Projection lens apparatus and rear projection type image display apparatus
AssigneeHitachi, Ltd.
InventorsYuriko Inadachi, Shuji Kato, Hidehiro Ikeda, Naoyuki Ogura, Koji Hirata
Life of this patent
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AssigneeHitachi, Ltd.
InventorsYuriko Inadachi, Shuji Kato, Hidehiro Ikeda, Naoyuki Ogura, Koji Hirata
Estimating the term…
A projection lens apparatus includes a plurality of lenses, for enlarging and projecting, onto a screen, an original image displayed on an image generation source. The plurality of lenses are arranged, beginning with the lens nearest the screen, as first to sixth lens groups. The fourth lens group includes one meniscus lens that has a positive refracting power and has a concave lens surface directed toward the screen. The concave lens surface of the meniscus lens included in the fourth group lens has a curvature in the vicinity of an outer portion of the concave lens surface that is smaller than a curvature in a predetermined area of the concave lens surface defined between a light axis of the concave lens surface of the meniscus lens and the smaller curvature of the concave lens surface in the vicinity of the outer portion of the concave lens surface.
A projection lens apparatus comprising:
A rear projection apparatus image display apparatus comprising:
Dependencies are inferred from the claim text.