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1. a situation where an appropriate amount of deviation cannot be acquired 0007 According to an illustrative embodiment of the present invention there is provided an image forming appa ratus includes an automatic acquiring unit which is config ured to form a mark for detecting at least one of positional deviation and density deviation and acquire an amount of deviation by measuring the mark an image forming unit which is configured to form an image while adjusting at least Dec 29 2011 one of positional deviation and density deviation based on a correction value specified by the amount of deviation and an output unit which is configured to execute at least one of a pattern printing process and a notifying process when an amount of deviation within a permissible range is not acquired by the automatic acquiring unit the pattern printing process including printing a pattern image for specifying a correction value of at least one of positional deviation and density deviation on a recording sheet the notifying process including making notification for prompting execution of the pattern printing process 0008 According to the above configuration there is pro vided an image forming apparatus that forms a mark for image adjustment detects the mark to automatically acquire an amount of deviation and can simply solve a situation where an appropriate amount of deviation cannot be acquired BRIEF DESCRIPTION OF THE DRAWINGS 0009 The a
2. combinations for which an amount of positional deviation cannot be acquired due to the failure of a sensor or noise the narrow range is set 0066 That is when an amount of positional deviation exceeds the predetermined range it is possible that the pattern image of narrow range which is a typical pattern image exceeds a printable range For example FIG 4A shows an example of a pattern image of narrow range in which marks are formed while an interval of the adjustment color is made to be narrower by one dot than that of the reference color In this pattern image it is possible to detect an amount of posi tional deviation in a unit of one dot within a detectable range of 12 to 12 dots In other words when positional deviation exceeds this detectable range is caused it is difficult to detect the amount of positional deviation Accordingly regarding a pattern image of the wide range marks are formed while an interval of the adjustment color is made to be narrower by three dots as shown in FIG 7 Thereby although an amount of adjustment becomes a unit of three dots a range within which an amount of positional deviation can be detected becomes 36 to 36 dots so that the detectable range is three times than as large as the narrow range 0067 In the meantime as described above the pattern images of this illustrative embodiment are to find the number at which the positions of the reference color and the adju
3. correction value immediately or to input a manual correction value at the next automatic acquiring process timing Dec 29 2011 0070 When an instruction to execute the manual correc tion is received 1 when a user selects to input a manual correction value immediately S124 YES the manual acquiring process is executed S200 The manual acquiring process will be specifically described below On the other hand when an instruction to execute the manual correction is not received 1 e when the user selects to input a manual correction value at the next automatic acquiring process tim ing S124 NO the manual setting flag is turned on S141 After S200 or S141 the automatic correction process ends 0071 Manual Correcting Process 0072 Next the manual acquiring process of 5200 in FIG 5 will be described with reference to a flow chart of FIG 8 0073 First the automatic correction values the manual correction values and the setting of the amounts of adjustment are read out from the database 341 of the NVRAM 34 for each of the combinations of the adjustment colors and the scanning directions S201 Then it is determined whether the wide range is included in the setting of the amounts of adjustment S202 0074 When the wide range is not included in the setting of the amounts of adjustment S202 NO the pattern images of narrow range is printed on one sheet for all combinations S211 On the other hand when the
4. 011 wherein the automatic acquiring unit is configured to form the mark based on at least the correction value stored in the storage unit 4 The image forming apparatus according to claim 1 wherein the pattern image includes a pattern image for wide range correction and a pattern image for narrow range correction and wherein when an amount of deviation within the permis sible range is not acquired by the automatic acquiring unit the pattern image for wide range correction is printed in the pattern printing process 5 The image forming apparatus according to claim 1 wherein the patter image includes a pattern image for wide range correction and a pattern image for narrow range correction and wherein for a color whose amount of deviation exceeds the permissible range the pattern image for wide range cor rection is printed in the pattern printing process and for a color whose amount of deviation is within the permis sible range the pattern image for narrow range correc tion is printed in the pattern printing process 6 The image forming apparatus according to claim 1 wherein the patter image includes a pattern image for wide range correction and a pattern image for narrow range correction and wherein for a scanning direction whose amount of devia tion exceeds the permissible range the pattern image for wide range correction is printed in the pattern printing process and for a scanning direction whose amount of deviatio
5. 21 Configuration of MFP 0022 As shown in FIG 1 an MFP 100 of this illustrative embodiment includes a control unit 30 having a CPU 31 a ROM 32 a RAM 33 an NVRAM non volatile RAM 34 an ASIC 35 a network interface 36 and a FAX interface 37 In addition the control unit 30 is electrically connected to an image forming unit 10 that forms an image on a sheet an image reading unit 20 that reads out an image of a sheet and an operation panel 40 that displays an operation situation and receives an input operation by a user 0023 The CPU 31 executes operations for implementing various functions such as an image reading function an image forming function a FAX data transmission reception US 2011 0317175 Al function and an image adjustment function described later and functions as a center of control The ROM 32 stores therein various control programs for controlling the 100 various settings initial values and the like The RAM 33 is used as a work area from which the various control pro grams are read out or a storage area that temporarily stores image data The NVRAM 34 is a non volatile storage device and is used as a storage area that preserves various settings image data and the like 0024 Based on the control programs read out from the ROM 32 or signals transmitted from various sensors the CPU 31 controls the respective constitutional elements of the MFP 100 for example a turn on timing of an exposure device c
