Abstract: A light guide arrangement in which at least two light guides are coupled at one end to an optical integration Chamber for achieving a common field of view from the remote ends of both or all of the light guides even when the end of the optical integration chamber is in contact with a surface being scanned, in which the components of the optical integration chamber, that is a light guiding element, a sheath of optically insulating material, and an outer cladding are held together by a bond which does not involve the use of a bonding material, to attenuate the problems due to wear of the scanning end of the optical integration chamber. The scanning tip of the integration chamber may be drawn to a point during or after the bonding to form a well defined scanning point.

Abstract: A four-element composite prism assembly for splitting an incident beam into three colour components, the first and second pairs of elements being separated by respective air gaps, and colour separation occurring at respective spectrally selective dichroic coatings between the second and third and the third and fourth prism elements respectively, the separated colour components being directed in different directions by total internal reflection at the air gaps. To achieve the optimum separation upper and lower limits are defined in the claims for the apex angles of the three prism elements.