Hitachi, Ltd.

Eiichi Yamazaki

Iwao Ogura

Koichi Maruyama

Toshio Ueda

Hiromi Kanai

Masahiro Nishizawa

Takehiko Ueyama

Toshio Hurukawa

Shinichi Yamada

Takuya Imaide

Hiroshi Koizumi

Kouji Kitou

Ikuya Arai

Michitaka Ohsawa

Shigemi Hirasawa

Yuji Sano

Takeshi Hoshino

Kiyoharu Kishimoto

Hiroshi Yokomizo

Moritaka Taniguchi

Ryoji Hirai

Kenji Fukuda

Masaaki Kurosu

Fumiaki Yonai

Hitoshi Yamadera

Masao Taniguchi

Tomoko Ogawa

Mariko Tanaka

Yasuji Takami

Kenji Shimizu

The present invention is a color correction system including an imaging apparatus which inputs or outputs an image signal from a signal processor into or from an image device such as an input device such as a scanner or a camera or an output device such as a display device or a print device and which is constituted so as to correct colors by inputting or outputting image signals via a color converter, the conversion characteristic of which can be controlled according to a variation in the setting status or use environment of the imaging apparatus and faithful color reproduction can be realized between a plurality of imaging apparatuses having different characteristics.

Color correction system of imaging apparatus

When a picture display section (or screen) for high-quality TV system (HDTV system) is used for displaying pictures of ordinary TV system with an aspect ratio different from that of the high-quality TV picture, the blank portions on the screen where no picture is illuminated to display at a brightness level almost equal to a picture mean luminance so that there will be no local variations in the luminace on the screen due to deterioration of fluorescent materials on the screen. For this purpose, the picture display portion is moved over the screen; or the video signals are attenuated toward the ends of the picture display portion. As a result, the variations in luminance on the screen become small and unnoticeable.

Video display apparatus for pictures with different aspect ratios

A CRT display device has a phosphor plane of a bulb inclined to a plane normal to a center axis of an electron gun structure and a side of the bulb facing the phosphor plane inclined to the phosphor plane. A transmissive window for passing a light from the phosphor plane to an external is formed in the side of the bulb.

CRT display device

A color picture tube of shadow mask type includes a faceplate panel mounted on the tube. The faceplate panel has curvatures along its major and minor axes, respectively. When the outer surface contour of the faceplate panel is represented by a three-dimensional expression in the orthogonal coordinate system defined by the X-axis corresponding to the major axis, the Y-axis corresponding to minor axis, and the Z-axis corresponding to the axis of the tube, respectively, curved contours Z.sub.x and Z.sub.y of the faceplate panel along the major axis and the minor axis are so realized as to be approximated by Z.sub.x A.sub.1 X.sup.2 +A.sub.2 X.sup.4 and Z.sub.y =A.sub.3 Y.sup.2 +A.sub.4 Y.sup.4, respecvtively, where X and Y represent distances from the center of the faceplate panel along the X-axis and the Y-axis, respectively, and wherein the constants A.sub.1, A.sub.2, A.sub.3 and A.sub.4 are so selected that the conditions that 0.3.ltoreq.P.sub.x (X=X.sub.1).ltoreq.0.6 and 0.95.ltoreq.P.sub.y (Y=Y.sub.2).ltoreq.1.0 where P.sub.x =A.sub.1 X.sup.2 /(A.sub.1 X.sup.2 +A.sub.2 X.sup.4), P.sub.y =A.sub.3 Y.sup.2 /(A.sub.3 Y.sup.2 +A.sub.4 Y.sup.4) are satisfied at points X.sub.1 and Y.sub.2 on the boundaries defining an effective picture area on the faceplate. Further, the contours of the effective picture area defining boundaries extending in parallel with short and long sides of the outer surface of the faceplate panel are so curved as to have approximately equal curvature, the radius R (mm) of which on the boundary is so selected as to satisfy the condition that 1.5 (42.5 V+45.0).ltoreq.R.ltoreq.2.0 (42.5 V+45.0), where V represents the diagonal length of the effective picture area.

