Detection apparatus and method
First Claim
1. A substance detection apparatus, comprising:
- a light source to emit light to a planar transparent member, having a proximal first face and a distal second face opposite the first face, the light from the light source first striking the first face of the planar transparent member;
an image capture lens;
a polarization filter including a two-dimensional array of polarization filter areas that are adjacent to each other, each dimension of the two-dimensional array having more than two polarization filter areas;
an image sensor; and
a substance detection processor that executes a detection process to detect a substance present on the second face of the planar transparent member based on an image of the substance captured by the image sensor,wherein the polarization filter, disposed after the image capture lens and before the image sensor with respect to a direction of the light entering the image sensor, passes only a polarized light component having a polarized light direction substantially parallel to a virtual plane including an optical axis of the light source that emits the light to the planar transparent member and an optical axis of the image capture lens,wherein the image sensor is composed of a two-dimensional array of pixels having a plurality of light receiving elements,wherein the light emitted from the light source is reflected at the substance present on the second face of the planar transparent member, the image sensor receives a light reflected from the substance, via the image capture lens and the polarization filter, to capture an image of the substance present on the second face of the planar transparent member; and
wherein the focus of the image capture lens is set at a point in a distance beyond the planar transparent member and less than infinity.
1 Assignment
0 Petitions
Accused Products
Abstract
A substance detection apparatus and method including a light source to emit light to a planar transparent member having a proximal first face and a distal second face opposite the first face, the light from the light source first striking the first face of the planar transparent member. The substance detection apparatus and method including an image capture lens, a polarization filter, an image sensor, and a substance detection processor. The light emitted from the light source is reflected at the substance present on the second face of the planar transparent member, and the image sensor receives light reflected from the substance, via the image capture lens and the polarization filter, to capture an image of the substance present on the second face of the planar transparent member.
34 Citations
11 Claims
-
1. A substance detection apparatus, comprising:
-
a light source to emit light to a planar transparent member, having a proximal first face and a distal second face opposite the first face, the light from the light source first striking the first face of the planar transparent member; an image capture lens; a polarization filter including a two-dimensional array of polarization filter areas that are adjacent to each other, each dimension of the two-dimensional array having more than two polarization filter areas; an image sensor; and a substance detection processor that executes a detection process to detect a substance present on the second face of the planar transparent member based on an image of the substance captured by the image sensor, wherein the polarization filter, disposed after the image capture lens and before the image sensor with respect to a direction of the light entering the image sensor, passes only a polarized light component having a polarized light direction substantially parallel to a virtual plane including an optical axis of the light source that emits the light to the planar transparent member and an optical axis of the image capture lens, wherein the image sensor is composed of a two-dimensional array of pixels having a plurality of light receiving elements, wherein the light emitted from the light source is reflected at the substance present on the second face of the planar transparent member, the image sensor receives a light reflected from the substance, via the image capture lens and the polarization filter, to capture an image of the substance present on the second face of the planar transparent member; and wherein the focus of the image capture lens is set at a point in a distance beyond the planar transparent member and less than infinity. - View Dependent Claims (2, 3, 4, 5, 6, 9)
-
-
7. A method of detecting a substance, comprising the steps of:
-
emitting light, using a light source, to a planar transparent member, having a proximal first face and distal second face opposite the first face, the light from the light source first striking the first face of the planar transparent member; when the light emitted from the light source is reflected at a substance on the second face of the planar transparent member, receiving light reflected from the planar transparent member by an image capture lens; passing, via a polarization filter, only a polarized light component having a polarized light direction substantially parallel to a virtual plane including an optical axis of the light source that emits the light to the planar transparent member and an optical axis of the image capture lens; capturing an image of the substance present on the second face of the planar transparent member by using an image sensor composed of a pixel array having a plurality of light receiving elements arrayed two dimensionally, based on the light reflected from the planar transparent member and passed through the polarization filter, the polarization filter including a two-dimensional array of polarization filter areas that are adjacent to each other, each dimension of the two-dimensional array having more than two polarization filter areas; and detecting the substance based on the image of substance captured by the image sensor; wherein a focus of the image capture lens is set at a point in a distance beyond the planar transparent member and less than infinity. - View Dependent Claims (10)
-
-
8. A non-transitory computer-readable storage medium storing a program that, when executed by a computer, causes the computer to execute a method of detecting a substance, comprising the steps of:
-
emitting light, using a light source, to a planar transparent member, having a proximal first face and distal second face opposite the first face, the light from the light source first striking the first face of the planar transparent member; when the light emitted from the light source is reflected at a substance on the second face of the planar transparent member, receiving light reflected from the planar transparent member by an image capture lens; passing, via a polarization filter, only a polarized light component having a polarized light direction substantially parallel to a virtual plane including an optical axis of the light source that emits the light to the planar transparent member and an optical axis of the image capture lens; capturing an image of the substance present on the second face of the planar transparent member by using an image sensor composed of a pixel array having a plurality of light receiving elements arrayed two dimensionally, based on the light reflected from the planar transparent member and passed through the polarization filter, the polarization filter including a two-dimensional array of polarization filter areas that are adjacent to each other, each dimension of the two-dimensional array having more than two polarization filter areas; and detecting the substance based on the image of substance captured by the image sensor; wherein a focus of the image capture lens is set at a point in a distance beyond the planar transparent member and less than infinity. - View Dependent Claims (11)
-
Specification