CN212408306U - Universal LED standard light source for 2 pi method integrating sphere test - Google Patents

Abstract

The utility model belongs to the technical field of the semiconductor illumination, specifically be a general LED standard light source that is used for 2 pi method integrating sphere to test. The LED light source module is of an integrated packaging COB structure and comprises a multi-primary-color LED chip and fluorescent powder, wherein the fluorescent powder is packaged on the LED chip, and the primary colors of the LED light source module comprise an ultraviolet band, a purple light band, a blue light band, a cyan light band, a green light band, a yellow light band, an orange light band and a red light band; the LED light source module is detachably provided with a lens. The utility model discloses a standard light source can avoid different wavelength SNR differences, surveyed lamp and standard light source's light type difference and the measuring error who arouses, improves measurement accuracy.

Description

Universal LED standard light source for 2 pi method integrating sphere test

Technical Field

The utility model belongs to the technical field of the semiconductor illumination, concretely relates to general LED standard light source that is used for 2 pi method integrating sphere to test.

Background

The early integrating sphere is used for testing an incandescent lamp and a halogen tungsten lamp, and a standard light source configured by the early integrating sphere is also the incandescent lamp or the halogen tungsten lamp, so that the types are matched, and the testing error is small. Light sources are now evolving from incandescent and tungsten halogen lamps to LED lamps, but the standard lamp of the test system configuration is still tungsten halogen. These two light sources have a large difference in spectrum, which causes measurement errors. The radiation of the standard light source of the halogen tungsten lamp in the blue and violet light wave band is weak, the signal-to-noise ratio is not high enough, and the measurement precision is influenced. Most commercial white light LED light sources are formed by mixing a blue light chip and yellow light fluorescent powder. Therefore, the standard light source of the halogen tungsten lamp is used for measuring the LED light source, and a larger measurement error exists. And the common LED is used as a standard light source, different standard light sources are required to be adopted for different types of tested lamps, and the use is inconvenient.

Chinese patent CN 111076149 a proposes a full spectrum LED light source, which is formed by arranging two or more lamp beads with different spectra after giving different currents to obtain a final full spectrum, and the light uniformity obtained by this method is poor and the spectral energy is not uniform. Chinese patent CN 210241466U proposes a full spectrum LED light source and an LED lamp containing the light source, and the patent adds a far-red chip and mixed fluorescent powder on the basis of a common LED to obtain a sunlight spectrum close to the same color temperature. However, the spectrum appears jagged in the range of 400nm to 500nm, and the curve is not smooth. Chinese patent CN 106764691 a proposes a solar spectrum and blackbody radiation spectrum simulation system based on quantum dot LED, which achieves specified color temperature by fitting 21 monochromatic lights, but aims to fit blackbody spectrum without solving the problem of difference of signal-to-noise ratios of different wavebands.

There are 2 test methods for integrating sphere: the 4 pi method and the 2 pi method. Generally, the 4 pi method is applied to non-directional lamps, and if the 4 pi method is applied to directional lamps, the test error is large due to insufficient diffuse reflection and the like. In addition, the 4 pi test method cannot be used for LED modules with large radiators or complex accessories with temperature control and the like, and the LED modules cannot be installed in the integrating sphere. For both cases, the 2 pi law using integrating sphere wall openings is a more desirable choice.

However, the 2 pi method test requires that the light distribution of the standard light source is consistent with that of the light source to be tested, and when the difference between the light emitting angle of the standard light source and the light distribution of the light source to be tested is large, the test brings errors, so that no standard lamp specially aiming at the 2 pi method test exists at present.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing an send uniform spectral radiant intensity's isoenergetic white light source can be used as the general LED standard light source of 2 pi method integrating sphere test. The light source can well solve the problem that the signal-to-noise ratio of the halogen tungsten lamp and the common LED is low in the respective weak signal wave bands, can avoid measurement errors caused by the difference of the signal-to-noise ratios of different wavelengths and the difference of the light types of the measured lamp and the standard light source, and improves the measurement precision.

The technical scheme of the utility model specifically introduces as follows.

