The present invention relates to a cassette for receiving a photo¬ graphic film sheets from a setting machine, such as a laser image setter of the like, and for winding said film sheets on to a take-up core.

Within the technical field of generating photographic setting prints on a film sheets, it is a well-known art to provide a cassette for receiving the photographic film sheets generated by a setting machi¬ ne. The cassette is preferably of a light-proof structure, i.e. of a structure which excludes light from penetrating into the cassette after receipt of the film sheet therein. Examples of prior art cas¬ settes of this type are disclosed in German patent No. 32 20 455, British patent No. 536,662 and published German patent application No. 28 08 445.

It is an object of the present invention to provide a cassette of a novel structure as compared to the prior art cassettes, which casset¬ te is of a simple and compact structure comprising a minimum of components and providing a reliable operation.

A particular feature of the cassette according to the present in- vention is the provision of simple access to the cassette in case a film sheet is jammed within the cassette.

Another advantage of the cassette according to the present invention is that the cassette is able to receive film sheets with different widths and lengths in an arbitrary sequence.

An advantage of the cassette according to the present invention is that the cassette is of a structure in which the maintenance of the film sheet taken up by ^' the cassette on the take-up core of the cas¬ sette and the driving of the take-up core for causing take up of more film sheets input into the cassette are effected by the same components.

A further advantage of the present invention is that the take-up core is unjournalled within the cassette so that the take-up core and any film sheets taken up thereon are easily removed from the cassette in case the film sheets is jammed within the cassette and access has been provided to the inner space defined within the cassette. Thus, it will be understood that in order to save a film, such as the film jammed within the cassette, the film has to be removed from the cassette in a room from which light is excluded and that the removal of the film has to be extremely simple as the operator who removes the film jammed within .the cassette works without any light.

The above object, feature and advantages and other objects, features and advantages, which will be evident from the below detailed de¬ scription of a preferred embodiment of a cassette according to the present invention, are obtained by a cassette according to the pre- sent invention for receiving a photographic film sheets from a sett¬ ing machine, such as a laser image setter or the like, and for wind¬ ing said film sheets on to a take-up core, comprising: a housing having outer walls defining an inner chamber and defining a slot through which said film sheets is introduced from said setting machine into said cassette, at least two pulleys journalled on respective pulley shafts in said chamber, at least one of said pulleys constituting a drive pulley mounted on a drive pulley shaft, said at least two pulley shafts being journalled substantially in parallel with said slot, a motor assembly connected to said drive pulley shaft for dri¬ ving said drive pulley, one or more belts cooperating with said at least two pulleys each defining a closed loop belt path, and said take-up core being received within said chamber and being enwound by said belt or belts along at least 180° of its outer peri¬ phery.

Although the take-up core of the cassette according to the present invention may be journalled on journalling means within the inner chamber defined within the housing of the cassette, the take-up core is preferably unjournalled relative to the housing. Consequently, the take up core is supported by the belt or belts exclusively, which

preferably enwind or encircle the take-up core along approx. 270° of the outer periphery thereof.

The belt or belts may be implemented in numerous ways, such as by a continuous or integral foil or in accordance with the preferred embodiment of the cassette according to the present invention, by a plurality of belts such as four belts together defining a supporting surface,. which on the one hand serves the purpose of transmitting driving motion -from the drive pulley to the take-up core and on the other hand serves the purpose of encircling and maintaining the film wound on to the take-up core.

In accordance with the teachings of the present invention, two pulle¬ ys are provided with which pulleys the belt or belts cooperate. However, in the presently preferred embodiment of the cassette accor¬ ding to the present invention, three idler pulleys are provided together with a single drive pulley, which idler pulleys and which drive pulley are arranged at the corners of an imaginary box of a quadrangular section, within which imaginary box the take-up core is received.

In an alternative embodiment, two or more pulleys are provided, which constitute drive pulleys driven by independent or respective motors or by a single motor through appropriate transmission means, such as gear transmission means, belt transmission means or the like.

