MXPA98002417A - Optimal media digital recording and reproduction system - Google Patents

Abstract

The present invention relates to a method and system for producing a digital optical recording, the method can be divided into the elaboration of a master or master pattern for the recording medium, having an external surface (213), an elongated member (211). ), a data region (221), an auxiliary region (222), a laser beam (302) and a focusing system (317) to focus the laser beam on a selected region of the elongate member, and the rapid recline of the master recording on the surface of a flexible film and parallel to the surface of the elongated member

Description

¿ SYSTEM. OF DIGITAL RECORDING AND REPRODUCTION OF OPTICAL MEDIA BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a system for the development of a master pattern, recording and duplication of digital optical media, such as discs. digital optics. 2. Description of the Prior Art The technology of digital compact discs was developed twenty years ago by several organizations, including Philips Electronics, Sony, Thomson and Discovision Associates (DVA). This technology (with extensions and improvements) has been adapted as a standard by the largest consumer electronics and computer companies in the world. The capacity of relatively large storage and the low unit cost of both the discs and the reproduction units has resulted in worldwide sales and concession revenues amounting to many billions of dollars per year, including the contents of the disks too. This technology has become a norm P1189 / 98MX worldwide for the storage of permanent digital data of all types. Digital compact discs (or "CDs") consist of a disc made of high grade plastic approximately 120 mm in diameter and 1.2 mm thick coated with a thin layer (50 nm) of aluminum. These disks can contain up to 1.2 billion bytes of digital information. Commonly used error correction schemes typically reduce the effective storage capacity of these disks to approximately 680 million bytes of digital information. The main, fundamental, basic part of digital optical recording implemented in CD technology is the modulation of local reflectivity where the pluralities of the high and low reflectivity areas represent individual data bits. The most common method for modulating local reflectivity is called the "dimple phase" method. The phase dimples must be exactly as deep as the v length of a quarter of the wavelength of the light source that reads the data (approximately 120 nm). Phase dimples can be replaced by objects of amplitude where the reflectivity is reduced due to discontinuity in the reflective coating or due to light scattering in the convex or concave microscopic characteristics.

P1189 / 98MX The dimples (or amplitude objects) on the CDs are arranged in a spiral pattern starting from about 20 nm from the center of the "cube" of the disk and continuing on a spiral track, individual to within a few nm from the outer edge of the disk. The full length of this spiral track is considered to be a long line of locations where phase dimples may or may not exist. If the red laser light that bounces from one location detects a dimple, a photodetector of the related circuits interprets its presence as the number "1". If the location does not contain a dimple, this will be interpreted as "0" (zero). This continuous sequence of ones and zero comprises the digital information recorded on the disk. The nominal width of a dimple is 0.6 μm; the distance between a circuit in the spiral track and either its inner or outer adjacent circuit is 1.6 μm. The existing industrial process for making CD can be divided into three separate operations: elaboration of a master pattern, and production of the matrix and duplication. The general steps of CD processing of the prior art are described below.

A. Elaboration of a master or master pattern 1. The data is pre-recorded in a master pattern according to P1189 / 98MX to a specific format; 2. An optically polished glass disc (or glass standard) coated with a photoresist layer is provided; 3. The glass pattern is exposed in a laser engraver by a focused laser beam, modulated accordingly to the pre-recorded data in the master pattern. The focused laser beam follows a spiral path on the surface of the glass pattern with the intensity of the light that is turned on and off by an acousto-optic modulator. The exposed areas of the photoresist layer correspond to the position and dimension of the phase dimples; 4. The glass pattern is revealed, and the exposed areas are washed with the photoresist. 5. An inspection can be performed after each step described above.

B. Production of the matrix 1. A thin layer of plate is placed on the pattern of photoresist in the glass matrix by evaporation in vacuum; 2. A thick layer of nickel is deposited on the silver by electroplating, forming a nickel plate parent. A father is produced.

P1189 / 98MX 3. The nickel parent is a negative replica of the glass pattern (ie, the projection corresponds to the phase dimples). The nickel parent can be used as an injection molding matrix, but usually it is not used as a matrix given its high production cost. For this reason, several mothers (positive replicas) are produced by electroplating and separation. 4. Matrices are produced (negative copies of the glass pattern) from the mothers by electroplating and separation. 5. An inspection can be performed after each step described above.

C. Duplication 1. The nickel matrix is used in a high pressure injection molding of polycarbonate CD substrates. 2. After cooling, the substrate is coated with a reflective layer of aluminum by deposition; 3. A protective layer is coated with rotation to the top of the aluminum layer and subsequently cured by UV radiation; 4. Distraction efficiency of spiral tracks is used as a final inspection criterion.

P1189 / 98MX The labeling and packaging steps involved in the production of replicas are excluded from the prior art description because they are most commonly carried out offline. The master pattern processing operation (including the rotation and deposit of the photoresist) typically requires 3-4 hours in a class 100 transparent room installation. In the production of the matrix it requires 5-8 hours in an installation of Class 100 transparent room. Finally, a duplication by efficient injection molding produces an average of 1 CD for 4 seconds. The manufacturing method described above of the prior art for CD has, among others, the following disadvantages: • The elaboration of the master pattern and the production of the matrix require the prolonged use of expensive equipment and facilities; • The prior art process is low speed and discontinuous. Each CD is handled separately; and it takes at least 4 seconds to make a CD, a relatively long amount of time; • The process of the prior art comprises high temperature and high pressure. The plastic melts at a temperature of approximately 300 ° C, and is injected by P1189 / 98MX a force of 20-40 tons. Due to uniformly undissolved stresses due to temperature gradients and high pressure injection during rapid cooling, the problem of birefringence (ie, the anisotropy of the refractive index) appears; • In order to minimize the birefringence that appears from the optical non-uniformities induced by the process, a very expensive polycarbonate plastic is used as a substrate material; • The synthesis process - for the substrate polycarbonate resins includes a chlorination step. The residual chlorine atoms attack the reflective aluminum coating on a CD, resulting in an expected lifetime of the CD; • Due to the complexity and vulnerability of the injection molding process, a very high capital investment is required to meet the rapidly growing demand for audio CDs and CD ROMs. • Today, a commercially viable plant can be built for 75 million dollars; Very large facilities may require more than one billion dollars. Using ultrapure materials, CDs can be produced at a fully charged cost of at least approximately 40 cents per unit.

