Highly Visible Clothing

Abstract

An article of clothing comprising a material having a luminance of between about 67 cd/m2 and about 72 cd/m2 for light having a correlated color temperature of between about 5,000 Kelvin and about 25,000 Kelvin, for example, to provide a highly visible color conspicuous to observers.

Description

TECHNICAL FIELD

This disclosure relates to highly visible clothing or garments.

BACKGROUND

Outdoor enthusiasts and workers may be exercising or working outside in early dawn hours or late evening hours. At these times of day, the lighting generally makes it relatively more difficult for observers to see the person exercising or working. Generally, light colored clothing provides observers with a greater likelihood of seeing the person wearing the light colored clothing.

SUMMARY

One aspect of the disclosure provides an article of clothing comprising a material having a luminance of between about 67 cd/m² and about 72 cd/m² for light having a correlated color temperature of between about 5,000 Kelvin and about 25,000 Kelvin, for example, to provide a highly visible color conspicuous to observers.

Implementations of the disclosure may include one or more of the following features. In some implementations, the material has a spectral reflectance of between about 1 and about 1.2 for light having a wavelength of between about 600 nm about 700 nm. The material may have a spectral reflectance of between about 1 and about 1.2 for light having a wavelength of between about 600 nm about 700 nm and a correlated color temperature of about 6500 Kelvin. In some examples, the material has a pink color.

Another aspect of the disclosure provides an article of clothing comprising a material having a spectral reflectance of between about 1 and about 1.2 for light having a wavelength of between about 600 nm about 700 nm.

In some implementations, the material has a spectral reflectance of between about 1 and about 1.2 for light having a wavelength of between about 600 nm about 700 nm and a correlated color temperature of about 6500 Kelvin. Moreover, the material may have a luminance of about 70 cd/m2 for light having a correlated color temperature of about 6500 Kelvin. The material may have a pink color.

In yet another aspect, an article of clothing comprises a material having a spectral reflectance of between about 1 and about 1.4 for light having a wavelength of between about 590 nm about 750 nm and a correlated color temperature of between about 10,000 Kelvin and about 20,000 Kelvin. In some examples, the light has a correlated color temperature of about 15,000 Kelvin. The material may have a luminance of between about 67 cd/m² and about 72 cd/m² for light having a correlated color temperature of between about 5,000 Kelvin and about 25,000 Kelvin. The material may have a pink color.

Another aspect of the disclosure provides an article of clothing that includes a material having a percent of spectral reflectance of light of between about 110% and about 150% for light having a wavelength of between about 600 nm about 650 nm. The material may have a pink color and/or may comprise at least one of cotton and polyester.

The details of one or more implementations of the disclosure are set forth in the accompanying drawings and the description below. Other aspects, features, and advantages will be apparent from the description and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic view of exemplary article of clothing

FIGS. 2 and 3 are graphs of exemplary spectral reflectance data for a number of sample materials.

FIG. 4 is a graph of a difference between the data illustrated in the graphs shown in FIGS. 2 and 3.

FIG. 5 shows a distribution of several types of natural daylight.

FIG. 6 is a graph of reflectance factor versus wavelength of light for a number of sample materials.

FIG. 7 is a graph of spectral reflectance for a pink sample material under various types of daylight.

FIG. 8 is a graph of percentages of spectral reflectance for different colored samples of material under various types of daylight.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

People working or exercising outside may wear a highly visible garment or clothing item that assists others in seeing garment wearer. A runner may wear the highly visible garment to allow drivers of passing vehicles to more readily recognize and see the runner (e.g., so as to steer clear of the runner).

Referring to FIG. 1, in some implementations, an article of clothing 100 may comprise a material having a pink color of a certain luminance or spectral reflectance. Although a shirt is shown, the garment 100 may be any clothing item, including, but not limited to, pants, trousers, jackets, hats, scarves, gloves, socks, shoes, etc.

To determine a highly visible color for the garment 100, the effect of fluorescence under low-light morning and evening conditions may be quantified. Two physical phenomena which may be considered include fluorescence and daylight spectral power distribution (SPD). Fluorescence occurs when a material absorbs incident photons of one energy and reemits excited photons at a lower energy. Critical to the characterization of fluorescent materials is understanding the wavelength ranges of the incident and excited photons. These ranges are referred to as an excitation region and an emission region. Fluorescence, in which incident and reflected photon energy are different, is distinguished from conventional reflectance, where reflected photons are of identical energy to incident photons. The wavelength change is a characteristic of the fluorescent material. For example, office paper and fabric detergent may excite in ultraviolet (UV) and violet light ranges and emit in blue light ranges. Daylight fluorescents may excite in a visible region, typically blue and green, and also emit in the visible region, typically green and red. In either case, the effect on the reflected/emitted light is two-fold: 1) a decrease of reflectance in the excitation range and 2) an increase of apparent reflectance in the emission region. Both of these may have an effect on the perceived color and perception of the emitted light.

