Abstract: An optical fiber includes a core section and a cladding section. A k value expressed by k=4Aeff/(?MFD2) is 1.08 or larger, Aeff being an effective area and MFD being a mode field diameter, at a wavelength of 1550 nm, a chromatic dispersion is in a range from +19.0 ps/nm/km to +21.9 ps/nm/km, and MFD is in a range from 10.3 ?m to 13.0 ?m. The inequality, r1<r2<r3, is established, R=r3/r2 is larger than 1.0 and equal to or smaller than 5.4, and a relative refractive index difference ?12 of the maximum value N2 with respect to the minimum value N1 is 0.05% or higher, r1 and r2 being radial positions respectively with minimum and maximum value N1 and N2 of a refractive index in the core section and r3 being a radius of the core section.

Abstract: A method for the manufacture of an optical fiber preform for producing a low attenuation optical fiber with high yield, comprising preparing a core rod and adding a cladding region. At the step of preparing a core rod, the core rod is produced including a first core region with Cl density of less than 600 atm-ppm, a second core region with Cl density of less than 600 atm-ppm around the first core region, and a third core region with Cl density of 3000 atm-ppm or more around the second core region. An alkali metal is selectively added to the first core region among the first, second, and third core regions. A cladding region is formed around the core rod by heating at a temperature of 1200° C. or higher for 7 hours or less.

Abstract: There is provided a method for producing an optical fiber having low attenuation, the optical fiber including a core that contains an alkali metal element. An optical fiber preform that includes a core part and a cladding part is drawn with a drawing apparatus to form an optical fiber, the core part having an average concentration of an alkali metal element of 5 atomic ppm or more. During the drawing, the time the temperature of glass is maintained at 1500° C. or higher is 110 minutes or less. The drawing speed is preferably 1200 m/min or more and more preferably 1500 m/min to 2300 m/min. The optical fiber preform preferably has a diameter of 70 mm to 170 mm and more preferably 90 mm to 150 mm.

Abstract: An optical fiber preform has a core portion having a first core portion including a central axis, a second core portion disposed around the first core portion, and a third core portion disposed around the second core portion. The first core portion contains 10 atomic ppm or more of an alkali metal and 10 to 600 atomic ppm of chlorine, the second core portion contains 10 atomic ppm or less of the alkali metal and 10 to 600 atomic ppm of chlorine, and the third core portion contains 10 atomic ppm or less of the alkali metal and 2,000 atomic ppm or more of chlorine. An optical fiber has a core region doped with an alkali metal and chlorine, wherein the minimum concentration of chlorine in the core region is 1,000 atomic ppm or more, and the average concentration of the alkali metal therein is 0.2 atomic ppm or more.

Abstract: A method for producing an optical fiber preform according to the present invention includes an etching step of heating a silica-based glass tube using a heat source continuously traversed in the longitudinal direction of the glass tube to etch the inner surface portion of the glass tube containing impurities while an etching gas is allowed to flow into the glass tube. The glass tube has a maximum alkali metal concentration of 500 to 20,000 atomic ppm, a maximum chlorine concentration of 0 to 1000 atomic ppm, and a maximum fluorine concentration of 0 to 10,000 atomic ppm. In the etching step, the maximum temperature of the outer surface of the glass tube is in the range of 1900° C. to 2250° C., and the heating time is set to a time equal to or less than a time (min) given by ( 7 - alkai ? ? metal ? ? concentration ? ? ppm 5000 ) .

Abstract: A method for producing an optical fiber preform according to the present invention includes a collapse step of collapsing a silica-based glass tube by heating with a heat source continuously traversed in the longitudinal direction of the glass tube to form a first glass rod to be formed into a core part or part of a core part of an optical fiber, the glass tube having an inner surface doped with an alkali metal, in which the glass tube has a maximum alkali metal concentration of 500 to 20,000 atomic ppm, a maximum chlorine concentration of 0 to 1000 atomic ppm, and a maximum fluorine concentration of 0 to 10,000 atomic ppm, and in which in the collapse step, the maximum temperature of the outer surface of the glass tube is 2000° C. to 2250° C., and the traverse speed of the heat source is 30 mm/min to 100 mm/min.

