JP3430716B2 - Recording and playback device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing apparatus which does not use a pinch roller pressing mechanism. 2. Description of the Related Art In recent years, the biggest problem with magnetic recording / reproducing devices typified by VTRs is to reduce their size and weight, and at the same time, to reduce costs in accordance with the reduction in product prices. Conventionally, a magnetic recording / reproducing apparatus such as a cassette type video tape recorder generally employs a method of pressing a tape against a capstan with a pinch roller as a tape driving means. Further, a clutch mechanism for rotating a reel for winding the magnetic tape around the magnetic tape sent from the capstan at a constant torque has been usually employed. A tape drive mechanism of a conventional magnetic recording / reproducing apparatus will be described below with reference to FIG. FIG. 17 is a plan view of a conventional magnetic recording / reproducing apparatus. In FIG. 17, 200
Reference numeral 201 denotes a cassette containing a supply reel 207 on which a magnetic tape 212 is wound and a take-up reel 208. Reference numeral 201 denotes a rotary cylinder in which magnetic heads 203a to 203d are divided at 90 degrees on a circumference. An audio control head 209 records an audio signal and a control signal at both ends of the magnetic tape, an audio erase head 210 erases an audio signal already written at the time of recording, and a 211 erases a video signal already written at the time of recording. This is a full erase head. Tape guide post 2
04a, 204b, 204c, 204d, 204e and the inclined post 205a are arranged in the cassette opening (shown by a broken line) when the cassette is mounted, and after detecting the cassette mounting by a cassette detection switch (not shown), the tape guide post 204a. , 204b, 204c, 204
The d and 204e and the inclined post 205a are pulled out from the cassette opening and fixed at predetermined positions shown in the drawing.
Reference numeral 214 denotes a capstan motor having a capstan 213. When the apparatus is in a recording / reproducing mode, the magnetic tape 212 is pressed against the capstan 213 by a rubber pinch roller 215, and the magnetic tape 21 is driven at a predetermined speed.
2 are transported. 216a-216
b denotes a tape guide roller provided in the cassette 200. A reel drive gear 217 meshes with a gear formed on the take-up reel, and has a built-in torque limiter mechanism (clutch mechanism such as a magnet clutch) inside. The rotation of the capstan motor 214 is transmitted to the reel drive gear via the capstan belt 218, the relay pulley 219, and the idler gear 220, and drives the take-up reel 208 with a constant torque. [0005] However, in the above-mentioned conventional configuration, a mechanism for pressing a pinch roller against a capstan is required for recording and reproduction, and the mechanism is simplified to greatly reduce costs. Was a constraint on Further, there is a problem that a capstan shaft loss caused by pressing the pinch roller against the capstan and a friction loss in a torque limiter mechanism of the reel drive gear are large. An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a recording / reproducing apparatus which realizes power saving with a simple mechanism. [0007] In order to achieve this object, a recording / reproducing apparatus of the present invention comprises a first capstan, a first capstan parallel to the first capstan , and a first capstan parallel to the first capstan.
A second capstan that rotates quickly, a moving means for moving the second capstan during loading, and a tape passing between the first and second capstans during loading to the first and second capstans. Winding,
After the loading is completed , the rollers between the first and second capstans and the first and second capstans
First and second collars fixed and formed of a soft magnetic material
And a cylindrical member provided in parallel with the axis of the first and second capstans and magnetized and adsorbed to the first and second collars . One key
Tape wrapped around capstan wrapped around the roller
When the tape does not separate from the roller.
