Tape cassettes

Abstract: A tape cassette comprises a housing (1) and a pair of reels (4, 5) mounted for rotation and translation in the housing (1) so that the reels can assume either of first and second relative positions. A recording tape (T) is wound on the reels (4, 5) and extends therebetween for transport from one of the reels to the other. The housing is formed with a mouth (12) through which a transducer (61) can gain access to the recording tape (T) to record or reproduce signals on or from the recording tape (T). The reels (4, 5) in the first relative position conform to a first arrangement of a drive for driving the reels (4, 5) in rotation and afford a predetermined amount of space for accommodating the transducer (61) within the housing (1) for access to the recording tape (T) and in the second relative position correspond to a second arrangement of a drive for driving the reels (4, 5) in rotation and afford an additional amount of space for accommodating the transducer (61) within the housing (1) for access to the recording tape (T). The translation of the reels has a component parallel to a left-to-right direction of the housing as well as a front-to-rear direction of the housing, so that the reels in the second position are displaced towards the rear corners of the tape cassette.

Description: The invention relates to tape cassettes. Tape cassettes have been proposed for use in magnetic recording and reproducing devices such as videotape recorders (VTRs), such tape cassettes being designed particularly for recording information during a relatively short period of time. Reference should be made to our Patent Specification JP-A-60(1985)-171684 and Utility Model specification JP-A-62(1987)-14573. One such tape cassette for recording information for a short period of time is schematically shown in Figure 9 of the accompanying drawings which shows that the tape cassette has a cassette housing 51 accommodating a pair of rotatable tape reels 52, 53 with a magnetic tape T wound therearound. The magnetic tape T has a portion unreeled from the tape reels 52, 53 and guided by semicylindrical guides 54 a , 54 b disposed in spaced positions at the front of the cassette housing 51, the unreeled tape portion being kept taut and exposed in a front opening in the cassette housing 51. The cassette housing 51 has a mouth 55 formed in a lower panel of the cassette housing 51 between and somewhat forward of the tape reels 52, 53. The diameter of the tape reels 52, 53 is smaller than the reel diameter of a conventional, standard tape cassette, and therefore the mouth 55 is correspondingly larger. When the tape cassette is in use, the magnetic tape T is withdrawn forwardly from the cassette housing 51 by tape withdrawal guides 60 a , 60 b in the magnetic recording and reproducing device, and a head drum 61 and various tape transport members 62 including an impedance roller 63, tape guides 64, 65, 66, loading posts 67, 68, a capstan 69, and a pinch roller 70 are inserted to the extent feasible into the mouth 55. The magnetic tape T is thus wound around the head drum 61 for recording or reproducing signals on or from the magnetic tape T. Since the tape reels 52, 53 are smaller in diameter and the mouth 55 is correspondingly larger than in earlier tape cassettes of the same general construction, the head drum 61 and the tape transport members 62 can be inserted more deeply into the cassette housing 51. As a result, the magnetic recording and reproducing device may be made small. However, the increase in the size of the mouth is slight since only the diameter of the tape reels is reduced in the conventional tape cassette for recording information during a relatively short period of time. This limits efforts to reduce the size of the magnetic recording and reproducing devices. In a conventional tape cassette, the cassette housing contains unused space near the rear corners of the tape reels; the space in the cassette housing of the conventional tape cassette is thus not effectively utilized. According to the invention there is provided a tape cassette comprising: housing means having at least a front, a rear and left and right sides; a pair of reels; means mounting both of the reels for rotation in the housing means; a recording medium wound on the reels and extending therebetween for transport from one of the reels to the other; wherein the housing means is formed with a mouth in the front through which transducer means can gain access to the recording medium to record or reproduce signals on or from the recording medium; characterised in that the cassette includes reel mounting means mounting at least one of the reels for translation in the housing means, so that the reel or reels can assume either of first and second relative positions; the reels in the first relative position conform to a first arrangement of drive means to drive the reels in rotation and afford a predetermined amount of space to accommodate transducer means within the housing means for access to the recording medium and in the second relative position conform to a second arrangement of drive means to