Daylight Measurements & Solid State Lighting PanelDesigning Based on Non-Visual Effects

Bipul Mohanto

Thesis Advisor: Prof. Jussi Parkkinen

Color in Informatics and MEdia TechnologyDepartment of Computing Science

University of Eastern Finland

23 June, 2015Bipul Mohanto University of Eastern Finland Daylight Measurements & Solid State Lighting Panel Designing Based on Non-Visual Effects23 June, 2015 1 / 35

Layout of Entire Work

Introduction

Motivation of the Work

Theoretical Background

Used Measurement Devices

Defining Horizontal and Vertical Measurement DirectionPart I. Outdoor Daylight Measurement, Data Acquisition, and Analysis

Outdoor Measurement Location for Data AcquisitionOutdoor Data Analysis

Part II. Open Exterior Daylight Measurement, Data Acquisition and AnalysisOpen Exterior Location for Data AcquisitionOpen Exterior Data Analysis

Part III. LED Panel Designing and TestingLight Booth Setup and Measurement TechniquesLED Panel DesigningLight Quality Testing

Future Work and Conclusion

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Introduction

Commercial, domestic buildings are being converted into green buildings.Toregulate green building LEED 1 standard system has been developed. Beforedesigning a building, the knowing daylight condition is a prerequisite.

Solid State Lighting (SSL) is taking place over all kind of traditional incandescentlamps because of its high luminous efficiency.

In future combination of daylight and SSL to generate Human Centric Lighting(HCL) will be a smart way of building lighting.

1. Leadership in Energy and Environmental Design (LEED), U.S. Green Building Council (USGBC)

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Motivation of the Work

SSL : LED, PLED, OLED.

Most common daily used LEDs (blue LED with yellow phosphorus coating) usuallyhave peak wavelength between 460 to 480 nm ; the intinsically photosensitiveretinal ganglion cell 5 (ipRGC) is sensitive around this region too.

The presence of peak in ipRGC sensitive zone may cause the suppression ofmelatonin secretion and that can create effect on human circadian rhythm. 2 3 4

In LED panel designing, to generate white light, peak wavelength is tried to shiftfrom melanopic lux region.

2. Brainard, G.C. et.al. : Action Spectrum for Melatonin Regulation in Humans : Evidence for a Novel CircadianPhotoreceptor.

3. Thapan, K. : An action spectrum for melatonin supression : evidence for a novel non-rod, non-cone photore-ceptor system in humans.

4. Gall, D. et.al. : Definition and Measurement of Circadian Radiometric Quantities5. ipRGC is third photo-receptor that controls melatonin and circadian rhythm of human.

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Theoretical Background

Additive Color Mixing : R+G+B = W ; when color are in equi-intensity.Opponent process color theory.RGBA system is better over RGB system, better CRI (80-90), better CCT.Two average illumination techniques has been applied :

1 Average Illumination/ Arithmetic Average Illumination 6, E = P2 True Average Illumination 7

E =π4 [a2 × A + (b2 − a2) × B + (c2 − b2) × C]

π4 c2

6. IES The Lighting Handbook, Tenth Edition, Reference and Application, page 9.28-9.317. J.R.Cravath et al. "The Calculation of Illumination by the Flux of Light Method"

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Used Measurement Devices

Gigahertz-Optik BTS256 LED Tester works in the wavelength 380 nm – 755 nmand Konical Minolta Spectrophtometer measures in the range of 360 nm–780 nm.

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Defining Horizontal and Vertical Measurement Direction

FIGURE: (a) Depending on the eye level and ground position defining horizontal (Eh) and vertical(Ez ) level measurement direction (b) Konica Minolta Spectrophotometer vertical directionmeasurement (c) Konica Minolta Spectrophotometer horizon level measurement direction

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Part I. Outdoor Daylight Measurement, Data Acquisition, and Analysis

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Outdoor Measurement Location for Data Acquisition

Global position : 62◦36′N, 29◦44′EMeasurement period : 3 days in a week, Monday, Tuesday and Friday, two times ina day, 12 pm and 4 pm, from February to May.

FIGURE: (a) The vertical measurement direction, considering the sensor position (b) South cardinalhorizon point considering standard eye level (c) West cardinal horizon point (d) North cardinalhorizon point (e)East cardinal horizon point

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Outdoor Data AnalysisVertical Irradiance Change Over Time

FIGURE: The vertical irradiance change over four months period of time at 12 pm and 4 pm, bluesolid line represents the irradiance of February at 12 pm, broken line irradiance at 4 pm, green solidline represents March at 12 pm, broken line represents at 4 pm, Yellow solid line representsirradiance of April at 12 pm, broken line represents at 4 pm, red solid line represents the irradianceof May, red broken line represents irradiance at 4 pm

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Outdoor Data AnalysisNorth Horizontal Cardinal Point Irradiance Change Over Time

