JPH0798872A - Recording method and recording/reproducing device - Google Patents

Abstract

PURPOSE:To evade thermal deterioration and to enable multi-valued recording by changing the shape of a recording mark in the manner of moving a light beat in the direction of track width against a center of the recording mark formed on the track. CONSTITUTION:With an optical pickup 11, optional laser power is continuously set by a system control circuit 9 through a semiconductor laser circuit 4, and one beam over-writing is also attained. When the multi-valued recording is made by overwriting on an optical recording medium 7, the difference between the kind of shapes of the beam scanning position detected by an optical pickup position control circuit 2 and of the already existing recording position detected from a light receiving signal processing circuit 3 and the kind of shapes of the recording position after the over-writing, is obtained by an operational function producing/controlling circuit 12. Then the operational function taking the beam scanning position, irradiating time, irradiation start point and irradiated power as the variables is produced and fed back to the circuits 2,4. Thus, the different informations are recorded on one recording mark.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording method and recording / reproducing apparatus utilizing light, heat or magnetization.

[0002]

2. Description of the Related Art In the conventional method, an optical change caused by the presence or absence of an information recording area is detected (Phillips Technical Review, Vol. 40, 1982, No. 6, p157).
Up to p164), the beam on one track is scanned once in the track direction to record / reproduce information with a binary signal.
As means for improving high density recording, 1) a method of recording by narrowing an information recording track interval (track pitch) and an array interval of information parts (pit pitch) (Japanese Patent Laid-Open No. 3-278).
No. 320), 2) There is a multilevel recording method in which one piece of information is represented by a plurality of pits. In the multilevel recording method, an attempt is made to change the size of the pits into a similar shape to make it ternary (Japanese Patent Laid-Open No. 3-2
No. 92631) and the same pit arrangement (presence or absence of pit)
An attempt has been made to carry out multi-value by giving information to (Japanese Patent Laid-Open No. 2-172039).

[0003]

[Problems to be Solved by the Invention] One of measures for high density recording
However, there is a limit to the method of recording at spatially close intervals. Therefore, a multi-valued recording method for improving the recording density in the same space is being studied. However, in the conventional multilevel recording method by power control, further multilevel recording cannot be expected unless the recording power is further increased, and when the irradiation power is high, there are problems such as a change in the shape of the recording portion and thermal deterioration of the substrate. Occurs. On the other hand, the multilevel recording method in which one piece of information is represented by a plurality of same-shaped pits is the same as the concept of reducing the size of the pits and spatially narrowing the intervals. In order to efficiently arrange pits having the same shape, it is necessary to constantly move the beam scanning position in the track width direction while keeping the irradiation start point and irradiation time constant.

An object of the present invention is to allow a plurality of information to be represented by one pit by giving information to the shape of the shaped pit itself, and to use a partial erasing method for a recording portion corresponding to one pit information. However, the beam irradiation scanning position, irradiation time, irradiation start point, and irradiation power were arbitrarily selected to reduce the influence of thermal deterioration and to improve the recording density. The present invention provides a recording system for expressing information by using recording marks, and a recording / reproducing apparatus using recording marks formed by partial division recording.

[0005]

According to the present invention, at least one of a scanning position, an irradiation time and an irradiation start point of a light beam focused on an information recording medium is changed to irradiate a power sufficient for erasing, A recording method involving an operation of partially erasing a recording mark, a recording method in which information is represented by recording marks having a plurality of shapes and a non-recording portion, a scanning position of a light beam focused on an information recording medium, an irradiation time, and At least one of the irradiation start points is changed to irradiate a power sufficient for the erasing action to partially erase the recording mark, and recording / reproducing in which information is represented by recording marks of a plurality of shapes and a non-recording portion. On the device.

