CN103728772A - Light-emitting diode encapsulation driving method - Google Patents

Abstract

The invention discloses a light-emitting diode encapsulation driving method. The method includes: applying different driving currents to multiple red LEDs, green LEDs and blue LEDs and driving the LEDs independently according to colors of the LEDs so as to form white light by color mixing, or applying current to white LEDs to emit white light, wherein the red LEDs, green LEDs, blue LEDs and white LEDs are separated and connected by circuit patterns of a printed circuit board, and the LEDs in each color are driven independently. The light-emitting encapsulation driving method has the advantages that the white LEDs are arranged together with the LEDs in the three primary colors for color mixing so as to form a light-emitting diode encapsulation, so that light with good color rendition and brightness can be provided, brightness of the white LEDs are used for improving brightness, light output of the LEDs in the three primary colors for color mixing needs not to be increased, the LEDs of the light-emitting diode encapsulation can be prevented from degradation, and the white light with superior color mixing characteristics can be emitted.

Description

A kind of driving method of LED package

Technical field

The present invention relates to a kind of driving method of LED package.

Background technology

According to the recent trend of various electrical equipment miniaturizations and lightness, liquid crystal display has become A: the center that frj pays close attention to.Therefore, in slim liquid crystal panel, also developed the liquid crystal panel that is used as display screen.

This liquid crystal panel is widely used as mobile terminal, spaceship, the display device of aircraft and notebook computer.Liquid crystal display comprises the secondary light source for light being transmitted into liquid crystal panel.

Cold-cathode fluorescence lamp (CCFL) is generally used as the light source of correlation technique.But, recently, thering is low power consumption, high power, the light emitting diode (being designated hereinafter simply as " LED ") of fast-response and environmental friendliness characteristic is widely used as light source.

In order to use LED as light source, realized white light.The method of using LED to realize white light is mainly divided into three kinds of methods.

First method, sends the light of three LED of primaries (red, green, blue) and realizes white light by mixing.These three LED are used to form a white light source.

Second method, by encouraging yellow fluorescent powder with blue LED as light source, realizes white light.

The third method, encourages three primary colors fluorescent powder by the LED with emitting ultraviolet light as light source, realizes white light.

Generally speaking, consider the reliability of light output under long-time service condition, by mixing, send the light of three LED of ruddiness, green glow and blue light and realize white light.

For example, as shown in Figure 1, on a side surface of liquid crystal panel 10, be provided with the LED32R that sends ruddiness, green glow, blue light is installed, the LED package of 32G and 32B, and use light that the guiding such as optical plate 40 sends from LED32R, 32G and 32B so that light to be provided.

In addition, as shown in Figure 2, optical plate 40 can be close to LED to be installed, and makes to mix the ruddiness, green glow and the blue light that from LED32R-1,32G-1,32B-1,32R-2,32G-2 and 32B-2, send.And offer liquid crystal display.

From red, green and blue LED32R-1,32G-1, the light that 32B-1,32R-2,32G-2 and 32B-2 send, in the interior mixing of optical plate 40, then incides liquid crystal panel to realize image.

That is to say light evenly mixing in the optical plate region 40a of contiguous LED of sending from thering is each LED of different time delay, and the pattern institute scattering being formed in all the other optical plate region 40b.Therefore the light, sending from LED is provided for liquid crystal panel.

Red, green and blue LED32R-1,32G-1 and 32B-1 must open simultaneously, to send white light by above method.Therefore, red, green and blue LED32R-1,32G-1 and 32B-1 are installed on printed circuit board (PCB) 31, on this printed circuit board (PCB) 31, formed circuit pattern to form LED package 30, make to apply signal according to even drive current, drive red, green and blue LED32R-1,32G-1 and 32B-1 simultaneously.

In order to increase the amount of light according to the size of liquid crystal panel and area, another red, green and blue LED32R-2,32G-2 and 32B-2 are arranged on printed circuit board (PCB) 31, on this printed circuit board (PCB) 31, formed circuit pattern, and drive this circuit pattern according to the control circuit shown in Fig. 3, make even drive current apply signal and drive red, green and blue LED32R-2,32G-2 and 32B-2 simultaneously.

But, although red, green and blue LED32R-1,32G-1 and 32B-1 are connected to a circuit, with simultaneously luminous by even driving current value (flowing into the uniform current of each LED), but, because red, green and blue LED32R-1,32G-1 and 32B-1 have the device property differing from one another, so send the light with different brightness.

Therefore, must control separately red, green and blue LED32R-1,32G-1 and 32B-1 to regulate drive current, to send the white light with required white balance.

Conventionally, correspond respectively to red LED32R-1, green LED32G-1 and blue LED32B-1 and form red LED voltage generator, green LED voltage generator and blue LED voltage generator, to control separately each LED.But owing to will manufacturing independent voltage generator, therefore, the method has increased manufacturing cost.

