BEST DESCRIPTION OF THE INVENTION

[0103] A single-reel tape cartridge, an information recording/playback apparatus, and an information recording/playback system according to the present invention will be described below with reference to the accompanying drawings, in the following order:

[0104] (1) General explanations of the single-reel tape cartridge and the magnetic recording/playback apparatus,

[0105] (2) Explanations of changer grips formed in the single-reel tape cartridge and a cartridge changer,

[0106] (3) Explanations of a memory module installed in the single-reel tape cartridge and memory-access modules of the magnetic recording/playback apparatus and the cartridge changer,

[0107] (4) Explanations of a leader tape and a striped portion used for identifying recording media of the single-reel tape cartridge and the recording/playback apparatus,

[0108] (5) Explanations of a leader block of the single-reel tape cartridge and the recording/playback apparatus, and

[0109] (6) Explanations of a reel lock of the single-reel tape cartridge, a reel lock disengaging member, and the magnetic recording/playback apparatus.

[0110] (1) General Explanations of the Single-Reel Tape Cartridge and the Magnetic Recording/Playback Apparatus

[0111] First, the single-reel tape cartridge and the information recording/playback apparatus will be described below with reference to FIGS. 5 to 11 .

[0112] The present invention can be applied to various kinds of information storing cartridges using various kinds of recording media, for example, tape-like recording media including tape-like recording media, disc-type recording media including optical discs, etc. In the present embodiment, a single-reel tape cartridge using a tape-like recording medium and a magnetic recording/playback apparatus, such as a tape streamer, which serves as an information recording/playback apparatus for recording and/or playback information on the tape-like recording medium, will be described.

[0113] The overall construction of a single-reel tape cartridge (hereinafter referred to simply as a tape cartridge) 1 will be described below with reference to FIGS. 5 to 10 . The tape cartridge 1 includes a cartridge housing 2 having a rectangular, flat shape constructed by combining an upper shell 3 and a lower shell 4 formed of a synthetic resin or the like. The upper and lower shells 3 and 4 have circular walls 5 , and a tape reel 6 having a large diameter is rotatably disposed inside the circular walls 5 , which are combined together. The tape reel 6 includes a hub 7 at the center and upper and lower flanges 8 and 9 at the upper and lower ends of the hub 7 . A long tape-like recording medium 10 is wound around the periphery of the hub 7 between the upper and lower flanges 8 and 9 , and the inner end of the tape-like recording medium 10 is attached to the periphery of the hub 7 by an inner leader tape (the leader tape will be described in detail in (4)).

[0114] The outer end 10 a of the tape-like recording medium 10 is connected to a leader tape 11 , which is connected to a leader block 12 formed of a synthetic resin or the like (the leader block will be described in detail in (5)).

[0115] The cartridge housing 2 is formed as a hexahedron having an anterior side 2 a corresponding to a front side, a posterior side 2 b corresponding to a rear side, a right side 2 c and a left side 2 d which are at the right and left, respectively, when the anterior side 2 a is seen from the front, a top side 2 e, and a bottom side 2 f. Approximately right-angle corners 2 A, 2 B, 2 C, and 2 D are formed at the peripheral region of the cartridge housing 2 , and triangular spaces 14 A, 14 B, 14 C, and 14 D are formed inside the four corners 2 A, 2 B, 2 C, and 2 D, respectively, and outside the circular walls 5 .

[0116] The triangular space 14 A at the corner 2 A between the anterior side 2 a and the left side 2 d of the cartridge housing 2 is provided with a tape-passage hole 13 , and the leader block 12 connected to the leader tape 11 is extracted through the tape-passage hole 13 . In addition, a reel-shaft receiving hole 16 is formed in the lower shell 4 at the center thereof. In addition, a pair of positioning reference holes 17 , a pair of positioning notches 18 , a plurality of detection holes 19 used for identifying the kind of the tape-like recording medium 10 , etc., are also formed in the lower shell 4 .

[0117] In addition, a reel lock mechanism 21 is disposed in the triangular space 14 B at the corner 2 B between the anterior side 2 a and the right side 2 c of the cartridge housing 2 . The reel lock mechanism 21 includes a peripheral gear 22 formed around the periphery of the upper flange 8 of the tape reel 6 , a lock lever 23 which is rotatably attached on the lower shell 4 with a fulcrum shaft 23 a and which becomes engaged and disengaged with the peripheral gear 22 , a shutter 24 which is able to slide inside the cartridge 2 along the right side 2 c in the front-rear direction and which rotates the lock lever 23 away from the peripheral gear 22 , a pressing unit which presses the lock lever 23 in the direction in which the lock lever 23 becomes engaged (interlocked) with the peripheral gear 22 , and a pressing unit which presses the shutter 24 in a direction in which the shutter 24 is shut.