drive the reels in rotation and afford an additional amount of space to accommodate transducer means within the housing means for access to the recording medium; and the translation has a component parallel to a left-to-right direction of the housing means. Advantageously the translation is effected by a pivoting movement of the mounting means in the housing means. Preferably the cassette is of the 8-mm format, wherein the housing means has first and second side walls; the reels are mounted for rotation in the housing means about respective first and second axes; the housing means has the shape of a rectangular parallelepiped measuring substantially 95 mm x 63 mm x 15 mm, and, with the reel mounting means conforming to the second arrangement, the first axis is located less than 25 mm from the first side wall, thereby affording, as compared to a standard eight-millimeter tape cassette having a side wall and a reel with an axis of rotation substantially 25 mm therefrom, an additional amount of space to accommodate transducer means within the housing means for access to the recording medium. Advantageously the cassette is of the 8-mm format, wherein the housing means has a rear wall and first and second side walls; the reels are mounted for rotation in the housing means about respective first and second axes; the housing means has the shape of a rectangular parallelepiped measuring substantially 95 mm x 63 mm x 15 mm, and, with the reel mounting means conforming to the second arrangement, each of the axes is less than 26 mm from the rear wall, the first axis is less than 25 mm from the first side wall, and the second axis is less than 25 mm from the second side wall, thereby affording, as compared to a standard eight-millimeter tape cassette having a rear wall and first and second side walls, a first reel with an axis of rotation substantially 26 mm from the rear wall and 25 mm from the first side wall, and a second reel with an axis of rotation substantially 26 mm from the rear wall and 25 mm from the second side wall, an additional amount of space to accommodate transducer means within the housing means for access to the recording medium. Thus a tape cassette can include a cassette housing whose internal space is more effectively utilized to define an enlarged mouth in the cassette housing. Such a tape cassette may be used in cooperation with a conventional recording/reproducing apparatus while also being compatible with a new type of recording/reproducing apparatus dedicated to use in combination with the new type of tape cassette. An 8-mm tape cassette in accordance with the invention may have an interior construction that makes it possible to reduce the size of a camcorder with which it cooperates. When a tape cassette according to the invention in its preferred embodiment is in its "normal" condition, the tape reels are in the same position as the tape reels of a conventional standard tape cassette, and the mouth is relatively small. The tape cassette is then compatible with a conventional cassette player. When the tape cassette is in use in a cassette player of a new design as disclosed herein the tape reels are moved or retracted towards the rear corners of the cassette housing, thereby enlarging the mouth. Thus, a head drum and other members can be inserted more deeply into the cassette housing. As a consequence, a recording and reproducing device which employs the tape cassette may be of a smaller size than has heretofore been achievable. The invention is diagrammatically illustrated by way of example in the accompanying drawings, in which:- Figure 1 is a top plan view of a tape cassette according to the invention, an upper housing portion of the tape cassette being omitted for clarity, the tape cassette being shown in a "normal" state in which it is capable of cooperating with a standard cassette player, and the tape reels being locked against rotation; Figure 2 is a view similar to Figure 1, but showing the tape reels unlocked so that they can rotate; Figure 3 is a view similar to Figure 2, but showing holders for the tape reels released for pivoting movement; Figure 4 is a view similar to Figure 3, but showing the tape cassette in a modified state, in which it is capable of cooperating with a new type of cassette player dedicated to use with a tape cassette constructed in accordance with the invention; Figure 5 is an exploded perspective view of the tape cassette of Figures 1 to 4; Figure 6 is a bottom plan view of the tape cassette of Figures 1 to 5; Figure 7 is an enlarged fragmentary plan view of a portion of the tape cassette of Figures 1 to 6; Figure 8 is an enlarged side elevational view illustrative of a back lid of the tape cassette of Figures 1 to 7; and Figure 9 is a top plan view of a conventional tape cassette. Referring to Figures 1 to 8, a tape cassette has a cassette housing 1 comprising an upper portion 2 and a lower portion 3 that are joined together in any conventional manner, for example by screws. The cassette housing 1 has an outer configuration and dimensions according to the internationally agreed-upon 8-mm video standards. The