Tape cartridge

Abstract: The tape cartridge according to the present invention is provided with a slider member (13) slidably mounted for sliding movement in forward and backyard directions at an outer side under surface on the bottom wall of a main casing (1) for closing and opening a pocket 5, a front lid (11) pivotally connected to the main casing (1) for covering a front face of the main casing (1), and an upper lind (12) for closing the open upper face of the pocket (5). A front edge of the upper lid (12) is pivotally connected to an upper edge of the front lid (11) through pins (20). When the front lid (11) is pivoted for upward opening, the upper lid (12) is displaced for retreat to a rear side from an open upper face of the pocket (5) in association with the movement of the front lid (11).

Description: The present invention generally relates to a magnetic tape cartridge or tape cassette, and more particularly, to a tape cartridge having a pocket for tape loading at a front face of its main casing, and arranged to receive a head cylinder at a side of a video tape recorder in said pocket. In a video tape recorder (VTR) such as a video camera or the like, there have been demanded a still further compact size and a light weight. In the above case, the tape cartridge to be dealt with has a pocket for tape loading at a front face of its main casing, and investigations have been made into a type in which a head cylinder at the side of the video tape recorder is reduced in size for accommodation into such a pocket, as a system which may meet the above requirements. However, since there is a limitation to the size reduction of the head cylinder, the problem is related to the arrangement of a lid around the pocket of the main casing for inserting the head cylinder into said pocket as far as possible without any obstruction by contact. Figs. 14 and 15 show the construction of a conventional tape cartridge of this kind, more specifically, a tape cartridge for 8mm video tape. As shown in Figs. 14 and 15, a front lid 11 for selective opening or closing of the front face of a main casing 1 is pivotally supported on said main casing 1, and at a position where a pocket 5 is formed, a back lid 130 is added to the front lid 11. By the above arrangement, in the lid closed state during non-use, the outer front face of a magnetic tape 3 is covered by the front lid 11 as shown in Fig. 14, while the rear face inner side of said tape 3 is covered by the back lid 130, and thus, the magnetic tape 3 is surrounded by the front lid 11 and the back lid 130 including the upper face side of the pocket 5 for being protected. The back lid 130 is pivotally connected at its upper and lower intermediate portion, to the front lid 11 at opposite side two points through shafts 131, and between the main casing 1 and the back lid 130, there is provided a guide means for opening the back lid 130 towards the upper face side of the pocket 5 for displacement. For the guide means, guide grooves 133 of a generally S-shape are formed on confronting faces of opposite side walls 6 at the left and right sides of the pocket 5, while arm pieces 134 are provided to depend from opposite side edges of the back lid 130, with slider pieces 135 being laterally formed to extend from the forward ends of said arm pieces 134, so that said slider pieces 135 are received in said guide grooves 133 for sliding movement. In the above arrangement, by the guiding action between the guide grooves 133 and the slider pieces 135, the back lid 130 is also raised upwardly for opening together with the front lid 11 as shown in Fig. 15. However, as is clear from Fig. 15, in the using state in which the front lid 11 is opened, the lower edge of the back lid 130 is in a state where it is extended forwardly to a large extent onto the upper surface of the pocket 5. In other words, the effective opening height H of the pocket 5 is low by the presence of the back lid 130. Therefore, if it is intended to cause the head cylinder D to enter deep into the pocket 5, said head cylinder D undesirably contacts the back lid 130 so as to be obstructed thereby, and this inconvenience has been a bottleneck to achieve a compact size at the side of the video tape recorder. Moreover, there is another conventional arrangement as disclosed in Japanese Patent Laid-Open Publication Tokkaisho No. 61-210584, in which in the back lid 130 as shown in Figs. 14 and 15, its main portion 130a and upper lid portion 130b are separately formed, and the forward edge of the upper lid portion 130b is pivotally connected to the upper edge of a front wall 11a of the front lid 11, with other construction