GB2050104A

GB2050104A - Screen-printing screen and methods of use and manufacture thereof

Info

Publication number: GB2050104A
Application number: GB8007785A
Authority: GB
Original assignee: CONS GROUP
Current assignee: CONS GROUP
Priority date: 1979-05-18
Filing date: 1980-03-07
Publication date: 1980-12-31
Also published as: FR2456620A1; DE3018879A1; BE883305A; ES491506A1; NL8001788A

Abstract

A screen for use in screen-printing has apertures whose centre- centre spacing is different in at least two portions of the screen and whose diameter or shape etc is non- constant in at least one area. The screen is useful for dye or resist chemical printing on carpets for textured appearance effects. The screen pattern is produced by scanning an original image and combining the signals with previously stored signals relating to desired aperture patterns etc. <IMAGE>

Description

SPECIFICATION Screen-printing screen and methods of use and manufacture thereof Hollow cylindrical screens electroformed or electrodeposited on suitable cylindrical anodes having patterns of spots of non-conducting material thereon are well known in the screenprinting art for use in conventional rotary screen printing processes. The spots of nonconducting material on the anodes cause the screens to have corresponding patterns of apertures therein where the nickel or other metal used for electroforming does not deposit.

Typically, the non-conducting spots are formed on the electrode photographically by coating the electrode surface with a photo-sensitive or photo-resist material, covering the photo-resist material with a photographic film suitably prepared to have an opaque background with clear spots corresponding to the apertures desired in the screen, exposing the photo-resist to light through the film, and developing the light-exposed spots to harden them, after which the unexposed portions of the photo-resist are dissolved away. Or the process may be performed in negative fashion to the above, as is well known in the art.

Film for such use has typically been prepared by conventional photographic methods in which designs have been pasted-up from commercially available or specially prepared sheets or screens covered with dots or openings of desired size, spacing, and geometric pattern; and then the designs have been photographically reproduced on film, with the usual positive and negative effects to get whatever final film is desired.

Such previously used processes for screen production are well known in the art, and are disclosed in U.S. Patent Nos. 4,118,288, 2,225,733, 3,586,610, 3,192,136, and 1,466,033. Also, by the use of the conventional half-tone, or continuous-tone photographic processes, as used in reproduction of photographs in newspapers, film is produced from shaded designs or photographs to have dots or openings whose size varies according to the shading of the original design or photograph, so that such film can be reproduced in an electroformed screen for screen-printing reproduction of the original on a suitable substrate.

While in some cases, the previously described techniques have been used to produce screenprinting screens having patterns of apertures comprised of two or more different pitches or meshes of apertures (number of apertures per lineal inch), the areas covered by the two pitches have been separate, and the hole size of the apertures for each pitch area have been constant, though different for each pitch area. Such screens are capable of producing different textured appearance effects in a screen-printed substrate such as a carpet, as well as darker or lighter shades of color, by either direct dyeing through the screen or by printing the carpet through the screen with a dye-resist chemical before dyeing to get a negative effect, but the appearance and shade in each pitch area will be constant.

Half-tone, or continuous tone, screens have provided apertures of variable size in an aperture pattern, but such patterns of apertures have all had the same pitch in a given screen-printing screen. While such continuous pitch half-tone screens are capable of producing continuous tone effects, or darker and lighter shades of color, in a screen-printed substrate such as a carpet by either direct dyeing or a dye-resist process, various areas of the carpet, whether having the same shade of color or not, will exhibit generally the same textured appearance, as determined by the mechanical characteristics of the carpet construction combined with the particular pitch or mesh used in the aperture pattern, especially as the mesh is normally so fine that it has no effect on the textured appearance of the carpet, but is purposely fine to reproduce a continuous tone ettect, as in an unenlarged photograph, without texture other than that of the carpet.

Screen-printing screens made according to the present invention have not only two or more different pitches of apertures, in different areas of the screen, but the aperture sizes in one or more of the areas may vary as in a half-tone or continuous tone screen; and even the pitches, shapes, and geometric relations to each other of the apertures may vary as desired, independently or in combination, more or less continuously, as desired, with or without generally simultaneous changes in aperture sizes. Normally, the apertures in at least some areas of a screen according to the present invention will be of a size to produce readily visible imprints on a carpet screen-printed therewith.Thus, carpets may be screen-printed by the methods of the present invention, using screens constructed according to the present invention, in a single pass under a single rotary screen, so that the resultant dyed carpet, whether direct-dyed through the screen or first dye-resist printed through the screen, exhibits unique shading and textured appearance effects not obtainable in a single pass with a conventional screen.

A unique combination of manufacturing steps for producing the screens of the present invention forms another part of the invention without which such screens probably would be impractical to produce, both economically and in terms of skilled labour.

A screen-printing screen according to the present invention includes apertures disposed therein in a predetermined pattern having successively adjacent portions in which at least one distinguishing characteristic of the pattern other than aperture size and portion shape varies between the adjacent portions for forming continuous texture effect shading on substrates screen-printed therethrough.

The center-to-center spacings of the apertures of such a screen may have gradations forming at least one distinguishing characteristic of the pattern and the shape of the pattern as disposed in the screen may form another distinguishing characteristic thereof, the geometric shape of the apertures may form at least one distinguishing characteristic of the pattern, or the geometric formation in which the apertures are arranged may form at least one distinguishing characteristic of the pattern.

Preferably, the pattern of apertures in such a screen includes apertures of gradated diameter in addition to the foregoing characteristics, and the predetermined pattern of such a screen may include apertures disposed to have at least two portions of the pattern having different center-tocenter spacings of the apertures as distinguishing characteristics of the pattern, and at least one of the portions having apertures of gradated diameter therewithin as another distinguishing characteristic thereof.

In the preferred embodiment of the screen of the present invention, the screen has a hollow cylindrical shape for rotation and engagement with a carpet substrate for application thereto through said screen of a dye-resist chemical or a dye-chemical by a screen printing process whereby the chemical is applied to the carpet in a dye-resist or dye chemical pattern corresponding to the predetermined pattern of apertures in the screen which upon subsequent dyeing of the carpet or fixing of the dye chemical in the carpet respectively, causes the carpet to exhibit a dyed pattern having different textured appearance effects therewithin corresponding to the predetermined pattern of apertures.

