Stanley Electric Co., Ltd

Future Vision Inc.

Koichi Masuyama

Naoya Sone

Yasuo Toko

Sadayuki Konishi

Shuichi Ajiki

Makoto Tsumura

Yuichiro Yamada

Hirokuni Osugi

Toshio Miyokawa

Yoshiro Honda

A vehicle lamp can include a light source unit including a light guide plate with a light emission surface, and a point or line light source opposed to one end face of the light guide plate. The light guide plate can be made of a transparent plate-like material. A convex projection lens can be configured to focus light emitted from the light source unit and project the light forward in a direction of light illumination. The light guide plate can have a prism array on a rear surface thereof extending with a serrated cross section from the one end face to the opposite end face of the light guide plate, and in a direction parallel with the end face. The prism array can include a plurality of prism surfaces, with each prism surface being obliquely formed so that when light enters the light guide plate from the light source side and impinges thereon, a substantial amount of the light can be totally reflected into small angles of incidence to the emission surface. The projection lens can be disposed such that a focus thereof on a light source unit side is located on the light emission surface of the light guide plate.

Vehicle lamp

A vehicle lamp can create a desired distribution pattern easily with a simple configuration while having a thin body and light weight. The vehicle lamp can include a light source unit and a convex projection lens configured to project light from the light source unit forward in the direction of light illumination. The light source unit can include a light guide plate having a light emission surface and made of a transparent material to the visible light range and can include a light source disposed in front of one end face of the light guide plate. The projection lens can have a focus arranged on or near the light emission surface of the light guide plate. The light source unit can include a reflection sheet configured to reflect light from the light guide plate back into the light guide plate and can have a shape configured to provide a cutoff pattern. The reflection sheet can be located adjacent an edge of the light guide plate adjacent the light source. A high beam light source unit can be disposed adjacent or on the reflection sheet closer to the projection lens.

An LED light source device can have a simple configuration which can easily create a desired light distribution pattern with a low profile and light weight. An illumination apparatus and a vehicle lighting device can also be configured to use the LED light source device. The light source device can include a light guide plate made of a flat plate-like material that is transparent in the visible range, and which has a front surface serving as a light emission surface. A point light source can be opposed to an end surface of the light guide plate. A rear surface of the light guide plate can include a luminance control element configured to control a luminance distribution on the light emission surface. The luminance control element controls light from the light source, incident through the end surface of the light guide plate, so that a reduced inversion of a light distribution pattern that is to be emitted is formed on the light emission surface as the luminance distribution. The light guide plate can include a polarizing film for making the light emission surface emit p-polarized (parallel polarized) light.

Light source device and vehicle lighting device

An LED light source device and an illumination device using the same, including vehicle lighting devices, can have a light weight and thin profile and can form a desired light distribution pattern while employing a simple configuration. The light source device can include a plate shaped light guide member made of a material that is transparent in a visible range. The light guide member can have a front surface serving as a light emitting surface and having a plate shape, and a rear surface having a luminance control element for controlling a luminance distribution on the light emitting surface. A point or linear light source facing towards an end surface of the light guide member can be provided. The luminance control element controls light reaching the element from the end surface of the light guide member and configures the luminance distribution on the light emitting surface, the luminance distribution being obtained by reducing a light distribution pattern to be projected (and in some cases horizontally and vertically reversing the pattern).

A reflecting plate in form of dual half-ellipses comprises a first ellipse having a first focal point and a second focal point, and a second ellipse having a first focal point and a second focal point. The first ellipse and the second ellipse commonly share the first focal point. A cross-section of the reflecting plate is designed in such a form that the dual half-ellipses are aligned with each other, and that contours of the first ellipse and the second ellipse are divided by a straight line, which includes the commonly shared first focal point and the other focal points. The reflecting plate encloses the line light source by the dual half-ellipses and reflects a light from the line light source toward the diffusion plate arranged above by specular reflection and by diffused reflection. As a result, uneven brightness is eliminated at the boundary of the reflecting plate designed in form of dual half-ellipses.

Surface light source device with half-ellipse reflecting plate

A vehicle lamp having inner and outer lenses and a reflector mirror surface. The inner lens is a Fresnel lens for converting light beams from a light source into parallel light beams, and the outer lens is an ordinary lens for obtaining a desired divergence property of the lamp. The reflector mirror may be a plane mirror, a mirror of a truncated cone shape, or a mirror of a parabolic cylinder shape. The Fresnel lens has as its focal point the virtual image of the light source as obtained by the reflector mirror, thus realizing a compact and small depth housing of the lamp while effectively using the light beams.

Growing community of inventors

Tokyo, Japan

Koichi Masuyama