Optical coherence tomographic device comprising dual correction beams of different path lengths

Patent metadata

Field	Value
Publication number	US-11243066-B2
Application number	US-201816225656-A
Country	US
Kind code	B2
Filing date	Dec 19, 2018
Priority date	Dec 22, 2017
Publication date	Feb 8, 2022
Grant date	Feb 8, 2022

Abstract

An optical coherence tomographic device may include a light source, a measurement light generator, a reference light generator, an interference light generator, an interference light detector, and a processor. The interference light detector may include a first and second detector that convert interference light to interference signals, a first signal processing unit that samples the interference signal from the first detector, and a second signal processing unit that samples the interference signal from the second detector. Each of the first and second signal processing units may sample the interference signal at a timing from outside. Light generated by the measurement light generator may at least include first and second correction light. The processor may correct a time lag between sampling timings of the first and second signal processing units by using a first and second correction signal converted from the first and second correction light.

First claim

What is claimed is:

1. An optical coherence tomographic device comprising:
a light source;
a measurement light generator configured to generate measurement light by using light from the light source, and generate reflected light from a subject by irradiating the subject with the generated measurement light;
a reference light generator configured to generate reference light by using the light from the light source;
an interference light generator configured to generate interference light by combining the reflected light from the subject generated by the measurement light generator and the reference light generated by the reference light generator;
an interference light detector configured to detect interference signals from the interference light generated by the interference light generator;
a processor; and
a memory storing computer-readable instructions,
wherein the interference light detector comprises:
a first detector and a second detector configured to convert the interference light to the interference signals;
a first signal processing unit configured to sample the interference signal outputted from the first detector; and
a second signal processing unit configured to sample the interference signal outputted from the second detector,

wherein each of the first and second signal processing units is configured to sample the interference signal at a timing that is inputted to the signal processing unit from outside,
wherein the reflected light generated by the measurement light generator at least includes first correction light having a first optical path length and second correction light having a second optical path length that is different from the first optical path length,
wherein the computer-readable instructions, when executed by the processor, cause the processor to:
generate a tomographic image by using the interference signals sampled respectively by the first and second signal processing units; and
correct a time lag in synchronization between sampling timings of the first and second signal processing units by using a first correction signal converted from the first correction light and a second correction signal converted from the second correction light, the first and second correction signals being included in the interference signals sampled respectively in the first and second signal processing units,

wherein the measurement light generator comprises:
a splitter configured to split an optical path of the light from the light source into a correction light and the measurement light;
an optical path length adjuster disposed on a first optical path split by the splitter,
wherein the measurement light is generated by the light from the light source on a second optical path split by the splitter, and
wherein the correction light comprises the first correction light and the second correction light, both being generated by light from the light source on the first optical path, and
wherein at least one of the first optical path length of the first correction light and the second optical path length of the second correction light is adjusted by the optical path length adjuster,

the optical path length adjuster comprises a glass block that is disposed on the first optical path split by the splitter, the glass block being configured to allow a part of the measurement light to pass through, and
the measurement light generator is configured to generate the first correction light by using light that passes through the glass block, and generate the second correction light by using light that does not pass through the glass block.

2. An optical coherence tomographic device comprising:
a light source;
a measurement light generator configured to generate measurement light by using light from the light source, and generate reflected light from a subject by irradiating the subject with the generated measurement light;
a reference light generator configured to generate reference light by using the light from the light source;
an interference light generator configured to generate interference light by combining the reflected light from the subject generated by the measurement light generator and the reference light generated by the reference light generator;
an interference light detector configured to detect interference signals from the interference light generated by the interference light generator;
a processor; and
a memory storing computer-readable instructions,
wherein the interference light detector comprises:
a first detector and a second detector configured to convert the interference light to the interference signals;
a first signal processing unit configured to sample the interference signal outputted from the first detector; and
a second signal processing unit configured to sample the interference signal outputted from the second detector,

wherein each of the first and second signal processing units is configured to sample the interference signal at a timing that is inputted to the signal processing unit from outside,
wherein the reflected light generated by the measurement light generator at least includes first correction light having a first optical path length and second correction light having a second optical path length that is different from the first optical path length,
wherein the computer-readable instructions, when executed by the processor, cause the processor to:
generate a tomographic image by using the interference signals sampled respectively by the first and second signal processing units; and
correct a time lag in synchronization between sampling timings of the first and second signal processing units by using a first correction signal converted from the first correction light and a second correction signal converted from the second correction light, the first and second correction signals being included in the interference signals sampled respectively in the first and second signal processing units,
wherein the measurement light generator comprises:
a splitter configured to split an optical path of the light from the light source into a correction light and the measurement light; and
an optical path length adjuster disposed on a first optical path split by the splitter,
wherein the measurement light is generated by the light from the light source on a second optical path split by the splitter,
wherein the correction light comprises the first correction light and the second correction light, both being generated by light from the light source on the first optical path, and
wherein at least one of the first optical path length of the first correction light and the second optical path length of the second correction light is adjusted by the optical path length adjuster,

the optical path length adjuster comprises a

glass block that is disposed on the first optical path split by the splitter, the glass block being configured to allow a part of the measurement light to pass through, and
the measurement light generator is configured to generate the first correction light by using light that passes through the glass block for a first number of times, and generate the second correction light by using light that passes through the glass block for a second number of times which is different from the first number of times.

Assignees

• Tomey Corp

Inventors

• Yamanari Masahiro

Classifications

• G01B9/02072

  by calibration or testing of interferometer · CPC title

• G01B9/02004 Primary

  using frequency scans · CPC title

• G01B9/02069

  Synchronization of light source or manipulator and detector · CPC title

• G01B9/02071 Primary

  by measuring path difference independently from interferometer · CPC title

• G01B9/02067

  by electronic control systems, i.e. using feedback acting on optics or light · CPC title