COLOR FILTERS FOR DISPLAYS AND METHODS FOR PREPARING SAME

Abstract: The present invention is directed to color filters (86) comprising a transparent substrate and a repeating pattern of colored pixels on the substrate thereby forming the color filter, wherein each of the pixels comprises a plurality of small colorant areas, referred to as a sub-pixel (88). Processes forming pixels comprising a plurality of sub-pixels exhibit a drastic increase in the formation of usable color filters, resulting in greatly improved yields.

Description: COLOR FILTERS FOR DISPLAYS AND METHODS FOR PREPARING SAME BACKGROUND OF THE INVENTION 1. The Field of the Invention The present invention is directed to color filters and methods for preparing color filters In particular, the present invention is directed to color filters for use in visual displays and methods for preparing the same. 2. The Relevant Technology Color filters are used to produce full color images in visual displays The three primary colors, red, green and blue used to produce full color images in projection displays, flat panel displays and other visual display devices are most commonly provided by color filters. Generally, color filters consist ofa transparent substrate having a repeating pattern of pixels on its surface Pixels are defined as the smallest controllable area on visual displays, having the same color that are capable of being located and turned "on" and "off' by a computer display Each pixel on a color filter is associated with a primary color, and is arranged with other color pixels in repeating arrays of red, green and blue triads Depending upon which pixels light is passed through, color filters containing pixels of the three primary colors are capable of producing color images of a wide variety of colors Although the use of color filters to produce full color images has long been known, color filters continue to occupy the highest proportion of material costs in visual displays, such as flat panel displays This expense can be attributed to a number of factors, such as color filter material costs and the number of manufacturing steps, however, the high cost of color filters is primarily due to low yields observed in color filter manufacturing processes. Yields in color filter manufacturing process are determined by the number of color filters produced that meet industry standards out ofthe total number of filters produced Panels not meeting industry standards of approximately 3 to 4 defects per ten inch diagonal must be discarded thereby reducing color filter manufacturing yields and resulting in high production cost and low consumer availability A common defect and major contributor to the low yields presently experienced in the industry is the omission of pixels, a phenomena commonly referred to as "drop out " When "drop out" occurs, uncolored, unfiltered light passes through the filter to the eye of an observer as opposed to the color intended to be produced Originally, color filters were prepared by a dyeing, or gelatin process in which a was colored using photolithography techniques. More recently, polyimide systems comprising thermally stable dyes combined with polyimides, have been incorporated into photolithography processes to improve filter quality. Although color filters prepared using photolithography exhibit good resolution and color quality, photolithography is labor intensive and results in poor yields. For example, photolithography requires that each color incoφorated onto the filter have a mask, a photoresist, baking and etching steps, and resist removal. To produce a color filter having the three primary colors, this process must be repeated three times. Because ofthe complexity ofthe photolithography process and the tedious steps that must be repeated for each primary color, photolithography processes have consistently given unsatisfactory yields, typically on the order of 50%. Even after repairing defective color filters by repeating the photolithography process for omitted pixels, the yield only increases to approximately 70%. Taking into consideration the cost of repair and the high percentage of filters that remain unusable, there has for some time existed a need for a color filter manufacturing process having greater yields and consequently producing color filters at lower costs. More recently, in an attempt to overcome the above-mentioned deficiencies, a dye difrusion process for making color filters has been proposed. In this process, a sublimable dye is transferred from a donor sheet containing the dye to a polymeric receiver sheet which becomes the color filter. An exemplary dye difϊusion process is disclosed in DeBoer et al. U.S. Patent No. 4, 965,242. In DeBoer et al., a dye-donor element is placed over a dye receiving element, wherein the dye receiving element comprises a temporary support having thereon a polymeric alignment layer, transparent conducting layer and a polymeric dye receiving layer. Heat is applied to the donor element by radiation energy means, such as a thermal printing head or heat absoφtion by infrared dyes, causing the dye image to be transferred from the donor sheet to the receiver sheet. Once the transfer has occurred, the dye donor sheet is replaced with a glass support to form the color filter. Other patents disclosing similar dye difϊusion processes for preparing color filters include U.S. Patent Nos. 4,962,081, 5,073,534, and 5,242,889. Here again, although the dye difϊusion process simplifies color filter manufacturing, adequate yields are still not attained. An additional drawback that adds ** to the low yields and increased cost ofthe color filter is that the dye difrusion process is presently limited to sublimable subtractive dyes, namely magenta, yellow and cyan. Producing primary colors using subtractive dyes requires layers of magenta, yellow and cyan to be formed in various combinations to make red, blue and green additive which discloses a blue sublimable dye. However, because the dye difϊusion process must be repeated to form pixels associated with red and green, there exists a greater oppoπunity for a defect to occur, resulting in an increased number of unusable coior filters and, consequently, the continuation of depressed yields. As expected, the "drop out" rate in color filter manufacturing increases during mass production In addition, as illustrated in Figure 1 , as the panel size increases, the number of "drop outs" rises dramatically For example, a defect level of one defect per square inch shaφly increases to approximately 50 defects per ten inch diagonal color filter as shown by line 30. A marked decrease can be attained by limiting the defects to 0 1 defects per square inch (line 32) and as shown by lines 34 and 36, the number of defects drops shaφly when the number of defects are reduced to 1/16 of a defect per square inch (line 34) and 1/160 of a defect per square inch (line 36) Typically, color filters have dimensions of approximately 200 pixeis per/inch (wherein 5 mils is equivalent to 127 microns) Panels having as few as three to four defects per ten square inch diagonal panel are considered unusable according to industry standards Hence, it is not suφrising that typical yields of current color filter manufacturing processes have heretofore been on the order of 50% and with repair approximately 70%. Because of its high color quality, and despite attempts to improve its low yields, photolithography remains the process of choice in the production of color filters for visual displays This being the case, there remains a need for a manufacturing process that produces color filters having good resolution and color quality in high yields SUMMARY In accord with the present invention, and contrary to conventional knowledge, it has been discovered that processes forming pixels comprising a plurality of sub-pixels exhibit a drastic increase in the formation of usable color filters When pixels comprising a plurality of sub-pixels are formed, the omission of less than all ofthe plurality of sub- pixels comprising the pixels will not necessarily result in an unusable pixel. Thus, color filters formed in accordance with the present invention have greatly improved yields The repeating pattern of pixels are composed ofa colorant material selected from — the group consisting of dyes, pigments, inks, and mixtures thereof. Depending on the process employed, the materials used, and the puφose ofthe color filter, the colorant material used to form the pixels is selected so as to optimize the color quality ofthe color filter