Kabushiki Kaisha Toshiba

Kazuhiko Shimizu

Takeo Itou

Hidemi Matsuda

Hajime Tanaka

Norio Koike

Ryoichi Ogura

An antireflection film includes a first light-transmitting thin film formed on a substrate, and a second light-transmitting thin film formed on the first light-transmitting thin film. The first light-transmitting thin film contains a coloring material, and the antireflection film satisfies

Antireflection film and display apparatus

A display device including a display screen having an optical film provided thereon. The optical film is a porous thin film made of fine magnesium fluoride particles and a binder containing a condensate of a silane compound having a fluoroalkyl group, a co-condensate of the silane compound and silicon, or a co-condensate of the silane compound and a metal oxide compound. The combination of the specific binder and fine magnesium fluoride particles permits forming a porous optical film having a surprisingly high mechanical strength, excellent resistance to humidity and reduced external light reflection from the display plane.

Display device with an anti-reflection film on the display plane

A cathode ray tube has a vacuum envelope which includes a faceplate, an optical filter formed on the faceplate, the optical filter including mainly of SiO.sub.2 and containing a coloring material, and a phosphor layer formed on the inner surface of the faceplate. The optical filter includes silicon having a fluorine-containing group and a siloxane bond at least on the surface thereof, and a maximum light absorption wavelength in a range of 400 to 650 nm is in a region of 575.+-.20 nm, and where the transmissivity for the wavelength of 450 nm is T.sub.450, that for 530 nm is T.sub.530, that for 550 nm is T.sub.550, that for 630 nm is T.sub.630, and that for the maximum absorption wavelength is Tmin, the following relationship is established:

Optical filter for cathode ray tube

A display device comprising a display screen, and an optical film formed on the display screen and having a porous lower layer mainly consisting of TiO.sub.2 and having a porosity of 30% to 75% and an average pore size of 10 nm or less and an upper layer stacked on the lower layer and essentially consisting of a silicon compound having a fluorine-containing group and a siloxane bond. In this display device, the optical film can be easily formed and has a satisfactory anti-reflection effect and satisfactory strength.

Display device with display screen and optical film on the display screen

A color picture tube comprising an envelope including a front panel, a phosphor screen formed in the inner surface of the front panel, and an electron gun arranged in the envelope. The phosphor screen includes a light absorbing layer having a plurality of holes and phosphor layers formed in the holes so as to partially overlap the light absorbing layer. The transmittance T of the light absorbing layer, the ratio a of the area of a light emitting region in a portion where the light absorbing layer overlaps the phosphor layers to the area of the phosphor screen, the ratio b of the area of the light absorbing layer to the area of the phosphor screen, and the ratio r of the light emitting region in the holes to the area of the holes satisfy the following relational expression: 1/T.gtoreq.1/2{(rb/a)-[a/(1-b)r]}.

Color picture tube with light absorbing layer on screen

A color picture tube includes a vacuum envelope having a faceplate, a phosphor screen formed to include semitransparent black light-absorption layers coated on a first region of the faceplate in stripes or in a matrix, and phosphor layers of blue, red and green emitting phosphors coated on a second region of the faceplate in stripes or in dots, and an electron gun, arranged within the vacuum envelope, for emitting and focusing electron beams. End portions of the phosphor layers extend over the black light-absorption layers, thereby forming overlapped portions. Gaps are provided between the phosphor layers and over the black light-absorption layers, thereby forming light-absorption sections on which no phosphor layer is provided.

Color picture tube having a phosphor screen with a semitransparent black

According to the present invention, there is provided a method for forming a color tube phosphor screen comprising the steps of forming a light-absorbing matrix having holes on a faceplate, coating a silica colloidal solution or an alumina colloidal solution containing a multivalent metal ion in said holes and washing said holes, and forming phosphor layers of three colors in said washed holes. The color tube phosphor screen formed through the method of the present invention has no phosphor residual, especially pigment residual.

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Fukaya, Japan

Kazuhiko Shimizu