JPS58188348A - Record readout device - Google Patents

Abstract

PURPOSE:To reduce the reading time, by reading out a recording signal of a recording medium by using electromagnetic waves as signal media, and transmitting the signals in synchronization with the moving speed of the recording medium between photodetectors of a reception system comprising the arrangement of plural reception elements via a transmission system. CONSTITUTION:Laser light generated from a light source 5 is irradiated on a soft magnetic film 4b of a magnetic recording medium 1 via a polarizer 6 and a beam splitter 7. The light reflected at a reflecting film 4c is made incident to a photodetection system 3 made of a CCD via the beam splitter 7 and an analyzer 8. Each cell of the system 3 controls and amplifies stored charges so as to be summed sequentially in synchronization with the running speed of the recording medium with a clock pulse. In this case, plural recording signals distributed on a plane region of the medium 1 are transmitted at the same time as the information group, the information is received as information at each unit and it is converted into an electric signal, allowing to reduce the reading time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention primarily relates to a recording/reading device for reading magnetic recording on a magnetic recording medium.

The most well-known magnetic recording readout device for reading magnetic recordings from magnetic recording media is one that uses a magnetic head, but a magnetic head requires a magnetic recording track width of at least three layers of meters. Because of the limitations of high-density magnetic recording due to the narrowing of the magnetic recording track width, recently a magnetic recording readout method that uses the magneto-optical effect has been proposed in place of the conventional readout device using a magnetic head. ing. This magnetic recording readout method using the magneto-optical effect transfers the @, ll'1 components of the magnetic recording signal of the magnetic recording medium to the soft magnetic film by placing a soft magnetic film in contact with the magnetic recording medium. However, it is an optical readout method that takes advantage of the fact that the light undergoes Faraday optical rotation depending on the magnetization direction of the domains of the soft magnetic film.

However, the conventional method focuses light on a soft magnetic film in the form of a spot, and reads out the magnetic recording of the magnetic recording medium as each l bin (i.e., focus, pi, bit). However, there was a drawback that the reading time was long.If the running speed of the magnetic recording medium was increased, the time for one reading could be shortened, but there is a limit to this.

As a technical means to eliminate this drawback, a method of reading out data in a planar manner using a planar imaging device such as a charge transfer device (hereinafter referred to as a CCD) can be considered. However, when these surface imaging devices are used, magnetic recording must be read from a magnetic recording medium running at a certain speed, so it is difficult to provide sufficient charge accumulation time to each cell of the CCD. There are technical difficulties that result in difficulty and low sensitivity.

The present invention provides a recording/reading device that overcomes the technical difficulties described in L when reading magnetically recorded values T+, etc. using a surface imaging device such as a CCD, and at the same time can significantly shorten the reading time. The purpose is to

- In order to achieve this goal, the recording/reading device according to the present invention includes an electromagnetic wave transmission system that reads and transmits recorded signals of a recording medium using electromagnetic waves as a signal medium, and a plurality of receiving elements arranged in a planar manner so as to transmit the electromagnetic waves. and a receiving system that receives the signal transmitted from the transmission system, and amplifies the received signal by transmitting the signal for 1,000 seconds from the reception of the receiving system in synchronization with the moving speed of the recording medium. Features.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The content of the present invention will be specifically described below with reference to the accompanying drawings, which are examples. FIG. 1 is a diagram showing the basic configuration of a recording/reading device according to the present invention. In the figure, l represents a magnetic recording medium such as a magnetic tape, which runs at a constant speed in the direction of the arrow rIJa. 1 on the magnet provided on the surface of this magnetic recording medium l.
It is assumed that pulse code modulation (hereinafter referred to as PCM) 1 layer No. 1 is magnetically recorded on the layer. However, magnetic recording using other modulation methods such as frequency modulation and pulse width modulation may also be used. Further, the magnetic recording method for the magnetic recording medium l is not limited to perpendicular recording, but may be one-plane recording.

Reference numeral 2 denotes an electromagnetic wave transmission system that reads and transmits magnetic recording signals from the magnetic recording medium 1- using electromagnetic waves as a transmission medium. Electromagnetic waves are generally light, but basically any electromagnetic wave that undergoes Faraday optical rotation may be used. The magnetic recording 6J/body 11
The magnetic recordings of - are simultaneously read out and transmitted by the electromagnetic wave transmission system 2 in a planar manner, that is, in a range of m focuses and n tracks in the width direction of the magnetic recording medium l along the running direction a.

Note that the magnetic recording of the magnetic recording medium can be read using the magneto-optical effect as in the conventional case.

A receiving system 3 receives signals transmitted from the electromagnetic wave transmission system 2, and has a configuration in which a plurality of receiving elements are arranged in a planar manner. Each receiving element of the receiving system 3 has at least m rows in the running force direction a of the magnetic recording medium 1 and n columns in the width direction so as to correspond to one half of the magnetic recording signal input manually through the electromagnetic wave transmission system 2. Make it a two-dimensional array. Furthermore, since light is generally used as the electromagnetic wave, the receiving system 3 is constructed as a combined light receiving system.

