Light source device and vehicle lighting device

A light source device configured to emit light along an optical axis comprising:

• a light guide member made of a material transparent in a visible range, the light guide member having a front light emission surface and a rear surface opposed to the front light emission surface, the front light emission surface and rear surface being separated by at least one end surface;
• a luminance control element located adjacent a surface of the light guide member and configured to control a luminance distribution of light on the front light emission surface, the luminescence control element including at least one of a plurality of indent structures located in the light guide member and a plurality of three-dimensional structures located adjacent a surface of the light guide member;
• and
• a light source including at least one of a point light source and a linear light source located adjacent and facing the at least one end surface of the light guide member;
• and
• a polarizing structure located adjacent the light guide member and configured to cause light emitted from the light emission surface to be polarized, wherein the polarizing structure is a stretched polymer film, the stretched polymer film having elliptically-shaped small areas of different refractive index.

A light source device configured to emit light along an optical axis comprising:

• a light guide member having a flat plate-like shape and made of a material transparent in a visible range, the light guide member having a front surface serving as a light emission surface and a rear surface opposed to the front surface and having a luminance control element configured to control a luminance distribution on the light emission surface, the front surface and rear surface separated by at least one end surface;
• a light source including at least one of a point light source and a linear light source facing the at least one end surface of the light guide member, wherein
• the luminance control element is configured to control light reaching the luminance control element from the at least one end surface of the light guide member and to configure the light into the luminance distribution of light on the light emission surface, the luminance distribution configured to form a light distribution pattern to be projected,
• the light guide member is configured to emit, from the light emission surface, only parallel polarized light out of the total light emitted from the light source, the parallel polarized light being p-polarized with a plane of vibration parallel to a plane that contains the optical axis and is normal to a surface that is to be illuminated;
• and
• a convex projection lens configured to project light emitted from the light source device along an optical axis of the lens and forward in a direction of light illumination, the projection lens having a focus on a side of the lens adjacent the light source device and located substantially at the light emission surface of the light guide member of the light source device.