A light-absorbing material includes a compound represented by the formula (1) below. In the formula (1), L.sup.1 to L.sup.3 are each independently represented by the formula (2) or (3) below:

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A light-absorbing material includes a compound represented by the formula (1) below. In the formula (1), L.sup.1 to L.sup.3 are each independently represented by the formula (2) or (3) below:

##STR00001##

A method of recording data to a layer (101) of a recording medium in which an organic luminescent precursor composition is irradiated with a first light beam (103) and a second light beam (105), the first light beam having a write wavelength for conversion of the organic luminescent precursor composition to an organic luminescent composition and the second light beam having a write inhibition wavelength for inhibiting conversion of the organic luminescent precursor composition to the organic luminescent composition. The second light beam has a central area and a surrounding area; an intensity of the second light beam in the central area being lower than an intensity of the second light beam in the surrounding area. The first light beam extends across the central area and the surrounding area of the second light beam surrounds the first light beam.

A data recording device includes a recording medium, a control circuit configured to execute a read operation to read data from the recording medium or a write operation to write data on the recording medium, in response to a read or write request from an external device, and in accordance with one of a plurality of recording methods, a cache, a storage circuit configured to store a cache priority table in which a priority for storing read data or write data in the cache is set for each of the recording methods, and a cache control circuit configured to store the read data or the write data in the cache according to a priority set in the cache priority table for the read data and the recording method for the read data or for the write data and the recording method for the write data.

A data recording device includes a recording medium, a control circuit configured to execute a read operation to read data from the recording medium or a write operation to write data on the recording medium, in response to a read or write request from an external device, and in accordance with one of a plurality of recording methods, a cache, a storage circuit configured to store a cache priority table in which a priority for storing read data or write data in the cache is set for each of the recording methods, and a cache control circuit configured to store the read data or the write data in the cache according to a priority set in the cache priority table for the read data and the recording method for the read data or for the write data and the recording method for the write data.

An example operation may include one or more of receiving, by a validation node, a copy request from a user node over a blockchain network, the request contains a copy token, invoking, by the validation node, a smart contract associated with the copy token to verify the copy token, in response to a verification, generating, by the validation node, media copy keys for generation of a Blu-ray copy, and recording, by the validation node, the copy token on a ledger of the blockchain network to indicate that the copy token is spent.

An example operation may include one or more of receiving, by a validation node, a copy request from a user node over a blockchain network, the request contains a copy token, invoking, by the validation node, a smart contract associated with the copy token to verify the copy token, in response to a verification, generating, by the validation node, media copy keys for generation of a Blu-ray copy, and recording, by the validation node, the copy token on a ledger of the blockchain network to indicate that the copy token is spent.

An example operation may include one or more of receiving, by a validation node, a copy request from a user node over a blockchain network, the request contains a copy token, invoking, by the validation node, a smart contract associated with the copy token to verify the copy token, in response to a verification, generating, by the validation node, media copy keys for generation of a Blu-ray copy, and recording, by the validation node, the copy token on a ledger of the blockchain network to indicate that the copy token is spent.

An example operation may include one or more of receiving, by a validation node, a copy request from a user node over a blockchain network, the request contains a copy token, invoking, by the validation node, a smart contract associated with the copy token to verify the copy token, in response to a verification, generating, by the validation node, media copy keys for generation of a Blu-ray copy, and recording, by the validation node, the copy token on a ledger of the blockchain network to indicate that the copy token is spent.

An optical disc drive device includes a spindle motor that rotates an optical disc, an OPU, a first controller that causes the spindle motor and the OPU to read recorded data from the rotating optical disc, and an transmitter that transmits the read recorded data to a signal processing device disposed external to the optical disc drive device. The recorded data transmitted by transmitter is stored in a buffer provided in the signal processing device. The first controller decreases the rotational speed of the optical disc based on free space information indicating the free space of the buffer.