Abstract: According to one embodiment, a display apparatus includes a generation unit and a presentation unit. The generation unit is configured to generate a CG image in a CG space having a coordinate system corresponding to a scene viewed from a view point of an observer. The CG image represents a target to be perceived by the observer. The presentation unit is configured to present the CG image to at least one eye of the observer. The generation unit generates a plurality of CG images of the target advancing to a specific coordinate in the CG space and going back from the specific coordinate based on a velocity of the vehicle. The target is perceived by the observer so that the target is advancing from of the vehicle to a specific location corresponding to the specific coordinate in the scene and stops at the specific location for a specific time.

Abstract: According to one embodiment, an optical element includes a first optical sheet having a first major surface. The first optical sheet includes a first Fresnel lens provided in the first major surface. An optical axis of the first Fresnel lens at the first major surface is disposed at a position different from a position of a center of an outline of the first major surface.

Abstract: An optical disc apparatus includes: an obtaining unit obtaining a sensitivity coefficient indicating a relation between a light power of a semiconductor laser and a monitor value; a first deriving unit deriving a first monitor value in setting the light power at a peak power; a second deriving unit deriving a second monitor value in setting the light power at an erase power; a converting unit converting the first and the second monitor values into first and second light power values based on the sensitivity coefficient; a first calculating unit calculating a ratio between the first and the second light power values; a second calculating unit calculating a correction coefficient based on a setting value of a ratio between the peak power and the erase power and a calculation value of the ratio between the first and the second light power values; and a correcting unit correcting the light power of the semiconductor laser based on the correction coefficient.

Abstract: An optical disc apparatus includes: an obtaining unit obtaining a sensitivity coefficient indicating a relation between a light power of a semiconductor laser and a monitor value; a first deriving unit deriving a first monitor value in setting the light power at a peak power; a second deriving unit deriving a second monitor value in setting the light power at an erase power; a converting unit converting the first and the second monitor values into first and second light power values based on the sensitivity coefficient; a first calculating unit calculating a ratio between the first and the second light power values; a second calculating unit calculating a correction coefficient based on a setting value of a ratio between the peak power and the erase power and a calculation value of the ratio between the first and the second light power values; and a correcting unit correcting the light power of the semiconductor laser based on the correction coefficient.

Abstract: A method for manufacturing an optical disc apparatus including: reading by an optical pickup head a medium on which signals are recorded with appropriate optical power; leading an RF signal corresponding to the recorded signal obtained from the medium by the reading by the optical pickup head to a ? value calculation circuit and calculating a ? value; and storing the calculated ? value as a circuit offset into a circuit offset storage section, and an optical disc apparatus thus manufactured are disclosed.

Abstract: A data writing method includes recording test data to a test writing area of an optical disc at a plurality of test recording power values, reproducing the test data, obtaining an asymmetry values for each the test recording power values on the basis of reproduction signals of the test data, obtaining a recording power value characteristics of the asymmetry values, determining a recording power value according to the recording power value characteristics, writing a write data into a program area of the optical disc on the basis of the recording power value, interrupting writing the write data, reproducing at least part of recorded written data before the interruption, obtaining an asymmetry value on the basis of reproduction signals of the recorded written data, updating the recording power value according to the asymmetry value, and resuming writing the write data from the interrupted position according to the recording power value.

Abstract: A method of determining a recording power, includes carrying out DC erase with respect to a power calibration area of a phase-change optical disc, recording data to with respect to the power calibration area carrying out the DC erase while changing recording power, reading the recorded data to obtain a read signal, and determining an optimum recording power based on the read signal.

Abstract: A method for manufacturing an optical disc apparatus including: reading by an optical pickup head a medium on which signals are recorded with appropriate optical power; leading an RF signal corresponding to the recorded signal obtained from the medium by the reading by the optical pickup head to a ? value calculation circuit and calculating a ? value; and storing the calculated ? value as a circuit offset into a circuit offset storage section, and an optical disc apparatus thus manufactured are disclosed.