Source: https://patents.google.com/patent/CN101284459A/en
Timestamp: 2020-08-14 12:19:23
Document Index: 123665952

Matched Legal Cases: ['arts 3', 'arts 3', 'arts 3', 'arts 3', 'arts 3', 'arts 3', 'arts 3']

CN101284459A - Printing apparatus and the method of acquiring correction value of conveying error - Google Patents
Printing apparatus and the method of acquiring correction value of conveying error Download PDF
CN101284459A
CN101284459A CNA2008100897384A CN200810089738A CN101284459A CN 101284459 A CN101284459 A CN 101284459A CN A2008100897384 A CNA2008100897384 A CN A2008100897384A CN 200810089738 A CN200810089738 A CN 200810089738A CN 101284459 A CN101284459 A CN 101284459A
CNA2008100897384A
CN101284459B (en
2008-10-15 Publication of CN101284459A publication Critical patent/CN101284459A/en
2012-01-25 Publication of CN101284459B publication Critical patent/CN101284459B/en
238000007639 printing Methods 0.000 title claims description 78
238000005755 formation reactions Methods 0.000 claims description 13
239000000976 inks Substances 0.000 description 27
While a conveying error of a roller depends on the eccentricity of the roller, the amount and the state of the eccentricity sometimes makes the roller have different conveying errors from one point in the longitudinal direction of the roller to another. There is provided a construction for obtaining a correction value that is suitable for the correction of the conveying error even in such a case as described above. To this end, plural test patterns are formed in the longitudinal direction of the roller. Then, a suitable correction value for correcting the conveying error that depends on the eccentricity of the roller is obtained on the basis of these test patterns.
Ink jet printing device has printhead, and printhead has the fine nozzle array, and discharges China ink according to print data from each nozzle.The China ink of discharging forms on print media a little to form image.Therefore, in order to form high quality graphic, it is very important that the position of wanting on print media forms point.Must avoid a displacement that forms the position as much as possible.The some of them of a variety of causes of this offset deviation are: the NF of the vibration of the difference of shape between the nozzle of printhead, the equipment that takes place when just printing etc. and the distance between print media and the printhead.Inventor of the present invention finds: the one of the main reasons that point forms this offset deviation of position is to carry print media to lack precision.Roller (conveying roller) is one of supply unit of normally used print media.Can this conveying roller be pressed on the print media by conveying roller being rotated specified angle, realize print media is carried desired distance.Here, the delivery precision of print media depends on the off-centre of conveying roller largely.
Utilize the conveying roller of the oval cross-section shape shown in Figure 34 A and the 34B to obtain adverse consequences.Even when conveying roller rotated equal angular R, this class conveying roller also provided different conveying capacities.Difference on the conveying capacity depends on the turned position of conveying roller.More specifically, for the turned position shown in Figure 34 A, the conveying capacity of print media is L1, and for the another location shown in Figure 34 B, the conveying capacity of print media is L2.Here, length L 0, L1 and L2 have the relation of L1＞L0＞L2.That is to say that cyclically-varying has taken place the conveying capacity of print media, and this variation depends on the cycle of conveying roller.
Alternatively, with the same in the situation of Figure 35, the turning cylinder of conveying roller with will may cause of the cycle generating period variation of the conveying capacity of print media sometimes for the skew of the central shaft O of turning cylinder corresponding to conveying roller.More specifically, suppose such situation: turning cylinder and central shaft O skew, and turning cylinder is positioned at some A shown in Figure 35 or some B.In these cases, identical rotational angle α produces different conveying capacities.This species diversity of conveying capacity causes carrying the cyclically-varying of print media.Here, this variation depends on the cycle of conveying roller.
The off-centre of above-mentioned roller comprises above-mentioned these states.Particularly, comprise that roller has state and the turning cylinder of conveying roller and the state of central shaft skew of the transverse shape of imperfect circle.Under the situation of the perfect precision that in conveying, realizes, should be with the mode print image as shown in the schematic diagram of Figure 36 A.Yet because above-mentioned off-centre, the image of printing will become inhomogeneous image shown in Figure 36 B, striped periodically occurs on throughput direction, and should the cycle with rotate the conveying capacity in a week corresponding to conveying roller identical.
Usually the offset of conveying roller is controlled to keep within the specific limits.The standard of offset is strict more, and the productivity ratio of conveying roller (yielding) is just low more.Therefore, the PRN device of producing like this becomes more expensive.Because this reason, the standard of the undue strictness of offset is worthless.
In order to address the above problem, various measures have been proposed.The corrected value of different convey errors is set at the out of phase of conveying roller, even thereby eccentric conveying roller also can have desirable circle transverse shape with conveying roller and its turning cylinder is similar with the situation that central shaft aligns just, realizes stable conveying capacity (TOHKEMY 2006-240055 and TOHKEMY 2006-272957).More specifically, can have the periodic function of same period and opposite polarity, proofread and correct the amplitude of fluctuation of conveying capacity that equals the girth of conveying roller with the reduction cycle by application.
Suppose in the predetermined design allowable deviation and make conveying roller.Even in this case, since the convey error that factors such as offset and eccentric state cause roller axially on position and another location between sometimes also may be different.Can the A3 size (297mm * 420mm) or in the large-scale ink jet printing device that prints on the bigger print media P employed roller trend towards that employed roller has more significant difference in the equipment than other type.Therefore, for the corrected value that the precalculated position obtained is used to proofread and correct the convey error that off-centre causes of conveying roller be not be always adapted to conveying roller axially on other position.
Controller is used for the axially a plurality of test patterns of formation on described print media along described roller, and wherein, described a plurality of test patterns are used to detect the convey error of described roller; And
The corrected value acquiring unit is used for the corrected value that is used to proofread and correct described convey error by using described test pattern, obtaining.
Another aspect of the present invention, a kind of method that is used to obtain corrected value is provided, described method is applied to comprise the PRN device of the roller that is used for carrying print media, and described corrected value is used to proofread and correct the convey error that is caused by described roller, said method comprising the steps of:
Along the axially a plurality of test patterns of formation on described print media of described roller, wherein, described test pattern is used to detect the described convey error of described roller; And
By using described a plurality of test pattern, obtain in order to proofread and correct the described corrected value of described convey error.
According to the present invention, even when roller axially on a point when there is the difference of convey error in another point, also can based on roller axially on formed a plurality of test patterns obtain the best corrected value of rollers, wherein, caused error depends on the offset and the eccentric state of roller.
Fig. 2 schematically shows the key diagram that forms face one side, the printhead that adopts embodiment illustrated in fig. 1 from nozzle;
Fig. 6 A and 6B are the key diagrams that is used to illustrate the different conditions of carrying print media;
Fig. 6 C is used to illustrate from the upstream side supply unit discharge print media is also only carried the state of this print media by the downstream supply unit key diagram;
Fig. 7 is used for the whole print area with print media is divided into the key diagram that the aspect in following two kinds of zones describes: a kind of zone, on this zone, utilize that related upstream side supply unit prints in the action of carrying print media; With another kind of zone, on this zone, by only carrying print media to print by the downstream supply unit;
Fig. 9 is used to illustrate the key diagram that how to use the method for nozzle when forming test pattern;
Figure 10 A～10E is the key diagram that is used to illustrate the method for the speckle (patch) that how to use upstream side nozzle sets NU and downstream nozzle sets ND to form test pattern or formation test pattern;
Figure 11 A and 11B are respectively separately by single main scanning benchmark speckle key element group of printing and the key diagram of adjusting speckle key element group;
Figure 12 is the key diagram that the test pattern that comprises one group of speckle is shown, and wherein, constitutes each speckle by benchmark speckle key element and adjustment speckle key element, and Figure 12 illustrates one of them of four test patterns shown in Figure 5 in the amplification mode;
Figure 13 is the key diagram that the benchmark speckle key element of amplification is shown or adjusts the speckle key element;
Figure 14 is the key diagram that the speckle key element of Figure 13 is shown in further amplification mode;
Figure 15 A and 15B are the key diagrams that is used to illustrate the change in concentration that is caused by the interference between benchmark speckle key element and the adjustment speckle key element;
Figure 16 A and 16B are the key diagrams that is used for illustrating the problem that causes owing to the injection failure that is taken place at the employed nozzle of formation test pattern;
Even Figure 17 A and 17B are used for illustrating that employed test pattern also can be alleviated the key diagram of this problem among this embodiment when the injection failure that forms the employed nozzle of test pattern causes problem;
Figure 20 is the key diagram that the difference of the convey error of each value of n and their mean value is shown;
Figure 22 A and 22B are the key diagrams that illustrates when forming a plurality of test pattern on main scanning direction in order to two examples that obtain the processing that final eccentric correction value carried out;
Figure 24 be used to illustrate external diameter corrected value generation error key diagram;
Figure 25 is used to illustrate that the external diameter corrected value changes the key diagram of this situation according to the order of obtaining the eccentric correction value and obtaining the external diameter corrected value;
Figure 26 is used to illustrate the key diagram that is used to store the method for eccentric correction value according to this embodiment;
Figure 28 is used to illustrate the key diagram that is used for the eccentric correction value is applied to carry the method for control;
Figure 32 is the key diagram that is used to illustrate the optional method that forms the speckle that constitutes test pattern;
Figure 36 A and 36B are respectively the key diagrams that has and do not have the uneven image that the off-centre owing to conveying roller causes.