In order to render it possible to easily remove the take-up core and any film taken up thereon from the inner chamber of the cassette, the housing of the cassette according to the present invention is pre¬ ferably composed of two housing parts, which are swingable relative to one another from a first, closed position, in which the chamber defined by the housing is sealed into a second, open position, in which access is provided to the inner chamber.

Although the housing of the cassette according to the invention may constitute a supporting frame to be received in a light excluding compartment for transport from the laser image setter or a similar machine after the receipt of a film sheets within the cassette, the

housing of the cassette according to the present invention preferably constitutes a hermetically sealed enclosure, which is provided with a movable housing component, which is normally in a closed position, in which the chamber is hermetically sealed and which is movable to a second, open position, in which the above slot is defined.

Furthermore, in accordance with the teachings of the present inven¬ tion, the housing is preferably composed of extruded wall components of an extrudable material, such as a plastics material or preferably aluminum, as in accordance with this particular embodiment of the present invention the housing is composed of a plurality of identical extruded wall components and consequently composed of a minimum number of separate components.

The belt or belts, which may constitute a continuous foil or film or be implemented as separate belts, preferably comprising a total of four belts, are preferably made from a pliable, elastic material, such as an elastomeric material, e.g. natural or synthetic rubber or a combination of such materials, e.g. a combination of natural or synthetic rubber.

The motor assembly of the cassette according to the present invention may be permanently supplied with a power supply voltage from an external power supply source permanently or be controlled in accor¬ dance with the operation of the setting machine feeding the film sheets to the cassette. Thus, the motor of the motor assembly is preferably connected to an external controllable power supply source for external control of the take-up of the film on the take-up core. The external controllable power supply source is in accordance with the teachings of the present invention preferably constituted by a controllable power supply source constituting a component of a set¬ ting machine from which the cassette receives the photographic film ^' sheets.

The motor assembly may comprise any appropriate motor means, such as an AC motor or a DC motor. The motor assembly, however, preferably comprises a reversible motor, which in a first operational mode takes

up film on the core and in a second operational mode discharges a film previously taken up by the take-up core.

The take-up core is in accordance with an additional and advantageous embodiment of the cassette according to the present invention consti- tuted by a length of a tube, such as a tube of a plastics material or a tube of e.g. aluminum. In the presently preferred embodiment of the cassette according to the present invention, the tube is simply constituted by a length of a PVC tube conventionally used within the plumbing industry.- Thus, the take-up core according to the present invention and the presently preferred embodiment of the cassette according to the present invention is unjournalled relative to the housing and constituted by an extremely simple and easily replaceable component.

The present invention will now be further described, with reference to the drawings, in which

Fig. 1 is a perspective and partly cut-away view of a presently preferred embodiment of a cassette according to the present invention to be used in connection with a laser image setter, from which the cassette receives a photographic strip or sheet, Fig. 2 is a vertical sectional view through the presently preferred embodiment of the cassette according to the present invention shown in Fig. 1.

In Figs. 1 and 2, a presently preferred embodiment of a cassette according to the present invention for use in connection with a laser image setter or a similar machine, such as a photo setting machine, an image setter or the like, is shown designated the reference nu¬ meral 10 in its entirety.

In the upper left-hand part of Fig. 2, an outer housing part 12 of the laser image setter is shown. The outer housing part 12 defines a recess 14, in which the cassette 10 is received, and in which a plate component 16 is provided. The plate component 16 serves the purpose of allowing that the cassette 10 is hung thereon. Within the recess 14, a protruding part 18 of the housing part 12 is further provided. The protruding part 18 constitutes a component serving the purpose of

opening the cassette 10, which in its state disconnected from the image setter, as shown in Fig. 1, is a hermetically sealed light- proof cassette, in which a photographic film'sheets or sheet is pro¬ tected from exposure to light from external sources, such as external artificial light sources or sunlight.