The effectiveness of incident light in creating fluorescence is dependent on the spectral (wavelength) distribution of that light. Therefore, daylight SPD varies significantly with the time of day as well as cloud cover and other weather conditions. For example, pre-dawn, early morning, and noon-day sun are spectrally very different and would therefore excite fluorescent materials very differently. To a certain extent, daylight fluorescents may also be excited by artificial light sources, such as tungsten lamps or automobile headlights.

Product visibility under various illumination conditions can be an important factor for providing a garment that is highly visible of conspicuous (i.e., a degree of which an observer is likely to notice the material under a specific set of lighting conditions). Factors affecting conspicuity may depend on the state of the observer (e.g., driving, distracted, focused, color deficient, etc.) as well as environmental conditions (e.g., daylight conditions, a background behind a subject of interest, a distance from the observer, apparent size of a test field, etc.).

One or more spectral reflectance measurement instruments may be used to determine an excitation region of a fluorescent material and an emission region of that material. For example, a Perkin Elmer Lambda 19 (L19) can be used to determine the excitation region of the fluorescent material and a GretagMacbeth Coloreye 7000A (CE7000A) can be used to determine the emission region. These instruments provide estimates. A complete characterization of fluorescent behavior requires a complete bi-spectral reflectance measurement. Data corresponding to the measured emission region may be relatively more representative of what an observer actually sees when viewing the test material.

FIG. 2 is a graph of exemplary spectral reflectance data for a number of sample materials (e.g., using the Perkin Elmer Lambda 19 (L19)). Sample 1 is a yellow color. Sample 2 is a green color. Sample 3 is an orange color. Sample 4 is a pink color. Sample 5 is a pink aura color. Sample 6 is a pacific blue color. Sample 7 is a white color. The graph illustrates spectral reflectance as function of a spectral reflectance factor (y-axis) versus a wavelength (x-axis). The spectral reflectance factor can be considered to be a ratio of light reflected off the sample material to that reflected off a perfect white standard. Therefore, areas exceeding 1.0 will appear “brighter than white” which is an indication of fluorescence. Fluorescent emissions are shown in each curve that has a peak above a reflectance factor of 1. These peaks are the emission regions of each respective material.

FIG. 3 is a graph of exemplary spectral reflectance data for a number of sample materials (e.g., using the GretagMacbeth Coloreye 7000A (CE7000A)). Emission regions of the sample materials are less apparent visually than in FIG. 2; however, they can be found in wavelength ranges where the L19 values are relatively greater than the corresponding CE7000A ranges shown in FIG. 2. For example, over the range of 400-500 nm, sample 4 is about 0.1 in FIG. 2 and 0.5 in FIG. 3, indicating an excitation range for sample 4. To visualize both excitation and emission ranges, FIG. 4 provides a graph representing a difference (subtraction) between the L19 data and the CE7000A data. In FIG. 4, negative areas approximate excitation regions and positive areas approximate emission regions. To compare the samples under morning and evening daylight illumination, the power of daylight in the excitation regions will determine the extent of emission for each sample material. FIG. 5 shows a distribution of several types of natural daylight, ranging in Correlated Color Temperature (CCT) from 5000 K to 20,000 K. The Correlated Color Temperature (CCT) in Kelvin is a common metric for illuminant color. Higher CCT indicates bluer colors while lower CCT indicates redder colors. Pre-dawn daylight generally has a much higher blue and violet component, simulated by the high CCT curves. After calculating an extent of emission, perception may be addressed. In some examples, to determine perception, one may model or simulate the spectral reflectance of each material under each type of daylight, predicting a color perception of an average person. Since the only light seen is what was reflected or emitted, the emission ranges (e.g., positive regions in FIG. 4) may be considered, especially given that human visual system is not equally sensitive to all wavelengths of visible light. From the spectral reflectance, color is calculated as L* (luminance) a* (redness-greenness) and b* (blueness-yellowness).

Given the limited availability of the fluorescent excitation and emission behavior, to predict the color of the materials under arbitrary light sources, the CE7000A spectral reflectance can be used as a baseline. The emission region of that baseline curve will be scaled up or down depending on the amount of light present in the excitation region for each type of daylight. From the negative regions of FIG. 4, these excitation regions are taken to be 350-500 nm for samples 1 and 2 and 340-560 nm for samples 3 and 4. In some examples, the amount of light in the excitation bands can be summed for each daylight type, and scaled by the sum of the 6500 curve, shown in FIG. 5, to determine a scaling factor for that material/daylight combination. This is a reasonable assumption since the CE7000A data are measured under light very similar to 6500 daylight. The emission scaling factors are shown in table 1. The 6500 scaling factors are 1.00, since they should not be scaled at all.

