AU4299493A - A method of producing spectrographic images - Google Patents

Description

λ METHOD OF PRODUCING SPECTROGRAPHIC IMAGES

The present invention relates to a method of producing spectrographic images.

Previously spectrographic images have been produced from "masters". The "master" itself is created by applying a photosensitive emulsion to a glass plate, etching the emulsion to form a diffraction grating and photographically reproducing an image on the emulsion. The "master" can then be copied by a variety of processes. However one of the most common is to transfer the spectrographic image to a thin nickel plate which can then be wound around a print roller and used to emboss an embossable material with the spectrographic image. The thin nickel plate bearing the spectrographic image is normally made by inserting the diffraction grating having the photographic image reproduced thereon as cathode into a nickel electroplating bath. After a thin film of nickel has built up on the surface of the photographic image it is withdrawn and the thin plate removed from the diffraction grating carrying the photographic image.

An object of the present invention is to provide a cheaper method of manufacturing spectrographic images.

Accordingly, the present invention provides a method of producing a spectrographic image which method comprises overlaying a diffraction grating with a sheet of embossable material and applying pressure to the sheet of embossable material to define an image and thereby produce a spectrographic image on the embossable material.

The term diffraction grating is used herein to define any high resolution surface relief such as holograms, digitalised information and electron beam etchings.

Pressure may be applied to the embossable material by using a ball tipped drawing device. The drawing device may be guided by mechanical means or it may be hand held. The image to be created may be first created by means of a computer system having a graphics package.

Preferably the embossable material is a sheet of metallised thermoplastics resin.

The image may also be applied to the embossable material by means of stamping or heat stamping. In such a process the image to be reproduced is embossed onto a die which is then applied to the embossable material whilst it overlays a diffraction grating. In addition the image may be embossed on the embossable material by means of a jet of fluid. Master copies produced by the method of the present invention may be reproduced by known techniques.

The "master" itself may take on any of the known styles, patterns and techniques and may be used separately or in conjunction with one or many different spectrographic patterns. An example of multiple use of the technique would be to use a standard hologram which has a 3-D effect and emboss the image from the 3-D master onto a metallised material then, using the new embossing process, design and emboss the new pattern over the desired area. This "master" may be made by any of the current techniques.

At this time it should be noted that it is not necessary to use metallised material as the image will be transferred to the material and the metallising is only a means of making the resulting art visible.

For ease of manufacture, and control of the end result, the best diffraction grating to use in the initial preparation stage is a 'cross hatch' diffraction grating. Although cross hatch pattern is probably the best, it is possible to use any diffraction grating which has been suitably 'etched' or 'engraved' by one of the aforementioned techniques. By cross hatch we mean a diffraction grating that consists of parallel lines 'etched' into a suitable material in one direction then 'etched' again at right angles to the first pattern. Whilst this gives the ideal result and allows for the correct angles to be predicted in the case of colour orientation when making new originals the "master" may have lines etched at any angle to the first set and it is also possible to 'etch' more than one set of lines. Lines need not necessarily be parallel and need not necessarily cover the entire grating. Lines may be 'etched concentrically for example. The angle at which the optical information is registered will also determine the best angle of view and colour orientation will also vary according to the angle of 'shot' .

Another consideration is that a "master" may be made from a copy, a copy of a copy and so on.

This "master" has many applications in many fields of many industries.

The first such application is to create individual artworks which have a spectrographic appearance. The means to create the individual artwork is to place the diffraction grating on a firm surface, a sheet of suitable material, such as metallised plastic (many varieties may be used and, as previously stated, the material need not be metallised) , is then placed on to the diffraction grating with the metallised side down (the process also works with the metallised side up and, also, without metallising) .

A hard implement or tool is then pressed onto the surface and moved to create a pattern. A hammering technique is another method of embossing the pattern onto the subject material. Drawing on to the surface of the material, to which the image is to be transferred, with a blunt instrument will also emboss the optical information. For example, a ball point pen or a graphite pencil are possible tools that may be used as these products are readily available from many sources. A teflon point may also be an alternative. The contact point is essentially round as the best effect is created at a tangent to the round surface of the embossing tool. Care must be taken not to drag or damage the surface as this may create problems at a later stage of reproduction.

The artist 'draws' onto the subject material, with a suitable diffraction grating or other optical information etc. beneath, and is in fact cold embossing. Alternatively the tool may be hot. The fine information from the "master" is transferred onto the surface of the foil in the area that comes into contact with the "master" and the point of the tool.

