CN101013288A - Image forming apparatus and image forming method - Google Patents
Image forming apparatus and image forming method Download PDFInfo
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- CN101013288A CN101013288A CN 200610064256 CN200610064256A CN101013288A CN 101013288 A CN101013288 A CN 101013288A CN 200610064256 CN200610064256 CN 200610064256 CN 200610064256 A CN200610064256 A CN 200610064256A CN 101013288 A CN101013288 A CN 101013288A
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Abstract
A disclosed image forming apparatus for recording images includes: an image processing unit to create toner image data on four colors of yellow (Y), cyan (C), magenta (M), and black (K) such that toner images have line-shaped periodic structures; and an image forming unit to form the toner images using coloring materials of the four colors and superposing the toner images on a recording medium, wherein the line-shaped periodic structures of the toner images of the four colors are determined based on screen ruling of 200.0, 180.3, 180.3, and 200.0 for Y, C, M, and K colors and screen angles of 0.0, 146.3, 33.7, and 90.0 for Y, C, M, and K colors.
Description
Technical field
The present invention relates generally to static color image forming apparatus and formation method, and the imaging device that relates more specifically to be suitable for the technology of chromolithographh system and use laser log/silver halide imaging technology.
Background technology
Be imported into the view data in the imaging device, in hierarchy chart picture such as photo, have the multi-value data of every pixel 8-12 position.Comparatively speaking, be used for go up forming at paper (that is, hard copy) imaging device (comprising static image forming apparatus) of image, actual have a considerably less level that available every pixel is represented.In order to address this problem, hard copy device is increased to for example 600dpi or 1200dpi with its resolution, and according to the area that uses a plurality of pixels, modulation image density shows pseudo-shadow tone (pseudo-halftone) image.Pseudo-halftone process refers to input image data is converted to the Flame Image Process of carrying out in the step of pseudo-half tone image.The present invention relates to as the dither algorithm in the above-mentioned pseudo-halftoning method and be applied to a kind of combination of the dither matrix (combination of screen frequency and screen angle in a plurality of dither matrixs) on the full-color image.
For example, in non-patent literature 1, described in dither method, the details of the processing that multivalue image data is quantized is so omitted description to this in instructions of the present invention.Image through dithering process has periodic structure.In addition, coloured image be by the multiple toner image that superposes (full-color image generally be the stack four kinds of colors form, that is, and Y: yellow, C: cyan, M: magenta, K: black) form.In addition, the image of these four looks colors is through mutually different dithering process repeatedly, and these toner images have different periodic structures.In the past, in some cases, the image of four look colors makes toner image have identical periodic structure through dithering process.But in these cases, according to the positional fluctuation of color stack place, color can change, so no longer often use such dithering process now.At present, normally used method can be avoided producing such problem, and the image of four kinds of colors is processed into and has different periodic structures (screen frequency and screen angle change).This method is widely used in print field, also in the heat copy field that is different from printing, as being used widely in the electrophotographic image forming field.
The type of dither matrix can be categorized into: (1) site screening type, (2) Bayer type, and (3) line screening type.The present invention relates to generate the combined method of coloured image by making up multiple line screening type dither matrix.Compare with site screening type dither matrix, line screening type dither matrix has the following advantages.In the screening type dither matrix of site, require the periodic structure at generation center to have foursquare substantially shape, make the screen frequency of definition dither matrix and the degrees of freedom of screen angle be restricted.On the contrary, in the online screening type dither matrix, the periodic structure that generates the center can be rectangle or parallelogram, and compares with the situation of square shape, any difference can be do not caused, thereby the quantity (degrees of freedom of selection) of the combination of screen frequency and screen angle may be increased.
In stack has method about the toner image of the different cycles structure of the image of four kinds of colors, may produce a kind of phenomenon, be applied and can be observed as the interference figure of clapping difference as ripple.This interference figure is called as " colored moire ".When this colored moire of generation and visual identity in low-frequency region (clap difference frequency be low), colored moire can bring sticky feeling to the user, and becomes a factor of image quality decrease.Usually, select combined method, this colored moire that makes generation when four-color image superposes, as much as possible not by vision attention to (frequency of moire is high), and be identified for the dither matrix of dithering process in four looks.But the method for also not set up is kept the balance of the colored moire of all colours (stacks of all CMYK colors), is the main suitable combination of determining so be extensive use of with the experience.
Now, shown in Fig. 2 and 3, determine to be widely used in the combination of the dither matrix of four looks by the method that is used for being arranged in the widely used C of industrial printing equipment, M, Y, four kinds of colors of K.In this method, screen angle is to be provided with like this: the Y color is set to have the screen angle of 0 degree, and the C color is 15 degree, and the K color is 45 jiaos, and the M color is 75 degree (though screen frequency is not limit, approximately 1751pi is used for each of CMYK color in the same way).In order strictly to realize screen angle, need be not less than the resolution of 2400dpi.So, can realize other screen angle, and selection and the above-mentioned close screen angle (Fig. 3 forms the situation that above-mentioned screening is arranged corresponding to the resolution of using 2400dpi) of screen angle when resolution during less than 2400dpi.In addition, in this arrangement method, periodic structure has square shape, and shadow tone site shape so change 90 angles of spending with respect to each screen angle, has identical axis of orientation based on site screening type.In this combination, the fact that the colored moire that generates between Y color and CM color by utilization is difficult for being noted, the difference of the screen angle between Y color and CM color is set to 15 degree (in print field, the colored moire that generates is thought little) between Y color and other CMY colors.In addition, eliminate by stack have periodic structure a plurality of colors toner image and the colored moire that produces comprises for example patent documentation 1.
But the combination (after, be used for the combination of the dither matrix of four colors, be called as the shake group) that is identified for the dither matrix of four kinds of CMYK colors is very difficult, because there is not the method determined as mentioned above.Especially, exploitation is different from the more excellent shake group based on the known shake group of experience, is very difficult.
The optical recording apparatus scan light electric conductor of electrophotographic image forming type imaging device also forms electrostatic latent image, and the light beam that wherein emits from semiconductor laser is modulated optically, and reflects on the surface of the polygon prism of high speed rotating.In the scan method of this use polygon prism, known light-beam position change on so-called sub scanning direction (moving direction of the photoconductor of rotation) on photoconductor.This problem is commonly referred to as " surface tilt (surface tilt) ".The generation reason of surface tilt comprises the inclination of the surface of polygon prism with respect to electric machine rotational axis, and the fluctuation of the inclination on each surface of polygon prism (with respect to the inclination of turning axle, that is, surficial inclination), perhaps similar reason.For example, patent documentation 2 discloses the measurement measure that is used for surface tilt.
