Polarization splitter, method of manufacturing same and ophthalmic lens incorporating projection inserts containing it

Abstract

Polarization splitter in which reflection for the 1 polarization is locally centered on at least one emission peak of the image-emitting source of a micro-display or in which reflection for the 1 polarization is locally centered on at least one peak corresponding to a wavelength selected from red, green and blue. Application to an ophthalmic lens incorporating inserts for projecting an image towards the user.

What is claimed is:  
     
         1 . A polarization splitter in which reflection of the S polarization is locally centered on at least one peak selected from the group consisting of (i) at least one emission peak of an image-emitting source of a micro-display, (ii) red, (iii) green and (iv) blue.  
     
     
         2 . The polarization splitter according to  claim 1  in which reflection is locally centered on at least two peaks.  
     
     
         3 . The polarization splitter according to  claim 1 , in which reflection is locally centered on at least one peak in the visible spectrum.  
     
     
         4 . The polarization splitter according to  claim 2 , in which reflection is locally centered on at least two peaks in the visible spectrum.  
     
     
         5 . The polarization splitter according to  claim 1 , in which reflection for the S polarization is centered on red, green and blue.  
     
     
         6 . The polarization splitter according to  claim 1 , in which peaks of its spectral reflectance curve for the S polarization, locally centered around the peaks, have their maximum level comprised between 60 and 100%.  
     
     
         7 . The polarization splitter according to  claim 1 , in which peaks of its spectral reflectance curve for the S polarization, locally centered around the peaks, have their maximum level comprised between 80 and 100%.  
     
     
         8 . The polarization splitter according to  claim 1 , in which its spectral reflectance curve for the S polarization has a level comprised between 0 and 35%, in all zones not locally centered around the peaks.  
     
     
         9 . The polarization splitter according to  claim 1 , in which its spectral reflectance curve for the S polarization has a level comprised between 0 and 20%, in all zones not locally centered around the peaks.  
     
     
         10 . The polarization splitter according to  claim 1 , in which each peak of the spectral reflectance curve of the S polarization centered around one of the peaks has a mid-height width of between 5 and 100 nm.  
     
     
         11 . The polarization splitter according to  claim 1 , in which each peak of the spectral reflectance curve of the S polarization centered around one of the peaks has a mid-height width of between 20 and 80 nm.  
     
     
         12 . The polarization splitter according to  claim 1 , in which each peak of the curve resulting from the product of the spectral transmittance for the P polarization and the spectral reflectance for the S polarization, centered around one of the peaks, has a mid-height width of between 5 and 100 nm.  
     
     
         13 . The polarization splitter according to  claim 1 , in which each peak of the curve resulting from the product of the spectral transmittance for the P polarization and the spectral reflectance for the S polarization, centered around one of the peaks, has a mid-height width of between 20 and 80 nm.  
     
     
         14 . The polarization splitter according to  claim 1 , in which spectral transmittance for the P polarization is greater than 80% on the emission spectrum of the source.  
     
     
         15 . The polarization splitter according to  claim 14 , in which the emission spectrum of the source is between 400 and 700 nm.  
     
     
         16 . The polarization splitter according to  claim 1 , in which spectral transmittance for the P polarization is greater than 90%, on the emission spectrum of the source.  
     
     
         17 . The polarization splitter according to  claim 16 , in which the emission spectrum of the source is between 400 and 700 nm.  
     
     
         18 . The polarization splitter according to  claim 1 , in which the integrated average transmittance between 400 and 700 nm is greater than 70%.  
     
     
         19 . The polarization splitter according to  claim 1 , comprising a substrate with a stack of thin layers.  
     
     
         20 . The polarization splitter according to  claim 1 , comprising a substrate with a holographic element.  
     
     
         21 . The polarization splitter according to  claim 19 , in which one of the materials is silicon dioxide.  
     
     
         22 . The polarization splitter according to  claim 19 , in which one of the materials is zirconium dioxide or praseodymium titanate.  
     
     
         23 . The polarization splitter according to  claim 1 , in the form of a cube made up of two prisms.  
     
     
         24 . A method of manufacturing a polarization splitter in which reflection of the S polarization is locally centered on at least one peak selected from the group consisting of (i) at least one emission peak of an image-emitting source of a micro-display, (ii) red, (iii) green and (iv) blue, comprising the following steps: 
 (i) providing a substrate; and    (ii) depositing thin layers.    
     
     
         25 . An ophthalmic lens with inserts for projecting an image towards the user, having a polarization splitter in which reflection of the S polarization is locally centered on at least one peak selected from the group consisting of (i) at least one emission peak of an image-emitting source of a micro-display, (ii) red, (iii) green and (iv) blue.  
     
     
         26 . The ophthalmic lens according to  claim 25 , in which the polarization splitter is provided in the form of a cube.  
     
     
         27 . A device for projecting an image towards the user, comprising an ophthalmic lens with inserts for projecting an image towards the user, having a polarization splitter in which reflection of the S polarization is locally centered on at least one peak selected from the, group consisting of (i) at least one emission peak of an image-emitting source of a micro-display, (ii) red, (iii) green and (iv) blue.  
     
     
         28 . The projection device according to  claim 27 , additionally comprising a liquid crystal micro-screen.  
     
     
         29 . The projection device according to  claim 28 , in which the liquid crystal micro-display emits a P polarized light in red, green and blue.