U.S. Precision Lens Incorporated

Vivitar Corporation

Eastman-kodak Company

3m Innovative Properties Company

Corning Precision Lens, Inc.

Other

Midmark Corporation

Benopcon, Inc.

Balcon Industries, Inc.

Fjw Industries, Inc.

Opcon Associates, Inc.

Melvyn H Kreitzer

Jacob Moskovich

Ellis I Betensky

Kevin M Montgomery

Thomas L Treon

Brian D Rau

Muh-fa Chen

A zoom lens includes an optical path extending between object and image ends, two or more zoom lens groups, an intermediate real image plane in optical path, and all zoom lens groups on an image side or an object side of intermediate real image plane. Zoom lens may include at least one optical path fold in optical path. Field optics in the vicinity of and associated with intermediate real image plane may be in optical path. Zoom lens may include a fixed rear optical group nearest to image end in optical path and a fixed aperture stop in fixed rear optical group wherein aperture stop remains stationary during zooming. Zoom lens may have a magnification with an absolute value greater than 0.4 between intermediate and final real image planes located at image end. Zoom lens may be entirely within a housing of a digital camera or cellphone during its operation.

Zoom lens optical system

A light is provided having a base unit, an arm extending from the base unit, and a lamp head coupled to the arm. The lamp head includes an LED configured to provide light based on an input drive current, an optical mixing element configured to collect the light produced by the LED and a zoom lens configured to adjust an output size of a spot generated by the light collected in the mixing element. A controller receives DC power from the base unit through the arm. The controller is configured to set the input drive current for the LED to control an output light density of the spot in response to an operator selected input and configured to adjust the output light density of the spot in response to a change in the size of the spot.

LED light for examinations and procedures

Projection lenses for use with pixelized panels (PP) are provided. The projection lenses have a first unit (U) separated from a positive second unit (U). The lenses are telecentric on the short conjugate side, have a large field of view in the direction of the long conjugate, have low aberration levels, and include a space between two of the lens elements making up the lens which is sufficient to accept a reflective surface (RS) for folding the lens' optical axis. The second or rear lens unit (U) includes at least a first color-correcting lens subunit (SU/CC) which has a positive-followed-by-negative form and contributes to the correction of the chromatic aberrations of the projection lens, including the correction of lateral color.

Projection lenses having color-correcting rear lens units

Projection lenses for use with pixelized panels (PP) are provided. The projection lenses have a first unit (U) separated from a positive second unit (U) by a distance sufficient to accept a reflective surface (RS) for folding the lens' optical axis. The lenses are telecentric on the short conjugate side, have a large field of view in the direction of the long conjugate, and have low aberration levels. By using negative lens elements (Land L) composed of plastic materials having large positive Q-values at the long conjugate side of the first lens unit (U), the lenses can achieve low levels of lateral color, including low levels of secondary lateral color, with reduced cost compared to lenses which employ anomalous dispersion glasses in the first lens unit.

Foldable projection lenses

Projection lenses for use with pixelized panels (PP) are provided. The projection lenses have a negative first unit (U) separated from a positive second unit (U) by a reflective surface (RS) which folds the lens' optical axis. The lenses are telecentric on the short conjugate side, have a large field of view in the direction of the long conjugate, and have low aberration levels, including, in particular, low levels of lateral color.

Folded, telecentric projection lenses for use with pixelized panels

A projection television system ( ) is provided which has a CRT ( ) and a projection lens system ( ) for forming an image on a screen ( ). The projection lens system ( ) is characterized by a diffractive optical surface (DOS) which provides color correction for the lens system. The diffractive optical surface (DOS) can be formed as part of a diffractive optical element (DOE) or as part of an existing lens element of the lens system. The diffractive optical surface (DOS) is located between the object side (S ) of the lens' first lens unit (U ) and the image side (S ) of the lens' third lens unit (U ). The distance between the diffractive optical surface (DOS) and the lens' aperture stop (AS) is less than 0.1&middot;f , where f is the focal length of the projection lens ( ).

