DE1211227B - Process for the thermographic production of a copy - Google Patents

Description

Process for Thermographically Making a Copy The present The invention relates to a method for thermographic production of a Copy.

The invention relates in particular to such a method, wherein a an image-forming substance is transferred onto a copy sheet in a pattern, which comes from the original image to be copied to have an image on it to represent. The image on the copy sheet can initially be invisible and therefore may require development, or may be useful directly without requiring subsequent development Development becomes necessary; the substance forming the image may be colorless Material, if subsequent development is applied, or may be colored so that subsequent development is not required.

One such method is that a sheet, which is an original image, that is to be copied, as well as carries a thin film of a vaporizable medium, is subjected to infrared radiation. The dark areas of the original image become hot, causing the vaporizable medium to be selectively of the heated ones To evaporate spots and to condense on an adjacent recording surface, to form a picture on it. If the image is invisible, it can then be applied a powder ink that adheres to the condensed, vaporizable medium adheres. An example of this copying process is described in more detail in British Patent Specification 943 401, however, the invention is also applicable to wax transfer processes and the like, provided that the transfer materials are suitable.

With transfer copying, regardless of the type, at which the image-forming substance is a vaporizable medium, which by Evaporation and condensation is transferred when the transfer is made by the Surface is made from that bears the original image, produces an inverted image, d. i.e., printed matter, etc. reads from right to left because the surface, from which the transfer takes place must face the receiving surface. In such In cases where a true-to-original copy is required, another copy must be made made from the first or intermediate copy; or the material which the reversed image can be determined from one intermediate support surface in a second transfer stage are transferred to a last copy area and, if necessary, can be developed on a final copy surface.

Of course, the production of a copy true to the original can be done under certain prerequisites are carried out directly in a stage by material is transferred from the back of the sheet bearing the original image; however, this can result in a loss of sharpness and is not always possible, especially not with thick or double-sided original sheets. Another such Method is to use copy paper and ink such that it developed Image is visible through the back of the copy paper, e.g. B. when the copy paper is transparent. This procedure imposes restrictions on the selection of the Material used in the copying process and is not always acceptable.

The present invention makes use of the above Method that uses two transmission stages, an intermediate image and of which a final copy can be made, and is based on a feature, which reduces the waste of paper that can occur in this process. as well how this saves paper and thereby reduces running costs, the problem of machine execution is simplified because the handling of undesirable Paper can be avoided.

The present invention relates to a method of manufacture a copy true to the original by a copying process consisting of two Transmission stages, the first being an inverted intermediate image and the second of which a true to the original Produces final image, and is characterized in that the inverted intermediate image of the one copy job is carried by a sheet of paper which is using to carry a final copy to another copy operation.

The invention is applicable where multiple copying operations are carried out need to be, either to make a number of copies from an original image or copies to produce different original images.

Each copy operation therefore consists of two transfer stages and thereby creates a picture that is true to the original, and the arch that is in the intermediate stage what would otherwise be wasted becomes in one way or another Stage used as final copy material.

In one form of the invention, the sheet material for the intermediate image of a copy operation be part of a strip, which is also the sheet material represents for the final copy of this copy operation. In this form of the invention, if the intermediate and final images of a copy pass are on opposite sides Sides of the strip, they can overlap, but become common kept separated on the strip at a sufficient distance so that the surfaces to which and from which transmission takes place, brought into contact with each other can be used for the second transfer stage.

In another form of the invention, separate sheets are used, to carry the intermediate and final images of a copying operation, whereby the sheet, which carries an intermediate image during an operation, is applied to a To carry the final copy during another copy operation.

In this form of the invention, where a sheet is in two separate copy operations plays different roles, d. H. an intermediate image in one operation and a End image in a different operation, it is preferred that the two operations immediately follow one another.

In any form of the invention, the sheet material having a Intermediate image during a copy operation and a final copy or a part of which carries during another copying operation, preferably the intermediate image on one side and the final copy (of another operation) on the other side wear. In this way, residual image-forming substance becomes the was not removed from the surface that bears the intermediate image, not in be able to make the final copy that is on the same sheet in a different operation is generated to influence. If, however, the intermediate picture of an operation and the final copy of another pass is on the same side of a sheet must be found during the transfer of the substance producing the image from the surface, that carries the intermediate image, really all of this substance is removed, or an additional heating stage must be used to remove the residue.

Usually the sheet, which is an intermediate image during a Copy operation carried, used to make a final copy during a subsequent copy operation to wear (and two embodiments of which will be described later), however this is not always necessary. For example, a sheet could have a final copy on it a surface (last stage of the copy process), then an intermediate image on its other surface (first stage of a later copy operation) and this intermediate image transferred to a second sheet to make a final copy on this to form the second sheet (still in the later copy operation). The first arch, who still carries his final copy (from the first copy pass) would have then played its part, and the second arc would proceed in the same way.

