Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
189 words
An information recording and reproducing apparatus using a disc shaped information recording medium having a plurality of recording tracks, each of which recording tracks is divided into a plurality of sectors, each of said sectors being composed of a sector ID field containing address information and a data field in which data are recorded, so that information is recorded and reproduced on and from said sectors, said apparatus comprising: means for detecting a sector, whose address can not be reproduced, to be a defective sector; means for detecting a sector, whose address can be reproduced and which is positioned preceding a target sector on and from which information is to be recorded and reproduced, to be a reference sector; and means for measuring a rotational latency time from said detected reference sector to said target sector, whereby, when a target sector is detected to be a defective sector, a reference sector is detected in the first place and then a rotational latency time from said detected reference sector to said defective target sector is measured, thereby effecting recording and reproduction of information on and from said defective target sector.
Claim 2
Dependent Claim
189 words
An information recording and reproducing apparatus using a disc shaped information recording medium having a plurality of recording tracks, each of which recording tracks is divided into a plurality of sectors, each of said sectors being composed of a sector ID field containing address information and a data field in which data are recorded, so that information is recorded and reproduced on and from said sectors, said apparatus comprising: means for detecting a sector, whose address can not be reproduced, to be a defective sector; means for detecting a sector, whose address can be reproduced and which is positioned preceding a target sector on and from which information is to be recorded and reproduced, to be a reference sector; and means for measuring a rotational latency time from said detected reference sector to said target sector, whereby, when a target sector is detected to be a defective sector, a reference sector is detected in the first place and then a rotational latency time from said detected reference sector to said defective target sector is measured, thereby effecting recording and reproduction of information on and from said defective target sector.
Claim 3
Dependent Claim
24 words
An information recording and reproducing apparatus according to claim 1, in which the rotational latency time is measured by using a time measuring circuit.
Claim 4
Dependent Claim
27 words
An information recording and reproducing apparatus according to claim 2, in which said time measuring circuit for measuring the rotational latency time is incorporated in a microprocessor.
Claim 5
Dependent Claim
66 words
An information recording and reproducing apparatus according to claim 1, in which said sector ID field includes a sector mark for indicating the presence of said associated sector ID field so that, as said sector mark is detected during the rotational latency time, the rotational latency time is measured by using a counter circuit for counting the number of said detected sector mark or sector marks.
Claim 6
Dependent Claim
26 words
An information recording and reproducing apparatus according to claim 4, in which said counter circuit for measuring the rotational latency time is incorporated in a microprocessor.
Claim 7
Dependent Claim
45 words
An information recording and reproducing apparatus according to claim 1, in which only a sector, whose address can be reproduced and which is positioned one or two sectors preceding a target sector on said discshaped information recording medium, is detected to be a reference sector.
Claim 8
Dependent Claim
61 words
An information recording and reproducing apparatus according to claim 1, in which, only when a target sector is detected to be a defective sector at the time of reproducing information, a reference sector is detected and then the rotational latency time from said detected reference sector to said defective target sector is measured, thereby reproducing information from said defective target sector.