Ink-jet printing apparatus and film nozzle member used in the same

An ink-jet printing apparatus comprises a thermal printing head having heating elements, and a film nozzle member having a plurality of holes for holding an ink and a plurality of connecting grooves for connecting same of the plurality of holes, said plurality of connecting grooves being formed in a surface thereof opposing the heating elements of the thermal printing head. While the heating elements are selectively heated, bubbles are formed in the heated ink filled in the plurality of holes in the film nozzle member as it passes over the heating elements, said bubbles being formed adjacently to the heating elements, and the ink ejected from the plurality of holes by the pressure created by the bubbles is attached to a printing member conveyed near the film nozzle member in the vicinity of the thermal printing head, thereby performing printing.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an ink-jet printing apparatus and a nozzle 
member used in the same and, more particularly, to a film nozzle member 
having a plurality of holes for holding ink and an ink-jet printing 
apparatus wherein the ink in the holes is selectively heated by heating 
elements formed on an upper end portion of a thermal printing head while 
the nozzle member is moved on the thermal head, the ink is ejected from 
the holes by the pressure of bubbles formed adjacently to the heating 
elements in the heated ink, and the ejected ink is attached to a recording 
medium which is being conveyed in the vicinity of the thermal head and 
close to the nozzle member, thereby performing printing. 
2. Description of the Related Art 
Conventionally, non-impact printing methods including an electrostatic 
printing method, a thermal printing method, a thermal transfer printing 
method, an ink-jet printing method, etc. and the like have been proposed. 
Among them, the ink-jet printing method is advantageous in that it 
generates low noise, requires low power, can be made compact, is easily 
applicable to color printing, and can perform relatively high-speed 
printing. 
The ink-jet printing method is roughly classified into a continuous 
jet-type, intermittent jet-type, on-demand type, and ink mist type ink-jet 
by the differences in the arrangements of the ink droplet generating 
means. The on-demand type ink-jet printing method is the main trend in 
these days due to a simple arrangement. As the on-demand type ink-jet 
printing method, a Gould method and a bubble jet method are used in 
practice. In the Gould method, ink droplets are ejected from a tubular 
nozzle member by radial contraction of a cylindrical piezoelectric 
transducer arranged to surround the nozzle member. In the bubble jet 
method, ink droplets are ejected from a tubular nozzle member by the 
pressure of bubbles that are formed adjacently to the heating elements in 
the ink in the nozzle number by instantaneously heating elements in the 
nozzle member. 
However, in either the Gould or bubble jet method, a single tubular nozzle 
member having a very small diameter corresponds to a single piezoelectric 
transducer or a heating element. Therefore, ink tends to clog in the 
nozzle member if the ink-jet apparatus is not used for a long period of 
time, or bubble retention in the nozzle member tends to occur immediately 
after ink ejection. In the Gould method, the integration density of 
tubular nozzle members is comparatively lower than the integration density 
of printing dot forming means of various other non-impact printing 
apparatuses. Therefore, the resolution of a printed character, figure, and 
other symbols is not higher than that of the various other non-impact 
printing apparatuses. Although the printing speed of a Gould or bubble 
jet-method non-impact serial printing apparatus is higher than that of 
various other non-impact serial printing apparatuses, it is lower than 
that of a non-impact line printing apparatus of another method. This is 
because it is difficult to increase the integration density of nozzle 
members. 
A non-impact ink-jet printing apparatus disclosed in Japanese Pat. 
Disclosure (Kokai) No. 60-71260 which is a base application for U.S. Pat. 
No. 4,608,577 is developed to eliminate the drawbacks of the conventional 
non-impact ink-jet printing apparatuses. 
The novel ink-jet printing apparatus uses as a nozzle member a film which 
is made of a metal, a heat-resistant synthetic resin, or a multilayer 
member of the metal and resin, and has a plurality of holes with a 
diameter of 10 to 200 .mu.m. The film nozzle member is slid on the heating 
elements of the thermal printing head while ink is filled in the holes. 
Bubbles are generated adjacently to the heating elements in the ink 
rapidly heated by the heating elements, and the pressure of the bubbles 
ejects ink droplets from the holes. The ejected ink droplets are attached 
to the recording medium (normally a recording paper), which is being 
conveyed close to the film nozzle member in the vicinity of the thermal 
printing head, and form ink dots. A character, figure, or other symbols is 
printed by a group of ink dots. 
In the novel ink-jet printing apparatus described above, since long and 
narrow tubular nozzle members are not used, ink clogging or bubble 
retention in the nozzle members does not occur in principle. The 
integration density of the holes can be increased to be considerably 
higher than that of small-diameter tubular nozzle members described above, 
and these holes can be formed in a relatively large area at a high 
density. Therefore, when such a film nozzle member haviing a plurality of 
holes formed in a relatively large area at a high density is combined with 
a thermal printing head having a plurality of heating elements, 
high-resolution, high-speed printing is enabled. 
