KR20070040710A - Light emitting package and back light unit and liquid crystal display device having the same - Google Patents

Abstract

A light emitting package is disclosed that can produce white light while simultaneously controlling red, green and blue LEDs.

In the light emitting package according to the invention, red, green and blue light emitting diodes are connected in series. These red, green and blue light emitting diodes respond to one drive voltage. The currents flowing through these red, green and blue light emitting diodes are controlled by a current regulator. Accordingly, the red, green, and blue light emitting diodes are driven by different amounts of currents.

Red, green, blue, LED, parallel, current regulation, backlight, liquid crystal display

Description

Light emitting package and back light unit and liquid crystal display device having the same}

In order to better understand the drawings used in the detailed description of the invention, a brief description of each drawing is provided.

1 is an exploded perspective view showing a backlight unit having a conventional cold cathode fluorescent lamp (CCFL).

2 is an exploded perspective view showing a backlight unit having a conventional R, G, B LED.

3 is a view showing in detail the R, G, B LEDs included in FIG.

4 is a view illustrating in detail the light source device included in FIG. 2.

5 is a view showing a liquid crystal display according to the present invention.

FIG. 6 is a circuit diagram of a light source device including a light emitting package having red, green and blue LEDs, illustrating a light source device that may be used in the backlight of FIG. 5.

7 is a circuit diagram of a light source device including a light emitting package according to an embodiment of the present invention.

FIG. 8 is a detailed circuit diagram of a light emitting package according to an embodiment of the present invention for explaining the embodiment of the current regulator shown in FIG.

9 is a detailed circuit diagram of a light emitting package according to an embodiment of the present invention for explaining another embodiment of the current regulator shown in FIG.

FIG. 10 is a detailed circuit diagram of a light emitting package according to an embodiment of the present invention for explaining another embodiment of the current regulator shown in FIG.

11 is a view showing a light emitting package according to another embodiment of the present invention.

<Brief description of the main parts of the drawing>

102: liquid crystal panel 104: gate driver

106: data driver 108: timing control unit

110: backlight unit 112a, LDr: red LED

112b, LDg: Green LED 112c, LDb: Blue LED

120: LED voltage generator 130: light emitting package

200: LED series circuit 210: current regulator

220: LED Lens

The present invention relates to a light emitting package for generating white light, and more particularly to a light emitting package including light emitting diodes. The present invention also relates to a backlight unit and a liquid crystal display device having a light emitting package.

Liquid crystal display devices (hereinafter referred to as "LCDs") control the light transmittance of the liquid crystal to display an image. To this end, the liquid crystal display includes a backlight unit for providing planar light to a liquid crystal panel capable of controlling light transmittance on a pixel area basis. In order to allow light to be incident on the liquid crystal panel in a uniformly distributed form, the backlight unit includes a light source for generating light and optical path control sheets for uniformly distributing light from the light source.

Cold Cathode Fluorescent Lamps (hereinafter referred to as 'CCFL') are most commonly used as light sources of such backlight units. A cold cathode fluorescent lamp (CCFL) causes two electrodes facing each other to emit electrons from the electrode by a high voltage therebetween. The emitted electrons excite mercury in the lamp to generate ultraviolet light, and the ultraviolet light stimulates the fluorescent material applied inside the lamp to emit visible light from the fluorescent material. The backlight unit using the cold cathode fluorescent lamp is configured as shown in FIG. 1.

Referring to FIG. 1, a conventional backlight unit having a cold cathode fluorescent lamp (CCFL) includes a plurality of cold cathode fluorescent lamps 1 for emitting light and fixing and supporting the cold cathode fluorescent lamps 1. And a cover bottom 3 and optical sheets 5a, 5a, and 5c disposed between the cold cathode fluorescent lamp 1 and the liquid crystal panel (not shown). The optical sheets 5a, 5b, and 5c are for preventing the shape of the cold cathode fluorescent lamp 1 from appearing on the surface of the liquid crystal panel and providing a light source having a uniform brightness distribution as a whole. These optical sheets include a plurality of prism sheets 5b and 5c and a diffusion sheet 5a disposed between the cold cathode fluorescent lamp 1 and the liquid crystal panel in order to enhance the light scattering effect. On the inner surface of the cover bottom 3, a reflecting plate 7 capable of reflecting the light generated by the cold cathode fluorescent lamp 1 to the liquid crystal panel is disposed, which increases the light utilization efficiency. Electrode connection lines 9a and 9b to which external power for driving a lamp are applied are formed at both electrodes (not shown) of the cold cathode fluorescent lamp 1.

The backlight unit configured as described above forms light emitted from the light source, that is, the cold cathode fluorescent lamp 1, as a white light source having high luminance through the optical sheets 5a, 5b, and 5c so as to display an image. In this case, the liquid crystal panel disposed on the backlight unit adjusts the amount of light transmitted by changing the arrangement of liquid crystal molecules injected therein. At the same time, a full color image is realized by mixing color filters (not shown) of three primary colors of red (R), green (G), and blue (B). That is, a predetermined image can be obtained by passing the light (white light source) emitted from the backlight unit through the R, G, and B color filters of the liquid crystal panel (not shown).

