Hoya Corporation

Shuhei Mikami

Yasuhiro Fujiwara

Hiroki Takazawa

Optical glass that has an Abbe number (Vd) of less than 23 and is suitable for use as a single-lens material constituting a photographic-imaging lens; an optical element including the optical glass; and an imaging lens containing a lens including the optical glass. Optical glass that has an Abbe number (Vd) of less than 23, wherein a flat plate of said optical glass with a thickness of 10 mm exhibits an ISO color contribution index (ISO/CCI) of 0 for blue (B), up to 9 for green (G), and up to 9 for red (R).

Optical glass and optical element

An optical glass may be a phosphate based glass containing at least any one of oxides selected from TiO2, Nb2O5, WO3, and Bi2O2. The total content (HR) of the TiO2, Nb2O5, WO3, and Bi2O2 may be 35 mol % or above, the noble metal content may be less than 2.0 ppm, and the &#x3b2;OH value, given by the following general formula, may be 0.1 mm-1 or above: &#x3b2;OH=&#x2212;[ln(B/A)]/t.

Optical glass and method for producing the same

A glass including at least one type of oxide selected from TiO, NbO, WO, and BiOas a glass component therefor, having a total TiO, NbO, WO, and BiOcontent of at least 20 mol %, and having a &#x3b2;OH value indicated in formula (1) that fulfills the relationship indicated in formula (2).&#x3b2;OH=&#x2212;[ln()]/&#x2003;&#x2003;(1);&#x3b2;OH&#x2267;0.4891&#xd7;ln(1/)+2.48&#x2003;&#x2003;(2).

Glass, optical glass, glass raw material for press molding, and optical element

[Problem] The transmittance of glass can be dramatically improved as a result of this glass production method. In addition, the amount of rare metal, such as platinum, that melts into glass can be greatly reduced. [Solution] A glass production method whereby the water content in molten glass is increased, in a melting step (i) in which a glass raw material including at least one type of component among TiO, NbO, WO, and BiOis heated inside a melting container and melted, and a molten glass is obtained.

Glass and optical element production method

A glass including at least one type of oxide selected from TiO, NbO, WO, and BiOas a glass component therefor, having a total TiO, NbO, WO, and BiOcontent of at least 20 mol %, and having a &#x3b2;OH value indicated in formula (1) that fulfills the relationship indicated in formula (2).&#x3b2;=&#x2212;[ln()]/&#x2003;&#x2003;(1);&#x3b2;&#x2267;0.4891&#xd7;ln(1/)+2.48&#x2003;&#x2003;(2).

The present invention relates to an optical glass with a high refractive index and good precision press moldability, and a preform for precision press molding and an optical element that are comprised of the optical glass. The present invention further relates to a method of manufacturing an optical element, a lens unit being equipped with an optical element and an image pickup device being equipped with a lens unit.

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Tokyo, Japan

Shuhei Mikami