When configuring the light receiving system, is it possible to use photoelectric conversion elements such as phototransistors as each light receiving element and arrange them two-dimensionally in an array?
A surface imaging device such as U is used.

The nXm-bit magnetic recording signal read planarly from the magnetic recording medium 1 by the electromagnetic wave transmission system 2 and transmitted to the receiving system 3 is input to each receiving element constituting the receiving system 3 in a state corresponding to each focus. and converted into electrical signals. in this case,
If each receiving element of the receiving system 3 is configured to operate independently regardless of W, the signals of the magnetic recording bits at the same position on the magnetic recording medium 1 will be transmitted in the direction of force a of the magnetic recording medium l. As the vehicle travels, it moves at high speed from one receiving element of the receiving system 3 to the other adjacent receiving element, so the signal reception time at the receiving element becomes short, and if the receiving system 3 is configured with a CCD, it will not be possible to receive the signal sufficiently. Charge accumulation time cannot be secured, and sufficient sensitivity cannot be secured. Therefore, in the present invention, by transmitting signals between the receiving elements of the receiving system 3 in synchronization with the moving speed of the magnetic recording medium l in the a force direction, the receiving elements 1. In order to amplify the signal and improve reception sensitivity, for example, n on the magnetic recording medium l at a certain time.
tW m-th bit (a) in track I+
If it is assumed that reception is being received by the receiving element (a) of the nth column and mth row of the 1st system 3, then the a of the magnetic recording medium l is
As it moves in the force direction, the bit (a) or (m-1)
When moving to the th bit position, in synchronization with this, a signal is transmitted from the receiving element (a) to the adjacent receiving element (m-1) l'' (b). As a result, the accumulated charge weight 4 of each cell of the COD constituting the receiving system 3 is sequentially accumulated in the set of receivers, increasing the received signal and significantly improving the receiving sensitivity. The charge movement in each cell of the COD is equal to the movement speed of the magnetic recording medium l by 11JI.
By supplying a clock pulse that has been adjusted, it is possible to easily synchronize the moving speed of the magnetic recording medium l.

No. 21 & shows a more specific embodiment of the recording/reading neck according to the present invention. In the figure, the same reference numerals as in FIG. 1 indicate the same components. This embodiment shows a specific example of a magnetic recording/reading device that utilizes the magneto-optical effect.

4 is a read head that utilizes the magneto-optical effect.

The read head 4 is provided so as to be in contact with the magnetic layer 1a serving as the magnetic recording surface of the magnetic recording medium 1, and is provided with an optical layer 1a having a thickness of 0.2 to 0.5 mm, for example, as shown in FIG. It has a structure in which the soft magnetic film D* 4b is deposited on the side of the transparent GdGa garnet substrate 4a facing the magnetic recording medium l, and the reflective film 4C is deposited on the seventh part of the soft magnetic film 4b. ing. The soft magnetic film 4b is optically transparent and has soft magnetic properties 1, for example, Y+Q'15m01Ca6q2Fe4. O
The film is formed using a YSmCaFeGe based magnet such as LG eOM 012 to have a film thickness of approximately 6 #Lm with the axis of easy magnetization aligned in the direction perpendicular to the film surface. Reflection! A protective film 4d made of, for example, silicon dioxide is provided on the surface of IQ 4 c.

When the read head 4 is brought into contact with the magnetic recording medium 1, the domains of the soft magnetic II layer 4b are magnetized in the direction perpendicular to the film surface by the perpendicular component of the leakage magnetic flux generated from the magnetic recording signal of the magnetic recording medium 1. be done. In this embodiment, since PCM4'1 is magnetically recorded on the magnetic recording medium 1, the change in the noise domain of the soft magnetic film 4b corresponds to the PCM signal.

In this embodiment, changes in domains in the soft magnetic I-4b are read out using the magneto-optical effect, and the reading method is the conventional bit, pi.

As an older brother of the readout method based on the human data, it simultaneously reads out and transmits a plurality of magnetic recording signals distributed in a planar manner, that is, in a flat area of the magnetic recording medium l as an information group, and transmits this information group over one width area. The structure is such that it repeatedly receives light and converts it into signals as information. Next, the configuration of the optical system for this purpose will be explained.

5 is a light source generating device that generates, for example, a He-Ne laser beam; 6 is a polarizer that linearly polarizes the light generated from the light source generating device 5; 7 is a beam splitter; 8 is an analyzer r; 9 is a condenser lens; 10 is an imaging lens.