Describe the present invention in detail below with reference to accompanying drawing.
Fig. 1 illustrates the integrally-built perspective schematic view of ink jet printing device according to an embodiment of the invention.When printing, print media P is kept by conveying roller 1 and hold-down roller 2 and remains between these two rollers, and wherein, conveying roller 1 is arranged in a plurality of rollers on the transport path, and hold-down roller 2 is driven and driven by conveying roller 1.Rotation by conveying roller 1 guides print media P on platen parts 3.Carry print media P on the direction shown in the arrow A in Fig. 1, print media P is supported on the platen parts 3 simultaneously.Although in Fig. 1, do not illustrate, pressure-producing parts such as spring are set so that hold-down roller 2 elasticity press conveying roller 1.Conveying roller 1 and hold-down roller 2 are supply unit assemblies of upstream side.
Platen parts 3 are arranged in and the relative print position place of the face that forms jet in the printhead 4 set with the form of ink jet-print head (following this face is called " jet face ").The platen parts 3 that are provided with are like this supported the back side of print media P, to keep constant or preset distance between the upper surface of print media P and jet face.
In case print being transported on the print media P of platen parts 3, then remain on the distributing roller 12 of rotation and the print media P between the ratchet roller 13 carrying on the direction A, wherein, ratchet roller 13 is driven and driven by distributing roller 12.Like this print media P is expelled to output pallet 15.Distributing roller 12 and ratchet roller 13 are assemblies of the supply unit in downstream.Should be noted that Fig. 1 only illustrates list to distributing roller 12 and ratchet roller 13 in a row, but as hereinafter described, two pairs of distributing rollers 12 and ratchet roller 13 in a row can be set also.
Relative with jet face with platen parts 3 or print media P, printhead 4 removably is assemblied on the balladeur train 7.By drive source is Motor Drive balladeur train 7, to move back and forth along two guide rails 5 and 6.Printhead 4 can carry out the ink-jet action during moving back and forth.The direction that balladeur train 7 moves is intersected with the direction (direction shown in the arrow A) of carrying print media P.Usually this direction is called " main scanning direction ", and will carries the direction of print media P to be called usually " sub scanning direction ".By repeating to replace the main scanning (print scanned) and the conveying print media P (subscan) of balladeur train 7 or printhead 4, the image that prints on the medium is printed.
As printhead 4, for example, can adopt the printhead that comprises the element (example of this class component has heating resistive element) that is used to generate the employed heat energy of ink-jet.This heat energy makes the state of China ink change (that is to say, the film boiling (filmboiling) of China ink takes place).As another example, can adopt comprise in order to the element that generates mechanical energy as the element that is used to generate energy printhead.The example of this class component has piezoelectricity (piezo) element.The mechanical energy of Sheng Chenging is used for ink-jet thus.
The PRN device of this embodiment utilizes the pigment inks of ten kinds of colors to form image.These ten kinds of colors are: cyan (C), nattierblue (Lc), magenta (M), shallow magenta (Lm), yellow (Y), first black (K1), second black (K2), red (R), green (G) and grey (Gray).When using term " K China ink ", be to say first black (K1) China ink or second black (K2) China ink.Here, first and second black ink (K1 and K2) can be respectively to be used for going up the photograph black ink of printing the gloss image and the mute light black ink that is suitable for matt solid matte paper (matt coated paper without gloss) at glossy paper (glossy paper).
In one of them of this two substrates, specifically, in type element substrate H3700, form nozzle array H3200, H3300, H3400, H3500 and H3600, with utilize provide separately grey, light cyan, first black, second black and shallow magenta ink carry out ink-jet.Simultaneously, at these two substrates wherein in another, particularly, in type element substrate H3701, form nozzle array H2700, H2800, H2900, H3000 and H3100, carry out ink-jet so that the cyan, redness, green, magenta and the yellow ink that provide separately to be provided.Form each nozzle array by 768 nozzles, wherein, with the nozzle that is spaced of 1200dpi (point/inch), and each nozzle array sprays the ink droplet of about 3 skin liters (picoliter) on the direction of carrying print media P.Each nozzle has the about 100 μ m of aperture area 2Jet.
Above-mentioned header structure makes it possible to carry out so-called " printing (one-passprinting) ".In this Method of printing, in the single main scanning, finish the printing on the single zone of print media P.Yet,, can also adopt so-called " multiple-pass printing (multi-pass printing) " in order to improve print quality by the negative effect that reduces the nozzle that inhomogeneities forms.Under this printing model,, finish the printing on the single scanning area of print media P by carrying out repeatedly main scanning.When having selected multiple-pass printing, suitably determine pass by considering conditions such as printing model.
Removably independently be installed in the printhead 4 with the corresponding a plurality of accumulators of the color of employed China ink.Alternatively, can be from the corresponding accumulator of a certain position being fixed on this equipment, the feed pipe by separately provides China ink to printhead 4.
Recovery unit 11 is set to make it jet face towards printhead 4.Position in the zone that recovery unit 11 is arranged on that printhead 4 can arrive when printhead 4 is mobile on main scanning direction.This position is positioned at the outside of the lateral section of print media P or platen parts 3.That is to say that this position is in the zone of not carrying out the image printing.Recovery unit 11 has well-known structure.Particularly, recovery unit 11 comprises the cap portion of the jet face that is used to cover printhead 4, is the China ink that is used to aspirate the jet face that the is capped aspirating mechanism with the China ink of forcing to aspirate out printhead 4.Recovery unit 11 also comprises the cleaning balde in order to the contaminated jet face of wiping in other parts.
Fig. 3 illustrates the example of structure according to the major part of the control system of the ink jet printing device of this embodiment.According to this embodiment, the each several part of 100 pairs of ink jet printing devices of controller is controlled.Controller 100 comprises CPU 101, ROM 102, EEPROM 103 and RAM 104.CPU 101 comprises the various calculation process and the judgement of the processing described processing procedure in back, relevant with printing action etc.In addition, CPU 101 carries out and relevant processing such as print data.ROM 102 storages and the performed processing procedure corresponding programs of CPU101, and store other fixed data.EEPROM 103 is nonvolatile memories, and, even when closing PRN device, also be used to keep tentation data.Print data that RAM 104 interim storages provide from the outside and the print data of launching according to the structure of this equipment.The workspace of the calculation process that RAM 104 is carried out as CPU 101.
Interface (I/F) 105 is set PRN device is connected to outside main equipment 1000.Between interface 105 and main equipment 1000, carry out two-way communication based on predetermined protocol.Should be noted that well-known form such as utilizing computer is provided with main equipment 1000.Main equipment 1000 is as the source of supply of print data, and the printing of the PRN device of this embodiment action is based on this print data.In addition, with printed driver---make PRN device carry out the program of printing action and be installed in the main equipment 1000.More specifically, send print data and carry out print setting informations such as kinds of information from printed driver based on the print media P of the printing of print data.Also send the control command that PRN device is controlled the action of this equipment from printed driver.
Linear encoder 106 is set to detect the position of printhead 4 on main scanning direction.Appropriate position in the path of carrying print media P is provided with thin slice sensor 107.By utilizing the front-end and back-end of thin slice sensor 107 detection print media P, can determine the transfer position (subscan position) of print media P.Motor driver 108 is connected with controller 100 with head drive circuit 109 with 112.Motor driver 108 drives the conveying motor 110 as the drive source of carrying print media P under the control of controller 100.By transmission mechanisms such as gears driving force is passed to conveying roller 1 and distributing roller 12 from carrying motor 110.Motor driver 112 drives the carriage motor 114 as the drive source that moves of balladeur train 7.By synchronous band transmission mechanisms such as (timing belt) driving force is passed to balladeur train 7 from carriage motor 114.Under the control of controller 100, head drive circuit 109 drives printhead 4 to carry out ink-jet.
Read sensor 120 detector as the concentration that is used to detect the image of printing on print media P is set.Can be with along printhead 4 or replace the form that printhead 4 is assemblied in the read head on the balladeur train 7 read sensor 120 is set.Alternatively, can be independent of PRN device shown in Figure 1 and the image-reading device that constitutes is provided with read sensor 120 with fuselage.
In having the PRN device of said structure, one of maximum reason that reduces delivery precision is the off-centre of roller.The off-centre of definition roller is a kind of like this state: the turning cylinder of roller and the skew of the central shaft of roller that is to say that the axle of the center of rotation of roller departs from the geometrical central axis of roller.In addition, off-centre is defined as roller and has a kind of like this state of transverse shape that is not desirable circle.The off-centre of roller causes periodically convey error, and this cycle depends on the rotational angle that begins from the reference position of roller.Suppose and have this class off-centre.In this case, even when the live-rollers equal angular, the length (arc length) of rotating on the corresponding circumferencial direction with equal angular is also different mutually.As a result, on the conveying capacity of print media P, produce error.The error of Chan Shenging has hindered on the throughput direction of print media P and has formed point in the position that should form a little like this.On the throughput direction of print media P, the point that forms in some zones is dense, and sparse in other zone.In a word, to equal to rotate with roller the cycle of corresponding conveying capacity of a week, the inhomogeneous of printing taken place.