To create thicker lines it is necessary to move the tool back and forth across the surface of the material being embossed. Other effects may be created by tapping the tool onto the surface of the subject material

With an orthogonally oriented diffraction grating there are specific angles to which the foil may be turned to give a required colour which essentially is calibrated throughout the entire spectrum. These angles can be defined on an information sheet which can be supplied to the user in order for a novice in the art to create a wide variety of spectrographic images, colours and effects. By using this technique it is possible to closely reproduce a picture made of continuous tone colours into spectral colours therefore giving the same appearance and colours, at a specific angle, to that of the original.

Each such hand embossed spectrographic image therefore becomes an original.

Dntil now there has not been a method of making random pattern spectrographic images to a large size as the current mass produced product has been limited to the circumference of the rollers used to micro emboss the regular holographic products currently on the market. The method of the present invention permits the production of large scale spectrographic images.

Embossing "masters" may also be made by hot stamping from a standard hot stamping master. The means to do this is to obtain the necessary hot stamping plate, for example a company logo, and hot stamp onto a suitable material overlayed onto the diffraction grating. Once an impression is made it then becomes possible to make a "master" for mass production of the resultant spectrographic image. In order to reduce cost per article it may be necessary to make multiples of the original and lay them out so as to run several of the same images on a sheet.

The other advantage of the process of the invention is that it is a new and inexpensive means of creating an original spectrographic pattern from which a "master" may be made. There are many advantages in this process alone in the field of promotional and packaging materials and merchandise.

The process may be further refined as images may be embossed by other means such as interfacing a graphic computer with an architects plotter, drawing machine, pantograph, daisywheel or dot matrix printer or other image generating methods etc. which use a tool to create the image, these being examples and not the only methods of making these original and "new masters". The equipment may be fitted with a, blunt, rounded end, ball or roller tool instead of an ink pen. The plotter is programmed to follow a course as dictated by the programme.

Automatic programmable drawing machines would expedite production of originals. Pictures or images may now be produced on a monotone screen and generated directly to the surface of a suitable material. The hammer mechanism of a dot matrix printer may be adjusted for the correct pressure to emboss the image. In this instance the diffraction grating may be positioned around a roller or a machine may be designed to allow the hammer mechanism to pass over a flat diffraction grating or for the diffraction grating and material to be embossed, to pass under the hammer mechanism. There is no necessity for the diffraction grating and the subject material to be fixed together as it may be necessary for the diffraction grating to rotate to give the various desired colours. In order to create desired colours it is preferable that the table holding the diffraction grating may be moved to different positions on the horizontal plane parallel to the subject material and rotated through degrees of arc. The benefit of a moving table is demonstrated in the ability to utilise a smaller master sheet which is easier to keep flat and cheaper to replace if damaged. The angle at which the image is viewed dictates the colour seen by the eye so in order to create a realistic image it is a requirement that the resulting image be viewed at the optimum angle for the particular diffraction grating that is used to create the original.

By allowing the diffraction grating to be moved it is therefore possible to feed a continuous roll of suitable embossable material over the table to create an infinite sized image. It is also preferable for the entire diffraction grating to be used in order to prolong the life of that diffraction grating. For this application it is desirable, though not essential, for the diffraction grating to be flat.

The mass production of the images for use, for example, by children as an educational toy or for novelty products may be achieved by an injection moulding process described in copending international patent application No. PCT/AU92/00277, but the method of the present invention is cheaper.

The method described is, therefore, also an inexpensive method of making images for injection moulding spectrographic images, and other optical information, onto plastics as well as for the micro (hot) embossing and cold embossing (as now described) of mass produced spectrographic images etc.

Images thus created may also be used to reproduce copies of the original in a number of known ways using a variety of methods. The original therefore becomes a "master" for mass production of copies of that original onto other surfaces.

The resulting originals containing a "master" embossing pattern may be mass produced and sold as an aid to artists for creation of more and varied spectrographic art forms or sold as a kit for craft purposes. It is possible for the embossed material to be then transferred to a variety of surfaces, such as, but not limited to, textiles for T- shirts etc., glass, or other plastics including thermo- setting or ϋ.V. setting resins and the like.

The second and most important aspect of this new approach to creating spectrographic originals is that in creating an original spectrographic image a much cheaper method of making a "master" original spectrographic image has been devised.

At this stage the holographic (or other optical) information is, for example, stored on a flimsy piece of material and may therefore be easily damaged. It is therefore desirable to transfer this information to a more substantial and durable surface and, for convenience, it may be transferred to a nickel plate by the previously described electroplating technique. Other materials may also be used to store the information.

The resulting "new master" is actually 'grown' in a plating tank and from this "new master" many "masters" may be created. During the transfer process a percentage deterioration will occur due to the fact that the image transfer process is not 100% efficient.