Resolution of the color filter formed in accordance with the present invention, is optimized by varying the size ofthe pixels and the number of sub-pixels comprising the pixel. For instance, reducing the size ofthe pixels in the repeating pattern of pixels and increasing the number of pixels on a transparent substrate produces a color filter having increased resolution. In a preferred embodiment of the present invention, the color filter comprises a transparent glass substrate and a repeating pattern of color pixels on the substrate forming the color filter, wherein each pixel is comprised of sixteen sub-pixels. With each pixel comprising sixteen sub-pixels, the omission of a few sub-pixels constructing the pixel is not visible to the human eye. Furthermore, it is highly improbable that more than three or four sub-pixels will be omitted during pixel formation. Hence, virtually one hundred percent yield will be achieved when the pixels formed on the substrate are composed of 16 sub-pixels. Higher than current yields may also be obtained when using pixels having more than one but less than 16 sub-pixels, although the yield may not be as high as when using 16 sub-pixels. These features ofthe present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS In order that the manner in which the above-recited and other advantages ofthe invention are obtained, a more particular description ofthe invention briefly described above will be rendered by reference to a specific embodiment thereof which is illustrated in the appended drawings. Understanding that these drawing depict only a typical embodiment ofthe invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use ofthe accompanying drawings in which: Figure 1 is a graph illustrating the prevalence of defects in color filter processing. Figure 2 is a side view ofa donor film 50 and a receiver panel 54 as used to form color filters in laser ablation transfer processes. Figure 3 demonstrates the laser ablation transfer ofa sub-pixel from a donor film 50 to a receiver panel 54. Figure 4 illustrates an alternative embodiment ofthe laser ablation process wherein the donor film 50 comprises an adhesive layer 74 on the surface ofthe colorant-containing layer to aid adherence of a sub-pixel to a receiver panel. Figure 5 illustrates color filter construction comprising the combination of three microsheet layers, each sheet comprising pixels associated with a primary color. Figure 6 illustrates a color filter having a primary color pixel array comprising red. green and blue pixels. Figure 7a is an exploded illustration of a conventional pixel. Figure 7b is an exploded illustration ofa pixel formed by a laser ablation transfer process comprising two sub-pixels. Figure 7c is an exploded illustration of a pixel formed by laser ablation transfer comprising four sub-pixels. Figure 7d is an exploded illustration of a pixel formed by laser ablation transfer comprising six sub-pixels. Figure 7e is an exploded illustration of a pixel formed by laser ablation transfer comprising nine sub-pixels. Figure 7f is an exploded illustration of a pixel formed by laser ablation transfer comprising sixteen sub-pixels. Figure 7g is an exploded illustration of a pixel formed by laser ablation transfer comprising twelve sub-pixels. Figure 8 is a view ofa black matrix formed on a color filter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is directed to color filters and methods for producing color filters for visual display devices Currently, color filter manufacturing technology suffers in that for various reasons pixels occasionally fail to form on the transparent substrate, resulting in the omission of pixels. This phenomena is referred to in the trade as "drop out." When a certain number of pixels, typically three to four pixels for a ten square inch diagonal substrate, do not form on the transparent substrate, the substrate is considered by industry standards to be unusable and must be discarded. "Drop out" resulting in poor color filter manufacturing yields has been a problem since the development of color filters for visual displays. These low yields increase the cost of color filters and consequently contribute to the high cost of color displays. It is a feature ofthe present invention that the yield can be greatly improved by forming a plurality of sub-pixels on a transparent substrate, so that the plurality of sub- pixels form one pixel. As used in this application, a sub-pixel is an area of colorant formed on substrates used for color filters. It is readily appreciated that forming each pixel with a plurality of sub-pixels significantly reduces the effect that of "drop out" or omission of sub-pixels on color filters. It is fuπher appreciated that the effect "drop out" has on the appearance of a pixel is dependent on the number of sub-pixels comprising the pixel. For example, if the pixel is comprised of sixteen sub-pixels, the omission of one sub-pixel will have viπually no effect on the appearance ofthe pixel to an ordinary observer. Even the loss of 3 or 4 sub-pixels per pixel does not significantly affect the effectiveness of the pixel. It is still further appreciated that unless all the sub-pixels comprising a pixel are omitted, the pixel will be at least partially operable. Hence, the chance that a substrate will be unusable shaφly decreases as the number of sub-pixels comprising the pixels increases As used herein, the term "color filter" defines materials used to provide color in visual display devices including, but not limited to. computers, calculators, televisions, clocks, analog displays in measuring devices, instruments, household appliances and audio equipment. Generally, color filters comprise a transparent substrate and a repeating pattern of colored pixels on the substrate. In color filters, the pixels are associated with the three primary colors red, green and blue, and are typically ananged in three color triads located on the surface ofthe substrate. Depending on the amount and manner in which light is passed through the pixels, full color images can be produced by a color filter having pixels conesponding to the three primary colors. As illustrated in Figure 6, color filters 86 have heretofore been comprised of a multiplicity of color pixels 88 associated with the primary colors, red, blue, or green Traditionally, these color pixels have been composed ofa single small area of one color that is controlled, or turned "on" and "off," electronically. As mentioned above, it is common in color filter manufacturing processes for a pixel to be unintentionally omitted for one reason or another, resulting in white light being emitted through the filter, tainting the color filter and often rendering it commercially unusable. As mentioned above, pixels formed according to the present invention can be composed of a plurality of sub-pixels rather than being made from one continuous area of color, and the plurality of sub-pixels forming the pixel can be "turned on and off" collectively. Depending on the size or shape ofthe pixel desired, the number of sub-pixels can widely vary. The flexibility of forming different shapes and sizes of pixels with — groups of sub-pixels not only allows the user to optimize resolution, but also allows for a greater margin of eπor when forming the pixels. For example, because the human eye cannot distinguish images below a ceπain level, a pixel comprising multiple sub-pixels is able to at least paπially conceal defects such as "drop outs". n Figure 7a schematically illustrates the conventional pixel being composed of one continuous area of dye. If a mistake occurs resulting in a failure to produce a pixel in this area, an observer will see white unfiltered light. Typically, three or four mistakes on a ten square inch screen will render the color filter commercially unusable. Mistakes resulting in the "dropout" of entire color pixels cost industry millions of dollars each year. It is a feature ofthe present invention to reduce the incidence of unusable color filters by forming each pixel from a plurality of sub-pixels rather than a single sub-pixel. For example, by referring to Figure 7b, it will be appreciated that if a pixel having the same area as the pixel illustrated in Figure 7a is composed of two sub-pixels, a mistake resulting in the absence of one sub-pixel does not have the same dramatic effect as the "drop out" ofa pixel, as shown in Figure 7a. Thus, the failure to produce one ofthe two sub-pixels forming the pixel is more acceptable, allowing for a higher percentage of failures to be