P1189 / 98MX In order to overcome some of the problems associated with the prior art, alternatives have been developed to the methodology of the prior art described above. For example, it has been proposed that mechanical and temperature stresses can occur where a relief method is used instead of injection molding. In this technique, phase dimples are replaced by objects of amplitude. In the reflectivity of the objects of amplitude it is reduced due to the scattering of light at the edges as well as due to the discontinuities of the metallic coating selectively deposited by the shadow mask method. Due to the complexity of the shadow mask manufactured by metal evaporation, as well as other disadvantages, the relief method has not become a viable commercial option to date. Another alternative for the high temperature / high pressure injection molding process is the contact photolithography duplication method suggested by US Patent No. 4,423,137, assigned to Quixote Corporation, and generally represented in Figures IA, IB, 1C and ID. As shown in Figure IA, this process consists of the use of contact photolithography with a standard, rigid, flat mask, which may comprise a coated flat glass substrate.

P1189 / 98MX with a reflective metal layer 2 having openings 3 corresponding to the dimple design of a CD. The rigid and flat standard mask is duplicated in a flat rigid substrate 4 covered by a reflective layer 5 and a layer of photoresist 6. In Figure IB, the area 61 of the photoresist 6 is exposed to light and removed , exposing the underlying areas 51 of the reflective liner 2. In Figure 1C, the areas 51 are not etched, and the photoresist 6 is removed in Figure ID. The resulting structure represents the plurality of objects of amplitude dimensioned and distributed over the surface of the substrate corresponding to the openings in the reflective coating on the master plate. In the subsequent steps of applying a protective coating, laminating on a transparent, rigid disc and labeling, a CD compatible with ISO 9660 can be produced. Contact photolithography has been well known since 1960 as a method for transferring a microscopic design in the manufacture of device in the drivers. The main requirement for the successful implementation of contact lithography is to reduce the separation between the photomask (by P1189 / 98MX example, the pattern plate with design, metal 1 and 2 in Figure IA) and the coating of the photoresist substance 61 of the substrate 4. This requirement can be arguably satisfied for small surface areas (1-5 cm), but it becomes extremely difficult, if not impossible, to reliably control the separation for large, flat surface areas, for example a CD substrate with a diameter of 12 cm. Furthermore, if contact lithography is proposed to be applied for a high performance duplication process, it becomes impossible to maintain a uniformly small separation between the pattern and the substrate. For this and other reasons, the duplication process described generally in US Patent No. 4,123,137, although theoretically possible, can not be implemented in commercial practice. It is generally accepted that a continuous manufacturing process has substantial advantages over a batch or discontinuous process, since a continuous process is much faster, more reliable and less expensive. Obviously, the injection molding techniques of the. Prior art are essentially discontinuous methods for the manufacture of CDs. In this way, the introduction of a method of P1189 / 98MX continuous CD duplication would constitute a substantial improvement over the prior art. A publication entitled "Continuous Manufacturing of Thin Cover Sheet Optical Media", described by W. Dennis Slafer and collaborators of Polaroid Corporation, and published in SPIE Vol. 1663 Optical Data Storage (1992) on page 324 (the "Polaroid Article") , describes a continuous manufacturing method for CD. In this method, a continuous mesh of a thin film substrate is formed in relief by microprotrusions on the surface of a roller and, consequently, metallized to achieve reflectivity and laminated to a thick transparent plastic sheet in order to add the thickness at normal value. This composite plastic mesh is handled and transported at constant speed during the entire duplication process until it separates into individual CDs. The duplication method introduced by the Polaroid article uses well-known techniques for the handling, printing and lamination of the continuous mesh. However, embossed microformation of a plastic film by microscopic projections on a curved surface of a roller is difficult to control, especially at high mesh speeds. In this way, this prior art also has significant disadvantages that make it impractical as an effective method for P1189 / 98 X duplicate CD. It is worthwhile that the existing standard for audio CD and CD ROM media is currently being replaced by a new standard that provides a greater storage capacity for information. The (DVD) uses smaller micro-features and smaller track spacing arranged in multi-layer structures. With these new requirements, the potential of the injection molding method of the prior art is to reach its limit in the microscopic spatial resolution as well as for the performance of the process. Additionally, the new technology of the CD is being other duplication techniques known from the prior art even more impractical. Therefore, there is a significant need for an alternative method and system for reduplicating optical means having high resolutions and for duplicating new types of media, such as those having multilayer structures and other new geometries.

