FR2507370A1 - MAGNETIC DISC CASSETTE HAVING A TRACK INDICATION MEANS - Google Patents

Abstract

THE INVENTION RELATES TO A CASSETTE FOR A MAGNETIC DISC INCLUDING A MEAN FOR INDICATOR OF THE NUMBER OF RECORDING TRACKS. THE CASSETTE 1 INCLUDES AN ENVELOPE 2 CONTAINING A ROTARY MAGNETIC DISC 3 HAVING A HUB 6 WHICH RECEIVES A ROTARY DRIVE SHAFT INTENDED TO DRIVE THE MAGNETIC DISC IN ROTATION. ENVELOPE 2 HAS AN OPENING 17A, 17B THROUGH WHICH THE ROTARY DRIVE SHAFT PASSES. WHEN THE DISC IS ROTATING, INFORMATION MAY BE RECORDED ON SEVERAL CIRCULAR TRACKS. THE ENVELOPE IS ALSO EQUIPPED WITH AN INDICATOR 20 USED TO INDICATE THE NUMBER OF TRACKS ON WHICH INFORMATION SIGNALS HAVE ALREADY BEEN RECORDED. THE INVENTION APPLIES IN PARTICULAR TO A FIXED IMAGE TAKING APPARATUS OF THE MAGNETIC RECORDING TYPE.

Description

The present invention relates to a magnetic disk cassette and, more

  especially, a cassette which is formed of an envelope in which is housed a rotating magnetic disk, the cassette being used in the recording device and / or of reproducing a fixed electronic camera and the envelope is provided with an indicator which indicates the

  number of "photos" that have been recorded.

  Rotating magnetic disks have been used for the recording of information in various types of devices for example, in calculators, word processors, etc., magnetic disks, known as "diskettes",

  were used to record typical information signals.

  these diskettes are housed in an envelope which serves to protect the magnetic recording surfaces of the magnetic disk information and, in addition, to prevent the magnetic disk from being

  folded, creased, or seriously damaged in any way.

  This protective envelope is provided with a window by which one or more magnetic transducers can be inserted to come into magnetic contact with the magnetic surface of the disc for the purpose of recording or reproducing information signals.

  information signals are recorded on several recording tracks.

very circular.

  In a magnetic disk of the type mentioned above, there is no indication on the envelope or on the means housing the disc that shows the user the number of tracks on which information signals have been recorded. such information is produced by the recording apparatus which keeps track of the number of tracks that have been used as well as that of

  tracks that are available for further recording.

  However, in most information recording devices,

  the user is not aware of the information so retained and therefore can not be aware of the

  which has been used or remains available.

  It is therefore an object of the invention to provide an improved magnetic disk cassette carrying an indicator which gives

  directly to the user the ability to record

  of the magnetic disc that has been used and / or which remains

  available for further registration.

  Another object of the invention is to provide an improved magnetic disk cassette having an envelope on which

  is placed the indicator mentioned above.

  Another object of the invention is to propose a magnetic disk cassette having an envelope which contains an indicator that directly informs the user of the number of tracks of the disc.

  magnetic signals on which information signals have already been recorded.

  tered. A further object of the invention is to provide a magnetic disk cassette having an envelope which contains a relatively simple structure indicator, easy to manufacture and operating in a simple manner, this indicator serving to inform the user of the number of tracks of the magnetic disk on which

  information signals have been recorded.

  According to the invention, there is provided a disk cassette for housing a magnetic disk, the latter being of the type which has a hub adapted to receive a rotary drive shaft and thus be able to rotate so that information signals can be recorded on each separate circular track The cassette is formed of an envelope that surrounds and protects the magnetic disk and has an opening through which the drive shaft above

  mentioned can pass to be received by the hub of the magnetic disk.

  The envelope is also provided with an indicator that provides a direct indication of the number of tracks on which information signals have already been recorded. The indicator thus provides an indication of the recording capacity of the disc that has already been recorded.

  used or which remains available for further recording

  tration. According to the aspect of the invention, the information indicator consists of a dial and a registration scale, the latter being provided with markers that indicate the number of tracks that can be recorded on the magnetic disk. dial and the tracking scale are movable relative to each other, and the dial includes a pointer which is intended to target the number marks.

  successive tracks carried by the tracking scale.

