CN1047349C - Reading method and device of ink levels of printing plate - Google Patents

Abstract

The present invention relates to a plate reading method of an ink color printing plate and a device, which belongs to the technical field of ink quantity control in printing industry. The method comprises the steps that gray values of ink areas of a standard plate are read out; digital filtering is carried out; a correction table of a grey level and the gray value is made; an actual plate is processed by gray level correction, etc. The device is characterized in that a plate reading signal generator uses a high frequency DC power supply capable of restraining the AC interference of an electric network and low frequency flicker, a green light source and a cellulated photoelectric type scanning head, wherein the length and width of the scanning head are the same as size of the ink area, and the principal spectrum of a photocell matches the green light source and the base color spectrum of the standard plate. The present invention has the advantage of high grey level resolution, and a user can design the standard plate for reason given above, etc.

Description

Mass colour galley read an edition method

Edition method of reading of mass colour galley belongs to press China ink amount control technology field.

Mass colour galley is read the abbreviation that edition device IPC is English " Ink Print Control Plate ".The PS version is the mother matrix of pictures such as printed pattern, literal.Its picture is made up of concavo-convex dot matrix.During printing, PS ' version is contained on the cylinder of printing machine, in order often to be divided into tens to tens ink-covered areas to PS ' version artificially the reasonably inking of picture each several part shade.The width of each ink-covered area is about 37.3mm, by ink fountain one by one through gauge tap to the ink-jet of corresponding ink-covered area.The at present most printing machine of the size of ink ejection amount is with human eye the PS version to be estimated estimation, is realized by the size of manual adjustment ink fountain switching value then.Though this control method for ink is simple, speed is slow, precision is low, poor performance, the consumption China ink is many and labour intensity is big, and it has greatly influenced the further raising of printing quality.

At present, generally adopt the printing concentration control apparatus in the world, it comprises concentration measurement apparatus and ink ejection amount control device two parts.The former is with reading edition method difference and different, and it is output as the ink ejection amount control signal, and this concentration measurement apparatus is referred to as mass colour galley and reads an edition device.China's press stipulates that it is numbered IPC-3.It is light, mechanical, electrical, the incorporate big system of computing machine, and according to the difference of reading edition method, the hardware of system is formed and software configuration all can have very big-difference.At present, have two kinds mainly to read an edition method in the world: a kind of is that the patent No. is clear 61-288961, the applying date to be the disclosed method of Jap.P. of 1986,12,5 " modified value of printing concentration control apparatus is represented method " by name.It is an actual value of obtaining PS version China ink amount earlier, removes to represent a kind of method for expressing of the difference of actual value and set-point again with algebraic value; Also have application number be 1987,5,25 the clear 62-125750 applying date, the Jap.P. of " automatically in the concentration management devices effectively the method for discrimination of band " by name is contained also belongs to this type of.Another kind be application number be clear 58-94547, the applying date are 1983,5,26, the method that Jap.P. proposed of " ink ejection amount establishing method " by name, it is a kind of assay method of China ink amount/area ratio, it is the China ink amount/area ratio of each ink-covered area of first The real time measure, determines to supply with the ink ejection amount of each ink-covered area more in view of the above.For some ink-covered areas, will be according to the China ink amount/area ratio of this at least one adjacent ink-covered area, both sides, ink-covered area, come the China ink amount of that ink-covered area of wanting ink-jet is made revisal with the multiple regression curve, can determine ink ejection amount according to this compensating value again corresponding to the ink fountain of this ink-covered area.

Their common drawback is: 1, can't improve the resolution of reading edition device with the method for segmentation ink-covered area.Because as long as the ink-covered area number of standard mass colour printing control version is certain, its resolution is also determined, both numerically equals thereupon.2, the user can't come the PS version of design standards voluntarily by the own actual mass colour galley of using, to adapt in the production because resolution is different or propose new demand according to some special circumstances to reading edition device.The discussion scope that does not then belong to us as for China ink amount control problem.

The objective of the invention is to: improve the resolution of reading edition device.And make the user only can design the standard edition that uses (proofreading and correct usefulness) for oneself as required as work.For this reason.It has proposed reading edition method and having provided corresponding device thereof of a kind of novel mass colour galley.