A method of dyeing a substrate with a dyed pattern having differences in textured appearance effects according to-the present invention includes the steps of printing the substrate with a dyeresist chemical or a dye chemical in a single pass by a rotary screen-printing screen having apertures disposed therein according to the previous portion of this summary whereby the dyeresist or dye chemical is applied to the substrate in a dye-resist or dye chemical pattern respectively corresponding to the predetermined pattern of the apertures in the screen, and either dyeing the dye-resist printed substrate in a process whereby the dye-resist pattern applied to the substrate causes the substrate to be dyed, or by fixing the dye chemical in the dye-printed substrate in a process whereby the dye chemical pattern applied to the substrate causes the substrate to be dyed, to exhibit the dyed pattern having the differences in the textured appearance effects corresponding to the predetermined pattern of the apertures in the screen.

A method of manufacturing a screen-printing screen according to the earlier portion of this summary and according to the present invention includes the steps of (a) providing a design original having areas of different shades disposed on the original to represent the pattern of apertures according to the earlier portion of this summary which is desired to be disposed in the screen, (b) making designations of the distinguishing characteristics of the pattern of apertures which is desired which are represented respectively by the different shades on the original, (c) entering the designations into electronic data processing means having a memory unit in suitable first electronic data from representative of the designations for entry of the designations into the memory by the electronic data processing means, (d) scanning the original with a scanning means connected to the electronic data processing means for discerning the shades and their dispositions on the original and entering the shades and their dispositions into the electronic data processing means in suitable second electronic data form representative of the shades and their dispositions for entry of the shades and their dispositions into the memory by the data processing means, (e) operating the electronic data processing means to suitably extract from the memory and merge the first electronic data and the second electronic data to form third electronic data representative of the desired pattern of apertures and their desired dispositions in the screen, and (f) applying the third electronic data to a laser beam apparatus means having a capability of reproducing the desired pattern of apertures and their dispositions in light energy patterns on a suitable substrate, the substrate being traversed past the apparatus in suitable synchronism with the applying of the third electronic data to the apparatus, for producing the screen having the desired pattern of apertures disposed therein in faithful reproduction of the design original and the designations of the distinguishing characteristics of the pattern of apertures respectively represented by the different shades on the original.

A preferable method of manufacturing a screen-printing screen according to the present invention includes the additional steps of exposing photographic film to produce latent images thereon of the desired pattern of apertures and their dispositions by applying the third electronic data to a laser beam apparatus connected to the electronic data processing means and having the capability of exposing the film to produce the latent images as the film is traversed past the laser beam apparatus in suitable synchronism with the applying of the third electronic data to the laser beam apparatus, developing the latent images on the film, using the developed film images to reproduce the desired pattern of apertures and their dispositions in latent images in photographic resist material an a suitable electro-forming electrode, developing the latent images in the photographic resist material on the electrode, dissolving away the undeveloped portions of the photographic resist material, and electro-forming on the electrode the screen-printing screen suitably to reproduce the developed images on the electrode as apertures in the printing screen, the apertures thereby forming the desired pattern of apertures in the screen.

A preferred method of manufacturing a screen-printing screen according to the present invention may include the step of perforating the pattern of apertures into a screen-printing screen blank by applying the third electronic data representative of the desired pattern of apertures and their dispositions to a laser beam apparatus connected to the electronic data processing unit and having the capability of perforating the screen blank to produce the pattern of apertures as the blank is traversed past the laser beam apparatus in suitable synchronism with the applying of the third electronic data to the laser beam apparatus, the desired pattern of apertures thereby being formed in the screen blank in faithful reproduction of the design original and the designations of the distinguishing characteristics of the pattern of apertures respectively represented by the different shades on the original to complete the manufacturing of the screen.

Embodiments of the invention will now be described by way of example, reference being made to the accompanying drawings, of which: Figure 1 is a perspective view of a rotary screen-printing screen according to the present invention rolling in printing relation to a substrate; Figures 2 through 8 are plan views of small broken-out screen sections having various aperture patterns as explained hereafter; Figure 9 is a schematic drawing showing the computer apparatus for practicing the screenmaking methods of the present invention; Figure 10 is an enlarged schematic representation of a grid pattern as used for creating aperture patterns in screens according to the present invention; Figure ii is a plan view of a small section of film bearing images for forming gradated patterns of apertures; and Figure 12 is an enlarged view of a single aperture image as seen in Fig. 11.

To obtain the unique combinations of aperture patterns of the screens of the present invention as disclosed herein, unique methods must be used in addition to, and may be substituted for, some of the conventional processes known in the art.

It has been known to produce different texture effects on screen-printed substrates by using visibly coarse-mesh screens having more than one mesh or pitch of printing apertures in separate respective areas thereof, and it has also been known to use "half-tone" or "continuous tone" effects in which the apertures of a single-mesh screen are gradated from comparatively very large with respect to the aperture center-to-center distances (perhaps 95% open area) to comparatively very small (even to zero size, 0% open area, no apertures at all) to produce shades of color on the printed substrate.Such continuous tone screens have generally, but not always, been fine mesh such that the screening or aperture dots as printed therethrough onto the substrates are generally not readily visible to the naked eye, purposefully, so that the shaded design reproduced on the substrates appears to the naked eye to have true continuous tone as in an unenlarged photograph.

However, it has not been known to use screens having more than one screen mesh therein in which at least one of the meshes also has gradated aperture sizes for producing continuous tones therefrom nor that such meshes should be visibly coarse for producing texture effects.