	TABLE 1
	Daylight Curve (CCT in Kelvin)
	Sample	5000	6500	10000	15000	20000
	1 and 2	0.7	1.0	1.37	1.55	1.51
	3 and 4	0.77	1.0	1.26	1.37	1.32

Referring to FIG. 6, in some implementations, to predict spectral reflectance, each respective factor can be multiplied by the appropriate CE7000A measurement, yielding a family of curves for each material. The factor is applied only to the emission region (dotted curves in FIG. 6). The non-emission area of the spectra is set to the reflectance of the CE7000A measurement (solid curves in FIG. 6). Two metrics may be considered: luminance and color difference from black. Luminance quantifies how bright the material will appear. Luminance is generally a photometric measure of the luminous intensity per unit area of light travelling in a given direction. Luminance is defined by

$\begin{array}{cc}{L}_v=\frac{{}^2F}{A\mathrm{\Omega cos}\theta }& \left(1\right)\end{array}$

where L_v is the luminance (cd/m²), F is the luminous flux or luminous power (lm), θ is the angle between the surface normal and the specified direction, A is the area of the surface (m²), and Ω is the solid angle (sr). Color difference from black is a simple conspicuity metric, which assumes that the material is viewed in isolation against a black background. In both cases, greater values indicate better performance.

FIG. 7 shows the spectral reflectance of sample 3 under each type of daylight. Tables II and III show the luminance and color difference of the fluorescent materials when illuminated by the range of daylight curves. Color is calculated using the 1931 2° standard observer and D65 illuminant Note that the use of D65 here is not related to the choice of the simulated illuminant in the model (i.e., the daylight curves of various CCTs). For the color calculation, the identical illuminant is required so that the colors can be reasonably compared. In effect, this assumes that the calculated spectral reflectance curves in FIG. 6 are simultaneously viewed under the same lighting.

TABLE 2
Predicted luminance of illuminated material.
ΔE* to black	Sample 1	Sample 2	Sample 3	Sample 4
D5000	101.3	81.7	67.7	73.7
D6500	103.8	86.3	69.6	75.8
D10000	106.7	91.5	71.6	78.2
D15000	108.0	93.8	72.4	79.1
D25000	107.7	93.3	72.0	78.7

TABLE 3
Predicted color difference between illuminated materials and black.
ΔE* to black	Sample 1	Sample 2	Sample 3	Sample 4
D5000	141.0	114.5	95.2	119.1
D6500	146.3	126.6	99.6	125.1
D10000	152.8	140.5	104.3	131.6
D15000	155.7	146.6	106.3	134.2
D25000	155.1	145.3	105.4	133.0

The predicted color difference between illuminated materials and black can be an approximation of conspicuity of the sample material. Sample 3 provided relatively higher luminance than any of the non-fluorescent materials.

In some implementations, the article of clothing 100 comprises a material having a luminance of between about 67 cd/m² and about 72 cd/m² for light having a correlated color temperature of between about 5,000 Kelvin and about 25,000 Kelvin. In some examples, the material has a spectral reflectance of between about 1 and about 1.2 for light having a wavelength of between about 600 nm about 700 nm. The material may have a spectral reflectance of between about 1 and about 1.2 for light having a wavelength of between about 600 nm about 700 nm and a correlated color temperature of about 6500 Kelvin. In some examples, the material has a pink color, such as that of sample 3.

The article of clothing 100 may comprise a material having a spectral reflectance of between about 1 and about 1.2 for light having a wavelength of between about 600 nm about 700 nm. Moreover, the material may have a luminance of about 70 cd/m2 for light having a correlated color temperature of about 6500 Kelvin. The material may have a pink color. In additional examples, the article of clothing 100 comprises a material having a spectral reflectance of between about 1 and about 1.4 for light having a wavelength of between about 590 nm about 750 nm and a correlated color temperature of between about 10,000 Kelvin and about 20,000 Kelvin. In some examples, the light has a correlated color temperature of about 15,000 Kelvin.

Reflectivity is generally the fraction of incident radiation reflected by a surface. It may be treated as a directional property that is a function of the reflected direction, the incident direction, and the incident wavelength. Reflectance percentage values obtained for a number of specimens using a Datacolor Spectroflash 600, having a D65 illuminant and a 10 degree observer angle, are provided in Tables 4-7 and graphically illustrated in FIG. 8. The samples each were made of the same material, but of different colors: white, pink, orange, green, and yellow.