being substantially the same as in the known construction of Figs. 14 and 15. The upper lid portion 130b covers the open upper face of the pocket 5 during non-use, while, during the upward opening of the front lid 11, it rides over the upper face of the upper wall of the main casing 1 for retreatment backwards. In the above arrangement, however, the main portion 130a also largely extends over the upper surface of the pocket 5, and the effective opening height H of the pocket 5 is still low. US-A-4 680 660, from which the preamble of claim 1 starts, has a design similar to the above-described state of the art. In a closed state of the tape cartridge, a front lid and a back lid surround the tape. An upper lid for closing the pocket for band loading is pivotally connected to the front lid. This design allows for an easier movement of the upper lid but has, nevertheless, the draw-back that the effective opening height of the pocket is still low. Accordingly, an essential object of the present invention is to provide a tape cartridge which is arranged to allow a cylinder head at a side of a video tape recorder to enter deep into a pocket of a main casing of the tape cartridge as far as possible, thereby to contribute to compact size and light weight at the side of the video tape recorder. Another object of the present invention is to provide a tape cartridge of the above described type which can accomplish the above object even when a depth of the pocket provided is not too large more than necessary. In accomplishing these and other objects, the tape cartridge according to the present invention is commonly provided with following essential items. (a) a main casing 1 having tape draw-out ports 4 formed on a front portion at left and right sides thereof, and a pocket 5 for tape loading, open at its upper and lower sides and front side between said tape draw-out ports 4 and formed in a recess at the front portion of said main casing 1, (b) a front lid 11 pivotally supported for upward movement on the main casing by shafts 14 for selective opening and closing of the front portion of said main casing 1, (c) an upper lid 12 for opening and closing an upper face of said pocket 5 following the opening and closing of said front lid 11. The upper lid 12 is pivotally connected, at a forward edge of a main face plate 12a of said upper lid 12, to an upper edge of a front wall 11a of said front lid 11 through pin means 20, and (d) a guide means provided between the main casing 1 and the upper lid 12 for guiding said upper lid 12 so that the main face plate 12a of said upper lid 12 retreats towards a rear portion on the upper face of said pocket 5 following the upward opening rotation of said front lid 11. According to the present invention, the tape cartridge having the essential items (a) to (d) as described earlier further includes, in a position where the said pocket 5 is present, a covering wall 11c for covering the forward edge of the main face plate 12a of said upper lid 12 from the front face side, which is integrally formed with the upper edge of the front wall 11a of the front lid 11 (Figs. 9 to 13). In this case, the covering wall 11c is to prevent dust from entering inside through the connecting portion between the upper edge of the front wall 11a and the forward edge of the main face plate 12a. The guide means for the upper lid 12 includes arm pieces 22 provided to depend from opposite sides of the main face plate 12a of said upper lid 12 and having sliding pieces 23 provided at forward ends of the arm pieces 22, and arcuate guide grooves 24 formed in forward and backward directions on opposite side walls 6 of said pocket 5, and said sliding pieces 23 of the arm pieces 22 are slidably received in said guide grooves 24. More specifically, the forward edge of said main face plate 12a of said upper lid 12 is formed into a convex arcuate shape in a longitudinal side sectional view, and said covering wall 11c is formed, in its inner face, into a concave curved face generally following the front edge shape of said main face plate 12a (Fig. 9). Moreover, on the upper edge of the front wall 11a of said front lid 11, boss portions 82 having the pins 20 are provided to extend rearwardly at the opposite sides of said covering wall 11c, with pin holes 21 pivotally receiving said pins 20 being provided at opposite ends on the front edge of the main face plate 12a of said upper lid 12, and at the upper edges of the opposite side walls 6 of said pocket 5, recesses 81 for receiving and supporting said boss portions 82 from above in the closed state of said upper lid 12 are provided (Figs. 10 to 13). Thus, it is intended