Abstract: A defocus adjustment method includes a step of storing in a memory a range of defocus values for smooth operation of an optical disc apparatus, a step of measuring the defocus value of the optical disc loaded in the optical disc apparatus, a step of comparing the defocus value and the range of defocus values, a step of determining the optimal defocus value, and a step of using the optimal defocus value as a focusing bias value. This helps easily and quickly perform defocus adjustment that suits the loaded optical disc. Using as a focus bias value the defocus value determined through the defocus adjustment helps enhance the quality with which data is read from and data is written to the optical disc.

Abstract: In a processing section 4, allowable gain-value range defining unit 41 measures a gain value k corresponding to a level ratio between an MPP signal and an SPP signal generated by a tracking error signal generating circuit 3 to define an allowable range of the gain value, and eccentricity measuring unit 42 measures an eccentricity of an optical disk. If the eccentricity is determined to be greater than or equal to a predetermined value by eccentricity determining unit 43, gain-value defining unit 44 selects a minimum value of the gain value k to define the minimum value as a gain value k of an amplifier 37. On the other hand, if the eccentricity is determined to be less than the predetermined value, the gain-value defining unit 44 selects a central value of the gain value k to define the central value as the gain value k of the amplifier 37.

Abstract: A defocus adjustment method includes a step of storing in a memory a range of defocus values for smooth operation of an optical disc apparatus, a step of measuring the defocus value of the optical disc loaded in the optical disc apparatus, a step of comparing the defocus value and the range of defocus values, a step of determining the optimal defocus value, and a step of using the optimal defocus value as a focusing bias value. This helps easily and quickly perform defocus adjustment that suits the loaded optical disc. Using as a focus bias value the defocus value determined through the defocus adjustment helps enhance the quality with which data is read from and data is written to the optical disc.

Abstract: With conventional test discs, changing them takes much time when a pickup is subjected to signal evaluation with respect to DVD- family discs (DVD-R and DVD-RW) and DVD+ family discs (DVD+R and DVD+RW), leading to low testing efficiency. A test disc of the invention has, formed on a single glass substrate, areas where there are provided regions where pits or no pits are formed and areas where there are provided regions where wobbles and land prepits are formed with varying parameters.

Abstract: In an optical disc apparatus, a loading operation and an unloading operation are performed a plurality of times while changing the movement speed of a tray. A movement speed of the tray at which a shock that is produced during a movement of the tray is smaller than an upper limit, and a time period required for the loading operation and the unloading operation is shortest is determined as the movement speed of the tray in the loading operation and the unloading operation. An optical disc placed on the tray can be prevented from being damaged by a shock produced during a movement of the tray, and the time period required for the loading operation and the unloading operation can be prevented from being prolonged.

Abstract: An evaluation disc for use in evaluating a pickup head of an optical disc device, including: an inner circular region: an intermediate circular region; and an outer circular region; wherein the outer circular region and the intermediate circular region are formed on the outer side of the inner circular region; the outer circular region is formed on the outer side of the intermediate circular region; each of the inner circular region, the intermediate circular region and the outer circular region being divided in to a CD evaluation region written with CD standard recording information and a DVD evaluation region written with DVD standard recording information.

Abstract: In a processing section 4, allowable gain-value range defining unit 41 measures a gain value k corresponding to a level ratio between an MPP signal and an SPP signal generated by a tracking error signal generating circuit 3 to define an allowable range of the gain value, and eccentricity measuring unit 42 measures an eccentricity of an optical disk. If the eccentricity is determined to be greater than or equal to a predetermined value by eccentricity determining unit 43, gain-value defining unit 44 selects a minimum value of the gain value k to define the minimum value as a gain value k of an amplifier 37. On the other hand, if the eccentricity is determined to be less than the predetermined value, the gain-value defining unit 44 selects a central value of the gain value k to define the central value as the gain value k of the amplifier 37.

Abstract: In an optical disc apparatus, loading operation and an unloading operation are performed a plurality of times while changing the movement speed of a tray. A movement speed of the tray at which a shock that is produced during a movement of the tray is smaller than an upper limit, and a time period required for the loading operation and the unloading operation is shortest is determined as the movement speed of the tray in the loading operation and the unloading operation. An optical disc placed on the tray can be prevented from being damaged by a shock produced during a movement of the tray, and the time period required for the loading operation and the unloading operation can be prevented from being prolonged.

Abstract: When a MD is inserted (step S1), AGC is executed for reading the TOC area of the MD 1, and thereafter the information stored in the TOC area of the MD are read to detect the kind and recording capacity, etc. of the MD (step S2, S3). Next, the data relative to the executing position of AGC corresponding to the kind of the detected MD is read out from the memory (step S4). Now, where the MD is of a pre-mastered type, according to the recording capacity, either the first executing position P1 or the second executing position P2 is read as occasion demands. On the other hand, where the MD is of the recordable type, two AGC executing positions of the first executing position R1 in a pit area and the second executing position R2 in a groove area are read out. At each of the executing positions thus read out, the AGC is executed (step S5).