JPS62184654A - Recording and reproducing device - Google Patents

Abstract

PURPOSE:To form accurately a track on the surface of a recording tape medium by providing a tape guide respectively to both ends of a head drum. CONSTITUTION:A plunger 98 drives a pressing lever 95, a projection provided to the tip depresses the upper face of a flange guide 31 and a moving stay 94 regulates upper/lower flange guides 31, 32 at a correct interval. Since the part opposite to the movable stay 4 is regulated to a correct interval by a fixed stay 93, it is possible to regulate correctly the position of both sides of the magnetic tape 10 in the broadwise direction by the two guides 31, 32. A slope face 100 is formed by chamfering the edge of the flange guides 31, 32 and the magnetic tape 10 is guided smoothly and led in.

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to a recording/reproducing device, and more particularly, a tape-shaped recording medium is wound around a head drum so as to coincide with the circumferential direction, and a plurality of tape-shaped recording media are wound in the longitudinal direction of the tape-shaped recording medium by a rotating head. The present invention relates to a recording/reproducing device for forming tracks of a book.

[Summary of the invention]

The present invention provides tape guides at both ends of a head drum for recording and/or playback by winding a tape-shaped recording medium, and regulates both sides of the tape-shaped recording medium in the width direction by these tape guides. This allows tracks to be accurately formed on the surface of a tape-shaped recording medium. BACKGROUND OF THE INVENTION Conventional analog recording VTRs employ a helical scanning method in which tracks are formed by winding a magnetic tape obliquely around a head drum. According to such a helical scanning method, tape paths cannot be formed on the same plane, and the tape bus becomes complicated. Furthermore, since the magnetic tape hangs obliquely on the guide, there is a drawback that the guide cannot be made rotatable. Furthermore, it is not possible to record on both the front and back sides of the magnetic tape, which reduces the recording capacity and prevents miniaturization of cassettes. Furthermore, since round-trip recording is not possible, access time is long and rewind operations are required.

[Problems to be solved by the invention]

