| 摘要 |
<p>An afocal zoom lens system comprises an objective lens group 1 of a positive refractive power, an erecting optical group 2, and an eyepiece lens group 3 of a positive refractive power. The objective lens group 1 includes a first lens unit 11 of positive refractive power, a second lens unit 12 of a negative refractive power and a third lens unit 13 of a positive refractive power. The first lens unit 11 and the second lens unit 12 are movable when zooming. Some of the surfaces of the objective 1 and eyepiece 3 may be aspheric. The lens units 11-13 and eyepiece lens group may be made of plastics.</p> |
