Uniform illumination for camera based imaging devices
A camera system for imaging a document including an enclosed imaging-optical-chamber, at least one camera mounted inside the imaging-optical-chamber and having a lens defining the primary FOV of the camera, at least one light source for illuminating the document; at least one light-occluding structures, wherein each light sources are operatively coupled with a light-occluding structures, a glass-window, wherein the document is operatively disposed on the glass-window, and wherein the glass-window extends the FOV of the camera thereby forming an extended FOV of the camera. The system further includes at least one mirror operatively coupled with at least one of the light sources. Preferably, the light sources are disposed inside the primary FOV of the camera, such that the imaginary light-source of the light source is disposed outside the extended FOV of the camera.
1. A camera system for imaging a document comprising:
(a) an enclosed imaging-optical-chamber;
(b) at least one camera mounted inside said imaging-optical-chamber, wherein said camera is configured to acquire image frames of at least a portion of the document, and wherein said camera includes a lens defining the primary FOV of said camera;
(c) at least one light source for illuminating said portion of the document being imaged;
(d) at least one light-occluding structures, wherein each of said light sources is operatively coupled with at least one of said light-occluding structures;
(e) a glass-window, wherein the document is operatively disposed on the external surface of said glass-window, and wherein said glass-window extends the FOV of said camera thereby forming an extended FOV of said camera; and
(f) at least one mirror operatively coupled with at least one of said light sources,
wherein said at least one light source is disposed inside said primary FOV of said camera;
wherein each of said light-occluding structures prevents each of said operatively coupled light sources from directly illuminating said glass-window;
wherein each of said light-occluding structures facilitates each of said operatively coupled light sources to directly illuminate said operatively coupled mirror; and
wherein the light rays illuminating said mirrors reflect from said mirrors to illuminate at least a portion of said glass-window, and thereby, also illuminate said portion of the document being imaged.
2. The system of claim 1 , wherein the document is an identity document.
3. The system of claim 1 , wherein said at least one light source is disposed inside said primary FOV of said camera, such that the imaginary light-source of said light source is disposed outside said extended FOV of said camera.
4. The system of claim 1 , wherein all internal walls of said imaging-optical-chambers, except for said at least one mirror and said glass-windows, are painted in black.
5. The system of claim 1 , wherein at least a portion of the internal walls of said imaging-optical-chambers, except for said at least one mirror and said glass-windows, coated with light absorbing material.
6. The system of claim 1 , wherein said at least one light source of said illumination system is selected from the group of light sources type: Infra Red (IR), Ultra Violate (UV), Visible Light (VL) and fluorescence image.
7. The system of claim 1 , wherein said at least one light source of said illumination system is a LED light source.
8. The system of claim 1 , wherein said at least one light source of said illumination system is a halogen light source.
9. The system of claim 1 , wherein all walls of said optical chamber are opaque, except for said glass-window.
10. A method for imaging a document, comprising the steps of:
(a) providing a camera system including:
i. an enclosed imaging-optical-chamber;
ii. at least one camera mounted inside said imaging-optical-chamber, wherein said camera is configured to acquire image frames of at least a portion of the document, and wherein said camera includes a lens defining the primary FOV of said camera;
iii. at least one light source for illuminating said portion of the document being imaged;
iv. at least one light-occluding structures, wherein each of said light sources is operatively coupled with at least one of said light-occluding structures;
v. a glass-window, wherein the document is operatively disposed on the external surface of said glass-window, and wherein said glass-window extends the FOV of said camera thereby forming an extended FOV of said camera; and
vi. at least one mirror operatively coupled with at least one of said light sources, by said at least one camera,
wherein said at least one light source is disposed inside said primary FOV of said camera, such that the imaginary light-source of said light source is disposed outside said extended FOV of said camera;
(b) illuminating the document with said at least one imaginary light-sources; and
(c) acquiring at least one image frame of at least a portion of the document.