Display device
A display device includes a light source, and a light guide which is transparent and flat, and into which light emitted from the light source is incident from a first lateral surface, wherein the light guide includes reflective parts at positions corresponding to respective symbols, the reflective parts each including a plurality of reflective surfaces inclined relative to a bottom surface of the light guide, each of the reflective parts reflects the light incident from the first lateral surface from the plurality of reflective surfaces, which results in displaying a corresponding one of the symbols on a display surface of the light guide, and the closer the reflective parts are to the light source, the smaller the inclination angles of the reflective surfaces relative to the bottom surface.
1 . A display device, comprising:
a light source; and
a light guide which is transparent and flat, and into which light emitted from the light source is incident from a first lateral surface,
wherein:
the light guide includes reflective parts at positions corresponding to respective symbols, the reflective parts each including a plurality of reflective surfaces inclined relative to a bottom surface of the light guide;
each of the reflective parts reflects the light incident from the first lateral surface from the plurality of reflective surfaces, which results in displaying a corresponding one of the symbols on a display surface of the light guide;
the closer the reflective parts are to the light source, the smaller the inclination angles of the reflective surfaces relative to the bottom surface; and
a projected area of each of the plurality of reflective surfaces is equal for all the reflective parts in plan view when viewed from a side where the display surface is.
2 . The display device according to claim 1 , wherein one of the reflective parts farthest from the light source has inclination angles of the plurality of reflective surfaces set to obtain maximum luminance when a symbol corresponding to the one of the reflective parts is viewed from a side where the display surface is.
3 . The display device according to claim 1 , wherein the inclination angles of the plurality of reflective surfaces are set for each of the reflective parts, so that the symbols displayed on the display surface have equal luminance.
4 . The display device according to claim 1 , wherein:
the light guide has a lateral reflective part on a second lateral surface opposite to the first lateral surface;
each of the reflective parts has a second reflective surface that is oriented toward the lateral reflective surface and that is integrally formed with a corresponding one of the plurality of reflective surfaces; and
the closer the reflective parts are to the lateral reflective part, the smaller the inclination angles of the second reflective surfaces relative to the bottom surface.
5 . The display device according to claim 4 , wherein the lateral reflective part includes:
an upper extended part extending from an upper end to the first lateral surface so as to cover a portion of the display surface; and
a lower extended part extending from a lower end to the first lateral surface so as to cover a portion of the bottom surface.
6 . The display device according to claim 1 , wherein the light source is provided only at a single end surface of the light guide.
7 . The display device according to claim 1 , wherein an inclination angle of each reflective surface relative to the bottom surface monotonically decreases as a distance from the light source decreases.