6. E 5122 CORRECTION VALUE SCALE INQUIRE MANUAL EXECUTION 5123 NO MANUAL EXECUTION INSTRUCTION MANUAL ACQUIRING PROCESS 141 MANUAL SETTING FLAG ON Patent Application Publication Dec 29 2011 Sheet 6 of 10 US 2011 0317175 Al FIG 6 341 COMBINATION ADJUSTMENT SCANNING COLOR DIRECTION MAIN SCANNING SUB SCANNING MAIN SCANNING CORRECTION VALUE RANGE AUTOMATIC MANUAL NARROW RANGE M COLOR er MA NARROW RANGE MAIN SCANNING Y COLOR DIRECTION SUB SCANNING Y COLOR DIRECTION NARROW RANGE NARROW RANGE Patent Application Publication Dec 29 2011 Sheet 7 of 10 US 2011 0317175 Al FIG 7 Patent Application Publication Dec 29 2011 Sheet 8 of 10 US 2011 0317175 Al FIG 8 MANUAL ACQUIRING PROCESS READ OUT CORRECTION VALUES 5201 WIDE RANGE PATTERN 5 INCLUDED PRINT PATTERN IMAGE PRINT PATTERN IMAGE OF 5203 OF NARROW RANGE WIDE AND NARROW RANGES WAIT FOR INPUT 5204 OF CORRECTION VALUE INSTRUCTION TO COMPLETE INPUT 2 YES UPDATE MANUAL CORRECTION VALUE RETRY INSTRUCTION CANCEL er UN MANUAL SETTING FLAG ON Patent Application Publication 86VC 86VM NARROW NARROW 86VY RANGE PATTERN IMAGE Dec 29 2011 Sheet 9 of 10 FIG 9 NARROW RANGE PATTERN IMAGE WIDE RANGE PATTERN IMAGE NARROW RANGE PATTERN IMAGE NARROW RANGE PAT
7. P adjusts an image As a result it is expected that the deterioration of a quality of an image is suppressed 0092 The present invention provides illustrative non lim iting embodiments as follows 0093 image forming apparatus includes an automatic acquiring unit which is configured to form a mark for detect ing at least one of positional deviation and density deviation and acquire an amount of deviation by measuring the mark an image forming unit which is configured to form an image while adjusting at least one of positional deviation and den sity deviation based on a correction value specified by the amount of deviation and an output unit which is configured to execute at least one of a pattern printing process and a noti fying process when an amount of deviation within a permis sible range is not acquired by the automatic acquiring unit the pattern printing process including printing a pattern image for specifying a correction value of at least one of positional deviation and density deviation on a recording sheet the notifying process including making notification for prompt ing execution of the pattern printing process 0094 The above image forming apparatus forms a mark for detecting at least one of positional deviation and density deviation and forms an image based on a correction value automatic correction value that is specified by an amount of deviation acquired by measuring the mark If an amount of deviation w
8. TERN IMAGE NARROW RANGE PATTERN IMAGE NARROW RANGE PATTERN IMAGE US 2011 0317175 Al 86VC 86VY Patent Application Publication Dec 29 2011 Sheet 10 of 10 US 2011 0317175 Al FIG 10 PRINTING PROCESS READ OUT CORRECTION VALUES 5301 ACQUIRE IMAGE DATA 5302 FORM IMAGE 5303 US 2011 0317175 Al IMAGE FORMING APPARATUS CROSS REFERENCE TO RELATED APPLICATION 0001 This application claims priority from Japanese Patent Application No 2010 146578 filed on Jun 28 2010 the entire subject matter of which is incorporated herein by reference TECHNICAL FIELD 0002 Aspects of the present invention relate to an image forming apparatus that forms a mark for image adjustment and performs image adjustment based on an amount of devia tion acquired by detection of the mark BACKGROUND 0003 An image forming apparatus performs an image adjustment so that a position or density of an image is not deviated A sequence of such image adjustment includes for example forming a registration pattern which is a mark for adjusting positional deviation on a belt member for sheet conveyance for each of colors acquiring an amount of devia tion between the registration pattern of a basic color and the registration pattern of a detection target color and correcting positional deviation of an image of the detection target color based on a correction value specified based on the amount of deviation 0004 A correctio
9. The intervals between the mark of the reference color and the adjustment colors are changed when positional deviation occurs in the sub scanning direction Therefore it is possible to specify an amount of deviation of the adjustment color relative to the reference color in the sub scanning direc tion Based on the amount of deviation a correction value by the automatic correction hereinafter referred to as auto matic correction value is calculated The automatic correc tion values are stored in the NVRAM 34 0044 It is noted that the configuration of the registration pattern 66 is just illustrative and is not limited to the above The registration pattern may be a general image pattern that is used to correct the positional deviation For example the registration pattern may include a pair of two rod shaped marks wherein at least one is inclined by a predetermined angle to a straight line following the main scanning direction Such registration pattern can specify an amount of deviation in the main scanning direction as well as in the sub scanning direction 0045 Inthe meantime the manual correction is executed by auser s operation A user inputs a desired correction value and then pushes an OK button When the OK button is pushed the MFP 100 acquires the input value Based on the input value a correction value by the manual correction Dec 29 2011 hereinafter referred to as manual correction value is cal cula
10. US 20110317175A1 a2 Patent Application Publication Pub No US 2011 0317175 Al as United States MURAYAMA et al 43 Pub Date Dec 29 2011 54 IMAGE FORMING APPARATUS Kentaro MURAYAMA Kasugai shi JP Osamu TAKAHASHI Nagoya shi JP 75 Inventors BROTHER KOGYO KABUSHIKI KAISHA Nagoya shi JP 73 Assignee 21 Appl No 13 073 893 22 Filed Mar 28 2011 30 Foreign Application Priority Data Jun 28 2010 nnn 2010 146578 Publication Classification 51 Int Cl GO6K 15 02 2006 01 PRINT PATTERN IMAGE OF NARROW RANGE MANUAL ACQUIRING PROCESS READ OUT CORRECTION VALUES WIDE RANGE PATTERN gt INCLUDED PRINT PATTERN IMAGE OF WIDE AND NARROW RANGES INSTRUCTION TO COMPLETE INPUT YES UPDATE MANUAL CORRECTION VALUE RETRY INSTRUCTION MANUAL SETTING FLAG ON 52 USC vanns 358 1 2 57 ABSTRACT An image forming apparatus includes an automatic acquiring unit which is configured to form a mark for detecting at least one of positional deviation and density deviation and acquire an amount of deviation by measuring the mark an image forming unit which is configured to form an image while adjusting at least one of positional deviation and density deviation based on a correction value specified by the amount of deviation and an output unit which is configured to execute at least one of a pattern printing process and a notifying proc