  According to one embodiment of the invention, the dial is rotatable and has a recess for receiving a driving rod associated with the recording and / or reproducing device in which the magnetic disk cassette is used. recess serves not only to rotate the dial during the rotation of the drive rod, but, in addition, makes

  also function of the pointer mentioned above.

  According to a particular embodiment of the invention, the dial is mechanically coupled to a pinion, and a releasable locking device can be inserted between the adjacent teeth of the pinion to releasably lock the dial in any particular angular position. in which it is located The dial is released when it is rotated, this

  which allows the successive teeth of the pinion to pass in front of the

  Preferably, the locking device is in the form of an elastic latch which is attached to a latch.

internal surface of the envelope.

  The following description, designed as an illustration

  of the invention, aims to give a better understanding of its features and advantages; it is based on the accompanying drawings, among which: Figure 1 is a plan view of the envelope or cassette containing a flexible magnetic disk, this view being partially cut away; Figure 2 is a plan view of the envelope or cassette of Figure 1, seen on its opposite side; Figure 3 is an enlarged sectional view taken along line 3-3 'of Figure 1; Figure 4 is an enlarged fragmentary top plan view of the envelope in which the top wall has been removed;

  FIG. 5 is an enlarged sectional view taken -

  along line 5-5 'of Figure 4 Figure 6 is an enlarged fragmentary top plan view of the envelope 3 in which the top wall has been removed and an indicator drive rod is inserted into a opening; and Figure 7 is an enlarged sectional view taken

  along line 7-7 'of Figure 6.

  Referring now to drawings 3 in which consistent reference numerals are used, and to begin with FIGS. 1, 2 and 3, these figures show that a cassette 1 for use in a recording device and / or a soft-disk reproduction comprises a substantially planar rectangular shell or housing 2 which may be molded from a suitable plastics material and has opposed walls 2a and 2b between which a flexible disk 3 of magnetic material may The disc 3 has a relatively small diameter, not exceeding for example about 50 mm, so that the envelope 2 can have a dimension corresponding to it, for example measurements of 60 mm × 54 μm × 3 mm, in order to facilitate handling, storage and transport, for example by air, and allowing

  use it in a recording device and / or reproduce

  a compact camera, which may for example be part of a still camera whose size does not substantially exceed

  that of a conventional 35mm single-lens reflex camera.

  The opposite walls 2a and 2b of the envelope 2 comprise aligned openings or windows 4 which extend, in the radial direction of the disc 3, at least to the inner and outer limits.

  of the circular recording tracks of the recording area.

  A door 5 is placed above the disc 3 and can slide along an edge of the envelope 2, parts of the door 5 being placed against the inner surfaces of the walls 2a and 2b so as to ability to effect a sliding movement in the direction of the arrow 5a of Figure 1 between the closed position shown

  and an open position in which the door 5 disengages the windows 4.

  A tension spring 5b can be connected to the door 5 so as to push the latter towards its closed position, and a projecting part 5c protrudes from the door 5 and can be actuated by a suitable element provided on the device which receives cassette 1 in the camera (not shown), in order to open the

  door 5 for the insertion of the cassette 1 into the recording device

  recording and / or reproduction When the door 5 is thus open, one or more magnetic heads can pass through one of the windows 4 in order to perform the magnetic recording of information signals, representing for example a photograph, on one chosen concentric circular recording tracks from the surface 3a

disc (see Figure 3).

  A hub 6 is provided in the center of the disk 3 and comprises

  a hole 7 which passes through it for the purpose of receiving a drive shaft.

  The hole 7 is preferably non-circular so as to define a pair of inclined positioning surfaces 8 intended to come into tangential contact with the circular periphery of the device. drive shaft for centering the rotating disk 3 with respect to the drive shaft An elastic rope member 9 passes through the hole 7 on the opposite side of the positioning faces 8 This rope member 9 is supported by an elongated hole 10 Oriented in the direction of the element 9 and lying on the opposite side to its surface 9a which faces towards the positioning surfaces 8 The hub 6 described can be easily molded from a suitable plastic material, which furthermore confers elasticity of the elastic element 9 The hole 7 is dimensioned so that, when the drive shaft is inserted therein, the element

  elastic 9 is flexed by the shaft in a spacing direction vis-a-vis

  screw positioning surfaces 8, so as to maintain a firm contact of the surfaces 8 with the outer periphery of the drive shaft.