A universal LED standard light source for 2 pi method integrating sphere test comprises an LED light source module and a lens, wherein the LED light source module is of an integrated packaging COB structure, the LED light source module comprises a multi-primary-color LED chip and fluorescent powder, the fluorescent powder is packaged on the LED chip, and the primary colors of the LED light source module comprise an ultraviolet band, a purple band, a blue band, a cyan band, a green band, a yellow band, an orange band and a red band; the LED light source module is detachably provided with a lens.

The utility model discloses in, lens pass through the screw and install on LED light source module.

In the present invention, the lens is a wide beam lens, a narrow beam lens or a batwing beam lens.

In the utility model, the types of the fluorescent powder are more than 4.

The utility model also comprises an LED radiator, a bracket and a temperature measuring element; the LED light source module is arranged above the bracket, and the temperature measuring element is pre-embedded on the bracket and used for testing the temperature of the back surface of the LED light source module; the LED radiator is connected with the LED light source module; when the LED lamp is used, the LED light source module is arranged on the inner wall of the integrating sphere through the support, and the LED radiator is arranged outside the integrating sphere.

In the utility model, a plurality of radiating fins are distributed at the back of the LED radiator; and a fan is arranged on the LED radiator.

In the utility model, the temperature measuring element is a thermocouple.

Compared with the prior art, the beneficial effects of the utility model reside in that:

the utility model discloses a LED chip and the synthetic isoenergetic white light spectrum of phosphor powder of multiple base colour, relative spectral radiant intensity in the effective band within range of target is unanimous, the white light standard light source of normalized synthetic isoenergetic is less than 0.6 with the least square deviation value of theoretical isoenergetic white light spectrum in the effective band within range of target, the least square deviation value is decided by monochromatic peak wavelength and half width, the half width is wider, the least square deviation value is smaller, because the half width of phosphor powder is big, therefore the quantity of phosphor powder is many better; the utility model discloses effectively solved the low problem of blue light wave band SNR of traditional halogen tungsten standard lamp, be applicable to and contain the light source luminous flux test of 380 + 780nm visible light wave band various spectrums within range at least.

The utility model discloses lens can dismantle the change, and standard light source is through carrying on different grading lens for the grading curve is adjustable, has solved the test deviation that is surveyed inconsistent production of light source and standard light source grading curve, and as general standard light source, the integrating sphere that can realize the directional lamp tests.

Drawings

FIG. 1 is a spectrum of a 26-color mixture of synthesized isoenergetic white light in example 1.

FIG. 2 shows a structure of a 2 π integrating sphere standard light source in example 1.

Fig. 3 shows a light distribution curve of a wide beam lens.

Fig. 4 shows a light distribution curve of a narrow beam lens.

FIG. 5 is a batwing beam lens light distribution curve.

FIG. 6 is a spectrum of 14 colors of white light of synthetic equipotency obtained by mixing in example 2.

FIG. 7 is a spectrum of a synthesized isoenergetic white light obtained by mixing 10 colors in example 3.

Reference numbers in the figures: the LED lamp comprises a light source module 1, a lens 2, a support 3, an LED radiator 4, a fan 5 and a thermocouple 6.

Detailed Description

The embodiments described below are only some of the embodiments of the present invention. All other embodiments that do not produce inventive results based on the embodiments of the present invention belong to the protection scope of the present invention.

Example 1

A universal LED standard light source for a 2 pi method integrating sphere test comprises an LED light source module; the LED light source module comprises 26 primary colors of 14 LED chips and 12 fluorescent powders. The parameters of the spectra of the various primary colors are shown in table 1.

Table 126 color synthesis of the primary color parameters of the isoenergetic white light spectrum

Wherein 375nm, 380nm, 385nm, 395nm, 400nm, 405nm, 420nm, 680nm, 700nm, 720nm, 740nm, 760nm, 780nm and 800nm are chips, and 440nm, 460nm, 480nm, 500nm, 520nm, 540nm, 560nm, 580nm, 600nm, 620nm, 640nm and 660nm are phosphors. The synthesis ratios of the primary colors calculated by the least square method are shown in table 1, and the synthesized isoenergetic white light spectrum is shown in fig. 1, and the least square deviation value of the synthesized spectrum and the theoretical isoenergetic white light spectrum in the range of 380-780nm is 0.05.

