1. Field of the Invention
The present invention relates to an image forming apparatus, a method of controlling the same, and a storage medium.
2. Description of the Related Art
Conventionally, an image forming apparatus sets parameters (for example, a density value) for image processing that is to be executed on image data to be formed on a sheet, processes the image data based on the set parameters, and forms an image on the sheet based on the processed image data.
Japanese Patent Laid-Open No. 2002-347987 has disclosed an image forming apparatus that performs image formation (printing) by shortening the interval between sheets to be conveyed in succession, in order to rapidly print images on sheets and rapidly discharge the printed sheets.
This prior art decreases the sheet interval based on the assumption that image processing executed on image data to be formed is complete between sheets. When further shortening the sheet interval in an image forming apparatus, however, image processing to be executed on image data to be formed on the successive sheet and the setting of each parameter to be executed before the image processing cannot be executed in time. This makes it impossible to further shorten the sheet interval and execute efficient image formation.
An aspect of the present invention is to eliminate the above-mentioned problems with the conventional technology.
A feature of the present invention is to provide a technique which, when shortening the interval between sheets, forms an image by conveying sheets at a short internal by executing image processing by setting some of parameters.
According to an aspect of the present invention, there is provided an image forming apparatus comprising:
a setting unit configured to set parameters of image processing to be executed on image data;
an image processing unit configured to process the image data in accordance with the parameters of the image processing set by the setting unit;
a conveyance control unit configured to convey, when conveying a plurality of sheets on each of which an image is to be formed, the plurality of sheets at one of a first interval and a second interval shorter than the first interval;
an image forming unit configured to form an image on a sheet conveyed by the conveyance control unit, based on the image data processed by the image processing unit; and
a control unit configured to (i) control the setting unit to set the parameters, when conveying the plurality of sheets at the first interval by the conveyance control unit and forming an image by the image forming unit, and (ii) control the setting unit not to set a part of the parameters, when conveying the plurality of sheets at the second interval by the conveyance control unit and forming an image by the image forming unit.
According to another aspect of the present invention, there is provided a control method of an image forming apparatus, comprising:
a setting step of setting parameters of image processing to be executed on image data;
an image processing step of processing the image data in accordance with the parameters of the image processing set in the setting step;
a conveyance control step of conveying, when conveying a plurality of sheets on each of which an image is to be formed, the plurality of sheets at one of a first interval and a second interval shorter than the first interval;
an image forming step of forming an image on a sheet conveyed in the conveyance control step, based on the image data processed in the image processing step; and
a control step of controlling the setting step to set the parameters when conveying the plurality of sheets at the first interval in the conveyance control step and forming an image in the image forming step, and
controlling the setting step to set a part of the parameters when conveying the plurality of sheets at the second interval in the conveyance control step and forming an image in the image forming step.
Further features and aspects of the present invention will become apparent from the following description of exemplary embodiments, with reference to the attached drawings.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
Embodiments of the present invention will now be described hereinafter in detail, with reference to the accompanying drawings. It is to be understood that the following embodiments are not intended to limit the claims of the present invention, and that not all of the combinations of the aspects that are described according to the following embodiments are necessarily required to solve the problems according to the present invention.
An image forming apparatus 100 is connected to host computers (in this embodiment, PCs 171 and 172) across a LAN 170 such as the Ethernet.
The image forming apparatus 100 includes a reader unit 120 used to read an original and obtain image data of the original, and a printer unit 130 for performing printing by an electrophotographic method based on the image data. The image forming apparatus 100 further includes a console unit 150 including a keyboard for designating input/output operations, and a liquid crystal panel for displaying and setting various functions. In addition, the image forming apparatus 100 includes a storage unit 160 for storing image data obtained by the reader unit 120, and image data generated from code data received from the PC 171 or 172 across the LAN 170. The image forming apparatus 100 also includes a control unit 110 connected to these constituent components to control them.
The reader unit 120 includes an original document feed unit 121 for feeding originals, and a scanner unit 122 for optically reading an original and converting it into image data as an electrical signal. The printer unit 130 includes a paper feed unit 131, marking unit 132, and paper discharge unit 133. The paper feed unit 131 includes a plurality of paper feed cassettes for accommodating sheets. The marking unit 132 has a mechanism for transferring image data onto a sheet, and fixing the data to the sheet. The paper discharge unit 133 has a mechanism for sorting and/or stapling printed sheets, and discharging the sheets outside the image forming apparatus 100.
