Recording device, recording method, and optical recording medium

Abstract

Void recording can be stably performed at a lower laser power than the laser power of a conventional void recording method wherein a void mark (void) is recorded in a bulk layer. With respect to an optical recording medium formed by a plurality of resin layers, a first beam is focused on and irradiated to a boundary surface of the resin layers, to thereby record a void mark on the boundary surface. Because recording sensitivity of the void mark is increased at the boundary surface of the resin layers, the laser power necessary for recording can be suppressed at a low level compared to the prior art by performing the void mark recording on the boundary surface as aforementioned. Therefore, without the need of using a special laser such as a short pulse laser, and even when a CW laser (CW: Continuous Wave) is used, sacrificing the recording speed is not necessary. The drawbacks of the conventional void recording method can be compensated for, and as a result, the possibility of realizing a large capacity recording medium as a bulk-type recording medium can be increased.

Description

technical field [0001] The present invention relates to a recording device for recording a signal onto / from an optical recording medium, a recording method thereof, and an optical recording medium in which a signal is recorded / reproduced by light irradiation. [0002] Patent Document 1: Japanese Patent Application Publication No. 2008-135144 [0003] Patent Document 2: Japanese Patent Application Publication No. 2008-176902 Background technique [0004] As optical recording media on / from which signals are recorded / reproduced by light irradiation, so-called optical discs such as CD (Compact Disc), DVD (Digital Versatile Disc) and BD (Blu-ray Disc: registered trademark) are widely used. . [0005] Regarding next-generation optical recording media following currently popular optical recording media such as CD, DVD, and BD, as disclosed in the above Patent Documents 1 and 2, the applicant has proposed a so-called block recording type optical recording medium. [0006] Here, b...

AI Technical Summary

Problems solved by technology

In other words, if Figure 11 As shown in (a), although in the positive micro-holography technique, recording marks (holograms) are formed by converging opposing light fluxes A and B at one position, the control of two light irradiation positions requires extremely high precision

[0017] As described above, since extremely high positional control accuracy is required, it is technically difficult to realize the positive-type micro-holography technology, and even if the technology is realized, the manufacturing cost of the device increases

Therefore, positive microholography is not a viable technology

[0018] In addition, there is a problem that pre-recording initialization processing is required in negative micro-holography

[0019] Furthermore, in particular, as Figure 12 As shown, in the case of performing initialization processing using parallel light, there is a problem that the initialization light requires extremely high power and it is difficult to form fine recording marks (deletion marks).

[0020] Specifically, based on the reference Figure 11 (a) The principle of the described positive-type micro-hologram, in the initialization process, two light fluxes should initially converge at the same position, but when the initialization process is performed by making the two light fluxes converge as described above, the initialization process requires is executed a number of times corresponding to the set number of layers, which is impractical

In this regard, the processing time is shortened by using parallel light as described above, but for forming interference fringes using parallel light as described above, extremely large power is required compared to the case of using the converging light technique as described above

In this regard, the recording sensitivity of the block layer 102 can also be improved, but in this case, it is extremely difficult to form fine marks

[0021] It can be understood from these points that it is extremely difficult to achieve negative micro-holographic technology

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