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
Visually tracking an object in real world using 2D appearance and multicue depth estimations
Electronic currency, electronic wallet therefor and electronic payment systems employing them
Data latch circuit and electronic device
Light fitting
Method for indicating the process of leaving a parking space
Pointer display device, pointer display/detection method, pointer display/detection program and information apparatus
Method and apparatus for providing very high throughput operation and capability signaling for wireless communications
  Randomly Featured Patents
Shotgun, fishing rod and golf utility cart
Method of fabricating a fabricating plug and near-zero overlap interconnect line
Method to control a printing process in an inkjet printing apparatus, and printing apparatus to execute such a method
Chip identification scheme
Device for detecting head movement
System and method for real-time blocking of a telephone call
Image information signal transmitting system
Circuitry for recovery of data from certain bit positions of a T1 span
Production of high capacity inorganic crystalline base exchange materials
Stroller with a receiving frame and support straps for receiving a car seat