Laser light, etc. generated from the light source generator 5 is linearly polarized through a polarizer 6 and supplied to a beam splitter 7, and the light reflected by the beam splitter 7 is sent to a soft magnetic film 4bl with a luminous flux of a certain solid angle. - irradiate. The light irradiated onto the soft magnetic film 4b is reflected by a reflective film 4C provided on the back surface thereof, enters a beam splitter 7, passes through a beam splitter 7, and is supplied to an analyzer 8. During this time,
The light undergoes Faraday rotation to the right or left depending on the direction of magnetization force of the domains of the soft magnetic film 4b. The light that has undergone the γ-radiation rotation is supplied to a light receiving system 3 composed of a CCD via an analyzer 8. The light receiving system 3 simultaneously receives the supplied information group as one unit of information and converts it into an electrical signal. In this embodiment, the PCM signal is magnetically recorded on the magnetic recording medium l, and the light receiving system 3 is composed of a CCD, so that the PCM information is decomposed into bits and corresponds to each cell of the COD, and the light is received simultaneously. It happens. Each cell of the light receiving system 3 receives a magnetic recording medium l by an external clock pulse.
In synchronization with the running speed in the direction a, the accumulated charges are controlled to be added sequentially to amplify the receiver 411 and the receiver 1'. The received signal thus amplified is reproduced by a (1) reproduction device (not shown).

), J, in this embodiment, the number of magnetic recording signals distributed in the planar area of the magnetic recording medium 1 are transmitted simultaneously as an information + v group, and this information group is transmitted as information for each condolence ☆. Therefore, the read speed f is determined by the number of pips included in the light beam irradiated onto the soft magnetic 11Q 4 b, that is, the magnetic recording trunk in the width direction of the magnetic recording medium l. JA n m, where the number n and the number m of bits in the running direction a, is multiplied by the running speed V of the magnetic recording medium l, so that f=nmv, and the conventional bit,
pie,.

It is significantly faster than the focus method. For example, the fourth
As shown in the figure, the magnetic recording I/rank number n of the magnetic recording medium l included in the light beam irradiated onto the soft magnetic film 4b is set to n=128, and the length of the direction of travel a is 1/several meters. m=16
Then, at the same medium running speed as before, the reading speed f
is 16x128 times the conventional value. Also, by adjusting the number of recording tracks n and the number of bits m in the running force direction,
It is also possible to adjust the running speed of the magnetic recording medium 1 without reducing the actual reading speed.

Moreover, since the structure is such that the accumulated charge of each cell of the CCD constituting the light receiving system 3 is transmitted and accumulated in sequence in synchronization with the traveling speed of the magnetic recording medium 1, and the received signal is amplified, the receiving sensitivity is significantly improved. can be improved.

As described above, the present invention includes an electromagnetic wave transmission system that reads and transmits recorded signals from a recording medium using electromagnetic waves as a signal medium, and an electromagnetic wave transmission system that arranges a plurality of receiving elements in a plane and transmits signals transmitted from the electromagnetic wave transmission system. 1) a receiver system for receiving a signal, and the received signal is amplified by transmitting signals between the receiving elements of the receiver system in synchronization with the moving speed of the recording medium. Therefore, when reading out magnetic recording signals using a surface imaging device such as a CCD, it is possible to significantly improve receiving sensitivity and to significantly shorten the reading time.
A magnetic recording/reading device can be provided.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the basic structure of the recording/reading device according to the present invention, FIG. 2 is a diagram showing another specific embodiment, and FIG. 3 is a cross-sectional view showing the embodiment number of the successive head. FIG. 4 is a diagram showing the arrangement of j+2 magnetic recording bits output by the reading device of the present invention. 1... Recording medium 2... Electromagnetic wave transmission system 3...@Reception system 4... Read head 4a... Fundamental root
4b...φ Soft magnetic film 5... Light source equipment PJ, 6.
・・Polarizer 7・・Beam splinter 8・Write Φ analysis i

Claims (9)

[Claims] (1) Recording on a recording medium using electromagnetic waves as a signal medium 100
An electromagnetic wave transmission system that reads and transmits the numbers and multiple lights. A receiving system having elements arranged in a planar manner and receiving signals transmitted from the electromagnetic wave transmission system, and transmitting signals between the receiving elements of the receiving system in synchronization with the moving speed of the recording medium, A recording/reading device characterized by amplifying a received signal. (2) The continuous recording device according to claim 1, wherein the recording medium is a magnetic recording medium. (3) The electromagnetic wave transmission system according to claim 1 or 2, wherein the electromagnetic wave transmission system simultaneously transmits a plurality of recording signals distributed within a planar area of the recording medium as an information group. Record reading device. (4) The recording/reading device according to item 3 of Patent No. 61'1, wherein the receiving system simultaneously reads out a group of distributed information transmitted from the electromagnetic wave transmission system. (5) The electromagnetic wave is light.
1. A recording/reading device according to claim 1, 2, 3 or @4da1. (6) - The recording/reading device according to claim 5, wherein the receiving system is constituted by a light receiving system in which a plurality of light receiving elements are arranged in a planar manner. (7) The continuous recording apparatus according to claim 6, wherein the light receiving system is constituted by a charge transfer device. (8) The electromagnetic wave transmission system includes a soft magnetic film disposed close to the recording medium and having an axis of easy magnetization 41 in a direction perpendicular to the surface, and a plurality of magnets included in a planar region formed by the soft magnetic film. and an optical system for simultaneously reading out the IN signal as an information group. Record reading device. (9) The recording/reading device according to claim 81J, wherein the electromagnetic wave transmission system utilizes a magneto-optical effect.