JP2007091958A - Process for producing led lamp emitting white light, process for producing backlight using the lamp and process for producing liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process for producing a white LED lamp using an LED emitting an ultraviolet light that can afford both high color rendering properties and high brightness by improving the combination of a blue light emitting phosphor, a green light emitting phosphor and a red light emitting phosphor. <P>SOLUTION: The process for producing an LED lamp 1 emitting a white light is provided with an LED chip 2 having an emission wavelength in a range of not less than 360 nm to not more than 440 nm and a light emitting portion comprising a blue light emitting phosphor, a green light emitting phosphor and a red light emitting phosphor and emitting a white light when excited by a light emitted from the LED chip 2 wherein as the blue light emitting phosphor is used at least one kind selected from the group consisting of an Eu-activated halophosphate phosphor and an Eu-activated aluminate phosphor; as the green light emitting phosphor is used an Au and Al-activated zinc sulfide phosphor and as the red light emitting phosphor is used at least one kind selected from the group consisting of an Eu and Sm-activated acid lanthanum sulfide phosphor and a Cu and Mn-activated zinc sulfide phosphor, which comprises the step of combining the blue light emitting phosphor, the red light emitting phosphor and the green light emitting phosphor. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a white light emitting LED lamp using a light emitting diode (LED) having a light emission wavelength of 360 to 440 nm as a light source, a method of manufacturing a backlight using the same, and a method of manufacturing a liquid crystal display device About.

  An LED is a semiconductor element that converts electric energy into light such as ultraviolet light and visible light and emits it, and LED lamps in which such LED chips are sealed with, for example, a transparent resin are used in various fields. Since the LED chip is a semiconductor element, it has a long life and high reliability. When used as a light source, the replacement work and the like are reduced. Therefore, portable communication devices, PC peripheral devices, OA devices, household electric devices, It has come to be widely used as a component of various display devices such as signal devices, various switches, and backlight type display panels.

  The color tone of the light emitted from the LED lamp is not limited to the emission wavelength of the LED chip. For example, the phosphor is applied to the surface of the LED chip, or the phosphor is contained in a transparent resin for sealing the LED chip. By doing so, it is possible to obtain light in the visible light region corresponding to the intended use from blue to red. In particular, white light-emitting LED lamps are rapidly spreading in applications such as backlights for mobile communication device displays and in-vehicle lamps, and are expected to greatly expand in the future as replacements for fluorescent lamps. ing.

  Currently, white light-emitting LED lamps that are widely used or tried include LED lamps that combine blue light-emitting LEDs and yellow light-emitting phosphors (such as YAG), ultraviolet light-emitting LEDs, and blue, green, and red light-emitting fluorescent lights. LED lamps combined with a mixture of bodies are known. At present, the former white LED lamp using the blue light emitting LED is more prevalent because it is superior in luminance characteristics and the like than the latter. However, the former has a drawback that it looks yellowish depending on the viewing direction, and yellow or blue unevenness appears when projected onto a white surface. For this reason, the former white LED lamp may be called pseudo white. Even in the average color rendering index representing the quality of white light, the former white LED lamp remains in the range of 70 to 75.

  On the other hand, the white LED lamp using the latter ultraviolet light-emitting LED is less in brightness than the former, but has little unevenness of light emission and projection light, and is expected to become the mainstream of white lamps for illumination in the future. Development is progressing rapidly. In such a white LED lamp using an ultraviolet light emitting LED, in addition to the characteristics of the phosphors emitting each color, the combination of these phosphors affects the lamp characteristics such as color rendering properties and luminance. Investigations regarding selection and combination of phosphors emitting red light are in progress.