cassette housing 1 is thus in the shape of a rectangular parallelepiped measuring approximately 95 mm x 63 mm x 15 mm. The upper and lower housing portions 2, 3 of the cassette housing 1 accommodate therein a pair of rotatable tape reels 4, 5 with a magnetic tape T wound therearound. The magnetic tape T has a portion unreeled from the tape reels 4, 5 and guided by roller guides 6 a , 6 b disposed in spaced positions at the front of the lower housing portion 3. The unreeled tape portion is kept taut and can be exposed in a front opening formed in the cassette housing 5. The tape reels 4, 5 have respective hubs 4 a , 5 a around which the magnetic tape T is wound, and respective pairs of upper and lower flanges 4 b , 4 c and 5 b , 5 c to guide upper and lower edges of the tape T around the hubs 4 a , 5 a and maintain the upper and lower edges of the tape coils in a smooth, flat condition. As Figure 6 shows, the tape reels 4, 5 have central reel shaft insertion- holes 4 d , 5 d , respectively, formed therein and opening downwardly. The upper and lower tape reel flanges 4 b , 4 c ,and 5 b , 5 c of the tape reel 4, 5 have a diameter smaller than that of tape reel flanges of a standard tape cassette. Therefore, the magnetic tape T wound around the tape reels 4, 5 is shorter than the magnetic tape in a standard tape cassette. For example, the magnetic tape may be able to record or reproduce information during a period of time ranging from 30 to 60 minutes. The tape reels 4, 5 are movable in translation in the cassette housing 1 between a normal position which is determined by the 8-mm video standards and a retracted position near the rear wall of the cassette housing 1. A mechanism enabling movement of the tape reels 4, 5 between the normal and retracted positions in the tape cassette 1 is constructed as follows: The lower panel of the lower housing portion 3 has a large recess 7 formed behind the portion of the magnetic tape T which extends under tension between the roller guides 6 a , 6 b . Two reel holders 8, 9 are disposed above the recess 7 in the cassette housing 1. The reel holders 8, 9 are supported for angular movement on laterally spaced opposite sides of the cassette housing 1 by respective support shafts 10, 11. The angular movement has a component in a transverse (i.e. front-to-back) direction of the cassette housing 1 and also has a component in the lateral (i.e. left-to-right) direction of the cassette housing. The tape reels 4, 5 are rotatably supported respectively on the reel holders 8, 9. The reel holders 8, 9 comprise respective support plates 8 a , 9 a on which the respective tape reels 4, 5 are placed, and respective shield walls 8 b , 9 b disposed in covering relation to front and inner sides of the tape reels 4, 5 respectively. The support plates 8 a , 9 a have respective holes 8 c , 9 c formed therein. As Figure 6 shows, the tape reels 4, 5 have respective annular ridges 4 e , 5 e projecting downwardly from the undersides thereof and extending around the edges of the reel shaft insertion holes 4 d , 5 d . The annular ridges 4 e , 5 e are loosely received respectively in the holes 8c, 9c. A mouth 12 for receiving therein a head drum and tape loading members to record signals on and reproduce signals from the magnetic tape T is formed between and in front of the shield walls 8 b , 9 b of the reel holders 8, 9. When the reel holders 8, 9 are angularly moved, the tape reels 4, 5 are moved (i.e., translated), thereby varying the size of the mouth 12. The lower panel of the lower housing portion 3 also has a pair of recesses 7 a , 7 b formed therein in alignment with the holes 8 c , 9 c of the reel holders 8, 9 and contiguous with the recess 7. The recesses 7 a , 7 b extend along paths defined by the swingable reel holders 8, 9. The support plates 8 a , 9 a of the reel holders 8, 9 have surface areas (shown hatched in Figure 6) exposed in the recess 7 and positioned so as to avoid physical interference with the lower housing portion 3 when the reel holders 8, 9 are turned. These surface areas are raised so as to lie flush with the lower surface of the lower panel of the lower housing portion 3. The raised surface areas serve as a positioning reference surface for positioning the tape cassette when the tape cassette is loaded into the magnetic recording and reproducing device. Roller guides 13 a , 13 b are rotatably fitted respectively over the support shafts 10, 11. The magnetic tape T wound around the tape reels 4, 5 is guided over the roller guides 13 a , 13 b toward the roller guides 6a, 6b at the front of the cassette housing 1, and extends between the roller guides 6 a , 6 b in the front opening of the cassette housing 1. The opposite side walls of the lower housing portion 3 and the shield walls 8 b , 9 b of the reel holders 8, 9 have through-holes 14 and 15 for passing therethrough beams of light for detecting the starting and finishing ends of the magnetic tape T. Only one of the through-holes 15 is visible in Figure 5. Reel presser springs 16, 17 in the form of leaf springs are mounted on the lower surface of the upper panel of the upper housing