 from the sheet tray 110 and transported by the
transporting rollers 152 in the direction of arrow c until the
leading edge of the sheet P arrives at registration rollers 154.
Thereafter, the sheet P is fed by the registration rollers 154 to
the position of the second transfer roller 170 in such a manner
that the sheet P arrives at the position at the same time as the
toner images transferred to the intermediate transfer belt 161
arrive at the position of the second transfer roller 170. Then, the
toner images are transferred to the sheet P by the operation of the
second transfer roller 170. The sheet P to which the toner images
have been transferred is transported further in the direction of
arrow d. The toner images are fixed to the sheet P by the fixing
device 180 and the sheet P is ejected to the paper exit tray 141 by
the paper exit rollers 153.
[0043] For a second printing on the same sheet, the engine loading
frame 120 is then drawn out so that the image forming engines 130
are replaced. When a reprint command is subsequently transmitted
from the notebook PC 200 (see FIG. 1), the paper exit tray 141 is
raised by the tray driving unit 191 to the paper supplying
position, drawn with a dot-dash line. Then, the sheet P that has
been temporarily ejected to the paper exit tray 141 is drawn into
the printer 100 through the paper supply port 102 by paper
supplying rollers 155.
[0044] The sheet P that has been drawn into the printer 100 is
transported by transporting rollers 156 in the direction of arrow e
and then by transporting rollers 157 in the direction of arrow
f.
[0045] After the sheet P is transported by the transporting rollers
157 in the direction of arrow f, the transporting rollers 157 start
rotating reversely, so that the sheet P is then transported in the
direction of arrow g by the transporting rollers 157. The sheet P
that has been transported in the direction of arrow g is then
transported in the direction of arrow h until the leading edge of
the sheet P arrives at the registration rollers 154. The following
process is performed in the same manner as in the first printing
and the sheet P subjected to the second printing (subsequent
printing) is ejected to the fixed paper exit tray 142.
[0046] In FIG. 2, the controller 190 of the printer 100 is
connected to only the tray driving unit 191. However, besides the
tray driving unit 191, the controller 190 controls the entirety of
the printer 100, including the processing described below.
[0047] The printer 100 performs image quality adjustment. For this
image quality adjustment, one or more image forming engines 130
form image-quality-adjustment toner images (toner patches) and
transfer the toner images (toner patches) to the intermediate
transfer belt 161. The toner images (toner patches) are measured by
the sensor 165 without the second transfer roller 170 transferring
the toner images to a sheet P. In accordance with the results of
measurement performed by the sensor 165, the controller 190
performs image quality adjustment such as registration between
single-color-toner images or tone correction of toner images.
[0048] This printer 100 changes image forming conditions, including
the transfer bias potential applied to the second transfer roller
170 or the heating temperature at the fixing device 180, depending
on the conditions for performing a subsequent printing. The image
forming conditions are so changed as to print out a high quality
image in accordance with the water content contained in the sheet P
or the temperature of the sheet P that varies with time elapsed
from the completion of a first printing on the sheet P.
[0049] The printing operation of the printer 100 involving a
subsequent printing illustrated in FIGS. 1 and 2 is further
described below.
[0050] FIG. 3 is a flowchart of a printing operation.
[0051] FIG. 4 is a flowchart of engine replacement performed
several times in the printing operation illustrated in FIG. 3.
[0052] The printer 100 is capable of receiving, from the notebook
PC 200, multicolor image data indicating images containing colors,
the number of which is larger than the number of colors in images
formed by the image forming engines 130 (four image forming engines
130, here) concurrently loadable into the printer 100. The printer
100 is also capable of printing out an image based on the
multicolor image data.
[0053] When the printer 100 receives from the notebook PC 200 image
data and a command of printing an image based on the image data,
the printer 100 firstly recognizes the types (colors of toners) of
image forming engines 130 newly loaded into the printer 100 (Step
S101).
[0054] Here, the image forming engines are described while colors
of their toners are distinguished by adding the prefixes (for
example, `Y` for yellow) denoting the colors of toners to the term
"engine". For example, the image forming engine that forms toner
images with a yellow (Y) toner is referred to as a "Y engine 130Y".
