A full spectrum LED lamp bead

Abstract

The present invention discloses a full-spectrum LED lamp bead, including a light-emitting chip, a bracket for placing the light-emitting chip, and a fluorescent glue for encapsulating the light-emitting chip and allowing the light emitted by the light-emitting chip to pass through and emit; the light-emitting chip includes a blue light chip and a purple light chip, the wavelength of the blue light chip is 440nm-470nm, and the wavelength of the purple light chip is 400nm-420nm; the fluorescent glue is composed of silica gel or epoxy resin glue mixed with fluorescent powder, and the fluorescent powder includes red fluorescent powder, yellow-green fluorescent powder and blue fluorescent powder, the excitation wavelength of the red fluorescent powder is 615nm-660nm, the excitation wavelength of the yellow-green fluorescent powder is 520nm-540nm, and the excitation wavelength of the blue fluorescent powder is 445nm-455nm. The present invention has the advantages of low energy consumption, high color rendering index, high brightness, more beneficial to human health and environment, and closer to sunlight.

Description

Technical Field

[0001] The invention belongs to the technical field of LED lighting, and in particular relates to a full-spectrum LED lamp bead. Background Art

[0002] LED (Lighting emitting diode) lighting technology has been welcomed for its high luminous efficiency, good impact and vibration resistance, high reliability, long life, and easy adjustment, and has become a widely used lighting technology. However, conventional LED light sources are point light sources with narrow spectrums, and their peak wavelengths are between 450 and 460nm, which is very different from the sunlight spectrum. The special structure of the human eye and the long-term living environment of humans determine that the human eye has the highest perception when reading and observing sunlight. In order to make the human eye feel comfortable in a certain lighting environment, it is necessary to make its luminous spectrum close to the sunlight spectrum.

[0003] At present, white light LED mainly uses "blue light technology" and phosphor to form white light. There are two ways to achieve this. The first method is to coat a layer of yellow phosphor excited by blue light on the blue light LED chip. The blue light emitted by the chip and the yellow light emitted by the phosphor complement each other to form white light. A fundamental disadvantage of this scheme is that the emission spectrum of Ce3+ ions in the phosphor does not have continuous spectrum characteristics, and the color rendering is poor. Generally, the color rendering index is about 65-75, which is difficult to meet the requirements of low-color lighting; the second method is to coat green and red phosphors on the blue light LED chip, and the blue light emitted by the chip is combined with the green and red light emitted by the phosphor to obtain white light. The color rendering index is generally about 75-85, which is higher than the above products. The spectra of these two methods are not much different, and they have the advantages of simple process and low cost. However, the white light LED prepared by them has low color rendering index and low light quality, and the luminous efficiency decreases and energy consumption is high when the driving current density is increased to increase the luminous intensity. With the demand for high-quality lighting, this method is obviously not recognized by everyone.

[0004] In recent years, the method of preparing white light LEDs by exciting RGB phosphors with purple light chips has received extensive attention and research. The white light LEDs prepared in this way have the advantages of high color rendering index, good color reproduction, and stable and reliable products. The RGB phosphors currently used are mainly Y2O3S:Eu2+, BaMgAlltlO17:Eu2+, ZnS:Cu+, Al3+, etc., but the blue powder systems used are mainly phosphates, silicates, and halosilicates. The prepared blue phosphors have the disadvantages of poor matching with purple light chips and low luminous intensity. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a full-spectrum LED lamp bead with low energy consumption, high color rendering index, high brightness, more beneficial to human health and the environment, and closer to sunlight.

[0006] In order to solve the above technical problems, the present invention provides a full-spectrum LED lamp bead, which includes a light-emitting chip, a bracket for placing the light-emitting chip, and a fluorescent glue for encapsulating the light-emitting chip and allowing the light emitted by the light-emitting chip to pass through and emit;

[0007] The light emitting chip includes a blue light chip and a purple light chip, the wavelength of the blue light chip is 440nm-470nm, and the wavelength of the purple light chip is 400nm-420nm;

[0008] The fluorescent glue is composed of silica gel or epoxy resin glue mixed with fluorescent powder, and the fluorescent powder includes red fluorescent powder, yellow-green fluorescent powder and blue fluorescent powder. The excitation band of the red fluorescent powder is 615nm~660nm, the excitation band of the yellow-green fluorescent powder is 520nm~540nm, and the excitation band of the blue fluorescent powder is 445nm~455nm.

[0009] As a preferred solution of the present invention, the wavelength band of the ultraviolet chip is 400nm to 410nm.

[0010] As a preferred solution of the present invention, the wavelength band of the ultraviolet chip is 410nm to 420nm.

[0011] As a preferred solution of the present invention, the fluorescent glue has a double-layer structure, and the fluorescent glue is provided with a first fluorescent glue layer and a second fluorescent glue layer from the inside to the outside, the first fluorescent glue layer is mixed with red fluorescent powder, and the second fluorescent glue layer is mixed with yellow-green fluorescent powder and blue fluorescent powder, and the particle size of the red fluorescent powder is larger than the particle size of the yellow-green fluorescent powder and the blue fluorescent powder.

