Discharge lamp lighting apparatus
First Claim
1. A discharge lamp lighting apparatus comprising:
- a switch circuit configured to convert a DC voltage of a DC power source into an AC voltage by turning on/off one or more switching elements;
a transformer having a primary winding connected to the switch circuit and a secondary winding to output an AC voltage;
a discharge lamp connected to the secondary winding of the transformer;
a current detector configured to detect an AC output current passing through the discharge lamp;
an error amplifier configured to output an error signal representative of an error voltage between a detected value of the current detector and a predetermined reference voltage;
a controller configured to generate, based on the error signal of the error amplifier, control signals that turn on/off the switching elements to control the AC output current at a predetermined value; and
a time division signal generator configured to generate a time division signal at the start of an ON/OFF operation of the switching elements, the time division signal being one of a signal that delays a change in a burst dimming signal and a signal that is formed by superimposing a signal having a predetermined inclination on the burst dimming signal, whereinthe error amplifier changes the error signal according to the time division signal of the time division signal generator.
1 Assignment
0 Petitions
Accused Products
Abstract
A discharge lamp lighting apparatus includes a switch circuit for DC/AC converting, a discharge lamp connected to a secondary winding of a transformer, a current detector detecting an AC output current of the discharge lamp, an error amplifier outputting an error signal to a detected current, a control circuit generating control signals that turn on/off the switching elements in such a way as to control the AC output current at a predetermined value, and a time division signal generator generating a time division signal at the start of an ON/OFF operation of the switching elements, wherein the time division signal delays a change in a burst dimming signal or has a predetermined inclination on the burst dimming signal. The error amplifier changes the error signal according to the time division signal from the time division signal generator.
14 Citations
5 Claims
-
1. A discharge lamp lighting apparatus comprising:
-
a switch circuit configured to convert a DC voltage of a DC power source into an AC voltage by turning on/off one or more switching elements; a transformer having a primary winding connected to the switch circuit and a secondary winding to output an AC voltage; a discharge lamp connected to the secondary winding of the transformer; a current detector configured to detect an AC output current passing through the discharge lamp; an error amplifier configured to output an error signal representative of an error voltage between a detected value of the current detector and a predetermined reference voltage; a controller configured to generate, based on the error signal of the error amplifier, control signals that turn on/off the switching elements to control the AC output current at a predetermined value; and a time division signal generator configured to generate a time division signal at the start of an ON/OFF operation of the switching elements, the time division signal being one of a signal that delays a change in a burst dimming signal and a signal that is formed by superimposing a signal having a predetermined inclination on the burst dimming signal, wherein the error amplifier changes the error signal according to the time division signal of the time division signal generator. - View Dependent Claims (2, 3, 4, 5)
-
Specification