However, in order to obtain a sufficient printing density with the novel 
ink-jet printing apparatus, the film nozzle member filled with ink in its 
holes must be conveyed at least the same speed as the conveying speed of 
the recording medium. During printing, nonused holes (i.e., a hole 
sufficiently filled with the ink) must constantly be supplied to heating 
elements of the thermal printing head. Accordingly, the film nozzle member 
must have a length larger than that of the recording medium. When a film 
nozzle member having such a length and a thermal printing head are 
combined as a detachable cartridge, the cartridge becomes comparatively 
large and the entire printing apparatus cannot be made compact. Also, the 
film nozzle member and the thermal printing head wear within a short 
period of time, resulting in a short service life. 
When the conveying speed of the film nozzle member is decreased to be lower 
than that of the recording medium, the length of the film nozzle member 
can be decreased. As a result, the cartridge and then the entire printing 
apparatus can be made compact, and progress of wear of the film nozzle 
member and the thermal printing head can be considerably delayed, 
resulting in a considerably long service life. In this case, however, if 
the same heating element is consecutively heated, a hole which contains no 
ink or only a small amount of ink upon the former ink ejection is heated 
again before it is refilled with ink. When such a hole is heated, it 
ejects substantially no ink, and the printing density is decreased. 
In the novel ink-jet printing apparatus described above, when the urging 
force of the film nozzle member against the thermal printing head is 
excessively large, an ink for refilling that must be retained between the 
thermal printing head and the film nozzle member is squeezed out from the 
gap between them. Therefore, even when the same heating element is not 
consecutively heated, the holes which contains no ink or only a small 
amount of ink upon the former ink ejection cannot be sufficiently refilled 
with ink, resulting in a decrease in printing density. 
SUMMARY OF THE INVENTION 
The present invention has been made based on the above situation and has as 
its object to provide an ink-jet printing apparatus wherein ink in a 
plurality of holes formed in a film nozzle member is heated by heating 
elements of a thermal printing head, the ink is ejected from the holes by 
the pressure of the bubbles generated adjacently to the heating elements 
in the heated ink, and the ejected ink is attached to a recording medium 
which is being conveyed close to the film nozzle member in the vicinity of 
the thermal printing head, thereby performing printing, while at the same 
time a cartridge as a combination of the film nozzle member and the 
thermal printing head and the entire printing apparatus can be made 
compact, the service life of the film nozzle member and the thermal 
printing head can be prolonged, and even when the same heating element is 
consecutively heated or when the urging force of the film nozzle member 
against the thermal printing head is excessively large, a sufficient 
printing density can be maintained; and to provide the film nozzle member 
used in such a printing apparatus. 
The above-described objects of the present invention can be achieved when 
the film nozzle member used in the ink-jet printing apparatus of the type 
described above has, in its surface opposing the heating elements of the 
thermal printing head, a plurality of grooves each connecting some of the 
plurality of holes, so that the some holes are connected to each other 
through the corresponding connection groove. 
More specifically, in the ink-jet printing apparatus of the present 
invention having the arrangement described above, when the film nozzle 
member is conveyed at a speed considerably lower than that of the 
recording medium or when the urging force of the film nozzle member 
against the thermal printing head becomes excessively large due to some 
reasons, once a hole contains no ink or only a small amount of ink upon 
printing, it is immediately refilled with ink from other nonused holes 
through a grovoe connecting the holes. Therefore, even when a heating 
element corresponding to a single hole is repeatedly and consecutively 
heated for performing printing, a sufficient printing density is 
maintained, and satisfactory printing can be performed. By conveying the 
film nozzle member at a speed considerably lower than that of the 
recording medium, its size along the convey direction can be reduced, and 
the cartridge as the combination of the film nozzle member and the thermal 
printing head and accordingly the entire printing apparatus can be made 
compact. Furthermore, wear between the film nozzle member and the thermal 
printing head is decreased, thereby prolonging their service life.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The preferred embodiment of the present invention will be described with 
reference to the accompanying drawings. 
The principle method for printing with an ink-jet printing apparatus using 
a film nozzle member is disclosed in FIG. 17 of U.S. Ser. No. 868,112 now 
U.S. Pat. No. 4,751,527. 
The film nozzle member used in this apparatus is made of a metal, a 
heat-resistant synthetic resin, or a multilayer member of the metal and 
resin, and has a plurality of holes with a diameter of 20 to 100 .mu.m. 
