Object information acquisition apparatus and object information acquisition method

• US 7,763,868 B2
• Filed: 10/09/2007
• Issued: 07/27/2010
• Est. Priority Date: 10/10/2006
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ouchi, Toshihiko, Itsuji, Takeaki, Kajiki, Kousuke
• Primary Examiner(s): Vanore; David A
• Application Number:
  US11/869,298
• Publication Number:
  US 20080116374A1
• Time in Patent Office: 1,022 Days
• Field of Search: 250/225, 250/251, 250/493.1, 340/540, 340/552, 342/22, 342/179
• US Class Current: 250/493.1
• CPC Class Codes: A61B 5/1074 Foot measuring devices
• CPC Class Codes: G01N 21/3563 for analysing solids; Preparation of samples therefor
• CPC Class Codes: G01N 21/3581 using far infrared light; using Terahertz radiation
• CPC Class Codes: G01S 13/887 for detection of concealed objects, e.g. contraband or weapons
• CPC Class Codes: G01S 13/89 for mapping or imaging
• CPC Class Codes: G01S 7/28 Details of pulse systems

Abstract

An object information acquisition apparatus for acquiring information on the inside of an object includes an electromagnetic wave generation unit capable of outputting a terahertz wave and of changing the output intensity, an irradiation unit that irradiates an electromagnetic wave onto an object, a scanning unit and a detection unit that detects the electromagnetic wave irradiated onto the object. The scanning unit changes the relative positions of the irradiated electromagnetic wave and the object. The detection unit detects the electromagnetic wave transmitted through or reflected by the object as a result of interaction of the object and the electromagnetic wave.

Claims

1. An object information acquisition apparatus for acquiring information on the inside of an object, the apparatus comprising:

an electromagnetic wave generation unit capable of outputting an electromagnetic wave containing a frequency component of part of the frequency range between 30 GHz and 30 THz and of changing an output intensity of the electromagnetic wave;

an irradiation unit that irradiates the electromagnetic wave to the object;

a scanning unit that changes the relative position of the irradiated electromagnetic wave and the object; and

a detection unit that detects the electromagnetic wave transmitted through or reflected by the object as a result of interaction of the object and the electromagnetic wave,

the apparatus being adapted to acquire tomographic information of planes of different levels in the inside of the object relative to the direction of depth thereof in the region of the object of information acquisition according to a signal detected by the detection unit by combining the operation of changing the relative position by the scanning unit and the operation of changing the intensity of the electromagnetic wave by the electromagnetic wave generation unit.

2. The object information acquisition apparatus according to claim 1, wherein the electromagnetic wave generation unit has at least two coherent light sources, each oscillating with a single frequency in the frequency range between 30 GHz and 30 THz, for different frequencies.

3. The object information acquisition apparatus according to claim 1, wherein at least one optical element contained in the apparatus illustrates a transmission characteristic or a reflection characteristic relative to at least part of electromagnetic wave found between 30 GHz and 30 THz that is differentiated from a transmission characteristic or a reflection characteristic, whichever appropriate, relative to at least part of an electromagnetic wave found at or above 30 THz for the at least one optical element of the apparatus.

4. The object information acquisition apparatus according to claim 1, further comprising:

a transmission unit that detects, if any, the existence of a target object of examination contained in an object from the acquired tomographic information of the plane of a level in the direction of depth of the object and transmits a signal providing notification of the existence thereof.

5. The object information acquisition apparatus according to claim 1, further comprising:

a detection unit that detects the region of an object of acquisition of tomographic information.

6. An object information acquisition apparatus for acquiring information on the inside of an object, the apparatus comprising:

an electromagnetic wave generation unit capable of outputting an electromagnetic wave containing a frequency component of part of the frequency range between 30 GHz and 30 THz;

an irradiation unit that irradiates the electromagnetic wave to the object;

a scanning unit that changes the relative position of the irradiated electromagnetic wave and the object;

a detection unit that detects the electromagnetic wave transmitted through or reflected by the object as a result of interaction of the object and the electromagnetic wave; and

a delay unit that changes a delay time between the timing of outputting the electromagnetic wave of the electromagnetic wave generation unit and the timing of detecting the electromagnetic wave by the detection unit,

the apparatus being adapted to acquire tomographic information of planes of different levels in the inside of the object relative to the direction of depth thereof in the region of the object of information acquisition according to a signal detected by the detection unit by combining the operation of changing the relative position by the scanning unit and the operation of changing the delay time by the delay unit.

7. The object information acquisition apparatus according to claim 6, wherein the delay unit includes a rotatable transmitting body capable of transmitting the electromagnetic wave and the delay time is made to vary by rotating the transmitting body so as to vary at least either the thickness or the refractive index of the region of the transmitting body for transmitting the electromagnetic wave.

8. The object information acquisition apparatus according to claim 6, wherein at least one optical element contained in the apparatus illustrates a transmission characteristic or a reflection characteristic relative to at least part of electromagnetic wave found between 30 GHz and 30 THz that is differentiated from a transmission characteristic or a reflection characteristic, whichever appropriate, relative to at least part of an electromagnetic wave found at or above 30 THz for the at least one optical element of the apparatus.

9. The object information acquisition apparatus according to claim 6, further comprising:

a transmission unit that detects, if any, the existence of a target object of examination contained in an object from the acquired tomographic information of the plane of a level in the direction of depth of the object and transmits a signal providing notification of the existence thereof.

10. The object information acquisition apparatus according to claim 6, further comprising:

a detection unit that detects the region of an object of acquisition of tomographic information.

