Abstract: A processing speed is improved when there is a pattern in which read requests making access to continuous areas in an LBA space repeatedly alternate with write requests making access to continuous or non-continuous areas in the LBA space. In one embodiment, when the pattern in which read requests making access to continuous areas in an LBA space repeatedly alternate with write requests making access to continuous or non-continuous areas in the LBA space is extracted or a notice that the pattern has occurred is given from a host, write data required by write requests is buffered while executing read requests, and when this buffering of the write data is started, the position at which write data is started to be written is set to a position where the capacity of the buffered write data maximizes, taking account of the ratio of the amount of data transferred to a cache memory during reading to the amount of data transferred to the cache memory during writing.

Abstract: Where realtime performance-critical processing is executed in parallel with data integrity-critical processing, embodiments of the invention improve the realtime performance by raising the data transfer efficiency for sequential access-dominant realtime processing. In one embodiment, if a non-realtime processing command is received while read-ahead is in progress for a realtime processing command, processing of the non-realtime processing command is not started until a certain amount of data is cached. In addition, in order to prevent the periodicity disturbance of realtime processing, when the processing of the non-realtime processing command is postponed, the read-ahead is continued maximally until the timestamp at which the next realtime processing command is expected to be issued.

Abstract: A processing speed is improved when there is a pattern in which read requests making access to continuous areas in an LBA space repeatedly alternate with write requests making access to continuous or non-continuous areas in the LBA space. In one embodiment, when the pattern in which read requests making access to continuous areas in an LBA space repeatedly alternate with write requests making access to continuous or non-continuous areas in the LBA space is extracted or a notice that the pattern has occurred is given from a host, write data required by write requests is buffered while executing read requests, and when this buffering of the write data is started, the position at which write data is started to be written is set to a position where the capacity of the buffered write data maximizes, taking account of the ratio of the amount of data transferred to a cache memory during reading to the amount of data transferred to the cache memory during writing.

Abstract: Where realtime performance-critical processing is executed in parallel with data integrity-critical processing, embodiments of the invention improve the realtime performance by raising the data transfer efficiency for sequential access-dominant realtime processing. In one embodiment, if a non-realtime processing command is received while read-ahead is in progress for a realtime processing command, processing of the non-realtime processing command is not started until a certain amount of data is cached. In addition, in order to prevent the periodicity disturbance of realtime processing, when the processing of the non-realtime processing command is postponed, the read-ahead is continued maximally until the timestamp at which the next realtime processing command is expected to be issued.

Abstract: A subject for the invention is to provide a lens which is lightweight and inexpensive and, despite this, which is large and has a high-precision aspherical reflecting surface reduced in distortion. The invention provides: a projection lens comprising a resin base having a given curved surface and a reflecting layer formed over the surface of the resin base, characterized in that the average of in-plane birefringent phase differences per unit thickness as measured with incident light from the direction perpendicular to the curved optical functional surface of the resin base is 30 nm/mm or less in a region accounting for at least 60% of the area of the optical functional surface; or a projection lens having a reflecting layer on an optical-function-imparted surface, wherein at least 60% of the optical-function-imparted surface has a surface roughness (Ra) of 200 Å or lower.

Abstract: A subject for the invention is to provide a lens which is lightweight and inexpensive and, despite this, which is large and has a high-precision aspherical reflecting surface reduced in distortion.

Abstract: A resin composition comprising a resin (a) and a conductive filler (b), wherein the resin (a) contains a styrene type thermoplastic elastomer and/or an olefin type thermoplastic elastomer, said resin composition having a volume resistivity of from 10.sup.2 to 10.sup.12 .OMEGA..multidot.cm and a compression set (Cs1) of at most 35% by JIS K6301.