that even when the laterally long front lid 11 supported at opposite two points is subjected to external forces, it is not readily deformed or damaged. Furthermore, at an outer side bottom surface of said main casing 1, a slider member 13 is slidably attached for sliding movement in forward and backward directions, and in a lower edge inner face of said front wall 11a of said front lid 11, a recess portion 83 is provided to extend laterally so that a forward edge of said slider member 13 engages said recess portion 83 (Fig. 9), whereby entry of dust from the junction between the front wall 11a and the slider member 13 is also obstructed. These and other objects and features of the present invention will become apparent from the following description taken in conjunction with the preferred embodiment thereof with reference to the accompanying drawings, in which; Fig. 1 is a fragmentary side sectional view of a tape cartridge according to a conventional design, in a state where its lid is closed. Fig. 2 is a top plan view of the tape cartridge in Fig. 1 partly broken away for clarity. Figs. 3(A), 3(B) and 3(C) are fragmentary side sectional views of a tape cartridge in Fig. 1 for explaining opening and closing of its pocket, Fig. 4 is a fragmentary top plan view in section showing on an enlarged scale, a lock mechanism portion for a slider member in the tape cartridge of Fig. 2, Fig. 5 is a cross section taken along the line V-V in Fig. 4, Fig. 6 is a fragmentary top plan view showing on an enlarged scale, a reel locking mechanism portion of the tape cartridge in Fig. 2, Fig. 7 is a bottom plan view of the tape cartridge in Fig. 2, Fig. 8 is an exploded perspective view of the tape cartridge in Fig. 2, Fig. 9 is a fragmentary side sectional view of a tape cartridge according to the present invention, with some portions thereof shown as enlarged, Fig. 10 is a fragmentary perspective view showing an essential portion of the tape cartridge in Fig. 9, Fig. 11 is a fragmentary cross section taken along the line XVIII-XVIII in Fig. 10, Fig. 12 is an exploded perspective view of the tape cartridge in Fig. 9, Fig. 13 is a fragmentary perspective view showing, on an enlarged scale, essential portions of the tape cartridge in Fig. 12, Fig. 14 is a fragmentary side sectional view showing a conventional tape cartridge, in a state where its lid is closed (already referred to), and Fig. 15 is a view similar to Fig. 14, which particularly shows the tape cartridge in the opened state (already referred to). Before the description of the present invention proceeds, it is to be noted that like parts are designated by like reference numerals throughout the accompanying drawings. Referring now to the drawings, there is shown in Figs. 1 to 8, a tape cartridge for video use according to a conventional design, which generally includes a main casing 1 having an upper casing 1a and a lower casing 1b made, for example, of a plastic material, which are butted against each other to be combined to form the main casing 1, and a pair of reels 2 rotatably provided at left and right sides within the main casing 1 so as to be wound with a magnetic tape 3. The main casing 1 is provided at left and right portions in its front side, with tape draw-out ports 4, and at a central portion in the front side of said main casing 1, a pocket 5 for tape loading is provided between the tape draw-out ports 4. The opposite side walls 5 for the pocket 5 are formed by wall members integrally depending from the upper casing 1a, and by these side walls 5, the pocket 5 is separated from the respective tape draw-out ports 4. A rear wall 7 of the pocket 5 is constituted by wall members integrally formed with the upper and lower casings 1a and 1b to extend outwardly therefrom and butted against each other to be joined, and this rear wall 7 serves as a partition between the pocket 5 and the tape accommodating space within the main casing 1. In Figs. 5 and 8, at the forward edges of the respective opposite side walls 6 of the pocket 5, tape guides 9 integrally formed with the lower case 1b to extend upwardly therefrom are provided. Each of the tape guides 9 is formed generally into a cylindrical shape in a cross section having a semi-circular outer peripheral portion 9a facing the tape draw-out port 4 and another semi-circular outer peripheral portion 9b directed towards the side of the pocket 5. The outer peripheral portion 9b directed to the pocket 5 is cut off approximately at its upper half as indicted by Numeral 10(Fig. 8). Meanwhile, each of the forward edges of the opposite side walls of the pocket 5 is also cut out generally at its lower half