tolerated. In fact, unless all ofthe sub-pixels comprising a pixel are omitted, the pixel will at least have the partial appearance of the desired color and, thus, at least be partially operable. Hence, pixels comprising four sub-pixels decrease the impact ofa mistake on the appearance ofthe color filter as shown in Figure 7c. It will be appreciated, looking to Figures 7d-7f which illustrate pixels composed of six, nine and sixteen sub- pixels, that as the number of sub-pixels composing a pixel increases, the less impact a mistake will have on the usability ofthe color filter. Although pixels composed of sixteen sub-pixels are currently prefeπed, any number of sub-pixels can be used to form pixels. It is noted that sub-pixels having a diameter in the range of 10 microns are capable of being formed using present technology, such as laser ablation transfer technology. This being the case, it is contemplated that a pixel of average size, i.e., 127 microns by 127 microns, can comprise at least 144 sub- pixels (12 sub-pixels by 12 sub-pixels). Pixels may be formed in any shapes and sizes, however, pixels are commonly formed in either square or rectangular shapes. For example, some color filters have wider horizontal than vertical pixel dimensions, i.e. pbcel dimensions of 127 microns horizontally by 95 microns vertically (Figure 7g). In this case, assuming the pixel is composed of a row of three vertical sub-pixels and four horizontal sub-pixels, the pixel would be an improvement by a factor of twelve over the "single area pixels" commonly used and — observable "drop out" would be virtually nonexistent. Therefore, the greater the number of sub-pixels used to form a pixel, the greater the margin of eπor in pbcel formation and consequently the greater the yield The greater the yield, the more efficient production is and, in turn, the lower the cost of production. absence of one ofthe sixteen sub-pixels is not distinguishable by the human eye In fact, the absence of two. three, or even four sub-pixels from a pixel composed of sixteen sub- pixels will likely result in little or no effect to the human eye It is viπually inconceivable that more than four sub-pixels will be absent from a given pixel and, therefore, using sixteen sub-pixels to form each pbcel results in virtually 100% yield as opposed to the 50% yields cuπently found in the commonly used color filter processes Figure 1 shows that, as the color filter panel size increases, the number of panel defects rises dramatically When the normal defect level of one defect per square inch is observed, as illustrated by reference character 30, it can be seen that the number of defects quickly rises Simply by cutting the defect level to 0 1 defect per square inch (32), a substantial improvement in yield is observed Where pixels are composed of multiple sub- pixels, the defect level diminishes to virtually no observable defects per ten square inch color filter panel Still further, using a plurality of sub-pixels to form each pixel avails the producer of color filters the ability to maintain a high color image resolution as well as an increased yield When a high yield is the primary concern, the number of sub-pixels per pixel is increased, whereas when increased resolution is desired, fewer sub-pixels per pixel are desired Furthermore, the resolution may be increased by decreasing the pixel size and increasing the number of pixels per visual panel display Although the optimal number of sub-pixels per p cel will vary from filter to filter, it is contemplated that the resolution will not be the primary concern because the resolution presently achieved with sixteen sub- pixels per pixel adequately meets the ability of the human eye to discern pixels It is, however, anticipated that the primary concern will be to increase the yield by increasing the sub-pixels per pixel Pbcels composed ofa plurality of sub-pixels may be formed by any method capable of producing small areas of colorant that can be grouped together to form a pixel One such method for forming sub-pixels and, coπespondingly, pixels, is laser ablation transfer As will be appreciated by one of ordinary skill in the art, various adaptations have been included in the laser ablation process to allow for the formation of color filters in high yields Although laser ablation is presently the prefeπed process for forming pixels composed of a plurality of sub-pixels, it is appreciated that other methods, such as the ~ thermodynamic printing method recited in U S 4,792,860 issued to Kuehrle, can be used Laser ablation transfer (LAT) imaging is a noncontact, intrinsically fast method of producing dry color images by direct laser writing In general, images are prepared using laser ablation transfer by iπadiating a donor film with an optical pulse, typically from a film causing a high-speed mass transfer of a color coating from the donor film to a receiving substrate where the colorant adheres. Accordingly, the receiver substrate is located in close proximity, preferably in direct contact, to the donor film so that the colorant has only a small distance to travel. Because the laser ablation transfer process involves mass transfer, both negative images formed on the donor film and positive images iocated on the receiver substrate are created simultaneously. An essential element in the laser ablation process is a film that undergoes laser ablation even though it has virtually no absorbance in the visible region. An advantage of the laser ablation technique is its compatibility with a wide variety of strongly colored dyes, pigments and inks. These two properties permit precise control over the color and image ofthe laser ablation product formed on receiver substrates. Presently, two basic donor structures have been developed for laser ablation transfer. The first type consists of a polyester transparent substrate coated with a thin (typically 1 micron) color coating consisting of printing ink. including nitrocellulose and other additives, and a near-infrared absorbing dye. Further details of this process are contained in I- Yin Sandy Lee et al., "Dynamics of Laser Ablation Transfer Imaging Investigated by Ultrafast Microscopy," JOURNAL OF IMAGING SCIENCE AND TECHNOLOGY, Vol. 36, Number 2, March April 1992, the disclosure of which is hereby incoφorated by reference. The second type of structure similarly consists ofa polyester substrate coated with a thin color coating (typically 0.5 microns). However, the second type of structure contains an additional layer refened to as a dynamic release layer (DRL) consisting ofa partially transmitting and absorbing film, preferably of titanium or metallic aluminum. In addition, absorbing dyes can be included in the color coating to lower the ablation threshold and to improve the adhesion ofthe dye to the receiver sheet. In further contrast to the first type of structure, the coating in the second type does not melt in the transfer process, but is removed as a solid flap of color coating. Furthermore, all the heat is concentrated at the aluminum substrate and aluminum coating interface in the second embodiment. Thus, a polymer in the color coating layer next to the aluminum is exposed to the heat, forms a gas, and ejects a pixel of colored material to the receiver sheet where it sticks to form a color image. Further details on laser ablation transfer can be found in William A. Tolbert et al, "High-Speed Color Imaging by Laser Ablation Transfer with a Dynamic Release Layer: Fundamental Mechanisms," JOURNAL OF IMAGING SCIENCE AND TECHNOLOGY, Vol. 37, Number 4, July/ August 1993, the disclosure of which is hereby incoφorated by reference. The laser ablation technique utilized in the present invention to form images on the color filter, provides a gentle, intrinsically fast method of manufacturing color filters. Any suitable mechanism that will transfer the colorant from the donor film to the receiver substrate can be used, although lasers are prefeπed for their clean, easy manner of transferring minute dye and other coiorant particles, to form precise images. Furthermore, lasers are ideally suited for use in imaging systems because they can be turned "on" and "off' rapidly, and when working in conjunction with an X-Y micro-positioning plot the entire color filter can be "digitally" processed. In a prefeπed embodiment ofthe present invention, as shown in Fig. 2, the color filters of the present invention are prepared using a donor film 50, having a layer containing a primary colorant 52 and a receiver panel 54 located in close proximity, preferably