However, the backlight unit configured as described above uses the cold cathode fluorescent lamp 1, the optical sheets 5a, 5b, 5c, and the reflector 7 together to realize uniform brightness and high brightness, but the voltage difference between the light sources There is a problem such that a large brightness difference occurs. This makes it difficult to apply to an increasingly large liquid crystal display device. In addition, in order to emit electrons, a high-voltage voltage must be applied to the anode of the cold cathode fluorescent lamp 1, and there is a problem in that heat generation is severe and light efficiency is lowered, and mercury harmful to the environment must be used.

In order to solve this problem, a backlight unit having a light emitting diode (LED) instead of a conventional cold cathode fluorescent lamp has been proposed. A conventional backlight unit having a light emitting diode includes a light source unit 11 having a plurality of R, G, and B LEDs on an inner surface thereof, and a cover bottom 13 which supports the light source unit 11 to be fixed. And optical sheets 15a, 15b, and 15c disposed between the light source unit 11 and the liquid crystal panel (not shown). The optical sheets 15a, 15b, and 15c are used to prevent the shape of the light source unit 11 from appearing on the surface of the liquid crystal panel and to enhance a light source having an overall uniform brightness distribution. A plurality of prism sheets 15b and 15c and a diffusion sheet 15a disposed between the light source unit 11 and the liquid crystal panel are included. The inner surface of the cover bottom 13 is disposed with a reflector 17 for reflecting the light generated from the light source 11 to the liquid crystal panel, which increases the efficiency of use of the light.

The light source unit 11 has a plurality of optical packages 14 arranged along a line, as shown in FIG. Each of the light emitting packages 14 consists of one red (R) LED 12a, two green (G) LEDs 12b, and one blue (B) LED 12c. In addition, the light emitting package 14 may be configured in various forms different from those of FIG. 3. In general, the red (R) LED 12a, the green (G) LED 12b, and the blue (B) LED 12c included in the light emitting package 14 are individually controlled. That is, since the red (R), green (G), and blue (B) LEDs 12a, 12b, and 12c have different device characteristics from each other, they are individually controlled. For example, in order for the same current to flow through each of the red (R), green (G), and blue (B) LEDs 12a, 12b, and 12c, the red (R), green (G), and blue (B) LEDs 12a , 12b and 12c may be applied with different voltages. In addition, the red (R), green (G), and blue (B) LEDs 12a, 12b, 12c generate light with different luminance even though the same current flows due to the characteristics of the other devices. Thus, in order to produce white light with the required white balance, the red (R), green (G) and blue (B) LEDs 12a, 12b, 12c are individually controlled, i.e. red (R). ), Green (G) and blue (B) LEDs 12a, 12b, 12c) respectively, the current flowing must be adjusted independently.

The red (R), green (G) and blue (B) LEDs 12a, 12b, 12c are individually driven, as shown in FIG. The red (R) LED 12a receives the voltage Vin-R from the red LED voltage generator 20a and has an intensity corresponding to the amount of current flowing in itself (ie, to the red (R) LED 12a). Generate light. The green (G) LED 12b receives the voltage Vin-G from the green LED voltage generator 20b and has an intensity corresponding to the current flowing in itself (ie, to the green (G) LED 12b). Generate light. The blue (B) LED 12c receives the voltage Vin-B from the blue LED voltage generator 20c and has an intensity corresponding to a current flowing in the blue (B) LED 12c. The light generated in the red (R), green (G), and blue (B) LEDs 12a, 12b, and 12c is incident on a liquid crystal panel (not shown) to display the required image. .

As such, the backlight unit having the light emitting package 14 of the red (R), green (G), and blue (B) LEDs 12a to 12b may have a red color to generate white light having a desired white balance. R), green (G) and blue (B) LEDs 12a, 12b, 12c must be driven separately. In order to drive the red (R), green (G) and blue (B) LEDs 12a, 12b, 12c separately, the red (R), green (G) and blue (B) LEDs 12a, 12b, The red LED voltage generator 20a, the green LED voltage generator 20b, and the blue LED voltage generator 20c corresponding to 12c must be provided. As a result, the driving circuit of the light emitting package becomes complicated and the manufacturing cost is increased.

Accordingly, an object of the present invention is to provide a light emitting package suitable for simplifying the configuration of a driving circuit, a backlight unit including the same, and a liquid crystal display device.

Another object of the present invention is to provide a light emitting package suitable for reducing manufacturing costs, a backlight unit including the same, and a liquid crystal display device.

A light emitting package according to an embodiment of the present invention for achieving the above object includes a plurality of light emitting diodes connected in series, and a current regulator connected to the light emitting diodes. A lens may be installed on the light emitting diodes.

In accordance with another aspect of the present invention, a backlight unit includes: a plurality of rectangular circuit boards arranged at predetermined intervals; And a light emitting package disposed on each of the circuit boards and including a plurality of light emitting diodes connected in series and a current regulator connected to the light emitting diodes.

In accordance with still another aspect of the present invention, there is provided a liquid crystal display device comprising: a plurality of rectangular circuit boards arranged at predetermined intervals, a plurality of light emitting diodes disposed on each circuit board, and connected in series; Light emitting packages comprising a current regulator connected to the light emitting device; And a liquid crystal panel which adjusts the transmittance of light from the light emitting diodes to display an image.