[0006]

[Function] As a shape shaping method of a recording part for multi-valued, by applying power for erasing action and irradiating, thermal deterioration is avoided, and multi-valued is achieved only by changing irradiation power. A variety of multi-valued recordings are possible and recording density is improved as compared with the trial.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a basic recording mark shape diagram using the present invention.

The mark shape shown in the drawing is a shape diagram of a recording mark formed when the mark is divided into four equal parts vertically and horizontally. In the conventional recording method, information is represented by two types of pits of recording (1) and erasing (0).

In the present invention, information is expressed using a combination of the pit shapes shown in the figure, using a total of 16 kinds of shapes including the shape types (3) to (16) in addition to the conventional 1,0 information. It becomes possible. However, if the same method as the conventional recording method is used to form the above-mentioned recording mark, the pit shape becomes large and the reading speed cannot be improved,
The recording density of information cannot be increased. Therefore, a method of forming a minute recording mark may be performed as follows.

Regarding the method of partially shaping the recording marks, 1. 1. When erasing power is applied to move the light beam irradiation scanning center arbitrarily and completely erase the irradiation area, 2. When the light beam irradiation scanning center is set to be the same and an erasing power that does not erase the entire irradiation area is given, 3. When erasing power is applied so that the light beam irradiation scanning center is arbitrarily moved and the entire irradiation area is not erased. When the erasing power for moving the light beam irradiation scanning center arbitrarily and for not erasing or completely erasing the irradiation area is given, the following four cases will be roughly explained. The shape of the initial recording mark is assumed to be an ellipse.

1. A partial shaping method when the erasing power for completely erasing in the irradiation area while arbitrarily moving the light beam irradiation scanning center is given will be described by exemplifying a case where the recording mark is equally divided into four.

First, as to the types of recording mark shapes, as described with reference to FIG. 1, in addition to the conventional shapes shown in (1) and (2), there are 14 kinds of shapes (3) to (16). By generating, the information is represented by a total of 16 types of recording marks.

Next, recording marks are formed as follows.

When forming marks of different shapes in the same area as the conventional recording mark area. When the mark shape and shaping are performed within the conventional recording mark area, at least one of the light beam scanning center, the irradiation time, and the irradiation start point is changed to irradiate the erasing power. Alternatively, 17 types of formation methods in total, including 3 operations of non-irradiation or complete erasing, are possible.

Table 1 shows mutual products of these 17 kinds of operation functions.

[0017]

[Table 1]

The individual operations are described in different cases with respect to the center position of the light beam scanning determined when the first recording mark is formed, the irradiation time (t), and the presence or absence of displacement with respect to the irradiation start point. The operation function follows the following notation.

1) The processing above the center line of the light beam scanning is on the left side in the parentheses following f, and the processing below is on the right side in the parentheses following f, 1, B / 2, F / 2, 0 Describe any one of the subscripts. 2) There are 5 types of subscripts in total, and w is the irradiation time with the same t, the irradiation start point is the same, and operation for giving power with recording action, 1 is the irradiation time At the same t, the irradiation start point is the same, and an operation of giving power having an erasing effect is performed, B / 2 is the operation of giving an irradiation time at t / 2, the irradiation start point is the same, and an operation having an erasing effect is given, F / 2 Indicates an irradiation time of t / 2, the irradiation start point is shifted by t / 2 in the beam traveling direction to give power having an erasing action, and 0 indicates an unirradiated operation.

For example, f (1, B / 2) represents an operation in which the upper half erases all and the lower half erases the left half.
The 17 kinds of operation functions shown in Table 1 are also a combination of the 5 kinds of operations shown as the above subscripts when the displacement is given to the scanning center of the light beam. Therefore, the operation indicated by the subscript will be referred to as a prime operation. An example shows a product (continuous operation) of operation functions including the above-mentioned elementary operations and combinations thereof. At least 1) the elementary operation w cancels any elementary operation, 2) the elementary operations of F / 2 and B / 2 at the same scan center are equivalent to the elementary operation 1, 3) the elementary operation 1 Cancel any remaining elementary operations that have the same scan center, 4) compatible operation sequence between F / 2, B / 2, 0 at the same scan center, 5) elementary operation or The five points of the combined operation function group are closed are clearly shown.