FIGURE: The horizontal north cardinal point irradiance change over four months period of time at 12pm and 4 pm, blue solid line represents the irradiance of February at 12 pm and broken line is theirradiance at 4 pm, green solid line represents March at 12 pm and broken line represents at 4 pm,Yellow solid line represents irradiance of April at 12 pm and broken line represents at 4 pm, redsolid line represents the irradiance of May and red broken line represents irradiance at 4 pm

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Outdoor Data AnalysisSouth Horizontal Cardinal Point Irradiance Change Over Time

FIGURE: The horizontal south cardinal point irradiance change over four months period of time at 12pm and 4 pm, blue solid line represents the irradiance of February at 12 pm and broken line is theirradiance at 4 pm, green solid line represents March at 12 pm and broken line represents at 4 pm,Yellow solid line represents irradiance of April at 12 pm and broken line represents at 4 pm, redsolid line represents the irradiance of May and red broken line represents irradiance at 4 pm

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Outdoor Data AnalysisEast Horizontal Cardinal Point Irradiance Change Over Time

FIGURE: The horizontal east cardinal point irradiance change over four months period of time at 12pm and 4 pm, blue solid line represents the irradiance of February at 12 pm and broken line is theirradiance at 4 pm, green solid line represents March at 12 pm and broken line represents at 4 pm,Yellow solid line represents irradiance of April at 12 pm and broken line represents at 4 pm, redsolid line represents the irradiance of May and red broken line represents irradiance at 4 pm

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Outdoor Data AnalysisWest Horizontal Cardinal Point Irradiance Change Over Time

FIGURE: The horizontal west cardinal point irradiance change over four months period of time at 12pm and 4 pm, blue solid line represents the irradiance of February at 12 pm and broken line is theirradiance at 4 pm, green solid line represents March at 12 pm and broken line represents at 4 pm,Yellow solid line represents irradiance of April at 12 pm and broken line represents at 4 pm, redsolid line represents the irradiance of May and red broken line represents irradiance at 4 pm

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Part II. Open Exterior Daylight Measurement, Data Acquisition, andAnalysis

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Open Exterior Location for Data Acquisition

Global Position : 62◦36′N, 29◦44′E

FIGURE: (a) The measurement location is 5 th floor from the ground, in Network Oasis Tower,Science Park, University of Eastern Finland (b) South cardinal point, no other equal height buildingparallel, shadow effect free, North horizon cardinal point, presence of CFL lamp, effects on overcastdaylight measurement (c) West cardinal horizon point measurement, presence of reflector wall, farenough from measurement point (d) East horizon cardinal point, presence of diffuse second glasswall.

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Open Exterior Data AnalysisHorizontal North Cardinal Point Irradiance Change Over Time

FIGURE: The horizontal north cardinal point irradiance change over four months period of time at 12pm and 4 pm, blue solid line represents the irradiance of February at 12 pm and broken line is theirradiance at 4 pm, green solid line represents March at 12 pm and broken line represents at 4 pm,Yellow solid line represents irradiance of April at 12 pm and broken line represents at 4 pm, redsolid line represents the irradiance of May and red broken line represents irradiance at 4 pm

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Open Exterior Data AnalysisHorizontal South Cardinal Point Irradiance Change Over Time

FIGURE: The horizontal south cardinal point irradiance change over four months period of time at 12pm and 4 pm, blue solid line represents the irradiance of February at 12 pm and broken line is theirradiance at 4 pm, green solid line represents March at 12 pm and broken line represents at 4 pm,Yellow solid line represents irradiance of April at 12 pm and broken line represents at 4 pm, redsolid line represents the irradiance of May and red broken line represents irradiance at 4 pm

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Open Exterior Data AnalysisHorizontal East Cardinal Point Irradiance Change Over Time

FIGURE: The horizontal east cardinal point irradiance change over four months period of time at 12pm and 4 pm, blue solid line represents the irradiance of February at 12 pm and broken line is theirradiance at 4 pm, green solid line represents March at 12 pm and broken line represents at 4 pm,Yellow solid line represents irradiance of April at 12 pm and broken line represents at 4 pm, redsolid line represents the irradiance of May and red broken line represents irradiance at 4 pm

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Open Exterior Data AnalysisHorizontal West Cardinal Point Irradiance Change Over Time

FIGURE: The horizontal west cardinal point irradiance change over four months period of time at 12pm and 4 pm, blue solid line represents the irradiance of February at 12 pm and broken line is theirradiance at 4 pm, green solid line represents March at 12 pm and broken line represents at 4 pm,Yellow solid line represents irradiance of April at 12 pm and broken line represents at 4 pm, redsolid line represents the irradiance of May and red broken line represents irradiance at 4 pm

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Part III. LED Panel Design and Quality Testing

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Light Booth Setup and Measurement Techniques

FIGURE: Light Booth Setup for LED Panel quality testing

Light booth dimension is 117×115cm.

Table height is 71 cm, surface is matte, covered by thick black cover to reducereflectance.Height between table surface and top of the LED matrix is 84 cm.