Usually, in order to reduce above-mentioned surface tilt, the optical system of optical recording apparatus is set, making has a kind of matching relationship between polygon prism surface and photoconductor drum surface.This method is general known to be as the function of avoiding surface tilt.But, even when using this surface tilt to avoid function, according to scanning position (position on main scanning direction), the light-beam position that incides on the polygon prism is different, is very difficult so eliminate the change of record position on sub scanning direction of being quoted by surface tilt fully.As a result, produced the change of record position.According to surface tilt, produce the unevenness (unevenness of the sweep spacing on sub scanning direction) of spacing (pitch), based on the quantity on the surface of polygon prism on sub scanning direction, the unevenness of spacing has space periodic.In this case, the unevenness of the corresponding density of unevenness of generation and spacing in image.This can and become a factor of image quality decrease by User Recognition (when the spacing of the unevenness of density big and when obviously visible), as a kind of abnormal image.
Non-patent literature 1: electrophotographic image forming art (Electrophotography), 24, the 1 phases (1985) of volume, 51-59 page or leaf;
Patent documentation 1: day disclosure is not examined patented claim 2002-112047 number
Patent documentation 2: day disclosure is not examined patented claim 2003-260813 number
The method of the colored moire of disclosed elimination in patent documentation 1 is used only to change the method for those phase places, and is used for the same periodic structure (identical screen frequency and screen angle) of Y color and a kind of color of CMY color.But only when the positional precision of overlay color was very high, this method was just effective, so when the position deviation of overlay color is big (approximately 10% of Dou Dong one-period), owing to the position deviation of overlay color, the tone of output image is changed.In other words, be different from above-mentioned use and change the method that screen angle is eliminated tone reversal, this method is not the basic solution that solves the positional precision of overlay color.
In addition, though disclosed method is considered to more excellent aspect colored moire in patent documentation 2,, for example, the number of combination that is used for the shake of CMYK color is 2, and discloses other combinations.In addition, patent documentation 2 does not have open about the description in preferred certain combination aspect the colored moire.
According to above-mentioned description, should understand the method for not set up, be used for determining four kinds of CMYK color combinations, make not generate colored moire, and exploitation is very difficult in preferred shake group aspect the colored moire.
As mentioned above, by using line screening type dither matrix, thereby form the shake group, may increase the number (degrees of freedom of selection) of the combination of screen frequency and screen angle (owing to improved degrees of freedom, the possibility of preferred combination increases aspect colored moire).Under the situation of site screening type shake, the axis of orientation (axle that parallels with the vector of indication cycle's property structure) that is necessary to be used for four CMYK colors is arranged in the scope of 90 degree, because in the screening type dither matrix of site, axis of orientation has the interval of 90 degree.On the contrary, in the online screening type dither matrix, can be set in the scope of 180 degree, because in the online screening type dither matrix, axis of orientation has the interval of 180 degree very fully the axis of orientation that is used for four kinds of CMYK colors.So, compare with the shake of site screening type, may in the CMYK color, have big screen angle.As a result, the shake of line screening type more may obtain preferred image aspect moire.
But, selecting shake prescription face, because up to ten thousand combinations are arranged, it is very difficult attempting all combinations.So, in fact, be used for the combination of the dither matrix (being called the shake group) of CMYK color, think suitable will being used on the experience.In other words, by combination line screening type shake, be chosen in the preferred combination in colored moire aspect and be not easy.
Summary of the invention
General target of the present invention provides a kind of improved and useful imaging device and formation method, has wherein solved the problems referred to above.
Target more specifically of the present invention provides a kind of imaging device and a kind of formation method, be used for the line screening shake of all four kinds of CMYK colors and the dither matrix that combination is different from traditional dither matrix by use, can export better pictures aspect colored moire.
In many examples, commercial ink-jet printer does not use above-mentioned dither method as pseudo-halftoning method based on error diffusion method, with represent images.Error diffusion method is the pseudo-halftoning method of a kind of frequency modulation (PFM) for the basis, and does not have the composition in cycle, so can not produce the colored moire that multiple overlay color brings on principle.In other words, the general ink-jet printer of supplying on the market is can not produce colored moire now.
Static image forming apparatus does not have periodic pseudo-halftoning method by using as error diffusion method same in the ink-jet printer, can avoid colored moire.But electrostatic methods has inadequate repeatability or stability, so its adaptability to error diffusion method is not enough for isolated single site.When use error method of diffusion in the Printer Engine that has inadequate repeatability or stability for isolated single site, can reduce graininess and identify the unevenness of strip.As a result, picture quality is on duty mutually.Based on the pseudo-halftoning method of shake, for the electrophotographic image forming method that has the inadequate stability in site, be only method, so, realize image processing method based on shake, and do not produce colored moire, be very important.
Another target of the present invention is when using dither method in the imaging device of electrophotographic image forming type, and more excellent imaging device and formation method is being provided aspect the colored moire.
The image output experiment that the present inventor carries out shows, in imaging device, record position is with the cyclomorphosis of 6 pixels (6 line) on sub scanning direction, the periodic structure of shake and the change interference of record position, and this interference is identified as density in low frequency change (in the back, the change of this density is called as " surface tilt moire ", to distinguish mutually with " colored moire ").In requiring inhomogeneity photographic image of image or graph image, this surface tilt moire can bring uncomfortable to the user, also can become a factor of image quality decrease.
When using when being defined as preferred traditional shake group with experience, on being created on sub scanning direction, be the above-mentioned record position in cycle when changing with 6 pixels, can clearly find out the generation of above-mentioned surface tilt moire.So, need not produce the shake group of this surface tilt moire.
A kind of method of eliminating the surface tilt moire is to reduce the change of record position.But,, be necessary further to improve the precision of element, the precision of driving etc. in order to reduce the change of record position.In other words, the standard of (1) polygon prism must be strict, and (2) must reduce the unevenness of photoconductor drum and the instability of rotation, thereby realizes with constant speed drive, and (3) must reduce the vibration of optical scanner (optical unit).As a result, increased the cost of whole imaging device.
Another target of the present invention is to realize imaging device cheaply, by using the shake group that can not produce the surface tilt moire (density unevenness in low frequency is spared property) that causes owing to the change at record position on the sub scanning direction.In addition, the shake group of Shi Yonging in the present invention is the combination of dither matrix more excellent aspect the colored moire that produces from the interference of dither matrix.
