Image forming apparatus
Contents
1. is calculated The automatic correc tion values are stored in the NVRAM 34 0043 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 a degree of deviation in the main scanning direction as well as in the sub scanning direction 0044 Inthe meantime the manual correction is executed by auser s operation The operation panel 40 is provided with a switch button for switching into a manual correction mode that enables an input of a correction value A user pushes the switch button inputs a desired correction value and then Dec 29 2011 pushes an OK button When the OK button is pushed the MFP 100 acquires the input value to release the manual correction mode Based on the input value a correction value by the manual correction hereinafter referred to as manual correction value is calculated The manual correction value is stored in the NVRAM 34 0045 The MFP 100 has a pattern printing function of printing a pattern image that is referred to when a user inputs a correction value As the pattern image a mark group as sh2. 7 The image forming apparatus according to claim 1 further comprising a storage unit which is configured to store the past correc tion value of at least one of the automatic correction value and the manual correction value wherein the second changing process returns one of the automatic correction value and the manual correction value to the past correction value stored in the storage unit 8 The image forming apparatus according to claim 1 wherein the automatic acquiring unit is configured to form the mark based on at least one of the automatic correc tion value and the manual correction value 9 The image forming apparatus according to claim 1 wherein the image forming unit is configured to form a pattern image to be referred to at the user input in the manual acquiring unit 10 The image forming apparatus according to claim 9 wherein the image forming unit is configured to form the pattern image based on at least one of the automatic correction value and the manual correction value x ki x
3. 103 DETECT REGISTRATION PATTERNS 104 CALCULATE DEGREE OF DEVIATION DEGREE OF DEVIATION IS WITHIN PREDE TERMINED RANGE 105 NO 121 YES UPDATE AUTOMATIC UPDATE MANUAL CORRECTION VALUE CORRECTION VALUE 122 106 THE NUMBER CONSECUTIVE FAILURES gt THRESHOLD VALUE NO 123 YES NOTIFY ERROR 107 ADJUSTMENT COLOR THAT HAS NOT YET DETERMINED IS REMAINING YES NO END Patent Application Publication Dec 29 2011 Sheet 6 of 8 US 2011 0317182 Al MANUAL ACQUIRING PROCESS READ OUT CORRECTION VALUES PRINT PATTERN IMAGE 203 ee COMPLETE THE INPUT 204 No 5205 YES UPDATE MANUAL CORRECTION VALUE 201 202 FIG 7 PRINTING PROCESS 301 READ OUT CORRECTION VALUES 302 ACQUIRE IMAGE DATA 8303 FORM IMAGE US 2011 0317182 Al Dec 29 2011 Sheet 7 of 8 Patent Application Publication ver ov TANYA OLLVWOLAY 135440 cv B1010 EEE WY ew aoa eA 4 pooo V H LIMS TYANYN 13534 13534 TWANVIN OLLVWOLNY Ob Lv gr cer ler Seb Ecv 8 Dld Patent Application Publication Dec 29 2011 Sheet 8 of 8 US 2011 0317182 Al FIG 9 s HE mane VALUE INITIAL VALUE US 2011 0317182 Al IMAGE FORMING APPARATUS CROSS REFERENCE TO RELATED APPLICATION 0001 This application claims priority from Japanese Patent A
4. the operation panel 40 of the MFP 100 has a liquid crystal panel 41 that displays an oper ating status and the like and a button group 42 that includes numerical keypads an OK button arrow buttons and the like The button group 42 includes an automatic correction value initializing button 421 that initializes the automatic correc tion value a manual correction value initializing button 422 that initializes the manual correction value an automatic correction value reducing button 423 that reduces the weight ofthe automatic correction value a manual correction value reducing button 424 that reduces the weight of the manual correction value an automatic correction value weight increasing button 425 that increases the weight of the auto matic correction value and a manual correction value weight increasing button 426 that increases the weight ofthe manual correction value 0077 Specifically when it is detected that the automatic correction value initializing button 421 is pushed the auto matic correction value stored in the NVRAM 34 is initialized In other words the automatic correction value is returned to the initial degree of deviation that is the degree of positional deviation before shipment ofthe MFP from a factory When it is detected that the manual correction value initializing button 422 is pushed the manual correction value that is stored in the NVRAM 34 is initialized In other words the manual correc tion value is retur
5. form an image based on an actual correction value wherein the actual correction value is determined Dec 29 2011 based on an automatic correction value which is specified based on the degree of deviation acquired by the automatic acquiring unit and a manual correction value which is the correction value acquired by the manual acquiring unit and a changing unit which is configured to execute at least one of a first changing process and the second changing process the first changing process including applying a weight to at least one of the automatic correction value and the manual correc tion value the second changing process including changing at least one of the automatic correction value and the manual correction value into a past correction value 0008 According to the above described configuration there is provided an image forming apparatus that uses both a manual correction value and an automatic correction value to calculate an actual correction value for image adjustment and can easily correct the actual correction value BRIEF DESCRIPTION OF THE DRAWINGS 0009 The above 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 co