By this arrangement, the light emitting package according to the present invention allows the number of LED voltage generators used individually to be reduced to only one, as well as ancillary circuitry such as a control unit for controlling them. Furthermore, the light emitting package according to the embodiment of the present invention can lower the manufacturing cost of the liquid crystal display and the backlight unit, simplify the manufacturing process, and also reduce the volume of the light source device of the backlight unit.

Other objects, advantages and features of the present invention in addition to the above objects will become apparent from the detailed description of the embodiments associated with the accompanying drawings.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

5 is a diagram illustrating a liquid crystal display according to an exemplary embodiment of the present invention. Referring to FIG. 5, a liquid crystal display according to an exemplary embodiment of the present invention includes a liquid crystal panel in which a plurality of gate lines GL1 to GLn and a plurality of data lines DL1 to DLm are arranged and a predetermined image is displayed. 102, the gate driver 104 and the data driver 106 for driving the liquid crystal panel 102, the timing controller 108 for controlling the gate driver 104 and the data driver 106, and the optical And a backlight unit 110 for injecting the generated light into the liquid crystal panel 102.

In the liquid crystal panel 102, a plurality of gate lines GL1 to GLn and a plurality of data lines DL1 to DLm are arranged, and thin film transistors MT serving as switching elements are formed at intersections therebetween. It is. The gate electrode of the thin film transistor MT is electrically connected to the corresponding gate lines GL0 to GLn, and the source electrode of the thin film transistor MT is electrically connected to the corresponding data lines DL1 to DLm. In addition, the drain electrode of the thin film transistor MT is electrically connected to a pixel electrode (not shown) (that is, one terminal of the liquid crystal cell Clc).

The thin film transistor MT is turned on when the scan signal, that is, the gate high voltage VGH is supplied from the corresponding gate lines GL1 to GLn, while the thin film transistor MT is turned on. When the gate low voltage (VGL) is supplied from the turn-off (turn-off). In addition, when the thin film transistor MT is turned on, the data voltages on the corresponding data lines DL1 to DLm are supplied to the pixel electrode via the source and drain electrodes of the thin film transistor MT. The data voltage is maintained at the pixel electrode until the gate high voltage VGH is supplied to the corresponding gate lines GL1 to GLn in the next frame.

The gate driver 104 sequentially supplies the scan signal, that is, the gate high voltage VGH, to the gate lines GL1 to GLn according to the gate control signal generated by the timing controller 108.

The data driver 106 supplies a data voltage to the data lines DL1 to DLm according to the data control signal generated by the timing controller 108. The data driver 106 also converts red (R), green (G), and blue (B) data supplied from the timing controller 108 into analog data voltages.

The timing controller 108 uses a vertical / horizontal synchronization signal (Vsync / Hsync), a data enable (DE) signal, and a clock signal supplied from an external system (for example, a graphic board of a computer system), which is not shown. Thus, a gate control signal for controlling the gate driver 104 and a data control signal for controlling the data driver 106 are generated. In addition, the timing controller 108 supplies red (R), green (G), and blue (B) data in units of frames supplied from an external system to the data driver 106 for each line.

The backlight unit 110 generates light to be irradiated onto the liquid crystal panel 102. The generation of light to be irradiated to the liquid crystal panel 102 is controlled by the control signal generated from the timing controller 108. The backlight unit 110 includes a plurality of optical sheets, a reflecting plate, and a light source device. The light source device included in the backlight unit 110 includes a plurality of light emitting packages including red (R), green (G), and blue (B) LEDs, and red (R) and green (G) included in each light emitting package. And an LED voltage generator configured to generate a driving voltage for driving the blue (B) LED. The red (R), green (G), and blue (B) LEDs included in the light emitting package are preferably implemented to emit light in response to a single driving voltage from the LED voltage generator. As a light source device including a light emitting package that can be driven by one driving voltage, a light emitting package 112 connected to the LED voltage generator 120 can be predicted as shown in FIG. 6.

Referring to FIG. 6, the light emitting package 112 includes red (R), green (G), and blue (B) LEDs 112a, 112b, and 112c connected in series to the LED voltage generator 120. The input voltage Vin generated by the LED voltage generator 120 is supplied to a series circuit of red (R), green (G), and blue (B) LEDs 112a, 112b, and 112c connected in series. The input voltage Vin from the LED voltage generator 120 is primarily attenuated by the red (R) LED 112a by the driving voltage (V (R)) of the red (R) LED 112a. This primarily attenuated voltage Vin-V (R) is supplied to the series circuit of the green (G) and blue (B) LEDs 112b and 112c. The primary attenuation voltage Vin-V (R) is attenuated secondly by the driving voltage V (G) of the green (G) LED 112b by the green (G) LED 112b. The blue (B) LED 112c is supplied with the secondary attenuated voltage Vin-V (R) -V (G). As a result, voltages having different levels are supplied to the red (R), green (G), and blue (B) LEDs 112a, 112b, and 112c. On the other hand, the same amount of current flows in each of the red (R), green (G), and blue (B) LEDs 112a, 112b, and 112c. This is because the red (R), green (G), and blue (B) LEDs 112a, 112b, 112c are connected in series.

