Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02598250 2007-08-22
INK CARTRIDGE DETECTOR,
INK JET PRINTER INCORPORATING THE SAME AND
INK CARTRIDGE DETECTED BY THE SAME
This is a divisional of Canadian patent application serial number 2,426,912
which was filed on April 16, 2003.
BACKGROUND OF THE INVENTION
The present invention relates to an ink cartridge detector operable to
detect whether or not an ink cartridge is properly mounted on a cartridge
holder. The invention also relates to an ink jet printer provided with the
above
mentioned ink cartridge detector, and to the ink cartridge to be employed in
the
above mentioned ink cartridge detector.
There has been widely used an ink jet printer of a type that prints
characters and images on a printing medium by discharging ink which is
supplied from an ink tank onto the printing medium through a print head. In
the ink jet printer of this type, the ink tank of a cartridge system
(hereinafter
referred to as an "ink cartridge") has been widely employed so as to
facilitate
supply of the ink.
In the above described ink jet printer, it has been required to detect
an amount of remaining ink in the ink cartridge and a mounting condition of
the
ink cartridge for the purpose of preventing defective printing due to shortage
of
the remaining ink in the ink cartridge or incomplete mounting of the ink
cartridge, or for the purpose of issuing an alarm indicating the shortage or
the
incomplete mounting. For this reason, there have been proposed
mechanisms for enabling the amount of the remaining ink and the incomplete
mounting of the ink cartridge to be detected by a single optical sensor of
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CA 02598250 2007-08-22
reflective type (disclosed in Japanese Patent Publications Nos. 10-230616A
and 9-174877A, for example).
In the above described detectors, a light beam is emitted from the
optical sensor onto two reflectors (prisms) which are provided in a bottom of
the ink cartridge, and the amount of the remaining ink and the mounting
condition are detected on the basis of amounts of reflective light beams
received from the reflectors. Specifically, the reflector for detecting the
amount of the remaining ink is transparent so that reflectivity (intensity of
reflected light) may vary according to the amount of the remaining ink, while
the reflector for detecting the mounting condition is mirror-finished so that
the
light can be reflected irrespective of the amount of the remaining ink.
However, in the above described related-art ink jet printer, there have
been such problems as described below.
i) It has been necessary for the ink cartridge to be provided with two
reflectors which are formed of separate members, and hence, the number of
components and production steps are increased, creating a high cost for the
ink cartridge.
ii) Because the reflectors of the ink cartridge are exposed inside the
printer even when a printing operation is performed, there has been such a
possibility that spots such as ink splashed during the printing operation
might
adhere to the reflectors to make the detection by the optical sensor unstable.
iii) When the optical sensor has received the reflective light, it is
decided that the ink cartridge has been properly mounted. Therefore, when the
optical sensor has received an exterior turbulent light, it has been liable to
be
decided that the ink cartridge has been properly mounted, even though the ink
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cartridge has not yet been mounted. As such, the printing operation might be
commenced without proper mounting of the ink cartridge.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an ink cartridge detector, in
which necessity for providing an ink cartridge with a reflector for detecting
the
mounting condition can be eliminated although the mounting condition of the
ink cartridge is detected by an optical sensor of reflective type, whereby not
only reduction of cost for the ink cartridge can be attained, but also an
erroneous recognition of the mounting condition due to soils or ink splash on
the reflector or an exterior turbulent light can be prevented.
It is also an object of the invention to provide an ink jet printer
incorporating such an ink cartridge detector, and an ink cartridge detected by
such an ink cartridge detector.
In order to achieve the above objects, according to the invention,
there is provided an ink cartridge detector, comprising:
an ink cartridge;
a cartridge holder, on which the ink cartridge is detachably mounted;
at least one first reflector, provided in the cartridge holder;
a reflective-type optical sensor, including a light emitter and a light
receiver, the optical sensor operable to form an optical path originated from
the
light emitter to the light receiver via the first reflector; and
a shading member, provided in the ink cartridge operable to shade
the optical path when the ink cartridge is mounted on the cartridge holder.
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The first reflector may be integrally fixed on a bottom portion of the
cartridge holder. In such a configuration, not only the structure can be
simplified, but also reliability of detecting the mounting condition of the
ink
cartridge can be enhanced, in comparison with a case where the reflector is
provided as a movable member.