to provided a cut-out portion 8, and when the outer peripheral portions 9b are fitted into the cut-out portions 8, said outer peripheral portions 9b are respectively directed to the forward edges at left and right sides of the pocket 5. In Fig. 2, the magnetic tape 3 is drawn out from one reel 2 into the tape draw-out port 4 provided before said one reel 2, and after being led into the other tape draw-out port 4 through the front face of the pocket 5, wound onto the other reel 2 behind said the other port 4. For protection of the tape and prevention of dust during non-use, the front face of the main casing 1 is closed by a front lid 11 for selective opening and closing, and the upper face of the pocket 5 is closed by an upper lid 12, and the under face of the pocket 5 is closed by a slider member 13 respectively for selective opening and closing. In Figs. 2 and 8, the front lid 11 is provided with a front wall 11a for blocking the front face of the main casing 1 including the pocket 5 and the tape draw-out ports 4, and opposite side walls 11b integrally formed with left and right side edges of the front wall 11a to extend toward the rear portion of the main casing 1. In the inner faces of the opposite side walls 11b, shafts 14 are respectively provided to extend towards each other, while shaft holes 16 are provided in side walls 15 of the main casing (at the side of the upper casing 1a), so that the shafts 14 are rotatably supported in the shaft holes 16 from outer sides as shown in Fig. 8, whereby the front lid 11 can be pivoted upwardly for opening about the shafts 14 on the whole. In order to allow the front wall 11a to be raised higher than the upper face of the pocket 5 for the upward opening rotation during the upward opening of the front lid 11, in the closed state of Fig. 1, a distance r between the front wall 11a of the front lid 11 and the center of the shaft 14 is set to be more than about two times larger than a distance h between the upper surface of the pocket 5 and the center of the shaft 14. Moreover, as shown in Fig. 2, the front lid 11 is normally urged to rotate in the closing direction by a torsion coil spring 17 attached to one of the shafts 14. In Figs. 1 and 8, the upper lid 12 has a flat main face plate 12a for closing the open upper face of the pocket 5, and the front edge of the main face plate 12a is pivotally connected to the upper edge of the front wall 11a through pins 20. More specifically, as shown in Fig. 8, the front wall 11a is cut out at its upper edge central portion to provide an elongated cut-out portion 19, with the pins 20 being provided at opposite sides in said cut-out portion 19. Thus, the forward edge of the main face plate 12a of the upper lid 12 is fitted into the cut-out portion 19 at the side of the front wall 11a, with said pins 20 being fitted into pin holes 21 provided at opposite sides of the front edge of said main face plate 12a. The front edge of the main face plate 12a of the upper lie 12, i.e., position for the pins 20 is located above and at a forward position with respect to the shafts 14 of the front lid 11. Between the main casing 1 and the upper lid 12, there is provided a guide means for guiding the upper lid 12 so that the main face plate 12a thereof is displaced from a position to close the open upper face of the pocket 5 to a position retreating to an upper face rear portion of the pocket 5, following the upward opening rotation of said front lid 11. The guide means including arm pieces 22 each provided to depend downwardly from opposite sides of the main face plate 12a of said upper lid 12, and having slider pieces 23 provided at outer side on forward ends of said arm pieces, and arcuate guide grooves 24 rising rearwardly, and formed in forward and backward directions on opposite side walls 6 of said pocket 5 at upper edge sides of vertical walls facing the pocket 5, with the sliding pieces 23 of said arm pieces 22 being slidably received in said guide grooves 24. The guide grooves 24 are each formed in a convex arcuate shape which coincides with a locus of displacement of said pins 20 drawn by the upward opening rotation of said front lid 11. By the above arrangement, the upper lid 12 is subjected to the parallel displacement in the forward and backward directions by maintaining the horizontally closed state at all times, between a closed position where the main face plate 12a continues on the upper rear edge of the front lid 11 to close of the upper surface of the pocket 5 (Fig. 3(A)) and an open position where the main face plate 12a retreats rearwardly from the upper surface of the pocket 5 (Fig. 3(C)). When the upper lid 12 