In order to overcome such drawbacks, for example, US Pat.
No. 40109 describes a parallel scanning VTR.
is proposed. By performing recording and reproducing using this method, as well as digitizing signal processing and processing the time axis, it becomes possible to create an organic connection between the mechanical system and the signal system, and it becomes possible to create an organic connection between the mechanical system and the signal system. It becomes possible to cover problems. However, in such a helical scanning method, if the position of the magnetic tape is not properly regulated with respect to the axial direction of the head drum, errors will occur in the positions at which tracks are formed. Therefore, in such a case, the distance between the first rack and the track must be widened, resulting in the disadvantage that high-density recording cannot be performed or the recording density of the magnetic tape decreases. The present invention has been made in view of these problems, and is a recording method in which tracks are formed on a tape-shaped recording medium with its position correctly regulated in the width direction in a parallel scanning method. The purpose is to provide a playback device. Means for Solving Problem K] The present invention involves winding a tape-shaped recording medium so as to coincide with the circumferential direction of a head drum, and also winding a plurality of tape-shaped recording media in the length direction of the tape-shaped recording medium by a rotating head. In an apparatus for forming tracks, tape guides are provided at both ends of the head drum, and these tape guides regulate both sides of the tape-shaped recording medium in the width direction. [K effect] Therefore, according to the present invention, both sides of the tape-shaped recording medium in the width direction are regulated by the tape guides provided at both ends of the head drum, so that the tape-shaped recording medium is regulated in the width direction. On the other hand, positional deviation does not occur, and it becomes possible to form a track with the position correctly regulated in the width direction. Therefore, it becomes possible to narrow the distance between tracks and perform high-density recording. K Embodiment The present invention will be described below with reference to illustrated embodiments. FIG. 1 shows a parallel scanning type VTR according to an embodiment of the present invention, and this VTR uses a tape cassette 11 in which a magnetic tape 10 is wound and stored. The magnetic tape 10 is wound around a supply reel 12 and a take-up reel 13, with both ends fixedly attached to these reels 12 and 13, respectively. Then, the magnetic tape 10 is pulled out from the casing of the tape cassette 11, and the head drum 15
．． It is designed to be mounted on 16. In order to make this mounting possible, tape guides 17 to 21 are used. In order to remove slack in the magnetic tape 10 mounted on the pair of head drums 15 and 16, coil springs 23.
Tension lever 25 being pulled by 24.
26 are used, and these levers 2
5. Tape guide 27 supported at the tip of 26.
28 prevents the magnetic tape 10 from becoming loose. Furthermore, the magnetic tape 10 is pressed by a pinch roller 30 against a capstan 29 that rotates at a constant speed. Although the device in FIG. 1 is provided with two head drums 15, 16, it is also possible to have one drum. That is, as shown in FIG. 2, it is also possible to perform recording and reproduction using only the head drum 16. In this case, the head drum 15 and tape guide 17 may be omitted. When using two drums 15.16,
Recording and reproducing can be performed on the front and end surfaces of the magnetic tape 10, but in the case of one drum, recording and reproducing are performed only on the front surface of the magnetic tape 10. Next, the structure of the head drum 15, 16 will be explained. As shown in FIGS. 3 and 4, for example, the head drum 16 is arranged so as to be sandwiched between upper and lower flange guides 31, 32. Moreover, the head drum 16 is fixed to the rotating shaft 33. This rotating shaft 33 also serves as the output shaft of the motor 34, and is rotatably supported by a bearing attached to the casing 35. A stator coil 36 is disposed within the casing 35, and a rotor core 37 is fixed to the rotating shaft 33, thereby rotating the head drum 16 via the rotating shaft 33. There is. To explain the flange guides 31 and 32 for regulating the position of both sides in the width direction of the magnetic tape 10 wound around the head drum 15 and 16, the lower flange guide 32 is fixed to the casing 35 of the motor 34. has been done. A fixed stay 93 is fixed to the upper surface of this flange guide 32 at the right end in FIGS. 3 and 4. The upper flange guide 31 is attached via this fixed stay 93. At a position opposite to the position provided on the fixed stay 93, the movable stay 94 is attached to the upper and lower flange guides 31, 32.
It is designed to be inserted between the desks. This movable stay 9
4 is inserted by a moving means (not shown), and in this state, the upper part of the upper flange guide 31 is pushed by a pressing lever 95. As shown in FIG. 4, this lever 95 is rotatably supported by a fulcrum pin 96 and a connecting link 97.
The plunger 9 is connected to a rod 99 via the plunger 99. Therefore, the pressing lever 95 is rotated by the plunger 98, and the projection provided at the tip thereof presses the upper surface of the flange guide 31, so that the upper and lower flange guides 31
．． 32 can be regulated at correct intervals by the movable stay 94. Furthermore, the part opposite to the movable stay 94 is the fixed stay 9.
3, the two guides 31 and 32 make it possible to correctly regulate the position of both sides of the magnetic tape 10 in the width direction. Therefore, with this structure, it is possible to correctly form tracks on the surface of the magnetic tape 10 without causing any positional deviation in the width direction of the magnetic tape 10. Moreover, since the magnetic tape 1o is wound so as to coincide with the circumferential direction of the head drum 16, it is possible to accurately regulate the position in the width direction regardless of the running direction or running speed of the magnetic tape 1o. . The tape guides 17 to 22 that guide the magnetic tee 110 are attached with reference to these flange guides 31 and 32. Further, the edges of the flange guides 31 and 32 are chamfered as shown in FIG. 3, thereby forming an inclined surface 100. Therefore, according to such a structure, the pair of flange guides 3
