Patent ID: 6555812
Filing Date: 2003-04-29
Classification: G02B,H04N

Abstract:
A method of reducing the level of contamination entering an optical assembly of a scanning device, said method comprising:providing said optical assembly of a scanning device, said optical assembly comprising at least one photodetector, a first portion and a second portion, wherein said first portion is separated from said second portion by a space, and wherein said at least one photodetector is located in said space between said first portion and said second portion; providing a sheath capable of transforming from a first state to a second state wherein the area of said sheath in said first state is greater than the area of said sheath in said second state; encompassing at least one portion of said sheath in a housing; locating said sheath adjacent at least one section of said first portion and at least one section of said second portion; encompassing at least one portion of said space between said first portion and said second portion with said sheath in said first state; and causing said sheath to transform from said first state to said second state.