[0012] As a preferred solution of the present invention, the fluorescent glue is formed by two glue pouring processes.

[0013] As a preferred solution of the present invention, the red phosphor is deposited on the bottom of the first phosphor glue layer.

[0014] As a preferred solution of the present invention, the yellow-green phosphor and the blue phosphor are deposited on the bottom of the second phosphor glue layer.

[0015] As a preferred solution of the present invention, the light emitting chip is a flip-chip or a face-up chip.

[0016] Compared with the prior art, the full-spectrum LED lamp beads provided by the present invention have the following beneficial effects:

[0017] (1) The present invention uses a combination of a blue light chip and a purple light chip with specific wavelengths, such as a blue light chip with a wavelength of 440nm to 470nm and a purple light chip with a wavelength of 400nm to 420nm, so that the blue light and the purple light are excited by a fluorescent glue mixed with red phosphor, yellow-green phosphor and blue phosphor to obtain white light that is closer to the full spectrum of sunlight, has rich spectral components, and a color rendering index of 98 to 100.

[0018] (2) The present invention uses the purple light chip as part of the excitation light source, which can reduce the phenomenon of luminescence rate decrease caused by increasing the driving current density when the blue light chip is used alone as the excitation light source to increase the luminescence intensity, thereby reducing energy consumption;

[0019] (3) Since the chip is equipped with a purple light chip of a specific wavelength, it can appropriately supplement ultraviolet rays indoors, allowing the human body to produce more vitamin D, which can reduce the incidence of colds by 30%. It can also improve visual sensitivity, help people distinguish true colors, and reduce visual fatigue;

[0020] (4) The fluorescent glue of the present invention adopts a double-layer structure, so that blue light and purple light are refracted through the first fluorescent glue layer mixed with red fluorescent powder with larger particle size and the second fluorescent glue layer mixed with yellow, green and blue fluorescent powder with smaller particle size, which can reduce the influence between fluorescent powders of different particle sizes and different colors, and solve the problem of fluorescent powder uniformity; and, because the particle size of red fluorescent powder is larger and the contact area with the chip is smaller, less blue light and purple light are refracted, more blue light and purple light are transmitted, and less red light is converted, thus ensuring that the first fluorescent glue layer can transmit blue light and purple light to the second fluorescent glue layer with a larger luminous flux, reducing light decay, improving light efficiency, high brightness and low cost.

[0021] (5) The present invention deposits red phosphor at the bottom of the first phosphor glue layer and deposits yellow-green phosphor and blue phosphor at the bottom of the second phosphor glue layer, which can reduce the influence of factors such as scattering and absorption of the phosphor and further improve light efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of a full-spectrum LED lamp bead provided by the present invention.

[0023] In the figure: 1. light-emitting chip, 11. blue light chip, 12. purple light chip, 2. bracket, 3. fluorescent glue, 31. first fluorescent glue layer, 32. second fluorescent glue layer. DETAILED DESCRIPTION

[0024] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0025] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like used in the present invention to indicate the orientation or position relationship is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0026] In the description of the present invention, it should be understood that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" used in the present invention should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] like Figure 1 As shown, a preferred embodiment of the present invention is a full-spectrum LED lamp bead, which includes a light-emitting chip 1, a bracket 2 for placing the light-emitting chip 1, and a fluorescent glue 3 for encapsulating the light-emitting chip 1 and allowing the light emitted by the light-emitting chip 1 to pass through and emit;

[0028] The light emitting chip 1 comprises a blue light chip 11 and a purple light chip 12, the wavelength of the blue light chip 11 is 440nm-470nm, and the wavelength of the purple light chip 12 is 400nm-420nm;

[0029] The fluorescent glue 3 is composed of silica gel or epoxy resin glue mixed with fluorescent powder, and the fluorescent powder includes red fluorescent powder, yellow-green fluorescent powder and blue fluorescent powder. The excitation band of the red fluorescent powder is 615nm~660nm, the excitation band of the yellow-green fluorescent powder is 520nm~540nm, and the excitation band of the blue fluorescent powder is 445nm~455nm.

[0030] Next, taking two groups of purple light chips 12 and blue light chips 11 of different wavelength bands as excitation light sources and one group of purple light chips 12 alone as excitation light sources as examples, a comparative test was conducted under the same other conditions, and the following results were obtained:

[0031] Table 1

[0032]

[0033] It can be seen from Table 1 above that the luminous flux Φ and luminous efficiency η of Test 1 and Test 2 are better than those of Test 3; while in Test 3, although the purple light chip 12 is used alone as the excitation light source, the luminous flux Φ and luminous efficiency η still have certain defects, as they can ensure that the color rendering index Ra reaches above 98.