6. interface 37 is connected to a tele phone line and enables connection with a FAX apparatus of the other party The MFP 100 performs data communication with an external apparatus through the network interface 36 or FAX interface 37 0025 Configuration of Image Forming Unit 0026 Next a configuration of the image forming unit 10 ofthe 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 ona 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 0027 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 the respective process units 50Y 50M 50C 50K and a mark sensor 61 that detects a pattern image formed on the conveyance belt 7 0028 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 roller
7. is pushed the manual correction value stored in the NVRAM 34 is updated to be 1 2 times of the correction value as a new manual correction value Each time the manual correction value weight increasing button 426 is pushed the weight of 1 2 is applied to the current manual correction value It is noted that the weight that is applied to each correction value is not limited to 1 2 That is any weight can be used inasmuch as it increases a weight of each correction value relative to another correction value 0080 That is in the MFP 100 the automatic correction value and the manual correction value are separately stored in the NVRAM 34 In the second illustrative embodiment the automatic and manual correction values can be changed sepa rately in response to that respective buttons which receive the instructions to change the automatic and manual correction values are pushed Thereby for example when a quality of an image is improved after the operation of reducing the weight of the manual correction value is performed the manual correction value initializing button 422 the manual correction value reducing button 424 or the automatic correc tion value weight increasing button 425 is pushed it is pos sible to recognize that there was an error in the manual cor rection value 0081 In the meantime the MFP 100 may include a back button for returning the automatic correction value to a pre vious value and a back button for returning
8. of toner for example 0040 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 66Y formed by the process unit 50 Y which are arranged in a sub scanning direction 0041 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 0042 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 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 itis possible to specify a degree of deviation of the adjustment color relative to the reference color in the sub scanning direc tion Based on the degree of deviation a correction value by the automatic correction hereinafter referred to as auto matic correction value
9. 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 0035 Image Adjustment in MFP 0036 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 cor rection that adjusts densities of the respective colors are per formed Both image adjustments include an acquiring pro cess of acquiring degrees of deviation of adjustment colors from a reference color and acquiring correction values speci fied by the degrees 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
10. P 100 of the illustrative embodiments by changing the weight of one of the automatic correction value and the manual correction value or returning one correction value to the past value it is possible to change the weights of both the correction values when calculating the actual correction value Accordingly the weight of the inappropriate correction value is reduced for example so that it is expected that an appropriate value will be acquired as an actual correction value In the mean time when the appropriate correction value is changed the deterioration of the image quality could be accelerated In this case it is expected that the inappropriate correction value will be specified Accordingly it is possible to easily adjust the actual correction value that is obtained from the automatic correction value and the manual correction value 0087 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 0088 For example the image forming apparatus is not limited to the MFP 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 formi
11. ROCESS correction value into a past correction value 101 READ OUT CORRECTION VALUES 102 FORM REGISTRATION PATTERN 103 DETECT REGISTRATION PATTERNS 104 CALCULATE DEGREE OF DEVIATION 105 DEGREE OF DEVIATION IS WITHIN PREDE TERMINED RANGE 106 107 YES UPDATE AUTOMATIC CORRECTION VALUE 121 UPDATE CORRECT 122 THRESHO 123 NOTIFY THE NUMBER CONSECUTIVE FAILURES gt MANUAL ON VALUE LD VALUE YES ERROR ADJUSTMENT COLOR THAT HAS NOT YET DETERMINED iS Patent Application Publication Dec 29 2011 Sheet 1 of 8 US 2011 0317182 Al FIG 1 100 IMAGE FORMING UNIT 10 RAM 33 j IMAGE READING i UNIT 20 ASIC 35 OPERATION PANEL 40 FAX I F 37 NETWORK F 36 Patent Application Publication Dec 29 2011 Sheet 2 of 8 US 2011 0317182 Al FIG 2 Patent Application Publication Dec 29 2011 Sheet 3 of 8 US 2011 0317182 Al FIG 3 Patent Application Publication Dec 29 2011 Sheet 4 of 8 US 2011 0317182 Al D co mn N gm ema N Br D zz ZIDI Ezzzzn 86K 86C 86K 86K 86C 86K FIG 4A 10 i pp FIG 4B Dez EEE l eN amara T EIER CA Patent Application Publication Dec 29 2011 Sheet 5 of 8 US 2011 0317182 Al FIG 5 AUTOMATIC ACQUIRING PROCESS 101 READ OUT CORRECTION VALUES 102 FORM REGISTRATION PATTERN
