JP2887296B2 - Optical information recording medium and information recording method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an optical information recording medium, such as an optical disk, an optical card, and an optical tape, for recording and reproducing information using a laser condensed beam, and information. Regarding the recording method.

[Problems to be solved by conventional technology and occurrence]

A conventional optical information recording medium having a configuration shown in FIG. 2 is known. In this recording medium, guide grooves 23, 25, and 27 having a depth of about 1/8 of the light wavelength are provided on a transparent substrate 21, and between these guide grooves 23, 25, and 27 (land portions) 22, 24, and 26 are provided. The uneven pre-pits 28, 29, 30, 31, and 32 are provided, and a light absorbing / reflective recording film (not shown) recordable with a laser condensed beam is provided thereon. The laser condensed beam 36 is diffracted by the diffraction action of the guide grooves 23, 25 and 27, detects a track shift by detecting the distribution of the reflected light, performs tracking control based on the detection signal, and performs Pre-pit information is read, and recording pits 33, 34, and 35 are formed in addition to the recording film in association with the pre-pit information.

However, in this method, only one of the guide grooves and the space between the guide grooves can be used, and it is difficult to increase the information recording density. Whether the tracking is performed on the guide grooves or between the guide grooves can be performed by simply reversing the polarity of the tracking. However, as shown in FIG. 2, the pre-pit exists only between the guide grooves. When the guide groove is tracked, the pre-pit on which the address information and the like are recorded cannot be read out, so that there is a disadvantage that the additional recording pit cannot be recorded in association with the pre-pit information. Therefore, the information recording density could not be increased.

The present invention solves such disadvantages of the prior art, and it is possible to reproduce pre-pit information regardless of whether tracking is performed on the guide groove or between the guide grooves, and between the guide groove and the guide groove. It is an object of the present invention to provide an optical information recording medium and an information recording method in which additional recording pits can be recorded in association with pre-pit information.

[Means for solving the problem]

In order to achieve the above object, according to the present invention, there is provided an optical information recording medium having a guide groove for tracking and a pre-pit row, wherein a center line of the pre-pit row is defined by a guide groove when an interval between the guide grooves is x. The optical information recording medium is provided so as to be shifted from the center line by approximately x / 4 to one of the right and left sides (claim 1).

In a preferred embodiment, an optical recording film having light absorption and reflection is provided on the information recording surface (claim 2).

Further, according to the present invention, an optical information recording medium having a light absorbing / reflective optical recording film on an information recording surface is irradiated with a laser condensed beam to track a guide groove or an intermediate position between guide grooves. In the meantime, an information recording method is provided in which the signal of the pre-pit train is reproduced and information is recorded based on the reproduced signal.

〔Example〕

 Hereinafter, the present invention will be described in detail based on examples.

FIG. 1 shows a configuration example of the optical information recording medium according to the present invention. On one surface of the transparent substrate 1, between the guide grooves 3, 5, 7 and the guide grooves 2, 4, 6 are formed, and prepits 8, 9, 10, 11, 12 are provided. Is characterized in that the center line of the pre-pit row is displaced from the center line of the guide grooves 2, 4, and 6 to one of the right and left sides by approximately 1/4 of the interval x between the guide grooves. A light absorbing and reflecting recording film is formed on the surface where the guide grooves and the prepits are formed. As the recording film, a film known as an optical disk recording film such as a simple substance or an alloy film of a metal or a semimetal, an organic dye or a magneto-optical recording film can be used. The desired information is additionally recorded on the recording film between the guide grooves and between and between the guide grooves and both of the recording films by the laser condensing beam 16 in association with the information of the pre-pits (for example, address information). Good. The interval x between the guide grooves is preferably 1 to 3.5 times, more preferably 1.3 to 2.5 times the full width at half maximum of the laser condensed beam for detecting a track shift. Further, the depth of the guide groove is preferably about 1/16 to 1/5 times, particularly about 1/8 times the wavelength of the used laser beam. It is preferable that the width of the guide groove is equal to the width between the guide grooves, because the reproduced signals are uniform. The depth of the prepit is particularly preferably about twice the depth of the guide groove and about 1/4 times the wavelength of the laser beam used in order to obtain a contrast for signal detection. In the present invention, since the center line of the pre-pit row is arranged at the position shown in FIG. 1, it is possible to reproduce the signal of the pre-pit row regardless of whether tracking is performed on the guide groove or between the guide grooves.

