BACKGROUND
1. FIELD OF THE PRESENT INVENTION
[0001] The present invention relates to an image forming apparatus.
2. DESCRIPTION OF THE RELATED ART
[0002] An image forming apparatus includes an antenna capable of communication with an RFID
tag in a detachable ink tank unit, and reads identification information from the RFID
tag using the antenna.
[0003] Fig. 3 shows a top-view diagram that indicates an example of a configuration of an
ordinary image forming apparatus. As shown in Fig. 3 for example, if a wireless tag
111 of an ink tank unit 101 is fixed on an upper surface of the ink tank unit 101
substantially in parallel with a mounting direction of the ink tank unit 101, then
in general, a mechanical design of it is done in consideration of transmission efficiency
of a radio wave or a magnetic field between an antenna 111a of the wireless tag 111
and an antenna 121 of a reader/writer 102 side such that (a) a width Wr of the antenna
121 of the reader/writer 102 side agrees with a width Wt of the antenna 111a of the
wireless tag 111, and (b) when the ink tank unit 101 is mounted, a position of a center
Ct of the antenna 111a of the wireless tag 111 and a position of a center Cr of the
antenna 121 of the reader/writer 102 side agree with each other.
[0004] However, there is a tolerance in a design of such mechanical detachable mechanism
of the ink tank unit 101, and therefore, when the ink tank unit 101 is actually mounted,
a position of the center Ct of the antenna 111a of the wireless tag 111 and a position
of the center Cr of the antenna 121 of the reader/writer 102 side do not agree with
each other in a mounting direction of the ink tank unit 101 and consequently, the
transmission efficiency may be decreased between the antenna 111a of the wireless
tag 111 and the antenna 121 of the reader/writer 102 side.
[0005] This feature may occur on a wireless tag of a part detachable from/to the image forming
apparatus other than the ink tank unit 101 as well.
SUMMARY
[0006] An image forming apparatus according to the present invention includes a wireless
tag of a part detachable from/to this image forming apparatus, and a main-body-side
antenna. The main-body-side antenna is configured to communicate with the wireless
tag. Further, the wireless tag includes an antenna in parallel with a mounting direction
of the part. The main-body-side antenna has a width larger by a predetermined width
than a width of the antenna in the mounting direction of the part. The predetermined
width is an allowable width of a mounting position of the part, the allowable width
corresponding to a tolerance of mechanical detachable mechanism of the part.
[0007] These and other objects, features and advantages of the present invention will become
more apparent upon reading of the following detailed description along with the accompanied
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008]
Fig. 1 shows a perspective-view diagram that indicates a configuration of an image
forming apparatus according to an embodiment of the present invention;
Fig. 2 shows a top-view diagram that indicates a configuration of an image forming
apparatus according to an embodiment of the present invention; and
Fig. 3 shows a top-view diagram that indicates an example of a configuration of an
ordinary image forming apparatus.
DETAILED DESCRIPTION
[0009] Hereinafter, an embodiment according to an aspect of the present invention will be
explained with reference to drawings.
[0010] Fig. 1 shows a perspective-view diagram that indicates a configuration of an image
forming apparatus according to an embodiment of the present invention. Fig. 2 shows
a top-view diagram that indicates a configuration of an image forming apparatus according
to an embodiment of the present invention. The image forming apparatus shown in Figs.
1 and 2 is an inkjet printer, an inkjet multi function peripheral or the like, for
example, and in this image forming apparatus, an ink tank unit 1 is detachable. The
ink tank unit 1 has a substantially cuboid shape and contains ink in an internal ink
storage unit of it.
[0011] The ink tank unit 1 includes a wireless tag 11 (here, RFID). In the wireless tag
11, stored are identification information, property information (Point of Production
information, toner counter information, and/or the like) and the like of the ink tank
unit 1. Here, in the ink tank unit 1, the wireless tag 11 is fixed on an upper surface
of the ink tank unit 1 parallel with a mounting direction (detachable direction) of
the ink tank unit 1 (Y axis direction in the figure).
[0012] Further, this image forming apparatus includes a main-body-side antenna 21 on a printed
wiring board 2. The main-body-side antenna 21 is used for communication with the wireless
tag 11 of the mounted ink tank unit 1. The main-body-side antenna 21 may be formed
as a printed wiring. The printed wiring board 2 is fixed to an internal structure
(frame or the like) of this image forming apparatus such that the main-body-side antenna
21 faces the wireless tag 11 of the mounted ink tank unit 1.
[0013] In particular, as shown in Fig. 1 for example, the wireless tag 11 includes an antenna
11a in parallel with a mounting direction of the ink tank unit 1. Further, as shown
in Fig. 2 for example, the main-body-side antenna 21 has a width Wr that is larger
by a predetermined width PR than a width Wt of the antenna 11a, and the predetermined
width PR is an allowable width of a mounting position of the ink tank unit 1 such
that the allowable width corresponds to a tolerance of mechanical detachable mechanism
of the ink tank unit 1 to a main body of the image forming apparatus.
[0014] Furthermore, in this embodiment, the main-body-side antenna 21 and the antenna 11a
are loop antennas that have substantially-rectangular shapes, and the wireless tag
11 is a wireless tag for an HF (High Frequency) band (i.e. for a frequency band of
shortwaves of which wave lengths are in a range from 10 meters to 100 meters).
[0015] Furthermore, in this embodiment, the antenna 11a is a loop antenna that has a substantially-square
shape, and the main-body-side antenna 21 is a loop antenna that has a substantially-rectangular
shape; and in a perpendicular direction to the mounting direction (X axis direction
in the figure), a width of the main-body-side antenna 21 and a width of the antenna
11a are substantially same as each other.