12. US 20110317182A1 a2 Patent Application Publication 10 Pub No US 2011 0317182 Al as United States MURAYAMA et al 43 Pub Date Dec 29 2011 54 IMAGE FORMING APPARATUS 652 US Cl aas aaa ag tian ee Aaa 358 1 9 75 Inventors Kentaro MURAYAMA Kasugai shi JP Osamu TAKAHASHI Nagoya shi JP 57 ABSTRACT 73 Assignee BROTHER KOGYO An image forming apparatus includes an automatic acquiring KABUSHIKI KAISHA unit which forms a mark for detecting at least one of posi Nagoya shi JP tional deviation and density deviation and acquire a degree of deviation by measuring the mark a manual acquiring unit 21 Appl No 13 072 736 which receives a user input to acquire a correction value an image forming unit which forms an image based on an actual 22 Filed Mar 27 2011 correction value determined by an automatic correction value specified based on the degree of deviation and a manual 30 Foreign Application Priority Data correction value which is the correction value acquired by the manual acquiring unit and a changing unit which executes at Jun 28 2010 IP 2010 146571 least one of a first changing process of applying a weight to at ares f least one of the automatic correction value and the manual Publication Classification correction value and the second changing process ofchanging 51 Int Cl at least one of the automatic correction value and the manual HOAN 1 60 2006 01 AUTOMATIC ACQUIRING P
13. adjustment color are not matched at the zero position and are matched at 3 posi tion Thereby a user can recognize that positional deviation of3 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 0048 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 0049 The printing of the pattern image 86 is executed when the switch button is pushed Accordingly a user can determine a correction value by referring to the sheet on which the pattern image 86 is printed In the meantime it may be also possible that the operation panel 40 is provided witha button for printing a pattern image and a user prints the pattern image 86 at any timing 0050 Inthe correction process an actual co
14. cess is executed so that it is expected that the problem will be rapidly solved 0098 The second changing process may initialize one of the automatic correction value and the manual correction value to an initial value thereof The initial value of the auto matic correction value may be a value on which an inherent characteristic of the apparatus measured at manufacturing is reflected In returning the correction value to the past value when one correction value is returned to its initial value if a problematic factor is in the initialized correction value the problem is solved Therefore it is possible to easily specify whether the inappropriate factor is in the automatic correction value or manual correction value 0099 The image forming apparatus may include a storage unit which is configured to store the past correction value of at least one of the automatic correction value and the manual correction value and the second changing process may return one of the automatic correction value and the manual correc tion value to the past correction value stored in the storage unit By changing the correction value to the past correction value it is possible to easily determine that the inappropri ateness has been caused due to which update of the correction values 0100 The automatic acquiring unit may be configured to form the mark based on at least one of the automatic correc tion value and the manual correction value It is exp
15. d Thereby it is possible to change both the correction values at one time and a user can determine which correction value is focused on 0084 In the second illustrative embodiment the auto matic and manual correction values are changed by the button operations of a user When the correction value that is an inappropriate value is changed by the button operation a possibility of improvement in a quality of an image is increased In the meantime when the correction value that is an appropriate value is changed a quality of an image is deteriorated so that it is expected that the correction value that is an inappropriate value can be specified 0085 In addition the automatic or manual correction value is changed when the button is pushed Accordingly the operation is easy and the usability is high In other words although the respective correction values can be also changed by inputting a numerical value when it is intended to appro priately change the weight it is required to know the current correction value Therefore a user should endure inconve nience However as this illustrative embodiment in the operation of changing the weight or returning the correction value to the past value it is possible to appropriately change the increase and decrease of the weight even when a user does not know a specific numerical value of the correction value Accordingly the usability is high 0086 As described above according to the MF
