JP2012004392A - Bulb-type led lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bulb-type LED lamp excellent in appearance of red, and in addition, suitable for a light source for rendering illumination in relatively inexpensive price.SOLUTION: A bulb-type LED lamp 1 includes: a base 2; and a white light-emitting body 3 having a blue light-emitting element 3a1 generating blue light and a yellowish light-emitting phosphor 3a2 disposed so as to convert light radiated from the blue light-emitting element in wavelength, and disposed on the base. The lamp further includes a thermoplastic translucent plastics cover 4 in which translucent plastics is the base material thereof, and in which an organic visible-selective absorption material, whose absorption peak is in the region of wavelength of 580-590 nm, which has a half value width of 40 nm or less as light absorption characteristics, and whose thermal decomposition temperature is equal to or higher than the fusion temperature of the translucent plastics base material is mixed in 10-50 ppm. The cover is disposed on one end side of the base so as to cover the white light-emitting body. The lamp further includes a cap 5 disposed on the other end side of the base. Its color temperature is 2500-3500 K.

Description

  Embodiments of the present invention relate to a light bulb shaped LED lamp having a white light emitter.

  Light bulb-type LED lamps using light-emitting diodes as light emitters are being replaced by conventional incandescent light bulbs and light bulb-type fluorescent lamps. The bulb-type LED lamp has a base similar to that of an incandescent bulb or a bulb-type fluorescent lamp, and is configured to be lit only by being mounted on a socket.

  As the white light emitting diode, what is generally called a blue-yellow pseudo white light emitting diode has become mainstream. This type of white light-emitting diode realizes a visually bright white light-emitting diode by combining a blue light-emitting diode and a phosphor that emits yellow light having a high visibility.

  Further, in order to improve the color rendering properties of the white light emitting diode or adjust the color temperature, it is possible to provide a filter function to the light emitting diode as shown in each prior art document.

  In addition, as a light source for production lighting to brighten the appearance of colors on display products and dishes on the table, especially warm colors such as red, yellow light is cut into bulbs for light sources with a color temperature around 3000K. Incandescent light bulbs using neodymium glass are used. In order to perform red effect illumination, this effect illumination light source is provided with a spectral radiant energy characteristic that sharply cuts yellow light having a wavelength of about 585 nm and needs to be deeply cut. As a result, the color rendering properties Ra and R9 of the color rendering index are not good.

Japanese Patent Laid-Open No. 11-039917 JP 2004-193581 A JP 2001-512287 A

  Currently, the bulb-type LED lamps available on the market are for general illumination and do not have a radiant energy distribution that sharply cuts yellow light with a wavelength of around 585 nm. Can not be effective.

  An object of the present invention is to provide a light bulb-type LED lamp suitable for a light source for production illumination that has a good appearance of red, is relatively inexpensive, and has good durability.

  According to the embodiment of the present invention, the light bulb shaped LED lamp includes a base. A white light emitter is disposed on one end side of the substrate. The white light emitter includes a blue light emitting element that generates blue light and a yellow light emitting phosphor that is disposed so as to convert the wavelength of light emitted from the blue light emitting element. The bulb-type LED lamp includes a thermoplastic translucent plastic cover disposed on one end side of the base so as to cover the white light emitter. This translucent plastics cover uses translucent plastics as a base material and is mixed with an organic visible selective absorption material at a ratio of 10 to 50 ppm. And it has the light absorption characteristic that a half value width is 40 nm or less while an absorption peak exists in the area | region of wavelength 580-590 nm. Moreover, the thermal decomposition temperature of the organic visible selective absorption material is equal to or higher than the melting temperature of the base material. Further, the bulb-type LED lamp is disposed on the other end side of the base. The bulb-type LED lamp has a color temperature of 2500 to 3500K.

  ADVANTAGE OF THE INVENTION According to this invention, it can be anticipated that the light bulb-type LED lamp suitable for the highly durable light source for production lighting with a good appearance of red and relatively inexpensive can be expected.

1 is a front cross-sectional view of a light bulb shaped LED lamp showing a first embodiment of the present invention. It is a typical sectional view of a white luminous body similarly. It is a figure which shows the radiant energy distribution of Example 1 with that of a comparative example. It is a figure which shows the radiant energy distribution of Example 2 with it of a comparative example.

