Information recording medium disc and method and apparatus for recording/reproducing information using the disc

Claim 5

A method of recording information as claimed in claim 2, further comprising the steps of: (a) putting said record head in stand by state, when a further piece of main information is to be recorded, so that light beam therefrom is located at a portion where said cumulative time data is pre-recorded on said RAM track over several revolutions of said disc; and (b) recording said further piece of main information by said record head on said RAM track in said main signal recording area together with a chapter number assigned to a piece of information to be recorded and with cumulative time data read out from said ROM track adjacent to said RAM track so that said further piece of main information is recorded at a place following a newest piece of main information recorded while said cumulative time data of recorded together with said further piece of main information represents time which continues from time represented by cumulative time data recorded together with the newest piece of main information.

Claim 6

A method of recording information as claimed in claim 3, further comprising the steps of: (a) recording cumulative time data read out from said ROM track adjacent to said RAM track, on said RAM track over several revolutions of said disc when recording of said main signal is interrupted; (b) recording lead-out signal in said RAM track at a portion subsequent to said cumulative time data; (c) shifting said record head so that a light beam therefrom is directed to said lead-in signal area; and (d) recording lead-in information, in said RAM track in said lead-in signal area, corresponding to said chapter number and said cumulative time data of said piece of information just recorded in said RAM track in said main signal recording area.

Claim 7

A method of recording information as claimed in claim 2, further comprising a step of: performing tracking control operation for said recording method by tracing two of said ROM tracks at both sides of said RAM track on which said main information is to be recorded or pre-recorded main information is to be reproduced therefrom, said tracking control operation being performed by using two laser light spots while recording and/or reproducing said main information on and from said RAM track being performed using one laser light spot arranged at the middle of said two laser light spots, said three laser light spots being arranged in line in a direction having a given angle with respect to said RAM track so that one of said two laser light spots, which spot precedes said laser light spot used for recording and/or reproducing said main information relative to disc movement, is used for reading out said synchronous signal and said cumulative time data and so that preceding light spot is positioned closer to an area in which the information signal is to be recorded than the other of said two laser light spots.

Claim 8

A method of recording information as claimed in claim 5, further comprising a step of: (a) reproducing pre-recorded main information from said main track; and (b) reducing the intensity of three laser light beams producing said three laser light spots when said reproducing said pre-recorded main information so that the intensity is lower than that used for recording main information.

Claim 9

A method of recording information as claimed in claim 2, further comprising the step of: recording only lead-out signal in said RAM track in said lead-out signal area when said lead-out signal is read out from said ROM track adjacent to said RAM track.

Claim 10

Apparatus for recording and/or reproducing information on an information recording disc having a recording layer in which information can be recorded repeatedly with pre-recorded information being erased, said recording layer having a spiral guide track formed in the form of geometrical variation so as to carry at least a synchronous signal and cumulative time data indicative of the lapse of time during either recording or reproducing from a predetermined point on said recording layer, said spiral guide track functioning as a ROM track being formed such tat a portion between adjacent spiral guide tracks is a flat land area which is used as a spiral RAM track for recording and/or reproducing information, said recording layer having a lead-in signal area, a main signal recording area, and a lead-out signal area, said cumulative time data being included in said ROM track in said lead-in signal area and said main signal recording area, said lead-out signal area including a lead-out signal indicating an end of said recording layer, said main signal recording area being interposed between said lead-in signal area and said lead-out signal area, said apparatus comprising: (a) disc drive means for rotating said information recording disc at a constant linear velocity using a synchronous signal; (b) record and/or reproduce head means for applying laser light beams to said disc so that three laser light spots are directed to said recording layer of said disc for writing and reading main information on and from said RAM track using one of said three laser light spots and for reading, during writing and reading of said main information, information from two adjacent ROM tracks on both sides of said RAM track used for writing or reading using remaining two laser light spots, said three laser light spots being arranged in line in a direction having a given angle with respect to said RAM track so that one of said two laser light spots, which spot precedes said laser light spot used for recording and/or reproducing said main information relative to disc movement, is used for reading out said synchronous signal and said cumulative time data, said record and/or reproduce head having a plurality of photosensitive elements responsive to light rays reflected at said recording layer of said disc at said three laser light spots, at least two of said photosensitive elements which are responsive to reflected light rays from said remaining two laser light spots producing tracking signals by reading the same from said two ROM tracks, while one of said two photosensitive elements producing synchronous signal and cumulative data by reading the same from one of said two said ROM tracks; (c) shifting means for shifting said record and/or reproduce head to place said three laser light spots at desired positions; (d) tracking control circuit responsive to said tracking signals from said record and/or reproduce head means for performing tracking control; (e) record and/or reproduce circuit means for processing a recording signal to be applied to said record and/or reproduce head and a reproduced signal from said record and/or reproduce head; (f) control means for controlling said motor drive means, said record/and/or reproduce head, said shifting means, said tracking control circuit, said record and/or reproduce circuit means so as to record and/or reproduce information on and from said disc at desired positions, said control means having a memory for storing chapter number and cumulative time data both read out from said ROM track in said lead-in signal area for controlling said shifting means when such number and data are pre-recorded; and (g) means within said control means for reading said cumulative time data from said ROM track adjacent to said RAM track and for recording said cumulative time data on said RAM track.