16. d Thus it may be possible to enable an offset value which is a correction value for reflecting the user s preference to be input and to calculate the actual correction value by using the offset value in addition to the automatic correction value and the manual correction value 0092 The present invention provides illustrative non lim iting embodiments as follows 0093 An 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 a degree of deviation by measuring the mark a manual acquiring unit which is configured to receive a user input and acquire a correction value based on the user input an image forming unit which is configured to form an image based on an actual correction value wherein the actual cor rection value is determined based on an automatic correction value which is specified based on the degree of deviation acquired by the automatic acquiring unit and a manual cor rection value which is the correction value acquired by the manual acquiring unit and a changing unit which is config ured to execute at least one ofa first changing process and the second changing process the first changing process including applying a weight to at least one of the automatic correction value and the manual correction value the second changing process including changing at least one of the automatic correction va
17. e correction value that is an inappropriate value is increased the deterioration of the image quality is accelerated That is it is expected that the inappropriate correction value can be specified 0096 The first changing process may apply a weight for reducing a relative weight of the manual correction value with respect to the automatic correction value In addition the second changing process returns the manual correction value to the past correction value thereof A problem of the actual correction value is caused in many cases due to a false input of a user when acquiring the manual correction value Accordingly it is expected that an appropriate actual correc tion value would be acquired by changing the manual correc tion value 0097 The automatic acquiring unit may be configured to form the mark by using at least the manual correction value and the changing unit may be configured to execute the first changing process or second changing process when the degree of deviation acquired by the automatic acquiring unit exceeds a predetermined range For a case where the mark for automatic correction is formed by using the manual correc tion value when the degree of deviation acquired exceeds the predetermined range it is difficult to specify whether a prob lematic factor is in the automatic correction value or manual correction value Accordingly when the automatic correction value exceeds the predetermined range the changing pro
18. e matched at a position of an image of the reference color S303 0073 As described above in the automatic acquiring pro cess the registration pattern is formed by using the manual correction value as well as the automatic correction value Therefore the new automatic correction value obtained in the automatic acquiring process is a value which can appropri ately adjust the degree of deviation while reflecting the manual correction value In the meantime also in the manual acquiring process the pattern image is formed by using the automatic correction value as well as the manual correction value Accordingly the degree of deviation that is checked in the pattern image is a value indicating an appropriate degree of deviation while reflecting the automatic correction value Dec 29 2011 Therefore in the printing process when acquiring the appro priate correction value it is required to use both the automatic correction value and the manual correction value After 303 the printing process ends 0074 In the first illustrative embodiment in performing the automatic correction when the degree of positional devia tion exceeds the predetermined range the manual correction value is reduced and the degree of positional deviation is then re calculated Thereby for example when a user falsely inputs the manual correction value and the degree of posi tional deviation thus exceeds the predetermined range the weight of the manual c
19. e of positional devia tion exceeds the predetermined range may bea case where the degree of positional deviation is so large that the adjacent marks are overlapped with each other This kind of large degree of positional 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 degree of positional deviation can be caused Also if the mark sensor 61 is out of order even the degree of positional deviation itself can not be acquired 0060 For an adjustment color having a degree of posi tional deviation that is within the predetermined range S105 YES the automatic correction value corresponding to the adjustment color is updated S106 Specifically the degree of positional deviation obtained in S104 is added to the cur rent automatic correction value and the result is stored in the NVRAM 34 as a new automatic correction value 0061 In the meantime for an adjustment color having a degree of positional deviation that exceeds the predetermined range S105 NO the manual correction value correspond ing to the adjustment color is changed S121 In this illus trative embodiment the manual correction value of the adjustment color which has a degree of positional deviation that exceeds the predetermined range is multiplied by the weight of 0 5 such that
