RU2513645C2 - Light-emitting diode device - Google Patents

Abstract

FIELD: physics, optics.

SUBSTANCE: invention pertains to optical instrument-making. The LED device according to the invention includes one or more emitter chips arranged arbitrarily on a single flat substrate and coated with a common layer of a compound gel, optionally with phosphor crystals, and a plate made of optical material placed on the flat surface of the gel without an air space. On the inner side of the plate bordering with the gel, there are mutually perpendicular grooves whose faces are inclined to the surface of the gel at an angle α=55°…65°, and the depth of the grooves is not more than h=0.8 mm. The vertices of the grooves form squares, the length of the sides of which is D=(1.75…2.3)D_c, where D_c is the size of the side of the chip, wherein D=D₀, where D₀ is the distance between optical axes of the emitter chips, wherein optical axes of the squares of the incision and corresponding chips coincide.

EFFECT: invention improves energy parameters of the device, specifically considerable increase in axial luminous intensity and low energy losses owing to increase in the radiation capturing angle of the chip to σ₁=±75°.

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Description

The invention relates to the field of optical instrumentation, and in particular to the class of powerful Chip-on-board LEDs, which are used as analogues of halogen lamps, as well as for ceiling, industrial, facade and other lamps.

The use of crystals that emit light in various colors of the optical range makes it possible to obtain LED devices with a wide variety of colors and shades of the light flux. The main advantage of these devices is their great energy efficiency and long, almost unlimited, service life compared to conventional halogen lamps.

The most important energy parameters of the LED device are the axial light intensity and the indicatrix of the distribution of light flux over the angle of divergence of the light radiation at the output of the device.

Known industrial designs of SOW company Optogan [1], the design of which is given in [2]. They are an array of one or more LED chips mounted on a single flat substrate according to different topography and coated with a common layer of a compound gel with phosphor crystals, and the outer surface of the gel in contact with air is flat. By technical nature, these devices are closest to the proposed LED device and are a prototype.

This design of the system does not allow to obtain high energy parameters, since the used angle of direct radiation of the crystal does not exceed ± 40 °, while direct radiation of the crystal propagates at angles of ± 90 °, which corresponds to the indicatrix of crystal radiation shown in Figure 1. This leads to a loss of energy of at least 25%, which is the main disadvantage of the prototype.

The aim of the invention is to increase the energy parameters of LED devices such as SOW, namely, a significant increase in the axial intensity of light when using direct radiation of the chip chip with a radiation coverage angle of at least ± 75 °.

This goal is achieved by the fact that the LED device consists of one or more emitter-chips installed on any topography on a single flat substrate and coated with a common layer of compound gel, possibly with phosphor crystals, and on the flat surface of the gel a plate of optical material, on the inner side of which, adjacent to the gel, mutually perpendicular grooves are cut, the edges of which are inclined to the surface of the gel by an angle α = 55 ° ... 65 °, the depth of groove cutting is not more than h = 0,8 m. The vertices of the grooves form squares whose sides are D = (1.75 ... 2.3) D _c , where D _c is the size of the side of the chip, and D = D ₀ , where D ₀ is the distance between the optical axes of the emitter-chips, while the optical axis of the squared slices and the corresponding chips coincide.

Figure 2 presents as an example a schematic diagram of the proposed LED device. It consists of emitter-chips (1) placed on a flat substrate (2) and coated with a common layer of compound gel (3), with a flat surface at the gel-air interface. A plate (4) of optical material is mounted on the surface of the gel without an air gap. Mutually perpendicular grooves (5) are cut on the inner side of the plate, the edges of which are inclined to the gel surface by an angle α = 55 ° ... 65 °, and the depth of groove cutting is not more than h = 0.8 mm. The vertices of the grooves form squares whose sides are D = (1.75 ... 2.3) D _c , where D _c is the size of the side of the chip, with D = D ₀ , where D ₀ is the distance between the optical axes of the emitter-chips, at The optical axis of the slicing squares and the corresponding chips coincide.

The specific design of the LED device corresponding to the above description of the present invention was developed on the basis of SOW, chips (1) of which thickness t = 0.15 mm have the shape of a square with a side size D _c = 1.15 mm, while the chips are located on the substrate ( 2) with a distance between the optical axes of adjacent chips D ₀ = 2.5 mm. 9 chips are placed on a substrate with a size of 10 × 10 mm and filled with a gel compound (3), and the distance from the chip emitting surface to the gel-air flat surface is d = 0.35 mm. The refractive index of the compound gel n ₁ = 1.54. A plate (4) made of an optical material, polymethylmethacrylate (PMMA), the refractive index of which is n ₂ = 1.49, is installed on the flat surface of the gel without an air gap.

Mutually perpendicular grooves (5) are cut on the inner side of the plate, the edges of which are inclined to the gel surface by an angle α = 60 °, and the cutting depth h = 0.8 mm, with a total plate thickness of 1.5 mm. The vertices of the grooves form squares whose sides are equal to D = 2.5 mm, which corresponds to a ratio of D = 2.17 D _c and is equal to the value of D ₀ . The optical axis of the squared slices and the corresponding chips coincide.

This design provides the use of the angle of coverage of radiation of the chip crystals:

- direct radiation through the gel and the plate within σ ₁ = ± 42 °;

- radiation through the gel, reflected according to the law of total internal reflection from the faces in the PMMA medium, within σ ₁ = ± (42 ° ... 75 °).

Thus, the total angle of radiation coverage of the chip of the chip for this LED device is Σσ ₁ = ± 75 °, due to which the value of the used radiation energy of the chip is ΣЕ = ~ 90% E ₀ , where E ₀ is the radiation energy of the chip, i.e. energy loss reduced to 10%.

The positive effect of the proposed design of the LED device is that it provides an increase in energy parameters at the output of the system through the use of a significantly increased angle of coverage of the radiation of the chip within σ ₁ = ± 75 ° (against σ ₁ = ± 40 ° in the prototype), and due to this, a decrease in energy loss to ~ 10% (versus ~ 25% in the prototype).

Information sources

[1] Electronic document. “Powerful LEDs” “Chip-on-board” http://www.optogan.ru/products/leds/chip-on-board.

[2] Article. E. Mukhina, P. Blashto. "CHIP-on-BoARD Technology: Key Processes and Equipment." Electronics. The science. Technology. Business, 2008, No. 3, 2008, pp. 54-58.

Claims (1)

An LED device consisting of one or more emitter-chips placed on any topography on a single flat substrate and coated with a common layer of compound gel, possibly with phosphor crystals, characterized in that a plate of optical material is installed on the flat surface of the gel without an air gap, On the inner side of which, adjacent to the gel, mutually perpendicular grooves are cut, the edges of which are inclined to the surface of the gel by an angle α = 55 ° ... 65 °, the depth of grooving is not more than h = 0.8 mm, and the vertices squares are formed on the side, whose sides are D = (1.75 ... 2.3) D _c , where D _c is the size of the side of the chip, and D = D ₀ , where D ₀ is the distance between the optical axes of the emitter-chips, while the axis of the squared slices and the corresponding chips coincide.

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