Apparatus for detecting information on object

• US 7,683,778 B2
• Filed: 02/07/2007
• Issued: 03/23/2010
• Est. Priority Date: 02/15/2006
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ouchi, Toshihiko
• Primary Examiner(s): Wu; Daniel
• Assistant Examiner(s): TUN, NAY L
• Application Number:
  US11/703,122
• Publication Number:
  US 20070195921A1
• Time in Patent Office: 1,140 Days
• Field of Search: 250/338.1, 250/330, 250/339.06, 250/341.1, 250/334, 324/96, 280/735, 310/300, 340/539.1
• US Class Current: 340/539.1
• CPC Class Codes: G01N 22/00 Investigating or analysing materials by the use of microwaves or radio waves, i.e. electromagnetic waves with a wavelength of one millimetre or more G01N3/00 - G01N17/00, G01N24/00 take precedence

Abstract

An apparatus for detecting information on an object includes an irradiating unit, a detecting unit, and an information-obtaining unit. The irradiating unit irradiates the object with electromagnetic waves as a rectangular shaped beam. The electromagnetic waves include a frequency component in (or range of) at least part of a frequency region of 30 GHz to 30 THz, and have variations in magnitude at intervals of 10⁻¹¹ seconds or more or a temporally constant magnitude. The detecting unit detects the electromagnetic waves transmitted or reflected by the object through interaction therebetween. The information-obtaining unit obtains information on the object from information on the electromagnetic waves detected by the detecting unit.

Claims

1. An imaging apparatus comprising:

an irradiating unit comprising;

a generating unit for generating electromagnetic waves having a frequency range of at least part of a frequency region of 30 GHz to 30 THz; and

a converting unit for converting an intensity distribution of the electromagnetic waves generated by the generating unit into a rectangular distribution;

wherein the irradiating unit irradiates an object with the electromagnetic waves having the intensity distribution of the rectangular distribution;

the imaging apparatus further comprising;

an array detecting unit for detecting, by a plurality of pixels, the electromagnetic waves having the intensity distribution of the rectangular distribution and transmitted through or reflected by the object;

an irradiated-position-changing unit for changing an irradiated position of the object that is irradiated with the electromagnetic waves having the intensity distribution of the rectangular distribution; and

an image-obtaining unit for obtaining a plurality of images of the object corresponding to the rectangular distribution from the electromagnetic waves detected by the array detecting unit with the irradiated position being changed by the irradiated-position-changing unit, and for obtaining a whole image of the object from the plurality of images.

2. The imaging apparatus according to claim 1, wherein

the generating unit generates the electromagnetic waves having variations in magnitude at intervals of 10⁻

11 seconds or more, or a constant magnitude; and

the converting unit includes a cylindrical lens or a parabolic cylindrical mirror, and a fly-eye lens or a diffuser.

3. The imagine apparatus according to claim 2,

wherein the fly-eye lens or the diffuser is arranged such that the intensity distribution of the electromagnetic waves generated by the generating unit is converted from a Gaussian distribution to a rectangular distribution, and

wherein the image-obtaining unit obtains one-dimensional images corresponding to the converted rectangular distribution and combines the images to obtain a two-dimensional image.

4. The imaging apparatus according to claim 1 further comprising;

a dividing unit for dividing the electromagnetic waves generated by the generating unit;

a delay optical unit for delaying electromagnetic waves not to be interacted with the object among the electromagnetic waves divided by the dividing unit; and

a combining unit for combining the electromagnetic waves that have interacted with the object and electromagnetic waves that have not interacted with the object,

wherein the image-obtaining unit obtains a phase shift distribution of the electromagnetic waves that have interacted with the object as an image.

5. The imaging apparatus according to claim 1, further comprising;

a dividing and combining unit for dividing electromagnetic waves that have interacted with the object;

a reflecting mirror for reflecting the electromagnetic waves divided by the dividing and combining unit; and

a movable mirror for adjusting a transmission distance of electromagnetic waves that are different from the electromagnetic waves reflected by the reflecting mirror among the electromagnetic waves divided by the dividing and combining unit,

wherein the dividing and combining unit combines the electromagnetic waves reflected by the reflecting mirror and the electromagnetic waves reflected by the movable mirror, and

wherein the image-obtaining unit obtains a phase shift distribution of the electromagnetic waves that have interacted with the object as an image.

6. The imaging apparatus according to claim 1, wherein the generating unit comprises a coherent light source that causes oscillation at any single frequency in the frequency region of 30 GHz to 30 THz.

7. The imagine apparatus according to claim 1, wherein the irradiated-position-changing unit comprises a movable mirror for changing a reflection direction of the electromagnetic waves generated by the generating unit.

8. The imaging apparatus according to claim 1, wherein the irradiated-position-changing unit moves the object to change the irradiated position.

9. An imaging apparatus for obtaining image information by using terahertz electromagnetic waves, comprising:

an irradiating unit comprising;

a generating unit for generating coherent terahertz electromagnetic waves;

a first converting unit for converting an intensity distribution of the coherent terahertz electromagnetic waves into a rectangular distribution;

a second converting unit for converting a beam shape of the coherent terahertz electromagnetic waves into a rectangular shape;

wherein the irradiating unit irradiates an object with the rectangular shaped beam formed by the first and second converting units;

the imaging apparatus further comprising;

an array detecting unit comprising a plurality of detecting units for respectively detecting a spatial intensity in each of a plurality of regions in the rectangular shape which is a beam shape of the rectangular shaped beam transmitted through or reflected by the object; and

an image information obtaining unit for obtaining image information on a region of the object irradiated with the rectangular shaped beam by using the spatial intensity in each of the plurality of regions which is detected by the array detecting means.

10. The imaging apparatus according to claim 9, further comprising an irradiated-position-changing unit for changing an irradiated position of the object that is irradiated with the rectangular shaped beam formed by the first and second converting units

wherein the image information obtaining unit obtains image information at each of a plurality of irradiated positions, and

wherein the image information corresponds to the spatial intensity distribution in the rectangular shape of the rectangular shaped beam which is detected by the array detecting unit.