Lens array structure
First Claim
1. A lens array structure comprising a first birefringent lens array and a second birefringent lens array arranged in series, whereinboth the first birefringent lens array and the second birefringent lens array are capable of operating to direct incident light of one polarisation into a respective directional distribution and to have substantially no effect on incident light of a polarisation perpendicular to said one polarisation,the first birefringent lens array and the second birefringent lens array are relatively oriented such that incident light of a first polarisation component is directed into a directional distribution by the first birefringent lens array and not affected by the second birefringent lens array whereas incident light of a second polarisation component polarised in a direction perpendicular to said first polarisation component is not affected by the first birefringent lens array and directed into a predetermined directional distribution by the second birefringent lens array, andat least one of the first birefringent lens array and the second birefringent lens array is an active lens array switchable between a first mode in which the active lens array directs incident light of one polarisation into a respective directional distribution and has substantially no effect on incident light of a polarisation perpendicular to said one polarisation and a second mode in which the active lens array has substantially no optical effect.
2 Assignments
0 Petitions
Accused Products
Abstract
A lens array structure comprises two birefringent lens arrays arranged in series, both being capable of operating to direct incident light of one polarisation into a respective directional distribution and to have substantially no effect on incident light of a polarisation perpendicular to said one polarisation. The lens arrays are relatively oriented such that incident light of two perpendicular polarisation components are directed into a directional distribution by a respective one of the birefringent lens arrays and not affected by other one of the birefringent lens arrays. Thus control of the polarisation allows switching between the effects of the two lens arrays. To allow switching into a third mode in which neither of the lens arrays has effect, one of the lens arrays may be active. The lens structure may be employed in a display apparatus to provide a switchable directional display.
112 Citations
12 Claims
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1. A lens array structure comprising a first birefringent lens array and a second birefringent lens array arranged in series, wherein
both the first birefringent lens array and the second birefringent lens array are capable of operating to direct incident light of one polarisation into a respective directional distribution and to have substantially no effect on incident light of a polarisation perpendicular to said one polarisation, the first birefringent lens array and the second birefringent lens array are relatively oriented such that incident light of a first polarisation component is directed into a directional distribution by the first birefringent lens array and not affected by the second birefringent lens array whereas incident light of a second polarisation component polarised in a direction perpendicular to said first polarisation component is not affected by the first birefringent lens array and directed into a predetermined directional distribution by the second birefringent lens array, and at least one of the first birefringent lens array and the second birefringent lens array is an active lens array switchable between a first mode in which the active lens array directs incident light of one polarisation into a respective directional distribution and has substantially no effect on incident light of a polarisation perpendicular to said one polarisation and a second mode in which the active lens array has substantially no optical effect.
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8. A display apparatus comprising:
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a spatial light modulator; a lens array structure comprising a first birefringent lens array and a second birefringent lens array arranged in series, wherein both the first birefringent lens array and the second birefringent lens array are capable of operating to direct incident light of one polarisation into a respective directional distribution and to have substantially no effect on incident light of a polarisation perpendicular to said one polarisation, wherein the first birefringent lens array and the second bireflingent lens array are relatively oriented such that incident light of a first polarisation component is directed into a directional distribution by the first birefringent lens array and not affected by the second birefringent lens array whereas incident light of a second polarisation component polarised in a direction perpendicular to said first polarisation component is not affected by the first birefringent lens array and directed into a predetermined directional distribution by the second birefringent lens array, and wherein at least one of the first birefringent lens array and the second birefringent lens array is an active lens array switchable between a first mode in which the active lens array directs incident light of one polarisation into a respective directional distribution and has substantially no effect on incident light of a polarisation perpendicular to said one polarisation and a second mode in which the active lens array has substantially no optical effect; a switchable polarisation control device arranged to control the polarisation of light passing through the display apparatus to output from the display apparatus light of a polarisation component selectively corresponding to either said first polarisation component or said second polarisation component; and a control circuit arranged to control switching of the at least one active lens array. - View Dependent Claims (9, 10, 11, 12)
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Specification