Adjustable apodized lens aperture

Abstract

An adjustable apodized lens aperture is described which is constructed using photochromic material. As the excitation energy increases, the aperture constricts so as reduce the amount of light through the aperture. As the excitation energy decreases, the aperture dilates so as increase the amount of light through the aperture.

1 . An optical element comprising a photochromic material, the photochromic material being configured such that when the photochromic material is exposed to excitation energy an apodized aperture operable to transmit visible light through the optical element is formed, wherein variance of the excitation energy causes corresponding adjustment of the apodized aperture.  
   
   
       2 . The optical element of  claim 1  wherein the apodized aperture is characterized by a Gaussian radial transmission curve.  
   
   
       3 . The optical element of  claim 1  wherein the photochromic material includes a photochromic dye which is substantially uniformly distributed throughout the photochromic material, and wherein a thickness of the photochromic material increases along a radius of the apodized aperture.  
   
   
       4 . The optical element of  claim 3  further comprising a plano-plano element and a plano-convex element, a convex surface of the plano-convex element having a point of contact with a flat surface of the plano-plano element, wherein the photochromic material is disposed between the plano-plano element and the plano-convex element around the point of contact such that the thickness of the photochromic material varies with the convex surface.  
   
   
       5 . The optical element of  claim 3  further comprising a plano-plano element and a plano-convex element, a truncated convex surface of the plano-convex element having an area of contact with a flat surface of the plano-plano element, wherein the photochromic material is disposed between the plano-plano element and the plano-convex element around the area of contact such that the thickness of the photochromic material varies with the truncated convex surface.  
   
   
       6 . The optical element of  claim 3  wherein the photochromic material is configured as one of a plano-concave element or a bi-concave element.  
   
   
       7 . The optical element of  claim 1  wherein the photochromic material includes a photochromic dye which is distributed throughout the photochromic material such that an active concentration of the photochromic dye increases along a radius of the apodized aperture.  
   
   
       8 . The optical element of  claim 7  wherein the active concentration of the photochromic dye relates to an inactive concentration of the photochromic dye which corresponds to dye molecules deactivated with a chemical inhibitor.  
   
   
       9 . The optical element of  claim 7  wherein the concentration of the photochromic dye relates to an inactive concentration of the photochromic dye which corresponds to dye molecules fatigued by exposure to ultraviolet light.  
   
   
       10 . The optical element of  claim 1  further comprising an ultraviolet (UV) blocking element configured to inhibit UV energy from impinging on at least a portion of a front surface of the photochromic material through which the visible light reaches the apodized aperture.  
   
   
       11 . The optical element of  claim 10  wherein the UV blocking element has a transmission characteristic for UV energy which increases along a radius of the apodized aperture.  
   
   
       12 . The optical element of  claim 10  wherein the UV blocking element blocks substantially all UV energy from impinging on the front surface of the photochromic material.  
   
   
       13 . The optical element of  claim 12  wherein the photochromic material includes a photochromic dye which is substantially uniformly distributed throughout the photochromic material, and wherein the photochromic material comprises a UV energy absorber, the optical element further comprising at least one excitation component configured to facilitate transmission of UV energy through an edge of the photochromic material, the UV energy absorber being operable to interact with the UV energy to define the apodized aperture.  
   
   
       14 . The optical element of  claim 13  wherein the at least one excitation component comprises at least one active source of UV energy.  
   
   
       15 . The optical element of  claim 14  wherein the at least one active source of UV energy comprises a plurality of UV light emitting diodes configured in a ring around the edge of the photochromic material.  
   
   
       16 . The optical element of  claim 14  wherein the at least one active source of UV energy comprises a single UV light emitting diode, and wherein the at least one excitation component further comprises an integrating cylinder for dispersing the UV energy around the edge of the photochromic material.  
   
   
       17 . The optical element of  claim 14  wherein the at least one active source of UV energy comprises a single UV light emitting diode, and wherein the at least one excitation component further comprises a toroidal waveguide for dispersing the UV energy around the edge of the photochromic material.  
   
   
       18 . The optical element of  claim 13  the at least one excitation component is configured to transmit ambient light to the edge of the photochromic material.  
   
   
       19 . The optical element of  claim 18  wherein the at least one excitation component comprises a substrate surrounding the photochromic material having grooves formed in a surface therefore for dispersing the UV energy around the edge of the photochromic material.  
   
   
       20 . The optical element of  claim 13  wherein the UV energy absorber comprises an additional material distinct from the photochromic dye.  
   
   
       21 . The optical element of  claim 13  wherein the UV energy absorber comprises the photochromic dye.  
   
   
       22 . The optical element of  claim 1  wherein the photochromic material comprises one of glass, plastic, liquid, gel, or solid.  
   
   
       23 . A lens system comprising a plurality of optical elements, at least one of the optical elements comprising a photochromic material, the photochromic material being configured such that when the photochromic material is exposed to excitation energy an apodized aperture operable to transmit visible light through the optical element is formed, wherein variance of the excitation energy causes corresponding adjustment of the apodized aperture.  
   
   
       24 . A camera comprising the lens system of  claim 23 .  
   
   
       25 . A cellular telephone comprising the camera of  claim 24.