Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
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
Light-emitting element, light-emitting device, and electronic device
Method for spore detection
Polymorphic forms of 3-(1-{3-[5-(1-methyl-piperidin-4-ylmethoxy)-pyrimidin-2-yl]-benzyl}-6-oxo- -1,6-dihydro-pyridazin-3-yl)-benzonitrile hydrochloride salt and processes of manufacturing t
Bicycle shifting method
Fuel cell and a method of manufacturing a fuel cell
Semiconductor device having a triple gate transistor and method for manufacturing the same
Integrated touch screen
  Randomly Featured Patents
Separation of mesitylene from 4-ethyl toluene by azeotropic distillation
Bourdon tube pressure gauge having a removable cover
Method and structure for reducing contact aspect ratios
DNA sequencing
Suspension system for a truck cab
Backstop construction for a stacking machine
Railway axle bearing and sealing assembly with integrated rotational speed detector
Short duration PTC resistor timer
Methods and apparatus for network congestion control
Fuel dewatering additives