  Hereinafter, embodiments of the present invention will be described.

  A first embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the bulb-type LED lamp 1 includes a base 2, a white light emitter 3, a translucent plastic cover 4, a base 5, and the like.

  The light bulb-shaped LED lamp is a light source that uses an LED that has an external shape substantially similar to an incandescent light bulb and is used for illumination. Accordingly, if the bulb-type LED lamp is provided with the same base as the incandescent bulb at one end, it can be lit by being mounted on a socket like an incandescent bulb and a bulb-type fluorescent lamp that have been widely used conventionally. The color temperature of the light bulb shaped LED lamp in the present embodiment is 2500 to 3500K, and generally corresponds to a light source color called a light bulb color. The preferable lower limit of the color temperature is 2700K.

  The base 2 includes a base body 2a, an insulating case 2b, and a lighting circuit board 2c.

  The base body 2a is made of a heat conductive material such as aluminum, the outer envelope surface has a substantially inverted truncated cone shape, and a white light emitter 3 described later at the upper end in FIG. It is mechanically supported while forming a heat conduction relationship. The base body 2a has a recess 2a1 formed in the lower portion thereof, and further includes a through-hole 2a2 that vertically penetrates the base body 2a. Furthermore, the base body 2a can increase the heat dissipation area by forming heat dissipation fins on the outer surface thereof.

  The insulating case 2b is housed in the recess 2a1 of the base body 2a, and has a through hole 2c1 that coincides with the through hole 2a2 of the base body 2a at the top, and a lighting circuit board 2c to be described later is housed in the base body 2a. It is insulated from the main body 2a.

  The lighting circuit board 2c is housed inside the insulating case 2b, has an LED lighting circuit mounted thereon, and drives the white light emitter 3 to light up. The LED lighting circuit forms a constant current circuit mainly composed of a DC converter, for example, and is equipped with those circuit components.

  In this embodiment, the white light emitter 3 includes a plurality of LED packages 3a and a common substrate 3b.

  Each LED package 3a is a known one configured by including a blue light emitting diode chip 3a1 and a yellow light emitting phosphor layer 3a2 as shown in FIG. One or a plurality of blue light emitting diode chips 3a are connected in series and mounted on the base 3a3, and the blue light emitting diode chip 3a1 is arranged on the base 3a3 so that the reflector 3a4 surrounds the blue light emitting diode chip 3a1. It is installed. The yellow light-emitting phosphor layer 3a2 is obtained by dispersing yellow light-emitting phosphor particles in, for example, transparent plastics such as silicone. The yellow light-emitting phosphor layer 3a2 is filled and solidified inside the concave portion formed by the reflector 3a4.

  Moreover, the LED package 3a can be equipped with the translucent member 3a5 depending on necessity. The translucent member 3a5 is made of transparent plastic, for example, transparent epoxy, and covers the upper side of the yellow light-emitting phosphor layer 3a2.

  The substrate 3b is circular in this embodiment, and a plurality of LED packages 3a are mounted in a distributed manner along substantially concentric circles. The substrate 3b has a wiring hole 3b1 at a position corresponding to the through hole 2a2 of the base body 2a. Further, the substrate 3b is mainly composed of a heat conductive material such as aluminum, for example, and the heat generated by the LED package 3a is conducted to the base body 2a via the substrate 3b and dissipated to the outside. Yes. Driving current supply from an LED lighting circuit to be described later for lighting a plurality of LED packages 3a is performed by an LED lighting circuit to be described later via a conductive line (not shown) that is connected via the through hole 2a2 and the wiring hole 3b1. This is performed from the mounted lighting circuit board 2c through the through hole 2c1.

  Since the translucent plastic cover 4 is located so as to be interposed between the white light emitter 3 and an illuminated body (not shown), an organic visible selective absorption material satisfying predetermined conditions described later is mixed therein. By absorbing the yellow light component of the light transmitted therethrough. Thereby, the yellow light component in illumination light is reduced and the appearance of red of the illuminated body is improved.

