JPH0721863B2 - Information recording / reproducing device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording / reproducing apparatus, and more particularly to an erasable information recording / reproducing apparatus that irradiates an optical disc with laser light to repeatedly record and reproduce information.

2. Description of the Related Art FIG. 3 shows a phase change between an amorphous state A and a crystalline state C of a phase change recording medium of a conventional information recording / reproducing apparatus. The reflectance of the amorphous state A is small and the reflectance of the crystalline state C is small. Greatly increases the temperature of the medium locally to near the melting point and gradually cools the portion to be in the crystalline state C, while locally increases the temperature of the portion in the crystalline state C to near the melting point and rapidly cools to the crystalline state A. . FIG. 4 (a) shows the structure of the light beam that realizes the temperature rising / quenching condition and the temperature rising / gradual cooling condition in the medium, and FIG. 4 (b) shows the light distribution thereof. In FIG. 4, 9 is a recording / reproducing light beam having a short diameter, 12 is its distribution, 10 is an erasing light beam having a long diameter, and 13 is its light distribution. Reference numeral 11 is a guide track on which a medium is deposited. The difference in light beam diameter has a function of making a quenching condition for a short diameter and a slow cooling condition for a long diameter. FIG. 4C shows the ID of the sector formed on the guide track 11 of the optical disc.
Represents the waveform of the reproduced signal from the section, data section, and gap section.

FIG. 4 (d) shows a write gate signal 105 for instructing that the recording / reproducing light beam is in the recording mode and is modulated by the write data and written in the data portion. FIG. 4 (e) shows the erase light beam 1
An erase gate signal 106 for controlling a period in which 0 is applied to the data portion of the guide track 11 at a constant intensity. In the data section, the write gate signal 105 and the erase gate signal 106 are enabled to erase the data section with the preceding erase light beam 10, the write data is recorded with the subsequent recording / reproducing light beam 9, and the write gate is completed at the end of the data recording. Signal 105 and erase gate signal 1
Turn off 06 together.

Problems to be Solved by the Invention However, in the above configuration, the write gate signal 10
Since 5 and the erase gate signal 106 are turned off at the same time, writing to the medium is performed by the erase light beam 10 as shown at 14 in FIG. 4 (c). The erasing of the medium is carried out by gradually increasing the temperature by the erasing light beam 10. Since this temperature rise and gradual cooling is realized as a whole action of the peak of the leading portion and the uniform light distribution of the trailing portion of the distribution 13 of the erasing light beam 10, the erasing light beam is emitted at the moment when the erasing gate signal 106 is turned off. A portion of the distribution 13 of 10 that is equal to or higher than the recording threshold optical power Pt of the medium is recorded as 14.

This recording mark 14 moves back and forth by several tens of μm to 100 μm due to jitter caused by eccentricity and rotation fluctuation of the disk, and since the previous recording mark 14 is only partially erased, it is several tens of μm wide after being erased many times. However, the reproduced signal has a waveform distortion such as a zag due to the change of the DC component in the gap, and thus the ID section of the next sector cannot be read accurately.

In view of the above point, the present invention has an object to provide an information recording / reproducing apparatus in which a recording mark due to an erasing light beam does not occur in a gap at a rear portion of a data portion of a sector.

Means for Solving the Problems The present invention comprises means for sequentially irradiating an optical disk for recording / reproducing information in sector units with an erasing light beam and a recording / reproducing light beam, and means for recording / reproducing information with a recording / reproducing light beam. An information recording / reproducing apparatus comprising means for erasing information with the erasing light beam and means for temporally controlling the light intensity of the erasing light beam.

Effect The present invention has the above-mentioned configuration, in which the erasing light beam irradiates the data portion prior to the recording / reproducing light beam in rewriting the information of the sector, and the erasing light beam is used to perform temperature gradual cooling to erase the old information, The recording / reproducing light beam is used as the recording light intensity to heat and quench to record new data, and after the recording of the new data is finished, the light intensity of the erasing light beam is gradually reduced and turned off, so that the erasing light beam is rapidly cooled. Make sure the conditions do not occur.

EXAMPLE FIG. 1 is a block diagram of an information recording / reproducing apparatus in an example of the present invention. In FIG. 1, 1 is a recording / reproducing laser, 2 is an erasing laser, 3 is a recording / reproducing laser drive circuit, 4 is an erasing laser drive circuit, 5 is a control voltage generating circuit for controlling the light intensity when the erasing laser is off, 6 Reference numerals 7, 7 are AND gates, and 8 is an inverter. 100 is a write data signal, 101 is a write gate signal, 102 is an erase gate signal,
103 is an erase power control gate signal, and 104 is an erase power variable signal.

FIG. 2 is an operation waveform diagram of FIG. In FIG.
Reference numeral 9 is a recording / reproducing light beam, 10 is an erasing light beam, and 11 is a guide track.