The control unit 110 provides a copy function to load image data of an original by controlling the reader unit 120, and printing the image data on a sheet by controlling the printer unit 130. The control unit 110 also has a scanner function to convert image data read by the reader unit 120 into code data, and transmit the code data to the PC 171 or 172 across the network 170. Furthermore, the control unit 110 has a printer function of converting code data received from the PC across the network 170 into image data, and printing the image data by the printer unit 130, and other functional blocks.
In the reader unit 120, originals stacked in the original document feed unit 121 are sequentially fed one by one from the top one of the stack onto a platen glass 211. After the scanner unit 122 completes a predetermined reading operation, the read originals are discharged to a paper discharge tray 219. Also, when an original is conveyed to the platen glass 211, a lamp 212 is turned on, and an optical unit 213 starts moving in the horizontal direction of
Note that when the original document feed unit 121 has a flowing document reading function, stacked originals respectively pass through a flowing document reading position 240 at a predetermined speed. In this case, the optical unit 213 moves to and stops in the flowing document reading position 240, irradiates each original conveyed at a constant velocity with the lamp 212, and sequentially reads images of main scan lines by the CCD 218, thereby generating image data of the original. The optical unit 213 transfers the image data to the control unit 110.
In the printer unit 130, a laser emitting unit 272 driven by a laser driver 271 emits laser light that corresponds to the image data supplied from the control unit 110. Consequently, an electrostatic latent image that corresponds to the laser light is formed on a photosensitive drum 273. A developing agent (toner) supplied from a developer 274 adheres to this electrostatic latent image, thereby forming a toner image corresponding to the image data.
On the other hand, at a timing synchronized with the start of laser light irradiation, a sheet is fed from one of cassettes 261, 262, 263, and 264 or a manual feed tray 265. The fed sheet is conveyed to a transfer unit 275 through a conveyance path 281, and the toner image on the photosensitive drum 273 is transferred onto this sheet. A conveyance belt 276 conveys the sheet having the transferred toner image to a fixing unit 277 where the toner image is fixed on the sheet by heating and pressing. More specifically, the fixing unit 277 includes a heater, and the control unit 110 warms the heater by supplying electric power to it. The toner is melted by heating by this heater, and the toner image is fixed to the sheet by pressing. Also, the control unit 110 controls whether to supply electric power to the heater of the fixing unit 277 by turning on or off a switch (not shown). The sheet to which the toner image is fixed in the fixing unit 277 is discharged to a discharge bin 278 through conveyance paths 285 and 284. When turning over the sheet before discharging it to the discharge bin 278, the fixed sheet is guided to conveyance paths 286 and 288, conveyed in the opposite direction, and discharged to the discharge bin 278 through a conveyance path 287 and the conveyance path 284. Note that although not shown, a paper discharge unit may also be attached instead of the discharge bin 278. This paper discharge unit is capable of, for example, sorting discharged sheets by bundling them, and stapling the sorted sheets.
When printing images on the both sides of the sheet, the sheet having passed through the fixing unit 277 is guided from the conveyance path 286 to a conveyance path 283 by a flapper 279, conveyed in the opposite direction, and guided to the conveyance path 288 and a paper re-feed conveyance path 282 by the flapper 279. The sheet thus guided to the paper re-feed conveyance path 282 is conveyed to the transfer unit 275 through the conveyance path 281 in the same manner as described above.
A main controller 311 mainly includes a CPU 312, a bus controller 313, and various I/F controller circuits. The CPU 312 and bus controller 313 control the whole control unit 110. The CPU 312 operates based on a program loaded in a DRAM 322 from a HD drive 332 via a HD controller 331. A ROM 320 stores a boot program and the boot program is read out via a ROM I/F 321 upon power on sequence to load the program into the DRAM 323 from the HDD 332. The process of interpreting PDL (Page Description Language) data received form the PC 171 or 172 across the network and rasterizing the data into image data is also executed by processing based on the program. The bus controller 313 controls the transfer of data input and output through each I/F, thereby performing bus arbitration and controlling DMA data transfer. A DRAM 322 is connected to the main controller 311 by a DRAM I/F 323, and used as a work area for the operation of the CPU 312 and an area for storing image data. An asynchronous serial communication controller 314 exchanges control commands with CPUs of the reader unit 120 and printer unit 130 via serial buses 372 and 373. The asynchronous serial communication controller 314 also communicates information of operations performed on the console unit 150 by the user, and information to be displayed on the display unit of the console unit 150.