The image forming engines that form toner images with toners of all
the colors Y, M, C, and K are collectively referred to as "YMCK
engines 130Y, 130M, 130C, and 130K".
[0055] When the currently loaded image forming engines 130 include
at least one engine other than the YMCK engines 130Y, 130M, 130C,
and 130K, engine replacement (Step S103) is performed.
[0056] When the currently loaded engines are the YMCK engines 130Y,
130M, 130C, and 130K (Step S102) or when engine replacement (Step
S103) to the YMCK engines 130Y, 130M, 130C, and 130K has been
properly performed (Step S104), the printer 100 determines whether
the image data for which a printing command is issued involves the
use of at least one color other than the YMCK colors (here, the
color other than the YMCK colors is referred to as a "spot color")
(Step S105). When the printer 100 determines that the image data
for which a printing command is issued does not involve the use of
a spot color and that the printer 100 is capable of printing out a
complete image with toners of YMCK colors, an image based on the
image data is printed out on a sheet P (Step S106) and the process
started in response to the current printing command is
finished.
[0057] On the other hand, when the printer 100 determines in Step
S105 that the image data involves the use of a spot color, the
printer 100 fetches the current time (Step S107) and then performs
a first printing (Step S108). Thereafter, engine replacement is
performed (Step S109). When engine replacement is not properly
performed, the printing operation is finished. When, on the other
hand, engine replacement is properly performed (Step S110), a timer
is turned on to start keeping time (Step S111) and the printer 100
starts waiting for a spot-color printing command (Step S112). The
timer that starts keeping time in Step S111 is a timer that keeps
the maximum standby time for which a spot-color printing command is
waited for. This spot-color printing command is issued by an
operation of the notebook PC 200. However, provided that the
printer 100 determines in Step S110 that engine replacement has
been properly performed, the printer 100 may proceed to a
spot-color printing operation without the need for waiting for a
command from a user.
[0058] When the timer runs out without receiving a spot-color
printing command (Step S113), an error message is displayed on a
display screen 201 of the notebook PC 200 (Step S114) and this
printing operation routine is finished without performing a
spot-color printing.
[0059] FIG. 5 illustrates an example of an error message displayed
in Step S114.
[0060] Here, the display screen 201 of the notebook PC 200 displays
"Temporarily stopped due to lack of spot-color printing command.
For spot-color printing, retransmit image data and instruct to
perform spot-color printing".
[0061] When the image data is retransmitted later and a command
instructing to perform a spot-color printing is transmitted in the
manner as instructed on the display illustrated in FIG. 5, the
printing operation illustrated in FIG. 3 is resumed from the step
of "spot-color printing command".
[0062] Upon receipt of a spot-color printing command, the printer
100 firstly recognizes the types of image forming engines 130
currently loaded into the printer 100 (Step S130), as in the case
of Step S101. The printer 100 then determines whether a spot-color
engine corresponding to a spot color used in the current image data
is loaded into the printer 100 (Step S131). When the printer 100
determines that the intended engine corresponding to the spot color
is not loaded into the printer 100, engine replacement is performed
(Step S132). Thereafter, the printer 100 determines whether the
engine replacement has been properly performed (Step S133).
[0063] When the printer 100 receives a spot-color printing command
before the timer runs out (Step S112), when the printer 100
determines in Step S131 that the intended spot-color engine has
been loaded into the printer 100, or when the replacement with the
intended spot-color engine has been properly performed (Steps S132
and S133), the printer 100 proceeds to the spot-color printing
operation from Step S120 onward.
[0064] Here, the printer 100 firstly fetches the current time (Step
S120) and determines whether the time elapsed from the time before
the first printing fetched in Step S107 falls within ten minutes
(Step S121). Here, the elapsed time in Step S121 corresponds to an
example of an "intermediate-image storage period".
[0065] When the printer 100 determines in Step S121 that the
elapsed time exceeds ten minutes, the second printing using a
spot-color engine is performed under the normal printing
conditions, that is, the same printing conditions as those for the
first printing.
[0066] On the other hand, when the printer 100 determines in Step
S121 that the elapsed time falls within ten minutes, the second
printing is performed after the printing conditions are changed
(Step S122).
