RU2789206C1 - Lighting device - Google Patents

Abstract

FIELD: spatial distribution measuring.

SUBSTANCE: invention relates to the field of measuring the spatial distribution of the brightness characteristics of samples, in particular a road asphalt concrete pavement, of a rectangular shape in laboratory conditions on a stationary installation at short photometric distances, illuminated by a collimated light beam incident on the test sample at certain fixed angles, and at different viewing angles. The claimed device contains a light source placed in the housing, and a glass mirror reflector fixed with the possibility of regulation on a rotatable arc, one of the ends of which is movably connected to the limb. At the same time, a rectangular fragment of a glass paraboloidal mirror reflector is used as a glass mirror reflector, and the light source is placed at the focus of a rectangular fragment of a glass paraboloidal mirror reflector. To form a light beam, a rectangular hole is made in the light source body, displaced relative to the center of the LED, which limits the size of the light beam according to the size of a fragment of a glass paraboloid mirror reflector.

EFFECT: ensuring uniform illumination over the entire surface of a rectangular sample by obtaining a collimated light beam while minimizing side illumination and minimal screening of the sample when changing the angle of illumination and increasing the compactness of the structure as a whole.

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Description

LIGHTING DEVICE

The invention relates to the field of measuring the spatial distribution of the brightness characteristics of samples, in particular a rectangular asphalt concrete pavement, under laboratory conditions on a stationary installation at small photometry distances, illuminated by a collimated light beam incident on the sample under study at certain fixed angles, and at different viewing angles.

An important task of ensuring the safety of public roads in Russia is the design and control of their artificial lighting. The main purpose of outdoor lighting on highways is to create safe and comfortable vision conditions for vehicle drivers in the dark. The reflection of the road surface has a pronounced directional character, depending on the direction of illumination, the type and condition of the reflecting surface.

One of the important criteria is the brightness of the pavement, the study of which is carried out both in field and in laboratory conditions using stationary installations. The transition to the brightness concept of rationing is associated with the need to conduct full-scale studies of the brightness characteristics of operated and developed types of domestic road surfaces with their subsequent standardization.

A device is known for a raster goniophotometer (patent RU 2006799, publ. 30.01.1994), containing a collimator with an optical raster, made in the form of a system of parallel opaque screens, including the input and output main screens and intermediate screens installed between them, each of which has uniformly distributed holes coaxial with each other, an integrating element, for example, in the form of a lens, a radiation receiver with a recording unit, and a rotary assembly of the goniophotometer. In this case, the block of photodetectors consists of a set of photodetectors, each of which is installed in a given direction. The disadvantage of this goniophotometer is a large number of intermediate screens required for reliable screening of rays deviating from a given direction, and large overall dimensions.

A known device for measuring the reflectivity of products (patent RU 2311631, publ. 27.11.2007), having an opaque housing and containing a light source, a test sample locating device, a photodetector and a beam-splitting device, including a translucent mirror face, the center of which forms with the locating center the main optical channel (or illumination-reflection channel), and with the source and photodetector - optical channels of radiation and photoreception, respectively, the axis of one of which is a continuation of the main axis of the channel, and the axis of the other is a continuation of the mirror image of the axis of the main channel in the mirror of the beam splitter, and the center this one is placed at the same distance from the outlet of the source and the inlet of the photodetector. As a sample locating device, the front part of the housing is used in the area of the main light hole of the device, through which the retroreflective sample is illuminated, while the hole contour plane determines the sample illumination angle.

The light source unit includes a diaphragm with an exit hole with a diameter smaller than the luminous body, illuminated by an incandescent lamp directly or through a lens with a diaphragm to reduce stray illumination. A diaphragm with a hole of approximately the same diameter as that of the light source is installed in front of the photodetector. The aperture holes of the source and receiver are placed relative to the mirror so that the center of the image of the receiver hole (created by the mirror) is separated from the center of the source hole by a distance at which the value of the divergence angle provided in the device passport is ensured (most likely α=20', i.e. α=0.0058 rad).

