JP2012009684A - Semiconductor light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that a color could not be satisfactorily adjusted by combination of a conventionally known phosphor with blue and near-ultraviolet light-emitting devices, i.e., B-LED and UV-LED.SOLUTION: A semiconductor light-emitting device comprises a B-LED 3 and a UV-LED 4 mounted on a substrate 1 and a phosphor layer 2 provided on top thereof. In this semiconductor light-emitting device, the phosphor layer 2 has mixed therein first red fluorescent particles R for modulating radiation light from the B-LED 3 and radiation light from the UV-LED 4 to a red outgoing beam Pr, green fluorescent particles G for modulating radiation light from the B-LED 3 and radiation light from the UV-LED 4 to a green outgoing beam Pg, and second red fluorescent particles R2 for modulating radiation light from only the UV-LED 4 to a red outgoing beam Pr2.

Description

  The present invention relates to a semiconductor light emitting device including a semiconductor light emitting element such as an LED element, and more particularly to a semiconductor light emitting device capable of adjusting the light emission chromaticity and having good light emission efficiency.

  In recent years, an LED element (hereinafter abbreviated as LED) is a semiconductor light emitting element, and therefore has a long life and excellent driving characteristics, is small in size, has high luminous efficiency, and has a bright emission color. It has come to be widely used for backlights and lighting. Also in the present invention, an LED light emitting device will be described as an embodiment as a semiconductor light emitting device.

Particularly in recent years, LED light emitting devices have come to be widely used as indoor lighting devices as LED efficiency increases, and there is a demand for changes in color tone in addition to efficient light emitting devices. Various proposals have been made for color-tuning lighting devices. (For example, cited reference 1 and cited reference 2)

The LED light emitting device as a conventional lighting device will be described below.
FIG. 10 is a cross-sectional view showing a configuration of a conventional LED light emitting device 100 disclosed in the cited document 1, and a blue semiconductor light emitting element 103 (hereinafter abbreviated as B.LED) is formed on one substrate 101. An ultraviolet semiconductor light emitting element 104 (hereinafter abbreviated as UV • LED) is mounted side by side, and the whole is covered with a wavelength conversion member 102.

In the wavelength conversion member 102, the following fluorescent particles are mixed in a transparent resin.
That is, by adding the yellow light Py obtained by wavelength conversion of the light emitted from the B • LED 103 to the yellow light and the blue light Pb from the original B • LED 103, the YAG phosphor that emits the white light Pw and the light emitted from the UV • LED. A metal aluminate-based phosphor that is converted into green light Pg and red light Pr to emit light is mixed.

  The LED light emitting device 100 causes the wavelength conversion member 102 to emit the green light Pg and the red light Pr by emitting the UV LED 104 alone. Further, the yellow light Py wavelength-converted by the wavelength conversion member 102 by causing the B • LED 103 to emit light alone and the blue light Pb of the original B • LED 103 become white light Pw as outgoing light. That is, the white light Pw obtained by the single light emission of the B • LED 103 is caused to emit light simultaneously with the B • LED 103 and the UV • LED 104, so that the intermediate color obtained by mixing the white light Pw with the green light Pg and the red light Pr has a color temperature. Becomes lower. That is, the color can be adjusted by controlling the lighting of the UV LED 104.

  FIG. 11 is a cross-sectional view showing a configuration of a conventional LED light emitting device 200 disclosed in the cited document 2, in which B • LED 203 and UV • LED 204 are mounted side by side on a single substrate 201, and the whole is a wavelength conversion member. 202.

  The blue light Pb is emitted light by the emission wavelength of the B LED 203, the green light Pg is emitted light obtained by converting the wavelength of the UV LED 204 by the green phosphor, and the red light Pr is emitted by the B LED 203 or the UV LED 204. At least one light emission selected from the light emission is emitted light whose wavelength is converted by the red phosphor. That is, the fluorescent resin that is the wavelength conversion member 202 has a green phosphor excited by the emission of the UV LED 204 and a red fluorescence excited by at least one emission selected from the emission of the B LED 203 or the emission of the UV LED 204. The body is mixed, and the white light Pw is emitted by combining the blue light Pb, the green light Pg, and the red light Pr.

