Driving circuit for backlight system of light-emitting diode

A technology of light-emitting diodes and driving circuits, which is applied to the layout of electric lamp circuits, light sources, electric light sources, etc., can solve problems such as changes in the brightness of light-emitting diodes, achieve the effects of reducing current differences, reducing circuit complexity and cost, and avoiding changes

CN101848575BInactive Publication Date: 2012-11-28华映视讯(吴江)有限公司 +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2012-11-28
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a driving circuit for a backlight system of a light-emitting diode, which comprises input voltage, input resistance, an operational amplifier, a first transistor and a current arithmetic unit, wherein the positive input end of the operational amplifier is electrically connected with the input voltage through the input resistance, and the output end of the operational amplifier is electrically connected with the negative input end of the operational amplifier through a feedback network; the first transistor is used for acquiring reference current according to the input voltage and the input resistance to control the output voltage of the operational amplifier; and the current arithmetic unit is used for generating a plurality of operating currents which are proportional to the reference current according to the output voltage of the operational amplifier to drive a plurality of light-emitting diode series groups.
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Description

technical field

[0001] The present invention refers to a driving circuit for a LED backlight system, especially a driving circuit for driving a LED backlight system with a constant current source Background technique

[0002] Since the liquid crystal panel itself does not emit light, the liquid crystal display must rely on the backlight module to provide sufficient and evenly distributed light sources to display images normally. Traditionally, the cold cathode tube (Code Cathode Fluorescent Lamp, CCFL) has become the main lighting source of the liquid crystal display due to its advantages of high brightness and low cost. However, with the rise of environmental awareness and the development of Light Emitting Diode (LED) technology, mercury-containing cold-cathode tubes have been gradually replaced by light-emitting diodes with high color saturation, small size, power saving, and fast response. To meet the needs of users on the characteristics of color, size, and life of liqu...

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Embodiment Construction

[0028] Certain terms are used throughout the description and claims to refer to particular components. Those of ordinary skill in the art will appreciate that manufacturers may refer to the same component by different terms. The specification and claims do not use the difference in name as a way to distinguish components, but use the difference in function of components as a basis for distinction. The "comprising" mentioned in the entire description and the following claims is an open-ended term, so it should be interpreted as "including but not limited to". In addition, the term "electrical connection" here includes any direct and indirect electrical connection means. Therefore, if it is described in the text that a first device is electrically connected to a second device, it means that the first device can be directly connected to the second device, or indirectly connected to the second device through other devices or connection means.

[0029] Please refer to Figure 4 ...