The disadvantage of this device is the difficulty of accurate positioning spaced apart due to the use of beam-splitting devices of the channels of the source and receiver of radiation relative to each other in the short base circuits of the device.

A device of an optical system for collimating light is known (patent RU 2644082, publ. 02/07/2018). One such optical system that is often used is the collimator, which finds application in total internal reflection (TIR). The optical system includes a body and a recess formed on the first side of the body. The recess has central and lateral light entry surfaces and a central light exit surface provided on the second side of the body opposite the first side. The central light input surface is disposed with respect to the central light output surface such that light incident on the central light input surface is directed towards the central light output surface. A total internal reflection surface is provided on the side surface of the body, located in such a way that the incoming light incident on the light input side surface belonging to the recess is directed to the total internal reflection surface and reflected to the second side of the body. In addition, the optical system includes a suppression zone surrounding the central light input surface. The suppression zone configuration ensures that light entering the suppression zone is prevented from escaping from the body through the second side. According to an embodiment, the lighting device may include a reflective housing that is disposed around a side surface and a first side of the body of the optical system, and light may be reflected by the housing back into the body and may also contribute to light output from the optical system substantially without collimation. The technical result is to reduce the unevenness of the emitted light. The disadvantage is the complexity of the design of the collimator.

To measure the reflective properties, whether it is the indicatrix of the brightness index or the brightness coefficient, special measuring complexes are used - goniorereflectometers, which are a complex photometric system consisting of several elements. On the basis of measurements on such devices in Europe, a classification and a database of road surfaces have been created.

Known laboratory setup developed in Germany (Peiner P. Die Erfassung der lichttechnischen Eigenschaften von Strabendecken - Ergebnisse einer Mebreihe. Maga2ine of Lichttechnik. 1973. No. 25) for measuring the reflective characteristics of asphalt concrete pavements. Installation requires large areas (at least two building modules -6x12 m). Illumination of horizontally placed samples is carried out by a system consisting of a light source with a power of 0.95 kW and a pair of mirrors, one of which is placed at a distance of 12 m, and the second mirror, inclined, is located between the sample and the light source and is rigidly connected to the latter. The angular aperture of the beam is 5.8⋅10 ^-4 sr. Rotary devices allow you to set the viewing angles in the meridional (from 0 to 180°) and equatorial (from 0 to 360°) planes. The disadvantage of the installation under consideration is its significant size, designed for large-sized pavement samples measuring 300 × 400 mm, cut down on real roads.

Known stationary laboratory installation for measuring the reflective characteristics of asphalt pavements (Frederiksen E., Gudum L. The quality of street lighting installation under changing weather conditions. Lighting Research and Technology. 1972. No. 4), in which the light source moves in a straight line at a constant height, above the selection of samples, the table on which the sample is installed rotates, and the brightness meter allows you to set different viewing angles. Measurements on such a setup are complicated by the constant movement of the source, which entails a change in the distance between the source and the sample, complex alignment, pointing the light beam at the sample, which is not only time-consuming, but also a source of additional errors.

The objective of the technical solution is to develop the design of a compact lighting device for use, in particular, in a stationary laboratory installation for studying the brightness characteristics of road asphalt concrete pavements, which provides uniform illumination on the entire surface of a rectangular sample when changing the position of the illuminator relative to the surface of the sample.

The technical result consists in the possibility of providing uniform illumination over the entire surface of a rectangular sample by obtaining a collimated light beam while minimizing side illumination and minimal screening of the sample when changing the illumination angle and increasing the compactness of the structure as a whole.

The created optical system is characterized by minimal dimensions, which makes it possible to reduce the overall dimensions of the illuminator and improve the reliability and quality of measurements.

Concepts and definitions:

Limb - a ring with evenly spaced strokes (divisions), an important part of goniometric instruments.

A collimated beam of light or other electromagnetic radiation has parallel beams and will therefore propagate with minimal expansion as it propagates (en.abcdef.wiki).

