CA1124122A - Information carrier and process for its manufacture - Google Patents
Information carrier and process for its manufactureInfo
- Publication number
- CA1124122A CA1124122A CA316,449A CA316449A CA1124122A CA 1124122 A CA1124122 A CA 1124122A CA 316449 A CA316449 A CA 316449A CA 1124122 A CA1124122 A CA 1124122A
- Authority
- CA
- Canada
- Prior art keywords
- light
- recording layer
- intensity
- scattering
- structures
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/42—Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect
- G02B27/4233—Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect having a diffractive element [DOE] contributing to a non-imaging application
- G02B27/4238—Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect having a diffractive element [DOE] contributing to a non-imaging application in optical recording or readout devices
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/0005—Production of optical devices or components in so far as characterised by the lithographic processes or materials used therefor
- G03F7/001—Phase modulating patterns, e.g. refractive index patterns
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/004—Photosensitive materials
- G03F7/022—Quinonediazides
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
- Photosensitive Polymer And Photoresist Processing (AREA)
- Optical Record Carriers And Manufacture Thereof (AREA)
- Silver Salt Photography Or Processing Solution Therefor (AREA)
Abstract
ABSTRACT
An information carrier comprising a recording layer disposed on a support and char-acterized in that the recording layer comprises in selected areas of its surface image-wise arranged statistically distributed structures which scatter the light irradiated for projection of the information carrier and whose thickness is reduced as compared with the original thick-ness of the recorded layer.
An information carrier comprising a recording layer disposed on a support and char-acterized in that the recording layer comprises in selected areas of its surface image-wise arranged statistically distributed structures which scatter the light irradiated for projection of the information carrier and whose thickness is reduced as compared with the original thick-ness of the recorded layer.
Description
~.2~;ZZ
INFORMATION CARRIER AND PROCESS
FOR ITS MANUFACTU~
BACKGROUND OF THE INVENTION
The present invention relates to an infor-mation earrier eomprising a reeording layer ap-plied to a support, and to a proeess for its manufaeture.
- The prior art teaehes produetion o~ pro-jeetion images with intensity-modulated light by light-seattering.
In the case of vesicular films, light is seattered by tiny bubbles ~vesicles) formed in softenable layers by the eombined action of light and heat upon aromatie diazo eompounds. Vesieular films are in use and yield images of very high contrast in conventional projectors. It is not possible, however, to produce metal matrices from a vesieular film and to duplicate the image by embossing with the aid of sueh metal matrices.
z In the case of frost imagesinthermoplastic materials, light is scattered by irregular surface deformations formed in the photoconductive thermo~
plastic layers by electrostatic charging~ image-wise exposure, and heating.
Frost images have not been known to be used in practice, which is probably due to the fact t~at their contrast is not sufficient for conventional projectorsO
As a consequence of the expansion of microfilm techniquest especially of micropublish-ing, i.e. the publication of new and hitherto unpublished information in the form of micro-copies for sale and for distribution to the public as by a publishing house, modern recording sys-tems are not only required to have certain sensi-tometric properties, but it is also desired that the master copies should lend themselves readily to duplication, so that large numbers of copies can be produced from them. For this purpose, embossing techniques are preferred, where struc-tured surfaces carrying information are transferred onto an embossable medium by pressure.
There is a demand for easy-to-handle infor-mation carriers on which the information is re-corded ln the form of surface structures which may be reproduced by embossing and can be read out by conventional projectors.
~.2~
Description of the Prior Art Images with grating-like screening may be produced by the ZOD ~zero order diffraction) tech-nique described in the journal "Laser und Opto-Elektroni]c", No. 3/1976, pages 16 and 17. Three nickel matrices are produced from three relief images which correspond, for example, to three primary-color grating patterns in three photore-sist layers r and colorless thermoplastic films of f for example, polyvinyl chloride are embossed with these matrices. The three films are super-imposed mechanically, and on projection with conventional projectors, colored projection images are oktained from the colorless relief images.
The grating-shaped screening is effected with re-lief gratings of rectangular cross-section, the grating periods bein~ approximately 1.5 ~m. The grating-li~e screening is periodical, both with respect to the grating distance, i.e. the density of the structures, and the grating depth for a certain color, i.e. the amplitude of the informa-tion. ~or each color separation, in magénta, ~ellow and cyan, a separate nickel matrix with different relief depths is made, from which separate embossed images are produced. The relief depths differ, the relief depth being the greatest for the cyan separation and the smallest for the yellow separation. These color separation images are screened. The embossed images are superimposed to form a three-layered relief image from which colored images can be projected. The technique described yields very bright color images with high resolution. The relief images can be dupli-cated relatively cheaply and rapidly by embossing.
A disadvantage which has hindered the intro-duction of this technique is the expensive produc-tion process requiring three completely separate operations for producing the individual embossed relief images corresponding to the color separa-tions. A further disadvantage is the necessity for putting together in register the three separate relief~images to form the duplicate image required for the colored projection.
If it is desired that the projection image produced by the ZOD technique include, among other colors, the color blac~, this color is pro-duced by the mechanical superposition of three films corresponding to the color separations for magenta, yellow and cyan. If only a black-and-white image is to be produced, two sinusoidal relief gratings of exactly predetermined relief depth are placed cross-wise upon each other in the black areas of the image. High precision is 2Q required to produce the gratings.
U.S. Patent Nos. 3,615,476 and 3,~15,486 disclose processes for the recording of informa-tion in polymers or polymer systems which can be - photo-chemically hardened. A reproduction of an electromagnetio image in the form of a shadow-image, which is either directly visible or may be made visible by light, is obtained by subject-ing the exposed recording layer to a treatment of heat and/or vapor. This treatment results in a softening and swelling of the recording layer in the exposed areas without removing any o~ it.
After this treatment, the exposed areas are dis-tinctl~ higher than the unexposed areas and dis-play micro deformations. ~hen viewed from above, the deformations are directly visible due to light ~.2~
scatteringO If the recording layer, which may be either self-supporting or disposed on a support, is transilluminated with light, the exposecl areas become ~isihle as a shadow image due to their light-scattering effect.
SUMM~RY OP T~-IE lNVENTION
It is the object of the present invention to provide an information carrier of simple structure which, upon projection, yields black-and-white images representing a positive or negative projection image of the original.
This object is achieved in that the recording layer contains in selected areas of its surface certain structures, image-wise arranged and statistically distributed, which scatter the light irradiated during projection of the information carrier and whose thickness is reduced as compared with the original thickness of the recording layer.
The scattered-light technique has the advantage of making it possible, simply by appropriately dosing the exposure energy, to produce structures in the photoresist layer which yield either a positive or a negative projection image of a given original.
