Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Kazuhiro Hayashi

Eiji Ohno

Kazuya Hisada

Masanari Mohri

Kazuo Inoue

Kazuhiro Higashimaru

Shinya Abe

Hidemi Isomura

Hideo Matsumoto

Daisuke Ogata

Akihiro Yasuda

Masahiko Tsukuda

Keiji Nishikiori

Masahiko Hirata

Sou Miyata

Fumiaki Ueno

Akihisa Yamada

Eiichi Ito

Keiichi Zaitsu

Yoshihiro Kawasaki

Suguru Matsumura

Masanari Mohrii

A surface light source apparatus includes an end face for taking in light emitted from a light source and a main surface for emitting the light. The surface light source apparatus further includes a plurality of structure bodies formed on an opposed surface disposed opposite to the main surface in the surface light source apparatus, each of which has a reflecting surface facing the point light source. Each structure body has a cut-off portion which removes a portion on the reflecting surface in a longitudinal direction of the structure body and in a height direction.

Surface light source apparatus having cut out portions where a reflecting portion is not present

A transfer layer on a surface of a mold has a thickness distribution along the radius direction that the layer is thick in an inner round portion but is gradually thinner toward an outer round portion. An adhesive layer is formed between a surface of a signal substrate which bears a signal recording film and the mold which seats the transfer layer. The adhesive layer has a thickness distribution that the layer is thin in an inner round portion but is gradually thicker toward an outer round portion. Since the thickness distributions along the radius direction of the transfer layer and the adhesive layer are opposite to each other, the thickness distribution of an isolation layer which comprises the two layers is uniform.

Method of and apparatus for manufacturing multi-layer optical information recording medium

A transparent protective layer () having a thickness of 100 &#x3bc;m is formed of a resin film (), a boundary layer () and an adhesive layer () on a signal recording layer (). When nf, ni and na are the indices of refraction of the resin film (), the boundary layer () and the adhesive layer (), respectively, the relationship among nf, ni, and na satisfies any one of the following equation: na&#x3c;ni&#x2266;nf; na&#x3e;ni&#x2267;nf; na&#x3c;nf&#x2266;ni; or na&#x3e;nf&#x2267;ni, and the relationship among nf, ni, and na satisfies the following equation |nf&#x2212;ni|&#x3c;|nf&#x2212;na|. At this time, a protrusion () and a scratch () are optically buried within the boundary layer (), reducing scattering of laser beams and disturbance in the wave front which occur in these portions, and thereby, the error rate can be reduced.

Optical information recording medium and method for manufacturing the same

A method of manufacturing an optical information recording medium to/from which signals can optically be recorded and reproduced. The recording medium includes a signal substrate (), a signal recording layer (), and a transparent cover layer () having a first transparent layer () and a second transparent layer (), which is harder than the first transparent layer (). Signals can be recorded and reproduced to and from the recording medium by a light transmitted to the signal recording layer through the transparent cover layer (). The first transparent layer is formed so as to have a first predetermined distribution of thickness. The second transparent layer is formed so as to have a second predetermined distribution of thickness to make the total thickness of the transparent cover layer () uniform. The first transparent layer () may be made of a plurality of thin laminated transparent layers.

Manufacturing method of optical information recording medium

A disc-shaped optical data recording medium has a signal recording layer for reading and/or writing data using light, and a 10 &#x3bc;m to 200 &#x3bc;m thick transparent protective layer disposed over the signal recording layer. The optical data recording medium includes a protrusion projecting from a surface of the transparent protective layer on a light-incidence surface side to which light is emitted to the signal recording layer. The protrusion is disposed in an area between a center hole and a clamping area where the optical data recording medium is held when reading and/or writing data in the signal recording layer.

Optical data recording disc with protrusion between clamping area and center hole

When a separation layer is formed using a stamper between a substrate and the stamper on a thick substrate, on the surface of which a rewritable recording multilayer film provided with signal guide grooves or pits and the signal guide grooves or pits are transferred from the stamper to the surface, variations in the thickness of the separation layer are produced due to unevenness of the distance between the stamper and the substrate. The surface of the kth signal recording layer of the kth signal substrate is shaped parallel to the surface with the guide grooves and pits of the (k&#x2212;1)th signal recording layer on the (k&#x2212;1)th stamper, a (k&#x2212;1)th separation layer is formed between the two and then the (k&#x2212;1)th stamper is peeled off. The distance between the surface with the guide grooves and pits of the (k&#x2212;1)th signal recording layer and the kth signal recording layer becomes uniform, and therefore the thickness of the (k&#x2212;1)th separation layer can be kept uniform.

Method of manufacturing multilayer optical information recording medium

Optical data recording medium with protrusion bonded between center hole and clamping area

A method of manufacturing an optical information recording medium that has a substrate having a signal recording layer formed on one principal surface thereof; and an optically transparent layer formed on the signal recording layer and made from a radiation cure type resin. According to the method, when the optically transparent layer is formed, the radiation cure type resin is supplied onto the substrate, and the radiation cure type resin is applied over the substrate by spinning the substrate at a predetermined number of application revolutions in a spin coating method. The number of revolutions of the substrate is increased after the application of the resin, and radiation is irradiated to cure the radiation cure type resin while the number of revolutions of the substrate is increased.

Optical information-recording medium manufacturing method and manufacturing apparatus

An optical disc manufacturing method suppresses thickness variation in intermediate layers disposed between any two data recording layers to achieve an intermediate layer of uniform thickness. A substrate having a center hole and data recording layer is first prepared. This center hole is then plugged with a capping member and a resin material is dripped from above the center hole while spinning the substrate around its center hole to coat the data recording layer with the resin by a spin coating method. The capping member is then removed. Then, a stamper having a groove or lands and pits on its surface is prepared. The groove or lands and pits side of the stamper is then pressed into the resin material on the substrate, and the resin is then cured to form an intermediate layer. The stamper is then separated from the substrate to leave a data recording layer in the surface of the intermediate layer with a groove or land-and-pit pattern corresponding to the groove or lands and pits in the stamper.

Optical data recording medium and manufacturing method for the same

A liquid material is applied by spin coating it onto a first main surface of a flat plate to form a coating of the liquid material thereon. The flat plate includes a second main surface which is opposite to the first main surface and a hole which passes through the flat plate. The application of the liquid material is carried out using an inner guide member, which is placed in the hole, and the spin coating is carried out while the flat plate is placed on a stage such that the inner guide member is placed generally adjacent to an inner peripheral side surface of the flat plate and an upper surface of the inner guide member and the first main surface are located at generally the same level. Thereby, a coating is obtained which extends on the upper surface of the inner guide member and the first main surface of the flat plate.

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Kadoma, Japan

Kazuhiro Hayashi