The film nozzle member having ink filled in its plurality of holes is slid 
above the heating elements of the thermal printing head. During sliding, 
the heating elements are selectively heated. The ink filled in holes 
located on each heated heating element is rapidly heated, and within the 
heated ink bubbles are formed which are adjacent to the heating element. 
The pressure created by the bubbles ejects the ink from the hole. The 
ejected ink droplets are attached to a recording medium (normally a 
recording paper) conveyed near the film nozzle member in the vicinity of 
the heating element of the thermal head, thereby forming an ink dot. 
Characters, figures, and other symbols can be printed by a group of the 
ink dots. 
FIG. 1 is a longitudinal sectional view schematically showing the entire 
arrangement of an ink-jet printing apparatus according to an embodiment of 
the present invention. 
Paper supply cassette 28 storing a stack of a plurality of recording paper 
sheets 26 is detachably mounted on the rear portion of the upper surface 
of housing 24 of the ink-jet printing apparatus. Housing 24 houses paper 
feed means 30 for picking up, one by one, recording sheets 26 in cassette 
28, printing cartridge 32 for performing printing on recording sheet 26 
fed by paper feed means 30, and recording paper discharge means 36 for 
discharging recording sheet 26, printed by cartridge 32, to tray 34 
provided in the front surface of housing 24. 
Paper supply cassette 28 is inserted along cassette guide 38 in housing 24 
from an upper right portion in FIG. 1 and mounted at a predetermined 
position on guide 38. The presence or absence of cassette 28 in guide 38 
is detected by cassette sensor 40 attached to guide 38, and the presence 
or absence of recording sheet 26 in cassette 28 mounted at the 
predetermined position on guide 38 is detected by a paper sensor (not 
shown). 
When paper feed roller 42 is rotated by a paper feed motor (not shown) in 
housing 24 in response to a printing instruction from a controller (not 
shown) connected to the ink-jet printing apparatus of this embodiment, 
recording sheets 26 having a number which corresponds to the printing 
instruction are sequentially picked up one by one from paper supply 
cassette 28. After recording sheet 26 is picked up, it is then guided by a 
pair of upper and lower paper guides 44 and 46 toward a rolling contact 
portion consisting of a pair of upper and lower aligning rollers 48 and 50 
arranged at the inlet of printing cartridge 32. When the leading end of 
recording sheet 26 is abutted against the rolling contact portion, it is 
aligned in the position. 
After a predetermined period of time has elapsed since a first single 
recording sheet 26 was feed, the pair of upper and lower aligning rollers 
48 and 50 begin to rotate. As a result, the leading end of recording sheet 
26, which is abutted against the rolling contact portion, is clamped by 
the pair of aligning rollers 48 and 50, and recording sheet 26 is supplied 
through a passage between a pair of upper and lower printing guides 52 and 
54 of printing cartridge 32. 
FIG. 2 is a longitudinal sectional view schematically showing printing 
cartridge 32 and recording paper discharge means 36. A pair of printing 
guides 52 and 54 and head roller 56 arranged at a downstream of the pair 
of printing guides 52 and 54 are mounted on arm 58 which is pivotally 
attached on upper aligning roller 48. Guide plate 60 made of a thin 
stainless steel plate having a thickness of about 0.2 mm is mounted on the 
upper surface of lower printing guide 54. The leading end of guide plate 
60 remains abutted against head roller 56 until recording sheet 26 is 
supplied to it. Guide hole 62 is formed in the side wall of arm 58, and 
cam shaft 64 extends through guide hole 62. Cam shaft 64 is coupled by 
means of a link (not shown) to a plunger-solenoid drive means (not shown) 
mounted on upper support frame 66 which rotatably supports the pair of 
upper and lower aligning rollers 48 and 50, so that cam shaft 64 is driven 
by the plunger-solenoid drive means. 
The free end of arm 58 is suspended by tension spring 70 fixed to 
projection 68 of upper support frame 66, and is located above printing 
cartridge 32. 
Printing cartridge 32 is detachably supported on lower stationary support 
frame 72, and upper support frame 66 is also rotatably mounted on upper 
aligning roller 48 and latched by a latching means (not shown) to lower 
stationary support frame 72. 
Recording paper discharge means 36 has a pair of upper and lowr paper 
discharge guide plates 74 and 76 at the downstream of head roller 56. 
Upper paper discharge guide plate 74 is fixed on upper support frame 66. 
A plurality of holes (not shown) are formed in lower paper discharge guide 
plate 76, and guide plate 76 is fixed on the upper surface of pivotal 
support member 78. Support member 78 is supported by pivot 82 to be 
pivotal within the upper end opening of duct 80 vertically extending in 
lower stationary support frame 72. In FIG. 2, the upper pivot position of 
support member 78 is indicated by an one-dot chain line, and its lower 
stationary position is indicated by a solid line. The outlet of blower 84 
is coupled to the lower end opening of duct 80. 
