The present invention relates to a recording apparatus comprising: a feeder including a hopper and a feeding roller to feed a recording medium to a recording section; and a discharging roller which discharges the recording medium. The present invention also relates to a method of manufacturing an elongated member such as the hopper, the feeding roller and the discharging roller which are to be incorporated in the recording apparatus.
An ink jet printer that is one of recording apparatuses is generally constituted so as to supply a sheet (recording medium) stored in a sheet feeding tray to a sheet feeding roller, transport the supplied sheet to a recording section while holding between a sheet feeding roller pair, cause a recording head to eject an ink droplet onto the sheet to perform recording, and discharge the sheet to a sheet ejection tray while holding between a discharging roller pair. Since recording on the sheet is thus performed between the discharging roller pair and the feeding roller pair, a rotary speed of the discharging roller is set slight higher than that of the feeding roller to tense the sheet between the discharging roller and the feeding roller, whereby the sheet becomes flat to improve recording accuracy.
In case that the first related-art discharging roller 1 is formed of synthetic resin, it is necessary to provide thickness reduction (recess) so as not to make the discharging roller thick in order to prevent deformation or sink of the shaft caused by internal stress in molding. Therefore, only rigidity of a certain level can be secured. On the other hand, it is necessary to enlarge a cross-sectional dimension of the discharging roller in order to enhance the rigidity. This causes increase of the dimension and the weight of the discharging roller. Similar problem can be discussed in connection with an elongated member which is extended in a widthwise direction of the sheet (e.g., a hopper and a sheet feeding roller constituting a sheet feeder). Further, since the rotation speed of the discharging roller 1 is set so as to become higher than that of the feeding roller, power pulled onto the feeding roller side acts on the discharging roller. Therefore, there is anxiety that deformation such as a flexure is produced in the discharging roller 1.
Since the deformation of the discharge roll 1 such as the flexure is restored when a rear end of the sheet is released from the feeding roller pair, there are instances where a so-called flip phenomenon of sheet is produced at this time. In case that an ink jet printer can record data on the whole surface of sheet or the nearly whole surface thereof, recording is continued to the rear end of the sheet even after the rear end of the sheet is released from the feeding roller pair. Therefore, in case that the above flip phenomenon is produced, a bad influence is exerted on recording accuracy.
Regarding the second related-art discharging roller shown in
It is therefore an object of the invention to provide a recording apparatus comprising an elongated member having a high flexural and torsional rigidity and a high straightness and a method of manufacturing such a elongated member.
In order to achieve the above object, according to the invention, there is provided a feeding roller, adapted to feed a recording medium to a recording section provided in a recording apparatus, comprising:
a shaft portion, comprised of synthetic resin and formed with a hollowed portion; and
a roller portion, formed on an outer periphery of the shaft portion.
Preferably, a diameter of the hollowed portion is identical at a portion of the shaft portion formed with the roller portion and a portion of the shaft portion formed without the roller portion.
Preferably, the synthetic resin is comprised of an additive enhancing stiffness of the shaft portion.
Preferably, a proportion of an outer diameter of the shaft portion with respect to an outer diameter of the roller portion is not less than 20%.
According to the invention, there is also provided a recording apparatus, comprising:
a recording section, adapted to perform recording with respect to a recording medium; and
a feeding roller, adapted to feed the recording medium to the recording section, and comprising:
Forming the shaft portion of the feeding roller with the hollowed portion, it is possible to make an outer peripheral face thereof uniform without deficiency such as a recess. In addition, there can be obtained many advantages such as enhancement in a gripping force with respect to the sheet, prevention of damage on the sheet and improvement on an appearance quality of the roller.
According to the invention, there is also provided a hopper, adapted to support a recording medium to be fed to a recording apparatus, comprising a hopper body comprised of synthetic resin and formed with a hollowed portion extending in a longitudinal direction of the recording apparatus.
Preferably, the synthetic resin is comprised of an additive enhancing stiffness of the hopper body.