Another example that reduces the main cause of delivery precision is the caused reason of external diameter error owing to roller.Suppose this class external diameter error that has roller.In this case, though when live-rollers when having the determined rotational angle of roller of special datum external diameter, can not always obtain the predetermined conveying capacity that should obtain.More specifically, when using external diameter greater than the roller of basic major diameter, conveying capacity becomes greater than the conveying capacity that should obtain.In this case, white stripes (stripe) may take place in print image.On the contrary, when using external diameter less than the roller of basic major diameter, conveying capacity becomes less than the conveying capacity that should obtain.In this case, in print image blackstreak may take place.
Fig. 4 is the flow chart that the overview of the processing procedure that is used to obtain eccentric correction value and external diameter corrected value is shown.In this process, at first, prepare to start the setting that comprises print media P and give the printing action of sending (step S9).When print media P is delivered to the precalculated position of printing, printing test pattern (step S11).Utilize these test patterns, can detect simultaneously because the error of eccentric and the caused conveying capacity of external diameter error (below, also be referred to as " convey error "), and the back will provide the detailed description of test pattern.
Fig. 5 illustrates the example of employed test pattern among this embodiment.In this embodiment, with the corresponding direction of the throughput direction of print media P on, that is, on sub scanning direction, mutually form side by side in order to detect because the test pattern of the test pattern of the convey error that conveying roller 1 causes and the convey error that causes owing to distributing roller 12 in order to detection.With the corresponding direction of direction of the turning cylinder of each roller on, that is, on main scanning direction, form two test patterns mutually side by side.Forming one of them of this two test patterns near the position of carrying reference component 14, and forming another, with the convey error of the respective rollers that detects the position away from the position of carrying reference component 14.More specifically, in Fig. 5, test pattern FR 1 is set detecting convey error, and test pattern ER1 is set to detect convey error near the distributing roller 12 of the position of carrying reference component 14 near the conveying roller 1 of the position of carrying reference component 14.In addition, test pattern FR2 is set, and test pattern ER2 is set to detect convey error away from the distributing roller 12 of the position of carrying reference component 14 with the convey error of detection away from the conveying roller 1 of the position of carrying reference component 14.
Conveying roller 1 has their mutual separately different major functions with distributing roller 12.Therefore, the delivery precision of conveying roller 1 is different from the delivery precision of distributing roller 12 usually.The major function of conveying roller 1 is each stage at print scanned action the appropriate location that print media P is in printhead 4 to be set.Therefore, form roller diameter enough greatly to carry out the conveying roller 1 of high-precision relatively conveying action.Discharge print media P when on the contrary, the major function of distributing roller 12 is printings on finishing print media P surely.Therefore, modal is that distributing roller 12 is inferior to conveying roller 1 on the delivery precision of print media P.
Apparent according to the above, when actual when relating to conveying roller 1 in the conveying of print media P action, the delivery precision of conveying roller 1 influences the convey error of print media P.On the contrary, when only relating to distributing roller 12 in the conveying action at print media P, the delivery precision of distributing roller 12 influences the convey error of print media P.
Why Here it is is divided into print media P two kinds of zones shown in Figure 7 in this embodiment is area I and area I I.For the printing on the area I, in carrying action, relate to conveying roller 1.When on area I I, printing, only carry print media P therebetween, by distributing roller 12.The roller that the conveying action of the printing on utilizing each area I and area I I relates generally to is carried in the print media P printing test pattern.According to each test pattern, obtain concentration information, so obtain employed corrected value in the actual printing in each zone.Incidentally, will be designed to be able in the fore-end of print media P or rear end part, print the image that does not have back gauge, i.e. " boundless " apart from printing according to the PRN device of this embodiment.Boundless when printing when in the rear end part of print media P, carrying out, can use this corrected value.Because this reason, it is useful obtaining this corrected value under the situation of only being carried print media P by distributing roller 12.
Fig. 6 B illustrates the state that print media P that the PRN device utilization only carried by the downstream supply unit carries out actual printing action.In this case, printing is used to detect the test pattern of the convey error of distributing roller 12, specifically, test pattern ER 1 and ER2, the zone be confined to area I I.Therefore, in order to ensure the employed enough zones of this purpose, can be when finishing the printing of test pattern FR1 and FR2, by discharging the state shown in hold-down roller 2 manual creation Fig. 6 C: the state of only carrying print media P by the downstream supply unit.Can manually carry out this release.Alternatively, can automatically perform this release movement by the PRN device of such configuration.
When both carried print media P by conveying roller 1 and distributing roller 12, the delivery precision of conveying roller 1 played the dominance influence to convey error.Because this reason is divided into aforesaid two kinds of zones with whole print area.Yet, only relate to convey error under the situation of conveying roller 1 (on the fore-end of print media P, printing) in the conveying of print media P and be different from the convey error that relates in this conveying under both situations of conveying roller 1 and distributing roller 2.So, can will further be divided into the more fraction of independent process with above-mentioned two kinds of corresponding zones of situation.
More specifically, as shown in Figure 8, at first, area I can be divided into two parts: with the corresponding part of conveying of only being undertaken by conveying roller 1 and with both carry out by conveying roller 1 and distributing roller 12 corresponding another part of conveying.So, in these two parts, distinguish the printing test pattern, and obtain concentration information and corrected value at each several part.In this case,, ratchet roller 13 can be designed to discharge to print and the corresponding test pattern of state of only carrying print media P in order to ensure enough spaces from distributing roller 12 by conveying roller 1.
What is given in the paragraph below in more close reasons of carrying the position of reference component 14 and forming conveying roller 1 and distributing roller 12 test pattern separately away from this two place, the position of carrying reference component 14.
Suppose and in predetermined design allowable deviation, make each roller.Even in this case, PRN device near the position of carrying the reference component side (carrying the reference side position) with away from the position (non-conveying reference side position) of carrying the reference component side between, also different when having owing to caused by factors convey errors such as offset and eccentric states.Compare with employed roller in the equipment of other type, can the A3 size (279mm * 420mm) or in the large-scale ink jet printing device that prints on the bigger print media P employed roller more obvious on this species diversity.In order to the possible method that minimizes the difference of carrying the convey error between reference side position and the non-conveying reference side position be: on main scanning direction, promptly, roller axially on center position print single test pattern, the concentration information according to this test pattern obtains corrected value then.Yet, in the present embodiment, on main scanning direction, print a plurality of test patterns (for example, print two test patterns in the present embodiment, but three or more being fine also).Then, relatively the test pattern of these printings is selected corrected value, to reduce convey error most possibly to the most remarkable negative effect (back will be explained) that is subjected to the test pattern that corresponding convey error influences.
Fig. 9 is used to illustrate the key diagram that how to use the method for nozzle when forming test pattern.When forming test pattern, for example, use nozzle sets NU and another nozzle sets ND in 768 included nozzles of the nozzle array H3500 of second black ink, wherein, nozzle sets NU is made up of a part of nozzle in continuous 768 nozzles that form of the upstream side of throughput direction, and nozzle sets ND is made up of a part of nozzle in continuous 768 nozzles that form in the downstream of throughput direction.The position pitch of nozzle sets NU and ND equals per twice each conveying capacity between print scanned and multiply by the print scanned number of times that is carried out till the speckle key element of explanation in the back coincides.In the present embodiment, make the nozzle sets (nozzle sets ND) that is positioned at the downstream as the benchmark nozzle sets, and use 128 nozzles that begin to count the 65th～the 193rd nozzle scope from the nozzle of the position that is arranged in downstream with fixed form, to print a plurality of benchmark speckle key element RPE (the first speckle key element).Make the nozzle sets (nozzle sets NU) that is positioned at upstream side as adjusting nozzle sets.The quantity of the nozzle among the employed nozzle sets NU is 128, and is identical with the quantity of employed nozzle among the nozzle sets ND.Yet, during main scanning with nozzle of the nozzle scope of nozzle sets NU displacement.Like this, print a plurality of adjustment speckle key element APE (the second speckle key element).
Figure 10 A～10E is the key diagram that is used to illustrate the method for the striped that how to use upstream side nozzle sets NU and downstream nozzle sets ND to form test pattern or formation test pattern.At first, form adjustment speckle key element with main scanning (that is), then, print media P is carried and 128 corresponding amounts of nozzle, form once more thereafter and adjust the speckle key element by first main scanning in the particular delivery position.When repeating above-mentioned a series of actions, when the 5th main scanning, the first speckle key element of the adjustment speckle key element of Xing Chenging arrives the residing position of nozzle sets ND, downstream like this.By forming benchmark speckle key element in this position, finish the speckle (the speckle kind of first row) that is used to obtain concentration information.
Equally, the 6th main scanning, arrive the residing position of nozzle sets ND, downstream in the formed adjustment speckle of main scanning second time key element.By form benchmark speckle key element in this position, finish the speckle of second row.With the speckle of similar approach formation the third line after this, on sub scanning direction, finish the multirow speckle like this.