Lira - (swivel arc).

Photometry is the process of measuring the coefficient of light reflection from the sample surface (http://www.complexdoc.ru/lib/TOCT R 51108-2016).

Photometry - measurement of quantities characterizing radiation in accordance with the accepted function of the relative spectral luminous efficiency R 58814-2020.

Indicatrix - (French indicatrice, lit. - pointing) in optics: a graphic representation of the dependence of the characteristics of the light field (brightness, light polarization) or the optical characteristics of the medium (refractive indices, reflectivity) on the direction. Big encyclopedic dictionary.

The indicatrix of a photometric quantity is the angular distribution of a photometric quantity in space or in a plane (GOST 26148-84).

The problem is solved in the following way.

SUBSTANCE: lighting device of a stationary installation for measuring the brightness characteristics of rectangular samples contains a light source and a glass mirror reflector fixed with the possibility of adjusting the position on a rotary arc made with the possibility of independent rotation, one of the ends of which is movably connected to the limb, while the glass mirror reflector is used a rectangular fragment of a glass paraboloid mirror reflector. The light source is fixed in the body. The mutual arrangement of the light source and the glass mirror reflector is corrected by adjusting elements to achieve uniform illumination of the sample. The lighting device is characterized by the fact that a rectangular hole is made in the light source body, displaced relative to the center of the LED, limiting the size of the light beam according to the size of a fragment of a glass paraboloid mirror reflector.

The design of the device is shown in the following graphical figures:

Fig. 1 - lighting device in operation.

Fig. 2 - light source with a fragment of a glass paraboloid mirror reflector.

Fig. 3 - photo of the source with a fragment of a glass paraboloid mirror reflector.

Fig. 4 - glass paraboloid mirror reflector OPS 495.192 TU 5927-001-96129164-201. Where:

1 - light source (standard LED);

2 - body of the light source;

3 - glass mirror reflector (a fragment of a glass paraboloid mirror reflector);

4 - swivel lyre (swivel arc);

5 - adjusting element of the light source;

6 - adjusting element of the glass mirror reflector;

7 - limbus;

8 - rectangular sample of the road surface;

9 - a rectangular hole in the body of the clarifier.

The proposed lighting device (Fig. 1) includes a light source, which is used as a standard LED (1), placed in a compact housing (2), fixed with the possibility of adjusting its position using the control element (5) on a rotary arc - lyre (4), a fragment of a glass paraboloid mirror reflector (3) measuring 180×180 mm, fixed in a hinged adjusting element (6) mounted on a swivel arc - lyre (4).

The swivel arc - lyre (4) is made with the possibility of independent rotation relative to the horizontal axis YY', which allows you to change the position of the illuminator relative to the sample under study, i.e. change the angle of illumination. The counting of the fixed angles is carried out with the help of a limb (7), which is movably connected to the swivel lyre (4).

The device works as follows.

The lighting device, which includes a light source (1) in a housing (2) and a fragment of a glass paraboloid mirror reflector (3), mounted on a rotary lyre (4) movably connected to the limb (7), is placed on a stationary installation for measuring the brightness characteristics of rectangular samples asphalt concrete pavement (Fig. 1 shows a fragment of the horizontal surface of the installation for placing the sample, the remaining elements of the installation are not shown), in the center of which is the investigated sample of the pavement of a rectangular shape with a size of 180x180 mm.

The study of just a rectangular fragment of optimal dimensions is due to the simplicity of its preparation, in contrast, for example, to round samples of the required dimensions, which provide reliable results for the illumination of the road surface. The LED light source (1) fixed on the lyre (4) is placed at the focus F of the glass mirror reflector (3) (Fig. 2). Adjusting elements (5), (6) of the structure on the lyre (4) allow the light source to be adjusted relative to the glass mirror reflector (3), so that the light beam completely hits the reflector, and allow the reflector to be aligned relative to the test sample (8) of a rectangular shape, so that the collimated light beam completely hits and coincides with the test sample (8) of the pavement. All this is ensured by the possibility of independent rotation of the light source (1) and a fragment of a glass paraboloid mirror reflector (3) to change the position of the illuminator with the reflector relative to the test sample (8).