As shown in FIG. 2, a pair of upper and lower first pinch rollers 86 (lower 
first pinch roller 86 is omitted in the drawing for the sake of clarity) 
and a pair of upper and lower second pinch rollers 88 (lower second pinch 
roller 88 is omitted in the drawing for the sake of clarity) are provided 
on both sides of the pair of paper discharge guide plates 74 and 76. Two 
pairs of first and second pinch rollers 86 and 88 clamp several-mm wide 
non-printing regions on both sides of printed recording sheet 26 which 
project from both sides of the pair of paper discharge guide plates 74 and 
76, and convey sheet 26 located between guide plates 74 and 76 toward 
paper discharge tray 34. 
Fan 90 of blower 84 is driven during printing, and air is supplied toward 
the upper end opening of duct 80. The air supplied by blower 84 flows from 
the upper end opening of duct 80 toward upper paper discharge guide plate 
74 through a plurality of holes (not shown) formed in lower paper 
discharge guide plate 76. A portion of the upper end opening of duct 80 
which is not covered by guide plate 76 is covered by another lower guide 
plate 92 fixed on the upper portion of the side wall of duct 80. Lower 
guide plate 92 also has a plurality of holes. Therefore, the air at the 
upper end opening of duct 80 flows also through the holes (not shown) in 
lower guide plate 92 toward upper paper discharge guide plate 74. 
Recording sheet 26 printed in printing cartridge 32 and introduced to a 
space between the pair of paper discharge guide plates 74 and 76 is 
pressed against upper paper discharge guide plate 74 by the air pressure 
flowing from the holes in lower paper discharge guide plates 76 and 92 
while it is being conveyed between the pair of guide plates 74 and 76 by 
first and second pinch rollers 86 and 88. 
Recording sheet 26 is conveyed between the pair of upper and lower paper 
discharge guide plates 74 and 76 without bringing its printed surface (the 
lower surface in FIG. 2) into contact with lower discharge guide plates 76 
and 92. Therefore, the undried ink remaining on recording sheet 26 
immediately after printing will not be smudged. Then air is blown onto the 
printed surface of sheet 26 to quickly dry the wet ink on sheet 26 
immediately after printing. 
Recording sheet 26 is then clamped at the outlets of the pair of upper and 
lower paper discharge guide plates 74 and 76 and another lower paper 
discharge guide plate 92 by upper and lower paper discharge rollers 94 and 
96 rotatably supported by upper and lower support frames 66 and 72, 
respectively, and is discharged onto paper discharge tray 34 shown in FIG. 
1 by rollers 94 and 96. 
Lower paper discharge roller 96 consists of a pair of clamp roller members, 
located at both ends in the axial direction, for clamping the non-printing 
regions on both sides of recording sheet 26, a plurality of spur gear 
shaped plates arranged between the pair of clamp roller members to be 
separated from each other in the axial direction, and a plurality of 
collars having a diameter smaller than that of the clamp roller members 
and arranged among the plurality of spur gear shaped plates. The pair of 
clamp roller members, the plurality of spur gear shaped plates, and the 
plurality of collars are coaxial each other. 
The outer diameter of each spur gear shaped plate is substantially the same 
as that of each clamp roller member, and the printing regions on the lower 
surface of recording sheet 26 are spotedly-supported by the plurality of 
tooth tops on the plurality of spur gear shaped plates. 
Since the plurality of spur gear shaped plates do not apply much pressure 
to the printing regions on the lower surface of recording sheet 26, the 
ink is not smeared in the printing regions of the lower surface of 
recording sheet 26 which is clamped and conveyed by the pair of upper and 
lower paper discharge rollers 94 and 96. 
As shown in FIG. 2, paper discharge check switch 98 is arranged immediately 
in front of the pair of upper and lower paper discharge rollers 94 and 96, 
and is mounted on upper support frame 66. Switch 98 detects the leading 
and trailing ends of recording sheet 26, discharged from a passage defined 
by the pair of upper and lower paper discharge guide plates 74 and 76 and 
another lower paper discharge guide plate 92, and detects whether sheet 26 
is discharged onto paper discharge tray 34 shown in FIG. 1. 
FIG. 3 is an enlarged view schematically showing printing cartridge 32. 
In printing cartridge 32, plate-like thermal printing head 18 is detachably 
mounted on cartridge support frame 100 so as to extend below head roller 
56 along its axis. The upper end face of printing head 18 is rounded and a 
plurality of heating elements 20 are embedded therein along the 
longitudinal direction thereof. 
