Record receiver having plural interactive leaves or a colorless – Having plural interactive leaves
Reexamination Certificate
1998-03-31
2002-04-30
Hess, Bruce H. (Department: 1774)
Record receiver having plural interactive leaves or a colorless
Having plural interactive leaves
C427S152000, C428S913000, C428S914000
Reexamination Certificate
active
06380131
ABSTRACT:
The present invention concerns a color ribbon for thermo-sublimation print, comprising a carrier, a color layer formed on the carrier, with a sublimable coloring substance dispersed in a polymer binding agent, a method for the manufacture of same and its application.
Print technology based on thermo-sublimation (TDD) has been known for a number of years. It inserts itself, seamlessly, into existing modern picture-taking-, printing-and transmission electronics. At the present time, the quality of the images which is being achieved with these instruments is already close to the quality of normal color photos. For most applications that is adequate. It seems to be only a question of a few years until the resolution of the so called “TDD pictures” will have obtained a top photo quality. Thus it is anticipated that in context with the “still-video camera”, traditional photography will be fundamentally revolutionized. The image obtained with a color video camera is first subjected to color separation by means of color filters. The obtained, by color separated, pictures are converted into electrical signals. These signals are further processed, whereby signals are obtained for cyanogen, magenta and yellow and transmitted to a thermo-printer.
The function of the thermo-sublimation print is briefly explained below, whereby this representation will only serve as an example. A special color ribbon with coating in one of the basic colors, cyanogen, magenta or yellow, is arranged on a receptor leaf. This arrangement is brought between a thermal- or print head and a print roller.
Located in the printhead, in single row, are tiny thermal dots, which transmit, with great precision, dot by dot, thermal energy to the reverse side of the color ribbon (100 to 400 thermal dots per inch). The thermal dots are targeted, according to the electronic signals, for either cyanogen, magenta or yellow. Subsequently, the process is repeated for the other two colors. Thus, a color print is obtained which corresponds to the original image seen on a picture screen. The picture is, perhaps, also coated with a very thin film and protected, in this fashion, against outside influences. The printing process is effected by means of a thermal head, which heats up the color ribbon in accordance with the image and transforms the coloring substance at these locations from solid to gaseous state. The coloring substance, in gaseous state, is transferred into the receiving layer of the receptor substrate, also called acceptor- or receiver substrate and is there fixated. Consequently, the entire process constitutes thermal sublimation. However, the coloring substance need not necessarily undergo the gaseous phase in order to dye a foil or plastic layer. Thus, the sublimeable coloring substance can, for example, be applied to the foil by means of thermal transfer print. This is then followed by an after-heating process, in which the coloring substance migrates into the acceptance layer of the receiver leaf. Further details relative to this process and an appropriate device are described in U.S. Pat. No. 4,621,271.
The state of the art already includes a multiplicity of systems of the above described type. Customarily, a TDD ribbon is constructed as follows. The color ribbon consists of at least one carrier and a binder-bonded and the sublimeable coloring substance containing color layer. The receiver leaf has a receiver layer for the coloring substance formed on a carrier. The carrier for the receiver leaf can be a transparent foil, a dual-sided, polyethylene-coated, a barite-coated or a synthetic paper. The carrier may have an inscribable and antistatic reverse side coating. Such system is evident for example from EP-B-O 334-323.
The known ribbons for thermo-sublimation print, however, have several drawbacks. The commercial sublimeable coloring substances frequently possess very low activation energies and are, consequently, transferred out of the color layer at only slightly increased temperature. The result is that already prior to the actual print action, a small amount of sublimeable coloring substance is transferred, within the supply ribbon winder, to the reverse-side coating of the neighboring loop, which in turn, leads to soiling of the print head or the ribbon-guiding components during printing and continued transport of the color ribbon.
In the worst case, the color ribbon may become blocked. The low activation energy of the sublimeable coloring substances leads, moreover, to additional problems. During printing of areas with high optical density, the print head is heated intensively. Since cooling down of the print head requires a certain period of time, it is possible that due to the residual head from the print head there may occur, in the adjacent regions, an unwelcome transfer of coloring substance to the receiver leaf. Said unwelcome transfer of coloring substance expresses itself in form of a color haze over the entire print. Furthermore, the unintentionally transferred color particles penetrate only insufficiently into the surface of the receiver leaf and adhere there superficially, which results in soiling of hands and other articles, which come into contact with the receiver leaf.
The low activation energy of the sublimeable coloring substance leads, in addition, to the transfer of the excessive amounts of coloring material during the printing process. This expresses itself detrimentally in excessive color intensity when printing half tones. The printing of genuine “gray” phases is not possible.
The known systems for thermo-sublimation print are frequently also inadequate in that with good compatibility between the resin systems of the color ribbon or the receiver leaf, there occurs, during printing, some sticking between the color layer of the color ribbon and the receiver layer of the receiver leaf. With finished print, this leads to a roughening of the surface of the receiver leaf or to soiling of the surface of the receiver leaf, due to partial transfer of the entire color layer of the color ribbon to the surface of the receiver leaf. In order to avoid this, it required, until now, excellent fixation of color layer to the color ribbon carrier.
Inasmuch as with thermo-sublimation print the receiver leaf is being printed, successively, with the three basic colors, cyanogen, magenta or yellow, there may be re-transfer of the previously transferred coloring material to or into the color layer of the color ribbon during subsequent printing of a different color. This expresses itself in a reduction of color intensity in regions with multiple print.
In order to solve some of the above described problems, it has already been suggested to chemically interconnect the binder in the color layer of the color ribbon. These methods, however, require complicated and time-consuming production runs, since pot times of coating solution must be accurately observed and thermal “after-curing” is required, frequently taking several hours or days. By chemically interlacing the binder in the color layer, the transferred amount of coloring substances is not only selectively reduced with low print energies, but also, in unwelcome fashion, in those locations where high color intensities are desired. The chemical interlacing of the binder in the color layer provides, furthermore, inadequate reduction of sticking between the color layer of the color ribbon and the receiver layer of the receiver leaf.
Alternatively, it has been suggested to employ in the color layer of the color ribbon, functional additives, for example lubricating or separation agents. These are to prevent any sticking between the color layer of the color ribbon and the color receiving layer of the receiving leaf during the printing process. Use of functional additives however leads to deterioration in the adhesion of the color layer to the carrier foil of the color ribbon and makes no contribution to the prevention or reduction of retransfer of previously transferred coloring substances to or into the color layer of the color ribbon. Functional additives, moreo
Griebel Thomas
Krauter Henrich
Fay Sharpe Fagan Minnich & McKee LLP
Hess Bruce H.
Pelikan Produktions AG
LandOfFree
Color ribbon for thermo-sublimation print, method for the... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Color ribbon for thermo-sublimation print, method for the..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Color ribbon for thermo-sublimation print, method for the... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2895468