A kind of mass colour galley read an edition method, comprise the gray-scale value of reading each ink-covered area of standard mass colour galley and the digital filtering of the data that read being eliminated sinusoidal wave and impulse disturbances, to draw the actual ink-covered area gray value data of N group, read and read edition gray-scale value of last each ink-covered area, steps such as the gray-scale value of being read each corresponding ink-covered area on version and the standard edition compare, it is characterized in that, it provides a kind of the gray-scale value of reading each ink-covered area of standard edition that edition device reads has been carried out interpolation arithmetic, thereby the corresponding relation between the ink-covered area of refinement gray-scale value of setting up the gray scale measured value of each ink-covered area of standard edition and setting up on their own, again according to this corresponding relation, the gray scale measured value that to be read each ink-covered area of version is converted into gray-scale value through the ink-covered area of refinement, to increase the ink-covered area number, the mass colour galley of refinement China ink amount controlled variable read an edition method, it is made up of following steps successively: (1) sets up " gray level and gray level correction table ", promptly the resolution of standard edition is brought up to and read an edition Design of device resolution R with segmentation quasi-interpolation in turn

If: the actual ink-covered area gray value data of N group is on the standard edition of reading: (i, D _i), i=1,2,3 ..., N, wherein:

I: i ink-covered area on the standard edition;

D _i: i the pairing analog/digital sampled value in ink-covered area, i.e. gray-scale value, D _iBe positive integer;

N: the ink-covered area number of standard edition is the grayscale bar number,

N group data (i, D from above-mentioned standard edition _i) extrapolate the R group data (K, the C that read edition device _k), K=1,2 ..., R, wherein:

K: read K level gray scale in edition device;

C _k: the pairing analog/digital conversion value of K level gray scale, i.e. gray-scale value;

R: read edition setting value of device resolution, be positive integer;

Step of segmentation quasi-interpolation is as follows in turn for this:

1. according to the feature of gray-scale value between R value and the adjacent ink-covered area of standard edition, the gray-level difference between adjacent two grayscale bar of established standards version is L _j, herein, j=i-1 (i ≠ 1); Be j=1,2 ..., N-1; R and L _jBetween the pass be: $R=1+\underset{j-1}{\overset{N-1}{\mathrm{\&Sigma;}}}{L}_j+1+{\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="C9211357200161.png"\; state="\{\{state\}\}">L</figure-callout>}}_1+L_2+L_3+...+L_{M-1};$

2. calculate on the standard edition the pairing average gray value of per unit gray-level difference between each adjacent grayscale bar successively, its integral part aV _Gi, remainder partly uses rem _iExpression:

aV _gi=|D _i-D _i+1|/L _j,

rem _i=|D _i-D _i+1|-L _j×aV _gi,

I=1,2 ..., N-1; J=1,2 ..., N-1; 3. make C _k=D _i, C _K+Lj=D _I+1, wherein, i only gets 1,2 ..., N-1;

K=1+L ₁+L ₂+L ₃+…+L _j-1；

C _kBe meant with standard edition on the gray-scale value D of i ink-covered area _iEquate, read the gray-scale value of corresponding K gray level on edition device;

C _K+Lj, be meant and read to differ L with K on edition device _jThe gray-scale value of this gray level of individual gray level;

The size of the average gray value of more adjacent each inter-stage, promptly compare | D _I-1-D _i|/L _J-1, | D _i-D _I+1|/L _j, | D _I+1-D _I+2|/L _J+1, just can understand C _kWith C _K+LjBetween the variation tendency of gray-scale value, carry out the inhomogeneous interpolation of approaching again with actual conditions, can draw C _k, C _K+1, C _K+Lj-1

From i=1,, repeat above step,, obtain (K, C until i=N-1 _k), K=1,2 ..., R, thus set up " gray level and the gray level correction table " of actual mass colour galley; (2) quilt of reality is read version and carry out gray level correction: read the data of actual version and offset of sinusoidal ripple and impulse disturbances and carry out filtering, actual version gray value data after eliminate disturbing and gray-scale value in " gray level and gray level correction table " are compared, can draw the gray level of actual version after calibrated.

