Playback system for an optical disc representing a character or a graphic pattern formed by specified pit patterns

A play back system for playing back data recorded on a rotational type information recording medium comprising:

• a motor which rotates an information recording medium mounted on the system;
• a pickup which reads out data from said information recording medium to output a reproduction signal;
• an apparatus which moves said pickup over said information recording medium;
• a processing unit which demodulates the reproduction signal read out from said information recording medium;
• and
• a controller which outputs the demodulated signal and controls operations of said pickup and said motor;
• wherein said controller includes a memory for storing therein positional information, with respect to said information recording medium to be played back, which is indicative of a position of a region provided at, at least one of an outer peripheral side of a lead-out area indicating an end position of a data recording area and an inner peripheral side of a lead-in area indicating a start position of said data recording area, for recording specific data in said region;
• said controller being operative to control reading out of the positional information stored in said memory when said information recording medium is mounted on the system, to have said pickup access said region storing said specific data, and to suspend further playback of the system upon failure of reading out of said data from said region.

A play back system for playing back data recorded on a rotational type information recording medium comprising:

• a motor which rotates an information recording medium mounted on the system;
• a pickup which reads out data from said information recording medium to output a reproduction signal;
• a circuit for controlling the rotation of said motor to rotate at a given rotating speed;
• an apparatus which moves said pickup over said information recording medium;
• a processing unit which demodulates the production signal read out from said information recording medium;
• and
• a controller which outputs the demodulated signal and controls the operation of said pickup and said motor;
• wherein said controller includes a memory for storing therein positional information, with respect to said information recording medium to be played back, which is indicative of a position of a region provided at, at least one of an outer peripheral side of a lead-out area indicating an end position of a data recording area and an inner peripheral side of a lead-in area indicating a start position of said data recording area, for recording specific data in said region;
• said controller being operative to control reading out of the positional information stored in said memory when said information recording medium is mounted on the system, and to have said pickup access at least two tracks in said region storing said specific data, and to compare rotation speeds of said information recording medium when accessing said at least two tracks to each other to determine a recording method of said data in said region, and to suspend further playback of the system, when the recording method of said data thus determined does not agree with a predetermined recording method.

A playback system for playing back an optical disc comprising:

• rotation means for rotating an optical disc mounted on the system;
• an optical pickup which traces tracks of the optical disc and detects pit patterns formed on the tracks;
• rotation control means which controls the rotating speed of said rotation means so that a fixed frequency is detected with respect to the pit pattern;
• rotation speed detecting means for detecting the rotating speed of said rotation means;
• a memory for storing therein positional information, with respect to said optical disc, which is indicative of a position of a region provided at, at least one of an outer peripheral side of a lead-out area indicating an end position of a data recording area and an inner peripheral side of a lead-in area indicating a start position of said data recording area, for recording specific data in the region;
• means for accessing at least two tracks in said region specified by said positional information stored in said memory;
• means for comparing rotation speeds of the motor when accessing said at least two tracks which are detected by said rotation speed detection means, and means for determining, based on the result of the comparison, whether or not the data in the region specified by said positional information stored in said memory is recorded based on a predetermined recording method;
• and
• means for suspending further playback of the optical disc when it is determined that the data in the region specified by the positional information stored in said memory is not recorded in the predetermined recording method.

A play back system for playing back data recorded on a rotational type information recording medium comprising:

• a device which rotates an information recording medium mounted on the system and which reproduces data from a specified region of the information recording medium;
• a controller controls the operation of the device for reproducing the data;
• wherein said controller includes a memory for storing therein positional information, with respect to the information recording medium to be played back, which is indicative of a position of a region provided at, at least one of an outer peripheral side of a lead-out area indicating an end position of a data recording area and an inner peripheral side of a lead-in area indicating a start position of said data recording area, for recording specific data in the region;
• said controller being operative to control reading out of the positional information stored in said memory when said information recording medium is mounted on the system, and to have the reproducing device to read out data from the region storing the specific data, and to suspend further playback of the system upon failure of reading out of the specific data from said region by the playback device.