Datasheet

12
8. Optical Characteristics
8.1 Specifications
Measurements are made with that the illumination is under an angle of 45 degrees, the detector is perpendicular
unless otherwise specified.
T = 25
o
C
Symbol Parameter Conditions Min. Typ. Max. Unit
Note
R Reflectance White
33 42
- %
Note
8-1
Gn N
th
Grey Level -
DS+(WS-DS)×
n/(m-1)
L*
-
CR Contrast Ratio - 10 16 -
-
WS: White state , DS: Dark state, Gray state from Dark to White :DS、G1、G2…、Gn…、Gm-2、WS
m:4、8、16 when 2、3、4 bits mode
Note 8-1: Luminance meter: Eye – One Pro Spectrophotometer
8.2 Definition of contrast ratio
The contrast ratio (CR) is the ratio between the reflectance in a full white area (Rl) and the reflectance in a dark
area (Rd): CR = Rl / Rd
8.3 Reflection Ratio
The reflection ratio is expressed as:
R = Reflectance Factor
white board
x ( L
center
/ L
white board
)
L
center
is the luminance measured at center in a white area (R=G=B=1). L
white board
is the luminance of a standard
white boa
rd. Both are measured with equivalent illumination source. The viewing angle shall be no more than 2
degrees.
9.7inch e-Paper