A network controller 325 is connected to the main controller 311 via an I/F 327, and connected to the network 170 by a connector 326. A general example of the network is the Ethernet. A serial connector 324 is connected to the main controller 311 and communicates with an external apparatus (not shown). A general example of the serial bus is USB. A fan 328 is connected to the main controller 311 and used to cool the control unit 110. A temperature monitor IC 342 is connected to the main controller 311 by a serial bus 343, and used to, for example, control the fan 328, and correct the temperature of a real time clock module 337.
A versatile high-speed bus 330 is connected to an extension connector 335 for connecting an extension board, an I/O control unit 336, the HD controller 331, and a codec (coder/decoder) 333. A general example of the versatile high-speed bus is a PCI bus. The codec 333 compresses raster image data stored in the DRAM 322 by, for example, MH/MR/MMR/JBIG/JPEG, and decompresses the compressed stored code data into raster image data. An SRAM 334 is used as a temporal work area of the codec 333. Data transfer between the SRAM 334 and DRAM 322 is performed by DMA transfer under the control of the bus controller 313. The HD controller 331 is used to connect an external memory. In this embodiment, the hard disk drive (HDD) 332 is connected via this interface. The HDD 332 is used to store programs and image data.
The I/O control unit 336 performs data communication with an LCD controller 340 and modem 390, and includes a port control unit 345 and interrupt control unit 346. A panel I/F 341 is connected to the LCD controller 340, and includes an I/F for displaying image data on the liquid crystal screen of the console unit 150, and a key input I/F 371 for inputting data by hard keys and touch panel keys. The console unit 150 includes a liquid crystal display unit, a touch panel input unit adhered on the liquid crystal display unit, and a plurality of hard keys. A signal input by the touch panel or hard keys is transmitted to the CPU 312 via the above-described panel I/F 341. The liquid crystal display unit displays image data transmitted from the panel I/F 341. This liquid crystal display unit displays, for example, image data and the functions of the operation of this image forming apparatus.
The real time clock module 337 is referred to when updating and saving the date and time managed by the image forming apparatus 100, and backed up by a backup battery 338. An SRAM 339 is also backed up by the backup battery 338, and stores, for example, user modes, various kinds of setting information, and file management information of the hard disk drive 332 in a nonvolatile manner.
A drawing processing unit 351 performs image rotation, image scaling, color space conversion, binarization, scanner image input, and printer image output on image data stored in the DRAM 322. A DRAM 352 is used as a temporal work area of the drawing processing unit 351. The drawing processing unit 351 is connected to the main controller 311 via an I/F 350, and data transfer between the drawing processing unit 351 and DRAM 322 is performed by DMA transfer under the control of the bus controller 313. Connectors 360 and 355 are respectively connected to the reader unit 120 and printer unit 130, and connected to asynchronous serial I/Fs (372 and 373) and video I/Fs (362 and 363).
A scanner image processing unit 357 is connected to the reader unit 120 via the connector 360, and to the drawing processing unit 351 via a scanner bus 361, and has a function of performing predetermined processing on image data received from the reader unit 120. The scanner image processing unit 357 also has a function of outputting, to the scanner bus 361, a control signal generated based on a video control signal transmitted from the reader unit 120. A FIFO 358 is connected to the scanner image processing unit 357, and used to perform line correction on a video signal transmitted from the reader unit 120.
A printer image processing unit 353 is connected to the printer unit 130 via the connector 355, and to the drawing processing unit 351 via a printer bus 356. The printer image processing unit 353 performs predetermined processing on image data output from the drawing processing unit 351, and outputs the image data to the printer unit 130. The printer image processing unit 353 also has a function of outputting, to the printer bus 362, a control signal generated based on a video control signal transmitted from the printer unit 130. The DRAM 354 is connected to the printer image processing unit 353, and used to delay a video signal by a predetermined time.