SUMMARY OF THE INVENTION The present invention provides a new method and system - for producing a digital optical recording. The process can be divided into two separate operations: the elaboration of a master pattern of the optical recording in P1189 / 98MX the surface of an elongated member, such as cylinder, etc., and the rapid duplication of the pattern recording on the surface of the flexible film that is essentially parallel to the surface of the cylinder, etc. In one embodiment, the brewing component of the master or master pattern of the present invention includes an elongate member, such as a cylinder or other suitably formed member, having a defined axis of rotation. The elongated member can be made of a material transparent to the radiated energy, such as the energy of a laser beam. The elongate member has an optically thick layer on its outer surface, which provides the passage for a relatively small amount of radiated energy. A laser beam, or other focused energy, can be focused on selected regions of the surface of the elongated member to fuse, with or without ablation, corresponding regions of the optically thick layer. Through the fusion, the selected regions of the optically thick layer become optically thin or are completely removed, thereby allowing a relatively large amount of irradiated energy to pass through it. The laser beam can be controlled to melt regions in the optically thick layer in order to create optically thin regions that encthe P1189 / 98MX arrangement of a compact disc (CD), for example. An index that correlates the Cartesian coordinates of the coding of a compact in a table containing the encoding information for that location can be used in order to encthe elongated member. After the elongate member is created as a master pattern, a uniform irradiation can be provided within the elongated member to begin the duplication process. The uniform irradiation may take the form of a light source positioned along the axis of rotation of the elongated member, or may take other forms, such as a source of electromagnetic radiation in any suitable frequency band. In order to carry out the duplication process, a film was proposed that includes an optically disturbing layer, wherein the optically disturbing layer can be modified, sensitive to the irradiated energy. For example, the film may include a reflective layer and a layer of photoresist in the upper layer of the reflective layer. The elongate member is subsequently rotated about its defined axis of rotation while the layer of photoresist of the film comes into direct contact with the outer surface of the elongated member. Because the elongated member is made from a P1189 / 98MX transparent material, the layer of photoresist of the film is exposed to uniform irradiation through each of the optically thin regions on the outer surface of the elongated member. In this way, the photoresist layer of the film is exposed to the enc data on the exterior of the elongated member. After the photoresist layer is exposed as described above, the photoresist layer of the film is removed in those regions that are exposed to uniform irradiation. The reflective layer of the film is subsequently removed by chemical etching, in other regions corresponding to the regions of the photoresist substance layer that were removed, and the entire photoresist substance layer is subsequently removed, thus leaving the reflective layer attacked with acid from the film as a copy of the master pattern. Rapid duplication of the master pattern design of the cylinder surface in the film is achieved by placing the surface in a uniform translational movement and the elongated member in a uniform rotational movement, correspondingly. The exposure dose of the optically disturbing layer is determined by the speed of movement and the intensity of the P1189 / 98MX uniform irradiation.

BRIEF DESCRIPTION OF THE DRAWINGS Figures IA, IB, 1C and ID are cross-sectional views of the prior art duplication method using contact photolithography. Figures 2A and 2B depict how data can be encoded in a master pattern in a raster fashion (Figure 2A), based on the spiral coding of a CD (Figure 2B), in accordance with the teachings of the present invention . Figure 3 depicts the components and a master pattern making system according to the teachings of the present invention. Figure 4 depicts a computer system that can be used to implement the present invention. Figure 5 is a flow diagram illustrating the basic steps that can be analyzed to convert the spiral coding (Figure 2B) into the coding of Cartesian frame coordinates (Figure 2A), in accordance with the teachings of the present invention. Figure 6 is a sample portion of a table shown can be created based on the basic steps of Figure 5, in accordance with the teachings of the present invention.

P1189 / 98MX Figures 7A and 7B depict a cross-sectional view and a plan view, respectively, of the sample data that can be encoded in a master pattern, according to the present invention. Figure 8 depicts a cross-sectional view of the film that can be used in the duplication phase of the present invention. Figure 9 represents the components that can be used during the doubling phase of the present invention. Figure 10 is a flow diagram illustrating the basic steps that can be performed during the duplication phase of the present invention. Figure 11 is a cross-sectional view of a final CD product made in accordance with the teachings of the present invention.

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises two parts: a process of elaboration of the master and system pattern and a duplication process and system. Each of these components will be described in detail later.