  The translucent plastic cover 4 is a thermoplastic plastic member that can function as a glove because it covers the light emitting part of the bulb-type LED lamp, and a white light emitter is disposed in the internal space thereof. . Therefore, the translucent plastic cover 4 surrounds the white light emitting body 3 that is a light emitting part to adjust the appearance of the bulb-type LED lamp, and can mechanically protect the white light emitting body 3.

  Since the base plastic used for the translucent plastic cover 4 is thermoplastic, it can be molded using an injection molding method, and molding is relatively easy and inexpensive. Thermoplastic translucent plastics are translucent, preferably transparent, and easily guide visible light emitted from a white light emitter to an illuminated space.

  Therefore, it is preferable that the plastic has a high visible light transmittance. For example, polycarbonate (PC), acrylic (PMMA), polyethylene terephthalate (PET), heat-resistant transparent ABS (SAN), methylbenten polymer (MPP), and cyclic olefin copolymer (COP) are used alone or in combination. And can be used as a main component. In view of cost, manufacturability, optical characteristics, and the like, PC and PMMA are particularly preferable among the above groups. When PC or PMMA is used, it is sufficient that they are main components, and other translucent plastics can be mixed as a subcomponent. In the above, the main component is more than 50% by mass ratio, preferably more than 70%.

  Furthermore, an ultraviolet cut material can be added to the translucent plastics constituting the translucent plastics cover 4 as desired. In addition, a known thing can be used for a ultraviolet-ray cut material. Thereby, even if it is a case where ultraviolet rays are contained in the light output radiated | emitted from the internal white light-emitting body 3, or the external light of a use environment, degradation of the translucent plastics cover 4 is suppressed by ultraviolet rays.

  The organic visible selective absorption material mixed with the translucent plastics and dispersed inside the translucent plastics cover 4 has an absorption peak at a wavelength of 580 to 590 nm, and greatly reduces yellow light near the wavelength of 585 nm. Preferably, it cuts by 70 to 90%, and its full width at half maximum is 40 nm or less. Further, an absorbent having a cut of 50 nm or less can be used in combination, and the chromaticity difference can be adjusted to a value around −0.001 to −0.013. The half-value width is the wavelength of the absorption peak value of the translucent plastics cover 4 in which the transmittance of the plastic substrate constituting the translucent plastics cover 4 and the organic visible selective absorption material are mixed. The difference between the two wavelengths on the long and short sides showing the transmittance of half of the difference between them and the sharpness of the absorption characteristics. That is, the smaller the half width, the sharper the absorption characteristics. When the half width exceeds 40 nm, yellow light in the vicinity of the wavelength of 585 nm cannot be sharply cut, and as a result, it becomes difficult to obtain a desired improvement effect with respect to the appearance of red.

  Further, the organic visible selective absorption material is an organic dye, and its thermal decomposition temperature is equal to or higher than the melting temperature of the base material of the translucent plastics cover 4, for example, in the case of PC, it is 310 ° C or higher. In the case, it is 220 ° C. or higher. The visible selective absorption material satisfying the above-described conditions can be obtained from organometallic compounds of various compounds such as cyanine, squarylium, azomethine, xanthene, oxonol, and azo polymethine. In particular, among organic dyes mainly used for suppressing neon emission in PDP displays, it is particularly preferable to use those having the above-mentioned conditions because of excellent durability and heat resistance. If the thermal decomposition temperature of the organic visible selective absorption material is equal to or higher than the melting temperature of the cover 4 base material, the organic visible selective absorption material can be dispersed inside the plastic translucent plastics cover 4, and at the time of molding and lighting Since the deterioration of the organic visible selective absorption material is suppressed, durability such as optical characteristics of the translucent plastic cover is improved.

