GB2083441A - A cinefilm cassette and a method of using this cassette during exposure, development and playing back of the film - Google Patents

Abstract

A cinefilm cassette (1) consists of a flat, preferably rectangular cassette housing (1a, 1b) with winding and rewinding mechanisms (10) situated in one plane. The cassette (1) comprises on either side of a narrow side a labyrinth-like opening (3). The cinefilm (5) emerges from one of the openings (3), is freely accessible guided over the narrow side and introduced into the other opening (3) after use. The cinefilm cassette (1) is provided with at least two data panels of which one panel is intended for visually-readable optical data and the other for machine- readable magnetic data. After the film has been exposed and the cassette removed from a camera, the cassette is first delivered to a data input unit 34, then the film is detached from a leader 32 and attached to a film from a preceding cassette and passed through a developing machine 30. When the film has been unwound from the cassette it is detached at its other end from leader 33 and attached to a following film. The empty cassette is conveyed at the same speed as the film to the output end of the developing machine where the first detached end is rejoined to leader 32, the film is wound back into the cassette and then the other end is detached from the following film and rejoined to other leader 33. The cassette then passes to a data reading and addressing station 31 and is then returned to the customer for projection. The use of the same cassette casing and winding mechanisms during exposure and projection lessens the danger of loss during mailing. <IMAGE>

Description

SPECIFICATION A cinefilm cassette for exposing, developing and playing back a cinefilm and a method of using this cassette This invention relates to a cinefilm cassette for exposing, developing and playing back a cinefilm, consisting of a flat, preferably rectangular cassette housing with a base and cover, winding and rewinding mechanisms situated in one plane and guide elements for the strip of film, and to a method of using this cassette.

Various types of cinefilm cassettes are known.

In one known type of cinefilm cassettes (the Super 8 cinefilm cassettes) the rolls of film lie coaxially above one another, the outer shape of the cassette corresponding to that of boxes with a substantially square base.

For photographic exposure, the cinefilm is unwound in one plane of the cassette, guided along the wall of the cassette past an exposure window with a built-in pressure plate into the second plane where it is rewound by a winding core.

The exposed film is sent with the cassette in despatch bags with accompanying address slips to developing laboratories where it is developed, and the developed film is wound onto a flanged spool, provided with a safety tag to stop it from unwinding and sent back to the customer. The cassettes are only used once for exposing the cinefilm and are then destroyed.

Super 8 cassettes contain approximately 1 5 metres of cinefilm and are relatively thick and large because space has to be provided for the roll of film both on the unwinding side and on the winding side. The cassette is expensive to produce and necessitates cinefilm cameras which are relatively wide to be able to accommodate the thick cassette.

Cinefilm or tape cassettes are also known in which the winding and unwinding units are situated adjacent one another in one plane, as is the case for example with the Single-8 cassette for cinefilms. The roll of film is accommodated in an elongate, rectangular box-like cassette housing. The strip of cinefilm is unwound from a full spool, guided past an exposure window arranged on the longer side of the cassette with a film pressure plate arranged in the camera for exposure and then rewound by a rewinding unit.

In cassettes of this type, the axles of the film winding units may be situated closer together than that distance which corresponds to twice the radius of the roll of film, because the diameter of the roll of film being unwound decreases as the diameter of the roll of film being wound increases.

Whereas originally these cassettes were made of sheet metal and, being the property of the manufacture, were repeatedly loaded with film for exposure, the modern plastic cassettes are destroyed after removal of the film.

The developed film is also returned from the developing laboratory on a separate projection spool which is provided with a winding lock. The cinefllm cassette is much thinner and smaller than the Super 8 cassette and thus allows the construction of a conveniently narrow cinefilm camera.

However the cassette is also expensive to make, although easier to inject and load with cinefilm.

However, all hitherto known cinefilm cassettes are in danger of being lost if mailed twice, although in some cases it is possible, with the aid of the subjects which have been photographed, to locate the photographer and to send the developed cinefilm to him despite losing the address.

In the developing laboratories, the despatch bags containing the incoming exposed cinefilms, the accompanying address slip and the cinefilms themselves are provided with a code number and.

after development, are put together again. Even in this case, however, it occasionally happens, in view of the large number of films to be processed, that a film can be no longer identified and is lost.

German Offenlegungsschrift No. 2,254,694 describes film cassettes for projection in cinefilm projectors containing two rolls of film lying in the same plane. In this case, the feed roll is accommodated on the standard film spool supplied by the developing laboratory. After projection in the cassette, the film is rolled up onto a winding core or another standard film spool.