portion 2. The reel presser springs 16, 17 comprise respective arms 16 a , 17 a whose proximal ends are fixed to the upper housing portion 2, and respective pressers 16 b , 17 b contiguous with distal ends of the arms 16 a , 17 a , respectively, for pressing respective central projections 4 f , 5 f of the tape reels 4, 5. The pressers 16 b , 17 b are of an arcuate shape extending along the paths of travel of the tape reels 4, 5 as they are pivoted by the respective reel holders 8, 9. The presser springs 16, 17 press lightly against the tape reels 4, 5 to prevent wobbling of the reels. The cassette housing 1 also houses in its rear portion a lock mechanism 18 to lock the tape reels 4, 5 and the reel holders 8, 9 against rotation. The lock mechanism 18 is constructed as follows: The lock mechanism 18 includes a lock member 20 positioned centrally on the rear portion of the cassette housing 1 and movable back and forth in a transverse (i.e. front-to-back) direction of the cassette housing 1, along a guide 19 disposed on the lower housing portion 3. The lock member 20 has a pair of fingers 21 a , 21 b projecting forwardly from laterally spaced opposite ends thereof. The reel holders 8, 9 have respective slots 22 a , 22 b formed in rear ends thereof to receive the respective fingers 21 a , 21 b of the lock member 20. The lower flanges 4 c , 5 c of the tape reels 4, 5 have engaging teeth 23 a , 23 b formed all around their outer circumferential edges, the engaging teeth 23 a , 23 b being engageable by the fingers 21 a , 21 b . A coil spring 24 is mounted under compression between the lock member 20 and the rear side wall of the lower housing portion 1, normally to urge the lock member 22, i.e., the fingers 21 a , 21 b , in a forward direction to engage in the slots 22 a , 22 b of the reel holders 8, 9 and also engage the engaging teeth 23 a , 23 b of the tape reels 4, 5. The lock member 20 has a central hole 20 a formed therein, and the lower panel of the lower housing portion 3 has an insertion hole 25 (Figure 6) formed therein in register with the hole 20 a . When the tape cassette is loaded in a magnetic recording and reproducing device, as described below, an unlocking member is inserted from the magnetic recording and reproducing device through the insertion hole 25 into the hole 20 a of the lock member 20 to displace the lock member 20 out of locking engagement with the tape reels 4, 5. The lower panel of the lower housing portion 3 has a groove 26 formed therein in front of the insertion hole 25 and extending rearwardly from the rear edge of the recess 7. When the tape cassette is loaded in the magnetic recording and reproducing device, an unlocking member is inserted from the magnetic recording and reproducing device through the groove 26 into the cassette housing 1 to -push a front end 20 b of the lock member 20 out of locking engagement with the reel holders 8, 9. A front lid 28 is mounted for pivoting movement on the front end of the cassette housing 1 selectively to open and close the front opening of the cassette housing 1. When the front opening of the cassette housing 1 is closed by the front lid 28, the front lid 28 protects the face of the magnetic tape T which extends under tension between the roller guides 6 a , 6 b . The front lid 28 has laterally spaced side walls 28 a , 28 b extending perpendicularly from the opposite ends of the front lid 28. The side walls 28 a , 28 b have respective horizontal shafts 29 projecting towards each other from inner surfaces thereof and received in respective holes 30 (only one of which is visible in Figure 5) defined by recesses in the front ends of opposite side walls of the upper housing portion 2 in combination with front ends of opposite side walls of the lower housing portion 3. Therefore, the front lid 28 is angularly movable in a vertical plane about the shafts 29 with respect to the cassette housing 1. The front lid 28 is normally urged to turn in a closing direction to cover the face of the magnetic tape T by a torsion spring 31 coiled around one of the shafts 29. Upon loading the tape cassette in either the standard or the dedicated magnetic recording and reproducing device, the front lid 28 is turned upwardly by a lid opening mechanism in the magnetic recording and reproducing device, thereby exposing the magnetic tape T between the roller guides 6 a , 6 b . A back lid 32 to protect the back of the magnetic tape T between the roller guides 6 a , 6 b is disposed behind the front lid 34. The back lid 32 comprises a back lid member 33 to cover the back of the magnetic tape T and an upper plate 34 for closing a cut-out 2 a formed in the upper panel of the upper housing portion 2. The cut-out 2 a receives the back lid member 33 when the back lid 32 is opened. The back lid member 33 and the upper plate 34 are joined to each other by joints 35. The back lid member 33 has shafts 36 on respective opposite side edges thereof, the shafts 36 being pivotally supported by respective supports 37 which project from the rear surface of the front lid 28. The back lid 32 is thus coupled to the front lid 28 for angular movement