Abstract: An installation assist apparatus according to an embodiment of the present disclosure includes hardware processor configured to: receive an input of installation positions of first and second optical wireless communication devices performing optical wireless communication and an input of an angle of elevation representing an inclination of an optical axis center line to a horizontal line, the optical axis center line connecting the first and second optical wireless communication devices; determine whether each of the first and second optical wireless communication devices is affected by solar light, the determination being carried out based on the installation positions of the devices, the angle of elevation, an influence angle representing a maximum value of an incident angle of solar light affecting the devices, and solar positions through a whole year; and cause a display device to display a result of the determination.

Abstract: An installation assist apparatus according to an embodiment of the present disclosure includes hardware processor configured to: receive an input of installation positions of first and second optical wireless communication devices performing optical wireless communication and an input of an angle of elevation representing an inclination of an optical axis center line to a horizontal line, the optical axis center line connecting the first and second optical wireless communication devices; determine whether each of the first and second optical wireless communication devices is affected by solar light, the determination being carried out based on the installation positions of the devices, the angle of elevation, an influence angle representing a maximum value of an incident angle of solar light affecting the devices, and solar positions through a whole year; and cause a display device to display a result of the determination.

Abstract: A rotary joint includes a fixed unit and a rotating unit arranged substantially orthogonal to a center axis and facing one another, as well as a substantially cylindrical light guide member arranged therebetween. A light-emitting device and a light-receiving device are provided on each of the units. The light guide member is configured such that an amount of the light from the light-emitting device on the fixed unit that is received by the light-receiving device on the rotating unit and an amount of the light from the light-emitting device on the rotating unit that is received by the light-receiving device on the fixed unit both exceed a prescribed minimum amount regardless of rotational positions of the rotating unit.

Abstract: A rotary joint includes a fixed unit and a rotating unit arranged substantially orthogonal to a center axis and facing one another, as well as a substantially cylindrical light guide member arranged therebetween. A light-emitting device and a light-receiving device are provided on each of the units. The light guide member is configured such that an amount of the light from the light-emitting device on the fixed unit that is received by the light-receiving device on the rotating unit and an amount of the light from the light-emitting device on the rotating unit that is received by the light-receiving device on the fixed unit both exceed a prescribed minimum amount regardless of rotational positions of the rotating unit.

Abstract: One object is to facilitate maintenance of an inspection apparatus for an optical recording disk. In accordance with one aspect, the present method includes: determining whether an inspection apparatus for inspecting recording conditions of an optical recording disk can be further used based on a divergence index correlated to divergence from a state where the inspection apparatus is calibrated or on a difference between the divergence index and a reference value of the divergence index; and, if it is determined that the inspection apparatus can be further used, setting authorization for inspecting the optical recording disk by the inspection apparatus. This method enables inspection of optical recording disks with ensured inspection performance of the inspection apparatus.

Abstract: Target levels in the PRML method are adaptively set under conditions of simplicity and a low cost. A method of setting a target level for reproduction of an optical information recording medium includes: a step of producing a reproduction signal from reflected light of laser light irradiated to an optical information recording medium; a step of performing waveform equalization processing, which depends on a predetermined partial response characteristic, on the reproduction signal to produce a waveform-equalized reproduction signal; a step of detecting peak levels for marks and spaces of a predetermined number of symbols from the waveform-equalized reproduction signal irrespective of a condition for a symbol adjoining each symbol; and a setting step of determining and setting values of a plurality of target levels, which is employed in Viterbi decoding and is arrayed with non-equal intervals among them, on the basis of a relative relationship among the detected peak levels.

Abstract: To ensure a favorable recording characteristic for a write-once recording medium for a bluish-purple laser, an optical information recording apparatus includes ways to write power to form recording marks, a space forming power to form spaces, a pulse width of a cooling pulse and ways to record information onto the optical information recording medium according to the setting of the write power, the setting of the space forming power and the setting of the pulse width of the cooling pulse. At this time, the pulse width of the cooling pulse and a ratio whose numerator is the write power and whose denominator is the space forming power have a preferable region of the recording characteristic, and information is recorded onto the optical recording medium by using values in this range.

