Liquid injection recording apparatus

A liquid injection recording apparatus includes a head having orifices provided to discharge liquid and form flying droplets, and energy generating members for generating energy utilized to form the droplets. Electrical contacts for inputting an electrical signal to the energy generating members are provided on a surface different from a surface in which the orifices are provided. The liquid injection recording apparatus has such liquid injection recording head mounted on a mounting portion on which is provided electrical contacts adapted to be connected to the electrical contacts of the recording head when the recording head is mounted on the mounting portion.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a liquid injection recording head and a liquid 
injection recording apparatus. 
In a liquid injection recording apparatus, it will be desirable that a 
liquid injection recording head (hereinafter referred to as the recording 
head) can be easily mounted and dismounted with respect to a carriage for 
the purpose of maintenance or interchange of the recording head. 
Therefore, in order to supply a driving power and a signal to the 
recording head, it may heretofore be considered to provide electrical 
contacts on the recording head and the carriage, respectively, and bring 
the electrical contacts of the two into contact with each other when the 
recording head will be mounted on the carriage, thereby accomplishing the 
supply of the driving power and the signal to the recording head. Most 
recording heads are of the type which may be mounted on the carriage and 
therefore, the electrical contacts of the recording head will be taken out 
from the recording head by flexible wiring or the like or may be provided 
on the lower portion of the orifice surface of the recording head in which 
orifices may be provided. 
In a recording head wherein the orifice surface in which orifices for 
injecting ink may be provided and an electrical wiring substrate having 
said electrical contacts may be formed on the same plane, the electrical 
contacts may be provided below the orifice surface for the reason set 
forth above, and this will result in an inconvenience that the electrical 
contacts are stained or corroded by the ink dropping from the orifices and 
cause unsatisfactory contact and thus, orifices do not discharge the 
liquid (ink) or the discharging condition becomes unstable. 
SUMMARY OF THE INVENTION 
In view of the above-described prior art, it is an object of the present 
invention to provide a recording head which can be easily mounted and 
dismounted with respect to a recording apparatus body or a carriage in the 
body and which causes no inconvenience by the mounting or dismounting 
thereof. 
It is another object of the present invention to eliminate the above-noted 
disadvantages peculiar to the prior art and to provide a liquid injection 
recording apparatus which can always realize a stable liquid discharging 
condition. 
It is still another object of the present invention to provide a liquid 
injection recording head having orifices provided to discharge liquid and 
form flying droplets and energy generating members for generating energy 
utilized to form said droplets and wherein electrical contacts for 
inputting an electrical signal to said energy generating members are 
provided on a surface different from a surface in which said orifices are 
provided. 
It is yet still another object of the present invention to provide a liquid 
injection recording apparatus having mounted thereon a liquid injection 
recording head having orifices provided to discharge liquid and form 
flying droplets and energy generating members for generating energy 
utilized to form said droplets and wherein electrical contacts for 
inputting an electrical signal to said energy generating members are 
provided on a surface of said liquid injection recording head different 
from a surface in which said orifices are provided and on the mounting 
portion of said apparatus, there are provided electrical contacts adapted 
to be connected to said electrical contacts when said liquid injection 
recording head is mounted on said mounting portion.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Some embodiments of the liquid injection recording head of the present 
invention will hereinafter be described specifically and in detail with 
reference to the drawings. 
FIG. 1 is a perspective view of a recording head 52 according to a first 
embodiment of the present invention, and the recording head 52 in its 
shown state is mounted on a carriage, not shown. Orifices 54 are provided 
in that surface of the recording head 52 which is opposed to printing 
paper, and electrical contacts 56 are provided on a surface of the 
recording head which is different from the surface in which the orifices 
54 are provided. Reference numeral 58 designates discharged droplets such 
as ink. The recording head 52 is mounted on the carriage (not shown) in 
such a manner that the electrical contacts 56 are in contact with the 
electrical contacts (not shown) of the carriage. A driving power signal is 
applied from the carriage side to the recording head 52 and the droplets 
(ink) 58 are injected from the orifices 54, whereby the recording by the 
recording head 52 is accomplished. At this time, in the present 
embodiment, the electrical contacts 56 can be prevented from being stained 
by the ink dropping from the orifices 54 because the orifices 54 and the 
electrical contacts 56 are provided in the different surfaces. 