The light beam, reflected from a glass mirror reflector (3), made of a rectangular fragment of a paraboloid mirror reflector (Fig. 4), is converted into a collimated square light beam and enters the surface of the square sample under study (8). Due to the fact that the collimated light beam has the shape of a square corresponding to the shape of the sample under study, uniform illumination is provided over the entire surface of the rectangular sample and side illumination is limited. Thanks to the compact design of the lighting device, which made it possible to eliminate the use of a traditional bulky lens system, physical interference is eliminated, shielding becomes minimal when the position of the illuminator relative to the sample surface changes, which improves the quality and reliability of the studies.

The swivel lyre (4) has the possibility of independent rotation about the YY' axis, which allows you to change the position of the illuminator, including the light source (1) and a fragment of a glass paraboloid mirror reflector (3), relative to the test sample (8), which is fixedly fixed on the object table of the setup ( Fig. 1), i.e. change the angle of illumination, count the fixed angles using the dial (7). Before measuring, the quoting device (the device for adjusting the position of the LED light source (1) and the square fragment of the glass paraboloid mirror reflector (3)) sets the position of the reflector, which ensures complete illumination of the object under study and the coincidence of the light spot with the test sample (8). The discrepancy between the light spot and the test sample (8) leads to a decrease in the measurement accuracy.

The LED light source (1) is placed at the focus F of the reflector (3) (Fig. 2), which provides uniform illumination over the entire surface of the rectangular pavement sample (8). To eliminate side illumination, a rectangular hole (9) is made in the illuminator body at a distance of 10 mm from the LED, shifted upward relative to the center of the LED towards a fragment of a glass paraboloid mirror reflector (3), limiting the size of the light beam by the size of the reflector fragment.

Adjusting elements (5) and (6) allow you to adjust the position of the light source (1) and a fragment of a glass paraboloid mirror reflector (3) to correct the light beam incident on the sample surface (8).

The photometric center of the setup O is located at the point of intersection of the XX' and YY' axes and is located in the center of the test sample on its outer surface.

To obtain a glass mirror reflector, which makes it possible to obtain a collimated beam of light rays, a glass paraboloid mirror reflector OPS 495.192 TU 5927-001-96129164-2014 (Fig. 4) was chosen, from which square fragments were cut at the manufacturer (Fig. 4) .

The presented lighting device makes it possible to measure the brightness characteristics of rectangular samples of asphalt concrete pavement on a stationary laboratory setup based on a goniometer, at short distances of photometry, illuminated by a collimated light beam incident on the test sample (8) at certain fixed angles, and at different angles observations. Thus, this design of the device makes it possible to obtain, as a result of research, reliable information about the spatial distribution of the brightness characteristics of rectangular samples of asphalt concrete pavement at small distances of photometry.

The device can be implemented in mass production using standard components.

Claims (3)

1. A lighting device for a stationary installation for measuring the brightness characteristics of rectangular samples, containing a light source placed in a housing and a glass mirror reflector, fixed with the possibility of regulation on a rotatable arc, one of the ends of which is movably connected to the limb, while as a glass mirror reflector, a rectangular fragment of a glass paraboloid mirror reflector is used, and the light source is placed at the focus of a rectangular fragment of a glass paraboloid mirror reflector. 2. The lighting device according to claim 1, characterized in that the light source housing has a rectangular hole offset from the center of the LED, which limits the size of the light beam to the size of a fragment of a glass paraboloid mirror reflector. 3. The lighting device according to claim 1, characterized in that the light source housing has a rectangular hole displaced upward relative to the center of the LED, which limits the size of the light beam to the size of a fragment of a glass paraboloid mirror reflector.

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