Acoustic signal receiving apparatus and imaging apparatus

Patent metadata

Field	Value
Publication number	US-9116111-B2
Application number	US-201214123234-A
Country	US
Kind code	B2
Filing date	Jul 11, 2012
Priority date	Jul 19, 2011
Publication date	Aug 25, 2015
Grant date	Aug 25, 2015

Abstract

There is used an acoustic signal receiving apparatus including a wavelength-tunable light source for irradiating measurement light, a controller for controlling a wavelength of the measurement light, a Fabry-Perot probe having a first mirror on a side where the measurement light enters, a second mirror on a side where an elastic wave from an object enters, and a spacer film positioned between the first and second mirrors and deforms in response to the elastic wave, an array photosensor for detecting a reflected light amount of the measurement light by the Fabry-Perot probe, and a signal processor for acquiring an intensity of the incident elastic wave based on a change in the reflected light amount. The controller sweeps the wavelength of the measurement light, and the signal processor determines the wavelength based on the reflected light amount at each wavelength subjected to the sweep.

First claim

The invention claimed is:

1. An acoustic signal receiving apparatus comprising:
a wavelength-tunable light source for irradiating measurement light;
a controller for controlling a wavelength of the measurement light;
a Fabry-Perot probe including a first mirror positioned on a side where the measurement light enters, a second mirror positioned on a side where an elastic wave from an object enters, and a spacer film that is positioned between the first and second mirrors and deforms in response to the entrance of the elastic wave;
an array photosensor for detecting a reflected light amount of the measurement light by the Fabry-Perot probe; and
a signal processor for acquiring an intensity of the elastic wave having entered the Fabry-Perot probe based on a change in the reflected light amount resulting from the deformation of the spacer film, wherein
the controller sweeps the wavelength of the measurement light, and
the signal processor determines, based on the reflected light amount at each position of the Fabry-Perot probe that is acquired at each wavelength subjected to the sweep, the wavelength of the measurement light used at the position.

2. The acoustic signal receiving apparatus according to claim 1 , further comprising an excitation light source for irradiating excitation light to the object, wherein the elastic wave from the object is a photoacoustic wave generated from the object to which the excitation light has been irradiated.

3. The acoustic signal receiving apparatus according to claim 2 , wherein the excitation light source irradiates the excitation light at a specific interval, and
the controller sweeps the wavelength of the measurement light during a period from when the Fabry-Perot probe receives the photoacoustic wave during a specific reception period in which the excitation light is used as a trigger to when the next excitation light is irradiated.

4. The acoustic signal receiving apparatus according to claim 1 , further comprising a transducer for transmitting the elastic wave to the object, wherein the elastic wave from the object is an echo wave of the elastic wave transmitted from the transducer.

5. The acoustic signal receiving apparatus according to claim 4 , wherein the transducer transmits the elastic wave at a specific interval, and
the controller sweeps the wavelength of the measurement light during a period from when the Fabry-Perot probe receives the echo wave during a specific reception period in which the transmission of the elastic wave is used as a trigger to when the next transmission is performed.

6. The acoustic signal receiving apparatus according to claim 1 , wherein the signal processor performs processing of determining the wavelength of the measurement light used at each position of the Fabry-Perot probe before measurement of the object using the wavelength.

7. The acoustic signal receiving apparatus according to claim 1 , wherein the signal processor performs processing of determining the wavelength of the measurement light used at each position of the Fabry-Perot probe simultaneously with measurement of the object using the wavelength.

8. An imaging apparatus comprising:
the acoustic signal receiving apparatus according to claim 1 ; and
an image display for displaying an internal portion of the object imaged based on the intensity of the elastic wave acquired by the signal processor.

Assignees

• Nakajima Takao
• Asao Yasufumi
• Canon Kk

Inventors

• Nakajima Takao
• Asao Yasufumi

Classifications

• G01H9/002

  for representing acoustic field distribution (sonar systems for imaging G01S7/56, G01S15/89; acoustic holography G03H3/00) · CPC title

• G01N29/2418 Primary

  using optoacoustic interaction with the material, e.g. laser radiation, photoacoustics (photoacoustic cells G01N21/1702; measuring characteristics of vibrations by using radiation-sensitive means G01H9/00; acousto-optical conversion techniques for short-range imaging G01S15/8965; sound-producing devices using laser bundle G10K15/046) · CPC title

• G01N21/1702 Primary

  with opto-acoustic detection, e.g. for gases or analysing solids · CPC title

• G01H9/00

  Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means · CPC title

• A61B5/0095

  by applying light and detecting acoustic waves, i.e. photoacoustic measurements · CPC title