DE2111561C2 - Process for producing an impression and use of a tellurium-containing semiconductor layer for offset printing - Google Patents

Description

10

2. The method according to claim 1, characterized in that an aqueous solution is used as the wetting agent is used.

3. The method according to claim 1 or 2, characterized in that a solution as the wetting agent 60% alcohol and 40% distilled water is used.

4. The method according to any one of the preceding claims, characterized in that the semiconductor layer is treated after wetting with the printing ink.

5. The method according to claim 1, characterized in that that a wetting agent is used which contains the printing ink.

6. The method according to any one of the preceding claims, characterized in that as electromagnetic Energy laser rays are used.

7. Use of a tellurium-containing semiconductor layer, which in some areas by applying electromagnetic and / or thermal energy between a stable, relatively crystalline atomic structure state and a stable, relatively amorphous atomic structure state is switchable so that the wettability with respect to a wetting agent depends on the atomic structure changes to offset printing.

8. Use of a semiconductor layer with Se ^ Te ^ Pto.i or Se ₉ STe ₄ GaI according to claim 7 for the purpose mentioned in claim 7.

The invention relates to a method for producing an impression of the preamble of the claim 1 and the use of a tellurium-containing semiconductor layer.

Such a method is already known (BE-PS 7 37 799) and has also been proposed (DE-OS 20 58 529).

In the known method, the property of a special semiconductor material is determined by the application of energy its physical structural state to change, exploited This happens for example by the fact that the with energy over a certain Areas exposed to the threshold value assume a different electrical conductivity than before. To the charging and application of triboelectric pigments or toner powder, these are distributed according to the electrical charged surface parts of the semiconductor

layer so that they can be printed from there on a base in the manner of a printing ink. Included it is also known (SCIENTIFIC AMERICAN, November 1969, pages 30-41) for the application of energy To use laser beams. This under the

The process known as ovographic printing forms due to its rapid working and rapidity Changeability numerous advantages. It has also already been proposed (DE-OS 20 25 767), the application of energy to be carried out in the form of short .impulses,

while the energy beacon in the layer parts switched to a stable structural state by a relatively long erase pulse can be switched back to the original state, whereby the stored information again to be deleted.

In the case of the earlier law mentioned above, the addition of energy leads to the the area exposed above a certain threshold has a larger volume than the non-exposed area

occupies the neighboring areas.This results in elevations corresponding to the areas affected. Take, for example, by rolling these bumps on an inked cushion the elevations to printing ink in order to then print them on the substrate during the subsequent rolling. Corresponding to a certain extent reciprocal applications are also affected, according to which the printing ink is due to brought by the application of energy formed recessed areas of the semiconductor layer surface in order to then produce prints, for example in accordance with the gravure printing process. Although this printing process offers many advantages, it is often undesirable. Layers with bumps and depressions on the Form surface.

It should also be noted that it is already known per se (BE-PS 7 36 529), so-called chaicogens to use for the production of lithographic matrices or patrizcn. By using electromagnetic

shear rays, the usual mechanical ablation processes are avoided, for example to create printed letters produce which, however, cannot be changed reversibly, since the removed material is not partially or can be easily replaced

Chalcogenic, tellurium-containing semiconductor material is also used in the invention, but for different purposes used

The invention is based on the object, sin such To improve printing processes in such a way that there are good impressions even without bumps and depressions made possible without having to resort to the photochemicals required in the photolithography process must be, as is the case with other known printing processes (US-PS 34 22 759) in which photochromic or thermochromic properties of the material are used. The to The semiconductor layer used to produce an imprint can also be reversibly changed and thus reused be, d. H. Simply enable corrections.