Although the same current is supplied to each of the red (R), green (G), and blue (B) LEDs 112a, 112b, and 112c connected in series, the voltages V (R) and V supplied to each of them are supplied. In view of the fact that (G), V (B)) are different from each other, it indicates that the device characteristics of each of the red (R), green (G) and blue (B) LEDs 112a, 112b, 112c are different. The difference in characteristics of the red (R), green (G), and blue (B) LEDs 112a, 112b, and 112c can be confirmed by Table 1 below. Table 1 describes the device characteristics of each of the red (R), green (G), and blue (B) LEDs 112a, 112b, 112c, using current, voltage, and power.

I (mA) Red LED Green LED Blue LED V (V) P (W) V (V) P (W) V (V) P (W) 50 1.92 0.096 2.69 0.135 2.91 0.146 100 1.99 0.199 2.8 0.28 3.0 0.3 150 2.04 0.306 2.86 0.429 3.04 0.456 200 2.08 0.416 2.89 0.578 3.06 0.612 250 2.12 0.53 2.93 0.733 3.08 0.770 300 2.15 0.645 2.95 0.885 3.10 0.930 350 2.18 0.763 2.98 1.043 3.13 1.10

As shown in Table 1, assuming that the same current flows through the red (R), green (G), and blue (B) LEDs 112a, 112b, 112c, red (R), green (G), and blue (B). ) Each of the LEDs 112a, 112b, and 112c is supplied with a different voltage (V). For example, in order for 50 mA of current to flow through all of the red (R), green (G), and blue (B) LEDs 112a, 112b, and 112c, a 1.92V voltage is applied to the red (R) LEDs 112a. A voltage of 2.69 V should be supplied to the green (G) LED 112b and a voltage of 2.91 V to the blue (B) LED 112c, respectively.

The difference in device characteristics is that red (R), green (G) and the same amount of current is supplied to the red (R), green (G) and blue (B) LEDs 112a, 112b, 112c. The amount of light emitted from each of the blue (B) LEDs 112a, 112b, 112c is varied. In other words, the red (R), green (G), and blue (B) LEDs 112a, 112b, 112c connected in series have different luminance even though they are driven by the same amount of current. Due to this, the red (R), green (G) and blue (B) LEDs 112a, 112b, 112c connected in series cannot form white light. As a result, the red (R), green (G) and blue (B) LEDs 112a, 112b, 112c had to be driven separately as shown in FIG. 4 to form white light.

7 illustrates a light source of a backlight unit including a light emitting package according to an embodiment of the present invention. Referring to FIG. 7, the light source device of the backlight unit includes a light emitting package 130 according to an embodiment of the present invention connected to the LED voltage generator 120. The light emitting package 130 according to an embodiment of the present invention includes an LED series circuit 200 responsive to the input voltage Vin from the LED voltage generator 120. The LED series circuit 200 includes red, green, and blue LEDs LDr, LDg, and LDb connected in series between the output terminal of the LED voltage generator 120 and the base voltage source GND. The red, green, and blue LEDs LDr, LDg, and LDb connected in series to the LED voltage generator 120 commonly respond to the input voltage Vin from the LED voltage generator 120. In addition, each of the red, green, and blue LEDs LDr, LDg, and LDb emits light corresponding to the amount of current supplied thereto.

In addition, the light emitting package 130 according to the embodiment of the present invention, the current regulator 210 for adjusting the amount of current flowing through each of the red, green and blue LEDs LDr, LDg, LDb in the LED series circuit 200. It includes. The current regulator 210 may be manufactured in one module form integrated with the LED series circuit 200 or may be manufactured separately from the LED series circuit 200. The current regulator 210 controls the amount of current flowing through each of the red, green, and blue LEDs LDr, LDg, and LDb so that the red, green, and blue LEDs LDr, LDg, and LDb form white light. To emit red, green and blue light.

Since the amount of current flowing through each of the series-connected red, green, and blue LEDs LDr, LDg, and LDb is controlled differently by the current regulator 210, the red, green, and blue LEDs (LDr, LDg, LDb) are controlled. Silver may emit red, green and blue light, which may form white light, respectively. In addition, all of the series-connected red, green and blue LEDs LDr, LDg, LDb emit red, green and blue light, respectively, which form white light in response to the input voltage Vin in common. In other words, the current regulator 210 has an amount of current flowing through each of the red, green, and blue LEDs LDr, LDg, and LDb so that the light output from the red, green, and blue LEDs LDr, LDg, and LGb is equalized. Makes this different.

Accordingly, the light emitting package according to the embodiment of the present invention reduces the number of LED voltage generators that have been individually used to only one and also simplifies ancillary circuits such as a control unit for controlling them. In addition, the light emitting package according to the embodiment of the present invention can lower manufacturing costs of the liquid crystal display and the backlight unit, simplify the manufacturing process, and provide advantages of reducing the volume of the light source device of the backlight unit. do.

