An illuminating device includes one or more light sources that output light, a translucent light guide member having one or more side surfaces and a light output surface, and a lens sheet positioned over the light output surface of the light guide member and including a first array of lenses and a second array of lenses extended in directions intersecting each other. The light source is positioned to have an optical axis substantially in agreement with a normal direction of the side surface of the translucent light guide member, and the first array or the second array of the lenses which is extended in a direction substantially orthogonal to the optical axis of the light source has a surface area in a range of from 20% to 50% with respect to a total surface area of the first and second arrays of the lenses.