20. ected that the correction value will be larger due to an aging change Accordingly it is possible to easily cope with the aging change by using the actual correction value at this time US 2011 0317182 Al 0101 Additionally the image forming unit may be con figured to form a pattern image to be referred to at the user input in the manual acquiring unit By this configuration it is possible to perceive a degree of deviation that actually occurs on a printing sheet and to thus input the manual correction value depending on types of the sheet 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 a degree of deviation by measuring the mark a manual acquiring unit which is configured to receive a user input and acquire a correction value based on the user input an image forming unit which is configured to form an image based on an actual correction value wherein the actual correction value is determined based on an auto matic correction value which is specified based on the degree of deviation acquired by the automatic acquiring unit and a manual correction value which is the correc tion value acquired by the manual acquiring unit and a changing unit which is configured to execute at least one of a first changing process and the second changing process the first changing proc
21. ess including applying a weight to at least one of the automatic correction value and the manual correction value the second changing process including changing at least one of the automatic correction value and the manual correction value into a past correction value 2 The image forming apparatus according to claim 1 wherein the first changing process applies a weight for reducing a relative weight of the manual correction value with respect to the automatic correction value 3 The image forming apparatus according to claim 1 wherein the second changing process returns the manual correction value to the past correction value thereof Dec 29 2011 4 The image forming apparatus according to claim 1 wherein the automatic acquiring unit is configured to form the mark by using at least the manual correction value and wherein the changing unit is configured to execute the first changing process or second changing process when the degree of deviation acquired by the automatic acquiring unit exceeds a predetermined range 5 The image forming apparatus according to claim 1 wherein the second changing process initializes one of the automatic correction value and the manual correction value to an initial value thereof 6 The image forming apparatus according to claim 5 wherein the initial value of the automatic correction value is a value on which an inherent characteristic of the apparatus measured at manufacturing is reflected
22. hat has been not yet determined is still remaining S107 YES the process is returned to S105 and the degree of positional devia tion of the adjustment color that has been not yet determined US 2011 0317182 Al is determined When the determination of S105 is completed for all adjustment colors S107 NO the automatic acquiring process ends 0064 Manual Correction Process 0065 Next a sequence of the manual acquiring process that is an acquiring process for manual correction will be described with reference to a flow chart of FIG 6 The manual acquiring process is executed by the CPU 31 when the switch button provided in the operation panel 40 is pushed 0066 First the automatic correction value and the manual correction value are read out from the NVRAM 34 S201 Then the pattern image 86 is printed on a sheet by using the automatic correction value and the manual correction value which are read out in S201 S202 After S202 an input ofa correction value by a user is waited The user inputs a correc tion value with the operation panel 40 0067 After that it is determined whether an instruction to complete the input of the correction value is input S203 When an instruction to complete the input of the correction value is not input S203 NO it is determined whether a cancel instruction is input S211 When a cancel instruction is also not input S211 NO the process is returned to S203 When a cancel instructio
23. image of a sheet and an operation panel 40 that displays an operation situation and receives an input operation by a user 0022 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 0317182 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 MFP 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 0023 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 ofthe MFP 100 for example a turn on timing of an exposure device configuring the image forming unit 10 driving motors of various rollers configuring aconveyance path ofa sheet anda 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 0024 The network interface 36 is connected to a network and enables connection with the other information processing apparatuses The FAX
24. ion value and the manual cor rection value are read out from the NVRAM 34 S101 The MFP 100 stores as an initial degree of deviation a degree of positional deviation before shipment from a factory in the ROM 32 The initial degree of deviation is a degree of posi tional deviation that is inherent to an apparatus measured for each apparatus when manufacturing the apparatus and is stored in the ROM 32 before shipment The initial degree 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 degree of deviation added thereto In the meantime zero is set as an initial value of the manual correction value 0058 Then the registration pattern 66 is formed on the conveyance belt 7 by using the automatic correction value and the manual correction value which are read out in S101 Dec 29 2011 S102 Then the mark sensor 61 detects the registration pattern 66 S103 Then the degrees of positional deviation of the respective adjustment colors are calculated based on sig nals from the mark sensor 61 S104 0059 Then it is determined whether the degree of posi tional deviation of each adjustment color which is obtained in 104 is within a predetermined range S105 The predeter mined range is a range within which the positional deviation can be adjusted and which is stored in the ROM 32 in advance For example the case where the degre