Stated more specifically, the present invention provides, according to a first aspect, an information carrier comprising an exposed and developed relief image on a recording layer, for example a photoresist layer, disposed on a support wherein said exposed and developed relief image comprises, in selected areas of the surface of the recording layer information-wise shaped statistically distributed structures of light-scattering centers of graded densities, said structures being irregularly distributed with regard to their mutual distances and depths, said light-scattering centers scattering the light irradiated for projection of the information carrier thereby forming a grey/white projected image, said structures having a thickness which is reduced as compared with the thickness of the recording layer prior to exposure and development of the relief imageO
According to another aspect, the invention provides a process for the manufacture of an information carrier as claimed in claim 1 comprising an exposed and developed relief image on a recording layer, for example a photo-resist layer, disposed on a support, comprising the step of e~posing thesurface of said recordlng layer through a scattering image transparency with graded densities of scattering centers ~o obtain in selected areas of the surface, :information-wise shapedl statistically distributed structures, sai,d structures being irregularly distributed with regard to their mutual distances and their depths, and the step of developing the recording layer with an alkaline medium to form out said structures.
'~J~ 6a-~.2~
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, the invention will be explained in detail by reference to the attached drawings:
In the drawings, Figure 1 shows, in section, a diagrammatic arrang~ment for exposing an information carrier through an original, Figure 2 shows, in section, a diagrammatic arrangement for exposing another information carrier through an original, Figure 3 shows an information carrier comprising light scattering and diffracting struc-tures, Figure 4 shows a color wedge comprising scattering centers of graded density distributed over the length of the wedge, Figures 5 and 6 show the relationship be-tween the density of the projection image and the density of the original, Figure 7 shows an arrangement for producing light-scattering structures in the photoresist - layer, and Figure 8 shows a further arrangement for producing light-scattering surface structures in a pnotoresist layer.
DETAILED DESCRIPTION OF THE PREFERRED EMsoDIMENTs For the production of the scattering struc-tures, photoresist layers are used, high-resolu-tion photoresistlayers comprising o quinone dia-zides being preferred in view of the small size of the scattering centers. The pho~oresist layers should have a thickness of at least 2 ~m~
The simplest method, which is therefore pre-ferred in practice, is by contact exposure under an original comprising a black-image separation film under conditions which will be specified hereinafter.
Figure 1 is a diagrammatic representation, in section, oE an arrangement for exposing an information carrier 1 through a master copy 6 of the type described. A medium section of the master copy 6 is covered by an alpha-numerical and/or image information 7 which comprises a plur-ality of light-impermeable spots indicated by points. If the information carrier 1, which is shown positioned under the master copy 6 in Figure 1 and whichconsists of a supporting layer 5 with a recording layer 2, e.g. a photoresist layer, coated thereon, is exposed, light passes through the areas of the master copy 6 t~ the right and to the left of the image information 7, without causing an information-wise distribution of the intensity in the corresponding portions of the recording layer 2.
In the middle section, which carries the image information 7, the incident light rays (in-dicated by arrows) are weakened or barred in accordance with the arrangement of the light~
impermeable spots, so that, after exposure, an image wise or information wise distribution of the intensity results on the surface of the recording layer 2 in the corresponding section of the infor-mation carrier 1 below. The thus exposed informa-tion carrier 1 is then treated with an aqueous-alkaline solution which dissolves away the exposed portions, so that in the middle section an arrange-ment of structures 3 is obtained whose degree of deformation corresponds to the distribution of light i~tensity previously falling on the surface of the recording layer 2, whereas to the left and to the right of the middle section, the recording layer 2, is substantially removed after alkaline development. As regards their distance from each other and their depth, the structures 3 are irreg-ularl~ distributed, or, in other words, their density and amplitudes correspond to a statistical, i.e. absolutely irregular, distribution. The ori~inal thickness of the recording layer 2, prior to development, is indicated by a broken line.
For the sake of clarity, the thickness of the recording layer 2 relative to the support 5 is shown grossly exaggerated in the figures. When the invention is utili~e~ in practice, the support is considerably thicker than the recording layer.
During projection of the information carrier 1, the irradiated light is scattered by the structures 3, so that the scattering structures appear as dark images in the projection, when the information carrier is reproduced through a lens.
The maximum contrast which can be achieved by the structures 3 during projection is, inter alia, a function of the projection lens which is used. The lower the light intensity of the lens, the higher the contrast. ~ practicable system must be adapted to conventional projection lenses with a light intensity of about l : 2.8, which means -that the scattered light must be deflected at an angle of 20 or more to the optical axis.
The light scattering structures in the recording layer 2 must be adapted to fullfil this require-ment.
The scattering angle requirement can be easily complied with under the following conditions:
If photoresists such as those marketed by Messrs.
Shipley Comp. Inc., ~ewton, Massachusetts~ USA, are exposed to actinic light of 400 nm through a silver halide original, for which e.g., step II
with a nominal densit~ of 0.35 of the color test wedge 8 diagrammatically shown in Figure 4 may be used, followed by a~ueous alkaline development and projection with a lens of a light intensity of 1 : 2,8 t maximum densities of more than l are obtained. Such a test wedge is composed of black-pigmented layers which stepwise are applied as sections 9 and whose density increases from step I to step X. Obviously, such a test wedge may also comprise more or less than 10 section5, and the density increase from step to step may vary with different types of test wedges.
The density of the scattering centers in the individual steps of the test wedge increases to such a degree that, starting approximately with step VII, the density is such that only a few areas are free from scattering centers and form scattering holes, whereas the other areas of the step appear a uniform black to the view. After transition from scattering centers to scattering holes, the number of holes decreases to such an extent that step X of the test wedye appears a uniform black, as indicated in Figure 4.
Surprisingly, practically iden-ticaldensities are achieved if transparent spacing films of up to 15 ~m thickness are positioned between the photoresist layer and the scattering film during exposure. This means that close contact or distance between recording layer 2 and scattering film are not critical during contact exposure. The projec-tion images show a neutral black color shade. If a nickel matrix is produced from the surface struc-ture of the photoresist layer and used for embossing - a thermoplastic polyvinyl chloride film, the em-bossed image produces projection images of the same density.
Comparable results are achieved when using other known scattering films designed as color test wedges comprising several steps and having, e.g., a nominal density of 0.45 at step III.
Common criteria for scattering films which are suitable for producing maximum projection den-sities are that they should contain scattering cen-ters of ~ut 1 ~m dimension or diameter, with a r~e of variation between 0.5 and 2 ~m, and that the dis-tances between scattering centers, projected on the surface of the photoresist layer, should be about 1.5 ,um, with a range of variation between 0.6 and 4 ~m. Such scattering films have trans-parencies between 0.25 and 0.65.
Scattering images which are rich in con~
trast may also be produced with scattering films of higher densities, but only after relatively long exposure times. By using test wedges r dif-ferent tone values may be reproduced in the pro-jection images.
~,.24~.Z~
The above described scattered image tech-ni~ue yields good sensitometric results and is distinguished by a particular ease and reliability of performance. This is by no means a matter of course, since, according to other known techniques, high~precision sinoidal relief gratings comprising about 600 lines per mm and having an exact relief depth of 0.87 ~m, which is stated to be the optimum depth, are required for the production of black-and-white projecticn images ~M.T. Gale, Opt. Comm.
l~, 1976, 2~2).