When use have screen angle be 0 the degree line screening type dither matrix (so-called side line on main scanning direction) time, if this dither matrix is assigned to highly enriched toner color, will see so-called band.This defective that is called as band is to be caused by the unevenness in the sub scanning direction upper density.The reason of band is believed to comprise the instability of the actuating speed of photoconductor, the vibration and the similar reason of pen recorder.Though the unevenness of the density on sub scanning direction is same phenomenon with the unevenness of the sweep span that is caused by above-mentioned surface tilt, but band refers to very macrocyclic density to be changed, and promptly 0.5mm is to 10mm (unevenness of the sweep span that is caused by surface tilt refers to about cycle of 0.2 to 0.4mm).In characteristic frequency, produce the band that can directly identify in this way, so the generation of band becomes the factor that picture quality descends in fact.
Another target of the present invention provides a kind of imaging device and method that does not generate band.
According to the present invention, a kind of imaging device that is used for document image is provided, comprise: graphics processing unit, the view data that generation is used to export, this view data comprises about the toner image data of four kinds of color yellow (Y), cyan (C), magenta (M) and black (K), makes toner image have the line style periodic structure; And image-generating unit, use the coloured material of four kinds of colors to form toner image, and toner image is superimposed upon on the recording medium, the line style periodic structure of the toner image of four kinds of colors wherein is based on the combination of the structure in cycle of screen frequency with appointment in the table of describing later 1 and screen angle and determine.
The quantity of combination with dither matrix of line style periodic structure is sizable (several ten thousand to tens), so, in fact can not the independent assortment dither matrix and find out preferred CMYK color combinations aspect colored moire.In view of the above, use aspect colored moire preferably combination with the dither matrix (shake group) of the known CMYK color of experience.Inventor of the present invention finds that by experiment the combination of the structure in the shake cycle of four kinds shown in the table 1 of Miao Shuing can be avoided colored moire in the back.The present invention relates to a kind of new technology, the structure in four kinds shown in the table 1 shakes cycle wherein is applied on the periodic structure of toner image of the CMYK color of using in the imaging device.In addition, carried out image output experiment, and output image is at length estimated, and test helps to reduce the component of colored moire.
(table 1) according to an aspect of the present invention, imaging device based on the shake group of this test result is provided, so, in all colours (comprising second color and the 3rd color) that the toner image by combination CMYK color forms, may be implemented in the more excellent color image forming apparatus in colored moire aspect.
(table 2) according to another aspect of the present invention, inventor of the present invention found through experiments, and the combination that is different from the dither matrix of table 1 also can be avoided colored moire.Combination shown in the table of describing 2 is the new combination that proposes for the first time in the present invention later.According to the present invention of (table 2) on the other hand, relate to imaging device based on the shake group that this test result is provided, so, in all colours (comprising second color and the 3rd color) that the toner image by combination CMYK color forms, may be implemented in the preferred color image forming apparatus in colored moire aspect.
According to another aspect of the present invention, the present invention helps to avoid colored moire in static image forming apparatus.In static image forming apparatus, the stability of the repeatability of isolated single site is inadequate, so when the dither method with periodicity toner image structure was used as pseudo-halftoning method, most probable was kept preferred picture quality.So, according to another aspect of the present invention, may in electrophotographic image forming type imaging device, keep the preferred picture quality that has preferred graininess and do not have tangible strip unevenness.Therefore, may be implemented in the preferred color image forming apparatus in colored moire aspect.
According to the present invention, can determine by image output experiment, by in the interference of the periodic structure of the variation of record position on the sub scanning direction and shake and the unevenness (human eye is the unevenness of density in low frequency as can be seen) of the density that causes can not produce, when in the resolution on the sub scanning direction be 600dpi or even when on sub scanning direction, produce when being the change of record position in cycle with 6 pixels (line).Traditionally, because record position produces on sub scanning direction the change of cycle of 6 pixels, with the periodic structure interference of shake, and this interference be density change in low frequency by User Recognition.This density in low frequency changes to the user to be brought sticky feeling and reduces picture quality.Especially, in the situation of photographic image or graph image, output image need be asked the homogeneity of image, and this can become the factor that picture quality descends in fact.According to the present invention, may be implemented in the more excellent imaging device in colored moire aspect, and can not generate change along with the density of change in low frequency of record position.So, possible outputting high quality image.Especially, in photographic image or graph image, may export better high quality graphic on homogeneity.
The present invention uses and allows laser beam to reflect on polygon prism, forms the structure of electrostatic latent image on photoconductor.Can determine by image output experiment, the unevenness of the density that produces along with the surface tilt of polygon prism traditionally (human eye is the unevenness of density in low frequency as can be seen) can be eliminated, when the resolution of optical recording on sub scanning direction is 600dpi, and the quantity (M) of the reflecting surface of quantity of LASER Light Source (N) and polygon prism satisfies equation: during N * M=6.Traditionally, use to reduce the method for surface tilt, as avoiding the method that density changes in low frequency, this density changes and is by causing along with the interference of surface tilt between the periodic structure of the change of record position on the sub scanning direction and shake.But this method requires polygon prism that strict surface tilt standard is arranged, so can cause the increase of element cost and imaging device cost.The present invention is not arranged to not the change of density in low frequency that caused by surface tilt, so can reduce the surface tilt standard of polygon prism, can realize imaging device cheaply.According to the present invention, may be implemented in the preferred color image forming apparatus in colored moire aspect, and the surface tilt standard needn't be too strict.So, when realizing low-cost imaging device, possible outputting high quality image, and can not produce change along with change density in low frequency of record position.Especially, in photographic image or graph image, may export better high-quality image on homogeneity.
The present invention uses has the dither matrix that screen angle is 0 degree (so-called side line), and dither matrix is appointed as the Y color, so, may avoid becoming an abnormal image factor, that be called as band of image quality decrease and outputting high quality image.
In conjunction with the accompanying drawings, by the following detailed description, other targets of the present invention, feature and advantage can more become more obvious.
