josh@polaris.UUCP (Josh Knight) (11/23/85)
%A T.H. Williams
%T Design and Implementation of the SELECTRIC* System/2000
%J IBM J R&D
%V 29
%N 5
%P 443-448
%D SEP 1985
%X The paper presents an overview of the papers in this issue of the IBM
Journal of Research and Development covering the design and implementation of
the SELECTRIC* System/2000 Typewriter/Printer products. The SELECTRIC*
System/2000 products comprise a nonimpact typewriter and printer, two impact
typewriters, and an impact printer which use printwheel technology. The
development approach for the SELECTRIC* System/2000 products, which included
design for automation, introduction of new technologies, and product
development concurrent with manufacturing, was accomplished by the use of
common architecture, hardware, and software. (* SELECTRIC is a registered
trademark of IBM)
%A Keith S. Pennington
%A Walter Crooks
%T Resistive Ribbon Thermal Transfer Printing: A Historical Review and
Introduction to a New Printing Technology
%J IBM J R&D
%V 29
%N 5
%P 449-458
%D SEP 1985
%X This paper describes a new high-quality thermal transfer printing process in
which a printhead consisting of a linear array of small-diameter electrodes
produces highly localized Joule heating of a resistive thermal transfer
printing ribbon. The heat generated in the resistive ribbon results in the
melting of a thermoplastic ink which is then transferred to a printable
medium, such as paper, by contact. The origins of the technology in IBM are
discussed, together with a description of the resistive ribbon materials and
structure, the printhead, and some experimental printer performance values.
%A S. Applegate
%A J. Bartlett
%A A. Bohnhoff
%A A. Campbell
%A J. Molloy
%T Implementation of the Resistive Ribbon Technology in a Printer and
Correcting Typewriter
%J IBM J R&D
%V 29
%N 5
%P 459-469
%D SEP 1985
%X This paper describes key technology implementation details and performance
characteristics of a printer and typewriter using the resistive ribbon
technology. The work describes the first commercial application of this print
and correction technology. Key parameters necessary for proper system function
such as current, various forces, velocities, and component integration are
discussed. The rationales behind various compromises and problem solutions
are given. A discussion of the characteristics of the print produced, along
with application strengths and weaknesses, completes the paper.
%A T.G. Twardeck
%T Characterization of a Resistive Ribbon Thermal Transfer Printing Process
%J IBM J R&D
%V 29
%N 5
%P 470-477
%D SEP 1985
%X Resistive ribbon thermal transfer printers transfer ink from a ribbon to
paper as the result of localized Joule heating of the ribbon structure. For
this printing process, this paper discusses the voltage-versus-current response
of the electrode-ribbon current path, the temperature distributions throughout
the ribbon structure, and the correlation of print response with electrical
input power and average ribbon temperatures. Nominal input power per electrode
is approximately 190 mW. For input power near this level, thermal models
predict that ribbon materials which pass directly under energized electrodes
reach the highest temperatures; the hottest zone in the ribbon surrounds the
composite-aluminum interface. Approximately 0.1 mm downstream from the
electrodes, the heated ribbon materials come to nearly constant temperature.
The area of printed image correlates with this average ribbon temperature and
input power.
%A S.F. DeFosse
%A G.T. Williams
%A D.A. Gostomski, Jr.
%A R.H. Cobb
%T Development of a Membrane Switch-type Full-travel Tactile Keyboard
%J IBM J R&D
%V 29
%N 5
%P 478-487
%D SEP 1985
%X This paper describes the approaches to design and the rationale that
successfully satisfied the requirements for a full-travel keyboard with usage
exceeding 10 million actuations per character, satisfactory N-key roll-over,
and phantom key control. Emphasis was placed on technical understanding of the
effects of all material and design decisions. Interactions among design,
material, and processing variables were revealed through statistical parameter
modeling and environmental exposure studies. This knowledge facilitated the
control of critical parameters to permit an order-of-magnitude reduction of
actuation forces and tolerances. Product reliability was achieved through
evaluation, environmental protection features, and stringent process controls.
This paper highlights the design, materials, and processing aspects of the
membrane switch developed for low-force keyboard applications. It also
discusses effects of environmental factors on the individual components and
overall system function.
