Philips has developed various optical disc systems (LaserVision, Compact Disc and Digital optical Recording) for storage of video and audio information and data. These systems require different types of moulds for the...
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Philips has developed various optical disc systems (LaserVision, Compact Disc and Digital optical Recording) for storage of video and audio information and data. These systems require different types of moulds for the manufacture of discs. These moulds are made by means of master discs. Because of the high information density new methods have been developed for the mastering process and for the electroforming of the moulds. Processes applied for the manufacture of records could not be used for the manufacture of optical discs. Mastering and electroforming for optical discs bring together thin-film photo lithography, thin-film vacuum technique and precision electroforming, under low-dust conditions.
This conference proceedings contains 4 papers. The main subjects are streaming tape drives for computer systems, extremely low error rate digital recording, opticalstoragetechnology and systems, and vertical Bloch l...
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This conference proceedings contains 4 papers. The main subjects are streaming tape drives for computer systems, extremely low error rate digital recording, opticalstoragetechnology and systems, and vertical Bloch line memory.
Efficient magnetic storage devices have been developed in Japan hand in hand with the formulation of several important technologies. These include small spacing head design methods, new structure and design methods fo...
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Efficient magnetic storage devices have been developed in Japan hand in hand with the formulation of several important technologies. These include small spacing head design methods, new structure and design methods for head positioners, improved media for higher wear resistance and recording density, and effective head-disk enclosing methods. In the future, the most important technology for achieving higher recording density will be tribology at the sub-submicron level, i. e. , microtribology. Write-once-read-many digital dataoptical disks having high recording densities are coming into use and erasable optical disks are now on the verge of being available. To meet their new demands, optical heads having a low moving mass must be developed in order to realize the short access time essential for digital data processing. Realizing effective optical mass storage systems will also necessitate investigation into disk autohandling mechanisms.
The market for both quarter and half inch streaming tape drives has stabilised, with standardisation and auto-loading being key factors. The features of each product class are considered, together with common applicat...
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ISBN:
(纸本)0903748649
The market for both quarter and half inch streaming tape drives has stabilised, with standardisation and auto-loading being key factors. The features of each product class are considered, together with common applications for them. Increased datastorage requirements are being met low cost GCR tape units and developments in this field are considered. Increased capacity is also available using half inch cartridges and trends in this direction, together with problems being addressed, are reviewed. opticaltechnology as a possible means of replacing some of the traditional uses of magnetic tape is now emerging. These developments and their impact on the market for streaming tape drives are discussed with consideration being given to both optical tape and optical disk drives.
Digital facsimile is an increasingly important component in office automation. Techniques for the compression of bi-level scanned image data are vital to the efficient storage, retrieval and transmission of office doc...
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ISBN:
(纸本)0444700684
Digital facsimile is an increasingly important component in office automation. Techniques for the compression of bi-level scanned image data are vital to the efficient storage, retrieval and transmission of office documents. A scheme for the compression of typewritten and printed documents is described. It incorporates a new pattern-matching algorithm which can handle a variety of styles and sizes of text more efficiently than existing methods.
optical recording media can be classified into three categories: pre-recorded (read-only), write-once, and erasable. Pre-recorded media includes those products for which all of the information or data is incorporated ...
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optical recording media can be classified into three categories: pre-recorded (read-only), write-once, and erasable. Pre-recorded media includes those products for which all of the information or data is incorporated on the disk at the time of manufacture and cannot be altered by the user. The best known example is the compact audio disk, but also included are videodiscs and CD-ROM or read-only computer memory. The second category, write-once, consists of media on which information is written by the end user, but once written, cannot be altered. It thus becomes a permanent record which can be stored for long periods of time and can be re-read at will. The third category, erasable, is also written by the end user, but can be erased and rewritten, much like a magnetic disk. The most important characteristic of all optical media is high-density, low cost storage capacity. The fabrication sequence for optical disks of all types is discussed. It is pointed out that current optical recording media fabrication makes extensive use of existing and well developed thin film process technology. Unique, however, are the specific material and process combinations and unusually stringent requirements for process control. Also unique is the extreme requirement for particulate cleanliness applied to large coating areas.
The pointing system for opticaldata transmission over unguided channels uses a return beacon from the receiver back to the transmitter to aid the reciprocal alignment of the two stations. In this paper, continuous-wa...
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ISBN:
(纸本)0444700684
The pointing system for opticaldata transmission over unguided channels uses a return beacon from the receiver back to the transmitter to aid the reciprocal alignment of the two stations. In this paper, continuous-wave (CW) or pulsed beacon acquisition with array detectors is examined in the presence of extended clutter in addition to background and receiver noises. Performance is evaluated in terms of probability of an acquisition error for Poisson statistics of the photodetector output.
Mass-storage devices for computers now range across three technologies-magnetic disk drives, optics, and bubble memories. Leading companies as well as startups and university researchers are pushing hard on the techno...
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Mass-storage devices for computers now range across three technologies-magnetic disk drives, optics, and bubble memories. Leading companies as well as startups and university researchers are pushing hard on the technology in each area. The article is a review of technical advances in magnetic, optical, and bubble memories.
Disk controller technologies are becoming a main focus in the world of electronics. Many companies are now offering these disk controllers to the mass market. Disk controllers exist in different forms. They may exist ...
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Disk controller technologies are becoming a main focus in the world of electronics. Many companies are now offering these disk controllers to the mass market. Disk controllers exist in different forms. They may exist as either chip products or board products. Chip products are becoming the focus due to their space saving capabilities. Hard disks are magnetic drives being rotated at high speeds. They are new to the disk controller mass market. The mechanical stability and rigidity allow for information to be quickly retrieved and read. The read heads can move accurately over a particular area of data to find the information.
A new method is presented for implementing the block truncation coding (BTC) process geared toward compression of data which can take on a wide range of values, such as terrain elevation data. The BTC process was deve...
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A new method is presented for implementing the block truncation coding (BTC) process geared toward compression of data which can take on a wide range of values, such as terrain elevation data. The BTC process was developed to facilitate the efficient storage and transmission of digital images (such as a digitized still photograph). The standard digitizing algorithm for this type of image uses 256 logarithmically spaced intensity levels, yielding eight data bits per pixel (picture element). The traditional BTC technique breaks the digitized map into N multiplied by N blocks and converts it to one bit per pixel, with the bit setting criterion being whether a pixel is above or below the threshold (mean) value for that block. This results in two output levels for each block of pixels. Digital terrain data are typically digitized to sixteen bits since the required accuracy is much higher than that of most optical images. Due to this increased accuracy, it becomes impossible to fit the whole range of values within one N multiplied by N block to two quantization levels without incurring some large errors. The algorithm implemented in this study accommodates this fact by using three or four quantizing bits per datum, yielding 8 or 16 quantization levels.
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