Two-dimensional imager with solid-state auto-focus
First Claim
Patent Images
1. An imaging apparatus having a solid state auto-focus, the apparatus comprising:
- a broadband light source configured to illuminate an object to be imaged;
an objective lens module configured to focus the broadband light reflected from the object, wherein the objective lens module has a chromatic aberration that separates focal planes of different wavelengths of light;
a two-dimensional image sensor configured to capture image data of the object;
a two-dimensional color filter array configured to filter light reflected from the object before reaching the image sensor, wherein the filtering comprises transmitting only one band of wavelengths at certain positions in the array, and at least two bands of wavelengths are transmitted over the array;
a range finder configured to determine a distance of the object from the image sensor; and
,a processor configured to construct a luminance plane containing an image of the object by adding weighted high and low spatial frequency contributions from the image data for each of the bands of wavelengths, wherein the weighting of the contributions is based at least upon the distance of the object from the image sensor.
1 Assignment
0 Petitions
Accused Products
Abstract
An imaging system having a solid-state auto focusing system advantageously images broadband light reflected from an object to be imaged using a lens objective having chromatic aberration, which focuses different colors of light at different focal planes. Using the color information in the focal planes in conjunction with an object distance determined by a range finder, a luminance plane is constructed that has a focused image of the object. The system provides the focused image of the object without the use of any moving parts.
-
Citations
20 Claims
-
1. An imaging apparatus having a solid state auto-focus, the apparatus comprising:
-
a broadband light source configured to illuminate an object to be imaged; an objective lens module configured to focus the broadband light reflected from the object, wherein the objective lens module has a chromatic aberration that separates focal planes of different wavelengths of light; a two-dimensional image sensor configured to capture image data of the object; a two-dimensional color filter array configured to filter light reflected from the object before reaching the image sensor, wherein the filtering comprises transmitting only one band of wavelengths at certain positions in the array, and at least two bands of wavelengths are transmitted over the array; a range finder configured to determine a distance of the object from the image sensor; and
,a processor configured to construct a luminance plane containing an image of the object by adding weighted high and low spatial frequency contributions from the image data for each of the bands of wavelengths, wherein the weighting of the contributions is based at least upon the distance of the object from the image sensor. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A method of auto-focusing an imaging system, the method comprising:
-
focusing broadband light reflected from an object to be imaged, wherein different wavelengths of light are focused at different focal surfaces; filtering the focused light to determine contributions of light to one or more color surfaces; capturing image data of the object, wherein the image data comprises the filtered focused light; constructing a resultant surface for the captured image data, including (i) decomposing the contributions of light to the one or more color surfaces into high frequency components and low frequency components and (ii) determining contributions of the high frequency components and the low frequency components for each of the one or more color surfaces to the resultant surface by empirically obtaining data for a modulation transfer function (MTF) as a function of object distance for the imaging system and determining contributions of the high frequency components and the low frequency components based upon the empirical data; and
,identifying the object imaged in the resultant surface, wherein the object imaged in the resultant surface is focused. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
-
-
15. An imaging apparatus having a solid state auto-focus, the apparatus comprising:
-
means for focusing broadband light reflected from an object to be imaged, wherein different wavelengths of light are focused at different focal planes; means for filtering the focused light to determine contributions of light to one or more color planes; means for receiving image data of the object, wherein the image data comprises the filtered focused light; means for constructing a composite plane for the captured image data; means for determining the object imaged in the composite plane, wherein the object imaged in the composite plane is focused. - View Dependent Claims (16, 17, 18, 19, 20)
-
Specification