Also, it has not been known to use screens in which the distinguishing aperture pattern characteristics of aperture geometrical shape, center-to-center spacings of the apertures, and geometric formations of arrangement of apertures are varied at will in successively adjacent areas either separately or in combination, and either with or without variations in aperture size, in order to create screens for printing substrates which exhibit a whole new dimension of "texture effect shading" or "continuous texture effect shading" which is entirely different from, and highly advantageous over, conventional "half-tone shading" or "continuous tone shading." In continuous texture effect shading, substrates exhibit printed texture effects in which generally visible aperture-sized and -shaped spots on the substrates duplicate the varied-at-will aperture pattern characteristics of screens as disclosed in the preceding paragraph to give an appearance, effect, or illusion, of depth, perspective, and deep texture which is not found in the usual flat-screened (uniform mesh and aperture sizes within separate areas) or continuous tone (uniform mesh over a whole screen and gradated aperture sizes) screen-printed substrates, where different textures have been visible uniformly in each of the various flat-screened pattern areas, but color shading has been the dominant characteristic of the continuous tone pattern areas. Continuous texture effect shading screens and methods for their manufacture and use are disclosed in full detail hereinafter.

Screens: A rotary screen-printing screen 20 of conventional hollow cylindrical shape may have various pattern portions on the surface thereof, such as those indicated by the numerals 22, 24, 26, and 28 of Fig. 1, in which small apertures are formed into an aperture pattern whose portions may have such distinguishing characteristics as the center-to-center spacings of the apertures, the geometric formations (or lack of them, i.e. random placement) in which the apertures are arranged, the sizes of the apertures, the geometric shapes of the individual apertures, gradations of the formations, sizes, shapes, and/or spacings of the apertures within a pattern portion, and, of course, the shapes of the pattern portions 22, 24, 26, 28 themselves.A free roller 29 inside the screen 20 squeezes printing chemicals (not shown) from the inside of the screen 20 through the apertures therein during rotation of the screen 20 in order to print the chemical onto a substrate (such as a web of carpet) 29' moving past the screen 20 in synchronized contact therewith. Dye-resist of dye chemical patterns 22', 24', 26', and 28' are thereby printed on or applied to substrate 29' in faithful reproduction of the corresponding aperture pattern portions 22, 24, 26, and 28.

Typically, the apertures 30 of the screen 20 may have a circular shape and may be arranged in an internesting, or honeycomb, pattern as illustrated in Fig. 2 in order to achieve the maximum open area consistent with suitably strong walls 32 between the apertures 30. To achieve the very maximum open aperture area and minimum walls between the apertures, hexagonally shaped apertures may be substituted for the apertures 30 to get a true honeycomb pattern and shape. The internesting pattern also breaks up straight line patterns to a degree and is helpful in preventing the appearance of moiré patterns when a substrate is printed through such screens-the regular geometric patterns of apertures 30 may also be turned at suitable angles to the cylindrical axis of the screen 20 to prevent moirés.

As illustrated in Fig. 3, a pattern of smaller (about one-half the size, about 25% the area) apertures 34 disposed at the same center distances as in Fig. 2 will obviously result in a lesser percentage of open area and not only a different apparent shade of color on a substrate printed therethrough, but also a different mottled textured appearance effect on the substrate when the apertures are of readily visible size such as when the apertures 34 are spaced ten to the inch, and considerably smaller apertures also produce such textured appearance effects readily visible to the naked eye.The "pitch," "mesh," "screen," "lines per inch,'' or number of apertures per inch of the aperture pattern may also be finer or coarser than that illustrated in Figs. 2 and 3, to produce yet other textured appearance effects, and Fig. 4 illustates apertures 30 of the same size as those of Fig. 2, but at about twice the center-to-center distance or half the mesh.

Thus, while aperture patterns are usually thought of in terms of different "percentages open area" to produce different printed shades on a substrate, the patterns of Figs. 3 and 4, which are intended to have the same percentage open area, will print a substrate with different mottled textured appearance effects, even though the average apparent shades printed by each of the screens might be identical (e.g., as seen blurred through an out of focus lens).

Fig. 5 illustrates a small section of a screen having apertures 36 in a pattern having a constant pitch or mesh, but in which the apertures 36 are gradated in size. Such a size gradation will produce the aforementioned half-tone or continuous tone effect on a substrate printed through such a screen, in which the color shade will vary from light to dark according to the sizes of the apertures 36 and the amount of printing matter printed onto the substrate therethrough.While the apertures 36 of Fig. 5 are illustrated as varying in size from aperture-toaperture in one major direction, such a uniform variation or gradation is not necessary to achieve a continuous tone effect, as several apertures of the same size might be adjacent each other in the direction in which the tone is changing, thereby spreading the change out over a wider area while still achieving a generally continuously changing effect. Also, gradations of aperture size might extend in any or all directions.

It has been known in the screen-printing art to use more than one pitch or mesh of apertures in a screen, e.g. putting a different mesh in each of the pattern areas 22, 24, 26 and 28 as shown in the screen 20 illustrated in Fig. 1, or even in comparatively smaller areas to form more intricate designs. Such intricacy is limited somewhat by the skilled and tedious craftwork required to produce such a screen. However, it has not been known to have screens with more than one pitch or mesh of apertures in which at least one of the pitches also has apertures of gradated size for producing "half-tone" or "continuous tone" effects therefrom.

Therefore, a continuous tone pattern of apertures in one or more of two or more different meshes of apertures in a single screen forms one aspect of the present invention, a simple example of which is illustrated in Fig. 6 where apertures 36 of gradated size and constant pitch of center-to-center spacing S lie in areas G among other areas C where the apertures 38 are of constant size and of another constant pitch of center-to-center spacing S'. Such combinations of different aperture pitches with gradated aperture sizes produce highly attractive textured appearance contrasts and effects on a substrate screen-printed therefrom.

Other aperture patterns not heretofore known and forming part of the present invention include that of Fig. 7, where apertures 40 of constant size but of generally gradated pitch or mesh are illustrated, and Fig. 8, where both size and pitch of apertures 42 are generally gradated in the same pattern. An aperture pattern such as that of Fig. 8 may have a generally constant percentage open area thereacross for printing the same average apparent shade, but here again the mottled textured appearance effects will vary across the pattern when the aperture-sized printed pattern spots are visible to the naked eye and are viewed clearly.Again, though the gradations illustrated in Figs. 7 and 8 are quite regular from row-to-row or apertures, such regularity is not essential to the invention, and the gradations may be spread, with multiple rows of apertures in each gradation, to generally gradate a pattern in pitch, or in pitch and aperture size together.