The combined information-wise exposure and scattered-light exposure through a master copy 6 is explained in the following by reference to the arrangement for exposing an information carrier l which is diagrammatically shown in Figure 2.
In this case, a black color ~eparation film is used, which may be a silver halide film of the original and which simultaneously serves as the original and the scattering film. The image areas on the recording layer 2 corresponding to the transparent areas of the original are thus opti-cally masked. For example, in the middle section according to Figure 2, the master copy 6 may com-prise optical densities of about 2 after exposure and development, which corresponds to transpar~
encies of OoOl and less, whereas the neighboring sections to the right and left thereof, which corre~pond to the black or gray image areas of the original, are only slightly exposed, up to trans-parencies between 0.25 and 0.65 for black, andbelow 0.25 for gray, a slight overlapping with the black areas being possible in the case of gray.
Alternatively, different tone values may be reproduced with the aid of known screening techniques, Furthermore, the described scattering image technique may be very advantageously combined with the technique of reproducing color images by means of rectangular relief gratings with different relief depths in one plane, as described ln Canadian Patent Application Serial No. 293,120 Eiled December 15, 1~77 and Canadian Patent Application Serial No. 3087353 filed July 28, 1978, both in the name of lloechst Aktiengesellschaft. If colored images containing black image elements are to be recorded, a black color separation is superimposed. This is achieved, in a relatively simple manner, by exposing the photoresist layer through a scattering film and a black color separation film in such a manner that light-scattering surface structures are formed in the black image areas only. This technique may also be employed if the photoresist layer was previously superficially exposed in the form of a screen.
Figure 3 shows an information carrier 1 which contains deflecting structures ~ in its middle region, which may be produced by exposure under a relie~ grating, while the neighboring regions to the right and left thereof contain scattering structures 3. During projection, the middle region appears colored, whereas the other regions are dark.
Figures 5 and 6 show density cha:racteristics which illustrate the density D2 of the projection image as a function of the density Dl of the image information on the color separation original. These density characteristics will be referred to in connection with Examples 1 and 3 below. A positive projection image is obtained by exposing the material first, image-wise, through a separation original of the image information which has a density Dl, and then, uniformly, through a scattering film.
~.2~L~2~
Alternatively, the sequence of these steps may be reversed. If image-wise or information-wise exposure and scattered~light exposure of the re-cording layer are performed simultaneously, either a negative or a positive projection image may be obtained, depending on the exposure time.
The density characteristics shown in Figure 5 appear at different exposure energies~ On the ordinate, the density D2 f the projection image, which was obtained with a lens of a light intensity of 1 : 2.8, is plotted as a function of the density Dl of the scattering film. Changes in the density Dl of the scattering film are produced by means o a test wedge, the indi~idual steps of which are placed one after the other on separate information carriers 1 for exposure. If ~he irradiated energy corresponds to 324 mWs/cm2, a negative projection image of the color separation original is obtained, and with an energy corresponding to 1800 mWs/cm2, a positîve projection image results. In the case of a negative projection image, the dark and light areas of the original are reversed, whereas they are unreversed in the positive projection image.
- It is not necessary for the information to be contained in the scattering film itself.
The density characteristic of Figure 6 was pro-duced by image-wise exposing first through the separation original and then, uniformly, through step III of a known test wedge used as the scat-tering film.
I~ images of high quality, e.g. screenedcolored images, are to be produced, a scattering film is used which is optimally adjusted to a maximum density of the scattering image. This scattering film may be a briefly exposed and devel-oped silver halide film or a pigment layer. This layer is coated with a photoresist layer which is so colored that it is impermeable to light within the short wave spectral range, and the photoresist layer is then removed in the black areas only.
Alternatively, an impermeable metal layer, e.g.
an aluminum layer, may ~e vapor-deposited on the scattering layer and then coated with a photore-sist layer. By image-wise exposure, development, and etching, the black image areas are removed down to the scattering layer.
Alternatively, the light-scattering sur-face structures in the recording layer may be produced by the arrangement shown in Figure 7, in which the rays of a light source 13 are directed, by a lens 14, upon a screen 15 consisting of re-flecting particles~ such as glass chips, and are deflected by the screen upon the recording layer.
Purthermore, a perforated screen may be reproduced on the recording layer with the aid of a light source.
~igure 8 shows an arrangement in which the - rays of a laser 16, e.g. an ~V laser, are deflected by a mirror 18 in the direction of an electro-optical deflector 17. The electro-optical deflec-tor 17, which is controlled by a random pulse generator 19, transmits the rays in accordance with the signals received from it and deflects them in the directionof the recording layer on the information carrier 1.
f~
Example 1 A 5 ~m -thick photoresist layer is applied to a 50 ~m thick polyester film which serves as the support. It is then exposed in a printing frame under a silver halide film original 10 with graded densities.
.Eigure 5 shows the silver halide film original 10 carrying the letter "A" as image infor-mation. As indicated diagrammatically, the den-sity Dl of the image information on the silver film original 10 corresponds to one of the steps VII to IX of the test wedge 8 shown in Figure 4 and thus contains a certain number of scattering holes. The other areas of the silver film ori ginal 10 correspond to the density of one of the sections II to IV of the test wedge 8.
In a first test, an energy corresponding to 324 mWs/cm2 is beamed upon the photoresist layer, and in a second test, a new photoresist la-yer is irradiated with 1,800 mWs/cm2. For this purpose, the actinic light o a mercury vapor lamp is collimated by means of a lens and is passed through a blue-colored glass with a rnaximum trans-mission at a wave length o~ 400 nm. Aqueous-alkaline development follows. Upon projection with a lens of a light intensity of 1 : 2.8, a projection irnage with neutrally colored areas of graded densities is obtained. With an irradiated energy of 324 mWs/cm2, a negative image is obtained, and with an energy o~ 1,800 mWs/cm2 a positive image of the original results. An irradiated energy of 324 mWs/cm2 corresponds to a short ex-posure time during which the image information Z~2 in the form of the letter "A" transmits very lit-tle light, whereas in the other areas the light is scattered by the scatteriny centers. ~fter development, the information carrier yields a projection image 11 which is shown in Figure 5a and in which the image information appears light, whereas the other areas are dark, which means that the projection image is a negative copy of the silver halide film original.
Using an irradiated energy of 1,800 mWs/cm2, which means that the exposure time is about 5.6 times that used in the first test, the areas of the recording layer on the information carrier co~ered by the image information are not burned in, but structures are burned into the recording layer in the areas oppositetothe scattering holes.
During projection! these structures form scattering centers and appear dark, as indicated in Figure 5b.
Due to the long exposure time, the areas of the 2Q information carrier lying outside of the image information which are positioned opposite to the scattering centers of the silver halide film ori-ginal are also exposed, so that the originally - formed structures are leveled and the resulting projection image shows a positive reproductlon 12 of the silver halide film original 10.
