1. A method of balancing a first waveform used to drive an LED, the first waveform having a first cycle with a first amplitude and a second cycle with a second amplitude, the method comprising:
adjusting the first amplitude of the first cycle to match the second amplitude of the second cycle, the result being a second waveform; and
driving the LED with the second waveform.
2. The method of claim 1, wherein the first amplitude is greater than the second amplitude and wherein the adjusting comprises attenuating the first cycle so that the first amplitude matches the second amplitude.
3. The method of claim 1 and further comprising determining if the first amplitude is within a predetermined value of the second amplitude and skipping the adjusting if the first amplitude is within a predetermined value of the second amplitude.
4. The method of claim 1, wherein the first waveform is rectified from a sinusoidal waveform being attenuated by a first conduction angle during the first cycle and a second conduction angle during the second cycle.
5. The method of claim 1, wherein the first cycle has a DC component and wherein the adjusting is performed by changing the DC component of the first cycle.
6. The method of claim 5, wherein the adjusting is performed by a DC to DC converter.
7. The method of claim 1, wherein the first amplitude is less than the second amplitude and wherein the adjusting comprises amplifying the first cycle so that the first amplitude matches the second amplitude.
8. The method of claim 1, wherein the first cycle has a peak associated therewith, the second cycle has a peak associated therewith, and wherein the amplitudes are based on the peaks.
9. The method of claim 1, wherein the first cycle has a trough associated therewith, the second cycle has a trough associated therewith, and wherein the amplitudes are based on the troughs.
10. An LED driver comprising:
an input for receiving an input current, the input current having a first cycle having a first conduction angle and a second cycle having a second conduction angle;
a decision circuit, wherein the decision circuit determines when the amplitude of the first cycle is within a predetermined value of the amplitude of the second cycle; and
a converter, wherein the converter adjusts the amplitude of the first cycle to be substantially equal to the amplitude of the second cycle when the amplitude of the first cycle is not within the predetermined value of the amplitude of the second cycle.
11. The LED driver of claim 10 and further comprising a rectifier connected to the input, wherein the rectifier rectifies the input current, and wherein the decision circuit acts on the rectified current.
12. The LED driver of claim 10, wherein the converter is a DC to DC converter.
13. The LED driver of claim 10, wherein the first cycle has a DC component and wherein the converter adjusts the DC component of the first cycle.
14. The LED driver of claim 10 and further comprising a balancing circuit, wherein the balancing circuit receives data from the decision circuit indicating that the first cycle needs to be adjusted and outputs data to the converter as to the amount to adjust the first cycle.
15. The LED driver of claim 14, wherein the converter, balancing circuit, and decision circuit are integrated into a single circuit.
16. The LED driver of claim 10, wherein the decision circuit determines whether the amplitude of the first cycle is lower than the amplitude of the second cycle and adjusts the cycle with the greater of the two amplitudes to the lower amplitude.
17. The LED driver of claim 10, wherein the first cycle has a peak associated therewith, the second cycle has a peak associated therewith, and wherein the amplitudes are based on the peaks.
18. The LED driver of claim 10, wherein the first cycle has a trough associated therewith, the second cycle has a trough associated therewith, and wherein the amplitudes are based on the troughs.
19. The LED driver of claim 10, wherein the LED driver is located in a bulb.
20. A method of balancing a first current waveform used to drive an LED, the waveform having a first cycle with a first amplitude and a second cycle with a second amplitude, the method comprising:
rectifying the first current waveform;
determining whether the first amplitude and the second amplitude have a difference that is greater than a predetermined value;
determining the amount that the greater of the first amplitude and the second amplitude has to be attenuated when the difference between the first amplitude and the second amplitude is greater than a predetermined value;
adjusting the greater of the first amplitude and the second amplitude to the lower of the first amplitude and the second amplitude, the resulting waveform being a second current waveform; and
driving the LED with the second current waveform.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1.-15. (canceled)
16. A photopolymer formulation comprising matrix polymers, writing monomers and photoinitiators, wherein the photopolymer formulation further comprises fluorourethanes as plasticizers.
17. The photopolymer formulation according to claim 16, wherein the fluorourethanes have at least one structural element of the formula (I)
and are substituted by at least one fluorine atom.
18. The photopolymer formulation according to claim 16, wherein the fluorourethanes comprise compounds having the formula (II)
wherein
n is from 1 to 8 and
R1, R2, R3 represent, independently of one another, hydrogen or linear, branched, cyclic or heterocyclic organic radicals which are unsubstituted or optionally also substituted by heteroatoms, at least one of the radicals R1, R2, R3 being substituted by at least one fluorine atom.
19. The photopolymer formulation according to claim 18, wherein R1 represents an organic radical having at least one fluorine atom.
20. The photopolymer formulation according to claim 18, wherein R1 comprises 1-20 CF2 groups andor one or more CF3 groups, R2 comprises a C1-C20 alkyl radical or hydrogen, and R3 comprises a C1-C20 alkyl radical or hydrogen.
21. The photopolymer formulation according to claim 18, wherein R1 comprises 1-10 CF2 groups andor one or more CF3 groups, R2 comprises a C1-C10 alkyl radical or hydrogen, and R3 comprises a C1-C10 alkyl radical or hydrogen.
22. The photopolymer formulation according to claim 18, wherein R1 comprises 1-8 CF2 groups andor one or more CF3 groups.
23. The photopolymer formulation according to claim 16, wherein the fluorourethanes comprise uretdione, isocyanurate, biuret, allophanate, polyurea, oxadiazadione andor iminooxadiazinedione structural elements andor mixtures of these structural elements.
24. The photopolymer formulation according to claim 16, wherein the fluorourethanes have a refractive index nD20 of \u22661.4600.
25. The photopolymer formulation according to claim 16, wherein the fluorourethanes have a refractive index nD20 of \u22661.4300.
26. The photopolymer formulation according to claim 16, wherein the fluorourethanes have a fluorine content of 10-80% by weight.
27. The photopolymer formulation according to claim 16, wherein the fluorourethanes have a fluorine content of 17.5-65% by weight.
28. The photopolymer formulation according to claim 16, wherein the matrix polymers comprise polyurethanes.
29. The photopolymer formulation according to claim 16, wherein the writing monomers comprise acrylates.
30. The photopolymer formulation according to claim 29, wherein the acrylates have a refractive index of nD20>1.50.
31. The photopolymer formulation according to claim 16, wherein the photopolymer formulation consists essentially of 15 to 79 by weight of matrix polymers, 5 to 50 by weight of writing monomers, 1 to 10 by weight of photoinitiators and 5 to 50 by weight of fluorourethanes and 0 to 10% by weight of further additives, wherein the sum of the constituents being 100% by weight.
32. Holographic elements and images formed from the photopolymer formulation according to claim 16.
33. A method for exposing holographic media comprising the photopolymer formulation according to claim 16, wherein the method comprises selectively polymerizing the writing monomers with spatial resolution by electromagnetic radiation.
34. Fluorourethane, obtained by reacting a polyisocyanate which comprises iminooxadiazinediones or oxadiazadione and has at least one free isocyanate group with an alcohol, wherein the polyisocyanate andor the alcohol are substituted by at least one fluorine atom.
35. Fluorourethanes according to the formula (III)
wherein
m is from 1 to 8 and
R4, R5, R6 represent, independently of one another, hydrogen or linear, branched, cyclic or heterocyclic organic radicals which are unsubstituted or optionally also substituted by heteroatoms and have iminooxadiazinedione andor oxadiazadione structural elements, wherein at the same time at least two of the radicals R4, R5, R6 are substituted by at least one fluorine atom.