Abstract Method for no-contact measurement of the relative velocity, position, or displacement path of objects without special optical markers with respect to a reference position in at least one coordinate direction, or of the degree of image quality of an image wherein the apparatus images the object on a grating and the light fluxes leaving this grating are measured by means of photoelectric elements. The output signals of the photoelectric elements exhibit a frequency component proportional to the velocity of travel. The present invention is distinguished from the prior art by having a physical beam splitter (6,13) inserted in the imaging beam path in front of the grating (5,14), and preferably several polarizing beam splitters (7,30-33) with at least respectively one associated photoelectric receiver pair (10,11,16-19 16'-19') are connected after the grating (5,14).
In a method for the no-contact measurement of the relative velocity, position or displacement path of an object with respect to a reference position in at least one coordinate direction, or of the degree of image definition of an image, the improvement comprising the steps of: a. illuminating an object of stochastic structures randomly distributed and without special ruled markings; b. utilizing light fluxes emanating from said object for forming an image of said object in an image plane; c. producing discernible images of said object; d. mounting in said image plane an optical structure of repetitive pattern displaying a specific spatial frequency component to receive said object images and to filter from said image structures a structure component corresponding with said spatial frequency component; e. generating from said filtered light fluxes at least one pair of optical push-pull signals; f. separating said optical push-pull signals in at least two directions; and g. generating from said optical push-pull signals electrical output signals which exhibit a frequency component being proportional to the velocity of travel of said object relative to a fixed reference point.
Claim 2
Dependent Claim
183 words
In a method for the no-contact measurement of the relative velocity, position or displacement path of an object with respect to a reference position in at least one coordinate direction, or of the degree of image definition of an image, the improvement comprising the steps of: a. illuminating an object of stochastic structures randomly distributed and without special ruled markings; b. utilizing light fluxes emanating from said object for forming an image of said object in an image plane; c. producing discernible images of said object; d. mounting in said image plane an optical structure of repetitive pattern displaying a specific spatial frequency component to receive said object images and to filter from said image structures a structure component corresponding with said spatial frequency component; e. generating from said filtered light fluxes at least one pair of optical push-pull signals; f. separating said optical push-pull signals in at least two directions; and g. generating from said optical push-pull signals electrical output signals which exhibit a frequency component being proportional to the velocity of travel of said object relative to a fixed reference point.
Claim 3
Dependent Claim
23 words
The method of claim 1, further comprising the step of effecting a continuous relative movement between said optical structure and said object images.