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US 2006/0230967 A1Published application
Methods for measurement and control of ink concentration and film thickness
AssigneeSun Chemical Corporation
InventorDanny Rich
Life of this patent
Estimating the term…
Abstract
A process is disclosed to measure or monitor ink concentration or ink thickness of an ink film as printed on a printing press, which consists of measuring light reflected from the ink film and the ink substrate.
Claims4
A method of measuring printed ink concentration on an opaque substrate on-line comprising:
- (a) projecting a light over the ink printed on the substrate measuring light reflectance as a camera response R, G or B, wherein R is the camera response for a red sensor, G is the camera response for a green sensor and B is the camera response for a Blue sensor;
- (b) Substituting the camera response R, G or B for reflectance (ρo) of the printed ink over the opaque substrate in order to calculate the extinction (E) of light by the printed ink as indicated in the following formula
- E
- =
-
- -
- 2
- b
- ·
-
- ln
-
- {
- -
- (
- 1
- -
- B
- 0
- )
- ·
- (
- 1
- -
- ρ
- 0
- )
- 2
- ·
- ρ
- ·
- B
- 0
- +
- [
- (
- 1
- -
- β
- 0
- )
- ·
- (
- 1
- -
- ρ
- 0
- )
- 2
- ·
- ρ
- ·
- B
- 0
- ]
- 2
- +
- 1
- B
- -
- B
- 0
- }
- wherein B, b and B0 are constants having values of about 1.0, 4.271 and 0.606, respectively;
- and
- (c) calculating printed ink concentration (c) based on the following formula:
- E=ε×c×t
- wherein (E) is as calculated in step (b), (ε) is the relative (relative to the scattering of the substrate) unit extinction coefficient, a predetermined measurement of the pre-printed ink per unit concentration per unit thickness and (t) is the thickness of the printed ink either predetermined prior to or measured after printing.
65 more elements
A method of measuring printed ink thickness on a substrate on-line comprising:
- (a) projecting a light over the ink printed on the substrate measuring light reflectance as a camera response R, G or B, wherein R is the camera response for a red sensor, G is the camera response for a green sensor and B is the camera response for a Blue sensor;
- (b) Substituting the camera response R, G or B for reflectance (ρo) of the printed ink over the opaque substrate in order to calculate the extinction (E) of light by the printed ink as indicated in the following formula
- E
- =
-
- -
- 2
- b
- ·
-
- ln
-
- {
- -
- (
- 1
- -
- B
- 0
- )
- ·
- (
- 1
- -
- ρ
- 0
- )
- 2
- ·
- ρ
- ·
- B
- 0
- +
- [
- (
- 1
- -
- β
- 0
- )
- ·
- (
- 1
- -
- ρ
- 0
- )
- 2
- ·
- ρ
- ·
- B
- 0
- ]
- 2
- +
- 1
- B
- -
- B
- 0
- }
- wherein B, b and B0 are constants having values of about 1.0, 4.271 and 0.606, respectively;
- and
- (c) calculating printed ink thickness (t) based on the following formula:
- E=ε×c×t
- wherein (E) is as calculated in step (b), (ε) is the relative (relative to the scattering of the substrate) unit extinction coefficient, a predetermined measurement of the pre-printed ink per unit concentration per unit thickness and (c) is the concentration of the printed ink either predetermined prior to or measured after printing.
65 more elements
Dependencies are inferred from the claim text.