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.

A device for detecting light includes a photoreceptor array that is sensitive to the visible light spectrum and has a first wavelength sensor, a second wavelength sensor, and a third wavelength sensor. The first wavelength sensor has a first peak sensitivity at a first wavelength. The second wavelength sensor has a second peak sensitivity at a second wavelength. The third wavelength sensor has a third peak sensitivity at a third wavelength. The first wavelength sensor has a first base sensitivity at least 30% of the first peak sensitivity at the second wavelength and third wavelength. The second wavelength sensor has a second base sensitivity at least 30% of the second peak sensitivity at the first wavelength and third wavelength. The third wavelength sensor has a third base sensitivity at least 30% of the third peak sensitivity at the first wavelength and second wavelength.

A device for detecting light includes a photoreceptor array that is sensitive to the visible light spectrum and has a first wavelength sensor, a second wavelength sensor, and a third wavelength sensor. The first wavelength sensor has a first peak sensitivity at a first wavelength. The second wavelength sensor has a second peak sensitivity at a second wavelength. The third wavelength sensor has a third peak sensitivity at a third wavelength. The first wavelength sensor has a first base sensitivity at least 30% of the first peak sensitivity at the second wavelength and third wavelength. The second wavelength sensor has a second base sensitivity at least 30% of the second peak sensitivity at the first wavelength and third wavelength. The third wavelength sensor has a third base sensitivity at least 30% of the third peak sensitivity at the first wavelength and second wavelength.

A nonlinear light absorption material includes a compound represented by the following formula (1) as a main component:

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in the formula (1), R.sup.1 to R.sup.10 are each independently a hydrogen atom, a halogen atom, a saturated hydrocarbon group, a halogenated alkyl group, an unsaturated hydrocarbon group, a hydroxyl group, a carboxyl group, an alkoxycarbonyl group, an aldehyde group, an acyl group, an amide group, a nitrile group, an alkoxy group, an acyloxy group, a thiol group, an alkylthio group, a sulfonate group, an acylthio group, an alkylsulfonyl group, a sulfonamide group, a primary amino group, a secondary amino group, a tertiary amino group, or a nitro group.

There is provided a method of producing a multilayer optical recording medium through which the occurrence of burrs is reduced. The method of producing a multilayer optical recording medium includes, when a UV curable adhesive is interposed between a first disk and a second disk, the first disk and the second disk are rotated, and when at least one of the vicinities of inner circumferential edges and the vicinities of outer circumferential edges of the first disk and the second disk is masked with a mask member, emitting ultraviolet rays for preliminarily curing the UV curable adhesive from the side of a light emission surface of the first disk during rotation.

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.

A device for detecting light includes a photoreceptor array that is sensitive to the visible light spectrum and has a first wavelength sensor, a second wavelength sensor, and a third wavelength sensor. The first wavelength sensor has a first peak sensitivity at a first wavelength. The second wavelength sensor has a second peak sensitivity at a second wavelength. The third wavelength sensor has a third peak sensitivity at a third wavelength. The first wavelength sensor has a first base sensitivity at least 30% of the first peak sensitivity at the second wavelength and third wavelength. The second wavelength sensor has a second base sensitivity at least 30% of the second peak sensitivity at the first wavelength and third wavelength. The third wavelength sensor has a third base sensitivity at least 30% of the third peak sensitivity at the first wavelength and second wavelength.

A device for detecting light includes a photoreceptor array that is sensitive to the visible light spectrum and has a first wavelength sensor, a second wavelength sensor, and a third wavelength sensor. The first wavelength sensor has a first peak sensitivity at a first wavelength. The second wavelength sensor has a second peak sensitivity at a second wavelength. The third wavelength sensor has a third peak sensitivity at a third wavelength. The first wavelength sensor has a first base sensitivity at least 30% of the first peak sensitivity at the second wavelength and third wavelength. The second wavelength sensor has a second base sensitivity at least 30% of the second peak sensitivity at the first wavelength and third wavelength. The third wavelength sensor has a third base sensitivity at least 30% of the third peak sensitivity at the first wavelength and second wavelength.

To realize efficient access in case of restoring read failure data by RMW at time of data rewriting, a recording apparatus includes a write/read unit capable of performing data writing in a second data unit, in which a plurality of first data units of a predetermined amount of data are consecutive, and data reading in the first data unit with respect to a recording medium and a control unit. In response to a rewrite instruction of data, the control unit instructs the write/read unit to generate write data in the second data unit using update data relevant to the rewrite instruction and recorded data read out from the recording medium and to write the write data at a non-recording address on the recording medium, and generates or updates replacement information for associating address at which the write data is written, as a replacement destination, with address of a replacement source.

To realize efficient access in case of restoring read failure data by RMW at time of data rewriting, a recording apparatus includes a write/read unit capable of performing data writing in a second data unit, in which a plurality of first data units of a predetermined amount of data are consecutive, and data reading in the first data unit with respect to a recording medium and a control unit. In response to a rewrite instruction of data, the control unit instructs the write/read unit to generate write data in the second data unit using update data relevant to the rewrite instruction and recorded data read out from the recording medium and to write the write data at a non-recording address on the recording medium, and generates or updates replacement information for associating address at which the write data is written, as a replacement destination, with address of a replacement source.