FIG. 8 is a detailed circuit diagram of a light emitting package according to an embodiment of the present invention for describing in detail an embodiment of the current regulator 210 in FIG. The current regulator 210 included in the light emitting package 130 of FIG. 8 includes first to third parallel connected to each of the red, green, and blue LEDs LDr, LDg, and LDb included in the LED series circuit 200. The resistors R1 to R3 are provided. In detail, the first resistor R1 is connected in parallel with the red LED LDr, the second resistor R2 is connected in parallel with the green LED LDg, and the third resistor R3 is connected with the blue LED ( LDb) is connected in parallel.

The currents Ir, Ig, and Ib flowing through the red, green, and blue LEDs LDr, LDg, and LDb to which the first to third resistors R1 to R3 are connected in parallel are different from each other in amount. Can be. This is because some of the currents Ir, Ig, Ib flowing through each of the red, green, and blue LEDs LDr, LDg, and LDb are bypassed through correspondingly connected resistors R1 to R3. Accordingly, the first to third resistors R1 to R3 may vary the amount of currents Ir, Ig, and Ib flowing through the red, green, and blue LEDs LDr, LDg, and LDb, respectively. Green and blue LEDs (LDr, LDg, LDb) can be made to emit red, green and blue light in an amount capable of forming white light. In other words, the first to third resistors R1 to R3 may be configured to emit red, green, and blue LEDs LDr, LDg, and LDb in the same amount (ie, the same luminance). And blue LEDs LDr, LDg, and LDb, respectively, so that different amounts of currents may be supplied.

The first to third resistors R1 to R3 are different from each other so that the red, green, and blue LEDs LDr, LDg, and LDb emit red, green, and blue lights of an amount capable of forming white light. It is set to have a resistance value. In this case, different amounts of currents flow through each of the red, green, and blue LEDs LDr, LDg, and LDb to which the first to third resistors R1 to R3 are connected in parallel. In other words, the current Ir flowing through the red LED LDr differs not only from the current Ig flowing through the green LED LDg but also from the current Ib flowing through the blue LED LDb. Then, the red, green, and blue LEDs LDr, LDg, and LDb included in the LED series circuit 200 each have an amount (i.e., brightness) according to the amount of current flowing through them, as mentioned above. The light is emitted to produce white light.

The resistance values of each of the first to third resistors R1 to R3 are red, green, and blue LEDs LDr, so that the red, green, and blue LEDs LDr, LDg, and LDb emit light having the same luminance. The ratio is set according to the difference in device characteristics between LDg and LDb). For example, the luminance generated by the red LED LDr is 100, the luminance generated by the green LED LDg is 150, and the luminance generated by the blue LED LDb is 200. Let's say this is required. Then, the ratio of the resistance value between the first to third resistors R1 to R3 increases as the first resistor R1 progresses from the first resistor R1 to the third resistor R3.

In addition, the resistance value of each of the first to third resistors R1 to R3 is set at a ratio according to the balance of the red, green, and blue lights forming the white light. For example, if the luminance of the red LED LDr for forming white light is 100, the luminance of the green LED LDg is 150, and the luminance of the blue LED LDb is 200, the first to third resistors are used. The ratio of the resistance value between R1 to R3 is set to be lowered as it progresses from the first resistor R1 to the third resistor R3.

As such, the resistance values of the first to third resistors R1 to R3 are set at an appropriate ratio based on the characteristic difference between the red, green, and blue LEDs LDr, LDg, and LDb and the white balance for forming white light. Will be. The first to third resistors R1 to R3 having the resistance values of the ratios satisfying the white balance and the characteristic difference between the red, green, and blue LEDs LDr, LDg, and LDb are red, green, and blue LEDs ( By parallel connection corresponding to LDr, LDg, and LDb, the red, green, and blue LEDs LDr, LDg, and LDb commonly receive white light in response to the input voltage Vin from the LED voltage generator 120. It may emit an amount of red, green and blue light that can be formed.

Accordingly, the light emitting package according to the embodiment of the present invention reduces the number of LED voltage generators that have been individually used to only one and also simplifies ancillary circuits such as a control unit for controlling them. In addition, the light emitting package according to the embodiment of the present invention can lower manufacturing costs of the liquid crystal display and the backlight unit, simplify the manufacturing process, and provide advantages of reducing the volume of the light source device of the backlight unit. do.

FIG. 9 is a detailed circuit diagram of a light emitting package according to an embodiment of the present invention for describing another embodiment of the current regulator 210 in FIG. 7 in detail. The current regulator 210 included in the light emitting package 130 of FIG. 9 forms first and third resistors R1 to R1 connected in parallel to the LED series circuit 200 in the form of loops whose lengths overlap gradually. R3). The first resistor R1 is connected in parallel with the series circuit of the red, green and blue LEDs LDr, LDg, LDb, and the second resistor R2 is connected with the series circuit of the green and blue LEDs LDg, LDb. The third resistor R3 is connected in parallel only to the blue LED LDb. In other words, the blue LED LDb forms a triple parallel circuit with all of the first to third resistors R1 to R3, and the green LED LDg is connected to the first and second resistors R1 and R2. Together, they form a double parallel circuit, and the red LED LDr forms only a parallel circuit with the first resistor R1.

