Development of Surface-mount-type Crown-shaped Lens for Reducing Glare Effect of Light-emitting Diode Light Source

This paper presents an experiment on the effect of light on the perception of paintings. The experiment was performed in a test-room where a typical museum exhibition set-up was simulated. Two different paintings were shown to 44 participants, under different light scenes obtained by using tuneable LED (Light Emitting Diode) wallwashers. To set the light scenes, the following parameters were modified: correlated colour temperature of the lighting, illuminance on the painting and the colour of the background wall. Participants answered a questionnaire to assess the perception of the paintings’ colours, the lighting conditions and the pleasantness of the exhibition set-up. The results demonstrated that illuminance is the parameter mainly affecting perception, for both paintings. However, correlated colour temperature and wall colour, as well as the combination of the three different considered parameters, can more or less influence perception depending on the chromatic composition of the painting.

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Comparison of the effects of operating microscopes with light emitting diode and halogen light source on the eye: a rabbit study

Cutaneous and Ocular Toxicology ◽

10.1080/15569527.2021.1949337 ◽

2021 ◽

pp. 1-7

Author(s):

Bahri Aydın ◽

Armagan Ozgur ◽

Huseyin Baran Ozdemir ◽

Pınar Uyar Gocun ◽

Mehmet Arda Inan ◽

...

Keyword(s):

Light Source ◽

Light Emitting Diode ◽

Light Emitting ◽

Halogen Light ◽

Halogen Light Source

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Influences of Spectral Power Distribution on Circadian Energy, Visual Comfort and Work Performance

Sustainability ◽

10.3390/su13094852 ◽

2021 ◽

Vol 13 (9) ◽

pp. 4852

Author(s):

Jack Ngarambe ◽

Inhan Kim ◽

Geun Young Yun

Keyword(s):

Light Source ◽

Power Distribution ◽

Work Performance ◽

Spectral Power ◽

Light Emitting Diode ◽

Essential Element ◽

Visual Comfort ◽

Light Emitting ◽

Organic Light Emitting Diode ◽

Spectral Power Distribution

Spectral power distribution (SPD) is an essential element that has considerable implications on circadian energy and the perception of lit environments. The present study assessed the potential influences of SPD on energy consumption (i.e., considering circadian energy), visual comfort, work performance and mood. Two lighting conditions based on light-emitting diode (LED) and organic light-emitting diode (OLED) were used as proxies for SPDs of different spectral content: dominant peak wavelength of 455 nm (LED) and 618 nm (OLED). Using measured photometric values, the circadian light (CL), melatonin suppression (MS), and circadian efficacy (CE) of the two lighting sources were estimated via a circadian-phototransduction model and compared. Additionally, twenty-six participants were asked to evaluate the said lit environments subjectively in terms of visual comfort and self-reported work performance. Regarding circadian lighting and the associated energy implications, the LED light source induced higher biological actions with relatively less energy than the OLED light source. For visual comfort, OLED lighting-based conditions were preferred to LED lighting-based conditions, while the opposite was true when considering work performance and mood. The current study adds to the on-going debate regarding human-centric lighting, particularly considering the role of SPD in energy-efficient and circadian lighting practices.

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Optimal Color Lighting for Scanning Images of Flat Panel Display using Simplex Search

Journal of Imaging ◽

10.3390/jimaging4110133 ◽

2018 ◽

Vol 4 (11) ◽

pp. 133

Author(s):

HyungTae Kim ◽

EungJoo Ha ◽

KyungChan Jin ◽

ByungWook Kim

Keyword(s):

Image Quality ◽

Light Source ◽

Light Emitting Diode ◽

Optical Filters ◽

Flat Panel Display ◽

Flat Panel ◽

Light Emitting ◽

Simplex Search ◽

Inspection Systems ◽

Color Control

A system for inspecting flat panel displays (FPDs) acquires scanning images using multiline charge-coupled device (CCD) cameras and industrial machine vision. Optical filters are currently installed in front of these inspection systems to obtain high-quality images. However, the combination of optical filters required is determined manually and by using empirical methods; this is referred to as passive color control. In this study, active color control is proposed for inspecting FPDs. This inspection scheme requires the scanning of images, which is achieved using a mixed color light source and a mixing algorithm. The light source utilizes high-power light emitting diodes (LEDs) of multiple colors and a communication port to dim their level. Mixed light illuminates an active-matrix organic light-emitting diode (AMOLED) panel after passing through a beam expander and after being shaped into a line beam. The image quality is then evaluated using the Tenenbaum gradient after intensity calibration of the scanning images. The dimming levels are determined using the simplex search method which maximizes the image quality. The color of the light was varied after every scan of an AMOLED panel, and the variation was iterated until the image quality approached a local maximization. The number of scans performed was less than 225, while the number of dimming level combinations was 20484. The proposed method can reduce manual tasks in setting-up inspection machines, and hence is useful for the inspection machines in FPD processes.

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