Table 2 shows the change in shape after a total of 17 kinds of operations are applied once to the recording marks of 16 kinds of shapes shown in FIG.

[0022]

[Table 2]

R is the remaining portion after the operation function is acted once, and subscripts a, b, c, and d are clockwise when the recording mark is divided into four vertically and horizontally evenly, with the upper left half as a and b clockwise. ，
c, d, and location are shown, 1 indicates that all the abcd recording areas remain, and 0 indicates that all the abcd non-recording areas. It can be seen from Table 2 and FIG. 3 that the recording mark shape group is closed for all the operation functions. For the actual rewriting of information, a combination of operation functions having the smallest number of operations is selected from Tables 1 and 2 and acted on.

Next, an operation method when there is a non-recording portion within the mark area to be recorded will be described.

When there is a non-recording portion in the mark area to be recorded, it is necessary to secure at least the mark area to be recorded by means for irradiating the recording power. Here, a power having a recording action is applied to secure the area. At this time, the light beam scanning center position,
The irradiation time t and the irradiation start point are reset. The subsequent operation follows the method for forming the recording mark described above.

A recording object such as a phase change recording medium or a magneto-optical medium is capable of high-speed conversion between recording and erasing.
It is an information recording material whose light beam irradiation area can be completely erased.

Next, the light beam irradiation scanning centers are made the same,
In addition, the partial shaping when the erase power that does not erase the entire irradiation area is given will be described by an example using the irradiation power dependency of the light beam of the crystal growth rate of the phase change optical recording medium.

First, the types of recording mark shapes will be described.

This embodiment will be described with reference to FIG.

In the phase change type optical recording medium used in this experiment, the recording portion is amorphous and the non-recording portion is crystalline.

For example, in the ternary compound InSbTe medium, the erasing process depends on the growth of the amorphous crystal interface, but in the medium showing the crystal growing process, the crystal of the unrecorded part after the initialization and the crystal after the erasing are the same. And the interface is extremely clear, and the starting point of crystal growth is limited to the interface. As a result of applying DC power over the existing recording mark in a range that does not reach complete erasure, (3) to (5)
Three types of recording marks having different shapes were obtained as shown in FIG.
Conventionally, information is represented by two types of recording (1) and erasing (2). In this way, as a result of the experiment, at least five kinds of light were shaped by shaping the interface shape without shifting the scanning center of the light beam and applying the irradiation power at a low value less than the erasing power. It was confirmed that the recording mark of 1 can be formed.

Next, the irradiation power dependence of the crystal growth rate will be described.

It has been found that the crystal interface growth rate of the ternary compound InSbTe medium having a definite structure quoted in the above example has a maximum value. Depending on which position in the vertical direction of the track the maximum crystal interface growth rate is, and conversely, which position is allocated so that the maximum crystal growth rate is controlled by controlling the irradiation power, for example, (3 in FIG. ) ~
The recording mark of (5) can be formed.

Next, the operation function and its object will be described.

Since the irradiation power exhibiting the erasing action differs for each recording mark shape shaping operation, there is no operation compatibility between the generated operation functions. The target is high-speed recording and erasing such as phase change type or magneto-optical medium, the starting point of the erasing operation exists only from the interface between the recording part and the erasing part, and the interface growth rate can be controlled by the irradiation power of the light beam. It is a recording medium.

First, if the erasing power that does not erase the entire irradiation region is given by arbitrarily moving the light beam irradiation scanning center, the interface position in the crystal growth temperature region within the light beam irradiation region is determined according to the irradiation power. This enables shape shaping.

