LED lamp, LED illumination device, and LED module

Abstract

An LED lamp provides a strong red color with a natural appearance. The LED lamp is provided with an LED module and a filter. The LED module includes a blue LED with a main emission peak in the 440 nm to 460 nm wavelength band, a green/yellow phosphor that is excited by light emitted by the blue LED, and a red phosphor that is excited by light emitted by at least one of the blue LED and the green/yellow phosphor. The filter reduces the spectral radiation intensity of at least a portion of the 570 nm to 590 nm wavelength band among light emitted by the LED module.

The invention claimed is: 
     
       1. An LED lamp comprising:
 an LED light source including a blue LED with a main emission peak in a wavelength band of 440 nm to 460 nm, a green/yellow phosphor that is excited by light emitted by the blue LED, and a red phosphor that is excited by light emitted by at least one of the blue LED and the green/yellow phosphor; and   a filter that reduces spectral radiation intensity of at least a portion of a wavelength range from 570 nm to 590 nm among light emitted by the LED light source,   wherein a color of light transmitted through the filter is light bulb color as specified by Japanese Industrial Standard Z9112, and   wherein a maximum peak wavelength of mixed light before transmission through the filter, the mixed light being a mix of light emitted by the green/yellow phosphor and light emitted by the red phosphor, is in a wavelength range from 580 nm to 630 nm, and a full width at half maximum for the maximum peak wavelength is in a range of 120 nm to 175 nm.   
     
     
       2. An LED lamp comprising:
 an LED light source including a blue LED with a main emission peak in a wavelength band of 440 nm to 460 nm, a green/yellow phosphor that is excited by light emitted by the blue LED, and a red phosphor that is excited by light emitted by at least one of the blue LED and the green/yellow phosphor; and   a filter that reduces spectral radiation intensity of at least a portion of a wavelength range from 570 nm to 590 nm among light emitted by the LED light source,   wherein a color of light transmitted through the filter is warm white as specified by Japanese Industrial Standard Z9112, and   wherein a maximum peak wavelength of mixed light before transmission through the filter, the mixed light being a mix of light emitted by the green/yellow phosphor and light emitted by the red phosphor, is in a wavelength range from 580 nm to 620 nm, and a full width at half maximum for the maximum peak wavelength is in a range of 120 nm to 175 nm.   
     
     
       3. An LED lamp comprising:
 an LED light source including a blue LED with a main emission peak in a wavelength band of 440 nm to 460 nm, a green/yellow phosphor that is excited by light emitted by the blue LED, and a red phosphor that is excited by light emitted by at least one of the blue LED and the green/yellow phosphor; and   a filter that reduces spectral radiation intensity of at least a portion of a wavelength range from 570 nm to 590 nm among light emitted by the LED light source,   wherein a color of light transmitted through the filter is white as specified by Japanese Industrial Standard Z9112, and   wherein a maximum peak wavelength of mixed light before transmission through the filter, the mixed light being a mix of light emitted by the green/yellow phosphor and light emitted by the red phosphor, is in a wavelength range from 575 nm to 610 nm, and a full width at half maximum for the maximum peak wavelength is in a range of 120 nm to 180 nm.   
     
     
       4. An LED lamp comprising:
 an LED light source including a blue LED with a main emission peak in a wavelength band of 440 nm to 460 nm, a green/yellow phosphor that is excited by light emitted by the blue LED, and a red phosphor that is excited by light emitted by at least one of the blue LED and the green/yellow phosphor; and   a filter that reduces spectral radiation intensity of at least a portion of a wavelength range from 570 nm to 590 nm among light emitted by the LED light source,   wherein a color of light transmitted through the filter is natural light as specified by Japanese Industrial Standard Z9112, and   wherein a maximum peak wavelength of mixed light before transmission through the filter, the mixed light being a mix of light emitted by the green/yellow phosphor and light emitted by the red phosphor, is in a wavelength range from 525 nm to 610 nm, and a full width at half maximum for the maximum peak wavelength is in a range of 125 nm to 180 nm.   
     