It becomes possible to smoothly guide and introduce the magnetic tape 10 between 1.32 and 32 seconds. Note that the tape guides for regulating both sides of the magnetic tape 10 in the width direction are not limited to those with structures shown in FIGS. 3 and 4, and may include modified examples shown in FIGS. 5 and 6. It is also possible to have a structure like this. In this modification, the upper flange guide 31 is directly attached to the magnetic tape 10.
A notch 102 is provided in this flange guide 31 without making contact with the upper tape guide 103, and the upper tape guide 103 is disposed within this notch 1Q2. The tape guide 103 is attached to the tip of the spring 104 housed in the notch 102.
Moreover, its downward movement is restricted by a stopper 105. Therefore, according to such a configuration, the tape guide 103 moves in the width direction of the magnetic tape 10 and guides the magnetic tape 10.
It comes to be regulated by pressing elastically. Therefore, even if there is an error in the width of the magnetic tape 10, this error can be absorbed by moving the tape guide 103. Therefore, in this case, the tape guide 10 is regulated in the width direction using the upper surface of the flange guide 32 as a reference surface. Note that the tape guide 103 is preferably made of a material such as ceramic. As shown in FIGS. 3 and 4, a coil 38 constituting a linear motor is disposed within the head drum 16 and is wound around a stator core 39. A movable element 40 is disposed movably with respect to the stator core 39, and is adapted to perform linear motion. This movable element 40 has four magnetic heads 41 arranged in a row vertically.
~44 are supported. That is, four heads 41~
44 is disposed in the axial direction of the head drum 16 and can be moved in the axial direction by the linear motor 38. and the upper two magnetic heads 41.4
2 are joined together to constitute an azimuth spare head, and similarly, the lower two heads 43 and 44 also constitute an azimuth spare head. Inside this head drum 16 are a pair of upper and lower circuit boards 45.
．． 46 are arranged. The upper circuit board 45 is connected to the magnetic heads 41 to 44 and forms a conversion circuit for parallel signals and serial signals. On the other hand, the lower circuit board 46 is connected to the linear motor 3.
8 drive circuits are formed. Further, an optical power pulling 47 made of a light guide is provided at the center of the rotating shaft 33, and is adapted to transmit video signals. Prisms 48 and 49 are arranged above and below this coupling 47, respectively, and a light emitting element 50 and a light receiving element 51 are provided so as to face the prism 48. Similarly, the prism 49 has a light emitting element 52 and a light receiving element 53 in close proximity to it.
and is provided. These elements 52 and 53 are connected to amplifiers 54 and 55, respectively. Further, a slip ring 56 is provided at the lower end of the rotary shaft 33 for driving the circuits on the circuit boards 45 and 46 or for supplying electric power for driving the linear motor 38. It is designed to supply power inside. For convenience, the circuit inside the head drum 16 is shown in block form as shown in FIG. That is, the light receiving element 51 is connected to a serial-to-parallel converter 60 via a recording optical modulator 59, and the output of this converter 60 is transmitted to four amplifiers 61.
It is connected to the four heads 41 to 44 via the corresponding field switch 62. Roughly four heads 41 to 44 are field switches 42.
are respectively connected to a reproduction amplifier 63 through fixed contacts on the reproduction side, and the output of the amplifier 63 is converted into a serial signal by a discrete converter 64. This converter 64 is connected to the light emitting element 50 through an optical modulator 65. Further, a controller 6 for controlling the switch 62, the serial-to-parallel converter 60, the discrete-to-parallel converter 64, and the head motor 38
6 is provided. Next, FIG. 8 shows the recording circuit of this VTR in more detail. A video signal input terminal 67 is connected to a serial-to-parallel converter 60 via a low-pass filter 38 and an A/D converter 69. The output side of this serial-parallel converter 60 is connected to each head 41 to 44.
is connected to the error correction circuit 70 corresponding to the
Each error correction circuit 70 has a corresponding pair of memories 71.7.
Furthermore, the output sides of the memories 71 and 72 are connected to a modulator 75 via a changeover switch 74. The output of this modulator 75 is supplied to the heads 41 to 44 through an equalizer 76 and an amplifier 61, respectively. A clock generator 89 is provided for supplying clock signals to the memories 71 and 72, and a selector 90 is provided for selecting one of a plurality of clocks having different frequencies generated by the clock generator 89. A clock signal selected by the selector 90 is used to write or read data into or from the memories 71 and 72. Next, the reproduction circuit is as shown in FIG. It is connected to paired memories 81 and 82. A changeover switch 83 for switching between the pair of memories 81 and 82 is provided, and a changeover switch 84 for controlling readout from the memories 81 and 82 allows the pair of memories 81 and 82 to be switched to parallel serial mode. Connect to converter 64. The output of this converter 64 is connected to a video signal output terminal 87 through a D/A converter 85 and a low-pass filter 86, so that the unregenerated video signal can be extracted from this terminal 87. There is. This reproducing circuit is also provided with a clock generator 89 and a selector 90 for time axis correction of N loading and reading of the memories 81 and 82. These are used in common with the recording circuit. Next, the operation of the parallel scanning VTR configured as described above will be explained. As shown in FIG. 1, the magnetic tape 10 in the tape cassette 11 is pulled out and mounted on a pair of head drums 15 and 16. In this case, the magnetic tape 10 is wound not helically but straightly, that is, so as to coincide with the circumferential direction of the head drum 15, 16. Then, the head in the drum 16 scans the front surface of the magnetic tape 10, and the head in the drum 15 scans the back surface of the magnetic tape 10. As shown in FIG.
are arranged in a direction parallel to the rotation axis 33 of the first
As shown in Figure 0, it moves in the direction of the rotation axis every scan. The magnetic heads 41 to 44 are moved in the axial direction in a section in which the magnetic tape 10 is not opposed to the heads 41 to 44 within the drum 15.16, that is, within a rotation angle of about 90° of the head drum 15.16. Drum 15.16 is 1