As another method, a method of arbitrarily moving the light beam irradiation scanning center and not erasing the entire irradiation area as described above, or applying an erasing power for complete erasing, the light beam irradiation area Since the interface position in the crystal growth temperature range is determined according to the irradiation power, the shape can be generated.

As described above, the basic recording mark shape diagram shown in FIG. 2 can be obtained. Furthermore, in this experiment, the ternary compound InSbTe phase change recording medium, the aperture ratio of the optical head was 0.55, the beam converging diameter was 1.2 μm, and the wavelength was 8
30 nm was used. Higher power than normal recording power 1
A recording mark was formed at 4 mW, and then DC light of 6 mW to 7.5 mW, which is lower than the erasing power, was irradiated. As a result, the shape change of the amorphous crystal interface of the recording mark shown in (3) to (5) was obtained. As the irradiation power applied increases, the temperature range where the maximum crystallization speed is reached moves away from the center of the information track in the direction perpendicular to the track, and only the amorphous crystal interface existing within the beam irradiation diameter becomes the irradiation power. The shape of the recording mark is controlled by being able to move at a speed according to the speed. In this case, the variables of the shape shaping operation function, that is, the scanning position of the light beam, the irradiation time, and the irradiation start point are not displaced, but the displacement is imparted by using the means for setting the power having an erasing action in the irradiation power every moment. It is an example. When at least one of the scanning position of the light beam, the irradiation time, and the irradiation start point is displaced, the number of types of recording mark shapes representing information is further increased. On the other hand, it is also suggested that more complicated shape shaping can be performed by using this recording method together. It should be noted that when operating the operation function, the operation order becomes incompatible when the erase power is changed at the same light beam scanning center.

Table 3 and FIG. 3 show an example of the recording method according to the present invention.

[0040]

[Table 3]

This table shows six types of operation functions (Ww, W shown in FIG. 2 when recording marks are equally divided into four vertically and horizontally.
u, Wd, We, Hf, Hb), A
10 is a table showing an operation function for completing the earliest mark shapes of 10 to N with a small number of 1-beam overwrites. The six kinds of operation functions are the recording operation (Ww) which forms a recording mark and serves as a reference, and the irradiation power is five kinds when the power having an erasing action is used, that is, the light beam scanning center position and the irradiation time. (t) and operation with the same irradiation start point (We), the light beam scanning center position is shifted to the upper part, irradiation time and irradiation start point are the same operation (Wu), the light beam scanning center position is shifted to the lower part The time and the irradiation start point are the same operation (Wd), the light beam scanning center position is the same, the irradiation time is t / 2, and the irradiation start point is an operation shifted by t / 2 minutes in the light beam scanning advancing direction (Hf). , The light beam scanning center position is the same, the irradiation time is t / 2, and the irradiation start point is the same operation (Hb).

For example, when it is desired to rewrite the existing recording mark H4 to Q1 after overwriting, Ww * Wd * Hb: H4 = Q1 according to the operation function table. In the formation of the partially divided recording mark, 1) if there is a portion that does not overlap with the existing recording portion in the recording portion after overwriting, it is necessary to first form a recording portion corresponding to 1-bit information (Ww), 2) a) When dividing off-track amount with the same irradiation time
(Wu, Wd), and b) When the irradiation time is divided with the same off-track amount (H
The pulse erase operation associated with f, Hb) is required.

In the case of this example, the operation of 2) is a) once, b) once, and in consideration of the operation of 1), a maximum of 3 operations is performed to obtain 1 beam between 10 arbitrary mark shapes. Overwriting is possible. According to this method, for example, 33 ms
In contrast to the case where 2 Nth information is recorded / reproduced over / track, 10 Nth information can be recorded / reproduced at 99 ms / track even at the slowest time. Also, in the past, 1
Although 8 bits were required for the byte, 3 bits are sufficient in this method.