in physical contact, to the donor film. The primary colorant can be any dye, pigment, ink, mixtures thereof, or other material used to color objects. Upon iπadiation of the donor film with the appropriate wavelength, the colorant on the donor film is transfened from the donor film to the receiver panel. As a result of this mass transfer, a negative image is produced on the donor film, as a positive image is simultaneously produced on the receiver panel. The laser ablation technique has proven to provide a simple, delicate method of producing pixels or color filters without harsh heating, wet chemicals and tedious mechanical steps. The laser causes a colorant to be quickly and precisely transferred from a colorant donor to a colorant receiver without any stress between the colorant donor and the colorant receiver. Hence, the receiver panel, which becomes the color filter, can be composed of a material thinner than has heretofore been possible. In a prefeπed embodiment ofthe present invention, the donor film 50 is composed ofa transparent donor substrate 56, a laser absoφtion layer 58 on the donor substrate, a gas generation layer 60 located on the laser absoφtion layer, and a layer containing a primary colorant 52. The receiver panel 54 which receives the colorant and subsequently becomes the color filter is composed of a transparent receiver substrate 62, preferably glass. In a more prefeπed embodiment, to aid in adherence ofthe colorant on the receiver panel 54, a polymeric layer 64 is added to the surface ofthe receiver substrate 62 on the side closest to the donor film 50. In addition, to aid in supporting the receiver substrate 62, a support 66 can be added to the surface of the receiver substrate 62 opposing the adherence aiding polymeric layer 64. Figure 3 , illustrates a prefeπed method for producing a single area of colorant (dot) on a receiver panel that subsequently becomes a color filter using laser ablation to one another Although this distance can vary, it is preferred that the donor film and the receiver panel be in physical contact with each other A laser beam 68 having a wavelength typically in the range between 760 to 920 nm, preferably 760, 820 or 920 nm is focused to a desired diameter, such as approximately 30 microns, onto the donor film It is noted that the size ofthe sub-pixel can be varied, typically by varying the size ofthe laser beam The laser iπadiates the donor substrate 56 with submicrosecond. near IR laser pulses which are absorbed by the laser absoφtion layer 58 The laser ablation layer transforms the radiation into heat resulting in a localized jump in temperature which is communicated from the laser absoφtion layer 58 to the gas generation layer 60 causing the gas generation layer 60 to vaporize or partially decompose, in a type of microexplosion The gas generated by the decomposition of gas generation layer 60 propels the primary colorant layer 52 to the receiver panel 54 in the form ofa dry mass or molten drop (depending on the structure type of donor film 50) with a force sufficient to attach the mass to the receiver panel, where it substantially instantaneously cools to form a sub-pixel 70 The sub-pixel 70 formed can be grouped with other sub-pixels to form a pbcel or may itself be a pixel By keeping the receiver panel 54 fixed in one place, the donor film 50 can be exchanged in sequence for each ofthe three primary colors to produce the color filter The gas generation causes the colorant to be expelled from the donor film at velocities approaching 331 meters per second. Here again, the size of sub-pixel 70 generated conesponds to the size of the laser beam 68 inadiating donor film 50 Using the above mentioned technique, images can be produced on the receiving panel at a typical frequency of 10 7 pixels/second In a prefeπed embodiment, a coating, preferably a polymeric material, can be deposited onto the surface of the receiver panel 54 by wet or dry methods (i e , vapor deposition) to aid adherence of the primary colorant to the receiver panel 54 In still a further prefeπed embodiment illustrated in Figure 4. an adhesive layer 74 is added to the outer surface ofthe donor film 50 on the colorant layer, so that when the colorant is thrust from the colorant donor to the receiver panel 54, the colorant will adhere to the receiver panel 54. The diameter ofthe sub-pixels produced in laser ablation transfer can be varied based on the diameter of the laser beam focused onto the donor film. Hence, — depending on the use of the filter, the sub-pixel size can be optimized by varying the diameter of the laser beam Furthermore, in contrast to other color filter manufacturing techniques, laser ablation transfer can be made to occur faster than any significant transfer between the iπadiated spot and its suπoundings by using a short duration laser pulse, thus In a prefeπed embodiment of the present invention, the laser is preferably programmed to stπke specific areas, to form desired patterns This is an improvement over cuπent processes for making filters, which not only require multiple steps, but for example in photolithography, require masks to define the boundary areas of ultraviolet light on the resist, which tends to be cost intensive For three color filters having these colors, three masks must be employed, tripling the cost of filter preparation The present invention replaces these hardware based processes with a computer that simply directs a laser to form the pattern required The radiation used in the laser ablation process can be produced by any suitable laser with sufficient power to transfer the pixel from the donor substrate to the receiver sheet Typically, the energy in the laser beam should be greater than 200 millijoules/cπr The wavelength ofthe laser used is related to the focal width, which, in turn, will relate to the number of sub-pixels per inch that can be transfened In general terms, as the wavelength decreases from the infrared region through the visible region to the ultraviolet region, the spot size can coπespondingly be decreased, since the spot size is directly related to the wavelength This being the case, the shorter the wavelength, the more sub- pixels can be transfened per linear inch Semi-conductor diode infrared lasers are commonly used in this process because they possess sufficient energy to cause transfer, while at the same time being relatively inexpensive and simple to operate In a prefeπed embodiment ofthe present invention, the laser is a solid state diode type laser operating at 860 nm, 820 nm or 780 nm Other suitable lasers that may be used include, but are not limited to neon-helium lasers (632 8 nm), argon ion lasers (488 nm or 514 nm), carbon dioxide lasers (10 6 μ), YAG (Yttrium Aluminum Garnet) lasers in frequency double mode, (λ = 532nm), Nd.YLF. (1 05 μ), Ruby (Cr Al 2 O 3 ) lasers (694 nm), and ultraviolet emission lasers such as Xe Cl (308 nm) or KrF (249 nm) It is readily understood that the laser used in laser ablation process can be programmed to strike a specific area of the donor film so that color filters having the desired pattern may be formed The donor substrate 56 generally has a thickness between approximately 12 μ and approximately 250 μ, preferably 50 μ, and can be any laser transparent material that allows the laser radiation to travel to the laser absoφtion layer 58, provided it is dimensional stable Suitable substrates include polyesters such as polyethylene terephthalate. polyamides, polycarbonate, glassine paper, condenser paper, cellulose esters, fluorine-based polymers, polyethers, polyacetals, polyolefins, and polyimides The laser absoφtion layer 58 located on the surface of the transparent substrate 630 nm and 990 nm more preferably 780-860 nm. and further imparts virtually no color to the resultant receptor film. Preferably, the laser absoφtion layer is a metal that completely oxidizes to its conesponding transparent oxide upon exposure to heat, so that the optical properties ofthe resulting color sub-pixels are not degraded by any residual laser absoφtion layer that may have followed to the receiver panel. Suitable metals include Al, Ti, Hf, or any alloys of these metals. In addition, other absorbing metals, or antireflected metals such as Al Ge, Ti/Si or Al/TiO x or even optical cavities can be employed, such as opaque metal-dielectric absoφtion layer designs. In the prefened embodiment, the laser absoφtion layer is titanium. The laser absoφtion layer generally has a thickness between approximately 50 and approximately 300 angstroms, and