The invention is characterized in claim 1 and in claim 7 there is a special use a tellurium-containing semiconductor layer for offset printing claims further developments of the invention are claimed in subclaims

In the method according to the invention, the printing ink adheres to those parts of the surface the semiconductor layer, which is opposite to the printing ink due to the applied wetting agent allow good adhesion, while the other areas are somewhat repellent to the printing ink works. There is one possibility that the printing ink only after it has been wetted with the wetting agent is applied, or it is ensured that the wetting agent itself is formed as a printing ink is or contains one

With the invention, high-speed printing processes can be carried out without elevations or depressions for example on a printing drum are required. It therefore offers itself, according to a special one Formation of the invention, the use of offset printing or on-line direct printing of data processing equipment. The invention has already proven itself to be outstanding for this purpose In contrast to the previously generic or generic methods, this is the case with the invention the use of electrical charges is superfluous.

An example of a material group that has structural changes are so-called amorphous semiconductor materials, described in US-PS 32 71 591 and are shown. According to the earlier patent DE-PS 20 58 529, these materials are used to form printing plates used and according to US-PS 35 30 441 for information storage systems used amorphous semiconductor materials can, depending on the application of electromagnetic energy, such as a light beam, an electron beam or an electric current, and also depending on energy, such as heat, be switched between two stable states. As in greater detail in the above Patents and the earlier patent, amorphous semiconductor materials are preferably structural polymer. They are subject to structural changes, changes in arrangement, constellation and design include in the atomic structure. I am in a state the material is essentially disordered and generally amorphous and has only a certain degree local order and / or localized bond between the atoms. In the other state is the atomic structure the material changed to a different or different local order and / or localized bond, for example, towards a more ordered crystalline-like state in which a number of atoms linked together in longer chains. This material can be anisotropic; H. in a state when its properties are measured along a predetermined axis and

ίο are in a different state if their Properties are measured along another axis. For the purpose of explaining the present Invention hereinafter becomes one of the states as the generally amorphous or disordered state and the other state referred to as the crystalline or more ordered state according to the present In the invention, the difference in the structure of materials, such as amorphous semiconductor materials, is used to create new and improved copying and printing techniques that do not require photochromics and which are reversible, correctable and reusable.

After an embodiment of the method according to the invention, a LASER beam is used to on the To write on the surface of an amorphous semiconductor material that is initially crystalline or stronger The LASER beam produces a generally amorphous or disordered state State wherever the beam touches the material. A wetting agent or a wetting or moisturizing agent Solution is applied to the entire surface and adheres only to the crystalline or stronger organized areas. Paint or ink or Indian ink given off by the wetting solution or rejected, are then abandoned on the entire surface, but can only be adhere to the "exposed", generally amorphous or disordered areas. An offset roller transfers the color on a document, piece of writing or a similar illustration surface. Because the material again in the initial crystalline or more ordered ones State can be reset, the pressure plate can be reused again and again. aside from that are the writing speeds with the printing speeds of data processing systems and the invention can accordingly be used for such applications.

Yet another advantage of the invention is the ability to create different tones or gray levels or - shade to copy or print. This can be done, for example, by changing the energy content in the LASER or other electromagnetic beam caused to reduce the density of rough or granular Change the surface structure of the material.

Other objects, advantages and features of the invention will become apparent to the person skilled in the following with reference to the claims and drawings in those

Fig. 1 is a diagram showing a copier, which creates an image on a printing plate by passing through a transparent film Light is used;

F i g. Figure 2 shows an enlarged partial section of the printing plate of Figure 1;

Fig. 3 a schematic representation of an "output printer" shows which forms a printing plate controlled by the movement of a LASER beam will;

F i g. 4 is an enlarged partial view of the printing plate of Fig. 3 shows;

Figure 5 shows a diagram of a printing plate in which Images are formed by electrical currents; and

F i g. 6 is a waveform diagram showing the current pulses generated in the printing plate of FIG F i g. 5 can be used.

The copier system of Fig. 1 uses a printing plate 10 in the form of a rotating drum. The image to be copied appears on a transparent or translucent film 12 which is moved through the focal line or the focal point of a cylindrical lens 14. The lens 14 focuses light 16 from a light source 18. The light 16 passing through the film 12 is collected by a spherical lens 20 and imaged again on the surface of the plate 10. The image produced on the plate 10 is colored with the aid of a roller 22, and the colored image is transferred to a rubber-covered cylinder 24 w which also rotates synchronously with the plate 10. The ink is then transferred from the cylinder 24 to a document 26 which is pressed against the cylinder 24 by an impression roller 28.