Further, the shading member may be integrally formed with the ink
cartridge at a lower portion thereof (a downstream portion with regard to an
inserting direction of the ink cartridge with respect to the cartridge
holder). In
such a configuration, the number of components and production steps of the
ink cartridge can be reduced.
The ink cartridge may be formed with a recess which covers the first
reflector when the ink cartridge is mounted on the cartridge holder, so that
at
least one of side walls forming the recess serves as the shading member. In
such a configuration, because the first reflector is covered when the ink
cartridge has been mounted, soils or ink splash on the first reflector caused
by
a printing operation can be reliably prevented.
The shading member may not shade the optical path when the ink
cartridge is provisionally mounted on the cartridge holder. In such a
configuration, such an inconvenience that the printing operation is conducted
in a provisionally mounted state of the ink cartridge can be avoided.
The ink cartridge detector may further comprise a first engagement
member provided in the ink cartridge, and a second engagement member
provided in the cartridge holder. The first engagement member may come
into contact with the second engagement member such that the ink cartridge is
retained at a first position in which the shading member does not shade the
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optical path. In addition, the first engagement member may engage with the
second engagement member such that the ink cartridge is retained at a
second position in which the shading member shades the optical path.
In one embodiment, the first engagement member is provided as a
convex portion formed on the ink cartridge; the second engagement member is
provided in a free end portion of an elastic member which is supported by the
cartridge holder in a cantilevered manner; the second engagement member is
a V-shaped member including a first slope portion and a second slope portion
so as to convex toward the ink cartridge; the convex portion is brought into
contact with the first slope portion when the ink cartridge is retained at the
first
position; and the convex potion is retained by the second slope portion when
the ink cartridge is retained at the second position.
Preferably, the optical sensor and the cartridge holder are movable
relative to each other. Here, it is preferable that a plurality of first
reflectors
are arranged in a direction of relative movement between the optical sensor
and the cartridge holder. In such a configuration, it is possible to detect
the
mounting conditions of a plurality of the ink cartridges by the same optical
sensor.
Also, the ink cartridge detector may further comprise a second reflector,
provided in the ink cartridge, which reflects light emitted from the light
emitter
and varies an intensity thereof in accordance with an ink amount remaining in
the ink cartridge. Here, the second reflector may be operable to form a part
of
an optical path originated from the light emitter to the light receiver, when
the
ink cartridge is mounted on the cartridge holder. In such a configuration, it
is
possible to detect both the mounting condition of the ink cartridge and the
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amount of the remaining ink by the same optical sensor.
According to the invention, there is also provided an ink jet printer
comprising the above ink cartridge detector.
Further, according to the invention, there is also provided an ink
cartridge, operable to be detachably attached to a cartridge holder provided
with a first reflector capable of forming a part of an optical path originated
from
a light emitter of an external optical sensor to a light receiver of the
optical
sensor, the ink cartridge comprising:
an ink reservoir, storing ink therein;
a second reflector, which reflects light emitted from the light emitter
and varies an intensity thereof in accordance with an ink amount remaining in
the ink reservoir, the second reflector operable to form a part of an optical
path
originated from the light emitter to the light receiver; and
a shading member, which shades the optical path, which has been
formed by the first reflector and the optical sensor, when the ink cartridge
is
mounted on the cartridge holder.
Preferably, the shading member shades the first reflector from the
light emitted from the light emitter, when the ink cartridge is mounted on the
cartridge holder.
Here, a recess may be formed so as to cover the first reflector when
the ink cartridge is mounted on the cartridge holder, so that at least one of
side
walls forming the recess serves as the shading member. The recess may be
shaped as to surround an outer periphery of the first reflector.
Also, it is preferable that the recess is formed on a face opposing to
the cartridge holder.
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The ink cartridge may further comprise a first engagement member. In one
embodiment, the first engagement member comes into contact with a second
engagement member provided in the cartridge holder, such that the ink
cartridge
is retained at a first position in which the shading member does not shade the
optical path. The first engagement member engages with the second
engagement member such that the ink cartridge is retained at a second position
in
which the shading member shades the optical path.
Preferably, the second reflector and the shading member are juxtaposed in
a direction in which the cartridge holder and the optical sensor are to be
moved
relative to each other.
In one aspect, the present invention resides in an ink cartridge, comprising:
an ink cartridge; a cartridge holder, on which the ink cartridge is detachably
mounted; at least one first reflector, provided in the cartridge holder; a
reflective-
type optical sensor, including a light emitter and a light receiver, the
optical sensor
operable to form an optical path originated from the light emitter to the
light
receiver via the first reflector; and a shading member, provided in the ink
cartridge
operable to shade the optical path when the ink cartridge is mounted on the
cartridge holder.
