Renishaw Plc

Letraset Corporation

Letraset International Limited

Brian J Smith

David N Batchelder

Chunwei Cheng

Geoffrey R Taylor

Raymond J Chaney

Kurt J Baldwin

Martin E Dowzall

Ronald B Collins

Andrew Woolfrey

Thomas Thurston

Ian Bell

Julie Green

A sample placed under a microscope is illuminated by light from a laser beam. Raman scattered light is passed back via a dichroic filter to various optical components which analyse the Raman spectrum, and thence to a CCD detector. The optical components for analysing the Raman spectrum include tunable dielectric filters in a filter wheel; a Fabry-Perot etalon; and a diffraction grating. These various components may be swapped into the optical path as desired, for example using movable mirrors, enabling the apparatus to be used very flexibly for a variety of different analysis procedures. Various novel analysis methods are also described.

Spectroscopic apparatus and methods

A diffraction grating receives a laser beam from a semiconductor laser diode. Light is diffracted in a first order of diffraction of the grating, through an aperture which selects a desired wavelength, free from side modes of the laser diode. A minor proportion of the light is reflected back by a glass window, and is fed back into the laser diode to stabilise it, preventing mode hopping. The majority of the light of the desired wavelength passes through the window to an output. Because the output light is both free from side modes and not subject to mode hopping, it is suitable for use as the exciting light in spectroscopy, including Raman spectroscopy.

Laser diode system for Raman spectroscopy

Spectrum splitting spectroscopic apparatus

Raman analysis apparatus

A method of making a sign is described which comprises taking a transfer material and a temporary support sheet, the transfer material comprising a transparent or translucent carrier sheet bearing on one side a plurality of transferable indicia, which are either sufficiently adhesive as such to enable their transfer to the support sheet or which bear a layer of adhesive on their face remote from the carrier sheet, or which are non adhesive but transferable by virtue of a coating of adhesive on the temporary support sheet, the adhesive if present being adapted to adhere the indicia to the temporary support sheet more strongly than they adhere to the carrier sheet, and wherein the material of the indicia is adhesive under the application of heat and pressure, transferring indicia from the transfer material to the temporary support sheet in the desired order to build up the desired legend for the sign, and applying the transferred indicia under heat and pressure to the surface of a transparent or translucent sheet, e.g. of acrylic plastics, to form the sign. After such transfer the indicia may be overcoated, e.g. with a contrasting color background. The legend is read through the transparent or translucent sheet which protects it against abrasion or other damage.

Manufacture of signs

Transfer materials are described which are of particular value in sign making applications. The materials consist of a carrier sheet, indicia thereon, usually formed by printing from a printing ink composition and adhesive over the indicia. The dry transfer material may be used in the usual way to assemble a desired legend on a temporary carrier sheet using the pulling power of the adhesive optionally assisted by the 'stretch release' technique if the carrier sheet and indicia are appropriately formulated. According to the invention, the indicia are formulated so that following their transfer to build up the desired legend, they may be adhered under the action of heat and pressure without plastic deformation to the surface of a transparent or translucent rigid sign sheet made of polymethylmethacrylate, polyvinylchloride or cellulose triacetate.

Transfer materials

Growing community of inventors

London, United Kingdom

Brian J Smith