Optical waveguide ,light source device ,display device and information terminal configured with them

Abstract

A light source device which is uniform in the intensity of distribution of an emitted light and high in the optical utilization efficiency, a display device which is high in recognability and is energy-saving, and an information terminal are provided. A reflecting portion is formed on a surface opposed to an emitting surface of a linear light guide. The reflecting portion is periodically formed with a total reflecting surface guiding a light incident on a linear light guide from a point light source, a light extracting surface allowing the light to reflect in such a way as to emit the light guiding the linear light guide from the emitting surface, and a re-incidence plane which takes the light transmitted but not reflected on the light extracting surface into the linear light guide again. By changing the size of the light extracting surface and the re-incidence plane, the intensity of distribution of the emitting light from the linear light guide can be made uniform.

Description

technical field [0001] The present invention relates to an optical waveguide, a light source device equipped with an optical waveguide, a display device and an information terminal using the light source device, and particularly relates to a light source device having an optical waveguide with uniform intensity distribution of emitted light and high emission efficiency, and a high recognition rate and Display devices requiring less power consumption, and information terminals equipped with them. Background technique [0002] Among display devices, a liquid crystal display (LCD) is characterized by light weight and thin volume. Accordingly, LCDs have been widely used as display devices for portable, notebook-type information processing terminals and the like, or as display devices for information terminals including, for example, portable televisions, electronic notebooks, portable phones, and the like. Generally in an LCD, the visibility of information is enhanced by illumi...

AI Technical Summary

Problems solved by technology

[0033] However, in the case of this structure, since the depth of the grooves is limited by the pitch of the grooves and the angle of the grooves, among the light incident on the optical waveguide, almost parallel light cannot be effectively reflected on the grooves.

As a result, optical loss becomes large due to repeated reflection of light within the optical waveguide or light is emitted from an incident surface opposite to that on which it was incident, resulting in a decrease in the optical utilization efficiency of the light source device.

That is to say, the light emitted from the optical waveguide is uniform when the utilization efficiency is low, and the resolution of the display device using this optical waveguide also becomes low.

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