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US 6,445,143 B1Granted
Inverter for LCD backlight
AssigneeSamsung Electro-Mechanics Co., Ltd.
InventorByoung Own Min
Life of this patent
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Abstract
An inverter for LCD backlight operates an analog dimming control, a PWM dimming control or a complex dimming control by a control signal set by a manufacturer, and in case of the complex dimming control, realizes an original circuit operated by a controlling method distinguished from the conventional controlling method to enhance responsive characteristics when shifting a dimming mode.
Claims5
An inverter for LCD backlight, comprising:
- a first switching element connected to an input terminal of a DC/AC converter operating a lamp by using an inputted power for determining supply of the inputted power;
- a dimming control section for comparing a first dimming signal with a second dimming signal inputted from outside in accordance with a dimming mode selection signal, and outputting first to third control signals to perform a PWM dimming, an analog dimming or a complex dimming control;
- an error amplifier for receiving a feedback signal F/B of a feedback part connected to the lamp by means of an inverting terminal, and a first control signal outputted from the dimming control section by means of a non-inverting terminal to output a compared signal in accordance with a state of the signals inputted to each terminal;
- a first comparator for receiving a pyramidal wave for controlling the PWM dimming having a predetermined cycle or a third control signal outputted from the dimming control section by means of the non-inverting terminal, and a second control signal outputted from the dimming control section by means of the inverting terminal, comparing the two signals, and outputting a signal in accordance with a compared value;
- a second switching element connected between an output terminal of the error amplifier and a ground terminal for performing on/off operation in accordance with a voltage level of a signal outputted from the first comparator, and converting a potential of the output terminal of the error amplifier to a ground potential;
- and
- a second comparator for receiving the output signal of the error amplifier by means of the non-inverting terminal and an oscillating signal of a predetermined cycle by means of the inverting terminal, and comparing the two signals to control on/off operations of the first switching element in accordance with the compared result.
4 more elements
Dependencies are inferred from the claim text.