FIG. 4 shows an operation example of an apparatus for recording / reproducing information represented by using a plurality of recording marks having different shapes according to the present invention. 1) Read the original signal (02) and take the difference with the rewrite signal (01) 2) Consider the maximum number of laser irradiations 3) Erase pulse pattern (W,
H, WH), and then irradiation is performed to complete rewriting. As a safety measure to reduce the writing failure, a complete erasing operation (We) is performed at every certain number of rewritings or when the noise level due to the deterioration of the shape of the recording mark exceeds a certain threshold value. It is completed by periodically adding this operation once to the shortest processing operation number.

FIG. 5 shows an optical recording / reproducing apparatus using the present invention.

The optical pickup (optical head) 1 sends and receives optical information. Reference numeral 2 is a position control circuit for controlling the optical pickup position, 3 is a signal processing circuit for processing a received signal, 4 is a semiconductor laser drive circuit for setting at least irradiation power or irradiation on / off control.
Is a drive motor for rotating the optical recording medium, 6 is a turntable, 7 is an optical recording medium, 9 is a system control circuit, 10 is a group of external input terminals, 11 is a laser beam, 12 is an operation function for recording or rewriting, and 3 shows a circuit for performing control. In addition to this, it is also possible to add an identification circuit 8 for identifying the melting points of the optical recording and magnetic recording layers so that the laser irradiation power can be set more easily when the medium is converted.

The optical recording medium 7 is placed on the turntable 6, and the turntable 6 is rotated by the motor 5.
The optical recording medium 7 is rotated. The rotation is stopped from the external input terminal 10 via the system control circuit 9.

The optical recording medium 7 is irradiated with the laser beam 11 by the optical pickup 1. Laser beam 1
The reflected light of 1 returns to the optical pickup 1 and the signal processing circuit 3
The height deviation of the optical pickup 1 and the deviation signal on the track are extracted via the optical pickup 1 and the optical pickup position control circuit 2 is used to obtain the focusing and tracking of the optical pickup 1 with respect to the optical recording medium. I am configuring. The focusing and tracking operations are stopped by the external input terminal 10 via the system control circuit 9.

Further, the optical pickup 11 can set an arbitrary laser power every moment by the system control circuit 9 via the semiconductor laser drive circuit 4, and one-beam overwrite is also possible.

The control track provided on the inner or outer periphery of the optical recording medium 7 can be overwritten at the melting point of the recording film of the optical recording medium 7 or at a temperature higher than the melting point.

When the optical recording medium 7 is overwritten by the recording action, the beam scanning position detected by the optical pickup position control circuit 2 and the shape type of the existing recording portion detected by the received light signal processing circuit 3 are selected. An operation that has at least the beam scanning position, the irradiation time, the irradiation start point, and the irradiation power as variables, which is obtained from the difference in the shape species of the recording site after overwriting introduced from the external input terminal 10 and transmitted through the system control circuit 9. The operation function generation control circuit 12 plays a role of generating and controlling a function and feeding back the result to the optical pickup position control circuit 2 and the semiconductor laser drive circuit 4.

By using a plurality of recording marks having different shapes to represent information and perform recording / reproduction, the recording density of the recording / reproducing apparatus is improved.

[0053]

EFFECTS OF THE INVENTION A recording method for forming recording marks having a plurality of different shapes and a recording mark having a plurality of different shapes by using an erasing power having a low thermal deterioration or an arbitrary scanning center shifting means of a light beam are used. It is possible to provide a high-density recording / reproducing system for expressing information and a device with improved performance of recording / reproducing information by using recording marks having a plurality of shapes.

[Brief description of drawings]

FIG. 1 is a diagram showing a recording mark shape formed when it is equally divided into four parts.

FIG. 2 is an example diagram of recording mark shaping using the irradiation power dependency of the existing position of the maximum crystallization speed.

FIG. 3 is a diagram showing six types of operation functions and recording mark shapes.

FIG. 4 is a diagram showing an example of an operation in the optical recording / reproducing system according to the present invention.

