Light guiding device and blinds with light guiding device

A light guiding device includes a light collector and a beam expander. The light collector comprises a light guiding plate and a plurality of light collecting elements. The light guiding plate comprises a first end portion and a second end portion which is opposite to the first end portion. The light collecting elements are respectively arranged side by side on the first end portion of the light guiding plate, every light collecting element has a curved surface. The beam expander is deposited on the second end portion of the light guiding plate, the width and thickness of the beam expander become wider and thicker from the end near the second end portion to the end far from the second end portion. When light beams respectively enter the light collecting elements and contact the curved surfaces, the light beams are reflected by the curved surface and enter the light guiding plate, and then the light beams are reflected and oscillated inside the light guiding plate and then focus on the second end portion, and