Reel driving apparatus for tape recorder

Abstract: A reel driving apparatus for a tape recorder includes two reel tables 10 and 20 and a plurality of intermediate gears 40 and 50 for connecting driving gears 30 with each other. The power is transmitted to the reel tables via the intermediate gears according to the rotating direction of the driving gear, thereby accomplishing a rapid mode change. Further, in the apparatus, tape loosening does not occur.

Description: Background of the Invention The present invention relates to a reel driving apparatus for a tape recorder, and particularly to a reel driving apparatus for a tape recorder having an improved structure to accomplish a rapid mode change. Fig. 1 schematically illustrates a conventional reel driving apparatus. In Fig. 1, a supply reel disk 6 and a take-up reel disk 1 for seating the reels of a tape cassette (not shown) are provided on the deck (not shown) of a tape recorder. A driving gear 4 driven by a driving source (not shown) is installed between reel disks 6 and 1. An idler 5 is connected to driving gear 4 by a connecting lever 7 so as always to engage the driving gear. Thus, idler 5 is movable while being engaged with the driving gear 4. A friction brake 3 is provided on the side of take-up reel disk 1 to be in frictional contact therewith. A tension band 8 operated by a tension pole (not shown) is wound around a lower disk (not shown) frictionally rotated with supply reel disk 6. Friction brake 3 is in frictional contact with take-up reel disk 1 to apply tensile force to the tape during a review (REV) mode or rewind (REW) mode. Tension band 8 gives tensile force to the tape by braking the lower disk during a play (PLAY) or fast-forward (FF) mode. In such a conventional reel driving apparatus, during the PLAY and FF modes, idler 5 is rotated clockwise by the rotational force of driving gear 4, to be driven while engaged with take-up reel disk 1. During the REV and REW mode, driving gear 4 is rotated counter-clockwise so that idler 5 is driven while engaged with supply reel disk 6. Accordingly, idler 5 is driven so as to be selectively engaged with reel disks 6 and 1, according to the selected modes. However, in the driving apparatus, since, during mode change, idler 5 is detached from reel disks 6 and 1 and at the same time the tape is compressively conveyed by a pinch roller (not shown) and a capstan shaft (not shown), the tape becomes loosened from the reels. Thus, in a tape recorder employing the conventional reel driving apparatus, the quality of reproduced pictures is deteriorated and noise is created. Further, the apparatus requires an additional device for driving the friction brake installed to provide the tape with specific tensile force, thereby complicating the structure. EP-A-0 455 548 and US-A-4 383 282 disclose reel driving apparatus with different mechanisms for changing the playing mode of a tape recorder apparatus. Summary of the Invention Therefore, it is an object of the present invention to provide a reel driving apparatus for a tape recorder in which mode change is rapidly carried out so as to prevent a tape from loosening. It is another object of the present invention to provide a reel driving apparatus for a tape recorder which has a simplified structure. To accomplish the objects, there is provided a reel driving apparatus for a tape recorder as defined in claim 1. In the present invention, during the PLAY and FF mode, the rotational force of the driving gear is transmitted to the direction controller built in the take-up reel table via the intermediate gear, and the direction controller is frictionally rotated with the felt table of the take-up reel table. Thus, the take-up reel disk is driven by the rotational force of the driving gear. Meanwhile, the reel disk of the supply reel table is raced by the direction controller built in the supply reel table. During the REV and REW modes, as the rotating direction of the driving gear is changed, the supply reel disk is frictionally rotated and the take-up reel disk is raced. The reel tables are driven while being connected with the driving gear via the intermediate gears, so that the mode change according to the rotating direction of the driving gear occurs immediately. Brief Description of the Drawings The above objects and other advantages of the present invention will become more apparent by describing in detail a preferred embodiment thereof with reference to the attached drawings in which: Fig. 1 is a schematic view of a conventional reel driving apparatus; Fig.2 is a schematic view of a reel driving apparatus of the present invention, so as to explain the PLAY mode and FF mode; Fig.3 is a schematic view of a reel driving apparatus of the present invention, so as to explain the REV mode and REW mode; Fig.4 is a schematic view of a reel driving apparatus of the present invention, so as to explain the operation of separating intermediate gears from a reel table; Fig.5 is a schematic