DE1436647B2 - Method and device for generating characters that remain visible on a recording medium - Google Patents

Description

30th

The [invention is a method and a Device for generating visible remaining characters on a recording medium, in which, dependent on an electromagnetic beam. for the representation of the character on the Recording medium provided color particles is supplied with an amount of energy through which the color particles still visible during the radiation exposure and remaining in the form of the character to be written are recorded on the recording medium.

A method according to the invention is intended to create the possibility of exposure to radiation To transfer characters to a recording medium in the manner of a typewriter. With usual Typewriters are required to be able to use any type of paper. Besides, he must The writing process of a single character should be at least as fast as the input with the finger Operator takes place. A typewriter should also work as quietly as possible and it must be guaranteed so that the last character written is immediately visible. However, all of these demands must achieved in an economically justifiable manner at the price of a typewriter in To keep boundaries.

Methods are known. To transfer characters using rays onto a recording medium. Thus, ¹ S 2,890,923, for example, a device shown and wherein an image formed on the screen of a CRT image is projected via an optical system to an electrostatic reproduction apparatus described in the US-I. Using radiation-permeable, light-sensitive layers, a latent image is generated, which is transferred to a recording medium using a special process. In this case, paint dust is applied to the recording medium in an electrostatic field according to the lines or characters to be imaged.

In another device, according to U.S. Patent 3,056,136, in continuous succession Lines of an image stretched on a drum are transferred to an electronic transducer. Even there the latent image is exposed to an electrostatic field using colored powder visible.

In both known devices it is necessary to have layers of different layers in front of the recording medium Provide materials or other devices that make it impossible to record immediately after recording to make the images visible. In addition, both devices can be used individually selected characters are not transferred to freely selectable writing positions on the recording medium will.

The invention has set itself the task of creating a Schi eibmaschine that the initially provided Demands. It is therefore proposed that for writing in the manner of a typewriter a bundle of rays shows the characters individually selected by an input device Projected direction of arbitrarily selectable writing positions of a line of the recording medium, and that the Beams of rays on the color particles used for recording. which are on the recording medium or are on a special ink carrier, and / or acts on their holding means, and that the An amount of energy is taken from the bundle of rays, which changes the color particles chemically or physically. Color particles made of thermoplastic material on a carrier have proven to be particularly advantageous Material which, as a result of the radiation, selectively softens in accordance with the characters or liquefied and transferred to the recording medium by mechanical pressure. Included the bundle of rays can expediently in a template, according to the selected characters, be profiled.

Such a method is characterized by a high writing speed and largely noiselessness the end. The devices required to carry out the method are for the most part simpler Design, so that an economical production of a typewriter, which according to the mentioned method works, is guaranteed. A suitable carrier for the color particles is one that consists of a radiolucent, z. B. consists of a transparent film on its, the writing surface facing surface with a thin, softenable under the action of the beam, z. B. thermoplastic paint layer provided that adheres sufficiently to the paint carrier when cold, to the locally softened or liquefied Places, however, is repelled by the carrier material. To the exposure time of the beam to soften Keeping the thermoplastic color particles as short as possible can be done according to a further suggestion According to the invention, the ink film base can be preheated to a value which is just before the melting point the color parallels lies.

A particularly economical method is in terms of on the ink carrier to see if it can be regenerated according to another suggestion. In addition it is useful to move the carrier after the writing position to a known charging device for

to bring an even electrical charge connected to the following devices:

a) an exposure device which illuminates the substrate at the written-off points of the ink layer and changes the electrical charge of the wearer at these points;

b) a dusting device by which the regions of changed charge in known manner with thermoplastic ^F: arbstaub be provided;

c) a heater for the transferred dye softens and melts it seamlessly into the unused areas of the dye layer.

This makes it possible to use an ink film carrier that rolls on at the print-off point passed, and after he has given up dye, can be regenerated. So it is no longer necessary Replace entire ribbons, but only need to be in a corresponding device new paint particles are refilled in due course.

Further details of the invention emerge from the claims. Patent protection is only claimed for the items characterized in the claims.

Exemplary embodiments of the invention are explained with reference to the drawing. It shows

F i g. I a basic arrangement of the main parts of a device for example implementation the procedure,

F i g. 2 a device for performing the method using a band-shaped, with thermoplastic dye-coated carrier and a pressure or stop system,

F i g. 3 shows a modified device according to FIG. 2 with a different pressure or stop system,

4 shows an example of a device for regeneration a ribbon-shaped ink carrier by renewing the ink layer,

F i g. 5 shows another, for example, a device for regenerating a ribbon-shaped ink carrier electrostatic replacement of the written off dye particles.

