Ultrasonic apparatus
An ultrasonic apparatus includes an ultrasonic wave generating member having a light absorbing member that generates an ultrasonic wave when irradiated by a light from a light irradiating portion, and a transducer that detects the ultrasonic wave and converts the ultrasonic wave into an electric signal. The ultrasonic wave generating member includes an area that has a different light absorption coefficient in an irradiation area irradiated by the light from the light irradiating portion. Furthermore, in an area in which the light absorbing member is disposed, when an area irradiated by the light from the light irradiating portion is referred to as a transmitted ultrasonic wave generating area, the transmitted ultrasonic wave generating area functions as a surface sound source.
1. An ultrasonic apparatus comprising:
a transducer configured to receive an ultrasound and convert the ultrasound into an electric signal;
a planar ultrasound generating member acoustically coupled to the transducer via an acoustic matching liquid and showing a planar distribution of an optical absorption property; and
a light emitting portion acoustically coupled to the planar ultrasound generating member via the acoustic matching liquid and configured to emit a pulsed light and form a planar illuminance distribution on the planar ultrasound generating member;
wherein the planar distribution of the optical absorption property and the planar illuminance distribution have a negative correlation with respect to each other.
2. The ultrasonic apparatus according to claim 1 ,
wherein the planar ultrasound generating member shows the planar distribution of the optical absorption property configured to compensate the planar illuminance distribution.
3. The ultrasonic apparatus according to claim 1 , wherein the ultrasound generating member includes a light absorbing member showing the planar distribution of the optical absorption property so as to form a planar intensity distribution of the sound pressure smaller than the planar illuminance distribution.
4. The ultrasonic apparatus according to claim 1 , further comprising a moving unit configured to change a relative position between an optical path of the pulsed light from the light emitting portion and the planar ultrasound generating member.
5. The ultrasonic apparatus according to claim 1 , wherein the planar ultrasonic generating member generates an ultrasound that has a planar intensity distribution of a sound pressure smaller than the planar illuminance distribution.
6. The ultrasonic apparatus according to claim 1 ,
wherein the optical reflective member and the planar ultrasound generating member are disposed on a sheet member disposed between the light emitting portion and the subject.
7. The ultrasonic apparatus according to claim 1 , wherein the optical reflective member masks a peripheral of an irradiation area.
8. The ultrasonic apparatus according to claim 6 ,
wherein the light emitted from the light emitting portion is irradiated to the planar ultrasound generating member and the optical reflective member.
9. The ultrasonic apparatus according to claim 4 ,
wherein the absorption coefficient distribution of the planar ultrasound generating member is ring-shaped.
10. The ultrasonic apparatus according to claim 1 ,
wherein the planar ultrasound generating member includes a plurality of sheet members.
11. The ultrasonic apparatus according to claim 1 ,
wherein the planar distribution of the optical absorption property is inversely correlated with the planar illuminance distribution.
12. An ultrasonic apparatus comprising:
a transducer configured to receive an ultrasound and convert the ultrasound into an electric signal;
a planar ultrasound generating member showing a planar distribution of an optical absorption property; and
a light emitting portion configured to form a planar illuminance distribution on the planar ultrasound generating member;
wherein the planar distribution of the optical absorption property is inversely correlated with the planar illuminance distribution.
13. The ultrasonic apparatus according to claim 12 ,
wherein the planar distribution of the optical absorption property compensates the illuminance distribution.
14. The ultrasonic apparatus according to claim 12 ,
wherein the planar ultrasound generating member generates an ultrasound that has a planar intensity distribution of a sound pressure smaller than the illuminance distribution.
15. The ultrasonic apparatus according to claim 1 , further comprising
an optical reflective member disposed at a peripheral region of the planar ultrasound generating member and configured to reflect a part of the light from the light emitting portion.
16. The ultrasonic apparatus according to claim 15 ,
wherein the optical reflective member reduces a noise from the peripheral region of the planar ultrasound generating member.
17. The ultrasonic apparatus according to claim 15 ,
wherein the optical reflective member reduces a photoacoustic wave from the peripheral region of the planar ultrasound generating member.
18. The ultrasonic apparatus according to claim 12 ,
wherein the planar ultrasound generating member is acoustically coupled to the transducer via acoustic matching liquid and the light emitting portion is acoustically coupled to the planar ultrasound generating member via the acoustic matching liquid.