In order to determine the densities of the images, the intensities in different areas of the projection images are measured by means of a photo-electric cell. The thus calculated optical den-sities D2 f the projection images are shown in Fiyure 5 as functions of the densities Dl of the test wedge used. Maximum values of about 1 are obtained.
INFORMATION CARRIER AND PROCESS
FOR ITS MANUFACTU~
BACKGROUND OF THE INVENTION
The present invention relates to an infor-mation earrier eomprising a reeording layer ap-plied to a support, and to a proeess for its manufaeture.
- The prior art teaehes produetion o~ pro-jeetion images with intensity-modulated light by light-seattering.
In the case of vesicular films, light is seattered by tiny bubbles ~vesicles) formed in softenable layers by the eombined action of light and heat upon aromatie diazo eompounds. Vesieular films are in use and yield images of very high contrast in conventional projectors. It is not possible, however, to produce metal matrices from a vesieular film and to duplicate the image by embossing with the aid of sueh metal matrices.
z In the case of frost imagesinthermoplastic materials, light is scattered by irregular surface deformations formed in the photoconductive thermo~
plastic layers by electrostatic charging~ image-wise exposure, and heating.
Frost images have not been known to be used in practice, which is probably due to the fact t~at their contrast is not sufficient for conventional projectorsO
As a consequence of the expansion of microfilm techniquest especially of micropublish-ing, i.e. the publication of new and hitherto unpublished information in the form of micro-copies for sale and for distribution to the public as by a publishing house, modern recording sys-tems are not only required to have certain sensi-tometric properties, but it is also desired that the master copies should lend themselves readily to duplication, so that large numbers of copies can be produced from them. For this purpose, embossing techniques are preferred, where struc-tured surfaces carrying information are transferred onto an embossable medium by pressure.
There is a demand for easy-to-handle infor-mation carriers on which the information is re-corded ln the form of surface structures which may be reproduced by embossing and can be read out by conventional projectors.
~.2~
Description of the Prior Art Images with grating-like screening may be produced by the ZOD ~zero order diffraction) tech-nique described in the journal "Laser und Opto-Elektroni]c", No. 3/1976, pages 16 and 17. Three nickel matrices are produced from three relief images which correspond, for example, to three primary-color grating patterns in three photore-sist layers r and colorless thermoplastic films of f for example, polyvinyl chloride are embossed with these matrices. The three films are super-imposed mechanically, and on projection with conventional projectors, colored projection images are oktained from the colorless relief images.
The grating-shaped screening is effected with re-lief gratings of rectangular cross-section, the grating periods bein~ approximately 1.5 ~m. The grating-li~e screening is periodical, both with respect to the grating distance, i.e. the density of the structures, and the grating depth for a certain color, i.e. the amplitude of the informa-tion. ~or each color separation, in magénta, ~ellow and cyan, a separate nickel matrix with different relief depths is made, from which separate embossed images are produced. The relief depths differ, the relief depth being the greatest for the cyan separation and the smallest for the yellow separation. These color separation images are screened. The embossed images are superimposed to form a three-layered relief image from which colored images can be projected. The technique described yields very bright color images with high resolution. The relief images can be dupli-cated relatively cheaply and rapidly by embossing.
A disadvantage which has hindered the intro-duction of this technique is the expensive produc-tion process requiring three completely separate operations for producing the individual embossed relief images corresponding to the color separa-tions. A further disadvantage is the necessity for putting together in register the three separate relief~images to form the duplicate image required for the colored projection.
If it is desired that the projection image produced by the ZOD technique include, among other colors, the color blac~, this color is pro-duced by the mechanical superposition of three films corresponding to the color separations for magenta, yellow and cyan. If only a black-and-white image is to be produced, two sinusoidal relief gratings of exactly predetermined relief depth are placed cross-wise upon each other in the black areas of the image. High precision is 2Q required to produce the gratings.
U.S. Patent Nos. 3,615,476 and 3,~15,486 disclose processes for the recording of informa-tion in polymers or polymer systems which can be - photo-chemically hardened. A reproduction of an electromagnetio image in the form of a shadow-image, which is either directly visible or may be made visible by light, is obtained by subject-ing the exposed recording layer to a treatment of heat and/or vapor. This treatment results in a softening and swelling of the recording layer in the exposed areas without removing any o~ it.
After this treatment, the exposed areas are dis-tinctl~ higher than the unexposed areas and dis-play micro deformations. ~hen viewed from above, the deformations are directly visible due to light ~.2~
scatteringO If the recording layer, which may be either self-supporting or disposed on a support, is transilluminated with light, the exposecl areas become ~isihle as a shadow image due to their light-scattering effect.
SUMM~RY OP T~-IE lNVENTION
It is the object of the present invention to provide an information carrier of simple structure which, upon projection, yields black-and-white images representing a positive or negative projection image of the original.
This object is achieved in that the recording layer contains in selected areas of its surface certain structures, image-wise arranged and statistically distributed, which scatter the light irradiated during projection of the information carrier and whose thickness is reduced as compared with the original thickness of the recording layer.
The scattered-light technique has the advantage of making it possible, simply by appropriately dosing the exposure energy, to produce structures in the photoresist layer which yield either a positive or a negative projection image of a given original.
Stated more specifically, the present invention provides, according to a first aspect, an information carrier comprising an exposed and developed relief image on a recording layer, for example a photoresist layer, disposed on a support wherein said exposed and developed relief image comprises, in selected areas of the surface of the recording layer information-wise shaped statistically distributed structures of light-scattering centers of graded densities, said structures being irregularly distributed with regard to their mutual distances and depths, said light-scattering centers scattering the light irradiated for projection of the information carrier thereby forming a grey/white projected image, said structures having a thickness which is reduced as compared with the thickness of the recording layer prior to exposure and development of the relief imageO
According to another aspect, the invention provides a process for the manufacture of an information carrier as claimed in claim 1 comprising an exposed and developed relief image on a recording layer, for example a photo-resist layer, disposed on a support, comprising the step of e~posing thesurface of said recordlng layer through a scattering image transparency with graded densities of scattering centers ~o obtain in selected areas of the surface, :information-wise shapedl statistically distributed structures, sai,d structures being irregularly distributed with regard to their mutual distances and their depths, and the step of developing the recording layer with an alkaline medium to form out said structures.
'~J~ 6a-~.2~
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, the invention will be explained in detail by reference to the attached drawings:
In the drawings, Figure 1 shows, in section, a diagrammatic arrang~ment for exposing an information carrier through an original, Figure 2 shows, in section, a diagrammatic arrangement for exposing another information carrier through an original, Figure 3 shows an information carrier comprising light scattering and diffracting struc-tures, Figure 4 shows a color wedge comprising scattering centers of graded density distributed over the length of the wedge, Figures 5 and 6 show the relationship be-tween the density of the projection image and the density of the original, Figure 7 shows an arrangement for producing light-scattering structures in the photoresist - layer, and Figure 8 shows a further arrangement for producing light-scattering surface structures in a pnotoresist layer.
