Abstract: A dual function viewfinder presents to a photographer the frame of a picture being taken by the camera having the viewfinder and enables the photographer to point the camera to the center of the frame. The frame is outlined by the front perimeter of an opening which extends between the rear and the front of the camera. Centered within the opening is a tubular member which blocks a portion of the field of view except when the camera is pointed so that the pupil of the photographer's eye is centered. The line of sight from the pupil to the center of the framed field of view is then along the axis of the tubular member. This condition is indicated by the walls of the member becoming virtually imperceptible to the photographer. No refracting optical elements, such as lenses, are required in the viewfinder; making the viewfinder low in cost and, therefore, especially suitable for single use cameras.

Abstract: An illuminating system, which illuminates a line and translates that line over a document on a platen of a scanner or copier which receives light from the line on an image (photo) receptor thereof, uses primary and secondary reflectors having internal reflective surfaces which are elliptical troughs. An elliptical trough is defined here as a surface having an elliptical cross section and maintaining that same cross section over its length. The primary reflector contains a lamp having a linear filament in a plane containing the major axis of the primary reflector ellipse and located at one of the focii thereof so as to provide a conjugate line for the light from the lamp along a line containing the other of the focii of the primary ellipse reflector. The primary elliptical trough is terminated by an aperture plate having an aperture in which the line is located. A secondary reflector has an internal reflective surface with a slit facing the document to be illuminated.

Abstract: A two element lens system provides a close up lens system which may be installed on a camera either above or under water, and allows the camera to be used in air and underwater without a means for lens position adjustment. The system uses two meniscus elements in a holder attachable to a receptacle on a camera body over an opening closed by a transparent window element. The lenses define therebetween a sealed compartment and a compartment which is located between one of the lenses and the window element having a vent which allows the water or air to flow into or out of that compartment. The curvatures of the lenses are selected so that the lens system has the same focusing power and focuses an image in an object space at the same image plane (the film plane with the aid of the camera's lens) when the vented compartment is filled with air or with water.

Abstract: A real image viewfinder with an objective having movable focusing lens(es) and a field lens at the end thereof furtherest from the field of view, an eyepiece lens and image inverting optics, preferably in the form of a Type II Porro prism wherein the real image is focused to fall on a surface of the field lens, which is desirably a plano surface facing the inverting optics. This field lens surface is also at the focus of the eye piece lens. A pattern (a reticle) is located on the field lens surface. Since the objective forms a focus at the location of the reticle, observation of the reticle indicates when the objective is focused. A camera picture taking lens may be coupled to a movable lens in the objective for focusing the taking lens.