JPS628339A - Optical tape device - Google Patents

Abstract

PURPOSE:To attain high density information recording not requiring any guide line by forming a synchronizing signal to both ends of a tape in running direction and a direction orthogonal thereto, forming an information recording part between them and correcting the relative position between the tape and the optical scanning in response to a signal from a synchronizing signal recording part at both the ends when the tape is subject to optical scanning. CONSTITUTION:In a tape device recording/reproducing information by using an optical signal, the synchronizing signal recording part is formed on the tape and the synchronizing signal is recorded on the part at recording separately from an information signal. The synchronizing signal is utilized at reproduction so as to allow the reproducing optical beam to be scanned on the recording of the information signal recording sector. For example, in the recording information signal sector by one scanning having an angle theta in the lengthwise direction of the tape, the range of one scanning is one side of the tape when the tape is used reversely and nearly from one end to the other of the tape when the tape is used unidirectionally. The one scanning includes the synchronizing signal recording sector on which the synchronizing signal is recorded and the information signal recording sector and the feeding speed and tilt of the tape are corrected while the reproducing signal of the synchronizing signal recording sector is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an information recording device, and particularly to an optical tape device that can record information at a higher density than a magnetic tape device.

[Background of the invention]

Large-capacity information recording devices include magnetic tape for computers, hard disks, and VT (video tape recorders).These are widely used optical disks that use light to record the amount of information per unit area. The problem is that there are fewer than .

This optical disk has the great advantage of having one to two orders of magnitude more information recording capacity per unit area than those using magnetism, and shortening the access time.

However, since this optical disk also forms the recording medium on a glass or plastic substrate by vapor deposition, etc., the above-mentioned
Compared to those using air tape or microfiche, there is a problem that the volume is not as small, making it inconvenient for storing large amounts of information. For this reason, there is a desire for an optical tape that can record information using optical signals capable of high-density recording.

As this optical tape, for example, JP-A-57-3344
No. 75, Japanese Unexamined Patent Publication No. 58-6645, etc., however, there is no disclosure of a method for realizing high-density information recording and reading. In other words, it is known that the optical recording method can improve the recording density to about 100 times that of the magnetic recording method, but it is difficult to record information at intervals of about 1.6 μm and read out the recorded information correctly. No technology has been disclosed that is viable.

By the way, when installing the optical disc mentioned above, as described in the magazine ``Hitachi Hyoron J (August 1984 issue), etc., a groove-shaped guideline is formed on the disk, and the groove is detected and followed. High-density recording is achieved by recording and reading information.In this way, it is common technical knowledge that groove-shaped guidelines are provided in advance for optical discs in order to achieve high density.This guideline In the process of manufacturing a disc, it is very easy to use a stamper to create a pre-cut original plate, similar to the process of manufacturing a record.However, with optical tape, it is extremely difficult to easily create such grooves. Therefore, it is necessary to record at high density without providing a groove-shaped guideline on the tape and to read it accurately.

[Purpose of the invention]

In view of the above, an object of the present invention is to provide an optical tape device that enables high-density information recording and reproduction.

[Summary of the invention]

In the present invention, by forming synchronization signal recording sections at both ends of the tape and forming an information recording section between them,
When phototaxis occurs on the tape, by correcting the relative position between the tape and the phototaxis according to the signal from the synchronization signal recording section, the recorded signal of the information recording section recorded during that time can be accurately recorded. can be read out. In other words, high-density information recording is possible without providing groove-like guidelines.

[Embodiments of the invention]

FIG. 1 is a diagram showing the concept of the present invention. As shown in FIG. 3, each line shows a recorded information signal section corresponding to one scan in nine sections having an angle of .theta. with respect to the longitudinal direction of the tape. This one scanning range is Vc when the tape is used back and forth.
e.On the outside of one side of the tape, in the case of one-way use, it will be approximately from one end of the tape to the other. There is a synchronizing signal recording section and an information signal recording section for recording the Vci synchronizing signal during one scan, and the tape feeding speed and tilt are corrected while detecting the reproduction signal of the synchronizing signal recording section. That is, by feeding back a synchronization signal to a servo mechanism that corrects the tape feeding speed and inclination, it is possible to synchronize the scanning line of the light beam and the information recording section line.