P1189 / 98MX 1. Master pattern development Before the master pattern development process begins, the input data for recording on a CD is pre-recorded in master pattern according to a specific format, for example the ECMA format -119, which is stored in a magnetic tape, a magneto-optic unit, or any other high-volume, high-density storage device 403 (see Figure 4, described in detail below). For purposes of the present invention description of the invention will be referred to as a compact disc (CD), but it will be understood by one skilled in the art that the principles described herein will be equally applicable to other types of media as well, including DVDs, or any other equivalent media technology. With reference to Figure 2B and as previously described, the bit sequence in a CD 201 is normally recorded in a spiral 202 defined in angular coordinates. The coding of the data typically begins at the innermost portion of the CD, and a spiral 202 extending outward defines the stream in data series. With reference to Figure 2A, in accordance with the teachings of the present invention, an elongate member 211, such as a hollow cylinder or any other member P1189 / 98MX properly formed is provided for master pattern making purposes. Elongated member 211 will be referred to later as "cylinder 211", although it will be readily apparent that alternative forms of member 211 may also be used. As will be explained in detail below, the outer surface 213 of the elongate member 211 can be encoded with the data corresponding to the data on a CD. However, instead of encoding the data on the exterior 213 of the elongate member 211 in a spiral manner (as shown in the prior art), the present invention introduces a new technique by which the data is reformatted from angular coordinates into Cartesian coordinates, in order to allow the coding of the outer surface 213 in a raster fashion. The weft coding of the outer surface 213 of the cylinder 211 is described in further detail below with respect to Figure 3. With reference to Figures 2A and 3, the hollow cylinder 211 has a defined axis of rotation 320 around which it can rotate. at a rate controlled by any suitable means 305 such as with a motion controller manufactured by Newport Corporation. The rotational movement of the elongate member 211, by P1189 / 98MX example, can be provided by an ultra precision rotation stage 305, part number PM500-360R. The translation movement of the optical head 302 can be provided by an ultra precision linear stage 308, part number PM500-6L. In one embodiment, the hollow cylinder 211 can be made of a UV transparent material (e.g., monocrystalline sapphire). The dimensions (width and diameter) of the cylinder 211 can provide sufficient surface area to accommodate one or more images of the 120 nm CDs. For other types of media, the dimensions of the cylinder 211 can be modified as necessary. The outer surface 213 of the cylinder 211 can be coated with a thin layer (eg, 30-50 nm) of a low melting point direction 250 (see Figures 7A, 7B and 8, and discussion) or any equivalent material. The outer surface area 213 of the cylinder 211 can be divided into two regions: a data region 221 which corresponds to the image of the data region of a flat CD wound around the cylindrical surface 213, and an auxiliary region 222. The region auxiliary 222 may contain alignment mark in the form of grooves 200 nm wide parallel to cylinder axis 320, or equivalent. The cross section of the grooves can be triangular, semicircular or any other shape that P1189 / 98MX reduce the reflectivity of the slot for a UV laser beam focused in the slot below 60% compared to a landing. Referring again to Figure 3, ultraviolet (UV) radiation of a TEM00 mode from a CW laser (e.g., a 257 nm line of an argon ion laser or a 325 nm line of a laser - Steam of cadmium-helium metal) can be focused on the outer surface 213 of the cylinder 211. The focus of the laser radiation from the laser 302 is achieved with the aid of a feedback-controlled fine focusing system 317, known commonly in the art. The fine focus system 317 may include an individual beam system or a two beam system with an infrared auxiliary semiconductor laser. The placement of the laser beam on the surface of the cylinder 213 can be controlled to an accuracy of 25 nm through two stages of movement; the linear movement of the focusing system 317 of the laser 302 along the ultra precision linear stage 308, as well as the rotational movement of the cylinder 211 about the axis of rotation 320 via the ultra-precision rotation stage 305. As described above, the data to be encoded in the cylinder 211 for the purposes of making the master pattern must be reformatted from P1189 / 98MX Angular to Cartesian coordinates before a raster recording of the data takes place in the cylinder 211. Referring again to Figures 2A and 2B, and while the data is traditionally coded in a spiral manner 202 in the CD, the present invention preferably encodes the data in the master pattern of the cylinder 211 in a frame format 212. By achieving this raster formation, the focusing system 317 travels the length of the ultra precision linear stage 308, the cylinder 211 it is rotated slightly around its axis of rotation by the ultra-precision rotation stage 305, and then this cycle is repeated. In this way, the data is encoded according to one embodiment of the present invention in the frame fashion represented by the reference number 212 of Figure 2A. In order for the laser 302 and the focusing system 317 to appropriately encode the data in the cylinder 211, the data coded angularly in a spiral must be reformatted first in Cartesian coordinates. Therefore, as the laser 302 travels along its route 307, and as the cylinder 211 is successively rotated between each laser movement 302, the appropriate data is being encoded. Figure 4 depicts a basic block diagram and a computer system 400 that can be used to P1189 / 98MX in order to convert from angular coordinates to Cartesian, so that the master pattern processing unit 405 shown in Figure 3 can be recorded in master pattern appropriately. In one embodiment, the computer system of Figure 4 may comprise a CPU 401, a random access memory 402, an inbound storage device 403, and an outbound storage device 404. The storage devices 403 and 404 are previously described as a magnetic tape, a magneto-optic unit, or any other high-volume, high-speed storage device. For example, the computer system of Figure 4 may comprise the normal PC configuration with sufficient memory and processing speed or equivalent. Figure 5 is a flow diagram representing the various steps that can be taken by the computer of Figure 4 to convert the angular location of each piece of data on the CD into its Cartesian coordinate equivalent. During this coordinate transformation, the position of the data bits in the original sequence formatted for recording in angular coordinates (step 501) (eg, where the recording head moves along a spiral path) is changed according to Cartesian placement P1189 / 98MX (for example, where the recording head moves along a raster path) in step 502. In order to properly correlate the angular coordinates to the Cartesian coordinates, the resolution of the positioning system must be sufficiently high to reproduce the original spiral design on the surface of the pattern drum 211. For CDs, this requirement infers that the precision of the placement of the laser beam must be at most 50 nm for any axis. Another suitable precision can be used for other types of media. Depending on the speed of the master pattern coding and the data conversion, the converted bit sequence is coupled to the master pattern forming unit 405 directly from the CPU 401 (real-time processor) along the line 411 or from the output storage device along line 412. The steps that can be performed by the CPU 401 in order to transform the input angular coordinates stored in the input storage device 403 into output Cartesian coordinates stored in the output storage device 404 represents a normal classification problem. One solution to this classification problem is to correlate a sequence of continuous bits in a rectangular template in such a way that the bits are P1189 / 98MX will sequentially arrange along a strictly defined spiral path, each bit being represented by a point region. The distance d between the adjacent convulsions of the spiral is equal to 1.6 μm, the distance between the adjacent point regions representing contiguous bits is 1 μm. Assuming that the dispersion of each bit location can not exceed 10% of the separation of adjacent bits, each point region has to be placed inside a square with one side of e = 0.1 μm. In this way, the square grid that represents the rectangular template must have cells that have a dimension of 0.1 μm or 0.1 μm. The total number of these cells within a CD area is equal to approximately 1.13 x 10, which is approximately hundreds of times as much as the total number of bits in the encoded CD sequence. To index the square cells of the grid described above, a numbering of two integers can be used. { x, y} . The first integer x denotes the number of a column from left to right; the second integer and denotes the order number of a row from the bottom to the top. The total number L of either the rows or columns is equal to 1.2 X 106. The objective is to correlate the binary sequence in the square grid. { x > -Y} so that all the positions of the bits are P1189 / 98MX will arrange sequentially along the spiral path. For example, the coordinates can be transformed as follows: x (n) = e_1. { R + r (n) cosf (n)} and (n) = e ~. { R + r (n) sinf (n)} Formulas 1 where: f (n) = 2pd-1. { r (n) -R0} r (n) = [R02 + Ddp_1n] 1 2 R = radius of the last outer convolution (view), R = 60 mm; R0 = radius of the first convolution RQ = 20 mm; n = is the bit order number in the binary sequence that starts from 0 to N-1; N = the total number of bits in the sequence, N - = 10, r (-n) = distance between the point region corresponding to the n-nth bit and the center of the disk; D = fixed distance between the adjacent point regions along the spiral path, D = 1 μm; d = fixed distance between adjacent convulsions (track preparation) d = 1.6 μm; x and y = rectangular coordinates with the origin in the center of the disk; and e = the size of the elementary cell, e - = 0.1 μm.

