BRIEF DESCRIPTION OF THE DRAWINGS
These and/or other aspects and advantages of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a partial perspective view of a conventional image forming apparatus.
FIG. 2 is a cross-sectional view of the image forming apparatus illustrated in FIG. 1.
FIGS. 3A and 3B are perspective views of a paper discharging tray of a conventional image forming apparatus.
FIGS. 4A and 4B are a perspective view and side view, respectively, of a main frame of an image forming apparatus including a paper discharging system according to an embodiment of the present general inventive concept.
FIG. 5 is perspective view of the paper discharging system illustrated in FIG. 4, according to an embodiment of the present general inventive concept.
FIG. 6 is a plan (top) view of the paper discharging system illustrated in FIG. 5, pursuant to an embodiment of the present general inventive concept.
FIG. 7 is a front cross-sectional view of the paper discharging system illustrated in FIG. 5, according to an embodiment of the present general inventive concept.
FIGS. 8A and 8B are side views of the paper discharging system illustrated in FIG. 5, pursuant to an embodiment of the present general inventive concept.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below so as to explain the present general inventive concept by referring to the figures.
The same elements are given the same reference numerals in various embodiments, and they will be typically described in an embodiment of the present general inventive concept, and may be omitted in the other embodiments of the present general inventive concept.
As illustrated in the embodiments of FIGS. 4A and 4B of the present general inventive concept, an image forming apparatus includes a base frame 102 and a paper discharging system 100 coupled to the base frame 102.
As illustrated in the embodiments of FIGS. 5 and 6 of the present general inventive concept, the paper discharging system 100 includes a first roller part 110, and a second roller part 140. The second roller part 140 transfers a printed paper P printed by a printing head (not illustrated) to the first roller part 110. The first roller part 110 which may be inclined at predetermined angles α and β (refer to the embodiments of FIGS. 6 and 7 of the present general inventive concept) with respect to a paper proceeding direction may bend the printed paper P passing over the second roller part 140. The first roller part 110 ultimately discharges the printed paper P discharges it to an outside thereof.
Referring to FIG. 5, the second roller part 140 may include a second shaft 142 connected with a gear (not illustrated) driven at a regular set speed by a motor (not illustrated), a plurality of second paper discharging rollers 144 installed in the second shaft 142 at predetermined intervals, and a plurality of second supporting rollers 146 positioned to rotate with respect to the second paper discharging rollers 144 to transfer rotating power of the second paper discharging rollers 144 to the printed paper P. The second shaft 142 may be transversely positioned on a second accommodating part (not illustrated) formed in the base frame 102 with the second paper discharging rollers 144. The second supporting rollers 146 may be coupled to a second supporting shaft (not illustrated) positioned to rotate with respect to a holder (not illustrated) and positioned in the base frame 102 at predetermined intervals to correspond to the position of the second paper discharging rollers 144. Accordingly, when the second shaft 142 is rotated by the gear connected to the motor, the second paper discharging rollers 144 transfer the printed paper P printed by a printing head to the first roller part 110 in cooperation with the second supporting rollers 146. The second supporting rollers 146 may include star wheels 147 in which saw teeth are formed along an outer circumference to impinge with the second supporting rollers 146 so as to minimize a trace caused by the second supporting rollers 146 while transferring the printed paper P to the first roller part 110.
As illustrated in the embodiment of FIGS. 5, 6 or 7 of the present general inventive concept, the first roller part 110 includes a middle roller part 120 positioned in the middle of a width direction of the printed paper P, and a side roller part 130 respectively connected with joints 115 on opposite sides of the middle roller part 120. The middle roller part 120 and the side roller part 130 respectively include at least one middle paper discharging roller 124 coupled to a middle shaft 122 at a predetermined interval, and at least one side paper discharging roller 134 coupled to side shafts 132 at a predetermined interval. Also, as illustrated in the embodiment of FIG. 5 of the present general inventive concept, on the middle paper discharging rollers 124 and the side paper discharging roller 134 are positioned middle supporting rollers 126 and side supporting rollers 136 respectively in contact with the middle paper discharging rollers 124 and the side paper discharging rollers 134 to transfer rotating power of the middle paper discharging rollers 124 and the side paper discharging rollers 134 to the printed paper P. The middle supporting rollers 126 and the side supporting rollers 136 may cooperate with star wheels 147 in which saw teeth are formed to impinge the printed paper P with the circumference of the middle supporting rollers 126 and the circumference of the side supporting rollers 136 to minimize a trace caused by the middle supporting rollers 126 and the side supporting rollers 136 while transferring the printed paper P. The middle shaft 122 and the side shafts 132 may be respectively positioned transversely on a first accommodating part (not illustrated) formed in the base frame 102 with the middle paper discharging rollers 124 and the side paper discharging rollers 134. The middle supporting rollers 126 and the side supporting rollers 136 may be respectively coupled to a middle supporting shaft (not illustrated) and a side supporting shaft (not illustrated) positioned on a holder (not illustrated) fixed on the base frame 102. The rollers 126 and 136 may be positioned at one or more predetermined intervals.
