Optics: motion pictures – Methods – Recording
Reexamination Certificate
1999-05-03
2001-06-05
Adams, Russell (Department: 2851)
Optics: motion pictures
Methods
Recording
C352S084000, C352S081000
Reexamination Certificate
active
06243156
ABSTRACT:
BACKGROUND OF THE INVENTION
Many of the technical advances in film have had as their objective to increase the realism of a motion picture film, as perceived by the viewers of that film. Color and sound films, along with the 70 mm format, were developed in the 1920s. Such nostandard systems as CinemaScope, VistaVision and Cinerama appeared in the 1950s. Today, such systems as IMAX (70 mm with fifteen perforations per frame, traveling horizontally at 24 frames per second) and SHOWSCAN (standard 70 mm film shown at 60 frames per second) provide a degree of realism not available with conventional exhibition methods, but the high cost and nonstandard equipment required of these systems currently limit their use to special venues.
Previous work by the inventor herein has added a degree of realism to motion pictures that can be shown in conventional venues, with a projector specifically designed or adapted for the purpose. Weisgerber (U.S. Pat. No. 5,627,614 (1997)) teaches the compositing of images photographed or printed at 24 frames per second, with others photographed or printed at 48 frames per second, on the same strip of motion picture film. The resulting film is projected at 48 frames per second, with the result that certain image components retain the artifacts (such is motion blur, graininess and strobescopic effects) that impart the “cinematic” look, while other image components look much more realistic to the viewer. The same invention disclosed the intercutting of highly realistic and “cinematic-looking” scenes or sequences. This method was later extended to other frame rate combinations (U.S. Pat. No. 5,793,894 (1998)).
Existing films for general release in such countries as the United States are photographed and conventionally shown at 24, frames per second. This frame rate limits the quality of presentation to the viewers of such motion pictures, due to the impartation of artifacts such as grain, image instability and flicker. Conventional exhibition of such motion picture films by projecting them at 24 frames per second through a double-bladed shutter delivers 48 image impressions (48 flashes of light) to the viewers per second, but this is not sufficient to reduce the aforementioned artifacts to the point where the viewers cannot perceive them. This is a difficultyuinherent in conventional exhibition of any existing film.
Earlier nonstandard exhibition systems attempted to reduce these artifacts, especially flicker. Cinerama, in use briefly during the late 1950s and early 1960s (films projected onto an extremely wide screen by three synchronized projectors), increased light brightness levels to enhance visual impact, but flicker remained objectionable. To reduce flicker, films were photographed and shown at 26 frames per second (52 flashes per second, since a double-bladed shutter was used), but this rendered motion pictures produced in that format incompatible with the general release format. Later Cinerama films, such as How the West Was Won and The Wonderful World of the Brothers Grimm were shot and presented at the conventional rate of 24 frames per second. Compatibility was increased, but so were flicker and other artifacts inherent at that frame rate. The Todd-AO system, also in limited use at the time, reduced flicker by using a rate of 30 frames Per second, but compatibility with general release formats remained a problem. Until now, the artifacts inherent in 24-fps projection could not be shown to audiences without the negative effects of these artifacts.
While the inventor's previous work disclosed the conversion of existing motion picture films to the format described, the use of his method for exhibiting such films was not fully developed. Accordingly, it is the objective of the present invention to provide a method for exhibiting existing motion picture films at a significantly higher frame rate than is conventionally in use, with the result that viewers of such films will witness a presentation that appears more realistic and produces a greater degree of visual impact than is available with conventional exhibition methods.
BRIEF DESCRIPTION OF THE INVENTION
For many years, the standard format for production and exhibition of motion picture feature films has been 35 mm film photographed and projected at 24 frames per second. While certain artifacts that limit the visual impact upon the viewers of the film are inherent in 24 fps photography, others are imparted by projection at that frame rate. Conventional projection at 24 fps with a double-bladed shutter (48 flashes of light per second) causes flicker and allows film grain to be perceived by the viewers. The amount of light used in conventional projection (typically SMPTE standard of 14 to 16 footlamberts) also limitsivisual impact.
The method described here eliminates or substantially minimizes these artifacts. In the practice of this invention, each frame of a conventional motion picture prepared for general release is printed twice. For example, each frame of a conventional film photographed at 24 frames per second is printed onto two successive frames of film. The resulting film is shown at 48 frames per second through a projector with a double-bladed shutter, which delivers 96 flashes of light to the viewers each second. The use of this high frame rate, along with the double-bladed shutter, delivers enough flashes of light to the viewers to eliminate flicker and randomize existing film grain, thereby substantially increasing the visual impact of the presentation. In addition, the reduced blanking time available in a pin-registered projector allows light to be flashed onto the screen for a greater Portion of total projection time than is feasible with conventional methods. This allows more light (twenty footlamberts or more is possible) to reach the viewers, thereby greatly increasing image brightness, contrast and color saturation.
The method described can be used with any film format. While it will enhance the perceived realism of films produced in the standard 35 mm format, modern films have sufficient resolution to allow conversion to the 70 mm format, with sufficient anamorphic expansion in the horizontal direction to restore the wide-screen 35 mm aspect ratio of 2.35 to 1. Films produced in certain nonstandard guages (such as IMAX, which uses a large film frame and 24 fps projection) can be converted to the format used here through optical printing techniques or computerized imaging methods known in the art. While an IMAX film will lose some impact in the transition from a larger to a smaller film size, the impact-enhancing features of the method described here will recover much more of the impact than would be available with conversion to conventional 35 mm release prints. Moreover, the method described here allows films produced in nonstandard formats to be shown in conventional motion picture theaters, rather than being limited to the special venues for which they were originally produced. In addition, light brightness can be increased or decreased to vary visual impact.
REFERENCES:
patent: 3410954 (1968-11-01), Erde
patent: 3511567 (1970-05-01), Dejoux
patent: 3741636 (1973-06-01), Nakayama
patent: 4889423 (1989-12-01), Trumbull
patent: 5096286 (1992-03-01), Weisgerber
patent: 5627614 (1997-05-01), Weisgerber
patent: 5739894 (1998-04-01), Weisgerber
Adams Russell
David Peter Alan, Esq.
Fuller Rodney
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