Optical material and optical system using it
AssigneeCanon Kabushiki Kaisha
InventorHideo Ukuda
Life of this patent
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Abstract
An optical material is a mixture of materials comprising a first material having a refractive index of not more than 1.45 for the d-line and a second material having an Abbe's number, indicating wavelength dispersion in the visible region, of not more than 25. A relation between the refractive index for the d-line (nd) and the Abbe's number (νd) is defined as follows: nd≦−6.667×10−3νd+1.70.
Claims36
An optical material which is a mixture of materials comprising a first material having a refractive index of not more than 1.45 for the d-line and a second material having an Abbe's number of not more than 25, wherein a relation between a refractive index for the d-line (nd) and an Abbe's number (νd) is defined as follows:
- nd≦−6.667×10−3νd+1.70.
An optical material wherein a relation between a refractive index for the d-line (nd) and an Abbe's number (νd) satisfies the following condition:
- nd≦−0.01νd+1.70.
An optical material which is a mixture of materials comprising a first material having a refractive index of not more than 1.40 for the d-line and a second material having an Abbe's number of not more than 15, wherein a relation between a refractive index for the d-line (nd) and an Abbe's number (νd) is defined as follows:
- nd≦−0.01νd+1.70.
An optical material which is a mixture of materials comprising a first material having a refractive index for the d-line in the range of 1.45 to 1.55 both inclusive and a second material having an Abbe's number of not more than 10, wherein a relation between a refractive index for the d-line (nd) and an Abbe's number (νd) is defined as follows:
- nd≦−6.667×10−3νd+1.70.
A method for producing an optical material, comprising a step of decreasing a filling factor of a first material, and a step of filling gaps of the first material of the decreased filling factor with a second material having an Abbe's number different from that of the first material, thereby producing an optical material having a desired refractive index and an Abbe's number.
Dependencies are inferred from the claim text.