11. bove and other aspects of the present invention will become more apparent and more readily appreciated from the following description of illustrative embodiments of the present invention taken in conjunction with the attached drawings in which 0010 FIG 1 is a block diagram showing an electrical configuration of an MFP 0011 FIG 2 shows a schematic configuration of an image forming unit of the MFP shown in FIG 1 0012 FIG 3 shows an arrangement of mark sensors 0013 FIGS 4A and 4B show a printing example of a pattern image for positional deviation correction 0014 FIG 5 is a flow chart showing a sequence of an automatic acquiring process 0015 FIG 6 shows an example of a database that stores correction values 0016 FIG 7 shows respective printing examples of a wide range pattern image and a narrow range pattern image 0017 FIG 8 is a flow chart showing a sequence of a manual acquiring process 0018 FIG 9 shows a sheet on which a wide range pattern image and a narrow range pattern image are mixed and 0019 FIG 10 is a flow chart showing a sequence of a printing process DETAILED DESCRIPTION 0020 Hereinafter an image forming apparatus and an image forming system according to illustrative embodiments will be described with reference to the accompanying draw ings In the illustrative embodiments the present invention is applied to a multi function peripheral MFP having a color printing function 00
12. cess The failure of the automatic acquirement of an amount of deviation may mean that the positional deviation or density deviation is considerably large In this case it may be preferable that the pattern image for wide range correction having a high correc tion scale is printed to easily perform the automatic correc tion 0099 Further the patter image may includes a pattern image for wide range correction and a pattern image for narrow range correction and for a color whose amount of deviation exceeds the permissible range the pattern image for wide range correction may be printed in the pattern printing process and for a color whose amount of deviation is within the permissible range the pattern image for narrow range correction may be printed in the pattern printing process When the pattern image for wide range correction is used even for a color for which an amount of deviation that is within the permissible range is acquired even an appropriate color may be greatly changed Therefore it may be preferable to use the pattern image for wide range correction only for an inappropriate color 0100 Further the patter image may include a pattern image for wide range correction and a pattern image for narrow range correction and for a scanning direction whose amount of deviation exceeds the permissible range the pat tern image for wide range correction may be printed in the pattern printing process and for a scanning direction who
13. cess conditions for example exposure position speed of the conveyance belt 7 or photosensitive member of the adjustment color are adjusted so that a position of an image of the adjustment color is matched with a position of an image of the reference color 0051 In the meantime the density deviation adjustment also includes the automatic correction and the manual correc tion For example in the automatic correction density pat terns having density differences in the sub scanning direction are formed by the respective process units 50Y 50M 50C 50K Then amounts of reflected light from the density pat terns are detected by the common sensor to the positional deviation correction or another optical sensor In this illustra US 2011 0317175 Al tive embodiment the detection is performed by the sensor 61L for example According to the amounts of reflected light the densities are specified and differences with a target den sity are calculated as automatic correction values In the manual correction a manual correction value can be received through a user input Then in the correction process an actual correction value is calculated based on the correction values and the process conditions for example exposure intensity exposure range and developing bias of the respective colors are adjusted to maintain a target density based on the actual correction value 0052 Sequence of Image Adjustment 0053 Next a sequence of posi
14. cor rection that adjusts densities of the respective colors are per formed Both image adjustments include an acquiring pro cess of acquiring amounts of deviation of adjustment colors from a reference color and acquiring correction values speci fied by the amounts of deviation and a correcting process of correcting an image based on the correction values Herein after the image adjustment will be described with reference to the positional deviation correction 0038 First the acquiring process of the positional devia tion correction will be described The MFP 100 has two modes of acquiring process which includes an automatic US 2011 0317175 Al correction and a manual correction The automatic correction is to adjust an image to an ideal position that is set for the MFP 100 The manual correction is to reflect a user s preference or to substitute for the automatic correction when the automatic correction does not function properly 0039 In the automatic correction a registration pattern that is a pattern image for detecting an amount of positional deviation and the mark sensor 61 detects the registration pattern and thus calculates an amount of deviation A correc tion value based on the amount of deviation is automatically acquired In the manual correction a user inputs a numerical value through the operation panel 40 so that a correction value is manually acquired 0040 Here a sequence of acquiring the correction value i
15. correc tion value acquired in the automatic acquiring process and the manual correction value However the present invention is not limited thereto For example the MFP may form an image based on a new automatic correction value that is obtained by adding the correction value which is acquired by a user input during the automatic acquiring process to the automatic cor rection value 0091 Inthe above illustrative embodiment the automatic acquiring process for positional deviation correction has been described However the inventive concept of the present invention can be also applied to the density deviation correc tion For the density deviation correction a pattern image that is compared with a sample is prepared in advance In this sample a density pattern in which a plurality of density differences is given for the respective colors is printed Then US 2011 0317175 Al when an appropriate amount of density deviation is not acquired during the automatic acquiring process for density correction the 100 prints on a sheet a density pattern in which a plurality of density differences is given for the respective colors like the sample and receives an input of a correction value for density deviation Then a user compares the density pattern that is printed during the automatic acquir ing process with the density pattern of the sample and inputs a manual correction value that can be specified from the patterns so that the MF