For example, Non-Patent Document 1 discloses an ultraviolet light emitting LED, an Eu activated halophosphate phosphor or Eu activated aluminate phosphor as a blue light emitting phosphor, and Cu and Al activated zinc sulfide phosphor as a green light emitting phosphor. Alternatively, a white LED lamp in which Eu and Mn activated aluminate phosphors and Eu activated yttrium oxysulfide phosphors as red light emitting phosphors are combined is described. Patent Document 1 discloses Eu-activated halophosphate phosphors or Eu-activated aluminate phosphors as blue-emitting phosphors, Eu and Mn-activated aluminate phosphors, and red-emitting phosphors as green-emitting phosphors. It is described that an Eu-activated lanthanum oxysulfide phosphor is used.
Mitsubishi Cable Industrial Time Bulletin No.99 July 2002 Japanese Unexamined Patent Publication No. 2000-073052

  Although the conventional white LED lamp described above has high color rendering properties and uniformity of light emission, which are characteristics of a lamp using an ultraviolet light emitting LED, it is insufficient in terms of luminance characteristics, and further improvement is required. ing. In order to achieve both high color rendering and high brightness with a white LED lamp using an ultraviolet light emitting LED, light in the vicinity of 450 nm, 560 nm, and 620 nm, where human color sensitivity peaks in the white light spectrum, are well balanced. In addition, it is necessary that the luminous efficiency of each of the phosphors of blue, green, and red light emitting components be balanced.

  However, among the phosphors used in the conventional white LED lamps, the red light emitting phosphors are inferior in luminous efficiency to ultraviolet rays or violet light having a wavelength of 380 nm or more compared to other phosphors. It has been found that the luminance characteristics and the like cannot be sufficiently improved. In addition, the characteristics of the blue and green light-emitting phosphors cannot be fully exerted by being dragged by the red light-emitting phosphors that are inferior in luminous efficiency, and this also causes deterioration of the luminance characteristics.

  The present invention has been made to cope with such a problem. In a white light emitting LED lamp using an ultraviolet light emitting LED, the combination of blue, green, and red light emitting phosphors is improved. An object of the present invention is to provide a white light-emitting LED lamp that achieves both color rendering and high luminance.

  A method for producing a white light emitting LED lamp of the present invention includes a light emitting diode having an emission wavelength in a range of 360 nm or more and 440 nm or less, a blue light emitting phosphor, a green light emitting phosphor, and a red light emitting phosphor. In the white light emitting LED lamp having a light emitting part that is excited by light and emits white light, the blue light emitting phosphor is at least selected from a europium activated halophosphate phosphor and a europium activated aluminate phosphor. The green light-emitting phosphor is composed of gold and aluminum activated zinc sulfide phosphor, and the red light-emitting phosphor is europium and samarium activated lanthanum oxysulfide phosphor and copper and manganese activated zinc sulfide phosphor. And the blue-emitting phosphor, the green-emitting phosphor and the red-emitting phosphor are at least one selected from A step of producing a combined phosphor bonded by a binding agent, a step of preparing a phosphor resin mixture for mixing the combined phosphor and a resin, and a light emitting part forming step of applying the phosphor resin mixture to a light emitting diode It is characterized by comprising.

  Since the manufacturing method of the white light emitting LED lamp of the present invention uses gold and aluminum-activated zinc sulfide phosphors containing a longer wavelength component as the green light emitting phosphor, the light emitting component (red component) by the red light emitting phosphor is used. ) Can be reinforced. As a result, the luminance characteristics can be improved without impairing the characteristic of the high color rendering properties inherent to the white light emitting LED lamp using the ultraviolet light emitting LED. Therefore, it is possible to provide a white light-emitting LED lamp that achieves both high color rendering properties and high luminance. Further, since the white light emitting LED lamp of the present invention has a small variation in emission chromaticity difference, chromaticity variation as a surface light source even when applied to a backlight using a plurality of LED lamps and a liquid crystal display device using the LED lamp. Can be suppressed.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the following, embodiments of the present invention will be described with reference to the drawings. However, the drawings are provided for the purpose of illustration only, and the present invention is not limited to the drawings.