In the figure, the reason why the contents of the synchronization signals are changed is to avoid misrecognition as adjacent synchronization signals, and the contents may be the same as long as they are separated enough to avoid misrecognition. A more specific explanation is as follows. As mentioned above, high f! Assuming that the scanning interval of the beam is set to about 2 μm to ensure accurate recording, as shown in Figure 2, if the tape is tilted by about 0.0058 with respect to the running direction, the light beam will read out the adjacent synchronizing signal. As shown in FIG. 2(b) VC, the signal in the information recording section between the synchronization signals cannot be read. For this reason, as mentioned above, the inclination of the tape can be corrected to avoid this erroneous recognition by changing the synchronization signal pits adjacent to each other, or the light beam can be moved along the recorded line by controlling the speed of the light beam. It will be irradiated correctly.

FIG. 3 is an overall f4 drawing showing an example of the present invention.

The signal generating circuit 36Vc generates a recording signal for recording information on the optical tape 2Vc, a reproduction signal for reading information recorded on the optical tape 2VC, or an erasing signal for erasing information recorded on the optical tape 2. be done. These operations are performed based on commands from the higher-level system. The signal generated by the signal generation circuit 36 is transmitted to the modulation circuit 3
svc, this output is input to the laser drive circuit 4 (l), the laser 4 is driven by the laser drive circuit 4 (l), the laser 4 oscillates according to the signal from the signal generation circuit 36, and the light beam 5 is This light beam 5 is controlled to the optimum intensity and time for recording, reproduction, and erasing.This light beam 5 is shaped into a parallel beam by a lens 6, and is shaped by a diffraction grating 3vc. The beam is split into a main beam and two sub-beams, transmitted through a horizontal beam splitter 8, a λ/4 plate 13, and reflected back by a mirror 9.
It travels in the direction of arrow A, and although it is discontinuous in the figure for convenience, it travels from A to A'. The focus is on Xiong Ni.

It is also configured to focus correctly on the track position by tracking control, which will be described later. Here, the polarizing beam splitter is used in combination with the λ/4 plate to prevent the light reflected on the optical tape 2 from returning to the laser 4Vc, and the light reflected from the optical tape 2 is redirected to the λ/4 plate. By transmitting
The direction of linearly polarized light is transformed. Therefore, the total amount of light reflected from the optical tape 2 is refracted by the polarizing beam splitter, transmitted through the lens 12 and the cylindrical lens 14, transformed into a main beam for reproduction and focusing, and then detected. Part 16K) Injects together with the sub-beam for racking.

The signal is demodulated and reproduced into the original signal by the reproduction circuit 44.

In addition, the detection unit 16 also uses tracking error signals Te,
A focus error signal Fe, a speed error signal ΔV, and a tape angle error signal Δθ are each output. Drives an actuator 11 that moves the objective lens 10 parallel to the two surfaces of the optical tape in response to the tracking error signal TeK by the operation of the tracking control unit 24, which will be described later.
A tracking system is used. In addition, the tape angle error signal Δ
A motor 2 that moves a tape guide 30 in the width direction of the optical tape, which sets the angle θ of the optical tape 2 with respect to the moving direction of the spot of the light beam on the optical tape 2 according to θ.
6 to control the optical tape angle. Further, by the operation of a tape 1 compression limiter 20 and a scan speed controller 21, which will be described later, a motor 28 rotates a roller 32 that moves the optical tape 2 in the longitudinal direction, and a light beam that is reflected by the mirror 9 is activated. The speed of the motor 7 that rotates the mirror 9 is controlled so that the mirror 9 moves on the surface of the optical tape 2, and the optical tape speed is changed in response to the speed change error signal Δvvc.