Printing cartridge 32 also has nozzle member holder 102 detachably mounted 
on cartridge support frame 100 and storing film nozzle member 12. Film 
nozzle member 12 extends along and contacts the upper end face of thermal 
printing head 18. Holder 102 has a pair of holder main bodies 104 and 106 
extending in the longitudinal direction of head roller 56 along the two 
side surfaces of thermal printing head 18. Nozzle member storing recess 
108 extending in the longitudinal direction of head roller 56 and having 
an upper open end is formed in each of the pair of holder main bodies 104 
and 106. A pair of nozzle member storing recesses 108 of the pair of 
holder main bodies 104 and 106 store a pair of film shafts 110 and 112, 
respectively. The two ends of film nozzle member 12 are fixed and wound on 
shafts 110 and 112. Both ends of each of shafts 110 and 112 are rotatably 
supported on both end walls of corresponding holder main body 104 or 106 
and coupled to a rotational drive means (not shown). 
The pair of holder main bodies 104 and 106 are integrally formed. When 
engaging pawls 114 formed on the bottom walls of main bodies 104 and 106 
are inserted in positioning holes 116 formed in the upper wall of 
cartridge support frame 100 and engaged by engaging lever 18 which is 
slidably mounted on frame 100, holder main bodies 104 and 106 are fixed at 
predetermined positions on frame 100. 
When the pair of holder main bodies 104 and 106 are fixed at predetermined 
positions on cartridge support frame 100, film nozzle member 12 extends 
along and contacts the upper end face of thermal printing head 18 between 
holder main bodies 104 and 106, as shown in FIG. 3. In this case, upper 
end faces 120 of opposing side walls of holder main bodies 104 and 106 are 
rounded in order to reduce friction with respect to the lower surface 
(surface friction to thermal head 18) of film nozzle member 12. 
Film nozzle member 12 is made of a metal (e.g., nickel or copper), a 
heat-resistant synthetic resin (e.g., a polyimide resin), or a film member 
obtained by stacking these elements in a multilayer manner, and has a 
thickness of about 10 to 30 .mu.m. As shown in FIG. 4, a plurality of 
holes 10 having a diameter of about 20 to 30 .mu.m are formed in hole 
formation region 122 of nozzle member 12. Hole formation region 122 has 
width W which is slightly larger than the length of the region of the 
upper end face of thermal printing head 18 on which a plurality of heating 
elements are arranged in the longitudinal direction. The plurality of 
holes 10 in region 122 form a row arranged in the widthwise direction W of 
region 122 at a pitch of about 40 to 50 .mu.m, and a plurality of such 
rows are arranged in feed direction B of nozzle member 12 (reciprocated in 
this embodiment between the pair of film shaft members 110 and 112 as will 
be described later) at predetermined intervals, as shown in FIG. 4. In 
this case, holes 10 of each row are staggered from holes 10 of any of the 
adjacent rows by half the pitch, and the pitch between a plurality of 
holes 10 of each row and a plurality of holes 10 of any of the adjacent 
rows is substantially the same as the pitch of a plurality of holes 10 in 
the same row. 
A plurality of ink supply grooves 124 are formed in hole formation region 
122 of the lower surface (i.e., the slidable contact surface with respect 
to thermal printing head 18) of film nozzle member 12. Ink supply grooves 
124 are arranged to be spaced a predetermined gap apart from each other in 
the widthwise direction W of nozzle mbmer 12 and extending in feed 
direction B of nozzle member 12, as shown in FIGS. 4 and 5. Each ink 
supply groove 124 has a depth (substantially 5 to 10 .mu.m) substantially 
1/2 to 1/3 that of the thickness (substantially 10 to 30 .mu.m) of nozzle 
member 12 and a width (substantially 20 to 25 .mu.m) substantially half 
that of the hole pitch. Each ink supply groove 124 overlaps a plurality of 
holes 10 staggered with respect to feed direction B of nozzle member 12 by 
an area substantially half that of each hole 10. Ink supply grooves 124 
can be formed by etching or electro-forming nozzle member 12 simultaneous 
to the formation of holes 10. 
Ink coating member 126 is made of a material having a good water absorption 
and coating character, such as a Teflon felt, a foamed nitrile rubber, a 
foamed polyvinyl resin or the like, arranged in the bottom of each of the 
pair of nozzle member storing recesses 108. Ink coating member 126 is 
abutted against film nozzle member 12 which is wound on film shaft 110 or 
112 in each recess 108. Ink is supplied to the pair of ink coating members 
126 from an ink supply source (not shown) detachably mounted on the outer 
walls of the pair of holder members 104 and 106 through ink supply grooves 
128 formed in the bottom of respective nozzle member storing recesses 108. 
