Nippon Sheet Glass Company, Limited

Shunsuke Ohtsuka

Yukihisa Kusuda

Seiji Ohno

Yasunao Kuroda

Takahisa Arima

Seiij Ohno

Hideaki Saitou

Tadashi Koyama

Shuhei Tanaka

Hisao Nagata

A surface light-emitting element having improved external light emission efficiency and a self-scanning light-emitting device using this surface light-emitting element are provided. To improve external light-emission efficiency, the light-emitting center is shifted to an area where there is no light shielding layer thereon. When the surface light-emitting element is a surface light-emitting thyristor of the PNPN structure, it is necessary to have such a construction that part of the injected current is prevented from flowing toward the gate electrode to improve external light emission efficiency. The self-scanning light-emitting device of this invention is accomplished by using this type of surface light-emitting element.

Surface light-emitting element and self-scanning type light-emitting device

The cost of a light-emitting element matrix array is reduced by implementing a function equivalent to a light-emitting thyristor by elements different therefrom. A plurality of combinational element are arrayed in one line. The plurality of combinational elements are divided into groups n by n. The bases of transistors included in each group are separately connected to base-selecting lines and the anodes of light-emitting diodes included in each group are commonly connected to one anode terminal every group.

Light-emitting element matrix array

A method for setting the amount of light in an array of light-emitting thyristors, each thyristor having I-L characteristic in which a luminous efficiency is decreased in a lower current field, is provided. According to the method, the amount of light emitted from a light-emitting thyristor is set so that a predetermined exposure energy may be obtained without decreasing a luminous efficiency of a light-emitting thyristor. The density D of a current to be supplied to the light-emitting thyristor to obtain a predetermined exposure energy is selected so as to satisfy the range of 3&times;D <D<100 MA/m , wherein D is a threshold current density for light emission which is defined as a current density corresponding to the value of a current at a point where a tangent drawn at the value of a current corresponding to a current density of 50 MA/m with respect to the curve of the I-L characteristic intersects a current axis.

Method for setting quantity of light of light-emitting element array

A method of designing an optimum mask pattern for forming a metal line by an etching process, the metal line also effectively serving as a light-shielding layer, is provided. In this method, assuming that a mask pattern for forming a first metal line on a transparent insulating film has a width of &ldquo;L &rdquo; overlapped with a first control electrode in a direction perpendicular to an array direction of of transfer elements, &ldquo;L &rdquo; is selected so as to satisfy the following relation L >(S&plus;dS)&plus;a, wherein &ldquo;S&rdquo; is the distance of side etching of the first metal line, &ldquo;dS&rdquo; is the dispersion of the distance of the side etching, and &ldquo;a&rdquo; is the misalignment of the mask pattern.

Method for designing mask pattern of a self scanning light emitting device

A surface light-emitting element having improved external light emission efficiency and a self-scanning light-emitting device using this surface light-emitting element are provided. To improve external light-emission efficiency, the light-emitting center is shifted to an area where there is no light shielding layer thereon. To achieve this, an insulating layer is provided on the electrode portion above which there is a light-shielding layer at a portion making contact with the semiconductor layer thereunder so as to prevent the injected current from flowing from that electrode portion. To increase the amount of light emission, the peripheral length of the electrode is increased. With an electrode of the same area, the larger the peripheral length, the larger becomes the amount of light emission because the current injected from the electrode is distributed evenly over the entire surface, causing light to emit evenly. When the surface light-emitting element is a surface light-emitting thyristor of the PNPN structure, it is necessary to have such a construction that part of the injected current is prevented from flowing toward the gate electrode to improve external light emission efficiency. The self-scanning light-emitting device of this invention is accomplished by using this type of surface light-emitting element.

In the manufacture of ultrafine particles of semiconductor compound, pulse laser with high output is irradiated on an evaporation source having the same or similar composition as the above semiconductor compound to evaporate the source in a moment and the ultrafine particles of the semiconductor compound are produced utilizing the nuclear growth in inert gas. A process wherein a material for ultrafine particles is heated/evaporated by laser in inert gas and the resulting vapor is rapidly cooled by a collision with the inert gas whereby the resulting ultrafine particles of said material is sticked on a base plate and another process wherein a material for matrix is heated/evaporated by laser whereby the matrix is formed on the base plate are carried out alternately so that the ultrafine particles are homogeneously dispersed in the matrix to prepare the material wherein the ultrafine particles are dispersed.

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Osaka, Japan

Shunsuke Ohtsuka