  FIG. 1 is a sectional view schematically showing a configuration of a white light emitting LED lamp (white LED lamp) according to an embodiment of the present invention. A white LED lamp 1 shown in the figure has an LED chip 2 as a light source. The LED chip 2 is bonded onto a wiring substrate 4 having lead terminals 3, and the LED chip 2 and the lead terminals 3 are electrically connected by bonding wires 5. The LED chip 2 is an ultraviolet light emitting LED that emits ultraviolet light or violet light having a wavelength in the range of 360 to 440 nm. Examples of such an ultraviolet light emitting LED chip 2 include an LED chip having a nitride compound semiconductor layer as a light emitting layer.

  A cylindrical resin frame 6 is provided on the wiring board 4, and a reflective layer 7 is formed on the inner wall surface thereof. A transparent resin 8 is filled in the resin frame 6, and the LED chip 2 is embedded in the transparent resin 8. The transparent resin 8 in which the LED chip 2 is embedded contains a phosphor (three-color phosphor) 9 including a blue light-emitting phosphor, a green light-emitting phosphor, and a red light-emitting phosphor. The three-color phosphor 9 dispersed in the transparent resin 8 emits white light when excited by ultraviolet rays or violet light emitted from the LED chip 2.

That is, the electrical energy applied to the white LED lamp 1 is converted into ultraviolet light or violet light by the LED chip 2, and the light is converted into light having a longer wavelength by the three-color phosphor 9 dispersed in the transparent resin 8. Converted. Then, white light is emitted from the LED lamp 1 based on the three-color phosphor 9 contained in the transparent resin 8. The transparent resin 8 containing the three-color phosphor 9 functions as a light emitting portion, and is disposed in front of the LED chip 2 in the light emitting direction. A white LED lamp (white light-emitting lamp) 1 is configured by such a light emitting unit and the LED chip 2 as a light source. For example, a silicone resin or an epoxy resin can be used for the transparent resin 8 containing the three-color phosphor 9.

  For each of the blue, green, and red light emitting phosphors constituting the three-color phosphor 9, a phosphor that efficiently absorbs ultraviolet rays or violet light in the wavelength range of 360 to 440 nm emitted from the LED chip 2 should be used. Is preferred. Among these phosphors that emit light of various colors, the blue light-emitting phosphor is selected from europium (Eu) -activated halophosphate phosphors and europium (Eu) -activated aluminate phosphors that are excellent in absorption efficiency of ultraviolet light and violet light. At least one kind is used.

As the Eu-activated halophosphate phosphor,
General formula: (M1 _1-c , Eu _c ) ₁₀ (PO ₄ ) ₆ · Cl ₂ (1)
(Wherein M1 represents at least one element selected from Mg, Ca, Sr and Ba, and c is a number satisfying 0.005 ≦ c ≦ 0.03)
The fluorescent substance which has a composition represented by these is illustrated. As Eu-activated aluminate phosphor,
General formula: m (M2 _1-d , Eu _d ) O.nAl ₂ O ₃ (2)
(In the formula, M 2 represents at least one element selected from Mg, Ca, Sr, Ba and Zn, and d, m and n are 0.05 ≦ d ≦ 0.3, 0 <m, 0 <n, 0.2 ≦ m / (It is a number that satisfies n ≦ 1.5)
The fluorescent substance which has a composition represented by these is illustrated.

Further, at least one selected from europium (Eu) and samarium (Sm) activated lanthanum oxysulfide phosphors and copper (Cu) and manganese (Mn) activated zinc sulfide phosphors is used as the red light emitting phosphor. . As Eu and Sm activated lanthanum oxysulfide phosphors,
General _{formula: (La 1-ab, Eu} a, Sm b) 2 O 2 S ... (3)
(Wherein, a and b are numbers satisfying 0.01 ≦ a ≦ 0.15 and 0.0001 ≦ b ≦ 0.03)
The fluorescent substance which has a composition represented by these is illustrated. As Cu and Mn activated zinc sulfide phosphors,
General formula: ZnS: Cu _v , Mn _w (4)
(Wherein v and w are numbers satisfying 0.0002 ≦ v ≦ 0.001 and 0.005 ≦ w ≦ 0.014)
The fluorescent substance which has a composition represented by these is illustrated.