P1189 / 98MX The set of pairs. { x (n), and (n)} obtained by formulas I above is arranged in order to increase n. In order to produce the binary sequence that can be used for the elaboration of the master pattern, this sequence must be arranged in order to increase x and y. In other words, the dependence on. { x, y} in n you must invest in the dependence of n on. { x, y} , keeping in mind that. { x, y} it only assumes some certain integer values defined by the previous formulas I. Taking into account the large length of the sequence, the initial subsequences suitable for the placement in the fast RAM can be subdivided in step 503. More specifically, the following set of sequences (which are the columns) must be obtained for each Fixed x: n. { 0, and}; n. { l, and}; n. { 2 and}; n. { 3, and}; .... n. { x, y}; .... n. { L-1, and} Formula 2 where: L = 1.2 x 10, and is the total number of columns (or rows). In step 504, each column (subsequence) of Formula 2 is arranged in order to increase the number of rows, and, as indicated below: P1189 / 98MX n. { and, x} = n. { x, yx} , n. { x, y2} , n. { x, y3} ... Formula 3 where: 0 < yx < y2 < y3 < y4 .... < L-l. Obviously, the number of rows and for each subset n. { x, y} from Formula 3 assumes only a small part of the integer values between 0 and L-1, each corresponding value describes the position of the point region of the corresponding bit n of the sequence. Figure 6 shows a sample table that can be created by the steps of Figure 5, as previously described. The bits in the table in Figure 6 are taken from an actual CD, although they only represent a sampling of the various bits on the CD. The relative numbers from 1 to 10 in the first column 601 (polar coordinates n { F, r.}.) Are assigned only for convenience. The second column 602 and the third column 603 of the table of Figure 6 represent the angular coordinates f (n) and r (n), respectively. The next two columns 604 and 605 contain the calculated Cartesian coordinates x (n) and y (n), respectively. Based on the value of the Cartesian coordinates, a new integer n is assigned. { x, y} 606 to the data bit. Again, the final step 504 in the increase of a table that can be P1189 / 98MX to use for the elaboration of a master pattern is to classify the rows in the table such that bit 606 is arranged in the order of n. { x, y} growing. Once in the table of Figure 6 is created, correlating the location of Cartesian coordinates, the laser beam 302 can be controlled by the modulator 303 to encode the data on the outside in the cylinder 211. As the laser 302 travels the Weighted route generally represented by the reference number 211 of Figure 2A, the table of Figure 6 is used to determine the location of the corresponding data in the spiral of the reference number 202. In this way, at each point a along the route of the laser 302, where the cylinder 211 has been rotated a known amount, the laser can be modulated to encode the appropriate data on the outer surface of the cylinder 211. The laser modulation 302 describes in detail further below. In order to encode the data in the cylinder 211, the laser 302 can control by an acousto-optic modulator 300 to focus its energy on the outer surface of the cylinder 211 in such a way that the metal alloy 250 melts. The laser radiation it is precisely coupled to the fine focus actuator 317 mounted on the linear stage 308 by means of optical fiber 315 individually. In one modality, the intensity of the PX189 / 98MX focused laser radiation from laser 302 is controlled to be above the local melting threshold of metallic coating 250 of cylinder 211 and below the threshold of local ablation of the same metallic coating 250. Exposure to emissions laser 302 of the metallic coating 250 on the surface of the cylinder 213 results in local melting of the metallic coating 250. In the melting, the liquid metal 250 tends to accumulate at the edges of the solid phase material, thereby forming an opening 251 (see Figure 7A, 7B and 8, and discussion) in the previously uniform coating 250. In one embodiment, the laser intensity 302 is chosen such that no ablation occurs in the metallic coating 250 of the cylinder 211. In this case, the heat generated by the laser 302 on the surface of the cylinder 211 can be controlled to be above the melting point of the metallic coating 250 on the surface of the Illindro 211, but below the melting point of the transparent material of the cylinder 211 itself. In another embodiment, the intensity of the laser 302 is chosen such that ablation occurs in the metallic coating 250. At the same time, the energy density of the UV light 910 during the exposure of the film 901 is the order of magnitude less than for the development of the master pattern P1189 / 98MX with a focused laser beam, therefore melting never occurs during duplication (described in detail below). The radiation intensity of the UV laser emitted by the laser 302 can be modulated by an electro-optical modulator 300, by a magneto-optical modulator 300, or the like, under the control of CPU 401. The CD pattern data shown in FIG. the Cartesian coordinate format, and stored in the storage device 404, are used to modulate the laser beam. If the energy of a laser pulse focused from the laser 302 is greater than the ablation threshold of the alloy coating 250 on the surface of the cylinder 211, a feature consisting of a circular opening 251 is formed at that location. This opening 251 is optically thin compared to the non-woven metal coating 250, and allows the radiated energy, such as the UV radiation emitted from inside the cylinder 211, to pass therethrough. The use of UV radiation from within the cylinder 211 is used in the duplication process of the present invention, and will be described in detail later. By selectively repeating the melting step described above, while the position of the focused, modulated laser beam is changed along the frame route 212, a plurality of data regions are formed, each of which P1189 / 98MX represents a binary bit of recording information, on the surface of the cylinder 211. Figures 7A and 7B depict a cross-sectional view and a plan view, respectively, of the data regions encoded on a portion of the surface 213 of the cylinder 211. The encoded data design of the cylinder 211, as described above, is analogous to the characteristics generated on the surface of a glass pattern formed by a conventional process of master-master processing, although there are two main differences and signifiers: (1) the process of making the master pattern of the present invention takes place on a three-dimensional cylindrical surface 213, while the formation of the master pattern is carried out in a two-dimensional plane; and (2) in the present invention, the laser beam of the laser 302 performs a raster movement (e.g., Figure 2A), while in the conventional process of forming the master pattern, the laser beam encodes the CD in a spiral way (e.g., Figure 2B). The master cylinder 211 of the present invention can be reshaped in master pattern many times. Specifically, the burnout 250, 251 on the surface 213 of the cylinder 211 can be erased on heating P1189 / 98MX uniformly above the melting point of the alloy. When melted, the alloy 250 spreads uniformly on itself over the entire surface and the openings 251 created by local melting or laser softening are filled. After solidification, the process of elaborating the master pattern can be repeated as described in the previous paragraphs. While cylinders 211 may be used in general, extensive use of pattern cylinder 211 may cause partial loss of alloy material due to ablation. However, the lost material can easily be filled by evaporation of the additional alloy 250 on the cylinder surface 213. The heating and reflux of the cylinder can be carried out with the same apparatus that is used for the elaboration of the master pattern. 2. Duplication Once the cylinder 211 has been encoded with the data, the duplication of the encoded data can be performed. Through the use of the duplication techniques of the present invention, the pattern design of the surface of the cylinder 213 can be replicated in the flexible substrate 901 in a very rapid manner through the use of contact photolithography or equivalent techniques. The provide the substrate of the medium in the P1189 / 98MX form a continuous mesh of the film material 901, extremely high duplication rates can be achieved, as will be described in detail further below. The duplication process is described with reference to Figures 8, 9 and 10. Figures 8 and 9 represent structural components of the duplication portion of the present invention, while Figure 10 represents the various steps that can be performed during the duplication process. Throughout the subsequent discussion, reference will be made to the steps of Figure 10. Step 1001. With reference to Figure 9, a flexible film 901, such as a three-layer film, is provided. Figure 8 provides, in part, a cross section of the film 901 of Figure 9. With reference to Figure 8, the film 901 may comprise, for example, a layer of 0.1 to 1.0 μm of the photoresist substance 801 (per example, Shipley 505A photoresist) coupled to a layer of approximately 0.05 μm reflective coating 802 (eg aluminum) which is coupled to a flexible polymer film 803 of 15 to 200 μm (eg D-type film Mylar DuPont) ). Of course, these thicknesses may comprise only one embodiment of the flexible film 901, P1189 / 98MX can work well with other appropriate thicknesses and equivalent materials. The elements 801, 802 and 803 of the film structure 901 serve the following purposes: the layer of the photoresist 801 is a photosensitive layer that can be selectively exposed through transparent regions of the cylinder 211; the aluminum layer 802 is a reflective medium that is subsequently encoded later in the duplication process; and the polymer film 803 is a flexible, but stable, substrate that provides the means of continuous transport of the media layer through the repeated steps of the duplication process. The photoresist layer 801 and the aluminum layer 802 together form an optically durable and subsequently modifiable layer sensitive to the radiated energy, as will be described in detail below. Step 1002. A linear UV light source 910 (eg, a long-arc high-pressure gas lamp) is positioned coaxial to the axis of rotation 320 of the cylinder 211. Such that its radiated energy is radiated uniformly radially. To expose the photoresist layer 801, the three layer composite film 901 is brought into intimate contact with the outer surface 213 of the cylinder 211, as shown in Figure 9.

