1. An ink-jet printer head comprising:
a nozzle plate having a nozzle plate surface for discharging ink
an organic film provided on the nozzle plate surface;
solid particles having abrasion resistance dispersed in said organic film; and
a water-repellent film provided on a surface of the organic film, the water repellant film comprising chains of fluorocarbon polymer.
2. The ink-jet printer head according to claim 1, wherein at least part of the solid particles protrudes from the chains of fluorocarbon polymer.
3. The ink jet printer according to claim 2, wherein the solid particles comprise an inorganic material.
4. The ink jet printer according to claim 2, wherein the solid particles comprise a material selected from the group consisting of silica, clay and alumina.
5. The ink-jet printer head according to claim 1, wherein, when a protrusion percentage of the solid particles (%) and a volumetric percentage of the solid particles (%) are defined according to following Equations (1) and (2), respectively, the protrusion percentage of the solid particles and the volumetric percentage of the solid particles fall in a range surrounded by four points of a (X=5, Y=20), b (X=5, Y=60), c (X=25, Y=55) and d (X=30, Y=20) in a correlation diagram with an X-axis indicating the protrusion percentage of the solid particles and a Y-axis indicating the volumetric percentage of the solid particles:
P (%) ((h1\u2212t1)t1)\xd7100\u2003\u2003(1)
C (%)=(v1v2)\xd7100\u2003\u2003(2)
wherein P (%) is the protrusion percentage of the solid particles; h1 is a height of protruded solid particles; t1 is a thickness of the organic film; C (%) is the volumetric percentage of the solid particles; v1 is thea volume of the solid particles; and v2 is a volume of the organic film.
6. A method for manufacturing an ink-jet printer head in which a water-repellent film is provided on a nozzle plate for discharging ink, wherein the water-repellent film is formed into a structure, in which part of the solid particles protrudes from the resinous film, by the steps of:
(a) coating a solution containing solid particles and a resinous film element on a nozzle plate;
(b) drying the coated solution at 150\xb0 C. to form a resinous film;
(c) coating a solution containing the chains of fluorocarbon polymer on the resinous film; and
(d) transpiring the solvent by heating at 130\xb0 C.
7. A method for manufacturing an ink-jet printer head in which a water-repellent film is provided on a nozzle plate for discharging ink, wherein the water-repellent film is formed into a structure, in which part of the solid particles protrudes from the resinous film, by the steps of:
(a) coating a solution containing solid particles, a resinous film element, and the chains of fluorocarbon polymer on a nozzle plate;
(b) pre-curing at 80\xb0 C.;
(c) drying the coated solution at 150\xb0 C. to form a resinous film;
(d) coating a solution containing the chains of fluorocarbon polymer on the resinous film; and
(e) transpiring the solvent by heating at 130\xb0 C.
8. A method of manufacturing an ink-jet printer head according to claim 6 or 7, wherein
a surface treatment is applied to the solid particles by a silane coupling agent prior to the process (a).
9. The ink jet printer manufactured by the method according to claim 6 or 7.
10. The ink jet printer according to claim 9, wherein the solid particles comprise an inorganic material.
11. The ink jet printer according to claim 9, wherein the solid particles comprise a material selected from the group consisting of silica, clay and alumina.
12. An ink-jet printer head comprising a nozzle plate and an ink-repellent layer,
wherein the ink-repellant layer comprises:
an organic film formed on a surface of the nozzle plate for discharging ink;
chains of fluorocarbon polymer being partially embedded in the organic film and being partially exposed at a surface of the organic film; and
particles having abrasion resistance dispersed in the organic film and at least part being protruded from the surface of the organic film,
wherein at least part of the particles being protruded from the chains of the fluorocarbon polymer in a direction opposite the nozzle plate surface.
13. The ink-jet printer headed according to claim 12, wherein the fluorocarbon polymer chains are fibrous and protrude from the surface of the organic film in the form of whiskers.