The plate 10 is constructed from an amorphous semiconductor layer which is applied to a structured support cylinder 32. The plate 10 is shown in greater detail in FIG. 2 in a partially enlarged view in which the same reference numerals for the same elements as in FIG. 1 are used. The amorphous semiconductor material 30 can consist of Se9sTe <. <) Pto.i; Se95Te * .oGai.o; or other materials, such as those described in US Pat. No. 3,271,591 and US Pat. No. 3,530,441, which can be switched from a generally amorphous or disordered state in response to energy from the light source 18. For amorphous semiconductor materials, the light source 18 can be a LASER or other strong light source. The materia) 30 may initially be in the generally amorphous or disordered state and be selectively switched to the crystalline or more ordered state to provide an image, e.g. B. the letters ECD, as in FIG. 2 shown to manufacture. The figure results from the heating of the surface of the material 30 up to the transition temperature of the amorphous semiconductor. The crystalline areas are represented by ECD and have a rough or grainy surface while the remainder of the surface of the material 30 is relatively smooth. Accordingly, the paint on the roller 22 does not wet the smooth areas of the surface of the material 30; however, it adheres to the rough or grainy areas represented by the letters ECD .

By rotating the plate 10 several times and re-inking the rough areas of the material 30 additional copies can be made using the inking roller 22 as soon as printing is desired a new imaging roller 22 is retrieved by a drive 34 and the surface of the material 30 is rotated past a cleaning station 36, which a jet of suitable cleaning fluid or a blow jet of dry air may have. The material 30 then becomes more electromagnetic at a focal line or at the focal point High intensity energy bypassed the by increasing the intensity of the light source 18 This causes the temperature to rise increases at the surface of the material 30 to above its melting point as the disk 10 rotates the surface of the material 30 is quickly guided under an erasing or cooling roller 38, which with the help of a Drive 40 is brought into contact with the material 30. The sudden drop in temperature of the surface of material 30 leads the crystalline or more ordered regions into the generally amorphous or disordered state. A new transparent film 12 can pass through the focal point of the lens 14 moved and imaged on the surface of the material 30 to create a new image, the can be colored by the roller 22 after the drive 34 has brought the roller 22 into contact with the material 30 brought.

F i g. Figure 3 shows another embodiment of the invention for performing the non-impact function Printer or light setter. To designate the same elements as in FIG. 1-3 are like reference numerals used. The image is produced on the plate 10 with the aid of a LASER beam 42 which passes through a Source 44 is generated. The ray 42 becomes mi «. help a modulator 46 is intensity-modulated. After passing through the modulator 46, the beam 42 becomes deflected with the aid of a scanning or decomposition device 48, which directs the beam 42 to a particular point directed to the plate 10. A data processing system 50 controls the operation of the source 44, the modulator 46 and the deflector 48 via a group of lines 52, 53 and 54, respectively. The illustration can be on the Plate IC formed by a series of LASER pulses across the width of the plate 10 corresponding to the raster or line scan of a television receiver be distracted or blanked. The beam 42 can also cast deflected to be continuous to form a curved track or path. Alternatively, alphanumeric characteristics can be entered through Arrangement of a cover panel, shield or mask in the deflector or in the deflection device 48 and by shaping the LASER beam 14 into the desired characteristic prior to directing the beam 42 on the plate 10 are formed.

F i g. FIG. 4 shows a typical illustration comprising the letters ECD appearing on plate 10 of the system of FIG. 3 are recorded. For the same elements in FIGS. The same reference numerals are used in 3 and 4. In this system, the amorphous semiconductor material 30 is initially in the crystalline or more ordered state and the beam 42 switches the surface of the material 30 to the generally amorphous or disordered state represented by the regions of the letters ECD . The material 30 is heated above its melting point with the aid of the beam 42 and the surrounding material is cooled by the rapid radiation of heat ..1. When the system of FIG Surface of the material 30 supplies a solution. This solution can be composed of a mixture of water and alcohol in a ratio of about 60% alcohol and 40% distilled water. Such a solution wets the areas of material 30 which are in the crystalline or more ordered state, but does not adhere to the letters ECD which are in the generally amorphous or disordered state. After being wetted by the roller 56, the image is rotated under the inking roller 22. There, paint or ink or Indian ink is repelled from those areas of the surface 30 which have been wetted or moistened by the solution on the roller 56.

the. The paint from roller 22 adheres to the letters ECD that are not wetted by the roller 56 solution. The colored image is then transferred onto the cylinder 24 and onto the document 26.

