Extended depth of field intraoral imaging apparatus

Abstract

An apparatus for intraoral imaging has an illumination source that directs light to an object. An imaging apparatus forms an image at an image sensor array from reflected light from the object, the imaging apparatus having an optical stop along an optical axis. A phase modulator is disposed at or near the optical stop. An image processor conditions data from the image sensor array and provides processed image data of the object.

1 . An apparatus for intraoral imaging comprising:
 a) an illumination source that directs light to an object;   b) an imaging apparatus that forms an image at an image sensor array from reflected light from the object, the imaging apparatus having an optical stop along an optical axis;   c) a phase modulator disposed at or near the optical stop; and   d) an image processor that conditions data from the image sensor array and provides processed image data of the object.   
     
     
         2 . The apparatus of  claim 1  wherein the image processor provides deblurring of the image data. 
     
     
         3 . The apparatus of  claim 1  wherein the optical stop is between an objective lens that directs the reflected light through the optical stop and a second lens that directs light from the optical stop to the image sensor array. 
     
     
         4 . The apparatus of  claim 1  further comprising a display for rendering the processed image data. 
     
     
         5 . The apparatus of  claim 1  wherein the phase modulator is a cubic phase modulator. 
     
     
         6 . The apparatus of  claim 1  wherein the phase modulator, from a view along the optical axis, is rectangular or circular in shape. 
     
     
         7 . The apparatus of  claim 1  wherein the phase modulator has different phase functions in orthogonal x- and y-directions. 
     
     
         8 . The apparatus of  claim 1  wherein the illumination source includes a solid-state light emitter. 
     
     
         9 . The apparatus of  claim 1  wherein the image sensor array is a color or monochromatic device. 
     
     
         10 . The apparatus of  claim 1  wherein the illumination source generates patterned illumination for surface contour imaging of the object. 
     
     
         11 . An apparatus for intraoral imaging comprising:
 a) an illumination source that directs light to an object;   b) an imaging apparatus that forms an image from reflected light from the object at an image sensor array, the imaging apparatus having an optical stop along an optical axis between an objective lens that directs the reflected light through the optical stop and a second lens that directs light from the optical stop to the image sensor array.   c) a phase modulator disposed at or near the optical stop;   d) an image processor that is programmed with instructions to condition data from the image sensor array for deblurring according to phase function characteristics of the phase modulator; and provides processed image data of the object; and   e) a display in signal communication with the image processor for rendering the processed image data.   
     
     
         12 . The apparatus of  claim 11  wherein the phase modulator is a cubic phase plate to increase a depth of focus for the intraoral imaging apparatus. 
     
     
         13 . An intraoral imaging method comprising:
 a) directing light to an object from an illumination source;   b) directing reflected light from the object along an optical axis through an objective lens that directs the light through an optical stop;   c) disposing a phase modulator along the optical axis, at or near the optical stop;   d) forming image data at an image sensor array from the imaged reflected light from the object;   e) conditioning the image data for deblurring; and   f) rendering the conditioned image data on a display.   
     
     
         14 . The method of  claim 13  wherein the optical stop is positioned between the objective lens and a second lens, and where the phase modulator causes the imaging system to have similar point spread functions over a range of object distances. 
     
     
         15 . The method of  claim 13  wherein conditioning the data for deblurring comprises digitally filtering the data based on a point spread function.