Patent Application
20140254166
This application claims the benefit of priority to Korean Patent Application No. 10-2013-0025524, filed on Mar. 11, 2013, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
The present application relates to light emitting diode (LED) lighting and a method of manufacturing the LED lighting.
Generally, light emitting diode (LED) lighting having high color reproduction characteristics has a high emission efficiency. Therefore, it is ideal to increase a high color rendering index (CRI), which is an index of the color reproduction characteristics, of the LED lighting.
A CRI of general LED lighting ranges between approximately 70 and 80. However, lighting used in places requiring high color reproduction characteristics, such as stores and shops, needs to have a CRI of about 90 or more. Therefore, halogen bulbs or incandescent bulbs, having a relatively lower emission efficiency than the LED lighting, are usually used for industrial lighting. Meanwhile, the industrial lighting may adopt LED lighting accomplishing the CRI of 90 or more. However, in this case, such industrial lighting may not be practically used since the structure becomes complicated and the price is increased.
LED lighting including a general white LED has a relatively low CRI of about 75 or lower, compared to an incandescent light source having a CRI of about 95 or more. The low CRI may be caused due to absence of light at a red part of a spectrum, where a wavelength is about 600 nm or more. A technology for integrating phosphor materials emitting red light has been developed to increase the CRI of the white LED. However, compared to yellow and green down converting phosphor materials, the phosphor materials emitting red light causes a great energy loss and a low efficiency of a light source.
General high-CRI LED lighting lacks red components having a wavelength of about 630 nm or more, which may cause a reduction in a CRI of LED lighting. To this end, LED lighting that achieves a CRI of about 90 or more is being developed, by combining a blue LED and a green LED phosphor material with a white LED and a red LED.
However, since the LED lighting controls current values of the white LED and the red LED using a feedback sensor, a circuit configuration may be complicated and a manufacturing cost may be increased.
According to an aspect of the present application, there is provided light emitting diode (LED) lighting including a white LED and a red LED, wherein chromaticity of the white LED may have a color temperature of between about 2800 K to about 3700 K within a range according to ANSI C78. 377-2008 standard, and a range of the color temperature may correspond to a higher range than a chromaticity locus defined by blackbody radiation.
A y-coordinate value of the chromaticity of the white LED is greater than an electrical locus.
According to an aspect of the present application, there is also provided LED lighting including a white LED, a red LED, and a diffusion plate, wherein chromaticity of the white LED has a color temperature of between about 3500 K to about 4800 K within a range according to ANSI C78. 377-2008 standard, and a lumen (lm) ratio of light radiated from the white LED and the red LED is defined by red LED:white LED=1:6˜red LED:white LED=1:14.
According to another aspect of the present application, there is provided a method of manufacturing LED lighting, the method including forming a substrate; forming at least one white LED on an upper surface of the substrate; and forming at least one red LED on the upper surface of the substrate, wherein chromaticity of the at least one white LED has a color temperature of between about 2800 K to about 3700 K within a range according to ANSI C78. 377-2008 standard, and a range of the color temperature corresponds to a higher range than a chromaticity locus defined by blackbody radiation.
According to another aspect of the present application, there is also provided a method of manufacturing LED lighting, the method including forming a substrate; forming at least one white LED on an upper surface of the substrate; forming at least one red LED on the upper surface of the substrate; and forming a diffusion plate at an upper portion of the at least one white LED and the at least one red LED, wherein chromaticity of the at least one white LED has a color temperature of between about 3500 K to about 4500 K within a range according to ANSI C78. 377-2008 standard, and a lumen (lm) ratio of light radiated from the at least one white LED and the at least one red LED is defined by red LED:white LED=1:6˜red LED:white LED=1:14.
Additional advantages and novel features will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following and the accompanying drawings or may be learned by production or operation of the examples. The advantages of the present teachings may be realized and attained by practice or use of various aspects of the methodologies, instrumentalities and combinations set forth in the detailed examples discussed below.
These and/or other aspects, features, and advantages of the application will become apparent and more readily appreciated from the following description of exemplary embodiments, taken in conjunction with the accompanying drawings of which:
In the following detailed description, numerous specific details are set forth by way of embodiments in order to provide a thorough understanding of the relevant teachings. However, it should be apparent to those skilled in the art that the present teachings may be practiced without such details. In other instances, well known methods, procedures, components, and/or circuitry have been described at a relatively high-level, without detail, in order to avoid unnecessarily obscuring aspects of the present teachings.
Reference will now be made in detail to exemplary embodiments of the present application, examples of which are illustrated in the accompanying drawings but are not limited to the embodiments.
Terms to be used below are defined to properly explain the embodiments and may vary according to users, user's intentions, or practices. Therefore, the definitions of the terms should be determined based on the entire specification.
Referring to
Referring to
The white LEDs 220 may adopt LEDs within a range of chromaticity defined by the American National Standards Institute (ANSI) C78. 377-2008 standard. This standard specifies the range of chromaticities recommended for general lighting with solid state lighting products, such as LED lighting, and ensures that the white light chromaticities of the products can be communicated to consumers. The standard applies to LED-based solid state lighting products with control electronics and heat sinks incorporated therein.