16. e respective process units 50 50 50C 50 and a mark sensor 61 that detects a pattern image formed on the conveyance belt 7 0029 In addition the image forming unit 10 is provided therein with a conveyance path 11 one dotted and dashed line in FIG 2 having a substantial S shape so that the sheet accommodated in the sheet feeding tray 91 positioned at a bottom passes through a feeder roller 71 registration rollers 72 the process unit 50 and the fixing device 8 and is then guided to the sheet discharge tray 92 through sheet discharge rollers 76 0030 The process unit 50 can form a color image and includes the process units corresponding to respective colors of yellow Y magenta cyan and black in par allel Specifically the process unit 50 has the process unit 50Y that forms an image of a Y color the process unit 50M that forms an image of an color the process unit 50C that forms an image of a color and the process unit 50K that forms an image of color The respective process units 50 50M 50C 50K are arranged at a predetermined interval in a con veyance direction of the sheet 0031 Inthe process unit 50 a surface of a photosensitive member is uniformly charged by a charging device Then the photosensitive member is exposed by the light from the expo sure device 53 and an electrostatic latent image correspond Dec 29 2011 ing to an image formed on a sheet is thus formed on the photos
17. ensitive member Then toner is supplied to the photo sensitive member through a developing device Thereby the electrostatic latent image on the photosensitive member becomes a visible image as a toner image 0032 The conveyance belt 7 is an endless belt member that is wound around the conveyance rollers 73 74 and is made of a resin material such as polycarbonate and the like The conveyance belt 7 is rotated in a counterclockwise direc tion as the conveyance roller 74 is rotated Thereby the sheet put on the conveyance belt is conveyed from the registration rollers 72 toward the fixing device 8 0033 The image forming unit 10 picks up the sheets accommodated in the sheet feeding tray 91 one by one and conveys the sheet onto the conveyance belt 7 Then the image forming unit 10 transfers the toner image formed in the pro cess unit 50 to the sheet At this time for a case of a color printing toner images are formed by the respective process units 50 50M 50C 50K and are then overlapped with each other on the sheet In the meantime for a case of a mono chrome printing a toner image is formed only by the process unit 50 and is then transferred on the sheet Thereafter the sheet on which the toner images are transferred is conveyed to the fixing device 8 and is then heat fixed on the sheet Then the sheet after the fixing is discharged to the sheet discharge tray 92 0034 The mark sensor 61 is provided downstream from the pr
18. ess when an amount of deviation within a permissible range is not acquired by the automatic acquiring unit The pattern printing process includes printing a pattern image for specifying a correction value on a recording sheet The noti fying process includes making notification for prompting execution of the pattern printing process 201 202 CANCEL INSTRUCTION Patent Application Publication Dec 29 2011 Sheet 1 of 10 FIG 1 100 CONTROL UNIT NETWORK I F US 2011 0317175 Al Patent Application Publication Dec 29 2011 Sheet 2 of 10 US 2011 0317175 Al FIG 2 Patent Application Publication Dec 29 2011 Sheet 3 of 10 US 2011 0317175 Al FIG 3 Patent Application Publication Dec 29 2011 Sheet 4 of 10 US 2011 0317175 Al 12 86K 86K 86K 86K EEn D KE P oom zen FIG 4A FIG 4B Patent Application Publication Dec 29 2011 Sheet 5 of 10 US 2011 0317175 Al GE ACQUIRING PROCESS 100 MANUAL SETTING FLAG IS ON ES NO READ OUT MANUAL ACQUIRING S101 CORRECTION VALUES PROCESS FORM END S102 REGISTRATION PATTERN DETECT 5103 REGISTRATION PATTERN si CALCULATE AMOUNT OF DEVIATION 5105 APPROPRIATE AMOUNT OF DEVIATION IS ACQUIRED YES S106 UPDATE CORRECTION VALUES FOR ALL COMBINATIONS 5107 SET WITH NARROW RANGE NO UPDATE APPROPRIATE 5121 CORRECTION VALUES SET INAPPROPRIAT
19. inventive concept of the present invention can also be applied to a monochrome printing apparatus inasmuch as it performs the positional deviation correction or density deviation correction 0088 In the above illustrative embodiment the manual acquiring process is executed by the automatic acquiring process However a user may execute the manual acquiring process at any timing For example the operation panel 40 may be provided with a switch button for switching into a manual correction mode where an input of a correction value is permitted Then when the user pushes the switch button the manual acquiring process may be executed 0089 In the above illustrative embodiment in S123 the user is inquired to select whether to input the correction value immediately or at a next automatic acquiring process timing However the selection item is not limited thereto For example a selection option with which a user can execute the manual acquiring process at any timing may be provided inasmuch as the arbitrary manual acquiring process can be executed In other words a selection option prompting a user to execute the manual acquiring process may be provided 0090 In the above illustrative embodiment the MFP 100 has the manual acquiring unit that acquires the manual cor rection value which is specified by the pattern image 86 by the user input and forms an image based on the actual correc tion value that is determined by using the automatic
20. is received from an information processing appa ratus connected to the MFP 100 0082 First the automatic correction value and the manual correction value are read out from the NVRAM 34 S301 Then image data to be printed is acquired S302 The pro cesses of S301 and S302 may be executed in a reverse order or at the same time 0083 Then an actual correction value is determined by using both the automatic correction value and the manual correction value which are read out in S301 and an image is formed while adjusting the process conditions of the adjust ment colors so that positions of images of the adjustment colors are matched at positions of images of the reference color S303 In other words even when it has been failed to acquire an amount of positional deviation it is possible to substitute with the manual correction value so that a quality of an image is suppressed from being deteriorated 0084 As described above when an appropriate amount of positional deviation is not acquired during the automatic acquiring process the MFP 100 according to this illustrative embodiment executes the manual acquiring process and prints the pattern images for image adjustment or notifying the execution of the manual acquiring process Thereby a user can recognize that an appropriate amount of positional deviation has not been acquired Furthermore from the pat tern image 86 printed on the sheet it is possible to specify a correctio
