DE1671571B1 - ELECTROTHERMOGRAPHIC RECORDING METHOD AND THE LAYER CARRIER USED IN IT - Google Patents

Description

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The invention relates to an electrothermographic aspect of uncontrolled decomposition, the dieleksches Recording method and a thereby irish layer in the immediate vicinity of the started one Support. In the case of the arc according to the invention, which the dielectric by-method visible images or patterns are looked up or pierced. Since piercing a Provided electrical signals are generated, the 5 dielectric with an electric arc Transition contact between two metals is basically unstable and essentially on is used to generate heat in a controlled manner witness what then black-and-white images of high-quality material runs more or less statistically solution can be generated. the pattern created by removing the dielectric

There are a number of arrangements for erio tricums, not exactly determined beforehand, the creation of images according to electrical signals, which makes the resolution of the position signals known, including such arrangements as the writing pen, which is an electrically conductive one Pen to earth the power supply area is not precisely defined. Creation of a visible trace on a suitable. Due to the same conditions, this medium also has a gray scale according to electrical signals, because those which are applied to the conductive pen are essentially coupled to the current flow. In such an arrangement, in addition to that amount of dielectric, a recording medium is used which is conductive and which is evaporated. So that a paper backing has evaporated. This paper backing is made small arcing only a small amount of the conductive by the fact that during the production 20 dielectric, while a strong discharge a soot or small metal particles in the whole paper evaporates a large amount of the dielectric, from which are distributed, whereby the surface of the particular one Changing the paper that conducts through the dielectric is coated with a dielectric layer of translucent darker background, usually of a contrasting color. This possibility of generating certain gray gradations via such a composite carrier 25 is used to a certain extent in facsimile generating systems, an electrically conductive pen od conductive backing paper and a pen is required for all variables. In the case of the known method, which occurs through the dielectric, a substantial instability can occur between the pen 30 that the electrical conditions are in a di- and the conductive paper, then the electrical conditions are below a relatively high level Voltage to get a track that a small arc strikes the dielectric through a low-voltage process with high current and burns it away, thereby leading to the point at which the image is generated by the darker background color due to the con, which both in the manufacture of In contrasting color, dielectric black and white patterns as well as halftone copies that are visible. Fidelity limits are determined in the U.S. Patent.
Such a method is described in No. 2 713 822. In contrast to the known method, after Erwelchem a wax coating is processed to produce a substantially stable electrotherlithographic pattern. mixer process used to create a visible image

The known processes of this type have to generate 4 ° in a thermographic manner. With a number of significant technical disadvantages. A method according to the invention, an electrical first disadvantage is the need for a circle which is essentially a fully specific paper on which to appear the permanent conductive path through the drawing which will produce the image. Such papers have a system whereby the properties of a metal-to-metal contact, which is disadvantageous over normal writing papers, are used to create an adhesive appearance and feel different from normal writing papers to produce the trace. Next is to enable the uncomfortable. Since this circuit is essentially a hindrance, which has odor when "writing" due to ohmic properties, the voltage of the evaporation of the dielectric layer occurs, and current conditions are normally stable and if the electrical or arc parts of the di- 50 exactly follow the electrical signal from which it burns down electrics to generate the ones below. In combination with such a part of the stable electrical system formed with a contrasting color, the conductive layer can be made visible in the invention. The main disadvantage of the known method is that it uses a heat-dependent working system, but with which the exact correspondence of the electrical system is to be seen in the fact that with its help, due to the size in the electrical system, one remains in the electrical system without good physical conditions can achieve the resolution in the counter solution or fidelity in the whole system. If the rate to the known is increased significantly,
The known method uses such a high voltage that the dielectric layer is penetrated by the mutual pressure which covers the contact between an electrically conductive paper, which is determined in a special way . This voltage is necessarily higher than the voltage that the coating applied over that surface would require if a conductive contact is to be made on which the recording is to be made. When making facsimile copies in order to obtain the same current flow, the electrical and if the beginning of the current flow only through a conductive coating would have the same extent as the copy that would again result in a voltage breakdown in the dielectric, and the pen moves successively. In the case of the known method, a changing current flow occurs on the way over closely adjacent changing current flows and one in certain lines over the corresponding surface parts. at

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a preferred embodiment of this arrangement can produce a corresponding track on the paper, the conductive layer is z. B. from a thin if such temperature increases occur during the metal foil made of aluminum or stainless steel, scanning or writing movement of the pen,
which has a much smaller thickness than the case of a particularly expedient embodiment of the

