Abstract: It is an object of the present invention to provide an optical pickup astigmatism adjusting method capable of easily correcting an astigmatism even if the spot shape of a light beam converged on an optical disc is not a true circle. An optical pickup astigmatism adjusting system of the present invention finds an inter-focal distance L0 between a focal position where a light beam is converged in RAD direction and another focal position where a light beam is converged in TAN direction, and a further inter-focal distance L45 between a focal position where a light beam is converged in a direction inclined 45 degrees from RAD direction and another focal position where a light beam is converged in a direction inclined 45 degrees from TAN direction, thereby measuring an astigmatism in accordance with the inter-focal distances L0 and L45. Then, an installation angle of a reflection mirror is adjusted in accordance with the inter-focal distances L0 and L45, thus correcting the astigmatism.

Abstract: It is an object of the present invention to adjust the focus position of an optical pickup. A brightness measuring apparatus having a half mirror and an objective lens focusing on the half mirror is disposed at a position facing an optical pickup PUi, in a manner such that the objective lens OB of the optical pickup PUi faces the half mirror. Then, the optical pickup PUi is operated to start a focus servo, while the position of multi-lens provided in the optical pickup PUi is changed continuously, thereby measuring a highest brightness of a spot light image incident on the half mirror through the objective lens, by virtue of the brightness measuring apparatus. Subsequently, a highest brightness change caused by changing the position of the multi-lens ML is inspected so as to fix the multi-lens ML at a position when the maximum highest brightness has been obtained, thereby effecting an optimum focus position adjustment for an optical pickup.

Abstract: It is an object of the present invention to provide an optical pickup astigmatism adjusting method capable of easily correcting an astigmatism even if the spot shape of a light beam converged on an optical disc is not a true circle. An optical pickup astigmatism adjusting system of the present invention finds an inter-focal distance L0 between a focal position where a light beam is converged in RAD direction and another focal position where a light beam is converged in TAN direction, and a further inter-focal distance L45 between a focal position where a light beam is converged in a direction inclined 45 degrees from RAD direction and another focal position where a light beam is converged in a direction inclined 45 degrees from TAN direction, thereby measuring an astigmatism in accordance with the inter-focal distances L0 and L45. Then, an installation angle of a reflection mirror is adjusted in accordance with the inter-focal distances L0 and L45, thus correcting the astigmatism.

Abstract: It is an object of the present invention to adjust the focus position of an optical pickup. A brightness measuring apparatus having a half mirror and an objective lens focusing on the half mirror is disposed at a position facing an optical pickup PUi, in a manner such that the objective lens OB of the optical pickup PUi faces the half mirror. Then, the optical pickup PUi is operated to start a focus servo, while the position of multi-lens provided in the optical pickup PUi is changed continuously, thereby measuring a highest brightness of a spot light image incident on the half mirror through the objective lens, by virtue of the brightness measuring apparatus. Subsequently, a highest brightness change caused by changing the position of the multi-lens ML is inspected so as to fix the multi-lens ML at a position when the maximum highest brightness has been obtained, thereby effecting an optimum focus position adjustment for an optical pickup.