[0118] As shown in FIG. 5 , at the corner 2 B of the cartridge housing 2 , a slit-shaped shutter opening/closing groove 120 is formed horizontally in the right side 2 c from the anterior side 2 a toward the posterior side 2 b, and the shutter 24 is disposed inside the shutter opening/closing groove 120 (The reel lock mechanism will be described in detail in (6)).

[0119] In addition, a write-protect switch 26 is disposed in the triangular space 14 D at the corner 2 D between the posterior side 2 b and the left side 2 d of the cartridge housing 2 . The write-protect switch 26 is able to slide along the posterior side 2 b in the right-left direction, and is positioned at either the right end or the left end in a slidable range thereof. In addition, a Memory In Cassette (MIC) 31 , which serves as a non-contact memory module, is stored (mounted) at the corner 2 C between the posterior side 2 b and the right side 2 c. The MIC 31 will be described in detail,in (3).

[0120] Next, a magnetic recording/playback apparatus 51 , such as a tape streamer, which serves as an information recording/playback apparatus stored in a computer system or the like, will be described below with reference to FIG. 11 . A cartridge-receiving hole 53 is formed in a front panel 52 , and a cassette compartment 54 is disposed horizontally inside the front panel 52 .

[0121] When the tape cartridge 1 is inserted horizontally from the anterior side 2 a thereof through the cartridge-receiving hole 53 into the cassette compartment 54 in the direction shown by the arrow a, a cassette-drawing device (not shown) disposed inside the cartridge compartment 54 horizontally draws the tape cartridge 1 into the cassette compartment 54 in the direction shown by the arrow a. When the tape cartridge 1 is drawn into the cassette compartment 54 , the tape reel 6 is released from the reel lock mechanism 21 located in the tape cartridge 1 . Then, although not shown in the figure, the cassette compartment 54 is moved vertically downward from an upper position to a lower position. Accordingly, a reel shaft 56 extending upward on a mechanical deck 55 is inserted through the reel-shaft receiving hole 16 of the tape cartridge 1 into the hub 7 of the tape reel 6 contained in the tape cartridge 1 , and becomes engaged with the hub 7 . Then, the tape reel 6 rises slightly above the lower shell 4 . Accordingly, an operation of loading the tape cartridge 1 is completed.

[0122] Alternatively, after the tape cartridge 1 is horizontally drawn into the cassette compartment 54 , the reel shaft 56 and a reel motor 57 may be moved vertically upward together, and the reel shaft 56 may be inserted into the hub 7 of the tape reel 6 from the lower side (this will be described in detail in (6)).

[0123] After the operation of loading the tape cartridge 1 is completed, as shown by the dotted chain line in FIG. 11 , the leader block 12 is extracted from the tape-passage hole 13 of the tape cartridge 1 , transferred approximately linearly along a tape path 58 in the direction shown by the arrow e, and attached to the a hub 60 of a take-up reel 59 mounted on the mechanical deck 55 by a leader-block loading unit of a tape-loading mechanism (not shown). While the leader block 12 is transferred in the direction shown by the arrow e, the reel motor 57 rotates the reel shaft 56 so that the tape reel 6 is rotated in the direction shown by the arrow g, that is, in the direction in which the tape-like recording medium 10 is unwound. Accordingly, the tape-like recording medium 10 is extracted from the tape cartridge 1 through the tape-passage hole 13 in the direction shown by the arrow e.

[0124] Then, as shown by the solid line in FIG. 11 , the tape-like recording medium 10 is loaded around the periphery of a rotating head drum 63 , which is placed on the mechanical deck 55 , in the shape like a letter ‘Ω’ by a pair of loading guides 62 of the tape-loading mechanism. Accordingly, the tape-loading operation is completed.

[0125] Then, when a recording and/or playback command signal is input to the magnetic recording/playback apparatus 51 from the computer device or the like, a part of the tape-like recording medium 10 which is at a position close to the take-up reel 59 is pressed against a capstan 65 , which is placed on the mechanical deck 55 , by a pinch roller 64 . At the same time, the tape reel 6 in the tape cartridge 1 is rotated by the supply reel motor 57 in the direction shown by the arrow g and the take-up reel 59 is rotated by a take-up reel motor 61 , which is placed on the mechanical deck 55 , in the direction shown by the arrow i, that is, in the direction in which the tape-like recording medium 10 is wound. Accordingly, the tape-like recording medium 10 is transferred in the direction shown by the arrow k at a constant speed, and the rotating head drum 63 records and/or plays back back-up information of the computer device, such as, image data and sound data, on the tape-like recording medium 10 .

