Abstract: An optical information recording medium including a ROM region in which pits are previously formed at a track pitch (P); and a RAM region including a groove which is to be exposed to laser light to form at least one of a pit and a mark therein and to record information to be reproduced, wherein the pits in the ROM region are wobbled in a radius direction of the recording medium, a wobbling inter-pit groove is formed along the wobbled pits, wherein the width (W) of the inter-pit groove is narrower than that of the groove in the RAM region. The ratio (W/P) of the width (W) of the inter-pit groove to the track pitch (P) is preferably from 0.2 to 0.4.

Abstract: An optical information recording medium having a ROM area in which pre-pits are arranged in a line in advance, wherein a groove having a depth smaller than a depth of the pre-pits is formed between the pre-pits, and the groove has a width at junction parts smaller than a width of a part of the groove other than the junction parts. Preferably the following relationships are satisfied: ½ Wg?Wpg<Wg; and Wpg<Wp, where Wp, Wpg and Wg represent a width of the pre-pit, the width of the groove at the junction parts, and the width of the other part of the groove other than the junction parts, respectively.

Abstract: An information recording technique for forming a recording mark with a multi-pulse sequence, which is increased by one pulse with an irradiation power Pw for every increase of 2T in a temporal length nT of the recording mark is provided. Particularly, this technique realizes a recording strategy that is simple in its configuration but is capable of improving the consistency of mark shapes in forming the recording marks when the value n of the temporal length nT is an odd number. More specifically, when n is an odd number and n?7, a period from the fall of a first pulse to the fall of a second pulse is set to 2.5T and a period corresponding to a last pulse is set to (2+?1o) T where the value of ?1o is optimized within a range of 0<?1o?1.

Abstract: An optical information recording medium having a ROM area in which pre-pits are arranged in a line in advance, wherein a groove having a depth smaller than a depth of the pre-pits is formed between the pre-pits, and the groove has a width at junction parts smaller than a width of a part of the groove other than the junction parts. Preferably the following relationships are satisfied: ½ Wg?Wpg<Wg; and Wpg<Wp, where Wp, Wpg and Wg represent a width of the pre-pit, the width of the groove at the junction parts, and the width of the other part of the groove other than the junction parts, respectively.

Abstract: An information recording medium includes a transparent substrate and a recording layer or a metal layer provided on the transparent substrate directly or via a ground layer. The information recording medium has a RAM area on which information is recorded, reproduced or erased, and a ROM area from which only reproduction is made, and an average thickness of the recording layer of said RAM area is larger than that of the recording layer or metal layer of the ROM area.

Abstract: An information recording apparatus performs an excellent recording, erasing and rewriting operation with respect to a recording medium, which can be recorded at a recording speed equal to or higher than 4× recording speed without large change in a recording strategy. The information recording apparatus records information on a recording medium by irradiating a pulsed light onto the recording medium. A controller controls an optical head to irradiate the pulsed light so that a length of a recording mark formed on the recording medium is an n times of a period Tw of a basic clock, where n is a natural number. The controller adds an off-pulse to an end of a final pulse of a train of multi-pulses contained in the pulsed light so that a light having a bias power Pb is irradiated during a period T1 of the off-pulse. The controller is capable of setting the period T1 of the off-pulse to a predetermined value so that a relationship 0≦T1≦0.2Tw is satisfied.

Abstract: An information recording technique for forming a recording mark with a multi-pulse sequence, which is increased by one pulse with an irradiation power Pw for every increase of 2T in a temporal length nT of the recording mark is provided. Particularly, this technique realizes a recording strategy that is simple in its configuration but is capable of improving the consistency of mark shapes in forming the recording marks when the value n of the temporal length nT is an odd number. More specifically, when n is an odd number and n≧7, a period from the fall of a first pulse to the fall of a second pulse is set to 2.5T and a period corresponding to a last pulse is set to (2+&dgr;1o)T where the value of &dgr;1o is optimized within a range of 0<&dgr;1o≦1. In this way, the multi-pulse sequence can be adjusted from the front pulse side and the rear pulse side so that an overall consistency can be realized in the mark shape upon recording the mark.

Abstract: An optical information recording medium having a ROM area in which pre-pits are arranged in a line in advance, wherein a groove having a depth smaller than a depth of the pre-pits is formed between the pre-pits, and the groove has a width at junction parts smaller than a width of a part of the groove other than the junction parts. Preferably the following relationships are satisfied: ½ Wg≦Wpg<Wg; and Wpg<Wp, where Wp, Wpg and Wg represent a width of the pre-pit, the width of the groove at the junction parts, and the width of the other part of the groove other than the junction parts, respectively.

Abstract: An optical information recording medium including a ROM region in which pits are previously formed at a track pitch (P); and a RAM region including a groove which is to be exposed to laser light to form at least one of a pit and a mark therein and to record information to be reproduced, wherein the pits in the ROM region are wobbled in a radius direction of the recording medium, a wobbling inter-pit groove is formed along the wobbled pits, wherein the width (W) of the inter-pit groove is narrower than that of the groove in the RAM region. The ratio (W/P) of the width (W) of the inter-pit groove to the track pitch (P) is preferably from 0.2 to 0.4.

Abstract: An information recording medium includes a transparent substrate and a recording layer or a metal layer provided on the transparent substrate directly or via a ground layer. The information recording medium has a RAM area on which information is recorded, reproduced or erased, and a ROM area from which only reproduction is made, and an average thickness of the recording layer of said RAM area is larger than that of the recording layer or metal layer of the ROM area.