DETAILED DESCRIPTION OF THE PREFERRED EMsoDIMENTs For the production of the scattering struc-tures, photoresist layers are used, high-resolu-tion photoresistlayers comprising o quinone dia-zides being preferred in view of the small size of the scattering centers. The pho~oresist layers should have a thickness of at least 2 ~m~
The simplest method, which is therefore pre-ferred in practice, is by contact exposure under an original comprising a black-image separation film under conditions which will be specified hereinafter.
Figure 1 is a diagrammatic representation, in section, oE an arrangement for exposing an information carrier 1 through a master copy 6 of the type described. A medium section of the master copy 6 is covered by an alpha-numerical and/or image information 7 which comprises a plur-ality of light-impermeable spots indicated by points. If the information carrier 1, which is shown positioned under the master copy 6 in Figure 1 and whichconsists of a supporting layer 5 with a recording layer 2, e.g. a photoresist layer, coated thereon, is exposed, light passes through the areas of the master copy 6 t~ the right and to the left of the image information 7, without causing an information-wise distribution of the intensity in the corresponding portions of the recording layer 2.
In the middle section, which carries the image information 7, the incident light rays (in-dicated by arrows) are weakened or barred in accordance with the arrangement of the light~
impermeable spots, so that, after exposure, an image wise or information wise distribution of the intensity results on the surface of the recording layer 2 in the corresponding section of the infor-mation carrier 1 below. The thus exposed informa-tion carrier 1 is then treated with an aqueous-alkaline solution which dissolves away the exposed portions, so that in the middle section an arrange-ment of structures 3 is obtained whose degree of deformation corresponds to the distribution of light i~tensity previously falling on the surface of the recording layer 2, whereas to the left and to the right of the middle section, the recording layer 2, is substantially removed after alkaline development. As regards their distance from each other and their depth, the structures 3 are irreg-ularl~ distributed, or, in other words, their density and amplitudes correspond to a statistical, i.e. absolutely irregular, distribution. The ori~inal thickness of the recording layer 2, prior to development, is indicated by a broken line.
For the sake of clarity, the thickness of the recording layer 2 relative to the support 5 is shown grossly exaggerated in the figures. When the invention is utili~e~ in practice, the support is considerably thicker than the recording layer.
During projection of the information carrier 1, the irradiated light is scattered by the structures 3, so that the scattering structures appear as dark images in the projection, when the information carrier is reproduced through a lens.
The maximum contrast which can be achieved by the structures 3 during projection is, inter alia, a function of the projection lens which is used. The lower the light intensity of the lens, the higher the contrast. ~ practicable system must be adapted to conventional projection lenses with a light intensity of about l : 2.8, which means -that the scattered light must be deflected at an angle of 20 or more to the optical axis.
The light scattering structures in the recording layer 2 must be adapted to fullfil this require-ment.
The scattering angle requirement can be easily complied with under the following conditions:
If photoresists such as those marketed by Messrs.
Shipley Comp. Inc., ~ewton, Massachusetts~ USA, are exposed to actinic light of 400 nm through a silver halide original, for which e.g., step II
with a nominal densit~ of 0.35 of the color test wedge 8 diagrammatically shown in Figure 4 may be used, followed by a~ueous alkaline development and projection with a lens of a light intensity of 1 : 2,8 t maximum densities of more than l are obtained. Such a test wedge is composed of black-pigmented layers which stepwise are applied as sections 9 and whose density increases from step I to step X. Obviously, such a test wedge may also comprise more or less than 10 section5, and the density increase from step to step may vary with different types of test wedges.
The density of the scattering centers in the individual steps of the test wedge increases to such a degree that, starting approximately with step VII, the density is such that only a few areas are free from scattering centers and form scattering holes, whereas the other areas of the step appear a uniform black to the view. After transition from scattering centers to scattering holes, the number of holes decreases to such an extent that step X of the test wedye appears a uniform black, as indicated in Figure 4.
Surprisingly, practically iden-ticaldensities are achieved if transparent spacing films of up to 15 ~m thickness are positioned between the photoresist layer and the scattering film during exposure. This means that close contact or distance between recording layer 2 and scattering film are not critical during contact exposure. The projec-tion images show a neutral black color shade. If a nickel matrix is produced from the surface struc-ture of the photoresist layer and used for embossing - a thermoplastic polyvinyl chloride film, the em-bossed image produces projection images of the same density.
Comparable results are achieved when using other known scattering films designed as color test wedges comprising several steps and having, e.g., a nominal density of 0.45 at step III.
Common criteria for scattering films which are suitable for producing maximum projection den-sities are that they should contain scattering cen-ters of ~ut 1 ~m dimension or diameter, with a r~e of variation between 0.5 and 2 ~m, and that the dis-tances between scattering centers, projected on the surface of the photoresist layer, should be about 1.5 ,um, with a range of variation between 0.6 and 4 ~m. Such scattering films have trans-parencies between 0.25 and 0.65.
Scattering images which are rich in con~
trast may also be produced with scattering films of higher densities, but only after relatively long exposure times. By using test wedges r dif-ferent tone values may be reproduced in the pro-jection images.
~,.24~.Z~
The above described scattered image tech-ni~ue yields good sensitometric results and is distinguished by a particular ease and reliability of performance. This is by no means a matter of course, since, according to other known techniques, high~precision sinoidal relief gratings comprising about 600 lines per mm and having an exact relief depth of 0.87 ~m, which is stated to be the optimum depth, are required for the production of black-and-white projecticn images ~M.T. Gale, Opt. Comm.
l~, 1976, 2~2).
The combined information-wise exposure and scattered-light exposure through a master copy 6 is explained in the following by reference to the arrangement for exposing an information carrier l which is diagrammatically shown in Figure 2.
In this case, a black color ~eparation film is used, which may be a silver halide film of the original and which simultaneously serves as the original and the scattering film. The image areas on the recording layer 2 corresponding to the transparent areas of the original are thus opti-cally masked. For example, in the middle section according to Figure 2, the master copy 6 may com-prise optical densities of about 2 after exposure and development, which corresponds to transpar~
encies of OoOl and less, whereas the neighboring sections to the right and left thereof, which corre~pond to the black or gray image areas of the original, are only slightly exposed, up to trans-parencies between 0.25 and 0.65 for black, andbelow 0.25 for gray, a slight overlapping with the black areas being possible in the case of gray.
Alternatively, different tone values may be reproduced with the aid of known screening techniques, Furthermore, the described scattering image technique may be very advantageously combined with the technique of reproducing color images by means of rectangular relief gratings with different relief depths in one plane, as described ln Canadian Patent Application Serial No. 293,120 Eiled December 15, 1~77 and Canadian Patent Application Serial No. 3087353 filed July 28, 1978, both in the name of lloechst Aktiengesellschaft. If colored images containing black image elements are to be recorded, a black color separation is superimposed. This is achieved, in a relatively simple manner, by exposing the photoresist layer through a scattering film and a black color separation film in such a manner that light-scattering surface structures are formed in the black image areas only. This technique may also be employed if the photoresist layer was previously superficially exposed in the form of a screen.
