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
Method and system for phase-sensitive magnetic resonance imaging
Method for testing multi-chip stacked packages
Modular utility rack
Printing device, printing system, program, and printing method for printing based on print data from a user authorized to issue a print instruction for the print data
Resuming piecewise calibration of a real-time-clock unit after a measured offset that begins at the next calibration period
Treatment of diabetes with milk protein hydrolysate
Live-attenuated compositions for bacterial infections
  Randomly Featured Patents
Low No.sub.x integrated boiler-burner cogeneration apparatus
Integrated docking station
Corner unit for a picture frame
Work light apparatus
Material thickness control over retro-reflective marker
Variable ratio transmission
Breathable fabric lamination
Vehicle wheel
Noise reduction in companding arrangements
Systems and methods for assessing the compliance of a computer across a network