White light led light source with good color rendering effect

Abstract

The white light LED light source with good color rendering effect has the advantages that the red light emitted by the red fluorescent powder can increase the red light component in the white light, effectively improves the color rendering index (CRI) and special color rendering index (R9) of the white light, and the light source has good color rendering effect. Since the red fluorescent powder surrounds the yellow fluorescent powder, the red fluorescent powder can absorb the excessive blue light escaping from the yellow fluorescent powder area, and the red light emitted by the red fluorescent powder and radiating outward from the peripheral side will not be absorbed by the yellow fluorescent powder, so that the effective output of the red light can be ensured.

Description

Technical Field

[0001] This utility model relates to a white LED light source. Background Technology

[0002] White LED light sources consist of multiple blue LED chips and yellow phosphor coated on top of the chips. The phosphor absorbs some of the blue light emitted by the chips and emits yellow light, which mixes with the unabsorbed blue light to form white light. This type of white LED has a low red light component, resulting in a low color rendering index (CRI) and a low special rendering index (R9, representing the ability to render saturated red), leading to poor color rendering and making it unsuitable for applications with high color requirements, such as stage performances and photography. Utility Model Content

[0003] The technical problem to be solved by this invention is to provide a white LED light source with good color rendering effect.

[0004] To solve the above-mentioned technical problems, the present invention provides a white LED light source with good color rendering effect, including a blue LED chip coated with yellow phosphor. The yellow phosphor absorbs the blue light emitted by the chip and emits yellow light. The yellow light mixes with the unabsorbed blue light to form white light. The chip is also coated with red phosphor, which surrounds the yellow phosphor and absorbs the blue light emitted by the chip to emit red light.

[0005] Furthermore, a transparent cover plate is provided to cover the chip, and phosphor is coated on the transparent cover plate.

[0006] Furthermore, the transparent cover is attached to the chip.

[0007] Furthermore, including a substrate, there are multiple chips arranged side by side on the substrate; a transparent cover plate covers the multiple chips and extends towards the substrate with a filling portion that fills the gap between two adjacent chips and contacts these two adjacent chips.

[0008] Furthermore, there are multiple chips arranged in a circular pattern, with yellow phosphor applied to the center of the pattern and red phosphor applied to the circumference.

[0009] Furthermore, including a thermally conductive substrate, the chip is mounted on the front side of the thermally conductive substrate, and the thermally conductive substrate transfers the heat of the chip to the back side of the thermally conductive substrate.

[0010] Furthermore, the thermally conductive substrate includes an insulating thermally conductive layer near the front side and a metal thermally conductive layer near the back side. The chip is mounted on the insulating thermally conductive layer, which transfers the heat from the chip to the metal thermally conductive layer.

[0011] Furthermore, the surface of the heat-conducting substrate is horizontal, and a heat-spreading pipe for accommodating the phase change material is horizontally laid inside the metal heat-conducting layer.

[0012] The red light emitted by red phosphors increases the red light component in white light, effectively improving the color rendering index (CRI) and specific color rendering index (R9) of white light, resulting in excellent color rendering of the light source. Because the red phosphor surrounds the yellow phosphor, it absorbs excess blue light escaping from the yellow phosphor region, while the red light emitted outwards from the red phosphor is not absorbed by the yellow phosphor, thus ensuring effective red light output. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a white LED light source.

[0014] Figure 2 This is an exploded view of a white LED light source.

[0015] Figure 3 This is a cross-sectional view of a white LED light source.

[0016] Figure 4 yes Figure 3 A magnified view of a portion of the image, showing a larger area. Figure 3 Part A. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to specific embodiments.

[0018] White LED light source (see) Figure 2 The system includes a horizontal substrate 5, with its top surface 51 being the front side. Multiple flip-chip blue LEDs 1 are soldered onto this surface, arranged in a circular pattern 10. The substrate 5 has two circular transparent silicone rings 41 and 42, one inner and one outer. The inner silicone ring 41 is located between the center 101 and the circumference 102 of the circular pattern 10, while the outer silicone ring 42 is located on the outer periphery of the circumference 102 of the circular pattern 10. (See...) Figure 1 , Figure 2 A circular cover plate 43 made of transparent silicone is supported on the inner silicone ring 41. The circular cover plate 43 covers and fits the multiple chips 1 located at the center 101, and... Figure 4 As shown, a first filling portion 431 extends downwards and fills the gap between two adjacent chips 1, contacting these two adjacent chips 1. Inner and outer silicone rings 41 and 42 together support a circular cover plate 44 made of transparent silicone. The circular cover plate 44 covers and adheres to multiple chips 1 located at the circumferential portion 102, as shown... Figure 4 The second filling part 441 extends downward as shown and fills the gap between two adjacent chips 1, contacting the two adjacent chips 1. YAG:Ce yellow-green phosphor 3 is coated on the circular cover plate 43, and CASN:Eu red phosphor 4 is coated on the annular cover plate 44, with the red phosphor 4 surrounding the yellow-green phosphor 3.