[0126] When an eject command is input after the information recording and/or playback operation is completed, the pair of loading guides 62 of the tape-loading mechanism and the pinch roller 64 automatically return to their original positions. In addition, the tape reel 6 in the tape cartridge 1 is rotated by the supply reel motor 57 in the direction shown by the arrow h, that is, in the direction in which the tape-like recording medium 10 is rewound, and the take-up reel 59 is rotated by the take-up reel motor 61 in the direction shown by the arrow j, that is, in the direction in which the tape-like recording medium 10 is unwound. Accordingly, the tape-like recording medium 10 is retracted into the tape cartridge 1 through the tape-passage hole 13 and rewound around the periphery of the tape reel 6 , and the leader block 12 returns to the tape-passage hole 13 of the tape cartridge 1 .

[0127] Then, although not shown in the figure, after the tape-like recording medium 10 is completely rewound, the tape cartridge 1 is moved vertically upward from the lower position to the upper position, and is pushed out from the cassette compartment 54 through the cartridge-receiving hole 53 for a predetermined amount in the direction shown by the arrow b. At this time, the tape reel 6 is locked by the reel lock mechanism 21 again. Then, the tape cartridge 1 is manually removed from the cartridge-receiving hole 53 in the direction shown by the arrow b.

[0128] (2) Explanations of changer grips formed in the single-reel tape cartridge and a cartridge changer.

[0129] Next, changer grips formed in the tape cartridge 1 and a cartridge changer of a library apparatus or the like will be described below with reference to FIGS. 1 to 10 , 12 , and 13 .

[0130] As shown in FIGS. 1 to 10 , among the three corners 2 B, 2 C, and 2 D of the cartridge housing 2 of the tape cartridge 1 excluding the corner 2 A at which the tape-passage hole 13 is formed, the corners 2 C and 2 D at the right and left ends of the posterior side 2 b are provided with changer grips 28 , which are formed symmetrically in the right-left direction. The changer grips 28 are formed at positions close to the posterior side 2 b in such a manner that the changer grips 28 extend from end to end of the cartridge housing 2 formed by the upper and lower shells 3 and 4 in the Vertical direction. The changer grips 28 are formed as bracket-like shaped grooves 29 which are approximately symmetrical in the right-left direction.

[0131] Thus, the pair of changer grips 28 having shapes symmetrical in the right-left direction and extending from end to end of the tape cartridge 1 in the vertical direction are formed at the two corners 2 C and 2 D at the right and left ends of the posterior side 2 b. Accordingly, this tape cartridge (single-reel tape cartridge) 1 can be exchanged automatically by a cartridge changer of a library apparatus. In addition, the mechanism and control of the cartridge changer is simplified.

[0132] More specifically, as shown in FIGS. 12 and 13 , a cartridge changer 71 used in a library apparatus or the like includes a magazine 72 placed in an upright position. The magazine 72 is provided with a plurality of shelves 73 , and a plurality of tape cartridges 1 are inserted between the shelves 73 from the anterior sides 2 a thereof. Accordingly, the tape cartridges 1 are arranged in the vertical direction inside the magazine 72 in such a manner that the posterior sides 2 b of the tape cartridges 1 project from the magazine 72 at the front side 72 a thereof.

[0133] The changer grips 28 formed in each of the tape cartridges 1 at positions close to the posterior side 2 b also project from the magazine 72 at the front side 72 a thereof. Accordingly, the tape cartridges 1 are arranged such that the changer grips 28 are aligned in the vertical direction.

[0134] The cartridge changer 71 also includes the above-described magnetic recording/playback apparatus 51 placed below (or above) the magazine 72 , and the cartridge-receiving hole 53 of the magnetic recording/playback apparatus 51 faces the same direction as the front side 72 a of the magazine 72 .

