Abstract: A photographic wide-angle lens system with internal focusing has a front array (II) of negative refractive power that is rigid within itself and fixed on the object-side, a rear array (III) of positive refractive power that is rigid within itself and fixed on the image side of an aperture diaphragm (A), and a focusing array (II) of positive refractive power having an optical single element (5) that is arranged between the front array (I) and the aperture diaphragm A and is axially movable from a maximum axial position on the object side to a maximum axial position on the image side to vary the focus distance from its maximum to its minimum value. The optical single element of the focusing array (II) has at least one aspheric surface (51, 52) and the image-side end lens (9) of the rear array (III) is configured as a positive, aspheric meniscus lens.

Abstract: A projection lens for magnifying and projecting input light on a screen is disclosed. The projection lens in accordance with an embodiment of the present invention includes: a first lens having a positive refractive power; a second lens having a negative refractive power and receiving the light that has passed through the first lens; and a third lens combined with the second lens to form a lens group having a positive refractive power and receiving the light that has passed through the second lens and projecting the light on the screen separated by a predetermined length from the lens group.

Abstract: Disclosed is an illumination optical apparatus that can enlarge a beam divergence angle. In accordance with an embodiment of the present invention, the illumination optical apparatus can include a light source, emitting a beam of light in a predetermined direction at a beam output point; a ball lens, arranged in a forward direction of the beam of light emitted from the light source; and a condensing lens group, condensing the beam of light which has passed through the ball lens on a predetermined point. With the present invention, the size and the volume of the illumination optical apparatus can be reduced by enlarging the beam divergence angle by further including a ball lens.

Abstract: A miniature color display apparatus are disclosed. In accordance with an embodiment of the present invention, the miniature color display apparatus can include N light sources, emitting each two-dimensional color beam of light, N is a natural number and is the same as or larger than 3; a path adjusting material, adjusting an emission path of each color beam of light to allow each color beam of light emitted from the N light sources to be emitted though the same path; an optical modulator, optically modulating each incident color beam of light according to light intensity information; and a beam converter, converting the two-dimensional color beam of light to a one-dimensional color beam of light to allow each color beam of light having the emission path adjusted by the path adjusting material to be one-dimensionally incident on the optical modulator.