1. Field of the Invention
The present invention relates to an information recording apparatus for detecting a temperature and controlling a data write operation, to record write data from a host computer to an optical recording medium using a write cache memory (temporary memory), and to a method for controlling write in the information recording apparatus.
2. Description of the Related Art
Heretofore, a magneto-optical disk apparatus heats a recording layer of a magneto-optical disk with laser light, eliminates magnetizing, and performs a write operation while applying an external magnetic field. This type of magneto-optical disk apparatus detects indirectly a temperature of a disk surface radiated with laser light, monitors its temperature, and performs a write operation with an adequate write power for every constant temperature range. Therefore, if the magneto-optical disk apparatus detects an abnormal temperature, it determines not to correctly write data in case of a continuing write operation, warns a user of abnormality, and forbids a write operation.
In addition, some recording apparatuses such as disk drives whose access time is relatively long try to make access high-speed through moving frequently referred data to a high-speed memory called a cache memory or a memory management unit.
In case that a magneto-optical disk apparatus uses the cache memory, in regard to data acquisition in a write operation, when the apparatus acquires data from a host computer to the cache memory, it reports normal completion of a write operation to the host computer, and then, it writes data in the cache memory to a recording medium.
In the above-mentioned prior art, there is a method for using a write cache memory, and reporting an error in data write or continuing data write at an abnormal temperature in case that plenty of data are in the cache memory and an abnormal temperature is detected.
In the former method, when an abnormal temperature is reported from a magneto-optical disk apparatus to a host side, it is common that the magneto-optical disk apparatus is usually turned off, and it is operated again after some time passes. Consequently, data after detecting an abnormal temperature are not written to a recording media, and become lost data.
Further, in the latter method, if the apparatus continues to write data on the recording medium in the state of an abnormal temperature, alternative sector number increases, there is a possibility of an inability to perform a write operation, and hence, it is not preferable.
For example, the case where the apparatus continues to write in the state of detection of an abnormal temperature with holding 20 blocks of 200 kBytes of data in the four MBytes of a cache memory will be considered. Assuming that the write speed of a drive is 200 kB/sec and average access time is 40 msec, EQU 40 msec.times.20+200 kB/200 kB/sec.times.20=nearly 21 sec.
Thus, a write operation should be done for 21 sec under an abnormal temperature, the possibility of an occurrence of alternate processing is high during this time, a write time becomes long, and further, there is a possibility of an inability to perform a write operation.
USPTO Backgrounds
USPTO Backgrounds