The bus controller 313 controls the transfer of raster image data rasterized on the DRAM 322 to the printer unit 130. The data is transferred by DMA to the printer unit 130 via the drawing processing unit 351, printer image processing unit 353, and connector 355.
The modem 390 is connected to the IO control unit 336 and an NCU (Network Control Unit) 391. The modem 390 modulates a signal to be transmitted by facsimile to the PSTN (Public Switched Telephone Network) via a connector 392, and demodulates a received signal. When receiving and printing FAX data, input data from the PSTN is demodulated by the NCU 391 and modem 390, and rasterized on the DRAM 322 by the main controller 311 via the I/O control unit 336. Then, under the control of the bus controller 313, the data is transferred by DMA to the printer unit 130 via the drawing processing unit 351, printer image processing unit 353, and connector 355. When scanning and transmitting FAX data, a video signal transmitted from the reader unit 120 is transferred to the main controller 311 via the connector 360, scanner image processing unit 357, and drawing processing unit 351. The modulated data is transmitted from the I/O control unit 336 to the PSTN via the modem 390 and NCU 391.
A copying process as the most basic function of the image forming apparatus 100 according to this embodiment will be described below.
This process is started when a copy instruction is input by a user using the console unit 150. First, in step S1, the copy setting of a copy job entered by the user is input. The contents of the copy setting include the number of copies, the sheet size, single/double-sided printing, the enlargement/reduction ratio, sort output, and with or without stapling. Note that details of the console unit 150 will be described later with reference to
The image data thus stored in the HDD 332 further undergoes image processing for printing, and the processed data is transferred to the printer unit 130. First, in step S7, if no image file to be printed exists on the DRAM 322, the image file is loaded into the DRAM 322 from the HDD 332. Then, in step S8, the main controller 311 transfers the image data stored in the DRAM 322 to the drawing processing unit 351, and transfers the image data output from the drawing processing unit 351 to the printer image processing unit 353. Subsequently, the process advances to step S9, and the printer image processing unit 353 processes the transferred image data. The process then advances to step S10 to store the processed image data in the DRAM 354. In step S11, while controlling the printer unit 130 via the connector 355, the main controller 311 transfers the processed image data stored in the DRAM 354 to the printer unit 130 at an appropriate timing. In step S12, the control unit 110 controls the printer unit 130 to print the image data. When the originals stacked in the original document feed unit 121 are copied by the number of copies designated by the copy setting, this process is terminated.
The console unit 150 is separated into a UI display section 500 and hard-key operation section 510. The user can set various copy modes (for example, double-sided printing, grouping, sorting, and stapling) by using the console unit 150. Note that these copy modes can be set by using the hard-key operation section 510 including hard keys, or by using soft keys displayed on the touch panel of the UI display section 500. A start button 511 is used to designate the start of a copying process or transmitting process. A key 512 is used to designate the setting of a power saving mode.
The scanner image processing unit 357 will be explained in detail below.
With respect to image data supplied from the reader unit 120 via the connector 360, a joint & MTF (Modulation Transfer Function) correction unit 601 adjusts the delay amount of each line in accordance with the read rate, thereby correcting the MTF having changed in accordance with the read rate. When the CCD 218 (
The printer image processing unit 353 will now be explained.
Image data supplied from the drawing processing unit 351 via the printer bus 356 is first input to a LOG transformation unit 701. The LOG transformation unit 701 converts RGB into CMY by LOG transformation. Then, a moire removing unit 702 removes moire. A UCR & masking unit 703 performs UCR processing on the CMY image data having undergone the moire removing process, thereby generating CMYK image data. A masking unit corrects this CMYK image data into image data suitable for the printer unit 130. A gamma correction unit 704 adjusts the density of the image data processed by the UCR & masking unit 703. After that, a filtering unit 705 performs a smoothing or edging process on the image data. A delay unit 706 stores the CMYK image data in the DRAM 354, delays the CMYK image data in order to correct the output timing of the image data of each color, and outputs the image data to the printer unit 130 via the connector 355.