The upper end opening of each nozzle member storing recess 108 is covered 
with seal member 128 made of a synthetic rubber (e.g., a styrene-butadiene 
rubber and a nitrile rubber) having a water resistance. One end of each 
seal member 128 is mounted on the upper end face of the outer wall of 
holder member 104 or 106, and its other end is in contact with the edge of 
the upper surface (the surface facing the head roller 56) of film nozzle 
member 12. 
The pair of seal members 128 are selectively applied with a load from a 
prssure applying mechanism in order to selectively seal the upper end 
openings of the pair of nozzle member storing recesses 108. The pressure 
applying mechanism has a pair of pivotal plates 130 extending along the 
outer side surface (side surfaces not opposing each other) of the pair of 
holder members 104 and 106, and pivotal plates 130 are rotatably mounted 
on the upper portions of both of the end faces (end walls supporting the 
two ends of film shafts 110 and 120) of the pair of holder members 104 and 
106. Elastic plates 132 are mounted on the upper ends of pivotal plates 
130 and extend above seal members 128. The distal ends of elastic plates 
132 contact the abutting end portions of seal members 128 for film nozzle 
member 12. Each elastic plate 132 is made of an elastic thin plate, such 
as stainless steel, having a thickness of about 0.1 to 0.4 mm. The lower 
ends of the pair of pivotal plates 130 contact the outer surfaces of the 
pair of holder members 104 and 106 through leaf springs 134 provided 
thereto. Each leaf spring 134 is also made of an elastic thin plate, such 
as stainless steel, having a thickness of about 0.1 to 0.4 mm. 
The outer surfaces of the pair of pivotal plates 130 of nozzle member 
holder 102 that are arranged at the predetermined positions on cartridge 
support frame 100, as shown in FIG. 3, oppose a pair of pressure control 
cam shafts 136 pivotally supported by lower support frame 72 shown in FIG. 
2. 
The pair of pressure control shafts 136 are rotated such that their outer 
circular surface portions abut against the outer surfaces of the pair of 
pivotal plates 130, as shown in FIG. 3, as far as a printing signal is 
input to the ink-jet printing apparatus of this embodiment from a 
controller (not shown) connected to it. When the outer circular surface 
portions of the pair of cam shafts 136 abut against the pair of pivotal 
plates 130, pivotal plates 130 are rotated in the directions of arrows C 
in FIG. 3 against the biasing force of leaf springs 134 and relieve the 
urging force applied on seal members 128 by leaf springs 134 through 
elastic plates 132. As a result, the edges of seal members 128 are brought 
to lightly contact the upper surface of film nozzle member 12. 
When the edges of seal members 128 lightly contact the upper surface of 
film nozzle member 12, they scrape the excessive ink attached on the upper 
surface of nozzle member 12 while they do not require a great increase in 
drive force of nozzle member 12. 
When the printing signal is not input to the ink-jet printing apparatus of 
this embodiment from the controller (not shown) connected to it or when 
nozzle member holder 102 is loaded on or unloaded from a predetermined 
position of cartridge support frame 100, pressure control cam shafts 136 
are rotated such that their outer circular surface portions do not abut 
against the outer surfaces of the pair of pivotal plates 130. Pivotal 
plates 130 are thus rotated in directions opposite to those indicated by 
arrows C in FIG. 3 by the biasing force of the pair of leaf springs 134 
and apply a load on the pair of seal members 128 through the pair of 
elastic plates 132. Upon reception of the load from leaf springs 134, seal 
members 128 strongly press film nozzle member 12 against the upper end 
faces of the inner walls of the pair of holder main bodies 104 and 106, 
and the upper end openings of the pair of nozzle member storing recesses 
108 are completely closed. Therefore, even when the printing apparatus is 
not used for a long period of time or when nozzle member holder 102 is 
loaded on or unloaded from the predetermined position of cartridge support 
frame 100, ink is not undesirably split or evaporated from the pair of 
nozzle member storing recesses 108. 
In order to load or unload nozzle member holder 102 on or from cartridge 
support frame 100 of the ink-jet printing apparatus, upper support frame 
66 is released from a latched state on lower support frame 72 shown in 
FIGS. 1 and 2 by the latching means, and upper support frame 66, together 
with part of housing 24 covering frame 66, is rotated clockwise about 
upper aligning roller 48 as a fulcrum. As a result, the upper end face of 
holder 102 and/or frame 100 is exposed to the outside. 
Finally, pivotal support member 78 of lower guide plate 76 is rotated 
counterclockwise about pivot 82 as a fulcrum, thereby enabling 
loading/unloading of nozzle member holder 102 on/from cartridge support 
frame 100. 
