JPH02236853A - Rotary head type magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To reduce the torsional stress of a magnetic tape and to improve the simplification, reliability and durability of the device by rotating slantly a rotary head on a circumferential surface of a ellipsoidal drum, guiding the tape with an air dynamic pressure floating means and preventing solid contact even at the time of stopping. CONSTITUTION:The magnetic tape is guided parallel to a chassis by ellipsoidal columnar upper drum 1 and lower drum 2 which are combined by a combining member 22 and fixed to the chassis 19. Magnetic heads 3 and 4 are rotated by motors 17 and 18 at a prescribed slanting angle respectively, whereas the heads are controlled not to contact with a surface 2a of the lower drum 2 via leaf springs by impressing a voltage on bimorph plates even at the time of stopping and floating above the surface 2a with an air dynamic pressure. By this method, since the magnetic tape does not travel three-dimensionally, no torsional stress is effective, and in addition, a loading mechanism can be simplified while the magnetic heads are prevented from undergoing solid contact and the drum surface can be prevented from flawing.

Description

[Detailed description of the invention] [Industrial field in Icheon] The present invention involves winding a tape around a drum having a magnetic head,
The present invention relates to a rotary head type magnetic recording/reproducing device that performs recording and reproduction.

[Prior art] Conventionally, video tape recorders (VTRs) and rotary head digital audio recorders (R-DATs) have been used.
), etc., the magnetic tape loading methods are M type, U type, etc. Omega type + JL type, etc. are used, but in both methods the tape is wound diagonally, so there is a step between the entrance and exit sides of the drum, and the magnetic The tape running path was lengthened and corrected with an inclined post, allowing the magnetic tape to run three-dimensionally. [Problems to be Solved by the Invention] In the conventional magnetic recording/reproducing apparatus as described above, the magnetic tape is wound diagonally around the rotating drum, and therefore, there are the following drawbacks.

■To compensate for the difference in level between the inlet and outlet sides of the rotating drum,
It was necessary to tilt the rotating drum and tape guide post, which made it impossible to make the device thinner and smaller.

■The loading mechanism was complicated and the cost was high. ■Precision was required for machining and assembly of sloped surfaces. ■A torsional force was applied to the magnetic tape, which had a negative effect on the magnetic tape itself.

This invention was made to solve the above problems, and is a rotating head type magnet that does not tilt the drum or tape, has a simple loading mechanism, and does not apply torsional force to the magnetic tape. The purpose is to provide a recording/playback device.

