RU2503095C1 - Optical module of light diode lamp - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: working surface of a generating optical system, through which light diode emission is released, represents in the general case an asymmetric aspherical surface. The optical module according to the invention comprises a light diode (a light diode crystal) and an adjoining generating optical system (GOS), through which light diode emission is released. The working light-releasing surface of the GOS represents an asymmetric aspherical surface, at the same time the shape of the working surface of the GOS is determined from the solution of the suggested system of equations.

EFFECT: development of an optical module, providing for generation of required radiation indicatrix.

1 tbl, 3 dwg

Description

The invention relates to lighting engineering, in particular to light devices using LEDs (LEDs). This invention can be used in systems of external (street lighting, highways, technical structures) and internal (lighting residential, office and industrial premises) lighting.

State of the art

Known designs of optical modules in which the formation of the required indicatrix is carried out by choosing the shape, size and materials of the forming optical system (FOS).

The closest technical solution is an LED with an optical element (optical module) (RF Patent No. 2265917, IPC H01L 33/00, publ. 10.12.2005). The optical module contains a light-emitting crystal with a single-lens FOS adjacent to it, which has an aspherical shape of the outer (working) surface formed by rotation of the curve around the axis of symmetry of the LED, obtained taking into account the optical properties of the LED crystal and the FOS material. In the device under consideration, the FOS collects and displays through the working surface all the radiation emitted by the crystal, and converts the initial indicatrix into an indicatrix of the desired shape.

However, using this device, you can get the indicatrix only axisymmetric shape.

Disclosure of invention

The objective of the invention is the creation of an optical module that provides the formation of the desired indicatrix, which in the general case is asymmetric, to solve a specific lighting problem, for example, to illuminate a section of a highway.

Moreover, the specified optical module is part of the LED lamp, consisting of many closely spaced identical directional modules, the number of which is determined by the requirements for the light-energy parameters of the developed lamp. Since all modules in the far zone (at a distance of 10 ... 20 times the transverse dimensions of the lamp) form the same light field, the entire lamp will give an identical light field. That is, the indicatrix of the entire lamp (field in the far zone) is almost identical to the indicatrix of a single module.

The essence of the invention lies in the fact that in an optical module consisting of a light emitting diode (LED crystal) and an adjacent FOS, its working surface through which the light emitting from the light emitting diode is a generally asymmetric aspherical surface. The shape of the working surface is determined from the solution of the system of equations

$$\{\begin{array}{c}F({\rho }_l,{\theta }_l,{\varphi }_l)=0\\ |\overrightarrow{\nabla }F({\rho }_l,{\theta }_l,{\varphi }_l)\times \overrightarrow{n}(({\theta }_l,{\varphi }_l)|=0\end{array}$$

- уравнение рабочей поверхности в сферической системе координат с центром в геометрическом центре светодиодного кристалла; $$\overrightarrow{\nabla }$$

- оператор градиента функции; $$\left\{{\overrightarrow{n}}_l\right\}=\left\{\overrightarrow{n}({\theta }_l,{\varphi }_l)\right\}$$

- векторного поля нормалей $$\left\{{\overrightarrow{n}}_l\right\}$$

к рассчитываемой рабочей поверхности в точках $$\left\{({\theta }_l,{\phi }_l)\right\};$$

$$l=\overline{1,N},$$

N - число точек на рабочей поверхности, для которых определены нормали; C_ij - - коэффициенты уравнения рабочей поверхности; М и К - максимальные степени полинома, а нормали $${\overrightarrow{n}}_l$$

определены на основании функции преобразования индикатрис, характеризующей процесс преобразования формирующей оптической системой исходной индикатрисы светодиодного кристалла в индикатрису требуемой формы и связывающей соответствующие телесные углы указанных индикатрис (Ω и Ω') через равенство потоков излучения, распространяющегося в пределах этих углов: Ф(Ω)=Ф(Ω').Where $$F(\rho ,\theta ,\phi )={\displaystyle \sum _{i=0}^M{\displaystyle \sum _{j=0}^K{C}_{ij}{(\rho sin\theta cos\phi )}^i}}{(\rho sin\theta sin\phi )}^j-\rho cos\theta =0$$