In Fig. I is schematically a device for implementation of the procedure shown. Therein 1 is a radiation source that is suitable. a bundle noble to generate parallel electromagnetic beams 4 and through the stencil arrangement 2 on the recording surface .3 project. The radiation energy in the beam 4 is essentially evenly distributed over the entire projection cross section, while the cross section of the rear of the stencil 2 exiting, for example, with blackened and transparent areas 4; / is profiled by the template according to a character to be recorded. On the Recording surface 3 thus creates an image of the character to be drawn.

In order to have a sufficiently high radiation area available for influencing, for example, discoloration of particles for displaying a character on the recording surface in the specified printing time in the area of the character shown, provision can also be made for the radiation source 1 ■ / .. B Is designed as a laser which generates a bundle of largely parallel radiation with a high energy content.

Due to the radiation distribution generated on the recording surface 3 after a certain stencil 2 has been switched on, it is possible with such an arrangement in the simplest case of implementing the method to influence particles of the recording surface 3 hit by the beam 4u in the sense of a color change. Such a color change can e.g. B. caused by chemical discoloration of the particles as a result of energy absorption from the radiation. However, it can also be advantageous to work with normal, unprepared writing paper and, as will be explained below, to selectively supply color particles under the influence of radiation to the writing surface from the outside and fix them in place.

The selection of the templates embodying a specific character can be based on electromagnetic Paths are made and controlled by a keyboard on the type of typewriter keyboards will. At the same time, pressing such a keyboard can also switch on the radiation be made with means known per se, so that each time immediately after setting a template the beam 4; / occurs. During the change of the template can, also in known Way, the advancement of the recording surface 3 can be accomplished.

A template made of radiolucent material can also be produced using the embossing process in such a way that that the characters to be generated corresponding, arranged perpendicular to the radiation direction Planes let through the groove / .antcil of the beam, whereas not for the direction of the radiation vertical, somewhat mirrored parts of the surface of the stencil follow the unused radiation reflect outside.

Numerous other designs and arrangements of templates are also possible. So it is B. (. steerable, reflection templates in such a way between the To attach the exit of the radiation generator and the writing surface so that the radiation emanating from the radiation generator, parallel rays corresponding to the respective characters, for example at an angle from 45 'with respect to the beam direction inclined mirror surfaces to the one arranged parallel to the beam direction Recording surface are reflected. In this case, too, the unused Radiation portion from non-character interfaces of the stencil in another Angles are reflected and therefore masked out.

Of course, z. B. caused by the type of radiation source, non-parallel beam 4 or for a reduced image of the stencil image on the recording surface, between the radiation generator and the recording surface 3 any suitable optical means can be switched on.

To further develop the method according to the invention, an arrangement according to FIG. 2 provided be. In it I is the radiation source, 2 a set of interchangeable templates, 3 roughly made from normal Recording surface in relation to writing paper. 5 one except for a thin, thermoplastic layer 5, / .radiolucent, For example, a carrier strip consisting of a flexible plastic, β a fixed one Solenoid. 7 a cup-shaped pressure or

Stop hammer with an iron ring attached to the upper edge 8. The latter two parts are held centrically to the axis of the radiation source 1 by a membrane 9 clamped in place at the edge and are attached so as to be movable in the axial direction towards the carrier strip 5 or the recording surface 3. Finally, there is a fixed counter-stop on the back of the recording surface 3 10.

The procedural mode of operation of this device is as follows: After advancement of the recording surface 3 in the position provided for the recording of a character and simultaneous activation a template of the template set 2 between the radiation source 1 and the carrier film 5 is the Generation of the beam 4 initiated. In doing so, what is profiled by the selected template meets Beams 4, -j on the carrier film 5 and after passing through the radiolucent film part of the thermoplastic color layer 5 <-j absorbed. The here- ao with local heating of the thermoplastic that occurs according to the cross-section of the beam Layer 5a corresponds in its distribution to the shape of the character to be printed and is sufficient. the to locally soften or wear a very thin layer liquid.