21. ithin a permissible range is not acquired the image forming apparatus executes a pattern printing process of printing a pattern image for specifying a correction value or a notifying process of prompting printing of a pattern image The notifying process may include displaying a message on an operation panel of the apparatus which prompts a user to input a correction value for example The pattern printing process or notifying process may be performed immediately when an amount of deviation exceeds a predetermined range or may be performed when an amount of deviation is acquired next time 0095 In other words the above image forming apparatus prints a pattern image for image adjustment or notifies a printing of a pattern image when an amount of deviation within a permission range is not acquired during the auto matic acquiring process Thereby a user can recognize that an appropriate amount of deviation has not been acquired Fur thermore from the pattern image printed on a sheet it is possible to specify a correction value that is necessary for image adjustment Thereby a user can recognize that there exists a method of inputting a correction value manual cor rection value that can be specified from the pattern image as a solving measure when an appropriate amount of deviation cannot be acquired 0096 The output unit may be configured to execute the pattern printing process or notifying process when the auto matic acquiring u
22. justment color are matched at a zero position 0048 FIG 4B shows a printing example where positional deviation occurs by 3 dots to the left In this case the mark of the reference color and the mark of the adjustment color are not matched at the zero position and are matched at 3 posi tion Thereby a user can recognize that positional deviation of 3 dots occurs in the left In this case the user can adjust the positional deviation of the C color by inputting 3 as a cor rection value When positional deviation of 3 dots occurs in the right the user inputs 3 as a correction value In this illustrative embodiment the K color is the reference color and the user can also input correction values for the M and Y colors in the same manner in addition to the C color 0049 In the meantime the configuration of the pattern image 86 is just illustrative and is not limited to the above The pattern image may be a general image pattern that is used to correct the positional deviation For example the mark group including the pattern image 86 is formed at a constant interval in the sub scanning direction vertical direction in FIG 4A so that a user can check the positional deviation of the sub scanning direction 0050 Inthe correction process an actual correction value is determined by using the automatic correction value and the manual correction value which are stored in the NVRAM 34 Based on the actual correction value pro
23. n the automatic correction will be described First when a predetermined execution condition is satisfied registration patterns for positional deviation correction are formed by the respective process units 50 50M 50C 50K The execution condition is determined based on an elapsed time period after a previous acquiring process the number of printed pages environmental changes such as temperature and humidity and a remaining amount of toner for example 0041 Specifically as shown in FIG 3 the registration pattern 66 includes a mark group which has a mark 66K formed by the process unit 50K a mark 66C formed by the process unit 50C a mark 66M formed by the process unit 50M and a mark 66 formed by the process unit 50 which are arranged in a sub scanning direction 0042 The registration pattern 66 is formed at a constant interval in the sub scanning direction a moving direction of the conveyance belt 7 shown in FIG 3 Each of the marks 66K 66C 66M 66Y has a rectangular rod shape and is long in a main scanning direction direction perpendicular to the sub scanning direction 0043 Next based on digitized signals output from the mark sensor 61 positions of the respective marks 66K 66Y 66M 66C are detected Then intervals of marks for example marks 66C 66M 66Y of respective adjustment colors relative to a mark of a reference color for example mark 66K in the sub scanning direction are respectively calculated
24. n is within the permissible range the pattern image for narrow range correction is printed in the pat tern printing process 7 The image forming apparatus according to claim 4 wherein a unit amount of adjustment of the pattern image for wide range correction with respect to a user input is larger than that of the pattern image for narrow range correction
25. n value Thereby a user can recognize that there exists a method of inputting a manual correction value that Dec 29 2011 can be specified from the pattern image 86 as a solving measure when an appropriate amount of positional deviation cannot be acquired In addition the MFP 100 can receive the manual correction that is input by a user and can adjust an image by using the manual correction value s a result it is expected that the deterioration of a quality of an image would be suppressed 0085 While the present invention has been shown and described with reference to certain illustrative embodiments thereof it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims 0086 For example the image forming apparatus is not limited to the In other words the inventive concept of the present invention can be applied to any apparatus having a printing function such as printer copier FAX apparatus and the like In addition the image forming apparatus is not limited to an electro photographic type and may be an inkjet type Further the 100 of the illustrative embodiment is a direct transfer tandem type However the may be an intermediate transfer type or 4 cycle type 0087 In the above illustrative embodiment the has the color printing function However the
26. n value may be input by a user For example JP A 2002 244393 describes a method of using both a correction value input by a user manual correction value and a correction value acquired by detection of a reg istration pattern automatic correction value to correct posi tional deviation in a color image SUMMARY 0005 However the above image forming apparatus has a following problem That is in the image forming apparatus that forms a plurality of registration patterns and detects the registration patterns to automatically acquire amounts of deviation an appropriate amount of deviation cannot be acquired in some cases For example when the amount of positional deviation is too large the registration patterns may be overlapped with each other so that it may be not possible to detect the registration patterns In addition when the trans fer belt has a damaged part or foreign substances they may be falsely detected as a registration pattern When the amount of deviation is calculated under such situations the amount may be inappropriate in some cases In the conventional image forming apparatus when an appropriate amount of deviation cannot be acquired it is not clear for a user how to easily solve the problem 0006 Accordingly it is an aspect of the present invention to provide an image forming apparatus that forms a mark for image adjustment detects the mark to automatically acquire an amount of deviation and can simply solve
