System for determining the nature of optical distortion in glass

Claim 3

The method as set forth in claim 1 wherein said step of scanning to produce a first surface contour profile includes the steps of: directing a beam of light toward the piece of glass to reflect a beam from the first surface and from the second surface through the first surface; providing relative motion between the piece of glass and the beam of light to reflect the beam of light from the first surface along a scan path onto position sensing means; shielding the sensing means from the beam of light reflected from the second surface through the first surface; and observing relative positions of the reflected beam of light on the sensing means caused by surface contours in the first surface.

Claim 4

The method as set forth in claim 2 wherein the relative motion between the piece of glass and the beam of light is at a constant speed and including the steps of: observing relative positions of the reflected beam of light as a function of time; and computing surface flatness of the first surface as a function of position on the article.

Claim 5

The method as set forth in claim 1 wherein the step of determining the optical power profile includes the steps of: transmitting a beam of light through the glass article onto position sensing means; providing relative motion between the glass article and the beam of light; and observing relative position of the beam of light on the position sensing means caused by index of refraction variations and contours in the first and second surface of the piece of glass.

Claim 6

The method as set forth in claim 1 including the steps of: directing a first beam of light toward the first surface of the glass article to reflect a beam of light from the first surface, from the second surface back through the first surface and transmit a beam of light through the piece of glass; reflecting the beam of light from the first surface onto a first position sensing means; shielding the beam of light reflected from the second surface back through the first surface from the first position sensing means; impinging the transmitted beam of light onto a second position sensing means; directing a second beam of light toward the second surface of the piece of glass to reflect a beam of light from the second surface and from the first surface back through the second surface; reflecting the beam of light from the second surface onto a third position sensing means; shielding the beam of light reflected from the first surface back through the second surface from the second and third position sensing means; displacing the glass article relative to the first and second beam of light; anD observing relative position of the reflected beam of light from the first surface on the first position sensing means, caused by surface contours in the first surface, of the transmitted beam of light on the second position sensing means caused by surface contours in the first and second surface and index of refraction variations in the glass, and of the reflected beam of light from the second surface on the third position sensing means caused by surface contours of the second surface.

Claim 7

The method as set forth in claim 5 including the step of: computing a first surface contour profile, a second surface contour profile, and an optical power profile.

Claim 8

The method as set forth in claim 1 wherein said scanning steps are performed simultaneously.

Claim 11

The apparatus as set forth in claim 8 wherein said first determining means includes: means for directing a beam of light onto the first surface; means for imparting relative motion between said directing means and the glass to reflect the beam of light from the first surface; means for observing changes in relative positions of the reflected beam of light from the first surface caused by contours in the first surface.

Claim 12

The apparatus as set forth in claim 8 wherein said third determining means includes: position sensing means; means for directing a beam of light through the glass onto said position sensing means; means for imparting relative motion between said directing means and the glass; and means for observing changes in relative positions of the beam of light transmitted through the glass caused by contours in the first and second surfaces of the glass and by index of refraction variations in the glass.

Claim 13

The apparatus as set forth in claim 8 wherein: said first determining means includes: a first position sensing means; a first means for directing a beam of light toward the piece of glass to reflect a beam of light from the first surface onto said first position sensing means, to reflect a beam of light from the second surface through the first surface of the piece of glass and to transmit a beam of light through the piece of glass; a first means for shielding the beam of light reflected from the second surface through the first surface from said first position sensing means; and means acted on by said first position sensing means to generate a first surface contour profile wherein the first surface contour profile shows optical power contribution of the first surface; said second determining means includes: a second position sensing means; a second means for directing a beam of light toward the piece of glass to reflect a beam of light from the second surface onto said second position sensing means, to reflect a beam of light from the first surface through the second surface of the piece of glass and to transmit a beam of light through the piece of glass onto said first shielding means; second means for shielding the beam of light refLected from the first surface through the second surface from said second position sensing means; and means acted on by said second position sensing means to generate a second surface contour profile wherein the second surface contour profile shows optical power contribution of the second surface; and said third determining means includes: a third position sensing means mounted in the path of the transmitted beam of said first determining means; and means acted on by said third position sensing means for generating a total optical power profile of the glass wherein said total optical power profile shows optical power contribution of the index of refraction variations and contours in the first and second surfaces of the piece of glass.

Claim 14

The apparatus as set forth in claim 11 further including: means for adding the first and second surface contour profile to produce a total surface contour profile in such a manner that the effect of contours in the first and second surface on said first and second position sensing means, respectively, has the similar effect on said third position sensing means; and means for subtracting the total surface contour profile from the total optical power profile to produce a profile showing optical power of the glass due to index of refraction variations.