- the equation of the working surface in a spherical coordinate system with a center in the geometric center of the LED crystal; $$\overrightarrow{\nabla }$$

- function gradient operator; $$\left\{{\overrightarrow{n}}_l\right\}=\left\{\overrightarrow{n}({\theta }_l,{\varphi }_l)\right\}$$

- vector field of normals $$\left\{{\overrightarrow{n}}_l\right\}$$

to the calculated work surface in points $$\left\{({\theta }_l,{\phi }_l)\right\};$$

$$l=\overline{\mathrm{one},N},$$

N is the number of points on the working surface for which the normals are determined; C _ij - are the coefficients of the equation of the working surface; M and K are the maximum degrees of the polynomial, and the normals $${\overrightarrow{n}}_l$$

are determined on the basis of the conversion function of indicatrixes, which characterizes the conversion process by the forming optical system of the initial indicatrix of the LED crystal into an indicatrix of the desired shape and connecting the corresponding solid angles of the indicated indicatrixes (Ω and Ω ') through the equality of the radiation flux propagating within these angles: Ф (Ω) = Φ (Ω ').

Brief Description of the Drawings

Figure 1 shows the indicatrixes of radiation: a) Lambertian and b) required;

Figure 2 presents the beam path in FOS;

Figure 3 presents axonometric projections (front and rear views) of the optical module with FOS with a calculated working surface.

The implementation of the invention

The device operates as follows. The luminous flux from the light-emitting crystal enters the single-lens FOS, converting the luminous flux with the Lambert indicatrix into a flux converted by the FOS. A fundamentally important feature of the claimed invention is that the working surface of the FOS is in the general case an asymmetric aspherical surface, the shape of which is obtained directly from the solution of a system of nonlinear equations.

Причем при определении ФПИ используется закон сохранения энергии Φ(Ω)=Φ(Ω'), где Φ(Ω) и Φ(Ω')- потоки излучения от СД до и после ФОС в пределах телесных углов Ω, и Ω' соответственно. Потоки излучения при известных индикатрисах I(θ,φ) и I'(θ',φ') определяются по формулам $$\Phi (\Omega )={\displaystyle \underset{\Omega }{\iint }I(\theta ,\phi )\sin \theta \text{}d\text{}\theta d\phi }$$

и $$\Phi ({\Omega }^{\prime })={\displaystyle \underset{{\Omega }^{\prime }}{\iint }{I}^{\prime }(\theta \text{},\phi )sin\theta d\text{}\theta \text{}d\phi }.$$

The surface shape was calculated taking into account the optical properties and overall characteristics of the LED crystal, the material of the optical system, and the requirements for the formed indicatrix. In order for the FOS that is part of the optical module to form the required radiation indicatrix, at the first stage of calculating its working surface, the indicatrix transformation function (FPI) is determined - the dependence of the angular spherical coordinates of the beam exit from the FOS (θ ', φ') on the angular spherical coordinates of the beam exit (θ, φ) from the light-emitting area of ​​the LED (LED) characterizing the required conversion of indicatrixes $$I(\theta ,\phi )\stackrel{FP\mathrm{AND}}{\to }{I}^{\prime }({\theta }^{\prime },{\phi }^{\prime }):\left(\begin{array}{c}\theta \text{'}\text{'}\\ {\phi }^{\text{'}\text{'}}\end{array}\right)FP\mathrm{AND}\text{A.}\left(\begin{array}{c}\theta \\ \phi \end{array}\right).$$

Moreover, when determining the FPI, the energy conservation law Φ (Ω) = Φ (Ω ') is used, where Φ (Ω) and Φ (Ω') are the radiation fluxes from the LEDs before and after the FOS within the solid angles Ω and Ω ', respectively. The radiation fluxes for the known indicatrixes I (θ, φ) and I '(θ', φ ') are determined by the formulas $$\Phi (\Omega )={\displaystyle \underset{\Omega }{\iint }I(\theta ,\phi )\sin \theta \text{A.}d\text{A.}\theta d\phi }$$

and $$\Phi ({\Omega }^{\prime })={\displaystyle \underset{{\Omega }^{\prime }}{\iint }{I}^{\prime }(\theta \text{A.},\phi )sin\theta d\text{A.}\theta \text{A.}d\phi }.$$