preferably is approximately 200 angstroms for a single metal. The thickness of the laser absorption iayer is important for a number reasons. First, the absoφtion ofthe layer is directly related to the thickness ofthe iayer. thus, it is important that the laser absoφtion layer have a thickness sufficient to absorb a sufficient amount of radiation and consequently provide a sufficient amount of heat to cause the organic layer to decompose. Furthermore, the laser absoφtion layer may accompany the colorant to the receiving layer, and if the absoφtion layer is of too great a thickness, the amount accompanying the colorant to the receiving layer may adversely affect the color ofthe resultant pbcels. Thicker layers ofthe absorbing layer may also be undesirable from the standpoint of raising the energy threshold for ablation since more material must be heated. The gas generating layer 60 in the donor film ofthe present invention can be any material that will produce a gas bubble in a type of microexplosion at temperatures less than 300 C C, preferably less than 250 °C, to propel a portion ofthe colorant layer to the surface ofthe receiver panel. In a prefeπed embodiment ofthe present invention, the gas generating layer is a transparent organic layer, such as polyethylene carbonate, polyvinyl chloride, ethyl cellulose, nitro-cellulose and polymers such as an acrylate containing a plasticizer having a low boiling point designed to decompose at low temperatures to produce a gas bubble sufficient to propel a colorant to a receiver panel. Typical plasticizers include chlorinated paraffins, organo-phosphates, phthalic acid derivatives and glycol derivatives. Low molecular components arising from partially uncured radiation or heat cured material, i.e. uncrosslinked components, may also be employed. The gas generating layer typically has a thickness of between approximately 0.1 microns and 5 microns, and is preferably in the range between 1 and 2 microns. The colorant layer 52 preferably comprises a polymer resin and a colorant material. acrylates, polyimides, polyurethanes or waxes, that are capable of maintaining their integrity during the manufacturing process steps. As mentioned above, the colorant can be any suitable dye. interference and non-interference pigment, ink or mixture thereof Moreover, both the colorant and polymer should be light stable to produce quality color filters that do not degrade in time due to light exposure. The wide variety of colored dyes, interference and non-interference, inorganic or organic based pigments, colored waxes, and inks that can be used in the laser ablation transfer process, makes it possible to produce high-resolution color images, especially when exact selection is critical. Transferable dyes include those based on azo. anthraquinone, quinophthalone and methine chemistries. Furthermore, the laser can transfer mass colorants (sub-pixels) as small as 10 microns in diameter. Therefore, the number and size ofthe pixels can be varied to include larger or smaller pixels, and more or fewer pbcels per display, to optimize the resolution ofthe display. By optimizing pixel color and size, using laser ablation transfer, a resolution comparable to that of photolithography ( 10 to 20 microns) can be achieved. The receiver panel 54 can be composed of any non-birefnngent material that suitably receives and retains the colorant propelled from the donor film such as a transparent substrate, preferably a glass sheet having a thickness in the between 25 and 50 microns. Until the present invention, glass of this thickness has not been feasible because of the strain and stress exerted on the receiver panel during conventional manufacturing processes. However, because there is no stress between the donor film and the receiver panel in laser ablation transfer techniques, delicate materials such as micro- thin glass can be employed in the production of color filters. The use of layer 66 aids in maintaining the integrity ofthe thin glass color filters. The thickness or lack thereof, of the receiver allows for a thinner, lighter color filter product that improves image quality. These qualities are especially useful in compact color displays, such as lap top computers. In a prefened embodiment, the receiver panel further comprises an adherence aiding Iayer 64. located on the transparent substrate nearest the donor film. Any material that will aid adherence of the colorant/polymer material transfer can be used, suitable materials include, but are not limited to: polyamides, melamines, acrylics, polyurethanes or polyesters and other high energy surface materials. In an alternative embodiment, an ultraviolet, visible light or heat activated adhesive is used to selectively remove sub-pixels from a donor film. In the present embodiment, the donor film and the receiver panel are oriented so that the heat activated adhesive layer 74 ofthe donor film and an adherence aiding Iayer 64 on the receiver panel are in contact. in diameter, of an absoφtion layer 58 which causes the adhesive layer 67 to activate and bond the colorant Iayer 52 to the adherence aiding polymeric layer 64 ofthe receiver panel 54. Instead of functioning as a gas generating layer, layer 60 may function as a release layer allowing the color sub-pixel to transfer to the receiver panel In this case, layer 60 may include compositions of cellulose, fluoropolymer, silicone or wax based chemistry. As with other embodiments ofthe laser ablation transfer process, the size ofthe heated area can be varied by adjusting the diameter ofthe iaser beam radiation. Subsequently, upon removal ofthe receiver panel 54 and the donor film 50, the sub-pixels produced by the laser ablation process are released to the panel. Here again, by keeping the receiver panel 54 fixed in one place, the donor film 50 can be exchanged in sequence for each of the three primary colors to produce the color filter. Any suitable adhesive material that does not adversely affect the optical quality or color of the filter can be used for the adhesive Iayer on the donor film, including, cyanoacrylates. nitrile-phenolic elastomers, epoxides, polyesters, modified acrylics, polyurethanes and polymethyl methacrylate or other materials that will bond to the receiver layer surface (64). Alternatively, the adhesive layer can contain infrared absorbing, but visibly transparent materials, such as infrared absorbing dyes, to aid the absoφtion of infrared radiation used to heat the adhesive layer 74. In a further related embodiment ofthe present invention, laser ablation transfer can be used to form color filters wherein a filter substrate comprising a transparent substrate and a colorant layer on the transparent substrate becomes the color filter. The colorant layer comprises a primary dye, pigment, ink or other colorant and an absorbing material, as disclosed above, for absorbing the laser radiation. As discussed above, laser ablation transfer involves mass transfer resulting in a positive image being formed on a receiver and a negative image being formed on the donor. Accordingly, it is possible to ablate all the colorant except the desired sub-pixel arrangement using a filter substrate having a colorant layer on one side ofa thin transparent substrate.. The present process is repeated three times, one for each primary color to produce three separate filter panels 81, 82 and 83 which are laminated, aligned and bonded together to form a color filter as illustrated in Figure 5. Alternatively, due to the precise nature ofthe laser ablation technique, one filter — substrate can be coated on both sides, one side with one primary color and the other side with another primary color. Subsequently, sub-pixels conesponding to the two primary colors can be formed by removing everything but the sub-pixel anangement by laser ablation, i.e. blue sub-pixels on one side ofthe sheet and red sub-pixels on the opposing combined with another filter substrate comprising sub-pixels conesponding to the third primary color The two filter substrates are laminated, aligned and bonded together to form the color filter This process reduces the thickness and the weight of the filter Whether two or three donor films are used, the thinness ofthe transparent substrates used prevents any substantial parallax from occurring In still a further embodiment, as illustrated in Figure 8, the black matrix grid 84 sunounding the color pixels can be formed using laser ablation transfer Figure 8 illustrates a color pixel comprising sub-pixels 88, sunounded by a black matrix grid 84 The role