JPS621136A - Optical tape information recording and reproducing device - Google Patents

Abstract

PURPOSE:To reproduce and erase exactly high density recording information without always depending on a tracking signal, by changing a spot shape of an irradiated light. CONSTITUTION:An optical beam spot which is long and slender in the direction vertical to the moving direction of an optical tape 2 is used for recording. A symbol Pss and a symbol Psm are binary signals for showing an information signal 'space' and the same signal 'mark', respectively. A symbol PR is an optical beam spot of the time when information is reproduced, made smaller than the recording signals Pss, Psm of information, deviated in the direction vertical to the moving direction, when moving the optical tape 2, and even if the center of an optical spot from an optical system is shifted from an information signal recording center line PN, a reproducing function of a signal can be performed exactly, if the optical spot PR of the time of reproduction exists within a range of a long and slender area of the recording signal pit Pss and Psm of the information. Accordingly, it will suffice that a size of the recording signal pits Pss, Psm and the optical spot PR of the time of reproduction is determined, so that the signal can be reproduced, even if the optical tape 2 is shifted from the optical system.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an information recording/reproducing device for an optical tape device, and in particular, a 4! possess gender.

[Background of the invention]

Examples of information recording devices using magnetic tape include Ltd.
- Precoders, VTRs (video tape recorders), etc. are known. These have the disadvantage that the amount of information recorded per unit area is smaller than that of optical discs.

Regarding information recording and reproducing equipment fIt using optical tape, for example, JP-A-57-3347 and JP-A-58-6664 are known. Not all measures to improve reliability are mentioned.

It is known that the optical recording method can improve the recording density by about 100 times compared to the magnetic recording method, but when recording and reproducing information at intervals of about 1 to 2 μm, Improvements in highly reliable song technology are desired.

By the way, as an example of adopting the optical recording method, there is an optical disk device described in the magazine [Hitachi Hyoron 4, August 1984 issue, etc.].

In this optical disc, in order to ensure high-density single-time recording and reproduction, a means for aligning the optical axis of the light irradiation with the recording medium using a guide signal called tracking is added.

However, in order to perform accurate tracking, the VC requires a sophisticated device structure, leading to an increase in the size of the device.

[Purpose of the invention]

The present invention does not necessarily rely on tracking signals;
Accurate reproduction and erasing of high-density recorded information VC
be.

[Summary of the invention]

The present invention enables information recording, reproduction, and erasing functions of an optical tape to be performed by changing the spot shape of irradiated light without controlling the optical axis using a tracking signal.

[Embodiments of the invention]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention. The symbols shown in the figure and their operations will be explained below.

1 is an optical system for irradiating a light beam onto an optical tape having a recording medium.

This is an optical tape with two additional recording media.

3 is a light source, for example, a semiconductor laser diode is used. The semiconductor laser diode records and reproduces information by accessing the optical tape 2.

Alternatively, it is possible to manipulate the output of the light source 1 in order to erase the data.

SWw is the switch that closes during recording, SWm is the switch that closes during playback, SW! 1 is a switch that closes when erasing.

By closing any one of the switches S Ww , S Wm or SWz, the optical output and wavelength of the light source 1 are determined according to the intended function, and the output light P of the light source 1 is determined.
yields 3.

At the same time, a signal 81Vc, which will be explained later, is also sent as an operation signal for controlling the shape of the light beam spot irradiated onto the optical tape 2.

4 is a collimating lens. Collimating lens 4B,
It is for outputting the input light P as parallel light, and the parallel light is indicated by the symbol P4.

Reference numeral 5 is a reflecting mirror, which is used to refract the input light beam P4 in the desired direction, and its output light is designated by symbol P,
Indicated by

6 is a polarizing beam splitter. The polarizing beam splitter 6 passes the input light P, and outputs the output light P6. Also, the light ray pat returned from the output side is output as the output light 6.
Reflect it in the direction of de.

Reference numeral 7 denotes a quarter-wave plate, which shifts the phase of the light passing through it. Let the output light be P.

8 is an objective lens. The objective lens 8 is used to connect the input light P to the optical chip 2 to form a desired spot shape of the gtPVC.

Let P be the output light of the objective lens 8.

The wavelength of the light source and the switch SWv to properly focus the tilPVC for the purpose of illumination.

Depending on which of sWR and SWz is closed,
The position and configuration of the objective lens 8 are varied.

8W is a lens drive unit for varying the configuration and position of the objective lens.

81 is a control circuit, which sends control commands 8 to the lens drive unit 8W.
This is for transmitting WS.

The control circuit 81 includes switches S Ww , S WR , S
The closed circuit condition of Wz and the reflected light from the irradiation point filP of the optical tape 2 are detected by the light beam P6° through the objective lens 8, the quarter wavelength plate 7, and the polarizing beam splitter 6, and the control command 8Wa is determined. do.

61 is a photodetector. The photodetector 61 includes four divided photodetection sensors F+, Ft, Fs, and F4, and detects the shape of the light beam spot irradiated onto the position of point P on the optical tape 2. For example, for a perfectly circular spot, the light detection sensor Fl + F@ + F3 + F4
Identification is possible by making the amount of light received equal to each other.

Further, by further providing a plurality of photodetection sensors, it is possible to actually detect a complex spot shape.

62 is a light spot discrimination circuit.

The light spot discrimination circuit determines the shape of the light spot received by the photodetector 61 from the light detection sensor F+rFt*Fa.
Received light amount of sF4 FIp, FtP, Fop, F4
By detecting p, the conditions of the irradiation spot at point P on the optical tape 2 can be determined, albeit indirectly.

Further, when it is detected that the irradiation spot at point P does not have the desired shape, a spot shape control output 63 is generated and the configuration of the objective lens 8 is varied to meet the desired conditions.