cross-sectional view of a reel driving apparatus according to the present invention; Fig.6 is a plan view of a driving disk for a direction controller provided in the take-up reel table; and Fig.7 is a plan view of a driving disk for a direction controller provided in the supply reel table. Detailed Description of the Invention The reel driving apparatus of the present invention will be described being employed in a miniature tape recorder such as a camcorder. Referring to Figs.2-5, a supply reel table 10 and a take-up reel table 20 each comprises a reel disk 14 or 24 for seating a tape reel (not shown), a felt table 17 or 27 having a frictional felt 16 or 26 and positioned at the same axis 10' or 20' as that of reel disk 14 or 24 to have the same rotation force as that of the reel disk, and a direction controller 35 or 45 provided between reel disk 14 or 24 and felt table 17 or 27 to be frictionally rotated and raced with felt table 17 or 27 according to a rotating direction. A spring 15 or 25 is installed between reel disk 14 or 24 and direction controller 35 or 45 to put direction controller 35 or 45 in contact with felt table 17 or 27. Reel table 10 or 20 is installed to be rotatable in a deck 100. Deck 100 is movable by a driving device (not shown) as shown in Fig.4. A driving gear 30 driven by a driving source is placed between the two reel tables 10 and 20. Intermediate gears 40 and 50 are placed between driving gear 30 and reel tables 10 and 20. Driving gear 30 and reel tables 10 and 20 are connected with each other by intermediate gears 40 and 50. Driving gear 30 is driven by being connected with the axis 30' of the driving source and a belt 70. Intermediate gears 40 and 50 can be coupled or detached to/from reel tables 10 and 20 by a detaching device. The detaching device is constructed to comprise a plurality of links 62-65 for connecting driving gear 30 and intermediate gears 40 and 50 so that they are always engaged with each other and intermediate gears 40 and 50 are movable along driving gear 30, a cam 60 driven by a driving source and having a cam flute 60', a cam lever 61 pivotally installed by a pivot 61' to be rotatable and one end of which is connected to links 62 and 63 and the other end of which is engaged with cam 60, and springs 66 and 66' connected between a plurality of links 62-65. Four links 62-65 are hinged at the respective rotational centers of intermediate gears 40 and 50 and driving gear 30. Links 62-65 are rotated by springs 66 and 66' so that intermediate gears 40 and 50 are detached from reel tables 10 and 20. Here, intermediate gears 40 and 50 are supported by links 62-65 to be installed on deck 100. Pivot 61' of cam lever 61 and the axis 30'' of driving gear 30, as shown in Fig.5, are fixed to a base 110 under deck 100. (The installation state of the pivot is not shown in Fig.5.) Here, with reference to Figs.5-7, direction controllers 35 and 45 each provided on reel table 10 or 20 comprises a driven disk 12 or 22 rotated at the same axis 10' or 20' as that of reel disk 14 or 24 and having an annular groove (no reference number), a driving disk 11 or 21 connected to the groove of driven disk 12 or 22, on the inner periphery of which a slanted groove 11' or 21' is formed and on the outer periphery of which a gear 11a or 21a is formed to be engaged with intermediate gear 40 or 50. One end of a spring 11'' or 21'' is fixed to the wall of slanted groove 11' or 21' and a ball 13 or 23 is connected to the other end of the spring. Here, ball 13 or 23 is moved according to the rotating direction of driving disk 11 or 21 in slanted groove 11' or 21' so as to be put between or released from the wall of the groove of driven disk 12 or 22 and the wall of slanted groove 11' or 21'. A tension device is provided on reel tables 10 and 20 to give a tensile force to the tape. A tension device for providing the tape coming out from the supply reel during PLAY or FF modes with tensile force is constructed by a tension band 90 tensioned by a tightening device (not shown) and looped around the driven disk 12 of supply reel table 10. As usual, tension band 90 may be tightened by a tension pole (not shown) engaged along the movement of a pole base in which a guide pole for discharging the tape from the tape cassette is installed. A tape tension device for providing the tape coming out from the take-up reel during REV or REW with tensile force comprises a fixed gear 80 driven being engaged with driven disk 22 of take-up reel table 20, a floating gear 81 engaged with fixed gear 80 and moved along fixed gear 80 so as to be connected to or separated from driven disk 22 in the rotating direction of fixed gear 80, and a connecting lever 84 for connecting fixed gear 80 and floating gear 81. An extended portion 82 is formed to be extended from connecting lever 84 and a stop 83 for blocking extended portion 82 is provided at one location within the rotation range of connecting lever 84, so as to prevent over-rotation of floating