[0135] A tray 74 used for transferring the cartridges 1 is disposed in such a manner that the tray 74 is able to slide along the front sides of the magazine 72 and the magnetic recording/playback apparatus- 51 in the vertical direction, that is, in the direction shown by the arrow m. The tray 74 is provided with a pair of hand arms 75 at the right and left sides thereof. The hand arms 75 move together in the direction shown by the arrows n 1 and n 2 , that is, in the direction in which the tape cartridges 1 are inserted and extracted to/from the magazine 72 and the magnetic recording/playback apparatus 51 . In addition, the hand arms 75 are formed symmetrically in the right-left direction, and end portions 75 a of the hand arms 75 are bent vertically toward each other, that is, in the direction in which they oppose each other. The hand arms 75 do not need to perform an opening/closing operation.

[0136] In the tape cartridges 1 and the cartridge changer 71 which are constructed as described above, when the tray 74 is moved vertically in the direction shown by the arrow m, the end portions 75 a of the hand arms 75 are able to move smoothly inside the changer grips 28 formed in the tape cartridges 1 , which are aligned vertically inside the magazine 72 , in the direction shown by the arrow m.

[0137] With reference to FIG. 13 , the tray 74 is stopped in front of a designated shelf, as shown by the solid lines, and then the hand arms 75 are moved together in the direction shown by the arrow n 1 to the positions shown by the dotted chain lines. Accordingly, the end portions 75 a, which are placed insides the changer grips 28 of the designated tape cartridge 1 , pull out the tape cartridge 1 from the magazine 72 in the direction shown by the arrow n 1 and place it on the tray 74 .

[0138] Then, the tray 74 is moved vertically downward (or upward) to the magnetic recording/playback apparatus 51 , and the hand arms 75 are moved together in the direction shown by the arrow n 2 in FIG. 13 . Accordingly, the end portions 75 a, which are placed inside the changer grips 28 of the tape cartridges 1 , push the tape cartridge 1 in the direction shown by the arrow n 2 , so that the tape cartridge 1 is inserted into the magnetic recording/playback apparatus 51 through the cartridge-receiving hole 53 from the anterior side 2 a. Then, the tape cartridge 1 is loaded in the magnetic recording/playback apparatus 51 and the information recording/playback operation is performed in the above-described manner.

[0139] After the information recording/playback operation is performed by the magnetic recording/playback apparatus 51 , the end portions 75 a of the hand arms 75 pull out the tape cartridge 1 by the changer grips 28 and place the tape cartridge 1 on the tray 74 . Then, the tray 74 is moved upward (or downward) to the designated shelf, and the tape cartridge 1 placed on the tray 74 is pushed by the end portions 75 a of the hand arms 75 , so that the tape cartridge 1 is inserted onto the designated shelf. In this manner, the tape cartridges 1 are automatically exchanged.

[0140] (3) Explanations of a Memory module of the Single-Reel Tape Cartridge and Memory-Access Modules of the Magnetic Recording/Playback Apparatus and the Cartridge Changer.

[0141] Next, the MIC 31 , which is a memory module mounted in the tape cartridge 1 , and remote interfaces 81 and 82 , which are memory-access modules mounted in the magnetic recording/playback apparatus 51 and on the tray 74 of the cartridge changer 71 , will be explained with reference to FIGS. 1 to 16 .

[0142] As shown in FIGS. 1, 2 , and 5 to 10 , the MIC 31 is formed as a non-contact, nonvolatile memory having no connecting terminals. The MIC 31 is constructed by mounting a memory unit on a surface 32 a of an MIC substrate 32 , which is a small printed substrate. An antenna unit 34 used for radio communication to/from the memory unit is formed on the surface 32 a by printing a copper foil pattern. The memory unit 33 stores management information for the tape-like recording medium 10 such as the length, the thickness, the material, etc.

[0143] The MIC 31 is placed in, for example, the triangular space 14 C at the corner 2 C between the posterior side 2 b and the right side 2 c of the cartridge housing 2 of the tape cartridge 1 . The MIC 31 may also be placed at the other corners, for example, at the corners 2 B and 2 D.

[0144] As shown in FIG. 10 , the end portions 32 b of the MIC substrate 32 in the longitudinal direction are fitted inside substrate-receiving grooves 35 , which are formed vertically in the upper and lower shells 3 and 4 , in the upright position. Accordingly, the MIC 31 is mounted in the triangular space 14 C in the upright position.

[0145] In addition, the MIC substrate 32 is disposed in the upright position in such a manner that the MIC substrate 32 is inclined by 45° relative to the posterior side 2 b and the right side 2 c of the cartridge housing 2 . Accordingly, the antenna unit 34 faces two directions which are perpendicular to the posterior side 2 b and the right side 2 c of the cartridge housing 2 , that is, the directions shown by the arrows A and B. One of the changer grips 28 is effectively disposed in a rectangular space 36 surrounded by the MIC 31 , the posterior side 2 b, and the right side 2 c.