P1189 / 98 X Figure 8 shows an enlarged track of a cross-sectional area of the surface of the cylinder 213 in contact with the composite film 901. During the exposure, the UV radiation from the linear source 910 inside the cylinder 211 is transmitted through the transparent structure of this cylinder 211, through any of the openings 251 in the metallic coating 250 of the outer surface 213 of the cylinder 211 , and reach the areas of the photoresist layer 801 which are located on the openings 251 on the surface of the cylinder 213. The openings 251 on the surface of the cylinder are those openings created during the process of forming the master pattern, previously described . The cylinder 211 rotates while the film mesh 901 is fed by a roller system 971 or 972, the linear speed of the outer surface 213 of the master cylinder 211 at any given moment of time is equal to the linear speed of the mesh of film 901 which is fed by rollers 971 and 972. The exposure starts when the film mesh 901 comes into contact with the surface of the cylinder 213 on the roller 971, and ends when the film mesh 901 is separated from the cylinder 211 on the roller 972. An opaque screen 980 is provided to protect the film mesh 901 from exposure before contact with the cylinder 211, and P1189 / 98MX after separation. The exposure dose is defined by intensity of the linear light source 910 and by the linear velocity of the film mesh 901. The preferred intensity of the light source 910 and the preferred linear velocity of the 901 film mesh can be related linearly, and can be expressed by the following Formula 4: Dv = I Formula 4 where: D = dose requirements of the photoresist substance 801 in J / cm 3; v = linear velocity in cm / sec; and I = intensity of the energy radiated from the linear light source 910, in J / (sec, cm). The mechanical optical geometry used in the present invention offers the following important advantages: • The exposure takes place while the film 901 is in motion. • the separation between the surface of the cylinder 213 and the film 901 is easily minimized due to the configuration shown in Figure 9, resulting in a possible maximum coding resolution. • the complicated optics typically used in alignment P1189 / 98MX of the flat field mask of the prior art in order to achieve uniformity of exposure are replaced by a linear, effective and inexpensive 910 light source. After the layer of the photoresist 801 is exposed as described above, the following steps can be performed to reveal the photoresist substance 801, acid etch the reflective layer 802, and remove the photoresist 801. These steps correspond to the Normal steps for the processing of photoresist material: 1. Step 1003: After the exposure, the film 901 is developed and the dimples are formed when the exposed photoresist 801 is washed. A mark of the photoresist with the dimples in the corresponding photoresist 801 is thus formed per dimension and position to the openings 251 in the metallic coating 250 of the surface in the cylinder 213. 2. Step 1004. The film 901 is rinsed in deionized water and dried 3. Step 1005. The photoresist is postcooked at a temperature of 100 ° C. 4. Step 1006. The 802 aluminum reflective layer is etched through the dimples in the substance P1189 / 98MX photoresist 801 by a recording with base, such as sodium hydroxide solution (NaOH). A dry plasma recording may also be used. Step 1007. Film 901 is rinsed in deionized water and dried. 6. Step 1008. The photoresist substance 801 is rinsed by an organic solvent. 7. Step 1009. The film is rinsed in deionized water and dried. In carrying out the contact exposure, and the seven steps 1003-1009 described above, the design coded on the surface 213 of the cylinder 211 is transferred onto the photoresist layer 801 by exposure and development, and subsequently transferred from the layer of photoresist 801 on metal layer 802 of film web 901 by acid washing. As a result, the plurality of apertures with reduced reflectivity in the aluminum layer 802 of the film mesh 901 represent a digital recording read by an optical reproduction device such as a normal CD player. Step 1010. With reference to Figure 11, in order to make the thin film 901 compatible with normal reproduction devices, the thickness of the P1189 / 98MX means 901 can be increased to between 1.0 and 1.2 nr- by adding a layer of optical grade non-birefringent 1101 transparent medium, and the CD design can be identified in the 901 film mesh according to the normal dimensions of CD. A polystyrene 1102 of a thickness of 1.2 nm can be laminated to the flexible substrate with a refractive index equalization adhesive 1103, and subsequently cured in a microwave field. After this step, the lamp structure interleaved at 1101, 901 and 1102 (for example: 1.2 mm polystyrene on a 2 μm aluminum design, -0.05 μm on a 50 μm Mylar substrate) will be so flexible, it should be preferred to process subsequently as a rigid sheet. Step 1101, 1012. The last procedure in the duplication is to separate the individual discs from a mesh using a precision water blade. Alignment marks made during the lithographic process can provide accuracy for the center hole and perimeter cuts. The labels can be printed on the finished CD either before or after the separation of the 901 film mesh. By printing the labels on the CD prior to separation of the 901 film screen, automated efficiencies can be achieved, such as using indirect printing. However, the marking of P1189 / 98MX individual disk after 901 mesh separation can also be realized by the methods and machines commonly used in the use, such as those that use shield screen techniques. The master pattern forming and duplication process of the present invention provides numerous important advantages over the prior art, including: • The process of making the master pattern is greatly simplified. If necessary, it can be carried out within a confinement by contact and does not require the use of a much more expensive open space installation. The duration of the master pattern making process can be from 1 to 1.5 hours (or less), as opposed to a minimum of 4-5 hours in the prior art processes (including photoresistor coating and inspections). • The steps to create the parent, mother and parent reproduction units are removed. • The processes of elaboration of the master pattern and duplication can be carried out by essentially the same apparatus, which can be relatively compact.