gear due to the rotation of fixed gear 80. The tape tension device provided on the side of take-up reel table 20 may be installed on the side of supply reel table 10. The operation of the reel driving apparatus of the present invention will be described below. Referring to Fig.4, first, when a tape cassette is still unloaded, cam lever 61 is rotated counterclockwise due to the rotation of cam 60. Then, intermediate gears 40 and 50 come toward each other by being rotated in the direction of links 62-65 approach to each other by springs 66 and 66'. The distance between intermediate gears 40 and 50 and driving gear 30 becomes smaller than that between reel tables 10 and 20. The tape cassette is mounted on reel table 10 or 20, and deck 100 is loaded toward a rotating head drum (not shown). Upon completion of the loading (as shown in Fig.2) cam lever 61 is rotated clockwise by cam 60 rotated by a driving source (not shown). Here, intermediate gears 40 and 50 are moved in the direction that they become far off by links 62-65, so as to be engaged with driving disks 11 and 21 of reel tables 10 and 20. Here, springs 66 and 66' are in the state of tension. (In Figs.2 and 3, driving disks 11 and 21 of direction controllers 35 and 45 are additionally illustrated.) During PLAY or FF, driving gear 30 is driven clockwise and the power is transmitted via intermediate gears 40 and 50 so as to rotate reel disks 14 and 24 clockwise. Here, as can be seen in Fig.6 (and Fig.5), ball 23 of driving disk 21 built in take-up reel table 20 is moved toward the narrower portion of slanted groove 21' due to the rotational inertial force, to be put between the wall of driven disk 22 and the wall of slanted groove 21'. Driving disk 21 and driven disk 22 are rotated together to frictionally rotate felt table 27. That is, reel disk 24 and felt table 27 are rotated at a specific rotation force by being frictionally rotated with driven disk 22. Fixed gear 80 engaged with driven disk 22 of take-up reel table 20 is rotated counter-clockwise so that floating gear 81 is detached from driven disk 22. As shown in Fig.7 (and Fig.2), driving disk 11 on the side of supply reel table 10 is rotated clockwise, so that ball 13 is moved toward the wider portion of slant groove 11' by contracting spring 11'' due to the inertial rotation. Driving disk 11 driven being engaged with intermediate gear 40 is raced with respect to driven disk 12. Thus, the tape is loosened from the supply reel (not shown) due to the rotational force of reel disk 24 on the side of take-up reel table 20. Here, tension band 90 is tightened by a tensile device (not shown). Therefore, driven disk 12 is stopped, and felt table 17 and reel disk 14 are frictionally rotated with driven disk thereby giving specific tensile force to the tape. Now, when the mode is changed from PLAY or FF to REV or REW, since driving disks 11 and 21 of reel tables 10 and 20 are connected with driving gear 30 via intermediate gears 40 and 50, the rotating direction of the driving disks is immediately changed. Reel disk 14 of supply reel table 10 is frictionally rotated with respect to direction controller 35, and reel disk 24 on the side of take-up reel table 20 is raced. Referring to Fig.3, since fixed gear 80 engaged with driven disk 22 of take-up reel table 20 is rotated clockwise, floating gear 81 is engaged with driven gear 81. Therefore, three gears 22, 80 and 81 are engaged at the same time and driven disk 22 is stopped. Thus, reel disk 24 gives tensile force to the tape travelling being frictionally rotated with direction controller 45. Tension band 90 installed on the side of supply reel table 10 is released from driven disk 12. The operation of direction controllers 35 and 45 in the REV and REW modes is similar to the operation in the PLAY and FF modes, so the detailed description thereof will be omitted. As described above, since reel tables 10 and 20 are connected with driving gear 30 via intermediate gears 40 and 50, the reel driving apparatus of the present invention provides a tape recorder in which a mode change is rapidly carried out. In the tape recorder employing the reel driving apparatus of the present invention, tape loosening does not occur, to thereby enhance the quality of reproduced pictures. Further, since the tension device for providing tape with tensile force is constructed only with the fixed gear and floating gear which are automatically operated according to the rotating direction of the reel table, a simplified tape recorder is accomplished. While the present invention has been particularly shown and described with reference to particular embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be effected therein without departing from the scope of the invention. For instance, the number of the intermediate gears connecting the two reel tables and driving gear is not limited to two, and an appropriate number of intermediate gears can be disposed depending on the specific structure of the mechanism.

