Typewriting machines – Carriage or carriage-moving or movement-regulating mechanism – Carriage – per se – or guideway therefor
Reexamination Certificate
2002-02-28
2004-09-14
Hirshfeld, Andrew H. (Department: 2854)
Typewriting machines
Carriage or carriage-moving or movement-regulating mechanism
Carriage, per se, or guideway therefor
C400S059000, C400S120170, C347S198000
Reexamination Certificate
active
06789966
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention is related to a printer which performs printing with a print head, a carriage supporting structure and a head assembly incorporated in the printer.
Generally speaking, in a printer, a printing operation is carried out by such a manner that either a carriage which mounts thereon a print head or a head assembly is relatively transported with respect to recording paper, while the head assembly is arranged by both a print head and a peripheral component thereof.
As disclosed in, for example, Japanese Patent Publication No. 11-192719A, a conventional carriage supporting structure for supporting and transporting a carriage mounted on such a printer employs such a structure that the carriage is supported on a carriage guide shaft so as to be transported.
FIG. 1
is a side view showing the conventional carriage supporting structure with employment such a carriage guide shaft.
In
FIG. 1
, a carriage
51
comprises a bearing portion
64
in which a cylindrical-shaped hole is formed. A carriage guide shaft
65
made of a metal comprises a cylindrical shape which may be fitted to the hole of the bearing portion
64
. The carriage
51
is supported by a carriage guide shaft
65
which is penetrated through the hole of the bearing portion
64
.
The carriage
51
also has a belt receiving portion
63
, while an endless belt (not shown) is fixed on this belt receiving portion
63
. Then, drive force which is produced by rotations of a drive source such as a motor is transferred via this endless belt to the belt receiving portion
63
, so that the carriage
51
is moved in the reciprocation manner along a main scanning direction.
Also, as described above, the carriage guide shaft
65
supports the carriage
51
in order that the carriage
51
can be moved in the reciprocation manner along the main scanning direction. Furthermore, this carriage guide shaft
65
regulates an interval between a print head
62
mounted on the carriage
51
and a recording surface of recording paper “P” which is transported while being slidably contacted to a platen
52
. This interval is a so-called “paper gap” (will be simply referred to as a “gap” hereinafter).
On the other hand, while the carriage
51
has a guide portion
66
, the carriage
51
is supported by this guide portion
66
with respect to a frame member
8
of the printer main body, so that a parallel degree of the head face of the print head
62
may be regulated.
As is well known in the art, the above-described gap “PG” may constitute the very important factor capable of greatly applying influences to printing qualities. Only when this gap “PG” is slightly changed from a defined gap value, the printing qualities would be largely changed. The conventional carriage supporting structure in which the carriage
51
is supported on the carriage guide shaft
65
comprises high gap precision, and thus, the gap “PG” is maintained substantially constant. Accordingly, there is a very small risk that the printing qualities are deteriorated since the gap “PG” is slightly changed from the defined gap value. As a consequence, very recently, this conventional carriage supporting structure could be widely employed even in printers capable of executing high-quality printing operations.
On the other hand, there is such a trend that printers are manufactured in lower cost. Considering price aspects of these low-cost printers, such an idea that carriage supporting structures manufactured in lower cost rather than such a carriage supporting structure constructed of the carriage guide shaft
65
are mounted on printers may effectively reduce resultant cost of these printers.
However, such a low-cost carriage supporting structure capable of maintaining the same level of the gap precision as that of the above-described conventional carriage supporting structure constituted by the carriage guide shaft
65
is not present in the carriage supporting structures known in this technical field.
Besides, in color printers, very high precision as to paper feeding mechanisms is necessarily required, so that these paper feeding mechanisms must be provided with complex constructions. In connection with these complex constructions, a total number of assembling steps for the respective components is also necessarily increased.
As a method capable of reducing total manufacturing steps, the following method has been considered. That is, while components are separately assembled to both a main frame and a sub-frame of a printer, these main frame and sub-frame are finally assembled to each other outside a printing area so as to reduce a total assembling step number of these components with respect to each of manufacturing lines for these frames, so that positional precision among these components may be increased.
However, in the case that such an assembling method is employed, an ink jet recording printer may have the following risk, while this ink jet recording printer requires a provision of a space (namely, home position) used for a maintenance purpose of a print head outside a printing area. That is, a carriage guide is flexed downwardly due to the own weight of the print head traveled to the home position side, so that a gap “PG” may be changed.
Furthermore, in such a printer that the print head
62
is mounted on the carriage
51
, the travel precision and the response precision of the carriage
51
are adversely influenced, depending upon the assembling precision of these components. In particular, there is a risk that these adverse influences may cause more or less problems when image qualities of color printers are improved.
Furthermore, in such a case that this sort of carriage
51
must be replaced by new one, the following cumbersome works are necessarily required. That is, while the carriage
51
is dismounted from the carriage guide shaft
65
which has been previously dismounted from the printer main body, a new carriage
51
is penetrated thereto, and thereafter, this carriage guide shaft
65
should be assembled to the printer main body. In such a case that a play is produced between the print head
62
and the carriage
51
, there is probability that the printing operation by the printer cannot be carried out under normal condition.
SUMMARY OF THE INVENTION
A first object of the present invention is to provide such a carriage supporting structure of a printer, while this carriage supporting structure can be made in low cost and can maintain a similar level of gap precision to that of a carriage supporting structure with employment of a carriage guide shaft.
A second object of the present invention is to provide a carriage supporting structure in which a gap is not changed due to the own weight of a print head, while a total number of manufacturing steps can be reduced.
A third object of the present invention is to provide such a head assembly capable of being a printer without employing a carriage, while superior drive operations and superior response characteristics can be maintained.
A fourth object of the present invention is to provide a head assembly capable of being mounted without dismounting a carriage guide shaft, and furthermore, capable of achieving high-precision printing operation.
A fifth object of the present invention is to provide such a printer equipped with the carriage supporting structure having the above-explained various merits.
A sixth object of the present invention is to provide a printer equipped with the head assembly having the above-described various merits.
In order to achieve the above objects, according to the present invention, there is provided a printer, in which printing is performed on a recording medium which is transported in a first direction, comprising:
a carriage, reciprocately moved in a second direction which is perpendicular to the first direction;
a print head, mounted on the carriage, the print head having a head face;
a first frame, placed in a first side of the print head; and
a first guide plate, extending in the second direction, which includes:
a first portion, prov
Hashii Kazuhiro
Iida Hiromu
Kumasaka Masaaki
Sugino Akira
Takeuchi Atsuhiko
Culler Jill E.
Hirshfeld Andrew H.
Seiko Epson Corporation
Sughrue & Mion, PLLC
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