[Means for Solving the Problems] In order to achieve the above object, the rotary head type magnetic recording/reproducing device of the present invention includes a drum around which a magnetic tape is wound, and a drum that is inclined with respect to the axis of the drum. means for obtaining a recording pattern by guiding the magnetic head using dynamic pressure from air and moving it in the width direction of the magnetic tape; , means for vertically moving the magnetic head when starting and stopping the magnetic head. [Function] With the above configuration, even when the magnetic head is stopped, a means is provided to prevent the magnetic head from floating and contacting the lower drum in the same way as when starting, so it can be driven with a small torque when starting. And besides, at startup,
There is no scratch on the drum surface when it stops, and there is no friction noise. [Embodiments] In explaining embodiments of the present invention, the basic idea will be explained using FIGS. 3, 4, 5, 6, and 7. 3 and 4 are a plan view and a side view, respectively, for explaining the principle of the present invention. In Figures 3 and 4,
27 and 28 are elliptical upper and lower drums for keeping the protrusion of the head constant, 29 is the center axis of the upper drum 27 and lower drum 28, and 30 is a magnetic drum having means for floating by dynamic pressure of air. head, 3l is the magnetic head 3;
A magnetic head similar to 0 but having a different azimuth angle; 32 is a leaf spring for pressing the magnetic head 30 against the surface 28a of the lower drum 28; The interval is kept constant. Reference numeral 33 indicates a plate spring that acts in the same way as the plate spring 32 for the magnetic head 31, and 34 indicates the plate spring 32, 33 and the magnetic head 3.
0.31 is a rotating disk for rotating it at a predetermined angle 35, 36 is a rotation center axis of the magnetic head 30.31, 37
38 is a connecting member for connecting the upper drum 27 and the lower drum 28, and 38 is a lead for guiding the tape to the drum. It is not spiral like the conventional example, but is connected to the center axis 29 of the drum.
It consists of planes perpendicular to . Reference numerals 39 and 40 are tape guide posts that regulate the angle at which the tape is wrapped around the drum and the upper end surface of the tape. FIG. 7 is a diagram showing the track pattern of the tape.
The track pattern shown by a solid line is a recording track defined in the standard, and the track pattern shown by a broken line is a recording track according to the fourth embodiment of the present invention.
The figure shows a case where the surface 28a of the lower drum 28 is a flat surface. For example, the winding angle of R-DAT is 90@, and the major axis of I'ram ellipse is 30. , drum ellipse short axis z+. t7. ．． Then, the off-track amount is about 50g. The track width of R-DAT format is 13.
．． 61. It cannot be ignored because it is only a small amount. In the present invention, this off-track amount (trajectory of the broken line shown in FIG. 7) is offset by the head floating by air dynamic pressure and guided by the surface 28a of the curved lower drum 28, and the track on the format is The feature is that it corrects patterns. Next, a specific example of the present invention will be explained using FIGS. 5 and 6. FIG. 5 is a plan view of an embodiment of the present invention, and FIG. 6 is a side sectional view of the apparatus shown in FIG. Figure 5. In FIG. 6, 23 is an elliptical upper drum for guiding the tape;
2 is an elliptical lower drum having a tape guide, a lead, a housing for a bearing, and a means for attaching it to the chassis of a magnetic recording/reproducing device; 3 is a magnetic head that floats on the surface 2a of the lower drum 2 by air dynamic pressure; 4 is this magnetic head; A magnetic head similar to Head 3, but with a different azimuth angle. 24 and 25 are leaf springs for pressing the magnetic heads 3 and 4 with a predetermined pressure; 22 is a connecting member for aligning and fixing the upper ram 23 and the lower drum 2; 26 is a magnetic head 3; , 4 and leaf spring 24.2
11 is a shaft for transmitting the rotational force of the motor to the rotating disk 26, l4 and l5 are ball bearings for supporting the shaft l1 on the lower drum 2, and l2 and l3 are ball bearings for supporting the shaft l1 on the lower drum 2. A rotary transformer for transmitting signals from the rotating magnetic heads 3 and 4.
2 is a stator, and 13 is a rotor. 16.17 and 1
8 constitutes a drum motor, 16 is a stator coil of the tram motor, 8 is a magnet, and 17 is a motor yoke.

19 is a chassis of the magnetic recording/reproducing apparatus of the present invention, and 20 and 2l are tape guide posts, which regulate the winding angle of the drum and the upper end surface of the tape. In the embodiment shown in FIGS. 5 and 6, the elliptical upper drum 23 and lower drum 2 are both used to guide the tape, and remain stationary and do not rotate. is pressed onto a rotating disk 26 by plate springs 24 and 25, and is rotated together with the shaft 11 by a motor to perform recording and reproduction. The off-track of the tape is corrected by the floating effect caused by the rotation of the lower drum 2 and the magnetic head 3.4.

However, in the above embodiment, in order to correct the amount of off-track of the magnetic head, the aerodynamic levitation force of the magnetic head and the force of the leaf spring that presses the magnetic head are balanced against each other so as to align the magnetic head along the drum. When the rotation of the disk is stopped, the flying surface of the magnetic head and the guide surface for correcting the off-track of the lower drum come into contact with each other, so it is necessary to consider the following points.

■When rotating the magnetic head, a very high torque is required because it is in solid contact, which puts a load on the motor and requires a large amount of power from the motor itself and the drive circuit.