It can now be provided that by an adjustable, electronic time control of a known type a predetermined duration of action of the beam 4a on the thermoplastic layer 5; i the Solenoid 6 is excited. As a result, the iron ring 8 is against the spring action of the membrane 9 in the Magnet coil 6 is drawn in and during this process takes the stop hammer 7 in the direction of the Carrier tape 5 with. The carrier tape is briefly held against that held by the counter-stop 10 Recording surface 3 pressed and thereby transfers the locally softened accordingly by the characters Coat of paint on this.

By suitable means it can be achieved that the typeface transferred in this way immediately after Stop adheres to the recording surface and hardens without the carrier tape 5 on the recording surface 3 is liable. A first means of solving this problem can be that by choosing the thermoplastic material, through additives to the thermoplastic dye and / or through properties of the carrier material the adhesion between the carrier material and the softened or liquefied Dye is reduced, or that, when exposed to heat, a substance between the thermoplastic Layer and the support is effective as a separating layer and the separation of the impact on the recording surface adhesive paint is facilitated by the paint carrier.

Another possibility is that a thin intermediate layer is provided between the carrier and the color layer during the manufacture of the color ribbon, which layer promotes the detachment of the color layer when the local heating occurs. The paint layer can also be made in such a way that it adheres sufficiently to the paint carrier in the cold, cohesive state through adhesion, but is repelled by the paint carrier at the locally softened or liquefied areas. ^e 5

A further reduction in the tendency of the carrier tape to adhere to the recording surface after this has taken place Imprint of a character can be achieved in that the carrier tape is always under one Certain tensile stress is held, so that it strives immediately after the impression, again a rest distance from the recording surface 3 to be assumed.

Finally, there is the possibility of using the Andruckbzw. Stop hammer 7 by suitable electromechanical Medium, e.g. B. by additionally attaching a reset winding U indicated by dashed lines accelerated back to its starting position and through the suction created on its stop surface to lift the carrier tape 5 from the recording surface 3. For this it can be advantageous to use the stop hammer with a rubber sleeve 12 which is in sealing contact with the carrier tape when it is hit or the like. To be provided. It can also be useful to have precise electronic control of the reset of the hammer to match the respective viscosity of the irradiated areas of the paint layer 5a in terms of time, that a separation of the carrier tape 5 from the recording surface before the hardening of the irradiated Color areas is done. Of course, several of the measures mentioned can also be used at the same time Find.

In addition to the means listed, magnetically operated cutting knives are of course also available if necessary or the like. Applicable after the print has taken place without touching the print area between the ink carrier and recording surface penetrate and separate both from each other.

Compared to the device according to FIG. 2 a somewhat modified arrangement is shown in FIG. 3 shown. In this is a stop hammer 13 on the side of the recording surface facing away from the radiation generator 1 3 attached, while a radiolucent counter-stop 14 on the side of the radiation generator serves as a guide for the ink carrier 5.

This arrangement has the advantage that the stop hammer can be made simpler. aside from that can be an electrodynamic drive in a structurally simple manner as a drive for its work and return movement System 15 of known type may be provided when maximum speed is required.

The to the F i g. The device described 2 and 3 has the advantage over the known arrangements that a ribbon is used as the color carrier 5, which is at the usual extreme ambient temperatures is clean to use and completely colourfast. The ribbon can also be made so thin that that with the same reel size it results in the same writing performance as a textile tape. In addition comes that the writing noise by low-cost damping measures (rubber stop surface od. Like.) The stop hammer 7 or 13 striking only with relatively little force to an extreme minimum is reducible.

In order to switch off the slight impact of the hammer, there are of course also constructions conceivable in which, for example, one on the back of the recording surface in the imprint area parallel to this rollable pressure roller during the action of the radiation on the recording surface presses the paint carrier so that it takes over its locally softened paint particles as characters.

Since the radiation power to be used to soften the thermoplastic ink layer depends on the difference between the softening temperature te and the ambient temperature / », preheating of the ink carrier 5 to a preheating temperature

409 528/122

for tv before it enters the recording area, the amount of heat to be supplied by the color particles from the beam is considerably reduced. While the required temperature rise Δ t = te-to without preheating, when the paint layer 5a is preheated to temperature tv a significantly lower difference value Δ f = te-tv is transmitted by the radiation. By choosing a suitable thermoplastic dye with a steep characteristic of its change of state as a function of the temperature Δ ( the surface-specific radiation power to be supplied can be reduced to a minimum value.

