Photographic exposure masks
AssigneeDurst (U.K.) Limited
InventorJohn G. Long
Life of this patent
Estimating the term…
Abstract
An exposure mask 9 for photographic material 4 includes a measuring wheel 23 and two adjustable mask blades 19 and 20. Movement of the photographic material 4 causes rotation of the wheel 23, which causes a switching member 34 to approach a switch 42. When the switching member 34 reaches the switch 42 it stops the transport of the material 4. Adjustment of one mask blade 20 adjusts the initial distance between the switching member 34 and the switch 42.
Claims6
An exposure mask for photographic material comprising a measuring wheel arranged in use to be caused to rotate by the transport of photographic material past the mask, switching means, a switching member that in use is caused to move towards and operate the switching means in response to the said rotation of the measuring wheel, and at least one adjustable covering member that in use defines an edge extending transversely of the direction of photographic material transport of an aperture through which light can reach the said photographic material, the arrangement being such that adjustment of the position of the said covering member causes an appropriate adjustment of the angle through which in use the measuring wheel must rotate in order that the switching member shall operate the switching means.
Dependencies are inferred from the claim text.