Screen-making methods: Since cylindrical screen-printing screens may be quite large, e.g. up to about 36 inches in diameter, about 11 3 inches in circumference, and several yards long, for rotation in engagement with a carpet substrate for application thereto of dye or dye-resist chemicals in a pattern corresponding to one of the previously described patterns of apertures, it is readily apparent that it would be a monumental task by conventional methods to form such aperture patterns as those described hereinbefore into designs covering a large screen with intricate and infinitely shaded patterns of apertures derived from variations in aperture size and spacing gradated at will and intermixed according to a designer's wildest imagination.Thus, screens according to the present invention as disclosed herein must almost of necessity have their aperture patterns formed by highly automated methods using electronic data processing or computer technology for scanning artists' designs or other design originals, merging such designs with memory-stored aperture patterns, and applying such aperture patterns to film or directly to printing screen blanks for production of screens having aperture patterns faithfully reproducing the design original in selected aperture patterns which will be reproduced in a dyed pattern in a substrate to produce whatever differences in textured appearance effects the designer may desire on the substrate printed from the predetermined pattern of apertures in the screen. Such methods are more fully explained hereinafter.

To use the automated methods of the preceding paragraph, it is desirable to have an electronic data processing unit or computer 44, such as a SCI-TEX SYSTEM R-200, SYSTEM R-220, or SYSTEM 21 MXE COMPUTER from the Sci-Tex Corporation, Ltd. of Israel. SYSTEM R-220 was described in an article published in the February, 1978, issue of the magazine PACKAGE PRINTING AND DIECUTTING, and SYSTEM 21 MXE is a refined computer system working on the same general principles, while SYSTEM R-200 is a less complex computer. The computer 44 includes a suitable memory 46, electronic scanning head 48, and a laser beam plotting apparatus 50, all as shown schematically in Fig. 9 and further explained hereinafter.

!t is desirable that a design original 52 be provided in sheet form for wrapping around a cylindrical drum 54 which has driving apparatus 56 connected (as indicated by broken lines in Fig. 9) for rotating the drum 54 as well as traversing the scanner head 48 along the length of the drum 54 in synchronism with its rotation. Thus, the design original 52 might be a design drawing, a piece of textile fabric, a sheet of wood veneer, a photographic print, or other sheet material having disposed thereon lighter and darker shaded areas representative of patterns desirable for reproduction in aperture patterns disposed in a screen-printing screen.

A second cylindrical drum or rotating means 58 also has driving means 60 connected (as shown schematically by broken lines in Fig. 9) for rotating the drum 58 as well as for traversing the laser beam apparatus 50 along the length of the drum 58 in synchronism with its rotation.

A sheet of film 62 wrapped around the drum 58 may thereby be exposed to light energy emitted from the laser beam apparatus 50 in patterns as prescribed by the computer 44, thereby producing latent images on the film 62 of the desired pattern of apertures and their dispositions. These latent images may be developed on the film 62 and used to reproduce the desired pattern of apertures and their dispositions in latent images in photographic resist material on a suitable electroforming electrode. The latent images in the photographic resist material may be developed and the undeveloped portions (not part of the latent images) of the photographic resist material dissolved away, leaving the developed images of photographic resist material (formed from the latent images) on the electrode in the desired aperture pattern.A screen 20 may then be electro-formed on the electrode, and the developed images of the apertures will shield the electrode from electroforming so that the images will be reproduced in the screen 20 as apertures therein, the apertures thereby forming the desired pattern of apertures disposed in the screen in faithful reproduction of the design original 52 and the designations of the distinguishing characteristics of the pattern of apertures respectively represented by the different shades on the original 52.

Alternatively, a blank for a screen-printing screen 20 might be substituted on the drum or rotating means 58 in place of the film 62 for direct perforation of apertures into the blank by light energy emitted from a suitably powerful laser beam apparatus used in place of the filmexposing laser beam apparatus 50 of Fig. 9 to obtain similar faithful reproduction of the design original 52 and the characteristic designations.

Suitable conventional means are provided for detecting rotation of the drums 54 and 58 and traversing of the scanner head 48 and the laser beam apparatus 50 to assure suitable coordination through the computer 44 of pattern data from the scanner head 48 into the memory 46 and from the memory 46 out to the laser beam apparatus 50.

An electronic data processing unit or computer 44, such as a Sci-Tex System 21 MXE Computer, while forming no part of the present invention, is used as a tool in practicing the method of manufacturing screen-printing screens 20 according to the present invention, and is explained immediately hereinafter along with its included and connected apparatus comprising a memory unit 46, an electronic scanner head 48, a laser beam apparatus 50, a cylindrical drum 54 and its driving apparatus 56, a second cylindrical drum 58 and its driving means 60, a television screen T, a design console or electronic grid board C, and an electronic stylus E.

A design original 52, having been prepared and stretched over the surface of the drum 54, may be rotated with the drum 54 by the drum's driving apparatus 56 at a closely controlled speed, such as 1 80 rpm, while it is scanned by the scanner head 48 which is traversed along the length of the drum 54 in synchronization with its rotation at a rate of 1/32 millimeter or .00125 inch per revolution of the drum by the driving apparatus 56. The scanner head 48 is controlled by the computer 44 to take a reading at each .00125 inch increment of rotation of the surface of the drum 54, discerning the color shade displayed on the surface of the drum 54 (or on the design original 52 stretched thereover) at each said increment and transmitting signals to the computer representing that shade.The computer determines which of twelve selectively chosen shade ranges encompasses the shade of each increment or scanned spot on the original 52 and sequentially enters signals representing the particular shade range of each scanned spot into the memory 46.