JP 2005-136006 A JP 2010-80935 A

  The prior arts disclosed in the cited document 1 and the cited document 2 are both mounted with a B.LED and a UV.LED on a single substrate, and by the combination of the light emission of each LED and the wavelength conversion member, By combining the blue light Pb of the B LED and the yellow light Py, the green light Pg, and the red light Pr by the wavelength conversion member, the white light Pw and the intermediate color are extracted as the emitted light.

  However, in the cited document 1, when the B • LED and the UV • LED are turned on simultaneously, the desired color can be set relatively freely. On the other hand, when only the B • LED is turned on, the white light Pw is reddish. There is a problem of poor color rendering. In Cited Document 2, color adjustment can be performed by changing the intensity ratio of B • LED or UV • LED. For example, if the B • LED is weakened, the red light Pr component decreases as the blue light Pb component decreases. It is not easy to lower. As described above, satisfactory color matching has not been achieved by the combination of the phosphor, B • LED, and UV • LED known so far.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems, and to provide a semiconductor light emitting device in which a relatively small amount of a fluorescent material is added to a wavelength conversion member and chromaticity can be easily adjusted.

  In order to achieve the above object, in the semiconductor light emitting device in which the B • LED and the UV • LED are mounted on a substrate and the B • LED and the UV • LED are sealed with a phosphor layer, The body layer includes first red fluorescent particles that modulate the emitted light from the B • LED and the emitted light from the UV • LED into red emitted light, and green fluorescent particles that modulate the green emitted light; And second red fluorescent particles that modulate only the emitted light from the UV LED into red light.

  According to the above configuration, the phosphor layer serving as the wavelength conversion member includes the first fluorescent particles that react to both the emitted light from the B • LED and the emitted light from the UV • LED, and the emitted light from the UV • LED. 2nd red fluorescent particle which reacts only to is provided. When the intensity of B • LED is relatively weak with respect to white light when B • LED and UV • LED are lit at the same time, the red component due to the second red phosphor changes as the blue component decreases. Therefore, a desired color temperature can be easily obtained. In addition, since the first red phosphor and the green phosphor are also excited by the UV LED, the use efficiency of these phosphors is increased, so that the addition of the second red phosphor particles is small.

  The first red fluorescent particles are nitride-based, oxide-based, oxynitride-based, or sulfide-based fluorescent particles having an emission wavelength of 570 to 670 nm, and the green fluorescent particles are an emission wavelength of 500 to 600 nm. The second red fluorescent particles may be oxide-based or fluoride-based fluorescent particles having an emission wavelength of 600 to 670 nm. .

  The phosphor layer may further be a phosphor layer containing second green phosphor particles that modulate only the emitted light from the UV / LED into a green emitting light.

  According to the above configuration, when the B LED is relatively weakened from the daylight color emission around 5000K when the B LED and the UV LED are turned on, red and green light due to the emitted light from the UV LED is obtained. Since the component does not decrease, light emission can be transferred to a warm color around 3000K more accurately and easily.

  The phosphor layer may further be a phosphor layer containing second blue fluorescent particles that modulate only the emitted light from the near-ultraviolet semiconductor light-emitting element into blue outgoing light.

  According to the above configuration, when the B LED is relatively weakened from the emission color when the B LED and the UV LED are turned on, the red, green, and blue light emitted from the UV LED is emitted. Since the component does not decrease, light emission can be transferred to a desired color more accurately and easily. At the same time, since the blue emission spectrum by the second blue fluorescent particles is wider than the blue emission spectrum by the B LED, the color rendering is improved.

  It is preferable to have two drive circuits for lighting the B • LED and the UV • LED independently.

  According to the above configuration, by turning on only the B • LED, the white light Pw having a high color temperature is used as the outgoing light, and the B • LED and the UV • LED are turned on at the same time, thereby correcting the warm tone (color). It is possible to efficiently perform two types of illumination using light (low temperature) as outgoing light.

  As described above, according to the present invention, the wavelength conversion member reacts only with the first fluorescent particles that react to both the emitted light from the B • LED and the emitted light from the UV • LED, and only the emitted light from the UV • LED. By using the second fluorescent particles, it is possible to provide a semiconductor light emitting device with appropriate chromaticity adjustment.