     
       5. An LED lamp comprising:
 an LED light source including a blue LED with a main emission peak in a wavelength band of 440 nm to 460 nm, a green/yellow phosphor that is excited by light emitted by the blue LED, and a red phosphor that is excited by light emitted by at least one of the blue LED and the green/yellow phosphor; and 
 a filter that reduces spectral radiation intensity of at least a portion of a wavelength range from 570 nm to 590 nm among light emitted by the LED light source, 
 wherein a color of light transmitted through the filter is daylight as specified by Japanese Industrial Standard Z9112, and 
 wherein when a maximum peak wavelength of mixed light before transmission through the filter, the mixed light being a mix of light emitted by the green/yellow phosphor and light emitted by the red phosphor, is in a wavelength range from 520 nm to 530 nm, a full width at half maximum for the maximum peak wavelength is in a range of 135 nm to 170 nm, and when the maximum peak wavelength of light before transmission through the filter is in a wavelength range from 530 nm to 580 nm, the full width at half maximum for the maximum peak wavelength is in a range of 130 nm to 145 nm. 
 
     
     
       6. The LED lamp according to  claim 1 , wherein
 the filter includes a neodymium compound.   
     
     
       7. The LED lamp of  claim 6 , wherein
 the filter also serves as a globe covering the LED light source.   
     
     
       8. The LED lamp of  claim 6 , further comprising:
 a globe covering the LED light source, wherein   the filter covers one of an inner surface and an outer surface of the globe.   
     
     
       9. The LED lamp of  claim 6 , wherein
 the filter is shaped as a plate and is provided with a space between the LED light source and the filter.   
     
     
       10. The LED lamp of  claim 6 , wherein
 the filter is shaped as a plate, and a translucent material is included between the LED light source and the filter, and   a refractive index of the translucent material is lower than a refractive index of the filter and is equal to or higher than a refractive index of a phosphor layer including the green/yellow phosphor and the red phosphor in the LED light source.   
     
     
       11. The LED lamp according to  claim 6 , wherein
 the filter is made from a glass material.   
     
     
       12. The LED lamp according to  claim 6 , wherein
 the filter is made from a resin material.   
     
     
       13. The LED lamp of  claim 11 , wherein
 the filter that includes the neodymium compound has been manufactured by adding neodymium oxide to soda glass that includes silica, an alkali metal oxide, and an alkaline earth oxide.   
     
     
       14. The LED lamp of  claim 11 , wherein
 the filter that includes the neodymium compound has been manufactured by adding neodymium oxide powder to a silicon alkoxide that includes tetraethyl orthosilicate.   
     
     
       15. The LED lamp of  claim 6 , further including:
 translucent material having dispersed therein at least one of the green/yellow phosphor and the red phosphor, wherein   the filter is implemented by dispersing a neodymium compound in the translucent material.   
     
     
       16. The LED lamp of  claim 15 , wherein
 a sol-gel method has been used to manufacture the translucent material, so that the translucent material has mixed therein the green/yellow phosphor, the red phosphor, and the neodymium compound.   
     
     
       17. The LED lamp of  claim 1 , wherein
 a main emission peak of the green/yellow phosphor is in a wavelength band of 500 nm to 595 nm, and   a main emission peak of the red phosphor is in a wavelength band of 600 nm to 690 nm.   
     
     
       18. The LED lamp of  claim 17 , wherein
 a main emission peak of the red phosphor is at least 626 nm.   
     
     
       19. An LED illumination device provided with the LED lamp of  claim 1 . 
     
     
       20. An LED module comprising:
 a blue LED having a main emission peak in a wavelength band of 440 nm to 460 nm;   a green/yellow phosphor that is excited by light emitted by the blue LED;   a red phosphor that is excited by light emitted by at least one of the blue LED and the green/yellow phosphor; and   a filter that reduces spectral radiation intensity of at least a portion of a wavelength range from 570 nm to 590 nm among light emitted by the blue LED, the green/yellow phosphor, and the red phosphor, wherein   a color of light transmitted through the filter is light bulb color as specified by Japanese Industrial Standard Z9112, and   a maximum peak wavelength of mixed light before transmission through the filter, the mixed light being a mix of light emitted by the green/yellow phosphor and light emitted by the red phosphor, is in a wavelength range from 580 nm to 630 nm, and a full width at half maximum for the maximum peak wavelength is in a range of 120 nm to 175 nm.   
     
     
       21. An LED module comprising:
 a blue LED having a main emission peak in a wavelength band of 440 nm to 460 nm;   a green/yellow phosphor that is excited by light emitted by the blue LED;   a red phosphor that is excited by light emitted by at least one of the blue LED and the green/yellow phosphor; and   a filter that reduces spectral radiation intensity of at least a portion of a wavelength range from 570 nm to 590 nm among light emitted by the blue LED, the green/yellow phosphor, and the red phosphor, wherein   a color of light transmitted through the filter is warm white as specified by Japanese Industrial Standard Z9112, and   a maximum peak wavelength of mixed light before transmission through the filter, the mixed light being a mix of light emitted by the green/yellow phosphor and light emitted by the red phosphor, is in a wavelength range from 580 nm to 620 nm, and a full width at half maximum for the maximum peak wavelength is in a range of 120 nm to 175 nm.   
     
