Ricoh Company, Ltd.

Hitachi Global Storage Technologies Netherlands B.v.

Masaki Kudoh

Mariko Kojima

Masahiro Shimizu

Tomohiro Nakagawa

Kiyofumi Nagai

Akihiko Matsuyama

Akihiko Gotoh

Akiko Bannai

Keita Katoh

Yuuki Yokohama

Ichiroh Fujii

Yasuhiro Iihara

Toshiaki Satoh

Junzoh Noda

Masanori Aratani

An inkjet recording ink containing a colorant, a surfactant A, a surfactant B, a water soluble organic solvent, and water, wherein the surfactant A is expressed by any one of Structural Formula (1) and Structural Formula (2), and the surfactant B is expressed by Structural Formula (3): in Structural Formula (1), R1 represents hydrogen, an alkyl group, or an acyl group; Rf represents &#x2014;CFor &#x2014;CFCF; and m, n and p are natural numbers; in Structural Formula (2), M represents alkali metal, ammonium, phosphonium, or alkanolamine; Rf represents &#x2014;CFor &#x2014;CFCF; and q is a natural number; in Structural Formula (3), Rand Reach represent hydrogen or an alkyl group; and r, s, t and u are natural numbers. 

Inkjet recording ink, inkjet recording inkset, ink cartridge, inkjet recording method, and recorded matter

An inkjet recording ink containing: water; a water-soluble organic solvent; a colorant; and at least one fluorochemical surfactant having a formula selected from the group consisting of (b), (a), (a'), and (h): [(RfSO)]NM&#x2003;&#x2003;(a),[(RfSO)(RSO)]NM&#x2003;&#x2003;(a&#x2032;),[(FSO)]NM&#x2003;&#x2003;(h),wherein Mis Li, Na, K, or NH, Rf is CF, CF, CF, or CF, and R is C1-C10 alkyl group.

Inkjet recording ink, ink cartridge and inkjet recording apparatus

Embodiments of the present invention provide a defect registration method for performing defect registration of sectors on a magnetic disk. In one embodiment, a rectangular detection window is applied to each defect sector. A threshold value of the detection window is set at 2. In addition, an additional sector group is defined for the detection window. The additional sector group is a target of the defect registration if the number of defect sectors exceeds the threshold value. The additional sector group covers sectors that are not judged as defects in defect detection inspection, but that are expected to be potentially defective. Even if the detection window is applied to a defect sector, an additional sector group is not generated. However, if the detection window is applied to a defect sector, an additional sector group is generated. If the detection window is applied to a defect pattern, an additional sector group is generated.

Defect registration method of magnetic disk, and magnetic disk drive

Embodiments of the present invention provide an inspection method for detecting a physical defect of a magnetic disk with high sensitivity without increasing the length of inspection time. In a magnetic disk drive according to one embodiment, the assembling of which has been completed, by reading inspection data written to a magnetic disk, a defect of the magnetic disk is detected in a state in which a read error occurs. Redundant bits of an ECC are added to the inspection data. If a head corresponding to a recording surface to be inspected has superior read performance, an ECC 2 is applied. If the head in question has inferior read performance, an ECC 4 is applied. Accordingly, as compared with a case where a single ECC is applied, the defect detectivity is further improved without increasing the length of inspection time.

Surface analysis test with mixed ECC symbol

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Tokyo, Japan

Masaki Kudoh