  The hub 6 further comprises an annular magnetic element

  11 is suitably mounted on its lower surface. A magnetic detection rod 13 for use in measuring the phase of rotation or the position of the disk 3, and a balancing rod 14.

  magnet having substantially the same weight as the rod 13 are incas-

  In one embodiment, at least three supports or feet 16 extend from the lower surface of the hub 6 at angularly distributed positions between them, these supports going radially out of the hub 6 into diametrically opposite positions. The lower surfaces 16 have supports 16 protruding slightly from the back of the hub 6 and define a reference level.

  relative to the magnetic recording surface 3a of the disk 3.

  In another embodiment, the feet 16 are replaced by a continuous annular flange The walls 2a and 2b of the casing 2 have central openings 17a and 17b in which the

  hub 6 can rotate without friction.

  According to the invention, the casing 2 of the cassette 1 is provided with an indicator 20 which is designed to display an indication of the part of the capacity of the disc 3 which has been used, or

  the one that remains available for further registration.

  More specifically, the indicator 20 indicates the number of tracks on which information signals have already been recorded. In FIGS. 1 and 2, it can be seen that the indicator comprises a rotary dial 21 and a registration scale 28 circularly surrounding the 21, and a pointer associated with the dial and serving to target an indication of the marking scale which represents the

  number of tracks recorded on the disc 3.

  In the embodiment shown, the dial 21 is adapted to rotate with respect to the registration scale. In another embodiment, the registration scale may be provided on the rotary dial and, therefore, rotate relative to the registration scale. Has a pointer that is fixedly mounted on the casing 2 It is therefore noted that the dial 21 and the marking scale 28 can turn relative to each other.

to the other.

  Preferably, as illustrated in FIG. 1, the registration scale 28 carries marks or marks which provide a numerical indication of the number of tracks which have been recorded on the disk. As an example, the disk 3 may have a capacity

  recording of 50 tracks. For example, the recording scale

  28 is equipped with digital indications ranging from track 1 to track 50.

  different numbers shown in Figure 1 These marks may represent

  run all the tracks, half of the tracks with one track out of two, etc. The envelope 2 has an additional opening 27

  by which the dial 21 for example is made accessible to a

  The dial 21 is placed within the space defined by the upper and lower walls 2a and 2b and is designed to rotate in this space. The pointer described above in relation to FIG. 4 can be observed through the opening 27 formed in the upper wall 2a, and the dial itself can be entralné by a suitable device which engages the dial via an opening 27b made in

the bottom wall 2 b.

  As can be better seen in FIGS. 4 and 5, the dial 21 is mechanically coupled to a pinion 24, which carries teeth on its periphery. In the preferred embodiment, the dial 21 and the pinion 24 are formed of a only one piece of a suitable plastic material It is also possible that pinion 24 is

  coupled to the dial 21 by a suitable mechanical transmission means.

  According to an embodiment in which the dial and the pinion are integral, the pinion is formed symmetrically with respect to the dial so that equal parts of the dial are disposed above and below the pinion, as shown in FIG. The dial can be considered as the central hub of the pinion In the embodiment shown in FIG. 5, the upper and lower surfaces of the dial 21 are respectively stepped so as to be able to rest respectively inside.

  openings 27a and 27b of the upper walls 2a and lower 2b.

  In another embodiment, the stepped portions may be omitted, in which case the upper and lower surfaces of the pinion 24 rest on the respective inner surfaces of the upper and lower walls of the envelope 2, the dial 21 being disposed

  inside the openings 27a and 27b.

  A releasable locking device 25 cooperates with the pinion and, consequently, the dial 21, at the present position of the dial. As will be described, the dial 21 can be rotated by an appropriate drive mechanism provided in FIG. the recording and / or reproducing device with which the magnetic disk cassette is used to maintain the indication provided by the pointer 23 when the number of circular tracks on which the information has already been recorded increases the dial 21 rotates step by step; and the releasable locking device 25 serves to hold the dial in the last position up to which it has rotated. This allows the magnetic disk cassette to be removed from the recording device and / or to reproduce 'indication

  of the last track recorded immediately before the removal.

  Thus, the dial 21 can not turn accidentally when

  the magnetic disk cassette is handled stored or transported.

  In the embodiment shown, the releasable locking device 25 is formed by an elastic ratchet 25 b

  which ends in a nose 25a which can be inserted between the adjacent teeth.

