FOCUSING DEVICE IN FIXED FOCUS CAMERA

• Main Author: GOTOU TADASHI
• Format: Patent
• Language: English
• Published: 10.04.1984
• Subjects: ACCESSORIES THEREFOR; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USINGWAVES OTHER THAN OPTICAL WAVES; APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FORPROJECTING OR VIEWING THEM; CINEMATOGRAPHY; ELECTROGRAPHY; HOLOGRAPHY; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHOTOGRAPHY; PHYSICS

PURPOSE:To focus a camera, where a photographing lens is fixed, to objects different in photographic distance while leaving the lens fixed, by interposing a parallel plane glass freely attachably and detachably between the photographing lens and a film in the fixed focus camera. CONSTITUTION:A parallel plane glass 3 is arranged between a photographing lens 1 and the film, and the optical path length from the lens 1 to the film is changed by inserting or removing the glass 3. That is, the glass 3 is removed when the film is placed in a position E' and an object (a) is photographed, and the glass 3 is inserted when an object (b) is photographed, thereby photographing objects (a) and (b), namely, short-distance and long-distance objects vividly while leaving the lens 1 and the film fixed. Thus the thickness of the glass 3 is changed to select freely the distance of rays of (b), namely, the long-distance object. The tip of a frame interlocking with a lever 4 is connected to this glass 3, and the glass 3 is inserted or removed between the lens 1 and the focus (image forming point) of the film by moving the lever 4.