A lens construction for a character projection unit and with the character projection unit including a plurality of light sources mounted in side-by-side relation, a plurality of corresponding condensor lenses, a plurality of corresponding projection lenses, and a plurality of corresponding characters disposed between the light sources and projection lenses to form a number of separate and individually complete projection systems within a confined volume, including at least one condensing lens plate in which is formed the plurality of individual condensing lenses, at least one projection lens plate in which is formed the plurality of individual projection lenses, and each of the complete projection systems including one of the individual condensing lenses formed in the condensor lens plate and the corresponding one of the individual projection lenses formed in the projection lens plate and with at least one of the lens surfaces of each of the complete projection systems formed as an aspheric surface whereby the projection system is less sensitive to the position of the corresponding light source.
An image projection apparatus in which an image object plane contains a plurality of reflecting images and a light source and optical system projects a beam on each of said plurality of images. Spaced projection lenses are positioned to receive the light reflected from the image and direct the light on a projection surface with the plurality of reflected images in coregistration.
An image projection apparatus in which an image object plane contains a plurality of reflecting images and a light source and optical system projects a beam on each of said plurality of images. Spaced projection lenses are positioned to receive the light reflected from the images and direct the light on a projection surface with the plurality of reflected images in coregistration.
A compact illumination system using a light source such as an array of light emitting diodes (LEDs) or laser diodes (LDs) having a long life span, and a projection display device employing the illumination system are provided. The illumination system includes a light source; a collimating lens array for making light emitted form the light source be parallel; an optical path conversion unit for reflecting the light incident in parallel from the collimating lens array back toward the light source to initially converge the light; and a secondary focusing lens disposed at a side where the light source is positioned, for converging the light, that has been reflected and converged through the optical path conversion unit, on a predetermined position. The illumination system reflected the light emitted from the light source back toward the light source through the optical path conversion unit so that the volumes of the illumination system can be greatly reduced to be compact.
An optical projection type display apparatus wherein the first MLA forming the integrator optical system is arranged integrally at the light emitting part of the reflecting and condensing mirror so as to function as a surface plate so that the distance between the effective reflecting part of the reflecting and condensing mirror and the first MLA can be shortened. In addition, being formed integral to function as a surface plate of the reflecting and condensing mirror, the number of optical elements is reduced by one.
An apparatus for projecting high precision optical images with a selective heating source, advantageously a laser, on a writable, erasable, editable electronic slide and simultaneously or sequentially projecting the images in registration, onto a receiving surface such as a projection screen or photosensitive material, in the former case for the purpose of displaying the projected image and in the latter case for the purpose of creating a hard copy of the projected image.