14. The ink-jet printer head according to claim 12, wherein, when a protrusion percentage of particles (%) and a volumetric percentage of particles (%) are defined according to following Equations (1) and (2), respectively, the protrusion percentage of particles and the volumetric percentage of particles fall in a range surrounded by four points of a (X=5, X=20), b (X=5, Y=60), c (X=25, Y=55) and d (X=30, Y=20) in a correlation diagram with an X-axis indicating the protrusion percentage of the particles being protruded from the chains of the fluorocarbon polymer and a Y-axis indicating the volumetric percentage of the particles in the ink-repellant layer:
P (%)=((h1\u2212t1)t1)\xd7100\u2003\u2003(1)
C (%)=(v1v2)\xd7100\u2003\u2003(2)
wherein h1 is a height of the part of the protruded particles being protruded from the chains of the fluorocarbon polymer; t1 is a thickness of the organic film formed on the surface of the nozzle plate; P (%) is the percentage of the protruded height h1 to the thickness t1; C (%) is the volumetric percentage of the particles in the ink-repellant layer; v1 is a volume of the particles; and v2 is a volume of the organic film.
15. The ink jet printer according to claim 12, wherein the particles comprise an inorganic material.
16. The ink jet printer according to claim 12, wherein the particles comprise a material selected from the group consisting of silica, clay and alumina.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for formation-keeping of a spacecraft in response to a displacement of the spacecraft to a displaced pose with respect to at least one direction of the displacement, wherein the spacecraft is configured to issue a compensative force, comprising the steps of:
determining the compensative force as a function of a sum of the base force configured for maintaining the spacecraft in the displaced pose with respect to the direction of the displacement and an excess force configured for optimizing the formation-keeping with respect to the direction of the displacement of the spacecraft at the displaced pose; and
generating a command to issue the compensative force, wherein the steps of the method are performed by a processor.
2. The method of claim 1, further comprising:
determining a magnitude of the base force based on a velocity of the spacecraft at the displaced pose.
3. The method of claim 2, wherein the base force is an impulsive force having a quantization resolution such that the magnitude of the base force is multiple of a quantization resolution, further comprising:
determining the magnitude of the base force based on the quantization resolution.
4. The method of claim 3, wherein the determining of the magnitude is according to
\u0394
\ue89e
\ue89e
V
base
=
\u2308
\uf603
v
x
\uf604
q
\u2309
\ue89e
q
,
wherein \u0394Vbase is the magnitude of the base force along the direction of the displacement x, vx is the velocity of the spacecraft along the direction of the displacement, and q is the quantization resolution.
5. The method of claim 1, wherein the displaced pose borders an error range, further comprising:
determining the excess force based on the error range.
6. The method of claim 1, wherein the excess force is an impulsive force having a quantization resolution such that the magnitude of the excess force is multiple of a quantization resolution, further comprising:
acquiring an error range along the direction of displacement; and
determining the excess magnitude based on the error range and the quantization resolution such the excess force optimizes a period of time between the compensative force and a next compensative force.
7. The method of claim 6, further comprising:
determining a discrete control set of magnitudes; and
selecting the magnitude of the excess force from the discrete control set.
8. The method of claim 7, further comprising:
determining the magnitude of the excess force from the discrete control set using a total enumeration technique.
9. The method of claim 7, further comprising:
determining the magnitude of the excess force from the discrete control set using an integer programming (IP).
10. The method of claim 9, wherein a number of elements in the discrete control set U\u2282N0, U={0, 1, . . . , NU\u22121} has finite cardinality NU, and the IP determines an optimal u* by maximizing a function \u03c6
max
u
\ue89e
\u03d5
\ue8a0
(
u
,
\u0394
\ue89e
\ue89e
V
base
,
t
)
,
u
\u2208
U
,
wherein u is the excess force, \u0394Vbase is a magnitude of the base force, t is the time when the compensative force is applied.