  The red light-emitting phosphors represented by the formulas (3) and (4) can be used as red light-emitting components that emit light with the ultraviolet light-emitting LED chip 2, but the light-emitting characteristics of the red light-emitting components In consideration of (emission intensity and the like), it is preferable to use at least Eu and Sm activated lanthanum oxysulfide phosphor as a red light emitting component. Further, since Eu and Sm-activated lanthanum oxysulfide phosphors alone lack red light emitting components, it is effective to use Cu and Mn-activated zinc sulfide phosphors together.

  The above-described red light-emitting phosphor does not necessarily have sufficient light emission efficiency with respect to ultraviolet rays or violet light in the wavelength range of 360 to 440 nm. Although the red light emitting component is reinforced by using the Eu and Sm activated lanthanum oxysulfide phosphor and the Cu and Mn activated zinc sulfide phosphor together, the luminous efficiency is inferior to the blue and green light emitting phosphors. Therefore, in the white LED lamp 1 of this embodiment, a green light-emitting phosphor that includes a longer wavelength component than a conventional green light-emitting component is used. Specifically, gold (Au) and aluminum (Al) activated zinc sulfide phosphors are used as green light emitting phosphors.

Examples of Au and Al-activated zinc sulfide phosphors include, for example, the general formula: ZnS: Au _x , Al _y (5)
(Wherein x and y are numbers satisfying 0.0002 ≦ x ≦ 0.0015 and 0.0001 ≦ y ≦ 0.0012)
A phosphor having a composition represented by: If the value of x in the formula (5) (molar ratio of Au to 1 mol of ZnS) is less than 0.0002, the emission chromaticity shifts in the blue direction and a desired color cannot be obtained. On the other hand, when the value of x exceeds 0.0015, the body color of the phosphor deteriorates and the luminance decreases. Further, if the value of y in the formula (5) (molar ratio of Al to 1 mol of ZnS) is less than 0.0001, Au cannot enter the zinc sulfide, thereby lowering the luminance. On the other hand, if the value of y exceeds 0.0012, the body color of the phosphor deteriorates and the luminance decreases.

FIG. 2 shows the emission spectrum (a) of Au and Al-activated zinc sulfide phosphor (ZnS: Au, Al phosphor), and the conventional Cu and Al-activated zinc sulfide phosphor (ZnS: Cu, Al phosphor). The emission spectrum (b) is shown in comparison with the emission spectrum (c) of Eu and Mn activated aluminate phosphor (3 (Ba, Mg, Eu, Mn) O.8Al ₂ O ₃ phosphor). As is apparent from FIG. 2, the zinc sulfide phosphor co-activated with Au and Al has a longer wavelength component than conventional Cu and Al activated zinc sulfide phosphors and Eu and Mn activated aluminate phosphors. Thus, the red light emitting component can be reinforced.

  Since the three-color phosphor 9 including the blue, green, and red light emitting phosphors described above contains light in the vicinity of 450 nm, 560 nm, and 620 nm in a well-balanced manner, the color rendering properties of white light can be improved. In addition, since a green light-emitting phosphor made of Au and Al-activated zinc sulfide phosphor (ZnS: Au, Al phosphor) containing a longer wavelength component than the conventional green light-emitting component is used, the red color is used. Insufficient light emission due to the light emitting phosphor can be reinforced. As a result, the luminance balance of each of the blue, green and red light emitting components is improved, so that the luminance characteristics of the white LED lamp 1 using the ultraviolet light emitting LED chip 2 can be enhanced. Therefore, it is possible to realize the white LED lamp 1 that achieves both high color rendering properties and high luminance.