When the i section is carried out accurate interpolation, | D _I-1-D _i|/L _J-1, | D _i-D _I+1|/L _j, | D _I+1-D _I+2|/L _J+1Among, because of peaked difference, treat with a certain discrimination, simultaneously, its inhomogeneous interpolation is 1 umber of pulse:＜1〉if | D _I-1-D _i|/L _J-1Maximum then illustrates at each C _kTo C _K+LjOne section the D on the close left side in the section _iOr C _kChange maximum, be surplus rem _iBe distributed near C _kThe C of end _K+1, C _K+2..., C _K+remi,

That is: C _K+g=C _K+g-1+ aV _Gi+ 1, g=1,2 ..., rem _i,

C _K+m=C _K+m-1+ aV _Gi, m=(rem _i+ 1) ..., (L _j-1);＜2〉if | D _i-D _I+1|/L _jMaximum then illustrates at each C _kTo C _K+LjIn the section, middle one section variation is the fastest, C in the middle of being distributed in surplus _kTo C _K+LjIn this section, that is: hL _j=round [L _j/ 2], hrem _i=round [rem _i/ 2],

C _k+g=C _k+g-1+aV _gi,g=1,2,…,(hL _j-hrem _i)，

C _k+m=C _k+m-1+aV _mi+1,m=(hL _j-hrem _i+1),…,(hL _j-hrem _i+rem _i),

C _K+p=C _K+p-1+ aV _Gi, p=(hL _j-hrem _i+ rem _i+ 1) ..., (L _j-1);＜3〉if | D _I+1-D _I+2|/L _J+1Maximum then illustrates at each C _kTo C _K+LjIn the section, the one section variation in the right is the fastest, be distributed in surplus near this C _K+LjThe C of section _K+Ljrem, C _K+Lj-rem+1..., C _K+Lj-1The place,

That is: C _K+h=C _K+g-1+ aV _Gi, g=1,2 ..., (L _j-1-rem _i),

C _k+m=C _k+m-1+aV _gi+1,m=(L _j-rem _i),…,(L _j-1)。

A kind of mass colour galley is read an edition device, comprise and read an edition signal generator, signal processor, computing machine, topworks, feedback element and gauge tap, it is constructed as follows, read that edition signal generator exchange to be disturbed by the suppressed electrical network of series connection successively and the high-frequency ac power of low frequency flicker and green light source and constitute with the scanner head that photoelectric cell is made photoelectric device, signal processor is successively by the amplification of its input from photosignal change-over circuit in the scanner head, low-pass filtering, level moves with A/D conversion circuit and is in series, computing machine is sent in its output, topworks is successively by being subjected to computer-controlled motor speed control circuit, the gear train that actuating motor and drive scanner head move on actual plate is formed by connecting, and motor shaft links to each other to the photo-electric feedback element of computing machine feedback with its output.Gauge tap comprises scanner head starting point, terminal point travel switch and sweep starting point counter switch, and their output terminal and computing machine link, and input is from actuating motor.

Use proof: its gray scale resolution of device of the present invention is very high., existing as follows for below employed accompanying drawing number of present specification and title brief introduction thereof in conjunction with the embodiments to the more detailed description of the present invention's do:

Fig. 1, main program block diagram; Fig. 2, scanning subroutine block diagram;

Fig. 3, quasi-interpolation subroutine block diagram;

Fig. 4, filtering subroutine block diagram;

Fig. 5, IPC-3 read an edition device block diagram:

Fig. 6, scanner head main body circuit diagram;

Fig. 7, scanning running control circuit figure.

Embodiment:

Edition method of reading of mass colour galley is undertaken by the program flow diagram in Fig. 1～4.Wherein filtering subroutine has been used the average value filtering method, now is summarized as follows:

If: the sinusoidal interference signal is N (t)=A _SIN(2 π Ft+ ₀), for eliminating this interference, be in each ink-covered area sampling twice, the time interval of each sampling is $t_2-{\mathrm{<figure-callout\; id="1"\; label="t"\; filenames="C9211357200161.png"\; state="\{\{state\}\}">t</figure-callout>}}_1=\mathrm{nT}+\frac{T}{2}=n\frac{1}{F}+\frac{1}{2F}=\frac{1}{F}(n+\frac{1}{2}),$ N is a positive integer in the formula, and T is the cycle of sinusoidal interference signal.