11. The method of claim 7, wherein the spacecraft is subjected to a displacement force with a magnitude bounded by a value dmax, wherein the determining a discrete control set further comprises:
determining a largest element of the discrete control set as a minimum magnitude of the excess force that causes the spacecraft to reach an opposite side of an error range, while starting from the displaced pose with substantially zero velocity and being opposed by the displacement force of the magnitude dmax; and
selecting a smallest element of the discrete control set as either zero or one.
12. The method of claim 1 further comprising.
determining a minimum continuous-magnitude \u0394v according to
\u0394
\ue89e
\ue89e
v
=
2
\ue89e
d
max
\ue89e
range
2
,
wherein range is an extent of the error range; and
determining the largest element maxU according to
max
\ue89e
\ue89e
U
=
\u2308
\u0394
\ue89e
\ue89e
v
q
\u2309
,
wherein q is the quantization resolution.
13. The method of claim 1, further comprising:
determining a time to issue the compensative force based on an extent of the displacement and an error range.
14. The method of claim 1, wherein the compensative, the base and the excess forces have a quantization resolution, the displaced pose borders an error range along the direction of the displacement, further comprising:
determining a magnitude of the base force according to
\u0394
\ue89e
\ue89e
V
base
=
\u2308
\uf603
v
x
\uf604
q
\u2309
\ue89e
q
,
wherein \u0394Vbase is the magnitude of the base force along the direction of the displacement x, vx is a velocity of the spacecraft along the direction of the displacement, and q is the quantization resolution;
determining a magnitude of the excess force from a discrete control set of magnitudes, wherein a largest element maxU of the discrete control set is determined according to
max
\ue89e
\ue89e
U
=
\u2308
\u0394
\ue89e
\ue89e
v
q
\u2309
,
wherein \u0394v is
\u0394
\ue89e
\ue89e
v
=
2
\ue89e
d
max
\ue89e
range
2
,
wherein range is an extent of the error range, and dmax is an upper bound of a displacement force.
15. A control module adapted for maintaining a pose of a spacecraft with respect to an error range defined along a direction of displacement, wherein the spacecraft is configured to issue a compensative force, comprising:
means for determining a base force, such that issuing the base force by the spacecraft results in a substantially zero velocity of the spacecraft at a displaced pose with respect to the direction of the displacement;
means for determining an excess force, such that issuing the excess force by the spacecraft having the substantially zero velocity at the displaced pose optimizes the pose of the spacecraft with respect to the error range; and
means for generating a command to issue the force in a direction opposite to the direction of the displacement, wherein the compensative force is a sum of the base force and the excess force.
16. The control module of claim 15, further comprising:
means for determining a time to issue the compensative force based on an extent of the displacement and an error range.
17. The control module of claim 16, wherein the means for determining the basic force includes a processor configured to determine a magnitude of the base force according to
\u0394
\ue89e
\ue89e
V
base
=
\u2308
\uf603
v
x
\uf604
q
\u2309
\ue89e
q
,
wherein \u0394Vbase is the magnitude of the base force along the direction of the displacement x, vx is a velocity of the spacecraft along the direction of the displacement, and q is the quantization resolution.
18. The control module of claim 16, wherein the means for determining excess force includes a processor configured to determine a magnitude of the excess force according to
max
\ue89e
\ue89e
U
=
\u2308
\u0394
\ue89e
\ue89e
v
q
\u2309
,
wherein \u0394v is
\u0394
\ue89e
\ue89e
v
=
2
\ue89e
d
max
\ue89e
range
2
,
wherein range is an extent of the error range, and dmax is an upper bound of a displacement force.
19. A method for determining a compensative force to compensate for a displacement of an object, comprising the steps of:
determining, by a processor, the compensative force as a function of a sum of a base force configured for preventing an increase of the displacement and an excess force configured for reducing the displacement, wherein a magnitude of the excess force is selected from a discrete control set of magnitudes.
20. The method of claim 19, further comprising:
determining a largest element of based on the displacement and a displacement force; and
selecting a smallest element of the discrete control set as either zero or one.
21. The method of claim 19, further comprising:
defining the displacement as a half of an extent of the error range.