Patent Application
20070235924
Embodiments will now be described, by way of example only, with reference to the accompanying drawings which are meant to be exemplary, not limiting, and wherein like elements are numbered alike in several Figures, in which:
a) and
Referring to the drawings, the embodiments of the present invention will be detailed in the following. However, the scope of the present invention is not limited to the embodiments described in the following.
The image forming apparatus is constituted by an image forming apparatus proper GH and a mass-storage paper sheet supplying apparatus LT, serving as a paper sheet supplying apparatus embodied in the present invention.
The image forming apparatus proper GH, called a tandem-type color image forming apparatus, is constituted by a plurality of image forming sections 10Y, 10M, 10C, 10K, a belt-type intermediate transfer member 6, a paper sheet feeding section 20, a fixing device 30, etc.
The image forming apparatus proper GH is provided with an image reading section A disposed on its upper side. An image of a document placed on a platen glass is exposed by scanning a light beam emitted from a document image exposure—scanning device equipped in the image reading section A, so that a line image sensor reads the image of the document. Analogue image signals generated by the photoelectric converting actions performed in the line image sensor are inputted into an image processing section, in order to apply various kinds of image processing, such as an analogue processing, an analogue-to-digital conversion processing, a shading correction processing, etc., to the inputted analogue image signals. Then, the digital image data generated from the analogue image signals are inputted into an exposing section 3.
Each of the image forming sections 10Y, 10M, 10C, 10K for forming unicolor images of colors Y (Yellow), M (Magenta), C (Cyan), K (Black), respectively, is provided with a photoreceptor drum 1, a charging section 2, the exposing section 3, a developing section 4, a cleaning section 5 and a primary transferring section 7. In
The belt-type intermediate transfer member 6 is threaded on a plurality of rollers, so as to circulate along the plurality of image forming sections 10Y, 10M, 10C, 10K.
The unicolor toner images of colors Y (Yellow), M (Magenta), C (Cyan), K (Black) respectively formed by the plurality of image forming sections 10Y, 10M, 10C, 10K are sequentially transferred one by one onto the belt-type intermediate transfer member 6 currently circulating along the plurality of image forming sections 10Y, 10M, 10C, 10K (primary transferring operation) by the primary transferring sections 7, respectively, in such a manner that the unicolor images are superimposed with each other so as to form a full color toner image.
A paper sheet S, accommodated in a paper sheet feeding cassette 21A of a paper sheet supplying section 20, is picked up by a paper sheet feeding section 22A and conveyed to a secondary transferring section 9 by pairs of paper sheet feeding rollers 23, 24, 25, 26, a pair of registration roller 27, etc. Then, the full color toner image formed on the belt-type intermediate transfer member 6 is further transferred onto the paper sheet S by the secondary transferring section 9 (secondary transferring operation).
Incidentally, since the paper sheet feeding cassettes, aligned in a vertical direction as three stages, have substantially the same structure, the same reference number of 21A is attached to each of them. Further, since the paper sheet feeding sections also have substantially the same structure, the same reference number of 22A is attached to each of them.
The paper sheet S, having the full color toner image transferred on it, is tightly griped by a pair of a heating roller 30A and a pressing roller 30B equipped in the fixing device 30, so as to apply heat and pressure onto the paper sheet S. As a result of this action, the full color toner image residing on the paper sheet S is fixed onto the paper sheet S. Then, the paper sheet S is tightly griped by a pair of ejecting rollers 28 so as to eject and stack it onto an ejecting tray 29 disposed outside the apparatus.
On the other hand, after the full color toner image is transferred onto the paper sheet S by the secondary transferring section 9 and the paper sheet S is peeled off the belt-type intermediate transfer member 6 by a curvature separating action, the belt-type intermediate transfer member 6 is cleaned by a cleaning device 8.
