Imaging system with optimized extended depth of focus
An optical processor is presented for applying optical processing to a light field passing through a predetermined imaging lens unit. The optical processor comprises a pattern in the form of spaced apart regions of different optical properties. The pattern is configured to define a phase coder, and a dispersion profile coder. The phase coder affects profiles of Through Focus Modulation Transfer Function (TFMTF) for different wavelength components of the light field in accordance with a predetermined profile of an extended depth of focusing to be obtained by the imaging lens unit. The dispersion profile coder is configured in accordance with the imaging lens unit and the predetermined profile of the extended depth of focusing to provide a predetermined overlapping between said TFMTF profiles within said predetermined profile of the extended depth of focusing.
1. An ophthalmic lens arrangement, comprising:
an ophthalmic lens for acting upon light comprising visible wavelengths;
a phase coder associated with the ophthalmic lens; and
a dispersion coder associated with the ophthalmic lens,
the phase coder comprising a first pattern of features that induces a non-diffractive phase effect to the light comprising visible wavelengths, the phase coder providing additional depth of focus in addition to a depth of focus of the ophthalmic lens,
the dispersion coder comprising a second pattern of features that induces a diffractive effect to the light comprising visible wavelengths, the second pattern of features having spatial frequency that varies with radius from a center of the ophthalmic lens, the second pattern having a spatial frequency at a first radius that is larger than a spatial frequency at a second radius, the first radius being larger than the second radius,
the dispersion coder providing focus shifts of through focus modulation transfer function (TFMTF) profiles associated with the ophthalmic lens and the phase coder for multiple wavelengths of the light comprising visible wavelengths so as to increase an amount of overlap of the TFMTF profiles for the multiple wavelengths.
2. The ophthalmic lens arrangement of claim 1 , wherein the phase coder provides the additional depth of focus without adding optical power beyond that of the ophthalmic lens.
3. The ophthalmic lens arrangement of claim 1 , wherein the phase coder provides the additional depth of focus without reducing an aperture of the ophthalmic lens.
4. The ophthalmic lens arrangement of claim 1 , wherein the phase coder provides the additional depth of focus without causing loss of energy.
5. The ophthalmic lens arrangement of claim 1 , wherein the phase coder provides the additional depth of focus without causing loss of resolution.
6. The ophthalmic lens arrangement of claim 1 , wherein the dispersion coder provides chromatic aberration correction.
7. The ophthalmic lens arrangement of claim 1 , wherein the first pattern is a radial pattern and the second pattern is a radial pattern.
8. The ophthalmic lens arrangement of claim 1 , wherein the first and second patterns are located at first and second surfaces, respectively, of the ophthalmic lens.
9. The ophthalmic lens arrangement of claim 1 , wherein the first and second patterns are in the form of first and second surface reliefs, respectively.
10. The ophthalmic lens arrangement of claim 1 , wherein the first and second patterns are incorporated in the ophthalmic lens.
11. The ophthalmic lens arrangement of claim 1 , wherein one of the first and second patterns is incorporated in the ophthalmic lens, and the other of said first and second patterns comprises a mask located at a side of the ophthalmic lens.
12. The ophthalmic lens arrangement of claim 1 , wherein the first and second patterns are disposed at a same surface and define together a combined pattern comprising a superposition of said first and second patterns.
13. The ophthalmic lens arrangement of claim 1 , wherein the ophthalmic lens is a multi-focal lens.
14. The ophthalmic lens arrangement of claim 1 , wherein the ophthalmic lens arrangement is configured as a contact lens.
15. The ophthalmic lens arrangement of claim 14 , wherein the contact lens is a multi-focal lens.
16. The ophthalmic lens arrangement of claim 14 , wherein the contact lens is a bi-focal lens.
17. The ophthalmic lens arrangement of claim 1 , wherein the ophthalmic lens arrangement comprises multiple zones having different optical powers.