公开(公告)号：US07317403B2

公开(公告)日：2008-01-08

申请号：US11212185

申请日：2005-08-26

申请人： Pieter Grootes ,  Noboru Kaito ,  Robert F. M. Hendriks ,  Charles A. Schrama ,  Emanuel Stassar ,  Dennis Claessens

发明人： Pieter Grootes ,  Noboru Kaito ,  Robert F. M. Hendriks ,  Charles A. Schrama ,  Emanuel Stassar ,  Dennis Claessens

IPC分类号： G08B5/22 ,  G09F9/33 ,  G09G3/36

CPC分类号： H05B33/0815 ,  G02F1/133603 ,  G02F1/133609 ,  H05B33/0821 ,  H05B33/0827 ,  H05B33/083 ,  H05K1/181 ,  Y02B20/347 ,  Y10S362/80

摘要： An LED backlight structure for setting voltages and currents for LEDs. Red LEDs are connected in series between a first voltage regulator and a first controllable current source, green LEDs are connected in series between a second voltage regulator and a second controllable current source, blue LEDs are connected in series between a third voltage regulator and a third controllable current source. The current sources may be linear current regulators controlled to balance the three colors to achieve a target light output of the board using a light detection chamber. PWM controllers control transistor switches connected in parallel across groups of LEDs, where the duty cycles set the average current through each group of LEDs. The control values used to achieve target light characteristics are stored in memory. The PWM controller may control brightness levels of the LEDs. The backlight may be for an LCD television.

摘要翻译： 用于设置LED电压和电流的LED背光结构。 红色LED串联连接在第一电压调节器和第一可控电流源之间，绿色LED串联连接在第二电压调节器和第二可控电流源之间，蓝色LED串联连接在第三电压调节器和第三可调电流源之间 可控电流源。 电流源可以是线性电流调节器，其被控制以平衡三种颜色，以使用光检测室来实现板的目标光输出。 PWM控制器控制晶体管开关并联在LED组中，其中占空比设置平均电流通过每组LED。 用于实现目标光特性的控制值存储在存储器中。 PWM控制器可以控制LED的亮度级别。 背光可能是液晶电视。

公开(公告)号：US20070046485A1

公开(公告)日：2007-03-01

申请号：US11212185

申请日：2005-08-26

申请人： Pieter Grootes ,  Noboru Kaito ,  Robert Hendriks ,  Charles Schrama ,  Emanuel Stassar ,  Dennis Claessens

发明人： Pieter Grootes ,  Noboru Kaito ,  Robert Hendriks ,  Charles Schrama ,  Emanuel Stassar ,  Dennis Claessens

IPC分类号： G09F9/33

CPC分类号： H05B33/0815 ,  G02F1/133603 ,  G02F1/133609 ,  H05B33/0821 ,  H05B33/0827 ,  H05B33/083 ,  H05K1/181 ,  Y02B20/347 ,  Y10S362/80

摘要： An LED backlight structure and technique for setting the voltages and currents for the LEDs are described. In one embodiment, red LEDs are connected in series between a first voltage regulator and a first controllable current source, green LEDs are connected in series between a second voltage regulator and a second controllable current source, and blue LEDs are connected in series between a third voltage regulator and a third controllable current source. The current sources may linear current regulators. After all the LEDs are mounted on a printed circuit board, each voltage regulator is controlled so that there is a minimum voltage drop across the current source to minimize energy dissipation by the current source. Also, after all the LEDs are mounted on the printed circuit board, the current sources are controlled to balance the three colors to achieve a target light output of the board using a light detection chamber. In another embodiment, a constant current source is connected to the series string of LEDs. PWM controllers control transistor switches connected in parallel across groups of LEDs, where the duty cycles set the average current through each group of LEDs. The control values used to achieve the target light characteristics are then stored in a memory on the board. With such a technique, LEDs do not need to be binned to match their efficiencies, since the controllable voltage and current sources compensate for the variety of LED efficiencies. Accordingly, all boards will have the same target light output using the particular values stored on each board. In other embodiments, not all the LEDs of a particular color are connected in series. The brightness levels of the LEDs may be further controlled by a PWM controller. The backlight may be for an LCD television or other color display.

摘要翻译： 描述了用于设置LED的电压和电流的LED背光结构和技术。 在一个实施例中，红色LED串联连接在第一电压调节器和第一可控电流源之间，绿色LED串联连接在第二电压调节器和第二可控电流源之间，蓝色LED串联连接在第三 电压调节器和第三可控电流源。 电流源可以是线性电流调节器。 在所有LED安装在印刷电路板上之后，每个电压调节器被控制，使得在电流源上存在最小的电压降，以最小化电流源的能量耗散。 此外，在将所有LED安装在印刷电路板上之后，控制电流源以平衡三种颜色，以使用光检测室来实现板的目标光输出。 在另一个实施例中，恒流源连接到串联的LED串。 PWM控制器控制晶体管开关并联在LED组中，其中占空比设置平均电流通过每组LED。 然后将用于实现目标光特性的控制值存储在板上的存储器中。 利用这种技术，由于可控的电压和电流源补偿了LED的各种效率，因此不需要将LED组合起来以匹配其效率。 因此，所有电路板将使用存储在每个电路板上的特定值来具有相同的目标光输出。 在其它实施例中，并非所有特定颜色的LED都串联连接。 LED的亮度水平可以由PWM控制器进一步控制。 背光可以用于LCD电视或其它彩色显示器。