Optics: motion pictures – Removable film strip magazine type
Reexamination Certificate
1999-05-10
2001-04-10
Adams, Russell (Department: 2851)
Optics: motion pictures
Removable film strip magazine type
C352S156000
Reexamination Certificate
active
06215544
ABSTRACT:
The present invention relates to motion picture film cameras. It more specifically applies to realizing a coaxial motion picture film reel housing device, to be associated with an optical block of a camera and containing a mechanism for driving and guiding the film, in a loop, between the reels and a rear presser facing a filming window of the optical block. The present invention more specifically relates to motion picture films, for example 16 or 35 mm films.
For such films, the film camera is conventionally associated with a magazine containing a film drive mechanism and defining film reel carrying compartments. The raw film is unwound from a supply reel engaged on an axis of a supply compartment to a filming optical system, guided by rollers of the magazine. The exposed film is wound on a take-up reel engaged on a motor driven axis of a take-up compartment of the magazine. Due to the large footage of film generally used in this type of camera, the supply and take-up reels are generally coaxial and wound on cores which cooperate with coaxial axes, respectively a supply and a take-up axis, linked to the magazine.
A disadvantage of conventional magazines is that the loading of a raw reel into the magazine and the unloading of an exposed reel require total darkness. Indeed, the loading of a raw reel is performed flat by engaging a first core, on which the film has been wound at its manufacturing, onto the supply axis of the magazine. The film leader is then engaged in the magazine rollers to be guided to a rear presser associated with a filming window of the optical block. The leader is then brought back, from the rear presser, to a second empty core, engaged on the take-up axis of the magazine and to which the leader is attached. Even though the magazine can be closed as soon as the raw reel has been placed on the supply axis and the leader engaged in a dedicated slot, the supply compartment being isolated from the rest of the magazine, the mere fact of having to place an unprotected reel in the supply compartment causes a risk of veiling the raw film. The unloading of an exposed film is performed by opening the take-up compartment and by extracting the core on which the exposed film reel is wound. The unloading is thus performed, like the loading, flat and without protection of the exposed film from light.
To enable a loading or an unloading of the magazine out of the daylight, the optical block of the camera, which includes the drive mechanism actuating means, is generally dissociated from the magazine comprising the actual drive mechanism. Indeed, 35-mm, or even 16-mm, films, are often used for filming feature films which requires the use of several film reels. Now, such filming is not necessarily performed in a studio and is thus often distant from a dark room enabling the secure loading or unloading of the magazine. Thus, this generally leads to having several magazines loaded in advance to film in acceptable security conditions for the film reels. However, the magazine drive mechanism is a particularly expensive system due to the noiseless operation it must have and to the accuracy with which it has to be made. To provide several magazines is thus expensive.
Another disadvantage of conventional magazines is that the contact of the film with the walls of the supply and take-up compartment is a source of noise due to a rubbing of the film during the core rotation. Indeed, it is important to ascertain that the windings of the film remain well superposed. The compartments are thus dimensioned accordingly. It is then generally necessary to provide acoustic damping means within the surfaces of the supply and take-up compartments, which further increases their cost and complexity.
U.S. Pat. No. 3,475,089 describes an 8-mm motion picture film camera. In an embodiment, two film reels are received coaxially in a magazine. Each reel includes two circular flanges for maintaining the film axially around the core. If the use of such circular flanges enables maintaining an axial clearance between the magazine walls and the reels to cancel the noise source due to the rubbing of the film against these walls, a new noise source is introduced due to the rubbing of the film when exiting one reel and entering into the other through their respective peripheries. Further, this noise increases with the unwinding film speed, which makes this solution impossible to apply to 16-mm films, and even less applicable to 35-mm films. In another embodiment, the film is housed in a cartridge receiving two coaxial reels. The same film rubbing problems as those discussed hereabove in relation with the walls of a magazine, arise with the walls of a cartridge. Further, if the use of a cartridge protects the film from an exposure to light in magazine loading or unloading steps, a new source of noise is introduced. Indeed, the film necessarily is in contact with elements linked, fixedly or pivotally, to cartridge walls, which constitutes a noise source due to the manufacturing tolerances in connection with the manufacturing of a disposable cartridge. Further, if the rear presser is contained in the cartridge, an optimal positioning in front of the filming window of the optical block cannot be guaranteed.
Some cameras are provided with magazine identification means for enabling the user to know the characteristics of the film contained therein. At the loading of a raw film reel in a magazine, the user configures a characterization device comprised in the magazine, for example, by means of switches. The camera then includes means for extracting the information contained in the characterization device when the magazine is associated thereto. The information which may be entered therein is, for example, the magazine number, the film sensitivity, the reel length, etc. The camera can store the information relative to several magazines. Throughout the filming, the camera decrements the information relative to the film length, to know, permanently, the remaining raw film length. When the user changes magazines, for example, to use a film of different sensitivity, the camera extracts from its memory all the information relative to this magazine, that it recognizes by its number, if said magazine has already been used. Thus, the user knows, by introducing this previously-used magazine into the camera, what film length remains available.
The present invention provides a coaxial film reel housing device for, respectively, raw film and exposed film, which cancels any noise generation while enabling an axial maintaining of the film around the respective reel cores.
The present invention also provides a cartridge housing device, for containing two coaxial film reels and dissociated from the reel driving and guiding mechanism, which ensures an optimal positioning of the film in front of a rear presser of a film camera to which it is associated.
The present invention also provides such a housing device which enables the film, in a use position, to be neither in contact with the cartridge walls, nor with elements connected, fixedly or pivotally, to the cartridge walls.
The present invention also aims at preventing the film from escaping radially from each reel except from a predetermined region of the magazine or of the cartridge.
The present invention also aims at enabling the film to be wound or unwound from this predetermined region only when the reel is in a use position.
The present invention also provides such a housing device which can be associated with a conventional optical block of a film camera.
The present invention also aims at making the housing device form an adapter between a same cartridge and different types of conventional camera optical blocks.
The present invention further aims at enabling an automatic identification by the camera of characteristics of the film contained in the cartridge.
To achieve these objects, the present invention provides a device for housing coaxial motion picture film reels, intended to be associated with an optical block of a film camera, including:
a stage for housing the reels a
Beauviala Jean-Pierre
Riviere Yves
Aaton
Adams Russell
Buchanan & Ingersoll PC
Fuller Rodney
Plevy Arthur L.
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