The drum 15.16 rotates once per 60 seconds, that is, 16.6 mm5 ec, so the time it takes for the drum 15.16 to rotate 906 times is 4.15 mm 5 ec. On the other hand, since the movement of the heads 41 to 44 is completed in approximately 2 mm5ec, the heads 41 to 44 can be moved with sufficient margin. In the track pattern shown in FIG. 10, the two lower heads 43 and 44 constituting the azimuth bare head first form tracks No. and 1, and then intermittently move upward in the axial direction of the drum 16. Accordingly, tracks No. 2, No. 003, and No. 34 are formed as shown by solid lines in the following group. After forming the track No. 004, the heads 43 and 44 will now move downward in the axial direction, resulting in the formation of the No. 6 track shown by the dotted line.
Tracks No. 5, No. 5, No. 006, No. 7 are formed in sequence. Between the tracks shown by solid lines formed when the magnetic head 43.44 moves upward or forward, there are track patterns No. 5 to No. 5 shown by dotted lines when the head 43.44 moves backward downward. , 7 are formed. Note that the upper heads 41 and 42 also form the same track. As is clear from FIGS. 3 and 10, the upper pair of heads 41.42 and the lower pair of heads 43.4
4 are each composed of an azimuth spare head, so the track pattern shown by a solid line or a dotted line in FIG. 10 is actually composed of two tracks formed close to each other and parallel to each other. . By forming such a track pattern, it becomes possible to perform high-density recording on a 1° magnetic tape. At this time, the feeding of the magnetic tape 10 and the head 41~
The relationship between the axial movements of the tape 44 is shown in FIG. 12, and the tape 10 is configured to run continuously at a constant speed. On the other hand, the heads 41 to 44 have head drums 15 and 16 that are not in contact with the magnetic tape 10 as described above.
The drum 15 is rotated intermittently over a period of approximately 90' at
．． 16 in the axial direction. Note that when the magnetic tape 10 is intermittently fed, the magnetic tape 10 is moved as shown in FIG.
When it is in contact with the heads 41 to 44, it is kept stationary, and it moves intermittently during periods when it is not in contact with the heads 41 to 44. Also, as shown in FIG. 1, two drums 15.
16, the two drums 15 and 16 record or reproduce signals alternately, as shown in FIG. It is also possible to perform movement. Next, in this type of VTR, as for the method of forming track patterns when performing 11 backward recordings, it is possible to form track patterns on either one side of the magnetic tape 10 or on both sides. The single-sided system has the advantage that it can be used with a single drum 16 as shown in FIG. 2, and the mechanism is simple. Furthermore, it becomes possible to use a single-sided magnetic tape 10. On the other hand, the feature of the double-sided method is that the area of the track formed by one head is large, and the area of the track formed by one head is large.
It becomes possible to reduce the zero speed, and it becomes easier to control. Also, it is possible to record for a longer time than when using a single drum. FIG. 11 shows a track pattern for reciprocating recording by this VTR, in which half areas are provided in the width direction of the magnetic tape 10 to form forward tracks and reverse tracks. In FIG. 11, the first or last portion of the track indicated by a solid line or a dotted line J5 coincides with each other in the length direction of the tape 10 in the forward direction track and the reverse direction track. Therefore, in the case of reciprocating recording, the magnetic tape 10
When changing direction in the middle of a track, by switching at a coincident position at the beginning or end of the track,
This makes it possible to eliminate image disturbances. Furthermore, in the case of reciprocating recording, in FIG. 11, the first track No. 5 in the reverse direction is formed after the last track No. 014 formed in the forward direction. Moreover, here, the last track No. 4 in the forward direction and the first track No. 5 in the reverse direction are formed at the same position in the length direction of the magnetic tape 10. With this configuration, time is provided for changing the running direction of the magnetic tape 10, or servo control of the capstan 29 is facilitated. Therefore, by forming such a track pattern, it is possible to eliminate signal disturbance when the direction of the tape 10 is changed. Next, considering the relationship between the running direction or running speed of the magnetic tape 10 and the rotational direction of the head drum 16,
When the running direction of the magnetic tape 10 and the rotating direction of the head drum 16 are the same, track formation is started at the position shown in FIG. Then, the magnetic head 41 rotates about 2706 revolutions and finishes forming the track at the position shown in FIG. In this case, the magnetic tape 10 is
6, and when forming a track with a length of 3/4 of the circumference πD of the head drum 16, the angle corresponding to φ is smaller than 270°. This will result in extra recording. Next, when the running direction of the magnetic tape 100 and the rotating direction of the head drum 16 are opposite, track formation is started at the position shown in FIG. 17, and recording is ended at the position shown in FIG. 18. When the running direction of the magnetic tape 10 and the rotating direction of the head drum 16 are opposite, the head drum 16
Since the magnetic tape 10 moves in the opposite direction by an angle corresponding to φ during the 3/4 rotation of A track having a length of 3/4 of the circumference πD of the drum 16 is formed. Next, in the case of sujiru, that is, when the magnetic tape 10 is not running, or when the magnetic tape 10 is stationary in the case of intermittent feeding and is in contact with the head 41, the position shown in FIG. Recording is started at the position shown in FIG. 20, which is rotated by 270°, and ends at the position shown in FIG. As a result, a length of 3/4 of the circumferential length πD of the head drum 16 is formed. By adjusting the position at which recording ends in accordance with the running direction or running speed of the magnetic tape 10 in this way, it is possible to form tracks of the same length in any case. Note that in the case of forward feeding of the magnetic tape 10 at N times the speed, φ may be replaced with Nφ. This value then regulates the wrap angle θ of the magnetic tape 10. Further, when the magnetic tape 10 is fed in the reverse direction at N times the speed, the wrap angle θ is 270'-Nφ. Next, considering the relationship between the correction angle φ and the track length °C, we will consider the quality of the track as shown in Figure 10.

