Tape cassette

Abstract: A tape cassette (1) comprises a housing (3) and a pair of reels (4, 5) for rotation and translation in the housing (3) 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 (3) is formed with a mouth (14) 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 to drive the reels (4, 5) in rotation and afford a predetermined amount of space to accommodate the transducer (61) within the housing (3) for access to the recording tape (T) and in the second relative position conform to a second arrangement of a drive to drive the reels (4, 5) in rotation and afford an additional amount of space to accommodate the transducer (61) within the housing for access to the recording tape (T).

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), and designed particularly for recording information during a relatively short period of time. Such proposed tape cassettes have a cassette housing that accommodates a magnetic tape wound in coils of small diameter, thereby enlarging a mouth in which a head drum and related portions of a cassette player can be partially inserted, so that the magnetic recording and reproducing device may be reduced in size. Reference should be made to our Japanese laid-open patent publication no. 60(1985)-171684 and Japanese utility model application no. 62(1987)-14573. One such tape cassette for recording information during a relatively short period of time is schematically shown in Figure 7 of the accompanying drawings. In Figure 7, 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 diameters of a conventional, standard tape cassettes, 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 now wound or loaded around the head drum 61 to record or reproduce 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 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 to the rear of the tape reels; the space in the cassette housing of the conventional tape cassette is thus not effectively utilized. Patent Specification US-A-4 453 683 discloses a cassette system wherein a housing has a pair of reels mounted therein for rotation with a tape wound on the reels, the housing having a mouth through which a transducer means can gain access to the tape to record signals thereon or reproduce signals therefrom. According to the invention there is provided a tape cassette comprising: housing means; 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, the housing means being formed with a mouth through which transducer means can gain access to the recording medium to record or reproduce signals on or from the recording medium; and characterised in that:- at least one of the reels is mounted for translation in the housing means, so that the reels can assume either of first and second relative positions; and the reels in the first relative position conforming 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 conforming 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. Such a tape cassette can utilise the internal space of the cassette housing more effectively to define an enlarged mouth in the cassette housing. The invention can thus provide a new type of tape cassette that can be used in cooperation with a conventional recording/reproducing apparatus and that is also compatible with a new type of recording/reproducing apparatus dedicated to use in combination with the new type of tape cassette. The cassette can be an 8-mm tape cassette that has an interior construction that makes it possible to reduce the size of a camcorder with which it cooperates. The connection between a lid and the cassette housing need not be a pivoting connection, although a pivoting connection is preferred. It is also not necessary that the lid open upwardly and the downward opening force be applied at a position to the rear of the pivot. Alternatively, the lid may open by being pivoted downwardly, and the opening force may be applied to the lid at a position forward of the pivot. When the tape cassette 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 parallel to each other rearwardly in 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, the 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 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 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 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 4 is an exploded perspective view of the tape cassette; Figure 5 is a bottom plan view of a lock member and an unlock block as they coact with each other; Figures 6A and 6B are cross-sectional views in a vertical plan parallel to the front-to-back direction of the tape cassette showing the manner in which a reel-moving member is locked (Figure 6A) and unlocked (Figure 6B); and Figure 7 is a top plan view of a conventional tape cassette. Referring to Figures 1 to 5, 6A and 6B, 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 cassette housing 1 accommodates therein a pair of tape reels 4, 5 with a magnetic tape T wound therearound. The tape reels 4, 5 are rotatably positioned over respective reel shaft insertion holes 3 a , 3 b which are formed in a bottom panel of the lower portion 3 of the cassette housing 1. 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 portion of the tape is kept taut and can be exposed in a front opening formed in the cassette housing 1. 