According to the invention, there is also provided a recording apparatus, comprising:
a recording section, adapted to perform recording with respect to a recording medium; and
a hopper, adapted to support the recording medium to be fed to the recording section, and comprising a hopper body comprised of synthetic resin and formed with a hollowed portion extending in a longitudinal direction of the recording apparatus.
With this configuration, it is not necessary to provide a reinforcement member (e.g., sheet metal) for enhancing the rigidity of the hopper body. Accordingly, it is possible to obtain many advantages such as reduction of manufacturing costs, reduction of a device weight, and elimination of sound generated from the sheet metal due to vibrations of the apparatus. Moreover, the hollowed space can be utilized as a wiring path of a wire harness, a passage for waste ink, or the like.
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:
Embodiments of the invention will be described below in detail with reference to accompanying drawings.
As shown in
On the rear side of the upper housing 101, a sheet feeding port 103 is formed. In this sheet feeding port 103, a sheet feeding tray 110 on which sheets to be supplied are stacked is attached. The sheet feeding tray 110 is attached so as to protrude to the diagonally upper backside, and holds the sheets in a slanting state. On the front side of the upper housing 101, a sheet ejection port 104 is formed. On the front sides of the upper housing 101 and lower housing 102, a stacker 120 on which the ejected sheets are stacked is provided.
The stacker 120 is attached to the front sides of the upper housing 101 and lower housing 102 pivotably about a rotary shaft located at its lower portion. When the stacker 120 is not used, it is pivoted upward to close the sheet ejection port 104. When it is used, it is pivoted downward to open the sheet ejection port 104, and stops at a position where it protrudes from the lower housing 102 to the diagonally upper front side to receive the sheet in the slanting state. This stacker 120 has two-stage structure comprising a first stacker member 121 and a second stacker member 122 which is slidably attached to the first stacker member 121 at a distal end portion thereof. The second stacker member 122 is housed in the first stacker member 121 when it is not used, and pulled out from the first stacker member 121 when it is used.
A window 105 is formed from the upper portion of the upper housing 101 to the front surface thereof. This window 105 is covered with a transparent or semitransparent openable cover 106. By opening this cover 106, an exchanging work of ink cartridge and a maintenance work of the internal mechanism can be readily performed. Further, a push button type of power switch 131 and operational switches 132, 133 are provided on the left backside of the upper housing 101.
As shown in
A control element and a memory element such as CPU, ROM, RAM, ASIC (they are not shown), and other various circuit elements are mounted on the control board 130. At the upper end of the control board 130, light emitting diodes 133 and 134 are located protrusively, which emit lights respectively when the power switch 131 or the operational switches 132, 133 are pushed on, whereby a user can confirm switch-ON.
The recording section 140 comprises a carriage 141, a recording head 142, a carriage motor 143, a timing belt 144, and a suction pump 145. On a sheet transported by the transporter 160, data is recorded by the recording head 142 mounted on the carriage 141 scanned by the carriage motor 143 and the timing belt 144. From ink cartridges 146 of four colors, for example, yellow, magenta, cyan, and black, housed in the carriage 141, each color ink is supplied to the recording head 142 so that full color printing can be performed.
The feeder 150 comprises the sheet feeding tray 110, a sheet feeding guide 111, a sheet feeding roller 151, a hopper 152, and a separation pad 153. Sheets P stacked on the sheet feeding tray 110 and aligned by the sheet feeding guide 111 are pushed against the sheet feeding roller 151 with the separation pad 153 by rising of the hopper 152 with rotation of the sheet feeding roller 151, separated one by one from the uppermost sheet P, and transported to the transporter 160.
The transporter 160 comprises a feeding roller 161, a driven roller 162, a discharging roller 163, a serrated roller 164, a sheet feeding motor 165, and the stacker 120. The sheet P supplied from the feeder 150 is transported to the recording section 140 while being held between the feeding roller 161 driven by the sheet feeding motor 165 and the driven roller 162, and further transported to the ejected sheet stacker 120 while being held between the discharging roller 163 driven by the sheet feeding motor 165 and the serrated roller 164.