In the ink-jet printing apparatus having the above-described arrangement, 
when a printing instruction is supplied to it from the controller (not 
shown) connected to it, recording sheets 26 of a number in accordance with 
the printing instruction are sequentially picked up from paper supply 
cassette 28. The gap defined by film nozzle member 12 and guide plate 60 
at the top portion of thermal head 18 is maintained at G1 by cam shaft 64 
inserted in guide hole 62 of arm 58, as shown in FIG. 7, until recording 
sheet 26 from cassette 28 is introduced between the pair of printing 
guides 52 and 54 and its distal end is clamped between head roller 56 and 
guide plate 60 of lower guide plate 54. G1 is about 0.75 mm in this 
embodiment. 
Gap R between upper paper discharge guide plate 74 and film nozzle member 
12 at the top portion of thermal head 18 is set to be larger than gap G1. 
In this case, since the outer circular surface portions of the pair of 
pressure control cam shafts 136 do not abut against the pair of pivotal 
plates 130, the pair of nozzle member storing recesses 108 of the pair of 
holder main bodies 104 and 106 are sealed by the pair of seal members 128 
biased by the biasing force of leaf springs 134. 
When a predetermined period of time elapses after the leading end of 
recording sheet 26 passes the distal end of guide plate 60, cam shaft 64 
is rotated counterclockwise from the position shown in FIG. 7 until its 
notched surface portion abuts against the periphery of guide hole 62 in 
arm 58. As a result, arm 58 is pivoted counterclockwise about upper 
aligning roller 14 as a fulcrum, as shown in FIG. 8, until the distal end 
of guide plate 60 is brought into light contact with film nozzle member 12 
at the top portion of thermal head 18. In this case, the gap between the 
upper surface of nozzle member 12 and the lower surface of recording sheet 
26 is maintained at G2 which corresponds to the thickness of guide plate 
60. G2 is about 0.2 mm in this embodiment. 
In this case, difference P of positions between the center of head roller 
56 and that of heating elements 20, and difference G of positions between 
the distal end of guide plate 60 and the center of heating elements 20 are 
produced. P and G are about 0.7 mm and about 0.3 mm, respectively, in this 
embodiment. 
In response to the printing instruction described above, the pair of 
pressure control can shafts 136 are also rotated such that their outer 
circular surface portions abut against the pair of guide plates 130. Since 
the pair of leaf springs 134 are released from being biased by the pair of 
seal members 128 through the pair of pivotal plates 130 and the pair of 
elastic plates 132, the edges of the free ends of seal members 128 are 
brought into light contact with film nozzle member 12. 
Simultaneously, left and right film shafts 110 and 112 are rotated 
counterclockwise and film nozzle member 12 fed from right film shaft 112 
is taken up by left film shaft 110. 
When hole formation region 122 of film nozzle member 12 shown in FIG. 4 is 
moved to the vicinity of heating elements 20 of thermal printing head 18, 
rotation of the pair of film shafts 110 and 112 is temporarily stopped. 
When the pair of aligning rollers 48 and 50 are started to rotate in order 
to feed recording sheet 26 supplied from paper supply cassette 28, the 
above-mentioned rotation of shafts 110 and 112 is restarted. 
When a predetermined period of time elapses after the leading end of 
recording sheet 26 passes the distal end of guide plate 60, and arm 58 is 
moved to a lower position as shown in FIG. 8, the plurality of heating 
elements 20 are selectively heated in accordance with the printing 
instruction described above. 
Bubbles are formed adjacently to heating elements 20 in ink 16 in the 
plurality of holes 10 of film nozzle member 12, that correspond to 
selectively heated heating elements 20. By the pressure of the bubbles, 
ink 16 is injected from holes 10 and attaches to and forms ink dots on 
recording sheet 26 opposing film nozzle member 12 through gap G2. A 
character, figure, and other symbols is printed by the group of ink dots. 
In this manner, in printing cartridge 32 of the printing apparatus of the 
present invention as a combination of flim nozzle member 12 having a 
plurality of holes 10 and thermal head 18 having a plurality of 
heat-generating elements 20, nozzle hole clogging or bubble retention in 
nozzle holes does not occur in principle compared to a conventional 
printing cartridge as a combination of tubular nozzle members and 
piezoelectric resonators or heating elements corresponding to them in 1:1 
correspondence. The respective distance between the plurality of holes 10 
in nozzle member 12 can be greatly reduced than those between a plurality 
of tubular nozzle members in the conventional apparatus. Therefore, the 
resolution of a printed character, figure, or other symbols is increased, 
and a plurality of characters, figures, and other symbols can be printed 
at once. 