The cassette 10 basically comprises a housing 20 of a square cross- section as shown in Fig. 2,. in which housing 20 an inner space 22 is defined. The housing 20 is basically composed of three outer wall components 24, 26 and 28, which constitute extruded profiled compo- nents made from e.g. high strength plastics material or preferably aluminum. The housing 20 further comprises a fourth wall component 30 and a fifth wall component 32, which is movable from a closed posi¬ tion shown in Fig. 1 and shown in dotted line in Fig. 2 into an open position shown in solid line in Fig. 2, in which open position a film sheet 34 is introduced into the inner space 22 of the housing 20 of the cassette 10 through an aperture or opening 36 defined between a plane surface part 38 of the fourth wall component 30 and a plane surface part 40 of the movable wall component 32. The aperture or opening 36 is hermetically sealed by the cooperating plane surfaces 38 and 40, when the cassette 10 is not mounted on the laser image setter, i.e. in a state in which the movable fifth wall component 32 is in the dotted line position shown in Fig. 2.

The fourth and the fifth wall components 30 and 32 are preferably made from the same material and also provided by extrusion as the three wall components 24, 26 and 28. As is evident from Fig. 2, the fourth wall component 30 is provided with an outer slot for coopera¬ ting with the above described plate component 16 of the outer housing part 12 of the laser image setter. The individual housing components 24, 26, 28, 30 and 32 are assembled by means of cooperating male and female locking components 42 and 44, respectively, which allow that the housing components interconnected through the male and female locking components in question may rotate or swing relative to one another. The wall components 24, 26, 28, 30 and 32 are further pro¬ vided with protruding wall parts 46 and 48, which protrude into the inner space 22 and define a central groove therebetween for receipt of fixing means, such as screws or rivets, for fixation of end plates

shown in greater detail in Fig. 1 to the wall components 24, 26, 28, 30 and 32. •

As is evident from Fig. 1, a first end plate 50 is fixed to the wall components 24, 26 and 30 by means of five screws providing a rigid trough shaped housing part, which is in an upside down position shown in Fig. 2. Similarly, a second end plate 52 shown in Fig. 1 is fixed to the wall components 28 and 32 by means of three screws for pro¬ viding a trough shaped housing part which fits into the above dis- cussed trough shaped housing part constituted by the end plate 50 and the housing components 24, 26 and 30. End plates identical to the end plates 50 and 52 shown in Figs. 1 and 2 are further provided at the opposite end of the housing 20, however, concealed by an end closure component 54. A similar end closure component 56 is further provided at the opposite end of the housing 20. The end closure components 54 and 56 are fixed to the adjacent end plates by means of screws and meshing nuts 58 and 60, respectively. Thus, the end closure component 56 is by means of a first screw and nut assembly fixed to the first end plate 50 and fixed to the second end plate 52 by means of the second screw and nut assembly.

At one of the end closure components 54 or 56, a handle (not shown on the drawings) is preferably provided, which handle is fixed to the end closure component by means of the above discussed screw and nut assemblies. The screw and nut fixation of the end closure components 54 and 56, which are further provided with circumpherential wall parts 62 and 64, respectively, which define an inner groove within the end closure components 54 and 56, respectively, into which groove the assembly constituted by the wall components 24, ^' 26, 28, 30 and 32 is received, maintains the above discussed trough shaped housing parts constituted by the housing components 24, 26, 30 and 28, 32, respectively, in a position shown in Fig. 1 and further shown in solid line in Fig. 2. If the end closure components 54 and 56 are removed, the above discussed trough shaped housing parts are allowed to rotate or swing relative one another so as to provide access to the inner space 22.

In Fig. 2, the second trough shaped housing part comprising the housing component 28 and the fifth housing component 32 is also shown in a dotted line position, i.e. in a position, in which the trough shaped housing parts are separated from one another. By allowing that the above discussed trough shaped housing parts may rotate relative to one another, an operator may, in case a film is jammed within the cassette 10, easily save the film by simply removing the end closure components 54 and 56 by obtaining access to the inner space -22 by moving the second or lower trough shaped housing part comprising the housing components 28 and 32 to the dotted line position shown in Fig. 2.

