Patent Number: 7,821,207

Title: Lighting unit and discharge lamp

Abstract: Provided is a lighting unit and a discharge lamp each of which is capable of causing a capacitor to break down by heat generated in a heat generating component, so that circuit operation is safely terminated without any additional cost. A compact self-ballasted fluorescent lamp is provided with a lighting unit (50) housed in a case. The lighting unit (50) causes an arc tube to emit light and is composed of a plurality of electronic components, including a rectifier/smoothing circuit portion, an inverter circuit portion having transistors (Q1 and Q2), a resonant circuit portion, and a preheating circuit portion having a positive temperature coefficient element. Among the plurality of electronic components, the transistors (Q1 and Q2) and the positive temperature coefficient element generate excessive heat when, for example, the lamp is operated at the end of electrode's life. Capacitors (C4 and C6) disposed in the vicinity of the positive temperature coefficient element would break down by heat in a short mode.

Inventors: Morimoto; Etsuji (Osaka, JP), Itou; Kazuhiko (Osaka, JP), Gyoten; Masayoshi (Shiga, JP), Takahashi; Akira (Osaka, JP)

Assignee: Panasonic Corporation

International Classification: H01J 23/16 (20060101)

Expiration Date: 2018-10-26 0:00:00