Diameter of the surface on which the invention is a thermal transfer pen-pressure contact coating with the foil. Because the material is on the side facing away from the stylus the stylus and such an aluminum foil of the metal foil are used. The metal foil is included are relatively good electrical conductors, the essential thing is coated with a substance, which is initially a good one electrical resistance in this circle of contact retention on the metal but has when melting and resisted at the point of contact between the io solidifying in contact with paper a mecha writing pen and the aluminum foil, against which there is a more solid bond with the paper, the pen with a predetermined force. In this way, any paper can be used is pressing. This pressure is generally so great that it can be used to produce the record that any non-conductive coating, e.g. B. aluminum oxide, such a copy is produced in that which basically on the surface of an aluminum 15 man the paper during the scanning or writing minium foil is to be found, at least on one operation in contact with the ver-coated part the contact surface is penetrated whereby the metal foil is pressed. It can be hochman it can be assumed that a completely conductive paper with printed letterheads and the like. the electrical path which the contact point may be used, and the finished one closes, exists. The theory of the electrical counter-20 copy is a very good black and white copy of the Status of such a contact between two Me originals with a particularly high resolution of the one on it tallen is not completely transparent up to now, located representation.

but it can be assumed that the transition Further advantages and details of the invention

resistance is higher than the resistance in the two can be seen from the description of FIG Metal ladders on either side of the transition. 25 exemplary embodiments with reference to the drawing thus becomes the largest voltage for a given current flow. In this shows

Amount of current heat at the transition as in a Fig. 1 schematically shows the writing process on a

normal load resistance generated. Carrier according to a preferred embodiment

The heat generated at the transition flows according to the invention,

known laws of heat conduction. On the basis of FIG. 2, a greatly enlarged cross-section of the other dimensions of the pen and the foil order according to FIG. 1 to explain the contact, the greatest heating occurs in that between the foil and the pen,
Area in which the pen in FIG. 3 in cross section the generated image or the

Is in contact with the foil. This is due to the trace that is obviously generated when proceeding according to FIG. 1 from the very small thickness of the foil, which has a 35 and 2,

Allows heat flow perpendicular to their surfaces, F i g. 4 one of the F i g. 2 corresponding illustration

before significant amounts of heat flow parallel to the upper surface in another embodiment of the invention from the periphery of the pen. The use of heat-sensitive paper and metal foil next to the contact surface of the writing to generate the track or image and
handle ice acts as a good heat converter and radiator, 40 F i g. 5 in cross section a further embodiment and the axial length of the pin itself is relatively large, of the carrier that can be used in the invention,
based on the thickness of the film, so that the first is with reference to F i g. 1 the

a given increase in temperature at the transition finding when making a facsimile after the progressive heat front described a fast tempe scanning method. The absorbing increase in temperature on the other surface of the foil 45 ger has a thin foil 11 made of metal, preferably immediately below the point of contact, without white aluminum, on the underside of which there is an excess in the areas next to the pen train 12 from traces of heat when exposed to heat significant temperature increase results. Is arranged in load-bearing substance. During this practical test it has been shown that the method according to the invention is carried out in a system that can produce visible traces depending on a temperature, which metal coating on a sheet of paper 13 can produce which traces which the image in the manner of a facsimile are considerably smaller than the actual ablation should be. The two layers 11 and 13 measurements of the contact surface between writing are supported in such a way that a pen 14 with the pen and foil, which shows that because of the force F shown schematically at 15, on the other hand, the small thickness of such a foil is the size of a 55 pressed can be. The relative movement between individual markings can be smaller than the movement between the pen 14 and the metal foil 11. The contact surface between the pen and the follow a regularly controlled scanning path under the foil. With a pen whose with the foil in the control effect of the scanning drive 16. The force 15 exerted on the contact point has a diameter of the pen 14 is equal to 0.05 cm, one can dictate well-defined traces of 60 speaking mechanical properties , only 0.0125 to 0.025 cm wide. z. B. the hardness of the film 11, the type of point

The locally increased temperature on the side of the foil opposite the writing contact between the pen 14 and the top pen can be used to surface the foil 11 and the pattern, according to which the tracer pen moves over the carrier in any way according to which a visible trace is generated. Be misused. You can z. B. a heat 65 speaking a non-prior art corresponding paper in contact with the sub. Hearing proposal will bring one side of the film as a pen 14, so that the locally increased i. Tungsten rod of 0.05 cm in diameter with 2% temperature one of this temperature increase ent-j thorium is used, and the force F is of one