  The effect of improving the luminance characteristics of the white LED lamp 1 by the green light emitting phosphor (ZnS: Au, Al phosphor) described above is that Eu and Sm activated lanthanum oxysulfide phosphors, Cu and Mn activated sulfides are used as red light emitting phosphors. It can be obtained when any of the zinc phosphors is used. Further, in order to obtain the effect of improving the luminance characteristics by the red light emitting phosphor itself, the red light emitting phosphor is used in combination with Eu and Sm activated lanthanum oxysulfide phosphor and Cu and Mn activated zinc sulfide phosphor as described above. It is preferable to do. Thereby, since the red light emitting component is further reinforced, the luminance characteristics of the white LED lamp 1 can be further enhanced. The mixing ratio of these red light-emitting phosphors depends on the target color temperature of the white light, but the mass ratio of Eu and Sm-activated lanthanum oxysulfide phosphor and Cu and Mn-activated zinc sulfide phosphor is, for example, 3 : It is preferable to set it as the range of 7-7: 3.

  FIG. 3 shows an example of an emission spectrum of the white LED lamp 1 using the three-color phosphor 9 including the blue, green, and red light-emitting phosphors described above. In FIG. 3, the emission spectrum of A is an Eu-activated halophosphate phosphor as a blue light-emitting component, Au and Al-activated zinc sulfide phosphor as a green light-emitting component, and Eu and Sm-activated lanthanum oxysulfide phosphor as a red light-emitting component. The emission spectrum of B is the emission spectrum of white LED lamp 1 in which Cu and Mn activated zinc sulfide phosphors are added as red emission components to the combination of phosphors of A. .

  In any of the phosphor combinations A and B described above, ultraviolet rays from an LED chip having a current value of 20 mA and a peak value of 400 nm are converted into white light having a chromaticity of (x = 0.300 to 0.350, y = 0.300 to 0.350). In this case, the peak value of the blue light emitting component is 450 nm, the peak value of the green light emitting component is 545 nm, and the peak value of the red light emitting component is 623 nm, respectively, and an average color rendering index of 90 or more and a luminance value of 300 mcd or more are obtained. ing. Further, comparing the emission spectra of A and B, it can be seen that the emission spectrum B has an increased emission component in the vicinity of 580 nm and beyond. This is based on the combined use of Eu and Sm activated lanthanum oxysulfide phosphors and Cu and Mn activated zinc sulfide phosphors as red light emitting components, thereby further improving the luminance characteristics of the white LED lamp 1. It becomes possible.

  In the present invention, the blue, green, and red light emitting phosphors described above are previously used as binders such as an inorganic binder and an organic binder in order to improve the uniformity of the dispersion state of each color light emitting phosphor in the transparent resin 8. It is preferable to disperse in the transparent resin 8 in a bonded state. A finely divided alkaline earth borate or the like can be used as the inorganic binder, and a transparent resin such as an acrylic resin or a silicone resin can be used as the organic binder. By performing an integration process using an inorganic binder, an organic binder, or the like, the phosphors are randomly connected to increase the particle size. As a result, non-uniformity of the dispersion state based on the difference in sedimentation speed of the respective phosphors in the transparent resin 8 can be eliminated, and white light reproducibility and emission chromaticity uniformity (chromaticity difference) can be eliminated. , Etc.) can be increased.

Furthermore, the particle size of each phosphor also affects the luminance characteristics of the white LED lamp 1. From such points, it is preferable that the blue, green, and red light emitting phosphors have an average particle size of 7 μm or more as a mixture thereof. In addition, the average particle diameter said here shows the median value (50% value) of particle size distribution. By setting the average particle size of the three-color phosphor 9 to 7 μm or more, the luminance of the white LED lamp 1 can be further increased. The average particle diameter of the three-color phosphor (mixed phosphor) 9 is more preferably 8 μm or more. In addition, the brightness improvement effect based on the average particle diameter of the three-color phosphor 9 is also effective for the phosphor subjected to the above-described integration process (bonding step).
The blue phosphor, the green phosphor, and the red phosphor are preliminarily bonded with a binder, and then a phosphor resin that is mixed with the bound phosphor and a resin. A step of producing a mixture and a step of forming a light emitting part for applying the phosphor resin mixture to a light emitting diode are provided.
Such a white LED lamp of the present invention can obtain a uniform LED with small chromaticity variation among individual LEDs. Therefore, for example, it is particularly effective in a field using a plurality of LEDs such as a backlight of a liquid crystal display device. As the backlight, it is effective for both the direct type and the side light type, and is particularly effective for those using 10 or more side by side. Therefore, according to the manufacturing method of the present invention, a uniform white LED lamp with small chromaticity variation can be manufactured. Moreover, when manufacturing a backlight, it is preferable to arrange an LED module by arranging a plurality of white LED lamps at a predetermined interval.