[0067] When the elapsed time falls within ten minutes, the sheet P
retains the residual heat and the water content of the sheet P has
been changed as a result of the sheet P being heated by the fixing
device 180 during the first printing. Thus, in this case, the
transfer bias of the second transfer roller 170 is lowered and the
heating temperature at the fixing device 180 is lowered. With such
adjustment, a higher quality image is printed out.
[0068] Here, the printer 100 determines whether the printing
conditions are to be changed depending on whether the elapsed time
falls within ten minutes. However, the printing conditions may be
changed at multiple stages or consecutively using a function of the
elapsed time. Alternatively, the printing conditions may be changed
in consideration of factors such as the thickness (basis weight) of
the sheet or the environmental temperature or humidity.
[0069] When the second printing is finished (Step S123), the
printing operation is complete.
[0070] Now, engine replacement illustrated in FIG. 4 is described.
The engine replacement is performed in Steps S103, S109, and S132
in the printing operation illustrated in FIG. 3.
[0071] In engine replacement, firstly, a timer is turned on to
start keeping time (Step S211). This timer is used to keep the
maximum standby time for waiting for the completion of engine
replacement.
[0072] In Step S212, the printer 100 determines whether the timer
that has been turned on in Step S211 has run out. The procedure
occasionally returns to Step S212 from multiple determination steps
described below (Steps S215, S217, S219, and S220) and the time
until the completion of replacement is continuously measured. When
the printer 100 determines in Step S212 that the timer has run out,
an error message is displayed on the display screen of the notebook
PC 200 (Step S213) and the procedure returns to the printing
operation illustrated in FIG. 3.
[0073] FIG. 6 illustrates an example of an error message displayed
in Step S213.
[0074] Here, the display screen of the notebook PC 200 displays
"Procedure is terminated due to incomplete engine replacement".
[0075] When the procedure is returned to the printing operation
after this error message is displayed, the printer 100 determines
that the engine replacement has been improperly finished (Steps
S104, S110, and S133 in FIG. 3) and the printing operation is
finished.
[0076] When the timer has not yet run out, the procedure proceeds
to Step S214 and an engine replacement message is displayed on the
display screen of the notebook PC 200.
[0077] FIG. 7 illustrates an example of the engine replacement
message.
[0078] The engine replacement message illustrated in FIG. 7 is
"Replace G engine with K engine". This engine replacement message
is an example for the engine replacement illustrated in FIG. 4 is
to be performed as Step S103 of FIG. 3 and the printer 100
determines in Step S101 that a G engine 130G has been loaded
instead of a K engine 130K.
[0079] FIG. 8 is another example of an engine replacement
message.
[0080] The engine replacement message illustrated in FIG. 8 is
"Replace two of currently loaded engines with G engine and O
engine". This engine replacement message is an example where the
engine replacement is to be performed as Step S109 of FIG. 3, four
YMCK engines 130Y, 130M, 130C, and 130K are newly loaded, and the
subsequent printing involves the use of spot colors of green (G)
and orange (0).
[0081] The message illustrated in FIG. 8 allows any two of the
currently loaded four YMCK engines 130Y, 130M, 130C, and 130K to be
replaced with spot-color engines. Instead, the position of each
spot-color engine at which the engine is loaded may be fixed, for
example, a G engine 130G is always replaced with a Y engine 130Y
and an O engine 1300 is always replaced with an M engine 130M.
[0082] As illustrated in FIGS. 7 and 8, the engine replacement
message displayed in Step S214 varies depending on the situation at
each replacement.
[0083] In Step S215, the printer 100 monitors whether the loaded
engine has been unloaded and, when the loaded engine has been
unloaded, the printer 100 records the time point of unloading in
association with the unloaded engine (Step S216). Then, the printer
100 monitors whether a new engine is loaded (Step S217) and, when
the printer 100 determines that a new engine has been loaded, the
printer 100 reads the type (ID) of the loaded engine from the
memory 136 (see FIG. 2) of the loaded engine (Step S218).
Thereafter, the printer 100 determines whether the loaded engine is
an intended engine (Step S219). When the newly loaded engine is
different from the intended engine, the procedure returns to Step
S214.