FIG. 5 is a diagram showing an example of an optical recording / reproducing apparatus according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical pickup, 2 ... Optical pickup position control circuit, 3 ... Receiving signal processing circuit, 4 ... Semiconductor laser drive circuit, 5 ... Optical recording medium rotation motor, 6 ... Turntable,
7 ... Optical recording medium having a tracking guide, 8 ... Melting point identification processing section of recording layer of optical recording medium, 9 ... System control circuit, 10 ... External input terminal, 11 ... Laser beam, 12
... Operation function generation control circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Isao Ikuta 7-1, 1-1 Omika-cho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi Research Laboratory (72) Inventor Hisashi Ando 7-chome, Omika-cho, Hitachi-shi, Ibaraki No. 1 Incorporated Hitachi Ltd. Hitachi Research Laboratory (72) Inventor Shoichi Nagai 7-1-1 Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi Ltd. Hitachi Incorporated (72) Inventor Yoshio Sato Hitachi City, Ibaraki Prefecture 7-1, Omika-cho, Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Tetsuya Fushimi, 7-1-1, Omika-cho, Hitachi, Ibaraki Prefecture Hitachi Research Laboratory, Hitachi, Ltd.

Claims (13)

[Claims] 1. A recording method for recording information by converging a light beam on an information recording medium, wherein an optical head for generating the light beam is provided with respect to a scanning center of a recording mark formed on a track of the information recording medium. Then, the recording mark shape is changed by moving in the width direction of the track and changing the unit irradiation time or the irradiation start point when the recording mark is formed, and different information is recorded in one recording mark. Characteristic recording method. 2. A recording method for forming a recording mark by converging a light beam on an information recording medium, when a new recording mark is formed using the previously formed recording mark,
Forming the new recording mark by making the size of the light beam smaller than the previously formed recording mark, and changing the irradiation time of the light beam and the irradiation start time required for forming the new recording mark. Characteristic recording method. 3. The method according to claim 2, wherein the irradiation start point is shifted based on the beam scanning center, the irradiation time and the irradiation start point which are determined when the preformed recording mark is formed, and the irradiation time is the same, or A recording method, wherein one recording mark is formed by changing the recording mark. 4. The method according to claim 2, wherein the irradiation start point is the same and the irradiation time is the same with reference to the beam scanning center, the irradiation time and the irradiation start point which are determined when the previously formed recording mark is formed. A recording method, wherein a new recording mark is formed by performing a changing operation. 5. A recording method for forming a recording mark by converging a light beam on an information recording medium, wherein the size of the light beam is set smaller than a recording mark formed in advance, and the light beam is set on the medium. When the new recording mark is formed by using the previously formed recording mark, the irradiation time of the light beam is shorter than the irradiation time of the light beam when the previously formed recording mark is formed, A recording method characterized in that the irradiation start time of the light beam is arbitrarily changed to set irradiation power having an erasing action to form the new recording mark. 6. The method according to claim 5, wherein the irradiation start point is shifted and the irradiation time is the same or changed with reference to a beam scanning center, an irradiation time and an irradiation start point which are determined when the recording mark formed in advance is formed. A recording method, wherein a new recording mark is formed by performing the recording. 7. The method according to claim 5, wherein the irradiation start point is the same and the irradiation time is the same or changed with reference to a beam scanning center, an irradiation time and an irradiation start point which are determined when the recording mark formed in advance is formed. A recording method, wherein a new recording mark is formed by performing the operation. 8. A recording method for forming a recording mark by converging a light beam on an information recording medium, wherein the irradiation power dependence of the magnetization reversal speed or crystal growth speed of the light beam on the medium is measured. A recording method, which is used for shaping the shape of a recording mark, wherein recording marks having different shapes are formed and information is recorded according to the difference in recording mark shape. 9. A recording method for forming a recording mark by converging a light beam on an information recording medium, wherein the erasing area of the previously formed recording mark is changed and the beam is irradiated within a power margin having an erasing action. A recording method, wherein recording marks having different shapes are formed by varying the power, and information is recorded by the difference in the shape of the recording marks. 