[
If the step length of the track is S, then S = t /n. Note that n here is the number of tracks formed by one magnetic head in one cycle, and in the case of FIG. 10, n=7. Next, the track length [is 1=(πD-s)·θ/360, and if s=v/60, then φ=360s/πD. Note that V and D represent the running speed of the magnetic tape 1o and the diameter of the head drum 15, 16. A video signal for forming a track as shown in FIG. 10 is transferred to the drum 16 through an optical power pulling 47 shown in FIGS. 3 and 7. The conversion circuit formed on the circuit board 45 converts the signal into a parallel signal, and this signal is sent to the four heads 41 driven by the linear motor 38.
It is distributed and supplied to 44 people. The optical power puller 47 is also adapted to transfer control signals for the linear motor 38, which signals are separated by circuitry on the circuit board 46 and adapted to drive the linear step motor 38. The head 4 mounted on the head carrier 40 is then driven by the step motor 38.
1 to 44 are moved in the axial direction of the drum 16. Note that power for supplying power to the circuit boards 45 and 46 and for driving the linear motor 38 is supplied from the fixed side to the rotating side through the slip ring 56. To explain in more detail the operation of the conversion circuit on the circuit board 45, in the recording circuit shown in FIG. On the other hand, it is written into the memory 71, for example. At the same time, the previously written contents of the memory 72 are taken out in a compressed state and applied to the heads 41-44 through the modulator 75 and equalizer 76. Therefore, in this case, standard clock signals are selected by the selector 90 and sent to the memory 71 from eight clock generators. On the other hand, a clock signal with a high frequency is selected and supplied to the memory 72. The frequency at this time is determined by the speed of the magnetic tape 10 and the running direction with respect to the head drum 16, so that a track of a constant length is always formed regardless of the correction angle φ. Next, in the reproducing circuit, as shown in FIG. The data is written to one of the memory 81, for example. The clock signal that determines the writing timing at this time is selected by the selector 90, thereby making it possible to write data into the memory 81 within a predetermined time. In contrast, the other memory 8
The readout of signals from memory 8 is done in real time, and standard clock pulses are read out from memory 8.
2. In the VTR according to this embodiment, the magnetic tape 10 can be wound so as to coincide with the circumferential direction of the head drum 15, 16, and the tape bus can be realized on the same plane, so that the tape running The system is simplified and all tape guides can be made rotary. Furthermore, since digital signals are recorded, even if the bit rate of recording and reproduction changes, the image is not affected, and it is possible to completely cope with forward/reverse J3 and stillness. Furthermore, serial transfer can be used to transmit signals to the head drums 15 and 16, and it becomes possible to include drive signals for moving the magnetic heads 41 to 44 in this signal. Further, such a VTR can be used in both the double drum system shown in FIG. 1 and the single drum system shown in FIG. 2, and has compatibility. Further, by using a multi-head drum, it becomes easy to realize double-sided recording on the magnetic tape 10, which is advantageous in making it into a cassette, and it is also convenient in terms of access. Furthermore, since the magnetic tape 10 can be run in both forward and reverse directions, trick play is also possible. This also shortens the access time. Furthermore, by matching the first part and the last part of the track pattern in the case of reciprocating recording, it is possible to completely eliminate image disturbances during forward/reverse switching. Furthermore, the VTR according to this embodiment has magnetic heads 41.42.
and 43 and 44 are respectively composed of azimuth spare heads, and these heads 41 to 44 are connected to the drum 15.
．． Between the tracks when moving forward in the axial direction of 16,
It is designed to form a track when making a backward movement. Therefore, it becomes possible to record signals at high density by effectively utilizing the surface of the magnetic tape 10, thereby making it possible to record for a long time and also to achieve miniaturization of the tape cassette 11. Become. K Effects of the Invention As described above, in the present invention, tape guides are provided at both ends of the head drum, and these tape guides regulate both sides of the tape-shaped recording medium in the width direction. Therefore, with this configuration, the tape-shaped recording medium wound around the head drum will not be misaligned in its width direction, and the rotating head will correctly form tracks in the circumferential direction of this drum. At the same time, it becomes possible to prevent the track from shifting in the width direction of the tape-shaped recording medium. This makes it possible to narrow the distance between tracks and perform high-density recording.