[0084] FIG. 9 illustrates an example of an engine replacement
message displayed when the procedure returns to Step S214 from Step
S219.
[0085] The engine replacement message illustrated in FIG. 9 is "T
engine is loaded. Replace T engine with K engine". This message is
displayed in the case where a T engine 130T is erroneously loaded
instead of a K engine 130K while the message "Replace G engine with
K engine" illustrated in FIG. 7 has been displayed in Step S214 of
FIG. 4.
[0086] When the printer 100 determines in Step S219 that an
intended engine has been loaded, the printer 100 subsequently
determines whether replacement has been finished (Step S220).
[0087] FIG. 10 illustrates an example of an engine replacement
message displayed when the procedure returns from Step S220 to Step
S214.
[0088] The engine replacement message illustrated in FIG. 10 is
"Load O engine". This message is displayed in the case, for
example, where a G engine 130G has been loaded but an O engine 1300
remains unloaded while the message "Replace any two of newly loaded
engines with G engine and O engine" illustrated in FIG. 8 has been
displayed.
[0089] Then, when the printer 100 determines in Step S220 that all
the engines that have to be replaced with other engines have been
completely replaced, the printer 100 fetches the time point of the
completion (Step S221). Then, the printer 100 determines whether
the time elapsed from the time when the newly loaded engine is
unloaded last time (time recorded in association with the engine in
Step S216) to the current time fetched in Step S221 falls within
ten minutes (Step S222). The elapsed time is an example of an
unloaded-engine storage period.
[0090] When the elapsed time exceeds ten minutes, the loaded engine
is set up (Step S223). Specifically, the engine is caused to form a
toner patch on the intermediate transfer belt 161, the toner patch
is measured by the sensor 165, and appropriate image quality
adjustment such as registration between colors or tone correction
is performed. The image quality adjustment is performed on only an
engine newly loaded during the current replacement and that has
been unloaded for more than ten minutes from the last unloading.
Thus, toner consumption for setting up engines is minimized and the
time for setting up engines is also minimized.
[0091] When the engine is completely set up in this manner (Step
S223) or setting up of the engine reloaded within ten minutes is
omitted (Step S222), the engine replacement is properly finished
and the procedure returns to the printing operation illustrated in
FIG. 3.
[0092] In this manner, in this exemplary embodiment, the image
forming conditions are changed depending on the elapsed time
between the first printing and the second printing. In addition,
the engine is set up depending on the period for which the engine
is stored after unloading. Thus, a high quality image is printed
out even when a sheet is subjected to printing multiple times while
engine replacement is performed.
[0093] Setting up (image quality adjustment) of an engine that is
performed in response to engine replacement has been described thus
far. However, image quality adjustment is also performed
periodically or in response to other conditional changes. Such
image quality adjustment is performed in the same manner as in the
existing technology and thus the illustration or description of
such image quality adjustment is omitted here.
[0094] FIG. 11 illustrates a flowchart of another example of a
printing operation, which is different from the printing operation
illustrated in FIG. 3.
[0095] In sequence of the flowchart illustrated in FIG. 3, the YMCK
engines 130Y, 130M, 130C, and 130K have to be always loaded for the
first printing and spot-color engines are used in the second
printing. On the other hand, in the printing operation illustrated
in FIG. 11, in the case where the printer 100 is loaded with a
spot-color engine at the time when the printer 100 receives a
printing command involving the use of the corresponding spot color,
the printer 100 performs a spot-color printing first.
[0096] Upon receipt of a printing command, the printer 100 firstly
recognizes the engines newly loaded into the printer 100 (Step
S301). Then, the printer 100 determines whether image data based on
which an image is printed this time involves the use of a spot
color (Step S302). When the printer 100 determines that the image
data does not involve the use of a spot color (Step S302) and the
currently loaded engines do not constitute a combination of the
YMCK engines 130Y, 130M, 130C, and 130K (Step S303), engine
replacement is performed so that the currently loaded engines
constitute the YMCK engines 130Y, 130M, 130C, and 130K (Step S304).