When the paper sheet S, having the fixed full color toner image is to be ejected in a reverse ejecting mode, the paper sheet S passes through a conveyance path located at the lower side of a switching gate 28A in
When the duplex image forming mode in which the toner images are formed on the both sides of the paper sheet S is to be performed, after the full color toner image formed on the first side of the paper sheet S is fixed onto the paper sheet S, the paper sheet S is conveyed into the first conveyance path r1 and further conveyed into a third conveyance path r3. Then, the conveyance direction of the paper sheet S is switched to the reverse direction, so that the paper sheet S is conveyed into a fourth conveyance path r4, serving as a detour path toward the upper direction, and further conveyed by the pair of paper sheet feeding rollers 26. Successively, through the same process as mentioned in the above, another full color toner image is transferred onto a second side of the paper sheet S, being a reverse side of the first side, and fixed onto the paper sheet S by applying heat and pressure onto both the full color toner image and the paper sheet S in the fixing device 30, and then, the paper sheet S having the fixed toner image is ejected outside the apparatus.
Incidentally, although the image forming apparatus proper GH described in the foregoing is an image forming apparatus for forming a full color image, it is needless to say that the present invention can be also applied for an image forming apparatus for forming a monochrome image.
The mass-storage paper sheet supplying apparatus LT for supplying a large number of paper sheets, for instance, more than 1000 paper sheets, is coupled to the right side surface of the image forming apparatus proper GH.
The mass-storage paper sheet supplying apparatus LT is provided with a paper sheet feeding tray 100A and a paper sheet feeding tray 100B, which serves as two-stage paper sheet accommodating sections divided into upper and lower stages.
A paper sheet feeding unit 103A picks up and separates a single paper sheet, namely, a paper sheet S, from paper sheets stacked on the paper sheet feeding tray 100A located at the upper stage. Then, pairs of conveyance rollers 104, 105 conveys the paper sheet S into the image forming apparatus proper GH through the pair of paper sheet feeding roller 24.
A paper sheet feeding unit 103B picks up and separates a single paper sheet, namely, a paper sheet S, from paper sheets stacked on the paper sheet feeding tray 100B located at the lower stage. Then, the pair of conveyance rollers 105 conveys the paper sheet S into the image forming apparatus proper GH through the pair of paper sheet feeding roller 24.
Each of numeral 108A and 108B indicates a paper sheet stacking plate on which the paper sheets S are stacked. Each of the paper sheet stacking plates 108A, 108B elevates in response to an upper surface detecting signal outputted from a paper sheet sensor 120 for detecting the uppermost surface of the stacked paper sheets S, so as to keep a height of the uppermost surface of the stacked paper sheets S constant, irrespective of a number of paper sheets currently stacked, as detailed later.
Each of numeral SW1 and SW2 indicates a switching unit serving as a mount/demount detecting element for detecting whether each of the paper sheet feeding tray 100A and the paper sheet feeding tray 100B is mounted or demounted into/from the mass-storage paper sheet supplying apparatus LT.
Referring to
a) shows a perspective view of a main section of the paper sheet feeding tray 100 in such a state that a cover is removed from the paper sheet feeding tray 100, while
As shown in
The positions of the pair of side regulating members 111, 112 and the trailing edge regulating member 118 are regulated (adjusted), corresponding to a size of the paper sheet to be employed.
When the delivery roller 103a rotates in a direction indicated by arrow a1, the uppermost paper sheet Sa progresses in the Y-axis direction indicated by arrow Y, and then, is separated into a single paper sheet by a separating unit including a separating roller 103b and a reverse roller 103c, and conveyed to a pair of conveyance rollers 104.
In order to detect a height of the uppermost surface of the stacked paper sheets, the paper sheet sensor 120 shown in
According to the abovementioned operation, it becomes possible to always keep the height of the upper surface of the paper sheet S, namely, the level of the surface of the uppermost paper sheet Sa, constant. The scope of a structure of the paper sheet sensor 120 is not limited to that shown in
The dehumidification dryer shown in
An air duct 113, which is provided with an air intake inlet 113A disposed at its upper section and an air exhaust outlet 113B disposed at its lower section, is equipped on the side surface of the paper sheet feeding tray 100, while a heater 114 is mounted inside the air duct 113.
