| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an LED bulb which can be handled similarly to a miniature bulb and is easy to use. <P>SOLUTION: The LED bulb 15 used by threadedly engaging with a bulb socket includes: an LED 17; a first external terminal P to which positive voltage is applied; a second external terminal N connected with a cathode terminal of the LED, to which negative voltage is applied; and an illumination adjusting module arranged between the first external terminal and an anode terminal of the LED, wherein illumination of the LED 17 is adjusted by applying the positive voltage to the LED 17 via a first resistor 48 connected in series when the positive voltage is less than designated voltage, and applying the positive voltage to the LED via a second resistor with a resistance smaller than that of the first resistor, connected in series, when the positive voltage is a predetermined voltage or higher. When the positive voltage is the predetermined voltage or higher, a zener diode 50 is conducted, and illumination of the LED 17 is made higher since the positive voltage is applied to the LED 17 via a second resistor having a resistance value smaller than a resistance value of the first resistor 48 as an equivalent series resistance. Thus, it is easily recognized that the applied voltage rises as the increase of illumination of the LED 17. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
