US 9,423,346 B2Granted

System and method for haze measurement

AssigneeDatacolor Holding AG

InventorZhiling Xu

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Abstract

The present invention is directed to an apparatus and method for measuring the haze value of transmissive samples. The apparatus comprises a first light source selectively configurable to emit a first light beam, a second light source selectively configurable to emit a second light beam, an integrating sphere having an outer surface and an inner surface, the inner surface configured to reflect light incident upon the inner surface, the inner surface further enclosing an interior volume. The integrating sphere is further equipped with an exit port configured to emit light from the interior volume of the integrating sphere. The exit port is positioned such that light from the first light source exits the integrating sphere without obstruction, and light from the second light source is diffused on the interior surface of the integrating sphere prior to exiting the exit port. A light detector is also included and is configured to generate a light-intensity signal when light exiting the integrating sphere has passed through a sample and is incident on the light detector. The apparatus further includes a processor configured to receive the light-intensity signal and generate an output signal to a user indicating the haze value. The present invention is also directed to a method of calculating the haze value of a sample using a stored calibration value, a diffuse transmission value (sample-absent diffuse light-intensity value), a direct transmission value (sample-absent direct light-intensity value), a measured diffuse transmission value (sample-present diffuse light-intensity value) and a measured direct transmission value (sample-present direct light-intensity value).

Claims20

Dependent claims

An apparatus for measuring the haze value of transmissive samples, the apparatus comprising:

a first light source selectively configurable to emit a first light beam,
a second light source selectively configurable to emit a second light beam,
an integrating sphere having an outer surface and an inner surface, the inner surface configured to reflect light incident upon the inner surface, the inner surface further enclosing an interior volume, the integrating sphere is equipped with at least one entrance port configured to allow light from one of the light sources to enter the integrating sphere the integrating sphere having an exit port configured to emit light from the interior volume of the integrating sphere, wherein the exit port is positioned such that light from the first light source exits the integrating sphere without obstruction, and light from the second light source is diffused on the interior surface of the integrating sphere prior to exiting the exit port;
a light detector configured to generate a signal when light that has left the exit port of the integrating sphere is incident on the light detector, and
a processor configured to activate only the first light source and receive the signal generated by the light detector and activate only the second light source and receive the signal generated by the light detector and calculate a haze value based on the signals generated by the light detector such that
haze
=
(
I
4
I
4
+
k
·
I
6
-
I
3
I
3
+
k
·
I
5
)
×
100
⁢
%
;
wherein k is a stored calibration coefficient value, I3 corresponds to a first measurement made by the light detector with the second light source activated and a sample located between the exit port and the light detector, I5 is a first measurement value with the first light source activated and a sample located between the exit port and the light detector, I4 is a second measurement value with the second light source activated and no sample is located between the exit port and the light detector, and I6 is a second measurement value with the first light source activated and no sample located between the exit port and the light detector direct transmission value.

31 more elements

A computer-implemented method for utilizing a particular connection with an electronic device in determining a set of haze characteristics of a sample using at least one light detection device, an integrating sphere having an interior surface and configured to enclose a given volume, at least a primary and secondary configurable light sources, the particular electronic device having a processor, a memory, an input device, an output device and a calculation application stored in the memory and executable by the processor, the method comprising the steps of:

projecting a first light beam from the primary light source into an integrating sphere, the light beam positioned so as to not interact with the interior surface of the integrating sphere;
measuring the first light output from an exit port of the integrating sphere with a light detecting device;
projecting a second light beam from the secondary light source onto an interior surface of the integrating sphere so as to generate a diffuse transmitted-light-intensity value (herein also called a diffuse transmission value) related thereto;
measuring the second light output from the exit port with the light detector device;
inserting a transmissive sample between the exit port of the integrating sphere and the light detection device;
projecting a third light beam from the primary light source into the integrating sphere and the transmissive sample being positioned outside the integrating sphere and the first light beam being positioned so as to pass unobstructed through the integrating sphere;
measuring the third light output from the exit and incident on the light detector device and generating a second direct transmission value;
projecting a fourth light beam from the secondary light source into the second entry port of the integrating sphere and onto an interior surface of the integrating sphere;
measuring the fourth light output from the exit and incident on the light detector device and generating a second diffuse transmission value;
calculating a haze value of the sample such that
haze
=
(
I
4
I
4
+
k
·
I
6
-
I
3
I
3
+
k
·
I
5
)
×
100
⁢
%
;
wherein k is a stored calibration coefficient value, I3 is the first diffuse transmission value, I5 is the first direct transmission value, I4 is the second diffuse transmission value and I6 is the second direct transmission value, and
outputting an audio-visual indicator correlated to the haze value of the sample.

37 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/213,064Filed 14 Mar 2014
Published: US 2015/0260648 A117 Sep 2015
Granted: 23 Aug 2016
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

G01N 21/59
Systems in which incident light is modified in accordance with the properties of the material investigated: transmissivity
G01N 21/4738
Scattering, i.e. diffuse reflection: diffuse reflection , e.g. also for testing fluids, fibrous materials
G01N 21/94
Investigating the presence of flaws or contamination: investigating contamination, e.g. dust
G01N 2021/4707
Angular selective: forward scatter; Low angle scatter