The advent of ink-jet technology in the field of three-dimensional printing has paved the way for its use in tactile map production. Tactile maps have raised features that are designed to convey spatial information to visually impaired people through touch. This research investigated the design of tactile ink-jet printers that had to embody printout quality principles to satisfy users' psychophysical preferences, via the manipulation of printout parameters such as: feature elevation, adhesion, texture, shape, contrast and size. Also, droplets coalescence and the control over build-up of three-dimensional micro-structures were investigated to enhance symbol discriminability and tactile map design. Analysis of data from a questionnaire helped formulate the Product Design Specification criteria. Collectively, these research elements culminated in a design methodology for tactile map production using tactile ink-jet printing. Research experiments were facilitated by a drop-on-demand ink-jet testing machine which jetted polymer ink. Tactile map production was enabled through a repetitive print process, depositing ink on the 'substrate and curing it via exposure to Ultraviolet light, resulting in elevated print features. Flexible configuration of the machine enabled the variation and isolation of subsystem parameters such as: Ultraviolet exposure, actuation, substrate types, printhead and ink as well as allowing the simulation of different printer setups. Machine performance data were collected along with data on users' performances and preferences from psychophysical experiments. Devised print algorithms, machine configurations and subsystems analyses established production process principles to yield the required printout quality. Print algorithms achieved three-dimensional profiles that improved adhesion to tested substrates and enhanced users' performance. The relationship between the structure of printed features', the printer's subsystems and users' psychophysical performance called for a two-strand convergent design methodology. While miniaturisation of this technology is possible, until it is more established, bureau-sized printers are best suited to improve the quality and availability of tactile maps.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:490297 |
| Date | January 2007 |
| Creators | Dinar, Snir |
| Publisher | Anglia Ruskin University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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