It has a configuration to wind around the second capstan. [0008] With this configuration, since a pressure bonding mechanism for a pinch roller, which has been conventionally required, is not required, the cost can be reduced by greatly simplifying the mechanism and the power consumption of the apparatus can be reduced. (Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a recording / reproducing apparatus. The outline of the entire apparatus will be described with reference to FIG. The magnetic tape 3 coming out of the supply reel 2 in the cassette 1 is drawn out of the cassette via guide rollers 4a and 4b provided in the cassette 1, and is supplied to the cassette 1 through the supply side tension post 39 and the guide post 40. After being loaded from the inside of the opening and wound around the guide post 5 and the inclined post 6 positioned at predetermined positions, it reaches the rotary cylinder 7. After the magnetic tape 3 is wound around the rotary cylinder 7 at a predetermined angle, the guide post 8 and the inclined post 9 are loaded from the opening of the cassette 1 and positioned at predetermined positions.
And a predetermined angle is wound around the AC head 11 via the guide post 10 which is loaded from the inside of the opening of the cassette 1 and positioned at a predetermined position in the same manner as the guide post 8.
The first capstan 12 is reached. Second capstan 1
3 is installed in parallel with the first capstan 12 and rotates in the same direction. The elastic roller 14 is held between the first capstan and the second capstan, and the magnetic tape 3
Is wound around the first capstan 12 by about 180 degrees, and then wound around the elastic roller 14 and further the second capstan 1
Wrap about 180 degrees around 3. After the magnetic tape 3 leaves the second capstan 13, the winding-side tension post 3
1. It is wound on the take-up reel 15 via the guide rollers 4e, 4c, 4d. The rotating cylinder 7 is provided with magnetic heads 16a and 16b having different azimuth angles and a flying erase head 17, and has a built-in motor for rotating them at a predetermined rotation speed. Next, a driving force transmitting mechanism of the take-up reel driving gear 18 will be described with reference to FIGS. Direct drive motor 1 for rotating the first capstan 12
9 (hereinafter referred to as a DD motor) and a relay pulley 21 rotatably provided on a substrate 20 are connected by a transmission belt 22. The gear portion provided on the relay pulley 21 is a link 2 that revolves the planetary gear 24 around the sun gear 25.
3 meshes with the gear portion 23a. The link 23 of the sun gear 25 is the sun gear shaft 2
6 is attached so as to be freely rotatable. An internal gear 27 meshing with the outside of the planetary gear 24 is rotatably attached to the link 23, and a braking member 29 provided on a braking arm 28 is pressed against the outer periphery. The braking arm 28 is rotatably mounted on a shaft provided on the substrate 20, and a spring 30 is mounted on one end, and the other end 28 a is connected to one end 32 a of a winding-side tension arm 32 provided with a winding-side tension post 31. When the winding tension of the magnetic tape 3 abuts and the winding-side tension post exerts a rotational force in a counterclockwise direction, the pressing force of the brake pad is reduced. The idler gear 33 is rotatably mounted around a rotation shaft 34 provided at one end of the idler arm 35, and meshes with the sun gear 25. The idler arm 35 is pressed against the lower surface of the link 23 by a spring 36 with a light force. The idler gear 33 rotates around the sun gear 25 by the action of the spring 36 and selectively meshes with the gear portion of the supply reel base 37 or the relay gear 38 depending on the rotation direction of the capstan. A supply-side tension arm 41 provided with a supply-side tension post 39 at one end is provided on a second substrate 42 with a rotating shaft 4.
3 and is urged in a counterclockwise rotation direction by a supply tension spring 44. Further, the supply reel table 37 is provided at the other end.
, And holds one end of a tension band 45 for applying a friction torque. A clutch felt 47 and a clutch plate 46 are provided below the relay gear 38.
When the main rod 48 moves to the right in the rewind mode, the claw 48d formed on the main rod 48 is configured to restrict the rotation of the clutch plate 46.
One end of the supply tension spring 44 is attached to the main rod 48, and relaxes in the rewind mode, and maintains the supply tension spring pulled leftward in the drawing in the recording / reproduction mode. 4 and 5, a mechanism for moving the main rod 48 left and right by the reversing operation of the idler arm 35 will be described. When the idler gear 33 is engaged with the relay gear 38, the gear portion of the relay pulley 21 and the intermittent gear formed on the outer periphery of the idler arm 35 are out of engagement. Further, even when the idler gear 33 is engaged with the supply reel base, the gear portion of the relay pulley corresponds to the missing portion of the gear of the idler arm 35 so that the engagement is released. A reversing gear 49 always meshes with the second gear portion 35a of the idler arm 35. A reversing lever 50 is provided coaxially below the reversing gear, and a slot 5 formed in the reversing lever 50 is provided.
