An illuminating device includes:
light source (101); light guiding means (102) where light from light (101) is supplied to one end surface, and light incident from the one end surface is propagated inside to exit from the other end surface; illuminating optical systems (103 to 107) that form an
optical image formed on the other end surface of light guiding means (102) on display element (22); reflective polarizing plate (109) that is located between illuminating optical systems (103 to 107) and display element (12), and transmits first polarized light while reflecting second polarized light whose polarized state is different from the first polarized light toward illuminating optical systems (103 to 107);
phase plate (108) located between light guiding means (102) and reflective polarizing plate (109); and reflecting means (21) that is located on a side opposite the one end surface of light guiding means (102), and reflects, among lights by reflective polarizing plate (109), light incident via
phase plate (108), illuminating optical systems (103 to 107), and light guiding means (102) toward the one end surface of light guiding means (102). The light emitting center of
light source (101) is shifted from a center axis of light guiding means (102).