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US 4,097,134 AGranted
Projection device
OwnerHans G. Jerieinventor
Life of this patent
Estimating the term…
Abstract
A projection device provided with at least two different enlarging projection systems for the projection on a screen of a set of at least two slides provided on one carrier, said slides covering the same area of a plan or map, one slide being more detailed than the other. The device projects the first less detailed slide entirely and the second or next, more detailed slide only in part but on a larger scale. The device comprises further a transparent runner indicating on the first slide the part of the next slide that is projected.
Claims8
A projection device comprising:
- a projection screen presenting a surface defining an image projection area;
- means defining a first area to be occupied by a first diapositive carrying a pictorial representation of a given subject;
- a first optical system arranged to project an image of the entirety of the first area onto said screen in a manner such that the image fills substantially the entire image projection area;
- means defining a second area to be occupied by a second diapositive carrying a pictorial representation of the same subject, and to the same scale, as the first diapositive;
- a second optical system producing a greater magnification than said first optical system and arranged to project an image of a portion constituting a fractional part of the second area onto said screen in a manner such that the image of such portion fills substantially the entire image projection area;
- and
- a transparent runner movable parallel to the first and second areas and provided with a window located adjacent the first area and corresponding in size to a portion of the first area, said runner carrying at least part of said second optical system at a location relative to said window such that the location of the portion of the first area which is adjacent said window corresponds to the location of the portion of said second area which said second optical system is arranged to project on said screen.
4 more elements
Dependencies are inferred from the claim text.