CONTROL SYSTEMS AND METHODS FOR THERMAL-JET PRINTING

1 . A printing apparatus comprising:

a) a dispensing mechanism for dispensing droplets of ink comprising a carrier liquid and a print material;

b) a thermal-jet comprising one or more micro-structures for receiving the droplets of ink from the dispensing mechanism;

c) a heating element thermally coupled to the thermal-jet for heating the thermal-jet through a temperature profile that evaporates the carrier liquid from the ink and vaporizes the print material from the micro-structures, directing the vaporized print material onto a substrate to produce a printed image;

d) at least one sensor configured to measure at least one quantity associated with said printing apparatus; and

e) a control unit for controlling the print head based on the at least one measured quantity by said at least one sensor.

2 . The printing apparatus of claim 1 , wherein the measured quantity comprises resistance of the heating element and, wherein the control unit is adapted to control the temperature profile.

3 . The printing apparatus of claim 1 , wherein the measured quantity comprises a size of the ink droplets and, wherein the control unit is adapted to control an amount of ink dispensed.

4 . The printing apparatus of claim 3 , further comprising a camera and a strobe light for determining sizes of the ink droplets.

5 . The printing apparatus of claim 1 , wherein the measured quantity comprises image quality of the printed image and, wherein the control unit is adapted to control one or more of the temperature profile and an amount of ink dispensed.

6 . A printing apparatus comprising:

a) a plurality of ink-jets for dispensing droplets of ink comprising a carrier liquid and a print material;

b) a plurality of thermal-jets including micro-structures for receiving the droplets of ink, wherein each thermal jet is configured to heat through a temperature profile for evaporating the carrier liquid from the ink and for vaporizing the print material from the micro-structures and directing the vaporized print material onto a substrate to produce a printed image;

c) at least one sensor configured to measure at least one quantity associated with said printing apparatus; and

d) a control unit for selectively controlling the printed image based on at least one quantity measured by said at least one sensor.

7 . The printing apparatus of claim 6 , wherein the measured quantity comprises resistance of heating elements coupled to the thermal jets and, wherein the control unit is adapted to selectively control the temperature profiles of the thermal jets.

8 . The printing apparatus of claim 6 , wherein the measured quantity comprises size of the ink droplets and, wherein the control unit is adapted to selectively control an amount of ink comprising the ink droplets.

9 . The printing apparatus of claim 8 , further comprising a camera and a strobe light for determining sizes of the ink droplets.

10 . The printing apparatus of claim 6 , wherein the measured quantity comprises a test pattern on the printed image and, wherein the control unit is adapted to align one or more of the printheads with the substrate.

11 . A method of controlling a printed image from a printing apparatus based on at least one measured quantity, the method comprising:

a) measuring the at least one quantity; and

b) adjusting an output from one or more printheads of the printing apparatus based on the at least one measured quantity, wherein the printing apparatus includes;

i) an ink-jet portion for dispensing droplets of ink comprising a carrier liquid and a print material; and

ii) a thermal-jet portion including micro-structures for receiving the droplets of ink, wherein the thermal jet is configured to heat through a temperature profile for evaporating the carrier liquid from the ink within the micro-structures and for vaporizing the print material from the micro-structures and directing the vaporized print material onto a substrate to produce the printed image.

12 . The method of claim 11 , wherein said measuring comprises measuring sizes of the droplets of ink.

13 . The method of claim 11 , wherein said measuring comprises measuring a temperature of the thermal-jet portion.

14 . The method of claim 11 , wherein said measuring comprises measuring a test pattern on the printed image.

15 . The method of claim 11 , wherein said measuring comprises measuring a layer thickness of the printed image.

16 . The method of claim 11 , wherein said measuring comprises measuring a surface coverage of the printed image.

17 . A method of controlling a printed image produced by a printing apparatus, the method comprising:

a) generating a test pattern from one or more printheads of the printing apparatus wherein the printing apparatus includes;

i) an ink-jet for dispensing droplets of ink comprising a carrier liquid and a print material; and

ii) a thermal-jet including micro-structures for receiving the droplets of ink, wherein the thermal-jet is configured to heat through a temperature profile for evaporating the carrier liquid from the ink within the micro-structures and for vaporizing the print material from the micro-structures and directing the vaporized print material onto a substrate to produce the test pattern;

b) measuring a quantity of the test pattern; and

c) adjusting an output from one or more printheads on the printing apparatus based on the measured quantity of the test pattern.