(a) Display. All signs with digital display:
(1) must contain a default mechanism that freezes the image in one position in case of a malfunction;
(2) must automatically adjust the sign brightness based on natural ambient light conditions in compliance with the following formula:
(A) the ambient light level measured in luxes, divided by 256 and then rounded down to the nearest whole number, equals the dimming level; then
(B) the dimming level, multiplied by .0039 equals the brightness level; then
(C) the brightness level, multiplied by the maximum brightness of the specific sign measured in nits, equals the allowed sign brightness, measured in nits. For example:
32768 =ambient
÷ 256
128 =dimming level
x .0039
.4992 =brightness level
x 9000 =(maximum brightness
of the example sign)
4492.8 =allowed brightness in
nits;
(3) may not display light of such intensity or brilliance to cause glare, impair the vision of an ordinary driver, or constitute a nuisance;
(4) must have a full color display able to display a minimum of 281 trillion color shades; and
(5) must be able to display a high quality image with a minimum resolution equivalent to the following table:
Digital Display Sign Resolution Chart
| |
Size of LED Panel | Maximum Pixel Size |
100 s/f to 125 s/f | 16 mm |
Greater than 126 s/f | 19 mm |
(b) Light intensity. Before the issuance of a sign permit for a sign with a digital display, the applicant shall provide written certification from the sign manufacturer that:
(1) the light intensity has been factory programmed to comply with the maximum brightness and dimming standards in the formula in Subparagraph (a)(2); and
(2) the light intensity is protected from end-user manipulation by password-protected software, or other method satisfactory to the building official.
(c) Change of message. Except as provided in this section, changes of message must comply with the following:
(1) Each message must be displayed for a minimum of eight seconds.
(2) Changes of message must be accomplished within two seconds.
(3) Changes of message must occur simultaneously on the entire sign face.
(4) No flashing, dimming, or brightening of message is permitted except to accommodate changes of message.
(d) Streaming information. If a special events permit has been issued for district activities, ticker tape streaming and streaming video are permitted.
(e) Malfunction. Digital display sign operators must respond to a malfunction or safety issue within one hour after notification. (Ord. 28071)