A boss 49a provided on the reversing gear is inserted into 0a. The reversing lever 50 has a boss 50b formed therein, and the boss 50b is fitted in a deformed hole 48a formed in the main rod 48. The deformed hole 48a includes a groove 60a and arcs 60b, 60c, 60d, 60e, and the arcs 60b, 60c are formed with a smaller radius than the arcs 60d, 60e. When the main rod 48 completes the movement, the boss 50b of the reversing lever 50 stops at a position in contact with the arc 60e or 60d as shown in FIG. 5 so as to be sucked by the tapered portion 60f or 60g. As a result, the slot 50a and the boss 49a have the positional relationship shown by the broken line in FIG. 4, the reversing gear 49 and the reversing lever 50 are in a free state, and the meshing between the gear of the pulley 21 and the gear 35d of the idler arm 35 is smooth. Will be lost. Next, a tape driving mechanism using the first capstan 12 and the second capstan 13 will be described with reference to FIGS. FIG. 6 is a perspective view of the mechanism. FIG. 7 is a side view of the mechanism, FIG. 8 is a top view of the mechanism, and FIG. 8A is a state in which tape loading is completed.
(B) is a schematic diagram showing an unloading state. FIG. 9 is a side view showing a configuration for holding the elastic roller 14. In FIG. 7, the first capstan 12 is rotated by a direct drive type DD motor 19 at a predetermined rotation speed. A first capstan holder 52 for rotatably holding the first capstan 12 and fixing the first capstan 12 to the substrate 20 is attached to the DD motor 19. The first capstan holder 52 rotatably holds the second capstan 13 and has a rotation center parallel to the first capstan 12 and eccentric with the center of the second capstan shaft. Two capstan holders 53 are rotatably mounted, and are configured to be rotationally driven by a gear 51 that rotates in conjunction with a tape loading operation. First and second collars are fixed to the first capstan 12 and the second capstan 13, respectively. These first and second collars are formed of a soft magnetic material. Rollers 54, which are magnetized cylindrical members, are attracted to the cylindrical surfaces of the first and second collars. Here, since the roller 54 is magnetized in the axial direction of the cylinder as shown in FIG. 7, it is possible to eliminate the fluctuation of the transmission force when transmitting the rotation of the first capstan to the second capstan. The diameter of the first collar 55 is set larger than the diameter of the second collar 56 so that the second capstan 13 rotates slightly faster than the first capstan 12. Further, as shown in FIG. 15, a configuration may be employed in which the roller 54 is directly attracted to the second capstan. further,
As shown in FIG. 16, the configuration may be such that the roller 54 is attracted to a part where the second capstan 13 is partially constricted, and the roller 54 is directly attracted to the first capstan. FIG. 9 is a view showing the structure of a roller arm that holds the elastic roller 14 and pulls out the magnetic tape 3 from inside the cassette 1. The center of the elastic roller 14 has a vertically-conical pivot receiving structure so as to minimize friction loss during rotation. The cylindrical portion 14a adjacent to the conical portion is held with a certain gap by the cylindrical concave portion 57a of the elastic roller arm 57, and the position of the elastic roller when the elastic roller 14 pulls out the magnetic tape 3 from the cassette 1 during tape loading. Is regulated. The roller arm 57 is positioned so that the cylindrical portion 14a does not come into contact with the cylindrical concave portion 57a in the tape running mode such as during recording and reproduction. 58 is a roller arm 57 provided on the substrate 13