The drawing processing unit 351 includes a rotation section 801, scaling section 802, color space conversion section 803, binarizing section 805, scanner input section 806, and printer output section 807 as modules. The DRAM 352 is used as a temporal work area of each module via a DRAM control unit 808. Work areas of the DRAM 352 are statically allocated to the individual modules in advance so that these work areas of the modules do not overlap each other. The drawing processing unit 351 is connected to the main controller 311 via the I/F 350, and data transfer between the drawing processing unit 351 and DRAM 322 is performed by DMA transfer under the control of the bus controller 313. The bus controller 313 controls the setting of, for example, a mode in each module of the drawing processing unit 351, and controls the timing at which image data is transferred to each module. An input interface 810 inputs image data input from the I/F 350 to a switching circuit 809. The format of this image data is, for example, binary raster image data, multilevel raster image data, or JPEG compression. When the image data is a JPEG image, the input interface 810 converts the JPEG image data into raster image data, and inputs the converted image data to the switching circuit 809. An output interface 811 outputs the input image data from the switching circuit 809 to the I/F 350. Although the format of this image data is raster image data, the output interface 811 may also perform JPEG compression on the image data, and then output the compressed image data to the I/F 350.
The image forming apparatus according to this embodiment can set the print density while executing a printing operation.
When printing is started, a sub window shown in
Note that the density value adjusted by the print density adjust section 905 during printing is stored in the DRAM 322 of the control unit 110. The density value adjusted by the print density adjust section 905 is stored in the volatile DRAM 322 because this density value is merely a density change during printing and need not be saved after the electric power supply of the image forming apparatus 100 is turned off.
The UI display section 500 displays this electric power saving setting window when a power saving mode key 521 of the console unit 150 is pressed. This power saving setting window includes radio buttons 1001 and 1002 for setting the power saving level; the radio button 1001 selects “high power consumption” (a normal mode), and the radio button 1002 selects “low power consumption”. When the radio button 1002 is selected (low power consumption), the user can select the presence/absence of exceptional time zone designation for designating a time zone during which the mode for suppressing the power consumption is canceled, by using radio buttons 1003 and 1004. The radio button 1003 is a button for designating no exceptional time zone designation. When the radio button 1003 is selected, a mode in which a power saving priority operation is always performed is set. The radio button 1004 is a button for designating a time zone during which no power saving priority mode is set. By selecting the radio button 1004, the user can designate the time zone by start time 1005 and end time 1006. When “low power consumption” is set in the image forming apparatus 100 of this embodiment, the control unit 110 (main controller 311) performs control so as to suppress the electric power to be supplied to the heater of the fixing unit 277, in order to reduce the power consumption. Also, the control unit 110 controls the paper feed unit (one of the cassettes 261 to 264 or the manual feed tray 265) to feed sheets at a short sheet interval. By thus feeding sheets by decreasing the sheet interval, images can be fixed while the amount of heat generated by the fixing unit 277 between sheets is suppressed. This makes it possible to reduce power required for reheating. Accordingly, it is possible to shorten the total heating time of the fixing unit 277 shown in
In addition, the control unit 110 of this embodiment partially omits the setting of a density register in order to decrease the sheet interval as described above. This is so because the density register has an LUT (Look-Up Table), and the size of the LUT is as large as 4.7 MB, so the density register cannot be set in time at a short sheet interval if the setting is unconditionally entirely performed. In this embodiment, the sheet interval can be shortened because the control unit 110 partially omits the setting of the density register. Thus, the control unit 110 can convey fed sheets at a first interval or a second interval shorter than the first interval.
A set button 1010 is used to give an instruction to update the power saving setting by set values set in this window. The set values are stored in the SRAM 339 backed up by the battery 338 in the control unit 110. Accordingly, these set values are held in a nonvolatile manner. Also, when a cancel button 1011 is touched, these set values in this window are canceled, and the power saving setting window is closed.
