Surface light source and electrically illuminated signboard
First Claim
1. A surface light source unit comprising:
- a box body of a tray shape, whose bottom surface is quadrilateral, whose upper side is open, on a bottom surface and side walls of which a light diffused-reflection member is provided, the side walls being inclined outward, andsemiconductor light emitting devices provided on at least two corners of edge parts of the bottom surface of the box body so as to irradiate light toward center parts of the side walls opposite to the corners,wherein the semiconductor light emitting devices have a directionality of 45 to 60 degrees, and the light irradiated from each semiconductor light emitting device is mixed mutually in the box body by being reflected diffusedly on the bottom surface and the side walls of the box body, and is averaged in brightness, chromaticity and luminescent hue, andwherein an inclined angle and a height of the side walls of the box body are set so as to make brightness on the opened upper surface above the side walls of the box body and above a center part of the box body substantially equal.
2 Assignments
0 Petitions
Accused Products
Abstract
LEDs (7) are arranged on at least opposite two corners of a bottom surface of a box body (11) of a tray shape whose bottom surface is quadrilateral, whose upper side is open, on an inner surface of which a light reflection member (11b) is provided, and whose side walls (11c) are inclined outward, so as to irradiate inside of the box body, wherein a plurality of LEDs (71) are arranged so that a region irradiated by each of the LEDs (71) rotates sequentially in a specific direction (same direction). As a result, there can be obtained a surface light source having high brightness and uniformity in an arbitrary size whether the light source is small or large while using semiconductor light emitting devices (LEDs), and an electrically illuminated signboard using the surface light source, which is thin and capable of uniform display and which operates with low electricity consumption.
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Citations
8 Claims
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1. A surface light source unit comprising:
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a box body of a tray shape, whose bottom surface is quadrilateral, whose upper side is open, on a bottom surface and side walls of which a light diffused-reflection member is provided, the side walls being inclined outward, and semiconductor light emitting devices provided on at least two corners of edge parts of the bottom surface of the box body so as to irradiate light toward center parts of the side walls opposite to the corners, wherein the semiconductor light emitting devices have a directionality of 45 to 60 degrees, and the light irradiated from each semiconductor light emitting device is mixed mutually in the box body by being reflected diffusedly on the bottom surface and the side walls of the box body, and is averaged in brightness, chromaticity and luminescent hue, and wherein an inclined angle and a height of the side walls of the box body are set so as to make brightness on the opened upper surface above the side walls of the box body and above a center part of the box body substantially equal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification