Samsung Aerospace Industries, Ltd.

Geon-Mo Kang

Seok-won Lee

Heui-Jae Park

Hae-jin Lee

Ho-Gyun Moon

A zoom lens system includes, when viewed from an object side, a first lens group with a positive refractive power; a second lens group with a positive refractive power; and a third lens group with a negative refractive power. When zooming from a wide-angle position to a telephoto position, the first, second and third lens groups move towards the object side while the distance between the first lens group and the second lens group increases and the distance between the second lens group and the third lens group decreases. The zoom lens system is compact and has a high zoom ratio of more than 3.5.

Zoom lens system with a high zoom ratio

The invention comprises a fast zoom lens system comprising, from an object side to an image side, three lens groups. The first lens group has an overall positive refractive power, the second lens group has an overall positive refractive power, and the third lens group has an overall negative refractive power. The first lens group, the second lens group and the third lens group move toward the object side during operation. In addition, a distance between the first lens group and the second lens group increases while a distance between the second lens group and the third lens group decreases when zooming from a wide-angle position to a telephoto position. Fast zoom lens systems consistent with the invention satisfy the following conditions:

Compact camera zoom lens system

The invention comprises a zoom lens system including two lens groups. The first lens group has an overall positive refractive power, and includes three sub-group lens units. The first sub-group lens unit has a negative refractive power, the second sub-group lens unit has a positive refractive power, and the third sub-group lens unit has a positive refractive power. The second lens group has an overall negative refractive power and includes two sub-group lens units. The fourth sub-group lens unit has a positive refractive power, and the fifth sub-group lens unit has a negative refractive power. The magnification of the system can be changed by varying a distance between the first lens group and the second lens group, wherein the following conditions are satisfied:

Compact wide-angle zoom lens system

An automatic inspection system for camera lenses and method thereof using a line charge coupled device (CCD) which can process a signal easily and perceive a focal distance of lenses exactly by focusing automatically using a modulation transfer function (MTF) method when designing lenses. The automatic inspection system for camera lenses using a line CCD comprises a light source, a chart, a collimator, camera lenses, a mirror, an image pickup part, a signal converter, and a control part.

Automatic inspection system for camera lenses and method thereof using a

A compact lens system is disclosed which includes a first lens group and a second lens group. The first lens group, which has an overall positive refractive power, includes a first meniscus lens, convex toward an object, and having a positive refractive power. Also included is a second biconcave lens having a negative refractive power, and a third biconvex lens which is connected to the second lens and which has a positive refractive power. The first lens group further includes a fourth biconvex lens which has a positive refractive power. The second lens group has an overall negative refractive power, and includes: a fifth concave lens having a positive refractive power; a sixth concave lens having a negative refractive power; and a seventh lens having a negative refractive power. The magnification of the system can be changed by varying a distance between the first and the second lens group in accordance with the following condition:

Compact zoom lens system

A zoom lens system using inexpensive lens materials and having a high magnification zoom ratio of more than 2 times and good aberration performance. A first lens group has a positive refractive power, and a second lens group has a negative refractive power. The distance between the first lens group and the second lens group varies during zooming. 0.37&lt;f.sub.I /(f.sub.bT -f.sub.bw)&lt;0.7; m.sub.2T /m.sub.2w &gt;2.0, where f.sub.I is a combined focal length of the first lens group, f.sub.bT is a back focus distance at a telephoto position f.sub.bw is a back focus distance at a wide angle position, m.sub.2T is a magnification of the second lens group at a telephoto position, and m.sub.2w is a magnification of the second lens group at a wide angle position.

Zoom lens

A zoom lens system using inexpensive plastic lens materials and having a good aberration performance and good optical performance includes a first lens group having a positive refractive power and a second lens group having a negative refractive power, a distance between the first lens group and the second lens group being variable during zooming, wherein 37&lt;(F.sub.I .multidot.f.sub.bT /D.sub.T .multidot.f.sub.bW)&lt;48; and 2.5&lt;D.sub.T /N.sub.nI &lt;3.5 where f.sub.I is focal length of the first lens group, f.sub.bT is back focus distance at a telephoto position, f.sub.bW is back focus distance at a wide angle position, D.sub.T is distance between the first lens group and the second lens group at a telephoto position, and N.sub.nI is refractive ratio of the lens having a negative refractive power in the first lens group.

A device for adjusting an air gap between lenses having a lens barrel. First and second lenses are disposed within the lens barrel, a spring provided within the lens barrel between the first and second lenses maintains the air gap between the first and second lenses, and a retainer is screw jointed to the lens barrel. The spring is compressed or expanded by tightening or loosening the retainer with respect to the lens barrel. The air gap between lenses can be adjusted to improve the lens performance and the focusing characteristic without dismantling the lenses from the lens barrel.

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Kyeongsangnam-do, South Korea

Geon-Mo Kang