(фиг.2) к рассчитываемой рабочей поверхности в точках: $$\left\{({\theta }_l,{\phi }_l)\right\}:{\overrightarrow{n}}_l=\overrightarrow{n}({\theta }_l,{\phi }_l):$$

FPI is necessary to determine the vector field of normals $$\left\{{\overrightarrow{n}}_l\right\}$$

(figure 2) to the calculated working surface at the points: $$\left\{({\theta }_l,{\phi }_l)\right\}:{\overrightarrow{n}}_l=\overrightarrow{n}({\theta }_l,{\phi }_l):$$

, $${\overrightarrow{n}}_l=\frac{{\overrightarrow{q}}_l^{\text{'}\text{'}}-\frac{n}{n\text{'}\text{'}}{\overrightarrow{q}}_l}{\left|{\overrightarrow{q}}_l^{\text{'}\text{'}}-\frac{n}{n\text{'}\text{'}}{\overrightarrow{q}}_l\right|}$$

,

- направляющий вектор луча, выходящего с поверхности светоизлучающей площадки СД (1), проходящего в ФОС и приходящего в точку (θ_l,φ_l), $${\overrightarrow{q}}_l({\theta }_l,{\varphi }_l)=\left\{sin{\theta }_{l}cos{\varphi }_l;sin{\theta }_{l}sin{\varphi }_l;cos{\theta }_l\right\}$$

; $${\overrightarrow{q}}_l^{\text{'}}$$

- направляющий вектор луча, выходящего из ФОС в точке (θ_l, φ_l), $${\overrightarrow{q}}_l^{\text{'}}({\theta }_l^{\text{'}},{\phi }_l^{\text{'}})=\left\{sin{\theta }_l^{\text{'}}cos{\phi }_l^{\text{'}};sin{\theta }_l^{\text{'}}sin{\phi }_l^{\text{'}};cos{\theta }_l^{\text{'}}\right\};$$

l - точки, $$l=\overline{1,N},$$

N - число точек.where n is the refractive index of the material FOS (2); n 'is the refractive index of air, n' = 1.0; $${\overrightarrow{q}}_l$$

- the directing vector of the beam exiting from the surface of the light-emitting area of the LED (1) passing through the FOS and arriving at the point (θ _l , φ _l ), $${\overrightarrow{q}}_l({\theta }_l,{\varphi }_l)=\left\{sin{\theta }_{l}cos{\varphi }_l;sin{\theta }_{l}sin{\varphi }_l;cos{\theta }_l\right\}$$

; $${\overrightarrow{q}}_l^{\text{'}\text{'}}$$

is the directing vector of the beam emerging from the FOS at the point (θ _l , φ _l ), $${\overrightarrow{q}}_l^{\text{'}\text{'}}({\theta }_l^{\text{'}\text{'}},{\phi }_l^{\text{'}\text{'}})=\left\{sin{\theta }_l^{\text{'}\text{'}}cos{\phi }_l^{\text{'}\text{'}};sin{\theta }_l^{\text{'}\text{'}}sin{\phi }_l^{\text{'}\text{'}};cos{\theta }_l^{\text{'}\text{'}}\right\};$$

l are points $$l=\overline{\mathrm{one},N},$$

N is the number of points.

At the second stage of the calculation, the working surface of the FOS itself is determined. To do this, first choose the type of equation of the working surface of the WCF. In particular, the equation can be represented as a power polynomial (in a spherical coordinate system centered at the geometric center of the LED crystal):

$$F(\rho ,\theta ,\phi )={\displaystyle \sum _{i=0}^M{\displaystyle \sum _{j=0}^K{C}_{ij}{(\rho sin\text{A.}\theta cos\phi )}^i}}{(\rho sin\text{A.}\theta sin\phi )}^j-\rho cos\theta =0,$$

where (ρ, θ, φ) are the spherical coordinates of the points of the working surface of the FOS; M and K are the maximum degrees of the polynomial.

