A guide plate has a back face provided with a great number of micro-reflectors which has a guide portion and a conversion output portion including a valley. The conversion output portion reflects twice input light P at inner slopes, generating inner output light Q directed obliquely as to be distant from an incidence end face. Inner output light Q is inner-incident to a slope of projection row PR on an emission face, with the result that some of the inner-incident light becomes a direct escaping light and much of the other reaches the emission face again after travelling along various paths. At the second time or later chances of escaping, an actual escaping occurs to generate an indirect escaping light. A mixed emission suitably blended of the direct and indirect light is directed to directions, which are modified to directions around a roughly frontal direction by prism sheet PS before being supplied to a LCD panel or the like to be illuminated. Blending of direct/indirect escaping light prevents fine brightness unevenness from appearing. Reflector RF, if arranged, brings an increased indirect escaping light. An emission has travelling directions inclinations of which are controlled while fine brightness unevenness are reduced.