The shade range signals may be sequentially retrieved or extracted from the memory 46 by the computer and further processed to record them on magnetic tape for storage and later retrieval from the tape for re-entry into the memory 46 for further use, or they may be used directly from the memory 46. In either case, the shade range signals form a plot or record, in electronic data form, of the shades and dispositions of something over 800 million tiny spots or dots forming a grid pattern covering the surface of a design original 52 having the maximum allowable size of about 36 X 36 inches. This electronic plot data is sent to the computer 44 in suitable form for entry thereby into the memory unit 46, and by repeated scanning passes over the design original any number of shade ranges may be plotted.The drum 54 has a circumference of about 32 inches, and a length in about the same range, to accommodate design originals up to about 36 X 36 inches, so that while the electronic plot of an original may consist of electronic signal data for any some 800 million discrete points scanned on a design original 52, the data may be electronically repeated to plot data for the the approximately 2 billion points which may be plotted on the film 62 by the laser beam apparatus 50 as explained further hereinafter. A common use of these shade range signals might be to form a shade separation by programming the computer 44 to pass the shade range signals representing one particular selected shade range while blocking the remainder of the shade range signals during a sequential retrieval of shade range signals from the memory 46 or a tape.The passed signals might then be processed and used for causing the laser beam apparatus 50 to sequentially project or apply a beam of light energy to a sheet of film 62 mounted on the surface of the second cylindrical drum 58 for rotation therewith.

The drum 58 is rotated at a closely controlled 1000 rpm by the driving means 60 which also traverses the laser beam apparatus along the length of the drum 58 in synchronization with its rotation at a rate of .00125 inches per revolution of the drum 58. A discrete application of the beam of light energy may be made to the film 62 for each .00125 inch increment of rotation of the surface of the drum 58, and whether or not the beam is applied at each .00125 inch increment of rotation may be determined by the respective passed or blocked retrieved shade range signals explained in the previous paragraph.

Thus, a sheet of film 62 may be exposed to exactly reproduce each grid point scanned on an original 52 and determined by the computer 44 to have a shade within the particular shade range selected, and, upon development, the film will form a shade separation for that particular selected shade range-i.e., a faithful reproduction of those portions of the design original 52 which lie in the selected shade range. This is particularly useful where several colors are to be screen-printed from several screens onto a single substrate, for in that case a color separation film made as just described (a given color may be programmed to be within the acceptable shade range, leaving out other colors, just as well as a monochromatic shade) could then be used conventionally to manufacture a color separation screen-printing screen. The just-described process, while forming no part of the present invention, illustrates the availability of the shade range signals from each scanned point on the original 52 for reproduction of corresponding points on the film 62.

However, in order to use the electronic data representative of the shade ranges on the scanned original 52 to produce a single screen-printing screen having different aperture patterns representing those shade ranges, it is necessary to introduce an electronic screen, or screens, so as to speak, between the electronic data representing the scanned original 52 and the laser beam apparatus 50. In its simplest terms, this is done by entry into the computer of electronic screen data representing a plot of a single aperture repeat portion which may be repeated electronically to form a complete pattern of apertures covering the approximately 2 billion discrete points which may be plotted by the laser beam apparatus 50 onto the film 62 rotating on the urum 58.

Creation of the electronic screen data is explained in the following paragraphs.

The electronic data processing means or computer 44 has a capability for electronically generating or creating geometric patterns, on a television screen T thereof on a grid pattern zither selectively automatically for a variety of programmable patterns, or manually by use of an electronic stylus E thereof on a design console or electronic grid board C thereof where any desired pattern can be created by use of the stylus E to individually selectively actuate the thousands of electrosensitive grid points displayed on the design console C.By manipulation of the computer 44 controls, such generated patterns may be expanded, contracted, multiplied, repeated, shifted, or otherwise manipulated to generate electronic data representing such patterns to cover each of the approximately 2 billion discrete points plottable by the laser beam apparatus 50 on the typical 75 inch circumference by 42 inch length of the drum 58, as the drum rotates at 1000 RPM in operation. As shown in Fig. 10, each grid square 64 represents one of the aforementioned 2 billion discrete points, and the aforesaid electronic screens comprise electronic data signals indicating a binary 0 or 1 signal for each square 64.

In view of the repeating capacity of the computer 44, it is only necessary to create a suitably large portion of the screen pattern so that the complete pattern may be formed by repeats of the portion to cover the 2 billion plot points possible for the laser beam apparatus 50 and the drum 58. A simple example is illustrated in Fig. 10 where a repeat portion 66 (as enclosed by broken lines) of such an electronic screen pattern comprises 100 grid squares 64 arranged in a 10 X 10 block. The largest aperture possible in such a 10 X 10 square portion 66 would be a 9 x 9 block 68 of squares 64 as indicated by the dots 70 in the peripheral squares 64 thereof.

Repeated indefinitely, such a screen pattern would have an 81 % open area, since 81 of each 100 squares 64 would represent aperture area, and only the open squares 64 just within the right and lower borders of the portion 66 would represent the solid walls between apertures.

Similarly, other screens with other open area percentages could be formed from the same portion 66 by letting the 7 X 7 block 72 of squares 64 (as indicated by the slash marks 74 in the peripheral squares 64 thereof) represent an aperture, so that the screen would have 49% open area, or a 5 X 5 block 75 of squares 64 (lying within the slash marks 74) for a 25% open area screen. Such electronic screen data signals suitably processed by the computer 44 and applied to the laser beam apparatus 50 to expose the film 62 at each of the 2 billion points thereon represented by the squares 64 within the blocks 68, e.g., would result in a film covered by a uniform pattern of square exposed areas, or aperture areas, corresponding to the blocks 68.Such a film could be used to produce an electroformed screen-printing screen of uniform mesh of 80 lines per inch, with 81% open area formed by square apertures.

In typical practice, the blocks of squares 64 representing apertures, such as the block 78, might be considerably larger, such that the apertures might form a 10 mesh or line per inch screen in which each repeat portion 66 would consist of 80 X 80 or 6400 squares 64, and a 76 X 76 block of 5776 squares 64 representing an aperture would result in a roughly 90% open area screen having approximately .005 inch walls between .095 inch square apertures.