The cassette for accommodating the films for projection has the disadvantage that a large amount of space is needed, since the radii of the disc-like flanges determine the size of the cassette.

If a projection cassette is provided for each film approximately 1 5 metres in length for projection purposes, the individual films can, it is true, be quickly changed in the projector, but unfortunately considerable additional costs are involved in the large number of cassettes required. If, on the other hand, only one cassette or a few cassettes is or are used and in each case the film spools are inserted and threaded, then projection of the film takes a considerable time.

The spools may also be directly put onto a projector. In this case, the film is automatically threaded onto the projector, taken up by the second spool acting as the take-up spool and wound. After one or more spools have been projected, the films are wound back onto their original spool.

All currently known cinefilm cassettes are only intended for accommodating film and are usually destroyed after development of the film, resulting in a considerable loss of material and a corresponding increase in the cost of a cinefilm.

Separate, standardised projection spools are used for projecting the cinefilm and for rewinding it. These spools are only able to take a standard film length of the order of 1 5 metres, so that the projection time is correspondingly short. After each spool, projection has to be interrupted for a while in order to fit the next spool onto the projector and thread it on. Modern projectors with automatic film threading shorten the intervals between projection. Although projection cassettes can shorten the intervals between projection, they involve considerable costs.

Accordingly, the object of the present invention is to provide a cinefilm cassette of the type mentioned at the beginning, with which it is readily possible to expose, identify and develop a cinefilm and to project the developed film using only one cassette which can be manufactured at low cost.

According to the invention, there is provided a cinefilm cassette for exposing, developing and playing back a cinefilm, comprising a flat cassette housing with a base and a cover, winding and rewinding mechanisms situated in one plane and guide elements, wherein the cassette housing of the cinefilm cassette comprises on either side of a narrow side, a labyrinth-like opening with a guide element, wherein the cinefilm emerges from one of the openings, is guided over the narrow side of the cassette housing whilst remaining freely accessible and is introduced into the other opening after use, and wherein on the flat outer side of the cassette housing, the cinefilm cassette is provided with at least two data panels of which one is intended for visually readable optical data and the other for machine-readable magnetic data.

Preferably, the cassette housing is rectangular.

The cinefilm cassette according to the invention is surprisingly simple in design and very inexpensive to make. It does not require a pressure plate for pressing the film onto a film platform in a camera or in a projector. Instead, the film is freely accessible on one narrow side of the cassette and may readily be taken up and manipulated by a cinefilm camera, a developing machine and a cinefilm projector.

The two data panels on one surface of the cinefilm cassette ensure that the film cannot be lost and always remains associated with the cassette. The data panels also ensure that, apart from the address of the photographer, the filling data, the theme of the film, the number of frames per second and other data remain associated with the film from the time it is taken, through the development stage and up to the projection stage.

This cassette, which is inexpensive to make, may be used for filming, as a bearer of data at dispatch, for development and return and as a projection cassette, and thus provides an extremely economical usage at all stages.

One advantageous embodiment of the cinefilm cassette is distinguished by the fact that the guide elements are arranged in the cassette housing in such a way that the cinefilm may be wound and rewound in the cassette housing with its photosensitive emulsion layer facing both inwards and outwards, and thus that, outside the cassette housing, when the film is being guided along the narrow side, the photosensitive emulsion layer lies on that side of the cinefilm which is remote from the housing.

By the arrangement of the guide elements, it is possible to introduce the film into the cassette in accordance with its natural rolling bias and hence to obtain good winding and rewinding characteristics for the film in the cassette. The winding and rewinding characteristics of the film are responsible to a considerable extent for a high image stability both in the camera and in the projector.

The present invention also provides an advantageous method for exposing, developing and playing back cinefilm using the described cinefilm cassette, wherein: a) the cassette is loading into a cinefilm camera, and the pressure plate of the camera engages behind the free strip of cinefilm and presses it against the film platform for feeding by the film gripper, b) the cinefilm is exposed whilst it is fed through the camera lens, c) the exposed cinefilm is removed from the camera together with its cassette, provided with the filming data and an address on the data panels and sent for development, d) for development, the cinefilm is separated from the cassette at its rear short end and the rest of the film, with its end attached to a preceding film, is passed through a developing machine, e) after the film has been unwound from the cassette, it is separated at its other end and attached to a following film, f) the empty cassette with the two projecting ends is conveyed at the same speed as the respective film to the output end of the developing machine, g) that end of the developed film which was the first to be separated is applied to the piece of film projecting from the cassette, the film is wound into the cassette and, after the other end has emerged from the developing machine, it is separated from the following film and applied to the other piece of film, h) the cassette loaded with the developed film is delivered to a data reading and addressing station and, addressed and franked, is returned to the customer, i) for projection, the cassette is introduced into a projector wherein the film positioning rollers engage behind the film and withdraw it from the cassette up to a film platform, a pressure plate and a mirror or prism are introduced between the film platform and the cassette in the projector and, for projection, the film is fed by a film gripper through the beam between the mirror or prism and the lens.