Figure 3 shows an information carrier 1 which contains deflecting structures ~ in its middle region, which may be produced by exposure under a relie~ grating, while the neighboring regions to the right and left thereof contain scattering structures 3. During projection, the middle region appears colored, whereas the other regions are dark.
Figures 5 and 6 show density cha:racteristics which illustrate the density D2 of the projection image as a function of the density Dl of the image information on the color separation original. These density characteristics will be referred to in connection with Examples 1 and 3 below. A positive projection image is obtained by exposing the material first, image-wise, through a separation original of the image information which has a density Dl, and then, uniformly, through a scattering film.
~.2~L~2~
Alternatively, the sequence of these steps may be reversed. If image-wise or information-wise exposure and scattered~light exposure of the re-cording layer are performed simultaneously, either a negative or a positive projection image may be obtained, depending on the exposure time.
The density characteristics shown in Figure 5 appear at different exposure energies~ On the ordinate, the density D2 f the projection image, which was obtained with a lens of a light intensity of 1 : 2.8, is plotted as a function of the density Dl of the scattering film. Changes in the density Dl of the scattering film are produced by means o a test wedge, the indi~idual steps of which are placed one after the other on separate information carriers 1 for exposure. If ~he irradiated energy corresponds to 324 mWs/cm2, a negative projection image of the color separation original is obtained, and with an energy corresponding to 1800 mWs/cm2, a positîve projection image results. In the case of a negative projection image, the dark and light areas of the original are reversed, whereas they are unreversed in the positive projection image.
- It is not necessary for the information to be contained in the scattering film itself.
The density characteristic of Figure 6 was pro-duced by image-wise exposing first through the separation original and then, uniformly, through step III of a known test wedge used as the scat-tering film.
I~ images of high quality, e.g. screenedcolored images, are to be produced, a scattering film is used which is optimally adjusted to a maximum density of the scattering image. This scattering film may be a briefly exposed and devel-oped silver halide film or a pigment layer. This layer is coated with a photoresist layer which is so colored that it is impermeable to light within the short wave spectral range, and the photoresist layer is then removed in the black areas only.
Alternatively, an impermeable metal layer, e.g.
an aluminum layer, may ~e vapor-deposited on the scattering layer and then coated with a photore-sist layer. By image-wise exposure, development, and etching, the black image areas are removed down to the scattering layer.
Alternatively, the light-scattering sur-face structures in the recording layer may be produced by the arrangement shown in Figure 7, in which the rays of a light source 13 are directed, by a lens 14, upon a screen 15 consisting of re-flecting particles~ such as glass chips, and are deflected by the screen upon the recording layer.
Purthermore, a perforated screen may be reproduced on the recording layer with the aid of a light source.
~igure 8 shows an arrangement in which the - rays of a laser 16, e.g. an ~V laser, are deflected by a mirror 18 in the direction of an electro-optical deflector 17. The electro-optical deflec-tor 17, which is controlled by a random pulse generator 19, transmits the rays in accordance with the signals received from it and deflects them in the directionof the recording layer on the information carrier 1.
f~
Example 1 A 5 ~m -thick photoresist layer is applied to a 50 ~m thick polyester film which serves as the support. It is then exposed in a printing frame under a silver halide film original 10 with graded densities.
.Eigure 5 shows the silver halide film original 10 carrying the letter "A" as image infor-mation. As indicated diagrammatically, the den-sity Dl of the image information on the silver film original 10 corresponds to one of the steps VII to IX of the test wedge 8 shown in Figure 4 and thus contains a certain number of scattering holes. The other areas of the silver film ori ginal 10 correspond to the density of one of the sections II to IV of the test wedge 8.
In a first test, an energy corresponding to 324 mWs/cm2 is beamed upon the photoresist layer, and in a second test, a new photoresist la-yer is irradiated with 1,800 mWs/cm2. For this purpose, the actinic light o a mercury vapor lamp is collimated by means of a lens and is passed through a blue-colored glass with a rnaximum trans-mission at a wave length o~ 400 nm. Aqueous-alkaline development follows. Upon projection with a lens of a light intensity of 1 : 2.8, a projection irnage with neutrally colored areas of graded densities is obtained. With an irradiated energy of 324 mWs/cm2, a negative image is obtained, and with an energy o~ 1,800 mWs/cm2 a positive image of the original results. An irradiated energy of 324 mWs/cm2 corresponds to a short ex-posure time during which the image information Z~2 in the form of the letter "A" transmits very lit-tle light, whereas in the other areas the light is scattered by the scatteriny centers. ~fter development, the information carrier yields a projection image 11 which is shown in Figure 5a and in which the image information appears light, whereas the other areas are dark, which means that the projection image is a negative copy of the silver halide film original.
Using an irradiated energy of 1,800 mWs/cm2, which means that the exposure time is about 5.6 times that used in the first test, the areas of the recording layer on the information carrier co~ered by the image information are not burned in, but structures are burned into the recording layer in the areas oppositetothe scattering holes.
During projection! these structures form scattering centers and appear dark, as indicated in Figure 5b.
Due to the long exposure time, the areas of the 2Q information carrier lying outside of the image information which are positioned opposite to the scattering centers of the silver halide film ori-ginal are also exposed, so that the originally - formed structures are leveled and the resulting projection image shows a positive reproductlon 12 of the silver halide film original 10.
In order to determine the densities of the images, the intensities in different areas of the projection images are measured by means of a photo-electric cell. The thus calculated optical den-sities D2 f the projection images are shown in Fiyure 5 as functions of the densities Dl of the test wedge used. Maximum values of about 1 are obtained.
2;2 By vaporization techniques, the relief irn-ages in the photoresist layer are provided with a thin copper layer, then a nickel layer of up to about 40 ~m is electro-deposited thereon so that an embossing die results. This die is used at about 130C, in a press, to emboss polyvinyl chloride film. Upon projection, the thus obtained embossed images also show neutrally colored areas of graded densities, whose contrast substantlally resembles that of the projection images o the original information carrier.
Example 2 An image is recorded under the conditions stated in Example 1, the silver halide film ori-ginal showing the photographic negative of a land-`
scape. After a short exposure, i.e. with an energy of 324 mWs/cm2, and aqueous-alkaline development, an image of the landscape in the correct tonal values is projected from the structured photo-resist layer.
Example 3 A 3 ,um thick photoresist layer disposed ona support consisting of a 50 ~m thick polyester film is irradiated with an energy of 710 mWs/cm2 through an ungrained step wedge with 2 mm wide steps. The step wedge consists of a transparent yellowish film whose optical density at a wave length of 400 nm is 0.26; thus, densities of 0.26, 0.52, 0.78 and 1.04 may be adjusted for this wave length by superimposing one, two, three, or four films. Then a test wedge with a density of 0.45 is superimposed and light of an energy of 500 mWs/cm2 2;2 i5 irradiated (Figure 6). After ayueous-alkaline development of the pho-toresist layer, projection yields an image containing neutrally colored areas of graded densities. I'he optical densities D2 are calculated from the light intensities measured in the individual areas. In Figure 4, these optical densities D2 are shown as functions of the optical densities Dl of the test wedge.
