JPS62184601A - Recording and reproducing device - Google Patents

Abstract

PURPOSE:To increase recording capacity and to miniaturize a tape cassette by providing two head drums and making recording on the surface of a tapelike recording medium by one head drum and at the same time, making recording on the back by another head drum. CONSTITUTION:A magnetic tape 10 is wound not helically, but wound to conform with circumferential direction of head drums 15, 16. A head in the drum 16 scans the surface of the magnetic tape 10, and a head of the drum 15 scans the back of the magnetic tape 10. Magnetic heads 41, 42 and 43, 44 are constituted respectively of azimuth pair heads, and tracks when moving backward are formed between tracks for moving these heads 41-44 are moved forward in the direction of axis lines of drums 15, 16. Thereby, it becomes possible to record signals at high density utilizing the surface of the magnetic tape 10 effectively, and the long time recording is made possible. Further, the miniaturization of a tape cassette 11 can be attained.

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 configured to form one rack of books.

[Summary of the invention]

The present invention has two head drums, one head drum records on the surface of a tape-shaped recording medium, and the other head drum records on the back side of the tape-shaped recording medium. This allows recording to be performed on both the front and back sides of the 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, the tape paths cannot be formed on the same plane, and each tape path becomes rough. Furthermore, since the magnetic tape is attached to the guide diagonally, there is a drawback that the guide cannot be made rotatable. In general, it is not possible to record on both the surface and center 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. [Problem to be solved by Invention X] In order to overcome these drawbacks, for example,
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, even with this method, recording on magnetic tape is performed by placing a rotating head in contact with the surface of the magnetic tape, as in the past, so it is difficult to record on both sides of the magnetic tape.・I can't. Therefore, if such a system were adopted, the recording capacity on the magnetic tape would be reduced and the downsizing of the tape cassette would be hindered. The present invention has been made in view of the above problem, and is a parallel scanning type recording/reproducing apparatus which increases the recording capacity of a tape-shaped recording medium and makes it possible to downsize the cassettes 1 to 1. The purpose is to provide the following. 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, two head drums are used, one head drum records on the surface of the tape-shaped recording medium, and the other head drum records on the back surface of the tape-shaped recording medium. K effect] Therefore, according to the present invention, it is possible to record on both sides of a tape-shaped recording medium using two head drums, thereby increasing the recording capacity and It becomes possible to downsize the cassette. K Embodiment The present invention will be explained below with reference to illustrated embodiments. FIG. 1 does not show a parallel scanning type VTR according to an embodiment of the present invention. , this VTR uses a tape cassette 11 in which a magnetic tape 10 is wound and stored.The magnetic tape 10 is fixed at both ends to a supply reel 12 and a take-up reel 13, respectively. In this state, the magnetic tape 10 is wound around these reels 12 and 13.The magnetic tape 10 is pulled out from the casings of the tape force sets 1 to 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 1o 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 disk 10 is pressed against a capstan 29 rotating at a constant speed by a pinch roller 30. 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, recording and reproduction can be performed 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 reproduction can be performed on the front and back sides of the magnetic tape 10, but in the case of one drum, recording and reproduction are performed only on the front side of the magnetic tape 10. Next, the structure of the head drum 15, 16 will be explained. For example, the head drum 16 has upper and lower flange guides 3.
1.32, and 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. A coil 38 constituting a beam near 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 designed to perform linear motion. This movable element 40 supports four magnetic heads 41 to 44 in a row below F. That is, the four heads 41 to 44 are arranged 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 16
The air heads 41 and 42 are joined together to form an azimuth pair head, and similarly the lower two heads 43 and 44 also form an azimuth pair 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.
J which forms the drive circuit of 8: is turned. 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. A slip ring 56 is provided at the lower end of the rotating shaft 33 to drive the circuits on the circuit boards 45 and 46 or to supply electric power to drive the linear motor 38. It is designed to supply power inside. For convenience, the circuit inside the head drum 16 is shown in a block diagram 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. Furthermore, four heads 41 to 44 are connected to a field switch 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 parallel-to-serial converter 64. This converter 64 is connected to the light emitting element 50 through an optical modulator 65. Also, a controller 6 for controlling the switch 62, the serial-to-parallel converter 60, the parallel-to-serial converter 64, and the head motor 38.
6 is provided. Next, FIG. 6 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 six A/D converters. 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. Eight clock generators are 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 with different frequencies generated by the clock generators 89. The 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 selector switch 83 is provided for switching between the pair of memories 81 and 82, and a switch 84 for controlling reading from the memory 81 and 82 is connected to the pair of memories 81 and 82. .8
The two pairs are connected to a parallel-to-serial converter 64. The output of this converter 64 is passed through a D/A converter 85, B and a low-pass filter 86 to an output terminal 87 for a bidet Δ signal.