In film nozzle member 12 used in the ink-jet printing apparatus of the 
present invention, a plurality of holes 10 are formed in its surface 
opposing thermal head 18 to be staggered in moving direction B of nozzle 
member 12 and to constitute a plurality of rows. Holes 10 in respective 
rows are coupled to each other by ink supply grooves 124, as shown in 
FIGS. 5 and 6. Therefore, even when nozzle member 12 is conveyed at a 
speed considerably lower than that of recording sheet 26, or even when the 
urging force of nozzle member 12 against the top portion of head 18 is 
excessively large due to some reason, once hole 10 is emptied by ink 
ejection, ejection, it is refilled immediately with ink 16 in other holes 
10 through grooves 124. This ensures a constant sufficient printing 
density when the same hole 10 is consecutively used for printing, 
resulting in high-quality printing. 
When the convey speed of film nozzle member 12 is decreased, the length of 
nozzle member 12 in its feed direction B can be reduced, resulting in the 
size reduction of nozzle member holder 102, printing cartridge 32, and 
thus the entire ink-jet printing apparatus. Furthermore, since the amount 
of wear between nozzle member 12 and the top portion of thermal printing 
head 18 is decreased, the service life of them can be prolonged. 
When printing on single recording sheet 26 is to be ended, voltage supply 
to heating elements 20 for printing is stopped before the trailing end of 
the same recording sheet 26 passes the distal end of guide plate 60. 
Subsequently, film nozzle member 12 is taken up by left film shaft 110 
until its entire hole formation region 122 reaches ink coating member 126 
in left holder member 104. 
When next recording sheet 26 is supplied to a portion between head roller 
56 and thermal head 18, film nozzle member 12 is fed from left film shaft 
110 to right film shaft 112 in the same manner as described above, thereby 
performing printing on next recording sheet 26. More specifically, in the 
ink-jet printing apparatus of this embodiment, film nozzle member 12 is 
reciprocated above thermal head 18 to continuously perform printing on a 
plurality of recording sheets 26 that are supplied consecutively. 
When a predetermined period of time lapses after printing on single 
recording sheet 26 is ended, cam shaft 64 is rotated clockwise until its 
outer circular surface portion abuts against the periphery of guide hole 
62 in arm 58, as shown in FIG. 7. As a result, arm 58 is rotated clockwise 
about upper aligning roller 48 as a fulcrum and is returned to the upper 
position shown in FIG. 7. In this case, the non-printing region on the 
trailing end portion of printed recording sheet 26 is clamped by guide 
plate 60 of lower printing guide 54 and head roller 56. 
When single recording sheet 26 is supplied to thermal printing head 18 from 
paper supply cassette 28 to be printed, its leading and trailing end 
portions are clamped by guide plate 60 of arm 58 at its upper position and 
head roller 56 before and after printing, respectively, as described 
above. Therefore, the leading or trailing end portion of single recording 
sheet 26 supplied from cassette 28 to thermal printing head 18 to be 
printed is not bent or curled to contact the upper surface of film nozzle 
member 12. Even when a small amount of excessive ink is attached on the 
upper surface of nozzle member 12, it does not soil the leading or 
trailing end portion of recording sheet 26. 
When recording sheet 26 is introduced from a space between the distal end 
of guide plate 60 of lower printing guide 54, supported by arm 58 at its 
upper position, as shown in FIG. 7, and head roller 56 to a space between 
the pair of paper discharge guide plates 74 and 76 shown in FIG. 2, it is 
supplied to paper discharge tray 34 shown in FIG. 1 by first and second 
pairs of pinch rollers 86 and 88, as described above. 
When printing on recording sheets 26 of a number in accordance with the 
printing instruction supplied from the controller (not shown) connected to 
the ink-jet printing apparatus of this embodiment is completed, the pair 
of film shafts 110 and 112 are rotated clockwise until hole formation 
region 112 on film nozzle member 12 is taken up by right film shaft 112. 
Thereafter, the pair of pressure control shafts 136 are rotated to release 
them from abutting against the pair of pivotal plates 130 at its outer 
circular surface portions. As a result, the biasing force of the pair of 
leaf springs 134 is transmitted to the pair of seal members 128 through 
the pair of pivotal plates 130 and the pair of elastic plates 132, and 
seal members 128 abut against the upper end faces of opposite inner walls 
of the pair of holder main bodies 104 and 106 to clamp film nozzle member 
12. Then, the power source of the ink-jet printing apparatus is turned 
off, if necessary. 
This embodiment is used only for describing the present invention and does 
not limit the present invention. Any modifications or changes within the 
spirit and scope of the invention are included in the present invention.