Long-focal-length continuous zooming projection objective

The invention discloses a long-focal-length continuous zooming projection objective, which sequentially comprises a first lens group, a second lens group, a third lens group, a fourth lens group, a fifth lens group and a sixth lens group from an object side to an image side, the first lens group has a negative focal power and is fixed in position, the second lens group has positive focal power andcan move along the direction of the optical axis; the third lens group has negative focal power and is fixed in position; the fourth lens group has positive focal power and can move along the direction of the optical axis; the fifth lens group has positive focal power and is fixed in position; and the sixth lens group has negative focal power, and is fixed in position. The objective can realize continuous zooming of a long focal length with a zoom ratio of about 2 times. 本发明公开了一种长焦距连续变焦投影物镜，该物镜从物侧到像侧依次包括：第一透镜组，具有负光焦度且位置不动；第二透镜组，具有正光焦度且位置可沿着光轴方向移动；第三透镜组，具有负光焦度且位置不动；第四透镜组，具有正光焦度且位置可沿着光轴方向移动；第五透镜组，具有正光焦度且位置不动；第六透镜组，具有负光