Membrane Keyboards Research Articles

Mechanical and Membrane Keyboard Typing Assessment Using Surface Electromyography (sEMG)

There are many different types of keyboards available for use. However, the mechanical keyboard is becoming more popular with enthusiast computer users. Vendors and users alike proclaim that they provide increased typing speeds and that less physical effort is required to activate the keyswitches due to the additional tactile and auditory feedback from the keyswitch design. This study investigates words per minute (WPM), error percentage, and surface electromyography (EMG) of the flexor arm muscle activity during a typing task using a membrane and mechanical keyboard. Results showed statistical significance with both flexor muscles exerting less effort on a mechanical keyboard. Advantages were not limited the mechanical keyboard with WPM revealing greater typing speeds with the standard membrane keyboard.

Modelling and Simulation of High Fidelity CDU for Flight Simulator Based on Object-Oriented and Hardware-in-Loop Technique

A high fidelity, reliable and extensible real-time CDU simulation system is built on the basis of self-made membrane keyboard and object-oriented simulation method in this paper to improve the visual feelings and simulation fidelity of CDU in flight management system research. Based on embedded PC104 CPU and 8255 programmable peripheral equipment interface card, the membrane keyboard hardware circuit and the keyboard code scanning program are designed. Accordingly, the confused logical problem of keystokes is solved and meanwhile, the emulation CDU keyboard is realized. And then, an extensible and reliable CDU pages system is constructed utilizing object-oriented simulation technique, inheritance and polymorphism mechanisms. Thus, the tiresome generation and management problem of pages system is tackled. Simulation experiments illustrate that routing data and performance parameters can be input and displayed realistically on the CDU system developed in this paper.

Fabrication of Molded Interconnection Devices by Ultrasonic Hot Embossing on Thin Polymer Films

Ultrasonic hot embossing allows fabrication of metal patterns onto a polymer film with a low cost and rapid process. A polymer layer with a thin metal film on top is welded onto the polymer substrate where there are protruding micro structures on the tool. Edges around the protruding structures cut the metal layer and ensure electrical insulation. The entire process performs in a few seconds. The non-welded areas are mechanically removed after this process. An antenna of a radio frequency identification device (RFID) and a flexible membrane keyboard were fabricated by embossing 10- mum-thick conductive paths from an aluminum foil onto polypropylene films, 150 and 250 mum in thickness. Antenna circuits have been proven to show the expected resonance frequencies and the keyboard was successfully employed as an input device for a PC.

Using Conductive Thermal Transfer Ribbons for Printed Electronics

Thermal transfer printing is noted for its ability to produce a uniform line, and it is used extensively for high reliability bar coding around the world. Thermal transfer is capable of printing on a wide variety of flexible substrates including paper, film, fabric, etc. These characteristics make thermal transfer ideal for printed electronics.IIMAK has developed conductive ribbons based on metal nano-particles (silver, silver / copper composites) and on vapor deposited metals (aluminum, copper) that provide the potential to print flexible circuits, membrane key boards, RFID antennas, etc. on a number of substrates (paper, vinyl, polypropylene, polycarbonate, polyimide, etc.). Dielectric ribbons based on insulating polymers are also available and can be used to provide insulating layers between conductive layers. Characteristics of the ribbons, prints and some model applications will be discussed along with the benefits and limitations of thermal transfer.Potential to adapt these ribbons to the closely related technology of laser thermal transfer will also be discussed.

Electrochemical Characterization Of ElectroactivePoly(ani1ine)lEPDM Rubber Blends Obtained Chemically On AgSubstrates For Corrosion Protection.

Sensor devices, such as pressure gauges and membrane keyboards, contain Ag paths built from colloidal serigraphy. One of the steps in the manufacture of such devices is the deposition of graphite carbon to form a protective barrier that prevents the corrosion of the metallic paths. Nonetheless, several shortcomings are associated with such an approach. Corrosion protection requires the use of specialized high-valued materials to prevent even higher maintenance costs later on. The present work will address the possibility to replace graphite carbon coatings by conductive polymers. In this sense. Poly(aniline)iEPDM blends were prepared by casting rubber matrixes containing different oxidant agents and dodecylbenzene sulfonic acid in an organic solution exposed afterwards to aniline vapors to allow chemical polymerization. Secondary doping of the obtained blends was conducted with xylene. The influence of the nature of oxidant and the concentration of conductive polymer on the electroactivity of the blends as surface coatings on Ag were studied by Cyclic Voltammetry, Electrochemical Impedance Spectroscopy and Optic Microscopy.