27. nabling the manual set ting flag ON will be described below 0058 When the manual setting flag is ON S100 YES a manual acquiring process of acquiring a manual correction value is executed S200 The manual acquiring process will be specifically described below After executing the manual acquiring process the automatic acquiring process ends In the meantime before executing the manual acquiring pro cess it may be asked whether to execute the manual acquiring process so as to execute the manual acquiring process only when an execution instruction is input 0059 On the other hand when the manual setting flag is OFF S100 NO the automatic correction values and the manual correction values are read out from the NVRAM 34 S101 The MFP 100 stores in the ROM 32 an amount of positional deviation before shipment from a factory as an initial amount of deviation The initial amount of deviation is an amount of positional deviation that is inherent to an appa ratus measured for each apparatus when manufacturing the apparatus and is stored in the ROM 32 before shipment The initial amount of deviation is set as the initial value of the automatic correction value In other words the automatic correction value is a value having the initial amount of devia tion added thereto In the meantime zero 0 is set as an initial value of the manual correction value Dec 29 2011 0060 Then the registration pattern 66 is formed on the con
28. nit fails to acquire an amount of deviation When an amount of deviation is not acquired by the automatic acquiring unit it is difficult to cope with the situation only Dec 29 2011 with the automatic acquiring unit Therefore it may be pref erable that an amount of deviation is supplemented by a user input The case where it is failed to acquire an amount of deviation includes a case where an amount of deviation can not be acquired for example positional deviation is great and registration patterns of different colors are overlapped or a case where a failure cause is clear for example a sensor is out of order 0097 Additionally the image forming apparatus may include a storage unit which is configured to store a correction value acquired by a user input based on the pattern image and the automatic acquiring unit may be configured to form the mark based on at least the correction value stored in the storage unit The correction value input by a user is used to form the mark so that it is expected that an appropriate amount of deviation will be acquired by the automatic acquir ing unit from next time 0098 Further the pattern image may include a pattern image for wide range correction and a pattern image for narrow range correction and when an amount of deviation within the permissible range is not acquired by the automatic acquiring unit the pattern image for wide range correction may be printed in the pattern printing pro
29. ocess units 50 50M 50C 50K and upstream from the fixing device 8 with respect to the conveyance direction of the sheet and detects a pattern for image adjustment formed on the conveyance belt 7 0035 Specifically as shown in FIG 3 the mark sensor 61 includes two sensors i e a sensor 61R that is arranged at a right side of a width direction of the conveyance belt 7 and a sensor 61L that is arranged at a left side thereof Each of the sensors 61R 61L is a reflection type optical sensor having a pair of a light emitting element 62 for example LED and a light receiving element 63 for example photo transistor The mark sensor 61 illuminates light to a surface dotted ranges E in FIG 3 of the conveyance belt 7 in an oblique direction by the light emitting elements 62 and receives the light by the light receiving elements 63 respectively The mark sensor can detect a mark 66 for image adjustment mark 66 of FIG 3 is an example of a mark for positional deviation correction by a difference between an amount of reflection light received when the mark for image adjustment passes and an amount of reflection light received that is directly received from the conveyance belt 7 0036 Image Adjustment in MFP 0037 Next the image adjustment in the MFP 100 will be described In the MFP 100 regarding the image adjustment a positional deviation correction that adjusts positions of images of the respective colors and a density deviation
30. onfiguring the image forming unit 10 driving motors of various rollers configuring a conveyance path of a sheet and a moving motor of an image sensor unit configuring the image reading unit 20 through the ASIC 35 while storing results of the processing in the RAM 33 or NVRAM 34 0025 The network interface 36 is connected to a network and enables connection with the other information processing apparatuses The FAX interface 37 is connected to a tele phone line and enables connection with a FAX apparatus of the other party The 100 performs data communication with an external apparatus through the network interface 36 or FAX interface 37 0026 Configuration of Image Forming Unit 0027 Next a configuration of the image forming unit 10 of the MFP 100 will be described with reference to FIG 2 The image forming unit 10 has a process unit 50 that forms a toner image by an electro photographic method and transfers the toner image on a sheet a fixing device 8 that fixes unfixed toner on the sheet a sheet feeding tray 91 that accommodates sheets therein before the image transfer and a sheet discharge tray 92 which receives sheets thereon after the image transfer The image reading unit 20 is arranged above the image form ing unit 10 0028 The image forming unit 10 has an exposure device 53 that illuminates light to the respective process units 50Y 50M 50C 50K a conveyance belt 7 that conveys a sheet to transfer positions of th
31. ow range In other words in S203 as shown in FIG 9 the pattern images of wide range and the pattern images of narrow range are mixed However as described above the pattern image of the narrow range and the pattern image of the wide range have the same appearance except that the intervals of the adjust ment colors are different Accordingly there is little possibil ity to deteriorate user operability 0076 After S203 or S211 an input of a correction value by a user is waited S204 The user inputs a correction value with the operation panel 40 while referring to the sheet on which the pattern images are printed The user inputs a cor rection value for each of the combinations of the adjustment colors and the scanning directions 0077 After that it is determined whether an instruction to complete the input of the correction value is input S205 US 2011 0317175 Al When an instruction to complete the input of the correction value is not input S205 NO it is determined whether a cancel instruction is input S221 When a cancel instruction is also not input S221 NO the process returns to S205 When a cancel instruction is input S221 YES the manual acquiring process ends 0078 When an instruction to complete the input of the correction value is input S205 YES the input values of the respective combinations are acquired and the manual correc tion values corresponding to the respective combinations a