  Next, specific examples of the present invention and evaluation results thereof will be described.

Example 1
First, Eu-activated alkaline earth chlorophosphate ((Sr _0.59 , Ca _0.01 , Ba _0.39 , Eu _0.01 ) ₁₀ (PO ₄ ) ₆ · Cl ₂ ) phosphor as a blue light-emitting phosphor, Au and green as a green light-emitting phosphor Al-activated zinc sulfide (ZnS: Au _0.0008 , Al _0.001 ) phosphor, Eu and Sm-activated lanthanum oxysulfide ((La _0.94 , Eu _0.058 , Sm _0.002 ) ₂ O ₂ S) phosphors are available as red-emitting phosphors did.

1.74 g of the above-mentioned blue light-emitting phosphor, 2.17 g of the green light-emitting phosphor, and 2.33 g of the red light-emitting phosphor were weighed, and the phosphors of the respective colors were combined by the following binding process. The mixing ratio of each phosphor is set so that the CIE chromaticity value (x, y) of the LED lamp falls within the range of x = 0.30 to 0.31 and y = 0.30 to 0.31. The same applies to the following Examples 2 to 10 and Comparative Example 1. Moreover, the average particle diameter (distribution median diameter) as a mixture of each phosphor is 9.5 μm. The LED lamp 1 shown in FIG. 1 was produced using such a mixed phosphor. In the binding step, phosphors of each color emission were put into water to form a suspension. While this suspension was stirred, barium / calcium borate (3 (Ba, Ca) O.B ₂ O ₃ ) was added at a ratio of 0.1 mass% with respect to the total amount of each phosphor. Stirring was continued for 30 minutes and then stopped to allow the phosphor to settle. This was filtered and baked, and then passed through a 200 mesh nylon sieve to obtain a combined three-color mixed phosphor (coupled phosphor).

  In the manufacturing process of the LED lamp 1, first, a mixed phosphor was added to the silicone resin constituting the transparent resin 8 at a ratio of 30 mass% and mixed to form a slurry. This slurry is dropped on an ultraviolet light emitting LED chip 2 having a light emission peak wavelength of 400 nm and a shape of 300 μm square, and a silicone resin is cured at 140 ° C., whereby a mixed phosphor (blue, green and red mixed phosphor) is obtained. The ultraviolet light emitting LED chip 2 was sealed with the contained silicone resin. The LED lamp thus produced was subjected to the characteristic evaluation described later.

Example 2
The same and the same amount of each phosphor as in Example 1 was prepared, and these were combined by the method shown below. In the bonding step, first, an acrylic resin emulsion was added to each phosphor at a ratio of 0.1% by mass with respect to the phosphor, and these were mixed. Next, this mixture was dried at 120 ° C. and then applied to a nylon mesh to obtain an integrated phosphor. And LED lamp was produced like Example 1 using such an integrated fluorescent substance. This LED lamp was subjected to the characteristic evaluation described later.

Example 3
In addition to the same phosphors as in Example 1 described above, Cu and Mn activated zinc sulfide (ZnS: Cu _0.0005 , Mn _0.008 ) phosphors were prepared as red light emitting phosphors. 2.10 g of Eu-activated alkaline earth chlorophosphate, 2.22 g of Au and Al-activated zinc sulfide phosphor, 2.10 g of Eu and Sm-activated lanthanum oxysulfide phosphor, Cu and Mn-activated zinc sulfide phosphor 0.82 g was weighed and mixed and combined in the same manner as in Example 1. Then, using such a combined phosphor, an LED lamp was produced in the same manner as in Example 1. This LED lamp was subjected to the characteristic evaluation described later.

