Stored light intensity measurement device
AssigneeKyoto Electronics Manufacturing Co., Ltd.
InventorsTatusya Muraoka, Hisataka Mukai
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Abstract
A stored light intensity measurement device capable of measuring an afterglow intensity from a light storing sign in a simple way, even if the light storing sign is provided on walls or risers of stairs in facilities or underground shopping mall. The stored light intensity measurement device comprising the light measuring unit configured o measure afterglow from a part of a light storing section on a light storing sign, and calculation means for calculating an afterglow intensity from the light storing sign based on the measured results.
Claims7
A stored light intensity measurement device comprising:
- a light measurement unit configured to measure afterglow from a part of a light storing section on a light storing sign;
- and
- calculation means for obtaining an approximate expression,
- L
- =
- 1
- α
- +
- β
-
-
- t
- ,
- α
- ,
- β
- :
- constants
- ,
- L:intensity, and t:time
- based on the afterglow intensity measured from a first time t1 to a second time t2 after a beginning of the light interception, and predicting the afterglow intensity at an arbitrary time t3 after the beginning of the light interception using the approximate expression,
- wherein the time t1, t2, and t3 are t1<t2<t3, and a display means is used to display the afterglow intensity.
Dependencies are inferred from the claim text.