The terminal 87 is connected to the terminal 87 so that the reproduced video signal can be taken out. Also in this reproducing circuit, a clock generator 89 and a selector 90 are provided for correcting the time base of reading and aging of the memories 81 and 82. These are used in common with the recording circuit. Next, the operation of the parallel scanning A7 VTR configured as shown below 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 not helical but straight, that is, aligned with the circumferential direction of the head drum 15.16.
The inner head covers the surface of the magnetic tape 10 and the drum 15.
The heads scan the back side of the magnetic tape 10, respectively. As shown in FIG. 3, the heads 41 to 44 are arranged in a direction parallel to the rotation axis 33 of the drum 16.
The entire apparatus is mounted on the same carriage 40, so that it can be moved in the direction of the rotation axis for each scan, as shown in FIG. The axial displacement of the magnetic heads 41 to 44 occurs in a section where the magnetic tape 10 is not opposed to the heads 41 to 44 in the drum 15.16, that is, during a period of approximately 90' at the rotation angle of the head drum 15.16. Let's do it. The drum 15.16 rotates once in 1/60 seconds, that is, 16.6 years SaC, so the time it takes for the drum 15.16 to rotate 90° is 4.15 mm5ec. 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. 8, the lower two heads 43 and 44 constituting the azimuth bare head first form tracks numbered No. 1, and then intermittently form tracks numbered 1 on the drum 1.
By moving upward in the axial direction of No. 6, tracks No. 2, No. 2, No. 4, and No. 4 are formed as shown by solid lines in the following figures. After forming the No. 4 track, the heads 43 and 44 move downward in the axial direction, and as a result, the No. 4 track No. 4 is moved downward in the axial direction.
, No. 6, and No. 007 are sequentially formed. Then, between the 1-rack shown by the solid line formed when the magnetic head 43.44° moves upward or in the forward direction, the track pattern No. shown by the dotted line when the head 43.44 moves downward backward, 5 to No. 7 are formed. Note that the upper head 41.42
also form a similar track. As is clear from FIGS. 3 and 8, the upper pair of heads 41.42 and the lower pair of heads 43.44
Since each of the tracks is composed of an azimuth pair head, the track pattern shown by a solid line or a dotted line in FIG. 8 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 the magnetic tape 10. 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. 10, 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 intermittently rotated in an interval of approximately 90° at a rotation angle of
．． 16 in the direction of the @ line. Note that when the magnetic tape 10 is read intermittently, the magnetic tape 10 is moved to the heads 41 to 44 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, as shown in FIG. 12, signals are recorded or reproduced alternately by the two drums 15 and 16, and the steps of the heads 41 to 44 are performed during periods when signals are not recorded or reproduced. It is also possible to perform movement. Next, when performing round-trip recording in this type of VTR! - Regarding the method of forming the rack pattern, both a method of forming it on one side of the magnetic tape 10 and a method of forming it on both sides of the magnetic tape 10 are possible. 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 the magnetic tape 10 on a single-sided coat 1. 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. 9 shows the track pattern in the case of reciprocating recording by this VTR, in which half an area is provided in the width direction of the magnetic tape 10 to form a forward track and a reverse track. In FIG. 9, the first or last portion of the track consisting of a solid line or a dotted line is made to coincide with each other in the length direction of the tape 10 in the forward direction track and the backward direction rack. Therefore, when changing the direction of the magnetic tape 1o in the middle of the magnetic tape 1o in the case of reciprocating recording, it is possible to eliminate image disturbance by switching at a coincident position at the beginning or end of the track. In the case of reciprocating recording, track No. 4 is formed last in forward direction in FIG. 9, and then track No. 5 is formed first in reverse direction. The last track numbers 1 to 4 in the direction and the first track numbers 5 in the opposite direction are formed at the same position in the length direction of the magnetic tape 10. With this configuration, , to provide time margin when changing the running direction of the magnetic tape 10, or to facilitate the servo control of the two keys and buttons.Therefore, by forming such a 1-to-rack pattern, the tape 10 is This makes it possible to eliminate signal disturbances when changing direction.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 270 degrees, and the formation of racks 1 to 1 is completed at the position shown in FIG. In this case, the magnetic tape 10 moves in the same direction as the rotational direction of the head drum 1G, and for this reason, 3/4 of the circumference πD of the head drum 16 is
- When forming a rack, recording is performed by an angle corresponding to φ more than 270°. Next, if the running direction of the magnetic tape 10 and the rotational direction of the head drum 16 are opposite, the positions 1 to 1 as shown in FIG.
The formation of the rack starts 1J, and the recording ends at the position shown in FIG. When the running direction of the magnetic tape 10 and the rotating direction of the head drum 16 are opposite, the magnetic tape 10 moves in the opposite direction by an angle corresponding to φ while the head drum 16 rotates 3/4. Recording must be completed at a position that is less than 270° by an angle of φ, thereby forming a track with a length of 3/4 of the circumference πD of the head drum 16. Next, in the case of methyl, that is, when the magnetic tape 10 is not running, or when it is intermittently feeding and is in contact with the head 41, when the magnetic tape 10 is stationary, the position shown in FIG. Recording is started at the position shown in FIG. 18, which is rotated by 270°, and ends at the position shown in FIG. As a result, a track having a length of 3/4 of the circumferential length πD of the head drum 16 is formed. In this way, by adjusting the position at which recording ends depending on the running direction or running speed of the staple 100, 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. In addition, when the positive tape 10 is fed in the reverse direction and the speed is N (i1 m), 270° - Nφ becomes the wrap angle θ. Next, let us consider the relationship between the correction angle φ and the track length. , the appearance of the truck as shown in Figure 8.

