US 7,248,371 B2Granted

Optical image measuring apparatus

AssigneeTopcon Corporation

InventorsKinpui Chan, Masahiro Akiba, Yasufumi Fukuma, Hiroyuki Otsuka, Hisashi Tsukada

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Abstract

Provided is an optical image measuring apparatus capable of easily changing a scanning interval of an object to be measured in a depth direction with high precision. The apparatus includes an interference optical system for superimposing signal light propagating through the object to be measured on reference light subjected to frequency shift to produce interference light, a reference mirror driving unit for driving a mirror to scan the object to be measured in the depth direction, shutters for sampling interference light beams, CCDs for storing charges for only a predetermined storage time and outputting electrical signals, a control unit for changing the storage time of the CCDs, a signal processing portion for calculating intensities and phases of interference light beams corresponding to each depth of the object to be measured which are successively detected by the CCDs during scanning based on the electrical signals successively outputted from the CCDs every changed storage time, and a setting operation unit for setting the storage time of the CCDs by an operator.

Claims13

Dependent claims

An optical image measuring apparatus for obtaining an image of an object to be measured at a depth corresponding to a position of a reference object based on interference light, comprising:

a light source for emitting a light beam;
an interference optical system that divides the light beam emitted from the light source into signal light propagating through the object to be measured and reference light propagating through the reference object, shifts a frequency of the signal light and a frequency of the reference light relative to each other, and then superimposes the signal light propagating through the object to be measured and the reference light propagating through the reference object on each other to produce the interference light;
intensity modulating means for periodically modulating an intensity of the interference light from the interference optical system at a predetermined frequency;
photo detection means for receiving the interference light whose intensity is modulated by the intensity modulating means to perform photoelectric conversion, storing a charge for only a predetermined storage time, and outputting an electrical signal corresponding to an amount of charge stored;
control means for changing the storage time of the photo detection means;
and
calculation means for calculating a phase and an intensity of the interference light at a depth of the object to be measured, which is detected by the photo detection means based on the electrical signal outputted from the photo detection means every storage time changed by the control means.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/091,653Filed 29 Mar 2005
Priority: JP 2004-10074230 Mar 2004
Published: US 2005/0219545 A16 Oct 2005
Granted: 24 Jul 2007
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

G01N 21/49
Scattering, i.e. diffuse reflection: within a body or fluid
A61B 3/102
Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions: for optical coherence tomography [OCT]
A61B 5/0066
Arrangements for scanning: optical coherence imaging
A61B 5/0073
Using light, e.g. diagnosis by transillumination, diascopy, fluorescence: by tomography, i.e. reconstruction of 3D images from 2D projections