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. The lower flanges 4 c , 5 c have engaging teeth 7 a , 7 b formed around their outer circumferential edges, the engaging teeth 7 a , 7 b being engageable by lock members (described below). The upper and lower tape reel flanges 4 b , 4 c and 5 b , 5 c of the tape reels 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 T can 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 upper panel of the upper housing portion 2 and the lower panel of the lower housing portion 3 have respective recesses 8, 9 formed therein behind the stretch of the magnetic tape T between the roller guides 6 a , 6 b . The tape reels 4, 5 can be moved by a reel-moving member 10 disposed in the cassette housing 1 and partly covering the recesses 8, 9. The reel-moving member 10 comprises a reel holder 11 covering front portions of the tape reels 4, 5 and a guide 12 extending continuously rearwardly from the middle of the reel holder 11. The reel holder 11 has a channel-shaped cross section to hold the tape reels 4, 5 between upper and lower horizontal plates thereof. The guide 12 is of a portal shape as viewed from the front or rear of the reel holder 11, and has laterally spaced vertical plates respectively lying along outer side surfaces of parallel guide walls 13 a , 13 b . The guide walls 13 a , 13 b are vertically disposed on the middle region of the lower panel of the lower housing portion 3. When the guide 12 is guided along the parallel guide walls 13 a , 13 b , the reel moving-member 10 is moved back and forth transversely (i.e., front-to-back) with respect to the cassette housing 1. The cavity or space defined in front of the reel-moving member 10 serves as a mouth 14 to receive therein a head drum and other members when signals are to be recorded on or reproduced from the magnetic tape T. When the reel-moving member 10 is guided along the parallel guide walls 13 a , 13 b of the lower housing portion 3, the tape reels 4, 5 are moved by the reel-moving member 10, thereby varying the size of the mouth 14. To allow the tape reels 4, 5 to move parallel to each other back and forth in the cassette housing 1, the reel shaft insertion holes 3 a , 3 b of the lower housing portion 3 are elongate in the back-and-forth direction (front-to-back or transverse direction) of the cassette housing 1. The lower panel of the lower housing portion 3 has limit walls 15 a , 15 b to limit lateral movement of the tape reels 4, 5. The lower housing portion 3 has laterally spaced side walls each having recesses which, in combination with the laterally spaced side walls of the upper housing portion 2, define through-holes 16 a , 16 b , and 17 a , 17 b . The reel-moving member 10 also has through-holes 18 a , 18 b and 19 a , 19 b defined in a front portion of the reel holder 11 and a front end of the guide 12. These through-holes 16 a , 16 b , 17 a , 17 b , 18 a , 18 b , 19 a , 19 b serve to pass therethrough beams of light to detect the starting and finishing ends of the magnetic tape T during recording and reproducing. The through-holes 16 a , 16 b and 18 a , 18 b are used to pass detecting beams of light when the tape cassette is employed in a magnetic recording and reproducing device according to the 8-mm video standards, while the through-holes 17 a , 17 b and 19 a , 19 b are used to pass detecting beams of light when the tape cassette is employed in a magnetic recording and reproducing device dedicated to use in combination with a tape cassette according to the invention. The cassette housing 1 also houses in its rear portion a lock mechanism 20 to lock the tape reels 4, 5 against rotation when the tape cassette is not in use. The lock mechanism 20 is constructed as follows: The guide 12 of the reel-moving member 10 has a recess 21 defined in a pair of laterally spaced vertical side walls thereof and extending over a determined length. The lock mechanism 20 has a lock member 22 mounted for movement along the outer side surfaces of the parallel guide walls 13 a , 13 b . The lock member 22 is freely movable with respect to the reel-moving member 10 within a predetermined range which extends between front and rear vertical edges of the recess 21. The lock member 22 has a pair of locking arms 23 a , 23 b projecting in opposite, left-to-right directions from respective side walls thereof to engage the engaging teeth 7 a , 7 b of the tape reels 4, 5. The lock member 22 also has a spring retainer 24 disposed on the upper surface of its upper panel. A compression coil spring 25 is disposed under compression between the spring retainer 24 and the rear side wall of the cassette housing 1, normally to urge the lock member 22 in a forward direction to hold the locking arms 23 a , 23 b in locking engagement with the engaging teeth 7 a , 7 b of the tape reels 4, 5. The lock member 22 thus biased forwardly by the compression coil spring 25 abuts against the front vertical edge of the recess 21 of the reel-moving member 10, thereby urging the reel-moving member 10 in a forward direction to bring the laterally spaced opposite ends of the front surface of the reel holder 11 into abutment with respective stops 26 a , 26 b which are located at laterally spaced positions in