Abstract: An optical recording medium which includes a PMA area, a TOC area, program area, an area that includes a user area and lead-out area. A portion of the PMA area, which relates to the program area, is in a recorded state and the TOC area is in an unrecorded state. Alternatively, the PMA may be in an unrecorded state. In addition, a password may be recorded in a portion of an information area. A method of erasing the medium and a system for reading and recording information are also provided.

Abstract: An optical recording medium which includes a PMA area, a TOC area, program area, an area that includes a user area and lead-out area. A portion of the PMA area, which relates to the program area, is in a recorded state and the TOC area is in an unrecorded state. Alternatively, the PMA may be in an unrecorded state. In addition, a password may be recorded in a portion of an information area. A method of erasing the medium and a system for reading and recording information are also provided.

Abstract: This invention provides a method for the surface treatment of a metal, which comprises the steps of: placing at least a surface to be treated of a metal to be treated between two electrodes facing each other under an atmosphere of a mixed gas consisting of an inert gas and a reactant gas; and plasma exciting said mixed gas under atmospheric pressure to effect glow discharge between said electrodes. The method of the present invention uses an apparatus simpler than that used in a conventional method and can inject into the surface layer of a metal, even those elements which have been difficult to with the conventional method, and can readily modify surface properties of a metal such as surface hardness, surface wettability, etc.

Abstract: An optical information recording medium including a ROM area and a recordable area is composed of a light-transmitting substrate with prepits and/or guide grooves formed on the surface thereof, a light absorption layer serving as a recording layer which is composed of a dye as the main component overlaid on the light-transmitting substrate, and a light reflection layer which is composed of metallic film overlaid on the light absorption layer. The light absorption layer of this optical information recording medium is formed on the substrate by coating a solution composed of a dye and a solvent of a mixture of a fluoridated alcohol of formula (I) and an alcohol of formula (II):A--CH.sub.2 OH (I)wherein A represents CF.sub.3 --or H(CF.sub.2 --CF.sub.2).sub.l --in which l is an integer of 1 to 3; andHO--CH.sub.2 CH.sub.2 --OR (II)wherein R represents C.sub.n H.sub.2n+1 --, ##STR1## H, or C.sub.m H.sub.2m+1 --O--C.sub.n H.sub.2n -- in which n is an integer of 1 to 4 and m is an integer of 1 to 4.

Abstract: A magneto-optical recording medium is disclosed, which comprises a transparent substrate, a magnetic oxide layer formed on the substrate, and band-shaped reflection layers formed on the magnetic oxide layer.

Abstract: A magneto optical recording medium comprising laminating a reflective layer, a dielectric undercoat layer and a hexagonal magnetoplumbite-type metal oxide magnetic layer on a substrate in order, characterized by that said magnetic layer is made an excellently C axis - orientated perpendicular magnetic film by putting the crystal misfit between said reflective layer and said dielectric undercoat layer formed thereon within .+-.30% and the crystal misfit between said dielectric undercoat layer and said hexagonal magnetoplumbite -type metal oxide magnetic layer formed thereon within .+-.30%, and thus various characteristics are widely improved.

Abstract: A toner concentration control system for use in electrophotographic copying machines or the like, wherein light from a single light source is simultaneously detected by two photosensors, or by two sensing portions of a single photosensor, the light striking one of the photosensors (or portions) directly and the other after being reflected from developer comprising toner and carrier particles as the developer passes a viewing window in a chute provided for the transport thereof within the copying machine, the intensity of the reflected light being inversely proportional to the concentration of toner in the developer, whereby, by comparison of the output of the photosensors (or portions) by conventional means, the concentration of toner in the developer can be determined and adjusted, the photosensors (or portions) having been carefully selected as a pair of their essentially identical characteristics and response to ambient conditions so that, for example, their parallel deterioration with time or their identi

Abstract: A toner concentration control apparatus of the type for allowing developer to pass through a chute, which is capable of detecting stopping of the flow of the developer in the chute, clogging of the chute with the developer, or coating of a viewing window formed in the chute with the developer, and upon occurrence of such abnormalities, minimizing the trouble therefrom in the operation of the copying machine, in which light from a single light source is simultaneously detected by two photosensors, the light striking one of the photosensors directly and the other after being reflected from the developer comprising toner and carrier particles as the developer passes a viewing window in the chute provided for the detection of the toner concentration within the copying machine, and the output of the photosensors is compared with each other and the concentration of toner in the developer can be determined and adjusted by the comparison value.

Abstract: A powdered developer (26) comprising carrier and toner particles is caused to flow by gravity downwardly through a passageway (71). A transparent electrode (62) is disposed in the passageway (71). A light source (64) and photosensor (66) are arranged on opposite sides of the electrode (62) for sensing an amount of attracted toner. The electrode (62) is first de-energized and cleaned by aprtially restricting the passageway (71) below the electrode (62) and allowing developer (26) to accumulate in the passageway (71) from the restriction upwardly past the electrode (62) while a restricted amount of developer (26) flows downwardly through the restriction. Then, the restriction is removed and the passageway (71) blocked above the electrode (62), allowing the accumulated developer (26) to flow downwardly past the electrode (62). Then, the passageway (71) is completely unblocked and the electrode (62) energized with an electric potential causing toner to be attracted thereto.