The pre-pit (FIGS. 8, 9, 1) of the present invention
0, 11, and 12) are preferably uneven pits formed on the transparent substrate 1 because the productivity can be increased. After the light absorbing and reflecting recording film is formed, the additional recording is performed on the recording film. It may be a mark in which a change in optical characteristics such as a hole or a reflectance, or a mark recorded by magneto-optical recording.

In FIG. 1, a reflection film for increasing the reflectance can be provided on the surface on which the guide grooves and the prepits are formed. Providing a metal reflective film of gold, aluminum, or the like increases the reflectance and can increase the reproduction signal, so that it can be used as a read-only optical information recording medium. When a light absorbing / reflective recording film is provided, additional recording can be performed by irradiating an appropriate laser power stronger than that at the time of reproduction, by a thermal action or a photochemical action.

Particularly preferred is an optical information recording medium having a light absorbing and reflecting optical recording film on the information recording surface on which the guide grooves and prepits are formed. In such an optical information recording medium, pre-pit information can be reproduced, and based on the information, information can be additionally recorded, erased, or re-recorded in at least one of the guide grooves or the guide grooves. For example, if address information is recorded using pre-pits, it can be used for additional recording, erasing, and re-recording as information related to a specific address. Since this information can be reproduced, an easy-to-use and economical information storage device can be obtained.

Next, a method of recording information having twice the capacity of the related art using the above-described optical information recording medium will be described. By irradiating a laser focused beam onto an optical information recording medium having an optical recording film having light absorption and reflection properties, a signal in a pre-pit row is reproduced while tracking the guide groove or the middle of the guide groove, and based on the information, Then, additional recording is performed on an information track without prepits immediately after the prepit row. Next, if additional recording is performed in the same way while tracking either an unrecorded guide groove or the middle of the guide groove, additional recording can be performed twice on the information of the same pre-pit row, and the amount of information that can be additionally recorded Is twice the conventional value. Whether to track the guide grooves or to track between the guide grooves can be achieved by simply reversing the polarity during the tracking control, and by selecting the tracking polarity, the same pre-pit row of the same pre-pit row can be obtained. Even information can be reproduced separately.

〔The invention's effect〕

In the optical information recording medium according to the first aspect, since the pre-pit row is provided at the center between the guide grooves,
Since the pre-pit row can be reproduced regardless of the tracking between the guide groove and the guide groove, the reproduction reliability is high.

In the optical information recording medium according to claim 2, claim 1 is provided.
And the additional recording property, information can be recorded or reproduced in association with the information of the pre-pit row.

In the information recording method according to the third aspect, since two sets of information can be additionally recorded in association with the information of one pre-pit row, the recording capacity can be effectively increased.

[Brief description of the drawings]

FIG. 1 is a partial perspective sectional view showing the configuration of an optical information recording medium according to the present invention, and FIG. 2 is a partial perspective sectional view showing the configuration of a conventional optical information recording medium. 1 ... transparent substrate 2, 4, 6 ... between guide grooves (land portion) 3, 5, 7 ... guide grooves 8, 9, 10, 11, 12 ... prepit

Claims (3)

(57) [Claims] An optical information recording medium having a guide groove for tracking and a pre-pit row, wherein the distance between the guide grooves is x.
An optical information recording medium characterized in that the center line of the pre-pit row is displaced from the center line of the guide groove by approximately x / 4 to one of the left and right sides. 2. An optical information recording medium according to claim 1, further comprising an optical recording film having a light absorbing and reflecting property on an information recording surface. 3. The optical information recording medium according to claim 2,
An information recording method, comprising: irradiating a laser condensed beam and tracking a guide groove or an intermediate portion of the guide groove, reproducing a signal of the prepit row, and recording information based on the signal.