Static protection method eliminates buffers

Abstract A method is described of using a conductive layer to protect sensitive electronic equipment - particularly the company's membrane keyboards - from static discharge.

Electrostatic Discharge Protection Measures for Membrane Keyboards

The trend to minaturized solid-state electronics has made appliance controls more vulnerable to human electrostatic discharge (ESD). Membrane switches may increase the likelihood of damage, since the inherently thin membranes provide less isolation than traditional full travel switches. In contrast to the manufacturing environment, relatively little attention has been given to ESD protection in service, where conditions of use cannot be controlled and where protection depends on the choice of keyboard materials and design. Electronic components can be damaged or destroyed and digital signals and data altered when ESD penetrates or circumvents keyboard dielectrics or electromagnetically induces transients in interface circuitry. Keyboard protection measures fall into three categories: grounded shielding, dielectric encapsulation, and transient suppression. Specific illustrations of these are cited. ESD simulators are discussed and practical suggestions given on objectives, preparation, and approach to ESD evaluation and testing of membrane keyboards.

Human Factors and Behavioral Science: Membrane Keyboards and Human Performance

This paper describes systematic human factors research in which typing performance using a membrane keyboard and using a conventional, full-travel keyboard were compared for subjects representing different levels of typing proficiency. Membrane switch technology has become increasingly popular in many consumer-oriented products because of its low production cost and design flexibility. However, the absence of familiar key travel associated with membrane switches removes an important, direct source of feedback to the user with respect to specific keystrokes. Hence, the conventional wisdom has been that membrane switches without key travel are unacceptable for such keyboard applications as typing tasks. The results of the research discussed here indicate that for nontouch typists there was little difference in performance between keyboards. For touch typists, performance with the conventional keyboard was initially much better than with the membrane keyboard. Rapid learning resulted in improvement in typing performance with the membrane keyboard — both within an experimental session and across sessions — such that the advantage of the conventional keyboard over the membrane one for touch typists was reduced substantially, although not completely. Future work will be aimed at measurement of the additional improvement in performance that may result from extended practice with better-designed membrane keyboards.

Membrane Keyboards and Human Performance

Membrane switch technology has become increasingly popular in many consumer-oriented products due to its low production cost and design flexibility. However, the absence of familiar key travel associated with membrane switches removes an important, direct source of feedback to the user with respect to specific keystrokes. Hence, the conventional wisdom has been that membrane switches without key travel are unacceptable for keyboard applications such as typing tasks. This paper describes systematic human factors research in which typing performance using a commercially available membrane keyboard and a conventional, full-travel keyboard was compared for subjects representing different levels of typing proficiency. Each subject (N = 21) used a membrane keyboard for 3 consecutive (or nearly consecutive) days and a conventional keyboard for 3 consecutive (or nearly consecutive) days. Each day of experience consisted of a one-hour session in which various typing exercises were completed. Traditional tests of typing performance were administered at the beginning and end of each session. The results indicate that for non-touch typists there was little difference in performance between keyboards. For touch typists performance with the conventional keyboard was initially much better than that with the membrane keyboard. There was, however, rapid learning with the membrane keyboard such that, within a few sessions, the difference in typing performance between the conventional and membrane keyboards was reduced substantially. There remained some advantage for the conventional keyboard, compared with the membrane keyboard evaluated here. Future work will be aimed at measurement of the additional improvement in performance resulting from extended practice with better-designed membrane keyboards.

Interdigit Keying Intervals on a Membrane Keyboard

Fifty-three company personnel were asked to perform several copying tasks using a copier with a flat membrane keyboard. The digit portion of the keyboard was a 3 x 4 keypad. The time it took to key in seven particular two-digit numbers was electronically timed and recorded. The longest keying time was 1.75 s. Age had a reliable effect, though very small. Those over 45 took .1 s longer on average. There was no gender difference in keying times. Various reasons for much longer than average times are discussed. It was also noted that horizontal keying movement seemed faster than vertical movement.