Above-mentioned explanation illustrates: in order to finish speckle, must carry out four times and carry print media P between the scanning of adjusting the speckle key element in order to formation and the scanning in order to formation benchmark speckle key element.Therefore, the reflection of each speckle is by the convey error that causes carrying the zone (sector) of employed roller among the print media P four times, wherein, forming the conveying of carrying out these four print media P between the scanning of adjusting the speckle key element and the scanning that forms benchmark speckle key element.
Figure 11 A and 11B illustrate benchmark speckle key element group and the same adjustment speckle key element group of being printed by the single main scanning of printing respectively.As shown in figure 11, on main scanning direction, be in line and fitly print benchmark speckle key element RPE.On the contrary, Figure 11 B illustrates: when printing adjustment speckle key element APE, each adjusts speckle key element APE displacement and the corresponding speckle of nozzle.Adjust speckle key element APE group and comprise that being arranged in the standard that 128 nozzles that are in the 65th nozzle～193rd a nozzle scope of beginning to count from the nozzle of upstream-most position print by use adjusts speckle key element APEr.
The left side that standard in Figure 11 B is adjusted speckle key element APEr illustrates the adjustment speckle key element APE that adjusts the more close conveying reference component 14 in speckle key element APEr position than standard.By using adjustment nozzle sets NU to print each such adjustment speckle key element APE, but, be used to print the nozzle scope of adjusting the speckle key element from the nozzle scope that is used to print the adjacent adjustment speckle key element APE that is positioned at this adjustments speckle key element right side to the downstream of the carrying nozzle that is shifted.The right side that standard in Figure 11 B is adjusted speckle key element APEr illustrates than standard and adjusts speckle key element APEr position apart from carrying the farther adjustment speckle key element APE of reference component 14.By using adjustment nozzle sets NU to print each such adjustment speckle key element APE, but, be used to print the nozzle scope of adjusting the speckle key element from the nozzle scope that is used to print the adjacent adjustment speckle key element APE that is positioned at this adjustments speckle key element left side to the upstream side of the carrying nozzle that is shifted.For the conveying reference side, 3 nozzles of nozzle scope displacement, for non-conveying reference side, 4 nozzles of nozzle scope displacement.When the displacement of side upstream is represented as timing, then shift range is-3～+ 4 on the whole.
Here suppose under situation, between two main scannings, carry the corresponding distance of scope (128/1200 * 25.4=2.709[mm]) of print media P and 128 nozzles arranging with the pitch of 1200dpi without any error.The standard adjustment speckle key element APEr (shift amount=0) that is printed when so, the benchmark speckle key element RPE that is printed during the 5th main scanning is with main scanning after 4 times are carried print media P coincides together just.Notice that positive shift amount is corresponding to the situation of conveying capacity greater than above-mentioned distance, and negative shift amount is corresponding to the situation of conveying capacity less than above-mentioned distance.
Figure 12 illustrates and comprises test pattern a plurality of speckle key elements or that comprise the speckle group that constitutes by benchmark speckle key element and adjustment speckle key element.Figure 12 illustrates one of them of four test patterns shown in Figure 5 in the amplification mode.
Adjust speckle key element APEr for standard,, print and adjust speckle key element APE by in the scope of-3～+ 4 nozzles, making the nozzle that is actually used in printing from nozzle of adjacent nozzles displacement separately.Therefore, in each test pattern, on main scanning direction, form 8 speckles.In addition, in the present embodiment, the conveying capacity of the print media P between per two main scannings is set to 2.709mm (as ideal value).Repeat 30 main scannings altogether, to form 30 speckles in the scope of (on the throughput direction of print media P) on sub scanning direction.Therefore, the length of each test pattern on sub scanning direction is 2.709 * 30=81.27mm (as desired quantity).When the nominal outside diameter of roller was 37.19mm, the length of above-mentioned test pattern was corresponding to the twice girth greater than roller.
Speckle row A shown in Figure 12 comprises adjustment benchmark speckle key element APEr.The adjustment speckle key element APE that comprises following printing with each speckle row of A+1～A+4 mark: the scope of employed adjustment nozzle sets NU is shifted and 1 corresponding amount of nozzle～4 nozzle from adjusting the upstream side of benchmark speckle key element APEr on the throughput direction of print media P.The adjustment speckle key element APE that comprises following printing with each speckle row of A-1～A-3 mark: employed adjustment nozzle sets NU is shifted and 1 corresponding amount of nozzle～3 nozzle to the downstream of the throughput direction of print media P from adjusting benchmark speckle key element APEr.
Utilization in order to form respectively adjust the scanning of speckle key element APE with in order to the scanning that forms corresponding benchmark speckle key element RPE between carry the employed roller of print media P zones of different, the capable B1～B30 of formation speckle.Suppose the conveying that begins to carry out the print media P after the printing of adjustment speckle key element APE of the capable B1 of speckle from the reference position of roller.In this case, for the capable B1 of speckle, in order to scanning that print to adjust speckle key element (APE) with in order to the scanning of printing benchmark speckle key element (RPE) between the zone of employed roller begin to carry the zone (0mm～0.836mm) of four employed rollers of print media P corresponding to reference position from roller.For the capable B 2 of speckle, in order to scanning that print to adjust speckle key element (APE) with in order to the scanning of printing benchmark speckle key element (RPE) between the zone of employed roller begin to carry the zone (2.709mm～13.545mm) of four employed rollers of print media P corresponding to position from distance reference position 2.709mm.Similarly, for the capable B 3 of speckle, the zone of use roller (5.418mm～18.963mm), and for the capable B 4 of speckle, the zone of use roller (8.127mm～21.672mm).Like this, capable for different speckles, in order to scanning that print to adjust speckle key element (APE) with in order to the scanning of printing benchmark speckle key element (RPE) between the zones of different of use roller.
In addition, mutually adjacent speckle is capable partly is shared in order to print the scanning of adjusting speckle key element (APE) and zone in order to employed roller between the scanning of printing benchmark speckle key element (RPE).For example, capable B1 of speckle and B2 use the common region (2.709mm～10.836mm) of roller.
Benchmark speckle key element (RPE) transfer position afterwards of printing the capable B 1 of speckle can be alignd with the reference position of roller.Yet when forming test pattern, the control that above state is achieved is optional.Alternatively, can be printed on the benchmark speckle key element transfer position afterwards of printing the capable B 1 of speckle, and can use this transfer position conduct in order to obtain the benchmark of the relation between speckle capable (employed position in the roller) and the convey error, the back will describe this relation.
Figure 13 illustrates benchmark speckle key element or adjusts the speckle key element in the amplification mode.In Figure 14, the speckle key element is shown in the mode of further amplification.With the scalariform pattern formation speckle key element of printing block as base unit, each printing block has the dimension of 2 points on sub scanning direction, have the dimension of 10 points on main scanning direction.In addition, by considering the shift range of employed nozzle sets, guarantee the specific range on sub scanning direction between per two scalariform patterns.In example shown in Figure 14, employed nozzle sets is to the upstream side of throughput direction displacement 1～4 nozzle (+1～+ 4), and to 1～3 nozzle of the downstream of throughput direction displacement.Corresponding, as on sub scanning direction, to guarantee 6 nozzles space.
In the present embodiment, in upstream side nozzle sets NU and downstream nozzle sets ND, print as this class speckle key element shown in this Fig.Therefore, corresponding with the degree of convey error, the overlap condition of benchmark speckle key element (RPE) and adjustment speckle key element (APE) changes.As a result, in test pattern, as shown in figure 12, form the speckle of various concentration.
Particularly, shown in Figure 15 A, when aliging just mutually when the adjustment speckle key element of printing by upstream side nozzle sets NU (APE) with by the benchmark speckle key element (RPE) that downstream nozzle sets ND prints, concentration (OD value) step-down.On the contrary, shown in Figure 15 B, when these two kinds of speckles were unjustified, filling should be Blank Space, thereby concentration uprises.
Must strengthen the reliability of test pattern, thereby make and to detect convey error according to the concentration information of test pattern.For this purpose, the unlikely speckle that influences of condition of nozzles of preferred printhead 4.In the nozzle that uses continuously or use under given conditions, the injection that injection direction deflection (some deflection) may take place sometimes and do not spray China ink etc. is failed.When this class is sprayed the change of the concentration information that failure causes speckle, only can calculate the corrected value of convey error improperly.Therefore, strong hope forms a kind of like this speckle: even exist above-mentioned this class to spray failure, this speckle also can reduce the change of concentration information.The speckle key element that is adopted in the present embodiment can be tackled this requirement.Will be by using this reason of explanation in the naive model paragraph below.
Form the speckle key element with the pattern that on sub scanning direction, has the space shown in Figure 16 A, thus make can the measuring position side-play amount as concentration information.Yet when specific nozzle was not sprayed any China ink, shown in Figure 16 B, the All Ranges that should utilize this specific nozzle to print became blank.