Although can manufacture a kind of LED chip, in this LED chip, regulation output light, makes to apply uniform drive current and uniform brightness is provided,, the method increases because needs auxiliary process makes manufacturing cost.

In addition, because each LED red, green and blue, that launch in monochromatic LED generally has lower brightness compared with other light source, so it is lower to incide light intensity and the brightness of liquid crystal panel, thereby make display quality variation in the case of increasing drive current to obtain from the high-tension light of red LED32R-1 and 32R-2, green LED32G-1 and 32G-2 and blue LED32B-1 and 32B-2 output, temperature rise, because produced high temperature in LED, resistance is increased, thereby luminescence efficiency is declined.

In addition,, in optical plate, also need the light mixed zone 40a for obtain multicolor image from three primary colors (red, green, blue) to mix.Therefore, the photoconduction region 40b that sends actual light in optical plate 40 narrows, and the volume of liquid crystal panel increases.

Summary of the invention

Embodiments of the invention provide a kind of LED package that can realize high color rendition and the white light with fabulous brightness is provided, with and driving method.

Embodiments of the invention provide a kind of LED package, comprising: for using blend of colors to send the multiple red LED of white light, green LED and blue LED; Send at least one white LEDs of white light; And there is the printed circuit board (PCB) of the circuit pattern for driving above-mentioned multiple red LED, green LED, blue LED and white LEDs.

Embodiments of the invention provide a kind of driving method of LED package, this LED package has the printed circuit board (PCB) being formed with for the circuit pattern of driving LED, and be formed on the multiple red LED on this printed circuit board (PCB), green LED, blue LED and white LEDs, the method comprises: by applying different drive currents to described multiple red LED, green LED and blue LED, according to LED color, drive separately described multiple LED, to form white light by blend of colors; And send white light by applying electric current to white LEDs.

Embodiments of the invention provide a kind of liquid crystal display, comprising: the liquid crystal panel that shows image; LED package, comprise for using blend of colors to send the multiple red LED of white light, green LED and blue LED, send multiple white LEDs of white light, and there is the printed circuit board (PCB) of the circuit pattern for driving described multiple red LED, green LED, blue LED and white LEDs; And the light sending from LED package is offered to the optical plate of liquid crystal panel.

Useful effect is according to embodiments of the invention, white LEDs with for the primitive colours LED of blend color, be provided, to form LED package, thereby can provide the light with fabulous color rendition and brightness.

According to embodiments of the invention, can use white LEDs to improve brightness, without the light output increasing for the primitive colours LED of blend color.The LED that therefore, can prevent LED package degenerates.In addition,, because prevented the degeneration of liquid crystal display, also can prevent the variation of display screen aspect chromaticity coordinates, peak wavelength and full width at half maximum (fullwidthathalfmaximum).

According to embodiments of the invention, the multiple LED that are arranged in LED package are operated according to the color of sending, thereby send the white light with fabulous blend of colors characteristic.

According to embodiments of the invention, according to the colour purity of the white light that will send, depart from, control the luminous intensity of the independent LED of each color of light, thereby can improve color rendition.

Accompanying drawing explanation

Fig. 1 has liquid crystal panel electric that correlation technique emitting diode encapsulation is housed not have standby planimetric map.

Fig. 2 shows the skeleton view of the blend of colors of correlation technique emitting diode encapsulation.

Fig. 3 shows correlation technique and penetrates the circuit diagram of the driving method of diode package.

Fig. 4 has to be equipped with according to the liquid crystal panel of the emitting diode encapsulation of the embodiment of the present invention electric not have standby planimetric map.

Fig. 5 shows according to the skeleton view of the blend of colors of the emitting diode encapsulation of the embodiment of the present invention.

Fig. 6 shows according to the circuit diagram of the driving method of the emitting diode encapsulation of the embodiment of the present invention.

Embodiment

With reference to accompanying drawing, emitting diode encapsulation and driving method thereof are according to an embodiment of the invention described below.

With reference to figure 4, emitting diode encapsulation is arranged on liquid crystal panel according to an embodiment of the invention

100 side surface, makes emitting diode encapsulation be used as being contained in the side light type surface source of light of the liquid crystal panel 100 in mobile terminal.In emitting diode encapsulation, multiple red LED320R, green LED320G have been installed, blue LED320B and white LEDs 320W, make to send the white light with uniform high brightness.

With reference to figure 5, LED package 300 comprises three primary colors (red LED320R-1 and 320R-2, green LED320G-1 and 320G-2, and blue LED320B-1 and 320B-2) and white LEDs 320w-1 and 320Vw-2 according to an embodiment of the invention.