It is surprising to the expert, that the method according to the invention allows extremely simple handling of the cinefilm cassette at all stages and ensures that the film can always be identified.

Only one special cinefilm cassette is required, since the data stored thereon can control it. It is true that a system consisting of a handy cinefilm camera, a developing machine with the appropriate means for separating the film to be developed from and reattaching it to the cassette, an addressing machine with a data reader and a special cinefilm projector is necessary for the very simple and economical method and the inexpensive cinefilm cassette. However, the system as a whole does afford economical filming with cinefilms.

The invention is describedin more detail below, with reference to the accompanying drawings, wherein: Figure 1 shows a cinefilm cassette with its cover removed and a film wound with its emulsion side facing inwards.

Figure 2 shows the same cinefilm cassette as Figure 1, but with a film wound with its emulsion side facing outwards.

Figure 3 is a plan view of a closed cinefilm cassette of the type shown in Figures 1 and 2.

Figure 4 shows a cinefilm cassette in a cinefilm camera (schematically illustrated).

Figure 5 schematically illustrates the development of an exposed cinefilm with the cinefilm cassette.

Figure 6 shows a cinefilm cassette in a cinefilm projector (schematically illustrated).

Figure 1 shows a cinefilm cassette 1. The cassette 1 is rectangular and box-like in shape and' consists of a lower part 1 a and a cover 1 b (Figure 3), which in Figure 1 has been removed.

Two labyrinths 3 are arranged on one narrow side 2 2 of the cassette 1 on the outer edge thereof for guiding the film 5 out of and into the cassette. The labyrinths 3 seal off the inside of the cassette against the entry of light, are each provided with a guide roller for the film and may be additionally sealed off by means of felt or velvet seals. The film 5 is guided completely freely between th#e guide rollers 4 at a distance of several millimetres from the cassette wall 2, so that when the cassette 1 is loaded into a camera or into a projector, a film pressure plate or means for gripping the film 5 can be brought behind the film 5.

Labydnth-like bearings for the winding and unwinding cores 10 are provided in the usual way for the winding and unwinding mechanisms in the lower part 1 a of the cassette. The distance between the middles of the bearings of the winding cores 10 is smaller than the radius of the rolls 1 1 of film because as the diameter of the roll of film which is being unwound decreases, the diameter of the roll which is being wound increases correspondingly.

The film cassette 1 is made of plastic in a simple injection mould, although it may also be made of metal. The guide rollers 4, 8, 9 are mounted on bearing pins arranged in the lower part 1 a after the labyrinths, if desired, have been provided with a seal of felt or velvet strips (not shown). In a darkroom, the film 5 is attached to a winding core 10, for example by bonding, welding or fastening in the usual way, and rolled up into a roll 1 1 of film, the free end is attached to the second winding core 10, the film 5 with the winding core 10 is introduced into the lower part 1 a of the cassette, and the cassette cover 1 b is placed in position and joined to the lower part 1 a by ultrasonic welding, bonding or even by means of screws.

The cassette may also be made by providing each of the winding cores 10 with a short leader film which is guided out through the respective labyrinth 3.

The cassette 1 may thus be provided with the winding cores 10 and closed in daylight. The film 5 is then fastened to the first leader in a darkroom and wound into the cassette 1, after which the second end of the film is fastened to the second leader. This procedure not only avoids uncertain working in the darkroom, it also saves expensive film. By using thin film or by increasing the size of the cassette only marginally by comparison with known Single-8 cassettes, the cassette is able to accommodate 30 metres of film, resulting in twice the projection time as compared with conventional cassettes.

Figures 1 and 2 show cassettes which differ from one another in the fact that the film is wound and unwound with its emulsion side facing inwards in Figure 1 and outwards in Figure 2. The advantageous arrangement of the guide rollers 8 and 9 affords both film winding possibilities.