is at the open position in Fig. 3(C), the main face plate 12a is located above the upper wall of the main casing 1 to retreat rearwardly from the upper surface of the pocket 5 to a large extent. Moreover, as shown in Figs. 3 and 8, in the position where said pocket 5 is present, at a forward edge of the upper wall of said main casing 1, an eaves wall 26 for closing an upper surface at an inner rear side of said pocket 5 is formed to extend therefrom, and escape grooves 26a for receiving the arm pieces 22 of the upper lid 12 upon retreat of said upper lid 12 rearwardly are formed at opposite sides of said eaves wall 26, and thus, during the opening function of the upper lid 12, said arm pieces 22 enter the escape grooves 26a to avoid contact with the eaves wall 26. In Figs. 5 and 8, the slider member 13 is formed into a laterally elongated U-shape cross section having a bottom wall 13a located on an under surface outside the main casing 1 and opposite side walls 13b extending upwardly from opposite side edges of the bottom wall 13a and located at the outer sides of opposite side walls 15 of the main casing 1, and is slidably mounted to the main casing 1 for sliding movement in forward and backward directions. Specifically, the slider member 13 moves along the under surface of the main casing 1 in the forward and backward directions between the front closed position (Fig. 3(A)) for closing the under surface of the pocket 5, and the rear open position (Fig. 3(C)) for opening the under surface of the pocket 5. For urging the entire slider member 13 towards the forward closed position, a torsion spring member 27 is connected, at its coil portion, to one end of the rear wall 7 of the pocket 5, with an end of its one arm being engaged with a spring receiver 25 as shown in Fig. 8. It is necessary that the slider member 13 is locked so as not to be displaceable at the closed position. For this purpose, as shown in Figs. 4 and 8, locking plates 30 are slidably disposed for movement in a slantwise direction at a position towards the rear side from the tape guides 9 on the inner bottom face of the opposite tape draw-out ports 4, with projections 31 being provided on the upper face of the bottom wall 13a of the slider member 13 for engagement with claws 30a at the forward ends of the locking plates 30. In the inner bottom face of the tape draw-out ports 4, thickness reduced recesses 32 extending laterally slantwise are formed to receive the locking plates 30 therein, and the locking plates 30 are normally urged by spring member 33 so that each of the forward end claw 30a thereof is projected to one side outer portion of the tape end draw-out port 4. As shown in Fig. 8, each of the opposite side walls 15 of the main casing 1 facing the tape draw-out port 4 is constituted by butting a side wall upper half 15a against a side wall lower half 15b respectively provided on the upper casing 1a and a lower casing 1b. At each of the side wall lower half 15b of the lower casing 1b corresponding to the position where the claw 30a of the locking plate 30 projects, a notch 34 is provided. The outer side of each of the notches 34 is closed by a wall piece 35 extending outwardly from the side wall upper half 15a of the upper casing 1a. Thus, by the lower edges of the wall pieces 35 and the lower edges of the side walls 6 of the pocket 5, rising of the locking plates 30 from the recesses 32 is restricted by contact. As shown in Figs. 4 and 8, in each of the locking plates 30, a cam piece 36 having an inclined edge 36a is integrally formed to extend forwardly from a front edge of said locking plate 30. Meanwhile, at the forward edge on the inner bottom face of each tape draw-out port 4, and at the lower edge of the front wall 11a of the front lid 11, operating grooves 37 and 38 for permitting entry of releasing pins at the side of a video tape recorder are provided in a communicated state. Therefore, upon loading of the tape cartridge on the tape recorder, the releasing pins P (Fig. 4) at the side of the video tape recorder enter the operating grooves 37 and 38 from the front portions thereof, and contact and depress the inclined edge 36a of the cam pieces 36 as shown in Fig. 4. Thus, as shown in imaginary lines in Fig. 4, the locking plates 30 are displaced in the direction of the pocket 5 against the spring members 33, whereby the forward end claws 30a are released from the engagement with the projections 31 of the slider member 13, which is then allowed to be displaced rearwardly. As shown in Fig. 7, in order to correctly set the main casing 1 of the tape cartridge in a holder (not shown) at the side of the tape