When the engines are properly replaced (Step S305), the printer 100
starts printing. When the YMCK engines 130Y, 130M, 130C, and 130K
have already been loaded (Step S303), engine replacement is omitted
and the printer 100 starts printing (Step S306).
[0097] When the image data based on which an image is printed this
time involves the use of a spot color (Step S302), the printer 100
fetches the current time (Step S310) and starts the first printing
without engine replacement (Step S311). Specifically, when the YMCK
engines 130Y, 130M, 130C, and 130K have already been loaded at the
time point of Step S302, the first printing is performed using the
YMCK engines 130Y, 130M, 130C, and 130K. When a spot-color engine
is included in the loaded engines, the first printing is performed
using the loaded spot-color engine and the loaded ones of the YMCK
engines 130Y, 130M, 130C, and 130K. However, when all the
spot-color engines that are to be used (for example, the G engine
130G and the O engine 1300) have been loaded, a first printing may
be performed using only the spot-color engines and the use of the
YMCK engines 130Y, 130M, 130C, and 130K for printing images with
the Y, M, C, and K colors may be postponed for a second printing.
After the first printing is performed, engine replacement is
performed (Step S312). Here, the engines are replaced with
remaining engines that have not been loaded at the time of the
first printing among all the engines required for this
printing.
[0098] The following steps S313 to S323 are the same as the steps
S110 to S123 of the procedure illustrated in FIG. 3 and thus are
not redundantly described.
[0099] In the printing operation illustrated in FIG. 11,
transmission of a second printing command after a while is
prohibited. In the printing operation illustrated in FIG. 3, it is
known that the first printing is performed using the YMCK engines
130Y, 130M, 130C, and 130K and that the second printing is to be
performed using a spot color. On the other hand, in the printing
operation illustrated in FIG. 11, engines used in the first
printing are not fixed to the YMCK engines 130Y, 130M, 130C, and
130K. Thus, which engines are to be used in the second printing are
uncertain if a second printing command is received after a
while.
[0100] In the case where engines used in the first printing are
fixed to the YMCK engines 130Y, 130M, 130C, and 130K, the order in
which color toners are superposed is determined in advance. In this
case, image quality adjustment is relatively easy and a high
quality image is obtained. However, the case where engines used in
the first printing are fixed to the YMCK engines 130Y, 130M, 130C,
and 130K is disadvantageous in that a user has to replace a
spot-color engine, if already loaded by a previous user, with a
missing one of the YMCK engines 130Y, 130M, 130C, and 130K before
the first printing and then to load the spot-color engine again
after the first printing.
[0101] On the other hand, performing a first printing using a
spot-color engine, if already loaded, dispenses with the engine
replacement before the first printing. This case, however, is
disadvantageous in that the order in which color toners are
superposed is changed and thus the image quality may be impaired to
some extent.
[0102] Described thus far is an example of an image forming
apparatus that includes a movable paper exit tray 141, as described
in FIG. 2, and that performs a second printing, after prompt
replacement of image forming engines, with the movable paper exit
tray 141 moving to the paper supplying position without a need for
a user to supply a sheet to the apparatus again. However, the
movable paper exit tray 141 may be omitted. The invention is also
applicable to an image forming apparatus that performs a second
printing while a sheet subjected to a first printing is received on
the sheet tray 110 or on a manual-feeding tray, not
illustrated.
[0103] Described thus far is an example where the present invention
is applied to a so-called tandem image forming apparatus
illustrated in FIG. 2. However, the present invention is directly
applicable to a so-called rotary image forming apparatus that
includes a device in which multiple engines are loaded and that
rotates the device for printing.
[0104] The foregoing description of the exemplary embodiments of
the present invention has been provided for the purposes of
illustration and description. It is not intended to be exhaustive
or to limit the invention to the precise forms disclosed.
Obviously, many modifications and variations will be apparent to
practitioners skilled in the art. The embodiments were chosen and
described in order to best explain the principles of the invention
and its practical applications, thereby enabling others skilled in
the art to understand the invention for various embodiments and
with the various modifications as are suited to the particular use
contemplated. It is intended that the scope of the invention be
defined by the following claims and their equivalents.
* * * * *