Patent ID: 6538434
Filing Date: 2003-03-25
Classification: G01B

Abstract:
A thickness-measuring device for films on bases in which the thickness of said film is determined from the magnetic adhesive force of a permanent magnet on said film, the device comprising:a rotary system including a lever arm having front and rear sections, a rotary shaft about which said lever arm rotates and which divides said lever arm into said front and said rear sections and a film contacting permanent magnet secured to said front section of said lever arm; an electromagnet, including a coil attached to said rotary system lever arm rear section for generating a magnetic field, the force of which acts on a magnetic element selected from the group comprised of magnetically soft and magnetically hard elements and which is stationary relative to said rotary system; said force of said magnetic field acts on said rotary system for pulling said permanent magnet away from said film; and means for interpreting, as a function of elapsed time of current application to said electromagnet, the value of the force required for said pulling at the instant of release of said film contacting permanent magnet from said film as a measure of the thickness of said film.