Description of drawings
Figure 1A is the diagrammatic sketch that is illustrated in the periodic structure of shake in the example 1;
Figure 1B is the diagrammatic sketch of other periodic structures of shake in the expression example 1;
Fig. 2 is the diagrammatic sketch of the setting of the screen angle of CMYK color in the expression traditional printing method;
Fig. 3 is the diagrammatic sketch of the periodic structure of site screening type in the expression traditional printing method;
Fig. 4 is the diagrammatic sketch of the full color imaging device in the expression example 1;
Fig. 5 is the diagrammatic sketch of the optical device (laser optical unit) in the expression example 1;
Fig. 6 is the diagrammatic sketch of the optical path of optical device (laser optical unit) in the expression example 1;
Fig. 7 is the diagrammatic sketch of the relation between expression shake, master/secondary vector and the screen angle/line number;
Fig. 8 A is the diagrammatic sketch of the periodic structure of shake in the expression example 2;
Fig. 8 B is the diagrammatic sketch of other periodic structures of shake in the expression example 2;
Fig. 9 is the diagrammatic sketch of the optical path of optical device (laser optical unit) in the expression example 3;
Figure 10 is the diagrammatic sketch of the optical path of optical device (laser optical unit) in the expression example 4; With
Figure 11 is the diagrammatic sketch of the structure of imaging device in the expression example 5.
Embodiment
Below, with reference to accompanying drawing, embodiments of the invention are described.
(example 1)
Fig. 4 is the diagrammatic sketch of the structure of full color imaging device in the full color imaging devices in the expression example 1.The full color imaging device is used for the color component images by four kinds of colors of stack on recording paper in the example 1, promptly yellow (Y), cyan (C), magenta (M) and black (K) and formation image.In example 1,, arrange as shown in Figure 4 with each corresponding four image-generating unit 24 in the CMYK color component.The toner image of the rainbow member that will be in image-generating unit 24 forms on each is transferred on the intermediate transfer body (intermediate transfer belt) 29 of the band shape of arranging in abutting connection with ground with four image-generating units continuously.Intermediate transfer body 29 is rotated with predetermined sequential by not shown driver element, thus will with the corresponding toner image of each rainbow member, be superimposed upon on the preposition on the intermediate transfer body 29.The toner image that is superimposed upon the rainbow member on the intermediate transfer body 29 is transferred on the recording paper (transfer article, i.e. paper) 32 together, and becomes the image on the recording paper 32.
In example 1, has identical structure with each corresponding aforesaid image-generating unit 24 in four CMYK colors, so described in the unit.Image-generating unit 24 comprises: photoconductor drum; Charger 25 is used for photoconductor drum is charged to desired potential; Laser optical unit 23, the view data that will be used to export (through the described view data of carrying out pseudo-halftone process in back) records the photoconductor drum that is charged to desired potential; Developer 26 is used for using and the corresponding toner of each color component, and the electrostatic latent image on the photoconductor drum is developed, and wherein the record by laser optical unit 23 forms electrostatic latent image; Transfer printing device (the first transfer printing device) 28 is used for the toner image that develops by developer 26 on photoconductor, be transferred on the intermediate transfer body 29; And clearer 27, be used to clean remain on the photoconductor and be not transferred to residual toner on the intermediate transfer body.
Recording chart 32 (as paper) is carried by supply unit from not shown recording chart storer, is transported to the second transfer printing device 31 then after stoping roller 30 places adjusting scheduled timing.The second transfer printing device 31 is transferred to ideal position place on the recording chart 32 to the toner image on the aforesaid intermediate transfer body (toner images of four kinds of colors).Toner image is transferred to the recording chart 32 on it, and 33 places are provided heat and pressure in fuser, ejects from device then.According to above-mentioned running program, on recording chart such as paper, form and the corresponding full-color image of view data.
Next, with reference to Fig. 4, describing below with the view data that is used to export that is formed by the image processing equipment of describing later 20 is the operation of the laser optical unit 23 of fundamental operation.Video signal processing unit 21 receives the view data that is used to export (processing result image) that is formed by the image processing equipment of describing later 20, storage is about the data of light source 22 (semiconductor laser and laser diode) in linear memory, and according to rotating synchronous signal (promptly with polygon prism, synchronizing signal), that in linear memory, store and with the corresponding data of each pixel, be sent to the PWM controller with predetermined sequential (pixel clock) (in example 1, the quantity of light source is one in every kind of color).
The PWM controller is converted to width modulation (PWM) signal to data, and pulse-width signal is sent to the LD driver.The LD driver drives LD element (semiconductor laser) based on the optical modulation of using the light of predetermined quantity according to pulse width modulating signal.In example 1, width modulation (PWM) control is carried out according to the view data that is used to export of each rainbow member, and based on optical modulation and driving laser.
Next, the laser beam flying photoconductor that use drives based on optical modulation is described below and forms the structure of the optical unit (optical device) of electrostatic latent image.Fig. 5 is the diagrammatic sketch of the optical device in the expression example 1. Reference numeral 1Y, 1C, 1M and 1K represent the semiconductor laser of light source.Below, Y, C, M and the K in the Reference numeral back in turn represents yellow, magenta, cyan and black.Semiconductor laser 1Y represents to be used for the yellow of imaging, and semiconductor laser 1C, 1M and 1K represent to be used for cyan, magenta and the black of imaging respectively.In addition, Reference numeral 3Y, 3C, 3M and 3K represent to calibrate lens, Reference numeral 5Y, 5C, 5M and 5K represent cylindrical lens, Reference numeral 7 expression polygon prisms, and Reference numeral 8Y, 8C, 8M, 8K, 10Y, 10C, 10M and 10K represent lens (f-θ lens), as the image-forming component that constitutes scanned imagery optical system.Four semiconductor laser 1Y to 1K, four calibration lens 3Y to 3K, four cylindrical lens 5Y in 8K, use components identical in every group, and other four f-θ lens 10Y also are components identical to 10K to 5K, four f-θ lens 8Y.Reference numeral 9YC and 9KM represent to act on the sound control glass that is used for noise reduction on the polygon prism.Reference numeral 12Y, 12C, 12M and 12K represent to act on and are used for the dustproof dustproof glass on the optical system.Semiconductor laser 1Y, calibration lens 3Y, disc lens 5Y, polygon prism 7, f- θ lens 8Y and 10Y have formed " scanning optics of yellow image ", are used for forming on scanning of a surface 11Y the electrostatic latent image of yellow image.In the same way, semiconductor laser 1C, calibration lens 3C, cylindrical lens 5C, polygon prism 7, f- θ lens 8C and 10C have formed " scanning optics of cyan image ", are used for forming on scanning of a surface 11C the electrostatic latent image of cyan image.In addition, semiconductor laser 1M, calibration lens 3M, cylindrical lens 5M, polygon prism 7, f- θ lens 8M and 10M have formed " scanning optics of magenta color image ", are used for forming on scanning of a surface 11M the electrostatic latent image of magenta color image.And semiconductor laser 1K, calibration lens 3K, cylindrical lens 5K, polygon prism 7, f- θ lens 8K and 10K have formed " scanning optics of black image ", are used for forming on scanning of a surface 11K the electrostatic latent image of black image.Be used for yellow image these scanning opticss, be used for cyan image scanning optics, be used for the scanning optics of magenta color image and be used for the scanning optics of black image, optically all be components identical.
