Ink jet print head adapted to minimize orientation-induced line-width variation

1. An ink jet print head adapted to minimize orientation-induced line-width variation, the print head comprising:

n+q nozzles, wherein n nozzles are located at vertices of a polygon having an average side length s avg and q nozzles are located inside the boundary of said polygon, and wherein each side length of the polygon is less than 20% deviation from the average side length s avg ;

wherein the n+q nozzles are configured to ink jet a line having a line-width w; and

wherein each of the n+q nozzles is configured to ink jet a spot having an average area-equivalent spot diameter d which satisfies the inequality conditions (I)

0.7 w≦d +( n /π) s avg ≦1.3 w   (I).

2. The ink jet print head of claim 1 , wherein the polygon is a regular polygon.

3. The ink jet print head of claim 1 , wherein q=1.

4. The ink jet print head of claim 1 , wherein n ranges from 3 to 10.

5. The ink jet print head of claim 1 , wherein n ranges from 3 to 6.

6. The ink jet print head of claim 1 , wherein d ranges from about 20 μm to about 300 μm.

7. The ink jet print head of claim 1 , wherein w ranges from about 50 μm to about 2000 μm.

8. An ink jet print head adapted to minimize orientation-induced line-width variation, the print head comprising:

n+1 nozzles, wherein the n+1 nozzles are configured to ink jet a line having a line-width w; and

wherein n nozzles are located at vertices of a polygon having an average side length s avg and one nozzle is located inside the polygon boundary, and wherein each side length of the polygon is less than 20% deviation from the average side length s avg ;

wherein each of the n+1 nozzles is configured to ink jet a spot having an average area-equivalent spot diameter d which satisfies the inequality conditions (IIa, IIb, IIc) with coefficient λ=1.3:

½ s avg csc(π/ n ) ≦d≦λs avg when n= 2, 3, 4  (IIa),

½ s avg cot(π/ n ) ≦d≦λs avg when n= 5, 6  (IIb),

and

½ s avg cot(π/ n ) ≦d≦ ½ λs avg csc(π/ n ) when n= 7, 8, 9,  (IIc).

9. The ink jet print head of claim 8 , wherein the polygon is a regular polygon and the one nozzle located inside the polygon boundary lies at the center of the regular polygon.

10. An ink jet print head adapted to minimize orientation-induced line-width variation, the print head comprising:

n+1 nozzles, wherein the n+1 nozzles are configured to ink jet a line having a line-width w; and

wherein n nozzles are located at vertices of a polygon having an average side length s avg and one nozzle is located inside the polygon boundary, and wherein each side length of the polygon is less than 20% deviation from the average side length s avg ;

wherein the n+1 nozzles are configured to ink jet a polygonal array of ink spots having an average area-equivalent spot diameter d which satisfies the inequality conditions (IIIa, IIIb, IIIc) with coefficient λ=1.3:

w/[ 1+(2 n /π)sin(π/ n ) ]≦d≦λw/[λ+n /π], where n= 2, 3, 4  (IIIa),

w/[ 1+(2 n /π)tan(π/ n ) ]≦d≦λw/[λ+n /π], where n= 5, 6  (IIIb),

and

w/[ 1+(2 n /π)tan(π/ n ) ]≦d≦λw/[λ+ (2 n /π)sin(π/ n )], where n= 7, 8, 9,  (IIIc).

11. The ink jet print head of claim 10 , wherein the polygon is a regular polygon and the one nozzle located inside the polygon boundary lies at the center of the regular polygon.

12. An ink jet print head adapted to minimize orientation-induced line-width variation, the print head comprising:

n+1 nozzles, wherein n nozzles are located at vertices of a polygon having an average side length s avg and one nozzle is located inside the polygon boundary, and wherein each side length of the polygon is less than 20% deviation from the average side length s avg which satisfies the inequality conditions (IVa, IVb, IVc) with coefficient λ=1.3:

w/[λ+n/π]≦s avg ≦2 w sin(π/ n )/[1+(2 n /π)sin(π/ n )], where n= 2, 3, 4  (IVa),

w/[λ+n/π]≦s avg ≦2 w tan(π/ n )/[1+(2 n /π)tan(π/ n )], where n= 5, 6  (IVb),

and

2 w sin(π/ n )/[λ+(2 n /π)sin(π/ n ) ]≦s avg ≦2 w tan(π/ n )/[1+(2 n /π)tan(π/ n )], where n= 7, 8, 9,  (IVc).