The registers shown in
The process of controlling whether to set a parameter in the above-described registers in accordance with whether the power saving priority mode is set will be explained below with reference to a flowchart shown in
First, in step S21, a set value stored in the SRAM 339 and indicating whether power saving priority is set is loaded. Then, the process advances to step S22 to determine whether or not power saving priority (low power consumption) is set. Note that this power saving priority can be set by pressing the power saving key 512 of the console unit 150 shown in
On the other hand, if it is determined in step S22 that power saving priority (low power consumption) is set, the process advances to step S26 to load the present time from the real-time clock module 337. Then, the process advances to step S27 to determine whether the present time loaded in step S26 corresponds to the power saving exceptional time zone (the time zone during which no power saving mode is set). If it is determined that the present time corresponds to the power saving exceptional time zone, the process advances to the density setting information loading process in step S23, in the same manner as when no power saving priority is set. This power saving exceptional time zone is set by the start time 1005 and end time 1006 when the radio button 1004 shown in
On the other hand, if it is determined in step S27 that the present times does not correspond to the power saving exceptional time zone (the power saving operation is being executed), the process advances to step S28 to determine whether to print a plurality of copies. If it is unnecessary to print a plurality of copies (if it is necessary to print only one copy), the process advances to step S25 to set unset registers among the registers 1101, 1102, 1103, 1104, and 1105 except for the density-related registers.
If it is determined to print a plurality of copies in step S28, the process advances to step S29 to determine whether the next printing data is data to be printed on the first sheet of the respective copies. If it is determined that the next printing data is data to be printed on the first sheet of each copy, the process advances to the density setting information loading process in step S23, in the same manner as when no power saving priority is set.
On the other hand, if the next printing data is not data to be printed on the first sheet of the copy, the process advances to step S25 to set unset registers among the registers 1101, 1102, 1103, 1104, and 1105 except for the density-related registers 1110 and 1111.
As described above, when only one copy is to be printed in the power saving priority mode or when a plurality of copies are to be printed and the data is to be printed on a sheet except for the first sheet in the power saving priority mode, it is possible to omit setting process of the density-related parameters performed between a sheet currently being printed and a succeeding sheet to be printed next. Since this can shorten the processing time between sheets, it is possible to effectively shorten the total time required for printing, and reduce the power consumption required for the whole printing.
Also, even in the power saving priority mode, when printing a plurality of copies, the changed density parameters can be set in the registers before the first sheet of each copy is printed. Accordingly, an image having undergone image processing corresponding to the latest density setting can be printed for at least each copy.
The process of omitting setting process of the density parameters when printing only one copy will additionally be explained by noting the corresponding portion of the flowchart shown in
In step S28, it is determined whether to print a plurality of copies. Whether to print a plurality of copies or only one copy is determined by referring to the number of copies displayed in the copies display section 903 (
Accordingly, the fixing device for fixing printed sheets can successively fix sheets at a short sheet interval. This makes it possible to shorten the total heating time of the fixing unit 277 shown in
The procedure of omitting setting process of the density parameters when printing a plurality of copies will additionally be explained by noting the corresponding portion of the flowchart shown in
If it is determined in step S28 of
Thus, when printing a plurality of copies, the change in density is reflected when printing the first printing data for the first sheet in a copy, and the density is not changed during the printing process of the copy until the final sheet of the copy, even if the user performs a density adjusting operation during printing of the copy. While a copy is being printed, therefore, printing can be performed by decreasing the interval between a sheet currently being printed and a succeeding sheet to be printed next. It is also possible to shorten the time required for fixing because fixing is performed by decreasing the interval between successive sheets.
The embodiment of omitting setting process of the density-related parameters during printing in accordance with the power saving setting has been explained above. Next, the way the sheet interval shortens and the power saving effect occurs in practice when the setting process of the density-related parameters is omitted and is not omitted will be explained below with reference to timing charts shown in
First, an operation when the power saving setting is set to “high power consumption (no power consumption priority)” and a changed density set value is reflected during printing (image formation) will be explained with reference to
In
Before the first sheet is printed, all the registers of the printer image processing unit 353 are set in 1321, and the result of image processing performed in accordance with this setting is output as printing data of the first sheet at a timing 1331. In synchronism with the timing 1331 of the data of the first sheet, a sheet on which the printing data of the first sheet is to be printed is conveyed and printed in 1341.