The projection image i8 a positive image, image areas of high density in the original being re-produced by image areas of high density in the projection image.
Example 4 A 3 ,um thick photoresist layer is applied to a transparent support and irradiated with light of an energy of 150 mWs/cm2 through a screened, transparent original. The subject on the original is dissected by a screen comprising 80 screen elements per cm. Then, the material is exposed again to light of an energy of 150 mWs/cm2, this time through a scattering original, e.g, a test wedge. After aqueous-alkaline development, the pro~ection image of the information carrier, like the original used, reproduces continuous tones by screen dots of appropriate darkness. The op-tical density in the center of a screen dot is Example 5 A smooth, transparent polyester film is coated with a 2.5 ~m thick photoresist layer by whirler-coating anddrying. In a contact arrange~
ment, the resulting photoresist layer is exposed to light of 250 mT1~s/cm2 ener~y under a glass plate containing a screen composed of 600 metal wire lines per mm. The exposure time is adjusted to the projection c019x "green". Subsequentlyr the material is exposed, in register, under color separation originals which are transparent only in the image areas of the respective color separa-tion o~iginal and in the white areas, the irradi-ated light energies being 75 mWs/cm2 for red, 95 mWs/cm2 for yellow, and 130 mWs/cm2 for blue.
The black color separation original is a silver halide film which was exposed in such a manner that the light areas have maximum optical density and the black areas have an optical density of up to 0.45 ater development, For exposure under the black color separation film, a light energy of 300 mWs/cm2 is irradiated. After aqueous-alkaline de~elopment, the structured photoresist layer yields a colored projection image in which the black image areas are reproduced by an optical density of 0.95 which is neutral in color.
The projection colors do not quite corres-pond to the original colored image, because the times of exposure under the color separation ori~inals are corrected to take into account the different indices of refraction of photore-sist layer and embossed film. A thin copper layer is vapor-deposited on the relief image, and the copper layer is then, in turn, electro~
plated with a nickel la~er of up to ~0 ~m thick-ness. The resulting metal matrix is separated from the photoresist layer and used for embossing a highly transparent polyvinyl chloride film at 130C in a press. The embossed image thus ob-~ JL~
tained shows a colored projection image which cor-responds to the original colored image and which contains dark image areas corresponding to the black image areas of the original~
The foregoing detailed description is to be clearly understood as given by way of illustration and example only, the spirit and scope of this invention being limited solely by the appended claims.
Example 2 An image is recorded under the conditions stated in Example 1, the silver halide film ori-ginal showing the photographic negative of a land-`
scape. After a short exposure, i.e. with an energy of 324 mWs/cm2, and aqueous-alkaline development, an image of the landscape in the correct tonal values is projected from the structured photo-resist layer.
Example 3 A 3 ,um thick photoresist layer disposed ona support consisting of a 50 ~m thick polyester film is irradiated with an energy of 710 mWs/cm2 through an ungrained step wedge with 2 mm wide steps. The step wedge consists of a transparent yellowish film whose optical density at a wave length of 400 nm is 0.26; thus, densities of 0.26, 0.52, 0.78 and 1.04 may be adjusted for this wave length by superimposing one, two, three, or four films. Then a test wedge with a density of 0.45 is superimposed and light of an energy of 500 mWs/cm2 2;2 i5 irradiated (Figure 6). After ayueous-alkaline development of the pho-toresist layer, projection yields an image containing neutrally colored areas of graded densities. I'he optical densities D2 are calculated from the light intensities measured in the individual areas. In Figure 4, these optical densities D2 are shown as functions of the optical densities Dl of the test wedge.
The projection image i8 a positive image, image areas of high density in the original being re-produced by image areas of high density in the projection image.
Example 4 A 3 ,um thick photoresist layer is applied to a transparent support and irradiated with light of an energy of 150 mWs/cm2 through a screened, transparent original. The subject on the original is dissected by a screen comprising 80 screen elements per cm. Then, the material is exposed again to light of an energy of 150 mWs/cm2, this time through a scattering original, e.g, a test wedge. After aqueous-alkaline development, the pro~ection image of the information carrier, like the original used, reproduces continuous tones by screen dots of appropriate darkness. The op-tical density in the center of a screen dot is Example 5 A smooth, transparent polyester film is coated with a 2.5 ~m thick photoresist layer by whirler-coating anddrying. In a contact arrange~
ment, the resulting photoresist layer is exposed to light of 250 mT1~s/cm2 ener~y under a glass plate containing a screen composed of 600 metal wire lines per mm. The exposure time is adjusted to the projection c019x "green". Subsequentlyr the material is exposed, in register, under color separation originals which are transparent only in the image areas of the respective color separa-tion o~iginal and in the white areas, the irradi-ated light energies being 75 mWs/cm2 for red, 95 mWs/cm2 for yellow, and 130 mWs/cm2 for blue.
The black color separation original is a silver halide film which was exposed in such a manner that the light areas have maximum optical density and the black areas have an optical density of up to 0.45 ater development, For exposure under the black color separation film, a light energy of 300 mWs/cm2 is irradiated. After aqueous-alkaline de~elopment, the structured photoresist layer yields a colored projection image in which the black image areas are reproduced by an optical density of 0.95 which is neutral in color.
The projection colors do not quite corres-pond to the original colored image, because the times of exposure under the color separation ori~inals are corrected to take into account the different indices of refraction of photore-sist layer and embossed film. A thin copper layer is vapor-deposited on the relief image, and the copper layer is then, in turn, electro~
plated with a nickel la~er of up to ~0 ~m thick-ness. The resulting metal matrix is separated from the photoresist layer and used for embossing a highly transparent polyvinyl chloride film at 130C in a press. The embossed image thus ob-~ JL~
tained shows a colored projection image which cor-responds to the original colored image and which contains dark image areas corresponding to the black image areas of the original~
The foregoing detailed description is to be clearly understood as given by way of illustration and example only, the spirit and scope of this invention being limited solely by the appended claims.
Claims (22)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Information carrier comprising an exposed and developed relief image on a recording layer, for example a photoresist layer, disposed on a support wherein said exposed and developed relief image comprises, in selected areas of the surface of the recording layer information-wise shaped statistically distributed structures of light-scattering centers of graded densities, said structures being irregularly distributed with regard to their mutual distances and depths, said light-scattering centers scattering the light irradiated for projection of the information carrier thereby forming a grey/white projected image, said structures having a thickness which is reduced as compared with the thickness of the recording layer prior to exposure and development of the relief image.
2. Information carrier according to claim 1, characterized in that the arrangement of the structures and their degree of deformation correspond to the distribution of intensity on the surface of the recording layer during information-wise exposure of the information carrier.
3. Information carrier according to claim 1, characterized in that the arrangement of the structures and their degree of deformation is inversely proportional to the distribution of intensity on the surface of the recording layer during information-wise exposure of the information carrier.
