Dariusz Czyżewski

Warsaw University of Technology · Faculty of Electrical Engineering, Institute of Electrical Power Engineering; Lighting Division

A variety of LED types can be employed for street and road lighting purposes. White phosphor-converted LEDs represent the most widely used option. However, amber LEDs are increasingly being used to reduce some negative effects associated with light pollution. These LEDs can be manufactured using both phosphor-converted and monochromatic direct chip...

Abstract: In this review paper, information about bicycle lamp technical parameters is provided. The review is based on the searched Web of Science (WoS) and Scopus bibliographic databases and Transportation Research Information Services, which include references to books, technical reports, conference proceedings, and journal articles. This review...

Electronic version available at: https://www.sklep.pw.edu.pl/produkty/laboratorium-podstaw-techniki-swietlnej

Luminance measurements are the least frequent of all photometric measurements. This article characterizes and systematizes the various methods of luminance measurement. In particular, the method of direct luminance measurement using modern luminance meters (ILMD) is described in detail. This paper presents the results of the study on the influence...

Over the last few years, light-emitting diodes have completely dominated the lighting field. In road lighting, high-power LEDs have replaced traditional light sources. That is why various technical aspects of LEDs have been researched extensively worldwide. However, little research has been conducted in the area of luminance measurement. This paper...

This paper presents that the opto-electrical characteristic of a typical CCD based digital camera is nonlinear. It means that digital electric signal of the camera's CCD detector - is not a linear function of the luminance value on camera's lens. The opto-electrical characteristic feature of a digital camera needs to be transformed into a linear fu...

This paper presents the results of linearity testing of the integrated image sensor of a CCD-equipped digital camera. The study demonstrated the lack of linearity of the characteristics of the sensor when scaling with the luminance standard signal. In the course of the research the function approximated by the fifth-degree polynomial was determined...

This paper presents the research of optimization of road lighting energy consumption by utilizing the fact of human twilight and night vision (mesopic vision) dependency on luminance level and lamp’s light spectral composition. The research was conducted for a suburban street illuminated by smart LED road luminaires with a luminous flux control sys...

Luminance measurements are used in a vast range of lighting technology fields. The author’s research has proved that measuring the luminance distribution on light source surface is the most challenging part of this process. The research has been conducted for a commercially available digital luminance distribution meter, with the goal of analyzing...

Lighting technologies developed significantly in the last decade. New LED light sources, dedicated luminaires and improved lighting control techniques gave rise to new possibilities in improving energy efficiency of lighting solutions. The article is an overview of interior, road and exterior architectural object lighting design strategies. It also...

This article presents the research on a road lighting design. In this kind of design for a specific type of a roadway, the number and spacing of luminaires are calculated on the basis of luminaire photometric parameters such as intensity curve (LPIC) and luminous flux. The values of these parameters are measured using the luxmeter, i.e., a measurin...

This work presents luminance distributions across the surface of mid- and high-power diodes. The changes in luminance on diode surfaces following changes in the observation angle were verified. On the basis of the conducted tests, non-uniform luminance distribution on LED surface for diverse observation angles (including the axial direction) was ob...

Chip-On-Board Light-Emitting Diodes (COB LED) are increasingly more common. Their development in recent years has directly contributed to increasing the power of LED sources, whilst simultaneously increasing the luminous flux from the entire COB. Consequently, it has led to new developments in some applications. Information regarding the size of th...

LEDs now are the fastest developing light sources. Photometric parameters improvement is closely connected with structure evolution. The increase of luminous efficiency cause increase of LEDs surface luminance also. The new direction of development of light emitting diodes are COB LEDs. The paper will present the research results, indicating the lu...

In recent years there has been a significant improvement in technical parameters of light-emitting diodes. LEDs are more and more frequently used for luminaire construction. Photometric parameters given by manufacturers (distributors) are neither complete nor reliable. As a result of the cooperation between Municipal Roads Authority (ZDM) in Warsaw...

LEDs now are the fastest developing light sources. Photometric parameters improvement is closely connected with structure evolution. The increase of luminous efficiency cause increase of LEDs surface luminance also. The increasing current ranges, which can power the LED, cause a significant increase of LED chips luminance. In the paper will be pres...

LEDs are more and more frequently used for luminaire construction. Photometric parameters given by manufacturers (distributors) are neither complete nor reliable. As a result of the cooperation between ZDM in Warsaw and Lighting Division of the Warsaw University of Technology, arose the idea to verify such installations operating in practice. The n...

The conventional incandescent lamps have been consecutively withdrawn from retail last years. LED substitutes instead have been offered more and more frequently. Their quality, parameters stability and conformity declaration are questionable in many cases. In this paper the results of electrical, photometric and colorimetric parameters investigatio...

Till today, existing software for matrix measurers of luminance did not allow for precise place of measuring points and areas (in accordance with current regulations standards) for street lighting measurers. New system, designed by employees of Lighting Technology Department in Warsaw University of Technology changed this situation. New system allo...

LEDs are more and more frequently used for luminaire construction. Photometric parameters given by manufacturers (distributors) are neither complete nor reliable. As a result of the cooperation between ZDM in Warsaw and Lighting Division of the Warsaw University of Technology, arose the idea to verify such installations operating in practice. Two s...

As a result of the cooperation between ZDM in Koszalin and Lighting Division of the Warsaw University of Technology, the photometric measurements of the chosen streets in Koszalin were carried out. The results of the study permit to designate the streets that require urgent lighting modernization. The measurements became also the ground for lightin...

Independent on application, in design process of optical elements for LEDs information about luminance distribution on a light source surface is crucial. The problem consists in straightforward evaluation of LED luminous surface, that is whether the light source is only LED matrix or primary optical system, or often used secondary optical system. A...

The concept of LED use in road lighting is new and not widely known. On the lighting market many LED luminaire constructions have appeared. Lighting parameters given by the manufacturers (distributors) are questionable. Moreover, there are no many practical solutions of road lighting with the use of LED luminaires. There is lack of experience showi...

The development of street lighting luminaires with LEDs is growing very fast at this time. There is the question during notice development of LEDs, luminaires with LEDs and their commerce offer: ls it possible that LED street lighting luminaire can exchange traditional street lighting luminaire? The market offer and technical data put by the part o...

In tradition spectroradiometric measurements means always times consuming procedure, but due to possibility given by modern CCD type instruments, this is not correct meaning any more. In the paper we presented all important parameters of CCD type spectroradiometer and also there is given some measurement tips which could be used to achieve spectror...

The article contains analysis of the area devoted to chosen electroluminescent diodes. The presented initial results of the research work pointed to a considerable changeability of size, shape and luminance of the luminous area of LEDs for various directions of observation.