FIG. 2A shows the waveform of the reproduced signal, and the sector n is composed of an ID section, a gap 1, a data section and a gap 2. 2B shows a write data signal, FIG. 2C shows a write gate signal, and FIG. 2D shows a waveform of an erase gate signal.
FIG. 2 (e) is a diagram showing the positional relationship between the erase light beam 10 and the recording / reproducing light beam 9 on the guide track 11, and FIG. 2 (f) is the erase power control gate signal. FIG. 2 (g) is a diagram of the optical output level of the erase light beam 10, and FIG. 2 (h) is the waveform of the erase power variable signal.

The operation of the information recording / reproducing apparatus of this embodiment configured as described above will be described below.

Now, a case where the data part of the sector n is rewritten will be described as an example. The erase gate signal 102 is output upon detection of the ID portion of the sector n, and after the time of the gap 1, the write gate signal 10 and the write data signal 100 are output. As shown in FIG. 2 (e), the erasing light beam 10 precedes the recording / reproducing light beam 9 by t in time. Therefore, the old data portion is first heated and gradually cooled by the erasing light beam 10 to be in the amorphous state A, that is, the erasing state (level of the gaps 1 and 2). The erasing gate signal 102 is input to the erasing laser drive circuit 4 to turn on the erasing laser 2 with a constant light output. The write data signal 100 and the write gate signal 101 are input to the recording / reproducing laser drive circuit 3 via the AND gate 6, the recording / reproducing laser 1 is modulated at the recording light intensity level, and the temperature is rapidly cooled to record data.

When the data recording is completed, the write gate signal 101 turns off. The write gate signal 101 is inverted by the inverter 8, the erase gate signal 102 and the erase power control gate signal 103 (FIG. 2 (f)) are generated by the AND gate 7, and the erase power variable signal 104 is generated by the control voltage generating circuit 5. (Converted to FIG. 2 (h). The erasing power variable signal 104 is applied to the erasing laser drive circuit 4 to gradually reduce the optical output of the erasing laser 2 for a time T as shown in FIG. 2 (g). While controlling to turn off.

The light intensity of the erasing light beam 10 is set to a constant output level during irradiation of the data portion as shown in FIG. 2 (g), and the period T after the end of data recording is turned off while gradually decreasing monotonically. As the waveform of the erase power variable signal 104 in this period T, a straight line, a curve such as an exponential function, or the like is used. Further, the erasing laser 2 may be turned off at once when the value becomes sufficiently smaller than the recording threshold Pt of the medium. By thus turning off the erasing laser 2 under the power control sequence as described above, it is possible to prevent the erasing light beam 10 from generating a temperature rising and quenching condition.

EFFECTS OF THE INVENTION As described above, according to the present invention, by controlling the light intensity of the erasing light beam, it is possible to always realize the temperature rising and slow cooling conditions, and the practical effects thereof are great.

[Brief description of drawings]

FIG. 1 is a block diagram of an information recording / reproducing apparatus of an embodiment of the present invention, FIG. 2 is an operation waveform diagram of the same embodiment, FIG. 3 is a phase change diagram of a medium of a conventional information recording / reproducing apparatus, and FIG. The figure is an operation waveform diagram of a conventional information recording / reproducing apparatus. 1 ... recording / reproducing laser, 2 ... erasing laser, 3 ... recording / reproducing laser drive circuit, 4 ... erasing laser drive circuit, 5 ... control voltage generating circuit, 6, 7 ... AND gate,
8 ... Inverter, 9 ... Recording / reproducing light beam, 10 ... Erase light beam, 11 ... Guide track, 12 ... Recording / reproducing light beam distribution, 13 ... Erase light beam distribution, 14 ... Recording mark , 100 ... write data signal, 101 ... write gate signal, 102 ... erase gate signal, 103 ... erase power control gate signal, 104 ... erase power variable signal.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Norihisa Fukushima 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor, Yuji Takagi, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. 56) References JP-A-60-247839 (JP, A)

Claims (2)

[Claims] 1. A means for sequentially irradiating an optical disk for recording / reproducing information in sector units with an erasing light beam and a recording / reproducing light beam, a means for recording / reproducing information with the recording / reproducing light beam, and the erasing light beam. Means to erase information with
And an erase light beam intensity control means for controlling the light intensity of the erase light beam, irradiating the erase light beam in advance when recording information, and gradually decreasing the intensity of the erase light beam after the recording of information is completed. An information recording / reproducing apparatus characterized in that it is turned off after that. 2. The information erasing means outputs an erase gate signal,
The information recording apparatus according to claim 1, wherein the recording / reproducing means outputs a write gate signal, and after the write gate signal is turned off, the light intensity of the erasing light beam is gradually reduced and turned off at a predetermined time. Playback device.