[0146] The MIC 31 may also be constructed as shown in FIGS. 3 and 4 . This MIC 31 is constructed by mounting a memory unit 33 and printing an antenna unit 34 on a surface 37 a of an MIC substrate 37 , which is a flexible printed substrate. The MIC substrate 37 is inserted in substrate-receiving groove 38 which are formed in the upper and lower shells 3 and 4 in such a manner that the substrate-receiving grooves 38 are curved approximately perpendicularly along the posterior side 2 b and the right side 2 c. Accordingly, the MIC substrate 37 is disposed in the upright position in such a manner that-the MIC substrate 37 is bent approximately perpendicularly.

[0147] Accordingly, the antenna unit 34 is also bent approximately perpendicularly along the posterior side 2 b and the right side 2 c, so that the antenna unit 34 faces two directions which are perpendicular to the posterior side 2 b and the right side 2 c of the cartridge housing 2 , that is, the directions shown by the arrows A and B.

[0148] As shown by the solid lines in FIGS. 1 to 4 and in FIG. 11 , the magnetic recording/playback apparatus 51 includes a memory interface 81 used for writing and/or reading the management information on the MIC 31 , which is installed in the tape cartridges 1 . The memory interface 81 is mounted on, for example, the cassette compartment 54 in such a manner that the memory interface 81 is parallel to the right side 2 c of the tape cartridge 1 and is at a position close to the MIC 31 when the tape cartridge 1 is loaded.

[0149] In addition, as shown by the dotted chain lines in FIGS. 1 to 4 and in FIGS. 12 and 13 , the cartridge changer 71 includes a memory interface 82 used for writing and/or reading the management information on the MIC 31 , which is installed in the tape cartridges 1 . The memory interface 82 is mounted on, for example, the inside surface of one of the hand arms 75 of the tray 74 in such a manner that the memory interface 82 is parallel to the posterior side 2 b of the tape cartridges 1 and is at a position close to the MIC 31 when the tape cartridge 1 is disposed in the magazine 72 .

[0150] Accordingly, as shown in FIG. 11 , when the operation of loading the tape cartridges 1 in the magnetic recording/playback apparatus 51 is completed, the MIC 31 is placed at a position close to the memory interface 81 , which is parallel to the right side 2 c. Then, electric power is supplied to the memory unit 33 of the MIC 31 and the operation of reading and/or writing the management information is performed by radio communication (access) between an antenna unit of the memory interface 81 , which will be described below, and the antenna unit 34 of the MIC 31 .

[0151] Since the memory interface 81 can be disposed at one of the sides in the magnetic recording/playback apparatus 51 , the depth of the magnetic recording/playback apparatus 51 in the front-rear direction can be prevented from being increased as in the case in which the memory interface 81 is placed between the posterior side 2 b of the loaded tape cartridge 1 and the front panel 52 . In addition, even when the magnetic recording/playback apparatus 51 is of the type in which the posterior side 2 b of the loaded tape cartridge 1 projects outside from the cartridge-receiving hole 53 , the radio communication (access) with the MIC 31 is reliably performed.

[0152] In addition, as shown in FIGS. 12 and 13 , in the cartridge changer 71 , the memory interface 82 is mounted on, for example, the inside surface of one of the hand arms 75 of the tray 74 in such a manner that the memory interface 82 is parallel to the posterior side 2 b of the tape cartridge 1 when the tape cartridge 1 is disposed in the magazine 72 . Accordingly, the moving space of the hand arm 75 with the memory interface 82 in the direction shown by the arrows m and n can be prevented from being increased as in the case in which the memory interface 82 is mounted on the outside surface of the hand arm 75 . In addition, when the end portions 75 a of the hand arms 75 are inserted in the changer grips 28 of the designated tape cartridge 1 stored in the magazine 72 , the memory interface 82 immediately comes to a position close to the MIC 31 from the direction shown by the arrow B. Accordingly, the management information recorded in the MIC 31 can be obtained quickly, so that the time required for exchanging the tape cartridges 1 can be reduced.

