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
Inspection systems and methods for detecting defects on extreme ultraviolet mask blanks
Method of adenoviral vector synthesis
Image forming apparatus with enhanced display of guidance information
Probe for ultrasound diagnostic apparatus
Field of view matching in a visual prosthesis
Prioritizing application data for transmission in a wireless user device
  Randomly Featured Patents
Apparatus and method for detecting malicious process
Method of producing dopant material for iron or nickel-base alloys
Cathode ray tube including an electron gun with specific main lens section
Soybean variety D5624041
Diverter system test tool and method
Silicon nitride sintered material and process for production thereof
Ultrasonic oscillating device with a detachable ultrasonic oscillating assembly
High frequency DC to AC inverter