  Further, the organic visible selective absorption material is mixed at a ratio of 10 to 50 ppm with respect to the thermoplastic translucent plastic base material when the thickness of the translucent plastic cover 4 is 1 to 3 mm. With this mixing ratio, the above-mentioned light absorption characteristics can be obtained, and the distance between the absorbents when dispersed is wide and embedded in the resin, so that high durability can be obtained. The unit of mixing is mass. When the mixing ratio is less than 10 ppm, it becomes difficult to cut yellow light out of visible light emitted from the white illuminant. In order to cut to the required level, the thickness of the translucent plastic cover exceeds 3 mm. It must be enlarged to an excessive degree. That is, in order to cut yellow light to a desired degree, it is necessary to set the thickness of the translucent plastic cover to be large. As a result, the external shape of the bulb-type LED lamp is large and heavy, and the transmittance of the translucent plastics itself is not 100%. The luminous efficiency of the LED lamp decreases. When the mixing ratio of the organic visible selective absorption material exceeds 50 ppm, the durability of the translucent plastic cover is lowered. The mixing ratio of the organic visible selective absorption material is preferably 20 to 35 ppm.

  It has been found that organic visible selective absorption materials have a significantly reduced durability when used as membranes. This is considered to be due to the interaction between the translucent member and the vapor film adhering to the surface. Therefore, in this embodiment, the durability is improved by dispersing the organic visible selective absorption material in the translucent plastic cover 4, and the mixing ratio in the range of 10 to 50 ppm is particularly effective.

  Further, a light diffusing means can be provided to the translucent plastic cover 4 as desired. For example, one or more kinds of fine particles of metal oxides such as alumina, silica, and titania are mixed in the inside of the plastics, or formed on the inner surface or the outer surface of the translucent plastics cover 4, so that the light diffusion means The translucent plastic cover 4 can be disposed.

  In the present embodiment, the translucent plastic cover 4 has a dome shape, and is disposed on one end side of the base 2 so as to cover the white light emitter 3. The thermoplastic translucent plastic is polycarbonate, and the organic visible selective absorption material is mixed within the predetermined amount range so that the organic visible selective absorption material has a predetermined light absorption characteristic.

  The base 5 is preferably a screw base and is attached to the lower portion of the base 2 in FIG. 1 and connected to the input end of the LED light source lighting circuit.

It is the structure shown in FIG. 1 and FIG.
Translucent plastic cover: 2mm thick, polycarbonate material, organic visible selective absorption material
Thermal decomposition temperature of about 320 ℃, mixing ratio 27ppm
Light absorption characteristics: Light cut rate around peak wavelength 585nm about 80%, half width 32nm

Durability: No significant deterioration of optical properties was observed after 60000 hours.

  Next, the spectral radiant energy distribution in Example 1 is shown in FIG. In FIG. 3, the curve indicated by the bold line is Example 1, and the curve indicated by the thin line is Comparative Example 2. The comparative example 2 is a conventional 100V36W type incandescent lamp provided with neodymium glass.

  As can be seen from FIG. 3, according to Example 1, the light absorption characteristics are equivalent to those of Comparative Example 2, and the yellow light in the vicinity of 585 nm is obtained although the amount of red light is significantly smaller than that of Comparative Example 2. Because it absorbs sharply, the appearance of red is excellent.

  Next, Table 1 shows the chromaticity (x, y), color temperature (K), relative light quantity, and color rendering index (Ra, R9) of Example 1 together with those of Comparative Examples 1 and 2. In addition, the comparative example 1 is a light bulb shaped LED lamp having the same configuration as that of the example 1 except that the translucent plastic cover does not mix the organic visible selective absorption material.

In Table 1, from the left side to the right side of the first row, the column “sample” distinguishes between the example and the comparative example, “x” indicates the chromaticity value x, and “y” indicates the chromaticity value y. “CCT (K)” is the color temperature, “duv” is the chromaticity difference, and “relative light quantity” is the relative light quantity when the comparative example 1 in which the organic visible selective absorption material is not mixed is 100%. , “Ra” indicates the average color rendering index, and “R9” indicates the special color rendering index red. The optical characteristic data of each sample is shown in the second and subsequent rows.

  As can be understood from Table 1, according to Example 1, the appearance of red is almost the same as that of Comparative Example 2, and optical characteristics with high color rendering properties can be obtained.

  A second embodiment of the present invention will be described. In this embodiment, the plastics of the translucent plastic cover is acrylic. Other configurations are allowed to be the same as those in the first embodiment. When acrylic is used as the substrate, an organic visible selective absorption material having a low thermal decomposition temperature can be used.