Further, a side regulating member 111 is shaped in a vertically lengthy box, and provided with an air exhaust outlet 111A disposed at its upper section, an air intake inlet 111B disposed at its lower section and a fan 116 disposed at its lower section.
Still further, a side regulating member 112 is shaped in a vertically lengthy box, and provided with an air exhaust outlet 112A disposed at its upper section, an air intake inlet 112B disposed at its lower section and a fan 117 disposed at its lower section.
By activating a fan 115, the fan 116 and the fan 117, the air circulates inside the paper sheet feeding tray 100 according to the arrows indicated in
Since the air is brown against the upper portion of the stacked paper sheets, the air also has a role for separating a single paper sheet form the stacked paper sheets, in order to help the separating operation to be conducted by the pair of separating roller 103b and the reverse roller 103c and to securely achieve the single paper separating operation.
Further, by blowing the dried air, the relative humidity of which is decreased by the heating action of the heater 114, against the stacked paper sheets, the dehumidifying operation for reducing a moisture content included in the paper sheet S can be conducted.
Although the dehumidification dryer, which blows the dried air against the paper sheets, is exemplified in the foregoing, any one of conventional dehumidification dryers, such as a dryer that is provided with a heater disposed at its lower side to heat and dehumidify the paper sheet, a dehumidification dryer that performs both the heating operation of the paper sheet and the blowing operation of the dried air, etc., can be employed in the embodiment of the present invention.
In the embodiment of the present invention, based on information representing a kind of paper sheets (hereinafter, referred to as paper kind information) sent from a paper kind setting section SK, only when enamel paper sheets, such as art papers, coated papers, etc., are loaded in the paper sheet feeding tray 100, a control section CR activates a dehumidification dryer HC to conduct the dehumidifying operation of the paper sheets accommodated in the paper sheet accommodating section.
An operating section of the image forming apparatus includes the paper kind setting section SK, so that paper kind information are inputted into the control section CR, when the operator sets a kind of paper sheets to be accommodated in the paper sheet accommodating section. In addition, at the time when the operator selects and draws out the paper sheet feeding tray either 100A or 100B, the switching unit either SW1 or SW2, serving as the mount/demount detecting switch, is turned ON so as to designate the paper sheet feeding tray either 100A or 100B. Then, the control section CR receives information indicating that paper sheets of the specific kind set by the operator are loaded into the paper sheet feeding tray either 100A or 100B.
A humidity sensor HS is attached to an outer wall of the image forming apparatus. Since a rate of moisture absorption of the paper sheet, accommodated in the supplemental paper sheet accommodating section installed outside the image forming apparatus, substantially corresponds to a humidity of the outside air, the rate of moisture absorption of the paper sheets to be loaded can be estimated by detecting the humidity of the outside air with the humidity sensor HS.
Further, based on outside humidity information sent from the humidity sensor HS serving as a humidity detecting element, the control section CR determines whether or not the dehumidifying operation should be conducted and sets a duration time for the dehumidifying operation, corresponding to the rate of moisture absorption of the paper sheets to be loaded.
Still further, based on a paper-sheet differential residual amount detected from the difference between a residual amount of paper sheets remaining in the paper sheet accommodating section before the paper sheet loading operation and that after the paper sheet loading operation, the control section CR not only can determine whether or not the dehumidifying operation should be conducted, but also can set the duration time for the dehumidifying operation based on the residual amount of paper sheets.
Correlation between the humidity and the duration time of the dehumidifying operation, and correlation between the residual amount of paper sheets and the duration time of the dehumidifying operation are found from the experiments in advance, and a operating time table of them are stored in a storage section MR in advance.
As aforementioned, the control section CR receives the paper kind information sent from the paper kind setting section SK (Step S1) to determine whether or not the concerned paper sheets are enamel paper sheets (Step S2). When determining that the concerned paper sheets are not enamel paper sheets (Step S3; No), the control section CR finalizes the operation (END).