Further, 5WS is a reflection mirror control signal for adjusting the reflection angle of the reflection mirror 5 so that the light spot is irradiated in the desired direction.

The reflection mirror suppressing signal 5w5h is given by the light spot discrimination circuit 62.

5W reflection mirror 50 This is a reflection mirror drive unit for adjusting the reflection angle.

20 is an information output signal of the optical tape 2, for example, a light detection sensor F8. Received light amount FJ of P,, Fat F,
'+Ft P s F3 P r F4 F can also be detected by using a light spot determination circuit.

9 is a folder for moving the optical tape 2, and is an example of the structure seen from the front.

10 is m for irradiating a light beam spot onto the optical tape 2;
This is an optical tape drive device for moving the position relative to the optical system 1 in order to vary p.

Number 11 is a reel unit that moves the optical tape 2 and performs winding and unwinding.

The optical girder 2 is moved forward and backward by the optical tape drive device 1 (l), and is wound up by the reel 11Vc.

When one scan is completed, move the folder 9 to the left or right relative to the light beam spot 9 in the same figure.
By moving the optical tape 2 in the same way as described above, the functions of recording, reproducing, and erasing information on the flat recording medium of the optical tape 2 can be accessed.

FIG. 2 is a conceptual diagram seen from the surface of the optical tape.

2 indicates a portion of the optical tape.

PtH erasure light beam spot, Part reproduction light beam spot, Psm is the light beam spot of the recording signal,
For example, it indicates information "mark".

This is an example of a binary signal indicating the information "space", which is a light beam spot of the P ss H recording signal.

During playback, VC only needs to be able to reliably identify Paws and Psa.

PM is the center line of the signal group.

In order to process the information on the optical tape 2, V indicates the direction of movement in the front and back direction, as shown in FIG.

tb, in the present invention, the information PBwa t P sg is 1μ
However, it is quite conceivable that the optical tape 2 may wobble in a direction perpendicular to the moving direction V.

For this reason, it is possible to adjust the irradiation light beam spot so that it hits the center line Pw using the tracking control g41vc, but for this purpose, it is necessary to write a tracking signal in advance, and to add a detection control circuit for it. , it is clear that the device becomes more complex.

In the present invention, a light beam spot elongated in a direction perpendicular to the moving direction V of the optical tape 2 is used for recording. Examples of recording pits for information signals by this recording light beam spot are symbols Pss and Ps+m.

Pill is the information signal "space" and Pswa is also "
This is a binary signal indicating "mark".

Pa is a light beam spot during information reproduction, which is made smaller than the information recording signal Pga, pH+m mentioned above, and is shifted in a direction perpendicular to the moving direction V when the optical tape 2 is moved. Even if the center of the light spot from the optical system l shown in FIG. 1 deviates from the information signal recording center line PM in FIG.

If the reproducing light beam (substrate) PR exists within the long and narrow area of , a reliable signal reproducing function can be achieved.

Therefore, in order to reproduce the signal even if there is a deviation of the optical tape 2 with respect to the optical system 1, the recorded signal is
, Pgm and optical aperture during playback) PR size can be determined.

Moreover, it is a light beam spot for Pe fd erasing.

The erasing light beam Pry is larger than the information recording signal pits PBs, Ps-, and can reliably erase the recording pits Pss, rim even when the position shifts perpendicular to the moving direction V of the optical tape 2. to cover.

FIG. 3 shows an embodiment in which a plurality of recording lines Pwl, Pg, . . . , PNN are obtained by irradiating the optical tape 2VC with a plurality of light beam spots.

The subscripts 1.2...N indicate the order of the center lines of the recording lines, and Paw, Psg+ PR, and Pg indicate the same as in FIG. 2, respectively.

As a means for irradiating a plurality of light beam spots, a plurality of light sources 1 shown in FIG.
Psl, Pwz... Signals may be recorded, reproduced, and erased on the PNN lines at the same time.

Also, Pw+ + Put + Pww VC irradiation f
The recording density can be increased by shifting the fill of the light source 'eM3.

〔Effect of the invention〕

As described above, according to the present invention, high-density information recording and reproduction is possible, and information can be easily reproduced and erased even when the surface of the optical tape is shaken.

[Brief explanation of the drawing]

FIG. 1 shows an overall configuration diagram for implementing the present invention. Figures 2 and 3
The figure shows an embodiment of a light beam spot according to the invention.

Claims (1)

[Claims] 1. In a device that records information by irradiating electromagnetic waves such as a light beam onto a recording medium, and reproduces or erases information, an optical tape containing a recording medium in the form of a tape is used. An optical tape information recording and reproducing device characterized by comprising means for changing the spot shape of an irradiated light beam according to a desired function. 2. The optical tape information recording and reproducing apparatus according to the above item, characterized in that the reproducing light beam spot is made smaller than the size of the recording pit of the information signal. 3. The optical tape information recording and reproducing apparatus according to the preceding item, characterized in that the recording pit erasing means for the information signal irradiates a light beam spot having an area larger than the recording pit. 4. The optical tape information recording and reproducing apparatus according to the preceding item, characterized in that the recording pits are elongated into components perpendicular to the moving direction of the optical tape. 5. The optical tape information recording and reproducing apparatus according to item 1, characterized in that a substance that undergoes a phase transition from crystal to crystal is used as the recording medium. 6. The optical tape information recording and reproducing device according to item 1, characterized in that a substance that undergoes a phase transition between crystalline and amorphous states is used as the recording medium. 7. The optical tape information recording and reproducing apparatus according to item 1, characterized in that a tracking signal is not used in recording, erasing, or reproducing a signal.