25. ise 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 0032 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 Y 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 50K 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 0033 The mark sensor 61 is provided downstream from the process units 50 Y 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 0034 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
26. llowing problem That is in the image forming apparatus that uses both the manual correction value and the automatic correction value to calculate an actual correction value which is a final correction value and performs the image adjustment based on the actual correction value it is difficult to adjust the actual correction value For example when a quality of an output image is poor i e when the actual correction value is problematic it is difficult to specify whether the problematic factor of the actual correction value is in the manual correc tion value or automatic correction value and therefore it is difficult to appropriately correct the actual correction value 0006 Accordingly it is an aspect of the present invention to provide an image forming apparatus that uses both a manual correction value and an automatic correction value to calculate an actual correction value for image adjustment and can easily correct the actual correction value 0007 According to an illustrative embodiment of the present invention there is provided an image forming appa ratus comprising an automatic acquiring unit which is con figured to form a mark for detecting at least one of positional deviation and density deviation and acquire a degree of devia tion by measuring the mark a manual acquiring unit which is configured to receive a user input and acquire a correction value based on the user input an image forming unit which is configured to
27. lue and the manual correction value into a past correction value 0094 The image forming apparatus according to the above configuration forms an image based on both the auto matic correction value and the manual correction value The image forming apparatus can change at least one of the auto matic correction value and the manual correction value Spe cifically regarding the changing process the image forming apparatus can execute at least one of a first changing process of applying a weight to at least one of the automatic correction value and the manual correction value and a second changing process of changing one of the automatic correction value and the manual correction value into a past correction value which may be an initial value A condition for executing the changing process may include detecting an inappropriate value as a correction value and a user instruction through a panel operation for example Dec 29 2011 0095 That is according to the image forming apparatus at least one of the automatic correction value and the manual correction value is applied with a weight or is changed into the past value so that relative weight of the correction values in the actual correction value is changed Thereby for example by reducing the weight of the correction value that is an inappropriate value it is expected that the actual correc tion value will become closer to an appropriate value In contrast when the weight of th
28. n is input S211 YES the manual acquiring process ends 0068 When an instruction to complete the input of the correction value is input S203 YES input values of the respective adjustment colors which are input as correction values are acquired S204 Then the manual correction values ofthe respective adjustment colors are updated S205 Specifically the input value is added to the current manual correction value and the result is stored it in the NVRAM 34 as a new manual correction value After S205 the manual acquiring process ends 0069 Printing Process 0070 Next a sequence of the printing process of printing image data will be described with reference to a flow chart of FIG 7 The printing process is executed by the CPU 31 when a print instruction is received from the operation panel 40 or a print job is received from an information processing appa ratus connected to the MFP 100 0071 First the automatic correction value and the manual correction value from the NVRAM 34 S301 Then image data to be printed is acquired S302 The processes of S301 and S302 may be executed in a reverse order or at the same time 0072 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 ar
29. ned to zero US 2011 0317182 Al 0078 When it is detected that the automatic correction value reducing button 423 is pushed the automatic correction value stored in the NVRAM 34 is updated to be 0 8 times of the correction value as a new automatic correction value Each time the automatic correction value reducing button 423 is pushed a weight of 0 8 is applied to the current automatic correction value When it is detected that the manual correc tion value reducing button 424 is pushed the manual correc tion value stored in the NVRAM 34 is updated to be 0 8 times of the correction value as a new manual correction value Each time the manual correction value reducing button 424 is pushed a weight of 0 8 is applied to the current manual correction value It is noted that the weight that is applied to each correction value is not limited to 0 8 That is any weight can be used inasmuch as it reduces a weight of each correction value relative to another correction value 0079 When it is detected that the automatic correction value weight increasing button 425 is pushed the automatic correction value stored in the NVRAM 34 is updated to be 1 2 times of the correction value as a new automatic correction value Each time the automatic correction value weight increasing button 425 is pushed the weight of 1 2 is applied to the current automatic correction value When it is detected that the manual correction value weight increasing button 426