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Feather applied, which the pen 14 with current heat is through the pen 14 so einer Force of 4 to 15 grams against the film 11 limits that the heat by conduction presses, the recording medium 11, of course, the film 11 flowing in the direction of its thickness dimension 12, 13 e.g. B. with the help of a plate below the Pa- and the corresponding area of the thermal piercing sheet 13 must be supported. 5 action of transferable material 12 directly

The pen 14 receives current pulses from one below the pen 14 melts. Because in Signal current generator 21 which is responsive to binary signals from a source 22 suitable for all directions in the plane of the film 11. The signal generator material connects to the contact point and that in 21 then delivers current impulses in the form of rectangles - this direction does not take place a great heat conduction, which can be found from a reference line corresponding to the io because of the small thickness of the foil 11, Starting out with a value of zero and the amplitudes of which a limitation is predetermined for the heated area have a fixed value. The create. This effect is made even more under pen so always leaves behind when the occurrence supports that the surface sections 18 directly of a current pulse and leaves no trace next to the touched surface sections of the film 11 Track during the breaks between the individual 15 radiate any heat received and through Current pulses. The convection generated by the signal generator 21 emit. In this way there is a heat flow is of the film 11 z. B. in the at 23 inflow in the lateral direction through the slight interpreted way back. In the practical case, heat dissipation through the film 11 is limited and can be removed see the film and the paper 13 below that due to the heat-insulating properties of the Move writing station, and the indicated at 23 20 paper layer 13; the heat generated becomes practical Contact can be through a metal plate or a substantially limited portion small roller be given, which beFolie with the surface of the substance 12 transferred under the action of heat 11 is in contact while under the restricts. Writing station passes through. The transmitted through the film 11 through

In the following, with reference to FIG. 2 of the 25 heat melts the transferred when exposed to heat occurring mechanism for generating a bare substance 12, and in the molten state visible trace described. this substance has good adhesion to the

Like F i g. Figure 2 shows is the diameter of that relatively porous or rough surface of the paper Surface with which the pen 14 is in contact 13. Coated papers can be used with the surface of the film 11 stands, considerably 30 to a completely flat contact with greater than the thickness of the film 11. The diameter of the substance 12 to be obtained, of course to bedes Pen 14 in the area of this metal contact must be taken into account that the surface of the paper 13 tes approximately determines the achievable resolution of the material 12 in the molten state at copy. In other words, this means: under which must take. The paper types »Scanamaster« and Assumption that there is no relative movement between the 35 "Dependoweb" of the company "Oxford Paper Co." Pen 14 and the film 11 takes place, should the proven.

When current flows from the pen 14 to the film 11, the pen 14 is on its scanning path

The point generated will be as small as the smallest point will move on, the transferred subder will be melted can still be resolved by the system when punch 12 firmly again and adheres to the it reproduces a copy. As already mentioned above, the surface of the paper 13 is stronger than that of the film 11. If the facsimile copy is finished after the Dots are created as the diameter of the touch scanning process is complete and the sheet 11 area corresponds, so that is peeled off with a pen 14 from the paper 13, then remain on 0.05 cm in diameter (at the tip) still those surface parts at which current flow instead of points found 0.025 cm in diameter or less at 45, image elements 17 on paper 13 the transfer of the substance 12 to the paper sheet as shown in FIG. 3 is indicated.

13 can be resolved. This is indicated in FIG. in which the transferred substance 12 at punch can be composed as follows: 17 is indicated, the dimensions being 10 parts of ethyl cellulose, 3 parts of Sudan black, of the transferred portion are smaller than the 50 150 parts of solvent, e.g. B. amyl acetate and ethyl diameter the contact surface of the pen alcohol. One kilogram of this mass is enough

14 in FIG. 2. for coating 1000 pieces of aluminum foil on As F i g. 2 further shows, presses on one side. The aluminum foil expediently has a

Pen 14 force exerted the surface of the thickness of 0.00095 cm. Slide 11 slightly so that with a scanning 55 _R. . process with linear feed a sequence of line-like impressions in the surface of the film 11 A transfer sheet was produced as follows: are produced. This pressure is sufficient to First, as a conductive layer, a hardened guarantee of good electrical contact was made of aluminum foil with a thickness of 0.00095 cm and between the pen 14 and the foil 11, in 60 a thermal conductivity of 0.52 cal / sec / cm ² / ° C / cm from which the pen mechanically takes at least one (Type 1235 Hl 8) from Reynolds and penetrates part of the contact surface of any oxide or a corresponding lubricant or the like on the stamped side, laying drum a coating of the following composition which applied to the upper surface of the film: 10 parts by weight of ethyl cellulose with one can find. When a current pulse is applied, a viscosity of 7 cP, 3 parts by weight of Sudan black begins to flow through metal-to-metal contact (condensation product of 1.8 naphthalenediamine, e.g. with a voltage of 2 volts and 7 or more Acetone and 2,3-dihydro-2,2-dimethylperimidine), amperage. The 100 parts by weight of amyl acetate produced by this stream. In doing so,