Examples 4-5
A combined phosphor was produced in the same manner as in Example 1 or Example 2 except that the combination of blue, green and red light emitting phosphors shown in Table 1 was applied. Using each of these combined phosphors, LED lamps were produced in the same manner as in Example 1. This LED lamp was subjected to the characteristic evaluation described later.

Comparative Example 1
Eu-activated alkaline earth chlorophosphate ((Sr, Ca, Ba, Eu) ₁₀ (PO ₄ ) ₆ .Cl ₂ ) phosphor as a blue light emitting phosphor, Eu and Mn activated alkaline earth as a green light emitting phosphor Aluminate (3 (Ba, Mg, Eu, Mn) O.8Al ₂ O ₃ ) phosphor, Eu-activated lanthanum oxysulfide ((La, Eu) ₂ O ₂ S) phosphor as a red-emitting phosphor did. 1.44 g of the blue light-emitting phosphor, 1.49 g of the green light-emitting phosphor, and 3.32 g of the red light-emitting phosphor were weighed and mixed using a three-roller. Using such a mixed phosphor, an LED lamp was produced in the same manner as in Example 1. This LED lamp was subjected to the characteristic evaluation described later. In Comparative Example 1, the bonding step was not performed.

Comparative Example 2
Eu-activated alkaline earth chlorophosphate ((Sr, Ca, Ba, Eu) ₁₀ (PO ₄ ) ₆ · Cl ₂ ) phosphor as blue-emitting phosphor, Eu-activated alkaline earth silicate as green-emitting phosphor An Eu-activated lanthanum oxysulfide ((La, Eu) ₂ O ₂ S) phosphor was prepared as a ((Ba, Sr, Ca, Eu) ₂ SiO ₄ ) phosphor and a red light-emitting phosphor. 2.71 g of the blue light-emitting phosphor, 0.45 g of the green light-emitting phosphor, and 1.85 g of the red light-emitting phosphor were weighed and mixed using a three-roller. Using such a mixed phosphor, an LED lamp was produced in the same manner as in Example 1. This LED lamp was subjected to the characteristic evaluation described later. In Comparative Example 2, the bonding step was not performed.

  The white LED lamps of Examples 1 to 5 and Comparative Examples 1 and 2 described above were turned on by passing a current of 20 mA, and the emission luminance, average color rendering index, and chromaticity of each white LED lamp were measured. These measurement results are shown in Table 2. In addition, the light emission characteristic of each white LED lamp was measured using CAS 140B COMPACT ARRAY SPECTROMETER by Instrument System, and MCPD apparatus by Otsuka Electronics.

As can be seen from Table 2, each of the white LED lamps according to Examples 1 to 5 is excellent in luminance characteristics as compared with Comparative Example 1 and Comparative Example 2 in addition to being excellent in color rendering. Therefore, it is possible to achieve both high color rendering properties and high luminance in a white LED lamp using an ultraviolet light emitting LED.
Next, the chromaticity variation of the white light emitting LED lamps of Examples 1 to 5 was measured. As for chromaticity, 20 white LEDs according to each example are prepared, chromaticity (CIE chromaticity coordinates) is measured directly above each LED, and the difference between the maximum value and the minimum value (Δx , Δy). In addition, the thing similar to Example 1 was prepared except not performing a coupling | bonding process as a reference example. The results are shown in Table 3.

As can be seen from Table 3, it can be seen that the white LED according to this example has small chromaticity variation. Such a white LED lamp is effective as a component of various display devices such as portable communication devices, PC peripheral devices, OA devices, home electric devices, various switches, backlight type display panels, and general lighting devices. Can be used.
In particular, since the chromaticity variation is small, a surface light source having a uniform white color can be obtained even when used for a backlight using a plurality of white LED lamps. Therefore, the characteristics of the liquid crystal display device using the same are also improved.

