I am looking for a reference design for a laser range estimator. I actually don't want to measure the absolute distance but the relative position of the object that is interest. i.e. if it is getting closer or not.
The range of the object is between 50 to 20 cm and object has a movement of a few millimeters and i like to measure this movement using laser. Ultrasound is not an option due to the speed of the object.
Any ideas or pointers?