Imaging system with relaxed assembly tolerances and associated methods
View Patent ↗An imaging system includes an extended depth of field (EDOF) optical system, a sensor on a sensor substrate, and a securing mechanism adapted to secure the EDOF optical system directly to the sensor substrate.
1. An imaging system, comprising:
an extended depth of field (EDOF) optical system, wherein the EDOF optical system is a single element including a phase element adapted to provide a more uniform modulation transfer function over a range of focus than the optical system alone, wherein an effective focal length of light output from the phase element is a function of at least one of an angular component and a radial component on which the light is incident on the phase element;
a sensor on a sensor substrate; and
a securing mechanism adapted to secure the EDOF optical system directly to the sensor substrate.
2. The imaging system as claimed in claim 1 , wherein the sensor substrate includes a package surrounding the sensor.
3. The imaging system as claimed in claim 2 , wherein securing mechanism attaches the EDOF optical system to the package, the package and the EDOF optical system enclosing the sensor.
4. The imaging system as claimed in claim 1 , wherein the securing mechanism includes standoffs between a bottom surface of the EDOF optical system and the sensor substrate.
5. The imaging system as claimed in claim 4 , wherein the standoffs are integral with the bottom surface of the EDOF optical system.
6. The imaging system as claimed in claim 5 , wherein the bottom surface of the EDOF optical system and the standoffs enclose the sensor.
7. The imaging system as claimed in claim 4 , wherein the bottom surface of the EDOF optical system and the standoffs enclose the sensor.
8. The imaging system as claimed in claim 1 , wherein the function includes a radial component and an angular component.
9. The imaging system as claimed in claim 8 , wherein the angular component and the radial component of the function are separable.
10. The imaging system as claimed in claim 9 , wherein the angular component is a first order equation and the radial component is a second order equation.
11. The imaging system as claimed in claim 1 , wherein the angular component approximates sin(θ/2).
12. The imaging system as claimed in claim 1 , wherein a deviation between modulation transfer functions (MTFs) within a range of at least 5% of a height between the sensor and the EDOF optical system, around a focus is less than about 0.1 MTF.
13. The imaging system as claimed in claim 1 , further comprising an electrical I/O on a same surface of the sensor substrate as the sensor.
14. The imaging system as claimed in claim 1 , further comprising an electrical I/O on a surface of the sensor substrate opposite the sensor.
15. A mobile phone including an image system according to claim 1 .
16. A portable computer including an image system according to claim 1 .
17. A method of making an imaging system, comprising:
providing an extended depth of field (EDOF) optical system, wherein the EDOF optical system is a single element including a phase element adapted to provide a more uniform modulation transfer function over a range of focus than the optical system alone, wherein an effective focal length of light output from the phase element is a function of at least one of an angular component and a radial component on which the light is incident on the phase element; and
securing the EDOF optical system directly to a sensor substrate having a sensor.
18. The method as claimed in claim 17 , wherein securing includes securing a plurality of EDOF optical systems to the sensor substrate having a corresponding plurality of sensors thereon, creating a plurality of imaging systems on the sensor substrate.
19. The method as claimed in claim 18 , further comprising separating along the z-axis of the sensor substrate to form individual imaging systems from the plurality of imaging systems.
20. The method as claimed in claim 17 , wherein securing seals the sensor.
21. The method as claimed in claim 17 , wherein securing includes attaching the EDOF optical system to a package on the sensor substrate surrounding the sensor.
22. An imaging system, comprising:
an extended depth of field (EDOF) optical system;
a sensor on a sensor substrate, wherein a deviation between modulation transfer functions (MTFs) within a range of at least 5% of a height between the sensor and the EDOF optical system, around a focus is less than about 0.1 MTF; and
a securing mechanism adapted to secure the EDOF optical system directly to the sensor substrate.