Matsushita Electric Industrial Co., Ltd.

Fuji Chemicals Industrial Co., Ltd.

Nissei Plastic Industrial Co., Ltd.

Shunsuke Matsuda

Tooru Tamura

Reiji Sano

Soji Tsuchiya

Akio Ito

Gentaro Nagamatsu

Katsue Hasegawa

Masami Honma

Katsuaki Mitani

Masaaki Sunohara

Yoshinobu Murakami

Masaaki Ueda

Shirow Asakawa

Kensuke Kuchiba

Yasuhiro Hioki

Yasumasa Komatsu

Murakami Yoshinobu

Mitani Katsuaki

Hironori Yoda

Shirow Askawa

Kesaji Nishizawa

Akio Itoh

Tamura Tooru

This invention relates to a method of writing, erasing, and reading of a large volume, high-density information. The writing is accomplished by ionizing an element different from a substrate element, and scanning the substrate by a focused ion beam of the ionized element for depositing the atoms of the ionized element on or implanting them into the surface layer of the substrate in accordance with an information signal. The erasing is done by sputtering to scatter the written element existing on the substrate with a focused ion beam of another element. The reading is accomplished by scanning the substrate with a focused electron beam, and detecting a difference in the intensity of energy spectrum of the scattering electrons, secondary electrons and Auger electrons emitted by the element of the substrate and the written element.

Method of erasable recording and reading of information

An optical disc comprises a resin disc substrate, a recording medium layer formed on the disc substrate, a high purity of transparent layer, and a transparent protective resin layer. The transparency of the transparent layer is larger than that of the transparent protective resin layer. A laser beam is focused on the recording medium layer through the transparent protective layer and the transparent layer. The transparent layer is a transparent adhesive layer or an air layer. The focused laser beam is not affected by foreign matter in the vicinity of the recording medium layer due to the high transparency of the transparent layer on the recording medium layer.

Optical disc and method of manufacturing

There are provided acrylic plastic lenses having a wide range of refractive indices as well as excellent physical and optical properties by polymerization of specific acrylic monomers in the presence of a photopolymerization initiator and a thermal polymerization catalyst.

Plastic lens of neopentyl glycol dimethacrylate copolymerized with

An injection compression molding apparatus has a mold unit having a stationary die plate and a movable die plate movable toward and away from the stationary die plate with mold plates therebetween defining a mold cavity into which an injection nozzle is directed, a supporting plate, a main cylinder supported on the supporting plate and a main cylinder ram having the outer end connected to the movable die plate for moving the movable die plate between a position in which the mold is fully closed and a position in which the mold is open to permit discharge of a molded product, and a compression stroke setting device for setting the position of the movable die plate at a position spaced a distance away from the fully closed position corresponding to a desired compression stroke of the mold. The device includes an adjustment part positioned either between the stationary die plate and the movable die plate or between the movable die plate and the supporting plate which is movable laterally of the direction of movement of the movable die plate for permitting the movable die plate to move to the fully closed position or permitting the movable die plate to move to the open position of the mold.

Apparatus for injection compression molding

A heat cycle injection compression molding method comprises several steps: heating a synthetic resin until it becomes fluidized; injecting the fluidized synthetic resin into a large and nonuniform cavity formed by a cavity block and a mold which is slightly opened; cooling the injected fluidized resin until the center portion temperature of the resin is equal to or lower than a solidifying temperature of the resin, thereby solidifying the resin; reheating the solidified resin uniformly until the temperature of the resin is higher than the solidifying temperature, thereby making the resin fluidized again; compressing the refluidized resin by reducing the volume of the cavities; cooling the refluidized resin until the temperature of the refluidized resin is lower than a take-out set temperature, while continuing the compressing step, thereby resolidifying the resin; stopping the compressing step; and ejecting out of the mold a formed product having a large and nonuniform thickness.

Heat cycle injection compression molding method

Method of manufacturing a tone arm by superposing a sheet of graphite flakes bound with resin, on a carbon fiber prepreg, winding the resultant double layer product around a core, heat-hardening the resultant assembly, and removing the core to form a pipe-shaped tone arm.

Tone arm manufacturing method

A resist material used for forming a positive image by application of radiation, said material comprising as principal constituent poly(ethyl .alpha.-cyanoacrylate), poly(ethyl .alpha.-amidoacrylate) or a binary copolymer thereof or a ternary copolymer of poly(ethyl .alpha.-cyanoacrylate), poly(ethyl .alpha.-amidoacrylate) and polymethacrylonitrile. The minimum incident charge of radiation required for forming a desired resist pattern by use of this resist material is as low as 10.sup.-7 coulomb/cm.sup.2, or far lower than the level required in use of other known resist materials, and a positive resist image which can well stand the chromium etching solutions is obtained by short-time irradiation.

Positive resist for high energy radiation

A film of poly(methacrylamide) is heated to partially form imide bonds with elimination of ammonia, and such imide bonding causes crosslinking in the polymer to form a crosslinked polymer film. This film can be advantageously adapted as a positive resist capable of forming a positive image by exposure to radiation such as electron beams. The minimum incident charge required for such exposure is of the order of 10.sup.-7 coulomb/cm.sup.2, which is far lower than the level required in the use of conventional resists. The resist provided according to this invention is also capable of forming an excellent heat-resistant positive resist image by short-time exposure to radiation.

A film coated with a dispersion of an N-vinyl compound, an organic halogen compound and a sensitizer in gelatin is preheated at 60.degree.-120.degree.C before an imagewise exposure to sensitize the film and to destroy fog-nuclei. After the imagewise exposure the film is subjected to a red light flood exposure for intensifying latent image, heating for development and flood light exposure for fixing to give a negative image of high contrast. The preheating may be applied to a film once exposed to extinguish the resulting latent image and thereby to be subjected to another exposure.

Dry working photographic process relating to N-vinyl compound system

A light and heat sensitive composition useful particularly in photographic reproduction, the composition comprising a combination of an electron donative material, such as a .pi.-base and an electron acceptive material such as a .pi.-acid both dispersed in an aqueous dispersion medium in the form of discrete particles, at least one of the electron donative and electron acceptive materials being capable of polymerization upon irradiation by actinic light or an actinic corpuscular ray and the materials producing a colored charge transfer complex under predetermined heating conditions.

Growing community of inventors

Osaka, Japan

Shunsuke Matsuda