In order to address this problem, shown in Figure 17 A, form the speckle key element by a plurality of printing blocks that between two adjacent blocks arranging on the main scanning direction, also have the space.In addition, disperse the scope of employed nozzle, thereby make that pattern can be non-conterminous mutually in printing block.Therefore, can reduce the negative effect of specific nozzle to pattern.Particularly, even when having the injection failure of specific nozzle, reduced owing to benchmark speckle key element (RPE) and adjusted speckle key element (APE) not overlapping the white space (white space of the example among Figure 17 B is half among Figure 16 B) that produces mutually.Therefore, can prevent to reduce the concentration of speckle key element, and finally prevent to reduce the concentration of speckle itself.The area coefficient of the pattern among Figure 17 B (speckle pattern compares with the area in speckle zone) equals the area coefficient of the pattern among Figure 16 B.Here, make the mean value of the concentration of constituent parts area in the summation of concentration of the constituent parts area in the pattern or the pattern as the concentration value in the whole zone of pattern.So even work as pattern not simultaneously, it is identical that concentration value also becomes.
And, in the present embodiment, use mute light black ink to form test pattern.Can use any China ink of different colours for this purpose, as long as can utilize read sensor to obtain concentration information in good mode.In addition, can use the China ink of different colours to print benchmark speckle key element (RPE) respectively and print adjustment speckle key element (APE).
In addition, for the quantity of employed nozzle sets and the position of employed nozzle, be not limited to each example that provides in the foregoing description.The nozzle of any amount of nozzle sets and any position all can allow, as long as can obtain change corresponding to the concentration information of convey error with good way, and as long as the negative effect of the injection of nozzle failure is less.In order to improve owing to the off-centre of roller and the accuracy of detection of the convey error that the external diameter error is caused, the preferred feasible distance that is used to print the nozzle sets of benchmark speckle key element (RPE) and is used for printing between the nozzle sets of adjusting speckle key element (APE) is bigger, and this speckle key element of two types preferably has identical patterns.
In the present embodiment, utilize read sensor 120 to measure the concentration of each speckle that constitutes test pattern.In the measurement that utilizes read sensor 120, utilize the optical pickocff that comprises optical transmitting set and photodetector on it that test pattern is scanned, determine the concentration of each speckle (Figure 15 A and 15B) like this, wherein, in each speckle, reference pattern and adjustment pattern are interfered mutually.When being transmitted in light on the speckle, detect the light quantity (catoptrical intensity) of the concentration of speckle as reflection.Can only carry out once this detecting operation for each zone to be detected, perhaps can carry out repeatedly to reduce the negative effect that detects error.
After the concentration that has detected speckle, a plurality of speckles concentration separately of printing on the main scanning direction is compared mutually.Then, according to the position of the speckle of the speckle of least concentration and inferior low concentration and the concentration difference between them, calculate the error of conveying capacity.Here, represent with N 1 according to the concentration value that speckle obtained of least concentration, and represent with N2 according to the concentration value that speckle obtained of inferior low concentration.So, with concentration difference (N=N2-N1) and three threshold value T1, T2 and T3 (T1＜T2＜T3) compare.When N＜T1, the difference between N1 and the N2 is little.In this case, determine that convey error is the median (length of the side-play amount of the speckle of least concentration+1/2 nozzle) of side-play amount of the speckle of the side-play amount of speckle of least concentration and time low concentration.When T1＜N＜T2, the difference between N1 and the N2 is a bit larger tham poor under the previous case.Under the situation of T1＜N＜T2, determine that convey error is further to the be shifted value (length of the side-play amount of the speckle of least concentration+1/4 nozzle) of amount of 1/4 nozzle of the speckle side of least concentration from above-mentioned median.When T2＜N＜T3, the difference between N1 and the N2 is poor greater than under the previous case more.Under the situation of T2＜N＜T3, determine that convey error is the value of length of side-play amount+1/8 nozzle of the speckle of least concentration.When T3＜N, concentration difference N is very big.In this case, convey error is defined as the side-play amount of the speckle of least concentration.
As mentioned above, three threshold values being set in the present embodiment, can be the detection that unit carries out convey error with 2.64 μ m therefore, and wherein, this unit equals 1/8th of nozzle pitch 9600dpi (=1200 * 8).Capable for formed a plurality of speckles on sub scanning direction, more specifically, each row during 30 speckles are capable is carried out this processing.Like this for (2.709mm * 4=10.836mm) detects convey error for four times of the capable print media P of each speckle at carrying employed each girth in the action.
In Figure 19, convey error X nValue change according to the value of n.This is to produce different conveying capacities owing to the reference position from roller begins different rotational angles, and because the off-centre of roller causes that this class of conveying capacity is poor.Note, because the off-centre of roller causes convey error X nThe change of value, thereby this change is the cyclical movement that has just all corresponding cycles of rotating with roller.
In the paragraph below, provide detailed description for the processing of obtaining these corrected values.Carry out following explanation as an example by processing, still, can carry out similar processing for distributing roller 12 with conveying roller 1.In addition, carry print media P, and definite convey error is the result of the combination of these rollers although conveying roller 1 is cooperated with hold-down roller 2, for convenience, the following description based on prerequisite be that convey error is the convey error of conveying roller 1.
At first, provide explanation for the overview by using the conveying control that the eccentric correction value before obtained and external diameter corrected value carried out among this embodiment.Although the back will provide the detailed description of this conveying control,, before explanation is used to obtain eccentric correction value and external diameter corrected value, only provide the summary description of this conveying control.
In the present embodiment, as shown in figure 28, begin that from the reference position roller is divided into 110 zones and (form piece BLK1～BLK110) like this.Then, prepare to be used for table that piece is associated with their eccentric correction values separately.Figure 26 illustrates the example of this table.Respectively eccentric correction value e1～e110 is distributed to piece BLK1～BLK110.
As mentioned above, in order to carry out the conveying control of present embodiment, must obtain the eccentric correction value that is divided into each piece of creating in 110 zones by girth, perhaps in other words, have 0.338mm (=37.19mm/110) the eccentric correction value of each piece of girth of roller roller.
Yet, in the present embodiment,, detect convey error for each girth (length is 10.836mm) of four employed rollers of each speckle capable conveying print media P according to test pattern.In addition, capable carry out them four times the part in employed their the roller zones separately of conveying action of print media P separately shared of two adjacent speckles in the test pattern.Therefore, carry out process described below subsequently, obtain the eccentric correction value according to the test pattern of each piece of roller, wherein, each piece of this roller has by the girth with roller and is divided into 110 formed girths in zone (0.338mm).
Incidentally, the form of periodic function that equals the girth of roller with the cycle occurs Pian Xin cycle.Therefore, at first obtain following periodic function in the present embodiment, this periodic function has the periodic component of the girth that equals roller, and has and the opposite polarity polarity of convey error function (below, this function is called " correction function ").Then, will with the reference position of roller apart from this correction function of substitution.Therefore, obtain by roller being divided into the eccentric correction value of 110 formed each pieces in zone.
By selecting farthest to reduce for SIN function y=A sin (2 π/L * T+ θ) because the amplitude A of the convey error that the off-centre of roller causes and the combination of initial phase θ, convey error X promptly shown in Figure 19 nRange weight, obtain the correction function in the present embodiment.Here, L is the girth (particularly, the girth of conveying roller 1 is 37.19mm) of roller, and T is the distance with the reference position of roller.Can be in particular 0,0.0001,0.0002 and 0.0003 for amplitude A is provided with four different values, can be in particular-5m * 2 π/110 for initial phase θ is provided with 22 different values simultaneously (m=0,1,2,3 ..., 21).In a word, under the situation that does not comprise amplitude A=0, in the present embodiment can selecting range and 66 various combinations of initial phase, and when comprising the situation of amplitude A=0, can select 67 various combinations.In these various combinations, the amplitude A of the off-centre of selection corrector roll and the best of breed of initial phase θ.
At first, at step S21, judging whether need be in order to obtaining the calculation process of eccentric correction value, and this judgement must be carried out before obtaining the eccentric correction value according to correction function.For example, when because the eccentric convey error that is caused during less than certain threshold level, judging need be in order to not to obtain this calculation process of eccentric correction value.If this is the case, then the amplitude of correction function is set to 0, and finishes this process.In the present embodiment, provide in the paragraph below that be used to judge whether need be in order to the process of the calculation process of obtaining the eccentric correction value.
At first, obtain convey error X shown in Figure 19 nThe mean value X of (n=1～30) nAnd calculating mean value X (ave), n(ave) and convey error X nBetween poor X n'.Figure 20 is that the value with n is transverse axis and difference X n' value and difference X that n are shown for the longitudinal axis n' between the figure of relation.Then, to each difference X n' absolute value | X n' | carry out square, and calculate quadratic sum value ∑ | X n' | 2When calculate like this and ∑ | X n' | 2During less than above-mentioned certain threshold level, judging does not need the eccentric correction value.
On the contrary, when calculate like this and ∑ | X n' | 2During greater than above-mentioned certain threshold level, operating process enters and is used to obtain the processing that correction function is proofreaied and correct with the off-centre of pair roller.At step S24, calculate to have and proofread and correct best amplitude A and the correction function of initial phase θ for the off-centre of roller.Provide example in the paragraph below in order to the method for calculating this corrected value.
At first, for each combination in all combinations (not comprising 66 combinations under the situation of amplitude A=0) of amplitude A in the above-mentioned SIN function and initial phase θ, compose variable T by 2.709 34 different values of being spaced apart that will since 2.709 to 92.117, obtain described value to SIN function.