     
       22. An LED module comprising:
 a blue LED having a main emission peak in a wavelength band of 440 nm to 460 nm;   a green/yellow phosphor that is excited by light emitted by the blue LED;   a red phosphor that is excited by light emitted by at least one of the blue LED and the green/yellow phosphor; and   a filter that reduces spectral radiation intensity of at least a portion of a wavelength range from 570 nm to 590 nm among light emitted by the blue LED, the green/yellow phosphor, and the red phosphor, wherein   a color of light transmitted through the filter is white as specified by Japanese Industrial Standard Z9112, and   a maximum peak wavelength of mixed light before transmission through the filter, the mixed light being a mix of light emitted by the green/yellow phosphor and light emitted by the red phosphor, is in a wavelength range from 575 nm to 610 nm, and a full width at half maximum for the maximum peak wavelength is in a range of 120 nm to 180 nm.   
     
     
       23. An LED module comprising:
 a blue LED having a main emission peak in a wavelength band of 440 nm to 460 nm;   a green/yellow phosphor that is excited by light emitted by the blue LED;   a red phosphor that is excited by light emitted by at least one of the blue LED and the green/yellow phosphor; and   a filter that reduces spectral radiation intensity of at least a portion of a wavelength range from 570 nm to 590 nm among light emitted by the blue LED, the green/yellow phosphor, and the red phosphor, wherein   a color of light transmitted through the filter is natural light as specified by Japanese Industrial Standard Z9112, and   a maximum peak wavelength of mixed light before transmission through the filter, the mixed light being a mix of light emitted by the green/yellow phosphor and light emitted by the red phosphor, is in a wavelength range from 525 nm to 610 nm, and a full width at half maximum for the maximum peak wavelength is in a range of 125 nm to 180 nm.   
     
     
       24. An LED module comprising:
 a blue LED having a main emission peak in a wavelength band of 440 nm to 460 nm; 
 a green/yellow phosphor that is excited by light emitted by the blue LED; 
 a red phosphor that is excited by light emitted by at least one of the blue LED and the green/yellow phosphor; and 
 a filter that reduces spectral radiation intensity of at least a portion of a wavelength range from 570 nm to 590 nm among light emitted by the blue LED, the green/yellow phosphor, and the red phosphor, wherein 
 a color of light transmitted through the filter is daylight as specified by Japanese Industrial Standard Z9112, and 
 when a maximum peak wavelength of mixed light before transmission through the filter, the mixed light being a mix of light emitted by the green/yellow phosphor and light emitted by the red phosphor, is in a wavelength range from 520 nm to 530 nm, a full width at half maximum for the maximum peak wavelength is in a range of 135 nm to 170 nm, and when the maximum peak wavelength of light before transmission through the filter is in a wavelength range from 530 nm to 580 nm, the full width at half maximum for the maximum peak wavelength is in a range of 130 nm to 145 nm. 
 
     
     
       25. An LED lamp comprising:
 an LED light source including a blue LED with a main emission peak in a wavelength band of 440 nm to 460 nm, a green/yellow phosphor that is excited by light emitted by the blue LED, and a red phosphor that is excited by light emitted by at least one of the blue LED and the green/yellow phosphor; and   a filter that reduces spectral radiation intensity of at least a portion of a wavelength range from 570 nm to 590 nm among light emitted by the LED light source,   wherein when a maximum peak wavelength of mixed light before transmission through the filter, the mixed light being a mix of light emitted by the green/yellow phosphor and light emitted by the red phosphor, is in a wavelength range from 520 nm to 530 nm, a full width at half maximum for the maximum peak wavelength is in a range of 135 nm to 170 nm, and when the maximum peak wavelength of light before transmission through the filter is in a wavelength range from 530 nm to 580 nm, the full width at half maximum for the maximum peak wavelength is in a range of 130 nm to 145 nm.   
     
     
       26. The LED lamp according to claim 25, wherein a color transmitted through the filter has a color temperature between 5700 to 7100 degrees Kelvin. 
     
     
       27. The LED lamp according to claim 25, wherein a special color rendering index R9 of the LED lamp is 64 or greater. 
     
     
       28. The LED lamp according to claim 25, wherein the filter is configured as a globe covering the LED light source.