recorder, positioning reference holes 40 and 41 to be fitted with reference pins at the tape recorder side are provided at four places in total in front and rear portions of the under face at the outer side of the main casing 1. The front two positioning pins 40 are formed in positions corresponding to the portions immediately below the tape guides 9. In other words, the lower inner ends of the hollow tape guides 9 are utilized for the reference holes 40. By this construction, the problem that the positioning reference holes are difficult to be provided at the front portion due to the fact that the sliding region of the slider member 13 for selective opening and closing of the under face of the pocket 5 is required at the under face of the main casing 1, may be simultaneously solved. The tape cartridge is also provided with a locking mechanism for preventing the reels 2 from rotation during non-use period. As shown in Figs. 6 and 8, for the reel locking mechanism, at a forward position between the reels 2 on the inner bottom face of the main casing 1, a pair of support shafts 43 are erected on the bottom wall of the main casing 1, and reel locking members 42 are rotatably fitted onto the shafts 43 from above for horizontal pivotal movement. Each of the reel locking members 42 is normally urged in a locked posture direction where a claw 44 at its end portion is engaged with corresponding engaging teeth 2a of the reel 2, by a spring member 45. There is also provided a releasing member 46 for simultaneously releasing the respective reel lock members 42 from retained state against rotation. The releasing member 46 is movably disposed in forward and backward directions between the left and right side reel locking members 42 on the inner bottom face of the main casing 1, and is formed into a strip plate shape having an elongated hole 47 formed in the forward and backward directions, with a releasing projection 48 being integrally formed to project upwardly from its upper face at the forward end side. In the bottom wall of the main casing 1 in which the releasing member 46 is incorporated, an elongated through-hole 49 is formed between the shafts 43. Meanwhile, an operating projection 50 is provided at generally a central portion toward the front side on the upper surface of the slider member 13, and the projection 50 is engaged with the elongated hole 47 of the releasing member 46 through the through-hole 49 from the bottom of the main casing 1. By the above arrangement, when the tape cartridge is loaded on the tape recorder, a releasing claw (not shown) at the side of the tape recorder contacts a forward end portion 13c of the slider member 13 through notches 51 (Fig. 8) formed in the lower edge of the front lid 11, and after the sliding lock of the slider member 13 has been released as described earlier, the slider member 13 is pushed open towards the rear portion of the main casing 1 against the spring member 27. At approximately an intermediate position in the rearward displacement of the slider member 13, the operating projection 50 engages the rear end 47a of the elongated hole 47 of the releasing member 46 (Fig. 3(B)), and thereafter, displaces the releasing member 46 backwards as the slider member 13 moves still more rearwardly (Fig. 3(C)). In the vicinity of an end position of the backward movement of said releasing member 46, the releasing projection 48 depresses the projections 42a of the left and right reel locking members 42, and by this depressing action, both of the reel locking members 42 rotate about the respective support shafts 43, whereby the claws 44 are disengaged from the engaging teeth 2a of the reels 2, thus allowing said reels 2 to be rotated (two-dotted chain lines in Fig. 6). After the slider member 13 has been displaced for opening, with the respective reels 2 released from locking, the entire tape cartridge is caused to descend within the video tape recorder, and the positioning pins at the video tape recorder side are fitted into the front and rear positioning reference holes 40 and 41, and thus, the tape cartridge is positioned and loaded on the video tape recorder. Simultaneously, the front lid 11 is rotated upwardly for opening about the shafts 14 against the spring member 17 by the contacting action with the lid opening member at the side of the video tape recorder. Upon upward opening rotation of the front lid 11 about the shafts 14, the upper lid 12 is displaced rearwardly in parallel for opening as the sliding pieces 23 at the forward ends of the arm pieces 22 are subjected to the sliding movement rearwardly along the guide grooves 24. In the using state where the front lid 