Lens holder which reduces internal reflections
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsKatsuaki Mitani, Masayuki Takahashi, Syunsuke Kimura
Life of this patent
Estimating the term…
Abstract
In a lens-barrel etc. for holding lenses, a thin film composed of a fluororesin compound having a refractive index lower than that of a material constituting the lens-barrel is formed on an inner surface of the lens-barrel, thereby lowering an amount of the reflective light appeared on the inner surface of the lens-barrel.
Claims4
A lens holder comprising:
- a lens-barrel;
- and
- a thin film formed on an inner surface of said lens-barrel, said thin film being composed of a fluororesin compound having a refractive index lower than a refractive index of a material which constitutes said lens-barrel.
A projection type TV set comprising a blue CRT, a green CRT and a red CRT and three lens holders, respectively coupled to said blue CRT, said green CRT, and said red CRT, each of said lens holders having a thin film of fluororesin compound on an inner surface thereof, wherein
- a first thin film in one of said lens holders used for said blue CRT has a thickness which makes a reflectance minimum within a region of wavelength from 420 nm to 480 nm;
- a second thin film in one of said lens holders used for said green CRT has a thickness which makes a reflectance minimum within a region of wavelength from 525 nm to 575 nm;
- and
- a third thin film in one of said lens holders used for said red CRT has a thickness which makes a reflectance minimum within a region of wavelength from 580 nm to 620 nm.
A lens holder comprising:
- a lens barrel;
- a coupler for coupling said lens barrel with a CRT;
- a thin film formed on an inner surface of at least one of said lens-barrel and said coupler, said thin film being composed of a fluororesin compound having a refractive index lower than a refractive index of a material which constitutes said lens-barrel.
Dependencies are inferred from the claim text.