in a vertical plane. The back lid 32 also has engaging pins 38 projecting from respective opposite ends thereof. The engaging pins 38 are movably received in respective cam grooves 40 defined in the inner surfaces of vertical guide walls 39, which are located in laterally spaced positions in the front end of the lower housing portion 3. Only one of the cam grooves 40 is visible in Figures 5 and 7. When the front lid 28 is opened or closed with respect to the cassette housing 1, the engaging pins 38 are guided by and along the cam grooves 40 to cause the back lid 32 to be opened or closed in coordination with the front lid 28. The tape cassette is constructed to allow the front lid 28 to be closed after a head drum and tape transport members are inserted into the mouth 12, drawing the magnetic tape into the mouth 12 so that the magnetic tape T will be loaded around the head drum. More specifically, the back lid 32 has a pair of gaps a , defined in the respective opposite sides thereof, for passage therethrough of the portion of the magnetic tape T drawn into the mouth 12. Two arms project downwardly from the opposite ends of the upper plate 34 of the back lid 32, and the respective engaging pins 38 project outwardly from respective lower ends thereof. The gaps a are defined between the arms 41 and the opposite ends of the back lid member 33, as shown in Figures 7 and 8. A portion t of the magnetic tape T drawn into the mouth 12 passes through the gaps a , as indicated by the dot-and-dash line in Figure 7. Accordingly, the back lid 32, which moves in coaction with the front lid 28 does not physically interfere with the portion t of the magnetic tape T. The front lid 28 can thus be closed without being obstructed. The guide walls 39 of the lower housing portion 3 have respective front edges retracted largely from the roller guides 6 a , 6 b , thus providing gaps between themselves and the front lid 28 when it is closed, so that the magnetic tape portion t drawn into the mouth 12 is held out of physical interference with the guide walls 39. The upper panel of the upper housing portion 2 has a pair of laterally spaced relief grooves 42 communicating with the cut-out 2 a , to receive the respective arms 41 of the back lid 32 when the front lid 28 is opened. The tape cassette thus constructed operates as follows: Normally, the tape reels 4, 5 are held in respective positions prescribed according to the 8-mm video standards, as shown in Figure 1. The fingers 21 a , 21 b of the lock member 20 engage respectively in the grooves 22 a , 22 b of the reel holders 8, 9 and also engage the respective teeth 23 a , 23 b of the tape reels 4, 5. The reel holders 8, 9 are locked against pivoting with the tape reels 4, 5 in the respective prescribed positions. The tape reels 4, 5 are locked against rotation. Since the tape reels 4, 5 are normally in the predetermined positions according to the 8-mm video standards, the tape cassette can compatibly be used in the same manner as a general 8-mm video tape cassette without the use of any adapter. When the tape cassette is loaded into a standard magnetic recording and reproducing device designed according to the 8-mm video standards, an actuating member (not shown) is inserted from the magnetic recording and reproducing device through the insertion hole 25 into the hole 20 a of the lock member 20, thereby retracting the lock member 20 against the bias of the compression coil spring 24. The retraction movement of the lock member 20 causes the fingers 21 a , 21 b to be displaced out of locking engagement with the teeth 23 a , 23 b of the tape reels 4, 5, which are now unlocked as shown in Figure 2 and can rotate. Upon use of the tape cassette in a standard magnetic recording and reproducing device, the fingers 21 a , 21 b of the lock member 20 are only moved out of locking engagement with the teeth 23 a , 23 b of the tape reels 4, 5; they remain in locking engagement in the grooves 22 a , 22 b of the reel holders 8, 9. Therefore, the tape reels 4, 5 are unlocked for rotation, but their axes of rotation remain in the standard prescribed positions with respect to the cassette housing 1. Accordingly, the tape cassette can compatibly be employed in a standard magnetic recording and reproducing device just as though it was a standard 8-mm video cassette. If the tape cassette is loaded into a dedicated magnetic recording and reproducing device, the lock member 20 is engaged by an actuating member (Figure 4) of the dedicated magnetic recording and reproducing device. The lock member 20 is thus retracted through a substantial distance, and the tape reels 4, 5 are moved towards the rear corners of the cassette housing 1. As a consequence, the mouth 12, is enlarged as shown in Figure 4. The tape loading operation described above is carried out while the front lid 28 is being opened by a lid opening mechanism of the magnetic recording and reproducing device. Because all of the head drum 61 and the tape transport members 62 are accommodated completely in the mouth 12, the front lid 28 can be closed again after the magnetic tape T has been loaded around