For example, give above-mentioned variable T, the y1 of acquisition value respectively, y2 and y3 by composing with SIN function of specific amplitude A and specific initial phase θ with 2.709,5.418 and 8.128.Calculate continuously, up to giving variable T acquisition value y by composing with 92.117 34Till.Must carry out this processing to all 66 various combinations of amplitude A under the situation that does not comprise amplitude A=0 and initial phase θ.
Then, four successive value y in the particular combinations of amplitude A and initial phase θ are added together, to produce 30 accumulated value Y n'.For example, y 1'=y 1+ Y 2+ y 3+ y 4And y 2'=y 2+ y 3+ y 4+ y 5Like this, calculate from y 1' to y 30' value.Must carry out this processing to all 66 combinations of amplitude A and initial phase θ.
Note, give variable T, acquisition value y by composing 2.709,5.418,8.128 and 10.836 respectively 1, y 2, y 3And y 4, wherein, T is the distance with the reference position of roller.Therefore, in the SIN function of particular combinations, by being worth y with amplitude A and initial phase θ 1～y 4The value y that obtains added together 1' be and the regional corresponding value of the roller that begins from the reference position to finish to the 10.836mm position.Equally, in the SIN function of particular combinations, by being worth y with amplitude A and initial phase θ 2～y 5The value y that obtains added together 2' be and the regional corresponding value that begins from the 2.709mm position to finish to the 13.545mm position.
Subsequently, for each combination of amplitude A and initial phase θ, with accumulated value y n' and convey error X separately nAnd the poor X between the mean value n' addition.For example, with y 1' and x 1' addition, with y 2' and X 2' addition.Carry out following addition similarly, up to y 30' and X 30' till the addition.Obtain additive value X like this n".Then, to each additive value X n" absolute value carry out square, and calculate quadratic sum value ∑ | X n" | 2Figure 21 is that the value with n is a transverse axis and with | X n" | 2Value be that the longitudinal axis illustrates the value of n and the squared absolute value of additive value | X n" | 2Between the figure of relation.By will with n among this figure respectively be worth corresponding squared absolute value | X n" | 2Added together, the additive value after can calculating square be Xn's and ∑ | X n" | 2
According to the similar process of said process, for each combination in all 66 various combinations of amplitude A and initial phase θ, obtain additive value Xn squared absolute value and ∑ | X n" 2|.Then, select to make the quadratic sum ∑ in 66 combinations | X n" | 2A combination of value minimum.Acquisition can farthest reduce the correction function owing to the convey error that off-centre caused of roller like this, that is, and and convey error X nRange weight.After this, by the distance of each piece and reference position is composed the variable T that gives correction function, can obtain by roller being divided into the eccentric correction value of 110 formed each pieces in zone.
According to the above-mentioned method that is used to obtain the eccentric correction value, even utilize test pattern, as the test pattern in the present embodiment, also can obtain the eccentric correction value in the zone of the roller that is associated with distance apart from the reference position of roller, in the method, according to the capable detected convey error X of each speckle nCorresponding to the girth of repeatedly carrying the corresponding roller of action of print media P, and two capable benchmark speckle key elements of sharing to print separately of adjacent speckle and the parts of printing the zone of the employed roller of adjustment speckle key element separately.
When on main scanning direction, only printing single test pattern,, off-centre is proofreaied and correct with the best of breed that uses amplitude A and initial phase θ based on determining correction function according to the concentration information that this test pattern obtained.Then, use correction function arithmetical operation corrected value (step S27).
Even for the roller of in the predetermined design allowable deviation, making, because the offset of roller and the caused convey error of eccentric state change when also having between the conveying reference side of PRN device and non-conveying reference side.In order to solve this phenomenon, in the present embodiment, can on main scanning direction, print two test patterns.Therefore, for each pattern, obtain to be used for amplitude A that off-centre is proofreaied and correct and the best of breed of initial phase θ.Then,, two combinations that obtain are like this compared at step S29, identical still different to judge these two combinations.When these two combinations when identical, based on the correction function with common amplitude A and common initial phase θ, arithmetical operation corrected value (step S31).
On the contrary, may exist the combination of the amplitude A of carrying reference side and initial phase θ to be different from the situation of the combination of the amplitude A of non-conveying reference side and initial phase θ.In this case, select to make the quadratic sum ∑ of carrying reference side and non-conveying reference side | X n" | 2Value in the amplitude A of a bigger minimum and the combination of initial phase θ.Adopting the reason of selecting like this is the inconvenience of avoiding following.Can select to make the quadratic sum ∑ of carrying reference side and non-conveying reference side | X n" | 2Value in the amplitude A of a less minimum and the combination of initial phase θ.The convey error that such selection may cause the off-centre owing to roller can not being caused is limited in this unfavorable situation in the scope that designs allowable deviation.When the combination of amplitude A of carrying reference side and initial phase θ is different from the combination of the amplitude A of non-conveying reference side and initial phase θ, carry out the described processing of following paragraph.
At first, in three amplitude conditions (particularly, A=0.0001, A=0.0002 and A=0.0003) each, when changing initial phase θ, mark and draw (plot) quadratic sum ∑ | X n" | 2The two carries out this plotting to carrying reference side and non-conveying reference side.That obtain and that represent each side relatively so mutually two curves.According to these two curves, select wherein one, that value is bigger than the value of the appropriate section of another curve part in these two curves.Figure 22 A and 22B schematically show this operation.
Figure 22 A and 22B illustrate all by near a side of carrying benchmark and away from each side in the side of carrying benchmark along with the quadratic sum ∑ is marked and drawed in the variation of initial phase θ | X n" | 2And the curve that obtains.Figure 22 A is the curve of carrying under the situation of curve intersection of the curve of reference side and non-conveying reference side.In this case, the part of representing with heavy line is the quadratic sum ∑ on this curve | X n" | 2Value greater than the part of the analog value on the corresponding curve.On the other hand, Figure 22 B illustrate carry reference side curve not with the situation of the curve intersection of non-conveying reference side.In this case, the All Ranges of a curve in these two curves is constant has a bigger quadratic sum ∑ | X n" | 2Value, therefore in Figure 22 B, this part is shown with heavy line.
Subsequently, in selected zone or have a bigger quadratic sum ∑ | X n" | 2The zone of value in (shown in the heavy line among Figure 22 A and the 22B), select to make the quadratic sum ∑ | X n" | 2The value of the minimum initial phase θ of value, as the optimum value under the amplitude conditions of this situation.When these two curves intersect as shown in figure 22 mutually, select to have the quadratic sum ∑ | X n" | 2The intersection point of minimum in one, as the optimum value under the amplitude conditions of this situation.Under the situation shown in Figure 22 B, select the value of the initial phase θ at the minimum point place on the heavy line, as the optimum value under the amplitude conditions of this situation.
Carry out aforesaid operations for each amplitude conditions.Then, will with the corresponding quadratic sum ∑ of determining respectively at amplitude conditions of initial value separately | X n" | 2Value compare mutually.Thereafter, with the quadratic sum ∑ | X n" | 2The minimum situation of value under amplitude A and initial phase θ select as optimum value.After this, based on correction function arithmetical operation corrected value (step S33) with optimum range A and best initial phase θ.
As so far the above, in the present embodiment, obtain the optimum value of amplitude A and initial phase θ, the correction function of determining to have this class optimum value then according to single test pattern or a plurality of test pattern.Then, based on this correction function, obtain the eccentric correction value.
In the above description, obtain that (formed each the regional eccentric correction value of piece BLK1～BLK110) is associated the eccentric correction value simultaneously with each distance from the reference position of roller to each zone by roller being divided into 110 parts.Notice that this is not the unique method that obtains the eccentric correction value.For example, can obtain the eccentric correction value, simultaneously the eccentric correction value is associated with each rotational angle from the reference position of roller to each zone.
In the present embodiment, for example, be mounted to 14080 pulses of rotary encoder 116 revolutions output of the moving week of conveying roller 1.Then, 14080 pulses are divided into the group that all has 128 pulses, to be fit to 110 zones.Therefore, can be according to the current location of the pulse detection roller of exporting from rotary encoder 116.Then, in 110 zones (piece) each, the rotational angle that eccentric correction value and reference position from roller are begun is associated.Subsequently, these eccentric correction values (step S35) are set, form eccentric correction value table by form with table.For example, these set values are stored in (with reference to figure 3) among the EEPROM 103, can when this equipment self is closed, also can keep these values even this makes.Also making can be according to the set value of this topology update.
At first, with the content application of eccentric correction value table in the capable detected convey error X of each speckle according to test pattern n, and with Y nThe value (step S41) that expression obtains like this.Then, calculate Y nMean value, and with Y n(ave) expression (step S43).Note, as mentioned above, each convey error X nIt is the convey error that the girth of corresponding roller is carried in print media P four times.Therefore, before the eccentric correction value was applied to convey error, the eccentric correction value in the eccentric correction value that must the add up table was with the convey error X that is fit to obtain like this n
Subsequently, judge on main scanning direction, whether there are a plurality of test patterns (step S45).When on main scanning direction, only printing single test pattern, calculate desired value (dimension equals the value of the roller of nominal dimension just, therefore without any convey error) and mean value Y n(ave) poor between.Then, poor based on what calculate, determine external diameter corrected value (step S47).