As illustrated in the embodiment of FIG. 6 of the present general inventive concept, the side roller parts 130 are positioned on opposite sides of the middle roller part 120 inclined at a predetermined angle α in a horizontal direction corresponding with the paper proceeding direction so that the printed paper P can be maintained without being bent (e.g., downward in a direction transverse to the horizontal direction) until the printed paper P is transferred from the second roller part 140. According to an embodiment of the present general inventive concept, the inclined angle α between the middle roller part 120 and the side roller parts 130 may independently be from about 5° to about 30°.
As illustrated in the embodiment of FIG. 7 of the present general inventive concept, the side roller parts 130 are positioned on opposite sides of the middle roller part 120 and inclined in a predetermined angle β toward a vertical direction in relation to the paper proceeding direction. Then, the side roller parts 130 may bend up the opposite sides of the printed paper P with respect to the paper proceeding direction to maintain the paper in a sufficiently stiff state without being bent (e.g., downward) onto discharging tray 103 until the printed paper P transferred from the second roller part 140 is completely discharged. According to an embodiment of the present general inventive concept, the inclined angle β between the middle roller part 120 and the side roller parts 130 may be from about 2° to about 20°.
Also, the middle shaft 122 of the middle roller part 120 and the side shafts 132 of the side roller parts 130 may be coupled to each other by joints 115 to enable the middle shaft 122 and the side shafts 132 to cooperatively rotate, according to an embodiment of the present general inventive concept.
The joint 115 may be provided as a universal joint but may also include bevel gears to couple the middle shaft 122 and the side shafts 132.
As illustrated in the embodiment of FIGS. 8a and 8b of the present general inventive concept, a first angle γ1 (between a straight line linking the outer circumference of the second paper discharging rollers 144 with the outer circumference of the side paper discharging rollers 134 of the side roller parts 130 and with the paper proceeding direction) may be larger than a second angle γ2 (between a straight line linking the outer circumference of the second paper discharging rollers 144 with the middle paper discharging rollers 124 of the middle roller part 120 and the paper proceeding direction). According to an embodiment of the present general inventive concept, the first angle γ1 may be from about 5° to about 30°, and the second angle γ2 may be from about 0° to about 5°. Thus, the side roller parts 130 bends the opposite sides of the printed paper P upwards so that the printed paper P can be maintained stiffly until the printed paper P may be completely (or nearly completely) transferred from the second roller part 140, according to an embodiment of the present general inventive concept.
As described in the foregoing embodiments of the present general inventive concept, the image forming apparatus and especially, the paper discharging system 100 of an ink jet printer is designed to prevent printing damage (e.g., smearing) by maintaining the printed paper P stiffly (without being bent by its own stiffness) and preventing the printed paper from directly falling on a discharging tray 103 until the printed paper is completely discharged over the first roller part 110.
In the image forming apparatus with the above configuration, an operation of the paper discharging system 100 will be described with reference to the embodiments of FIGS. 4a through 8b of the present general inventive concept as follows.
The printed paper P on which data is printed (e.g., by ink jetted from nozzles of a printing head) gradually moves on the base frame 102 to reach the second roller part 140. After reaching the second roller part 140, the printed paper P is transferred to the first roller part 110 through the second supporting rollers 146 and the second paper discharging rollers 144 rotated by an operation of a motor connected with the second shaft 142. The opposite sides of the printed paper P which has reached the first roller part 110 is bent upwardly by the middle roller part 120 and the side roller parts 130 getting rotating power from a second shaft 142. The opposite sides of the paper are bent upward toward a vertical direction in relation to the horizontal paper proceeding direction of the middle width direction of the printed paper P, pursuant to an embodiment of the present general inventive concept.
Because the opposite sides of the printing paper P are upwardly bent, the paper is maintained in a stiff state, and does not fall downward as shown in FIG. 4A until the end side of the printed paper P is discharged through the first roller part 110. Accordingly, the previously printed paper (P0) and ultimately discharged on the discharging tray 103 has sufficient time to adequately dry the ink while the printed paper P is maintained in the stiff state. That is, until the printed paper P is completely discharged over or from the first roller part 110, according to an embodiment of the present general inventive concept.
As described, pursuant to an embodiment of the present general inventive concept, after the printed paper P is completely discharged through the first roller part 110, the printed paper P falls on discharging tray 103 and may be collected thereon.
Also, pursuant to an embodiment of the present general inventive concept, side roller parts 130 may be provided in the shape of V without the middle roller part 120.
As described above, according to one or more embodiments of the present general inventive concept, there is provided an image forming apparatus, and especially an ink jet printer in which the printed paper does not fall on the discharging tray and is provided sufficient time to dry ink printed thereon while being maintained stiffly (e.g., without being bent downward such by stiffness) until the paper is completely (or sufficiently) discharged. Especially, because the side roller part is inclined toward a vertical direction to the paper proceeding direction (e.g., cupped upwards), it optimally delays time for the printed paper to fall downward, to prevent printing damage (such as smearing) caused by overlapping contact with the previously printed paper before the printing ink has had sufficient time to adequately dry.
Although a few embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents.
Patent Application
20070291094