ofthe black matrix is to block the thin film transistor from the light, separate the color patches from each other, to define the areas of the pixels, and to improve the contrast ratio ofthe color filter by preventing color contamination or light flare The Iaser ablation transfer process is used in the same manner as described above for the formation of sub-pixels on the receiver panel (i) the donor film is irradiated with a suitable wavelength, (ii) the absorbing layer heats up causing the gas generating layer to decompose producing a gas bubble, (iii) the gas produced by the gas generating layer propels a mass of black colorant precisely to the desired location on the receiver substrate to form a black matrix 84 sunounding and slightly overlapping the color pixels Alternatively, as mentioned above, pbcels composed ofa plurality of sub-pixels can be formed by the thermodynamic printing process disclosed in U.S 4,792,860, the disclosure of which is hereby incoφorated by reference Accordingly, the pixels ofthe present invention are prepared by forming a printing means having a printing surface and a multiplicity of independently electrical chargeable capacitor microcells adjacent to the printing surface. Selected microcells are activated in accordance with incoming data so that the activated microcells are geometrically related to the sub-pixels printed Electrical charges are deposited on the microcells selected for activation at controlled variable colombic charge levels to create, at the printing surface, localized electric fields of various strengths that are proportional to the print densities desired for the related data in the sub- pixels printed The printing surface is then contacted with the a voltage sensitive ink, whereby the ink, under the influence of said fields, is deposited on the printing surface only at the locations ofthe microcells selected for activation, with the thickness of each ofthe ink deposits being proportional to the strength ofthe field at that microcell thereby ~ to form a uniform or a variable thickness ink pattern on the printing surface The sub- pixels are subsequently transfened to the printing medium to form a pixel By adjusting the thickness ofthe pnnt layer, compensation for absoφtion strengths ofthe colorants is easily accomplished Using the present method, sub-pixels of any size ranging from as small as 10 - 30 microns can be formed. The printing medium onto which the sub-pixels are transferred can be any suitable substrate, including glass and plastic substrates, having a wide range of thicknesses These substrates will become the color filters Furthermore, the thermodynamic printing method is capable of printing fully variable color filters utilizing pixels comprising a plurality of sub-pixels, on demand at speeds in excess of 1 sq. meter/sec. In addition, the present thermodynamic printing method can be used to form the black matrix 84 illustrated in Figure 8 The thermodynamic printing process is performed in the same manner as described above, except, a black colorant is deposited onto the printing medium to form a black matrix sunounding, and typically slightly overlapping with, the color pixels The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics The described embodiments are to be considered in all respects only as illustrated and not restrictive The scope ofthe invention is, therefore, indicated by the appended claims rather than by the foregoing description All changes which come within the meaning and range of equivalency ofthe claims are to be embraced within their scope

Claims: What is claimed is I A color filter for use in visual displays, comprising (a) a transparent substrate, and (b) a repeating pattern of pixels on said substrate forming a color filter, each of said pbcels of said repeating pattern of pbcels comprising a plurality of sub- pbcels, so that an omission from the surface of said substrate of less than all ofthe plurality of sub-pixels comprising said pixel will not necessarily result in an unusable pixel 2 A color filter for use in visual displays as recited in claim 1 , wherein said transparent substrate has a thickness between 25 and 250 microns 3 A color filter for use in visual displays as recited in claim 1, wherein said transparent substrate has a thickness of approximately 25 microns 4 A color filter for use in visual displays as recited in claim 1. wherein said transparent substrate further comprises a Iayer for aiding adherence of said pixels osa substrate. 5 A color filter for use in visual displays as recited in claim 1, wherein said receiver panel further comprises a support layer 6 A color filter for use in visual displays as recited in claim 1, wherein said transparent substrate further comprises a support iayer and a layer for aiding adherence of said pixels to said substrate 7 A color filter for use in visual displays as recited in claim 1. wherein said sub-pixels are between 10 microns and 50 microns in size. 8 A color filter for use in visual displays as recited in claim 1 , wherein said sub-pixels are approximately 30 microns in size 9 A color filter for use in visual displays as recited in claim 1 , wherein said plurality of sub-pixels forming said pixel comprises at least two sub-pixels 10 A color filter for use in visual displays as recited in claim 1, wherein said plurality of sub-pbcels forming said pbcel is a number of sub-pixels between two sub-pixels and sixteen sub-pixels I I A color filter for use in visual displays as recited in claim 1, wherein said — pixel is rectangular in shape 12 A color filter for use in visual displays as recited in claim 1, wherein said pixel is square in shape 13 A method for preparing a color filter for use in visual displays, said method (a) orienting a donor film and a receiver panel in close proximiu. wherein said donor film comprises a transparent donor substrate having a first side and a second side, an absoφtion layer on said second side of said donor substrate and a colorant layer on said absoφtion Iayer, (b) irradiating said first side of said donor film with an inadiating means, so that said absoφtion layer absorbs said radiation and causes a portion of said colorant iayer to be transfened to said receiver panel to form a sub-pixel, and (c) repeating said inadiating step so that a repeating pattern of pixels is formed on said receiver panel to form a color filter 14. A method for preparing a color filter for use in visual displays as recited in claim 13, wherein said pixels comprise a plurality of sub-pixels, so that an omission from the surface of said substrate of less than all of he plurality of sub-pixels compnsing said pixel will not necessarily result in an unusable pixel 15 A method for preparing a color filter for use in visual displays as recited in claim 13, further comprising repeating said process so that said color filter compnses a repeating pattern of red, green and blue pixels. 16 A method for preparing a color filter for use in visual displays as recited in claim 13, wherein said inadiating means is a Iaser 17 A method for preparing a color filter for use in visual displays as recited in claim 13, wherein said inadiating means is a semi-conductor infrared laser. 18 A method for preparing a color filter for use in visual displays as recited in claim 13, wherein said sub-pixels size corresponds to the focused Iaser beam size 19. A method for preparing color filters for use in visual displays, said method comprising the steps of (a) forming a pixel on a transparent substrate, said pixel comprising a plurality of sub-pixels oriented in close proximity so that each of said plurality of sub-pixels is indistinguishable to an ordinary observer, so that omission from the transparent substrate of less than all of the plurality of sub-pixels will not necessarily result in an unusable pixel; and (b) repeating step (a) so that a repeating pattern of pbcels is formed on said transparent substrate to form a color filter. 20 A method for preparing a color filter for use in visual displays as recited in claim 19, wherein said pixel forming step comprises the steps of (a) orienting a donor film and a receiver panel in close proximity. and a second side, an absoφtiori layer on said second side of said donor substrate and a colorant layer on said absoφtion layer; (b) irradiating said first side of said donor film with an irradiating means, so that said absorption layer absorbs said radiation and causes a portion of said colorant layer to be transfened to said receiver panel to form a sub-pixel; and (c) repeating said inadiating step so that a repeating pattern of pixels is formed on said receiver panel to form a color filter. 