As shown in
Since the shaft portion 163a of the discharging roller 163 is thus formed in the hollowed shape having larger sectional area than sectional area of the related-art discharging roller 1, flexural rigidity of this discharging roller 163 can be enhanced more than that of the related-art discharging roller 1. Specifically, the diameter Dr1 (see
As a material of the shaft portion 163a of the discharging roller 163, thermoplastic resin is used, for example, ABS (copolymer of acrylonitrile, butadiene and styrene), PS (polystrene), POM (polyacetal), modified PPE (polyphenylene ether), PC (polycarbonate), PBT (polybutylene terephthalate), and alloy system. Further, in order to heighten more the flexural rigidity, an additive such as GF (glass fiber), GB (glass beads), carbon, nylon, or potassium titanate is added. The amount of this additive is preferably 5 to 50% and particularly 10 to 30% in order to further enhance the flexural rigidity.
As shown in
Since molding accuracy of each bore part in the shaft portion 163a of the discharging roller 163 affects greatly accuracy of rotation of the discharging roller 163, in order to improve the molding accuracy, the upper die 210 and the lower die 220 are respectively divided into three parts at portions where a part other than the bore portions is molded. In other words, each bore section including at least one bore portion is molded by a single die (a first upper die 211, a second upper die 212, a third upper die 213, a first lower die 221, a second lower die 222, and a third lower die 223) as shown in
Thus, through-work such as wire cut electrical discharge machining or cutting can be performed at the time of manufacturing the die, working accuracy of the die can be enhanced, and a die manufacturing cost can be reduced. Accordingly, the molding accuracy of the shaft portion 163a of the discharging roller 163 can be improved, and the eccentric rotation of the discharging roller 163 can be suppressed. Further, since the sectional shape of the shaft portion 163a of the discharging roller 163 is simplified, a cost of the discharging roller 163 can be reduced.
Due to limitation of a shape in the vicinity of each bore portion, there may be portions where the cavity portions 201 and 202 cannot be collectively formed. However, insert dies 214 and 224 are inserted into these portions to obtain desired shape of the cavity portions.
As shown in
Since the cavity portion 201 in the upper die 210 and the cavity portion 202 in the lower die 220 can be faced with each other with high accuracy, occurrence of flash extending in the axial direction of the periphery of the shaft portion 163a can be suppressed and the molding accuracy can be improved, so that the eccentric rotation of the discharging roller 163 can be suppressed.
As shown in
Hereby, since the inner surfaces of the cavity portions 201, 202 can be cooled, when the melted plastic is injected, the outer surface of plastic is solidified in a state where it is adhered onto the inner surfaces of the cavity portions 201, 202, and void is easy to be produced on the inside thereof. Therefore, occurrence of internal stress of molded products for the shaft portion 163a can be suppressed, so that a sink and a warp can be prevented. Further, dimensional accuracy of outer diameter of the shaft portion 163a can be improved, so that the eccentric rotation of the discharging roller 163 can be suppressed. Further, since the die 200 is cooled relatively quickly, an operation cycle for molding can be reduced.
Further, as the injection method, a gas injection method can be adopted.
Under a condition that the cavity portions 401, 402 of the die 400 are heat regulated at a predetermined temperature, the predetermined amount of the melted plastic is injected from an injection port 403 of the die 400. Subsequently, the predetermined amount of gas is injected from the injection port of the die 400. Hereby, a plastic outer surface coming into contact with the inner surfaces of the cavity portions 401, 402 is quickly cooled and pressed by gas pressure from the plastic inside. Therefore, the plastic is solidified in a state where it is adhered onto the inner surfaces of the cavity portions 401, 402.