32. re updated S206 In other words the input values are added to the current manual correction values and the results are stored in the NVRAM 34 as new manual correction values After 5206 a retry instruction to print the pattern images is received 5207 0079 When a retry instruction to print the pattern images is received S207 YES the process proceeds to S211 and only the pattern images with narrow range are printed Thereby it is possible to check whether the input correction value is properly reflected on a quality of an image That is when the pattern images of wide range are printed it is difficult to adjust the image in more detail For example when an interval of the adjustment color is set to be narrower by three dots from that of the reference color it is difficult to adjust the image in a precision of three dots or less Accord ingly after performing the adjustment by the wide range the adjustment by the narrow range is performed to allow the image adjustment of high precision When a retry instruction to print the pattern images is not received S207 NO the manual setting flag is turned off S208 and the manual acquiring process ends 0080 Printing Process 0081 Next a sequence of the printing process of printing image data will be described with reference to a flow chart of FIG 10 The printing process is executed by the CPU 31 when a print instruction is received from the operation panel 40 or a print job
33. ropriate amount of positional deviation is acquired S105 YES the amount of positional deviation acquired in S104 is added to the current automatic value and the result is stored in the database 341 as new automatic correction value for each of the combinations of the adjust ment colors and the scanning directions S106 In the mean time there may be set an upper limit value for the automatic correction value If an automatic correction value is greater than the upper limit value an automatic correction value that is adjusted to the upper limit value may be stored Then the amount of adjustment of the pattern image for all combina tions is set with the narrow range S107 After 107 the automatic correcting process ends US 2011 0317175 Al 0065 When an appropriate amount of positional deviation cannot be acquired S105 NO an automatic correction value for a combination for which an appropriate amount of positional deviation can be acquired is at first updated S121 Then the amount of adjustment of the pattern image is set as the narrow range for that combination Then the amount of adjustment for a combination for which an appropriate amount of positional deviation cannot be acquired is set S122 Specifically for a combination for which an amount of positional deviation can be acquired but a value thereof exceeds the predetermined range the wide range is set and for the other combinations for example
34. se amount of deviation is within the permissible range the pat tern image for narrow range correction may be printed in the pattern printing process When the pattern image for wide range correction is used even for a scanning direction for which an amount of deviation that is within the permissible range is acquired even an appropriate scanning direction may be drastically changed Therefore it may be preferable to use the pattern image for wide range correction only for an inap propriate scanning direction 0101 Further a unit amount of adjustment of the pattern image for wide range correction with respect to a user input may be larger than that of the pattern image for narrow range correction In other words regarding a unit amount of adjust ment with respect to a user input value the pattern image for wide range correction has a factor N and the pattern image for US 2011 0317175 Al narrow range correction has a factor M M lt N When a user input is 1 for example the correction value for wide range correction becomes 1xN dots and the correction value for narrow range correction becomes 1xM dots Accordingly the pattern image for wide range correction can approximately determine a correction value with the number of patterns smaller than that of the pattern image for narrow range cor rection so that it is possible to suppress the pattern image from being larger In the meantime the pattern image for narrow range correc
35. st ment color are matched from the marks indicated with the numbers of 12 to 12 regardless of the narrow range or wide range and the layouts of the images are the same Accordingly it is possible to make the input interface of the correction value same regardless of the pattern images so that a user does not have to be aware of the difference between the pattern images 0068 The MFP 100 acquires as the correction value an amount of adjustment Nxinput value dots by a user input At this time for the narrow range the amount of adjustment N is 1 and for the wide range the amount of adjustment N is 3 Thereby for example if a value input by a user is 1 the correction value is 1x1 dot for the narrow range and the correction value is 3x1 dots for the wide range In addition even if the same numerical value is input for the wide range and the narrow range different manual correction values are set The MFP 100 determines the amount of adjustment N by the correctable range or resolution 0069 After S122 the user is inquired whether to execute the manual correction S123 As the inquiring method a message is displayed on the operation panel 40 for example In addition a predetermined information processing appara tus may be caused to display a message Specifically in S123 a message is displayed on the operation panel 40 so as to inquire the user to select whether to input a manual
36. ted The manual correction value is stored in the 34 0046 The 100 prints a pattern image that is referred to when a user inputs a correction value As the pattern image a mark group as shown in FIG 4 or 4B hereinafter referred to as pattern image 86 is printed 0047 In the pattern image 86 of this illustrative embodi ment marks of the same color having a rectangular rod shape are formed at a constant interval in the main scanning direc tion horizontal direction in FIG 4A In the example of FIG 4A the reference color is black color and the adjustment color is cyan C color and an interval of the marks 86C of the adjustment color are narrower than that of the marks 86K of the reference color by N dots N is natural number and N 1 in this illustrative embodiment The marks 86K ofthe reference color are formed as the number 25 in FIGS 4A and 4B corresponding to a permissible range of the manual correc tion value for the adjustment color and numbers 12 to 12 in FIG 4 corresponding to the permissible range are added in ascending order from the left The marks 86C of the adjust ment color is the same as the number of the marks of the reference color and a zero mark is printed so that its position of the main scanning direction is matched with a zero mark of the reference color FIG 4A shows a case where positional deviation does not occur and the mark of the reference color and the mark of the ad