The preheating itself can be achieved by any known heating element 16 (FIG. 3) and expediently act on the entire carrier tape 5. The heat supply can be by convection or be effective through radiation. To get the right one regardless of the outside temperature To ensure the setpoint of the preheating temperature Λ, the heating output can be regulated, for example an electrical circuit by means of a thermostat 17 is always kept at the correct value will.

In general, it will not be required in future typewriters. To make breakthroughs, because two pieces are more convenient through a z. B. xerographic copying process or by a typewriter can be produced.

However, in special cases, the procedure described should be used be trained for the production of copies, it can be provided that between the stop hammer 7 or 13 and the counter stop 10 or 14 recording surfaces 3 and Color carrier 5 can be inserted alternately in several layers, and that, for. B. by choosing one primarily Far infrared radiation a division of the absorption areas into those corresponding to the number of layers Number of color carriers, e.g. B. ribbons and / or carbon foils, so that after activation of the radiation pulse when the hammer 7 or 13 hits the imprint of the beam predetermined typeface takes place on several recording media in the individual layers at the same time.

Particularly in the case of automatic typists, it may furthermore be desirable that the carrier 5 and the thermoplastic Ink layer 5.7 to regenerate existing ink ribbon after one pass through the writing position. For this purpose, the carrier, as shown in FIG. 4 shows to be designed as an endless belt 5. It goes through in this case, after passing the writing position 51, for example an arrangement of heatable calender rollers 52, to which new dye can be supplied from the storage container 54, which is also heatable. By preheating of the strip in the area before it enters the roller arrangement 52 by means of a heating device 55, z. B. an infrared radiator, it can be achieved that the paint layer when exiting the roller assembly is available again in uniform strength and quality.

Another type of regeneration is shown in FIG. 5.

This works according to the known xerographic principle. In a device 56, the carrier provided with an evenly distributed electrical charge. This charge is when fluoroscopic written off points of the carrier changed locally by means of a light source 57 at these points. In an adjoining dusting chamber 58 becomes thermoplastic to the areas of the changed charge Color powder supplied, which is liquefied in a further adjoining heating chamber 59, whereby it fits sufficiently into the unused areas of the paint layer and after it has hardened is available for the new write process.

It is Z. B. possible to design at least one of the deflection devices as a mirror wheel. According to the state The latest developments also make it possible to deflect the beam by means of an optical one Make a system whose refractive index can be changed directly by deflection voltages, so that the deflection of the focal point can also be achieved without mechanically moving means.

It should also be noted that in the writing method according to the invention, write errors are very similar Way as with normal typewriters can be eliminated after removal of the ink ribbon or other procedural ink carrier from the recording area and after introduction a radiation-permeable replacement ink carrier with thermoplastic ink particles in the ink the recording area, so z. B. in white color, by repeatedly writing with the wrong one Characters a deletion of the erroneously written character is possible.

When using stencils as type image carriers, additional, i. H. not stenciled characters a supplementary image carrier that can be introduced into the imprint area instead of the main carrier or the like be provided. This can consist, for example, of a piece of film with a cover layer is provided which has a radiolucent typeface. Such supplementary templates can be kept in stock in a magazine and inserted into the impression area by hand, possibly with a mechanical auxiliary device.

The supplementary stencils can also be introduced into the impression area by a mechanism Foil strips be summarized in such a way that they can be moved by shifting the strip in the line direction are selectable.

Finally, an embodiment of the supplementary template is also conceivable, which od on a film strip. carries a heat-resistant top layer. Each additional layer can be added to this cover layer, for example with a stylus desired typeface can be engraved with local removal of the top layer.

The last-mentioned supplementary template can also be used on the other side with a be provided thermoplastic color layer, so that the supplementary stencil without the involvement of Normally involved in the writing process or the like. Can be used.

1 sheet of drawings

Claims (17)