Melting plastic inside the plastic between the injection port 403 of the die 400 and the exhaust port 404 is pushed out from the exhaust port 404 by gas and fed out into the auxiliary cavity 451. Hereby, occurrence of internal stress of molded products for the shaft portion 163a of the discharging roller 163 can be suppressed, so that the sink and the warp can be prevented. Further, the dimensional accuracy of outer diameter of the shaft portion 163a can be improved, and a uniform hollowed portion 163c can be formed stably in the shaft portion 163a throughout the entire region in the axial direction. Therefore, the eccentric rotation of the discharging roller 163 can be suppressed.
As shown in
The shaft portion 151d of the sheet feeding roller 151 is molded by an injection method or a gas injection method which generates a void that can prevent a sink and a warp by suppressing internal stress produced when molding is performed using a die. The roller portions 151e, 151f of the sheet feeding roller 151 is molded on the shaft portion 151d by an injection method. The above molding method described in connection with the discharging roller 163 can be similarly applied. Forming the shaft portion 151d of the sheet feeding roller 151 with the hollowed portion 151g as described the above, it is possible to make an outer peripheral face thereof uniform without deficiency such as a recess. In addition, there can be obtained many advantages such as enhancement in a gripping force with respect to the sheet, prevention of damage on the sheet and improvement on an appearance quality of the roller.
As a material of the shaft portion 151d of the sheet feeding roller 151, thermoplastic resin is used, for example, ABS (copolymer of acrylonitrile, butadiene and styrene), PS (polystrene), POM (polyacetal), modified PPE (polyphenylene ether), PC (polycarbonate), PBT (polybutylene terephthalate), and alloy system. Further, in order to heighten more the flexural rigidity, an additive such as GF (glass fiber), GB (glass beads), carbon, nylon, or potassium titanate is added. The amount of this additive is preferably 5 to 50% and particularly 10 to 30% in order to further enhance the flexural rigidity.
Specific dimensions of the respective members in the sheet feeding roller 151 are shown in
The invention can be applied to a thin member elongated in the longitudinal direction (widthwise direction of the sheet), in other words, to a member which is likely to be flexed by an own weight or an external force. As such a member, a sheet feeding guide, a hopper, a frame, a platen, a carriage guide shaft or the like can be exemplified.
An example that the invention is applied to the hopper 152 in the sheet feeder 150 is shown in
With this configuration, it is not necessary to provide a reinforcement member (e.g., sheet metal) for enhancing the rigidity of the elongated member. Accordingly, it is possible to obtain many advantages such as reduction of manufacturing costs, reduction of a device weight, and elimination of sound generated from the sheet metal due to vibrations of the apparatus. Moreover, the hollowed space can be utilized as a wiring path of a wire harness, a passage for waste ink, or the like.
Specific dimensions of the respective parts in the hopper 152 are shown in
Though the invention has been described in the above various embodiments, it is not limited the above embodiments but may be applied also to other embodiments within the scope of the appended claims. For example, though the ink jet printer has been described as an example of a recording apparatus, the invention is not limited to this but can be applied to another recording apparatus having a discharging roller, for example, a thermal transfer type printer, and an ink jet type or thermal transfer type facsimile or copying machine.
Number | Date | Country | Kind |
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P2002-069554 | Mar 2002 | JP | national |
P2003-061845 | Mar 2003 | JP | national |
This is a continued-in-part application of Ser. No. 11/144,823 filed on Jun. 6, 2005 which is a continuation application of Ser. No. 10/878,396 filed on Jun. 29, 2004 which is a divisional application of Ser. No. 10/388,177 filed on Feb. 24, 2003.
Number | Date | Country | |
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Parent | 10388177 | Mar 2003 | US |
Child | 10878396 | Jun 2004 | US |
Number | Date | Country | |
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Parent | 10878396 | Jun 2004 | US |
Child | 11144823 | Jun 2005 | US |
Number | Date | Country | |
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Parent | 11144823 | Jun 2005 | US |
Child | 11214890 | Aug 2005 | US |