When determining that the concerned paper sheets are enamel paper sheets (Step S3; Yes), the control section CR receives residual amount information sent from a paper-sheet residual amount detecting section PD (Step S4). The paper-sheet residual amount detecting section PD detects the height of the paper sheet stacking plate 108 shown in
When the paper-sheet residual amounts before and after demounting/mounting operations of the paper sheet feeding tray 100, namely, before drawing it and after reloading it, differ from each other, it can be determined that additional paper sheets are newly loaded into the paper sheet feeding tray 100. While, when the paper-sheet residual amounts before and after demounting/mounting operations do not differ from each other, it can be determined that the demounting/mounting operations are conducted without loading additional paper sheets.
Accordingly, when determining that the paper-sheet residual amounts before and after demounting/mounting operations are the same (Step S5; No), the control section CR finalizes the operation (END).
On the other hand, when determining that the paper-sheet residual amounts before and after demounting/mounting operations differ from each other (Step S5; Yes), the control section CR reads the output value of the humidity sensor HS (Step S6).
The presence or absence of the change of paper-sheet residual amount can be detected by employing the information sent from the paper-sheet residual amount detecting section PD and the other information sent from the switching units SW1, SW2.
Concretely speaking, a paper-sheet residual amount before drawing the paper sheet feeding tray 100 is detected by employing information sent from the paper-sheet residual amount detecting section PD before drawing it, a mount/demount status of the paper sheet feeding tray 100 is detected by employing information sent from the switching units SW1, SW2, and a paper-sheet residual amount after mounting the paper sheet feeding tray 100 is detected by employing information sent from the paper-sheet residual amount detecting section PD after mounting it. Then, by comparing the paper-sheet residual amount before drawing with that after mounting, the presence or absence of the change of paper-sheet residual amount can be detected.
When the output value of the humidity sensor HS, namely, the humidity of outside air, is a sufficiently low value to such an extent that the dehumidifying operation is not necessary (Step S7; No), the control section CR finalizes the operation (END). On the other hand, when the output value of the humidity sensor HS indicates a necessity of the dehumidifying operation (Step S7; Yes), the control section CR implements the dehumidifying operation of the paper sheets S (Step S8).
Concretely speaking, to implement the dehumidifying operation of the paper sheets S, the control section CR not only activates the fan 115, the fan 116 and the fan 117, but also drives the heater 114 so as to circulate the dried air around the inside of the paper sheet feeding tray 100 (Step S8).
At the time when the dehumidifying operation is commenced, the control section CR immediately bans the paper sheet feeding operation during the dehumidifying operation (Step S8).
The control section CR reads the table of dehumidifying duration time so as to select an appropriate duration time corresponding to the humidity of outside air. Table 1 is an example of the table of dehumidifying duration time.
The control section CR deactivates the dehumidifying operation, just after the selected duration time has elapsed, and removes the ban on the paper sheet feeding operation to finalize the operation.
The control section CR deactivates the dehumidifying operation, just after each of the duration times indicated in Table 1 has elapsed, and removes the ban on the paper sheet feeding operation (Step S9) to finalize the operation (END).
Incidentally, although the two-stage controlling operation corresponding to the presence or absence of the change of paper-sheet residual amount is conducted in the example shown in
According to the present invention, since the dehumidifying operation is conducted only when a specific kind of paper sheets are accommodated in the paper sheet accommodating section, even if the paper sheet feeding operation is deactivated during the dehumidifying operation, the reduction rate of the image forming efficiency is kept at a low level. Accordingly, it becomes possible to provide a paper sheet supplying apparatus having a high operating efficiency, and therefore, it also becomes possible to provide an image forming apparatus to be operated at a high efficiency.
Specifically, since no deactivation of the image-forming operation due to the dehumidifying operation of the recording materials occurs during the image forming operation employing normal paper sheets whose usage frequency is normally high, it becomes possible to drastically improve its practical operating efficiency.
While the preferred embodiments of the present invention have been described using specific term, such description is for illustrative purpose only, and it is to be understood that changes and variations may be made without departing from the spirit and scope of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| JP2006-108395 | Apr 2006 | JP | national |