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LED Panel Designing : 1.1RGBA Column Matrix Pattern

Target spectrum has been optimized for the highest CAF 0.773 to 1.135.

Four different package of LEDs have been used, each of 54 LEDs, total 216 LEDs.

Red (625 nm), Amber (601 nm), Green (520 nm) and Blue (458 nm).

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LED Panel Designing : 1.1RGBA Column Matrix Pattern

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LED Panel Designing : 1.2RGBA Circular Matrix Pattern

FIGURE: RGBA circular matrix pattern LEDs arrangement

Five LED packages have been used, each of 63 LEDs, total 252 LEDs.

Two type of amber colored LEDs have been used, previous amber from columnmatrix panel, 12 pcs, and brighter amber LEDs 51 pcs.

Red (625 nm), Amber1 (601 nm), Green (520 nm), Blue (458 nm).

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LED Panel Designing : 1.2RGBA Circular Matrix Pattern

FIGURE: RGBA circular pattern spectrum

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LED Panel Designing : 1.3RGBA Circular Randomized Matrix Pattern

FIGURE: RGBA Circular Randomized Matrix Pattern

To make the spectra equi-intensity, 5 LED packages have been used from theprevious circular matrix pattern but different in numbers.Red (625 nm) 55 pcs, Amber1 (601 nm) 51 pcs, Amber2 (601 nm) 49 pcs, Green(520 nm) 65 pcs and blue (458 nm) 32 pcs.Blue and Amber has been randomized in their position with ratio 1 : 2.

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LED Panel Designing : 1.3RGBA Circular Randomized Matrix Pattern

FIGURE: Circular randomized pattern

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LED Panel Designing : 1.413 LED Circular Panel for Maximum and Minimum Melanopic Lux

FIGURE: 13 lightest LED arrangement pattern considering highest CAF.

Brightest irradiance are classified and normalized.The normalized irradiance has been optimized depending on highest CAF valuesDifferent highest CAF gives different melanopic lux, CAF : 1.012, melanopic-lux354.447 and CAF : 1.181, lowest melanopic-lux 303.725 is used for design thispanel.

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LED Panel Designing : 1.413 LED Circular Panel for Maximum and Minimum Melanopic Lux

FIGURE: Spectrum for melanopic lux354.447

FIGURE: Spectrum for melanopic lux303.725

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Light Quality Testing

Depending on the purpose of light, four criteria are specified for light qualitytesting, two criteria have taken into action. 8.

Minimum required average illuminance per task(Em) : 300–1000 Lx , European Standardis Horizontal Eh > 500 and Vertical illuminance Ez = 500lx .Minimum required color rendering index(Ra), minimum requirement is 80 for an officeenvironmentMaximum unified glare rating (UGRL), for a typical office environment, UGR should be19 or lessMinimum uniformity (U0), standard is 0.6

8. European Committee for Standardization (CEN), EN 12464–1

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Light Quality TestingObtained Average Illuminance for Different Panels

Average illuminance (Ez ) gain in lx for different LED panelsPanel Type Without

DiffuserWith Diffuser True Without

DiffuserTrue With

DiffuserRGBA Co-lumn Matrix

534 n/a n/a n/a

RGBA Circu-lar Matrix

562 181 n/a n/a

RGBA Circu-lar Randomi-zed Matrix

617 198 734 199

13 LEDs MaxMelanopicLux

107 67 132 112

13 LEDs MinMelanopicLux

133 51 123 51

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Light Quality TestingUniformity of the Table Surface

Uniformity of the surface (lx)PanelType

Without Diffuser With Diffuser

p1 p2 p3 p4p1 p2 p3 p4

RGBAco-lumn

540 477 508 610 197.25 186 193 206

RGBAcircu-lar

560 582 479 628 180 190 154 200

RGBAcir-cularran

595 616 458 799 199 177 195 222

13LEDmax

150 149 150 279 74 67 64 64

13LEDformin

143 115 118 157 53 45 49 56

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Light Quality TestingColor Rendering Index Ra

Target RGBA gives the CRI between the range 49–91 ; no relation between CAFoptimized light and CRI.

For 13 LED, maximum melanopic lux (354.447), CRI is 71 and for minimummelanopic lux (303.725), CRI is 56.

Color Rendering Index Ra

LED Panel Without Diffuser With DiffuserRGBA Column Matrix –79 n/aRGBA Circular Matrix –79 –5RGBA Circular Rando-mized Matrix

–44 –25

13 LED Max MelanopicLux

81 86

13 LED Min Melanopiclux

85 85

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Future Works and Conclusion

Well planned daylight provides a wide range of benefits, including enhancement tothe visual environment, improvement worker satisfaction and productivity, andafter all enhancement of circadian rhythm through exposure to higher luminancesand energy saving.

Manually or programmable tunable light simulated with the change of daylightirradiance will give better HCL over fixed spectrum lights nowadays.

From the outdoor and open exterior spectrum, it will be possible to design LEDspectrum mocking the daylight condition.

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