Patent claims: 1. A method for generating characters that remain visible on a recording medium, in which, depending on an electromagnetic beam, the one for the representation of the character An amount of energy is supplied to color particles provided on the recording medium through which the color particles are still visible during the exposure to radiation and remain in Shape of the character to be written are recorded on the recording medium, d a by characterized in that the beam for writing in the manner of a typewriter (4a) the characters individually selected by an input device in the direction of arbitrarily selectable Write positions of a line of the recording medium (3) that the beam is projected (4a) on the color particles used for recording, which are on the recording medium (3) or on a special ink carrier (5), and / or acts on the holding means, and that an amount of energy is taken from the beam (4; j) that chemically or physically changes the color particles. 2. The method according to claim 1, characterized in that the color particles located on the carrier consist of thermoplastic material and the radiation corresponds to the characters locally selectively softened or liquefied and by mechanical pressure on the recording medium be transmitted. 3. The method according to claim 1, characterized in that for generating an electromagnetic Radiation (4) a laser is provided. 4. The method according to claims 1 to 3, characterized in that the radiation generated (4) profiled by a template (2) corresponding in each case to the typeface to be recorded will. 5. The method according to claims I to 4, characterized in that the beam generated (4) optically focused in a manner known per se and in a manner known per se by means of deflection Way is influenced so that the written image to be generated is recorded as a facsimile or raster image will. 6. Apparatus for performing the method according to claim 1, characterized in that the Carrier (5) of the color particles from a radiolucent, z. B. consists of transparent film, the on its surface facing the writing surface with a thin one under the action of the beam softenable, e.g. B. thermoplastic color layer (5a) is provided, which is sufficient in the cold state adheres to the paint carrier (5), but from the locally softened or liquefied areas Carrier material is repelled. 7. Apparatus according to claim 6, characterized in that the locally softened for the impression Make the paint layer (5a) applied to the carrier (5) a mechanical or electromechanical one Pressing device, e.g. B. a stop hammer (7, 13) is provided, which is adjustable Time relation to the occurrence of the radiation pulse is effective. 8. Device according to claims b and 7, characterized in that by choosing the thermoplastic Materials, through additives to the thermoplastic dye and / or through properties of the carrier material, the adhesion between the carrier material and the softening or liquefied Dye is reduced, for example, that a substance when exposed to heat is effective as a separating layer between the thermoplastic layer (5; j) and the carrier (5) and the separation of the ink adhering to the recording surface upon impact from the ink carrier relieved. 9. Device according to claims 6 to 8, characterized in that the ink carrier (5) between a radiolucent, e.g. B. made of glass or plastic stop device (7) and the recording surface resting against a counter-stop (10) is guided. 10. Device according to claims 6 to 9, characterized characterized in that the Fafbträger (5) between one of the radiation source facing, radiolucent, e.g. B. made of glass or plastic counter-stop (14) and the recording surface (3) out and arranged by a on the back of the recording medium Hammer (13) can be hit against the guide. 11. The device according to claim 10, characterized in that that in place of the hammer (13) a pressure roller is provided on the back of the recording surface (3) in the print area can be rolled off parallel to this in such a way that the recording surface rests under pressure on the ink carrier (5) and its locally softened ink particles as Character takes over. 12. Device according to claims b to II. Characterized in that with a thermoplastic Color layer (5 .;) provided carrier (5) before the activation of the locally heating the color layer Radiation or before F. enters the area of the beam initiating the recording (4; /) is preheated to just below the softening point of the thermoplastic layer. 13. Device for carrying out the method according to claim 12, characterized in that to keep the preheating temperature constant fluctuating ambient temperatures a known control device is provided. the influences the resistance of the electrical preheating circuit as a function of the outside temperature. 14. Apparatus according to claim 5, characterized in that for deflecting the beam at least one optical system known per se is provided, the refractive index of which is through the deflection voltages can be influenced. 15. Device according to claims 6 to 8, characterized characterized in that for the regeneration of the color layer (5a) of the carrier (5) in its progression, then to the writing position (51), a known charging device (56) is provided for uniform, electrical charging of the carrier (5), to which the following devices connect: a) an exposure device (57), which the carrier at the written off points of the color layer x-rayed and changed the electrical charge of the carrier (5) at these points; b) a dusting device (58) by which the areas of changed charge in per se be provided in a known manner with thermoplastic paint dust; c) a heating device (59) which softens the transferred dye and transfers it into the unused areas of the dye layer (5; /) melts. 10 16. Device according to claims b to 15, characterized in that in connection with a method known in principle for erasing incorrectly printed characters by introduction of a correction color carrier and by hitting the wrong symbol again the main color carrier (5, 41) can be removed from the recording area and temporarily by a primarily from a radiolucent, with thermoplastic dye in the color of the recording surface, z. B. a white dye coated correction ink carrier, is replaceable. 17. Device according to claims b to Ib. characterized in that additional, d. H. Non-stenciled typefaces each have a supplementary stencil that can be introduced into the imprint area is provided.