Pioneer Electronic Corporation

Pioneer Video Corporation

Yutaka Murakami

Hiroyuki Ohira

Nobuki Yamaoka

Minemasa Ohta

Manabu Mochizuki

Hiroki Iwata

A laser-diode-pumped solid state laser comprises: a solid laser medium; a laser-diode capable of producing a laser beam for exciting the solid laser medium; a pair of mirrors which forms a resonator for resonating a light excited by the solid laser medium. An interval between the pair of mirrors is determined such that a gain width GW of the solid laser medium and a frequency interval FS (between every two resonator modes) satisfies an equation 0.1&lE;FS/GW<1.

Laser-diode-pumped solid state laser and an optical system using the same

In a method for manufacturing a master disc for optical discs, patterns to be displayed on the disc are classified into a main object and a background. The background is commonly assigned as the background pattern for glittering rainbow colors by diffracted light reflected from dummy pits of diffraction gratings or a hologram. The main object is individually assigned as the main object pattern of a diffused reflection portion or mirror surface. The manufacturing method comprises one group of steps for forming the common background pattern and the other group of steps for forming the individual main object pattern in the common background pattern. A development substrate for the master disc is formed by using a mask disc in a first light-exposure of a photoresist layer thereof and by using a displaying-pattern mask in a first light-exposure of the photoresist layer. The individual main object pattern is drawn in the common background pattern of the master disc by using a laser-marking or an etching. The mask disc and displaying-pattern mask can be used repeatedly as families for the background and main object patterns so as to facilitate the replication of the optical discs.

Method for manufacturing a master disc for optical discs

An optical disk in which a pattern such as a character that can be recognized is displayed in an information recording area by display pits or grooves formed between recording tracks constructed by pit trains indicative of information signals. An apparatus for manufacturing the optical disk in which information and display modulation light beams obtained by modulating a light beam in accordance with pattern signals for information and display, respectively, are separated from each other in the disk radial direction and are simultaneously irradiated to a resist layer formed on a recording surface of a disk.

Optical disk having pattern displayed thereon and apparatus for

An optical disk having both recording surfaces on which are formed pits trains. A recognizable display pattern is formed by a group of dummy pits formed on one of the recording surfaces. An apparatus for manufacturing the optical disk in which a light beam is modulated in accordance with a dummy forming signal obtained by selectively stopping a dummy pulse, and the modulated light beam is irradiated to a resist layer formed on a recording surface of a disk to form a group of dummy pits representing a display pattern.

Optical disc having large display patterns and its manufacturing

An optical disc is provided with: a disc substrate of light transmissive type having an information record surface including an information recorded region, where pits or grooves carrying an information signal are coaxially or spirally formed, and an information not-recorded region, where the pits or grooves carrying the information signal are not formed; a light reflective layer wholly disposed on the information record surface in the information recorded region, and partially disposed on the information record surface in the information not-recorded region such that an indication pattern is formed of the partially disposed light reflective layer on the information record surface in the information not-recorded region; and a protection layer disposed on the light reflective layer and a portion of the information record surface in the information not-recorded region where the light reflective layer is not disposed.

Optical disc having indication portion

An optical information recording medium, such as an optical disk, includes a meandering guide groove being varied in period according to first additional information and in amplitude according to second additional information. The optical information recording medium enables recording a plurality of kinds of information in addition to the first and second additional information in accordance with a multiple recording system.

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Yamanashi, Japan

Yutaka Murakami