Resources Contact Us Home
Compact zoom lens system

Image Number 5 for United States Patent #5412508.

A zoom lens system consists of five lens elements arranged in two groups. Counting from the object side, the first three elements form a front lens group with positive refracting power and the last two elements form a rear lens group with negative refracting power. An airspace is reserved between the front lens group and the rear lens group and it is made variable for zooming. The first lens element in the front lens group is a negative meniscus lens element having its concave lens surface directed toward the object side. Both the second and third lenses in the front lens group are positive lens element. The fourth lens in the rear lens group is positive meniscus lens element, and the fifth lens is a lens element with negative refracting power. In the lens composition, both the front lens group and the rear lens group at least include an aspherical surface respectively.

  Recently Added Patents
Difference detecting apparatus, difference output apparatus, and medium
Maize variety hybrid X03A157
Aisle barrier
Hybrid interconnect scheme including aluminum metal line in low-k dielectric
Heterocyclic compounds as CCR2B antagonists
Voltage regulator structure that is operationally stable for both low and high capacitive loads
Video-recording reservation management apparatus, method, program, and system
  Randomly Featured Patents
Scoop coater
System and method for involving users in object management
Apparatus and bit-shift method for eliminating interference of cross polarization
Synchronization for cylic redundancy check based, broadband communications network
Handle for cooking utensil
Baton for police
Scope-based breakpoint selection and operation
Methods and apparatus for determining wellbore parameters
Fluidic optical devices
Stable, base serum compositions and preparation thereof