Patent ID: 7944554

Claim:
An inspection head supporting structure applied to a surface inspecting apparatus, which irradiates an inspection light to an inspection object from an outer circumference of an inspection head with rotating the inspection head around its axis, receives reflection light reflected from the inspection object to the inspection head, and inspects the surface of the inspection object on the basis of the light amount of the reflection light, wherein the inspection head comprises a hollow tubular bearing fitting part and a main shaft part extending to its tip side from the bearing fitting part, the inspection head supporting structure comprising: a head supporting shaft disposed coaxially inside the bearing fitting part of the inspection head; a pair of bearings, which are disposed with a distance from each other in an axial direction of the inspection head and between an outer circumference of the head supporting shaft and an inner circumference of the bearing fitting part, and which are capable of respectively applying a radial load and a unidirectional axial load; inner race constraining devices, each of which constrains each inner race of the pair of bearings at a constant position in an axial direction on atop of the head supporting shaft; a first and a second pressure preloading members in cylindrical or annular shapes, which are disposed juxtaposed between outer races of the pair of bearings in a movable manner in the axial direction relative to the inspection head; a spring device which is disposed between the first and the second pressure preloading members and each of which urges each pressure preloading member toward each outer race of the pair of bearings; a ring of elastic material disposed between the first pressure preloading member and an outer race of one of the bearings, and an outer circumference of the ring being contacted with the inner circumference of the bearing fitting part; and outer race constraining devices each of which constrains each outer race of the pair of bearings from outside in the axial direction with a first constraining part, which is disposed within the bearing fitting part, and a second constraining part, which is disposed removably and installably at a base end part of the inspection head, wherein, the inspection head is configured to be capable of taken out from atop of the pair of bearings toward the tip side in the axial direction, in a condition wherein the inspection head contains the bearing fitting part and the main shaft part, by removing the second constraining part from the inspection head.