The current regulator 210 including the first to third resistors R1 to R3 connected in parallel to the LED series circuit 200 to form loops having a shorter overlap length is red according to the difference in device characteristics and the white balance. It is possible to adjust the amount of current to be supplied to each of the green and blue LEDs LDr, LDg, and LDb in stages. In this case, the red, green, and blue LEDs LDr, LDg, and LDb are connected to form multiple parallel circuits together with the first to third resistors R1 to R3 as the device characteristics and the white balance are better.

In the connection pattern between the first to third resistors R1 to R3 and the LED series circuit 200 illustrated in FIG. 9, the red LED LDr has green and blue LEDs LDg and LDb in device characteristics and white balance. If it is worse than the green LED (LDg) than the blue LED (LDb) in the device characteristics and white balance, the current regulator 210 may have. Therefore, it will be appreciated by those skilled in the art that the positions of the red, green, and blue LEDs LDr, LDg, and LDb may be interchanged with each other, unlike in FIG. 9.

Among the first to third resistors R1 to R3 included in the current regulator 210, the first resistor R1 is adjusted to appropriately set the amount of current Ir flowing through the red LED LDr. In addition, the resistance value of the first resistor R1 may be adjusted to appropriately set the amount of current flowing through the LED series circuit 200. The resistance value of the second resistor R2 is adjusted to appropriately set the amount of current Ig flowing in the green LED LDg in a range less than the amount of current Ir flowing in the red LED LDr. Finally, the resistance value of the third resistor R3 is adjusted to appropriately set the current Ib flowing through the blue LED LDb in a range smaller than the amount of the current Ig flowing through the green LED LDg. Can be.

These first to third resistors R1 to R3 satisfy the differences in device characteristics and white balance of currents Ir, Ig, and Ib flowing through the red, green, and blue LEDs LDr, LDg, and LDb, respectively. It may be set in a form that gradually decreases. Accordingly, the red, green, and blue LEDs LDr, LDg, and LDb have a quantity of red, green, and blue light that forms white light in response to the input voltage Vin from the LED voltage generator 120 in common. Can emit them.

As a result, the light emitting package according to the embodiment of the present invention allows the white balance according to the amount of red, green and blue lights to be easily adjusted by gradual current adjustment. In addition, the light emitting package according to the embodiment of the present invention reduces the number of individually used LED voltage generators to only one and also simplifies ancillary circuits such as a control unit for controlling them. Furthermore, the light emitting package according to the embodiment of the present invention can lower manufacturing costs of the liquid crystal display and the backlight unit, simplify the manufacturing process, and provide advantages of reducing the volume of the light source device of the backlight unit. .

FIG. 10 is a detailed circuit diagram of a light emitting package according to an embodiment of the present invention for describing another embodiment of the current regulator 210 in FIG. 7 in detail. The current regulator 210 included in the light emitting package 130 of FIG. 10 includes a first resistor connected in parallel with the series circuits of the red, green, and blue LEDs LDr, LDg, and LDb included in the LED series circuit 200. (R1) and second and third resistors R2 and R3 connected in parallel to the green and blue LEDs LDg and LDb, respectively. In other words, the red LED LDr forms a double parallel circuit together with the first and second resistors R1 and R2, and similarly, the blue LED LDb is connected to the first and third resistors R1 and R3. Together to form a double parallel circuit. On the other hand, the green LED LDg forms a parallel circuit only with the first resistor R1.

The first resistor R1 has a resistance value adjusted to appropriately set the amount of current Ig flowing in the green LED LDg equal to the amount of current flowing in the LED series circuit 200. The resistance value of the second resistor R2 is adjusted to appropriately set the amount of current Ir flowing in the red LED LDr in a range smaller than the amount of current Ig flowing in the green LED LDg. Similarly, the resistance value of the third resistor R3 is also adjusted to appropriately set the amount of current Ib flowing through the blue LED LDb in a range less than the amount of current Ig flowing through the green LED LDg. .

The amount of currents Ir and Ib flowing in each of the red and blue LEDs LDr and LDb is adjusted based on the amount of current Ig flowing in the green LED LDg. Because it affects. In view of this, the resistance value of the first resistor R1 takes into account the difference in device characteristics and the white balance, and the brightness is improved, so that the amount of current Ig flowing through the green LED LDg is appropriately adjusted. To set, it can be adjusted. After the amount of current Ig flowing through the green LED LDg is set in this way, the resistance values of the second and third resistors R2 and R3 flow through the currents Ir and Ib flowing through the red and blue LEDs LDr and LDb. In order to appropriately set the amount of) in a range smaller than the amount of current Ig flowing through the green LED LDg, the amount of? Accordingly, the red, green, and blue LEDs LDr, LDg, and LDb have a large amount of red and green in response to the input voltage Vin from the LED voltage generator 120 to form white light having high luminance. And blue light.

As a result, the light emitting package according to the embodiment of the present invention can emit white light of high luminance. In addition, the light emitting package according to the embodiment of the present invention reduces the number of individually used LED voltage generators to only one and also simplifies ancillary circuits such as a control unit for controlling them. Furthermore, the light emitting package according to the embodiment of the present invention can lower manufacturing costs of the liquid crystal display and the backlight unit, simplify the manufacturing process, and provide advantages of reducing the volume of the light source device of the backlight unit. .