21. A pbcel for use in a repeating pattern of pbcels on a color filter, comprising. a plurality of sub-pbcels, said sub-pbcels oriented in close proximity on a substrate, so that said plurality of sub-pbcels appear to be one pixel, and so that omission from the substrate of less than all ofthe plurality of sub-pixels will not necessarily result in an unusable pixel. 22. A pixel for use in a repeating pattern of pixels on a color filter as recited in claim 21. wherein said plurality of sub-pixels comprises at least two sub-pixels 23. A method for preparing a pixel for use on color filters in visual displays, said method comprising the steps of: (a) orienting a donor film and a receiver panel in close proximity, wherein said donor film comprises a transparent donor substrate having a first side and a second side, an absoφtion Iayer on said second side of said donor substrate and a colorant layer on said absoφtion layer; (b) irradiating said first side of said donor film with an irradiating means, so that said absoφtion layer absorbs said radiation and causes a portion of said colorant layer to be transfened to said receiver panel so that a sub-pixel is formed on the receiver panel; and (c) repeating said inadiating step to form a plurality of sub-pixels on said receiving panel to form a pixel. 24. A method for preparing a pixel for use on color filters in visual displays, comprising forming a plurality of sub-pixels oriented in close proximity so that each of said plurality of sub-pixels is indistinguishable to an ordinary observer, and so that omission from the transparent substrate of less than all ofthe plurality of sub-pixels will not necessarily result in an unusable pixel. 25. A method for preparing a black matrix for use on color filters, said method comprising the steps of: (a) orienting a donor film and a receiver panel in close proximity, wherein said donor film comprises a transparent substrate having a first side and substrate, and a black colorant containing layer on said absoφtion layer, said receiver panel comprising a transparent substrate having formed thereon a repeating pattern of pixels; and (b) inadiating said donor film with an inadiating means, so that said absoφtion layer absorbs said radiation and causes a portion of said black colorant containing layer to be transfened to said receiver panel to form a grid pattern on said receiver panel between said color pixels. 26. A process for preparing pixels for use in a color filter, said pixels being formed in response to an incoming digital data stream, said pixel comprising a plurality of sub-pixels, said method comprising the steps of: (a) forming printing means having a printing surface and a multiplicity of independently electrical chargeable capacitor microcells adjacent to said printing surface; (b) activating selected ones of said microcells in accordance with the incoming data stream so that the activated microcells are geometrically related to the sub- pixels to be printed; (c) depositing electrical charges on said microcells selected for activation at controlled variable colombic charge levels to create at said printing surface localized electrical fields of various strengths that are proportional to the print densities desired for said related data in the sub-pixels to be printed; (d) contacting said printing surface with a voltage sensitive ink, whereby the ink. under the influence of said fields, is deposited on said printing surface only at the locations of said microcells selected for activation, with the thickness of each said ink deposit being proportional to the strength ofthe field at that microcell thereby to form a variable-thickness ink pattern on said printing surface; and (e) transferring said sub-pixels to a printing medium to form said pixels. 27. A process for preparing pixels for use in a color filter as recited in claim 26, wherein said printing medium is selected from the group consisting glass and plastic. 28. A process as recited in claim 26, further comprising repeating steps (b), (c), (d) and (e), so that a repeating pattern of pixels is formed on said printing medium to ** form a color filter. 29. A process as recited in claim 28, wherein said repeating pattern of pixels is a pattern of red, green and blue pixels. AMENDED CLAIMS [received by the International Bureau on 27 May 1997 (27.05.97); original claims 1-29 replaced by amended claims 1-29 (5 pages)] I . A color filter for use in visual displays, comprising: (a) a transparent substrate; and (b) a repeating pattern of pbcels on said substrate forming a color filter, each of said pixels of said repeating pattern of pbcels comprising a plurality of sub- pbcels, so that an omission from the surface of said substrate of less than all ofthe plurality of sub-pixels comprising said pixel will not necessarily result in an unusable pixel. 2. A color filter for use in visual displays as recited in claim 1, wherein said transparent substrate has a thickness between 25 and 250 microns. 3. A color filter for use in visual displays as recited in claim 1, wherein said transparent substrate has a thickness of approximately 25 microns. 4. A color filter for use in visual displays as recited in claim 1, wherein said transparent substrate further comprises a layer for aiding adherence of said pixels tosaid substrate. 5. A color filter for use in visual displays as recited in claim 1, wherein said transparent substrate further comprises a support layer. 6. A color filter for use in visual displays as recited in claim 1, wherein said transparent substrate further comprises a support layer and a layer for aiding adherence of said pixels to said substrate. 7. A color filter for use in visual displays as recited in claim 1 , wherein said sub-pixels are between 10 microns and 50 microns in size. 8. A color filter for use in visual displays as recited in claim 1 , wherein said sub-pixels are approximately 30 microns in size. 9. A color filter for use in visual displays as recited in claim 1, wherein said plurality of sub-pbcels forming said pbcel is a number of sub-pixels between two sub-pixels and sixteen sub-pixels. 10. A color filter for use in visual displays as recited in claim 1, wherein said pixel is rectangular in shape. I I. A color filter for use in visual displays as recited in claim 1, wherein said pixel is square in shape. 12. A method for preparing a color filter for use in visual displays, said method comprising the steps of: (a) orienting a donor film and a receiver panel in close proximity, and a second side, an absoφtion layer on said second side of said donor substrate and a colorant layer on said absoφtion layer; (b) irradiating said first side of said donor film with an inadiating means, so that said absoφtion Iayer absorbs said radiation and causes a poπion of said colorant layer to be transfened to said receiver panel to form a repeating pattern of pbcels, each of said pbcels comprising a plurality of sub-pixels so that an omission from the surface of said substrate of less than all ofthe plurality of sub- pixels comprising said pixel will not necessarily result in an unusable pixel: and (c) repeating said inadiating step so that a repeating pattern of pixels is formed on said receiver panel to form a color filter. 13. A method for preparing a color filter for use in visual displays as recited in claim 13, further comprising repeating said process so that said color filter comprises a repeating pattern of red, green and blue pixels. 14. A method for preparing a color filter for use in visual displays as recited in claim 13, wherein said inadiating means is a laser. 15. A method for preparing a color filter for use in visual displays as recited in claim 13, wherein said inadiating means is a semi-conductor infrared laser. 16. A method for preparing a color filter for use in visual displays as recited in claim 13, wherein said sub-pixels size conesponds to the focused laser beam size. 17. A method for preparing color filters for use in visual displays, said method comprising the steps of: (a) forming a pixel on a transparent substrate, said pixel comprising a plurality of sub-pixels oriented in close proximity so that each of said plurality of sub-pbcels is indistinguishable to an ordinary observer, so that omission from the transparent substrate of less than all of the plurality of sub,-pixels will not necessarily result in an unusable pixel; and (b) repeating step (a) so that a repeating pattern of pbcels is formed on said transparent substrate to form a color filter. 