FIG. 2 shows another embodiment of the present invention. A feature of this 
embodiment is that the electrical contacts 56 are provided above the 
orifices 54. Thus, the electrical contacts 56 can be better prevented from 
being stained by the ink than in the above-described embodiment. 
In the above-described embodiments, the electrical contacts have been shown 
as being provided on the underside or a side surface of the recording 
head, but alternatively, the electrical contacts may be provided on any 
other surface of the recording head such as the upper surface or the back 
surface which is opposite to the orifices 54. 
An embodiment of the liquid injection recording apparatus of the present 
invention will now be described specifically and in detail. 
FIG. 3 is a perspective view of the liquid injection recording apparatus 72 
according to the present embodiment. In FIG. 3, reference numeral 74 
designates a platen rotatable in the direction of arrow A about a platen 
shaft 76, and reference numeral 78 denotes a recording medium (hereinafter 
referred to as paper) such as printing paper. The paper 78 is rotated in 
the same direction as the platen 74 when the platen 74 is rotated. 
Reference numerals 80 and 82 designate guide shafts. A carriage 84 is 
provided for sliding movement in the directions of bilateral arrow B 
relative to the guide shafts 80 and 82. Reference numeral 86 denotes a 
flexible cable for transmitting a driving power and a signal to the 
carriage 84. Reference numeral 88 designates a liquid injection recording 
head (hereinafter referred to as the recording head) mounted on the 
carriage 84. 
FIG. 4 is a detailed view of the carriage 84 and recording head 88 
according to the present embodiment. Recording head side electrical 
contacts 90 (hereinafter referred to as the first contacts) for 
transmitting an electric power and a signal are formed on a surface of the 
recording head 88 which is different from a surface in which orifices 92 
are provided. Reference numeral 94 designates a liquid reservoir for 
containing therein liquid such as ink, and reference numeral 96 denotes 
discharged droplets such as ink. 
The carriage 84 is provided with a protruded portion 98, which in turn is 
provided with carriage side electrical contacts 100 (hereinafter referred 
to as the second contacts) adapted to contact the first contacts 90 of the 
recording head 88. To mount recording head 88 on the carriage 84, the 
recording head 88 is placed onto the upper surface 102 of the carriage 84 
in such a manner that the first contacts 90 of the recording head 88 
contact the second contacts 100 of the carriage 84. When effecting the 
printing, a driving power and a control signal supplied through a flexible 
cable 86 provided on the carriage 84 are supplied to the first contacts 
90, the former being directly supplied and the latter being converted into 
a driving signal voltage by a control circuit (not shown) in the carriage, 
whereafter they are transmitted to the second contacts 100 which are in 
contact with the first contacts 90, whereby liquid (ink) is injected from 
the orifices 92. 
FIG. 5 shows still another embodiment of the present invention. A feature 
of this embodiment is that for the recording head 88 in which the first 
contacts 90 are formed above the orifices 92 to be mounted on the carriage 
84, the second contacts 100 formed on the protruded portion 98 are 
disposed at a higher position than in the previous embodiment and 
correspondingly the height of the protruded portion 98 is greater than in 
the previous embodiment. According to this embodiment, the first contacts 
90 and the second contacts 100 are located above the orifices 92 and 
therefore, the contacts can be even better prevented from being stained by 
the ink flowing out of the orifices. 
FIG. 6 shows yet still another embodiment of the present invention. In this 
embodiment, a groove 104 which partitions the orifices 92 and the first 
contacts 90 is provided in the bottom surface of the recording head 88 
provided with the orifices 92 in a side surface thereof and provided with 
the first contacts 90 on the bottom surface thereof. Second contacts 100 
adapted to contact the first contacts 90 and a barrier 106 engageable with 
the groove 104 of the recording head 88 are provided on the upper surface 
of the carriage 84 for mounting the recording head 88 thereon, and 
partition means is formed by the groove 104 and the barrier 106. By the 
barrier 106 being so provided between the orifices 92 and the first 
contacts 90 and between the orifices 92 and the second contacts 100, the 
first and second contacts 90 and 100 can be better prevented from being 
stained by the ink dropping from the orifices 92. 