It is sectional drawing of the LED light-emitting device in 1st Embodiment of this invention. It is a block diagram of the LED light-emitting device and its drive circuit in 1st Embodiment of this invention. It is sectional drawing which shows the light emission state of only B * LED of each LED light-emitting device shown in FIG. It is sectional drawing which shows the light emission state of only UV * LED of each LED light-emitting device shown in FIG. It is sectional drawing which shows the light emission state of B * LED and UV * LED of each LED light-emitting device shown in FIG. It is a characteristic view which shows an example of the light emission characteristic of the LED light-emitting device shown in FIG. It is a characteristic view which shows an example of the light emission characteristic of the LED light-emitting device shown in FIG. It is a characteristic view which shows an example of the light emission characteristic of the LED light-emitting device shown in FIG. It is sectional drawing of the LED light-emitting device in other embodiment of this invention. It is sectional drawing of the conventional LED light-emitting device. It is sectional drawing of the conventional LED light-emitting device.

(First embodiment)
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of an LED light emitting device according to a first embodiment of the present invention. In FIG. 1, the LED light emitting device 10 has B • LED 3 and UV • LED 4 mounted side by side on a single substrate 1, and the whole is covered with a wavelength conversion member 2.

In the wavelength conversion member 2, the following fluorescent particles are mixed in a transparent resin.
That is, in response to the light emission of both the B • LED 3 and the UV • LED 4, the light emission of the green / green fluorescent particle G and the red fluorescent particle R that converts the wavelength of the light emission into green light Pg and red light Pr, and the light emission of the UV / LED 4 ( 400 to 405 nm), and red fluorescent particles R2 that convert the emitted light into red light Pr2 are mixed therein.

  In the embodiment of the present invention, as the fluorescent particles mixed in the transparent resin of the wavelength conversion member 2, the first red fluorescent particles R are nitride-based and oxide-based having an emission wavelength of 570 to 670 nm. , Oxynitride-based or sulfide-based phosphor particles. The green phosphor particles G are silicate, oxynitride, or sulfide phosphor particles having an emission wavelength of 500 to 600 nm. The second red fluorescent particles R2 are oxide-based and fluoride-based fluorescent particles having an emission wavelength of 600 to 670 nm.

FIG. 2 is a block diagram of the LED light-emitting device 10 and its drive circuit. The drive circuit 15 has a B / LED drive circuit 16 and a UV / LED drive circuit 17, and the B / LED drive circuit 16 is turned on by the B / LED. The B LED 3 is driven to be lit by operating the switch 18, and the UV LED driving circuit 17 is configured to be lit to drive the UV LED 4 by operating the UV LED lighting switch 19.

  3 to 5 are cross-sectional views showing the lighting states of the LED light emitting device 10, and FIG. 3 shows a state in which only the B LED 3 is turned on by the B LED driving circuit 16 by operating the B LED lighting switch 18. Show. In other words, as indicated by the solid line, the light emitted from the B LED 3 is directly emitted as blue light Pb, wavelength-converted in response to the green fluorescent particles G and red fluorescent particles R, and emitted as green light Pg and red light Pr. Is done.

  FIG. 4 shows a state in which only the UV / LED 4 is turned on by the UV / LED driving circuit 17 by operating the UV / LED lighting switch 19. That is, as shown by the dotted line, the light emitted from the UV LED 4 is wavelength-converted in response to the green fluorescent particles G and the red fluorescent particles R, and is emitted as green light Pg and red light Pr, and the second red light system. In response to the fluorescent particle R2, the wavelength is converted and emitted as the second red light Pr2.

  In FIG. 5, when both the B / LED lighting switch 18 and the UV / LED lighting switch 19 are operated simultaneously, the B / LED driving circuit 16 and the UV / LED driving circuit 17 operate, and the B / LED 3 and UV The LED 4 is turned on at the same time. In this state, the light emission state shown in FIG. 3 and the light emission state shown in FIG. 4 are added.

