Information recording and reproducing device providing faster access time to a recording medium

An information recording and reproducing device employing a disk recording medium having pre-recorded information formed thereon, said pre-recorded information including rotation control information for controlling a disk rotation at a predetermined constant linear velocity, comprising:

• an optical head means for recording and reproducing information on said medium;
• rotation control means for controlling by CLV control the linear velocity of the recording medium relative to the optical head means;
• first recording clock generation means for generating a first recording clock for signal processing in a recording mode, which processing is performed at an actual linear velocity of the recording medium just after said optical head means reaches a target recording portion and is in synchronization with the pre-recorded information and for outputting digital pre-recorded information;
• second recording clock generation means for generating a second recording clock having a frequency which is responsive to the predetermined constant linear velocity;
• means for detecting a present address of the optical head means based on the digital pre-recorded information;
• switching means for alternatively selecting either the first recording clock or the second recording clock;
• and
• control means for controlling a switching operation based on distinctive information which determines whether information recorded on the recording medium is continuous or discrete and for starting the recording operation after detecting that the optical head means has reached a target address based on an output from the present address detection means.

A method for recording information on a recording medium having pre-recorded information formed thereon, said pre-recorded information including rotation control information for controlling a rotation of said medium at a constant linear velocity, comprising the steps of:

• (a) determining whether information to be recorded is analog information or digital information;
• (b) moving an optical head means to a target address;
• (c) controlling by CLV control the linear velocity of the recording medium relative to the optical head;
• (d) determining whether or not the optical head means has reached the target address by detecting a present address of the optical head means;
• (e) generating a first recording clock in synchronism with the pre-recorded information, said first reading clock having a frequency which is proportional to an actual linear velocity which said recording medium acquires when said optical head means reaches said target address;
• (f) generating a second recording clock having a determined reference frequency;
• (f) recording by using the second recording clock in the case of analog information, immediately after determining that the optical head means has reached the target address;
• and
• (h) recording by using the first recording clock in the case of digital information, immediately after determining that the optical head means has reached the target address.

An information recording and reproducing device having memory means for storing reproduced data which includes pre-recorded information for the purpose of absorbing a time based deviation of the reproduced data from a recording medium, wherein the reproduced data is written in the memory means using a writing clock in synchronization with the reproduced data from the recording medium, comprising:

• optical head means for recording and reproducing information on said recording medium;
• rotation control means for controlling by CLV control the linear velocity of the recording medium relative to the optical head means;
• means for amplifying and digitizing the reproduced data from said optical head means and for outputting a digital reproduced signal therefrom;
• pre-recorded information detection means for extracting the pre-recorded information from the digital reproduced signal;
• address detection means for detecting a present position of the optical head means based on the pre-recorded information thus extracted;
• first reading clock generation means for generating a first reading clock in synchronization with the reproduced data as a reading clock, said first reading clock having a frequency which is proportional to an actual linear velocity which said recording medium acquires when said optical head means reaches a target reproducing portion of said medium, said first reading clock being used for reading out the reproduced data from the memory means;
• second reading clock generation means for generating a second reading clock having a determined reference frequency;
• switching means for alternatively selecting either the first reading clock or the second reading clock as the reading clock;
• and
• control means for controlling a switching operation of said switching means based on distinctive information which determines whether information recorded on a determined area of the recording medium is successive or discrete.

A method for reproducing information recorded on a recording medium having pre-recorded information formed thereon, said pre-recorded information including rotation control information which is used to control a rotation to be reproduced at a predetermined constant linear velocity, comprising the steps of:

• (a) determining whether recorded information to be reproduced is analog information or digital information;
• (b) moving an optical head means to a target address;
• (c) controlling by CLV control the linear velocity of the recording medium relative to the optical head;
• (d) determining whether or not the optical head means has reached the target address by detecting a present address of the optical head means;
• (e) generating a first reference clock in synchronization with the pre-recorded information, said first reading clock having a frequency which is proportional to an actual linear velocity which said recording medium acquires when said optical head means reaches said target address;
• (f) generating a second reference clock having a determined reference frequency;
• (g) reproducing by using the second reading clock in the case of analog information, immediately after determining that the optical head means has reached the target address;
• and
• (h) reproducing by using the first reading clock in the case of digital information, immediately after determining that the optical head means has reached the target address.