Matsushita Electric Industrial Co., Ltd.

Jun Kuwata

Atsushi Abe

Tomizo Matsuoka

Yosuke Fujita

Takao Tohda

Tomoko Suzuki

Tsuneharu Nitta

Atsushi Omote

Masahiro Nishikawa

Kazuo Tomida

Masaki Hirohashi

Hiroko Imamura

A method of driving a gas discharge tube is provided. Each field of images is divided into three periods for luminescence-rest, luminescence-preparing, and luminescence steps. During the luminescence-rest step, two voltages whose amplitudes are the same and constant are applied to two sustaining electrodes composing each pair, so that the sustaining electrodes rest the discharge. During the luminescence-preparing step, two voltage pulses whose phases are the same are applied to the two sustaining electrodes composing each pair and a voltage to cause a preparatory discharge is applied to an auxiliary electrode. And during the luminescence step, two voltage pulses whose phases are mutually shifted are applied to the two sustaining electrodes composing each pair, so that the sustaining electrodes cause discharges for the luminescence.

Display apparatus with gas discharge tube and method of driving gas discharge tube

Using as a negative thermal expansion material a double oxide containing at least partly a compound represented by the chemical formula: RQ,O, (wherein R is Zr, Hf or a tetravalent metallic element represented by a mixture system of these, and Q is a hexavalent metallic element selected from W and Mo), and using as a positive thermal expansion material a material containing at least partly a compound represented by the chemical formula: MQX, (wherein M is Mg, Ca, Sr, Ba, Ra or a divalent metallic element represented by a mixture system of any of these, Q is a hexavalent metallic element selected from W and Mo, and X is an element selected from O and S), these are mixed preferably in a weight ratio of 1:1 and are synthesized to obtain a material whose coefficient of thermal expansion is substantially zero over a wide temperature range, i.e., a zero thermal expansion material. Using this zero thermal expansion material, high-precision and high-performance practical component parts can be obtained.

Zero thermal expansion material and practical component parts making use of the same

Using as a negative thermal expansion material a double oxide containing at least partly a compound represented by the chemical formula: RQ O (wherein R is Zr, Hf or a tetravalent metallic element represented by a mixture system of these, and Q is a hexavalent metallic element selected from W and Mo), and using as a positive thermal expansion material a material containing at least partly a compound represented by the chemical formula: MQX (wherein M is Mg, Ca, Sr, Ba, Ra or a divalent metallic element represented by a mixture system of any of these, Q is a hexavalent metallic element selected from W and Mo, and X is an element selected from O and S), these are mixed preferably in a weight ratio of 1:1 and are synthesized to obtain a material whose coefficient of thermal expansion is substantially zero over a wide temperature range, i.e., a zero thermal expansion material. Using this zero thermal expansion material, high-precision and high-performance practical component parts can be obtained.

Zero thermal expansion material

An electroluminescence apparatus in which voltage is applied to a lamination of a fluorescent material layer and a dielectric layer through a pair of electrodes one of which is light-transmissible to extract fluorescence. A reflecting mirror layer is provided on the lamination while a particular relationship is established between the refractive index and the thickness of the lamination, thereby improving the efficiency with which the fluorescence is extracted.

Thin-film electroluminescence apparatus including optical interference

A dielectric thin film element comprising a dielectric substrate and a dielectric thin film formed on the substrate. The thin film is made of a perovskite type oxide and formed by sputtering in an atmosphere containing nitrogen, by which the dielectric constant and the breakdown electric field strength are greatly improved. Thin film devices using the film and a method for making the thin film are also described.

Dielectric thin film, and method for making the thin film

In a thin film EL display device wherein a transparent electrode, a first dielectric layer, an EL emission layer, a second dielectric layer and a back electrode are laminated in order on a transluscent substrate, a 10 nm-200 nm thickness of thin film made of calcium sulfide or a mixture containing calcium sulfide which is formed by an electron beam vapor deposition method provided between the first dielectric layer and the EL emission layer and between the EL emission layer and the second dielectric layer, thereby obtaining a thin film EL display device which maintains a stable operation for a long period even when it is driven by A.C. pulses which are a symmetric with respect to the time relationship of the driving pulses (e.g., the time period between the start of a positive pulse and the start of the subsequent negative pulse is different than the time period between the start of a negative pulse and the start of the subsequent positive pulse) or are different in amplitude in a positive side and a negative side.

Thin film electroluminescence display device

An electroluminescent display panel formed of phosphor and dielectric layers sandwiched between opposing mutually intersecting arrays of drive electrodes, has the thickness of the phosphor layer set to a value which provides minimum power consumption, for a given level of display brightness. This is achieved by determining a value of capacitance per unit area of the panel which results in a maximum allowable value of time being required to charge each display element, then determining a value of phosphor layer thickness providing minimum power consumption, using the latter value of capacitance and the known value of light emission efficiency of the display.

Electroluminescence display panel configured for minimized power

An electroluminescent element, especially a thin-film electroluminescent element in which the dielectric film layer provided on at least one side of an electroluminor layer is essentially composed of the materials represented by the following compositional formula:

Thin-film electroluminescent element

The development of a dielectric thin-film which is high (140 MV/cm or above) in product of dielectric constant .epsilon..sub.i and dielectric breakdown field strength E.sub.ib is essential for realizing an EL element which can operate stably at a low voltage. Such dielectric film is also required which can withstand heat treatments at high temperatures above 500.degree. C. and is proof against clouding and in which the electrical breakdown caused by a minute fault produced in the process of film formation is self-healed. A film material which satisfies all of these requirements could be obtained from a TiO.sub.2 -BaO based composition by partially substituting the position of Ti with Sn, Zr or Hf and also partially substituting the position of Ba with Ca or Mg. By using these dielectric films, it is possible to obtain a low-voltage drive thin-film electroluminescent element which are high in production yield and reliability.

Growing community of inventors

Tokyo, Japan

Jun Kuwata