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图的简单说明:图中是表示本发明的一个实例。第1图表示变焦距镜筒的纵剖面图,第2图表示电气系统框图,第3图是表示不同焦距时的透镜系移动量和调焦刻度的关系。本发明的详细说明:一般的变焦镜头摄影距离的调节是由前组透镜的进退实现的,由于采用该方式操作,到最近距离时,前组透镜就要伸出,则随着前透镜外径急剧地增大的同时,象差就显著恶化,因此缺乏实用价值。特别是对于广角变焦镜头,这种缺点显得更突出。本发明是为了消除这个缺点而作的,是在摄影距离的调节时,能具有象以往的固定焦距的镜头系统那样,靠镜头系统整体的进退
Brief Description of the Drawings: In the drawings, an example of the present invention is shown. Fig. 1 is a longitudinal sectional view of a zoom lens barrel, Fig. 2 is a block diagram of an electrical system, and Fig. 3 is a diagram showing the relationship between the amount of movement of a lens system and a focus scale at different focal lengths. DETAILED DESCRIPTION OF THE INVENTION In general, the adjustment of the photographing distance of the zoom lens is realized by the advance and retreat of the front lens. Due to the operation in this way, the lens of the front lens is extended to the nearest distance, and as the front lens outer diameter At the same time as the sharp increase, the aberrations have deteriorated markedly and therefore lack practical value. Especially for wide-angle zoom lens, this shortcoming is more prominent. The present invention has been made in order to solve the above drawbacks, and is capable of advancing and retreating the entire lens system as in the case of a conventional fixed focal length lens system at the time of adjusting the image capturing distance