Color picture tube of shadow mask type with particular faceplate panel

In a CRT for constituting a display apparatus in which the fluorescent screen is composed of a large number of CRTs arranged in the matrix form, a plurality of holes for passing an electron beam are provided in an electrode for controlling the electron beam which is so placed as to confront the cathode for emitting the electron beam, for the purpose of attaining improved modulation characteristics and a simplified drive circuit requiring lower power consumption. A plurality of fluorescent screens having individual luminous colors are formed on respective portions obtained by dividing the inside of the panel of said CRT and individual electron beams are respectively applied to those fluorescent screens, resulting in a picture of good quality because of increased picture elements.

Cathode-ray tube for constituting large picture display apparatus

A cathode-ray tube having an electron gun for emitting an electron beam and a reflecting electrode for forming in front thereof a substantially planar reflecting potential surface which reflects the electron beam from the electron gun toward an anode target formed on the inner surface of the tube.

Cathode-ray tube

A video projector has a structure wherein a projection lens is disposed to be fixed at a predetermined distance with respect to a front surface of a faceplate of a projection cathode-ray tube through a medium. The medium has substantially the same refractive index as that of the glass used for the faceplate and the projection lens. A resin adhesive, for example, may be used as the medium.

Video projector

In a shadow mask type color picture tube, the radius of curvature of the peripheral portion of the inner surface of a faceplate on which a phosphor screen is formed is set to be smaller than that at the central portion thereof.

Shadow mask type color picture tube

A phosphor screen for a post-focusing type color picture tube comprising a faceplate, a phosphor layer on the faceplate, a metal back layer on the phosphor layer and a secondary electron emission suppressing layer on the metal backed phosphor screen, in which the thickness of the metal back layer and the density of the secondary electron emission suppressing layer take particular values for effective suppression of emission of secondary electrons from the phosphor screen.

Phosphor screen for post-focusing type color picture tube

An exposure method and apparatus for forming phosphor stripes or black matrix stripes on the inner surface of a face plate of a stripe phosphor screen type color picture tube or CRT (cathode-ray tube), in which a single linear light source is used as the exposure light source, and a prism device including many juxtaposed prisms is disposed between the linear light source and the face plate. The taper angle of the prisms is continuously changed so that the single linear light source can be observed as a plurality of discontinuous virtual linear light sources at whatever point on the inner surface of the face plate, and the virtual linear light sources have a most suitable center-to-center distance at individual positions on the face plate. The above arrangement eliminates the necessity for drive means for moving the linear light source, and a phosphor screen having three color phosphor stripes of satisfactorily uniform width can be formed on the entire inner surface of the face plate with use of the single linear light source.

Method and apparatus for exposure of phosphor screen

A method of forming a stripe type phosphor screen on inner surface of a face plate of a color picture tube or CRT through the irradiation with light stripes. A single linear light source is employed in combination with a plurality of juxtaposed prisms between the face plate and the linear light source with the taper angles of the prisms being continuously varied so that a plurality of virtual linear light sources may be observed from any points on the inner surface of the face plate with the distances between mid-points of the virtual linear light sources taking optimum values at respective positions on the inner surface of the face plate. With such arrangement, an improved phosphor screen composed of phosphor stripes of three colors having uniform stripe width can be formed over the whole inner surface of the face plate by using a single linear light source without requiring driving apparatus for moving the light source to different positions.

Method and apparatus for forming phosphor screen of color picture tubes

The correcting lens comprises a plurality of regions which are formed at at least one portion of the effective surfaces on both sides of the lens by means of a plurality of border lines which are discontinuous in only one direction. The regions on one side are inclined in a direction different from that of the regions on the opposite side of the lens.

Correcting lenses utilized in the manufacture of fluorescent screen of

The correcting lens comprises a plurality of regions which are formed at at least one portions of the effective surfaces on both sides of the lens by means of a plurality of border lines which are discontinuous in only one direction. The regions on one side are inclined in a direction different from that of the regions on the opposite side of the lens.

In an electron gun for use in a cathode ray tube of the class wherein a main electron lens system is constituted by a plurality of discrete electron lens systems, the plurality of electron lens systems are of the unipotential type and the intensity of the preceding lens system is made larger than that of the succeeding lens system.

Electron guns for use in cathode ray tubes

A method for making a phosphor screen of a black matrix type color picture tube wherein use is made of two light sources, one being placed inside the faceplate of the tube and the other placed outside the faceplate, for carrying out a light exposure operation. An apparatus useful for such light exposure operation is also disclosed.

Growing community of inventors

Ichihara, Japan

Eiichi Yamazaki