Next, FIG. 2(a) is an example of the configuration of the optical tape used in the present invention, and is a conceptual diagram showing how the optical tape 2 is installed in the optical tape device 100.

The optical tape 2 is spirally wound around the reel 101 at two locations, and the optical tape 2 is wound from each reel via a roller 32.
The optical tape 2 is held by two tape guides 30 so as to be in close contact with the rotating drum 34VC.

An optical head 34 is provided within the rotating drum, and a light beam is irradiated onto the optical tape 2 from this optical head 34. FIG. 2(b) is a schematic view of the rotating drum @ viewed in the direction of arrow A in FIG. 2(a). The optical tape 2 is adjusted by the tape guide 30 so as to maintain a certain tape angle θ with respect to the rotating drum 34. Furthermore, the optical head 34 rotates at an extremely high speed similar to the speed of the optical tape 2 fed by the roller 32 so that the irradiated light from the optical head 34 that focuses on the optical tape 2 moves on the dotted line in the figure. do.

FIG. 3(C) is a schematic diagram showing the information string 102 on the two sides of the optical tape when recorded using the method described above. The angle θ of this information string 102 with respect to the optical tape 2Vc is the upper and lower sides tj1 . The pitch h of this information string 102 changes depending on the feeding speed of the optical tape 2 and the rotation speed of the optical head 34. The recording density of this optical tape 2 can be increased by reducing the pitch P of the information strings. Since optical tape uses laser light for recording and reproduction, theoretically the pitch P can be increased to at least twice the wavelength of the laser light (for example, ij 830 nm for a semiconductor laser).
can be lowered and extremely high recording density can be obtained. In order to obtain such a high recording density, the tracking control shown in the present invention is used.

Furthermore, in order to realize such an extremely small pitch P of the information string, the tape angle θ must be controlled extremely accurately. The tape angle control as well as tape speed control provided by the present invention is used for the aforementioned purposes.

The above-mentioned control shown in the present invention will be explained with reference to FIG. 3 and subsequent figures.

FIG. 3 is a block diagram illustrating the detection section 16 of FIG. 1. A 6-split photodetector 126VcH, a tracking spot light receiving section 127, 128, and a 4-split spot light receiving section 129 for reproduction and focusing are provided. The outputs of the opposing parts of the light receiving section 1290 are added,
By subtracting the difference between the results in a subtracter 132, the focus error signal Fe is obtained, and by adding the results in an adder 133, the sum of the outputs of all parts of the 4-division light receiving section 129 is obtained, and the information reading signal Sr is obtained. Calculated.

The principle that a focus error signal can be detected by adding and subtracting the 7-lindrical lens 14 in FIG. Since this method is well known in 2010, etc., its explanation will be omitted here.

Next, the difference between the outputs of the tracking spot light receiving sections 127 and 128 is taken by a subtracter 121, and the output of the subtracter 121 becomes a tracking error signal Te. Since this is also a well-known technique, its explanation will be omitted here. This track error signal Te is integrated over a certain period t, → by two integrators 122 to calculate a first track error integral value Ie, and this track error signal Te is integrated over another period t, →t. 123Vc to calculate a second track error integral value Iet. By taking the difference between the t-th and #r2 track error integral values Iel and Ie, the angle error Δθ is obtained, and similarly, the angle error Δθ is obtained.
The speed error ΔV is obtained by adding e+ and Ie in an adder 125. The time tl + F + t, at which this tracking error is integrated, occurs at the timing shown in Fig. 3 (see Fig. 3). That is, the start time of the information string [34] recorded on the optical tape 2 is tI, and the information string 134 is
The time point at which the image passes through the center of the optical tape 2 is t, the information string
The ending point is t.

It is. Specifically, when recording information on the optical tape 2, information that can be clearly distinguished from other information may be recorded as start point, center point, and end point signals at the start point, center point, and end point of the information string. . Further, as long as the optical tape 2 is running, new information strings are sequentially detected by the optical head, and new track error signals are sent to the integrators 122 and 12.
3, so before detecting a new information string, the integrators 122 and 123 are reset and their outputs, Ie+.