30. nfiguration ofan 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 0014 FIG 5 is a flow chart showing a sequence of an automatic acquiring process according to a first illustrative embodiment 0015 FIG 6 is a flow chart showing a sequence of a manual acquiring process according to the first illustrative embodiment 0016 FIG 7 is a flow chart showing a sequence of a printing process according to the first illustrative embodi ment 0017 FIG 8 shows an operation panel according to a second illustrative embodiment and 0018 FIG 9 shows a history information database DETAILED DESCRIPTION 0019 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 0020 Configuration of MFP 0021 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
31. ng apparatus is not limited to an electro photographic type and may be an inkjet type Further the MFP 100 in the above illustrative embodi US 2011 0317182 Al ments isa direct transfer tandem type However the MFP may be an intermediate transfer type or four cycle type 0089 Inthe above illustrative embodiments the MFP has the color printing function However the 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 0090 In the above illustrative embodiments the pattern image is printed on the sheet when performing the manual acquiring process However a configuration of receiving an input from a user without performing such printing may be also possible In addition when printing the pattern image a type of the sheet may be designated 0091 In the above illustrative embodiments the final actual correction value is calculated by using the automatic correction value and the manual correction value However the parameters for calculating the actual correction value are not limited thereto For example in the illustrative embodi ments after the automatic correction the content of the auto matic correction has the priority over the manual correction value that is input by the user Accordingly even when the user wants to intentionally cause the deviation the content thereof is not reflecte
32. of the respective colors are adjusted to maintain a target density based on the actual correction value 0052 Sequence of Changing Correction Value 0053 Next a process of changing the automatic and manual correction values will be described The MFP 100 can change the automatic correction value and the manual cor rection value which are stored in the NVRAM 34 by another way than the process of updating the correction values by the above described acquiring processes for the respective cor rection values Specifically the MFP 100 has an automatic changing function of automatically changing the correction values by the MFP 100 itself and a manual changing function of changing the correction values by a user s instruction First Illustrative Embodiment 0054 The first illustrative embodiment relates to the auto matic changing function In the automatic changing function when an inappropriate degree of positional deviation is acquired during the acquiring process of the automatic cor rection value the manual correction value is automatically changed 0055 Automatic Correction Process 0056 First a sequence of an automatic acquiring process that is an acquiring process for automatic correction will be described with reference to a flow chart of FIG 5 The auto matic acquiring process is executed by the CPU 31 when a predetermined execution condition for automatic correction is satisfied 0057 The automatic correct
33. orrection value is reduced so that it is expected that the degree of positional deviation will become closer to a degree of positional deviation for which the posi tional deviation can be adjusted When the degree of posi tional deviation after the re calculation is within the prede termined range it is possible to acquire the automatic correction value That is even when there occurs a false input in the manual correction value it is possible to complement it with an appropriate amount of correction by the automatic correction value Accordingly a possibility of improvement in a quality of an image is increased In the meantime in a case where the degree of positional deviation exceeds the predetermined range due to the failure of the mark sensor 61 or the conveyance belt 7 it is not expected that the degree of positional deviation will become closer to an appropriate degree of positional deviation even when the manual correc tion value less affects Accordingly it is possible to assume that the problem is not caused due to the false input by a user In this case it is possible to notify a detailed handling method by an error message and the like Second Illustrative Embodiment 0075 The second illustrative embodiment relates to the manual changing function In the manual changing function the automatic and manual correction values are changed at any timing by a panel operation that is performed by a user 0076 As shown in FIG 8