a front portion of the lower housing portion 3. An unlock block 27 to unlock the tape reels 4, 5 for rotation is positioned between the parallel guide walls 13 a , 13 b underneath the lock member 22. The unlock block 27 has an oblong hole 27 a defined in its upper surface and extending transversely (i.e. front-to-back) with respect to the cassette housing 1. The oblong hole 27 a receives therein a post 28 projecting downwardly from a lower surface of the upper panel of the lock member 22. Therefore, the unlock block 27 is movable with respect to the lock member 22 in a range corresponding to the distance between the front and rear ends of the oblong hole 27 a with which the post 28 is engageable, as shown in Figure 5. The lower panel of the lower housing portion 3 has an insertion hole 29 in register with the oblong hole 27 a of the unlock block 27. When the tape cassette is loaded into magnetic recording and reproducing apparatus, as described below, an actuating member is inserted from the magnetic recording and reproducing apparatus through the insertion hole 29 into the oblong hole 27 a of the unlock block 27 to displace the lock member 22 out of locking engagement with the tape reels 4, 5. A reel presser spring 30 is fixed to the lower surface of the upper panel of the upper housing portion 2 by laterally spaced pins 31 a , 31 b . The reel presser spring 30 presses against the tops of the tape reels 4, 5 to prevent undesired wobbling or rattling movement and also to lock the reel-moving member 10 against undesired movement. More specifically, the reel presser spring 30 comprises a pair of resilient reel presser arms 30 a , 30 b to press the tape reels 4, 5, respectively, and a resilient lock member 30 c to lock the reel-moving member 10. The reel presser arms 30 a , 30 b extend linearly along the paths (in translation) that are followed by the tape reels 4, 5 during movement between the normal and retracted positions. The presser arms 30 a , 30 b have distal ends bent slightly downwardly toward the lower housing portion 3. The bent distal ends of the reel presser arms 30 a , 30 b are resiliently pressed against respective central projections 4 d , 5 d of the tape reels 4, 5 to prevent the tape reels 4, 5 from wobbling or rattling. The reel-moving member 10 has an engaging step 32 on the upper surface of the guide 12 thereof. The resilient lock member 30c has a distal end normally to engage the engaging step 32 of the reel moving member 10 to lock the reel-moving member 10 against rearward movement. The front surface of the reel-moving member 10 is then held in abutment against the respective stops 26 a , 26 b of the lower housing portion 3. The lower panel of the lower housing portion 3 also has a pair of insertion holes 33 a , 33 b , one each side of the parallel guide walls 13 a , 13 b , below the resilient lock member 30 c of the reel presser spring 30. When the tape cassette is loaded into dedicated magnetic recording and reproducing apparatus, an actuating member 44 with two arms 44 a , 44 b , (Figure 4) is inserted from the magnetic recording and reproducing apparatus through the insertion holes 33 a , 33 b into the cassette housing 1 to displace the resilient lock member 30 c out of locking engagement with the reel-moving member 10, which is then released. A front lid 34 is mounted to pivot 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 34, the front lid 34 protects the face of the magnetic tape T which extends under tension between the roller guides 6 a , 6 b . The front lid 34 has laterally spaced side walls 34 a , 34 b extending perpendicularly from the opposite ends of the front lid 34. The side walls 34 a , 34 b have respective horizontal shafts 35 a , 35 b projecting towards each other from inner surfaces thereof and received in respective holes 36 (only one of which is visible in Figure 4) 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 34 is angularly movable in a vertical plane about the shafts 35 with respect to the cassette housing 1. The front lid 34 is normally urged to turn in a closing direction to cover the face of the magnetic tape T by a torsion spring 37 coiled around one of the shafts 35. Upon loading the tape cassette into either standard or dedicated magnetic recording and reproducing apparatus, the front lid 34 is turned upwardly by a lid opening mechanism in the magnetic recording and reproducing apparatus, thereby exposing the magnetic tape T between the roller guides 6 a , 6 b . A back lid 38 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 38 has shafts 39 (only one of which is visible in Figure 4) on respective opposite side edges thereof. The shafts 39 are pivotably supported by respective supports 40 a , 40 b that project from the rear surface of the front lid 34. The back lid 38 is thus coupled to the front lid 34 for pivotal movement with respect thereto. The back lid 38 also has engaging pins 41 (only one of which is visible in Figure 4) projecting from respective opposite ends thereof. The engaging pins 41 are movably received in respective cam grooves 43 a , 43 b respectively formed in the inner surface of vertical walls 42 a , 42 b , which are located in laterally spaced positions towards the front of the lower housing portion 3. When