The creating of intelligent marks on a substrate by means of thermal energy has been in use for thousands of years, e.g., branding of livestock and burning images onto wood. During the past 30 years, this type of imaging has been significantly refined. Recent advances allow the creation of color images, 16 shades of gray and letter quality printing on white substrates. Permanent images are now being written with direct thermal processes. The foregoing make thermal writing very attractive for numerous applications. The general technology of how thermal writing is accomplished today, its applications, and why society should use thermal writing are the topics of this paper. To attempt to cover in great technical detail all of the current advancements in thermal writing is beyond our scope here. What is intended is the proposition that THERMAL WRITING is a superior form of creating images on paper substrates for Society's on demand hard copy requirements. First let's look at how thermal writing is being accomplished with today's technologies.
Resistive Ribbon Thermal Transfer Printing (1-3) is the basic technology used in the IBM "Quietwriter" Printer family. This technology is a non-impact technology that has several characteristics that make it very appropriate for use in several low-end (low speed), high quality office printing and publishing systems. At the present time the available Resistive Ribbon printers have been designed to have characteristics and resolution suitable for use in typewriter, word processing and related desk top publishing applications. Inherently the technology is capable of achieving higher resolution as well as demonstrating several other characteristics that can be of use in the evolving office and computer assisted publishing application areas. This paper will briefly review the Resistive Ribbon Thermal Transfer Printing technology and its associated physical and materials (chemical) requirements. Although emphasis will be placed upon the present technology, several other properties of the Resistive Ribbon technology which are potentially suited to a wider range of office and publishing applications will be discussed.
Ink jet technology for computer controlled printing has been under development for 25 years or so. A number of technological approaches have been developed, several of these approaches resulting in commercial products with an impressive range of capabilities. This paper is a brief summary of ink jet printing, emphasizing technological approaches of contemporary technical and commercial importance.
Significant advances in system reliability and droplet control, resulting in improved image quality, have opened up new opportunities for continuous-flow ink jet technology -a relatively mature non-impact printing technique. These opportunities exist within the graphic arts industry--an industry experiencing an upheaval in its fundamental methods of operation because of the increasing use of powerful, highly sophisticated computer systems for both the design and creation of images and the electronic manipulation of images and text in preparation for high volume printing. High resolution computer systems are increasingly supplanting much of the manual, crafts-oriented nature of the business. Skilled graphic design and production personnel are exchanging keyboards, function menus and electronic pucks for drawing tables, T-squares, and X-acto knives.
In a first part magnetographic printing, as embodied in the Bull MP technology, is introduced in terms of operating principles, functional steps and associated technological components. In a second part, a couple of specific technical problems such as magnetic crosstalk in head arrays, print background control, electrostatic and pneumatic perturbations at transfer, are shortly reviewed while indications as to solutions are provided. Finally, future improvement to the technology are briefly discussed.
Many electronic imaging technologies which produce hardcopies require transparent, electrically conductive ground planes. Electrophotographic and electrostatic imaging systems generally require highly transparent coatings, but the optimum conductivity varies for different systems. The advantages and limitations of thin semitransparent metallic coatings and wide band-gap semiconducting oxide coatings are considered here with respect to their uses in these technologies.
The basic principle of electrophotographic non-impact printers is to expose a photoconductor by a light beam which is modulated by the information to be printed and to process the latent image in the same way as usually done in plain paper office copiers. Key components of non-impact printers to be matched are, therefore, light source and photoconductor. Currently used light sources and light shutters are gas and solid-state lasers, cathode ray tubes (CRT, OFT), light emitting diodes (LED), magneto-optical light shutters (LISA) , liquid crystal light shutters (LCS) , and electrooptical light shutters (PLZT-ceramics). Photoconductors are: selenium based materials (amorphous Se-based alloys, As2Se0, binder layers (mainly CdS), organic photoconductors (OPC), and amorphous silicon (a-Si).
A photoconductor which is used in an IBM laser printer is described as to composition and performance. The key mechanisms that apply to the performance of the photoconductor are elucidated, and the sensitometric parameters are discussed. Photoconductor concerns are presented, and considerations with respect to development of photoconductors for use in future laser printers are investigated.
Dry Silver technology was discovered at 3M and introduced into various imaging applications in the mid-sixties. In the early 1980's, quality films and papers with extended spectral responses, greater dynamic ranges, and improved sensitivity and edge acuity were introduced into sophisticated imaging systems. These products also have improved shelf life at elevated storage temperatures, and improved print stability. At the present time, 3M is developing a full-color dry silver product. This product has the same rapid-access, easy-to-use characteristics as the black and white dry silver recording materials. It has high resolution, long gray scale, and adequate sensitivity for CRT's and other electronically addressable exposure devices. The product can be processed in the same processors used for the black and white dry silver products.