Additional copies can be made by rotating the image on the surface of the material 30 below the Rolls S6 and 22 are generated. After a desired number of copies have been made, the roller 56 is brought out of engagement with the aid of a drive 58 and the roller 22 is disengaged with the aid of a drive 34. The cleaning station 36 acts so that the precipitated by the rollers 22 and 56 paint and solution removed. The material 30 is then returned to the crystalline or more ordered state in that the entire surface or parts thereof are coated with the LASER beam 42. The beam 42 is controlled by the data communication system 50 with the aid of the modulator 46 adjusted so that the temperature at the surface of the material 30 rises to the transition point and is thereby caused that the generally amorphous or disordered part of the material is transformed into the crystalline or more ordered state. The transition temperature in amorphous semiconductors is usually below the melting temperature. After the surface of the material 30 returns to the crystalline or more ordered state has been fed back, another image can be produced by using a LASER beam 42 werdwii.

FIG. 5 shows another way of working for producing an image on a printing plate 60. In this case, the image is produced by applying heat which is generated by electromagnetic energy in Form of electric current is generated. The pressure plate 60 is composed of glass or some other non-conductive support 62 of the 7 resistor segments 64,65,66,67,68,69,70 deposited thereon having. Conductors 74,75,76,77,78,79,80,81 are connected to a Group of electrodes 84,85,86,87,88,89,90,91,92, 93,94 connected, which are the ends of the segments 64,65, 66, 67, 68, 69, 70 make electrical contact. Amorphous semiconductor material 30 is over the top of segments 64,65,66,67,68,69,70 and conductors 74, 75, 76, 77,78,79,80,81 down.

A character generator 98 supplies the lines 75, 76, 77, 78, 79, 80, 81 with power which are connected to the printing plate are connected by a set of connector pins 100 which allow the board to be disconnected from the character generator 98. The segments 64,65,66,67,68,69, 70 are selectively or alternatively current is applied to ensure that one or several of the segments 64,65,66,67,68,69,70 heat radiate. For example, current from the character generator 98 is passed through the electrode via line 78 85, the resistor segment 65, the electrode 84 and via the line 74 back to ground. Of the Current passed through resistor segment 65 causes that segment to radiate heat from The heat radiated from the segment 65 is divided into a part of the amorphous semiconductor material 30 with which the segment 65 is coated

Reference is now made to the waveform diagram shown in FIG. 6, in which the current / entlag is plotted along the ordinate and the time T is plotted along the abscissa. The setting pulse 102 shown has a duration of approximately 10 ms and the reset pulse 104 shown has a greater intensity or greater amperage, but a shorter period of about 10 \ is. The adjustment pulse 102 causes the selected segments 64, 65, 66, 67, 68, 69, 70 to cover Material 30 is switched to the crystalline or more ordered state during the reset pulse 104 switches the material 30 to the generally amorphous or disordered state following the sudden fall of the reset pulse 104.

ίο In operation, the pressure plate 60 of FIG be designed that you can select all numbers from 0 to 9 and some letters by applying Current to segments 64, 65, 66, 67, 68, 69, 70 forms. After the amorphous semiconductor material 64,65,66,67,

is 68,69,70 switched to the appropriate pattern printed on any of the operations described in connection with the systems of Figs will. The segments 64,65,66,67,68,69,70 can be used in of any suitable shape, including a dimension trix of points that are knocked down by orthogonal conductors can be selected according to standard matrix selection procedures. In some applications it may be advantageous to pass current directly through the amorphous material in order to heat it instead of it is guided by an underlying resistance, such as segments 64,65,66,67,68,69,70.

