Abstract: Provided are a structure of molding tools and an injection molding device that can easily perform molding of an optical element even from a resin of low velocity or the like and can suppress any negative effects by air. The structure of the molding tools includes between the molding tools (61, 62) a fixed molding tool (61) and a movable molding tool (62) and an O-ring (63a) for keeping air tightness and a resin seal (63b) for preventing any resin leakage. The O-ring (63a) performs decreasing of the pressure in a cavity (CV) formed by joining the molding tools (61, 62), whereby the vacuum molding in which resin supply and resin curing is carried out under a decreased pressure can be performed. Accordingly, the effects such as prevention of air bubbling due to air trapping by injected resin within the cavity (CV) can be attained. Furthermore, the resin seal (63b) can prevent any resin leakage from the molding tools (61, 62) even when the resin having a low viscosity is used.

Abstract: A method of optical-film treatment in which coating troubles apt to occur in the formation of a functional layer, e.g., an antireflection layer, on a continuous film by coating fluid application, such as transverse thickness-difference lines, coating streaks, and tailing, are diminished. The method of optical-film treatment comprises wetting with a liquid a continuous film which is being continuously conveyed, continuously rubbing the continuous film with an elastomer, and then removing the liquid from the continuous-film surface, and is characterized in that the surface of the elastomer has a coefficient of static friction of 0.2-0.9.

Abstract: A zoom optical system has lens groups, and performs zooming by varying distances between the respective lens groups in an optical axis direction thereof. The zoom optical system has two or more lens groups having a negative optical power and a positive optical power in this order from an object side. The first lens group (Gr1) and the second lens group (Gr2) each have three or less lens elements. The second lens group (Gr2) includes a positive lens element having a refractive index of 1.7 or more. The positive lens element has at least one aspherical surface. With this arrangement, provided are a compact and superfine zoom optical system with a zoom ratio of about two to three times, an imaging lens device incorporated with the zoom optical system, and a digital apparatus loaded with the imaging lens device.