  The pawl 25b is integrally formed with a portion 25c constituting a mounting block, this mounting block and the pawl being made of a suitable plastic material. As shown, the pawl 25b is protruding vertical with respect to block 25 c The mounting block is intended to be mounted on

  the inner surface of the upper wall 2 has, for example, the enve-

  For this purpose, it is possible to use suitable mounting elements such as screws. It is also possible to provide mounting rods secured to the inner surface of the upper wall of the housing.

  the casing 2, the mounting block 25c having openings

  nables concordant with these mounting rods so that the block of

  mounting is mounted by press fit.

  The resilient pawl 25b pushes the nose 25a so that it engages the teeth of the pinion 24 When the pinion is

  rotated (as will be described below), the displacement of

  The tooth formation bends the pawl 25b so as to temporarily remove the nose 25a from between the teeth. As will be described, the dial 21 rotates to rotate the pinion 24 in correspondence so that a tooth passes. In front of the nose 25a After this passage of a tooth, the nose 25 is found again inserted between adjacent teeth of the pinion 24 Thus, the dial 24 rotates by an angle equal to the angular separation existing between adjacent teeth

  of the pinion at each recording of a circular track of the disk 3.

  After the next track has been recorded, the dial 21 is driven to once again advance the pinion of that amount; and the pointer 23 advances a notch to indicate the number

  tracks on which information signals have been recorded.

  As shown in FIG. 4, the aperture 22 of the dial 21 is in the form of a keyhole 1 so that the pointer 23 is constituted by a recess or an elongated notched portion of

  this opening Thus, the pointer 23 is constituted by an extension

  of the opening 22, the latter being designated as a recess The function of this recess will be better understood in relation

with Figures 6 and 7.

  When the cassette 1 of magnetic disk loaded into

  a suitable support (not shown) of the recording device

  recording and / or magnetic reproduction, a training tree

  30 having a radial projecting portion 31 fits into the opening 22. As best seen in FIG. 6, the projecting portion 31 is received in the recess 23. The drive shaft 30 is partially surrounded by a The driving shaft 301, together with the projecting portion 31, is designed to be displaced in its axial direction, that is to say the vertical direction of FIG. 7. drive shaft 30 is movable relative to the sleeve 32 As will be explained, this movement

  axial axis of the drive shaft allows for an appro-

  When the desired concordance is obtained, the recording and / or reproducing device is excited by rotating the disc 3 and recording information signals on a track. respectively through the window 4 The magnetic head of the recording and / or reproducing device is mechanically linked to the drive shaft 30 The positioning of the magnetic head with respect to a respective track of the disk 3 is realized when the projecting portion 31 has been inserted in the recess 23 Thus, when the drive shaft 30 turns the mechanical connection with the magnetic head has the effect of also changing the position of this

  head to allow recording of another track of the disc.

  So, to allow a correct recording, it is necessary that the part

  protruding 31 is engaged in the recess 23.

  In a device for recording and / or reproducing

  duction with which the magnetic disk cassette is used,

  the drive shaft 30 is, under normal conditions, elastically

  applied to an initial angular or circumferential position such that the projecting portion 31 is opposite an indication "O" carried by the registration scale 28 However, if one or more tracks have been recorded on the magnetic disk

  contained in the cassette which has been inserted in the recording device

  In fact, the recess 23 will initially not match or align with the protruding portion 31 and, therefore, when the magnetic disk cassette is loaded, the dial 31 comes into contact with the recess 31. the projecting portion 31 so as to drive the drive shaft 30 inside the sleeve 32 The fact that the drive shaft is thus depressed has the effect of actuating a drive motor with which the sleeve 32 is driven and rotates the drive shaft 30 and the projecting portion 31 so as to move the magnetic head of a track to the next track of the disc 3 When the drive shaft 30 has been properly driven, of in order to position the protruding portion 31 in alignment with the recess 23, the upwardly biasing force exerted on the drive shaft allows the projecting portion to fit into the recess and deactivates the drive motor cit. Therefore, the projecting portion 31 is then in appropriate driving contact with the dial 21 and, in addition, the

  magnetic head is placed next to the desired track of disc 3.

  The recording operation can then begin At the end of this recording operation, the sleeve 32 is driven by the above-mentioned drive motor so as to rotate the drive shaft 30 and the drive. projecting portion 31, and thus advance the dial 21 so that the recess 23 then targets the number of the last track that has been recorded In addition, the magnetic head is advanced so as to position itself for recording on the

  next track of the magnetic disk 3.

