초록 ▼

The lighting device is equipped with a light guide having a linear Fresnel reflection surface consisting of steps of continuously alternating reflecting surfaces having two different reflection angles. A light source is installed at one end of the light guide of the above construction so that the li

The lighting device is equipped with a light guide having a linear Fresnel reflection surface consisting of steps of continuously alternating reflecting surfaces having two different reflection angles. A light source is installed at one end of the light guide of the above construction so that the light from the light source is emitted from the irradiation surface of the light guide after being reflected by the linear Fresnel reflection surface.

대표청구항 ▼

A lighting device for backlighting a passive display device having a planar display surface and an acute optimum viewing angle qaa-1 (Sin qn)+135°. A lighting device for backlighting a passive display device comprising: a fluorescent lamp having a cylindrical light emitting surface; a transparent c

A lighting device for backlighting a passive display device having a planar display surface and an acute optimum viewing angle qaa-1 (Sin qn)+135°. A lighting device for backlighting a passive display device comprising: a fluorescent lamp having a cylindrical light emitting surface; a transparent cylindrical housing for said fluorescent lamp, said housing having a transparent surface spaced substantially equidistant from the cylindrical light emitting surface of said fluorescent lamp to form an air cavity therebetween, said air cavity forming a heat insulating layer to improve the luminous efficiency of said fluorescent lamp; a light guide, having a first irradiating surface, collecting light from the transparent surface of said housing and directing said light through said passive display device to be emitted therefrom at substantially an acute optimum viewing angle; and diffusion means, disposed between said light guide and said passive display device and having a low diffusion property, for scattering light between said light guide and said passive display device to provide a uniform light distribution with a limited light loss; said transparent surface acting to receive light from said lamp such that a portion is propogated through the light guide at various acute, non-parallel angles to said first irradiating surface.