Claims: A reel driving apparatus for a tape recorder comprising reel disks (14, 24) on which a tape reel is seated; two reel tables (10, 20) having felt tables (17, 27) installed on the same axis as said reel disks to have the same rotation force and having friction felts (16, 26) and direction controllers (35, 45) frictionally rotated with or relatively rotated to said felt tables according to the rotating direction; a driving gear (30) provided between said two reel tables and driven by a specific driving source; tape tension means provided on the side of at least one of said reel tables so as to give tensile force to the tape, wherein said direction controllers (35, 45) comprise driving disks (11, 21) on the outer periphery of which gears (11a, 21a) are formed, characterized in that intermediate gears (40, 50) connect said driving gear (30) and the direction controllers (35, 45) of said reel tables (10, 20); and said direction controllers (35, 45) are provided between said reel disks (14, 24) and said felt tables (17, 27) and comprise driven disks (12, 22) rotated on the same axis (10', 20') as those of said reel disks and having an annular groove, said driving disks (11, 21) being connected to said groove of said driven disks (12, 22), on the inner periphery of which slanted grooves (11', 21') are formed, one end of a spring (11", 21") is fixed to the wall of said slanted grooves and balls (13, 23) are connected to the other end of said springs, wherein said balls are moved in said slanted grooves according to the rotating direction of said driving disks (11, 21) engaged with said intermediate gears (40, 50), so as to be put between or released from the wall of the groove of said driven disks and the wall of said slanted grooves. Reel driving apparatus for tape recorder according to claim 1, characterized in that said tape tension means comprises a fixed gear (80) engaged with said driven disk (22), a floating gear (81) engaged with said fixed gear and moved along said fixed gear so as to be connected to or separated from said driven disk (22) in the rotating direction of said fixed gear (80), and a connecting lever (84) for connecting said fixed gear and floating gear, so that said floating gear is engaged with said driven disk according to the rotating direction of said fixed gear. Reel driving apparatus for a tape recorder according to claim 2, characterized in that an extended portion (82) is formed to be extended from said connecting lever and a stop (83) for blocking said extended portion is provided at one location within the rotation range of said connecting lever (84), so as to prevent over-rotation of said floating gear (81) due to the rotation of said fixed gear (80). Reel driving apparatus for a tape recorder according to at least one of the previous claims, characterized by a detaching means (60, 61, 62, 63, 64, 65, 66) for attaching or detaching said intermediate gears (40, 50) from said reel tables (10, 20). Reel driving apparatus for a tape recorder according to claim 4, characterized in that said detaching means comprises a plurality of links (62-65) for connecting said driving gear (11, 21) and intermediate gears (40, 50) so that said gears are always engaged with each other and said intermediate gears are movable while engaged with said driving gear (30), a cam (60) driven by a driving source, a cam lever (61) pivotally installed by a pivot (61') to be rotatable and one end of which is connected to said links and the other end of which is engaged with said cam, and springs (66, 66') connected between said plurality of links (62-65), so that said intermediate gears are attached or detached from said reel tables according to the rotation of said cam (60).

Inventors: KIM WOON-BAE, KIM, WOON-BAE
Applicants: SAMSUNG ELECTRONICS CO LTD, SAMSUNG ELECTRONICS CO. LTD.
Application year: 1993
Main classification: G11B15
IPC codes: G11B15