11 is a view illustrating a light emitting package 130 according to another embodiment of the present invention. Referring to FIG. 11, the light emitting package 130 according to another exemplary embodiment has the same configuration as the light emitting package illustrated in FIG. 7 except that the LED lens 220 is installed on the LED series circuit 200. Have elements. Elements of FIG. 11 having the same names, functions, and effects as those shown in FIG. 7 will be referred to by the same reference numerals, and detailed description thereof will be omitted since it is the same as in FIG.

The LEE series circuit 200 includes red, green, and blue LEDs LDr, LDg, and LDb that commonly respond to an input voltage Vin from the LED voltage generator 120. A current regulator 210 that adjusts the amount of currents Ir, Ig, Ib flowing through each of these red, green, and blue LEDs LDr, LDg, LDb is shown in FIGS. 8 to 10. Can be implemented. This matter will be known to those of ordinary skill in the art.

The LED lens 220 focuses and mixes the red, green, and blue lights emitted from the red, green, and blue LEDs LDr, LDg, and LDb included in the LED series circuit 200 to produce a white light effect. In addition, the LED lens 220 protects not only the LED series circuit 200 including the red, green, and blue LEDs LDr, LDg, and LDb, but also the current regulator 210 from an external shock, Contamination of red, green and blue LEDs (LDr, LDg, LDb) can be prevented.

The LED lens 220 may be manufactured in an integrated form with the LED series circuit 200 and the current regulator 210. Alternatively, the LED lens 220 may be manufactured in an integrated form with the LED series circuit 200 except for the current regulator 210.

As described above, in the light emitting package according to the present invention, a different amount of current flows to each of the red, green, and blue LEDs, so that the red, green, and blue LEDs respond to the white light in common to one voltage Vin. Allow to emit red, green and blue lights of the amount to form. Accordingly, the light emitting package according to the embodiment of the present invention reduces the number of LED voltage generators that have been individually used to only one and also simplifies ancillary circuits such as a control unit for controlling them. Furthermore, the light emitting package according to the embodiment of the present invention can lower manufacturing costs of the liquid crystal display and the backlight unit, simplify the manufacturing process, and provide advantages of reducing the volume of the light source device of the backlight unit. .

As described above, the embodiments of the present invention have been described in connection with FIGS. 7 to 11, but these are merely exemplary, and those skilled in the art to which the present invention pertains have the spirit and scope of the present invention. It will be apparent that various modifications, changes and equivalent other embodiments are possible without departing from the scope of the present invention. Accordingly, the technical scope and features of the present invention should not be limited to the description of the embodiments, but should be set by the matters set forth in the appended claims.

Claims (52)

