EWG:Draft Oct 26 Reflectance Contrast for Legends and Passive Displays

2.1-B - Reflectance Contrast for Legends and Passive Displays

This page is the text proposed in the Nov Plenary Meeting.

Go to the Oct 26 Draft of this Provision

Go to the Sandbox of this Provision

Proposed text in Oct 26 draft:
If the legend or instructions on the device are the only means of conveying information, then the luminance contrast shall be at least 3:1.

Note: If other means of conveying the information in the label or instructions exists (e.g. uniquely tactilely discernible though shape), then the luminance contrast requirement does not apply.

Note: This requirement excludes product information labels, such as the regulatory labels, where information can be found in other sources associated with the product either in hard- or soft copy format.

Note: Reflectance contrast (RC) is calculated in the following manner RC = (R(h) +0.02)/(R(l)+0.02) where R(h) = Reflectance of high (bright) element; R(s) = Reflectance of low (dark) element. Where the reflectance is always a value between 0 and 1.

Note: Additionally, I think we need to convey at least for computers that there are different levels. E.G the alphanumeric labels are the primary labels and should meet this convention; however, the secondary functions (such as the blue numbers on an embedded numpad on a notebook) should not meet this convention as they are infrequently used and in the case of the numpad may add to visual clutter and additional confusion relative to the keyboard interaction.

Version 2 proposed by Rob N, November 14, 2007 to address issues raised:
If legends or instructions printed on the device are the only means of conveying information, then the reflectance contrast shall be at least 3:1.

Note: If other means of conveying the information in the label or instructions exists (e.g. uniquely tactilely discernible though shape), then the reflectance contrast requirement does not apply.

Note: This requirement excludes product information labels, such as the regulatory labels, where information can be found in other sources associated with the product either in hard- or soft copy format.

Note: Reflectance contrast (RC) is calculated in the following manner RC = (R(h) +0.02)/(R(l)+0.02) where R(h) = Reflectance of high (bright) element; R(s) = Reflectance of low (dark) element, where the reflectance is always a value between 0 and 1.

Note: This requirement does not apply to legends that serve secondary functions. For example, on keyboards the alphanumeric labels are the primary legends and should meet this convention; however, the secondary functions (such as the blue numbers on an embedded numpad on a notebook) should not meet this convention as they are infrequently used and in the case of the numpad may add to visual clutter and additional confusion relative to the keyboard interaction.