  It will be assumed that the sleeve 32 is rotated by an angle which corresponds to the angular separation between the adjacent teeth of the pinion 24. Thus, the dial 21 rotates by one unit increment after the recording of a track. unit increment is proportional to the indication carried by the registration scale 28 which corresponds to a single track, Thus, the angular distance between the teeth of the pinion 24 is proportional to the angular distance between indications of the registration scale 28, which allows to obtain gradual indications of the number of tracks

which have been registered.

  On the basis of what has just been described, it will be admitted that the recess 23 of the dial 21 serves not only to receive the projecting portion 31 of the drive shaft 30, but also to indicate the number of tracks that have been recorded on the disc 3 The dial 31 turns notch by a distance

  angular corresponding to an increment of the fiducial scale 28.

  In addition> the connection between the drive shaft 30 and the magnetic head has the function of preventing recording until

  that the protruding portion 31 is engaged in the recess 23.

  This pocketing to record on the same track information that

  destroy those previously recorded on this track.

  After a track has been recorded, the dial 21 rotates to position the recess 23 opposite the next indication of the registration scale 28. Therefore, the dial and the registration scale cooperate to display a indication of the number of tracks that have been recorded on the magnetic disk 3 These indications may be similar to the indications normally given on a photographic film to inform the user of the number of photos he has taken or the number of photos that remain In other words, the recess 23 cooperates with the registration scale 28 to inform the user of the remaining capacity.

  on the magnetic disk 3 for further recording.

  Of course, those skilled in the art will be able to imagine.

  from the magnetic disk cassette whose description comes

  to be given as merely illustrative and not limiting, various variants and modifications not outside the scope of the invention.

Claims (11)

R E V E N D I C A T IO N S   A magnetic disk cassette of the type having an envelope (2) for holding a rotating magnetic disk (3), the disk having a hub (6) for receiving a drive member for rotating the disk to record therein information on circular tracks, an opening (17a, 17b) being formed in the casing for receiving the hub, the cassette being characterized in that it comprises an indicator means (20) arranged on the casing in order to 'indicate the number of tracks on   which information has been recorded.   2 cassette according to claim 1, characterized in that the indicator means (20) comprises a circular dial (21), a pointer (23) associated with the dial, and a tracking scale (28) which provides indications of the number of tracks. , the dial and the scale   of locating being movable relative to each other.   3 cassette according to claim 2, characterized in that the dial is rotatably mounted in the casing, and the casing is provided with an additional opening (27) for receiving a   means to turn the dial.   4 cassette according to claim 3, characterized in that the dial is provided with a recess (23) for receiving a projecting portion of the means for rotating the dial, so that the rotation of the projecting portion rotates the dial. Cassette according to claim 4, characterized in that   that the recess forms said pointer.   6 cassette according to claim 3, characterized in that the indicator means further comprises a releasable locking means (25) disposed in the casing to lock so   releasable the dial in distinct rotational positions.   7 cassette according to claim 6, characterized in that the dial comprises a rotary pinion (24) having teeth on its periphery, and the releasable locking means comprises an elastic pawl (25 b) intended to be inserted between adjacent teeth so to lock the rotary pinion and the dial in their current position.   8 cassette according to claim 7, characterized in that the envelope comprises upper walls (2 a) and lower (2 b) spaced apart from each other which define a space for the magnetic disk, and in that it further comprises means (25c) for mounting the resilient pawl on the inner surface of one of said walls. 9 cassette according to claim 8, characterized in that the elastic pawl comprises an elastic arm having a nose portion (25 a) intended to be inserted between adjacent teeth of the rotating pinion.   Cassette according to claim 9, characterized in that the means for mounting the elastic pawl comprises a mounting block (25c) mounted on the inner surface of said wall, the mounting block and the elastic arm being integrally formed the   elastic arm protruding from the mounting block downwards.   11 cassette according to claim 8 characterized in that the dial is formed on the rotary pinion and is jointly built with this one.   12 cassette according to claim 11, characterized in that the pinion is disposed symmetrically with respect to the dial of   way that substantially equal parts of the dial extend beyond above and below the pinion.   Cassette according to claim 7, characterized in that   that the adjacent peripheral teeth of the pinion are spread angu-   stretching each other a distance that corresponds to the   existing separation between adjacent tracks of the disc.   Cassette according to Claim 13, characterized in that the indications of the number of tracks are angularly separated from one another by an integer multiple of the angular separation.   existing between the adjacent peripheral teeth of the pinion.