Autofocus

 

Definition

 An Autofocus (or AF) optical system uses a sensor, a control system and a motor to focus fully automatic or on a manually selected point or area. An electronic rangefinder has a display instead of the motor; the adjustment of the optical system has to be done manually until indication.[wiki]

Focus the out coming light beam of lens on none- Smooth panel

Motivation

A lenses runs independently   and could move in left right (x & y) direction, N of them lined from the left to right side.

 

 

 

 The lens not allowed moving in UP-DOWN direction, the out coming light focused on the surface of panel. The panel does not allowed to move in left-right direction but in up-down direction

 

 

 

 

 Calculation the distance from the point A (the lens) to Point B (surface of panel), the point B is variable, so the distance to any point of panel might be changeable according to where the target point is located.

The figure below show that,

In analytic geometry, the distance between two points of the xy-plane can be found using the distance formula. The distance between A (a1, a2) to t (x_i, y_i) is given by:

 

 

 We can use the laser distance finder to find out how far apart they are. 

 

 

 

 

 

 

 

 

 

 

To be continue ..... 

 

 

 Ammar