The mode that semiconductor laser 1C, calibration lens 3C, cylindrical lens 5C install, the same with semiconductor laser 1Y, calibration lens 3Y, cylindrical lens 5Y be installed in scheme vertical direction on the identical position of (sub scanning direction).In the same way, the mode that semiconductor laser 1M, calibration lens 3M, cylindrical lens 5M install, the same with semiconductor laser 1K, calibration lens 3K, cylindrical lens 5K be installed in scheme vertical direction on the identical position of (sub scanning direction).In addition, the path from polygon prism 7 to scanning of a surface 11Y, 11M, 11C and 11K is shown as " optical path of linear expansion ".As the polygonal mirror of the movable part of polygon prism, with constant speed, around being rotated with the perpendicular axle of figure.
Below, based on " scanning optics of yellow image " as an example, the summary of optical scanning is described.According to be used to export with the corresponding view data of yellow image, semiconductor laser 1Y is driven and the laser beam of transmitting optics modulation.Laser beam is converted to by calibration lens 3Y and is suitable for the light beam form that the used optical system in back is used.Though by this light beam form of calibration lens 3Y conversion, be parallel beam or have the weak diversity or the light beam of weak aggregation that this light beam form is called as " parallel beam " in this manual.
Be called as this light beam of parallel beam, 5Y assembles on sub scanning direction by cylindrical lens, and near the deflector surface of polygon prism 7, is imaged as " image that elongates on main scanning direction ".Image becomes basis and the deflected beam of polygon prism with the corresponding to Constant Angular Velocity deflection of the rotation of constant speed, and enters into f-θ lens 8Y.Then, owing to pass through the imaging effect of f- θ lens 8Y and 10Y, image accumulates on the scanning of a surface 11Y as luminous point, and spot scan scanning of a surface 11Y.By the optical scanning carried out by the scanning optics of cyan, magenta and black is identical.
Fig. 6 is the diagrammatic sketch of optical path that expression comes from each color of polygon prism 7.Optical scanner in the part presentation graphs 5 that with dashed lines centers on.The light beam that is used to form yellow image is by polygon prism 7 refractions, and by f-θ lens 8Y, reflection changes optical path on mirror mY, by f-θ lens 10Y, and forms luminous point on the photoconductor as scanning of a surface.The light beam that is used to form cyan image is by polygon prism 7 refractions, by f-θ lens 8C, then changes optical path in mirror mC1 reflection to the mC3, by f-θ lens 10C, and forms luminous point on the photoconductor as scanning of a surface.The light beam that is used to form magenta color image is by polygon prism 7 refractions, by f-θ lens 8M, then changes optical path in mirror mM1 reflection to the mM3, by f-θ lens 10M, and forms luminous point on the photoconductor as scanning of a surface.The light beam that is used to form black image is by polygon prism 7 refractions, and by f-θ lens 8K, reflection changes optical path on mirror mK, by f-θ lens 10K, and forms luminous point on the photoconductor as scanning of a surface.
In example 1, the number (N) that is used for the light source of CMYK color is one in every kind of color, and the number (M) of the reflecting surface of polygon prism (shared this polygon prism of CMYK color) is 6.
In image processing equipment 20 (Fig. 4), when generating the above-mentioned image that is used to export from input image data, the program that Flame Image Process is carried out is as described below.For example, example 1 relates to so-called laser printer type, so the input data are assumed to many-valued (8) image (under the situation of data duplicating machine, increased the scanner that is used to read literal, and transmitted the input data from scanning element) from personal computer.
Handle through emphasizing in the MTF filter process unit of input data in image processing equipment, to the color conversion of CMYK color space, the line density of going forward side by side control is with realization predetermined hierarchy in color separation/level correction processing unit (Y conversion) through the RGB color space of associating for acquired image data then.Then, view data is through the dithering process (back is described in detail it) as pseudo-halftone process, with consistent with the printer characteristic in pseudo-halftone process unit, and acquired image data is sent to image outgoing side (Laser Modulation driving side), as the view data that is used to export.Identical in MTF filter process, color correction process and Y treatment for correcting and the conventional art, omit its details at this.
Next, many-valued dithering process as pseudo-halftone process is described below in the example 1.In example 1, carry out 4 dithering process, the data after the wherein pseudo-halftone process are 4 (16 systems).In 4 dithering process, each pixel (each pixel is expressed as 256 levels of from 0 to 255) of 8 bit data as the input data is converted into the view data that is used to export, and is expressed as from grade 0 to grade 16 levels of 15.In this conversion, the level value (256 levels) of each pixel of input data, with the threshold in (in the storer or hard disk of image processing equipment) above-mentioned 16 level of hierarchy that preestablish and store, belong to from grade 0 to grade which grade in 15 the scope with each pixel of determining the input data.In other words, 4 dither matrixs use 15 of wherein having set threshold value to show that battle array forms (for example, about the computing method of the view data that is used to export, examining patented claim 2000-299783 number with reference to day disclosure in dither method).In example 1,, also can use other numerals in dithering process though the numeral that quantizes is 4 (16 systems).For example, except 1,2 and 8, also can use three-shift and quinary.As long as form the toner image of the structure with following cycle from dither matrix, any numeral based on quantizing all can obtain identical effect.
In example 1, the periodic structure of dither matrix has the structure of line style, and this dither matrix is considered to the shake of line screening.Screen angle and screen frequency are used as the numerical characteristics of the periodic structure of dither matrix.
Have in use under the situation of dither matrix of the periodic structure shown in Fig. 7, calculate screen angle and screen frequency uniquely according to the computing formula among Fig. 7.Generally speaking, use two two-dimensional vectors to represent the periodic structure of two dimension.These two vectors are called as master vector and secondary vector in the back.
Below table 1 show when using above-mentioned master vector and secondary vector the combination of four dither matrixs in the example 1.
