Hitachi Displays, Ltd.

Hitachi, Ltd.

Other

Yoichi Ito

Satoshi Muto

Atsushi Yoshioka

Susumu Ohtsuka

Koji Hagiwara

Naotoshi Sumiya

Fumihiko Yamanushi

A backlight structural body of a liquid crystal display device includes, between a back plate and a frame-like mold frame, a plurality of external electrode fluorescent lamps which is arranged in parallel to each other and a pair of side frames which includes electricity supply terminals which electrically connect electrode portions of the plurality of external electrode fluorescent lamps in parallel to each other. The side frame is constituted of a lower side frame which fixes the electricity supply terminals and an upper side frame which is assembled to the lower side frame while covering the electrode portions of the external electrode fluorescent lamps which are connected to the electricity supply terminals. The upper side frame includes eaves which project in the longitudinal direction of the external electrode fluorescent lamps in a state that the eaves individually cover the respective electrode portions of the external electrode fluorescent lamps.

Liquid crystal display device using external electrode fluorescent lamps

A correction filter used in the exposure for forming a phosphor screen includes three kinds of correction filters consisting of a grading filter, a monochroic local correction filter and a multi-color local correction filter. With the use of three kinds of correction filters, it is possible to improve the whiteness uniformity which may be degraded due to the wall thickness difference at the center and a peripheral portion of a panel portion of a flat-face-type color cathode ray tube.

Manufacturing method of color cathode ray tube

In an exposure step for forming a phosphor screen of a color cathode ray tube, correction lenses which are arranged between a light source and a panel are used in a state that a common correction lens which is used in common for three colors and three kinds of monochroic correction lenses are combined. The present invention can, in a flat-face-type color cathode ray tube, prevent the generation of the mislanding attributed to the difference in a wall thickness between a center portion and a peripheral portion of a panel thus improving the color purity.

The invention provides a color cathode ray tube using a shadow mask capable of avoiding ruptures or cracks during press-working. The shadow mask has an apertured region having color selecting apertures, and an unapertured region which surrounds the apertured region. A skirt portion is bent from the unapertured region in the direction of the tube axis. The shadow mask has at least two inclined surfaces in a boundary portion between the unapertured region and the skirt portion.

Color cathode ray tube

A color cathode ray tube includes a shadow mask structure composed of a frame, a shadow mask attached to the frame and suspension springs attached to the frame, and studs embedded in a skirt portion of its panel portion. Each suspension spring is composed of a base member including a portion attached to the frame, a sloped portion extending from the portion toward the skirt portion, and a first joint portion extending axially from the sloped portion; and a spring member including a second joint portion fixed to the first joint portion, a resilient portion extending at an angle &thgr; from the second joint portion, and a stud-engaging portion extending from the resilient portion and formed with a hole engaged with one of the studs, where 0&deg;&lE;&thgr;&lE;10&deg;. A length L of the resilient portion satisfies 20 mm&lE;L&lE;an axial length of the frame.

Color cathode ray tube having an improved shadow mask supporting structure

A reproducing circuit for use in a magnetic recording and reproducing apparatus having a recording circuit operable to record a video luminance signal in either a conventional recording mode or in a High-Band mode has a first automatic gain control circuit for holding a level of a reproduced FM signal at an input thereof constant, a recording mode determination circuit having an input connected to the first automatic gain control circuit and responsive to an output of the first automatic gain control circuit for determining which the first or second recording mode is used to record the FM signal under reproduction, a first equalizer circuit for equalizing the reproduced FM signal suitably for the first recording mode, a second equalizer circuit for equalizing the reproduced FM signal suitably for the second recording mode, a switch circuit for selecting an output of either the first equalizer circuit or the second equalizer circuit according to an output of the recording mode determination circuit, a second automatic gain control circuit for holding an output level of the switch circuit, whereby the recording mode of the signal undergoing reproduction is automatically determined and the characteristics of the reproducing circuit is changed automatically suitably.

Growing community of inventors

Kawasaki, Japan

Yoichi Ito