The least squares deviation value is the sum of the squares of the residuals. For n repeated measurements (x)₁,x₂,…,x_n) Best estimate of

The least square deviation value

As shown in fig. 2, the structure of the standard light source for the 2 pi integrating sphere method test further includes a lens 2, a support 3, an LED heat sink 4, a fan 5 and a thermocouple 6 in addition to the LED light source module 1. The LED light source module 1 is of an integrated packaging (COB) structure, chips are uniformly distributed, and light is uniformly emitted; the lens 2 is installed on the COB light source by screws, and a proper lens can be selected according to the light distribution of the light source, such as a wide light beam shown in fig. 3, a narrow light beam shown in fig. 4 and a batwing light beam shown in fig. 5; the LED light source modules 1 are arranged on the bracket 3, distributed in the ball and made of aluminum and connected with the LED radiator 4; the LED radiator 4 is made of aluminum, has high heat conductivity coefficient, is arranged outside the integrating sphere, and is distributed with a plurality of radiating fins at the back; the fan is arranged on the LED radiator 4 to help the heat energy on the LED light source module 1 to be quickly LED out to the air; the thermocouple 6 is pre-buried on the support 3, and the reverse side temperature of the LED light source module 1 is monitored.

Example 2

A synthetic isoenergetic white light standard light source adopting an LED chip and fluorescent powder comprises 8 LED chips and 6 fluorescent powders which have 14 primary colors. The parameters of the spectra of the various primary colors are shown in Table 2, where 375nm, 385nm, 400nm, 420nm, 680nm, 720nm, 760nm and 800nm are chips, and 440nm, 480nm, 520nm, 560nm, 600nm and 640nm are phosphors. The synthesized isoenergetic white light spectrum is shown in fig. 6, and the least square deviation value of the synthesized spectrum and the theoretical isoenergetic white light spectrum in the range of 380-780nm is 0.05.

The standard lamp construction was the same as in example 1.

TABLE 214 Primary color parameters of color-synthesized isoenergetic white light spectra

Example 3

A white light standard light source with equal energy synthesized by LED chips and fluorescent powder comprises 10 primary colors of 6 LED chips and 4 fluorescent powders. The parameters of the spectra of the various primary colors are shown in Table 3, with 380nm, 400nm, 420nm, 680nm, 740nm and 800nm being chips and 440nm, 500nm, 540nm and 620nm being phosphors. The synthesized isoenergetic white light spectrum is shown in fig. 7, and the least square deviation value of the synthesized spectrum and the theoretical isoenergetic white light spectrum in the range of 380-780nm is 0.11.

The standard lamp construction was the same as in example 1.

Table 310 base color parameters of color synthesis equipotent white light spectrum

Claims (7)

1. A universal LED standard light source for a 2 pi method integrating sphere test is characterized by comprising an LED light source module and a lens, wherein the LED light source module is of an integrated packaging COB structure and comprises a multi-primary-color LED chip and fluorescent powder, the fluorescent powder is packaged on the LED chip, and the primary colors of the LED light source module comprise an ultraviolet band, a purple band, a blue band, a cyan band, a green band, a yellow band, an orange band and a red band; the LED light source module is detachably provided with a lens.

2. The universal LED standard light source for the 2 pi method integrating sphere test is characterized in that the lens is installed on the LED light source module through screws.

3. The universal LED standard light source for 2 pi method integrating sphere test as claimed in claim 1 or 2, wherein the lens is a wide beam lens, a narrow beam lens or a batwing beam lens.

4. The universal LED standard light source for the 2 pi method integrating sphere test as claimed in claim 1, wherein the kinds of the phosphors are more than 4.

5. The universal LED standard light source for the 2 pi method integrating sphere test is characterized by further comprising an LED radiator, a bracket and a temperature measuring element; the LED light source module is arranged above the bracket, and the temperature measuring element is pre-embedded on the bracket and used for testing the temperature of the back surface of the LED light source module; the LED radiator is connected with the LED light source module; when the LED lamp is used, the LED light source module is arranged on the inner wall of the integrating sphere through the support, and the LED radiator is arranged outside the integrating sphere.

6. The universal LED standard light source for the 2 pi method integrating sphere test is characterized in that a plurality of radiating fins are distributed behind an LED radiator; and a fan is arranged on the LED radiator.

7. The universal LED standard light source for the 2 pi method integrating sphere test according to claim 5, wherein the temperature measuring element is a thermocouple.

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