Within the inner space 22, two further plates 70 and 72 are arranged. The plates 70 and 72 are arranged parallel with the end plates 50 and 52 and are fixed to the end plates 50 and 52, respectively, through shafts extending between the plates 50, 70 and 52, 72, respectively. Thus, a total of three shafts 74, 76 and 78 are provided as shown in Fig. 2 extending between the end plate 50 and the plate 70 and a total of four shafts 80, 82, 84 and 86 extend between the end plate 52 and the plate 72. The shaft 74 constitutes a drive shaft, on which a motor assembly 88, a drive pulley 90 and an encoder (not shown on the drawings) are mounted. The motor assembly 88 and the encoder are connected to respective pins of a multipin plug 92 received within the end closure component 54. The shafts 76, 78, 80, 82, 84 and 86 constitute idler shafts, on which idler pulleys 96, 98, 100, 102, 104 and 106, respectively, are mounted.

As is evident from Figs. 1 and 2, the idler pulleys 96, 98, 100 and 106 are composed of a total of nine sections each defining four small diameter parts of each of the Idler pulleys and five larger diameter parts of each of the pulleys drive, on which smaller diameter parts four belts 110, 112, 114 and 116 are arranged. The belts 110, 112, 114 and 116 are guided by the adjacent larger diameter idler pulley parts. Contrary to the idler pulleys 96, 98, 100 and 104, the idler pulleys 102 and 104 and further the drive pulley 90 are solid unsec- tioned pulleys, i.e. pulleys not divided into a plurality of separate sections. As will be readily understood, the smaller diameter pulleys of the idler pulleys 96, 98, 100 and 104 are aligned relative to one

another so that the belts 110, 112, 114 and 116 are not twisted or otherwise deformed from their belt shape. The belts 110, 112, 114 and 116 are further, as clearly disclosed in Fig. 1 and 2, wound around a central take-up core 118, which is simply constituted by a hollow tube of a plastics material, such as a length of a PVC tube. The take-up core 118 is not provided with journalling means, however, guided by the end plates 50, 52 and 70, 72, respectively, and by the belts 110, 112, 114 and 116. The belts 110, 112, 114 and 116 encircle or enwind approximately 270° of the outer periphery of the take-up core 118 and any film received thereon and forces the take-up core

118 against the outer periphery of the drive pulley 90 and the outer periphery of the idler pulley 102 as the take-up core is empty as indicated by solid lines in Fig. 2 and against the outer periphery of the drive pulley 90 and the outer periphery of the idler pulley 104 as the take-up core 118 has taken up more film as indicated by dotted lines in Fig. 2.

The cassette 10 discussed above is operated in the following manner. The cassette 10 is from its hermetically sealed state positioned within the recess 14 of the outer housing part 12 of the laser image setter, from which the cassette 10 is about to receive a film sheet, such as the film sheet 34 shown in Fig. 2. The aperture or opening 36 is provided as the protruding part 18 of the recess 14 of the laser image setter causes the outer wall component 32 of the cassette to rotate from its dotted line position shown in Fig. 2 to its solid line position shown in Fig. 2. The film 34 is introduced into the aperture or opening 36, and the motor assembly 88 is energized for causing the drive pulley 90 to rotate clockwise. The clockwise rota¬ tion of the drive pulley 90 is transmitted to the drive belts 110, 112, 114 and 116 and further to the take-up core 118, which is caused to rotate anti-clockwise. The film 34 is squeezed between the belts

110, 112, 114 and 116 and the outer periphery of the take-up core and is caused to rotate along with the take-up core 118.

During transport of film sheets, e.g. when a film sheet leaves a laser image setter, the film become charged with static electricity, leading to a risk of the film receiving dust from the surroundings or of a discharge of electric charge that may expose the film. To pre-

vent the film from being statically charged when entering the cas¬ sette, an antistatic brush 35 made of conducting fibre is mounted in the wall component 30 and extends along the width of the cassette. The length of the fibers of the brush 30 is adapted so that they do not touch the film surface. The antistatic brush 35 is connected to earth by a cable (not shown in the drawing) .