the front lid 34 is opened or closed with respect to the cassette housing 1, the engaging pins 41 are guided by and along the cam grooves 43 a , 43 b to cause the back lid 38 to be opened or closed with respect to the front lid 34 is coordination with the movement of the front lid 34. The tape cassette thus constructed operates as follows: Normally, the reel-moving member 10 is locked in its foremost (forward) position by the resilient lock member 30 c of the reel presser spring 30, as Figure 6A shows. The lock member 22 is displaced forwardly under the bias of the compression coil spring 25, keeping the locking arms 23 a , 23 b in locking engagement with the teeth 7 a , 7 b of the tape reels 4, 5, respectively, and pressing the tape reels 4, 5 forwardly. The tape reels 4, 5 are therefore locked against rotation in respective positions that conform to the 8-mm video standards, as shown in Figure 1. 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 conventional 8-mm videotape cassette without the use of any adapter. When the tape cassette is loaded into standard magnetic recording and reproducing apparatus designed according to the 8-mm video standards, an actuating member (not shown) is inserted from the magnetic recording and reproducing apparatus through the insertion hole 29 into the oblong hole 27 a of the unlock block 27, thereby retracting the unlock block 27 toward the rear wall of the lower housing portion 3. Through its interaction with the post 28, the retraction of the unlock block 27 causes the lock member 22 also to be retracted. The locking arms 23 a , 23 b of the lock member 22 are therefore displaced out of locking engagement with the teeth 7 a , 7 b of the tape reels 4, 5, which are thus unlocked for rotation, as Figure 2 shows. In the operation described above, the lock member 22 is movable only through a distance related to the length of the recess 21 of the reel-moving member 10. The reel-moving member 10 remains locked by the reel presser spring 30. Accordingly, the tape reels 4, 5 are unlocked for rotation, but stay in the positions conforming to the 8-mm video standards. When the tape cassette is loaded into dedicated magnetic recording and reproducing apparatus, the reel-moving member 10 is unlocked and moved by the actuating member 44 (Figure 4) in the dedicated magnetic recording and reproducing apparatus. More specifically, the two actuating fingers 44 a , 44 b of the actuating member 44 are inserted through the respective insertion holes 33 a , 33 b into the cassette housing 1 to press the resilient lock member 30 c upwardly toward the upper panel of the upper housing portion 2. The resilient lock member 30 c is displaced upwardly out of locking engagement with the engaging step 32 of the reel moving member 10, which is now unlocked, as Figure 6B shows. When the reel-moving member 10 is unlocked, the actuating member 44 is moved rearwardly to enable the actuating fingers 44 a , 44 b to engage and push the locking arms 23 a , 23 b of the lock member 22 rearwardly. The lock member 22 is thus retracted through a substantial distance, so that it pushes against the rear edge of the recess 21 of the reel-moving member 10. The reel-moving member 10 is therefore retracted in unison with the lock member 20, whereby the tape reels 4, 5 are moved parallel to each other towards the rear of the cassette housing 1. As a consequence, the mouth 14, whose rear end is defined by the reel-moving member 10, is enlarged as shown in Figure 3. Since the unlock block 27 is movably coupled to the lock member 22, when the lock member 22 is retracted as described above, the unlock block 27 moves with it. The lock member 22 can thus smoothly be retracted without being obstructed by the unlock block 27. Then, 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 (Figure 3) of the magnetic recording and reproducing apparatus can be inserted substantially fully into the enlarged mouth 14. Signals can then be recorded on and reproduced from the magnetic tape T in the usual manner by the head drum 61. More specifically, the tape guides 64, 65, 66, the loading posts 67, 68, and the capstan 69 are mounted on a fixed chassis of the magnetic recording and reproducing device, and are positioned in the mouth 14 when the tape cassette is loaded into the magnetic recording and reproducing apparatus. The head drum 61, the impedance roller 63, and the pinch roller 70 are mounted on a movable chassis plate which is displaceable with respect to the fixed chassis of the magnetic recording and reproducing apparatus. Before the tape cassette is loaded into the magnetic recording and reproducing apparatus, the head drum 61, the impedance roller 63, and the pinch roller 70 are positioned outside of a region which will be occupied by the mouth 14 when the tape cassette is loaded. After the tape cassette is loaded into the magnetic recording and reproducing apparatus, the movable plate is moved to insert the head drum 61, the impedance roller 63, and the pinch roller 70 from the front of the tape cassette into the mouth 14. The magnetic tape T stretched between the roller guides 6 a , 6 b is drawn by the head drum 61 into the mouth 14 where the magnetic tape T extends along a determined path. At the same time, the loading posts 67, 68 move arcuately around the head drum 61 to wind the magnetic tape T around the head drum 61, whereupon the loading of the magnetic tape T is completed. Since the mouth 14 is substantially enlarged when a tape cassette according to the invention is loaded into magnetic recording and reproducing apparatus dedicated to use with such a tape cassette, the head drum 62 and the tape transport members 62 can be inserted deeply into the cassette housing 1 and substantially fully accommodated in the mouth 14. 