Patent ID: 6621600
Filing Date: 2003-09-16
Classification: H04N

Abstract:
An optical image scanner comprising:a lens system; an iris within the lens system, the iris having at least a first aperture size and a second aperture size, the second aperture size being larger than the first aperture size; the iris further comprising: an annular electrochromic material, having an inner diameter equal to the first aperture size and an outer diameter equal to the second aperture size, and the electrochromic material capable of being electronically switched between a first state and a second state, where when the electrochromic material is in the first state the electrochromic material transmits more light than when the electrochromic material is in the second state; and the iris set to the first aperture size when scanning at a first speed and the iris set to the second aperture size when scanning at a second speed, the second speed faster than the first speed.