Table 1
| Sequence number | The line number | Angle | a0x | a0y | a1x | a1y |
| Y | 200.0 | 0.0 | 3 | 0 | 0 | -3 |
| C | 180.3 | 146.3 | -3 | 2 | 3 | 2 |
| M | 180.3 | 33.7 | 3 | 2 | 3 | -2 |
| K | 200.0 | 90.0 | 0 | 3 | 3 | 0 |
Shake group in the example 1 (screen frequency and the screen angle of the shake of YCMK color)
Figure 1A and 1B show the periodic structure by the dither matrix of master vector in the table 1 and secondary vector representation.Figure 1A represents the jitter mode when image area number percent is 30%.Figure 1B represents the jitter mode when image area number percent is 50%.In example 1, the input data make the view data that is used to export in each color of CMYK color have the periodic structure shown in institute's table 1 through dithering process.And on photoconductor, form electrostatic latent image by above-mentioned laser optical unit (optical device).Then, by above-mentioned full color imaging device, can on paper, form the full-color image of expectation.In table 1, when the M color is appointed as No. 0, with the C look be appointed as No. 1, with the Y look be appointed as No. 2, when the K look is appointed as No. 3, obtain following table 1-1.
Table 1-1
| Sequence number | The line number | Angle | a0x | a0y | a1x | a1y |
| 0 | 180.3 | 33.7 | 3 | 2 | 3 | -2 |
| 1 | 180.3 | 146.3 | -3 | 2 | 3 | 2 |
| 2 | 200.0 | 0.0 | 3 | 0 | 0 | -3 |
| 3 | 200.0 | 90.0 | 0 | 3 | 3 | 0 |
(example 2)
The structure of example 2 most of with example 1 in identical.Used with example 1 in identical full color imaging device, laser optical unit, optical unit (optical device).Though image processing equipment most of with example 1 in identical, different in the dither matrix that in dithering process, uses and the example 1 as pseudo-halftone process.So the periodic structure of the view data that is used to export is through the dithering process different with example 1.
Dithering process in the example 2 is described below.Below table 2 expression when with example 1 in identical mode when using master vector and secondary vector, be used for the combination of the dither matrix of CMYK color in the example 2.
Table 2
| Sequence number | The line number | Angle | a0x | a0y | a1x | a1y |
| Y | 200.0 | 0.0 | 3 | 0 | 0 | -3 |
| C | 180.3 | 146.3 | -3 | 2 | 3 | 2 |
| M | 180.3 | 33.7 | 3 | 2 | 3 | -2 |
| K | 189.7 | 108.4 | -1 | 3 | 3 | 1 |
Shake group in the example 2 (screen frequency and the screen angle that are used for the shake of YCMK color)
Fig. 8 A and 8B are the diagrammatic sketch that shows the periodic structure of the dither matrix by master vector in the table 2 and secondary vector representation.Fig. 8 A represents the jitter mode when image area number percent is 30%.Fig. 8 B represents the jitter mode when image area number percent is 50%.In example 2, input image data makes the view data that is used to export in each color of CMYK color have the structure in cycle as shown in table 2 through dithering process.And with example 1 in identical mode, by laser optical unit, optical unit (optical device), on photoconductor, form electrostatic latent image.Then, by with example 1 in identical full color imaging device on paper, form conceivable full-color image.In table 2, when the M color is appointed as No. 0, with the C look be appointed as No. 1, with the K look be appointed as No. 2, the Y look is appointed as No. 3, obtain following table 2-1.
[table 2-1]
| Sequence number | The line number | Angle | a0x | a0y | a1x | a1y |
| 0 | 180.3 | 33.7 | 3 | 2 | 3 | -2 |
| 1 | 180.3 | 146.3 | -3 | 2 | 3 | 2 |
| 2 | 189.7 | 108.4 | -1 | 3 | 3 | 1 |
| 3 | 200.0 | 0.0 | 0 | 0 | 0 | -3 |
(comparative experiments 1)
Next, the comparative experiments 1 that the inventor carries out has been described.In this experiment, generated in table 1 (example 1) and the table 2 (example 2) and had the dither matrix group of aforesaid periodic structure, and carried out dithering process.Image reality is exported from experimental facilities, estimates the generation of colored moire based on ocular estimate.
Based on the evaluation of ocular estimate, be to carry out according to following method to the generation of colored moire.Generate five grades (1: bad at 5: good) of boundary sample in advance, select 140 color lumps from whole color dub zone, and output is used to estimate the image of generation.140 all color lumps as described below, are divided into 1 to 5 grade, and calculate the mean value that is used to estimate.The grade of above-mentioned boundary sample is represented with following the description qualitatively.
Class 5: unidentifiedly go out colored moire
Class 4: examine and to identify slight colored moire
Grade 3: identify moire to a certain degree
Grade 2: can obviously perceive colored moire
Grade 1: identify obviously unusual colored moire
In addition, use when changing pseudo-halftone process can output image experimental facilities (based on RicohIPSiO Color 5100 repackings), carry out image output experiment.The parameter of experimental facilities is as follows.
Log resolution: 600dpi
Quantity of light source (quantity of semiconductor laser): every kind of color of CMYK color has one
The wavelength of semiconductor laser: 655nm
The quantity of polygon prism reflecting surface: 6
Processing speed (peripheral speed of photoconductor drum): 125mm/sec
The revolution of polygon prism: about 29500rpm
The periodic structure of shake group (being used for the combination of the dither matrix of CMYK color) is carried out image output experiment according to its comparative experiments, as shown in the table of describing in example 1 and 21 and 2, below table 3 to shown in 5 those are examples of comparison.The dither matrix that uses in comparative example 1 to 3 is based on 4 shakes, and the data after the wherein pseudo-halftone process are 4 (16 systems), with example 1 and 2 in identical mode.
[table 3]
| Sequence number | The line number | Angle | a0x | a0y | a1x | a1y |
| Y | 189.7 | 161.6 | -3 | 1 | 1 | 3 |
| C | 212.1 | 135.0 | -2 | 2 | 2 | 2 |
| M | 189.7 | 108.4 | -1 | 3 | 3 | 1 |
| K | 200.0 | 90.0 | 0 | 3 | 3 | 0 |
The shake group of comparative example 1 (screen frequency and the screen angle that are used for the shake of YCMK color)
[table 4]
| Sequence number | The line number | Angle | a0x | a0y | a1x | a1y |
| Y | 189.7 | 161.6 | -3 | 1 | 1 | 3 |
| C | 189.7 | 108.4 | -1 | 3 | 3 | 1 |
| M | 212.1 | 135.0 | -2 | 2 | 2 | 2 |
| K | 200.0 | 90.0 | 0 | 3 | 3 | 0 |
The shake group of comparative example 2 (screen frequency and the screen angle that are used for the shake of YCMK color)
[table 5]
| Sequence number | The line number | Angle | a0x | a0y | a1x | a1y |
| Y | 189.7 | 161.6 | -3 | 1 | 1 | 3 |
| C | 180.3 | 146.3 | -3 | 2 | 3 | 2 |
| M | 180.3 | 56.3 | 2 | 3 | 2 | -3 |
| K | 189.7 | 108.4 | -1 | 3 | 3 | 1 |
Shake group in the comparative example 3 (screen frequency and the screen angle that are used for the shake of YCMK color)
Table 6 shows the evaluation result based on the colored moire generation of ocular estimate.