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 apparatus are positioned along with the tape reels 4, 5 within a region which is of substantially the same size as the tape cassette. The dedicated magnetic recording and reproducing apparatus may thus itself be of small size, corresponding to the size of the tape cassette, and hence may be rendered more compact than conventional magnetic recording and reproducing apparatus. In addition, the reel-moving member 10 is movably locked against movement merely by a portion of the reel presser spring 30, rather than by a complex lock mechanism. Consequently, a tape cassette according to the invention can be made up of a relatively small number of parts and can be assembled with ease and manufactured at relatively low cost. While the invention has been described as being applied to an 8-mm video cassette, it is also applicable to other tape cassettes for recording and reproducing information using rotary heads, such as a conventional 13mm (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 has a mouth capable of enlargement to allow the head drum and the tape transport members to be inserted more deeply into the cassette housing. Magnetic recording and reproducing apparatus which employ 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 is movable to the rear, the recording/reproducing head or transducer can 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 important point is simply that the reels be capable of assuming either of first and second relative positions and that 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 a transducer within the housing 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 a transducer within the housing for access to the recording medium. It is also not essential that a tape cassette according to the invention 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 distant the normal 26mm or so from the rear wall, they are less distant than 26mm, or the centre of at least one of the tape reels is distant less than 26mm, and preferably both reels are approximately 21mm from the rear wall.

Claims: A tape cassette (1) comprising: housing means (2, 3); a pair of reels (4, 5); means (10) mounting both of the reels (4, 5) for rotation in the housing means (2, 3); a recording medium (T) wound on the reels (4, 5) and extending therebetween for transport from one of the reels to the other, the housing means being formed with a mouth (14) through which transducer means (61) can gain access to the recording medium (T) to record or reproduce signals on or from the recording medium; and characterised in that:- at least one of the reels is mounted for translation in the housing means (2, 3), so that the reels can assume either of first and second relative positions; and the reels (4, 5) 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 (61) within the housing means (2, 3) 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 within the housing means for access to the recording medium (T). A tape cassette according to claim 1, wherein the mounting means (10) mounts both of the reels for translation in the housing means (2, 3) A tape cassette according to claim 1, wherein the translation has a component parallel to an intended direction of movement of the transducer means (61), to gain access to the recording medium with respect to the housing means (2, 3). A tape cassette according to claim 1, further comprising detection means formed on the housing means (2, 3), the detection means being capable of co-operating 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 lock means (30 c , 32) operatively associated with the detection means (33 a , 33 b ), to maintain the first relative position of the reels 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 claim 4, wherein the detection means comprises means defining an aperture (33 a , 33 b ) in the housing means and capable of admitting an actuating member (44) of a cassette player for co-operation with the lock means (30 c , 32). A tape cassette according to claim 5, wherein the lock means comprises a resilient lock member (30 c ), further comprising a reel-moving member (10) capable of moving the reels, the reel-moving member (10) being formed with an engaging step (32) and the resilient lock member (30 c ) normally engaging the engaging step (32) to lock the reel-moving member (10) in a normal position corresponding to which the reels are in the first relative position and being moved upon co-operation with an actuating member (44) of a cassette player away from the engaging step (32) to enable the reel-moving member (10) to move the reels (4, 5) to the second relative position.

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: G11B25, G11B23, G11B15