In the systems of FIG. 1,3 and 5 can also be called. Grayscale printing and copying can be performed. For example, in the system of FIG. 1 the The intensity of the beam 16 after it has passed through the transparent film 12 is a produce a very rough or grainy surface when a dark image is to be printed and a less rough or grainy surface who made when a light gray image is desired. the Ink from roller 22 will adhere in an amount depending on the condition of surface 30. The system of FIG. 3 can be operated in a corresponding manner by changing the intensity of the LASER beam 42 to produce a gray scale or gray tones. This can be done in that material 30 from the initially crystalline or more ordered state to a generally amorphous or disordered state in varying amounts is switched. Some residues of crystalline or more ordered structure can be found in the surface of the Material 30 remain, so that a slight wetting is caused by the solution located on the roller 56 will. Accordingly, color or ink is used by the whale ze 22 not to such a large extent in such a way Surface as it would adhere to a surface entirely in the generally amorphous or disordered state is switched In this way the gray tone or gray shade can be changed in order to generate different contrasts in the training, which ultimately affect the document 26 to be printed.

The invention can also be used to ensure that only a portion of the Ab produced on the plate 10 education is optionally deleted or erased. To F i g. 1, a transparent film 12 with transparent openings can be produced in those areas in which deletion or erasure is to take place. To Fi g. 3, the LASER beam 42 can be on selected Be rich of material 30 are directed to specific Characters or parts of the entire plate and remapping of the entire pattern can be made. The invention can also be used to

9

that a permanent image is formed on the plate 10 by applying paint or ink with the aid of the roller 22 and the paint or ink are able to dry in order to produce a fixed or firmly adhering, permanent record of the image Case it may be desirable. To produce material 30 that can be removed from the support member 32 again.

In some applications of the invention, it may be desirable to deposit material 30 onto substrates that have various shapes, such as a disk, a flat, rectangular plate or flexible sheet, like a ribbon or strip, forming on a wheel can be saved or rolled up.

Although the invention has been described with reference to a crystalline or more ordered state, it is not necessary to actually be crystals to form in the surface of the amorphous material. Other changes to the atomic structure are also made applicable e.g. B. Atoms that are initially connected or concatenated in the form of long chains, the are traceable in rings. Chains in the form of helical lines or spirals or some other compressed configuration can also be converted into a new Shape can be stretched or pulled apart. Also other changes to the local order or phase changes can lead to new bonds between atoms that make up new ones form structural or chemical figurations that result in a different wettability. These changes in the atomic structure and the mixture of different phases of the material can produce a change in the surface roughness of the material, so that solutions adhere to varying degrees. Alternatively, the roughness of the surface can be essentially the same in every state of the amorphous material. rials remain, but the degree of attraction between the surface and the solution can change depending on the material phase, thereby reducing the wettability of the solution is changed on the surface.

For this purpose 3 sheets of drawings

50

55

60

65

Claims (1)

Patent claims: 1. Method for making an impression, in which a) a tellurium-containing semiconductor layer, the physical structure of which is caused by exposure with electromagnetic and / or thermal energy between a stable, relatively crystalline structural state and a stable, relatively amorphous structural state is switchable, is charged with energy according to the desired image, that the layer is stable in the exposed areas from one to the other Structural state passes. b) the layer is then treated with printing ink in such a way that it is either at the one or at the regions on the semiconductor layer that are in the other stable structural state adheres, and c) finally, the printing ink is printed on a base, characterized in that, that for the semiconductor layer a material with by electromagnetic or thermal Energy changeable wettability used and so applied with the energy that the wettability of the exposed areas compared to the non-exposed areas changes, and that the semiconductor material / before printing is treated with a wetting agent that only selectively either the; il the energy applied or the areas that are never exposed are wetted. 9. Use of a semiconductor layer according to claim 7 or 8 for on-line direct printing in data processing systems using a wetting agent with the proviso that the data processing system the energy generated according to the data to be printed out and applied to the semiconductor layer projected before the wetting agent is applied there