Patent ID: 7057804

Claim:
An ultraviolet imaging system comprises at least two negative lens elements, and at least two positive lens elements, wherein said ultraviolet imaging system satisfies the following conditions: −3 <f (i=330) /r 1 <−0.5 65<ν (ALL) 0<ν (i=330) ( P )−ν (i=330) ( N )<10 wherein f (i=330) designates the focal length of the entire ultraviolet imaging system with respect to a wavelength “i” of 330 nm; r 1 designates the radius of curvature of the object-side surface of the most object-side lens element; ν (ALL) designates the Abbe number of the glass material of all of said lens elements; ν (i=330) (P) designates the reciprocal of the dispersion value, for said positive lens elements, with respect to the wavelength of 330 nm; and ν (i=330) (N) designates the reciprocal of the dispersion value, for the negative lens elements, with respect to the wavelength of 330 nm.