[0034] It can be seen that the present invention matches the blue light chip 11 and the purple light chip 12 in specific bands, such as: the blue light chip 11 with a band of 440nm to 470nm is matched with the purple light chip 12 with a band of 400nm to 420nm, so that the blue light and the purple light are jointly excited by the fluorescent glue 3 mixed with red phosphor, yellow-green phosphor and blue phosphor to obtain white light that is closer to the full spectrum of sunlight, has rich spectral components, and a color rendering index of 98 to 100; and, using the purple light chip 12 as a part of the excitation light source can reduce the phenomenon of decreased luminous efficiency caused by increasing the driving current density when the blue light chip 11 is used alone as an excitation light source to increase the luminous intensity, thereby reducing energy consumption; in addition, since the chip is matched with the purple light chip 12 with a specific band, it can appropriately supplement ultraviolet rays indoors, produce more vitamin D in the human body, reduce the incidence of colds by 30%, and improve visual sensitivity, which is beneficial for people to distinguish true colors and reduce visual fatigue.

[0035] For example, in order to obtain a better color rendering index Ra, the wavelength band of the ultraviolet chip 12 is preferably 400nm to 410nm, as shown in Table 1 above.

[0036] Exemplarily, in order to obtain better luminous flux Φ and luminous efficiency η, the wavelength band of the purple light chip 12 is preferably 410nm to 420nm, see Table 1 above.

[0037] Exemplarily, the fluorescent glue 3 has a double-layer structure and is formed by two glue filling processes. The fluorescent glue 3 is provided with a first fluorescent glue layer 31 and a second fluorescent glue layer 32 from the inside to the outside. The first fluorescent glue layer 31 is mixed with red phosphor, and the second fluorescent glue layer 32 is mixed with yellow-green phosphor and blue phosphor. The particle size of the red phosphor is larger than that of the yellow-green phosphor and the blue phosphor. Therefore, the fluorescent glue 3 of this embodiment adopts a double-layer structure, so that the blue light and the purple light are refracted through the first fluorescent glue layer 31 mixed with the red fluorescent powder with larger particle size and the second fluorescent glue layer 32 mixed with the yellow, green and blue fluorescent powder with smaller particle size, which can reduce the influence between the fluorescent powders of different particle sizes and different colors, and solve the problem of uniformity of the fluorescent powder; and because the particle size of the red fluorescent powder is larger and the contact area with the chip is smaller, the refracted blue light and purple light are less, the transmitted blue light and purple light are more, and the converted red light is less, so it is ensured that the first fluorescent glue layer 31 can transmit the blue light and purple light to the second fluorescent glue layer 32 with a larger luminous flux, reduce light decay, improve light efficiency, high brightness and low cost.

[0038] It should also be noted that another reason for using mixed red phosphor as the first phosphor glue layer 31 is that in the existing phosphor ratio, the amount of red phosphor is relatively small, and the absorption of blue light is relatively small, so that the yellow-green phosphor in the second phosphor glue layer 32 can better stimulate the efficiency of the blue light chip.

[0039] Exemplarily, the red phosphor is deposited at the bottom of the first phosphor glue layer 31, and the yellow-green phosphor and the blue phosphor are deposited at the bottom of the second phosphor glue layer 32. Such a design can reduce the influence of factors such as scattering and absorption of the phosphors, and further improve light efficiency.

[0040] Exemplarily, the light emitting chip 1 is a flip-chip or a face-up chip.

[0041] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A full-spectrum LED lamp bead, characterized in that: It comprises a light-emitting chip, a bracket for placing the light-emitting chip, and a fluorescent glue for encapsulating the light-emitting chip and allowing the light emitted by the light-emitting chip to pass through and emit; The light emitting chip includes a blue light chip and a purple light chip, the wavelength of the blue light chip is 440nm-470nm, and the wavelength of the purple light chip is 400nm-410nm; The fluorescent glue is composed of silica gel or epoxy resin glue mixed with fluorescent powder, and the fluorescent powder includes red fluorescent powder, yellow-green fluorescent powder and blue fluorescent powder. The excitation band of the red fluorescent powder is 615nm-660nm, the excitation band of the yellow-green fluorescent powder is 520nm-540nm, and the excitation band of the blue fluorescent powder is 445nm-455nm. The fluorescent glue has a double-layer structure, and is provided with a first fluorescent glue layer and a second fluorescent glue layer from the inside to the outside. The first fluorescent glue layer is mixed with red fluorescent powder, and the second fluorescent glue layer is mixed with yellow-green fluorescent powder and blue fluorescent powder. The particle size of the red fluorescent powder is larger than the particle size of the yellow-green fluorescent powder and the blue fluorescent powder; the fluorescent glue is formed by two glue filling processes; the red fluorescent powder is deposited at the bottom of the first fluorescent glue layer; the yellow-green fluorescent powder and the blue fluorescent powder are deposited at the bottom of the second fluorescent glue layer.

2. A full-spectrum LED lamp bead as claimed in claim 1, characterized in that: The yellow-green phosphor and the blue phosphor are deposited on the bottom of the second phosphor glue layer.

3. A full-spectrum LED lamp bead as claimed in claim 1, characterized in that: The light emitting chip is a flip chip or a face-up chip.

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