Color corrected projection lenses employing diffractive optical surfaces

Projection lenses ( ) for use with pixelized panels (PP) are provided. The projection lenses have a negative first unit (U ) which has at least one aspheric surface and a positive second unit (U ) which has three subunits (U , U , U ) which have a positive/negative/positive configuration. The lens' aperture stop (AS) is located at the short conjugate end of the lens and is either in the third subunit (US ) or close to that subunit. The lenses are particularly well-suited for use in the manufacture of compact projection systems which employ side illumination of a reflective pixelized panel.

Projection lenses for use with reflective pixelized panels

Projection lens systems (,) for use in CRT projection televisions (,) are provided. From the screen side, the systems have three lens units (U,, U,, U,), the first two units (U,, U,) forming a retrofocus lens and the third unit (U,) being associated with the CRT during use and serving to correct field curvature. At its screen end, the first lens unit (U,) has a negative element (E,) which has a screen surface (S,) which is concave to the screen. The second lens unit (U,) has two positive subunits (U,, U,), the first subunit (U,) being a color correcting doublet composed of glass and the second subunit having a positive lens element (E,) at its screen end. The projection lens systems are fully color corrected, have f/&num;'s of 1.0 for an infinite conjugate, have half fields of view of at least 25&deg;, and are economical to manufacture.

High speed retrofocus projection television lens systems

Long focal length projection lenses

Projection lens for use with pixelized panels are provided which consist of a first lens unit which has a negative power and a second lens unit which has a positive power. The V-values and Q-values of the lens elements of the first and second lens units are selected so that the projection lenses can simultaneously have: (1) a high level of lateral color correction, including correction of secondary lateral color; (2) low distortion; (3) a large field of view in the direction of the image (screen); (4) a telecentric entrance pupil; and (5) a relatively long back focal length.

Projection lenses having reduced lateral color for use with pixelized panels

A zoom projection lens for use with pixelized panels is provided. The projection lens has a negative/positive (retrofocus) form, with the positive lens unit (U,) having two positive subunits (U,, U,). The image (screen) side subunit (U,) serves as focus corrector for the lens, i.e., after zooming, this subunit is moved to adjust the focus of the lens. Compared to moving the negative unit (U,), this approach achieves better aberration correction and involves moving less mass through smaller distances.

Focus corrector for zoom projection lenses used with pixelized panels

Focusable, color corrected, high performance projection lens systems are provided which include three lens units (U1, U2, U3), the first lens unit being composed of two subunits (U.sub.S1, U.sub.S2). The lens systems can have f/190 's less than 1.0, total fields of as much as 90.degree., low vignetting losses, and MTF values greater than 0.5 at 10 cycles/mm through 0.85 of the full field. By varying the space between the first and second lens units, these performance levels can be maintained as the lens system is focused over a range of conjugates of approximately .+-.7.5% from a center value of about 4 meters. The lens systems can be used in such demanding applications as flight simulators.

Focusable, color corrected, high performance projection lens systems

Lenses for electronic imaging systems

A projection lens for use with LCD panels is provided. The lens has a first lens unit which has a positive power and a second lens unit which has a negative power. The first lens unit contains at least four lens elements, namely, a positive first lens element, a negative second lens element which is composed of a high dispersion material, a third lens element of weak optical power, and a positive fourth lens element of strong optical power. The projection lens achieves a correction of chromatic aberration on the order of about a quarter of pixel for large LCD panels having pixels on the order of 200 microns.

Projection lenses for use with large pixelized panels

Projection lens having long focal lengths for use with LCD panels are provided. The lenses have a first lens unit which has a positive power and a second lens unit which has a negative power. The first lens unit contains at least three lens elements organized into two subunits, namely, a positive first lens subunit having a positive lens element and a negative lens element and a positive second lens subunit having a positive lens element. The second lens unit contains at least two lens elements, namely, a positive lens element and a negative lens element. The projection lens preferably employs only five lens elements arranged in a positive, negative, positive, positive, negative configuration.

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Cincinnati, OH, United States of America

Melvyn H Kreitzer