Aston University

Eyoto Group Limited

Thomas Drew

Karl Obszanski

Jonathan Dean

Omkar Joshi

Jiteen Ahmed

Afzal-Ur-Rahman Mohammed

Suraj Sudera

Michal Krawczynski

Joseph Davies

Eman Dahmash

James S Wolffsohn

Andrew Tulloch

A test pattern () comprising a set of dots () which define a first ellipse () of best fit in which the major and minor axes R, Rare equal (i.e. a circle) is displayed on a plane surface and a digital image of the (usually distorted) test pattern seen through a lens is captured. A second ellipse of best fit joining the dots in the set is derived from the distorted test pattern in the image. Characteristics of the first and second ellipses are compared to determine the degree and nature of distortion to the test pattern, from which the power of the lens is calculated. The major and minor axes of the first and second ellipses may be compared. The test pattern can include a number of said sets of dots distributed over an area of the surface with each set being analysed to determine the optical parameters of the lens at multiple locations.

Lens examination equipment and method

The present invention relates to an apparatus for coating carrier particles with guest particles. The apparatus comprises a cylindrical processing vessel rotatable about its axis and having solid walls defining a chamber for receiving the particles, and a hollow shaft extending within the chamber at least partly along the axis of the cylindrical processing vessel, the hollow shaft defining a gas flow path connected to a gas inlet. The hollow shaft comprises one or more axially-extending slots or one or more axially-extending rows of apertures allowing fluid communication between the gas flow path and the chamber. The apparatus may be used in a process for coating carrier particles with guest particles, the process comprising: adding the particles to the chamber defined by the cylindrical processing vessel; rotating the cylindrical processing vessel about its axis; and flowing gas from the gas inlet along the gas flow path in the hollow shaft and into the chamber through the one or more axially-extending slots or one or more axially-extending rows of apertures.

Coating apparatus and method

Growing community of inventors

Birmingham, United Kingdom

Thomas Drew