11 and the upper lid 12 are opened, the pocket opening height H may be enlarged and the head cylinder D can be directed deep into the pocket 5 as shown in Fig. 3(C). With respect to the relative positional relation between the head cylinder D and the height direction of the tape cartridge, the tape cartridge can be set at a low position towards a downward direction with respect to the head cylinder D. This means that within the video tape recorder, the head cylinder D and surrounding mechanism thereof may be disposed in a state where they are as close to a driving shaft for the reels 2 as possible, and the arrangement serves for the compact size of the video tape recorder by that extent. When the head cylinder D is disposed deep into the pocket 5, reduction of a flat area in the mechanism for the entry of the head cylinder D may be achieved. Meanwhile, the magnetic tape 3 is wound onto the outer peripheral portions of the tape guides 9 directed towards the pocket 5 so as to be stably guided onto the head cylinder D for movement thereover. Figs. 9 to 13 show the tape cartridge according to the present invention, in which the front lid 11, the upper lid 12, and the slider member 13 are mounted on the main casing 1 substantially in the similar manner as in the first embodiment, and like parts are designated by like reference numerals for brevity of explanation. According to the invention, it is intended when the front lid 11 and the upper lid 12 are in the closed state, to prevent formation of a clearance for the dust to enter the connected portion between the forward edge of the main face plate 12a of the upper lid 12 and the upper edge of the front wall 11a of the front lid 11 in the portion where the pocket 5 is present. For this purpose, as shown in Fig. 9, at the upper edge of said cut-out portion 19 at the front wall 11a of the front lid 11, a covering wall 11c for covering the forward edge of the main face plate 12a of the upper lid 12 from the front face side is integrally formed to extend upwardly and rearwardly. It is desirable that the upper edge of said covering wall 11c is set to be as close to the forward edge of the main face plate 12a as possible without any interference to the pivotal movement of the upper lid 12 about the pins 20. Therefore, the forward edge of said main face plate 12a of said upper lid 12 is formed into a convex arcuate shape in a longitudinal side sectional view as in a semi-circle- drawn about the pin 20, and thus, the covering wall 11c is formed, in its inner face, into a concave curved face generally following the convex arcuate shape in cross section of said main face plate 12a. Subsequently, although the front lid 11 is supported by the left and right shafts 14 with respect to the main casing 1, when an external load is applied to the front wall 11a of the front lid 11 from above or from a front portion, the front wall laterally long tends to be deflected and deformed, and by such deformation, a clearance may be formed between the front lid 11 and the main casing 1 or the upper lid 12 for possible entry of dust. In order to prevent the deformation of the front lid 11 as described above, as shown in Figs. 10 and 11, on the upper wall of the main casing 1, i.e., on the upper side of the front edge of each of the opposite side walls 6 of the pocket 5, recesses 81 open at the upper and front portions are provided so that left and right boss portions 82 having the pins 20 at the side of the front lid 11 enter the recesses 81 from above in the closed state of the front lid 11 and the upper lid 12, thereby to receive each of the boss portions 82 at the inner bottom face 81a of the recess 81. In other words, the front lid 11 laterally long is so arranged that its front wall 11a may be supported at the left and right two points by the recesses 81 at the side of the main casing 1 through the boss portions 82 so as not to be easily deformed. Furthermore, for close contact without forming any clearance with respect to the front lid 11 in the state where the slider member 13 is closed, as shown in Fig. 9, in a lower edge inner face of the front wall 11a of said front lid 11, a recess potion 83 is provided to extend laterally so that a forward edge of the bottom wall 13a of said slider member 13 engages said recess portion 83 in the state where front lid 11 is closed, and slider member 13 engages said recess portion 83 in the state where front lid 11 is closed, and slider member 13 advances forwards to close the under face of the pocket 5 (Fig. 9). By this arrangement also, entry of dust at such portion is prevented for improving the dust prevention effect as a whole.