Circular apertures in screen-printing screens such as those of Figs. 2-8 will then not be microscopically perfect circles, but rather close approximations as may be formed by a group of squares 64 whose centers are circumscribed by a circie. Any other desired shape of aperture may be approximated by a similar suitable selection of a group of squares 64.

Having once scanned an original 52 and entered the shade range of each scan point thereof into the memory unit 46, a designer may decide that in the final result he wants, for example, a screen-printing screen 20 in which the areas corresponding to various shade ranges of the original should have aperture patterns with open areas formed by apertures and meshes according to the following table A: TABLE A Shade % Lines/ Range Open Inch Aperture No.Area Mesh Shape S1 90% 10 Square S2 80 10 Square S3 70 10 Square S4 60 10 Square S5 50 10 Square S6 50 1 5 Circle S7 40 1 5 Circle S8 40 1 5 Circle S9 20 15 Circle S10 10 15 Circle S11 7 15 Circle The designer then creates electronic data representing each of the aperture patterns desired on the screen 20 and manipulates and enters such electronic screen data into the memory unit 46 to form a record of an electronic screen as described hereinbefore for each aperture pattern.

The designer also designates or programs into the computer 44 which electronic screen is to be represented by each shade range scanned on the design original 52. These designations are entered into the memory 46 for use as described hereinafter.

The computer 44 then has the capability to merge the scan point shade range data and the electronic screen data by calling up or extracting from the memory 46 the binary electronic data signal for the designated electronic screen for each scan point according to the scan point shade range data just previously called up from the memory 46 and using the binary signal to produce an electronic exposure signal for the scan point accordingly. In further detail, electronic screen point data signals signifying whether each particular electronic screen point lies within or without an aperture for each of as many as 12 different electronic aperture pattern screens of constant mesh may be entered into the memory 46 for selective retrieval or extraction in sequence for each screen point at a single pass.

Then, the scan point shade range data for a particular scan point may be used to select the particular one of the 1 2 electronic screen point aperture pattern data signals that has been designated for a particular scan point shade range. That particular screen point aperture pattern data signal (which is in binary form) may then be used to produce the electronic exposure signal corresponding to each scan point Where electronic screens of different meshes are to be used to represent different scan point shade ranges, it is necessary to enter the screen point data for the different meshes in separate sections of the memory and to make separate passes of the scan points and the memory to merge the scan point shade range data with the electronic screen data for each different mesh.

Likewise, if it is desired to use more than 1 2 different aperture patterns of a given mesh, it would be necessary to put those in excess of 1 2 into a separate section, or sections, of the memory 46 for multiple passes. Data from each pass would normally be transferred from the memory 46 to a magnetic tape, so that in the end a single tape would have the exposure signals in sequence for each of the two billion plot points, and a single pass of the tape through the computer 44 to operate the laser beam apparatus 50 would produce a completely plotted sheet of film 62.

These exposure signals form a third group of electronic data signals representing each point capable of being plotted by the laser beam apparatus 50 on the film 62 and are capable of suitably signaling whether or not the laser beam apparatus 50 is to expose the film 62 at each of the respective 2 billion plot points.This third group of electronic data signals may be stored on magnetic tape and then run off in synchronism with the rotation or traverse of the drum 58 past the laser beam apparatus 50 as the apparatus 50 traverses the length of the drum 58 in order to expose the film 62 substrate on the drum 58 so that each shade range area scanned from the design original 52 is represented on the film 62 by a corresponding area covered by the designated aperture pattern so that the film can be used for producing the aforementioned texture effect shading screen-printing screens Thus, referring to Fig. 10, if a particular scan point corresponding to the grid square 64 designated P falls in a shade range designated to be represented by an 81% open area aperture pattern, it will be compared or merged to the electronic screen pattern including the block 68 of squares 64, and the resulting electronic data signal entered into the third group of electronic data signals will be a signal to expose the film 62 at that particular plot point. Likewise, if the particular scan point corresponding to the square 64 designated P falls in a shade range designated to be represented by a 49% open area aperture pattern, it will be compared to the screen pattern including the block 72 of squares 64 and the resultant electronic data signal will again result in exposure of the film 62 at that particular plot point.However, if the scan point corresponding to the square designated falls in a shade range designated to be represented by a 25% open area pattern of apertures, it will be compared to the screen pattern including the block 75 of squares 64 and the resultant signal in the third group of electronic data signals will result in non-exposure of the film 62 at that particular plot point since the square designated P lies outside the block 75 representing a 25% open area aperture.

To further illustrate, Fig. 11 shows enlarged and in broken lines on a portion of film 62 the effective boundaries of shade ranges S3, S5, S7, S9, and S11 as scanned on a design original 52. Assuming that the shade ranges represent the aperture pattern characteristics designated in Table A hereinbefore, and that such aperture pattern characteristics have been designated or programmed into the computer 44 accordingly, the aforesaid merging of the first electronic data representing the designated aperture pattern characteristics and the second electronic data representing the scanned shades of each scan point results in third electronic data comprising electronic exposure signals corresponding to each scan point.Application or non-application of laser beam energy at coresponding points on the film 62 according to the exposure signals as explained hereinbefore, will then produce on the film 62 the exposed spots designated 76, 78, 80, 82, and 84 in Fig. 11, respectively representing the aperture patterns designated for the shade range numbers S3, S5, S7, S9, and S11 as listed in Table A. Assuming that the scanning and laser beam plotting have been done at their finest resolutions of .00125 inches per scan point and plot point (various other resolutions are available), the spots 84 will be sixteen scan or plot points or .020 inches in diameter to achieve approximately 7% open area in the fifteen line per inch mesh.The plot points are designated 86 in Fig. 12, which is a much enlarged view of a splot 84 as shown in Fig. 11 whose actual periphery is generally represented by the broken-line circle designated 84 in Fig. 12, and only a small number of the exposed plot points 86 are shown hatched in Fig. 1 2 to show the microscopically irregular nature of the actual periphery of the spot 84. The plot points 86 correspond to the grid squares 64 of Fig.