[table 6]
| The example numbering | The visual observation of colored moire | Note |
| Example 1 (table 1) | 4.52 | Very good, there is not colored moire |
| Example 2 (table 2) | 4.51 | Very good, there is not colored moire |
| Comparative example 1 (table 3) | 3.34 | Between the M-K color, can be observed moire |
| Comparative example 2 (table 4) | 3.54 | Between the C-K color, can be observed moire |
| Comparative example 1 (table 3) | 3.78 | Between the Y-C color, can be observed moire |
Example 1 and 2 and comparative example 1 to 3 in based on the evaluation result of the colored moire of ocular estimate
From table 6,, be appreciated that according to the combination of the shake shown in table 1 (example 1) and the table 2 (example 2) based on the evaluation result of ocular estimate, the output image that may obtain, and can not generate colored moire.The ground that compares according to the combination of the shake shown in table 3 (comparative example 3), table 4 (comparative example 4), the table 5 (comparative example 5), can identify colored moire, so only to obtain those low-quality output images.
In this mode, the shake combination shown in table 1 (example 1) and the table 2 (example 2) is the preferred and new combination about colored moire.In addition, from image output result of experiment, can find out significantly, verify preferred high quality graphic output about colored moire.
(comparative experiments 2)
The comparative experiments of being undertaken by the present inventor 2 is described below.In comparative experiments 2,, used same experimental facilities (based on Ricoh IPSiO Color 5100 repackings) to carry out image output experiment with the same in comparative experiments 1.
In the experimental facilities that in comparative example 2, uses, the light source (semiconductor laser) with each color that is used for the CMYK color, and polygon prism has 6 reflecting surfaces.So, when using many ribs scanner of the above-mentioned precision that aspect the surface tilt degree, has relative mistake, be the cycle with 6 pixels, record position changes on sub scanning direction.In comparative example 2, " the surface tilt moire " that periodic structure generated of the interference of the change of record position and shake estimated by ocular estimate on sub scanning direction.In the evaluation of surface tilt moire, output image is used the SCID-N1 table, this table is an integrated table, the mark below using is by estimating based on ocular estimate test entire image.
Zero: a bit do not observe the surface tilt moire
△: generated the surface tilt moire, but not clearly
*: generated the surface tilt moire, and obviously
In addition, in comparative experiments 2, use the shake group shown in table 1 (example 1) and the table 2 (example 2) and following shown in comparative example 4 and 5 in the shake group, output image.In addition, table 7 (comparative example 4) shows those site screening types of shake group (other shake groups of Miao Shuing comprise that table 8 all is the shake group of line screening type in this manual) only use to(for) all four kinds of CMYK colors.
[table 7]
| Sequence number | The line number | Angle | a0x | a0y | a1x | a1y |
| Y | 200.0 | 0.0 | 3 | 0 | 0 | -3 |
| C | 189.7 | 71.6 | 1 | 3 | 3 | -1 |
| M | 212.1 | 45.0 | 2 | 2 | 2 | -2 |
| K | 189.7 | 18.4 | 3 | 1 | 1 | -3 |
Shake group in the comparative example 4 (screen frequency and the screen angle that are used for the shake of YCMK color)
(only using the shake group of those site screening types for all four kinds of CMYK colors)
[table 8]
| Sequence number | The line number | Angle | a0x | a0y | a1x | a1y |
| Y | 200.0 | 0.0 | 3 | 0 | 0 | -3 |
| C | 189.7 | 161.6 | -3 | 1 | 1 | 3 |
| M | 212.1 | 135.0 | -2 | 2 | 2 | 2 |
| K | 189.7 | 108.4 | -1 | 3 | 3 | 1 |
Shake group in the comparative example 5 (screen frequency and the screen angle that are used for the shake of YCMK color)
Table 9 is depicted as and generation about the relevant surface tilt moire of the precision of many ribs scanner of surface tilt degree, based on the evaluation result of the image output experiment of ocular estimate.
[table 9]
| The example numbering | At many ribs scanner that good precision is arranged aspect the surface tilt degree | At many ribs scanner that poor precision is arranged aspect the surface tilt degree | Note |
| Example 1 (table 1) | ○ | ○ | The surface tilt moire does not observe |
| Example 2 (table 2) | ○ | ○ | The surface tilt moire does not observe |
| Comparative example 4 (table 7) | ○ | × | In C and M color, can be observed the surface tilt moire |
| Comparative example 5 (table 8) | ○ | × | In the C color, can be observed the surface tilt moire |
Example 1 and 2 and comparative example 4 and 5 in about the evaluation result of surface tilt moire based on range estimation of output image
From result, be appreciated that based on the evaluation of range estimation the table 9, make up according to the shake shown in table 1 (example 1) and the table 2 (example 2), even under the situation of the precision of relative mistake aspect the surface tilt, also may obtain more excellent output image, and can not generate the surface tilt moire.Comparatively speaking, according to the combination shown in table 7 (comparative example 4) and the table 8 (comparative example 5), though it is no problem under the situation that has good relatively precision aspect the surface tilt degree, but under the situation of the precision that has relative mistake aspect the surface tilt degree, can identify surface tilt moire and image quality decrease.
In this mode, the shake combination shown in table 1 (example 1) and the table 2 (example 2) is being more excellent aspect the colored moire, even under the situation of the precision that has relative mistake aspect the surface tilt, also produces the surface tilt moire hardly.In other words, from image output result of experiment, can find out significantly, verify high quality graphic output more excellent aspect colored moire and surface tilt moire.
(example 3)
Fig. 9 is the diagrammatic sketch of the structure of laser optical unit in the expression example 3.In example 3, used rib scanner more than two (7YC and 7MK) as shown in Figure 9.
(example 4)
Figure 10 is the diagrammatic sketch of the structure of laser optical unit in the expression example 4.In example 4, on the end portion of optical unit shown in Figure 10, arrange many ribs scanner.