In another aspect, the present invention resides in an ink cartridge,
operable to be detachably attached to a cartridge holder provided with a first
reflector capable of forming a part of a first optical path originated from a
light
emitter of an external optical sensor to a light receiver of the optical
sensor, the
ink cartridge comprising: an ink reservoir, storing ink therein; a second
reflector,
which reflects light emitted from the light emitter and varies an intensity
thereof in
accordance with an ink amount remaining in the ink reservoir, the second
reflector
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operable to form a part of a second optical path originated from the light
emitter
to the light receiver; and a shading member, which shades the first optical
path
when the ink cartridge is mounted on the cartridge holder.
In another aspect, the present invention resides in an ink cartridge
comprising: an ink reservoir, storing ink therein; a reflector provided on one
side of the cartridge, the reflector being adapted to reflect an external
light
beam impinging thereon, the reflectance of the reflector being a function of
the
ink amount remaining in the ink reservoir; and a shading member provided on
said one side of the cartridge next to the reflector, the shading member being
opaque to the external light beam.
In yet another aspect, the present invention resides in an ink cartridge
comprising: an ink reservoir, storing ink therein; a reflector, arranged so
that
light emitted from an external light emitter is absorbed by the ink when the
reflector is in contact with the ink in the ink reservoir, and light emitted
from the
external light emitter reflects to an external light receiver when the
reflector is in
contact with air in the ink reservoir; and a shading member, which shades an
optical path originated from the external light emitter to the external light
receiver when the ink cartridge is mounted on a cartridge holder.
In a further aspect, the present invention provides an ink cartridge
comprising: an ink reservoir, storing ink therein; a reflector provided on one
side of the cartridge, the reflector being adapted to reflect an external
light
beam impinging thereon, the reflector for detecting the amount of the ink
remaining in the ink reservoir; and a shading member provided on said one
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side of the cartridge next to the reflector, the shading member being opaque
to the
external light beam, wherein a recess is formed in the ink cartridge, the
shading
member is a shield part provided at one side face of the recess for shielding
the recess
from the external light beam.
In a still further aspect, the present invention provides an ink cartridge
which is
mountable on an external cartridge holder provided with a first reflector
configured
such that light emitted from a movable external light emitter is reflected to
an external
light receiver, the ink cartridge comprising: an ink reservoir, storing ink
therein: a
second reflector, configured such that light emitted from the movable external
light
emitter is (i) absorbed by the ink when the second reflector is in contact
with the ink,
and (ii) reflected to the external light receiver when the second reflector is
not in
contact with the ink; and a shading member, configured to block the light
emitted from
the external light emitter to the first reflector when the ink cartridge is
mounted on the
external cartridge holder, wherein the second reflector and the shading member
are
juxtaposed in a direction in which the external light emitter is moved; and
wherein a
bottom of the ink cartridge is recessed to define a recessed part so that the
first reflector
can be inserted into the recessed part, and the shading member is integrally
formed with
the casing of the ink cartridge and is configured to cover the first reflector
inserted into
the recessed part.
In a still further aspect, the present invention provides a printer
comprising: an
external cartridge holder provided with a first reflector configured such that
light
emitted from a movable external light emitter is reflected to an external
light receiver;
an ink cartridge mountable on said external cartridge holder, said ink
cartridge
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comprising an ink reservoir, storing ink therein, and, a second reflector,
configured
such that light emitted from the movable external light emitter is (i)
absorbed by the ink
when the second reflector is in contact with the ink, and (ii) reflected to
the external
light receiver when the second reflector is not in contact with the ink; and a
shading
member, configured to block the light emitted from the external light emitter
to the first
reflector when the ink cartridge is mounted on the external cartridge holder,
wherein
the second reflector and the shading member are juxtaposed in a direction in
which the
external light emitter is moved.