Here, when by from desired value, deducting mean value Y n(ave) difference that is obtained is timing, and the girth of this roller is longer than the girth that dimension equals the roller of nominal dimension just.In other words, in addition use the single of this roller carry conveying capacity that action carries print media P more than should conveying capacity.Therefore, in this case, determine corrected value (external diameter corrected value) at step S47, so that mean value Y n(ave) equal desired value.
On the other hand, when printing a plurality of test pattern on main scanning direction (being two test patterns in the present embodiment), addition is according to mean value Y that each test pattern obtained n(ave), to obtain the mean value Y of mean value n(ave) (step S49).Use the mean value and the difference between the desired value that obtain like this to determine external diameter corrected value (step S51).Also the external diameter corrected value can be stored in (with reference to figure 3) among the EEPROM 103.
Here, providing in the paragraph below must be in the explanation of the reason before obtaining the external diameter corrected value for why obtaining the eccentric correction value.
Yet employed test pattern length on sub scanning direction is 80mm in the present embodiment.When using the nominal periphery as the roller of 37.19mm, the length of 80mm has surpassed the integral multiple (having surpassed the amount that roller rotated for two weeks) of the roller with nominal periphery.Therefore, in the present embodiment, according to zone in conveying roller rotates corresponding test pattern of two weeks and with the corresponding zone that exceeds of little beginning part of rotating for the 3rd week, detect convey error.
Note, in fact, be difficult to form the test pattern of integral multiple that length on the sub scanning direction accurately equals the girth of roller.In addition, the allowable deviation of the external diameter of conveying roller 1 may cause the change in cycle of the off-centre of conveying roller 1 sometimes.Therefore, more preferably the length of test pattern on sub scanning direction greater than the nominal circumference of conveying roller 1 integral multiple.Yet, when test pattern being uneven in length during integral multiple in the girth of roller on the sub scanning direction, perhaps, in other words, when when comprising that the test pattern that exceeds the zone detects convey error, this class problem described in the following paragraph may take place.
Figure 25 illustrates at first by the processing of eccentric correction value, obtain the example of corrected value by the processing of external diameter corrected value then and illustrate by these two examples of handling the corrected value that is obtained according to reverse order carried out.Here, in order to simplify, the result of calculation of the test pattern FR1 that carries reference side is compared.
At first, suppose the order computation corrected value of processing before the processing of eccentric correction value with the external diameter corrected value.In this case, when calculating mean value Yn (ave) under state shown in Figure 24, this value is 9.31 μ m.Reflection is worth the external diameter corrected value that 9.31 μ m are obtained based on this after, carry out the operation of eccentric correction.In this case, be amplitude A selective value 0.0003.Select value=13 of n therebetween, for initial phase θ.On the contrary, the calculating of supposing the eccentric correction value is before the calculating of external diameter corrected value, in the situation at present embodiment.In this case, be amplitude A selective value 0.0003.Select value=13 of n therebetween, for initial phase θ.So, when using the eccentric correction value, calculate the value of Yn (ave).As a result of the value that generates is that 8.74 μ m are (based on Y n(ave) value 8.74 μ m obtain the external diameter corrected value).Relatively making of the process of different order is apparent: the eccentric correction value is identical, but the external diameter corrected value is different mutually.
Notice that, when extract the value of rotating corresponding Xn of two weeks with roller by the state from Figure 24, when calculating the external diameter estimated value, the theoretical value of external diameter corrected value is 8.54 μ m here.Therefore, with the same in the situation of present embodiment, when before obtaining the external diameter corrected value, obtaining the eccentric correction value, can obtain and depart from the littler external diameter corrected value of this theoretical value.
As mentioned above, in the present embodiment, be mounted to 14080 pulses of rotary encoder 116 revolutions output of the moving week of conveying roller 1.So, in the present embodiment,, 14080 pulses are divided into 110 circumferential areas that all have 128 pulses from the reference position of rotary encoder 116.Subsequently, be formed for storing the table of the eccentric correction value of obtaining by the calculation process of eccentric correction value, so that the eccentric correction value is corresponding to each above-mentioned circumferential area.
Figure 27 illustrates the example of the procedure segment of carrying control.Figure 28 is the key diagram that is used to illustrate with the corresponding operation of this process.Note,, carry out process shown in Figure 27 in order to judge the conveying capacity (subscan) of per twice print media P between print scanned, therefore, can be during print scanned, perhaps finish print scanned after, carry out this process.
At first, at step S61, be written into basic conveying capacity.Basic conveying capacity is the theoretical value of per twice subscan amount between print scanned continuously.Then, at step S63, with basic conveying capacity and the corrected value except that the eccentric correction value, that is, and the addition of external diameter corrected value.And, at step S65, carry out calculating and where begin to turn to from current turned position with the end value conveying roller of obtaining in response to above-mentioned addition 1.In example shown in Figure 28, conveying roller 1 turns to the position in the piece BLK4 from the position in the piece BLK1.
Thereafter, at step S67, in addition and at this moment the rotation process the corresponding eccentric correction value of piece of process.More specifically, in example shown in Figure 28, during turning passed through piece BLK2 and BLK3, so addition eccentric correction value e2 and e3.The end value that will draw by addition drives then and carries motor 110 to obtain this conveying capacity (step S69) as final conveying capacity.
Notice that in the present embodiment, dispose the eccentric correction value of the piece of only addition process, still, other structure also is fine.According to the position (that is, piece BLK1) in the current block before rotating with the position (that is, piece BLK4) in the piece after rotating, the eccentric correction value of these pieces is suitably changed, and the value after can addition changing like this.Yet, compare with this meticulous the recomputating of corrected value, can be more easily with the shorter time simply use the corrected value of each piece of process.
So far described corrected value is the corrected value of conveying roller 1, but can obtain the corrected value of distributing roller 12 with similar approach, and this corrected value can be stored among the EEPROM 103.When a roller that will be used to carry or a plurality of roller switch to single distributing roller 12, can use the corrected value of the distributing roller of being stored 12.
Can obtain eccentric correction value and external diameter corrected value based on being assemblied in the concentration information that the read sensor 120 sweep test patterns on the balladeur train 7 are obtained along printhead 4 by utilizing.Alternatively, can obtain eccentric correction value and external diameter corrected value based on the concentration information that is obtained by the read sensor 120 sweep test patterns form setting, that replace printhead 4 to be assemblied in balladeur train 7 that utilize with printhead.
Figure 29 illustrates the example with the corresponding processing procedure of said structure.When this process of startup, place print media P (step S101), and print test pattern (step S103) as shown in Figure 5.Then, once more the print media P that forms test pattern on it is placed in this equipment, and carries out the operation of read test pattern, to obtain concentration information (step S105)., based on concentration information, successively obtain eccentric correction value and external diameter corrected value (step S107 and S109), then these corrected values are stored (or renewal) in EEPROM 103 (step S111) thereafter.
Do not have under the situation of built-in read sensor (comprising the situation that PRN device is configured to have the multifunctional equipment of integrated scanner equipment unit) at PRN device, there is the print media P of test pattern to be placed on the external scan device equipment, with printing on it to read.
Figure 31 illustrates the example of the processing procedure under the processing of this situation.Use external scan device equipment to read the print media P that has formed test pattern on it, the concentration information that will read like this offers main equipment 1000 with calculated correction value then.PRN device is waited for the input (step S135) of corrected value.Under actual situation of carrying out this input, with corrected value storage (renewal) in EEPROM 103 (step S111).
Also above-mentioned processing is carried out in the instruction that can provide in response to the user.Alternatively, the user can entrust attendant's representative of consumer to carry out this processing, and perhaps the user can take equipment to service centre and carries out this work.Under any circumstance, corrected value is stored among the EEPROM 103, this makes it possible to upgrade where necessary corrected value.As a result, can suitably solve the deterioration that causes along with the aging of roller.
Yet suppose such a case: deterioration in time is not a practical problem, and does not need to upgrade.In this case, during the detection that can be carried out is handled, determine the default value of corrected value before PRN device dispatches from the factory.Then, the default value of determining like this is stored among the ROM 102 that is installed in the PRN device.On this meaning, " being used to obtain the method for the corrected value of conveying capacity error " is characterised in that: needn't carry out the arithmetical operation of eccentric correction value and determining of the external diameter corrected value after the above-mentioned arithmetical operation in PRN device, be independent of the set equipment of PRN device or detection system is carried out and can use.
For example, in said structure, conveying roller 1 and distributing roller 12 are set respectively in the upstream side and the downstream of the throughput direction of print media P.Since packing print media P into before finishing printing, carry print media P by various supply units.Suppose the unit that in conveying, also comprises except that above-mentioned two kinds of rollers, and the off-centre of each unit or external diameter change caused convey error and may influence print quality.Consider each roller separately or obtain the correction value of conveying error of each roller in conjunction with other roller if this is the case down.Equally, in this case, with above-mentioned situation in adopt the similar fashion of a roller, printing test pattern at first, the concentration information based on test pattern obtains eccentric correction value and external diameter corrected value then.In a word, the printing of test pattern and obtaining of corrected value are carried out in the quantity of the supply unit that the conveying in the time of can be according to actual printing is included and the combination of supply unit.Like this, can on whole print media P, carry out even high-quality printing.
