Device and method for uniform in vivo illumination
An in vivo imaging device comprises a viewing window, an illumination unit, a lens holder and a light guide. The light guide may be positioned to create uniformly dispersed illumination and to eliminate backscatter from the viewing window. The light guide may guide light from the illumination unit to a desired position within the in vivo device. In one embodiment, the light guide may be embedded into the lens holder.
1. A device for in vivo imaging comprising:
a dome-shaped window;
a substrate perpendicular to a device's optical axis;
an illumination unit;
a light guide;
an image sensor installed on said substrate, said image sensor centered along the device's optical axis,
wherein said illumination unit illuminates an object through said light guide and through said window and wherein said image sensor collects light reflected from the object through said window;
a lens holder centered along the device's optical axis and having a first end that is adjacent to the apex of the window, said first end being closer to the apex of the window than the illumination unit and at least partially obscuring a field of illumination of said illumination unit; and
wherein said light guide is to guide light from the illumination unit to a light source exit area at the same plane of the first end of the lens holder or at a plane closer to said apex of said window than said first end of the lens holder, said planes being parallel to the substrate plane.
2. The device according to claim 1 wherein the dome-shaped window is structured as an ellipsoid, and wherein said light is guided to a focal curve of the ellipsoid.
3. The device according to claim 1 , wherein said light guide comprises optical fibers.
4. The device according to claim 1 , wherein said light guide comprises a light pipe.
5. The device according to claim 4 , wherein said light guide is shaped to reduce the light exit area of the illumination unit.
6. The device according to claim 1 , wherein said illumination unit is a LED or an MED.
7. The device according to claim 6 , wherein said light guide comprises a plurality of optical fibers for guiding light from said LED or OLED to the light source exit area, to provide uniformly dispersed illumination.
8. The device according to claim 1 , wherein said in-vivo imaging device is a swallowable capsule.
9. The device according to claim 1 , wherein said lens holder comprises a tunnel ending at said exit area and wherein said light guide is disposed within said tunnel.
10. The device according to claim 1 , wherein said light guide comprises a plurality of optical fibers for guiding light from said illumination unit to said light source exit area.
11. A method for manufacture of an in vivo imaging capsule, the method comprising the steps of:
installing on a substrate an imager and a light source behind a dome-shaped window, said substrate perpendicular to the imaging capsule's optical axis, and said light source;
installing on the substrate a lens holder centered along the imaging capsule's optical axis and having a first end that is adjacent to the apex of the window, said first end being closer to the apex of the window than the light source and at least partially obscuring a field of illumination of said light source, and a light guide, said light guide to direct illumination from said light source to a light source exit area at the same plane of said first the end of the lens holder or at a plane closer to said apex of said window than said first end of the lens holder, said planes being parallel to the substrate; and
encapsulating the substrate in a housing of the in vivo imaging capsule.
12. The method of claim 11 further comprising: reducing the exit area of the light source to achieve a nearly linear illumination exit.