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
Flat panel display
Semiconductor memory device and manufacturing method thereof
Tandem electric machine arrangement
Sample holder and method for treating sample material
Method of allocating IP address of image forming apparatus using DHCP, image forming apparatus and system of allocating IP address using DHCP
Center spreader adapter tool for toilet paper rolls and paper towel rolls that do not have inner cardboard tubes
Electronic dispersion compensation within optical communications using reconstruction
  Randomly Featured Patents
Direct injection diesel engine
Latent property diagnosing procedure
Integrated circuit memory devices having data input and output lines extending along the column direction
System and method for active geographic redundancy
Bedding or seating product made with coil springs having unknotted end turns with bumps
Fuel consumption control system for cooking machines
Process for preparing optically active cyclopentenone derivative
Heterodyne laser instantaneous frequency measurement system
Device for turning tubular textile products inside out
Cyclonic furnace