Depending on the direction of rotation of the winding cores, the emulsion layer may be arranged facing inwards or outwards in the cassette to achieve a required rolling bias. Outside the cassette 1, the emulsion layer is always arranged remote from the narrow side 2 of the cassette between the guide rollers 4. If a cinefilm does have a rolling bias, it rests better on the unwinding core and is easier to roll onto the winding core if the rolling tendency is in the same direction of curvature as the curvature of the winding cores 10.

Image stability in the camera and in the projector is thus improved.

The cassette 1 may be provided in the usual way with radial protuberances in the lower part 1 a and on the cover 1 b or may have other sliding surfaces on which the roll of film slides easily when it is being unwound, rewound or wound.

Figure 3 shows a cinefilm cassette filled with a film 5 and provided with a cover 1 b. Two data panels 6, 7 are provided on one surface of the cassette, in this case for example on the surface of the cassette cover 1 b. The data panel 6 is intended, for example, for visually readable optical data. The upper part of the panel 6a may be reserved for manufacturing data of the cinefilm 5, such as film type, film format, film sensitivity, length, manufacturers comments and other information which may be useful to the user for exposing and using the cinefilm. The second part of the panel 6b may be reserved for the user to record the place, data and recording speed or other data after exposure of the film.

Finally, a third part of the panel 6c is provided for the address of the user. The data panel may be occupied by a paper label partly printed and written on by the manufacturer or even by an electrosensitive paper imprinted by means of a special writing instrument (electroerosion, laser beam etc.). The data panel 6 is integral with the cassette.

The second data panel 7 is intended for machine-readable magnetic data and consists of a magnetic layer which is directly applied to the surface of the cassette or which is bonded or welded thereto in the form of magnetic tape. The manufacturer's data and data relating to the developing process required for the film are recorded in the panel 7. These data are machineread in the developing laboratory and the address of the customer is transferred to the magnetically readable data panel 7 by means of a data translator. The manufacturer's data in the panel 7 control the cassette 1 in the necessary developing process and influence the developing time. The data transferred from the data panel 6 to the magnetically readable data panel 7 ensure, in an addressing machine 31 (Figure 5), that the cassette containing the developed film reaches the correct customer.

The customer thus gets his cassette 1 back (with his original written observations still intact) ready for projection and, from the data in the data panel 6, is immediately able to see the sequence of filming, the location etc. and to project the cassettes in order. He is also able, on rewinding the cassette, to remove unsuccessful parts from the film or to replace them by other parts or to introduce titles into the film.

Figure 4 schematically illustrates the described cinefilm cassette 1 on a camera feed system.

The cassette is preferably inserted laterally into a camera 13, the projecting part of the film 5 passing between the pressure plate 14 and the film platform 16. When the camera is closed, the pressure plate 14 is pressed against the film 5 which in turn is pressed against the film platform, so that the film gripper 15 is able to feed the film and the film 5 is exposed through the lens 17.

(Only the important and new parts of the camera have been shown.) The exposed film 5 is wound back onto the winding core 10 in the cassette 1 through the camera 13 over a friction coupling. At one end, the film 5 has an opening or perforation which prevents the film from being further fed and possibly torn out of the cassette through the camera. If one or more feed perforations have been punched into the end of the film, the gripper 15 stops feeding the film and the camera runs empty.

On the other hand, a perforation in the film may be used to stop the drive of the camera and hence to prevent any further feeding of the film. To prevent an already exposed cassette 1 from being loaded back into a camera, the optically readable warning "exposed" is shown on the end of the film in the usual way. If the cassette is externally shaped in such a way that it can only be loaded into the camera in one way, double exposure is impossible because the film gripper does not feed the film in the absence of the feed perforations.

The exposed film is removed by the user and sent with his personal filming data and his address to a developing laboratory.

The developing process for a cassette of the type described above is schematically illustrated in Figure 5.

On arrival in the developing laboratory. the cassettes are delivered to a data input unit 34 and the address written by the user on the data space 6 is transferred to the machine-readable magnetic data panel 7.

However, the other filming data, such as for example "Holiday 1980", "Part 1" or other data relating to the film may also be transferred from the data panel 6 to the machine-readable magnetic data panel 7 by the data input unit 34.

During the subsequent development of the film 5, these data are read in a special unit 35 and introduced as a clear text onto a leader 36. The leader 36 is then fastened to the leader 33 projecting from the cassette 1 as the film title, after which the film 5 is fastened to the leader 36.

The unit 35 may also be designed in such a way that it exposes the clear text onto a leader 36 consisting of a film strip by means of a light source and attaches the leader 36 to the end of the film 5 to be developed before the developing process, so that the leader 36 containing the optically recorded title may be developed at the same time (not shown).

