Photoelectric coordinate measuring system

Claim 1

A DEVICE FOR DETERMINING THE RELATIVE COORDINATES OF TWO OR MORE OBJECT POINTS COMPRISING: A UNITARY TRANSPORT PROVIDING AN INSPECTION STATION AND BEING SUPPORTED FOR RECIPROCABLE DISPLACEMENTS GENERALLY IN THE DIRECTIONS OF TWO COORDINATES AXES DISPOSED AT SUBSTANTIALLY RIGHT ANGLES WITH RESPECT TO EACH OTHER; MEANS FOR SELECTIVELY DISPLACING SAID TRANSPORT RELATIVE TO EACH SUCH AXIS; A PAIR OF MEASURING GRATINGS FIXEDLY RELATED TO SAID TRANSPORT AND RESPECTIVELY INCLUDING A PLURALITY OF LONGITUDINALLY EXTENDING APERTURES DEFINING MEASURING GRADUATIONS; SUCH GRADUATIONS OF ONE OF SAID GRATINGS BEING ORIENTED FOR MEASURING DISPLACEMENTS OF SAID TRANSPORT ALONG ONE COORDINATE AXIS AND THE GRADUATIONS OF THE OTHER OF SAID GRATINGS BEING ORIENTED FOR MEASURING DISPLACEMENTS OF SAID TRANSPORT ALONG THE OTHER COORDINATE AXIS; MEANS FOR SUPPORTING AT SAID INSPECTION STATION AN OBJECT HAVING AT LEAST TWO POINTS THE COORDINATES OF WHICH ARE TO BE DETERMINED; MEANS FOR INSPECTING SUCH OBJECT TO POSITION SUCH POINT AT A KNOWN LOCATION BY APPROPRIATE DISPLACEMENT OF SAID TRANSPORT; A PAIR OF TRANSMISSION OPTICAL REFERENCE GRATINGS RESPECTIVELY DISPOSED IN JUXTAPOSITION WITH THE AFORESAID MEARSURING GRATINGS AND EACH INCLUDING A PLURALITY OF LONGITUDINALLY EXTENDING LIGHT-TRANSMITTING APERTURES ORIENTED IN SUBSTANTIALLY PARALLEL RELATION WITH THE APERTURES OF THE ASSOCIATED MEASURING GRATINGS; SAID REFERENCE GRATINGS BEING FIXEDLY LOCATED WHEREBY SAID TRANSPORT AND MEASURING GRATINGS ARE MOVABLE RELATIVE THERETO; AND LIGHT-RESPONSIVE MEANS FOR READING CHANGES IN THE INTENSITY OF THE LIGHT TRANSMITTED THERETO BY EACH ASSOCIATED PAIR OF MEASURING AND REFERENCE GRATINGS AS A CONSEQUENCE OF THE DISPLACEMENT OF SAID TRANSPORT TO ESTABLISH THE POSITION THEREOF WITH ANY OBJECT POINT AT SUCH KNOWN LOCATION AND THEREBY DETERMINE THE COORDINATES OF SUCH POINT; SAID MEASURING GRATINGS BEING SO ORIENTED THAT PROJECTIONS OF THE GRADUATIONS OF ONE OF SAID MEASURING GRATINGS INTERSECT SIMILAR PROJECTIONS OF THE GRADUATIONS OF THE OTHER OF SAID MEASURING GRATINGS AT SUBSTANTIALLY RIGHT ANGLES; AND THE LENGTH AND WIDTH OF EACH OF SAID MEASURING GRATINGS BEING SUFFICIENTLY GREAT TO DEFINE AN AREA AT LEAST AS LARGE AS SAID INSPECTION STATION SO THAT MAXIMUM DISPLACEMENTS IN ALL DIRECTIONS OF MOVEMENT THEREOF IN LOCATING AN OBJECT POINT ARE ACCOMMODATE BY SAID MEASURING GRATINGS.