A number of Color Hard Copy (CHC) market drivers are currently indicating strong growth in the use of CHC technologies for the business graphics marketplace. These market drivers relate to product, software, color monitors and color copiers. The use of color in business graphics allows more information to be relayed than is normally the case in a monochrome format. The communicative powers of full-color computer generated output in the business graphics application area will continue to induce end users to desire and require color in their future applications. A number of color hard copy technologies will be utilized in the presentation graphics arena. Thermal transfer, ink jet, photographic and electrophotographic technologies are all expected to be utilized in the business graphics presentation application area in the future. Since the end of 1984, the availability of color application software packages has grown significantly. Sales revenue generated by business graphics software is expected to grow at a compound annual growth rate of just over 40 percent to 1990. Increased availability of packages to allow the integration of text and graphics is expected. Currently, the latest versions of page description languages such as Postscript, Interpress and DDL all support color output. The use of color monitors will also drive the demand for color hard copy in the business graphics market place. The availability of higher resolution screens is allowing color monitors to be easily used for both text and graphics applications in the office environment. During 1987, the sales of color monitors are expected to surpass the sales of monochrome monitors. Another major color hard copy market driver will be the color copier. In order to take advantage of the communications power of computer generated color output, multiple copies are required for distribution. Product introductions of a new generation of color copiers is now underway with additional introductions expected during 1987. The color hard copy market continues to be in a state of constant change, typical of any immature market. However, much of the change is positive. During 1985, the color hard copy market generated $1.2 billion. By 1990, total market revenue is expected to exceed $5.5 billion. The business graphics CHC application area is expected to grow at a compound annual growth rate greater than 40 percent to 1990.
This talk covers the use of Computer generated color output in the preparation of professional, memorable presentations. The focus is on this application and today's business graphic marketplace. To provide a background, on overview of the factors and trends influencing the market for color hard copy output is essential. The availability of lower cost computing technology, improved graphic software and user interfaces and the availability of color copiers is combining with the latest generation of color ink jet printers to cause a strong growth in the use of color hardcopy devices in the business graphics marketplace. The market is expected to grow at a compound annual growth rate in excess of 25% and reach a level of 5 Billion by 1990. Color lasography and ink jet technology based products are expected to increase share significantly primarily at the expense of pen plotters. Essential to the above mentioned growth is the latest generation of products. The Xerox 4020 Color Ink Jet Printer embodies the latest ink jet technology and is a good example of this new generation of products. The printer brings highly reliable color to a broad range of business users. The 4020 is driven by over 50 software packages allowing users compatibility and supporting a variety of applications. The 4020 is easy to operate and maintain and capable of producing excellent hardcopy and transparencies at an attractive price point. Several specific applications areas were discussed. Images were typically created on an IBM PC or compatible with a graphics application package and output to the Xerox 4020 Color Ink Jet Printer. Bar charts, line graphs, pie charts, integrated text and graphics, reports and maps were displayed with a brief description. Additionally, the use of color in brainscanning to discern and communicate information and in computer generated Art demonstrate the wide variety of potential applications. Images may be output to paper or to transparency for overhead presentation. The future of color in the business graphics market looks bright and will continue to be strongly influenced by future product introductions.
In today's business world it is essential that information be communicated in a clear, concise and timely manner. In order to accomplish this, graphs are often used to make comparisons between groups of data or to illustrate trends. They can be a visual aid in seeing correlations between sets of data or the variation of data over time. These factors are important in determining causal relationships between data or for predicting the future value of data by analyzing its movement on a curve. Without the effective use of graphs, trends or correlations could go unnoticed even by experts whose only method of analysis was to examine the raw data. Graphs are effective devices in any situation where ideas must be communicated quickly and understandably. Graphs alone however, are necessary but not sufficient for effective business communication. Seventy percent of all presentation material is in the form of word charts. These charts must also communicate information and concepts clearly and concisely and should complement any graphical information which is being presented.
In today's computer driven world, there are a host of outstanding color hardcopy devices that provide far-reaching power to presenters. In many cases, however, the connection between software and hardcopy output devices is incomplete or insufficient to meet user needs. A new interface technology, color raster image processing, is now available [from Matrix Instruments] to bridge the graphics software-peripheral gap, enabling business users to easily take advantage of the high resolution color output devices.
There are several factors to consider when addressing the issue of non-impact printer resolution. One will find differences between the imaging resolution and the final output resolution, and most assuradly differences exist between the advertised and actual resolution of many of these systems. Beyond that some of the technical factors that effect the resolution of a system in-clude:
. Scan Line Density
. Spot Size
. Energy Profile
. Symmetry of Imaging
Generally speaking, the user of graphic arts equipment, is best advised to view output to determine the degree of acceptable quality.
Hardcopy halftone image patterns produced by a high resolution electrophotographic (EP) printer are studied. Reflection optical density is measured as a function of dot area coverage with screen size as a parameter. As screen size increases so does the slope of the optical density curve along with an attendant increase in the size of the saturation region and location of the threshold point. The linear region extends from 10% to 90% tints up to an 81 line screen. A semi-empirical model is used to curve fit the density curves with good results. Auxiliary experiments are discussed involving latent image voltage scans and images produced using only the optics section of the EP printer to give a better understanding of EP process effects.
RCA has developed a High Resolution Laser Beam Recorder (HRLBR) image generator for tactical operation. This ruggedized film recorder uses 9.5 " film and is designed for tactical shelters. It contains an in-line processor for dry silver film operation providing non-chemical, almost immediate output usable imagery. It also has a take-up cassette for wet film off-line processing operation. The first application was for 8000 picture elements per scan but can be conveniently scaled to handle 20,000 picture elements per scan. The image data input is computer compatible with many extra control and computer interface setup characteristics. An additional unique characteristic is the ability to directly record raster format image data on film at any angle between +45° from normal to provide for scene orthogonalization. This HRLBR has application to many tactical/reconnaissance sensors. Its features and characteristics will be reviewed.
The configuration of several different film recorder architectures is discussed with a review of attributes and applications for each. The use of Internal Drum Film Recorder Architecture in three specific areas, Remote Sensing, Printed Circuit Board Photoplotting, and Graphic Arts, is described in detail with specifications and key functional requirements of actual machines. It is shown that installation of a film recorder often requires substantial system design and integration activity to be successful.