the head drum 61. The gaps a formed at opposite ends of the back lid 32 enable passage of the magnetic tape T therethrough, as described above. The back lid 32 does not physically interfere with the magnetic tape T as it passes through the gaps a , making it possible to close the front lid 28 smoothly and reliably. Since the mouth 12 is substantially enlarged when the tape cassette is loaded into a dedicated magnetic recording and reproducing device, the head drum 61 and the tape transport members 62 can fully be accommodated in the mouth 12 when the tape loading operation is completed (see Figure 4). While signals are being recorded on or reproduced from the magnetic tape T in the tape cassette, the head drum 61 and the tape transport members 62 in the magnetic recording and reproducing device are positioned along with the tape reels 4, 5 within a region which is of substantially the same size as the tape cassette. Moreover, as the front lid 28 can be closed after the tape loading operation is completed, the thickness of the magnetic recording and reproducing device can be reduced by the height that would be added if it were impossible to close the front lid 28. As a result, the dedicated magnetic recording and reproducing device can be of a miniature size whereby the magnetic recording and reproducing device can correspond to the size of the tape cassette itself. In other words, it can be rendered much more compact than conventional magnetic recording and reproducing devices. Furthermore, the roller guides 13 a , 13 b are fitted over the respective support shafts 10, 11 about which the reel holders 8, 9 are angularly movable, and the magnetic tape T is guided around the roller guides 13 a , 13 b into the front opening of the cassette housing 1. Even when the tape reels 4, 5 change their position upon angular movement of the reel holders 8, 9, therefore, the magnetic tape T is prevented from slackening and is reliably transported during use of the tape cassette. The roller guides 6 a , 6 b are disposed on opposite sides of the front opening of the cassette housing 1, and the guide walls 39 are spaced rearwardly from the roller guides 6 a , 6 b . When the magnetic tape T is to be loaded around the head drum 61, the magnetic tape T can smoothly be drawn into the mouth 12 without the need for the tape withdrawal guides 60 a , 60 b shown in Figure 9 that are used in conventional tape cassettes, as described above in connection with Figure 9. As a consequence, the number of components of the magnetic recording and reproducing device is reduced. This can contribute further to the reduction in its size. Moreover, the reel presser springs 16, 17 are shaped in conformity with the paths of travel of the tape reels 4, 5 in the cassette housing 1. The tape reels 4, 5 are thus held in position under constant forces irrespective of whether the tape reels 4, 5 are in the normal positions shown in Figure 1 or in the retracted positions shown in Figure 4. The tape reels 4, 5 can therefore be rotated stably at all times smoothly to transport the magnetic tape T. While the invention has been described as being applied to an 8-mm video cassette, the principles of the invention are also applicable to other tape cassettes for recording and reproducing information using rotary heads, such as a conventional 13 mm (1/2-inch) video cassette and a tape cassette for use in a DAT (digital audio tape recorder). A tape cassette according to the invention can be compatible with players for conventional standard tape cassettes, yet have a mouth capable of enlargement to allow the head drum and the tape transport members to be inserted even more deeply into the cassette housing. The magnetic recording and reproducing device which employs the tape cassette according to the invention may therefore be extremely small. Many modifications of the preferred embodiment of the invention described above will readily occur to those skilled in the art upon consideration of this disclosure. For example, although it is highly desirable for both of the tape reels to be mounted for translation in the housing, it is not strictly necessary that both be so mounted in order to achieve some of the advantages of the invention. Even if only one of the reels was movable to the rear, the recording/reproducing head or transducer could in principle be inserted more deeply into the mouth of the cassette by displacing it somewhat towards the side of the reel that is moved to the rear. The new tape cassette need not be compatible with standard, conventional tape cassette players, that is, it is possible to construct a tape cassette which fully conforms to the international standards (for example, the standards applicable to 8-mm tape cassettes) except that the tape reels are permanently "out of position" by being moved towards the rear wall of the tape cassette so that, instead of their centres being spaced the normal 26 mm or so from the rear wall, they are spaced less than 26 mm, or the centre of at least one of the tape reels is spaced less than 26 mm, and preferably both reels are approximately 21 mm from the rear wall.