• The cylinder 211 of the present invention allows the film of the medium 901 to be exposed while in continuous motion. All the consequent steps of the P1189 / 98MX duplication process can be carried out while the 901 medium film is transported continuously. • The continuity of the duplication process provides increased performance at a lower cost. Depending on the size of the cylinder 211, the process of the present invention can produce one CD every 0.1 to 0.3 seconds (or less) at a cost of approximately 5 cents per unit (or less). • Contact photolithography during duplication takes place on a cylindrical surface 213. This eliminates difficulties for contact lithography on a flat, rigid surface, while increasing resolution. • The characteristic resolution achievable through the use of the present invention may be 250 nm, or less *. This exceeds the requirements imposed by the recently introduced high density recording standards. • The microscopic characteristics in the 901 medium film are manufactured by optical and mechanical means only. The mechanical alteration between the morphology of the surface is completely excluded and therefore, the non-uniformities caused by the mechanical stress and the corresponding birefringence P1189 / 98MX delete. • The process is carried out at temperatures below 180 ° F, and therefore the corresponding temperature gradients and birefringence are eliminated. • Reduced birefringence allows the use of materials substantially cheaper than polycarbonate plastic as the transparent substrate of cylinder 211. • Improved resolution and decreased birefringence provides reduced error rates and allows the use of higher speed playback device. • A duplication method of the present invention is suitable for the production of multilayer structures, such as those that are being introduced into new optical media technologies. While the invention has been described in detail with specific reference to the preferred embodiments thereof, it is understood that variations and modifications thereof may be made without departing from the spirit and scope of the invention.

