The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 14, 1983
Filed:
Dec. 04, 1980
Koji Sato, Yokohama, JP;
Tadahiro Kaneko, Tokyo, JP;
Toshiba Electric Equipment Corporation, Tokyo, JP;
Abstract
A straight cylindrical light source formed of, for example, a fluorescent lamp is set in place at a predetermined distance from a desk top surface. A reflector whose cross section is shaped substantially like a parabola is positioned at the back of the light source. A housing having an opening formed at least on the underside is provided to enclose the light source and reflector. Where a vertical angle defined by a straight line l.sub.0 connecting the axis of the light source to the front edge of the desk top surface defines .theta..sub.0, then a vertical angle .theta..sub.1 defined by a straight line l.sub.1 tangentially contacting the upper peripheral surface of the cylindrical light source and extending to the front end of the lower opening of the housing is also prescribed to be substantially .theta..sub.0. A vertical angle .theta..sub.2 defined by a straight line l.sub.2 passing through the upper terminal end of the reflector and tangentially contacting the lower peripheral surface of the cylindrical light source is also chosen to be substantially .theta..sub.0. The reflector is so positioned that the focal point of its parabolic cross section is substantially aligned with the axis of the light source, and a vertical angle .theta..sub.3 defined by a straight line l.sub.3 extending along the axis of the parabolic cross section of the reflector is likewise taken to be .theta..sub.0.