Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
211 words
In an interference filter comprising a plurality of alternately high and low refracting light transmitting layers, applied on a light transmitting surface, reflecting a certain wave length band within a given wave length range while letting pass other wave length bands of the range, which filter includes a periodically symmetrically constructed inner system between two reflection-reducing outer systems each constructed from alternating high and low refracting layers, where all low refracting layers form one group of the outer systems and all high refracting layers form another group of the outer systems, and wherein all low refracting layers of said inner system form a first group and all high refracting layers of said inner system form a second group, for the attenuation of undesired secondary reflection bands: the improvement comprising the layers of one outer system group having the same index of refraction nconst as one layer group of said inner system and each other layer of the outer systems having an index of refraction ni differing from nconst, and fulfilling the condition that the absolute value of the product nconst - ni X di is less than this product for the other group of inner system layers having an index of refraction differing from nconst, where di is the layer thickness.
Claim 2
Dependent Claim
211 words
In an interference filter comprising a plurality of alternately high and low refracting light transmitting layers, applied on a light transmitting surface, reflecting a certain wave length band within a given wave length range while letting pass other wave length bands of the range, which filter includes a periodically symmetrically constructed inner system between two reflection-reducing outer systems each constructed from alternating high and low refracting layers, where all low refracting layers form one group of the outer systems and all high refracting layers form another group of the outer systems, and wherein all low refracting layers of said inner system form a first group and all high refracting layers of said inner system form a second group, for the attenuation of undesired secondary reflection bands: the improvement comprising the layers of one outer system group having the same index of refraction nconst as one layer group of said inner system and each other layer of the outer systems having an index of refraction ni differing from nconst, and fulfilling the condition that the absolute value of the product nconst - ni X di is less than this product for the other group of inner system layers having an index of refraction differing from nconst, where di is the layer thickness.
Claim 3
Dependent Claim
40 words
In an interference filter, the improvement claimed in claim 1, in which the index of refraction of one group of layers of the outer sytems is equal to the index of refraction of the low-refracting layers of the inner system.
Claim 4
Dependent Claim
40 words
In an interference filter, the improvement claimed in claim 1, in which the index of refraction of one group of layers of the outer systems is equal to the index of refraction of the high-refracting layers of the inner system.
Claim 5
Dependent Claim
63 words
In an interference filter, the improvement claimed in claim 1, in which the outer systems have the layer sequence A/2, B1, A, B1, A/2, where A is a layer of lambda /4 optical thickness and B1 is a layer with a different index of refraction but also having lambda /4 optical thickness, lambda representing the wave length of minimum transmission of the filter.
Claim 6
Dependent Claim
49 words
In an interference filter, the improvement claimed in claim 1, in which the absolute value of the product nconst - ni di, for the additional layers of the outer system differing in their index of refraction from nconst of one group of layers thereof, decreases from the interior outwardly.