APPARATUS FOR DENTAL OCT IMAGING

1 . An apparatus having an optical axis, for obtaining an image of a tooth comprising:

a) an image sensor for obtaining a visible light image which comprises a white light image, a fluorescent light image, or both;

b) a white light source providing broadband polychromatic light for obtaining the white light image;

c) an ultraviolet light source providing narrow-band light for obtaining the fluorescent light image;

d) a light beam combiner disposed to direct the broadband polychromatic light from the white light source and the narrow band light from the ultraviolet light source along a common illumination path to illuminate the tooth;

e) a polarization beamsplitter disposed to direct polarized light from the illumination path along the optical axis as polarized illumination;

f) an optical coherence tomography (OCT) imaging apparatus comprising a low coherence light source and light guiding components that split the low coherence light into a sample path low coherence light and a reference path low coherence light;

g) a dichroic element disposed to direct the polarized illumination and the sample path low coherence light along the optical axis;

h) an image processor programmed to identify a region of interest of the tooth according to either the white light image, the fluorescent light image, or both; and

i) a control logic processor programmed to actuate the OCT imaging apparatus to obtain an OCT image over the region of interest.

2 . The apparatus of claim 1 further comprising a scanner for scanning the sample path low coherence light toward the tooth.

3 . The apparatus of claim 2 wherein the scanner comprises an optical fiber.

4 . The apparatus of claim 1 further comprising a imaging lens for obtaining a visible light image which comprises a white light image, a fluorescent light image, or both.

5 . An apparatus having an optical axis, for obtaining an image of a tooth comprising:

a) an image sensor for obtaining a visible light image which comprises a white light image, a fluorescent light image, or both;

b) a white light source providing broadband polychromatic light for obtaining the white light image;

c) an ultraviolet light source providing narrow-band light for obtaining the fluorescent light image;

d) a first polarization element disposed in the optical path of the white light source to direct polarized light onto the tooth;

e) a second polarization element disposed in the imaging path to attenuate specular reflection from the tooth surface;

f) an optical coherence tomography (OCT) imaging apparatus comprising a low coherence light source and light guiding components that split the low coherence light into a sample path low coherence light and a reference path low coherence light;

g) a dichroic element disposed to direct the polarized illumination and the sample path low coherence light along the optical axis;

h) an image processor programmed to identify a region of interest of the tooth according to either the white light image, the fluorescent light image, or both; and

i) a control logic processor programmed to actuate the OCT imaging apparatus to obtain an OCT image over the region of interest.

6 . An apparatus having an optical axis, for obtaining an image of a tooth comprising:

a) an image sensor for obtaining a visible light image which comprises a white light image, a fluorescent light image, or both;

b) a white light source providing broadband polychromatic light for obtaining the white light image;

c) an ultraviolet light source providing narrow-band light for obtaining the fluorescent light image;

d) a light beam combiner disposed to direct the broadband polychromatic light from the white light source and the narrow band light from the ultraviolet light source along a common illumination path to illuminate the tooth;

e) one or more polarization elements disposed in the illumination path and imaging path to eliminate specular reflection;

f) an optical coherence tomography (OCT) imaging apparatus comprising a low coherence light source and light guiding components that split the low coherence light into a sample path low coherence light and a reference path low coherence light;

g) a dichroic element disposed to direct the polarized illumination and the sample path low coherence light along the optical axis;

h) an image processor programmed to identify a region of interest of the tooth according to either the white light image, the fluorescent light image, or both; and

i) a control logic processor programmed to actuate the OCT imaging apparatus to obtain an OCT image over the region of interest.

7 . An apparatus for making automatic focus adjustment for optical coherence tomography (OCT) scanning comprising:

a) an image sensor for obtaining an image;

b) a first light source providing a first collimated light beam;

c) a second light source providing a second collimated light beam;

d) a scanning lens for focusing the first and the second collimated beams on a surface;

e) a control logic processor which determines positions of the first and the second collimated beams based on said image;

f) a device for moving the lens to overlap the first and the second collimated beams on the surface.

8 . The apparatus of claim 7 wherein the image is reflected from the surface.

9 . The apparatus of claim 7 wherein the surface is a tooth surface.

10 . An optical coherence tomography (OCT) imaging apparatus comprising:

a) an image sensor;

b) a low coherence light source;

c) light guiding components that split the low coherence light into a sample path low coherence light and a reference path low coherence light;

d) a scanning optical fiber optically coupled to the sample path to scan the low coherence light on a surface; and

e) a scanning lens in the path of light from the scanning optical fiber, wherein a chief ray of the lens lies along an optical axis of the scanning optical fiber.

11 . The apparatus of claim 10 wherein the surface is a tooth surface.