Coefficient C ₀₀ is the thickness of the FOS along the optical axis, which is determined from structural and technological considerations (including overall limitations on the FOS). The remaining coefficients of the surface equation C _{ij are} unknown and are determined in the calculation process.

Next, they compose and solve a system of equations for the set of normals to the surface:

, $$\{\begin{array}{c}F({\rho }_l,{\theta }_l,{\varphi }_l)=0\\ |\overrightarrow{\nabla }F({\rho }_l,{\theta }_l,{\varphi }_l)\times \overrightarrow{n}(({\theta }_l,{\varphi }_l)|=0\end{array}$$

,

N - число точек на рабочей поверхности, для которых определены нормали; $$\overrightarrow{\nabla }$$

- оператор градиента функции.Where $$l=\overline{\mathrm{one},N},$$

N is the number of points on the working surface for which the normals are determined; $$\overrightarrow{\nabla }$$

- function gradient operator.

The spherical coordinates ρ _l are unknown and they are determined in the calculation process.

Moreover, for N normals, 2N equations with N + M · K unknowns are obtained ({ρ _l }, {C _ij }). To obtain a quality solution, it is necessary that N≥ (1.5 ... 2.5) M · K.

The desired solution to the system of equations for all normals are the coefficients C _ij equations of the working surface of the FOS.

As an example, an optical module was developed, which is used in an LED lamp designed to uniformly illuminate a section of a two-lane roadway with a size of 30 × 5.6 m ² when the lamps are located on poles 10 m high with a gander angle of 15 °, the distance between the poles is 30 m along canvases of the road.

The equation of the working surface of the FOS of an optical module is a power polynomial of two variables: $$F(\rho ,\theta ,\phi )={\displaystyle \sum _{i=0}^{\mathrm{one}0}{\displaystyle \sum _{j=0}^{\mathrm{one}0}{C}_{ij}{(\rho sin\theta cos\phi )}^i}}{(\rho sin\theta sin\phi )}^j-\rho cos\theta ,$$

The values of the coefficients C _2ij obtained as a result of the solution are shown in the table.

Two axonometric projections (front and rear views) of the optical module with FOS with the working surface calculated in the example are presented in FIG. 3.

Claims (1)

An optical module comprising a light emitting diode (LED crystal) and an adjacent forming optical system (FOS) having a working light output surface, characterized in that the working surface of the FOS is an asymmetric aspherical surface, while the shape of the working surface of the FOS is determined from a solution of the system of equations
$$\{\begin{array}{c}F({\rho }_l,{\theta }_l,{\phi }_l)=0\\ |\overrightarrow{\nabla }F({\rho }_l,{\theta }_l,{\phi }_l)\times \overrightarrow{n}(({\theta }_l,{\phi }_l)|=0,\end{array}$$

Where $$gdeF(\rho ,\theta ,\phi )={\displaystyle \sum _{i=0}^M{\displaystyle \sum _{j=0}^{\mathrm{TO}}{C}_{ij}{(\rho sin\theta cos\phi )}^i}}{(\rho sin\theta sin\phi )}^j-\rho cos\theta =0$$

- the equation of the working surface in a spherical coordinate system with a center in the geometric center of the LED crystal; $$\overrightarrow{\nabla }$$

- function gradient operator; $$\left\{{\overrightarrow{n}}_l\right\}=\left\{\overrightarrow{n}({\theta }_l,{\varphi }_l)\right\}$$

is the vector field of normals $$\left\{{\overrightarrow{n}}_l\right\}$$

to the calculated work surface in points $$\left\{({\theta }_l,{\phi }_l\right\};$$

$$l=\overline{\mathrm{one},N},$$

N is the number of points on the working surface for which the normals are determined; C _ij are the coefficients of the equation of the working surface; M and K are the maximum degrees of the polynomial, and the normals $${\overrightarrow{n}}_l$$

are determined on the basis of the conversion function of indicatrixes, which characterizes the conversion process by the forming optical system of the initial indicatrix of the LED crystal into an indicatrix of the desired shape and connecting the corresponding solid angles of the indicated indicatrixes (Ω and Ω ') through the equality of the radiation flux propagating within these angles: Ф (Ω) = Φ (Ω ').

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