Abstract: By avoiding the problem that in a hybrid optical disc, an optical pickup suitable for a standard-density recording area cannot operate as desired in a high-density recording area, damage to the disc drive or optical disc is prevented and optimal control is enabled. Access operation identification information such as reproducing identification information indicating whether or not information recorded in the user data area of the optical disc can be reproduced under the reproducing conditions of the optical disc driving apparatus is recorded in the lead-in area. The optical disc driving apparatus reads this type of access operation identification information, compares it with access operation identification information possessed by the optical disc driving apparatus, and if they do not correspond, does not carry out access operations by the optical head to the user data area, because reproducing or recording compatibility with the optical disc is lacking.

Abstract: By avoiding the problem that in a hybrid optical disc with a standard-density recording area and a high-density recording area, an optical pickup designed to be suitable for the standard-density recording area cannot operate as desired in the high-density recording area and may cause a malfunction, damage to the disc drive or optical disc is prevented and optimal control is enabled. Access operation identification information such as reproducing identification information 225 indicating whether or not information recorded in the user data area 222 of the optical disc can be reproduced under the reproducing conditions of the optical disc driving apparatus is recorded in the lead-in area 222.

Abstract: An object is to provide a frame number detecting device having a frame counter which is less apt to output a wrong frame number even if a sync signal type was erroneously detected from a DVD etc. and the combination of variation of the sync signal types corresponds to an existing frame number. A sync number encoding portion (6) specifies a read frame number and provides it as an output. First and second frame counters (7) and (13) run by themselves and output their count numbers. A state detecting counter (9) causes a state variable to go up/down according to whether a signal (S5) and a signal (S7) agree with each other. When the state variable is at its lowest value and the sync number encoding portion (6) was able to specify the frame number, the signal (S5) is reflected in the signal (S7). When the state variable has reached its highest value, the signal (S7) is reflected in a signal (S13).

Abstract: An object is to provide a frame number detecting device having a frame counter which is less apt to output a wrong frame number even if a sync signal type was erroneously detected from a DVD etc. and the combination of variation of the sync signal types corresponds to an existing frame number. A sync number encoding portion (6) specifies a read frame number and provides it as an output. First and second frame counters (7) and (13) run by themselves and output their count numbers. A state detecting counter (9) causes a state variable to go up/down according to whether a signal (S5) and a signal (S7) agree with each other. When the state variable is at its lowest value and the sync number encoding portion (6) was able to specify the frame number, the signal (S5) is reflected in the signal (S7). When the state variable has reached its highest value, the signal (S7) is reflected in a signal (S13).

Abstract: For recording data on and reproducing data from an optical disk of a single spiral land/groove configuration, a header detector detects header regions on the optical disk, a PID error detector judges whether the address information read from the header regions is erroneous, using error detection codes, and detects the number of errors per sector. An error count comparator compares the number of errors per sector with a predetermined value, and a state judging circuit identifies the state of the optical disk device by causing transition to a higher or lower state according to the output of the error count comparator. The recording and reproduction are controlled according to the state thus identified.

Abstract: In a device for controlling rotation of a disk, if a determination is made that a signal is not normally detected by a pre-pit-region detection circuit, an error signal is obtained from a pulse generator to control the rotation of the disk. If a determination is made that a signal is normally detected by the pre-pit-region detection circuit and if the synchronizing signals are not normally detected at predetermined intervals, an error signal is obtained from the wobble signal so that the rotations of the disk are controlled. If a determination is made that synchronizing signals are detected by the pre-pit-region detection circuit at predetermined intervals, an error signal is obtained from clocks synchronized with the reproduced signal generated by the PLL circuit so that rotations of the disk are controlled.

Abstract: A data recorder for recording data onto a record medium on which a sync signal is inserted at a given interval, has a sequence controller, wherein, after receiving the command from the system controller which triggers an initiation of a recording operation, the sequence controller activates the first encoder in response to a leading end signal of the encoded block from the sync signal set-up section, activates the first encoder and the second encoder in response to a leading end signal of the next encoded block, and activates the first encoder, the second encoder and the data reader in response to a leading end signal of the next following encoded block, and wherein, during the absence of the command from the system controller which triggers an initiation of a recording operation, the sequence controller deactivates the first encoder in response to a leading end signal of an encoded block from the sync signal set-up section, deactivates the first encoder and the second encoder in response to a leading end sig

Abstract: When a detected value of the signal processing speed from a frequency comparator is larger than a prescribed value input from an input terminal, the rotation control of a disk is switched from constant linear velocity control to constant angular velocity control using an error signal from an arithmetic unit. Alternatively, when a detected value of the rotational velocity from a frequency comparator is larger than a prescribed value input form an input terminal, the rotation control of the disk is switched from the constant angular velocity control into the constant linear velocity control.

Abstract: If a determination is made that a signal is not normally detected by the pre-pit-region detection circuit 53, an error signal is obtained from a pulse generator 58 to control the rotations of the disk 50. If a determination is made that a signal is normally detected by the pre-pit-region detection circuit 53 and if the synchronizing signals are not normally detected at predetermined intervals, an error signal is obtained from the wobble signal so that the rotations of the disk 50 are controlled. If a determination is made that synchronizing signals are detected by the pre-pit-region detection circuit 53 at predetermined intervals, an error signal is obtained from clocks synchronized with the reproduced signal generated by the PLL circuit 54 so that rotations of the disk 50 are controlled.