Unlock instant, AI-driven research and patent intelligence for your innovation.

Light emitting diode (LED) lamp with high color rendering index

A blue light and violet light technology, applied in electrical components, electrical solid devices, circuits, etc., can solve problems such as color instability, and achieve the effect of low cost and good CRI

Inactive Publication Date: 2015-03-11
郑榕彬
View PDF7 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Variations in LED operating temperature make the color emitted from the LED unstable
Also, the blue and red LEDs do not change color at the same rate, which makes the colors emitted from both sets of LEDs less stable

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Light emitting diode (LED) lamp with high color rendering index
  • Light emitting diode (LED) lamp with high color rendering index
  • Light emitting diode (LED) lamp with high color rendering index

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0011] The present invention describes a cost-effective method of producing a white light source with a high color rendering index. The present invention relates to a method of manufacturing a white light source by using only blue LEDs. Violet light (wavelength 380nm-420nm) can be obtained by coating a layer of red phosphor on top of a blue LED. The blue LED excites the red phosphor to produce violet light with a wavelength of 380nm-420nm. The emitted violet light is further excited by a light emitter (fluorescent and / or phosphorescent solid material) so that the radiation from the violet light is down-converted by the light emitter to produce white light. The resulting white light has a high CRI and has a wavelength from 500nm to 650nm.

[0012] Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. see figure 1 , which shows a cross-sectional view of an embodiment of an LED lamp according to the present inventi...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to a light emitting diode (LED) lamp with high color rendering index. In manufacture of LED bulbs, a method can help acquire higher color rendering index (CRI), which is generally greater than 80. According to the method, a group of white LED and one or more red LED are adopted, and the red LED provides higher R9 value, so that higher CRI can be acquired. The color of the red LED drifts according to the temperature of a working environment. Some LED bulb manufactures make extra electronic driven circuits to control the red LED, so that the LED lamp has more complicated electronic circuit and has no cost effectiveness. The LED lamp only uses blue LED and is topped with a layer of red phosphorescent powder, which is used for converting the light output by the blue LED into purple spectrum, and then the purple light passes through a transmission optical phosphorescent membrane to change the wavelength into white light. Through adoption of the method, low-cost LED bulbs with high CRI can be obtained without using the red LED.

Description

Background technique [0001] Nichia Corporation of Japan developed blue LED chips in 1996. The chip emits blue light and excites the phosphor to emit bluish yellow light. This development opened the era of white LEDs. However, white light produced from blue and yellow light does not have any red spectrum, therefore, the produced light has a low color rendering index (CRI), and such light is not a preferred light source for everyday use. White light contains several colors. White light can only be formed from the mixture of two or more colors. Many LED bulbs provide bluish light, which is common in the lighting industry. To achieve a higher CRI, quite a few LED bulbs now consist of one or more red LED chips and a set of white LEDs. Red LEDs emit red light with a wavelength of 600nm-630nm. This introduces a higher R9 value and, therefore, a higher CRI can be obtained. Although a higher CRI can be achieved, the color shift of the LED chip at high temperature is quite signif...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): H01L33/48H01L33/62H01L33/50
CPCH01L25/0753H01L33/504
Inventor 郑榕彬
Owner 郑榕彬