US 3859920 A
A master for hectographic printing is made by advancing a paper sheet or tape having an obverse and reverse side in incremental steps past an operating station. At the same time, a carrier web having a thermo-melting color layer is similarly moved past the operating station at which latter is brought into contact with the reverse side of the paper, whose obverse side is sensitized so as to change color when subjected to heat. The obverse side is thereupon contacted at the station with heated instrumentalities which produce local color changes in form of indicia, and the heat passing through the paper causes corresponding local portions of the color layer to melt and adhere to the reverse side of the paper which faces the carrier web, thus producing on this side of the paper mirror-reversed replicas of the indicia, which replicas can subsequently be used for hectographic printing.
Description (OCR text may contain errors)
United States Patent [1 1 Ritzerfeld Jan. 14, 1975 METHOD OF MAKING A HECTOGRAPHIC MASTER  Inventor: Gerhard Ritzerfeld,Schorlemer Allee 14, 1000 Berlin 33, Germany  Filed: Mar. 30, 1973  .Appl. No.: 346,701
 Foreign Application Priority Data Apr. 12, 1972 Germany 2218267  US. Cl 101/467, 101/469, 346/135  Int. Cl B4lm 5/18  Field of Search 101/463, 1, 469, 470, 471, 101/467, 468; 346/76 R, 135; 219/216 Primary ExaminerClyde I. Coughenour Attorney, Agent, or Firm-Michael S. Striker  ABSTRACT A master for hectographic printing is made by advancing a paper sheet or tape having an obverse and reverse side in incremental steps past an operating station. At the same time, a carrier web having a thermomelting color layer is similarly moved past the operating station at which latter is brought into contact with the reverse side of the paper, whose obverse side is sensitized so as to change color when subjected to heat. The obverse side is thereupon contacted at the station with heated instrumentalities which produce local color changes in form of indicia, and the heat passing through the paper causes corresponding local portions of the color layer to melt and adhere to the reverse side of the paper which faces the carrier web, thus producing on this side of the paper mirrorreversed replicas of the indicia, which replicas can subsequently be used for hectographic printing.
5 Claims, 2 Drawing Figures WENI JAH 1 4197:;
METHOD OF'MAKING A HECTOGRAPI-IIC MASTER BACKGROUND OF THE INVENTION The present invention relates to masters for hectographic printing, and more particularly to an improved master of this type and to a method of making the same.
It is already known to pass a thermally sensitive carrier past an operating station where it is contacted by heated instrumentalities, for instance electrically resistance-heated wires or the like, which record images on the carrier by causing localized color changes in the sensitized surface of the carrier. Indicia, such as symbols, letters, numerals or the like, can be recorded in this manner. It is customary to utilize a recording head having a number of the heatable instrumentalities so combined that each of the instrumentalities will form a dot on the sensitized surface of the carrier, with the overall formation of the particular indicia being effected by electrically heating only those instrumentalities of the head whose dots together will produce the outline or shape of the desired indicium.
The above approach is a well-established part of the art and readily permits the formation of any desired type and number of indicia. These can, of course, subsequently be read off the carrier.
However, there are many instances where it is desirable to further disseminate the thus-recorded information. Naturally, the carrier with the indicia thereon SUMMARY OF THE INVENTION It is, accordingly, an object of the present invention to provide a method of recording indicia in the aforementioned manner on a carrier which at the same time constitutes a master that can be used for subsequent hectographic printing of the thus-recorded indicia.
An additional object of the invention is to provide such a method which eliminates all intermediate steps required for reproducing the recorded indicia, so that the latter can be produced directly from the carrier on which they have been recorded and which also serves as the aforementioned master.
Another object of the invention is to provide an improved master for hectographic printing.
In keeping with the above objects, and with others which will become apparent hereafter, one feature of the invention resides in a method wherein a paper web and a carrier having a thermo-melting color layer thereon are advanced in incremental steps past an operating station. The color layer is contacted with one side of the paper web at this operating station, and indicia are thermally produced in the paper web at another side thereof while to the one side there are simultaneously adhered portions of the color layer which form on this one side mirror-reversed replicas of the indicia.
Thus, these mirror-reversed replicas of the indicia can be used at any desired time either immediately after their formation or after expiration of a greater or lesser period of time to hectographically print copies of the information recorded on the carrier/master in form of the aforementioned indicia.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a somewhat diagrammatic side view of an arrangement for carrying out the novel method; and
FIG. 2 is a fragmentary partly sectioned detail view of FIG. 1, on an enlarged scale.
DESCRIPTION OF THE PREFERRED EMBODIMENTS Before entering into a detailed discussion of the drawing it is recalled once more that the principle of producing indicia by causing localized portions of a heat-sensitive carrier to change color through contacting them with a heated instrumentality is well established in the art. A recording head used for such purposes usually is provided with a plurality of electrodes in form of wires or small rods which are arranged in form of a grid or raster. The free ends of these rods contact the thermally sensitive carrier and, when a particular rod is electrically energized, its free end in contact with the carrier will cause the latter to become discolored locally, namely forming a dot. The rods are usually arranged in form of a grid having seven lines of five rods each, so tht such a head may have 35 rods and can correspondingly produce 35 dots. Of course, the number may be greater or lesser. To produce a particular indicium, such as a letter, numeral or the like, selected ones of the rods are heated so as to produce a number of dots which together form the outline of the indicium in question. The selection of the rods to be heated is carried out bya signal generator which can be controlled from a keyboard or from an automatic programming device. The indicia thus formed are of course legible but cannot be conveniently reproduced, for the reasons set forth earlier.
