摘要:
An exposure apparatus of an optical disk master having a laser source, a deflector for deflecting a recording laser beam obtained based on the laser beam of the laser source and an objective lens for focusing the recording laser beam on an optical disk master, has a lens system provided between the laser source and the deflector, which has a first lens for focusing the laser beam and a second lens for adjusting the focused laser beam to a desired beam diameter; and a pinhole placed at a practical focal position of the lens system.
摘要:
Apparatus and method for exposing an optical disk master having a laser source, a deflector for deflecting a recording laser beam based on the laser beam of the laser source and an objective lens for focusing the recording laser beam on an optical disk master, including a liquid crystal plate provided between the laser source and the deflector, a parallel flat plate provided between the deflector and the objective lens, a photodetector that detects reflected light from the parallel flat plate, and an adjusting device for adjusting a voltage applied to the liquid crystal plate based on information on wavefront fluctuation of the recording laser beam detected by the photodetector.
摘要:
A method for exposing an optical disk master includes rotating a substrate disk coated with a photoresist, focusing a beam on the photoresist for exposure through an objective lens, and exposing the photoresist so as to form tracks on the substrate disk in its circumferential direction. At this time, the beam is deflected at least temporarily by passing through a deflector. The beam is divided into a first beam and a second beam after passing through the deflector, and the first beam is focused on the photoresist. A difference between the current position and the target position of an optical path of the second beam is detected, and the deflection operation of the deflector is corrected based on the difference so that the optical path of the second beam is located at the target position. This method can improve the track pitch accuracy of an optical disk having a narrow track pitch.
摘要:
An exposure apparatus of an optical disk master having a laser source, a deflector for deflecting a recording laser beam obtained based on the laser beam of the laser source and an objective lens for focusing the recording laser beam on an optical disk master, has a lens system provided between the laser source and the deflector, which has a first lens for focusing the laser beam and a second lens for adjusting the focused laser beam to a desired beam diameter; and a pinhole placed at a practical focal position of the lens system.
摘要:
An exposure apparatus of an optical disk master having a laser source, a deflector for deflecting a recording laser beam obtained based on the laser beam of the laser source and an objective lens for focusing the recording laser beam on an optical disk master, has a lens system provided between the laser source and the deflector, which has a first lens for focusing the laser beam and a second lens for adjusting the focused laser beam to a desired beam diameter; and a pinhole placed at a practical focal position of the lens system.
摘要:
An exposure apparatus of an optical disk master having a laser source, a deflector for deflecting a recording laser beam obtained based on the laser beam of the laser source and an objective lens for focusing the recording laser beam on an optical disk master, has a lens system provided between the laser source and the deflector, which has a first lens for focusing the laser beam and a second lens for adjusting the focused laser beam to a desired beam diameter; and a pinhole placed at a practical focal position of the lens system.
摘要:
A method for manufacturing an optical disk master includes: forming a resist layer by the application of a chemically amplified resist; converting an information signal into a multipulse signal having a symmetrical shape; exposing the resist layer in accordance with the multipulse signal; heat-treating the resist layer; and developing the resist layer to form signal pits. The signal pits are exposed to the multipulse signal, which is obtained by dividing a pulse into symmetrical pulses, thereby adjusting the exposure area and achieving a desired pit shape.
摘要:
A disk-shaped optical information recording medium (115) includes a substrate (101), first to nth information layers (102-104) layered upon the substrate (where n is an integer of 3 or more), kth intermediate layers (105, 106) provided between a kth information layer and a (k+1)th information layer (where k=1, 2, and so on up to n−1), and a protective layer (107) provided upon the nth information layer. The fluctuation range of the thicknesses from the protective layer surface (107a) to each of the information layers (102-104) is no more than ±3 μm relative to the average value of the thicknesses within a range from a radius of 23 mm to 24 mm from the center of the optical information recording medium.
摘要:
The recording/reproducing quality of a multilayer optical information recording medium deteriorate not only due to interference from other layers caused by light converging on other information layers but also due to stray light converging on the surface of a protective layer and stray light that does not converge on other information layers but rather returns to an optical head through the same optical path as the reproducing signal. The thickness composition of intermediate layers (106, 107, and 108) and the protective layer (109) in a four-layer optical information recording medium are set so as to eliminate the influence of interference caused by stray light from other layers reflected up to three times.
摘要:
The recording/reproducing quality of a multilayer optical information recording medium deteriorate not only due to interference from other layers caused by light converging on other information layers but also due to stray light converging on the surface of a protective layer and stray light that does not converge on other information layers but rather returns to an optical head through the same optical path as the reproducing signal. The thickness composition of intermediate layers (106, 107, and 108) and the protective layer (109) in a four-layer optical information recording medium are set so as to eliminate the influence of interference caused by stray light from other layers reflected up to three times.