Abstract: To ensure a favorable recording characteristic for a write-once recording medium for a bluish-purple laser, an optical information recording apparatus includes ways to write power to form recording marks, a space forming power to form spaces, pulse width of a cooling pulse and ways to record information onto the optical information recording medium according to the setting of the write power, the setting of the space forming power and the setting of the pulse width of the cooling pulse. At this time, the pulse width of the cooling pulse and a ratio whose numerator is the write power and whose denominator is the space forming power have a preferable region of the recording characteristic, and information is recorded onto the optical recording medium by using values in this range.

Abstract: In order to ensure a favorable recording characteristic for a write-once recording medium whose recording layer is made of an organic dye having an absorption spectrum at a wavelength ?=405 nm, this optical information recording apparatus includes a unit to set a write power to form recording marks, a space forming power to form spaces and a pulse width of a cooling pulse, and a unit to record information onto the recording medium according to the setting. The pulse width of the cooling pulse and a ratio of the space recording power to the write power are determined from a favorable region in a plane whose one coordinate axis represents the ratio and whose other coordinate axis represents the pulse width of the cooling pulse.

Abstract: An optical disc recording method includes: determining that an optical disc to be recorded is an optical disc including a recording layer comprising organic dye; and controlling a laser such that space formation power Ps necessary for space formation is equal to or smaller than bias power Pbw. In a case wherein the relation of Ps<Pbw is satisfied, the relation between the asymmetry value, ? value, and main power Pw includes substantial linearity. Accordingly, control of the main power Pw can be performed with the asymmetry value and ? value as evaluation indexes, and accordingly, disturbance or the like can be readily handled.

Abstract: Playback durability of a writable optical disk is ensured. A method of controlling a playback condition includes continuously irradiating an optical disk with a laser beam having a power level lower than a mark formation level and detecting a change of a state of a signal caused by a return light from the optical disk, and setting a playback condition for the optical disk according to the change of the state of the signal. The playback durability of the optical disk can be ensured by adaptively controlling the playback condition as stated above.

Abstract: There is disclosed a method of permitting recording setup information required to perform a test recording on an optical disk to be obtained from an external device as the need arises. The method comprises the steps of: measuring an evaluation index associated with recording characteristics with which data was recorded on the optical disk by an optical disk drive; making a decision as to whether the measured evaluation index indicates a state in which recording setup information used in data recording by the optical disk drive should be updated; acquiring recording setup information corresponding to at least the machine ID of the optical disk drive and the medium ID of the optical disk when the evaluation index is judged to indicate the state in which the recording setup information should be updated; and setting the acquired recording setup information in the optical disk drive.

Abstract: A recording condition approximate to the optimal is obtainable for a media even if unknown to the drive. A technique is provided that is effective for improving the signal quality, particularly, at a Wobble and Lpp. By regulating an intermediate pulse condition PWD, Tmp of a recording pulse configured with a top pulse, an intermediate pulse and a last pulse, the pit width W in a saturation code is controlled. The pit length and phase in the saturation code is controlled based on a front phase correction amount Ttop and rear phase correction amount Tlast.

Abstract: Novel evaluation indexes are introduced to allow both a total evaluation of data recording and an evaluation of individual detection patterns. A data recording evaluation method includes a step of reproducing a result of data recording performed on an optical disk and identifying a predetermined detection pattern in a reproduction signal, a step of detecting a signal state of the reproduction signal associated with the predetermined detection pattern, and a first calculation step for calculating a first evaluation index value based on the detected signal state and a reference state identified from the predetermined detection pattern. When there is a plurality of predetermined detection patterns as described above, a second calculation step is further provided for calculating a second recording state evaluation index value using the first evaluation index value calculated from each of the predetermined detection patterns.

