Patent ID: 7133138
Filing Date: 2006-11-07
Classification: G01B

Abstract:
1. An optical imaging device comprising: a light source for supplying low coherence light to irradiate an object so that tomographic images of the object can be constructed based on returning light reflected or scattered from the object; a light irradiating/receiving unit for irradiating the object with said low coherence light and for receiving said returning light, said light irradiating/receiving unit including a first optical scanning block capable of scanning said object at least one-dimensionally in a direction of light reception or irradiation; a first light path member over which a portion of the low coherence light is propagated to said object and said returning light is propagated to said light irradiating/receiving unit; a second light path member over which a further portion of the low coherence light is propagated to provide a reference light beam; a first optical branching unit, interposed between said light source and said first optical scanning block, for branching the low coherence light supplied from said light source into said first optical scanning block and said second light path member; a second optical branching unit, included in said first optical scanning block, for branching out the returning light from said first optical scanning block; a third light path member over which the returning light branched out by said second optical branching unit is propagated; a coupling unit for coupling the reference light beam propagated over said second light path member and the returning light propagated over said third light path member to create interference between the reference beam and the returning light; a detection unit for detecting the interference caused by said coupling unit to produce an interfering signal; an optical length variation unit, coupled to one of said second and third light path members, for varying at least one of a phase delay and a group delay of light between an incident light path and an emitted light path, said optical length variation unit including: a movable light-transmissive optical element interposed between the incident light path and emitted light path, and a drive mechanism operative to impart cyclic motion to the light-transmissive optical element so that a point at which light in the second and third light paths interfere is scanned in the optical-axis direction as the light-transmissive optical element moves; and an image production unit for processing the interfering signal detected by said detection unit to produce a tomographic image of said object, wherein said drive mechanism is operative to rotate said light-transmissive optical element on an axis of rotation, and said rotation causes light propagated along said incident light path to be deflected cyclically relative to said axis of rotation.