For example, only using single roller to carry under the situation of print media P, only utilize single roller to carry all the time.As a result, one type printing of test pattern and one type correction value of conveying error are only arranged.When in conveying, using two rollers,, the processing of being carried out can be divided into the situation that only comprises distributing roller 12 in the situation that comprises conveying roller 1 in the conveying and the conveying as in above-mentioned situation.In addition, can also be further the last situation of above-mentioned consequent two kinds of situations is divided into the situation that only comprises conveying roller 1 in the conveying and carry in comprise the situation of the conveying roller 1 of cooperating with distributing roller 12, carry out the processing of being carried out.Under the situation of three rollers, can in a similar manner the processing of being carried out be divided into maximum 5 kinds of situations (zone).Generally speaking, when utilizing n roller (n 〉=2) when carrying, the processing of being carried out can be divided into 3+1/2[n (n-1) at most] individual zone.
In addition, in above-mentioned example, equally also obtain the eccentric correction value and the external diameter corrected value of distributing roller 12.Yet suppose such a case: distributing roller 12 is made by rubber.Rubber is the material for environmental change sensitivity and Nian Jiuyi deterioration, and also the possibility effect is little for the resultful words of eccentric correction value of reflection distributing roller 12.If this is the case, then can omit the arithmetical operation or the application of the eccentric correction value of distributing roller 12.
And, in above-mentioned example, use the part of the nozzle array of the upstream side that is positioned at throughput direction to print adjustment speckle key element (the second speckle key element).Alternatively, for example, shown in figure 32, can use to print thereon in advance has the print media P that adjusts speckle key element RPEs '.So, use the specific nozzle group in all nozzle arrays regularly, print benchmark speckle key element APE, and therefore finish the formation of test pattern.Based on the test pattern of such formation, carry out in order to obtain the processing of corrected value thereafter.Notice that pre-printed speckle key element can be benchmark speckle key element RPE ', and can in handle back one, print and adjust speckle key element APE.
In addition, the explanation that provides above only provides following example: the quantity of kind, the nozzle of the quantity of the tone (color and concentration etc.) of China ink, China ink, the method for scope of nozzle that actual use is set and the method that the conveying capacity of print media P is set.Equally, the various numerical value that provide in the above-mentioned explanation also only are the examples of operable numerical value.
In the above description, when on main scanning direction, printing a plurality of test pattern (particularly, in the above-mentioned explanation that provides, print two test patterns, one of them test pattern is being carried reference side, and another test pattern is in non-conveying reference side), by mutual more a plurality of test patterns, select corrected value.Here, selected corrected value can farthest reduce the influence of that convey error that has appreciable impact in the convey error.Particularly, by in all combinations of amplitude and initial phase, selecting to produce the quadratic sum value ∑ of carrying reference side and non-conveying reference side | X n" | 2In the combination of bigger one minimum of a value, determine correction function.
The following object lesson that carries out this selection.At first, for carrying reference side and non-conveying reference side to determine separately for amplitude and initial value in order to corrected value the best of the off-centre of corrector roll.Then, by being calculated as the mean value of the determined initial phase of each side, determine initial phase.For example, suppose and determine to carry the best initial phase of reference side to be-5 * 2 π/110, and determine that the best initial phase of non-conveying reference side is-25 * 2 π/110.Then, according to these values, the best initial phase that is identified for proofreading and correct the off-centre of whole roller is-15 * 2 π/110.Equally, can determine optimum range by calculating mean value.Here, may there be such situation:, only have a small amount of adoptable range value with the same in the situation of the present embodiment that only has three this values.Then, carry the roller portion of reference side to carry print media owing to utilize more continually, thereby can adopt the amplitude of carrying reference side simply same as before.Alternatively, can be weighted carrying reference side and non-conveying reference side initial phase or amplitude separately.Then, can adopt the mean value of weighted value to carry out this correction.Have the PRN device of the roller of eccentric and deflection for use, this method is the effective ways in order to the high quality graphic of acquisition good uniformity.In this case, can separately for the influence of image, determine weighted factor by considering off-centre and deflection.
Following another object lesson that carries out this selection.At first, for all combinations of amplitude and initial phase, will carry the quadratic sum value ∑ of reference side and non-conveying reference side | X n" | 2Added together.Then, in the combination of amplitude and initial phase, determine that selection has the combination of the minimum of the quadratic sum value of carrying reference side and non-conveying reference side.
In addition, in the above example that provides, illustrated that the present invention is applied to the ink jet printing device of so-called serial type.Yet the present invention can be applicable to the so-called line printing type ink jet printing device that is equipped with line head (line-type head), in line head, strides with the corresponding scope of the width of print media and arranges nozzle.In this case, preferred construction can be provided with a line head at the upstream side of throughput direction, and in the downstream another line head is set.Then, when by the aforesaid benchmark speckle of printhead prints key element in these printheads of use,, adjust the speckle key element by using another line head to print with the printing timing of displacement.According to the test pattern of such acquisition, can obtain the convey error of roller, and can obtain the corrected value of roller.
Although the present invention has been described, should be appreciated that the present invention is not limited to disclosed exemplary embodiments with reference to exemplary embodiments.The scope of appended claims meets the wideest explanation, to comprise all these class modifications, equivalent structure and function.
A plurality of described corrected values are provided, and described corrected value comprises:
The first corrected value group, it is associated with the rotational angle that described roller begins from the reference position separately, and the described first corrected value group is used to proofread and correct the convey error of the off-centre that depends on described roller; And
Second corrected value is used to proofread and correct the convey error of the external diameter that depends on described roller,
Described corrected value acquiring unit comprises:
The acquiring unit of the described first corrected value group; And
The acquiring unit of described second corrected value, and
The more described a plurality of test patterns of the acquiring unit of the described first corrected value group, and use the test pattern that at utmost reflects the influence of the convey error that depends on described off-centre, obtain the described first corrected value group.
Carry out the printing of image by following operation:
Print scanned, by moving the printhead that disposes in order to the nozzle of ink-jet, described print media is scanned with the direction different with the orientation of described nozzle; And
Carry described print media along the direction vertical with described print scanned direction.
In described a plurality of test pattern each comprises concentration different a plurality of speckles mutually, and wherein, each in described a plurality of speckles has two speckle key elements, and described concentration depends on the overlap condition of described two speckle key elements,
Form described a plurality of speckle with following method: use continuously arranged a part of nozzle in all described nozzles with fixed form, form the first speckle key element of described speckle key element, and be used for a part of nozzle beyond the portion nozzle of the described first speckle key element, the portion nozzle that will be used for the second speckle key element from a displacement in the another location, form the second speckle key element of described speckle key element.
5. PRN device according to claim 4 is characterized in that, the length of described test pattern on described throughput direction is not the integral multiple of the girth of described roller.
6. PRN device according to claim 5, it is characterized in that being used to form the portion nozzle of the described first speckle key element of described speckle key element and the distance that is used between the portion nozzle of the described second speckle key element of described speckle key element is by following two distances that multiply each other and obtain:
Performed described print scanned number of times before two speckle key elements are overlapped, and
Described print media is in per twice conveying capacity between continuously print scanned.
7. PRN device according to claim 5 is characterized in that, also comprises computing unit, and described computing unit is used for by using the poor of described concentration, calculates the capable described convey error of each speckle,
Wherein, the acquiring unit of the described first corrected value group obtains the corrected value of the amplitude of fluctuation that reduces described convey error according to each of described a plurality of test patterns,
The acquiring unit of the described first corrected value group is selected respectively according to the maximum correction in described a plurality of corrected values that described a plurality of test pattern obtained, and obtains selected corrected value as the described first corrected value group, and
The acquiring unit of described second corrected value obtains described second corrected value by the mean value of the change of the described convey error of calculating, wherein, has reduced the amplitude of described change by using the described first corrected value group.
8. PRN device according to claim 7, it is characterized in that described computing unit is two speckles in capable according to described speckle, calculate described convey error, wherein, described two speckles are speckles that concentration is minimum or concentration is the highest in described speckle all described speckles in capable.
9. PRN device according to claim 4 is characterized in that, also comprises the detector that detects described concentration.
A plurality of described rollers are set,
Also, form a plurality of described test patterns along described throughput direction corresponding to the state that relates to of a plurality of rollers described in the described conveying, and
Obtain described first corrected value group and described second corrected value at each described state that relates to.
11. a method that is used to obtain corrected value, described method are applied to comprise the PRN device of the roller that is used for carrying print media, and described corrected value is used to proofread and correct the convey error that is caused by described roller, said method comprising the steps of:
CN2008100897384A 2007-04-10 2008-04-10 Printing apparatus and the method of acquiring correction value of conveying error CN101284459B (en)
CN201110399433.5A Division CN102514394B (en) 2007-04-10 2008-04-10 Printing apparatus and method of acquiring correction value of conveying error
CN101284459A true CN101284459A (en) 2008-10-15
CN101284459B CN101284459B (en) 2012-01-25
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