Further aspects of the invention will become apparent upon reading the
following detailed description and drawings which illustrate the invention and
preferred
embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objects and advantages of the present invention will become more
apparent by describing in detail preferred exemplary embodiments thereof with
reference to the accompanying drawings, wherein:
Fig. 1 is a side view schematically showing an interior structure of a
printer;
Fig. 2 is a plan view schematically showing the interior structure of the
printer;
Fig. 3 is a perspective view of a carriage on which a print head is mounted;
Fig. 4 is a front view of an ink supply section showing a state in which ink
cartridges are not mounted;
Fig. 5 is a front view of the ink supply section showing a state in which
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the ink cartridges are mounted;
Fig. 6 is a perspective view of the ink supply section showing the state
in which the ink cartridges are not mounted;
Fig. 7 is a perspective view of the ink supply section showing the state
in which the ink cartridges are mounted;
Fig. 8 is a perspective view of the ink cartridge as viewed from a
bottom thereof;
Figs. 9A to 9C are explanatory views showing detection of mounting
condition and detection of an amount of remaining ink;
Fig. 10 is a sectional view of the ink supply section taken along a line
X-X in Fig. 7, showing a state where the ink cartridge is plenarily mounted;
and
Fig. 11 is a sectional view of the ink supply section taken along a line
Y-Y in Fig. 7, showing a state where the ink cartridge is provisionally
mounted.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
One embodiment of the invention will be described referring to the
accompanying drawings. As shown in Fig. 1, an inlet 11 for inserting paper P
by hand is provided on a front face of a printer 10. An outlet 12 for
discharging the paper P after printing is provided on an upper face of the
printer 10. Inside the printer 10, there is formed a paper feeding path 13 in
a
V-shape in a side view extending from the inlet 11 to the outlet 12, and a
paper
feeding roller unit 14 and a print head 15 are arranged on the paper feeding
path 13. The paper feeding roller unit 14 includes a paper feeding roller 16
and a paper holding roller 17 which are opposed to each other on both sides of
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the paper feeding path 13, and adapted to clamp and transport the paper P in
accordance with driving rotation of the paper feeding roller 16.
The print head 15 is mounted on a carriage 18 which reciprocates in a
lateral direction of the paper feeding path 13 (in a direction from the left
to the
right in Fig. 2), and adapted to perform dot matrix printing on the paper P.
The position of the paper P is regulated by a platen 19. The printing system
of the print head 15 is an ink jet system in which characters or images are
printed on the paper P by discharging ink, and the ink used for printing is
supplied to the print head 15 from an ink supply section 20 which is provided
in
a rear area of the printer 10.
The carriage 18 is supported by a pair of front and rear guide shafts
21, 22 so as to move from the left to the right, and is forcibly moved in
accordance with driving motion of a carriage driving mechanism 23. The
carriage driving mechanism 23 includes a cam shaft 24 which is arranged
below the front guide shaft 21 in parallel thereto, and a carriage motor 26
for
actuating the cam shaft 24 to rotate by way of a reduction gear train 25 (Fig.
2).
On an outer peripheral face of the cam shaft 24, there is formed a cam groove
in a spiral shape (not shown), with which a cam follower 27 extending from the
carriage 18 is adapted to be engaged. When the cam shaft 24 is rotated in
accordance with the driving motion of the carriage motor 26, the cam follower
27 is shifted in an axial direction with spiral shifting action of the cam
groove.
In this manner, it will be possible to reciprocate the carriage 18 from the
left to
the right in accordance with normal and reverse drives of the carriage motor
26.
As shown in Fig. 3, the print head 15 is mounted on an upper part of
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the carriage 18. A flat cable 28 and ink tubes 29 having flexibility are drawn
from a side area of the print head 15, and the ink is supplied to the print
head
15 from the ink supply section 20 by way of the ink tubes 29. The carriage 18
has a sensor mounting part 18a which is extended downwardly from its rear
part, and an optical sensor 30 of a reflective type which includes a light
emitting element 30a for emitting a light beam to the rear and a light
receiving
element 30b for receiving a reflective light beam is attached to a back face
of
the sensor mounting part 18a.
As shown in Fig. 4, the ink supply section 20 includes a cartridge
holder 31 which is provided in a rear area inside the printer 10, and two ink
cartridges 32A, 32B which are detachably mounted on the cartridge holder 31
from the above. As shown in Fig. 8, an ink reservoir 34A is partitioned inside
the ink cartridge 32A to store secondary ink (for example, colored ink such as
cyan, magenta, yellow, red, green, blue). The secondary ink is appropriately
discharged from an ink outlet 33A formed in a bottom of the ink cartridge 32A.