Establish again: sampled signal is ${\mathrm{<figure-callout\; id="1"\; label="S\; amp"\; filenames="C9211357200161.png"\; state="\{\{state\}\}">S</figure-callout>}}_{\mathrm{amp}}1=S_{a_1}+N\left(t_1\right).=S_{a_1}+A_{\mathrm{SIN}}(2\mathrm{\&pi;<figure-callout\; id="1"\; label="F\; t"\; filenames="C9211357200161.png"\; state="\{\{state\}\}">F</figure-callout>}{t}_{}{}_1+{\mathrm{\&phi;}}_0),$ $S_{\mathrm{amp}}2+S_{a_2}+N\left(t_2\right),=S_{a_2}+A_{\mathrm{SIN}}(2\mathrm{\&pi;F}{t}_2+{\mathrm{\&phi;}}_0),$ After averaging, the two addition can eliminate sinusoidal wave the interference, because of it differs 180 degree. ${\mathrm{<figure-callout\; id="1"\; label="S"\; filenames="C9211357200161.png"\; state="\{\{state\}\}">S</figure-callout>}}_1=({\mathrm{<figure-callout\; id="1"\; label="S\; amp"\; filenames="C9211357200161.png"\; state="\{\{state\}\}">S</figure-callout>}}_{\mathrm{amp}}1+S_{\mathrm{amp}}2)/2=S_{a_1}+S_{a_2};$

In order to eliminate sine wave and impulse disturbances simultaneously, scheme is defined in each ink-covered area four groups of data of sampling, two sampled values of every group of array differ ( $\mathrm{nT}+\frac{T}{2}$ ) cycle, more every group of data are averaged, then: four groups of sampled datas are:

S ₁=(S _amP1+S _amP2)/2；

S ₂=(S _amP3+S _amP4)/2；

S ₃=(S _amP5+S _amP6)/2；

S ₄=(S _amP7+S _amP8)/2；

At S ₁～S ₄In four data, remove maximal value and minimum value, again two groups of data of remainder are averaged, can eliminate impulse disturbances.

How the inhomogeneous in turn quasi-interpolation that below will illustrate the present invention's proposition carries out:

If: read the gray value data of standard edition and behind digital filtering, obtained data set (i _i, D _i), set R=45 and press (i, D _i) in the development trend of gray level be allocated as follows:

i	1	2	3	4	5	6	7	8	9	10
											D i	22	30	37	44	58	69	81	90	98	109
L i	4	5	5	5	5	5	5	5	5	/

If: with i=5 is example:

D ₅=58,D ₄=44,D ₆=69,L ₅=5,

AV _G5=round (| 58-69|/5)=2,

rem ₅=|58-69|=5*2=1

K=1+L ₁+ L ₂+ L ₃+ L ₄=20, order: C ₂₀=D ₅=58; C ₂₀₊₅=C ₂₅=69, A then ₁=| D ₄-D ₅|/L ₄=| 44-58|/5=14/5,

A ₂=|D ₅-D ₆|/L ₅=|58-69|/5=11/5,

A ₃=| D ₆-D ₇|/L ₆=| 69-81|/5=12/5, as seen, A ₁Maximum, then C ₂₁=C ₂₀+ aV _G5+ 1=58+2+1=61, C ₂₂=C ₂₁+ aV _G5=61+2=63, C ₂₃=C ₂₂+ aV _G5=63+2=65, C ₂₄=C ₂₃+ aV _G5=65+2=67,

It is as follows to obtain " gray level and gray level correction table " from i=1 to i=10 repetition above-mentioned steps:

K	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15
																C k	22	24	26	28	30	32	34	35	36	37	38	39	40	42	44
K	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
																C k	46	49	52	55	58	61	63	65	67	69	71	73	76	79	81
K	31	32	33	34	35	36	37	38	39	40	41	42	43	44	45
																C k	83	85	87	89	90	91	92	94	96	98	100	102	105	107	109