13. The ink jet print head of claim 12 , wherein the polygon is a regular polygon and the one nozzle located inside the polygon boundary lies at the center of the regular polygon.

14. An ink jet print head adapted to minimize orientation-induced line-width variation, the print head comprising:

n+1 nozzles, wherein n nozzles are located at vertices of a polygon having an average side length s avg and one nozzle is located inside the polygon boundary, and wherein each side length of the polygon is less than 20% deviation from the average side length s avg ;

wherein each of the n+1 nozzles is configured to ink jet a line having a line width w which satisfies the inequality conditions (Va, Vb, Vc) with coefficient λ=1.3:

[ n/π+ ½ csc(π/ n ) ]s avg ≦w≦[λ+n/π]s avg , where n= 2, 3, 4  (Va),

[ n/π+ ½ cot(π/ n ) ]s avg ≦w≦[λ+n/π]s avg , where n= 5, 6  (Vb),

and

[ n/π+ ½ cot(π/ n ) ]s avg ≦w≦[n/π+ ½λ csc(π/ n ) ]s avg , where n= 7, 8, 9,  (Vc).

15. An ink jet print head adapted to minimize orientation-induced line-width variation, the print head comprising:

n+1 nozzles, wherein n nozzles are located at vertices of a polygon having an average side length s avg and one nozzle is located inside the polygon boundary and configured for ink jetting a polygonal array of ink spots having an average area-equivalent spot diameter d; and

wherein each side length of the polygon is less than 20% deviation from the average side length s avg which satisfy the inequality conditions (VIa, VIb, VIc) with coefficient)λ=1.3:

d/λ≦s avg ≦2 d sin(π/ n ), where n= 2, 3, 4  (VIa),

d/λ≦s avg ≦2 d tan(π/ n ), where n= 5, 6  (VIb),

and

(2 d /λ)sin(π/ n ) ≦s avg ≦2 d tan(π/ n ), where n= 7, 8, 9,  (VIc).

16. An ink jet print head adapted to minimize orientation-induced line-width variation, the print head comprising:

n+1 nozzles, wherein n nozzles are located at vertices of a polygon having an average side length s avg and one nozzle is located inside the polygon boundary, and wherein each side length of the polygon is less than 20% deviation from the average side length s avg ; and configured for ink jetting a polygonal array of ink spots having an average area-equivalent spot diameter d; and

wherein each of the n+1 nozzles is configured to ink jet a line having a line width w which satisfies the inequality conditions (VIIa, VIIb, VIIc) with coefficient λ=1.3:

[1+( n /πλ) ]d≦w≦[ 1+(2 n /π)sin(π/ n )] d , where n= 2, 3, 4  (VIIa),

[1+( n /πλ) ]d≦w≦[ 1+(2 n /π)tan(π/ n )] d , where n= 5, 6  (VIIb), and

[1+(2 n /π)sin(π/ n ) ]d≦w≦[ 1+(2 n /π)tan(π/ n ) ]d , where n =7, 8, 9,  (VIIc).

17. An ink jet print head adapted to minimize orientation-induced line-width variation, the print head comprising:

n+q nozzles, wherein the n nozzles are located at vertices of a regular polygon and q nozzles are located inside the boundary of the regular polygon;

wherein n ranges from 2 to 30 and q ranges from about 0 to 8.

18. The ink jet print head of claim 17 , wherein n=3 and q=0.

19. The ink jet print head of claim 17 , wherein n=3 and q=1.

20. The ink jet print head of claim 17 , wherein n is an odd integer and n≧3.