It is necessary to reduce Ie2 to zero. Therefore, a reset circuit 135 is provided, and each time the pulse train detection synchronization signal Ps is input to the reset circuit 135, the integrator 122, 123
Reset. As will be described later, this detected synchronization signal Ps is recorded as a synchronization signal sequence at, for example, the starting point of the information sequence on the optical tape 2 during recording, and is generated from the reproduced signal.

Next, this angle error signal Δθ and velocity error signal ΔV
The calculation principle of is explained.

Figure 3 (C) shows the angle error signal Δ when there is an angle variation error.
This is the detection principle of θ. If the angle of the optical tape 2 with respect to the rotating drum is large Q, and the angle θ' of the beam light trajectory 136 with respect to the optical tape 2 becomes small due to the angle θ of the information string 134 on the optical tape 2 with respect to the optical tape 2, then vcri
, the first value Iel, and the second value Iet of the track error integral value are as shown in the figure. Here, it is assumed that when the beam light deviates from the information string in the tape running direction, the track error signal becomes negative. These two track error integral values Ie+ and Iet have opposite polarities because the positional relationship between the beam light trajectory 136 and the recorded information string 1340 is reversed between the upper half and the lower half of the optical tape 2, so that Ie and Iet
The angle error signal Δθ that takes the difference between is 1, and Ie+
is the sum of the absolute values of and Ie2, and the speed error signal ΔV is t
becomes zero at the point of . Therefore, by holding the angle error signal Δθ at time t, an angle error signal Δθ corresponding to the deviation of the tape angle can be obtained.

Further, if there is a related error, the result will be as shown in FIG. 3(d). The speed of optical tape 2 is too fast, and beam light trajectory 1
36 is shifted in the opposite direction to the tape running direction with respect to the recording information string 134Vc, the track error value lamps will each have a positive value, and the angle error signal Δθ, which takes the difference between e and let, will be t. The speed error signal ΔV, which is zero at time t, becomes a positive value as shown in FIG. 3(d), and by holding the speed error signal ΔV at time t, etc.,
A speed error signal ΔV is obtained in response to variations in tape speed.

In this way, tape angle errors and tape speed errors can be detected with the configurations shown in the fjgx diagram and Figure 3 (a).
By controlling the error to zero,
Stable reproduction of information becomes possible.

FIG. 4 explains an example of tape speed control performed using the speed error ΔV, and shows the contents of the tape speed control section 20 and scan speed control section 18 of FIG. 1.

(a) is a tape speed control section, and (b) is a scan speed control section. Further, (a) and (b) show an example in which the two controllers described above are operated based on the tape speed.

In (a), the phase comparator 202vc compares the phases of the pulse train detection synchronization signal Ps obtained by the method described later and the pulse train reference synchronization signal PSr generated from the synchronization signal generator, and the output corresponding to the phase difference is output to the amplifier. 203 and applied to the motor 28, the roller 32 rotates and the optical tape 2 is run. In (b), the speed error ΔV obtained by the above-mentioned detection section is applied to the motor 7 by the amplifier 205 via the integrator 204, and the mirror 9 is rotated. With this configuration, the optical tape runs at a constant speed with high accuracy by following the reference synchronization signal Psrπ of the synchronization signal generator 2010, and the speed error ΔV is controlled to be zero by controlling the scan speed of the optical head.
It's a monkey. In this example, the detected synchronization signal Pa and the reference synchronization signal Psr are considered to be pulse trains, but the same effect can be obtained by using analog quantities proportional to PS+PSr instead of Ps and Psr and simply taking the difference and adding it to the amplifier. It will be done. Also, a mirror 9 is used to scan the light beam, but
Any other method that can scan the light beam, such as scanning the head itself, can produce the same effect.

Cases (c) and (d) are examples of configurations in which tape speed control and scan speed control are performed based on the scan speed. These are obtained by replacing the motor parts in (a) and (b), and operate in the same way as in (a) and (b), so the explanation will be omitted.