37. tion can finely determine a correction value What is claimed is 1 An image forming apparatus comprising an automatic acquiring unit which is configured to form a mark for detecting at least one of positional deviation and density deviation and acquire an amount of devia tion by measuring the mark an image forming unit which is configured to form an image while adjusting at least one of positional deviation and density deviation based on a correction value speci fied by the amount of deviation and an output unit which is configured to execute at least one of a pattern printing process and a notifying process when an amount of deviation within a permissible range is not acquired by the automatic acquiring unit the pattern printing process including printing a pattern image for specifying a correction value of at least one of positional deviation and density deviation on a recording sheet the notifying process including making notification for prompting execution of the pattern printing process 2 The image forming apparatus according to claim 1 wherein the output unit is configured to execute at least one of the pattern printing process and the notifying process when the automatic acquiring unit fails to acquire the amount of deviation 3 The image forming apparatus according to claim 1 further comprising a storage unit which is configured to store a correction value acquired by a user input based on the pattern image Dec 29 2
38. tional deviation adjustment of the above described image adjustment will be described The MFP 100 adjusts the positional deviation by using both the automatic correction value and the manual correction value 0054 The MFP 100 prompts a user to input the manual correction value when an appropriate amount of deviation cannot be acquired during the automatic acquiring process of acquiring the automatic correction value Specifically a user is asked whether to execute the manual acquiring process of acquiring a manual correction value immediately or later When executing immediately the manual acquiring process is executed immediately On the other hand when executing later a manual setting flag is turned on and the manual acquir ing process is executed when executing a next automatic acquiring process or at any timing by a user 0055 Automatic Correcting Process 0056 Next a sequence of the automatic acquiring process that implements the above operations will be described with a reference to a flow chart of FIG 5 The automatic acquiring process is executed by the CPU 31 when an execution con dition which is determined for automatic correction in advance is satisfied 0057 First it is determined whether the manual setting flag is ON S100 An initial value of the manual setting flag is OFF and the manual setting flag becomes ON when a predetermined condition is satisfied during the automatic acquiring process The condition of e
39. tment colors C M and Y and for each of scanning directions main scanning direction and sub scan ning direction In other words there exist the amounts of positional deviation as the number of combinations of the adjustment colors and the scanning directions Therefore the MFP 100 has a database 341 as shown in FIG 6 in the NVRAM 34 and stores the automatic correction value and the manual correction value for each of the combinations of the adjustment colors and the scanning directions In 105 it is determined whether an appropriate amount of positional deviation can be acquired for all combinations 0063 In the meantime a narrow range and a wide range of the database 341 is a set value for an amount of adjustment of a pattern image In this illustrative embodi ment when the narrow range is set an image pattern with which an amount of positional deviation can be detected by a unit of one dot is formed On the other hand when the wide range is set an image pattern with which an amount of positional deviation can be detected by a unit of three dots is formed That is the pattern image of wide range can approximately determine a correction value with the number of patterns smaller than that of the pattern image of narrow range so that it is possible to suppress the pattern image from being larger In contrast the pattern image of narrow range can finely determine a correction value 0064 When an app
40. veyance belt 7 by using the automatic correction value and the manual correction value which are read out in S101 S102 Then the mark sensor 61 detects the registration pattern 66 S103 Then the amounts of positional deviation of the respective adjustment colors are calculated based on signals from the mark sensor 61 S104 0061 Then it is determined whether an appropriate amount of positional deviation is acquired S105 The appro priateness of the amount of positional deviation is determined based on whether the acquired amount of positional deviation is within a predetermined range The predetermined range is a range within which the positional deviation can be adjusted and is stored in the ROM 32 in advance The case where an appropriate amount of positional deviation cannot be acquired may be a case where the amount of positional devia tion is so large that the adjacent marks are overlapped with each other for example This kind of large amount of posi tional deviation could be caused by an error input of the manual correction value by a user for example In addition when the conveyance belt 7 has a damaged part and the mark sensor 61 falsely detects the damaged part as a mark an inappropriate amount of positional deviation can be caused Also when the mark sensor 61 is out of order even the amount of positional deviation itself cannot be acquired 0062 The amount of positional deviation is determined for each of the adjus
41. wide range is included in the setting of the amounts of adjustment S202 YES the pattern image of wide range is printed for a combination for which the wide range is set and the pattern image of narrow range is printed for a combination for which the narrow range is set on one sheet respectively S203 0075 FIG 9 shows an arrangement example of the respec tive pattern images when printing the pattern images on a sheet In the manual acquiring process there are printed on a sheet 90 a pattern image 86SC for indicating an amount of positional deviation in the main scanning direction of the C color a pattern image 86SM for indicating an amount of positional deviation in the main scanning direction of the M color a pattern image 86SY for indicating an amount of positional deviation in the main scanning direction of the Y color a pattern image 86VC for indicating an amount of positional deviation in the sub scanning direction of the C color a pattern image 86VM for indicating an amount of positional deviation in the sub scanning direction of the M color and a pattern image 86VY for indicating an amount of positional deviation in the sub scanning direction of the Y color In S211 the all pattern images 86SC 86SM 86SY 86VC 86VM 96VY are printed with the narrow range In S203 the pattern image for which the wide range is set is printed with the wide range and the pattern image for which the narrow range is set is printed with the narr

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