Diffractive lenses for vision correction
First Claim
1. A diffractive optical element comprising:
- at least one diffractive structure having a plurality of zones wherein each of the zones has locations in accordance with the equation wherein aj and φ
j are the amplitude and phase, respectively, of a finite number of terms j from 0 to jmax, and ξ
is a fractional position at or between zero and one within the zone.
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Accused Products
Abstract
Diffractive lenses for vision correction are provided on a lens body having a first diffractive structure for splitting light into two or more diffractive orders to different focal distances or ranges, and a second diffractive structure, referred to as a multiorder diffractive (MOD) structure, for diffracting light at different wavelengths into a plurality of different diffractive orders to a common focal distance or range. In a bifocal application, the first and second diffractive structures in combination define the base power for distance vision correction and add power for near vision correction of the lens. The first and second diffractive structures may be combined on the same surface or located on different surfaces of the lens. The first diffractive structure may have blazed (i.e., sawtooth), sinusoidal, sinusoidal harmonic, square wave, or other shape profile. A sinusoidal harmonic diffractive structure is particularly useful in applications where smooth rather than sharp edges are desirable.
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Citations
50 Claims
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1. A diffractive optical element comprising:
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at least one diffractive structure having a plurality of zones wherein each of the zones has locations in accordance with the equation wherein aj and φ
j are the amplitude and phase, respectively, of a finite number of terms j from 0 to jmax, and ξ
is a fractional position at or between zero and one within the zone. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An ophthalmic lens comprising:
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a lens body having first and second surfaces;
a first diffractive structure for splitting light of different wavelengths into two or more diffractive orders to different focal distances or ranges;
a second diffractive structure for diffracting light into a plurality of different diffractive orders to a common focal distance or range, in which said first and second diffractive structures are located on the same or different ones of said first and second surfaces; and
said first and second diffractive structures in combination provide at least near and distance vision correction, in which said first diffractive structure represents a sinusoidal harmonic diffractive structure having a plurality of zones that is continuous within each of the zones and at the boundaries between zones. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
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34. A method for providing a bifocal ophthalmic lens having a base power and an add power comprising the steps of:
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selecting a first diffractive structure for the lens for diffracting light in a plurality of different diffractive orders to a common focal distance or range in accordance with needed base power of the lens; and
selecting a second diffractive structure for the lens for splitting light into two or more diffractive orders to different focal distances or ranges in which the base power for distance vision correction and add power for near vision correction are in accordance with a combination of said first and said second diffractive structures, in which said second diffractive structure represents a sinusoidal harmonic diffractive structure having a plurality of zones that is continuous within each of the zones and at the boundaries between zones. - View Dependent Claims (35, 36, 37, 38, 39, 40, 41, 42)
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43. An optical element comprising:
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a lens body having first and second surfaces;
a first diffractive structure for splitting light into two or more diffractive orders to different focal distances or ranges;
a second diffractive structure for diffracting light into a plurality of different diffractive orders to a common focal distance or range, in which said first and second diffractive structures are located on the same or different ones of said first and second surfaces; and
said first diffractive structure and said second diffractive structure in combination provide a plurality of different focal distances or ranges for vision correction at different distances or ranges, in which said first diffractive structure represents a sinusoidal harmonic diffractive structure. - View Dependent Claims (44, 45)
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- 46. An ophthalmic lens comprising a lens body having a sinusoidal harmonic diffractive structure for splitting light of different wavelengths into two or more diffractive orders to different focal distances or ranges to provide two or more different powers, and said lens body provides refractive base optical power to the lens.
Specification