Two embodiments of the invention will now be presented in the form of examples described with reference to the accompanying drawings, in which F i g. 1 one Figure 10 shows tape feed copier according to the invention and Fig. 2, 3 and 4 stages in the operation of a sheet feed copier according to the invention demonstrate.

In Fig. 1, a strip of sheet 1 is fed from a supply roll 2 to an intermediate transfer station 3 and from there via rollers 4 and 5, through a final transfer station 6 in a looping path around a roller 7 and back to the final transfer station 6 and finally to a cutting device B.

At the intermediate transfer station 3, an original sheet 9 is transferred the roller 10 is guided so that its image side is brought into contact with the sheet 1 will. An infrared lamp 11 is located on the other side of the sheet 1 (the is transparent to infrared radiation).

At the final transfer station 6, two parts of the sheet 1 in Pressure contact with each other is maintained by rollers 12 and 13, roller 12 being from the infrared lamp 11 is heated with the aid of reflectors 14.

In carrying out the method, the original sheet 9, which has a transferable image-forming substance on its image side, is brought into contact with the strip 1 at the intermediate transfer station. The image-forming substance may be a pre-applied film of a vaporizable medium such as e.g. B. glycerin or glycol; or, if the original z. B. Newsprint, it can be a material that is included in the print itself. Irradiation with the infrared lamp 11 heats dark areas of the original image and causes the transfer of the image-forming substance to the strip 1 in a pattern determined thereby. An intermediate image is thereby produced on a part of the surface of the strip 1 which is reversed with respect to the original image, but which is usually invisible or barely visible.

The intermediate image thus produced then becomes the final transfer station 6, and there it is transferred to another part by heat and pressure the surface of the strip 1 in order to produce a final image that is true to the original. It it will be noticed that both surface parts of the strip 1 are in the same direction run, and that the second surface part is on the first surface part opposite side of the strip 1 is located. It will also be noticed that when an original image is to be copied which is longer than the loop path round around the roller 7, the two surface parts will overlap, but this is in no way detrimental to the inventive teaching.

After he has received his original latent image, will the sheet carrying the image is cut off by the knife 8 and the image becomes then developed and using powder ink which has adhered to the image fixed with the application of heat.

According to FIG. Figure 2 of the drawings includes a sheet feed copier machine a sheet feed tray 21, an oil station 22 for applying a film of a vaporizable medium on an original sheet, an infrared heating station 23 and a Intermediate station 24 to hold the sheet at an intermediate stage in the process.

At the start of a copying operation, a sheet 25, which has been introduced during a previous copying operation, and a black auxiliary sheet 26, which can be simple black paper, are held at the intermediate station 24. A second sheet 27 from container 21 is then brought into contact with the image side of an original sheet 28 after the original sheet 28 has received a film of a vaporizable medium at the oil station 22 . The original sheet 28 and sheet 27 are passed together through the infrared heating station 23, whereby irradiation causes the vaporizable medium to be transferred to the sheet 27 in a pattern which is reversed with respect to the original image, thereby producing the aforesaid intermediate image .

The original sheet 28 is then fed out of the machine, and the sheet 27 bearing the inverted image becomes the intermediate station in FIG guided a position between the sheet 25 and the black auxiliary sheet 26, such as on the right side of FIG. 2 shown. The three leaves 25, 26 and 27 become then fed back through the infrared heating station as shown in FIG. 3 shown, and returned to the intermediate station 24 as shown in FIG. 4, with irradiation causes the black auxiliary sheet to become hot, which causes the transfer of the image generating substance from sheet 27 to sheet 25 and thus a true to the original Image on sheet 25 is generated.

The image on sheet 25 can then be developed and fused to make a final copy; Sheet 27 (which is an intermediate image in the described Copy operation received) will be available at the intermediate station for the next one Copy operation where a final copy is received and thus takes on the role which previously held sheet 25.

A strip feed device according to the invention can also if desired, in principle the sheet feeding device described above Use of a black auxiliary sheet and intermittent, reverse feeding work.

Claims (2)

Claims: 1. A method for the thermographic production of a Copy in a copy sequence that consists of two transmission stages, with the the first is an inverted intermediate image and the second is a true-to-original Final image is produced, characterized in that the reversed intermediate image the one copy sequence is carried by a sheet which is used to to carry a final copy in a different copying sequence. 2. The method according to claim 1, characterized in that the intermediate image of a copy sequence from one Bow is worn in strip form, this strip also the bow for the Represents the final copy of this copying sequence.