Method of enabling entry of data into a computer system via a printed form

1. A method of enabling entry of data into a computer system via a printed form, said method comprising the steps of:

providing the printed form, said form containing human-readable information and machine-readable coded data, the coded data being indicative of: an identity of the form and a plurality of locations on the form;

operatively positioning a sensing device relative to the form;

sensing at least some of the coded data;

generating indicating data using the sensed coded data, said indicating data being indicative of the identity of the form and the position of the sensing device relative to the form; and

sending the indicating data to a computer system, thereby enabling the computer system to identify the data for entry,

wherein said coded data comprises an ink composition containing an IR-absorbing dye and a singlet oxygen quencher.

2. The method of claim 1 , wherein said IR-absorbing dye is a metal-dithiolene dye.

3. The method of claim 2 , wherein the metal-dithiolene dye is of formula (II):

wherein:

M is selected from Ni, Pd or Pt;

j is selected from 0, 1, 2, 3 or 4;

k is selected from 0, 1, 2, 3 or 4;

n is selected from 1, 2 or 3;

W is a hydrophilic group selected from the group comprising: a substituent comprising an ammonium group; a substituent comprising an acid group, including salts thereof; and a substituent comprising a sulfonamide group;

up to three —(CH 2 ) groups in the carbocycle may be optionally replaced by a group independently selected from —C(O), —NH, S, O;

up to three CH groups in the carbocycle may be optionally replaced by N;

up to four H atoms in the carbocycle may be optionally replaced by a group independently selected from C 1-6 alkyl, C 1-6 alkoxy, C 5-12 aryl, C 5-12 arylalkyl, halogen, hydroxyl or amino; and

provided that at least one of j or k is greater than 0.

4. The method of claim 3 , wherein at least one of R 10 , R 11 , R 12 or R 13 comprises a hydrophilic group.

5. The method of claim 3 , wherein M is Ni.

6. The method of claim 3 , wherein j is 1 and k is 2.

7. The method of claim 3 , wherein W is of formula —(CH 2 ) t SO 3 Z, wherein t is 0 or an integer from 1 to 6, and Z is H or a water-soluble cation.

8. The method of claim 1 , wherein the indicating data includes movement data regarding movement of the sensing device relative to the form, the sensing device generating the movement data using at least some of the coded data.

9. The method of claim 8 , wherein the indicating data enables the computer system to identify at least one field.

10. The method of claim 9 , wherein the at least one field is an action field and the computer system sends a message to an application associated with the action field.

11. The method of claim 10 , wherein the action field is a form submission action field and the message includes form data derived from at least one other field of the form.

12. The method of claim 9 , wherein the at least one field is a text field and the computer system converts at least some of the movement data to text.

13. The method of claim 9 , which the at least one field is a drawing field.

14. The method of claim 9 , wherein the at least one field is a checkbox field and the computer system interprets at least some of the movement data as a check mark.

15. The method of claim 9 , wherein the at least one field is a signature field and the computer system verifies that at least some of the movement data represents a signature of a user associated with the sensing device.

16. The method of claim 1 , wherein the coded data is formed from a plurality of coded data portions, each coded data portion being indicative of the identity of a product item.

17. The method of claim 16 , wherein the coded data is indicative of at least one of a UPC or an EPC associated with the product item.

18. The method of claim 1 , wherein said ink composition is a water-based inkjet ink.

19. The method of claim 1 , wherein the singlet oxygen quencher is selected from the group consisting of: ascorbic acid, 1,4-diazabicyclo-[2,2,2]octane, sodium azide, histidine and tryptophan.

20. The method of claim 1 , wherein the coded data is substantially invisible to an unaided human eye.