It is a rotating shaft of. Next, the operation of the winding tension control mechanism using the planetary gear mechanism will be described with reference to FIG. FIG. 10 is a schematic diagram for explaining the winding tension control mechanism. FIG. 13 shows the number of rotations and the direction of rotation of each gear of the planetary gear mechanism. Here, z1, z2, and z3 are the number of teeth of the internal gear 27, the sun gear 25, and the planetary gear 24, and n
Is an arbitrary value. FIG. 13 shows a case where the entire planetary gear is rotated once in the first row (1) and a case where the link 23 is fixed and the internal gear 27 is rotated once in the second row (2). The third row shows (3) obtained by adding n times (2) to (1). In (3), when the link 23 makes one rotation, the internal gear 27, the sun gear 25, and the planetary gear 24 are (1+
n), (1-n * z1 / z2), (1 + n * z1 / z)
3) Rotate. As an example, z1 = 51, z2 = 18,
Consider the case where z3 = 16. FIG. 14 shows a change in the number of rotations of each gear as n on the horizontal axis and the number of rotations of the gear on the vertical axis. Since the sun gear 25 is proportional to the rotation speed of the take-up reel 15, the rotation speed gradually decreases as the tape moves from the beginning to the end of the winding, and the internal gear 27 on which the braking member 29 is pressed against the outer periphery. Means that the rotational speed increases. Further, since the link 23 is driven by the DD motor 19, it constantly rotates at a constant speed. Where n
Should be larger than −1 and smaller than z2 / z1 = 0.35, but the rotational speed of the internal gear 27 should be set to be small in order to minimize the friction loss due to the braking member 29. Therefore, at the beginning of the winding, n is-
It is good to set to about 0.9. Here, the tension t of the tape emitted from the second capstan, which is obtained by the winding tension control mechanism of the present apparatus, is obtained. In FIG. 10, tensions t and t '
The force F applied to the tension post is: ## EQU2 ## Here, the running loss of the tape guide post, the shaft loss, and the transmission loss of the gear are neglected. That is, t = t ′. From the balance condition of the moment applied to the tension arm, Is required. Here, f is the force by which the braking member 29 is pressed against the outer periphery of the internal gear 27, b is the distance between the rotation axis center of the tension arm and the point of application of f, P is the spring force of the tension spring, and c is the tension The distance between the center of the rotation axis and the point of action of P, a is the distance between the tension post and the center of the rotation axis of the tension arm. (Equation 2) is rearranged with respect to f. Is obtained. By substituting (Equation 1) into (Equation 3), ## EQU1 ## With this f, the torque Φ1 acting on the internal gear 27 is given by: ## EQU1 ## Here, e is the radius of the outer peripheral drum portion of the internal gear 27, and μ is the friction coefficient of the braking member 29. FIG. 11 shows the relationship of forces acting on the planetary gear 24. Since it is equal to the sum of the force applied to the teeth meshing with the internal gear 27 and the force applied to the teeth meshing with the sun gear 25, the torque Φ2 applied to the sun gear 25 is given by: ## EQU1 ## Take-up reel 15 from sun gear 25
, And the tape winding diameter of the take-up reel 15 is r. Since the rotation torque applied to the take-up reel is equal to the value obtained by multiplying the rotation torque Φ2 of the sun gear 25 by the reduction ratio 、, the following expression is obtained. The following relationship is obtained. (Equation 4) is substituted into (Equation 7) to obtain: (Equation 8) is rearranged with respect to t. ## EQU1 ## In order to determine the winding tension controllability, the winding radius of the winding reel 15 at the beginning of the tape is represented by r.