[If the step length of the track is S, then s = t / n. J3 Here, n is the number of tracks formed by one magnetic head with 11 nicles, and in the case of FIG. 8, n=7. Next, the track length [is 1=(πD-3)·θ/360, and if S=V/60, then φ=360S/πD. Note that V and D represent the running speed of the positive tape 10 and the diameter of the head drum 15, 16. A video signal for forming a track as shown in FIG. 8 is transferred to the drum 16 through an optical power pulling 47 shown in FIGS. 3 and 5. 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 to 41 driven by the linear motor 38.
It is distributed and supplied to 44 stations. 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 41 mounted on the head printer 40 is driven by the step motor 38.
44 in the axial direction of the drum 16. Note that the power supply to the circuit board 45.4G and the power for driving the linear motor 38 are 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 male circuit board 45, in the recording circuit shown in FIG. On the other hand, it may be written to 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, a standard clock signal is selected by the selector 90 and sent to the memory 71 from the clock generator 89. 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 1o 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. 7, the parallel signals read by the heads 41 to 44 are passed through an amplifier 63, an equalizer If 78 , seven demodulators, and an error correction circuit 80 to a pair of memories 81 . 82, for example, the memory 81. Then, the clock signal that determines the writing timing at this time is selected by the selector 90, and J'-3 is selected by the selector 90, so that the memory 81 is
It is possible to import data into. On the other hand, signals are read out from the other memory 82 in real time, and standard clock pulses are supplied to this memory 82. 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 path can be realized on the same plane. The system is simplified and all tape guides can be made rotary. Furthermore, since digital signals are recorded, even if the bit rays 1 to 1 for recording and reproduction change, the image is not affected, and it is possible to completely cope with forward/reverse and still motion. Furthermore, serial transfer can be used for signal transmission to the head drums 15 and 16, and drive signals for moving the magnetic heads 41 to 44 can also be superimposed on this signal. Further, such a VTR can be applied to 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. In general, 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. Roughly speaking, 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 disturbances in the image in J3 when switching between forward and reverse directions. 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. [Effects of the Invention] As described above, the present invention includes two head drums, one head drum records on the surface of a tape-shaped recording medium, and the other head drum records on the back surface of the tape-shaped recording medium. It was designed to do this. Therefore, according to such a method, it is possible to perform high-density recording on a tape-shaped recording medium, thereby increasing the recording density and reducing the size of the tape cassette when converting this tape-shaped recording medium into a cassette. It becomes possible to achieve this goal.

[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 block diagram of the conversion circuit, FIG. 6 is a block diagram showing the configuration of the recording circuit, and FIG. 7 is a block diagram showing the configuration of the reproduction circuit.
Fig. 8 is a plan view showing a track pattern formed on a magnetic tape, Fig. 9 is a plan view showing a 1-rack pattern in the case of reciprocating recording, and Fig. 10 shows the operation in the case of continuous tape feeding. Graphs, FIG. 11 is a graph showing the operation in the case of intermittent feeding of the tape, and FIG. 12 is a graph showing the operation in the case of intermittent feeding of the tape by two drums.
3 to 18 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 numerals used in the drawings, 1o...Magnetic tape 15. 16...Head drum 38...Coil (linear motor) 40...Movable elements 41 to 44...Magnetic head.

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, two A head drum is installed,
A recording/reproducing apparatus characterized in that one head drum records on the front surface of the tape-shaped recording medium, and the other head drum records on the back surface of the tape-shaped recording medium.