(example 5)
Figure 11 is the diagrammatic sketch of the imaging device in the expression example 5.In example 5, full color imaging devices comprises so-called rotation type development unit.This rotary-type imaging device comprises the single photoconductor drum different with the device in the example 1, and uses single photoconductor drum to carry out the imaging operation of four kinds of CMYK colors.
(example 6)
In example 6,, in lithographic plate imaging device (printing machine), be used for dithering process (screening (the netting)) combination of CMYK color in the combination of the dither matrix shown in table 1 (example 1) and the table 2 (example 2).Static image forming apparatus describes though example of the present invention is based on, when the present invention is applied on the general printing machine (lithography), also may obtain identical effect (when the laser scanning record position is when changing in the cycle with 6 pixels, more excellent aspect colored moire, do not generate the surface tilt moire).
(example 7)
In the present invention, the screen frequency and the screen angle of the periodic structure of shake in table 1 and table 2, have been defined.But different according to the definition of coordinate system (definition of the direction of the angle of positive and negative and 0 angle position) might be used a plurality of numerical value definition screen angles.But aspect target of the present invention, the absolute figure of this angle is not extremely important.The relation of screen angle is even more important relatively in four kinds of jitter modes, so that avoid generating colored moire.So, if jitter mode is different from described in Fig. 1 or Fig. 8 those, then according to the shake group that is defined in those the corresponding screen angles in table 1 or the table 2 of coordinate system, also in protection scope of the present invention.
(example 8)
Though the image processing apparatus in example 1 carries out dithering process on input picture, and output as above the above result, can be integrated in image processing equipment other Flame Image Process.In other words, the pseudo-halftone process except dithering process also can be used, in order to be created on the periodicity toner image of definition in table 1 or the table 2.In an example of this pseudo-halftoning method, the threshold value table about the information of periodic structure that has in table 1 or table 2 definition can be used for the threshold value part that error diffusion is handled.
The invention is not restricted to concrete disclosed embodiment, and do not departing from protection scope of the present invention, can make a change and revise.
The present invention is based on 2005-325150 number of submitting on November 9th, 2005 and 2006-116771 number the Japanese priority patented claim of submitting on April 20th, 2006, its full content is incorporated into for your guidance at this.
Claims (8)
1, a kind of imaging device that is used for document image comprises:
Graphics processing unit generates the view data toner image data, that be used to export that comprises about four kinds of color yellow, cyan, magenta and black, makes described toner image have the line style periodic structure; And
Image-generating unit uses the coloured material of four kinds of colors to form described toner image, and described toner image is superimposed upon on the recording medium, wherein
Based on the combination of the periodic structure of screen frequency with appointment in the following table 1 and screen angle, and determine the line style periodic structure of the toner image of four kinds of colors:
[table 1]
Wherein, four values a0x, a0y, a1x and a1y, corresponding with x component, the y component of x component, y component and the secondary vector of master vector respectively, and also four kinds of colors are designated as No. 0 to No. 3.
2, a kind of imaging device of document image comprises:
Graphics processing unit generates the view data toner image data, that be used to export that comprises about four kinds of color yellow, cyan, magenta and black, makes described toner image have the line style periodic structure; And
Image-generating unit uses the coloured material of four kinds of colors to form described toner image, and described toner image is superimposed upon on the recording medium, wherein
Based on the combination of the periodic structure of screen frequency with appointment in the following table 2 and screen angle, and determine the line style periodic structure of the toner image of four kinds of colors:
[table 2]
Wherein, four values a0x, a0y, a1x and a1y, corresponding with x component, the y component of x component, y component and the secondary vector of master vector respectively, and also four kinds of colors are designated as No. 0 to No. 3.
3, imaging device as claimed in claim 1, wherein
The method of record toner image is the electrophotographic image forming recording method on recording medium.
4, imaging device as claimed in claim 2, wherein
The method of record toner image is the electrophotographic image forming recording method on recording medium.
5, imaging device as claimed in claim 1 comprises:
Optical recording/fetch equipment is used for reflecting on polygon prism and scanning latent image carrier by the light beam that allows to come from light source, and forms electrostatic latent image, wherein
Resolution at the above optical recording/fetch equipment of sub scanning direction is 600dpi, and the quantity (M) of the quantity (N) that is used to form the light source of solid color toner image and the reflecting surface of polygon prism satisfies equation: N * M=6.
6, imaging device as claimed in claim 2 comprises:
Optical recording/fetch equipment is used for reflecting on polygon prism and scanning latent image carrier by the light beam that allows to come from light source, and forms electrostatic latent image, wherein
Resolution at the above optical recording/fetch equipment of sub scanning direction is 600dpi, and the quantity (M) of the quantity (N) that is used to form the light source of solid color toner image and the reflecting surface of polygon prism satisfies equation: N * M=6.
7, a kind of formation method that is used for document image may further comprise the steps:
Use four kinds of coloured materials of yellow, cyan, magenta and black to form toner image, make described toner image have the line style periodic structure; And
Described toner image is superimposed upon on the recording medium, wherein
Based on the combination of the periodic structure of screen frequency with appointment in the following table 3 and screen angle, and determine the line style periodic structure of the toner image of four kinds of colors:
[table 3]
Wherein, four values a0x, a0y, a1x and a1y, corresponding with x component, the y component of x component, y component and the secondary vector of master vector respectively, and also four kinds of colors are designated as No. 0 to No. 3.
8, formation method as claimed in claim 7, wherein
The method that is used for record toner image on recording medium is the electrophotographic image forming recording method.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102984429A (en) * | 2011-09-05 | 2013-03-20 | 富士施乐株式会社 | Image processing apparatus, image processing method, and non-transitory computer readable medium |
| CN110086956A (en) * | 2019-05-21 | 2019-08-02 | 温州立可达印业股份有限公司 | A kind of halftoning hidden image relief effect shows hidden method |
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| CN102984429A (en) * | 2011-09-05 | 2013-03-20 | 富士施乐株式会社 | Image processing apparatus, image processing method, and non-transitory computer readable medium |
| CN102984429B (en) * | 2011-09-05 | 2016-12-14 | 富士施乐株式会社 | Image processing equipment and image processing method |
| CN110086956A (en) * | 2019-05-21 | 2019-08-02 | 温州立可达印业股份有限公司 | A kind of halftoning hidden image relief effect shows hidden method |
| CN110086956B (en) * | 2019-05-21 | 2020-12-04 | 增和包装股份有限公司 | Display and hiding method for halftone hidden image floating effect |
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