With this in mind it will be seen that FIGS. 1 and 2 show an arrangement for carrying out the novel method, that is for producing a hectographic master at.
the same time as indicia are being recorded, with the carrier on which they are recorded serving simultaneously as the hectographic master. Reference numeral 1 in the drawing designates the finished master for hectographic printing. Reference numeral 2 designates a thermal activatorhaving a recording head 2a of the type discussed earlier and well known to the art. Selection of the particular rods which are to be energized in the head 2a to produce a given indicium is controlled by a non-illustrated coding matrix in a data processing system, that is via a pre-selected program. This is too well known to require detailed discussion and does not in itself form a part of the present invention. The head 2a may have the aforementioned raster arrangement of seven lines of rods, each line having five of the rods so that the head can produce 35 dots. It is located, or rather the free ends of the rods are located, immediately adjacent the heat-sensitive paper web la on which those of the rods which are activated produce respective dots the totality of which forms an indicium 3.
The paper web la is provided with a heat-sensitive layer 112 which will change color where it is subjected to the heat produced at the free ends of the respective rods, thus forming the dots. Thus far, there is nothing novel involved.
However, in accordance with the present invention, it is desired that the paper web not only be provided with a recording of the respective indicia but that it at the same time be constituted as a master capable of melting, that is, when subjected to localized heat, local portions of the substance melt and are transferred to the web 1a. Such substances are well known, and'the web 4 may for instance be produced in accordance with the disclosure in my prior US. Pat. No. 3,096,711.
The web 4 is withdrawn from a supply roll 5 and taken up on a take-up roll 7. Intermediate these rolls is locateda pressure roller 6 which engages the web directly opposite the recording head 2a. The carrier la, which may for instance be provided with leporellofolds, has the aforementioned heat-sensitive layer lb. It may be stored in a container 8 from which it is made to pass between the web 4 (so that the latter is located between the paper web la and the roller 6) and a pressure roller 9 so that its side 1a" comes in contact with the coloring substance layer 4b of the web 4.
The carrier 1a and the web 4 are moved in incremental steps past the head 2a. This means, of course, that they must be moved past the head at identical speeds, for which purpose an electromotor 10 is provided which is controlled by the same programming system that also controls the activation of the various rods in the head 24a. The motor 10 drives the roller 6, a transport roller 16 for the carrier la and subsequently the master 1 which is deposited in a receptacle 17, and the roller 7, for which purpose a timing belt 11 and timing gears 12, l3, l4 and 15 are provided which cooperate with the belt 11. A transport roller 18 cooperates with the roller 16, and rollers 19 and 20 are provided which serve as guide rollers for the carrier 1a and subsequently the master 1. FIG. 2 shows on an enlarged scale how the indicia 3 are formed on the side la of the carrier la by the head 2, and how simultaneously the mirror-reversed replicas ofthe indicia 3 are formed at the reverse side la" of the carrier la. The heat which forms the replicas 3 at the side la passes through the carrier 1a and locally melts the coloring substance of the layer 4b which is in contact with the side la", so that the melted portions adhere to the side la" in registry with the indicia 3, forming mirror-reversed replicas 4b on the side la". It is these replicas which, after the now completed master 1 is separated from the web 4, permit direct hectographic printing of the recorded information.
The head 2a may be made to advance axially along the roller 6 to produce individual indicia 3 (the socalled bit-serial operation"), or it maybe stationary and extend over the entire axial length of the roller 6 and produce entire lines of indicia simultaneously (the so-called bit-parallel operation). Both of these approaches are already known from the art.
It goes without saying that the carrier la can be in form of an elongated web, or in form oflindividual sheets, and the same is evidently also true of the web 4. t
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.
While the invention has been illustrated and described as embodied in the making of a hectographic master, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.
What is claimed as new and desired to beprotected by Letters Patent is:
1. A method of making a master for a hectographic copying process, comprising the steps of simultaneously advancing a non-transparent paper web having an obverse and a reverse side and provided with a thermally sensitive layer on its obverse side, together with a carrier web having a thermally transferably color layer, in incremental steps past an operating station; contacting said color layer with said reverse side of said paper web at said operating station; and applying heat to selected portions of said obverse side of said paper web at said operating stationso as to-produce trueimage indicia on said obverse side by localized discoloration of said thermally sensitive layer and to simultaneously transfer to said reverse side portions of said color layer corresponding in shape to said indicia, said portions of said color layer adhering to said reverse side and forming thereon mirror-image replicas of said indicia which are subsequently transferable to copy sheets in a hectographic copying process as true images of said indicia.
2. A method as defined in claim l,'wherein the step of applying heat comprises contacting said ,paper web at said obverse side with heated indicia-forming instrumentalities.
3. A method as defined in claim 1; and further comprising the'final step of separating said paper web with said indicia and replicas formed thereon, from said carrier web and advancing it to a collecting station.
4. A method as defined in claim 1, wherein the step of applying heat comprises contacting said obverse side of said paper web with heated indicia-forming instrumentalities, and contacting a side of said carrier web which faces away from said paper web with a roller located opposite said instrumentalities.
5. A method as defined in claim 4, wherein said carrier web is a tape; and wherein the step of advancing said carrier web comprises withdrawing the same from a supply roll past said roller, and forwarding the carrier to a take-up roll.