It is the structure shown in FIG. 1 and FIG.
Translucent plastic cover: wall thickness 2mm, material acrylic, organic visible selective absorption material
Thermal decomposition temperature of about 320 ℃, mixing ratio 27ppm
Light absorption characteristics: Light absorption rate of about 80% near wavelength 585nm, half width 32nm

Durability: No significant deterioration of optical properties was observed after 60000 hours.

  Next, the spectral radiant energy distribution in Example 2 is shown in FIG. In FIG. 4, the curve indicated by the bold line is Example 2, and the curve indicated by the thin line is Comparative Example 4. Comparative Example 4 is a conventional 100V36W type incandescent lamp provided with neodymium glass.

  As can be understood from FIG. 4, according to Example 2, the light absorption characteristic is the same as that of Comparative Example 4, and yellow light in the vicinity of 585 nm is obtained although the amount of red light is significantly smaller than that of Comparative Example 2. Because it absorbs sharply, the appearance of red is excellent.

Next, Table 2 shows the chromaticity (x, y), color temperature (K), relative light quantity, and color rendering index (Ra, R9) of Example 2 together with those of Comparative Examples 3 and 4. Comparative Example 3 is a light bulb shaped LED lamp having the same configuration as that of Example 2 except that the translucent plastic cover does not mix the organic visible selective absorbing material. Table 2 has the same format as Table 1.

  In addition, Example 2 is adjusted so that the appearance of red is better than that of Example 1, and the optical characteristics relating to the appearance of red closer to Comparative Example 4 can be obtained. However, since the appearance of red is further improved, the color rendering is slightly reduced. That is, how red appears depends only on the cut rate around 585 nm. For this reason, the greater the cut rate, the better the appearance of red. For example, if the cut rate is extremely increased, the appearance of red will be improved. On the other hand, the color rendering properties depend on the original light, that is, the light color of the white illuminant, but there are optimum values for the cut rate and the cut wavelength. In Example 2, since the appearance of red is the same as that of Comparative Example 4, it is out of this optimum value, and the color rendering is slightly deteriorated.

  On the other hand, in Example 1, the appearance of red is improved, but Example 2 is more similar to Comparative Example 4 in appearance. That is, the color rendering properties are improved because the values are close to the optimum values of the cut rate and the cut wavelength.

  In the present embodiment, when an LED is used as the light emitting source, the appearance of red can be improved.

DESCRIPTION OF SYMBOLS 1 ... Light bulb-shaped LED lamp, 2 ... Base | substrate, 2a ... Base | substrate body, 2b ... Insulation case, 2c ... Lighting circuit board, 3 ... White light-emitting body, 3a ... LED package, 3a1 ... Blue light emitting diode chip, 3a2 ... Yellow light emission Phosphor layer, 3b ... common substrate, 4 ... translucent plastic cover, 5 ... base

Claims (3)

A substrate;
A blue light emitting element for generating blue light, and a white light emitting element disposed on a substrate including a yellow light emitting phosphor disposed to convert the wavelength of light emitted from the blue light emitting element;
An organic visible selective absorption material having a thermal decomposition temperature equal to or higher than the melting temperature of the base material, having a light-absorbing property having an absorption peak in a wavelength range of 580 to 590 nm and a half-value width of 40 nm or less, using translucent plastics as a base A thermoplastic light-transmitting plastics cover mixed with 10 to 50 ppm and disposed on one end side of the substrate so as to cover the white light-emitting body;
A base disposed on the other end of the substrate;
A light bulb shaped LED lamp having a color temperature of 2500 to 3500K.   The light-transmitting plastics cover has a light-transmitting LED as claimed in claim 1, wherein the light-transmitting plastic base material is mainly composed of polycarbonate, and the organic visible selective absorption material has a thermal decomposition temperature of 310 ° C or higher. lamp.   The light-transmitting plastic cover is characterized in that the light-transmitting plastic base material is mainly composed of acrylic, and the organic visible selective absorption material has a thermal decomposition temperature of 220 ° C or higher. lamp.

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