| 摘要 |
PROBLEM TO BE SOLVED: To prevent the temperature rises of electronic parts and the deteriorations of their display characteristics, by providing electrically insulating members on both the surfaces of a thermally conductive board to form a printed board, and by providing on one surface of the printed board light emitting elements in the form of a matrix to provide on the other surface thereof control parts for controlling the flashings of the light emitting parts. SOLUTION: On one surface side of a printed board 1, LEDs 2 are provided in the form of a matrix to provide on the other surface thereof metal fittings 4 and such IC parts 3 for controlling the flashings of the LEDs 2 as controlling parts and driving parts. The printed board 1 is so formed that on both the surfaces of such a thermally conductive board as a metallic plate 11, electrically insulating members 12, 13 are provided. Conducting a heat generated in the IC parts 3, etc., from the metallic plate 11 to the whole of the printed board 1, the heat is dissipated to the outside via the metal fittings 4 connected with a housing 5 to prevent the temperature rises of the IC parts 3, etc. |