According to the area of liquid crystal panel, be provided with multiple red lED320R-1 and 320R-2, green LED320C-Asia and 320G-2, blue LED 320B-1 and 320B-2 and white LEDs 320w-1 and 320W-2, and its quantity can be variable.

Here, it is one embodiment of the present of invention that the order of LED is arranged, and can become various forms. for example, blue LED can be set in order, and red LED, green LED and white LEDs, or, first white LEDs can be set.Certainly, at least one LED can sequentially and side by side be set together with multiple LED.

Therefore,, when three primary colors are as red LED, when green LED and blue LED mix simultaneously, can send white light by mixing these three kinds of colors.In an embodiment of the present invention, be also provided with white LEDs 320W-1 and 320W-2, make to send and there is the more white light of high brightness.The quantity of white LEDs can be variable, and can form with at least one.

Here, LED package 300 comprises printed circuit board (PCB) (PCB) 3II0 that LED is installed.PCB310 comprises insulation course and the driving circuit corresponding to the power lead for operating installed light emitting diode, control line and output line.On the surface of PCB310, formed photosensitive solder resist agent (photosolderresist, PSR) layer 311, so that holding circuit pattern.

In addition, driving circuit is formed the LED that makes simultaneously to operate each glow color.The drive current AR that applies to red LED 320R-1 and 320R-2, the drive current AG applying to green LED 320C-1 and 320G-2, the drive current AB applying to blue LED320B-1 and 320B-2 and can differing from one another to the drive current AW that white 320W-II and 320W-2 apply.

When flowing through uniform current, because red LED320R-Asia and 320R-2, green LED320G-1 and 320G-2 and blue LED320B-1 and 320B-2 have different device properties each other, generate the light with different brightness.

Therefore, mutually control individually the electric current that is applied to red LED 320R-1 and 320R-2, green LED320C-direct sum 320G-2 and blue LED 320B-1 and 320B-2, make to send the light with uniform luminance, to meet the desired white balance of blend of colors.

Can operate take color as unit sequence described multiple red LED 320R-1 and 320R-2, green lED 320G-1 and 320C-2, blue LED 320B-1 and 320B-2 and white LEDs 320W-1 and 320W-2.Or, can operate described multiple red LED320R-1 and 320R-2, green LED320G-1 and 320G-2, blue LED320B-1 and 320B-2 and white LEDs 320W-1 and 320W-2 simultaneously.

Can, according to the emission peak of red LED320R-1 and 320R-2, green LED320G-1 and 320G-2 and blue LED320B-1 and 320B-2, control the emission peak of described multiple white LEDs 320W-1 and 320W-2.

In the liquid crystal display that comprises LED package according to an embodiment of the invention, contiguous LED package has been installed optical plate 400, and the light sending from LED is incided liquid crystal panel.

In liquid crystal display according to an embodiment of the invention, can form the bottom that is arranged on optical plate 400 the light of bottom that is transmitted into optical plate 400 is reflexed to the positive reflector plate 500 of liquid crystal display.In addition, multiple prismatic lenses and diffusion sheet 600 can be installed between reflector plate 500 and liquid crystal panel.

Here, in optical plate 400 exist mix ruddiness, green glow and blue light light mixed zone 400a and for light being transmitted into the light scattering district 400b of liquid crystal panel.

Meanwhile, in the LED being arranged in LED package according to an embodiment of the invention, can use GaAsP compound semiconductor to form red 320R-1 and 320R-2.In addition, can use GaP:N type compound semiconductor to form green LED320G-1 and 320G-2.Can use GaN compound semiconductor to form blue LED320B-1 and 320B-2.

For example, white LEDs 320W-1 and 320W-2 can be with by encouraging yellow fluorescent powder to realize the LED of white light with blue LED as light source.In addition, white LEDs 320W-1 and 320W-2 can also be by encouraging three primary colors fluorescent powder to form with ultraviolet LED as light source.

For example, after the semi-conductor chip that can send blue light is arranged on substrate, can form white LEDs 320W-1 and 320W-2, be included in the particle of interior mixed uniformly at least one luminescent phosphor of epoxy resin of packaged chip.

Fluorescent powder grain is converted to a part of light sending from light-emitting diode chip for backlight unit the light of different spectrum wavelengths.

By a part of blue light that at least one various luminous fluorescent powder particles that use on the top of blue LED are sent, be converted to the much longer light of wavelength, the luminescent system based on fluorescent powder LED can generate white light.

By mixing in proportion green fluorescence powder, red fluorescent powder and yellow fluorescent powder, can form fluorescent powder.The fluorescent powder of transmitting green light represents to send by absorbing blueness all fluorescent powder of green glow.Corresponding to the fluorescent powder of this group, be exemplified as SrGa2S4:Eu, ZnS:CuAI, ZnS:CuAuAI, SrGa2S4:Eu, ZnGa2S4:Eu and SrS:Ce.