[0153] In the present embodiment, the MIC 31 is disposed such that the antenna unit 34 opposes both the posterior side 2 a and the right side 2 c of the tape cartridge 1 . However, the MIC 31 may also be disposed such that the antenna unit 34 opposes the posterior side 2 a and the left side 2 d, the posterior side 2 a and the top side 2 e, the posterior side 2 a and the bottom side 2 f, the right side 2 c and the top side 2 e, the right side 2 c and the bottom side 2 f, the left side 2 d and the top side 2 e, or the left side 2 d and the bottom side 2 f. In addition, the MIC 31 may also be disposed such that the MIC 31 is inclined relative to the posterior side 2 b and the right side 2 c by 450 and the surface 32 a of the MIC 31 is inclined upward or downward by 450 , so that the antenna unit 34 opposes three surfaces: the posterior side 2 b, the right side 2 c, and the top side 2 e or the bottom side 2 f.

[0154] Next, the MIC 31 mounted in the tape cartridge 1 and a control circuit 84 for the magnetic recording/playback apparatus 51 will be explained below.

[0155] As shown in FIG. 14 , the MIC 31 mounted in the tape cartridge 1 includes the memory unit 33 and the antenna unit 34 . The memory unit 33 is constructed as a semiconductor IC including a power circuit 40 , a radio frequency (RF) processing unit 41 , a controller 42 , and an Electrically Erasable Programmable Read-Only Memory (EEP-ROM) 43 . The memory unit 33 , for example, is mounted on the MIC substrate 32 , and the antenna unit 34 is formed as a copper foil pattern.

[0156] The MIC 31 is driven by receiving electric power from the external environment via a communication antenna of the remote interface 81 , which will be described below. More specifically, carrier waves of, for example, 13 MHz frequency band, are used for the communication between the MIC 31 and the communication antenna. The carrier waves of 13 MHz frequency band are transmitted from the communication antenna, received by the antenna unit 34 , and converted into a direct current by the power circuit 40 . Then, the direct current is fed to the RF processing unit 41 , the controller 42 , and the EEP-ROM 43 .

[0157] The RF processing unit 41 demodulates the received information and modulates the information to be transmitted. The controller 42 decodes the received signals obtained from the RF processing unit 41 , and performs processes, for example, read/write processes on the EEP-ROM 43 , in accordance with the decoded information (command).

[0158] More specifically, the MIC 31 is activated by receiving the electric waves transmitted from the communication antenna, and the controller 42 performs processes corresponding to commands carried by the carrier waves and manages data stored in the EEP-ROM 43 , which is a nonvolatile memory.

[0159] The MIC 31 stores date and place of manufacture, the thickness and material of the tape-like recording medium 10 , information for identifying the kind of the tape cassette, etc., for each tape cartridge 1 . When the tape cartridge 1 is loaded in the magnetic recording/playback apparatus 51 , these data items are read out via the communication antenna. In addition, the MIC 31 also stores information regarding the usage history, etc., of the data recorded on the tape-like recording medium 10 , user information, etc.

[0160] Next, with reference to FIG. 15 , the control circuit 84 , which is stored in the magnetic recording/playback apparatus 51 and which includes a memory drive circuit and a system control circuit, will be described below.

[0161] As described above, the magnetic recording/playback apparatus 51 is constructed such that the rotating head drum 63 performs the data recording/playback operation on the tape-like recording medium 10 of the loaded tape cartridge 1 by a helical scan method. The rotating head drum 63 includes two write heads WH 1 and WH 2 having different azimuth angles and three read heads RH 1 , RH 2 , and RH 3 having a predetermined azimuth angle, the read heads RH 1 , RH 2 , and RH 3 being formed at a predetermined angle-pitch. In addition, the magnetic recording/playback apparatus 51 includes a plurality of driving motors such as a supply reel motor SRM, a take-up reel motor TRM, a drum motor DM, a capstan motor CM, a tape-loading motor LDM, and a cartridge-loading motor EM. These motors are rotated by electric power supplied from a mechanical driver 85 .

[0162] A servo controller 86 controls the mechanical driver 85 , which drives each of the driving motors. The servo controller 86 controls the rotational speed of each driving motor so as to control the movement of the tape during normal recording/playback operation, high-speed playback, fast-forward, wind-back, etc., and to perform tape-cartridge receiving/ejecting operation, tape loading/unloading operation, tape-straining operation, etc.

[0163] In order for the servo controller 86 to perform servo-control of each driving motor, each driving motor is provided with a frequency generator (FG), so that information regarding rotation of each driving motor can be obtained.

[0164] The servo controller 86 determines the rotational speed of each driving motor on the basis of FG pulses, calculates the error between the determined rotational speed and the desired rotational speed for each driving motor, and controls the mechanical driver 85 such that the mechanical driver 85 supplies electric power corresponding to the error. Thus, a closed-loop control is performed for the rotational speed of