For certain applications it is possible to reproduce the image direct from the material being used in the transfer process. For example if an image is produced onto, say, a polyester sheet then that sheet may be used to directly reproduce onto other suitable materials.

These methods of making a "master" will be cheaper than producing a photo resist glass plate which is the normal or popular method of making a "master" .

Costs vary greatly on the production of an original by known techniques but, as an indication, the process requires that artwork is created either by conventional animated drawing, sketching, painting etc. or by computer graphics, not including computer controlled embossing as previously described. The latter method requires expensive colour separations which are also required prior to exposing the photo resist plates. In all, costs could be expected to be in the vicinity of $US12,000.00. Using the method of the present invention it becomes possible to make an original simply by drawing onto a surface, sufficiently receptive to embossing procedures, overlaying a diffraction grating with the stored optical information as previously described and making a suitable original for reproduction purposes.

When using the method of the present invention the cost is approximately $ϋS25.00, thus providing enormous cost savings. An alternative to the roll method of producing embossed material is a hand or motorised hot roller that will accept individual sheets. In this method a sheet of material to be embossed is overlayed onto a diffraction grating and rolled simultaneously through the hot rollers under pressure.

There are many advantages over the old procedures and the main one being the cost savings. Business cards are currently embossed from mass produced spectrographic hot stamping materials. Using the process of the present invention, the hot stamping procedure is eliminated and a new hologram in one of the prescribed manners. Adhesive may also be applied to the back of the product.

This process enlarges the scope of the current techniques for producing spectrographic images as it is able to incorporate such a wide variety of art. Any image may be used for this process including corporate logos, text, landscapes, portraits, flora, fauna, fantasy etc. The products would therefore be cheaper to make as the up front cost of creating an original are much less than the conventional method. This process would therefore find many applications in, for example, the souvenir industry which is extremely cost conscious.

In the printing industry it becomes possible, using this new method to make large "masters" for coordinating in-line micro embossing of spectrographic images with commercial printing methods. This application of the process has many advantages over present methods and facilitates the ability to manufacture packaging products, wrappers, packets, box coverings, bags etc. at lower costs. It is also possible to cold emboss onto a material that has already been hot embossed. New masters may be produced by a cold embossing process but heat may also be applied via a hand held instrument in order to broaden the field of effects.

The new method of making an original also makes possible the production of animated imaging on a single sheet. The method utilises the colour orientation process, as described, to make the image appear and disappear and a second image to reappear in a different position across or up and down the sheet as the sheet is moved.

If it becomes necessary to have a background then the background may be mass produced by either the new method or the old method of embossing and the foreground is embossed over the other previously embossed pattern. The second embossing is done at a different temperature to the first so that both images may be seen at the same time. The process therefore allows for hot and cold embossing on the same sheet.

Double embossing one image over another would allow a much wider scope for creating new and unique masters.

When the same "background" is used then the

"foreground" image may be made to appear to move. What is actually happening is that the colours are turning on and off as the orientation of the sheet is changed giving the illusion of movement of the "foreground" image.

The price factor in manufacturing the "new masters" will allow the manufacture of animated hologram cartoon strips. Once the "new master" has been made they may be mass produced by present methods but they may also be produced by one of the other methods described.

Another advantage of the process is that, by controlling the embossing by computer or other mechanical means, the original art may be enlarged or reduced as required and at low cost. This is not possible at the moment as, in the usual etching techniques, each image requires the art to be actual size. Limited edition spectrographic images become very easy to produce by the new method and if computer generation of image is applied then a numbering system is possible. The artist may sign and number each reproduction by hand using the cold embossing process of the present invention.

Claims (7)

1. A method of producing a spectrographic image which method comprises overlaying a diffraction grating with a sheet of embossable material and applying pressure to the sheet of embossable material to define an image thereon and thereby produce a spectrographic image on the embossable material.

2. A method according to claim 1 wherein the diffraction grating is a hologram.

3. A method according to claim 1, wherein pressure is applied to the embossable material by a ball tipped drawing means.

4. A method according to claim 1 wherein the image is computer generated and applied to the sheet of embossable material by a computer controlled drawing means.

5. A method according to claim 1 wherein the sheet of embossable material is a sheet of metallised thermoplastics resin.

6. A method according to Claim 1 wherein the method includes the steps of forming the image on a heatable stamp, heating the stamp and applying it to the embossable material.

7. A method according to Claim 1 wherein the diffraction grating consists of parallel lines etched into a suitable material in a first direction and parallel lines etched into the material in a second direction that is orthogonal to the first direction.

SUBSTITUTE SHEET