That is, blue light Pb, green light Pg, and red light Pr are emitted as the light emission of the B LED 3 indicated by a solid line, and second red light Pr2 is emitted in addition to the green light Pg and the red light Pr as light emission indicated by a dotted line. That is, since the green light Pg and the red light Pr are excited by both the B • LED 3 and the UV • LED 4, strong outgoing light can be obtained efficiently.
Further, by performing color correction of the second red light Pr2 excited by the UV • LED 4 with respect to the white light having a high color temperature obtained by the B • LED 3, bright warm color light can be emitted.

Next, the emission wavelength characteristic for each lighting condition will be described.
6 to 8 are light emission characteristic diagrams showing the light emission characteristics of the LED light emitting device 10 with respect to the operating conditions of the drive circuit 15, and FIG. 6 shows a state in which only the B / LED lighting switch 18 of the drive circuit 15 is operated. 3 shows emission wavelength characteristics when only the LED 3 is turned on. As shown in FIG. 3, the characteristic curve of FIG. 6 has a peak near the blue wavelength (450 nm) due to the blue light Pb, the green light Pg, and the red light Pr. As a whole, the characteristic curve OB of the white light Pw is obtained.

  FIG. 7 shows the emission wavelength characteristics when only the UV / LED lighting switch 19 of the drive circuit 15 is operated, that is, when only the UV / LED 4 shown in FIG. 4 is lit. As shown in FIG. Due to Pr and the second red light Pr2, the characteristic curve of FIG. 7 becomes a characteristic curve OUV of the correction light having a peak near the red wavelength (650 nm).

  FIG. 8 shows the emission wavelength characteristics when both the B / LED lighting switch 18 and the UV / LED lighting switch 19 of the drive circuit 15 are in operation, and the characteristic curve OUV by the lighting of the UV / LED 4 indicated by the dotted line and the dotted line The characteristic curve BUV is obtained by adding the characteristic curve OB obtained by turning on the B LED. That is, as shown in FIG. 5, the characteristic curve BUV of FIG. 7 has a peak near the red wavelength (650 nm) due to the blue light Pb, the green light Pg, the red light Pr, and the second red light Pr2 indicated by the solid and dotted lines. A characteristic curve of the corrected warm color light having a light emitting component in each wavelength region is obtained. The red phosphor R and the green phosphor G are not saturated by the light emitted from the B LED 3. Similarly, the light emitted from the UV LED 4 is not saturated. For this reason, the light emission intensities of the red phosphor R and the green phosphor G are approximately proportional to the sum of the light emission intensities of the B • LED 3 and the UV • LED 4.

  As described above, the LED light emitting device 10 according to the first embodiment of the present invention emits daylight light as shown in the OB characteristic diagram of FIG. 6 when only the B / LED lighting switch 18 of the drive circuit 15 is operated. When operating both the B • LED lighting switch 18 and the UV • LED lighting switch 19, two types of lighting devices can be realized by performing bright warm light emission of reddish orange color as shown in FIG. 8. In the present embodiment, the ON / OFF control is performed on the B • LED 3 and the UV • LED 4. However, if the LED drive circuit 15 can control the current amount, intermediate color adjustment can be performed.

(Second Embodiment)
Next, an LED light emitting device according to a second embodiment of the present invention will be described with reference to FIG. FIG. 9A is a cross-sectional view of the LED light-emitting device 20 in the second embodiment, and the basic configuration is the same as that of the LED light-emitting device 10 in the first embodiment. Description to be omitted is omitted.

  The cross-sectional view of the LED light-emitting device 20 shown in FIG. 9A corresponds to the cross-sectional view of the LED light-emitting device 10 in the first embodiment shown in FIG. That is, the LED light emitting device 20 shown in FIG. 9A differs from the LED light emitting device 10 shown in FIG. 5 in that the second green fluorescent particles that react only with the light emitted from the UV LED 4 in the transparent resin of the wavelength conversion member 2. G2 is mixed. As a result, when both the B / LED lighting switch 18 and the UV / LED lighting switch 19 of the drive circuit 15 are operated, the second red fluorescent particle R2 in addition to the red light Pr2 as shown in FIG. By correcting the green fluorescent particles G2 with the green light Pg2, a wider range of chromaticity correction is performed, and soft and bright warm color light emission can be performed.

