Resources Contact Us Home
Zoom lens

Image Number 11 for United States Patent #6646815.

A zoom lens, comprises: three lens groups including a first lens group having a negative refracting power, a second lens group having a positive refracting power and a third lens group having a positive refracting power arranged serially in this order from the object side. The second lens group comprises a positive lens, a cemented lens including a positive lens and a negative lens and one lens arranged serially in this order from the object side. The following conditional expression is satisfied;where f.sub.2 represents a focal length of the second lens group and f.sub.w represents a focal length of the total optical system at a wide-angle end.

  Recently Added Patents
Reframing circuitry with virtual container drop and insert functionality to support circuit emulation protocols
Method and apparatus for receiving signals in a MIMO system with multiple channel encoders
Catalysts for polyurethane coating compounds
Downhole telemetry system
Piezoelectric device and fabricating method thereof
Using interrupted through-silicon-vias in integrated circuits adapted for stacking
Traffic flow analysis mitigation using a cover signal
  Randomly Featured Patents
Snow stop
Optical transmission system and dispersion compensation method for optical transmission system as well as simulation equipments
System and method for secure communication of mode of access information
Helicopter integrated fire and flight control having a pre-launch and post-launch maneuver director
Thermal clearance control method for gas turbine engine
Process for production of fluoroalkane carboxamide derivatives
Process for the electroporation of beet cossettes and device for carrying out this process
Carbon nanotube array for focused field emission
Systems and methods for calibrating inkjet print head nozzles using light transmittance measured through deposited ink
Custom mouthguard