Claims: A tape cartridge which comprises: a main casing (1) having tape draw-out ports (4,4) formed on a front portion at left and right sides thereof, and a pocket (5) for tape loading, open at its upper and lower sides and front side between said tape draw-out ports (4,4) and formed in a recess at the front portion of said main casing (1), a front lid (11) pivotally supported for upward movement on the main casing by shaft means (14) for selective opening and closing of the front portion of said main casing, an upper lid (12) for opening and closing an upper face of said pocket (5) following the opening and closing of said front lid (11), said upper lid (12) being pivotally connected, at a forward edge of a main face plate (12a) of said upper lid (12), to an upper edge of a front wall (11a) of said front lid (11) through pin means (20), a guide means (22,23,24) provided between the main casing (1) and the upper lid (12) for guiding said upper lid (12) so that the main face plate (12a) of said upper lid (12) retreats towards a rear portion on the upper face of said pocket (5) following the upward opening rotation of said front lid (11), characterised in that at the upper edge of the front wall (11a) of said front lid (11), a covering wall (11c) for covering the forward edge of the main face plate (12a) of said upper lid (12) from the front face side is integrally formed. A tape cartridge as claimed in claim 1, wherein said guide means (22,23,24) including arm pieces (22,22) provided to depend from opposite sides of the main face plate (12a) of said upper lid (12) and having sliding pieces (23,23) provided at forward ends of the arm pieces (22,22), and arcuate guide grooves (24,24) formed in forward and backward directions on opposite side walls (6,6) of said pocket (5), and sliding pieces (23,23) of said arm pieces (22,22) being slidably received in said guide grooves (24,24). A tape cartridge as claimed in claim 2, wherein the forward edge of said main face plate (12a) of said upper lid (12) is formed into a convex arcuate shape in a longitudinal side sectional view, said covering wall (11c) being formed, in its inner face, into a concave curved face generally following the front edge shape of said main face plate (12a). A tape cartridge as claimed in claim 2 or 3, wherein on the upper edge of the front wall (11a) of said front lid (11), boss portions (82,82) having pins (20,20) are provided to extend rearwardly at the opposite sides of said covering wall (11c), with pin holes (21,21) pivotally receiving said pins (20,20) being provided at opposite ends on the front edge of the main face plate (12a) of said upper lid (12), and at the upper edges of the opposite side walls (6,6) of said pocket (5), recesses (81,81) for receiving and supporting said boss portions (82,82) from above in the closed state of said upper lid (12) are provided. A tape cartridge as claimed in claim 1, wherein at an outer side bottom surface of said main casing (1) , a slider member (13) is slidably attached for sliding movement in forward and backward directions. A tape cartridge as claimed in claim 5, wherein in a lower edge inner face of said front wall (11a) of said front lid (11), a recess portion (83) is provided to extend laterally so that a forward edge of said slider member (13) engages said recess portion (83).

Inventors: KAKU NOBUYUKI, MAEHARA YOSHIMI, MIZUTANI HIKARU, NISHIJIMA TATSUMI, OGIRO KENJI, TAKEDA HIDEKAZU, KAKU, NOBUYUKI, MAEHARA, YOSHIMI, MIZUTANI, HIKARU, NISHIJIMA, TATSUMI, OGIRO, KENJI, TAKEDA, HIDEKAZU
Applicants: HITACHI LTD, HITACHI MAXELL, HITACHI MAXELL, LTD., HITACHI, LTD.
Application year: 1993
Main classification: G11B23
IPC codes: G11B23