Reference numerals 1311 and 1312 each denote the timing of an event in which the print density is changed during the printing operation. In this timing chart, the density changing event 1311 occurs during the printing of the first sheet, and this density change is reflected on all the registers of the printer image processing unit 353 at a timing 1322 before an image is formed on the second sheet. Image data to be printed on the second sheet is processed in accordance with the reflected density changing parameters, and output as printing data of the second sheet in 1332. In 1342, the second sheet is conveyed, and a printing process is performed on the second sheet. In page presetting 1323 before the third sheet, no density change occurs from the console unit 150, so processing is performed based on the full register setting set for the second sheet. Image processing is thus performed in the same manner as for the second sheet to output printing data to be printed on the third sheet in 1333, and the third sheet is conveyed and printed in 1343.
If the density changing event 1312 occurs while the third sheet is being printed, this density change is reflected in 1324 by setting the change in all the registers of the printer image processing unit 353. As shown in the timing chart as described above, a sheet conveyance interval T1 (equivalent to the sheet interval) prolongs because all the registers of the printer image processing unit 353 are set between sheets. In
For comparison, an operation of omitting the setting of the density-related parameters in the registers when the power saving setting is set to “low power consumption (power saving priority)” will be explained below with reference to the timing chart shown in
In
In the same manner as described above, before the first sheet is printed, all the registers of the printer image processing unit 353 are set in 1421, and the result of image processing performed in accordance with this setting is output as printing data to be printed on the first sheet at a timing 1431. In synchronism with the timing 1431, a sheet on which the printing data of the first sheet is to be printed is conveyed and printed in 1441.
A marker 1411 indicates the occurrence timing of an event in which the print density is changed from the console unit 150 while the first sheet is being printed. In this timing chart, the density change occurs during the printing of the first sheet, but the setting process of the density-related parameters designated in 1411 is omitted in 1422 (the processes in steps S23 and S24 of
Similarly, the setting process of the density-related parameters changed by the user in 1411 for the first sheet is omitted at timings 1423 and 1424. Accordingly, printing data of the third sheet to be output in 1433 and printed in a sheet conveyance/printing process of 1443 is also printed by neglecting the density change in 1411.
Consequently, an interval T2 (equivalent to the sheet interval) at which sheets to be printed are conveyed becomes shorter than T1 shown in
That is, printing is performed by decreasing the interval (sheet interval) between sheets by a time of (T1−T2). When printing, for example, 10 sheets, therefore, the printing time can be made shorter by a time equivalent to {(T1−T2)×10} than that when all the registers are set for every sheet as shown in
An operation of omitting the setting of the density-related parameters when printing sheets of a plurality of copies will be explained below with reference to the timing chart shown in
In
In the same manner as described previously, before the first sheet is printed, all the registers of the printer image processing unit 353 are set in 1521, and the result of image processing performed in accordance with this setting is output as printing data of the first sheet at a timing 1531. In synchronism with this data output, the first sheet is conveyed and printed in 1541.
Reference numeral 1511 indicates the occurrence timing of an event in which the print density is changed by a user's operation while the first sheet is being printed. In this timing chart, the density change occurs during the printing of the first sheet, but the setting process of the density-related parameters is omitted in the setting of the registers of the printer image processing unit 353 in 1522. Therefore, the density change performed in 1511 is not reflected in 1532 at which printing data of the second sheet is output. In 1542, the second sheet is conveyed, and the printing data of the second sheet is printed on the sheet.
Subsequently, in register setting in 1524, the second sheet of the second copy is printed, so the processing is performed by omitting the setting process of the density-related parameters.
As has been explained above, the sheet conveyance interval is T1 only when a break occurs between copies (before the first sheet of each copy), and is T2 (T1>T2) between sheets in other cases. Similar to
In addition, the total heating time of the fixing unit 277 can be shortened in proportion to the time equivalent to {(T1−T2)×10}. This makes it possible to reduce the accumulated power consumption from the start to the end of printing.
Also, when printing sheets of a plurality of copies, all the registers are set only between copies (before the first sheet of each copy is printed). Therefore, images printed on sheets of the same copy have the same density, and images are printed on sheets of the next copy by the density corresponding to the changed density-related parameter.
When the print density adjusting section 905 shown in
As described above, when “low power consumption” is set in the power saving priority mode and the user performs an operation of changing the density during the printing of one copy, display control is performed to display the message indicating the impossibility of density change shown in
When power saving priority is set and the user performs a density changing operation from the console unit 150 while printing is being performed on sheets of a plurality of copies, this density change is delayed before being executed. This operation will be explained below.