It is sectional drawing which shows the structure of the white LED lamp by one Embodiment of this invention. It is a figure which shows an example of the emission spectrum of the green light emission fluorescent substance applied to this invention compared with the conventional green light emission fluorescent substance. It is a figure which shows an example of the emission spectrum of the three-color fluorescent substance applied to this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... White LED lamp, 2 ... LED chip, 6 ... Resin frame, 7 ... Reflective layer, 8 ... Transparent resin, 9 ... Three-color fluorescent substance.

Claims (7)

A light emitting diode having a light emission wavelength in a range of 360 nm to 440 nm, a blue light emitting phosphor, a green light emitting phosphor, and a red light emitting phosphor, and a light emitting portion that emits white light when excited by light from the light emitting diode; In the manufacturing method of the white light emitting LED lamp comprising:
The blue light emitting phosphor is composed of at least one selected from a europium activated halophosphate phosphor and a europium activated aluminate phosphor, and the green light emitting phosphor is composed of gold and aluminum activated zinc sulfide phosphor, And the red light emitting phosphor comprises at least one selected from europium and samarium activated lanthanum oxysulfide phosphor and copper and manganese activated zinc sulfide phosphor,
And the blue light emitting phosphor, the green light emitting phosphor, and the red light emitting phosphor are prepared in advance by binding a phosphor,
Producing a phosphor resin mixture to be mixed with the combined phosphor and resin;
A light emitting part forming step of applying the phosphor resin mixture to a light emitting diode;
A method of manufacturing a white light emitting LED lamp. In the manufacturing method of the white light emission type LED lamp of Claim 1,
The green light emitting phosphor is:
General formula: ZnS: Au _x, Al _y
(Wherein x and y are numbers satisfying 0.0002 ≦ x ≦ 0.0015 and 0.0001 ≦ y ≦ 0.0012)
A method for producing a white light emitting LED lamp, characterized by comprising gold and aluminum activated zinc sulfide phosphors having a composition represented by the formula: In the manufacturing method of the white light emission type LED lamp of Claim 1 or Claim 2,
The red light-emitting phosphor is
General _{formula: (La 1-ab, Eu} a, Sm b) 2 O 2 S
(Wherein, a and b are numbers satisfying 0.01 ≦ a ≦ 0.15 and 0.0001 ≦ b ≦ 0.03)
Europium and samarium activated lanthanum oxysulfide phosphors having a composition represented by the general formula: ZnS: Cu _v , Mn _w
(Wherein v and w are numbers satisfying 0.0002 ≦ v ≦ 0.001 and 0.005 ≦ w ≦ 0.014)
A method for producing a white light-emitting LED lamp, comprising: at least one selected from copper and a manganese-activated zinc sulfide phosphor having a composition represented by: In the manufacturing method of the white light emission type LED lamp of any one of Claim 1 thru | or 3,
The method of manufacturing a white light emitting LED lamp, wherein the red light emitting phosphor includes both the europium and samarium activated lanthanum oxysulfide phosphor and the copper and manganese activated zinc sulfide phosphor. In the manufacturing method of the white light emitting LED lamp of any one of Claims 1 thru | or 4,
The blue-emitting phosphor is
General formula: (M1 _1-c , Eu _c ) ₁₀ (PO ₄ ) ₆ · Cl ₂
(Wherein M1 represents at least one element selected from Mg, Ca, Sr and Ba, and c is a number satisfying 0.005 ≦ c ≦ 0.03)
And a europium-activated halophosphate phosphor having a composition represented by the general formula: m (M2 _1-d , Eu _d ) O.nAl ₂ O ₃
(In the formula, M 2 represents at least one element selected from Mg, Ca, Sr, Ba and Zn, and d, m and n are 0.05 ≦ d ≦ 0.3, 0 <m, 0 <n, 0.2 ≦ m / (It is a number that satisfies n ≦ 1.5)
A method for producing a white light-emitting LED lamp, comprising at least one selected from europium-activated aluminate phosphors having a composition represented by:   A method for manufacturing a backlight, wherein a plurality of white light emitting LED lamps according to any one of claims 1 to 5 are used.   A method of manufacturing a liquid crystal display device using the backlight according to claim 6.

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