Solid-state image sensor having micro-lenses arranged to collect light of which the incidence angle has been moderated by a transparent film disposed thereon
View Patent ↗A solid-state image sensor includes a plurality of light-receiving elements arranged in a light-receiving area, and a plurality of micro-lenses corresponding to the light-receiving elements, and has a flattening film formed on the plurality of the micro-lenses. At a center of the light-receiving area, the micro-lenses are placed in positions directly above corresponding photodiodes, and placed in positions which are progressively offset from positions directly above the corresponding photodiodes, towards a center of the light receiving area, as micro-lenses are located farther from the center of the light-receiving area.
1. A solid-state image sensor comprising:
light-receiving elements arranged in a light-receiving area;
micro-lenses corresponding to said light-receiving elements; and
a transparent film on said micro-lenses for moderating incidence angle of oblique light, entering the solid-state image sensor from above the solid-state image sensor, at a periphery of said light-receiving area,
wherein, in a central portion of said light-receiving area, a corresponding one of said micro-lenses is directly above a corresponding one of said light-receiving elements, and in a portion of said light-receiving area that is closer to the periphery of said light-receiving area than a center of said light-receiving area, corresponding ones of said micro-lenses are offset from directly above corresponding ones of said light-receiving elements, said micro-lenses being arranged to collect the light of which the incidence angle has been moderated by said transparent film.
2. The solid-state image sensor according to claim 1 , wherein
a refractive index of said transparent film is less than a refractive index of said micro-lenses.
3. The solid-state image sensor according to claim 2 , wherein
said solid-state image sensor is a CCD-type image sensor.
4. The solid-state image sensor according to claim 2 , wherein
said solid-state image sensor is an MOS-type image sensor.
5. The solid-state image sensor according to claim 1 , wherein
said solid-state image sensor is a CCD-type image sensor.
6. The solid-state image sensor according to claim 1 , wherein
said solid-state image sensor is an MOS-type image sensor.
7. The solid-state image sensor according to claim 1 , further comprising
color filters between said light-receiving elements and said micro-lenses.
8. The solid-state image sensor according to claim 7 ,
wherein each of said color filters has a convex shape.
9. The solid-state image sensor according to claim 7 ,
wherein a refractive index of said transparent film is between 1.4 to 1.5 inclusive.
10. The solid-state image sensor according to claim 7 ,
wherein a refractive index of said micro lenses is between 1.6 to 1.7 inclusive.
11. The solid-state image sensor according to claim 9 ,
wherein a refractive index of said transparent film is between 1.4 to 1.5 inclusive.
12. The solid-state image sensor according to claim 1 ,
wherein said transparent film is formed to fill-in spaces between said micro-lenses that are adjacent to one another.
13. The solid-state image sensor according to claim 12 ,
wherein a refractive index of said micro lenses is between 1.6 to 1.7 inclusive.
14. The solid-state image sensor according to claim 13 ,
wherein a refractive index of said transparent film is between 1.4 to 1.5 inclusive.
15. The solid-state image sensor according to claim 12 ,
wherein a refractive index of said transparent film is between 1.4 to 1.5 inclusive.
16. The solid-state image sensor according to claim 1 , further comprising
color filters corresponding to said light-receiving elements,
wherein, in the portion of said light-receiving area that is closer to the periphery of said light-receiving area than the center of said light-receiving area, corresponding ones of said color filters are offset from directly above corresponding ones of said light-receiving elements towards the center of said light-receiving area.
17. The solid-state image sensor according to claim 16 ,
wherein an amount of offset of each of said corresponding ones of said micro-lenses is greater than an amount of offset of a respective one of said corresponding ones of said color filters.
18. The solid-state image sensor according to claim 1 ,
wherein a distance from one of said light-receiving element to a bottom of a corresponding one of said micro-lenses is between 3μm to 5μm inclusive.
19. The solid-state image sensor according to claim 1 ,
wherein a refractive index of said micro lenses is between 1.6 to 1.7 inclusive.
20. The solid-state image sensor according to claim 19 ,
wherein a refractive index of said transparent film is between 1.4 to 1.5 inclusive.
21. The solid-state image sensor according to claim 1 ,
wherein a refractive index of said transparent film is between 1.4 to 1.5 inclusive.
22. The solid-state image sensor according to claim 1 ,
wherein the micro-lenses also serve as color filters.