When the print density adjusting section 905 changes the print density during printing, a sub window 1700 displaying the delay of density change is popped up on the UI display section 500 of the console unit 150. A message 1701 in the sub window 1700 displays information indicating that the density change performed during the printing of a copy of a plurality of copies is reflected on the printing of the succeeding copy. In addition, a help message is displayed as indicated by 1703. The sub window 1700 is closed when the user touches a close button 1702. The help message 1703 displays that when the power saving setting is set to “high power consumption”, the density change performed by the print density adjusting section 905 can be reflected on the printing of the subsequent sheet even during printing.
As described above, when “low power consumption” is set in the power saving priority mode and the user performs a density changing operation while the printing of sheets of a plurality of copies is being designated and executed, the message 1701 indicating the delay of the density change shown in
The power saving exceptional time zone setting section will solely be explained below.
As already explained earlier,
The radio button 1003 is a button for designating no exceptional time zone. When the radio button 1003 is checked, an operation giving priority to power saving is performed in the entire time zone. The radio button 1004 is a button for designating an exceptional time zone. When the radio button 1004 is checked, power saving priority is canceled in a time zone set by the start time 1005 and end time 1006, and the operation is performed with “high power consumption” in this time zone. The user can set each of the start time 1005 and end time 1006 by touching the inside of the frame and entering numerals from the hard-key operation section 510 of the console unit 150.
Thus, a time zone in which power saving priority is canceled can be set. Therefore, in an office in which, for example, a worker performs copying quickly and immediately goes out for business in the morning, a time zone from 8:00 a.m. to 9:00 a.m., for example, is excluded from the power saving time zone. As a consequence, a density changing instruction given by the user can rapidly be reflected on the printing result.
In this embodiment as has been explained above, when setting power saving priority, the setting process of the density-related parameters performed between sheets is omitted. Since this advances the timing of the start of printing of the succeeding sheet, printing can be performed by decreasing the sheet interval when printing a plurality of sheets. Consequently, the total heating time of the fixing unit can be shortened because fixing can be performed by decreasing the sheet interval. Therefore, the accumulated power consumption from the start to the end of printing can be reduced when printing a plurality of sheets.
Also, when printing only one copy in this embodiment, the setting process of the density-related parameters designated by a density adjusting operation during printing is omitted for all sheets in the copy. Accordingly, all the sheets of the copy can be fixed by decreasing the sheet interval.
Furthermore, in this embodiment, even when a density adjusting operation is performed during the printing of one copy, the density adjustment is reflected for the first time on the printing of the succeeding copy. Therefore, printing and fixing can be performed by decreasing the sheet interval during the printing of one copy. Also, even when a density adjusting operation is performed during the printing of one copy, the density adjustment is reflected only between copies. This makes it possible to change the density for sheets of the succeeding copy while holding a uniform density in the same copy.
In this embodiment, when a density changing operation is performed during the printing of one copy, it is possible to present the user performing the operation with information indicating that the density cannot be changed during the printing of the copy, and a method of avoiding the problem.
In this embodiment, when a density changing operation is performed during the printing of a plurality of copies, it is possible to present the user performing the operation with information indicating that the density change is reflected on the subsequent copy, and a method of avoiding (coping with) the problem.
In this embodiment, a time zone in which power saving priority is canceled can be set. Accordingly, a density change or the like of copying can rapidly be reflected in this time zone.
Aspects of the present invention can also be realized by a computer of a system or apparatus (or devices such as a CPU or MPU) that reads out and executes a program recorded on a memory device to perform the functions of the above-described embodiment(s), and by a method, the steps of which are performed by a computer of a system or apparatus by, for example, reading out and executing a program recorded on a memory device to perform the functions of the above-described embodiment(s). For this purpose, the program is provided to the computer for example via a network or from a recording medium of various types serving as the memory device (e.g., computer-readable medium).
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. 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.
This application claims the benefit of Japanese Patent Application No. 2009-144643, filed Jun. 17, 2009, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | Kind |
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2009-144643 | Jun 2009 | JP | national |