Edition device of reading of mass colour galley is seen Fig. 5.Wherein, the 1st, interference free performance favorable industrial control bus computing machine and necessary interface circuit; The 2nd, be used to suppress that high-frequency ac disturbs and the high-frequency ac power of low frequency flicker; The 3rd, spectrum is the wideband green light source of 540 μ m and optically focused, reflex reflector; The 4th, reveal the PS version of surveying gray scale; 5 for photohead (also claiming scanner head), and running control circuit, its photoelectric device is used photoelectric cell that to be wavelength mate with the primary colours frequency spectrum of light source, PS version; Tens of photoelectric cells are arranged in cellular structure by the size and the systematic parameter of PS ink-covered area that version is decided, and can timesharing pick up the grey scale signal of each ink-covered area of PS version synchronously and can convert electric signal to; 2,3 and 5 collaborative works produce PS version grey scale signal; The 6th, signal processor. it circuit such as moves by amplification, low-pass filtering, level successively and is in series, and its output is sent to 7,7th, the analog/digital conversion small-mouthed jar, its course of work is subjected to computer control, and in this example, it also is an ingredient of computing machine; Topworks is formed by connecting by the gear train 10 that moved on actual version by computer-controlled motor speed control circuit 8, executive circuit 9 and drive scanner head successively.This gear train is connected and can drives the leading screw that scanner head moves and constitute by the speed gear that is connected with motor coaxle, another speed gear that meshes with the rectangle cingulum of speed gear engagement, with this cingulum and with this speed gear is coaxial; Actuating motor has driven a photoelectricity disc type counter 11 simultaneously.The interrupt counter of computing machine is sent in its output; Gauge tap comprises that their output of scanner head starting point, terminal point travel switch 12,13 and sweep starting point counter switch 14. all is sent to computing machine, and its input is controlled by actuating motor.Among the figure

It is the light transmission symbol.

Fig. 6 is a scanner head main body circuit diagram.Wherein, the output of photoelectric tube is through amplification, level mobile filter, transport to the mould/number conversion circuit of computing machine after amplifying once more.U ₁Use operational amplifier 09-07, U ₂And U ₃Share an operational amplifier TL082, R ₁～R ₇Be fixed resistance, W ₁, W ₂It is variable resistor.C ₁, C ₂Be electric capacity.V is a supply voltage.Fig. 7 is the control circuit of scanner head operation.Wherein, 16,17th, SSR2 type solid-state relay, 18,19th, DT-1A type DC motor speed-regulating device is made trace and return speed regulator usefulness respectively, D ₁～D ₆It is isolating diode.J ₁Be the trace pilot relay that puts in place, J ₂Be the return pilot relay that puts in place, J ₃Be the forward and reverse pilot relay of motor M, L _MBe the magnetizing coil of motor, K ₁Be the trace location switch, K ₂Be the return location switch, J _1-1, J _1-2, J _2-1, J _2-2, J _3-1, J _3-2Be respectively J ₁～J ₃Normally closed or normally opened contact.A, b be respectively computing machine input one output board to just, the trace sent of return control solid-state relay 16 and 17 and the input end of return instruction.C, d transport to computing machine to import put in place the output terminal of signal of the trace of an output board and return.V+, V-are respectively supply voltages.(V+ for+12V, V-are alternating current 220V) e then is the input end that computing machine is imported the motor horizontal control signal that an output board sends to the scanner head running control circuit by J3, just sending, after the return instruction, specifically just carry out by the motor commutation control signal, the return operation.By shown in Figure 7, there is not signal indication trace, otherwise the expression return.Just, after return puts in place, then by as just, the travel switch K of return location switch ₁, K ₂Control J ₁, J ₂An output board is just sending, return puts signal in place so that import to computing machine by c, d two ends.

Evidence: the ink ejection amount control problem that has solved the used PS version of press with method and apparatus provided by the invention well.