Abstract: There is provided a method for producing an optical fiber preform used in producing an optical fiber having low attenuation. The production method includes (1) a rod formation step of forming a glass rod of a silica glass containing an alkali metal element, the average concentration of the alkali metal element being 5 at·ppm or more, (2) a heat treatment step of heat-treating the glass rod, (3) a core part formation step of forming an alkali metal element-free silica glass layer having a chlorine concentration of 6000 at·ppm or more around the perimeter of the glass rod heat-treated in the heat treatment step to form a core part including the glass rod and the silica glass layer, and (4) a cladding part formation step of forming a cladding part of a silica-based glass having a lower refractive index than the core part around the perimeter of the core part.

Abstract: An optical fiber preform includes a core portion, in which the core portion includes an alkali-metal-doped core glass portion doped with an alkali metal, the maximum concentration of oxygen molecules in the core portion is 30 mol ppb or more, and the average concentration of the alkali metal in the core portion is 5 atomic ppm or more. A method of manufacturing an optical fiber preform includes an alkali-metal-doping step of doping a pipe composed of silica-based glass with an alkali metal, an oxygen-molecule-doping step of doping the glass pipe with oxygen molecules, and a collapsing step of collapsing the glass pipe by heating the glass pipe, in which the optical fiber preform is manufactured.

Abstract: An electronic device includes: a cabinet on whose end surface is formed a slot for insertion of a card; a card access unit that has a terminal that contacts an electrode of the card inserted from the slot. The card access unit is disposed in a position spaced from the slot, houses part, on a front end side of the insertion direction, of the card, and accesses the card via the terminal. The electronic further includes an electronic part disposed on a shield plate that is placed on the bottom surface, in a position overlapping with the card access unit. The shield plate serves also as a guide plate that guides the card inserted from the slot, to the card access unit in conjunction with the bottom surface of the cabinet.

Abstract: An electronic device includes: a cabinet on whose end surface is formed a slot for insertion of a card; a card access unit that has a terminal that contacts an electrode of the card inserted from the slot. The card access unit is disposed in a position spaced from the slot, houses part, on a front end side of the insertion direction, of the card, and accesses the card via the terminal. The electronic further includes an electronic part disposed on a shield plate that is placed on the bottom surface, in a position overlapping with the card access unit. The shield plate serves also as a guide plate that guides the card inserted from the slot, to the card access unit in conjunction with the bottom surface of the cabinet.

Abstract: A low cost image forming apparatus capable of detecting a moving speed or meandering of a revolving endless belt with high accuracy to thereby prevent the color shift includes: a revolving endless belt sequentially superimposing and transferring toner images formed on a plurality of photoconductive drums directly thereon or onto a recording sheet conveyed thereby; an emission part irradiating light to the endless belt; an image receiving part receiving light reflected on the endless belt to obtain successive images of the endless belt; and a control part comparing the successive images obtained by the image receiving part with one another, calculating either of a moving speed and an amount of meandering of the endless belt, and correcting either of the moving speed and the meandering of the endless belt based on a result of the calculation.

Abstract: The electronic apparatus includes: a housing having an opening for inserting a card and a cover member, the opening being closed when a medium is not inserted, the cover member being pressed by the medium when the medium is inserted so that the cover member is rotated to go down at least partially; a medium slot disposed at a position facing the opening and receives a medium inserted through the opening; and an insulation sheet spread under the medium slot and extended to a position in which the cover member rotated to go down by being pressed by the inserted medium covers the insulation sheet.

Abstract: A wire electrode supply device capable of preventing slack and snapping of a wire electrode even using a heavy wire bobbin without using a wire electrode tension detector. A pulley is provided between the wire bobbin driven by a torque motor and a brake roller. The wire electrode unwinds from the wire bobbin, passes through the pulley, brake roller and a workpiece work area, and is taken up by a wind-up roller. When the wire electrode traveling speed is changed from fast to slow, the pulley descends to prevent the wire electrode from slackening between the wire bobbin and the brake roller. When the traveling speed is changed from slow to fast, the back tension from the torque motor is reduced for a predetermined period of time, reducing tension on the wire electrode and preventing it from snapping.