Claims: A tape cassette comprising: housing means (1) having at least a front, a rear and left and right sides; a pair of reels (4, 5); means (4 e , 5 e , 8 c , 9 c ) mounting both of the reels (4, 5) for rotation in the housing means (1); a recording medium (T) wound on the reels and extending therebetween for transport from one of the reels to the other; wherein the housing means is formed with a mouth (12) in the front through which transducer means (61) can gain access to the recording medium (T) to record or reproduce signals on or from the recording medium (T); characterised in that the cassette includes reel mounting means (8, 9) mounting at least one of the reels for translation in the housing means (1), so that the reel or reels (4, 5) can assume either of first and second relative positions; the reels in the first relative position conform to a first arrangement of drive means to drive the reels (4, 5) in rotation and afford a predetermined amount of space to accommodate transducer means (61) within the housing means (1) for access to the recording medium (T) and in the second relative position conform to a second arrangement of drive means to drive the reels (4, 5) in rotation and afford an additional amount of space to accommodate transducer means (61) within the housing means (1) for access to the recording medium (T); and the translation has a component parallel to a left-to-right direction of the housing means (1). A tape cassette according to claim 1, wherein the translation also has a component parallel to the front-to-rear direction of the housing means (1). A tape cassette according to claim 1, wherein the translation is effected by a pivoting movement of the mounting means (8, 9) in the housing means. A tape cassette according to claim 3, wherein the mounting means comprises a pair of support shafts (10, 11) and a pair of roller guides (13 a , 13 b ) rotatably fitted on the respective support shafts (10, 11), the support shafts (10, 11) enabling pivoting movement of the recording medium being trained around the roller guides (13 a , 13 b ). A tape cassette according to claim 3, wherein the reels (4, 5) are movable along arcuate paths, and the cassette includes presser spring means (16, 17) having portions (16 b , 17 b ) respectively extending along the paths and engaging the reels (4, 5) to prevent wobbling of the reels. A tape cassette according to claim 1, including detection means (20) formed on the housing means, the detection means being capable of cooperating with a cassette player employing either of the first and second arrangements of drive means and of detecting the arrangement of drive means employed; and means (21 a , 21 b ; 22 a , 22 b ) connected to the detection means (20) to maintain the first relative position of the reels (4, 5) in response to detection of the first arrangement of drive means and to enable translation to the second relative position of the reels (4, 5) in response to detection of the second arrangement of drive means. A tape cassette according to claim 1, of the 8-mm format, wherein the housing means (1) has first and second side walls; the reels are mounted for rotation in the housing means about respective first and second axes; the housing means (1) has the shape of a rectangular parallelepiped measuring substantially 95 mm x 63 mm x 15 mm, and, with the reel mounting means (8, 9) conforming to the second arrangement, the first axis is located less than 25 mm from the first side wall, thereby affording, as compared to a standard eight-millimeter tape cassette having a side wall and a reel with an axis of rotation substantially 25 mm therefrom, an additional amount of space to accommodate transducer means (61) within the housing means (1) for access to the recording medium (T). A tape cassette according to claim 7, wherein the second axis is less than 25 mm from the second side wall. A tape cassette according to claim 1, of the 8-mm format, wherein the housing means (1) has a rear wall and first and second side walls; the reels are mounted for rotation in the housing means about respective first and second axes; the housing means (1) has the shape of a rectangular parallelepiped measuring substantially 95 mm x 63 mm x 15 mm, and, with the reel mounting means (8, 9) conforming to the second arrangement, each of the axes is less than 26 mm from the rear wall, the first axis is less than 25 mm from the first side wall, and the second axis is less than 25 mm from the second side wall, thereby affording, as compared to a standard eight-millimeter tape cassette having a rear wall and first and second side walls, a first reel with an axis of rotation substantially 26 mm from the rear wall and 25 mm from the first side wall, and a second reel with an axis of rotation substantially 26 mm from the rear wall and 25 mm from the second side wall, an additional amount of space to accommodate transducer means (61) within the housing means (1) for access to the recording medium (T).

Inventors: KONDO YOSHIO C O PATENTS DIVIS, KONDO, YOSHIO, C/O PATENTS DIVISION
Applicants: SONY CORP, SONY CORPORATION
Application year: 1991
Main classification: G11B23
IPC codes: G11B23, G11B15, G11B25