Claims (3)

1, a kind of mass colour galley read an edition method, comprise the gray-scale value of reading each ink-covered area of standard mass colour galley and the digital filtering of the data that read being eliminated sinusoidal wave and impulse disturbances, to draw the actual ink-covered area gray value data of N group, read and read edition gray-scale value of last each ink-covered area, steps such as the gray-scale value of being read each corresponding ink-covered area on version and the standard edition compare, it is characterized in that, it provides a kind of the gray-scale value of reading each ink-covered area of standard edition that edition device reads has been carried out interpolation arithmetic, thereby the corresponding relation between the ink-covered area of refinement gray-scale value of setting up the gray scale measured value of each ink-covered area of standard edition and setting up on their own, again according to this corresponding relation, the gray scale measured value that to be read each ink-covered area of version is converted into gray-scale value through the ink-covered area of refinement, to increase the ink-covered area number, the mass colour galley of refinement China ink amount controlled variable read an edition method, it is made up of following steps successively: (1) sets up " gray level and gray level correction table ", promptly the resolution of standard edition is brought up to and read an edition Design of device resolution R with segmentation quasi-interpolation in turn

If: the actual ink-covered area gray value data of N group is on the standard edition of reading: (i, D _i), i=1,2,3 ..., N, wherein:

I: i ink-covered area on the standard edition;

D _i: i the pairing analog/digital sampled value in ink-covered area, i.e. gray-scale value, D _iBe positive integer;

N: the ink-covered area number of standard edition is the grayscale bar number,

N group data (i, D from above-mentioned standard edition _i) extrapolate the R group data (K, the C that read edition device _k), K=1,2 ..., R, wherein:

K: read K level gray scale in edition device;

C _k: the pairing analog/digital conversion value of K level gray scale, i.e. gray-scale value;

R: read edition setting value of device resolution, be positive integer;

Step of segmentation quasi-interpolation is as follows in turn for this:

1. according to the feature of gray-scale value between R value and the adjacent ink-covered area of standard edition, the gray-level difference between adjacent two grayscale bar of established standards version is L _j, herein, j=i-1 (i ≠ 1); Be j=1,2 ..., N-1; R and L _jBetween the pass be: $R=1+\underset{j-1}{\overset{N-1}{\mathrm{\&Sigma;}}}{L}_j=1+L_1+L_2+L_3+...+L_{N-1};$

2. calculate on the standard edition the pairing average gray value of per unit gray-level difference between each adjacent grayscale bar successively, its integral part aV _Gi, remainder partly uses rem _iExpression:

aV _gi=|D _i-D _i+1|/L _j,

rem _i=|D _i-D _i+1|-L _j×aV _gi,

I=1,2 ..., N-1; J=1,2 ..., N-1; 3. make C _k=D _i, C _K+Lj=D _I+1, wherein, i only gets 1,2 ..., N-1;

K=1+L ₁+L ₂+L ₃+…+L _j-1；

C _kBe meant with standard edition on the gray-scale value D of i ink-covered area _iEquate, read the gray-scale value of corresponding K gray level on edition device;

C _K+LBe meant and read to differ L with K on edition device _jThe gray-scale value of this gray level of individual gray level;

The size of the average gray value of more adjacent each inter-stage, promptly compare | D _I-1-D _i|/L _J-1, | D _i-D _I+1|/L _j, | D _I+1-D _I+2|/L _J+1Just can understand C _kWith C _K+LjBetween the variation tendency of gray-scale value, carry out the inhomogeneous interpolation of approaching again with actual conditions, can draw C _k, C _K+1, C _K+Lj-1

From i=1,, repeat above step,, obtain (K, C until i=N-1 _k), K=1,2 ..., R, thus set up " gray level and the gray level correction table " of actual mass colour galley; (2) quilt of reality is read version and carry out gray level correction: read the data of actual version and offset of sinusoidal ripple and impulse disturbances and carry out filtering, actual version gray value data after eliminate disturbing and gray-scale value in " gray level and gray level correction table " are compared, can draw the gray level of actual version after calibrated.

2, mass colour galley according to claim 1 read an edition method, it is characterized in that: in the described quasi-interpolation of segmentation in turn, inhomogeneous value is a umber of pulse.

3, mass colour galley according to claim 1 read an edition method, it is characterized in that: when the segmentation quasi-interpolation is made inhomogeneous interpolation in turn, remainder rem _iBe assigned in the slower gray level of gray-value variation trend.

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