Method and apparatus for determining physical characteristics of objects and object surfaces

Apparatus for determining physical characteristics of a surface comprising

• means for directing electromagnetic radiation onto selected portions of the surface;
• means for receiving radiation reflected from said surface;
• means for producing an electrical signal representative of the radiation reflected from a said selected surface portion;
• means for providing said signals representative of a plurality of surface portions simultaneously at an output thereof;
• electronic averaging means for providing an averaged signal representive of an average of at least the produced signals representive of the radiation reflected from a second and a third selected surface portion;
• said second and third selected surface being spaced apart and proximate to a first selected surface portion;
• means coupled to said averaging means for comparing the produced signal representive of the radiation reflected from the first selected surface portion with said averaged signal;
• means for determining a physical characteristic of the surface based on said comparisons;
• and
• control means including a clock for periodically, selectively sampling said signal producing means and for controlling a surface determination being made by said determining means.

Apparatus for determining a physical characteristic of a surface comprising:

• means for directing electromagnetic radiation onto a surface;
• means for imaging radiation reflected from selected portions of said surface onto an electromagnetic radiation detector, said selected surface portions comprising a first portion and two further portions, said further portions being located on either side of and proximate to said first portion, said detector deriving a time varying electrical signal representing said first and said two further portions spaced in time with each other;
• means for summing the electrical signals from both further portions to thereby provide an average thereof;
• means for comparing the electrical average signal with the electrical signal from said first portion;
• and
• means for determining a physical characteristic of said surface based on said comparison.

Apparatus for determining the physical characteristics of a surface based on the receipt of reflected radiation therefrom by an array of transducer cells which can be serially scanned and each of which produces a signal representative of the radiation reflected from a portion of the surface and incident thereon, said apparatus comprising:

• a serial-in, parallel-out delay means comprised of a plurality of delay stages for receiving the array signals in a serial manner, for storing the array signal from a group of proximate transducer cells in corresponding ones of said delay stages and serially transferring said stored signals among said delay stages thereby changing the group of stored signals, and for producing an output of each said group of array signals at a parallel output;
• averaging means coupled to said parallel output for producing an average of at least some of each said group of stored signals;
• comparator means for comparing said averaged signal with a signal from the output of a central delay stage and for producing an output comparison signal indicative of said comparison;
• control means including a clock connected to and for controlling the periodic, selective sampling of the transducer cells in a serial manner and controlling said transferring of said stored signals between said delay stages such that said comparator means under the direction of said control means makes a comparison for each group of stored signals;
• and
• means for determining a physical characteristic of the surface based on said outputs of said comparator means.

Apparatus for determining physical characteristics of a surface comprising:

• means for directing electromagnetic radiation onto selected portions of the surface;
• means for receiving radiation reflected from said surface;
• means for producing an electrical signal representative of the radiation reflected from a said selected surface portion;
• means for providing said signals representative of a plurality of surface portions simultaneously at an output thereof;
• first averaging means for providing an averaged signal represented of an average of at least the produced signals representive of the radiation reflected from a second and third selected surface portion, said second and third selected surface portions being spaced apart and proximate to a first selected surface portion;
• means coupled to said first averaging means for comparing the first selected surface portion with said averaged signal;
• means for determining a physical characteristic of the surface based on said comparisons;
• control means including a lock for periodically selectively sampling said signal producing means and for controlling a surface determination being made by said determining means;
• and
• averaging means comprising two electronic averaging means for providing two signals one such signal somewhat greater in amplitude, the other such signal somewhat lower in amplitude, than said representative average signal.

Apparatus for determining physical characteristics of a surface comprising

• means for directing electromagnetic radiation onto selected portions of the surface;
• means for receiving radiation reflected from said surface;
• means for producing an electrical signal representative of the radiation reflected from a said selected surface portion;
• means for providing said signals representative of a plurality of surface portions simultaneously at an output thereof;
• first averaging means for providing an averaged signal represented of an average of at least the produced signals representive of the radiation reflected from a second and a third selected surface portion, said second and third selected surface portions being spaced apart and proximate to a first selected surface portion;
• means coupled to said first averaging means for comparing the first selected surface portion with said averaged signal;
• means for determining a physical characteristic of the surface based on said comparisons;
• control means including a clock for periodically selectively sampling said signal producing means and for controlling a surface determination being made by said determining means;
• and
• second averaging means comprising two electronic averaging means for providing two signals, one such signal somewhat greater in amplitude, the other such signal somewhat lower in amplitude, than said averaged signal provided by said first averaging means;
• and wherein said comparing means includes means for producing a digital output signal that is coupled to said determining means, and said determining means comprises an evaluation circuit that includes a counter which receives said digital output signal and a means for comparing the count in said counter with a reference count and providing an output signal indicative of said comparison.