A waste ink reservoir 36 is also partitioned inside the ink cartridge 32A to
store
waste ink supplied from a recovery inlet 35 formed in the bottom. When the
ink cartridge 32A has been mounted at a predetermined (specific) position on
the cartridge holder 31, the ink outlet 33A and the recovery inlet 35 are
communicated with connecting ports 37A, 38 which are formed in a bottom of
the cartridge holder 31, thus permitting supply of the secondary ink and
recovery of the waste ink.
On the other hand, inside the ink cartridge 32B, there are partitioned
an ink reservoir 34B which stores primary ink (for example, black ink) and
appropriately discharges the primary ink from an ink outlet 33B in a bottom of
CA 02598250 2007-08-22
the ink cartridge 32B. When the ink cartridge 32B has been mounted at a
predetermined (specific) position on the cartridge holder 31, the ink outlet
33B
is communicated with a connecting port 37B which is formed in the bottom of
the cartridge holder 31, thus permitting supply of the primary ink.
The ink cartridges 32A, 32B are arranged in a row along a moving
direction of the carriage 18 (the optical sensor 30). The ink cartridges 32A,
32B are respectively provided, at positions opposed to a moving path L (see
Fig. 5) of the optical sensor 30 on their front faces, with reflectors
(reflectors for
detecting an amount of remaining ink) 39A, 39B in a shape of prism having
transparency. The reflectors 39A, 39B have a shape of a right triangle prism,
and two prism reflective faces S1, S2 which are at a right angle with respect
to
each other are protruded into the ink reservoirs 34A, 34B. As shown in Fig.
9B, when the optical sensor 30 is moved to a position opposed to the reflector
39A and a light is emitted thereto, the emitted light is reflected at the
prism
reflective faces S1, S2 sequentially while passing interiors of the reflector
39A,
and received by the light receiving element 30b. When the optical sensor 30
is moved to a position opposed to the reflector 39B and a light is emitted
thereto, the emitted light is reflected at the prism reflective faces S1, S2
sequentially while passing interiors of the reflector 39B, and received by the
light receiving element 30b.
Reflectivity (refraction index) of the prism reflective faces S1, S2 is
low in the case where levels of the remaining ink in the ink reservoirs 34A,
34B
are higher than the prism reflective faces S1, S2, and is high in the case
where
the levels of the remaining ink are lower than the prism reflective faces S1,
S2.
In short, in a state where the prism reflective faces S1, S2 are in contact
with
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the ink as shown in Fig. 9A, an emitted light beam of the optical sensor 30 is
absorbed by the ink to have a low reflectivity (the intensity of reflected
light is
made low), and in a state where the prism reflective faces S1, S2 are in
contact with air as shown in Fig. 9B, the light beam is not absorbed by the
ink
to have a high reflectivity (the intensity of reflected light is made high).
In this
manner, it will be possible to detect the amount of the remaining ink
(presence
or absence of the ink at the predetermined level) in the ink cartridges 32A,
32B
on the basis of a value detected by the light receiving element 30b of the
optical sensor 30.
As shown in Figs. 4 and 6, on the bottom of the cartridge holder 31,
two reflectors (reflectors for detecting mounting condition) 40A, 40B are
fixed
in a row along the moving direction of the carriage 18 (the moving path L of
the
optical sensor 30), in an upwardly protruding posture. Each of the reflectors
40A, 40B has a prism part 40a in a shape of a right triangle prism, and
reflective light paths of the optical sensor 30 are formed by two prism
reflective
faces S3, S4 which are at a right angle with respect to each other, in the
same
manner as the reflectors 39A, 39B for detecting the amount of the remaining
ink. On the other hand, recesses (hollowed parts) 41A, 41 B are integrally
formed in respective lower portions of the ink cartridges 32A, 32B. When the
ink cartridges 32A, 32B have been mounted at the predetermined positions of
the cartridge holder 31, the reflectors 40A, 40B are inserted into the
recesses
41 A, 41 B, and the surroundings are covered. On this occasion, shield parts
42A, 42B which are integrally formed on one side faces of the recesses 41A,
41 B (wall portions opposed to the optical sensor) are interposed between the
optical sensor 30 and the reflectors 40A, 40B, so as to' shield light paths
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(irradiation paths and reflective paths) between the optical sensor 30 and the
reflectors 40A, 40B.
