Testing light transmitting articles

Claim 3

A method as in claim 1, wherein said calculating spacial deviations step further includes the steps of: providing information indicative of an image of said two dimensional pattern viewed without said article to be tested; and comparing said signal representative of an image viewed through said article to be tested with said information indicative of said image without said article to be tested.

Claim 4

A method as in claim 1, wherein said calculating spacial deviations step further includes the steps of comparing different portions of said image viewed through said article to be tested with each other in order to derive said spacial deviations.

Claim 5

Apparatus for testing the optical quality of a light transmitting article, comprising: means for presenting a two-dimensional target pattern; image sensor means positioned for viewing said pattern; support means for supporting said article between said pattern presenting means and said image sensor means; digitizer means, connected to said image sensor means, for forming a series of digital signals representative of respective pixels of the image received by the image sensor means; frame storing means, connected to the digitizer means, for storing said digital signal; computer means, connected to the frame storing means, for processing said signals to calculate a spacial deviation of predetermined features of the pattern due to the presence of said article; and indicating means for producing an indication of defects in said optical quality proportional to the magnitude of said spatial deviations.

Claim 6

Apparatus for testing the optical quality of a light transmitting article, comprising: means for presenting a two-dimensional target pattern; image sensor means positioned for viewing said pattern; support means for supporting said article between said pattern presenting means and said image sensor means; digitizer means, connected to said image sensor means, for forming a series of digital signals representative of respective pixels of the image received by the image sensor means; frame storing means, connected to the digitizer means, for storing said digital signal; computer means, connected to the frame storing means, for processing said signals to calculate a spacial deviation of predetermined features of the pattern due to the presence of said article; and indicating means for producing an indication of defects in said optical quality proportional to the magnitude of said spatial deviations.

Claim 7

Apparatus according to claim 2, wherein said computer means includes means for image subtracting an undistorted image and the distorted image to produce an indication indicative of said distortion.

Claim 8

A system according to claim 5, in which the distorted image is used to derive geometrical relationships between different portions thereof, said geometrical relationships being then applied to the distorted image by one of comparing said geometric relationships with prestored relationships, and polynomial equation fits and their correlations.

Claim 9

A system according to claim 5, in which said computer means is also for generating a displayed image containing display elements corresponding to parts of the image for which said deviation has a small value, and means for causing a brightness of said display elements to vary dependent on a distortion of the corresponding parts of said pattern.

Claim 10

A system according to claim 7, in which the display elements are displayed in colour.

Claim 11

An apparatus as in claim 4, wherein said computer means calculates said spacial deviation by providing a prestored signal indicative of said target pattern viewed without said article, and comparing said prestored digital signal with said digital signal produced by said digitizer means.

Claim 12

An apparatus as in claim 4, wherein said computer means calculates said spacial deviation by comparing portions of said digital signal indicative of different portions of said image with one another.

Claim 15

Apparatus for testing the optical quality of a transparent article, the apparatus comprising: an area imaging device for forming a video signal indicative of an optical image viewed by the device via said article; computer means for checking said video signal against parameters indicative of the view which would be seen by the device if the article were not present; and output means for providing an indication of discrepancies between the video signal and said parameters proportional to a magnitude of said discrepancies.

Claim 16

Apparatus for testing the optical quality of a transparent article, the apparatus comprising: an area imaging device for forming a video signal indicative of an optical image viewed by the device via said article; computer means for checking said video signal against parameters indicative of the view which would be seen by the device if the article were not present; and output means for providing an indication of discrepancies between the video signal and said parameters proportional to a magnitude of said discrepancies.