Patent ID: 7372430
Filing Date: 2008-05-13
Classification: G09G

Abstract:
1. A light emitting device comprising: A housing having a bar shape a plurality of LEDs (light-emitting diodes) disposed in said housing; an electric circuit for controlling light emission of said plurality of LEDs, said electric circuit being disposed in said housing, wherein said electric circuit comprises at least two driving circuit(s) for supplying said plurality of LEDs with electric power to let said plurality of LEDs emit light, the number of said driving circuits being less than the number of said plurality of LEDs; at least two multiplexers being between said plurality of LEDs and each of said at least two driving circuits; a storage member for storing a residual light image data and a main control unit for letting said plurality of LEDs emit light by outputting a control signal to each of said at least two multiplexer(s) based on said residual light image data Wherein said at least two driving circuits and said at least two multiplexers are provided at least in pairs respectively, Wherein said plurality of LEDs are connected to said at least two multiplexers in a state where each of said LEDs is connected to one selected from said at least two multiplexers and at least one adjacent LED of said each of said LEDs is connected to another multiplexer different from said multiplexer being selected, Wherein each of said at least two driving circuits has a wiring connected to said LEDs via one of said at least two multiplexers and a light receiving section for outputting a received light level signal based on a voltage level of said wiring, and Wherein said main control unit outputs said control signal to one of said at least two multiplexers for letting said LEDs emit light, reads said received light level signal of said driving circuit connected to another on of said at least two multiplexers, generates a residual light image data based on a comparison result of said received light level signal with at least a threshold value, and stores the generated residual light image data in said storage member.