11. An object information acquisition apparatus for acquiring information on the inside of an object, the apparatus comprising:

an electromagnetic wave generation unit capable of outputting an electromagnetic wave containing a frequency component of part of the frequency range between 30 GHz and 30 THz;

an electromagnetic wave bifurcating unit that bifurcates the electromagnetic wave into reference light and object light;

an irradiation unit that irradiates the object light to the object;

a scanning unit that changes the relative position of the irradiated object light and the object;

a delay unit arranged on either or both of the light path of the reference light and that of the object light to change a relative delay time between the reference light and the object light;

an electromagnetic wave coupling unit that couples the object light transmitted through or reflected by the object as a result of interaction with the object and the reference light provided with the relative delay time to the object light by the delay unit; and

a detection unit that detects an interference signal of the reference light and the object light coupled by the electromagnetic wave coupling unit,

the apparatus being adapted to acquire tomographic information of planes of different levels in the inside of the object relative to the direction of depth thereof in the region of the object of information acquisition according to a signal detected by the detection unit by combining the operation of changing the relative position by the scanning unit and the operation of changing the delay time by the delay unit.

12. The object information acquisition apparatus according to claim 11, wherein the delay unit includes a rotatable transmitting body capable of transmitting the electromagnetic wave and the delay time is made to vary by rotating the transmitting body so as to vary at least either the thickness or the refractive index of the region of the transmitting body for transmitting the electromagnetic wave.

13. The object information acquisition apparatus according to claim 11, wherein at least one optical element contained in the apparatus illustrates a transmission characteristic or a reflection characteristic relative to at least part of electromagnetic wave found between 30 GHz and 30 THz that is differentiated from a transmission characteristic or a reflection characteristic, whichever appropriate, relative to at least part of an electromagnetic wave found at or above 30 THz for the at least one optical element of the apparatus.

14. The object information acquisition apparatus according to claim 11, further comprising:

a transmission unit that detects, if any, the existence of a target object of examination contained in an object from the acquired tomographic information of the plane of a level in the direction of depth of the object and transmits a signal providing notification of the existence thereof.

15. The object information acquisition apparatus according to claim 11, further comprising:

a detection unit that detects the region of an object of acquisition of tomographic information.

16. An object information acquisition method for acquiring information on the inside of an object, the method comprising:

a first output step of outputting an electromagnetic wave containing a frequency component of part of the frequency range between 30 GHz and 30 THz with a predetermined output power;

a first scanning step of irradiating object light produced by bifurcating the electromagnetic wave of the first output step, while changing the relative position thereof to the region of existence of the object;

a first detection step of defining a relative delay time between reference light produced by bifurcating the electromagnetic wave of the first output step and the object light as a first time at each scanning position of the first scanning step and detecting an interference signal of the reference light and the object light produced as a result of coupling the object light transmitted through or reflected by the object as a result of interaction with the object and the reference light provided with the relative delay time;

a second output step of outputting the electromagnetic wave output in the first output step with the predetermined output power;

a second scanning step of irradiating object light produced by bifurcating the electromagnetic wave of the second output step, while changing the relative position thereof to the region of existence of the object;

a second detection step of defining a relative delay time between reference light produced by bifurcating the electromagnetic wave of the second output step and the object light as a second time at each scanning position of the second scanning step and detecting an interference signal of the reference light and the object light produced as a result of coupling object light transmitted through or reflected by the object as a result of interaction with the object and the reference light provided with the relative delay time; and

a tomographic information acquisition step of processing the signal detected in the first detection step and the signal detected in the second detection step and acquiring tomographic information of planes of different levels relative to the direction of internal depth of the object within the region of the object for acquiring information thereof.

17. The object information acquisition method according to claim 16, further comprising:

a transmission step of, after detecting, if any, the existence of a target object of examination contained in an object in the tomographic information acquisition step, transmitting a signal providing notification of the existence thereof.

18. An object information acquisition method for acquiring information on the inside of an object, the method comprising:

an output step of outputting an electromagnetic wave containing a frequency component of part of the frequency range between 30 GHz and 30 THz;

a scanning step of irradiating the electromagnetic wave, while changing the relative position thereof to the region of existence of the object;

a detection step of varying an output power of the electromagnetic wave from a predetermined output power, and detecting the electromagnetic wave transmitted through or reflected by the object as a result of interaction with the object at each time of varying the output power;

a tomographic information acquisition step of subjecting a signal detected in the detection step to a process including an arithmetic process of determining a variations of the signal and acquiring tomographic information of at least a plane of a level relative to the direction of internal depth of the object within the region of the object for acquiring information thereof.

19. The object information acquisition method according to claim 18, further comprising:

a transmission step of, after detecting, if any, the existence of a target object of examination contained in an object in the tomographic information acquisition step, transmitting a signal providing notification of the existence thereof.

20. An object information acquisition method for acquiring information on the inside of an object, the method comprising:

an output step of outputting an electromagnetic wave containing a frequency component of part of the frequency range between 30 GHz and 30 THz with a predetermined output power;

a scanning step of irradiating the electromagnetic wave, while changing the relative position thereof to the region of existence of the object;

a detection step of changing a delay time between the timing of outputting the electromagnetic wave and the timing of detecting the electromagnetic wave from a predetermined time at each scanning position of the scanning step and detecting the electromagnetic wave transmitted through or reflected by the object as a result of interaction with the object at each time of changing the delay time; and

a tomographic information acquisition step of processing a signal detected in the detection step and acquiring tomographic information of at least a plane of a level relative to the direction of internal depth of the object within the region of the object for acquiring information thereof.

21. The object information acquisition method according to claim 20, further comprising:

a transmission step of, after detecting, if any, the existence of a target object of examination contained in an object in the tomographic information acquisition step, transmitting a signal providing notification of the existence thereof.