[Brief explanation of drawings]

FIG. 1 is a plan view of essential parts of a VTR according to an embodiment of the present invention, FIG. 2 is a plan view of essential parts in the case of one drum, FIG. 3 is a vertical cross-sectional view of the head drum, and FIG. 4 is a cross-sectional view of the same. 5 is a plan view of the main parts showing a modified example of the tape guide, FIG. 6 is a longitudinal sectional view of the same, FIG. 7 is a block diagram of the conversion circuit, and FIG. 8 is a block diagram showing the configuration of the recording circuit. , FIG. 9 is a block diagram showing the configuration of a reproducing circuit, FIG. 10 is a plan view showing a track pattern formed on a magnetic tape, FIG. 11 is a plan view showing a track pattern in the case of reciprocating recording, and FIG. Figure 12 is a graph showing the operation when the tape is continuously fed, Figure 13 is a graph showing the operation when the tape is being fed intermittently, and Figure 14 is a graph showing the operation when the tape is being fed intermittently by two drums. , and FIGS. 15 to 20 are plan views of essential parts showing the recording time correction operation based on the difference in running direction and running speed of the magnetic tape. In addition, in the reference numbers used in the drawings, 10...Magnetic tape 15.16...Head drums 41-44...Magnetic head 93...Fixed stay 94...Movable stay 95...Press lever 98. ... Plunger 102 ... Notch 103 ... Tape guide 104 ... Spring.

Claims (1)

[Claims] In an apparatus in which a tape-shaped recording medium is wound so as to coincide with the circumferential direction of a head drum, and a plurality of tracks are formed in the length direction of the tape-shaped recording medium by a rotating head, 1. A recording and reproducing apparatus, characterized in that tape guides are provided at both ends, and these tape guides regulate both sides of the tape-shaped recording medium in the width direction.