A plurality of light emitting diodes connected in series; And And a current regulator connected to the plurality of light emitting diodes. The light emitting package of claim 1, wherein the current regulator includes a plurality of resistors connected in parallel with the plurality of light emitting diodes. The light emitting package of claim 2, wherein each of the plurality of resistors is connected to one of the plurality of light emitting diodes. The light emitting package of claim 2, wherein the plurality of resistors are connected to at least one of the plurality of resistors. The light emitting package of claim 4, wherein the plurality of light emitting diodes include first to third light emitting diodes, and one of the plurality of resistors is connected to the first to third light emitting diodes. 6. The light emitting package of claim 5, wherein a second of the plurality of resistors is connected to the second and third light emitting diodes. 6. The light emitting package of claim 5, wherein another one of the plurality of resistors is connected with a second light emitting diode, and another one of the plurality of resistors is connected with a third light emitting diode. 8. The light emitting package of claim 7, wherein the first light emitting diode emits green light. The light emitting package of claim 2, wherein each of the plurality of resistors has a different resistance value to set a white balance. The method of claim 1, Wherein the plurality of light emitting diodes comprises at least one red light emitting diode, a green light emitting diode, and a blue light emitting diode to form white light. The semiconductor light emitting device of claim 10, wherein the plurality of light emitting diodes include a red light emitting diode, a green light emitting diode, and a blue light emitting diode, and wherein the current regulator comprises first to third resistors connected in parallel with the red, green, and blue light emitting diodes. A light emitting package comprising a. 12. The device of claim 11, wherein the first resistor is connected in parallel with the red light emitting diode, the second resistor is connected in parallel with the green light emitting diode, and the third resistor is connected in parallel with the blue light emitting diode. Light emitting package. 13. The light emitting package of claim 12, wherein a ratio of the first to third resistors is set to be substantially equal to the amount of light emitted from the red light emitting diode, the green light emitting diode, and the blue light emitting diode. The light emitting package of claim 2, wherein each of the plurality of resistors is connected to one of the plurality of light emitting diodes. 15. The light emitting package of claim 14, wherein each of the plurality of resistors has a resistance value set to control a current flowing through a corresponding one of the plurality of light emitting diodes. The light emitting package according to claim 15, wherein the resistance values are set equal to the amount of light emitted from each of the light emitting diodes. The light emitting package of claim 1, further comprising a lens installed on the plurality of light emitting diodes. A plurality of circuit boards; And And a light emitting package mounted on the plurality of circuit boards, the light emitting package including a plurality of light emitting diodes connected in series and a current regulator connected thereto. 19. The backlight unit of claim 18, wherein the current regulator includes a plurality of resistors connected in parallel with the plurality of light emitting diodes. 20. The backlight unit of claim 19, wherein each of the plurality of resistors is connected to one of the plurality of light emitting diodes. 20. The backlight unit of claim 19, wherein the plurality of resistors are connected to at least one of the plurality of resistors. The backlight unit of claim 21, wherein the plurality of light emitting diodes include first to third light emitting diodes, and one of the plurality of resistors is connected to the first to third light emitting diodes. 23. The backlight unit of claim 22, wherein a second one of the plurality of resistors is connected to the second and third light emitting diodes. 23. The backlight unit of claim 22, wherein another one of the plurality of resistors is connected with a second light emitting diode, and another one of the plurality of resistors is connected with a third light emitting diode. 25. The backlight unit of claim 24, wherein the first light emitting diode emits green light. 20. The backlight unit of claim 19, wherein each of the plurality of resistors has a different resistance value to set a white balance. The method of claim 18, And the plurality of light emitting diodes includes at least one red light emitting diode, a green light emitting diode, and a blue light emitting diode to form white light. 28. The light emitting device of claim 27, wherein the plurality of light emitting diodes comprises a red light emitting diode, a green light emitting diode, and a blue light emitting diode, and wherein the current regulator comprises first to third resistors connected in parallel with the red, green, and blue light emitting diodes. Backlight unit comprising a. 29. The device of claim 28, wherein the first resistor is connected in parallel with the red light emitting diode, the second resistor is connected in parallel with the green light emitting diode, and the third resistor is connected in parallel with the blue light emitting diode. Backlight unit. 30. The backlight unit of claim 29, wherein the ratio of the first to third resistors is set so that the amount of light emitted from the red light emitting diode, the green light emitting diode, and the blue light emitting diode is approximately equal. 20. The backlight unit of claim 19, wherein each of the plurality of resistors is connected to one of the plurality of light emitting diodes. 32. The backlight unit of claim 31, wherein each of the plurality of resistors has a resistance value set to control a current flowing through a corresponding one of the plurality of light emitting diodes. 33. The backlight unit of claim 32, wherein the resistance values are set equal to the amount of light emitted from each of the light emitting diodes. 19. The backlight unit of claim 18, further comprising a lens installed on the plurality of light emitting diodes. A backlight unit having a plurality of circuit boards, at least one light emitting package including a plurality of light emitting diodes installed on the plurality of circuit boards, each of which is connected in series, and a current regulator connected to the light emitting diodes; And And a liquid crystal panel for displaying an image by using the light generated by the backlight unit. 36. The liquid crystal display device according to claim 35, wherein the current regulator has a plurality of resistors connected in parallel with the plurality of light emitting diodes. 37. The liquid crystal display device according to claim 36, wherein each of said plurality of resistors is connected to one of said plurality of light emitting diodes. 37. The liquid crystal display of claim 36, wherein the plurality of resistors are connected to at least one of the plurality of resistors. 39. The liquid crystal display device according to claim 38, wherein the plurality of light emitting diodes comprise first to third light emitting diodes, and one of the plurality of resistors is connected to the first to third light emitting diodes. 40. The liquid crystal display of claim 39, wherein a second of the plurality of resistors is connected to the second and third light emitting diodes. 40. The liquid crystal display device according to claim 39, wherein another one of the plurality of resistors is connected with a second light emitting diode, and another one of the plurality of resistors is connected with a third light emitting diode. 42. The liquid crystal display device according to claim 41, wherein the first light emitting diode emits green light. 37. The liquid crystal display of claim 36, wherein each of the plurality of resistors has a different resistance value to set a white balance. 36. The method of claim 35 wherein The plurality of light emitting diodes include at least one red light emitting diode, a green light emitting diode, and a blue light emitting diode to form white light. 45. The light emitting device of claim 44, wherein the plurality of light emitting diodes comprises red light emitting diodes, green light emitting diodes, and blue light emitting diodes, and wherein the current regulator comprises first to third resistors connected in parallel with the red, green, and blue light emitting diodes. Liquid crystal display device comprising a. 46. The device of claim 45, wherein the first resistor is connected in parallel with the red light emitting diode, the second resistor is connected in parallel with the green light emitting diode, and the third resistor is connected in parallel with the blue light emitting diode. Liquid crystal display device. 47. The liquid crystal display device according to claim 46, wherein the ratio of the first to third resistors is set so that the amount of light emitted from the red light emitting diode, the green light emitting diode and the blue light emitting diode is substantially equal. 37. The liquid crystal display of claim 36, wherein each of the plurality of resistors is connected to one of the plurality of light emitting diodes. 49. The liquid crystal display of claim 48, wherein each of the plurality of resistors has a resistance value set to control a current flowing through a corresponding one of the plurality of light emitting diodes. 50. The liquid crystal display device according to claim 49, wherein the resistance values are set equal to the amount of light emitted from each of the light emitting diodes. 36. The liquid crystal display of claim 35, further comprising a lens provided on the plurality of light emitting diodes. Voltage generator; A plurality of light emitting diodes connected in series with the voltage generator; And And a current regulator connected to the plurality of light emitting diodes.

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