The film cassette 1 provided with the machine readable magnetic data is delivered through a reader to the developing machine 30 in accordance with the film developing process. The film 5 to be developed is detached from the leader 32 which remains in the cassette 1 , the detached film 5 is attached to film from a suitable preceding cassette which is already entering the developing machine 30 and is unwound from the cassette 1.

Just before the end of the unwinding process, the second end of the film 5 is detached from the second leader 33 and fastened to a following film to convey it through the developing machine 30.

During development of the film 5, the cassette 1 containing the two leaders 32 and 33 carried to the output end of the developing machine 30 at the same speed as the film 5. In the meantime, a title leader may be prepared as described above and attached to the leader 33 of the cassette.

When the film 5 leaves the developing machine 30, it is guided to the free end of the leader 32 of the cassette 1 and fastened thereto by welding or bonding. The developed film 5 is wound into the cassette 1 and its second end is fastened to the second leader 33 projecting from the cassette 1.

The film 5 is now back in its respective cassette 1, which is provided with its data and its addressee.

The cinefilm cassette is delivered to an addressing machine 31 which reads the magnetic data and writes out the address to which the cassette 1 will be safely returned.

Figure 6 schematically illustrates a cinefilm projector 23 suitable for the cassette 1 described above.

The cassette 1 is introduced laterally into the projector 23 so that the positioning rollers 28 lie between the film 5 and the cassette wall 2.

By closing a projector flap or by operating a lever (not shown), the film positioning rollers 28 are moved in the arrowed direction and draw the film 1 towards the film platform 26 so that the pressure plate 24 and a mirror or prism 29 can be pivoted between the film cassette 1 and the film 5. By means of a film gripper 25, the film 1 is conveyed along the film platform 26 and the film 1 is projected through the lens 27. (The other known parts of a projector have not been shown, in order to clearly illustrate only the important aspects of the operation.)

Claims (6)

1. A cinefilm cassette for exposing, developing and playing back a cinefilm, comprising a flat cassette housing with a base and a cover, winding and rewinding mechanisms situated in one plane and guide elements, wherein the cassette housing of the cinefilm cassette comprises, on either side of a narrow side, a labyrinth-like opening with a guide element, wherein the cinefilm emerges from one of the openings, is guided over the narrow side of the cassette housing whilst remaining freely accessible and is introduced into the other opening after use, and wherein, on the flat outer side of the cassette housing, the cinefilm cassette is provided with at least two data panels of which one is intended for visually readable optical data and the other for machine-readable magnetic data.

2. A cinefilm cassette according to claim 1, wherein the cassette housing is rectangular.

3, A cinefilm cassette according to claim 1 or 2, wherein the guide elements are arranged in the cassette housing in such a way that the cinefilm can be wound and unwound in the cassette housing with its photosensitive emulsion layer facing both inwards and outwards, and thus that, outside the cassette housing, when the film is being guided along the narrow side, the photosensitive emulsion layer always lies on that side of the cinefilm which is remote from the housing.

4. A cinefilm cassette, substantially as herein described with reference to the accompanying drawings.

5. A method of exposing, developing and playing back a cinefilm using a cinefilm cassette according to claim 1, wherein: a) the cassette is loaded into a cinefilm camera, and the pressure plate of the camera engages behind the free strip of cinefilm and presses it against the film platform for feeding by the film gripper, b) the cinefilm is exposed whilst it is fed through the camera lens, c) the exposed cinefilm is removed from the camera together with its cassette, provided with the filming data and an address on the data panels and sent for development, d) for development, the cinefilm is detached from the cassette at its rear short end and the rest of the film, with its end attached to a preceding film, is passed through a developing machine, e) after the film has been unwound from the cassette, it is detached at its other end and attached to a following film, f) the empty cassette with the two projecting ends is conveyed at the same speed as the respective film to the output end of the developing machine, g) that end of the developed film which was the first to be detached is applied to the piece of film projecting from the cassette, the film is wound into the cassette and, after the other end has emerged from the developing machine, it is detached from the following film and applied to the other piece of film, h) the cassette loaded with the developed film is delivered to a data reading and addressing station and, addressed and franked, is returned to the customer, i) for projection, the cassette is introduced into a projector wherein the film positioning rollers engage behind the film and withdraw it from the cassette up to a film platform, a pressure plate and a mirror or prism are introduced between the film platform and the cassette in the projector and, for projection, the film is fed by a film gripper through the beam between the mirror or prism and the lens.

6. A method of exposing, developing and playing back a cinefilm substantially as herein described with reference to the accompanying drawings.