s / te, where s and the winding radius at the end of the tape are re, ts / te is given by: ## EQU1 ## Next, the rotational speeds ω1, ω2, ωr of the internal gear 27, the sun gear 25, and the link 23 will be obtained. The rotation speed ω2 of the sun gear 25 is given by: Where V is the tape speed. The rotation speed ω1 of the internal gear 27 and the rotation speed ωr of the link 23 are as shown in FIG. [Mathematical formula-see original document] Is as follows. By substituting (Equation 11) for (Equation 13), Is given by Therefore, the reduction ratio ξ ′ from the DD motor 19 to the link 23 is given by the following equation, assuming that the rotational speed of the DD motor 19 is ω0. Where d0 is the diameter of the first capstan 12, and Is given by FIG. 12 shows the tape winding radius of the T-side reel and t
9 is a graph showing a result of calculating a DD motor load. The tape tension t set in FIG. 12 is maintained at about 30 gr, and the capstan load increases as the winding radius of the take-up reel 15 increases. When the tape tension t is constant regardless of the winding diameter of the take-up reel 15, a motor dedicated to reel driving has generally been used conventionally, but from the viewpoint of cost and power consumption. It was not a good idea because there was no great merit. Further, when the clutch torque generated by the reel drive gear 217 in the prior art is mechanically controlled by a tension arm and a braking member (not shown) so that the take-up tape tension is constant, the reel drive gear 217 may be used.
The initial setting of the clutch torque must be increased by an amount corresponding to the loss by the braking member. As a result, the load torque of the capstan motor increases. Therefore,
It can be said that the method of the present invention is effective in terms of both low power consumption and low cost. Next, the rewind (REW, REV) operation will be described. When the device switches to REW mode, D
The D motor 19 reverses and the spring 36 in FIG.
The idler arm 35 starts rotating counterclockwise due to the friction torque between the link 23 and the idler arm 35 generated by the rotation. As a result, the gear portion of the relay pulley 21 and the gear portion of the idler arm 35, which have not been meshed, start to mesh. At this point, the idler arm 35 is directly driven by the DD motor 19. The idler arm 35 further rotates, and the reversing gear meshing with the idler arm 35 largely swings clockwise,
At the same time, the reversing lever 50 also swings clockwise, and the main rod 48 moves rightward. As a result, the main rod 4
One end 48b of 8 acts on the winding-side tension arm 32, and the winding-side tension arm 32 and the braking arm 28 are separated from each other. The supply tension spring 44 is in a relaxed state in which no spring force acts on the supply-side tension arm 41 because the supply tension spring mounting portion 48c of the main rod 48 moves rightward. And the main rod 48
Claw portion 48d fixes the clutch plate 46 and generates a rotating load of the take-up reel 15 in REW. When the main rod 48 has finished moving to the right, the gear portion of the relay pulley is located in the second missing portion 35c of the gear of the idler arm 35, and the idler arm 35 is engaged with the supply reel table 37 and starts the REW operation. Due to the tension of the magnetic tape 3 wound by the supply reel 2, the supply-side tension post 39 rotates clockwise about the rotation shaft 43.
The braking arm 28 and the supply-side tension arm 41 are connected by a connecting rod 59. If the winding tension at the time of REW increases, the pressure of the braking member 29 of the braking arm 28 is reduced, and as a result, the winding of the supply reel table 37 is reduced. The take-up torque decreases, and the tension of the magnetic tape 3 decreases. In this way, the winding tension during REW is kept substantially constant. Conventionally, the winding by the REV has been performed by a clutch mechanism, so that the winding tension greatly changes depending on the winding diameter of the magnetic tape 3 of the supply reel 2. For this reason, the tape tension is large near the end of the tape having a low tension, and there is a risk that the tape may be damaged, and it is necessary to suppress the clutch torque for the REV. Conversely, the tape tension becomes low near the tape start end, and the reproduction output at the time of REV decreases, so that there is a problem that it is difficult to set the clutch torque. This is an effective solution to this problem. In the present embodiment, the structure in which the supply tension spring is loosened during REV and REW is shown. However, the tape tension near the supply-side tension post 39 during normal reverse running is higher than when the tape runs in the forward direction. Therefore, the supply tension spring 4 is driven by the tape tension in the reverse running.
