Abstract: The present invention relates to a method and apparatus used for the reduction of laser speckle, and in particular, though not limited to, the projection of images. The method of reducing or supressing speckle of a divergent light beam from a light source includes directing an incoming divergent light beam at an optical element, the optical element having an entry face, a first pair of reflective surfaces and a second pair of reflective surfaces and an exit face, each pair of reflective surfaces having reflective surfaces positioned orthogonal to one another the distance between the first and second pair of reflective surfaces is D > Cl 2 ? n where D is the distance between the prism roof edges, Cl is the coherence length of the laser and n is the refractive index of the optical material or prism.

Abstract: The present invention relates to an image projection device having a linear array of LED's in a common substrate, a common lens group to collimate light from each LED, and a single dichroic wedge having dichroic coatings for reflecting each light source to a condensing means which condenses the light to a distal surface. The image projection device therefore provides for a smaller optical package which is more easily accommodated in mobile devices such as mobile telephones, and which is simple and cheap to manufacture.