In this case, even if analog quantities proportional to the pulses are used for Ps and Psr, the same effect can be obtained by any method that scans another light beam without using the mirror 9f. Needless to say.

Next, FIG. 5 explains an example of tape angle control performed using the tape angle error Δθ, and this shows the contents of the tape angle division # section 22 of FIG.

Tape angle error Δ obtained from the aforementioned detection unit 16&t
θ is passed through the integrator 221 to the amplifier 222VC (P) f
-7' Drive the actuator 26 that moves the guide 30. As a result, the tape guide 30 is moved to change the angle of the optical tape 2 until the tape angle Δθ becomes zero. Therefore, the tape angle is always controlled to a predetermined magnitude.

FIG. 6 explains an example of tracking control performed using the tracking error Te, and shows the contents of the tracking control section 24 in FIG. 1. This is similar to the method used in conventional compact discs, etc., and the tracking error Te is
1, the signal is applied to the actuator 11 by the amplification 4242, and the objective lens 10 is driven in a direction horizontal to the optical tape 2 and perpendicular to the information string on the optical tape, thereby performing tracking creation.

〔Effect of the invention〕

According to the present invention, a synchronization signal is formed at both ends of the tape in a direction perpendicular to the running direction, an information recording section is formed between these, and when the tape is optically scanned, the synchronization signal from the synchronization signal recording section at both ends is generated. By correcting the relative position between the tape and the optical scanning according to the signal, high-density information recording without the need for guidelines becomes possible.

Further, the relative position between the tape and the optical scanning is detected by the signal processing of the present invention based on the tracking error signal obtained by the conventional technique, and the tape speed is also detected by similarly detecting the tracking error signal. , optical scanning can be performed correctly with an extremely simple configuration, and high-density information recording is possible with an extremely simple configuration.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the concept of the present invention, Fig. 2 is a diagram showing the inclination of the light beam and tape, Fig. 3 is an overall structural diagram of an embodiment of the invention, and Fig. 4 is a diagram of the embodiment of the invention. A conceptual diagram, FIG. 5 is an explanatory diagram of a detection section, and FIG. 6 is an explanatory diagram of a tape speed control scan speed control section. 2... Optical tape, 16... Detection section, 30... Tape guide, 32... Roller, 22... Tape angle control section, 20... Tape speed control section, 21... Scanning Speed control section.

Claims (1)

[Claims] 1. In a tape device that records and reproduces information using optical signals, by forming a synchronization signal recording section on the tape and recording the synchronization signal separately from the information signal during recording,
An optical tape device characterized in that, during reproduction, this synchronization signal is used to cause a reproduction light beam to scan over the recording of an information signal recording section. 2. In the apparatus described in item 1, at least two synchronizing signal recording sections and an information recording section are formed between them on the tape, and when the reproducing light beam is scanned on the tape, at least two synchronizing signal recording sections are formed. An optical tape device characterized by having a mechanism for correcting the relative position between the tape and optical scanning according to a signal obtained from a synchronization signal recording section. 3. An optical tape device according to item 2, further comprising a mechanism for correcting the inclination of the tape in order to correct the relative position between the tape and the optical scanning. 4. In the apparatus described in item 1, so that the reading light beam scans the recording line of the information signal recording section,
An optical tape device characterized in that a light beam is scanned with a certain time delay from a synchronization signal that has already been obtained. 5. In the apparatus described in item 2, so that the reading light beam scans the recording line of the information signal recording section,
An optical tape device characterized in that a light beam is scanned with a certain time delay from a synchronization signal that has already been obtained. 6. The optical tape device according to item 2, wherein the signal pits in the synchronization signal sections at both ends of one line are the same. 7. The optical tape device according to item 2, wherein the signal pits in the synchronization signal sections of adjacent lines are different. 8. The apparatus described in item 1 is characterized in that the address signal following the synchronization signal is formatted so that it can be read during high-speed tape feeding.