As shown in Figs. 4 and 9C, in the state where the ink cartridges 32A,
32B are not mounted on the cartridge holder 31, the reflectors 40A, 40B are
exposed. When the optical sensor 30 is moved to a position opposed to the
reflector 40A in this state, the emitted light is sequentially reflected at
the
reflective faces S3, S4 while passing the interior of the reflector 40A, and
will
enter the light receiving element 30b. When the optical sensor 30 is moved to
a position opposed to the reflector 40B in this state, the emitted light is
sequentially reflected at the reflective faces S3, S4 while passing the
interior of
the reflector 40B, and will enter the light receiving element 30b. On the
other
hand, as shown in Figs. 9A and 9B, in the state where the ink cartridges 32A,
32B have been mounted on the cartridge holder 31, front areas of the
reflectors 40A, 40B are covered with the shield parts 42A, 42B. When the
optical sensor 30 is moved to the position opposed to the reflector 40A in
this
state, the emitted light is shielded by the shield part 42A, and will not
reach the
reflector 40A nor the light receiving element 30b of the optical sensor 30.
When the optical sensor 30 is moved to the position opposed to the reflector
40B in this state, the emitted light is shielded by the shield part 42B, and
will
not reach the reflector 40B nor the light receiving element 30b of the optical
sensor 30.
In this manner, it is possible to detect the mounting condition of the
ink cartridges 32A, 32B by the optical sensor 30, without providing the ink
cartridges 32A, 32B with the reflectors for detecting the mounting condition.
Moreover, in the state where the ink cartridges 32A, 32B are not mounted on
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the cartridge holder 31 as described above, since the light receiving element
30b is always subjected to the light emission, an exterior turbulent light
will not
influence detection results of the mounting condition of the ink cartridges
32A,
32B, even though the exterior turbulent light is emitted to the light
receiving
element 30b. Further, in the state where the ink cartridges 32A, 32B have
been mounted on the cartridge holder 31, since the reflectors 40A, 40B are
covered with the recesses 41A, 41 B, the ink will not adhere to the reflectors
40A, 40B, even though the ink is splashed during the printing operation. As a
result, it is possible to prevent an erroneous detection caused by ink
adhering
to the reflectors 40A, 40B.
Fig. 10 is a sectional view of the ink supply section taken along a line
X-X in Fig. 7, showing a state where the ink cartridge is plenarily mounted,
and
Fig. 11 is a sectional view of the ink supply section taken along a line Y-Y
in
Fig. 7, showing a state where the ink cartridge has been provisionally
mounted.
As shown in these drawings, there are provided, in a rear part of the
cartridge
holder 31, two lock plates 43A, 43B in an upright manner. The lock plates
43A, 43B are elastic plate members formed with V-shaped locking portions
44A, 44B in their upper end portions. When the ink cartridges 32A, 32B have
been mounted on the cartridge holder 31 from above, convex portions 45A,
45B projected from back faces of the ink cartridges 32A, 32B lie on the lock
portions 44A, 44B of the lock plates 43A, 43B, as shown in Fig. 11, to hold
the
ink cartridges 32A, 32B in a provisionally mounted state. On this occasion,
the shield parts 42A, 42B of the ink cartridges 32A, 32B are located above the
prism parts 40a of the reflectors 40A, 40B, and the light paths between the
optical sensor 30 and the reflectors 40A, 40B will not be shielded.
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Further, in the above described provisionally mounted state, when the
ink cartridges 32A, 32B are pushed downward, the lock plates 43A, 43B are
pressed by the convex portions 45A, 45B to be tilted so as to once retreat
backward, and then, ride over the convex portions 45A, 45b to be tilted so as
to be returned forward. After the lock plates 43A, 43B have been tilted to be
returned, the locking portions 44A, 44B are engaged with upper parts of the
convex portions 45A, 45B as shown in Fig. 10, and the ink cartridges 32A, 32B
are held (locked) in their mounting positions. On this occasion, the shield
parts 42A, 42B of the ink cartridges 32A, 32B are interposed between the
prism parts 40a of the reflectors 40A, 40B and the optical sensor 30 to shield
the light path of the optical sensor 30.
