Matsushita Electric Industrial Co., Ltd.

Other

Keiichi Kawashima

Takashi Yumiba

Yuji Takagi

Koichi Morioka

Satoshi Kondo

Hideki Fukuda

Yoshinari Takemura

Masaaki Kondo

Kouichi Morioka

Hiroshi Sugimoto

Kenzo Ishibashi

Hirofumi Ide

When recording and reproduction are performed at the same time, if a system controller detects that an amount of data accumulated in a buffer memory exceeds a predetermined value, the system controller stops data reading from an optical disk temporarily and records data accumulated in the buffer memory continuously to the optical disk. Then, an image is prevented from becoming abnormal when a reproduction position catches up to a recording position. Further, a system controller monitors a zone in an optical disk, to which recording is performed and controls a motor at an appropriate revolution number for the recording to the zone. Further, reproduction is performed by maintaining the revolution number. Then, even if the recording position and the reproduction position belong to different zones in a recording medium, a transition time from recording to reproduction is prevented from becoming long.

Simultaneous recording and reproduction apparatus and simultaneous multi-channel reproduction apparatus

A plurality of tracks on an optical disk are optically read to obtain a signal containing a plurality of LOW segments. Each of the plurality of LOW segments should correspond to a certification pit. Accordingly, if the interval between LOW segment Xand nth succeeding LOW segment Xexceeds the length of one track, a defect pit that could be confused with a certification pit is judged as being present between two certification pits.

Device and program for checking optical disks

An optical disc storing a copyrighted digital product has a data area in which N processed parts are provided in order to certify that the stored digital product is an original one. A BCA provided on the optical disc stores judgment criteria information as well as N pieces of physical feature information. The judgment criteria information includes a numeric value N being the total number of processed parts, and a numeric value M being an integer between 0 and N inclusive and representing the security level to be assured for the digital data stored. When a numeric value P being the total number of processed parts in a normal state exceeds the numeric value M, a reproduction device reproduces the optical disc. When the numeric value P falls short of the numeric value M, the reproduction device does not reproduce the optical disc.

Optical disc, recording device, and recording device

An optical disc includes a processed area that has been processed by the irradiation of a YAG laser. Concave pits and convex pits having a length 3T&#x2013;14T (T=0.133 &#x3bc;m) are formed in an area of the optical disc other than the processed area. The processed area includes (1) a concave pit having a length X or (2) a pit string that has a length X and includes a convex pit from which a reflection layer has been removed. A specific area of the optical disc records physical character information that shows the location and length of the concave pit or the pit string in the processed area.

Optical disc, reproduction apparatus, and disc identifier selecting apparatus

An optical disc includes a processed area that has been processed by the irradiation of a YAG laser. Concave pits and convex pits having a length 3T-14T (T=0.133 &#x3bc;m) are formed in an area of the optical disc other than the processed area. The processed area includes (1) a concave pit having a length X or (2) a pit string that has a length X and includes a convex pit from which a reflection layer has been removed. A specific area of the optical disc records physical character information that shows the location and length of the concave pit or the pit string in the processed area.

Optical disc, having a certification pit for certifying that data recording thereon is original

When recording and reproduction are performed at the same time, if a system controller detects that an amount of data accumulated in a buffer memory exceeds a predetermined value, the system controller it stops data reading from an optical disk temporarily and records data accumulated in the buffer memory continuously to the optical disk. Then, an image is prevented from becoming abnormal when a reproduction position catches up to a recording position. Further, a system controller monitors a zone in an optical disk, to which recording is performed and controls a motor at an appropriate revolution number for the recording to the zone. Further, reproduction is performed by maintaining the revolution number. Then, even if the recording position and the reproduction position belong to different zones in a recording medium, a transition time from recording to reproduction is prevented from becoming long.

A control adjustment method for adjusting a control of a recording/reproduction apparatus for a disc-shaped recording medium is provided, wherein the control is adjusted in response to an environmental change inside the recording/reproduction apparatus, such as a temperature change, the control adjustment method comprising the steps of: requesting an execution of the control adjustment; determining whether to inhibit or approve the execution of the control adjustment; and executing the control adjustment in the case where the execution of the control adjustment is approved in the step of determining the execution of adjustment.

Growing community of inventors

Hirakata, Japan

Keiichi Kawashima