RU2572817C2 - Narrow field of view optical system for light-emitting diode - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: optical system for a light-emitting diode comprises a system holder, an aspherical lens and a Fresnel lens, configured to change the distance in between. The technical result is achieved due to that the optical system holder is in the form of a single monolithic structure which holds the Fresnel lens and the aspherical lens. The holder is mounted to a base on which the system is mounted. The aspherical lens is in the form of a paraboloid of revolution and forms light flux in a wide solid angle of up to 60 degrees at the level of 0.1. The distance between the Fresnel lens and the aspherical lens is set using a shifting mechanism and is defined by the width of the light flux formed by the aspherical lens.

EFFECT: designing a unified narrow field of view optical system for a light-emitting diode, capable of retaining its axial optical power when dimensions of the light body of the light-emitting diode change.

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Description

The invention relates to lighting devices, and in particular to narrow-degree optical lighting devices based on LEDs.

Known devices for focusing light devices, which consists in the fact that when focusing light bodies, the sizes of which are comparable with the dimensions of the reflectors, the angular size of elementary displays increases significantly, and, as a result, the total width of the light beam of the entire device also increases (Trembach V.V. Lighting devices: a textbook for universities in the specialty “Lighting Engineering and Light Sources” - 2nd ed., Revised and supplemented - M .: Higher school, 1990 - 66 pp.).

The disadvantage of such technical solutions is that for focusing a large light body, it is necessary to develop a large reflector to obtain acceptable light characteristics.

Known modular LED floodlight (RF patent No. 2510644 for the invention of 08/09/2012) containing detachable collapsible focusing assemblies, individual for each LED, covering plates, and the focusing assemblies consist of an aspherical lens and a holder based on polycarbonate.

The disadvantage of this device is the need for processing the size and shape of the focusing lens when changing the types or sizes of LEDs due to the rigid connection of the shape of the lens and the LED.

A known floodlight with a Fresnel lens with an interconnected change in the distance between the lighting elements (RF patent No. 2293250 for an invention dated 12/21/2004), adopted as a prototype and containing an elliptical reflector, a lamp and at least one Fresnel lens, the distance between the lens The fresnel and the reflector can be changed according to a certain geometric function depending on the distance between the lamp and the reflector, in accordance with the adjustable angle of the aperture, for a beam of light coming out of the searchlight.

The disadvantage of this device is that with large sizes of the light body, the light beam is not completely collected in the second focus of the elliptical reflector, and, as a result, the use of the Fresnel lens becomes ineffective. In addition, such a system has large dimensions due to the need to have focus between the Fresnel lens and the reflector.

The aim of the invention is the creation of a unified narrow-angle optical system for the LED, capable of maintaining its axial light intensity when changing the size of the light body of the LED.

This goal is achieved in that the lens design consists of a system holder, an aspherical lens and a Fresnel lens, the distance between which can be adjusted.

The essence of the invention lies in the fact that the holder of the system is made in the form of a single monolithic structure holding the Fresnel lens and aspherical lens, while the holder is attached to the base on which the system is mounted, while the aspherical lens forms a luminous flux into a wide solid angle up to 60 degrees at the level of 0.1, and the distance between the Fresnel lens and the aspherical lens is set using the shear mechanism and is determined by the width of the light flux formed by the aspherical lens.

In FIG. 1 shows the course of the rays through the optical system:

1 - aspherical lens

2 - Fresnel lens,

3 - light flux,

4 - virtual continuation of the rays of the light flux that hit the Fresnel lens.

5 - focus of the Fresnel lens.

In FIG. 2 shows a general view of the system:

6 - LED

7 - shear mechanism,

8 - system holder,

9 - device for mounting the holder to the supporting base,

10 - bearing base.

The optical system operates as follows:

The aspherical lens 1 forms the light flux 3 of the LED 6 into a wide angle. The radiation angle is selected up to 60 degrees (a wider luminous flux is ineffective to direct to the Fresnel lens) at the level of 0.1 (10% of the axial luminous intensity). The Fresnel lens 2 is mounted at such a distance from the aspherical lens 1 that the extensions of the rays 4 incident on its surface are collected at the focus of the Fresnel lens 5. Initially, the system is configured for a certain type of LED 6. The axial light intensity of this system is basic. When changing the type of LED 6, the flow width of the aspherical lens 1 changes slightly, to preserve the parameters of the optical system, the Fresnel lens 2 must be moved to a new position, which can be realized by the shift mechanism 7. The axial luminous intensity of a system with a new LED is set equal to the axial luminous intensity of the system with a reference LED . To reduce the influence of the external environment and the stability of the system parameters during mechanical stresses, a common system holder 8 is used, which is attached to the base 10 (for example, to a printed circuit board), on which the system is installed using screws 9, latches or glue.

Thus, in the proposed technical solution, the change in the size of the light body is compensated by the change in the distance between the aspherical lens and the Fresnel lens, and does not affect the change in the axial light intensity of the system.

Therefore, a unified narrow-degree optical system for the LED has been created, capable of maintaining its axial luminous intensity when changing the dimensions of the light body of the LED.

Claims (1)

An optical system for an LED containing a system holder, an aspherical lens and a Fresnel lens, mounted with the possibility of changing the distance between them, characterized in that the system holder is made in the form of a single monolithic structure holding the Fresnel lens and the aspherical lens, while the holder is attached to the base, on which the system is installed, while the aspherical lens forms a luminous flux into a wide solid angle up to 60 degrees at the level of 0.1, and the distance between the Fresnel lens and the aspherical lens tanavlivaetsya using the shift mechanism and determined by the width of the luminous flux formed by an aspherical lens.

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