4. Information carrier according to claim 1, characterized in that, in addition to the structures scattering the irradiated light, the recording layer comprises surface areas comprising structures which diffract the irradiated light.
5. Information carrier according to claim 4, characterized in that the structures which diffract the incident light differ in their grating depth in different surface areas.
6. Information carrier according to claim l, characterized in that the distances between the light-scattering structures range from 0.6 µm to 4 µm.
7. Information carrier according to claim 6, characterized in that, on the average, the distance between two neighboring light-scattering structures is 1.5 µm.
8 Information carrier according to claims 1, 2 or 39 characterized in that the dimensions of the light-scattering structures range from 0.5 to 2 µm.
9. Process for the manufacture of an information carrier as claimed in claim 1 comprising an exposed and developed relief image on a recording layer, for example a photoresist layer, disposed on a support, comprising the step of exposing the surface of said recording layer through a scattering image transparency with graded densities of scattering centers to obtain in selected areas of the surface, information-wise shaped, statistically distributed structures, said structures being irregularly distributed with regard to their mutual distances and their depths, and the step of developing the recording layer with an alkaline medium to form out said structures.
10. Process according to claim 9 comprising the step of simultaneously exposing said recording layer through a scattering image transparency and through a screening film to obtain, respectively, an information wise distribution in the image area, and a statistical irregular distribution of intensity of the incident light for projection of the information carrier.
11. Process according to claim 9 comprising the steps of first irradiating said recording layer with actinic light of an information-wise distribution of intensity and then with actinic light of a statistical, irregular distribution of intensity.
12. Process according to claim 9 comprising the steps of first irradiating said recording layer with actinic light of a statistical, irregular distribution of intensity and then with actinic light of an information-wise distribution of intensity.
13. Process according to claim 10, further including the steps of superimposing an exposure of actinic light of a grating-like distribution of intensity upon an exposure to actinic light of a statistical, irregular distribution of intensity.
14. Process according to claims 10, 11 or 12, comprising the step of subjecting the information-wise distribution of intensity to grating-like modulation.
15. Process according to claim 10, 11 or 12 comprising the step of subjecting the information-wise distribution of intensity to grating-like modulation.
16. Process according to claim 13 comprising the step of subjecting the information-wise distribution of intensity to grating-like modulation.
17. Process according to claim 10, 11 or 12 comprising the step of subjecting the information-wise distribution of intensity to grating-like modulation.
18. Process according to claim 10, 11 or 12 comprising the step of irradiating the recording layer with actinic light of a statistical, irregular distribution of intensity through a light-scattering original.
19. Process according to claim 10, 11 or 12 comprising the step of irradiating the recording layer with actinic light of a statistical, irregular distribution of intensity while it is in contact with a light-scattering original.
20. Process according to claim 10, 11 or 12 comprising the step of irradiating the recording layer with actinic light of a statistical, irregular distribution of intensity through a light-scattering original which comprises scattering centers with dimensions of 0.5 to 2 µm spaced from each other by distances of 0.6 to 4 µm.
21. Process according to claim 9 comprising the step of irradiating with actinic light of a statistical, irregularly varying distribution of intensity by reproducing a screen of reflecting particles by means of a lens on the recording layer.
22. Process according to claim 9 comprising the step of irradiating with actinic light of a statistical, irregularly varying distribution of intensity by irradiating the recording layer with UV laser light over a deflector which is controlled by a random pulse generator.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP2751741.5 | 1977-11-19 | ||
| DE19772751741 DE2751741A1 (en) | 1977-11-19 | 1977-11-19 | INFORMATION CARRIERS AND METHOD FOR ITS MANUFACTURING |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1124122A true CA1124122A (en) | 1982-05-25 |
Family
ID=6024114
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA316,449A Expired CA1124122A (en) | 1977-11-19 | 1978-11-17 | Information carrier and process for its manufacture |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0002043B1 (en) |
| JP (1) | JPS5489621A (en) |
| AT (1) | AT359829B (en) |
| CA (1) | CA1124122A (en) |
| DE (2) | DE2751741A1 (en) |
| IT (1) | IT7851940A0 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5712730A (en) * | 1993-04-16 | 1998-01-27 | Siemens Aktiengesellschaft | Diffractive optical device for the optical imaging of a spatial point onto other spatial points |
| US8187771B2 (en) * | 2006-04-06 | 2012-05-29 | Ovd Kinegram Ag | Multi-layer body with volume hologram |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2826380A1 (en) * | 1978-06-16 | 1980-01-03 | Hoechst Ag | COLOR EXTRACTION TRANSPARENT AND METHOD FOR THE PRODUCTION THEREOF |
| WO1998010324A1 (en) * | 1996-09-04 | 1998-03-12 | Electrowatt Technology Innovation Ag | Surface pattern with at least two different light-diffracting relief structures for optical security elements |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3249436A (en) * | 1960-06-29 | 1966-05-03 | Du Pont | Process for preparing printing plates from photopolymerizable materials by the use of a masking technique |
| US3674591A (en) * | 1969-11-28 | 1972-07-04 | Stromberg Datagraphix Inc | Surface deformation imaging process |
| US3901705A (en) * | 1973-09-06 | 1975-08-26 | Du Pont | Method of using variable depth photopolymerization imaging systems |
| DE2657246C2 (en) * | 1976-12-17 | 1978-09-28 | Hoechst Ag, 6000 Frankfurt | Original of an information carrier, method for producing the original, method for producing a die for embossing the original and information carrier which is produced with the die |
| DE2734580C2 (en) * | 1977-08-01 | 1979-02-15 | Hoechst Ag, 6000 Frankfurt | Method for producing an original of an information carrier |
-
1977
- 1977-11-19 DE DE19772751741 patent/DE2751741A1/en not_active Withdrawn
-
1978
- 1978-11-11 EP EP78101352A patent/EP0002043B1/en not_active Expired
- 1978-11-11 DE DE7878101352T patent/DE2861294D1/en not_active Expired
- 1978-11-17 JP JP14125078A patent/JPS5489621A/en active Pending
- 1978-11-17 AT AT822278A patent/AT359829B/en not_active IP Right Cessation
- 1978-11-17 CA CA316,449A patent/CA1124122A/en not_active Expired
- 1978-11-17 IT IT7851940A patent/IT7851940A0/en unknown
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5712730A (en) * | 1993-04-16 | 1998-01-27 | Siemens Aktiengesellschaft | Diffractive optical device for the optical imaging of a spatial point onto other spatial points |
| US8187771B2 (en) * | 2006-04-06 | 2012-05-29 | Ovd Kinegram Ag | Multi-layer body with volume hologram |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0002043B1 (en) | 1981-11-04 |
| AT359829B (en) | 1980-12-10 |
| DE2861294D1 (en) | 1982-01-14 |
| JPS5489621A (en) | 1979-07-16 |
| ATA822278A (en) | 1980-04-15 |
| DE2751741A1 (en) | 1979-05-23 |
| EP0002043A1 (en) | 1979-05-30 |
| IT7851940A0 (en) | 1978-11-17 |
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