10, and in actuality on the film 62 will be generally circular spots slightly overlapping each other where adjacent, due to the inevitable scattering of the light rays from the laser beam apparatus 50.

As may be noted in Fig. 11, where the effective boundary of a shade range passes at random across an aperture pattern, any portion of an aperture may be included within a shade range.

When the boundary lies between different aperture patterns, portions of two different apertures may join to form odd-shaped apertures which may enhance the textured appearance effect in substrates printed from screens made accordingly.

Screen-use methods: It is new in the carpet-dyeing art to screen-print a dye chemical onto a carpet substrate through a screen according to the present invention in a single pass and then to fix or set the dye in the substrate by conventional means to achieve continuous texture effect shading thereon. It is novel to achieve such continuous texture effect shading by screen-printing a dyeresist chemical onto a carpet substrate through a screen according to the present invention in a single pass and then dyeing the carpet in a bath wherein dyeing is prevented in those portions of the carpet where the dye-resist chemical has been applied but normal dyeing takes place in the ramainder of the carpet and the dye chemical is subsequently fixed in the carpet conventionally.

It is new in the carpet-dyeing art to screen-print a dye chemical or a dye-resist chemical onto a carpet substrate through a single textured appearance effect screen constructed according to the present invention for subsequent fixing or dyeing and fixing to achieve the depths, perspectives, varieties, and subtleties of textured appearance effects on the carpet which are otherwise available only by repeated screen-printing through a plurality of different screens.

The present invention has been described in detail above and illustrated in the drawings for disclosure purposes only and is not intended to limit the scope of the invention, which is to be determined by the scope of the appended claims.

Claims

1. A screen-printing screen comprising apertures disposed therein in a predetermined pattern having successively adjacent portions of said pattern in which at least one distinguishing characteristic of said pattern other than aperture size and portion shape varies between said adjacent portions for forming continuous texture effect shading on substrates screen-printed therethrough.

2. A screen-printing screen according to claim 1 and characterized further in that the center to-center spacings of said apertures have gradations forming said at least one distinguishing characteristic of said pattern and the shape of said pattern as disposed in said screen forms another distinguishing characteristic thereof.

3. A screen-printing screen according to claim 1 and characterized further in that said at least one distinguishing characteristic is the geometric shape of said apertures.

4. A screen-printing screen according to claim 1 and characterized further in that said at least one distinguishing characteristic is the geometric formation in which said apertures are arranged.

5. A screen-printing screen according to claim 1, 2, 3, or 4 and characterized further in that said pattern includes apertures of gradated diameter therewithin.

6. A screen-printing screen comprising apertures disposed therein in a predetermined pattern having at least two portions thereof having different center-to-center spacings of said apertures as distinguishing characteristics thereof, and at least one of said portions having apertures of gradated diameter therewith in as another distinguishing characteristic thereof

7.A screen-printing screen according to claim 1 or 6 and characterized further by having a hollow cylindrical shape for rotation in engagement with a carpet substrate for application thereto through said screen of a dye-resist chemical by a screen-printing process whereby said dye-resist is applied to said carpet in a dye-resist pattern corresponding to said predetermined pattern of apertures which, upon subsequent dyeing, causes said carpet to exhibit a dyed pattern having different textured appearance effects therewithin corresponding to said predetermined pattern of apertures.

8. A screen-printing screen according to claim 1 or 6 and characterized further by having a hollow cylindrical shape for rotation in engagement with a carpet substrate for application thereto through said screen of a dye chemical by a screen-printing process whereby said dye chemical is applied to said carpet in a dye chemical pattern corresponding to said predetermined pattern of apertures which, upon subsequent fixing of said dye chemical in said carpet, causes said carpet to exhibit a dyed pattern having different textured appearance effects therewithin corresponding to said predetermined pattern of apertures.

9. A method of dyeing a substrate with a dyed pattern having differences in textured appearance effects comprising the steps of: (a) printing said substrate with a dye-resist chemical in a single pass by a rotary screenprinting screen having apertures disposed therein according to claim 1 whereby said dye resist is applied to said substrate in a dye-resist pattern corresponding to said predetermined pattern of said apertures; and (b) dyeing said dye-resist printed substrate in a process whereby said dye-resist pattern applied to said substrate causes said substrate to be dyed to exhibit said dyed pattern having said differences in said textured appearance effects corresponding to said predetermined pattern of said apertures.

10. A method of dyeing a substrate according to claim 9 and characterized further in that said predetermined pattern of apertures includes apertures of gradated diameter therewithin.

11. A method of dyeing a substrate with a dyed pattern having differences in textured appearance effects comprising the steps of: (a) printing said substrate with a dye-resist chemical in a single pass by a rotary screenprinting screen having apertures disposed therein in a predetermined pattern according to claim 6 whereby said dye-resist is applied to said substrate in a dye-resist pattern corresponding to said predetermined pattern of said apertures and (b) dyeing said dye-resist-printed substrate in a process whereby said dye-resist pattern applied to said substrate causes said substrate to be dyed to exhibit said dyed pattern having said differences in said textured appearance effects therewithin.

1 2. A method of dyeing a substrate with a dyed pattern having differences in textured appearance effects comprising the steps of: (a) printing said substrate with a dye chemical in a single pass by a rotary screen-printing screen having apertures disposed therein in a predetermined pattern according to claim 1 whereby said dye chemical is applied to said substrate in a dye chemical pattern corresponding to said predetermined pattern of said apertures; and (b) fixing said dye chemical in said dye-printed substrate in a process whereby said dye chemical pattern applied to said substrate causes said substrate to be dyed to exhibit said dyed pattern having said differences in said textured appearance effects corresponding to said predetermined pattern of said apertures.

1 3. A method of dyeing a substrate according to claim 1 2 and characterized further in that said predetermined pattern of apertures includes apertures of gradated diameter therewithin.

