Single pass printing for spherical balls
Single pass printing methods designed to reduce or prevent unwanted image distortion and/or image defects when printing on a ball. In some embodiments, the methods can tailor one or more of nozzle firing time, nozzle firing frequency, or ink volume to reduce or prevent unwanted image distortion and/or image defects. Some embodiments are directed to golf balls comprising one or more images printed according to a single pass printing method described herein.
1 . A single pass printing method for a spherical ball, the method comprising:
rotating the spherical ball on a first central axis of the ball;
printing an image on the ball with a plurality of nozzles while the ball is rotating;
wherein:
the image on the ball is defined by an image area comprising a top boundary line and a bottom boundary line;
the image area is printed by printing ink droplets correlating to pixels arranged in consecutive image lines, each image line defined by a plurality of the pixels disposed between the top boundary line and the bottom boundary line;
a center location of each pixel is defined by:
a positive angle θ or a negative angle −θ, and
a positive linear distance Y from a second central axis of the ball perpendicular to the first central axis or a negative linear distance-Y from the second central axis;
each pixel comprises one or more ink droplets printed by a respective one of the nozzles;
a nozzle firing time of each of the plurality of nozzles is based on the center location of the pixel correlating to an ink droplet the nozzle prints; and
θ, −θ, Y and −Y are defined by the following equations, where R is the radius of the ball measured on the second central axis:
sin
(
θ
)
=
Y
R
,
and
sin
(
-
θ
)
=
-
Y
R
.
2 . The single pass printing method of claim 1 , wherein the nozzle firing time of each of the plurality of nozzles is based on an absolute value of Y or −Y (|Y|) for the pixel correlating to an ink droplet the nozzle prints.
3 . The single pass printing method of claim 2 , wherein the nozzle firing time for a first nozzle printing an ink droplet correlating to a first pixel located at a higher |Y| is earlier than the nozzle firing time for a second nozzle printing an ink droplet correlating to a second pixel located at a lower |Y|.
4 . The single pass printing method of claim 3 , wherein the nozzle firing time for the first nozzle is about 1.6 microseconds earlier than the nozzle firing time for the second nozzle.
5 . The single pass printing method of claim 2 , wherein the nozzle firing time of each of the plurality of nozzles is proportional to the |Y| for the respective pixels in the image line.
6 . The single pass printing method of claim 5 , wherein, as |Y| decreases, the nozzle firing time increases.
7 . The single pass printing method of claim 1 , wherein the nozzle firing time of each of the plurality of nozzles is based on an absolute value of 0 or −θ (|θ|) for the pixel correlating to an ink droplet the nozzle prints.
8 . The single pass printing method of claim 7 , wherein the nozzle firing time for a first nozzle printing an ink droplet correlating to a first pixel located at a higher |θ| is earlier than the nozzle firing time for a second nozzle printing an ink droplet correlating to a second pixel located at a lower |θ|.
9 . The single pass printing method of claim 8 , wherein the nozzle firing time for the first nozzle is about 1.6 microseconds earlier than the nozzle firing time for the second nozzle.
10 . The single pass printing method of claim 7 , wherein the nozzle firing time of each of the plurality of nozzles is proportional to |θ| for the respective pixels in the image line.
11 . The single pass printing method of claim 10 , wherein, as |θ| decreases, the nozzle firing time increases.
12 . The single pass printing method of claim 1 , wherein the image area comprises a continuous image band wrapped around all or a portion of the ball and having a constant height.
13 . The single pass printing method of claim 12 , wherein the continuous image band is printed by printing ink droplets correlating to pixels in consecutive image lines having a different number of pixels.
14 . The single pass printing method of claim 12 , wherein the continuous image band wraps completely around the ball.
15 . The single pass printing method of claim 12 , wherein the continuous image band wraps around the ball such that a first portion of the image band overlaps a second portion of the image band.
16 . The single pass printing method of claim 15 , wherein the image lines correlating to the first portion of the image band and the second portion of the image band are printed with a smaller volume of ink compared to the image lines correlating to the remainder of the image band.
17 . The single pass printing method of claim 1 , wherein the ball is rotating at a rate of about 160 revolutions per minute.
18 . The single pass printing method of claim 1 , wherein the plurality of nozzles prints at a resolution of at least 360 dpi.
19 . The single pass printing method of claim 1 , wherein a volume of the ink droplets printed by the plurality of nozzles varies based on an absolute value of Y or −Y (|Y|) for the pixels correlating to the ink droplets the nozzles print.
20 . The single pass printing method of claim 1 , wherein the dpi of ink droplets printed by the plurality of nozzles varies based on an absolute value of Y or −Y (|Y|) for the pixels correlating to the ink droplets the nozzles print.
21 . The single pass printing method of claim 1 , wherein the plurality of nozzles are configured to print the image on an upper hemisphere and a lower hemisphere of the spherical ball in a single pass.