Abstract: A folding travel bag with a cart, which can be used not only as an ordinary travel bag but also as a cart. The folding travel bag includes: a box-shaped travel bag body having a pair of wheels on the bottom face of the body closer to the back: a folding plate having two flat plates connected so that they can be freely folded and borne perpendicularly to the body surface and so that one end of the flat plates is hinged to the lower position on the surface side of the body; a pair of wheels disposed at the leading end portion of said folding plate; and support member extending obliquely upward of the two sides of the body from the two sides of the folding plate. Both the paired wheels on the leading end portion of the folding plate and the paired wheels on the body bottom face are arranged on the floor to bear the body, when the folding plate is folded and brought closer to the side of the body surface or when the folding plate is extended perpendicularly to the body surface.

Abstract: A suitcase with a foldable chair usable as a normal suitcase and also usable as a cart, a chair or a buggy, comprising a suitcase body (11), a pair of wheels (14b) attached onto the bottom surface of the suitcase body near the rear surface, a foldable base plate (12) rotatably installed on the front surface side of the suitcase body at the lower position, a pair of wheels (14a) fitted to the tip of the foldable base plate, fixing devices (13) fixing the foldable base plate to the suitcase body, a foldable seat plate (21) rotatably installed on the front surface of the suitcase body at the position over the installed the foldable base plate, and auxiliary rails (24) opposedly installed on both sides of the foldable base plate rotatably relative to the suitcase body.

Abstract: A suitcase with a foldable chair usable as a normal suitcase and also usable as a cart, a chair or a buggy, comprising a suitcase body (11), a pair of wheels (14b) attached onto the bottom surface of the suitcase body near the rear surface, a foldable base plate (12) rotatably installed on the front surface side of the suitcase body at the lower position, a pair of wheels (14a) fitted to the tip of the foldable base plate, fixing devices (13) fixing the foldable base plate to the suitcase body, a foldable seat plate (21) rotatably installed on the front surface of the suitcase body at the position over the installed the foldable base plate, and auxiliary rails (24) opposedly installed on both sides of the foldable base plate rotatably relative to the suitcase body.

Abstract: A folding travel bag with a cart, which can be used not only as an ordinary travel bag but also as a cart. The folding travel bag includes: a box-shaped travel bag body (11) having a pair of wheels (14b) on the bottom face of the body closer to the back: a folding plate (12) having two flat plates connected so that they can be freely folded and borne perpendicularly to the body surface and so that one end of the flat plates is hinged to the lower position on the surface side of the body; a pair of wheels (14a) disposed at the leading end portion of said folding plate; and support member (13) extending obliquely upward of the two sides of the body from the two sides of the folding plate. Both the paired wheels on the leading end portion of the folding plate and the paired wheels on the body bottom face are arranged on the floor to bear the body, when the folding plate is folded and brought closer to the side of the body surface or when the folding plate is extended perpendicularly to the body surface.

Abstract: A process for forming a multilayered coating film is disclosed, comprising forming a liquid film of a coating composition, increasing the viscosity of the liquid film, and laminating the liquid film having an increased viscosity onto a support or onto a coating film on a support. A multilayered coating film can thereby be formed easily and efficiently without involving interlaminar mixing between adjacent layers.

Abstract: There is provided a process for producing a high-manganese iron alloy from a manganese ore and/or a pre-reduced product thereof in a top and bottom blown converter type reaction vessel holding molten iron or a molten manganese iron alloy, together with a molten slag, said molten iron or alloy and said molten slag being the products of a separate smelting furnace, gas being blown into said vessel through a bottom blowing nozzle, said process comprising charging said vessel with a supply of raw materials including at least one source of manganese and iron selected from a manganese ore containing manganese oxide and iron oxide and a pre-reduced product thereof, a solid carbonaceous substance and a slag forming agent, while simultaneously blowing gas selected from oxygen and a gas containing oxygen into said vessel through a top blowing lance to burn said carbonaceous substance so as to heat, melt and reduce said raw materials to form a melt containing manganese oxide and iron oxide; supplying an additional carbo

Abstract: In a developing device, a developing roller is disposed at a fixed position to oppose an electrostatic latent image-forming surface rotating in one direction, and a submagnet roller is disposed to be parallel to the electrostatic latent image-forming surface, to have an axis perpendicular to the one direction, and to oppose the developed area opposing the developing roller at a downstream side from the developing roller along the one direction. The developing roller supplies a magnetic developing agent by a magnetic force to that portion of an electrostatic latent image which opposes the developing roller and is defined as a developed area to develop the electrostatic latent image in the developed area by the magnetic developing agent.