As described above, according to this embodiment, the printer 10 is
constructed by including the optical sensor 30 of a reflective type which
projects the light to the cartridge holder 31 to detect the mounting
conditions of
the ink cartridges 32A, 32B on the basis of the reflective light, the
reflectors
40A, 40B which are provided on the cartridge holder 31 to form the reflective
light path of the optical sensor 30, and the shield parts 42A, 42B which are
provided in the ink cartridges 32A, 32B, and adapted to shield the light path
of
the optical sensor 30 when the ink cartridges 32A, 32B have been mounted on
the cartridge holder 31. In short, although the mounting condition of the ink
cartridges 32A, 32B is detected by the optical sensor 30 of the reflective
type,
necessity for providing the ink cartridges 32A, 32B with the reflectors for
detecting the mounting condition can be eliminated. Therefore, not only
reduction of the cost for the ink cartridges 32A, 32B can be attained, but
also,
an erroneous recognition of the mounting condition due to soils such as ink
CA 02598250 2007-08-22
splash on the reflectors or an exterior turbulent light can be prevented.
Moreover, because the reflectors 40A, 40B are fixed members which
are integrally provided in the bottom of the cartridge holder 31, as compared
with the reflectors 40A, 40B formed of movable members, not only the
structure can be simplified, but also reliability of detecting the mounting
condition can be enhanced.
Further, because the shield parts 42A, 42B are integrally formed in
the lower parts of the ink cartridges 32A, 32B, the number of the components
and the production steps of the ink cartridges 32A, 32B can be decreased.
Still further, because the ink cartridges 32A, 32B have the recesses
41 A, 41 B which cover the reflectors 40A, 40B when they have been mounted
on the cartridge holder 31, and the shield parts 42A, 42B are formed at the
one
side faces of the recesses 41 A, 41 B, the reflectors 40A, 40B can be
protected
when the ink cartridges have been mounted, and defective detection due to
soils such as ink splash or damage of the reflectors 40A, 40B can be
prevented.
Furthermore, the shield parts 42A, 42B will not shield the light path of
the optical sensor 30 when the ink cartridges 32A, 32B are provisionally
mounted on the cartridge holder 31, and therefore, problems such as
conducting the printing operation in the provisionally mounted state of the
ink
cartridges 32A, 32B can be avoided.
Still further, because the cartridge holder 31 and the optical sensor 30
are relatively movable with respect to each other, it is possible to detect
the
mounting conditions of a plurality of the ink cartridges 32A, 32B, and to
detect
the amount of the remaining ink in the ink cartridges 32A, 32B by the same
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CA 02598250 2007-08-22
optical sensor 30.
Still further, the cartridge holder 31 is provided with a plurality of the
reflectors 40A, 40B which are arranged in a row along the direction of the
relative movement of the optical sensor 30 (along the line L shown in Figs. 4
and 5), and accordingly, the same optical sensor 30 can detect the mounting
conditions of the plurality of the ink cartridges 32A, 32B.
In addition, the ink cartridges 32A, 32B are provided with the
reflectors 39A, 39B for detecting the amount of the remaining ink, enabling
the
amount of the remaining ink to be detected by the optical sensor 30, and
accordingly, the same optical sensor 30 can detect the amounts of the
remaining ink as well as the mounting conditions of the ink cartridges 32A,
32B.
Although one of the embodiments according to the invention has
been described heretofore, the present invention is not limited to those
matters
shown in the above described embodiment, but may include such a scope as
those skilled in the art can make modification and application of the
invention,
on the basis of the description in the claims and in the detailed description
of
the invention, and the well known art.
For example, although in the above described embodiment, the shield
part is formed on one side face of the recess which is integrally formed in
the
ink cartridge, the shield part may be in any shape, provided that it can
shield
the light path of the optical sensor 30 when the ink cartridge has been
mounted on the cartridge holder. For example, the shield part may be formed
in a hook-like shape (L-shape) on the one side face of the ink cartridge.
Moreover, although in the above described embodiment, the ink
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CA 02598250 2007-08-22
cartridges are mounted on the printer body, the invention can be realized in
the
printer in which the ink cartridges are mounted on the carriage. Specifically,
by providing the reflectors on the cartridge holder which is mounted on the
carriage, and detecting them by the optical sensor which is provided on the
printer body, similar function and advantageous effects to those in the above
described embodiment can be obtained.
According to the present invention as has been herein before
described, although the mounting condition of the ink cartridge is detected by
the optical sensor of a reflective type, necessity for providing the ink
cartridge
with the reflectors for detecting the mounting condition is eliminated, and
not
only reduction of the cost for the ink cartridge can be attained, but also, an
erroneous recognition of the mounting condition due to soils such as ink
splash
on the reflectors or an exterior turbulent light can be prevented.
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