The range 310 of ANSI C78. 377-2008 standard may be determined according to chromaticity as shown in
The LED lighting may achieve high efficiency of a color temperature, a chromaticity, and a color rendering index (CRI), by adjusting an available chromaticity range and a ratio between the white LEDs and the red LED, for example, a ratio of lumen (lm) values or a ratio of a number of packages. For example, the chromaticity of the white LEDs 220 ranges from about 2800 K to about 3700 K within the range of ANSI C78. 377-2008 standard, which corresponds to a higher range than a chromaticity locus defined by the blackbody radiation. In the chromaticity of the white LEDs, a y-coordinate value may be greater than an electrical locus.
In the LED lighting, the lm ratio of light radiated from the white LEDs 220 and the red LED 230 may be defined by Equation 1.
red LED:white LED=1:6˜red LED:white LED=1:14 [Equation 1]
The LED lighting may obtain a simulation result of chromaticity as shown by the graph of
For example, when the ratio between the red LED and the white LEDs is 1:5, the to LED lighting may obtain a color temperature of about 2640 K and a CRI of about 94.2 as a simulation result value 450 according to the lm ratio between the red LED and the white LED, as indicated by 451. When the ratio is 1:6, the LED lighting may obtain a color temperature of about 2721 K and a CRI of about 92.7, as indicated by 452 in
In the LED lighting including a white LED and a red LED, the chromaticity and the CRI may be varied according to a mixture ratio of light. For example, the chromaticity may be located on a straight line connecting chromaticity of the white LED and chromaticity of the red LED after colors are mixed. As red components are increased, the chromaticity after the color mixture may be approximated to chromaticity of the red LED. When the red components are insufficient, the CRI may not be satisfactorily increased. However, when the red components are excessive, the CRI may rather be decreased. Therefore, it is exemplary that the CRI of the LED lighting is about 90 or more and the chromaticity after the color mixture is within the range of the ANSI C78. 377-2008 standard.
Referring to
Also, a ratio of a number of packages between the white LEDs and the red LED may to be defined by Equation 2.
red LED:white LED=1:4˜red LED:white LED=1:8 [Equation 2]
For example, when the white LEDs and the red LED are driven in serial connection, the LED lighting ratio of the number of packages between the white LEDs and the red LED may be adjusted to between 1:4 and 1:8.
As another example, an lm ratio of light radiated from the white LEDs and the red LED may be adjusted to between 1:6 to 1:14.
Additionally, an available chromaticity range of the white LEDs may be increased by adding a material for absorbing a blue wavelength to an already manufactured diffusion plate or diffusion cover. Also, in this case, the manufacturing cost may be reduced. Since emission efficiency of the white LEDs of the LED lighting may be limited, the diffusion plate or diffusion cover may be added to relieve conditions for an available LED.
Referring to
Referring to
Referring to
Here, a coordinate 830 refers to chromaticity of a white LED. A coordinate 840 may obtain a chromaticity of LED lighting without a diffusion plate, in which a color temperature is about 3033 K and a CRI is about 92.8. A coordinate 850 may obtain a chromaticity of LED lighting with a diffusion plate, in which transmittance of a diffusion plate is about 60%, a color temperature is about 2778 K and a CRI of about 91.0. A coordinate 860 may obtain chromaticity of LED lighting with a diffusion plate, in which transmittance of a diffusion plate is about 53%, a color temperature is about 2740 K and a CRI is about 90.5. A coordinate 870 may obtain chromaticity of LED lighting with a diffusion plate, in which transmittance of a diffusion plate is about 46%, a color temperature is about 2703 K and a CRI is about 90.0.
Since the white LED of the LED lighting may be used around 4000 K within the range of ANSI C78. 377-2008 standard, the LED lighting may be used at a relatively low cost.
Referring to
Referring to
The LED lighting may include the white LED, the red LED, and the diffusion plate. Chromaticity of the white LED may have a color temperature of between about 3500 K to 4500 K within the range of ANSI C78. 377-2008 standard. An lm ratio of light radiated from the white LED and the red LED may be defined by Equation 3.
red LED:white LED=1:6˜red LED:white LED=1:14 [Equation 3]
Here, a wavelength of 580 nm is standardized as 100%, transmittance of the diffusion plate may be about 45% to about 60% with respect to a wavelength of 450 nm
Referring to
An lm ratio of light radiated from the at least one white LED and the at least one red LED and a ratio of a number of packages may be referenced from the foregoing description and therefore will not be described again.
In operation 1140, a diffusion plate may be formed at an upper portion of the at least one white LED and the at least one red LED. In operation 1150, a heat sink may be provided at a lower surface of the substrate.
In addition, although the LED lighting may be manufactured by the foregoing manufacturing method, the color temperature of chromaticity of the white LED may be adjusted to from about 3500 K to about 4500 K within the range of ANSI C78. 377-2008 standard.
A number of examples have been described above. Nevertheless, it will be understood that various modifications may be made. For example, suitable results may be achieved if the described techniques are performed in a different order and/or if components in a described system, architecture, device, or circuit are combined in a different manner and/or replaced or supplemented by other components or their equivalents.
While the foregoing has described what are considered to be the best mode and/or other examples, it is understood that various modifications may be made therein and that the subject matter disclosed herein may be implemented in various forms and examples, and that the teachings may be applied in numerous applications, only some of which have been described herein. It is intended by the following claims to claim any and all applications, modifications and variations that fall within the true scope of the present teachings.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2013-0025524 | Mar 2013 | KR | national |