14. A method of dyeing a substrate with dyed patterns having differences in textured appearance effects comprising the steps of: (a) printing said substrate with a dye chemical in a single pass by a rotary screen-printing screen having apertures disposed therein in a predetermined pattern according to claim 6 whereby said dye chemical is applied to said substrate in a dye chemical pattern corresponding to said predetermined pattern of said apertures; and (b) fixing said dye chemical in said dye-printed substrate in a process whereby said dye chemical pattern applied to said substrate causes said substrate to be dyed to exhibit said dyed pattern having said differences in said textured appearance effects therewithin.

1 5. A method of manufacturing a screen-printing screen characterized according to claim 1, 2, 3, 4, 5, or 6 comprising the steps of: (a) providing a design original having areas of different shades disposed on said original to represent said pattern of apertures according to claim 1, 2, 3, 4, 5, or 6 respectively which is desired to be disposed in said screen; (b) making designations of the distinguishing characteristics of said pattern of apertures according to claim 1, 2, 3, 4, 5, or 6 respectively which are represented respectively by said different shades on said original; (c) entering said designations into electronic data processing means having a memory unit in suitable first electronic data form representative of said designations for entry of said designations into said memory by said electronic data processing means;; (d) scanning said original with a scanning means connected to said electronic data processing means for discerning said shades and their dispositions on said original and entering said shades and their dispositions into said electronic data processing means in suitable second electronic data form representative of said shades and their dispositions for entry of said shades and their dispositions into said memory by said electronic data processing means; (e) operating said electronic data processing means to suitably extract from said memory and merge said first electronic data and said second electronic data to form third electronic data representative of said desired pattern of apertures and their desired dispositions in said screen; and applying said third electronic data to a laser beam apparatus means having a capability of reproducing said desired pattern of apertures and their dispositions in light energy patterns on a suitable substrate, said substrate being traversed past said apparatus in suitable synchronism with said applying said third electronic data to said apparatus, for producing said screen having said desired pattern of apertures disposed therein in faithful reproduction of said design original and said designations of the distinguishing characteristics of said pattern of apertures respectively represented by said different shades on said original.

1 6. A method of manufacturing a screen-printing screen characterized according to claim 1, 2, 3, 4, 5, or 6 comprising the steps of: (a) providing a design original having areas of different shades disposed on said original to represent said pattern of apertures-according to claim 1, 2, 3, 4, 5, or 6 respectively which is desired to be disposed in said screen; (b) making designations of the distinguishing characteristics of said pattern of apertures according to claim 1, 2, 3, 4, 5, or 6 respectively which are represented respectively by said different shades on said original; (c) entering said designations into electronic data processing means having a memory unit in suitable first electronic data form representative of said designations for entry of said designations into said memory by said electronic data processing means;; (d) scanning said original with a scanning means connected to said electronic data processing means for discerning said shades and their dispositions on said original and entering said shades and their dispositions into said electronic data processing means in suitable second electronic data form representative of said shades and their dispositions for entry of said shades and their dispositions into said memory by said electronic data processing means; (e) operating said electronic data processing means to suitably extract from said memory and merge said first electronic data and said second electronic data to form third electronic data representative of said desired pattern of apertures and their desired dispositions in said screen;; (f) exposing photographic film to produce latent images thereon of said desired pattern of apertures and their dispositions by applying said third electronic data to a laser beam apparatus connected to said electronic data processing means and having the capability of exposing said film to produce said latent images as said film is traversed past said laser beam apparatus in suitable synchronism with said applying said third electronic data to said laser beam apparatus; (g) developing said latent images on said film; (h) using said developed film images to reproduce said desired pattern of apertures and their dispositions in latent images in photographic resist material on a suitable electro-forming electrode; (i) developing said latent images in said photographic resist material on said electrode; (j) dissolving away the undeveloped portions of said photographic resist material; and (k) electroforming on said electrode said screen-printing screen suitably to reproduce said developed images on said electrode as apertures in said printing screen, said apertures thereby forming said desired pattern of apertures disposed in said screen in faithful reproduction of said design original and said designations of the distinguishing characteristics of said pattern of apertures respectively represented by said different shades on said original.

1 7. A method of manufacturing a screen-printing screen characterized according to claim 1, 2, 3, 4, 5, or 6 comprising the steps of: (a) providing a design original having areas of different shades disposed on said original to represent said pattern of apertures according to claim 1, 2, 3, 4, 5, or 6 respectively which is desired to be disposed in said screen; (b) making designations of the distinguishing characteristics of said pattern of apertures according to claim 1, 2, 3, 4, 5, or 6 respectively which are represented respectively by said different shades on said original; (c) entering said designations into electronic data processing means having a memory unit in suitable first electronic data form representative of said designations for entry of said designations into said memory by said electronic data processing means;; (d) scanning said original with a scanning means connected to said electronic data processing means for discerning said shades and their dispositions on said original and entering said shades and their dispositions into said electronic data processing means in suitable second electronic data form representative of said shades and their dispositions for entry of said shades and their dispositions into said memory by said electronic data processing means; (e) operating said electronic data processing means to suitably extract from said memory and merge said first electronic data and said second electronic data to form third electronic data representative of said desired pattern of apertures and their desired dispositions in said screen; and (f) perforating said pattern of apertures into a screen-printing screen blank by applying said third electronic data representative of said desired pattern of apertures and their dispositions to a laser beam apparatus connected to said electronic data processing unit and having the capability of perforating said screen blank to produce said pattern of apertures as said blank is traversed past said laser beam apparatus in suitable synchronism with said applying said third electronic data to said laser beam apparatus, said desired pattern of apertures thereby being formed in said screen blank in faithful reproduction of said design original and said designations of the distinguishing characteristics of said pattern of apertures respectively represented by said different shades on said original to complete said manufacturing of said screen.

1 8. A screen-printing screen substantially as herein described with reference to and as shown in the accompanying drawings.

19. A method of dyeing a substrate substantially as herein described with reference to and as shown in the accompanying drawings.

20. A method of manufacturing a screen-printing screen substantially as herein described with reference to and as shown in the accompanying drawings.