Tdk Corporation

Alps Electric Co., Ltd.

Hironori Namba

Kiyoshi Kobayashi

Tomoo Otsuka

Sumihito Morita

Mitsuo Kawasaki

Motoki Hirayama

Yusuke Kanekuni

A light receiving device includes an optical substrate disposed over a light receiving surface. In the optical substrate, a first optical multilayer film is formed on an incident surface, a second optical multilayer film is formed on a surface opposite the incident surface, and a third optical multilayer film is formed on the light receiving surface. Light of two wavelength regions separated from each other is transmitted, and light of wavelength regions other than the two wavelength regions is blocked. The two wavelength regions include a first wavelength region on the short wavelength side and a second wavelength region on the long wavelength side. At least a predetermined proportion of light of the second wavelength region is transmitted, and the transmittance of light of the first wavelength region is limited within a predetermined range less than the predetermined proportion.

Light receiving device

A thin-film magnetic head comprises a reproducing element formed on an undercoat film on a head substrate surface, a recording element formed on the upper side of the reproducing element, and a heater formed on the upper or lower side of the reproducing element, the heater generating heat upon energization so as to project at least the reproducing element by thermal expansion toward a recording medium. A shield layer is formed between the reproducing element and the heater by a plurality of layers including at least first and second shield layers. In the first and second shield layers, the second upper shield layer located closer to the heater is formed by a material having a coefficient of thermal expansion smaller than that of the first shield layer located closer to the reproducing element.

Thin-film magnetic head that locally projects an element part toward a recording medium by thermal expansion

A thin film magnetic head includes a recording and playback element, a lead conductor layer for feeding a power to the recording and playback element, an electrically conductive bump for conductively connecting the lead conductor layer to an electrode pad for external connection, and an insulating protective layer filling between the recording and playback element and the electrically conductive bump. A thermal deformation-preventing layer composed of a material having a thermal expansion coefficient smaller than that of the insulating protective layer is disposed in the insulating protective layer in such a way as to locate between a medium-facing surface and the electrically conductive bump without being exposed at the medium-facing surface. In the resulting thin film magnetic head, protrusion of the recording and playback element toward the recording medium side can be prevented without changing the configuration of the recording and playback element nor the forming material.

Thin film magnetic head including thermal deformation-preventing layer

Growing community of inventors

Niigata-ken, Japan

Hironori Namba