Method and means for producing multidensity tint screens

Claim 2

The process for producing tint screens having areas of different shading density from a single master tint screen of uniform density using point sources of light and comprising the steps of: a. covering an area of unexposed film with a master tint screen; b. masking all but that portion of the master tint screen which overlies certain portions of the film to be shaded; c. exposing said certain portions of the film through said master tint screen to a point source of light while producing relative motion between the source and film that is circular and of one diameter in a plane parallel to the film; d. masking all but that portion of the master tint screen which overlies portions of the film to be shaded to a different density; e. exposing said other portions of the film through said master tint screen to a point source of light while producing relative motion between the source and film that is circular and of a second diameter in said plane parallel to the film; f. developing the film so exposed; and g. in which said film is exposed simultaneously to a plurality of point sources of light all moving relatively to the film on the same diameter and in the same plane.

Claim 3

Apparatus for making multiple density tint screens comprising in combination, film-holding means for holding an unexposed film in a plane, a light source spaced from said film-holding means comprising a point source rotatable in a circle parallel to said first-mentioned plane and overlying said film-holding means, means for rotating said point source in its circle, and a uniformly shaded master tint screen interposed between said film holding means and said light source and adapted to lie flat against a film held in said film holding means; in which said light source comprises a plurality of point light sources each equidistant from the center of said circle and each rotatable in said circle.

Claim 4

Apparatus for making multiple density tint screens comprising in combination, film-holding means for holding an unexposed film in a plane, a light source spacEd from said film-holding means comprising a point source rotatable in a circle parallel to said first mentioned plane and overlying said film-holding means, means for rotating said point source in its circle, and a uniformly shaded master tint screen interposed between said film-holding means and said light source and adapted to lie flat against a film held in said film holding means; in which said light source comprises a plurality of point sources each rotatable in a circle having different diameter and lying parallel to said film-holding means and all rotatable about a common axis, and means for illuminating selected ones of said point sources.

Claim 5

Apparatus for making multiple density tint screens comprising in combination, film-holding means for holding an unexposed film in a plane a light source spaced from said film-holding means comprising a point source rotatable in a circle parallel to said first-mentioned plane and overlying said film-holding means, means for rotating said point source in its circle, and a uniformly shaded master tint screen interposed between said film-holding means and said light source and adapted to lie flat against a film held in said film-holding means; in which said light source comprises an assembly rotatable about an axis substantially normal to the central portion of said film-holding means, a plurality of point sources of light carried by said assembly each disposed at a different radial distance from said axis, and means for illuminating said point sources selectively, the difference between successive ones of the radial distances decreasing with radial distance.

Claim 6

The invention defined in claim 6 in which said light source comprises a plurality of point light sources at each of said radial distances and the point sources at equal radial distance being disposed on different radial lines eminating from said axis.