TABLE 4
Percent Reflectance.
Color	% Reflectance per Wavelength (nm)
Sample	400 nm	410 nm	420 nm	430 nm	440 nm	450 nm	460 nm	470 nm
White	40.85	64.51	90.90	100.03	101.11	94.85	89.51	86.90
Pink	44.85	48.75	50.87	51.26	48.49	43.13	37.60	31.15
Orange	18.61	15.98	12.94	10.48	8.53	7.56	7.19	7.03
Green	14.83	11.34	8.84	7.22	6.38	6.38	7.37	11.83
Yellow	13.82	10.47	8.12	6.61	5.85	5.84	6.82	11.37

TABLE 5
Percent Reflectance.
Color	% Reflectance per Wavelength (nm)
Sample	480 nm	490 nm	500 nm	510 nm	520 nm	530 nm	540 nm	550 nm
White	86.03	84.40	83.76	83.22	82.66	82.33	82.27	82.34
Pink	25.42	41.40	18.13	13.35	11.34	10.95	10.27	9.93
Orange	8.49	11.07	10.94	9.13	8.81	9.36	8.96	9.98
Green	27.02	58.61	100.73	122.52	118.30	103.94	88.30	75.34
Yellow	27.06	60.48	107.37	138.32	142.97	134.16	121.72	111.49

TABLE 6
Percent Reflectance.
Color	% Reflectance per Wavelength (nm)
Sample	560 nm	570 nm	580 nm	590 nm	600 nm	610 nm	620 nm	630 nm
White	82.44	82.56	82.66	82.90	83.06	83.18	83.33	83.46
Pink	13.84	28.26	59.06	100.57	139.91	155.17	152.80	153.11
Orange	17.84	39.32	74.72	110.54	139.86	152.62	151.78	150.15
Green	65.04	56.62	49.97	45.00	41.10	37.60	34.90	33.54
Yellow	104.28	98.66	94.01	90.66	88.84	87.21	85.83	85.22

TABLE 7
Percent Reflectance.
Color	% Reflectance per Wavelength (nm)
Sample	640 nm	650 nm	660 nm	670 nm	680 nm	690 nm	700 nm
White	83.63	83.90	84.11	84.20	84.35	84.48	84.64
Pink	147.12	132.54	123.19	112.67	104.87	98.80	99.20
Orange	141.90	128.05	121.10	113.12	106.58	100.35	84.64
Green	33.32	33.59	33.88	33.67	33.43	33.72	101.15
Yellow	84.89	84.56	84.56	84.32	84.21	84.18	35.74

As shown in FIG. 8, the pink sample provided the highest average percent reflectance over the 600-650 nm wavelength of light.

A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.

Claims

1. An article of clothing comprising a material having a luminance of between about 67 cd/m2 and about 72 cd/m2 for light having a correlated color temperature of between about 5,000 Kelvin and about 25,000 Kelvin.

2. The article of clothing of claim 1, wherein the material has a spectral reflectance of between about 1 and about 1.2 for light having a wavelength of between about 600 nm about 700 nm.

3. The article of clothing of claim 2, wherein the material has a spectral reflectance of between about 1 and about 1.2 for light having a wavelength of between about 600 nm about 700 nm and a correlated color temperature of about 6500 Kelvin.

4. The article of clothing of claim 1, wherein the material has a pink color.

5. An article of clothing comprising a material having a spectral reflectance of between about 1 and about 1.2 for light having a wavelength of between about 600 nm about 700 nm.

6. The article of clothing of claim 5, wherein the material has a spectral reflectance of between about 1 and about 1.2 for light having a wavelength of between about 600 nm about 700 nm and a correlated color temperature of about 6500 Kelvin.

7. The article of clothing of claim 5, wherein the material has luminance of about 70 cd/m2 for light having a correlated color temperature of about 6500 Kelvin.

8. The article of clothing of claim 5, wherein the material has a pink color.

9. An article of clothing comprising a material having a spectral reflectance of between about 1 and about 1.4 for light having a wavelength of between about 590 nm about 750 nm and a correlated color temperature of between about 10,000 Kelvin and about 20,000 Kelvin.

10. The article of clothing of claim 9, wherein the light has a correlated color temperature of about 15,000 Kelvin.

11. The article of clothing of claim 9, wherein the material has a luminance of between about 67 cd/m2 and about 72 cd/m2 for light having a correlated color temperature of between about 5,000 Kelvin and about 25,000 Kelvin.

12. The article of clothing of claim 9, wherein the material has a pink color.

13. An article of clothing comprising a material having a percent of spectral reflectance of light of between about 110% and about 150% for light having a wavelength of between about 600 nm about 650 nm.

14. The article of clothing of claim 13, wherein the material has a pink color.

15. The article of clothing of claim 13, wherein the material comprises at least one of cotton and polyester.