In addition, the fluorescent powder of red-emitting represents to send by absorbing blueness all fluorescent powder of ruddiness.

Corresponding to the fluorescent powder of this group, be exemplified as (2nCd) S:AgCI, (2nCd) S:AgAuCI, (2nCd) S:AgAuAl, ZnGa2S4:Mn, SrY2S4:Mn and SrS:Eu.

Below, using describe as the light source of liquid crystal display according to the driving method of the LED package of the embodiment of the present invention.

With reference to figure 6, from LED driving integrated circuit (1C), to the light emitting diode of each color, provide different electric currents, make all to realize the light transmitting with uniform luminance for each color.Light emitting diode drive IC can be formed in the module of liquid crystal display.For example, light emitting diode drives IIC can be designed such that, by receiving from the voltage of battery input, to each light emitting diode, to provide steady current.

The drive current AR applying to red LED320R-1 and 320R-2, the drive current AG applying to green LED320G-1 and 320G-2, the drive current AB applying to blue LED320B-1 and 320B-2 and can being controlled separately to the drive current AW that white LEDs 320W-1 and 320W-2 apply, makes to send the light with uniform luminance from each LED.

About the drive current applying to white LEDs 320W-1 and 320W-2, in the case of the brightness of the white light that sent by red LED, green LED and blue LED is lower, can apply drive current, white LEDs is opened separately.Therefore, can improve brightness.

In addition,, about the color rendition of white LEDs 320W-1 and 320W-2, in the case of the quantity not sufficient of the light of predetermined wavelength, can regulate the drive current of red LED, green LED and blue LED, thereby can improve color rendition.

Can select the light wavelength band sending in each LED, make, by LED arrangement according to an embodiment of the invention, to obtain good colour balance.Red LED can send the light of the spectrum wavelength with about 610 nanometers (am), and green LED can send the light of the spectrum wavelength with about 530am, and blue LED can send and has the light of about 450nm to the spectrum wavelength of 470nm.

Resistance ratio is variable according to each color, to control LED according to each color simultaneously, make according to each color, from LED, send the light with uniform luminance, regulate the electric current of crossing LED according to each color stream, to regulate light intensity and the brightness that will send simultaneously.

By said method, from the light that LED package 300 is sent according to an embodiment of the invention, be transferred to optical plate 400 as described in Figure 5.By sending trichromatic LED as red LED, green LED and blue LED, in the 400a of the light mixed zone of optical plate 400, send mixed light-white light.In addition, mix the white light sending from white LEDs, to generate the white light that brightness improving is a lot.

The light that incides the light mixed zone 400a of optical plate 400 is mixed to produce white light.The white light mixing is transmitted into expand from the light scattering district 400b of optical plate 400 penetrates sheet 600.Therefore, can provide uniform planar light to liquid crystal panel.

As mentioned above, according to embodiments of the invention, by further interpolation white LEDs, can form the LED package of the brightness with improvement.

In addition, by red LED, green LED and blue LED, realize the white light with high color rendition, and by white LEDs, improved brightness, thereby can carry out color rendition and realize like a cork colored live image.

In addition, also have an advantage to be, because by using white LEDs to improve brightness, the light output of red LED, green LED and blue LED can excessively not increase, so, can reduce the reduction of optical efficiency, degeneration and the power consumption of liquid crystal display.

According to embodiments of the invention, white LEDs with for the primitive colours LED of blend color, be set together, to form LED package, thereby can provide the light with fabulous color rendition and brightness.

According to embodiments of the invention, can use white LEDs to improve brightness, without the light output increasing for the primitive colours LED of blend color.Therefore, can prevent the degeneration of the LED of LED package.In addition, because prevented the degeneration of liquid crystal display, so, also can prevent that display screen is at chromaticity coordinates, the variation of peak wavelength and full width at half maximum aspect.

According to embodiments of the invention, be arranged on the color operations that the multiple LED bases in LED package are sent, thereby send the white light with fabulous blend of colors characteristic.

According to embodiments of the invention, according to the excitation of the white light that will send, depart from, control the luminous intensity of the independent LED of each color of light, thereby can improve color rendition.

Claims (2)

1. a driving method for LED package, is characterized in that, by applying different drive currents to multiple red LED, green LED and blue LED, according to LED color, drive separately multiple LED, to form white light by blend of colors, or by applying electric current to white LEDs, send white light.

2. method according to claim 1, is characterized in that, described multiple red LED, and green LED, blue LED and white LEDs are separated and are connected by the circuit pattern of described printed circuit board (PCB), and the LED of each color is driven separately.

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