Manual drives provide a rotatable knurled ring to vary magnification. A second rotatable ring, on some models, permits varying focus.


Detented drives are essentially a manual drive with a positive "click stop" at various positions in the zoom range. These stops may be calibrated and used as a repeatable magnification reference for Metrology, etc.


Motorized

Navitar's motorization design, available on the 12X and Zoom 6000 systems, integrates magnetic Hall-Effect sensors to reference position location. Hall-Effect sensors are solid state devices with no moving parts. The Hall-Effect sensing mechanism utilizes a magnetic field to trigger a pulse in a semiconductor circuit. Compared to photo-electric sensors, the Hall-Effect sensors are not affected by harsh, dirty or dusty environments, ambient room light, or variation in system voltages.

Our motorized zoom lenses include LabView "VI" and Windows user interface. They can be controlled via serial RS-232 or USB. The control system is available as either table top or board level.

Users can choose to motorize the zoom and focus axis, or just the zoom. We have three different motor types available:

• 2 Phase Stepping Motor (Faulhaber)
• 5 Phase Stepping Motor (Oriental, Vexta)
• DC Servo with Encoder (Faulhaber)

The selection of motors depends on other existing motors in the application and physical considerations. The 2 phase and DC Encoded are more compact but the 5 phase has the potential for finer steps. The 2 phase, compared to the 5 phase, also gets warmer with the holding torque. In a "high torque situation", the Encoded feedback guarantees motion, whereas the steppers assume motion based on an input pulse.

A DC motorized version is also available in limited models and operates with a simple mechanical push-button driver.

Motorized versions are available with an optional flat back plate for secure mounting.