18. A method for preparing a color filter for use in visual displays as recited in claim 19, wherein said pixel forming step comprises the steps of: (a) orienting a donor film and a receiver panel in close proximity, wherein said donor film comprises a transparent donor substrate having a first side and a second side, an absoφtion Iayer on said second side of said donor substrate and a colorant layer on said absoφtion layer; (b) irradiating said first side of said donor film with an inadiating of said colorant Iayer to be transfened to said receiver panel to form a sub-pixel; and (c) repeating said inadiating step so that a repeating pattern of pixels is formed on said receiver panel to form a color filter. 1 . A pbcel for use in a repeating pattern of pbcels on a color filter, comprising: a plurality of sub-pbcels. said sub-pbcels oriented in close proximity on a substrate, so that said plurality of sub-pixels appear to be one pixel, and so that omission from the substrate of less than all ofthe plurality of sub-pbcels will not necessarily result in an unusable pixel. 20. A method for preparing a pixel for use on color filters in visual displays, said method comprising the steps of: (a) orienting a donor film and a receiver panel in close proximity, wherein said donor film comprises a transparent donor substrate having a first side and a second side, an absoφtion layer on said second side of said donor substrate and a colorant layer on said absoφtion iayer; (b) irradiating said first side of said donor film with an inadiating means, so that said absoφtion layer absorbs said radiation and causes a portion of said colorant layer to be transfened to said receiver panel so that a sub-pixel is formed on the receiver panel; and (c) repeating said inadiating step to foπn a plurality of sub-pixels on said receiving panel to form a pixel. 21. A method for preparing a pixel for use on color filters in visual displays, comprising forming a plurality of sub-pixels oriented in close proximity so that each of said plurality of sub-pixels is indistinguishable to an ordinary observer, and so that omission from the transparent substrate of less than all ofthe plurality of sub-pixels will not necessarily result in an unusable pixel. 22. A method for preparing a black matrix for use on color filters, said method comprising the steps of: (a) orienting a donor film and a receiver panel in close proximity, wherein said donor film comprises a transparent substrate having a first side and a second side, an absoφtion Iayer on said second side of said transparent substrate, and a black non-sublimable colorant containing layer on said absoφtion layer, said receiver panel comprising a transparent substrate having formed thereon a repeating pattern of pixels; and (b) inadiating said donor film with an inadiating means, so that said absoφtion Iayer absorbs said radiation and causes a portion of said black colorant containing layer to be transfened to said receiver panel to form a grid pattern on said receiver panel between said color pixels. 23. A process for preparing pixels for use in a color filter, said pixels being formed in response to an incoming digital data stream, said pixel comprising a plurality of sub-pixels, said method comprising the steps of: (a) forming printing means having a printing surface and a multiplicity of independently electrical chargeable capacitor microcells adjacent to said printing surface; (b) activating selected ones of said microcells in accordance with the incoming data stream so that the activated microcells are geometrically related to the sub- pixels to be printed; (c) depositing electrical charges on said microcells selected for activation at controlled variable colombic charge levels to create at said printing surface localized electrical fields of various strengths that are proportional to the print densities desired for said related data in the sub-pixels to be printed; (d) contacting said printing surface with a voltage sensitive ink, whereby the ink, under the influence of said fields, is deposited on said printing surface only at the locations of said microcells selected for activation, with the thickness of each said ink deposit being proportional to the strength ofthe field at that microcell thereby to form a variable-thickness ink pattern on said printing surface; and (e) transferring said sub-pixels to a printing medium to form said pixels. 24. A process for preparing pixels for use in a color filter as recited in claim 26, wherein said printing medium is selected from the group consisting of glass and plastic. 25. A process as recited in claim 26, further comprising repeating steps (b), (c), (d) and (e), so that a repeating pattern of pixels is formed on said printing medium to form a color filter. 26. A process as recited in claim 28, wherein said repeating pattern of pixels is a pattern of red, green and blue pixels. 27. A method for preparing a color filter for use in visual displays, said method comprising the steps of: (a) orienting a donor film and a receiver panel in close proximity, wherein said donor film comprises a transparent donor substrate having a first side and a second side, an absoφtion layer on said second side of said donor substrate and a colorant layer on said absoφtion layer, wherein said colorant layer is (b) irradiating said first side of said donor film with an inadiating means, so that said absoφtion layer absorbs said radiation and causes a portion of said colorant layer to be transfened to said receiver panel to form a pixel; and (c) repeating said inadiating step so that a repeating pattern of pixels is formed on said receiver panel to form a color filter. 28. A method for preparing a color filter for use in visual displays, said method comprising the steps of: (a) orienting a donor film and a receiver panel in close proximity, wherein said donor film comprises a transparent donor substrate having a first side and a second side, an absoφtion layer on said second side of said donor substrate and a colorant layer on said absoφtion layer, wherein said colorant layer is a non- subtractive colorant, (b) irradiating said first side of said donor film with an inadiating means, so that said absoφtion layer absorbs said radiation and causes a portion of said colorant layer to be transfened to said receiver panel to form a pixel; and (c) repeating said inadiating step so that a repeating pattern of pixels is formed on said receiver panel to form a color filter. 29. A method for preparing a color filter for use in visual displays, said method comprising the steps of: (a) orienting a donor film and a receiver panel in close proximity, wherein said donor film comprises a transparent donor substrate having a first side and a second side, an absoφtion iayer on said second side of said donor substrate and a colorant layer on said absoφtion layer, wherein said colorant layer is a non- sublimable colorant, (b) irradiating said first side of said donor film with an inadiating means, so that said absoφtion layer absorbs said radiation and causes a portion of said colorant layer to be transfened to said receiver panel to form a pixel; and (c) repeating said inadiating step so that a repeating pattern of pixels is formed on said receiver panel to form a color filter. STATEMENT UNDER ARΗCLE 19 Please amend the claims in the above-identified application by cancelling sheets 18-23 of this application which contain the claims and abstract. Please substitute therefore, sheets 18-23 attached hereto, which contain the new claims to be entered in this application The abstract is identical to the abstract as originally filed and is found on substitute page 23 The amendments submitted herein are intended to conect obvious typographical errors and place this application into conformity with the amendments entered in the corresponding U S application No new matter has been introduced by these amendments Applicants believe that the amended claims submitted herewith more accurately and distinctly point out the inventive concepts Applicants wish to claim. Original claims 5, 13, 25, and 27 are amended by this document, and original claims 9, 14, and 22 have been cancelled. Claims 27, 28, and 29 have been added hereto. The claims as submitted herewith have been re-numbered accordingly

Inventors: PHILLIPS ROGER WINSTON, PHILLIPS, ROGER, WINSTON
Applicants: FLEX PRODUCTS INC, FLEX PRODUCTS, INC.
Application year: 1997
Main classification: G02B5
IPC codes: G02B5