■The flying surface of the magnetic head and lower drum is easily scratched when the drum is started or stopped, which tends to cause uneven flying gaps. ■Undesirable noise for audio equipment may be generated during the time the magnetic head levitates and during the 9m distance until it stops. FIG. 1 is a plan view of an improved embodiment of the invention, and FIG. 2 is a side sectional view of FIG. 1. In FIGS. 1 and 2, 1 and 2 are an elliptical upper drum and an elliptical lower drum, 3 and 4 are magnetic heads that fly and rotate, and 5 and 6 are magnetic heads that connect the magnetic head 3.4 to a lower tram. 2, 7 and 8 are highmorph plates made of electromechanical transducers for vertically moving the magnetic head; 9 is a rotary disk for transmitting the rotational force from the motor; 10 is the bimorph plate 7; 11 is a rotatable shaft inclined at a predetermined angle with respect to the lower drum 2, l2 is a stator of a rotary transformer. 13 is a rotor of a rotary transformer, 14.15 is a ball bearing that rotatably supports the shaft 11 on the lower tram 2, 16 is a stator coil of a motor that rotates a rotating disk, 17 is a yoke of this motor, 1
Reference numeral 8 designates the magnet of the motor, reference numeral 19 designates the chassis of the magnetic recording/reproducing device, and reference numerals 20 and 21 designate tape guide posts that regulate the winding angle around the drum and the upper end surface of the tape. The configuration of this embodiment will be explained below, but since the basic principle and configuration are almost the same as those in FIGS. 5 and 6, the device in FIGS. We will explain the differences between the devices shown in the figure. An elliptical upper tram l and lower drum 2 are arranged perpendicularly to the chassis l9, the magnetic head 3.4 is floated using the lower drum 2 as a guide, off-track is corrected, and the tape is run three-dimensionally. Record without letting
The reproduction is the same in this embodiment as in the devices shown in FIGS. 3 and 4. The layout in Figures 3 and 4 is, of course,
Due to the relative movement of the floating surface between the lower drum 2 side and the magnetic heads 3 and 4, it is levitated by air dynamic pressure, so when the magnetic heads 3 and 4 are stopped, they come into contact with the lower drum 2. Because of this, high torque is required at startup. To solve this problem, when the magnetic head 3.4 is stopped, bimorph plates 7, 8 and leaf springs 5, 6 are interposed between the rotating disk 9 and the magnetic heads 3, 4. The magnetic heads 3, 4 are controlled to fly by applying voltage to the bimorph plates 7, 8 so as not to contact the floating guide surface of the lower drum 2. According to this embodiment, in order to correct the trajectory of the upper drum 1, the lower drum 2, the motor that rotates the magnetic head at a predetermined inclination angle, and the magnetic head 3.4 to a prescribed track pattern, The upper drum 1 and the lower drum 2 are disposed perpendicularly to the chassis 19. , the tape is not run three-dimensionally, and the solid friction that occurs when the magnetic heads 3 and 4 start and stop rotating is eliminated. [Effects of the Invention] As explained above, the present invention has a rotary head obliquely rotated around the circumferential surface of a stationary elliptical drum, and off-track is corrected by air dynamic pressure floating means of the drum and magnetic head. In addition, by providing a means to prevent the air bearing surface from coming into contact with solid matter even when the magnetic head is stopped, as when it is started, it is compatible with helical scan type magnetic recording and reproducing devices without running the magnetic tape three-dimensionally. However, it has the effects of reducing torsional stress on the magnetic tape, simplifying the tape bus, and improving the reliability and durability of the device.

[Brief Description of the Drawings] Figure 1 is a plan view of an improved embodiment of the present invention, Figure 2 is a side sectional view of an IF diagram, and Figures 3 and 4 are for explaining the principle of the present invention. 5 is a plan view of an embodiment of the present invention, FIG. 6 is a side sectional view of the device shown in FIG. 5, and FIG. 7 is a diagram showing the track pattern of the tape. In the figure. 1, 23.27 = Elliptical upper drum 28: Elliptical lower drum 3, 4, 30, 31: Magnetic head 5, 6, 24, 25, 32, 33: Leaf spring 7.8:
Bimorph plates 9, 26: Rotating disk 10: Slip ring 1l: Shaft l2: Stator of rotary transformer 13: Rotor 14 of rotary transformer, Iss ball bearing 16: Stator coil of motor l7: Motor yoke 18: Motor magnet 19; Chassis 20 , 21, 39, 40: Table guide boss 22,:
17 Two connecting members 29: Central axis 35: Inclination angle 6: Motor shaft 38: Lead Figure 1 Figure 2 Agent Patent attorney Takashi Takashi Figure Figure Figure Figure

Claims (1)

[Claims] It has a drum around which a magnetic tape is wound, and a magnetic head that rotates around the circumferential surface of the elliptical drum with a rotating shaft inclined with respect to the axis of the drum. A rotary head type magnet, comprising means for guiding the magnetic tape and moving it in the width direction of the magnetic tape to obtain a recording pattern, and means for moving the magnetic head up and down when starting and stopping the magnetic head. Recording and playback device.