The supply side tension arm 41 is also rotated clockwise even in the state where 4 is engaged. This allows the tension band 45
Is released, and it is not always necessary to loosen the supply tension spring 44. Next, the drawing operation of the elastic roller 14 will be described with reference to FIG. In FIG. 7, the elastic roller 14 is pulled out from the cassette 1 and is sandwiched between the first capstan 12 and the second capstan 13, and has the arrangement shown in FIG. At this time, in order to allow the elastic roller 14 to pass between the capstans slightly smaller than the diameter of the elastic roller itself, the second capstan holder 53 holding the second capstan 13 as shown in FIG. 8B, the state is shifted from the state shown in FIG. 8B to the state shown in FIG. As described above, the present invention relates to a first capstan, a second capstan parallel to the first capstan and rotating at the same speed, and a second capstan rotating at the time of loading. Moving means for moving the capstan, the tape passing between the first and second capstans during loading, and winding the tape around the first and second capstans, and after the loading is completed, the first and second capstans. And a roller pinched between the first and second capstans, and a magnetized cylindrical member provided in parallel to the axis of the second capstan. In the position mode, only the position where the cassette is removed and loading is completed can realize a significant cost reduction. You. Further, since the capstan has no friction loss due to pinch crimping and uses the magnetized third cylindrical member for the mechanism for transmitting the rotational force from the first capstan to the second capstan, the transmission loss is reduced. Can be reduced. Furthermore, since the take-up control mechanism is a planetary gear mechanism, there is no clutch mechanism conventionally used, and it is possible to realize an excellent recording / reproducing apparatus capable of greatly reducing the power required for operating the mechanism. .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a magnetic recording / reproducing apparatus according to an embodiment of the present invention. FIG. 2 is a plan view of a winding tension control mechanism of the magnetic recording / reproducing apparatus according to the embodiment. FIG. 4 is a side view of a winding tension control mechanism in the embodiment. FIG. 4 is a plan view of a main part of an idler arm mechanism in the embodiment. FIG. 5 is a perspective view of a main part of an idler arm mechanism in the embodiment. FIG. 7 is a perspective view of a tape drive device using first and second capstans in the embodiment. FIG. 7 is a side view of a tape drive mechanism using first and second capstans in the embodiment. FIG. FIG. 9 is a schematic diagram of a tape loading operation by an elastic roller of a tape driving mechanism using first and second capstans. FIG. 9 is a sectional configuration diagram of a roller arm in the embodiment. FIG. FIG. 11 is an operation explanatory view of the winding tension control mechanism in the embodiment. FIG. 11 is an operation explanatory view of the winding tension control mechanism in the embodiment. FIG. 12 is a control characteristic diagram of the winding tension control mechanism in the embodiment. FIG. 14 is a diagram showing the number of rotations of each gear of the planetary gear mechanism in the winding tension control mechanism in the example. FIG. 15A is an enlarged plan view of the vicinity of the capstan in the embodiment. FIG. 15B is an enlarged side view of the vicinity of the capstan in the embodiment. FIG. 16A is a view of the vicinity of the capstan in the embodiment. Enlarged plan view (b) Enlarged side view near capstan in the same embodiment [FIG. 17] Plan view of conventional magnetic recording / reproducing apparatus [Explanation of symbols] Yapusutan 13 second capstan 14 elastic roller 54 roller 55 first collar 56 second color

Claims (1)

(57) [Claim 1] A first capstan, which is parallel to the first capstan and faster than the first capstan.
A second capstan that rotates quickly, moving means for moving the second capstan during loading, and a tape that passes between the first and second capstans during loading to remove the tape from the first and second capstans. After completion of the winding and loading on the stan, a roller sandwiched between the first and second capstans, and first and second collars fixed to the first and second capstans and formed of a soft magnetic material And a cylindrical member provided in parallel with the axis of the first and second capstans and magnetized and adsorbed to the first and second collars. The tape wrapped around the stans wraps around the roller, and the tape wraps around the second capstan without leaving the roller. Recording and playback device.