Abstract: Correction of recording power is appropriately performed to an optical disk. The recording power correction method includes a step of temporarily stopping data recording into an optical disk, reproducing a result of the relevant data recording, and specifying a detection pattern including a predetermined code in a reproduction signal; a step of detecting a signal state in the reproduction signal corresponding to the detection pattern; and a determination step of determining at least a correction direction of recording power in the data recording based on the detected signal state and a reference state specified from the detection pattern. Processing is performed on the basis of the detection pattern in this way, thereby the method can cope with even a recording and reproduction system for optical disk employing the PRML signal processing method.

Abstract: A novel evaluation index is introduced so as to allow both a total evaluation of data recording and an evaluation of individual detection patterns. A data recording evaluation method includes a step of reproducing the result of data recording performed on an optical disk and identifying a predetermined detection pattern in a reproduction signal, a step of detecting the signal state of the reproduction signal corresponding to the predetermined detection pattern, and a first calculation step of calculating a first recording state evaluation index value based on the detected signal state and a reference condition which is identified from the predetermined detection pattern and adjusted so as to reflect the signal state of the reproduction signal.

Abstract: Target levels in the PRML method are adaptively set under conditions of simplicity and a low cost. A method of setting a target level for reproduction of an optical information recording medium includes: a step of producing a reproduction signal from reflected light of laser light irradiated to an optical information recording medium; a step of performing waveform equalization processing, which depends on a predetermined partial response characteristic, on the reproduction signal to produce a waveform-equalized reproduction signal; a step of detecting peak levels for marks and spaces of a predetermined number of symbols from the waveform-equalized reproduction signal irrespective of a condition for a symbol adjoining each symbol; and a setting step of determining and setting values of a plurality of target levels, which is employed in Viterbi decoding and is arrayed with non-equal intervals among them, on the basis of a relative relationship among the detected peak levels.

Abstract: In order to ensure a favorable recording characteristic for a write-once recording medium whose recording layer is made of an organic dye having an absorption spectrum at a wavelength ?=405 nm, this optical information recording apparatus includes a unit to set a write power to form recording marks, a space forming power to form spaces and a pulse width of a cooling pulse, and a unit to record information onto the recording medium according to the setting. The pulse width of the cooling pulse and a ratio of the space recording power to the write power are determined from a favorable region in a plane whose one coordinate axis represents the ratio and whose other coordinate axis represents the pulse width of the cooling pulse.

Abstract: It is an object of the present invention to provide a recording condition closer to an optimum even for a medium unknown to a drive, and more particularly to provide a method especially effective when applied to code identification methods, such as PRML, wherein codes are identified based on amplitude information of an RF signal. In order to accomplish the object, an RF signal received from a photo-receiving part 108 of a pickup is converted into sampling data by an A/D converter 300, and a Viterbi decoder 302 performs code determination using the sampling data. Codes included in a reproduction signal are then determined by synchronizing recording pulses with the reproduction signal using the result of the code determination. Then, the result is used to specify a part to be detected in the codes, and finally an amplitude of the specified part is detected.

Abstract: An optical information recording reproduction device is disclosed, in which aberration detection is stably performed, so that an excellent record grade can be achieved. An RF signal is subjected to differential operation along a time axis of the signal, the RF signal being obtained from reflected light including primary light situated in the periphery of a primary dark ring enclosing zero-order light in a central portion of a beam spot formed on a pit; pulse signal waveforms are represented in an absolute value form, the pulse signal waveforms being generated in correspondence with front and rear ends of the beam spot on the time axis; the pulse signal waveforms represented in the absolute value form are stored into a storage medium; the stored, two pulse signal waveforms are combined to generate a beam profile of the beam spot formed on an optical recording medium; and a beam spot diameter, spherical aberration, and coma aberration of a record laser beam are adjusted based on the beam profile.