[0019] See Figure 1 , Figure 2 When chip 1 is powered on, it emits blue light. The yellow-green phosphor 3 absorbs the blue light emitted by chip 1 at the center 101 and emits yellow light. The yellow light mixes with the unabsorbed blue light to form white light. The red phosphor 4 absorbs the blue light emitted by chip 1 at the circumference 102 and emits red light. This increases the red light component in the white light, effectively improving the color rendering index (CRI) and special color rendering index (R9) of the white light, resulting in good color rendering of the light source. Because the red phosphor 4 surrounds the yellow-green phosphor 3, it can absorb excess blue light escaping from the center region, while the red light emitted outwards from the red phosphor 4 is not absorbed by the yellow-green phosphor 3, ensuring effective red light output. Since the circular cover plate 43 is attached to chip 1 at the center region 101, it is in direct contact with chip 1, effectively dissipating the heat generated when chip 1 heats up; and because the first filling part 431 (see...) Figure 4 The first filling part 431 (see) is filled into the gap between two adjacent chips 1 to contact these two adjacent chips 1. Figure 4 This increases the contact area between the circular cover plate 43 and the chip 1, thereby effectively enhancing the heat conduction effect. Similarly, the annular cover plate 44 can effectively conduct the heat generated by the chip 1 when it heats up in the circumferential region 102. The second filling part 441 (see...) Figure 4 It can effectively enhance the heat conduction effect.

[0020] See Figure 3 and Figure 4 The substrate 5 is a thermally conductive substrate with two layers: the upper layer is an insulating thermally conductive layer 53 made of ceramic, with a copper circuit (not shown in the figure) on the top surface of the insulating thermally conductive layer 53, on which the chip 1 is soldered; the lower layer is a metal thermally conductive layer 54, with transverse heat spreaders 55 laid horizontally inside the metal thermally conductive layer 54. The heat spreaders 55 contain a phase change material 56, such as water or acetone. Part of the heat generated by the chip 1 emitting light is transferred vertically downward through the insulating thermally conductive layer 53 to the bottom surface of the metal thermally conductive layer 54 (i.e., the back surface 52 of the substrate 5). During this process, the phase change material 56 inside the heat spreaders 55 of the metal thermally conductive layer 54 absorbs heat and undergoes a phase change, thereby diffusing the heat laterally to the entire metal thermally conductive layer 54, achieving uniform heat dissipation and preventing local overheating.

[0021] See Figure 2 In this embodiment, chip 1 is an existing flip chip; in other embodiments, a conventional chip can be used instead. In this embodiment, the circular cover plate 43 and the annular cover plate 44 are made of transparent silicone; in other embodiments, other transparent materials can be used, such as plastic or glass. See also Figure 4In a non-preferred embodiment, the cover plates 43 and 44 are not attached to the chip 1 and / or the filling portions 431 and 441 are omitted, which results in a slightly weaker heat conduction effect of the cover plates 43 and 44.

[0022] The above description is merely an embodiment of the present invention and does not limit the scope of patent protection. Any non-substantial changes or substitutions made by those skilled in the art based on the present invention will still fall within the scope of patent protection.

Claims

1. A white LED light source with good color rendering effect, comprising a blue LED chip, wherein a yellow phosphor is coated on the chip, the yellow phosphor absorbs the blue light emitted by the chip and emits yellow light, and the yellow light mixes with the unabsorbed blue light to form white light, characterized in that: The chip is also coated with red phosphor, which surrounds the yellow phosphor. After absorbing the blue light emitted by the chip, the red phosphor emits red light.

2. The white LED light source according to claim 1, characterized in that: A transparent cover plate is provided to cover the chip, and phosphor is coated on the transparent cover plate.

3. The white LED light source according to claim 2, characterized in that: The transparent cover is attached to the chip.

4. The white LED light source according to claim 3, characterized in that: The device includes a substrate, multiple chips arranged side by side on the substrate, a transparent cover plate covering the multiple chips, and a filling portion extending towards the substrate to fill the gap between two adjacent chips and contact the two adjacent chips.

5. The white LED light source according to claim 1, characterized in that: There are multiple chips arranged in a circular pattern. Yellow phosphor is applied to the center of the pattern, and red phosphor is applied to the circumference.

6. The white LED light source according to claim 1, characterized in that: It includes a thermally conductive substrate, with the chip mounted on the front side of the thermally conductive substrate, and the thermally conductive substrate transfers the heat from the chip to the back side of the thermally conductive substrate.

7. The white LED light source according to claim 6, characterized in that: The thermally conductive substrate includes an insulating thermally conductive layer near the front and a metal thermally conductive layer near the back. The chip is mounted on the insulating thermally conductive layer, which transfers the heat from the chip to the metal thermally conductive layer.

8. The white LED light source according to claim 7, characterized in that: The surface of the heat-conducting substrate is horizontal, and a heat-spreading pipe for accommodating the phase change material is laid horizontally inside the metal heat-conducting layer.

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