Illuminating device, and liquid crystal display device and portable terminal device including the illuminating device

An illuminating device comprising:

• a light source that emits light spreading in a fan-shape;
• and
• an optical guide plate including a light-incident end surface that receives therein light emitted from said light source, a luminescence section that converts the received light into a surface-emission light for emission thereof, and a protrusion that fixes the optical guide plate onto a housing, wherein:
• said protrusion is formed on the side surface of the optical guide plate that crosses at right angles said light-incident end surface of said optical guide plate at a position outside an outgoing-angle range of the light that travels through said light-incident end surface while spreading in a fan-shape.

A liquid crystal display device comprising:

• a light source that emits light spreading in a fan-shape;
• an optical guide plate including a light-incident end surface that receives therein light emitted from said light source, a luminescence section that converts the received light into a surface-emission light for emission thereof, and a protrusion that fixes said optical guide plate onto a housing;
• and
• a liquid crystal display panel that uses light emitted from said luminescence section of said optical guide plate as a backlight source, wherein:
• said protrusion is formed on a side surface of said optical guide plate that crosses at right angles said light-incident end surface of said optical guide plate at a position that does not overlap an effective display area of said liquid crystal display panel.