A real image type zoom finder that, albeit being reduced in size and thickness, can gain high enough zoom ratios and an imaging system equipped with such a real image type zoom finder. The real image type zoom finder comprises an objective optical system, an image-erection optical system and an eyepiece optical system. The objective optical system comprises a negative first lens group, a positive second lens group, a negative third lens group and a positive fourth lens group. Upon zooming, the first lens group and the fourth lens group remain fixed, the second lens group moves toward the object side at the telephoto, not the wide-angle end, and the third lens group moves toward the image side at the telephoto, not the wide-angle end. The first lens group consists of one single lens of double-concave shape, and that single lens satisfies condition regarding a shape factor.

 
Web www.patentalert.com

> Method of forming a recess channel trench pattern, and fabricating a recess channel transistor

~ 00341