Patent ID: 6542301
Filing Date: 2003-04-01
Classification: G02B

Abstract:
A zoom lens consisting of three lens units, said three lens units being a first unit having a negative refracting power, a second unit having a positive refracting power, and a third unit having a positive refracting power in the stated order from the side of an original surface, in which zooming is effected by changing an air space between the first unit and the second unit and an air space between the second unit and the third unit,wherein said three lens units move on the optical axis during zooming and said second unit has a diffractive optical element, and wherein, in order from the side of the original surface, said first unit has three lenses, said three lenses being a negative lens, a negative lens, and a positive lens, said second unit has five lenses, said five lenses being a positive lens, a positive lens, a negative lens, a negative lens, and a positive lens, and said third unit has two lenses, said two lenses being a positive lens and a negative lens.