P1189 / 98MX

Claims (23)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following CLAIMS is claimed as property: 1. A system for encoding data regions in optical media, comprising: (a) ) an elongate member having a defined axis of rotation, wherein the elongated member has a plurality of regions on its outer surface, each region is either optically thin or optically thick; (b) a means for providing a uniform irradiation from within the elongated member; (c) a film that includes an optically durable layer, wherein the optically durable layer can be modified sensitive to the irradiated energy; (d) means for rotating the elongated member about its defined axis of rotation while placing the film in direct contact with the outer surface of the elongate member, wherein the film is exposed to uniform irradiation through each of the optically thin regions on the outer surface P1189 / 98MX of the elongated member; and (e) a means for modifying the optically durable layer of the film in those regions that were exposed to uniform irradiation. A system according to claim 1, wherein the plurality of regions on the outer surface of the elongated member are arranged to correspond to the coding of a compact disc. The system according to claim 1, wherein the elongated member comprises a material transparent to the irradiated energy. The system according to claim 1, wherein the elongate member comprises a cylinder. The system according to claim 1, wherein the elongate member is hollow. The system according to claim 1, wherein the uniform irradiation medium emits ultraviolet light. The system according to claim 1, wherein the uniform irradiation means comprises a linear light source positioned along the defined axis of rotation of the elongate member. The system according to claim 1, wherein the optically durable layer of the film comprises a material to reflect the radiated energy. P1189 / 98MX 9. The system according to claim 8, wherein the modification means modifies the optically durable layer so that the optically durable layer does not reflect the energy radiated in those regions that were exposed to uniform irradiation. A system for encoding data regions in optical media, comprising: (a) an elongate member having a defined axis of rotation, wherein the elongate member has a plurality of regions on its outer surface, each region being optically thin or optically thick; (b) a means for providing a uniform irradiation from within the elongated member; (c) a film including a reflective layer and a photoresist layer; (d) a means for rotating the elongate member about its defined axis of rotation while placing the photoresist layer of the film in direct contact with the outer surface of the elongate member, wherein the photoresistor layer of the film it is exposed to uniform irradiation through each of the optically thin regions on the outer surface of the elongated member; P1189 / 98MX (e) a means to remove the photoresist layer in the film in those regions that were exposed to uniform irradiation; and (f) a means for removing the reflective layer of the film in those regions that are adjacent to the regions of the photoresist layer that were removed by the removal medium. The system according to claim 10, further comprising a means for removing the photoresist layer from the film. A system for encoding data regions in optical media, comprising: (a) an elongate member having a defined axis of rotation, wherein the elongate member has an optically thick layer on its outer surface; (b) a means for focusing the energy on the surface of the elongated member; (c) the energy focusing means for focusing the energy of selected regions of the optically thick layer, whereby the focused energy melts the optically thick layer in selected regions, thus forming P1189 / 98MX optically thin regions on the outer surface of the elongated member; (d) a means for providing a uniform irradiation from inside the elongated member; (e) a film including an optically durable layer wherein the optically durable layer can be modified sensitive to the radiated energy; (f) means for rotating the elongated member about its defined axis of rotation, while placing the film in direct contact with the outer surface of the elongate member, wherein the film is exposed to uniform irradiation through each of the optically thin regions on the outer surface of the elongated member; and (g) a means for modifying the optically durable layer of the film in those regions that were exposed to uniform irradiation. The system according to claim 12, wherein the focused region comprises a laser beam. The system according to claim 12, wherein the control means controls the energy focusing means such that the focused energy melts the optically thick layer in selected regions without ablation. P1189 / 98MX 15. The system according to claim 14, wherein the melting point of the optically thick layer is less than the melting point of the elongated member. 16. A system according to claim 12, wherein the control means controls the energy focusing means such that the focused energy melts the optically thick layer in selected regions with ablation. 17. The system according to claim 16, wherein the optically thick layer has a different energy absorption band than the elongate member. The system according to claim 12, wherein the control means comprises: (i) a means for sequentially storing a plurality of data bits found on a compact disc, wherein each of the plurality of data bits has a unique angular location on the compact disc; (ii) a means for storing a Cartesian coordinate location associated with the equivalent for each of the plurality of data bits; (iii) a means for controlling the energy focusing means such that the focused energy hit the optically thick layer at the location of Cartesian coordinates for each of the P1189 / 98MX plurality of data bits having a digital value thereby selecting optically thin regions on the outer surface of the elongated member. The system according to claim 12, wherein the film is a reflective layer and a layer of the outer photoresistor, and wherein the modification means comprises: (i) a means for removing the photoresist layer from the film in those regions that were exposed to uniform irradiation; and (ii) a means for removing the reflective layer of the film in those regions that are adjacent to the regions of the photoresistor layer that were removed by the removal medium. The system according to claim 19, wherein the modification means further comprises: (iii) a means for removing the ability to remove the photoresist layer from the film. 21. A method for coding data regions in optical media, comprising the steps of: (a) creating a plurality of regions in the P1189 / 98MX inner surface of an elongated member, each region being either optically thin or optically thick, and wherein the elongated member has a defined axis of rotation; (b) providing a uniform irradiation from within the elongated member; (c) coating a film with an optically durable layer; (d) rotating the elongated member about its defined axis of rotation while placing the film in direct contact with the outer surface of the elongated member, whereby the film is exposed to uniform irradiation through each of the regions optically thin on the outer surface of the elongated member; and (e) modifying the optically durable layer of the film in those regions that were exposed to uniform irradiation. 22. A method for encoding data regions in optical media, characterized in that it comprises the steps of: (a) creating a plurality of regions on the outer surface of an elongated member, each region being either optically thin or optically P1189 / 98MX thick, and where the elongated member has a defined axis of rotation; (b) providing a uniform irradiation from within the elongated member; (c) coating a film with a reflective layer and a layer of photoresist; (d) rotating the elongated member about its defined axis of rotation while placing the photoresist layer of the film in direct contact with the outer surface of the elongated member, wherein the layer of photoresist of the film is exposed to uniform irradiation through each of the optically thin regions on the outer surface of the elongated member; (e) removing the photoresistor layer from the film in those regions that were arranged for uniform irradiation; and (f) removing the reflective layer of the film in those regions that are adjacent to the regions of the photoresist layer that were removed by the removal medium. 23. A method for encoding data regions in optical media, comprising the steps of: (a) coating the outer surface of the member P1189 / 98MX elongated with an optically thick layer, wherein the elongated member has a defined axis of rotation; (b) focusing the energy in selected regions of the optically thick layer, whereby the focused energy where the optically thick layer in the selected regions, thereby taking optically thin regions on the outer surface of the elongate member; (c) providing irradiation from within the elongated member; (d) coating a film with an optically durable layer; (e) rotating the elongate member about its defined axis of rotation while coming into direct contact with the film with the outer surface of the elongated member, wherein the film is exposed to uniform irradiation through each of the optically thin on the outer surface of the elongated member; (f) modify the optically durable layer of the film in those regions that were exposed to uniform irradiation. 8HX