(Third embodiment)
Next, the LED light-emitting device in 3rd Embodiment of this invention is demonstrated with FIG.9 (b). FIG. 9B is a cross-sectional view of the LED light-emitting device 30 in the third embodiment, and the basic configuration is the same as the LED light-emitting devices 10 and 20 in the first and second embodiments, and the same numbers are assigned to the same elements. A duplicate description will be omitted.

  The cross-sectional view of the LED light-emitting device 30 shown in FIG. 9B corresponds to the cross-sectional view of the LED light-emitting device 20 in the second embodiment shown in FIG. That is, the LED light emitting device 30 shown in FIG. 9B is different from the LED light emitting device 20 shown in FIG. 9A in that the second blue that reacts only with the light emitted from the UV LED 4 in the transparent resin of the wavelength conversion member 2. That is, the system fluorescent particles B2 are mixed. As a result, when both the B / LED lighting switch 18 and the UV / LED lighting switch 19 of the drive circuit 15 are operated, the red light Pr2 and the second green light of the second red fluorescent particles R2 as shown in FIG. 9B. By performing correction using the blue light Pb2 of the second blue fluorescent particles B2 in addition to the green light Pg2 of the fluorescent particles G2, a wider range of chromaticity correction is possible.

  As described above, as shown in the present invention, in the wavelength conversion member, the fluorescent particles for basic light emission excited by both the B • LED and the UV • LED and the correction fluorescent particles excited only by the UV • LED are provided. By mixing, wide-range chromaticity correction is possible. In the combination of B • LED 3 and the red phosphor R and the green phosphor G to obtain a desired color, the red phosphor R and the green phosphor G are often not saturated yet. For this reason, in warm coloration, the UV LED 4 also excites the red phosphor R and the green phosphor G, so that a small amount of the second red phosphor R2 is added. In addition, the utilization efficiency of the red phosphor R and the green phosphor G increases with this excitation, and illumination with easily increased emission luminance can be obtained.

1, 101, 201 Substrate 2, 102, 202 Wavelength conversion member 3, 103, 203 B LED
4, 104, 204 UV LED
10, 20, 30, 100, 200 LED light emitting device 15 Drive circuit 16 B / LED drive circuit 17 UV / LED drive circuit 18 B / LED lighting switch 19 UV / LED lighting switch R, R2 Red fluorescent particles G, G2 Green fluorescence Particles Pr, Pr2 Red light Pg, Pg2 Green light Pb Blue light Pw White light

Claims (5)

  In a semiconductor light emitting device in which a blue semiconductor light emitting element and a near ultraviolet semiconductor light emitting element are mounted on a substrate, and a phosphor layer is provided on both the semiconductor light emitting elements, the phosphor layer is the blue semiconductor light emitting element. First red fluorescent particles that modulate the emitted light from the near-infrared semiconductor light-emitting element to the red-based outgoing light, green-based fluorescent particles that modulate the green-based outgoing light, and a near-ultraviolet semiconductor 2. A semiconductor light emitting device comprising: second red fluorescent particles that modulate only the emitted light from the light emitting element into red emitted light.   The first red fluorescent particles are nitride-based, oxide-based fluorescent particles, oxynitride-based fluorescent particles, or sulfide-based fluorescent particles having an emission wavelength of 570 to 670 nm, and the green-based fluorescent particles are Silicate fluorescent particles, oxynitride fluorescent particles, or sulfide fluorescent particles having an emission wavelength of 500 to 600 nm, and the second red fluorescent particles are oxides having an emission wavelength of 600 to 670 nm The semiconductor light-emitting device according to claim 1, which is a phosphor-based phosphor particle or a fluoride-based phosphor particle.   3. The semiconductor according to claim 1, wherein the phosphor layer is a phosphor layer further containing second green phosphor particles that modulate only the emitted light from the near-ultraviolet semiconductor light-emitting element into green-based emitted light. Light emitting device.   4. The phosphor layer according to claim 1, further comprising a second blue fluorescent particle that modulates only the emitted light from the near-ultraviolet semiconductor light emitting element into a blue outgoing light. 5. The semiconductor light emitting device according to item. 5. The semiconductor light emitting device according to claim 1, further comprising two drive circuits for lighting the blue semiconductor light emitting element and the near ultraviolet semiconductor light emitting element independently.

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