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this mass 1 kg on about 1000 sheets (300 square meters; were applied. In some cases, however, were

Dry substance) applied. conductive and non-conductive lubricants on the

After removing the solvent, the film turned out to be applied to the movement of the writing

so produced layer of conductor material and to facilitate the pressure on the pen

transferring substance as excellently suited to the 5 pen and the shape of the same chosen

Implementation of the described invention were that the pen when moving through

Procedure. cut through the lubricant film when it is

Ethyl cellulose with viscosities of 7, 10 and a non-conductive lubricant film acted.

15 cP has so far been considered the best thermal over- The conductive layer must be so strong that

bearing material found. It goes without saying that they cannot occur in the

also other thermally transferable forces can tear.

Substances can be used as long as they only have different combinations of Have a suitable color, use appropriate softening pen or conductor foil, wound Melting points, adhesion to the conductive layer, but with the selection of materials and the Have resistance to pollution and the like. All 15 related dimensions observe the following these properties can be achieved without difficulty: it is important that the film is relative to be determined by a person skilled in the art. It also became thin because foils with a thickness of more than Polyvinyl acetate as a thermoplastic polymer with 0.025 cm do not produce very good results. Successful used, and it was also nigrosine to Also the thermal conductivity should be lower than Place used by Sudan colors. The heat through that of the copper, since copper foil heats up so quickly Impact transferable coating can also lead to the point that the dissolution suffers from it. Particularly a through-coloring can be pigmented, and good results have been achieved with stainless foils achieved either with a single color or a color steel or aluminum, their heat-conductive mixture. The coating can also be in the molten state if it is still below half the value of the copper, d. H. warm state or made of 25 The material for the pen can be: a water solution instead of the described charcoal, titanium, tungsten carbide, carbon with vitreous solvent. U.S. Patents 3,048,695, Construction, Copper-Tungsten Mixtures and Alloy-2 939009 and 3 054 692 describe suitable rangen and tungsten with 2% thorium. This latter materials that can be transferred by the action of heat. Material is already there in the form of welding electrodes

The expression "heat transfer- 30 available with very small diameters, and bare materials ”also includes the known use of such a pen thermoplastic resins such as B. polyethylene and / also has the additional advantage that the or waxes, like carnuba wax composed rods anyway with cylindrical cross-section compositions a. Because the pen is delivered to you, so you don't miss the contact surface Pressure applied when driving over the carrier, 35 will change as the pen wears. It it is necessary that the coating can also contain other conductive materials for the Carrying out the method as well as using the stock pen use, as mentioned above cannot be transmitted by pressure. This has been mentioned, preferably with such pressure a reason why films made from thermoplastics resin against those made from foil, coating and paper against films of wax and the like material is pressed that the surface be preferred. the metal foil along the scanning lines

As solvents continue to come under pressure.

those in question: acetone, methyl-ethyl-ketone, toluene With reference to F i g. 4 will be a

and dioctyl phthalate. Mixtures can also describe further embodiments of the invention. at

The conductive pen comes into contact with these or other solvents

if used. 14 the surface of a film 11 to form a

In general it has been shown that the results around heat-generating transition when current flows, the better, the lower the weight of the cover. Instead of a sub-layer that can be transferred when exposed to heat. It is particularly expedient to use such punching covers, in this case the film 11 Thickness that is obtained when one is in close contact with a heat-sensitive sheet on about 1000 sheets of 5 ° Applies 0.25 to 2.5 kg (dry matter). The Er-sheet 19 is arranged. There are a number of on softening or transfer point of papers that respond to heat and heat transferable material is appropriately known. In particular, this includes the papers between 65 and 180 ° C, with the transition temperature in so-called »Thermofax« copier machines rature should be defined as precisely as possible, what is used by 55. Generated in this arrangement Appropriate selection and composition of the process enough heat on the surface of the Materials can be achieved. The conductive layer of foil 11 immediately below the pen 14, if is usually a flexible, conductive metal foil, a pulse of current through the stylus 14 and the such as B. made of aluminum or stainless steel. Foil 11 flows to the desired mark or It can also be any other trace that corresponds to that of the aluminum, which is discolored when exposed to heat minium in thermal and electrical terms to produce paper 19. Depending on the characteristics of the Talking material used, if used, discolored when exposed to heat is mechanically strong enough to achieve the desired resolution when scanning the paper 19 Endure pressure. Usually has hold. The mentioned, in the Thermofax process earn The side of the conductive paper written on with the pen gives as good a resolution as you can the film does not have an insulating coating and is used in the process described above the rest is appropriately obtained from all lubricants or heat transferable material, wherein Oils made free, but of course not as in the above case the advantage during its production

it is achieved that you can use any paper for copying.