FIG. 7 shows a further embodiment of the present invention. In this 
embodiment, there is shown a carriage 84 for mounting thereon the 
recording head 88 provided with orifices 92 in a side surface thereof and 
provided with first contacts 90 on the bottom surface thereof. Second 
contacts 100 are provided on the upper surface 102 of the carriage 84, and 
a groove 108 which is partition means is formed in the upper surface of 
the carriage 84 so as to partition the orifices 92 and the first and 
second contacts 90, 100 when the recording head 88 is mounted on the 
carriage 84. According to this embodiment, the ink having flowed out of 
the orifices 92 does not come to the first and second contacts 90 and 100 
and thus, these contacts 90 and 100 are very rarely stained by the ink 
dropping from the orifices 92. 
According to the present invention, as described above specifically and in 
detail, by a simple structure in which the orifices and the electrical 
contacts are disposed in different surfaces and further the electrical 
contacts are disposed above the orifices, the electrical contacts can be 
prevented from being stained or corroded by the ink dropping from the 
orifices and causing unsatisfactory contact and thus, a stable droplet 
discharging condition can always be kept. 
Also, according to the present invention, as described above specifically 
and in detail, the recording head in which the orifices and the electrical 
contacts are disposed in different surfaces is mounted on the carriage, 
whereby the electrical contacts can be prevented from being stained or 
corroded by the ink dropping from the orifices and causing unsatisfactory 
contact and thus, a stable droplet discharging condition can always be 
kept. 
An embodiment of the method of fixing the recording head shown in FIG. 6 to 
the carriage and of the method of connecting the contacts will now be 
described in detail by reference to the drawings. 
As shown in FIG. 8, the recording head 88 has on side surfaces thereof a 
mounting portion 111 having a hole 110 which is a positioning fitting 
portion, and an engaging portion 112. The carriage 84 has on the upper 
surface 102 thereof a head keeping plate spring 113 engageable with the 
mounting portion 111, a head keeping plate spring 114 engageable with the 
engaging portion 112, and a positioning pin 115 for fitting in the hole 
110. 
The second contacts 100 are formed by plate spring-like members curved so 
as to protrude toward the recording head 88 so as to correspond to the 
first contacts 90 formed on the bottom of the recording head 88. As the 
first contacts 90, use may sufficiently be made, for example, of an 
electrical wiring portion formed on a printed wiring substrate or contacts 
of the heretofore known contact shape. It is preferable from the viewpoint 
of preventing unsatisfactory contact that the second contacts 100 be 
formed of a material such as phosphor bronze having resiliency, but any of 
generally known materials may be used for the second contacts if they have 
electrical conductivity. 
To mount the recording head 88 on the carriage 84 thus constructed, the 
recording head 88 may be simply urged against the carriage 84 from above 
against the forces of the head keeping plate springs 113 and 114. If the 
positions of the hole 110 and the pin 115 are accurately coincident with 
each other at that time, the mounting portion 111 and the engaging portion 
112 are engaged with the plate springs 113 and 114, respectively, and at 
the same time, electrical connection is completed. 
While the mounting portion 111 and the engaging portion 112 have been shown 
as being directly integral with the recording head 88, they may be 
separate from and adapted to be attached to the recording head 88. 
However, making the mounting portion and the engaging portion integral 
with the recording head is preferable because, in that case, detachment or 
positional deviation of those portions does not occur. 
The schematic cross-sectional views of FIGS. 9 and 10 show the engaged 
condition and the electrically connected condition in a state in which the 
recording head 88 is mounted. 
The relation between the hole and pin which are positioning means may be 
reverse. 
FIG. 11 shows the structure of the liquid injection recording head used in 
the present invention. In FIG. 11, reference numeral 10 designates an 
orifice, reference numeral 11 denotes an orifice plate, reference numeral 
12 designates a flow path wall, reference numeral 13 denotes a base plate, 
and reference numeral 14 designates an energy generating member. 
According to the present embodiment, the positioning, mounting and 
dismounting of the recording head can be easily accomplished by means of 
the positioning pin and plate spring and therefore, when the ink in the 
recording head has become exhausted or non-discharge of droplets has 
occurred, the recording head can be simply interchanged to continue the 
recording. 
By making the recording head interchangeable from above, the interchanging 
operation becomes easy and the recording head hardly interferes with other 
mechanism such as the platen during the interchange of the recording head 
and compactness and light weight of the apparatus body can be achieved. 
Also, by making the recording head mountable and dismountable by one touch, 
the ordinary user can easily interchange the recording head, and this 
leads to a further effect that the down-time of the apparatus is shortened 
.