The motor assembly 88 is controlled by the central computer of the laser image setter by the supply of a power supply voltage to the motor assembly from the laser image setter. Preferably, the rotation of the drive pulley 90 is an intermittent rotation as the motor assembly 88 is energized and de-energized controlled by the above central computer. The rotation of the drive pulley 90 is further controlled by means of the above mentioned encoder, which generates an encoder signal in response to the rotation of the drive pulley 90. As will be readily understood, the diameter of the take-up core 118 varies or increases as the film 34 is introduced into the cassette 10 and taken up by the take-up core. However, the diameter of the drive pulley 90 does not vary and the encoder signal generated in response to the rotation of the drive pulley 90 is consequently independent of the take-up of film by the cassette and provides true information representing the rotation of the drive pulley in terms of speed and angular distance to the above central computer. Alternatively, the motor assembly 88 may be permanently energized causing the belts 110, 112, 114 and 116 to rotate permanently.

As more and more film introduced into the cassette is taken up by the take-up core 118, the total outer diameter of the take-up core 118 and film received on the outer periphery thereof increases causing the center of the take-up core 118 to be displaced from a position indicated by the reference numeral 120 to a position indicated by the reference numeral 122 along a line designated the reference numeral .124. When the outer diameter of the film received or taken up on the take-up core 118 has reached a predetermined maximum, a microswitch (not shown on the drawings) is activated so as to supply information to the above central computer interrupting the operation of the cassette 10 and further informing an operator that a substitution cassette has to be provided. The microswitch is connected to the

central computer of the laser image setter through respective pms of the multipin plug 92.

In its normal operational mode, the motor assembly 88, which compri¬ ses a DC motor rotating at a speed of 5-6,000 r.p.m. and a reduction gear, causes the drive pulley 90 and further the take-up core 118 to rotate at a speed resulting in the take up of approx. 1-10 m film sheet/minute, such as e.g. 0.5 m film sheet/10 sec.

The film received in the cassette 10 and taken up on the take-up core 118 is discharged from the cassette 10 in a darkroom by the supply of a supply voltage of reverse polarity to the motor assembly as com¬ pared to the above described operation for causing the drive pulley 90, the belts 110, 112, 114 and 116 and further the take-up core 118 to rotate in opposite directions as compared to the above described directions.

In the above specification, the terms "upper", "lower", "left-hand" and "right-hand" refer to the orientation defined by the vertical section view of Fig. 2, exclusively. However, the cassette 10 is preferably mounted in a position substantially as disclosed in Fig. 2 having its take-up core 118 arranged horizontally.

EXAMPLE

The above described presently preferred embodiment of a cassette 10 according to the present invention was made from the following compo¬ nents:

- the wall components 24, 26, 28, 30 and 32 were made from aluminum extrusions of a wall thickness of approx. 2 mm,

- the housing 20 defined by the wall components 24, 26, 28, 30 and 32 had a square section measuring 19 cm x 19 cm,

- the length of the wall components 24, 26, 28, 30 and 32 was 59.2 cm, - the distance between the end plates 50 and 52 and the plates 70 and 72 was 28 cm

- the end plates 50, 52, the plates 70, 72 and further the end plates concealed by the closure component 56 were made from 1.5 mm cadmium plated steel,

- the shafts 76, 78, 80, 82, 84 and 86.of the idler pulleys 96, 98, 100, 102, 104, and 106 were journalled on needle bearings supplied from the German company INA and were of the type HK 1622,

- the solid unsectioned idler pulleys 102 and 104 were constituted by steel tubes of an outer diameter of 22 mm,

- the smaller diameter sections of the idler pulleys 96, 98, 100, and 106 were constituted by steel tubes of an outer diameter of 22 mm, and the larger diameter sections of the idler pulleys 96, 98, 100, and 106 were constituted by hollow plastics bodies made from POM of an outer diameter of 28 mm,

- the belts 110, 112, 114 and 116 were made from natural rubber of a width of 25 mm,

- the DC motor of the motor assembly 88 was a 24 V DC motor supplied from the German company Dunker,

- the end closure components 54 and 56 were cast from the plastics material ABS. - the take-up core 118 was a PVC tube of an outer diameter of 9 cm and of a length of 58.0 cm.

The film cassette may, e.g., be adapted to receive at least 60 film sheets of varying widths and lengths.