%A R.D. Mayo
%T System Control for a Printwheel Typewriter
%J IBM J R&D
%V 29
%N 5
%P 488-493
%D SEP 1985
%X This paper presents the design goals and architecture of the IBM
WHEELWRITER* typewriters. Some of the development efforts and resulting
technical innovations, such as a unique print hammer design which minimizes
sensitivities to current variations, are discussed. Included is a discussion
of a variable-reluctance stepper motor driver that has selectable damping. A
novel scheme for initializing the printwheel and escapement motors is given;
this includes sensing the font weight. The electronic architecture of the
typewriter and the design of a simplified algorithm to handle the many
different keyboards that can be attached to the machine with a minimum amount
of data storage are explained. (* WHEELWRITER is a registered trademark of IBM)
%A A. Bohnhoff
%A D. Croley
%A S. Dyer
%A T. Greem
%A R. Maddox
%A L. Struttmann
%T System Controls for a Resistive Ribbon Printer
%J IBM J R&D
%V 29
%N 5
%P 494-508
%D SEP 1985
%X The system controls for a printer using the resistive ribbon print
technology involve conventional requirements, such as moving the print
mechanism relative to the paper, with a new requirement, controlling the
electrical energy to the ribbon, an electrothermal component. Other special
requirements are dictated by using the same ribbon for hard copy print/erase
while ensuring that the print and erase operations are acceptable to the user.
This paper discusses the design and performance of the system controls for a
resistive ribbon printer that was developed for use in an interactive
typewriter application and as an output printer for a personal computer.
%A T.C. Chieu
%A O. Sahni
%T Ink Temperatures in Resistive Ribbon Thermal Transfer Printing
%J IBM J R&D
%V 29
%N 5
%P 509-518
%D SEP 1985
%X A knowledge of ink temperatures is important in thermal transfer printing
technologies. This paper reports on an experimental technique which uses an
infrared radiometric microscope to measure the temperature of ink deposited by
the resistive ribbon process on transparent substrates. A detailed examination
has been made of the spatial and temporal profiles of ink temperatures as a
function of input current, printing speed, substrate materials, and a number of
active electrodes. The results on a Kapton* substrate permit estimation of the
ink temperatures reached during printing on paper. The peak ink temperatures
are observed to depend linearly on input current and inversely on an
approximately linear function of writing speed from 2 to 8 inches per second.
Based on a phenomenological model, these results lead to a functional
relationship among speed, print current, and ink temperature during printing.
The model permits projections to be made of the current required over a wide
range of printing speeds. (* Kapton is a registered trademark of E.I. du Pont
de Numours and Co. Inc.)
%A K.K. Shih
%A D.B. Dove
%T Electrical Properties of Resistive Ribbon
%J IBM J R&D
%V 29
%N 5
%P 519-526
%D SEP 1985
%X In resistive ribbon thermal transfer printing, a printhead consisting of
an array of electrodes passes current into a thin ribbon to generate heat for
transferring ink to paper. The ribbon is made of a polymeric material
containing carbon black so as to be conducting, and has aluminum deposited on
one side of the ribbon for a base contact. In this paper, the electrical
conduction processes within the ribbon are discussed. Current-voltage
measurements have been made with electrodes of various types in order to
separate effects due to contact resistance, aluminum/resistive ribbon
interfacial resistance, and bulk conduction in the resistive ribbon.
Measurements have been made over a range of frequency and temperature to
determine the basic conduction mechanisms. A model of conduction is presented
that is in qualitative agreement with the data.
%A Robert A. Laff
%A Claus D. Makowka
%T Thermal Behavior of Resistive Ribbon for Single-stylus Excitation
%J IBM J R&D
%V 29
%N 5
%P 527-537
%D SEP 1985
%X This paper provides a quantitative description of the heating and cooling
behavior of the resistive ribbon used in resistive ribbon thermal transfer
printing. Since the focus is upon the ribbon, this description has been
facilitated by substituting a single, tapered tungsten stylus as a model for a
single printhead element. The experiment used an infrared spot pyrometer to
measure ribbon surface temperatures downstream from the stylus while a laminate
of ribbon and paper was subjected to current pulses. Measured cooling rates
under steady-state excitation at different velocities showed a behavior
consistent with two simple analytic models which describe heat loss into the
stylus during heating and two-dimensional diffusion into a half-plane during
cooling. A detailed, time-dependent computer simulation using finite-element
methods was used to provide a more detailed description of the process by
taking into account the local geometry of the heat input distribution and the
layered nature of the ribbon-paper laminate. The resulting three-dimensional
temperature distributions are given for the steady-state case.
--
Josh Knight, IBM T.J. Watson Research
josh at YKTVMH on BITNET, josh.yktvmh@ibm-sj on CSnet,
...!philabs!polaris!josh