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Showing papers by "Tetsu Tanaka published in 2002"


Patent
Onishi Seiji1, Tetsu Tanaka
08 Aug 2002
TL;DR: In this article, a simplified optical pickup device is proposed to secure sufficient quantity of converged light required for recording and reproducing onto/from respective optical disks, can obtain required imaging magnification of respective optical systems, and does not generate performance degradation at lens shift, when recording or reproduction is performed on/from optical disks with different base material thickness by plural optical systems.
Abstract: The present invention has for its object to provide a compact and simplified optical pickup device which secures sufficient quantity of converged light required for recording and reproducing onto/from respective optical disks, can obtain required imaging magnification of respective optical systems, and does not generate performance degradation at lens shift, when recording or reproduction is performed onto/from optical disks with different base material thickness by plural optical systems of a single optical pickup device. A first light source and second light source which emit light beams with different wavelength corresponding to plural kinds of optical information recording media, a beam splitter as a synthesizing means, a collimator lens as an optical converting means, and an objective lens as a converging means are equipped, and a light path length converting means such as a prism mirror, which is made of material having high refractive index, for lengthening light path length (air reduction length) is provided between the synthesizing means and the converging means in a state where the first light source is located nearer to the optical converting means than a back focus thereof is and the second light source is located farther from the optical converting means than a back focus thereof is, thereby to making the synthesizing means close to the converging means.

12 citations


Journal ArticleDOI
TL;DR: In this paper, the SiN-induced boron penetration has been investigated in detail by using BORON-doped polysilicon gated capacitors with several kinds of thick SiN films.
Abstract: Applications of SiH-free silicon nitride (SiN) films, formed by tetrachlorosilane (TCS) and ammonia, have been proved to effectively suppress the SiN-induced boron penetration. The SiN-induced boron penetration has been investigated in detail by using boron-doped polysilicon gated capacitors with several kinds of thick SiN films. It was clarified for the first time that the SiN-induced boron penetration becomes worse with SiH content in SiN films and deposition technique of SiH-free TCS-SiN films is essential for realization of the high-performance PMOSFETs.

10 citations