34. own in FIG 4A or 4B hereinafter referred to as pattern image 86 is printed 0046 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 K 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 of the 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 adjustment color are matched at a zero position 0047 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
35. positional deviation correction 0037 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 0317182 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 0038 In the automatic correction a registration pattern that is a pattern image for detecting a degree of positional deviation and the mark sensor 61 detects the registration pattern and thus calculates a degree of deviation A correction value based on the degree 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 0039 Here a sequence of acquiring the correction value in 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 Y 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
36. pplication No 2010 146571 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 adjusts a position or density of an image based on at least one of a correction value obtained by detection of the mark and a correction value input by a user 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 a degree of deviation between the registration pattern of a basic color and the reg istration 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 degree of deviation 0004 A correction 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 obtained by detection ofa reg istration pattern automatic correction value to correct posi tional deviation of each color image in a color image SUMMARY 0005 However the above image forming apparatus has a fo
37. rrection 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 process conditions for example exposure position speed of the conveyance belt 7 or US 2011 0317182 Al 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 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
38. s 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 0029 The process unit 50 can form a color image and includes the process units corresponding to respective colors of yellow Y magenta M cyan C and black K 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 M color the process unit 50C that forms an image of a C color and the process unit 50K that forms an image of a K color The respective process units 50Y 50M 50C 50K are arranged at a predetermined interval in a con veyance direction of the sheet 0030 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 photosensitive 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 0031 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 counterclockw
39. the manual cor rection value to a previous value at the operation panel 40 and may perform a changing process of returning the automatic and manual correction values to the past values In this case the MFP 100 has a correction value history database 341 that stores past values as shown in FIG 9 The correction value history database 341 stores past values for each of the correc tion values 0082 When the back button for an automatic correction value is pushed the automatic correction value is returned to amost recent past value of the automatic correction value that is currently selected When the back button for a manual correction value is pushed the manual correction value is returned to a most recent past value of the manual correction value that is currently selected Thereby when a quality of an Dec 29 2011 image is improved after the back button for a manual correc tion value is pushed for example it is possible to recognize that there was an error in the manual correction value In addition it is possible to determine which update timing of correction value the inappropriateness is caused by sequen tially returning the correction value to the past value 0083 In the above it may be also possible that the weights which are respectively applied to the automatic and manual correction values are individually input and different weights are respectively applied to both the correction values when the OK button is pushe
40. the manual correction value becomes closer to zero In the meantime the weight that is applied to the manual correction value is not limited to 0 5 That is any weight can be used inasmuch as it reduces a weight of the manual correction value relative to the automatic correction value For example the manual correction value may be returned to zero that is the initial value thereof 0062 After that it is determined whether the number of consecutive failures is greater than a threshold value S122 When the number of consecutive failures is smaller than or equal to the threshold value S122 NO the process is returned to S102 Then a registration pattern is formed again by using the manual correction value changed in S121 anda degree of positional deviation is calculated again That is the degree of positional deviation is re calculated while the weight of the manual correction value is reduced In the meantime when the number of consecutive failures is greater than the threshold value S122 YES an error notification is issued which indicates that acquisition of the automatic cor rection value is failed S123 The notification may be mes sage display on a display unit of the operation panel 40 or generation of an alarm sound and writing of an error log for example 0063 After S106 or S123 it is determined whether an adjustment color that has been not yet determined in S105 is still remaining S107 When an adjustment color t
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