[0016] Here, a width Wb of a wiring bunch of the aforementioned loop antenna in the aforementioned
mounting direction may be equal to or larger than the aforementioned predetermined
width PR and thereby high transmission efficiency of the radio wave or the magnetic
field may be kept wherever the mounting position of the ink tank unit 1 is in the
aforementioned allowed range.
[0017] Here, the image forming apparatus further includes a printing device, a controller,
and the like. The printing device performs printing using the ink in the ink tank
unit 1. The controller includes a microcomputer, an ASIC (Application Specific Integrated
Circuit) and/or the like, causes the printing device to perform printing, and reads
and writes data (the aforementioned identification information and/or the property
information) from/to the wireless tag 11 of the ink tank unit 1 using the main-body-side
antenna 21. This controller may not have an anti-collision function, and may perform
communication between the main-body-side antenna 21 and the wireless tag 11 in a one-on-one
manner without an anti-collision function and thereby may read/write data.
[0018] The following part explains a behavior of the aforementioned image forming apparatus.
[0019] When the ink tank unit 1 is mounted to the main body of the image forming apparatus,
the center Ct of the antenna 11a of the wireless tag 11 of the ink tank unit 1 is
located at any position in the predetermined allowed range PR. At that time, the center
Ct of the antenna 11a may be shifted from the center Cr of the main-body-side antenna
21 due to a tolerance of detachable mechanism of the ink tank unit 1.
[0020] The controller communicates with the wireless tag 11 of the ink tank unit 1 using
the main-body-side antenna 21 and thereby performs reading/writing of the aforementioned
data. At that time, a radio wave or a magnetic field is emitted from the main-body-side
antenna 21 and sensed by the antenna 11a of the wireless tag 11.
[0021] For example, the controller applies a carrier wave of a predetermined intensity to
the main-body-side antenna 21 and thereby the carrier wave is emitted from the antenna
21 to the wireless tag 11. Further, the wireless tag 11 changes an impedance of the
antenna 11a correspondingly to data to be transmitted and changes a reflection intensity,
and thereby emits a modulated wave. Further, the main-body-side antenna 21 senses
the modulated wave from the wireless tag 11, and the controller acquires data from
the wireless tag 11 on the basis of the modulated wave.
[0022] Here, even if the center Ct of the antenna 11a of the wireless tag 11 is shifted
from the center Cr of the main-body-side antenna 21 in the allowed range, the transmission
efficiency of the radio wave or the magnetic field does not easily decrease because
the antenna 11a of the wireless tag 11 falls in a range of the main-body-side antenna
21 (i.e. within the width Wr).
[0023] As mentioned, in the aforementioned embodiment, the main-body-side antenna 21 communicates
with the wireless tag 11 of the mounted ink tank unit 1 detachable to the image forming
apparatus. The wireless tag 11 includes an antenna 11a in parallel with a mounting
direction of the ink tank unit 1. The main-body-side antenna 21 has a width that is
larger by a predetermined width than a width of the antenna 11a, and the predetermined
width is an allowable width of a mounting position of the ink tank unit 1 such that
the allowable width corresponds to a tolerance of mechanical detachable mechanism
of the ink tank unit 1 to the main body of the image forming apparatus.
[0024] Consequently, it is restrained to decrease the transmission efficiency of a radio
wave or a magnetic field between the antennas 11a and 21 of the ink tank unit 1 and
the main body side due to a tolerance in a detachable mechanism of the detachable
ink tank unit 1.
[0025] It should be understood that various changes and modifications to the embodiments
described herein will be apparent to those skilled in the art. Such changes and modifications
may be made without departing from the spirit and scope of the present subject matter
and without diminishing its intended advantages. It is therefore intended that such
changes and modifications be covered by the appended claims.
[0026] For example, in the aforementioned, the wireless tag 11 may be fixed on a side surface
or a bottom surface of the ink tank unit 1 parallel with the mounting direction.
[0027] Further, in the embodiment, the ink tank unit 1 is shown as an example of a detachable
part, but alternatively, for a detachable part other than the ink tank unit 1, the
same configuration of the wireless tag and the main-body-side antenna may be applied.
It should be noted that the aforementioned image forming apparatus may be an electrophotographic
image forming apparatus, and in such a case, the aforementioned detachable part may
be a toner cartridge or the like.
1. An image forming apparatus, comprising:
a wireless tag (11) of a part (1) detachable from/to this image forming apparatus;
and
a main-body-side antenna (21) configured to communicate with the wireless tag (11);
wherein the wireless tag (11) comprises an antenna (11a) in parallel with a mounting
direction of the part (1);
the main-body-side antenna (21) has a width larger by a predetermined width than a
width of the antenna (11a) in the mounting direction of the part (1); and
the predetermined width is an allowable width of a mounting position of the part (1),
the allowable width corresponding to a tolerance of mechanical detachable mechanism
of the part (1).
2. The image forming apparatus according to claim 1, wherein the main-body-side antenna
(21) and the antenna (11a) are loop antennas that have substantially-rectangular shapes;
and
the wireless tag (11) is a wireless tag for an HF band.
3. The image forming apparatus according to claim 1, wherein the antenna (11a) is a loop
antenna that has a substantially-square shape;
the main-body-side antenna (21) is a loop antenna that has a substantially-rectangular
shape; and
in a perpendicular direction to the mounting direction, a width of the main-body-side
antenna (21) and a width of the antenna (11a) are substantially same as each other.