10. An optical recording medium having a tracking guide, an optical pickup section which is installed facing the recording medium, a signal processing section which processes a signal received from the optical pickup section, and an optical recording medium. A semiconductor laser drive unit that controls power setting and irradiation on / off when irradiating a laser beam, a position control unit that controls a position of an optical pickup, a recording medium drive unit that rotates the recording medium, and a support unit for the recording medium. Optical recording / reproducing apparatus including a turntable, a light beam control unit for performing control for irradiating a light beam for recording on the recording medium, and a system control unit for controlling the entire system and introducing external information. In accordance with a command from the position control unit, the optical pickup is set to the scanning center of the recording mark formed on the track of the optical recording medium. To the width direction of the track,
The unit irradiation time or irradiation start point determined when forming the recording mark is changed by the semiconductor laser driving unit, and the intensity of irradiation light is changed by the light beam control unit according to the signal and recording information of the semiconductor laser driving unit. A recording / reproducing device characterized by being changed. 11. An optical recording medium having a tracking guide, an optical pickup section installed so as to face the recording medium, a signal processing section for processing a signal received from the optical pickup section, and an optical recording medium for the recording medium. A semiconductor laser drive unit that controls power setting and irradiation on / off when irradiating a laser beam, a position control unit that controls a position of an optical pickup, a recording medium drive unit that rotates the recording medium, and a support unit for the recording medium. An optical recording / reproducing apparatus including a turntable, a light beam control unit for performing control for irradiating a light beam for recording on the recording medium, and a system control unit for controlling the entire system and introducing external information. In the above, the light beam control unit sets an irradiation time of 1 / A or less (A is a natural number) of the irradiation time of the light beam necessary for forming a recording mark. A recording / reproducing apparatus comprising: an irradiation time setting means for controlling the irradiation start time, an irradiation start time setting means for arbitrarily changing the irradiation start time, and an irradiation power setting means for setting an irradiation power having an erasing effect. 12. An optical recording medium having a tracking guide, an optical pickup section installed facing the recording medium, a signal processing section for processing a signal received from the optical pickup section, and an optical recording medium for the recording medium. A semiconductor laser drive unit that controls power setting and irradiation on / off when irradiating a laser beam, a position control unit that controls a position of an optical pickup, a recording medium drive unit that rotates the recording medium, and a support unit for the recording medium. An optical recording / reproducing apparatus including a turntable, a light beam control unit for performing control for irradiating a light beam for recording on the recording medium, and a system control unit for controlling the entire system and introducing external information. In the above, the light beam control unit preliminarily records the dependency of the magnetization reversal speed or the crystal growth speed on the irradiation power of the beam with respect to the recording medium. A recording / reproducing apparatus comprising: a recording unit for recording, and determining and controlling an irradiation power and an irradiation time of the light beam according to the recording medium and information to be recorded. 13. An optical recording medium having a tracking guide, an optical pickup section installed facing the recording medium, a signal processing section for processing a signal received from the optical pickup section, and an optical recording medium for the recording medium. A semiconductor laser drive unit for controlling power setting and irradiation on / off, a position control unit for controlling the position of an optical pickup, and a control for irradiating a light beam for recording on the recording medium. An optical head device comprising a light beam controller,
An optical recording / recording / reproducing apparatus comprising: a recording medium drive unit that rotates the recording medium; a turntable that supports the recording medium; and a system control unit that controls the entire system and introduces external information. The optical head device for forming a recording mark by condensing a light beam on the recording mark formed by a beam formed by condensing the light beam of the optical pickup installed facing the recording medium. The recording / reproducing apparatus is characterized in that the erasing area is changed and the beam irradiation power is changed within a power margin having an erasing action to change the shape of the recording mark to represent information in each shape.