In Fig. 5 is another embodiment of a Shown carrier usable in the invention. The first is under the pen 14 Foil 11, and there is also the paper 13 on which the later copy appears. Between These a thin sheet is arranged, consisting of a layer of fabric or Mylar 31 or a another thin film that does not provide any appreciable thermal insulation. On the bottom of the Film 31 is attached to a layer 12 'which enables a transfer under the action of heat z. B. can be a wax transfer layer, as used in the known copying machines that work with heat transfer. This arrangement has the advantage that there is a certain choice among the available heat transfer materials 12 'can meet to various To meet requirements, e.g. B. different colors and the like, without aluminum layers 11 in different colors or with corresponding other properties of the covering must keep it in stock. The arrangement also allows the implementation of the invention a permanent foil sheet 11. If the copying process with a reusable foil 11 is carried out, then stainless steel is suitably used as the metal, so that repeated Scanning through the pen 14 is possible, with the only material that can only be used once Coated fabric 31 and the sheet 13 bearing the final copy. When you get the invention carried out in such a way that one and the same slide is used again and again for several copies used, then it must be ensured that the pen 14 is always precisely guided so that he when scanning is not distracted by previously impressed scan lines or grooves, which of course are present in the film after it has been used once. When to memorize the too copying pattern a die or similar device without relative movement between the The part corresponding to the pen and the foil is used, then a reusable one can be used Foil of any suitable material can be used.

The foregoing description of the invention shows that it can be taken in a variety of forms can be carried out. Use with a scanning or writing movement is only an example described. In this case, the response speed is so high that the relative speed between the pen and the base can be up to 100 cm / sec, with you can transfer up to 4000 contrasting points, each about 0.0125 cm in diameter. The so scored Resolution is far better than the normal requirements for facsimile transmission corresponds to a low bandwidth, whereby the method according to the present invention is also used can be if the signaling devices are improved in known systems. Since the melting point of the heat transferable substance 12 is a fixed temperature is and the various other parameters can also be determined so that a suitable one The temperature rises when the current flows and the transferable medium does not melt, when there is no current flowing, and because furthermore no melting occurs next to those places where the melting takes place immediately below the pen, the invention brings a significant Improvement in black and white reproduction.

All of the details shown are important for the invention.

Claims (7)

Patent claims: 1. Electrothermographic recording process, characterized in that man a) direct electrical contact between an electrode and a die produces the top layer of the recording material forming thin metal foil, wherein the size of the contact area is approximately the smallest that can be reproduced with good resolution Unit corresponds and the thickness of the film is significantly less than the main dimension the contact surface; b) allows such a strong current to flow through the contact surface that it causes a considerable Causes temperature rise at the point of contact, and c) allows the current to act only so long that the predetermined temperature rise is reached on the side of the foil opposite the electrode, but without that due to the thinness of the film, the temperature in the wider area of the Contact points increases significantly. 2. The method according to claim 1 for the production of a facsimile, characterized in that an original is scanned and generated signals corresponding to the captured data and sent to the Electrode are passed on, which is synchronized with the data corresponding to the original moving the carrier for the copy. 3. The method according to claim 2, characterized in that the electrical signals are binary Are waveforms which, when there is one amplitude thereof, represent a flow of current and thus create a pattern between the pen and the film and when the other amplitude of the same do not generate a visible pattern or interrupt the flow of current. 4. The method according to claim 2, characterized in that the thermal conductivity of the Metal foil is less than 0.85 cal / cm see ° C. 5. The method according to claim 2, characterized in that the foil made of aluminum or Made of stainless steel and thinner than 0.0025 cm. 6. The method according to claim 4 or 5, characterized in that the metal foil on a Side is coated with a substance that can be transferred under the action of heat, which at a Temperature melts, which is slightly below the locally increased temperature. 7. The method according to claim 6, characterized in that a sheet of paper is in contact with the coated surface of the