Abstract: Light from light source means (a wavelength-variable laser) is applied to a surface of a hydrogen absorbing thin metal film of a hydrogen detecting surface plasmon resonator including a surface plasmon resonance enhancement structure formed by providing in the thin film an array of periodic holes having a shape that is not 90-degree rotational symmetric in the plane of the film surface, and transmitted light is detected with light detecting means (a photometer). Hydrogen is detected on the basis of a change in light transmission frequency characteristic caused by hydrogen absorption in the hydrogen detecting surface plasmon resonator. Optical hydrogen detection that is highly safe and unaffected by variations in the amount of light from the light source and stray light can be achieved.

Abstract: Light from light source means (a wavelength-variable laser) is applied to a surface of a hydrogen absorbing thin metal film of a hydrogen detecting surface plasmon resonator including a surface plasmon resonance enhancement structure formed by providing in the thin film an array of periodic holes having a shape that is not 90-degree rotational symmetric in the plane of the film surface, and transmitted light is detected with light detecting means (a photometer). Hydrogen is detected on the basis of a change in light transmission frequency characteristic caused by hydrogen absorption in the hydrogen detecting surface plasmon resonator. Optical hydrogen detection that is highly safe and unaffected by variations in the amount of light from the light source and stray light can be achieved.

Abstract: A spindle motor in which a shaft and a sleeve are supported by a radial fluid bearing and a thrust bearing in a noncontact state via a bearing clearance and are relatively driven rotatively, a lubricant reservoir having one end communicating with the bearing clearance and another end communicating with the outside is provided on an outer peripheral side of the sleeve whose inner periphery opposes the shaft, and a lubricant supplying passage, which is a clearance of the lubricant reservoir on its side which communicates with the bearing clearance, is set to a size exhibiting capillarity. Bubbles in the lubricant inside the lubricant reservoir are discharged through the clearance communicating with the outside, and the bearing clearance is automatically lubricated stably through the lubricant supplying passage by means of capillarity.

Abstract: A disc drive device includes a rotational assembly which is adapted to mount a disc thereon and is rotatably driven by a motor. The rotational assembly is rotatably supported on a support assembly by a radial hydrodynamic fluid bearing and a thrust bearing. An axial load is applied to the thrust bearing by a magnetic attractive force of up to 30N and is greater than a dead weight of the rotational assembly.