Claim 11

Apparatus for recording and/or reproducing information on an information recording disc having a recording layer in which information can be recorded repeatedly with pre-recorded information being erased, said recording layer having a spiral guide track formed in the form of geometrical variation so as to carry at least a synchronous signal and cumulative time data indicative of the lapse of time during either recording or reproducing from a predetermined point on said recording layer, said spiral guide track functioning as a ROM track being formed such tat a portion between adjacent spiral guide tracks is a flat land area which is used as a spiral RAM track for recording and/or reproducing information, said recording layer having a lead-in signal area, a main signal recording area, and a lead-out signal area, said cumulative time data being included in said ROM track in said lead-in signal area and said main signal recording area, said lead-out signal area including a lead-out signal indicating an end of said recording layer, said main signal recording area being interposed between said lead-in signal area and said lead-out signal area, said apparatus comprising: (a) disc drive means for rotating said information recording disc at a constant linear velocity using a synchronous signal; (b) record and/or reproduce head means for applying laser light beams to said disc so that three laser light spots are directed to said recording layer of said disc for writing and reading main information on and from said RAM track using one of said three laser light spots and for reading, during writing and reading of said main information, information from two adjacent ROM tracks on both sides of said RAM track used for writing or reading using remaining two laser light spots, said three laser light spots being arranged in line in a direction having a given angle with respect to said RAM track so that one of said two laser light spots, which spot precedes said laser light spot used for recording and/or reproducing said main information relative to disc movement, is used for reading out said synchronous signal and said cumulative time data, said record and/or reproduce head having a plurality of photosensitive elements responsive to light rays reflected at said recording layer of said disc at said three laser light spots, at least two of said photosensitive elements which are responsive to reflected light rays from said remaining two laser light spots producing tracking signals by reading the same from said two ROM tracks, while one of said two photosensitive elements producing synchronous signal and cumulative data by reading the same from one of said two said ROM tracks; (c) shifting means for shifting said record and/or reproduce head to place said three laser light spots at desired positions; (d) tracking control circuit responsive to said tracking signals from said record and/or reproduce head means for performing tracking control; (e) record and/or reproduce circuit means for processing a recording signal to be applied to said record and/or reproduce head and a reproduced signal from said record and/or reproduce head; (f) control means for controlling said motor drive means, said record/and/or reproduce head, said shifting means, said tracking control circuit, said record and/or reproduce circuit means so as to record and/or reproduce information on and from said disc at desired positions, said control means having a memory for storing chapter number and cumulative time data both read out from said ROM track in said lead-in signal area for controlling said shifting means when such number and data are pre-recorded; and (g) means within said control means for reading said cumulative time data from said ROM track adjacent to said RAM track and for recording said cumulative time data on said RAM track.

Claim 12

Apparatus for recording and/or reproducing information as claimed in claim 8, further comprising a focus control means reponsive to an output signal from at least one of said photosensitive elements of said record/reproduce head.

Claim 13

Apparatus for recording and/or reproducing information as claimed in claim 8, further comprising a data input means for manually inputting data including a chapter number to be assigned to a piece of information to be recorded a chapter number for designating a pre-recorded piece of information.