Light-collecting apparatus and contact-type solid-state imaging apparatus using the same
The present invention provides a contact-type solid-state imaging apparatus which realizes high resolution and high sensitivity, and also implements downsizing and lowering the cost of the contact-type solid-state imaging apparatus. Each pixel includes a protection glass plate, a light-collecting device, a light-receiving device, a semiconductor integrated circuit, a light emitting diode (LED) and a mounting package. The light-collecting apparatus has two kinds of distributed index lens (o lens and convex lens), and Sin (N=2) film, which is a two-stage concentric structure, is embedded in SiO 2 (N=1.45) film.
1. A contact-type solid-state imaging apparatus comprising a plurality of unit pixels arranged in a two-dimensional array or a one-dimensional array, each of said unit pixels including a light-collecting device and a light-receiving device,
wherein said light-collecting device includes at least two different optical systems, each of which has an effective refraction index distribution in an incident window area,
the effective refraction index distribution includes a combination of a plurality of zone areas with a concentric structure, the plurality of zone areas being divided into line widths which are equal to or shorter than a wavelength of incident light,
the optical systems are located at a paraxial imaging position in-line with a transmission direction of an incident light, and
the incident window area of each of the optical systems has a rectangular shape in accordance with an aperture of each unit pixel.
2. The contact-type solid-state imaging apparatus according to claim 1 ,
wherein at least one of the plurality of zone areas includes:
a lower light-transmitting film with the concentric structure and having a first line width and a first film thickness; and
an upper light-transmitting film with the concentric structure, configured above said lower light-transmitting film, and having a second line width and a second film thickness.
3. The contact-type solid-state imaging apparatus according to claim 1 ,
wherein the effective refraction index distribution of said light-collecting device is asymmetric with respect to an optical axis.
4. The contact-type solid-state imaging apparatus according to claim 1 , wherein the light-collecting device comprises a plurality of light-collecting devices,
wherein a light incident to said plurality of light-collecting devices is transmitted to said light-receiving device.
5. The contact-type solid-state imaging apparatus according to claim 1 ,
wherein at least one of the two different optical systems located at the paraxial imaging position has a different chromatic aberration from an other of the at least two different optical systems.
6. The contact-type solid-state imaging apparatus according to claim 1 ,
wherein at least one of the two different optical systems at the paraxial imaging position has a different focal length from an other of the two different optical systems.
7. The contact-type solid-state imaging apparatus according to claim 1 ,
wherein said light-collecting device includes a first light-collecting unit for collecting light by a diffraction, and a second light-collecting unit for collecting light by refraction.
8. The contact-type solid-state imaging apparatus according to claim 1 ,
wherein said light-collecting device is formed in monolithic on a semiconductor integrated circuit on which a light-receiving device is formed.
9. The contact-type solid-state imaging apparatus according to claim 1 ,
wherein the optical systems form an optical waveguide structure having a light containing effect generated by a high-low difference in reflection indexes.
10. The contact-type solid-state imaging apparatus according to claim 1 ,
wherein a part or whole of the optical system comprises a convex structure having a curved cross-section.