Write-once data writing system for optical recording medium

Claim 2

A write-once data writing method for optical recording medium of a type which allows a data track to contain a plurality of sectors each storing at least data and a preamble having sync information, the method comprising the steps of: providing a deceleration region, at a position following the last recorded sector on a track including both recorded and blank areas, of a length corresponding to a deceleration time necessary to change the relative moving rate of a writing/reading head with respect to the optical recording medium from one for reading to another for writing; and writing additional data sector by sector at region following said deceleration region.

Claim 3

The write-once data writing method according to claim 1 wherein the recorded sector on a data track, on which additional data is to be recorded, is detected in a reading mode with said writing/reading head being moved at a reading rate, and wherein if no preamble is found within a predetermined period after detecting the end of the sector, the moving rate of the head is decelerated to a writing rate, while defining said deceleration region, followed by beginning to write the additional data.

Claim 4

A write-once data writing apparatus for optical recording medium of a type which allows a data track to contain a plurality of sectors each storing at least data and a preamble having sync information, the apparatus comprising: a writing/reading head; a drive circuit for moving said writing/reading head relative to an optical recording medium along the data track thereon at respective rates in writing and reading data; writing means for applying data to be recorded to said head and controlling the writing operation; reading means for processing signals detected by said head to retrieve control signals, data, etc.; mode switching means responsive to an instruction to record additional data, for first directing said drive circuit and said reading means to a reading mode and for then directing, when receiving a mode switching signal, the same to a writing mode; and mode changing judging means responsive to said instruction, for checking through monitoring the output from said reading means if the preamble is, after detecting the end of a sector, included in the next sector, and for generating said mode switching signal if no preamble is found.

Claim 5

A write-once data writing apparatus for optical recording medium of a type which allows a data track to contain a plurality of sectors each storing at least data and a preamble having sync information, the apparatus comprising: a writing/reading head; a drive circuit for moving said writing/reading head relative to an optical recording medium along the data track thereon at respective rates in writing and reading data; writing means for applying data to be recorded to said head and controlling the writing operation; reading means for processing signals detected by said head to retrieve control signals, data, etc.; mode switching means responsive to an instruction to record additional data, for first directing said drive circuit and said reading means to a reading mode and for then directing, when receiving a mode switching signal, the same to a writing mode; and mode changing judging means responsive to said instruction, for checking through monitoring the output from said reading means if the preamble is, after detecting the end of a sector, included in the next sector, and for generating said mode switching signal if no preamble is found.

Claim 6

The write-once data writing apparatus accoring to claim 3 wherein said drive circuit, in response to the output from said mode switching means for switching the mode, causes the moving rate to decelerate until the rate reaches a writing rate, and then sends a write enable signal to said writing means.