Magnification of television images
OwnerJames M. Inglisinventor
Life of this patent
Estimating the term…
Abstract
A compact, economical system for magnifying a television image. A fresnel lens of focal length up to 10 inches projects an image from a television image source onto a rear projection screen. Lens aberrations and light quality are controlled by an opaque enclosure which fits around the lens, extends toward the screen, and terminates at a variable aperture. A means is provided for intercepting nearly all light from the television source that is directed toward the screen but does not pass through the lens. The system may be adjusted to be compatible with any conventional television set.
Claims10
A system for magnifying a television image comprising:
- a fresnel lens of focal length up to 10 inches,
- an enclosure fitting all around the circumference of said lens and extending in a direction parallel to the optical axis of the lens,
- a means defining an aperture in the end of said enclosure away from said lens,
- a means for intercepting light arranged in combination with said lens so that if a television image source is placed on the side of the lens opposite to the direction in which said enclosure extends, substantially along the optical axis of the lens and within 18 inches of the lens, substantially all light emitted from said source and not passing through said lens will be intercepted,
- the distance between said lens and said aperture being between 20% and 50% of said focal length, and
- the area of said aperture being between 25% and 50% of the area of said lens.
In a system for magnifying a television image of the type employing a source of an inverted television image and a rear projection screen, the improvement comprising:
- a fresnel lens of focal length up to 10 inches located between said source and said screen so that it projects said image onto the screen,
- means for intercepting substantially all the light from said source which is directed toward said screen but does not pass through said lens,
- an enclosure fitting all around the circumference of said lens and extending forward toward said screen,
- means defining an aperture in the forward end of said enclosure,
- the distance between said lens and said aperture being between 20% and 50% of said focal length,
- and the area of said aperture being between 25% and 50% of the area of said lens.
Dependencies are inferred from the claim text.