| 摘要 |
PURPOSE: To provide a discharge lamp lighting device, which is apparently hard to generate a striation phenomenon in response to the condition of a dis charge lamp. CONSTITUTION: At the time of full lighting of a discharge lamp FL, a change- over switch SW is opened so as to turn on a transistor Q21, and the output of an invertor circuit 11 is increased, and the discharge lamp FL is lighted in the full lighting condition. Since a striation phenomenon preventing circuit 15 is opened from filaments FLa, FLb of the discharge lamp FL, the direct current is not supplied to the change-over switch SW. At the time of dimming lighting of the discharge lamp FL, the change-over switch SW is closed so as to turn off the transistor Q21, and the output of the invertor 11 is lowered, and the discharge lamp FL is lighted in the dimming condition. The striation phenomenon preventing circuit 15 is connected so as to apply the direct current to the discharge lamp FL, and the drift velocity of a light part and a dark part due to the unevenness of ionization of atom of a positive column is increased, and the normal ionization is apparently performed, and even in the case where the striation phenomenon is generated, the striation can not be visually recognized. |
